KR20210050537A - Organic electroluminescent device, display device, lighting device, composition for forming light emitting layer, and compound - Google Patents

Abstract

An organic electroluminescent device having a light emitting layer containing a host compound as a first component, a thermally activated delayed phosphor as a second component, and a compound having a boron atom as a third component. The excitation singlet energy level obtained from the shoulder) ≥ (the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component) ≥ (the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component An organic light emitting device that satisfies the relational expression of excitation singlet energy level obtained from

Description

Organic electroluminescent device, display device, lighting device, composition for forming light emitting layer, and compound

The present invention relates to an organic light emitting device including a host compound, a thermally activated delayed phosphor, and a compound having a boron atom, and a display device and a lighting device including the organic light emitting device. The present invention also relates to a composition for forming a light emitting layer of an organic light emitting device, and a compound.

Conventionally, a display device using an electroluminescent light emitting device can be reduced in power consumption or thinner, so it has been studied in various ways, and an organic light emitting device made of an organic material (organic EL device) is easily lightweight or large-sized. It has been reviewed. Particularly, with regard to the development of organic materials having luminescence properties such as blue, which is one of the three primary colors of light, and development of organic materials having charge transport capabilities such as holes and electrons, both high-molecular compounds and low-molecular compounds have been active so far. Has been studied.

The organic electroluminescent device has a structure consisting of a pair of electrodes including an anode and a cathode, and a layer or a plurality of layers disposed between the pair of electrodes and containing an organic compound. The layer containing the organic compound includes a light emitting layer, a charge transport/injection layer for transporting or injecting charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

As a light emitting mechanism of an organic electroluminescent device, there are mainly two types of fluorescence emission using light emission from an excited singlet state and phosphorescence light emission using light emission from an excited triplet state. Typical fluorescent light-emitting materials have low exciton use efficiency and are about 25%, and even if triplet-triplet fusion (TTF, or triplet-triplet fusion, TTA: Triplet-Triplet Annihilation) is used. The exciter usage efficiency is 62.5%. On the other hand, in the phosphorescent material, although the exciton use efficiency may reach 100%, it is difficult to realize deep blue light emission, and there is a problem in that the color purity is low because the light emission spectrum is wide.

Accordingly, a thermally assisted delayed fluorescence (TADF) mechanism was proposed by Professor Chiaya of Kyushu University (see Non-Patent Document 1), and by using a thermally activated delayed phosphor. The efficiency of using excitons of light emission reached 100%. The thermally activated delayed phosphor provides a wide emission spectrum with low color purity due to its structure, but the speed of crossover between reverse terms is extremely fast.

In addition, Adachi et al. took advantage of this advantage, using a thermally activated delayed phosphor as an assisting dopant (AD) and a dopant with a narrow half-value width as an emitting dopant (ED). ^TM (TADF Assisting Fluorescence: also referred to as TAF) was proposed, and a high-efficiency, high-purity, and long-life device was developed for red and green light-emitting organic electroluminescent devices (see Non-Patent Document 2). However, the deep blue light emission has problems in efficiency, color purity, and lifetime because both the emitting dopant and the assisting dopant require high energy.

Accordingly, a new molecular design that dramatically improves the color purity of TADF materials has been proposed by Professor Hatakeyama of Kansai Gakuin University (see Non-Patent Document 3). In addition, in Patent Document 1, for example, in the disclosed compound (1-401), absorption and light emission as a result of a solid planar structure using the multi-resonance effect of boron (electron providing property) and nitrogen (electron attraction property) It succeeded in obtaining a light emission spectrum with a small Stokes shift of the peak of and high color purity. In addition, in a dimer compound such as formula (1-422), by bonding two boron and two nitrogens to the central benzene ring, the multi-resonance effect in the central benzene ring is further enhanced, and as a result, extremely Light emission with a narrow emission peak width has become possible.

International Publication No. 2015/102118

Highly efficient organic light-emitting diodes from delayed fluorescence, Nature 492, 234-238 NATURE COMMUNICATIONS, 5: 4016, Published 30 May 2014, DOI: 10.1038/ncomms5016 Ultrapure Blue Thermally Activated Delayed Fluorescence Molecules: Efficient HOMO-LUMO Separation by the Multiple Resonance Effect, Advanced Materials, Volume28, Issue14, April 13, 2016, 2777-2781

As described above, various materials have been developed as materials used for organic electroluminescent devices, but in order to further enhance organic electroluminescence characteristics such as light emission characteristics, and increase the selection of organic electroluminescent materials such as a light emitting layer material, Combinations of compounds that have not been specifically known in the past have been desired.

In order to solve the above problems, the inventors of the present invention have conducted a thorough study to solve the above problems. As a result of using a light emitting layer containing a host compound, a thermally activated delayed phosphor, and a compound having a boron atom in the molecule, the excitation singlet energy level By defining the relationship, it was found that an excellent organic light emitting device can be obtained, and the present invention was completed. Specifically, the present invention has the following configuration.

[One]

An organic electroluminescent device having an emission layer, wherein the emission layer comprises:

As a first component, at least one host compound, and

As a second component, at least one thermally activated delayed phosphor,

As a third component, it contains a compound having at least one boron atom,

The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the first component is E(1, S, Sh), obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component When the excitation singlet energy level is E(2, S, Sh), and the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), Satisfies the relational expression (1) of,

The first component may be contained as a polymer compound having a structure in which two hydrogen atoms of the host compound are removed as a repeating unit,

The second component may be contained as a polymer compound having a structure in which two hydrogen atoms of the thermally activated delayed phosphor are desorbed as a repeating unit,

The third component may be contained as a polymer compound having a structure in which two hydrogen atoms of the compound having boron atoms are removed as a repeating unit,

Organic electroluminescent device.

Relation (1): E(1, S, Sh)≥E(2, S, Sh)≥E(3, S, Sh)

[2]

As the third component, at least one of a compound represented by any one of the following formulas (i), (ii), and (iii), and a multimeric compound having a plurality of structures represented by the following formula (i) is included. The organic electroluminescent device according to [1].

(In the above formula (i),

A ring, B ring, and C ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl or alkyl,

X ¹ and X ² are each independently O, NR, >CR ₂ , S or Se, and R of NR and R of >CR ₂ are optionally substituted aryl, optionally substituted heteroaryl, optionally substituted Cycloalkyl or alkyl to be used, and R of NR may be bonded to at least one selected from the A ring, B ring and C ring by a linking group or a single bond, and,

At least one hydrogen in the compound or structure represented by formula (i) may be substituted with cyano, halogen or deuterium.)

(In the above formula (ii),

A ring, B ring, C ring, and D ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y is B (boron),

X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR, >CR ₂ , >S or >Se, even if R of _{>NR and R of >CR 2 are substituted} Aryl, optionally substituted heteroaryl, optionally substituted cycloalkyl, or optionally substituted alkyl, and R of >NR is selected from the above ring A, ring B, ring C, and ring D by a linking group or a single bond. It may be combined with at least one of

R ¹ and R ² are each independently hydrogen, C 1 to C 6 alkyl, C 3 to C 12 cycloalkyl, C 6 to C 12 aryl, C 2 to C 15 heteroaryl or diarylamino (however, aryl is Aryl of 6 to 12 carbon atoms),

At least one hydrogen in the compound represented by formula (ii) may be substituted with cyano, halogen or deuterium.)

(In the above formula (iii),

A ring, B ring, and C ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl or alkyl,

X ¹ , X ² and X ³ are each independently O, NR, >CR ₂ , S or Se, and R of NR and R of >CR ₂ are optionally substituted aryl or optionally substituted heteroaryl , Cycloalkyl or alkyl which may be substituted, and R of NR may be bonded to at least one selected from the A ring, B ring and C ring by a linking group or a single bond, and,

At least one hydrogen in the compound or structure represented by formula (iii) may be substituted with cyano, halogen or deuterium.)

[3]

The organic electric field according to [1] or [2], containing at least one compound represented by any one of the following formulas (1), (2), (3) and (4) as the third component. Light-emitting device.

(In the above formula (1),

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, dia Ryl boryl, alkyl, cycloalkyl, alkoxy or aryloxy, and these may also be substituted with aryl, heteroaryl or alkyl, and adjacent among ^{R 1} to ^{R 3} , R ⁴ to ^{R 7} and R ⁸ to ^{R 11} Groups may be bonded to each other to form an aryl ring or heteroaryl ring together with the a ring, b ring, or c ring, and the formed ring is at least 1 selected from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy They may be substituted with dogs, and these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,

X ¹ and X ² are each independently >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl, cycloalkyl or alkyl, and these are aryl, heteroaryl , At least one selected from cycloalkyl and alkyl may be substituted,

However, X ¹ and X ² are not _{>CR 2} at the same time,

And,

At least one hydrogen in the compound and structure represented by formula (1) may be substituted with cyano, halogen or deuterium.)

(In the above formula (2),

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently hydrogen, aryl , Heteroaryl, diarylamino, diarylboryl, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl substituted silyl, wherein At least one hydrogen of may be substituted with aryl, heteroaryl, or alkyl, ^{and adjacent groups of R 5} to ^{R 7} and R ¹⁰ to ^{R 12} are bonded to each other to form an aryl ring or heteroaryl with ring b or ring d. A ring may be formed, and at least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, May be substituted with arylthio, heteroarylthio or alkyl substituted silyl, at least one hydrogen in these may be substituted with aryl, heteroaryl or alkyl,

Y is B (boron),

X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl of 6 to 12 carbon atoms, 2 -15 heteroaryl, C3-C12 cycloalkyl or C1-C6 alkyl, and R of >NR and R of >CR ₂ are -O-, -S-, -C(-R) ₂ -or may be bonded to at least one selected from the a ring, b ring, c ring and d ring by a single bond, and _{R of -C(-R) 2} -is hydrogen or alkyl having 1 to 6 carbon atoms. Is,

However, X ¹ , X ² , X ³ , and X ⁴ are not _{>CR 2} at the same time,

And,

At least one hydrogen in the compound represented by formula (2) may be substituted with cyano, halogen or deuterium.)

(In the above formula (3),

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diarylboryl, alkyl, cyclo Alkyl, alkoxy or aryloxy, these may be further substituted with at least one selected from aryl, heteroaryl and alkyl, and adjacent groups among ^{R 1} to ^{R 3} , R ⁴ to ^{R 6} and R ⁹ to ^{R 11} They may be bonded to each other to form an aryl ring or a heteroaryl ring together with the a ring, b ring, or c ring, and the formed ring is at least one selected from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy. May be substituted, these may also be substituted with at least one selected from aryl, heteroaryl, cycloalkyl and alkyl,

X ¹ , X ² and X ³ are each independently >O, >NR, or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl, cycloalkyl or alkyl, and these It may be substituted with at least one selected from aryl, heteroaryl and alkyl,

However, X ¹ , X ² , and X ³ are not _{>CR 2} at the same time,

And,

At least one hydrogen in the compound and structure represented by formula (3) may be substituted with cyano, halogen or deuterium.)

(In the above formula (4),

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently hydrogen, aryl , Heteroaryl, diarylamino, diarylboryl, alkyl, cycloalkyl, alkoxy or aryloxy, and these may also be substituted with at least one selected from aryl, heteroaryl and alkyl, and R ¹ to ^{R 3} , Adjacent groups among R ⁴ to ^{R 7} , R ⁸ to ^{R 10} and R ¹¹ to ^{R 14 may be} bonded to each other to form an aryl ring or heteroaryl ring together with the a ring, b ring, c ring or d ring, and the formed ring is Aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy may be substituted with at least one, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,

X is >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl or alkyl, even if these are substituted with at least one selected from aryl, heteroaryl and alkyl Become,

L is a single bond, >CR ₂ , >O, >S or >NR, and _{R in >CR 2} and >NR are each independently hydrogen, aryl, heteroaryl, diarylamino, alkyl, alkoxy Or aryloxy, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,

However, X and L are not _{>CR 2 at the same time,}

And,

At least one hydrogen in the compound and structure represented by formula (4) may be substituted with cyano, halogen or deuterium.)

[4]

As the third component, at least one compound represented by any one of formulas (1), (2) and (4) is included,

In the formula (1), X ¹ and X ² are each independently >O or >NR,

In the formula (2), X ¹ , X ² , X ³ and X ⁴ are each independently >O or >NR,

In the formula (4), X is >O and >N-R, and L is a single bond,

The organic electroluminescent device according to [3].

[5]

As the third component, at least one compound represented by any one of formulas (1), (2), (3), and (4) is included, and the valence of the ring present in the compound is , Aryl, heteroaryl, diarylamino, diarylboryl, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio and alkyl substituted silyl The organic electroluminescent device according to [3] or [4], which is substituted with at least one of which is used.

[6]

As the third component, containing at least one compound represented by the formula (2), and the valence of the ring present in the compound, aryl, heteroaryl, diarylamino, diarylboryl, diheteroaryl Substituted with at least one selected from amino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio and alkyl substituted silyl, these are also aryl, heteroaryl, cycloalkyl and The organic electroluminescent device according to [5], which may be substituted with at least one selected from alkyl.

[7]

The organic electroluminescent device according to any one of [1] to [6], wherein the third component includes a partial structure represented by the following formula.

However, the hydrogens in the partial structure may each independently be substituted with aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, and these may also be selected from aryl, heteroaryl, cycloalkyl and alkyl. It may be substituted with at least one to be used.

[8]

The organic electroluminescent device according to any one of [3] to [6], wherein the compound represented by any one of formulas (1) to (4) has any one of the partial structures described below.

(In the partial structural formula,

Me represents methyl, tBu represents tert-butyl, and the broken line represents the bonding site.

However, hydrogen in the partial structural formula,

Each independently may be substituted with aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy, and hydrogen in the aryl may also be substituted with aryl, heteroaryl or alkyl, and hydrogen in the heteroaryl May also be substituted with aryl, heteroaryl or alkyl, and hydrogen in the diarylamino may also be substituted with aryl, heteroaryl or alkyl.)

[9]

The compound represented by any one of the above formulas (1) to (4) is sp ^{3 carbon, sp 2} carbon atom bonded to the m position or p position with respect to the boron atom, or nitrogen substituted with the p position with respect to boron The organic electroluminescent device according to any one of [3] to [8], having any one of atoms.

[10]

The organic electroluminescent device according to [3], wherein the compound represented by the formula (2) is the following compound.

[11]

The organic electroluminescent device according to [4], wherein the compound represented by the formula (2) is the following compound.

[12]

The organic electroluminescent device according to any one of [1] to [11], wherein the first component is a compound having at least one selected from carbazole and furan as a partial structure.

[13]

The organic electroluminescent device according to any one of [1] to [12], wherein the first component contains at least one compound represented by any one of the following formulas (H1), (H2), and (H3). .

(In the above formulas (H1), (H2) and (H3), L ¹ is an arylene having 6 to 24 carbon atoms, a heteroarylene, a heteroarylene arylene, or an arylene heteroarylene arylene,

At least one hydrogen in the compound represented by each of the above formulas may be substituted with alkyl, cyano, halogen or deuterium having 1 to 6 carbon atoms.)

[14]

The second component, as a partial structure, carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, The organic electroluminescent device according to any one of [1] to [13], having at least one selected from oxadiazole, thiadiazole, and benzophenone.

[15]

The organic electroluminescent device according to any one of [1] to [14], wherein the second component contains at least one compound represented by any one of the following formulas (AD1), (AD2), and (AD3). .

(In the above formula (AD1), formula (AD2) and formula (AD3),

M is each independently a single bond, -O-, >N-Ar or >CAr ₂ ,

J is each independently an arylene having 6 to 18 carbon atoms, and the arylene may be substituted with at least one selected from phenyl, alkyl having 1 to 6 carbon atoms, and cycloalkyl having 3 to 12 carbon atoms,

Q is each independently =C(-H)- or =N-,

Ar is each independently hydrogen, a C6-C18 aryl, a C6-C18 heteroaryl, a C1-C6 alkyl, or a C3-C12 cycloalkyl, and at least 1 in said aryl and heteroarylene Hydrogen of the dog may be substituted with phenyl, alkyl having 1 to 6 carbon atoms, or cycloalkyl having 3 to 12 carbon atoms,

m is 1 or 2,

n is an integer of 2 to (6-m),

At least one hydrogen in the compound represented by each of the above formulas may be substituted with halogen or deuterium.)

[16]

The organic electroluminescent device according to any one of [1] to [14], wherein the second component contains at least one compound represented by the following formula (DAD1).

(D ¹ -L ¹ )nA ¹ (DAD1)

(In the above formula (DAD1), D ¹ is a donor group, L ¹ is a single bond or a conjugated linking group, A ¹ is an acceptor group, n is 2 or more, and A1 is an integer equal to or less than the maximum number that can be substituted. to be.)

[17]

The organic electroluminescent device according to [16], wherein the second component contains at least one compound represented by the following formula (DAD2).

D ² -L ² -A ² -L ³ -D ³ (DAD2)

(In the formula (DAD2), D ² and D ³ are each independently a donor group, L ² and L ³ are each independently a single bond or a conjugated linking group, and A ² is an acceptor group.)

[18]

In the above formulas (AD1), (AD2) and (AD3),

M is each independently a single bond, -O- or >N-Ar,

J is each independently phenylene, and the phenylene may be substituted with alkyl having 1 to 4 carbon atoms,

Q is each independently =N-,

Ar is each independently hydrogen or phenyl, and the phenyl may be substituted with phenyl or alkyl having 1 to 4 carbon atoms,

m is 1 or 2,

n is an integer of 4 to (6-m),

The organic electroluminescent device according to [17].

[19]

The organic electroluminescent device according to any one of [1] to [18], wherein the crossover speed between the inverse terms of the second component is 10 ⁵ s ^{-1 or more.}

[20]

The organic electroluminescent device according to any one of [1] to [19], wherein the delayed fluorescence lifetime of the third component is 0.05 µsec to 40 µsec.

[21]

The organic electroluminescent device according to any one of [1] to [19], wherein the delayed fluorescence lifetime of the third component is 0.05 µsec to 20 µsec.

[22]

The organic electroluminescent device according to any one of [1] to [21], wherein a Stokes shift calculated from the difference between the peak top of the fluorescence spectrum and the peak top of the absorption spectrum of the third component is 14 nm or less.

[23]

The organic electroluminescent device according to any one of [1] to [21], wherein a Stokes shift calculated from the difference between the peak top of the fluorescence spectrum and the peak top of the absorption spectrum of the third component is 10 nm or less.

[24]

The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component The energy level is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the phosphorescence spectrum of the third component When the excitation triplet energy level obtained from the shoulder of the peak short wavelength side is E(3, T, Sh), the singlet triplet energy difference (ΔE(2, ST, Sh) and ΔE(3 , ST, Sh)) is the organic electroluminescent device according to any one of [1] to [23] in the following relationship.

ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh) ≤ 0.50 eV

ΔE(3, ST, Sh)=E(3, S, Sh)-E(3, T, Sh)≤ 0.20 eV

[25]

The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component The energy level is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the phosphorescence spectrum of the third component When the excitation triplet energy level obtained from the shoulder of the peak short wavelength side is E(3, T, Sh), the singlet triplet energy difference (ΔE(2, ST, Sh) and ΔE(3 , ST, Sh)) is the organic electroluminescent device according to any one of [1] to [24] in the following relationship.

ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)

ΔE(3, ST, Sh)=E(3, S, Sh)-E(3, T, Sh)

ΔE(2, ST, Sh)≥ (3, ST, Sh)

[26]

The organic electroluminescent device according to any one of [1] to [25], wherein the singlet triplet energy difference (ΔE(2, ST, Sh)) of the second component has the following relationship.

ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)≤0.30eV

[27]

The organic electroluminescent device according to any one of [1] to [26], wherein the singlet triplet energy difference (ΔE(2, ST, Sh)) of the second component has the following relationship.

ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)≤0.15eV

[28]

The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component The energy level is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the phosphorescence spectrum of the third component The organic electroluminescence according to any one of [1] to [27], in which the excitation triplet energy level obtained from the shoulder on the peak short wavelength side of is E(3, T, Sh), which has the following relationship. device.

E(2, S, Sh)≥E(3, S, Sh)

E(2, T, Sh) ≤ E(3, T, Sh)

[29]

The organic electroluminescent device according to any one of [1] to [28], wherein a Stokes shift calculated from the difference between the peak top of the fluorescence spectrum and the peak top of the absorption spectrum of the third component is 10 nm or less.

[30]

The organic electroluminescent device according to any one of [1] to [29], wherein the third component is contained as a polymer compound having a group from which two hydrogen atoms of the compound having boron atoms are removed as a repeating unit.

[31]

The organic electroluminescent device according to [30], wherein the polymer compound having a group obtained by desorbing two hydrogen atoms of the boron atom as a repeating unit is a repeating unit obtained by desorbing two hydrogen atoms of the host compound.

[32]

The organic electroluminescence according to [30] or [31], wherein a polymer compound having a group from which two hydrogen atoms of the compound having boron atoms are desorbed as a repeating unit has as a repeating unit from which two hydrogen atoms of the delayed phosphor are desorbed. device.

[33]

A display device comprising the organic electroluminescent device according to any one of [1] to [32].

[34]

A lighting device comprising the organic electroluminescent device according to any one of [1] to [32].

[35]

A composition for forming a light emitting layer for coating and forming a light emitting layer of an organic light emitting device,

In addition to the first component, the second component, and the third component according to any one of [1] to [32], a composition for forming a light-emitting layer containing at least one organic solvent as a fourth component (however, the above The third component is not the following compound).

[36]

The composition for forming a light-emitting layer according to [35], wherein the boiling point of at least one organic solvent in the fourth component is 130°C to 350°C.

[37]

The fourth component includes a good solvent (GS) and a poor solvent (PS) for at least one of the first component, the second component, and the third component of the compound, and the good solvent (GS) The composition for forming a light-emitting layer according to [35] or [36], wherein the boiling point (BP _{GS ) is lower than the boiling point (BP PS} ) of the poor solvent (PS).

[38]

The first component is 0.0998% by mass to 4.0% by mass based on the total mass of the composition for forming a light emitting layer,

The second component is 0.0001% by mass to 2.0% by mass based on the total mass of the composition for forming a light emitting layer,

The third component is 0.0001% by mass to 2.0% by mass based on the total mass of the composition for forming a light emitting layer,

The fourth component is 90.0% by mass to 99.9% by mass based on the total mass of the composition for forming a light-emitting layer,

The composition for forming a light-emitting layer according to any one of [35] to [37].

[39]

An organic electroluminescent device having a light emitting layer formed using the composition for forming a light emitting layer according to any one of [35] to [38].

[40]

A compound in which at least one hydrogen of the compounds represented by formula (ii) described in [2] is substituted with the following partial structure (B), chlorine, bromine, or iodine.

(In the partial structure (B), R ⁴⁰ and R ⁴¹ are alkyl which may be bonded with a total of 2 to 10 carbon atoms, and the broken line is a bonding site with other structures.)

[41]

A repeating unit including a structure in which two hydrogen atoms are removed from a compound having a boron atom, a repeating unit including a structure in which two hydrogen atoms are removed from a thermally activated delayed phosphor, and two hydrogen atoms are removed from a host compound A polymer compound containing at least two repeating units selected from repeating units containing one structure.

[42]

At least one type of repeating unit including a structure obtained by desorbing two hydrogen atoms from a compound having a boron atom, at least one type of repeating unit including a structure obtained by removing two hydrogen atoms from a thermally activated delayed phosphor, and a host A polymer compound containing at least one of repeating units having a structure obtained by removing two hydrogen atoms from the compound.

The organic electroluminescent device of the present invention includes a host compound, a thermally activated delayed phosphor, and a compound having a boron atom in a molecule in the emission layer, and their excitation singlet energy level satisfies a predetermined condition, thereby producing organic electroluminescence. The properties can be further enhanced.

1 is an energy level diagram showing an example of an energy relationship between a host, an assisting dopant, and an emitting dopant of an organic light emitting diode to which the present invention is applied.
2 is an energy level diagram showing another example of the energy relationship between a host, an assisting dopant, and an emitting dopant of an organic light emitting diode to which the present invention is applied.
3 is an energy level diagram showing another example of the energy relationship between a host, an assisting dopant, and an emitting dopant of an organic light emitting diode to which the present invention is applied.
4 is a schematic cross-sectional view showing an organic electroluminescent device according to the present embodiment.
5 is an energy level diagram showing an energy relationship between a host, an assisting dopant, and an emitting dopant of a TAF device using a general fluorescent dopant.
6 is a view for explaining a method of manufacturing an organic light emitting device on a substrate having a bank by using an ink jet method.
7 is a diagram showing the relationship between the basic skeleton of the compound, Tau (Delay) and Stokes shift.
8 is a diagram showing the relationship between the basic skeleton of the compound and the half width, external quantum efficiency, and device life.
9 is a diagram showing the relationship between the substituent group of the compound, Tau (Delay) and Stokes shift.
10 is a diagram showing a relationship between a substituent group of a compound, a half value width, an external quantum efficiency, and a device lifespan.
11 is a diagram showing a relationship between a substituent group of a compound, a Stokes shift, and a half value width.

Hereinafter, the present invention will be described in detail. The description of the structural requirements described below may be performed based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In addition, in this specification, the numerical range expressed using "-" means a range including the numerical value described before and after "-" as a lower limit value and an upper limit value. In addition, room temperature means 20 degreeC.

1. Explanation of Terms and Mechanism of the Invention

The organic electroluminescent device of the present invention uses a host compound, a thermally activated delayed phosphor, and a compound having a boron atom in a molecule.

The term "host compound" in the present invention means that the excitation singlet energy level obtained from the shoulder of the peak short wavelength side of the fluorescence spectrum is higher than that of the compound having a thermally activated delayed phosphor as a second component and a boron atom as a third component. It means a compound.

The term "thermally activated delayed phosphor" refers to a compound capable of absorbing heat energy, causing a crossover between the excited triplet state to the excited singlet state, and radiating from the excited singlet state to emit delayed fluorescence. do. However, "thermally activated delayed fluorescence" includes passing through a higher order triplet in the excitation process from the excited triplet state to the excited singlet state. For example, a paper by Monkman et al at Durham University (NATURE COMMUNICATIONS, 7: 13680, DOI: 10.1038/ncomms13680), a paper by Hosokai et al., Sci. Adv. 2017; 3 : e1603282), a paper by Kyoto University Sato et al. (Scientific Reports, 7: 4820, DOI: 10.1038/s41598-017-05007-7) and similarly presented at a conference by Kyoto University Sato et al. (Japanese Chemical Society 98th Spring Banquet, Publication No.: 2I4-15, High-efficiency luminescence mechanism in organic electroluminescence using DABNA as a luminescent molecule, Kyoto University Graduate School, Graduate School of Engineering). In the present invention, when the fluorescence lifetime of the sample containing the target compound is measured at 300 K, the delayed fluorescence component is observed, and it is determined that the target compound is a "thermally activated delayed phosphor". Here, the delayed fluorescence component refers to a fluorescence lifetime of 0.1 μsec or more. The measurement of the fluorescence lifetime can be performed using, for example, a fluorescence lifetime measurement apparatus (manufactured by Hamamatsu Photonics, C11367-01).

A "compound having a boron atom in a molecule" can function as an emitting dopant, and a "heat activated delayed phosphor" can function as an assisting dopant that assists the light emission of a compound having a boron atom in the molecule.

In the following description, an organic electroluminescent device using a thermally activated delayed phosphor as an assisting dopant is sometimes referred to as a "TAF device" (TADF Assisting Fluorescence device).

Figure 5 shows the energy level of the light emitting layer of a TAF device using a general fluorescent dopant for the emitting dopant (ED). In the figure, the energy level of the ground state of the host is E(1, G), the excitation singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the host is E(1, S, Sh), and the phosphorescence spectrum of the host The excitation triplet energy level obtained from the shoulder on the short wavelength side is E(1, T, Sh), the ground state energy level of the second component, assisting dopant, is E(2, G), and the second component, assisting dopant. The excitation singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum of E(2, S, Sh), and the excitation triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescence spectrum of the assisting dopant as the second component E(2, T, Sh), the energy level of the ground state of the third component, the emitting dopant, is E(3, G), excitation 1 obtained from the shoulder on the short wavelength side of the fluorescence spectrum of the third component, the emitting dopant. The intermediate energy level is E(3, S, Sh), and the excitation triplet energy level obtained from the shoulder on the short wavelength side of the phosphorescence spectrum of the third component, the emitting dopant, is E(3, T, Sh). In the TAF device, when a general fluorescent dopant is used as the emitting dopant (ED), the energy up-converted from the assisting dopant moves to the excitation singlet energy level E(3, S, Sh) of the emitting dopant to emit light. . However, some of the excitation triplet energy E(2, T, Sh) on the assisting dopant shifts to the excitation triplet energy level E(3, T, Sh) of the emitting dopant, or the excitation singlet energy on the emitting dopant. Intersections occur from the level E(3, S, Sh) to the excitation triplet energy level E(3, T, Sh), and continue to thermally deactivate to the ground state E(3, G). Some energy is not used for light emission by this path, resulting in waste of energy.

In contrast, in the organic light emitting device of the present invention, energy transferred from the assisting dopant to the emitting dopant can be efficiently used for light emission, thereby realizing high luminous efficiency. This is presumed to be due to the following light emission mechanism.

That is, the preferred energy relationship in the organic electroluminescent device of the present invention is shown in FIG. 1. In the organic electroluminescent device of the present invention, a compound having a boron atom as an emitting dopant has a high excitation triplet energy level E(3, T, Sh). For this reason, the excitation singlet energy up-converted by the assisting dopant is up-converted on the emitting dopant even if it intersects the excitation triplet energy level E(3, T, Sh) in the emitting dopant, The excitation triplet energy level E(2, T, Sh) on the assisting dopant (thermally activated delayed phosphor) is recovered. Therefore, the generated excitation energy can be used for light emission without wasting it. In addition, by dividing the function of upconversion and light emission into two kinds of molecules, each of which can improve the function of light emission, it is expected that the residence time of high energy decreases and the burden on the compound decreases.

On the other hand, for a compound containing a boron atom, which is the third component of the present invention, by molecular orbital calculation, the excitation triplet energy involved in the interterm crossovers in the forward and reverse directions from the triplet state to the excitation singlet state is, It is pointed out that it is not the excitation triplet energy observed by the phosphorescence spectrum, but the excitation triplet energy, which is a higher dimension (Japanese Chemical Society 98th Spring Conference, Publication No.: 2I4-15, Organic using DABNA as a light emitting molecule). High-efficiency luminescence mechanism in electroluminescence, presented by Professor Toru Sato, Graduate School of Engineering, Graduate School of Kyoto University). According to the announcement, the inverse crossover in DABNA2 having a boron atom in the molecule is an FvHT (Fluorescence via Higher Triplet) mechanism using a higher-order triplet orbit, and the transition from the higher-order triplet orbit to the ground state is suppressed. Therefore, it is suggested that a transition to a singlet track occurs here rather than a higher-order triplet track.

When the above-described high-order triplet energy level is considered, the energy relationship in the emission layer of the organic EL device of the present invention is, when the high-order triplet energy level E(3, Tn) is slightly lower than the singlet energy level here (TADF mechanism In the case of ), it can be represented by the energy level of FIG. 2, and when the higher-order excitation triplet energy level is slightly higher than the excitation singlet energy level (in the case of the FvHT function), it can be represented by the energy level of FIG. 3. In either case, since the deactivation from the lowest triplet orbit is suppressed, it is expected to provide good device characteristics similar to the energy relationship in Fig. 1. However, the higher-order triplet orbits suggested from molecular orbital calculations are not spectroscopically clear at the present time. In this specification, for reasons that can be measured spectroscopically, it is assumed that the triplet energy level is obtained from the phosphorescence spectrum, except that the organic light emitting device of the present invention has the energy relationship shown in FIGS. 2 and 3. It is not.

From the point of view of the TADF-activated compound, the DA-type thermally activated delayed phosphor (D represents an electron donor atomic group, A represents an electron acceptor atomic group) has a high upconversion speed and a half width of light emission. It is characterized by wide and low color purity. On the other hand, the multi-resonance effect (MRE) type thermally activated delayed phosphor has a slow up-conversion, a narrow half-value width of light emission, a high color purity, a high fluorescence quantum yield (PLQY), and a fast light emission rate. There are features. The organic electroluminescent device of the present invention is designed to take advantage of these molecules. Thereby, a spectrum with a narrow half-width and good color tone, high external quantum efficiency, improvement in roll off, and long life are realized.

From the conditions of the TAF device shown in the paper and the above description, the host compound (first component), the thermally activated delayed phosphor (assisting dopant, the second component), and the compound having a boron atom in the organic light emitting device of the present invention ( The relationship between the energy of the emitting dopant and the third component) is summarized below.

The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the first component is E(1, S, Sh), and the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component. When E(2, S, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), the following relational expression (1) is obtained: Satisfy.

Relation (1): E(1, S, Sh)≥E(2, S, Sh)≥E(3, S, Sh)

That is, the host compound, which is the first component, is responsible for confinement and/or transmission of energy, and the emitting dopant, which is the third component, is responsible for light emission.

Here, E(1, S, Sh)-E(2, S, Sh) is preferably 0 to 1.0 eV, and E(2, S, Sh)-E(3, S, Sh) is 0 to 0.20 It is preferably eV.

The excitation singlet energy level obtained from the peak top of the short wavelength side of the fluorescence spectrum of the first component is E(1, S, PT), and the excitation singlet energy level obtained from the peak top of the short wavelength side of the fluorescence spectrum of the second component When E (2, S, PT) and the excitation singlet energy level obtained from the peak tower on the short wavelength side of the fluorescence spectrum of the third component is E (3, S, PT), the following two relational expressions are satisfied. It is desirable to make it.

E(1, S, PT)>E(2, S, PT)

E(1, S, PT)>E(3, S, PT)

E(2, S, PT) and E(3, S, PT) can be applied to the present invention no matter which one becomes larger, but it is preferable that E(3, S, PT)>E(2, S, PT) .

The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet energy level obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component. Is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the peak short wavelength side of the phosphorescence spectrum of the third component When the excitation triplet energy level obtained from the shoulder of is E(3, T, Sh), the singlet triplet energy difference (ΔE(2, ST, Sh) and ΔE(3, ST, Sh) obtained from these It is preferable that )) is in the following relationship.

ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)≤0.50eV

ΔE(3, ST, Sh)=E(3, S, Sh)-E(3, T, Sh)≤0.20eV

That is, in the second component, the size of ΔE(ST) is used as an index of TADF activity. The smaller ΔE(ST) is, the more advantageous it is to exhibit TADF activity. Here, ΔE(2, ST, Sh) is more preferably 0.30 eV or less, more preferably 0.15 eV or less, and most preferably 0.10 eV or less. ΔE(3, ST, Sh) is more preferably 0.15 eV or less, and even more preferably 0.10 eV or less.

It is preferable that ΔE(2, ST, Sh) and ΔE(3, ST, Sh) have the following relationship.

ΔE(2, ST, Sh)≥ΔE(3, ST, Sh)

In addition, it is also preferable to have the following relationship.

E(2, S, Sh)≥E(3, S, Sh)

E(2, T, Sh) ≤ E(3, T, Sh)

Here, E(2, S, Sh)-E(3, S, Sh) is preferably 0 to 0.20 eV, and E(3, T, Sh)-E(2, T, Sh) is 0 to 0.20 It is preferably eV. These show the design of the TAF device of the present invention shown in FIG. 1.

In addition, the crossover speed between the inverse terms of the second component is k (2, RISC), the crossover speed between the inverse terms of the third component is k (3, RISC), the emission speed of the second component is k (2, Prompt) and the third When the emission rate of the component is k (3, Prompt), it is preferable to satisfy the following relationship.

k(2, RISC)>k(3, RISC)

k(2, Prompt)<k(3, Prompt)

In addition, in this specification, for the host compound, the excitation singlet energy level obtained from the shoulder on the short wavelength side of the fluorescence spectrum is E(1, S, Sh), and calculated from the peak top on the short wavelength side of the fluorescence spectrum. The ground excitation singlet energy level is E(1, S, PT), the excitation triplet energy level obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum is E(1, T, Sh), and the short wavelength of the phosphorescence spectrum The excitation triplet energy level obtained from the peak top on the side is E(1, T, PT). In addition, E(1, S, Sh), E(2, S, Sh), E(3, S, Sh) are collectively referred to as E(S, Sh), and E(1, S, PT) , E(2, S, PT), E(3, S, PT) are collectively referred to as E(S, PT), and E(1, T, Sh), E(2, T, Sh), E( 3, T, Sh) are collectively referred to as E(T, Sh), and E(1, T, PT), E(2, T, PT), E(3, T, PT) are collectively referred to as E(T , PT), and ΔE(2, ST, PT) and ΔE(3, ST, PT) are collectively referred to as ΔE(ST).

In the present invention, the excitation singlet energy level E(S, Sh) obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum, and the excitation singlet energy level E(S, PT) obtained from the peak top on the short wavelength side of the fluorescence spectrum , Excitation triplet energy level E(T, Sh) obtained from the shoulder of the peak short wavelength side of the phosphorescence spectrum, excitation triplet energy level E(T, PT) obtained from the peak top of the short wavelength side of the phosphorescence spectrum, crossover between inverse terms The speed and the starting light speed will be calculated as follows.

Here, ``the shoulder on the short wavelength side of the peak'' means the inflection point on the short wavelength side of the emission peak, and the ``peak top on the short wavelength side'' means the position on the peak corresponding to the maximum emission maximum value on the shortest wavelength side among the emission maximum values of the emission peak. Means.

In addition, as a measurement sample for measuring each energy level, when the target compound is a host compound or an assisting dopant, a single film (Neat film, thickness: 50 nm) of the target compound formed on a glass substrate is used. When the compound is an emitting dopant, a polymethyl methacrylate film (thickness: 10 µm, target compound concentration: 1 mass%) formed on a glass substrate and in which the target compound is dispersed is used. As for the film thickness of the polymethyl methacrylate film in which the target compound is dispersed, the film thickness that provides sufficient intensity for the measurement of absorption spectrum, fluorescence spectrum and phosphorescence spectrum is sufficient. When the intensity is weak, it is thick, and when the intensity is strong, it is thin. do. For excitation light, the wavelength of the absorption peak obtained in the absorption spectrum is used, and among the emission peaks appearing in the fluorescence or phosphorescence spectrum, in the range of 400 to 500 nm in the case of blue light emission, and 480 in the case of green light emission. Each energy level is determined by using the data obtained from the emission peaks respectively appearing in the range of -600 nm and in the case of red light emission in the range of 580-700 nm. Further, when the absorption peak and the emission peak are close to each other, and excitation light is mixed in the emission peak, an absorption peak or absorption shoulder on a shorter wavelength side may be used.

[1] Excitation singlet energy level E(S, Sh) obtained from the shoulder of the peak short wavelength side of the fluorescence spectrum

A measurement sample containing the target compound is irradiated with excitation light at 77 K to observe a fluorescence spectrum. With respect to the emission peak appearing in the fluorescence spectrum, a tangent line passing through the inflection point (shoulder) on the short wavelength side is drawn, and from the wavelength (B _Sh ) [nm] of the intersection of the tangent line and the baseline, excitation 1 Calculate the intermediate energy level E(S, Sh).

E(S, Sh)[eV]=1240/B _Sh

[2] Excitation singlet energy level E(S, PT) obtained from the peak top on the short wavelength side of the fluorescence spectrum

A measurement sample containing the target compound is irradiated with excitation light at 77 K to observe a fluorescence spectrum. _{From the wavelength (maximum emission wavelength, B PT} ) [nm] corresponding to the peak top on the shortest wavelength side of the emission peak appearing in the fluorescence spectrum, the excitation singlet energy level E (S, PT) is calculated using the following equation. do.

E(S, PT)[eV]=1240/B _PT

[3] Excitation triplet energy level E(T, Sh) obtained from the shoulder on the short wavelength side of the peak of the phosphorescence spectrum

A measurement sample containing the target compound is irradiated with excitation light at 77 K to observe a phosphorescence spectrum. With respect to the emission peak appearing in the phosphorescence spectrum, a tangent line passing through the inflection point (shoulder) on the short wavelength side is drawn, and from the wavelength (C _Sh ) [nm] of the intersection of the tangent line and the baseline, using the following equation, excitation 3 Calculate the intermediate energy level E(T, Sh).

E(T, Sh)[eV]=1240/C _Sh

[4] Excitation triplet energy level E(T, PT) obtained from the peak top on the short wavelength side of the phosphorescence spectrum

A measurement sample containing the target compound is irradiated with excitation light at 77 K to observe a phosphorescence spectrum. _{From the wavelength (maximum emission wavelength, C PT} ) [nm] corresponding to the peak top on the shortest wavelength side of the emission peak appearing in the phosphorescence spectrum, the excitation triplet energy level E (T, PT) is calculated using the following equation. do.

E(T, PT)[eV]=1240/C _PT

Here, in the DA (donor-acceptor) type TADF material and the MRE (Multi Resonance Effect, multiple resonance) type compound, the luminescence width of the fluorescence and phosphorescence spectra are different depending on the fastness of the molecule, so even if the maximum emission wavelength is the same, the DA type It is believed that the heat-activated delayed phosphor has more energy than the MRE-type compound molecule. In the TAF element, since it is necessary to accurately predict the energy transfer between each component and design the configuration, the excitation singlet energy level and the excitation triplet energy level are predicted from the shoulder on the short wavelength side of the spectrum. In general, the intersection of the tangent line passing through the inflection point on the short wavelength side of the spectrum and the baseline is taken as the energy obtained from the shoulder on the short wavelength side.

The excitation singlet energy level E(S, Sh) and the excitation triplet energy level E(T, Sh) obtained from the shoulder on the short wavelength side are used for calculation and discussion of ΔE(ST), and the host compound as the first component It is also used for discussion of the confinement and transfer of energy of an assisting dopant and an assisting dopant, and confinement and transfer of energy of an assisting dopant and an emitting dopant.

[5] crossover speed between reverse routes

The crossover speed between the inverse terms represents the speed of the crossover between the inverse terms from the triplet here to the singlet here. The crossover velocity between the inverse terms of the assisting dopant and the emitting dopant was determined by transient fluorescence spectroscopy measurement, Nat. Commun. It can be calculated using the method described in 2015, 6, 8476 or Organic Electronics 2013, 14, 2721-2726, specifically, the crossover speed between the inverse terms of the assisting dopant is 10 ⁵ s ^-1 , more preferably , 10 ⁶ s ^-1 .

[6] luminous speed

The luminescence rate represents the rate at which the singlet of excitation is shifted from the excitation singlet to the ground state through fluorescence emission without going through the TADF process. The luminescence speed of the assisting dopant and the emitting dopant is similar to the crossover speed between inverse terms, Nat. Commun. It can be calculated using the method described in 2015, 6, 8476 or Organic Electronics 2013, 14, 2721-2726, specifically, the crossover speed between the inverse terms of the emitting dopant is 10 ⁷ s ^-1 , more preferably , 10 ⁸ s ^-1 .

2. Organic light emitting device

Hereinafter, each layer constituting the organic electroluminescent device of the present invention will be described.

2-1. Light-emitting layer in an organic light-emitting device

The light-emitting layer contains at least a host compound as a first component, a thermally activated delayed phosphor as a second component, and a compound having a boron atom as a third component.

In this specification, the thermally activated delayed phosphor as the second component is sometimes referred to as ``assisting dopant'' (compound), and the compound having a boron atom as the third component is sometimes referred to as ``emitting dopant'' (compound). .

The light-emitting layer may be a single layer, may consist of a plurality of layers, or either. Further, the host compound, the thermally activated delayed phosphor, and the compound having a boron atom may be contained in the same layer, or may be contained in a plurality of layers at least one component. The host compound contained in the light emitting layer, the thermally activated delayed phosphor, and the compound having a boron atom may each be one type, a combination of a plurality, or any one. The assisting dopant and the emitting dopant may be contained entirely or partially in the host compound serving as a matrix. For the light emitting layer doped with the assisting dopant and the emitting dopant, a method of depositing a host compound, an assisting dopant, and an emitting dopant by a three-way evaporation method, and simultaneously depositing after mixing the host compound, the assisting dopant and the emitting dopant in advance. It can be formed by a method such as a wet film forming method, in which a composition for forming a light emitting layer (paint) prepared by dissolving a host compound, an assisting dopant, and an emitting dopant in an organic solvent is applied.

The amount of the host compound used varies depending on the type of the host compound, and may be determined according to the characteristics of the host compound. The basis of the amount of the host compound used is preferably 40 to 99.999% by mass, more preferably 50 to 99.99% by mass, and still more preferably 60 to 99.9% by mass of the total material for the light emitting layer. Within the above range, for example, it is preferable from the viewpoint of efficient charge transport and efficient energy transfer to the dopant.

The amount of assisting dopant (thermal activated delayed phosphor) used varies depending on the type of assisting dopant, and may be determined according to the characteristics of the assisting dopant. The basis of the amount of the assisting dopant used is preferably 1 to 60% by mass, more preferably 2 to 50% by mass, and still more preferably 5 to 30% by mass of the total material for the light emitting layer. If it is the above range, it is preferable, for example, from the point of efficiently transferring energy to the emitting dopant.

The amount of the emitting dopant (a compound having a boron atom) is different depending on the type of the emitting dopant, and may be determined according to the characteristics of the emitting dopant. The basis of the amount of the emitting dopant used is preferably 0.001 to 30% by mass, more preferably 0.01 to 20% by mass, and still more preferably 0.1 to 10% by mass of the total material for the light emitting layer. If it is the above-described range, it is preferable, for example, from the point that concentration quenching can be prevented.

A low concentration of the emitting dopant is preferably used in that it can prevent concentration quenching. It is preferable from the viewpoint of the efficiency of the thermally activated delayed fluorescent device that the amount of the assisting dopant is high. Further, from the viewpoint of the efficiency of the thermally activated delayed fluorescent device of the assisting dopant, it is preferable that the amount of the emitting dopant is at a low concentration compared to the amount of the assisting dopant.

2-1-1. Host compound

As the host compound, a known compound can be used, for example, a compound having at least one of a carbazole ring and a furan ring, and among them, at least one of a furanyl group and a carbazolyl group, and an arylene and heteroaryl It is preferable to use a compound to which at least one of the enes is bound. As a specific example, mCP, mCBP, etc. are mentioned.

The excitation triplet energy level E(1, T, Sh) obtained from the shoulder of the peak short wavelength side of the phosphorescence spectrum of the host compound is the highest in the light emitting layer from the viewpoint of promoting without inhibiting the generation of TADF in the light emitting layer. It is preferable to be high compared to the excitation triplet energy levels E(2, T, Sh) and E(3, T, Sh) of the emitting dopant or assisting dopant having the triplet energy level here, and specifically, the host The excitation triplet energy level E(1, T, Sh) of the compound is preferably 0.01 eV or more, more preferably 0.03 eV or more, compared to E(2, T, Sh) and E(3, T, Sh). And more preferably 0.1 eV or more. Further, a TADF-activated compound may be used for the host compound.

As the host compound, for example, a compound represented by any one of the following formulas (H1), (H2), and (H3) can be used.

In the above formulas (H1), (H2) and (H3), L ¹ is an arylene having 6 to 24 carbon atoms, heteroarylene having 2 to 24 carbon atoms, heteroarylene arylene having 6 to 24 carbon atoms, or 6 carbon atoms. Arylene heteroarylene arylene of -24, C6-C16 arylene is preferable, C6-C12 arylene is more preferable, C6-C10 arylene is especially preferable, and specifically , Divalent groups such as a benzene ring, a biphenyl ring, a terphenyl ring, and a fluorene ring. As heteroarylene, C2-C24 heteroarylene is preferable, C2-C20 heteroarylene is more preferable, C2-C15 heteroarylene is still more preferable, C2-C10 heteroaryl Ren is particularly preferable, and specifically, a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring , Pyrimidine ring, pyridazine ring, pyrazine ring, triazine ring, indole ring, isoindole ring, 1H-indazole ring, benzimidazole ring, benzoxazole ring, benzothiazole ring, 1H-benzotriazole ring, quinoline ring, iso Quinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxatiine ring, phenoxazine ring, phenothiazine ring , Phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazane ring, and thianthrene ring. For example, qi.

At least one hydrogen in the compound represented by each of the above formulas may be substituted with alkyl, cyano, halogen or deuterium having 1 to 6 carbon atoms.

As the host compound, it is preferably a compound represented by any one of the structural formulas listed below. In the structural formulas listed below, at least one hydrogen may be substituted with halogen, cyano, alkyl having 1 to 4 carbon atoms (for example, methyl or tert-butyl), phenyl, naphthyl, or the like.

2-1-2. Thermally activated delayed phosphor (assisting dopant)

The thermally activated delayed phosphor (TADF compound) used in the present invention uses an electron-providing substituent called a donor and an electron-accepting substituent called an acceptor, and uses HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) in the molecule. Orbital) is localized to allow efficient reverse intersystem crossing to occur, and a donor-acceptor-type thermally activated delayed phosphor (DA-type TADF compound) is preferred.

Here, in the present specification, the term "electron-providing substituent" (donor) refers to a substituent and a partial structure in which the LUMO orbit is local among heat-activated delayed phosphor molecules, and the "electron-accepting substituent" (acceptor) refers to heat. Among the activated delayed phosphor molecules, the HOMO orbital refers to the localized substituents and partial structures.

In general, a thermally activated delayed phosphor using a donor or an acceptor has a large spin orbit coupling (SOC) due to its structure, and also has a small exchange interaction between HOMO and LUMO and a small ΔE(ST). Therefore, a very fast crossover speed between inverse terms is obtained. On the other hand, in the thermally activated delayed phosphor using a donor or acceptor, the structure relaxation in the excited state is increased (for some molecules, the stable structure is different between the ground state and the excited state, so the excited state from the ground state due to external stimulation) When the conversion to occurs, the structure changes to the stable structure in the excited state after that), it provides a wide emission spectrum, and thus, if used as a light emitting material, there is a possibility of lowering the color purity.

As the thermally activated delayed phosphor of the present invention, for example, a compound in which a donor and an acceptor are bonded directly or through a spacer can be used. As the donor and acceptor structures used in the thermally activated delayed phosphor of the present invention, for example, structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. As a donor structure, carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, Phenylbicarbazole, bicarbazole, dacarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis (tert-butyl)phenylamine, (diphenylamino)phenyldiphenylbenzenediamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydroindenoacridine and diphenyldihydrodibenzoazacillin, etc. Can be lifted. As an acceptor structure, sulfonyldibenzene, benzophenone, phenylenebis (phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, benzenetricarbonitrile, triazole , Oxazole, thiadiazole, benzothiazole, benzobis (thiazole), benzoxazole, benzobis (oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthonediox Seed, dimethylanthracenone, anthracendione, cycloheptabipyridine, fluorenedicarbonitrile, trisphenyltriazine, pyrazinedicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, pyridinedicarbonitrile, dibenzoquinoxaline Dicarbonitrile, bis(phenylsulfonyl)benzene, dimethylthioxanthenedioxide, thianthrenetetraoxide, and tris(dimethylphenyl)borane are exemplified. In particular, the compound having a thermally activated delayed fluorescence of the present invention, as a partial structure, carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalo It is preferably a compound having at least one selected from nitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole and benzophenone.

The compound used as the second component of the light-emitting layer of the present invention is a thermally activated delayed phosphor, and is preferably a compound whose emission spectrum at least partially overlaps with the absorption peak of the emitting dopant. In the following, a compound that can be used as the second component (thermally activated delayed phosphor) of the light-emitting layer of the present invention is illustrated. However, the compound that can be used as the thermally activated delayed phosphor in the present invention is not limitedly interpreted by the following exemplary compounds. In the following formula, Me represents methyl, t-Bu represents tert-butyl, Ph represents phenyl, and the broken line represents the bonding position.

Further, as the thermally activated delayed phosphor, a compound represented by any one of the following formulas (AD1), (AD2), and (AD3) can also be used.

In the above formulas (AD1), (AD2) and (AD3),

M is, each independently, a single bond, -O-, >N-Ar or >CAr ₂ , in terms of the depth of the HOMO of the partial structure to be formed and the height of the excitation singlet energy level and the excitation triplet energy level, Preferably, it is a single bond, -O-, or >N-Ar. J is a spacer structure dividing a partial structure of a donor and a partial structure of an acceptor, each independently, an arylene having 6 to 18 carbon atoms, in terms of the size of the conjugate exuding from the partial structure of the donor and the partial structure of the acceptor. And C6-C12 arylene is preferable. More specifically, phenylene, methylphenylene, and dimethylphenylene are exemplified. Q is each independently =C(-H)- or =N-, from the viewpoint of the shallowness of the LUMO of the partial structure to be formed and the height of the excitation singlet energy level and the excitation triplet energy level, preferably, =N-. Ar is each independently hydrogen, C6-C24 aryl, C2-C24 heteroaryl, C1-C12 alkyl, or C3-C18 cycloalkyl, and the depth and excitation of the HOMO of the partial structure to be formed From the viewpoint of the singlet energy level and the height of the triplet energy level here, preferably, hydrogen, aryl of 6 to 12 carbons, heteroaryl of 2 to 14 carbons, alkyl of 1 to 4 carbons, or cyclo of 6 to 10 carbons. Alkyl, more preferably hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazyl, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl , Benzimidazole or phenylbenzimidazole, more preferably hydrogen, phenyl or carbazolyl. m is 1 or 2. n is an integer of -(6-m), and from the viewpoint of steric hindrance, preferably, it is an integer of 4 to (6-m). In addition, at least one hydrogen in the compound represented by each of the above formulas may be substituted with halogen or deuterium.

The compound used as the second component of the light emitting layer of the present invention is more specifically stated, 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZ-TAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA- It is preferred that they are TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTRz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz and DCzmCzTrz.

The compound used as the second component of the light-emitting layer of the present invention may be a donor-acceptor TADF compound represented by DA in which one donor D and one acceptor A are directly bonded or bonded through a linking group. It is preferable to have a structure represented by the following formula (DAD1) in which a plurality of donors D are directly bonded to the Scepter A or through a connector, since the characteristics of the organic EL device are more excellent.

(D ¹ -L ¹ )nA ¹ (DAD1)

The compound represented by the following formula (DAD2) is contained in formula (DAD1).

D ² -L ² -A ² -L ³ -D ³ (DAD2)

In formulas (DAD1) and (DAD2), D ¹ , D ² and D ³ each independently represent a donor group. As the donor group, the above-described donor structure can be adopted. Each of A ¹ and A ² independently represents an acceptor group, and the above-described acceptor structure can be adopted as the acceptor group. L ¹ , L ² and L ³ each independently represent a single bond or a conjugated linking group. The conjugated linking group is a spacer structure dividing the donor group and the acceptor group, and is preferably an arylene having 6 to 18 carbon atoms, and more preferably an arylene having 6 to 12 carbon atoms. It is more preferable that L ¹ , L ² and L ³ are each independently phenylene, methylphenylene or dimethylphenylene. In formula (DAD1), n is 2 or more and represents an integer equal to or less than the maximum number that ^{A 1 can substitute.} n may be selected within the range of 2 to 10, or may be selected within the range of 2 to 6, for example. When n is 2, it becomes a compound represented by formula (DAD2). n D ^1s may be the same or different, and n L ^1s may be the same or different. Preferred specific examples of the compounds represented by the formulas (DAD1) and (DAD2) include 2PXZ-TAZ and the following compounds, but the second component usable in the present invention is not limited to these compounds.

2-1-3. Compounds with boron atoms (emitting dopants)

The light emitting layer of the organic electroluminescent device of the present invention contains a compound having a boron atom as a third component. The light-emitting layer is a compound having a boron atom, a compound represented by any one of the following formulas (i), (ii), and (iii), and a multimer compound having a plurality of structures represented by the following formula (i) It is preferable to include at least one.

The light emitting layer of the organic electroluminescent device of the present invention contains a compound represented by any one of the following formulas (1), (2), (3) and (4) as the third component (a compound having a boron atom). It is more preferable to include at least one.

For example, three types of light-emitting materials for organic electroluminescent displays are used: a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescence (TADF) material, but the fluorescent material has low luminous efficiency and is about 25 to 62.5. % Or so. On the other hand, the phosphorescent material and the TADF material sometimes have a luminous efficiency reaching 100%, but both have a problem of low color purity (a wide luminescence spectrum). In a display, various colors are expressed by mixing light emission of the three primary colors of light, red, green, and blue, but if each color purity is low, colors that cannot be reproduced are produced, and the image quality of the display is greatly degraded. Accordingly, in a commercially available display, the color purity is increased (after narrowing the spectrum width) by removing unnecessary colors from the emission spectrum with an optical filter. Therefore, since the removal rate increases when the original spectrum width is wide, even when the luminous efficiency is high, the practical efficiency is greatly reduced. For example, the half width of the blue emission spectrum of a commercially available smartphone is about 20 to 25 nm, but the half width of a general fluorescent material is about 40 to 60 nm, the phosphorescent material is about 60 to 90 nm, and TADF The material is about 70-100 nm. In the case of using a fluorescent material, the half width is relatively narrow, so it is sufficient to remove some unnecessary color, but in the case of using a phosphorescent material or a TADF material, it is necessary to remove more than half. From such a background, development of a luminescent material having both luminous efficiency and color purity is desired.

In general, TADF materials are designed to allow efficient reverse intersystem crossing by localizing HOMO and LUMO in a molecule using electron-providing substituents called donors and electron-accepting substituents called acceptors. , If a donor or acceptor is used, the structure relaxation in the excited state is increased (for some molecules, the stable structure is different between the ground state and the excited state, so when the transformation from the ground state to the excited state occurs due to external stimulation, Thereafter, the structure changes to the stable structure in the excited state), and a broad emission spectrum with low color purity is provided.

Accordingly, International Publication No. 2015/102118 proposes a new molecular design that dramatically improves the color purity of TADF materials. For example, in the compound (1-401) disclosed in the above document, by using the multi-resonance effect of boron (electron providing property) and nitrogen (electron attraction), three carbons on a benzene ring consisting of six carbons (black It has succeeded in localizing HOMO to the circle) and LUMO to the remaining three carbons (white circle). By this efficient crossover between inverse terms, the luminous efficiency of the compound reaches a maximum of 100%. In addition, boron and nitrogen in compound (1-401) not only localizes HOMO and LUMO, but also maintains a solid planar structure by condensing three benzene rings, and also plays a role in suppressing structural relaxation in an excited state. As a result, it has succeeded in obtaining a luminescence spectrum with high color purity with a small Stokes shift of the peaks of absorption and emission. The half-value width of the emission spectrum is 28 nm, and the color purity is at a level that exceeds even the high-color-purity fluorescent materials that have been put into practice. In addition, in a dimer compound such as formula (1-422), by bonding two boron and two nitrogens to the central benzene ring, the multi-resonance effect is further enhanced in the central benzene ring, and as a result, extremely Light emission with a narrow emission peak width has become possible.

As a result of our intensive research, (i) an element that controls the multi-resonance effect is introduced at an appropriate position, (ii) a substituent is introduced at an appropriate position to reduce the planarity by distorting the molecule, and (iii) the planarity By appropriately combining the three approaches, which introduces a high structure at an appropriate position, in a compound, adjustment of the half value width of the emission wavelength and emission spectrum, high luminous efficiency, and small ΔE(ST) were realized (WO2015/102118, JP 2016-174209, JP 2017-097142, JP 2017-248014, PCT/JP2018/18731, JP 2018-107092, JP 2018-110876). In the device of the present invention, by using the present compound as an emitting dopant, high energy transfer efficiency from the assisting dopant to the emitting dopant, appropriate luminous wavelength and half-value width of the luminous spectrum, high color purity, high device efficiency, and small roll-off , And long life.

A compound represented by any one of the above formulas (i), (ii), and (iii), a multimeric compound having a plurality of structures represented by formula (i), formulas (1), (2), and formulas The compound represented by either of (3) and formula (4) is a generalized one by further examining these specific compound examples. The third component may be an ordinary phosphor or a thermally activated delayed phosphor.

Below, each formula and its specific example are demonstrated.

2-1-3 (i). Third component: compound represented by the following formula (i)

In the above formula (i),

A ring, B ring, and C ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl or alkyl,

X ¹ and X ² are each independently O, NR, >CR ₂ , S or Se, and R of NR and R of >CR ₂ are optionally substituted aryl, optionally substituted heteroaryl, optionally substituted Cycloalkyl or alkyl to be used, and R of NR may be bonded to at least one selected from the A ring, B ring and C ring by a linking group or a single bond, and,

At least one hydrogen in the compound or structure represented by formula (i) may be substituted with cyano, halogen or deuterium.

It is preferable that the compound represented by formula (i) as the third component is a compound represented by the following formula (1).

In the above formula (1),

R ¹ to ^{R 11} (hereinafter, ^{also referred to as "R 1} etc.") are each independently hydrogen, aryl, heteroaryl, diarylamino, diarylboryl, alkyl, cycloalkyl, alkoxy or aryloxy (above, the first 1 substituent), and these may also be substituted with at least one (or more, second substituent) selected from aryl, heteroaryl and alkyl, and R ¹ to ^{R 3} , R ⁴ to ^{R 7} and R ⁸ to R ^{Among 11} , adjacent groups may be bonded to each other to form an aryl ring or heteroaryl ring together with the a ring, b ring or c ring, and the formed ring is from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy. They may be substituted with at least one selected (or more, first substituent), and these may also be substituted with at least one (or more, second substituent) selected from aryl, heteroaryl and alkyl,

X ¹ and X ² are each independently >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl, cycloalkyl or alkyl, and these are aryl, heteroaryl , At least one selected from cycloalkyl and alkyl may be substituted,

However, X ¹ and X ² are not _{>CR 2} at the same time,

And,

At least one hydrogen in the compound and structure represented by formula (1) may be substituted with cyano, halogen or deuterium.

The "aryl" (first substituent) such as R ¹ may be a monocyclic ring, may be a condensed ring in which two or more aromatic hydrocarbon rings are condensed, or a connecting ring in which two or more aromatic hydrocarbon rings are connected. When two or more aromatic hydrocarbon rings are connected, those connected in a straight chain may be used or may be connected in a branched manner. "Aryl" is, for example, an aryl having 6 to 30 carbon atoms, preferably an aryl having 6 to 20 carbon atoms, more preferably an aryl having 6 to 16 carbon atoms, still more preferably an aryl having 6 to 12 carbon atoms, and Particularly preferred are 6-10 aryls.

Specific examples of aryl include monocyclic phenyl, bicyclic biphenylyl, condensed bicyclic naphthyl, tricyclic terphenylyl (m-terphenylyl, o-terphenylyl, p-terphenylyl), and condensation 3 Cyclic phosphorus, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, condensed tetracyclic triphenylenyl, pyrenyl, naphthacenyl, condensed pentacyclic perylenyl, pentacenyl, and the like are exemplified.

"Heteroaryl" (first substituent) such as R ¹ may be monocyclic, may be a condensed ring in which one or more heterocycles and one or more heterocycles or one or more aromatic hydrocarbon rings are condensed, or two or more heterocycles. It may be a connecting ring connected by a summon. When two or more heterocycles are connected, those connected in a straight chain may be used or may be connected in a branched manner. "Heteroaryl" is, for example, a C2-C30 heteroaryl, a C2-C25 heteroaryl is preferable, a C2-C20 heteroaryl is more preferable, and a C2-C15 heteroaryl is More preferably, heteroaryl having 2 to 10 carbon atoms is particularly preferable. In addition, heteroaryl is, for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom.

Specific examples of heteroaryl include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridinyl, Pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, iso Quinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxatinyl, phenoxazinyl, phenothia Genyl, phenazinyl, indolidinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thiophenyl, benzothiophenyl, dibenzothiophenyl, furazinyl, thianthrenyl, and the like.

As ^{"aryl" in "diarylamino" (first substituent) such as R 1} and "aryl" in "aryloxy" (first substituent), the description of aryl described above can be cited.

As "aryl" in "diaryl boryl" (first substituent) such as ^{R 1, the description of aryl described above can be cited.}

"Alkyl" (first substituent) such as R ¹ may be linear or branched, for example, straight-chain alkyl having 1 to 24 carbon atoms or branched-chain alkyl having 3 to 24 carbon atoms. C1-C18 alkyl (C3-C18 branched chain alkyl) is preferable, C1-C12 alkyl (C3-C12 branched chain alkyl) is more preferable, C1-C6 alkyl (C3 C3) Branched chain alkyl of -6) is more preferable, and alkyl having 1 to 4 carbon atoms (branched-chain alkyl having 3 to 4 carbon atoms) is particularly preferable.

Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1- Methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n -Dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, and the like are exemplified.

"Cycloalkyl" (first substituent) such as R ¹ includes a cycloalkyl consisting of one ring, a cycloalkyl consisting of a plurality of rings, a cycloalkyl containing a double bond that is not conjugated in the ring, and branches other than the ring. Any of the cycloalkyl described above may be used, and for example, it is a C3-C12 cycloalkyl. Cycloalkyl having 5 to 10 carbon atoms is preferable, and cycloalkyl having 6 to 10 carbon atoms is more preferable.

Specific examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, bicyclo[2,2,1]heptyl, bicyclo[2.2.2]octyl, decahydronaphthyl, adamane Teal and the like are exemplified.

"Alkoxy" (first substituent) such as R ^{1 may be linear or branched.} For example, it is a C1-C24 linear chain or a C3-C24 branched alkoxy. C1-C18 alkoxy (C3-C18 branched chain alkoxy) is preferred, C1-C12 alkoxy (C3-C12 branched chain alkoxy) is more preferred, and C1-C6 alkoxy ( Branched chain alkoxy having 3 to 6 carbon atoms) is more preferable, and alkoxy having 1 to 4 carbon atoms (branched alkoxy having 3 to 4 carbon atoms) is particularly preferable.

Specific examples of alkoxy include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, and the like. have.

As ^{aryl, heteroaryl or alkyl (above, second substituent) further substituted for R 1} or the like (first substituent), the description of aryl, heteroaryl or alkyl as the first substituent can be cited.

Specifically, the ^{luminous wavelength can be adjusted by the steric hindrance, electron donation and electron attraction of the structure of R 1} or the like (first substituent), preferably a group represented by the following formula, and more preferably , Methyl, tert-butyl, bicyclooctyl, cyclohexyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2 ,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(tert-butyl)phenyl)amino, diphenylboryl, dimethylboryl, dibenzoxaborininyl, phenyldibenzo Divorininyl, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-tert-butylcarbazolyl and phenoxy, more preferably methyl, tert-butyl, phenyl, o-tolyl , 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(tert-butyl)phenyl)amino, carbazolyl, 3,6-dimethyl Carbazolyl and 3,6-di-tert-butylcarbazolyl. From the viewpoint of ease of synthesis, those having a large steric hindrance are preferable for selective synthesis, and specifically, tert-butyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, 3,6 -Dimethylcarbazolyl and 3,6-di-tert-butylcarbazolyl are preferred.

In the formula, Me represents methyl, tBu represents tert-butyl, and the broken line represents the bonding position.

^{Adjacent groups among R 1} to ^{R 3} , R ⁴ to ^{R 7} and R ⁸ to ^{R 11} in formula (1) are bonded to each other to form an aryl ring or heteroaryl ring with ring a, ring b, or ring c, In the polycyclic aromatic compound represented by formula (1), the ring structure constituting the compound changes depending on the mutual bond form of the substituents in the a ring, b ring, and c ring. For example, R ^{3 of the} a ring and R ⁴ of the b ring, R ⁷ of the ^{b ring and R 8} of the c ring, R ^{11 of the c ring and R 1} of the a ring do not correspond to ``adjacent groups'', and they are not bound. Does not. That is, "adjacent group" means a group adjacent to the same ring.

The formed "aryl ring" or "heteroaryl ring" is an unvalent ring of aryl or heteroaryl as the first substituent described above. However, the number of carbon atoms in the formed ring includes the number of carbon atoms in the ring before condensation.

Aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy (above, first substituent) substituted on the formed aryl ring or heteroaryl ring, and aryl, heteroaryl or alkyl further substituted on the first substituent As (above, the second substituent), the description of aryl, heteroaryl, diarylamino, alkyl, alkoxy, or aryloxy as ^{R 1 or the like (first substituent) described above can be cited.}

X in formula (1) is >O, >NR, >CR ₂ , >S or >Se, and >O and >NR are preferable.

As aryl, heteroaryl or alkyl (above, first substituent) which is R of >NR and R of >CR ₂ , and aryl, heteroaryl or alkyl (above, second substituent) which is further substituted with the first substituent, The above ^{description of aryl, heteroaryl or alkyl as R 1} and the like (first substituent) can be cited.

It is preferable that the compound represented by formula (1) is a compound containing the following partial structure.

Next, a specific structure is shown. In the following formula, Me represents methyl, tBu and t-Bu represent tert-butyl, and Ph represents phenyl.

2-1-3(ii). Third component: compound represented by the following formula (ii)

In the above formula (ii),

A ring, B ring, C ring, and D ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y is B (boron),

X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR, >CR ₂ , >S or >Se, even if R of _{>NR and R of >CR 2 are substituted} Aryl, optionally substituted heteroaryl, optionally substituted cycloalkyl, or optionally substituted alkyl, and R of >NR is selected from the above ring A, ring B, ring C, and ring D by a linking group or a single bond. It may be combined with at least one of

R ¹ and R ² are each independently hydrogen, C 1 to C 6 alkyl, C 3 to C 12 cycloalkyl, C 6 to C 12 aryl, C 2 to C 15 heteroaryl or diarylamino (however, aryl is Aryl of 6 to 12 carbon atoms),

At least one hydrogen in the compound represented by formula (ii) may be substituted with cyano, halogen or deuterium.

The compound represented by formula (ii) as the third component is preferably a compound represented by the following formula (2).

In the above formula (2),

R ¹ to ^{R 14} (hereinafter, ^{also referred to as "R 1} etc.") are each independently hydrogen, aryl, heteroaryl, diarylamino, diarylboryl, diheteroarylamino, arylheteroarylamino, alkyl, cyclo Alkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl substituted silyl, and at least one hydrogen in these may be substituted with aryl, heteroaryl or alkyl, and R ⁵ to R ⁷ and R ¹⁰ to ^{R 12} adjacent groups may be bonded to each other to form an aryl ring or heteroaryl ring together with the b ring or d ring, and at least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino , Diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl substituted silyl may be substituted, and at least one hydrogen in these, May be substituted with aryl, heteroaryl or alkyl,

Y is B (boron),

X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl of 6 to 12 carbon atoms, 2 -15 heteroaryl, C3-C12 cycloalkyl or C1-C6 alkyl, and R of >NR and R of >CR ₂ are -O-, -S-, -C(-R) ₂ -or may be bonded to at least one selected from the a ring, b ring, c ring and d ring by a single bond, and _{R of -C(-R) 2} -is hydrogen or alkyl having 1 to 6 carbon atoms. Is,

However, X ¹ , X ² , X ³ , and X ⁴ are not _{>CR 2} at the same time,

And,

At least one hydrogen in the compound and structure represented by formula (2) may be substituted with cyano, halogen or deuterium.)

In the above formula (2), aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy (above, first substituent), and aryl, heteroaryl or alkyl (above, first substituent) further substituted with the first substituent (above, As the second substituent), the description of aryl, heteroaryl, diarylamino, alkyl, alkoxy, or aryloxy as ^{R 1 or the like (first substituent) described above can be cited.}

It is preferable that the compound represented by the above formula (2) is a compound containing the following partial structure.

Hereinafter, the specific structure of the compound represented by the formula (2) is shown. In the following formula, Me represents methyl, tBu represents tert-butyl, and Ph represents phenyl.

R in the above-described structure is any one of the following groups.

2-1-3 (iii). Third component: compound represented by the following formula (iii)

In the above formula (iii),

A ring, B ring, and C ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,

Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl or alkyl,

X ¹ , X ² and X ³ are each independently O, NR, >CR ₂ , S or Se, and R of NR and R of >CR ₂ are optionally substituted aryl or optionally substituted heteroaryl , Cycloalkyl or alkyl which may be substituted, and R of NR may be bonded to at least one selected from the A ring, B ring and C ring by a linking group or a single bond, and,

At least one hydrogen in the compound or structure represented by formula (iii) may be substituted with cyano, halogen or deuterium.

It is preferable that the compound represented by formula (iii) is a compound represented by the following formula (3).

In the above formula (3),

R ¹ to ^{R 11} (hereinafter, ^{also referred to as “R 1} and the like”) are each independently hydrogen, aryl, heteroaryl, diarylamino, diaryl boryl, alkyl, cycloalkyl, alkoxy or aryloxy, and these are also It may be substituted with at least one selected from aryl, heteroaryl and alkyl, ^{and adjoining groups among R 1} to ^{R 3} , R ⁴ to ^{R 6} and R ⁹ to ^{R 11} are bonded to each other to form a ring a, a ring b, or a c An aryl ring or heteroaryl ring may be formed together with the ring, and the formed ring may be substituted with at least one selected from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy, and these may also be substituted with aryl, heteroaryl It may be substituted with at least one selected from aryl, cycloalkyl and alkyl,

X ¹ , X ² and X ³ are each independently >O, >NR, or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl, cycloalkyl or alkyl, and these It may be substituted with at least one selected from aryl, heteroaryl and alkyl,

However, X ¹ , X ² , and X ³ are not _{>CR 2} at the same time,

And,

At least one hydrogen in the compound and structure represented by formula (3) may be substituted with cyano, halogen or deuterium.

In the formula (3), aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy (above, first substituent), and aryl, heteroaryl or alkyl (above , As the second substituent), the description of aryl, heteroaryl, diarylamino, alkyl, alkoxy, or aryloxy as ^{R 1 or the like (first substituent) described above can be cited.}

Below, the specific structure of said formula (3) is shown.

2-1-3 (iv). Third component: compound represented by the following formula (4)

It is also preferable that the compound represented by the above formula (i) is a compound represented by the following formula (4).

In the above formula (4),

R ¹ to ^{R 14} (hereinafter, ^{also referred to as "R 1} etc.") are each independently hydrogen, aryl, heteroaryl, diarylamino, diarylboryl, alkyl, cycloalkyl, alkoxy or aryloxy, and these are also It may be substituted with at least one selected from aryl, heteroaryl and alkyl, ^{and adjoining groups among R 1} to ^{R 3} , R ⁴ to ^{R 7} , R ⁸ to ^{R 10} and R ¹¹ to ^{R 14} are bonded to each other to a An aryl ring or a heteroaryl ring may be formed together with the ring, b ring, c ring, or d ring, and the formed ring is substituted with at least one selected from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy. May be, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,

X is >O, >NR or >CR ₂ , and R of >NR is aryl, heteroaryl or alkyl, and these may be substituted with at least one selected from aryl, heteroaryl and alkyl,

L is a single bond, >CR ₂ , >O, >S or >NR, and _{R in >CR 2} and >NR are each independently hydrogen, aryl, heteroaryl, diarylamino, alkyl, alkoxy Or aryloxy, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,

However, X and L are not _{>CR 2 at the same time,}

And,

At least one hydrogen in the compound and structure represented by formula (4) may be substituted with cyano, halogen or deuterium.

In the above formula (4), aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy (above, first substituent), and aryl, heteroaryl or alkyl (above, first substituent) further substituted with the first substituent (above, As the second substituent), the description of aryl, heteroaryl, diarylamino, alkyl, alkoxy, or aryloxy as ^{R 1 or the like (first substituent) described above can be cited.}

L in formula (4) is a single bond, >CR ₂ , >O, >S or >NR, a single bond, >O or >NR is preferable, and a single bond is more preferable.

Aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy (or more, first substituent), which is R of >CR _{2 and >NR, and aryl, heteroaryl or alkyl (or more} , As the second substituent), the description of aryl, heteroaryl, diarylamino, alkyl, alkoxy, or aryloxy as ^{R 1 or the like (first substituent) described above can be cited.}

It is preferable that the compound represented by formula (4) is a compound containing the following partial structure.

Hereinafter, the specific structure of the compound represented by the formula (4) is shown. In the following formula, Me represents methyl, and t-Bu represents tert-butyl.

The third component of the present invention is at least one of the compounds represented by formulas (i) to (iii), and more specifically, preferably at least one of the compounds represented by formulas (1) to (4). Do. From the viewpoint of high PLQY, compounds represented by formulas (i) and (ii) are preferred, and compounds represented by formula (ii) are more preferred. More specifically, it is preferable that the planarity of the conjugated structure containing a boron atom is high, the formulas (1), (2) and (4) are preferable, and the formulas (2) and (4) are more preferable. Do. In addition, from the viewpoint of small ΔE(ST), compounds represented by formulas (i) and (ii) are preferred, and compounds represented by formula (ii) are more preferred. More specifically, it is preferable that X, X ¹ , X ² , X ³ and X ⁴ are nitrogen, and formulas (1), (2) and (4) are preferred, and formulas (1) and ( 4) is more preferable. Further, from the viewpoint of a large SOC, formulas (i) and (ii) are preferable. More specifically, it is preferable that the conjugated structure containing the boron atom is not completely planar but is distorted, the formulas (1), (2) and (4) are preferable, and the formulas (1) and (4) This is more preferable, and Formula (1) is still more preferable.

2-1-3 (V). Third component: preferred substituents

The compounds represented by formulas (i) to formula (iii) and formulas (1) to (4) that can be used as the third component may be unsubstituted substances in which a substituent group is not bonded to a ring present in the compound, but suitable It is preferable to use a compound substituted with a substituent. By using a compound substituted with an appropriate substituent as the third component, the characteristics of the organic electroluminescent device become more excellent than when an unsubstituted product is used. As a preferred substituent, aryl, heteroaryl, diarylamino, diarylboryl, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio and alkyl substitution Silyl is exemplified; As more preferable substituents, aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy are exemplified; Aryl, diarylamino, and alkyl are exemplified as more preferable substituents; Diarylamino and alkyl are exemplified as more preferable substituents; Diarylamino is exemplified as a particularly preferred substituent. Aryl, heteroaryl, diarylamino, diaryl boryl, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio and alkyl substituted silyl herein are , At least one hydrogen in these may be substituted with at least one selected from aryl, heteroaryl, cycloalkyl, and alkyl.

The two aryls in the diarylamino may be the same or different, but the same is preferable. Examples of aryl include monocyclic phenyl, bicyclic biphenylyl, condensed bicyclic naphthyl, tricyclic terphenylyl (m-terphenylyl, o-terphenylyl, p-terphenylyl), and condensed tricyclic Examples include system phosphorus, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, condensed tetracyclic system triphenylenyl, pyrenyl, naphthacenyl, and condensed 5 ring system perylenyl, pentacenyl, and the like. When the aryl of diarylamino is substituted, it is preferably substituted with at least one selected from aryl and alkyl. Further, a group in which the two aryl groups constituting the diarylamino are not bonded to each other may be particularly selected and used. Examples include diphenylamino, di(4-methylphenyl)amino, and di(4-tert-butylphenyl)amino.

Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1- Methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n -Dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, and the like are exemplified.

By using a compound having a preferable substituent as the third component, it is observed that the external quantum yield of the organic electroluminescent device is improved, the half-value width is narrowed, the device life is increased, and the like. Further, by substituting with an appropriate substituent, the lifetime Tau (Delay) of the delayed fluorescence can be shortened or the Stokes shift can be reduced, thereby improving the performance of the organic EL device.

By taking a method such as selecting a substituent appropriately, the following particularly preferable energy structures can be constructed and adopted for the second component and the third component.

E(3, T, Sh)≥E(2, T, Sh)

ΔE(2, ST, Sh)≥ΔE(3, ST, Sh)

Stokes shift of the third component is 10 nm or less

Moreover, the following energy structure is also preferable.

E(3, T, Sh) ≤ E(2, T, Sh)

ΔE(2, ST, Sh)≤ΔE(3, ST, Sh)

Stokes shift of the third component is 15 nm or less

Moreover, the following energy structure is also preferable.

E(3, T, Sh) ≤ E(2, T, Sh)

ΔE(2, ST, Sh)≥ΔE(3, ST, Sh)

Stokes shift of the third component is greater than 15 nm

In addition, in any of the aforementioned energy structures, it is preferable that E(3, S, PT) ≥ E(2, S, PT).

2-1-4. High molecular compound

The first component contained in the light emitting layer of the organic electroluminescent device of the present invention may be a polymer compound containing a structure obtained by removing two hydrogen atoms from a host compound as a repeating unit. The second component contained in the light emitting layer of the organic electroluminescent device of the present invention may be a polymer compound containing as a repeating unit a structure in which two hydrogen atoms are removed from a thermally activated delayed phosphor. The third component contained in the light emitting layer of the organic electroluminescent device of the present invention may be a polymer compound containing as a repeating unit a structure in which two hydrogen atoms are removed from a compound having a boron atom. The two hydrogen atoms to be desorbed can be any two atoms in the compound. It may or may not be two hydrogen atoms bonded to the same ring structure.

The polymer compound contained in the light-emitting layer may include a structure in which two hydrogen atoms are desorbed from a host compound as a repeating unit, and a structure in which two hydrogen atoms are desorbed from a heat-activated delayed phosphor is also included as a repeating unit. The polymer compound contained in the light-emitting layer may include a structure in which two hydrogen atoms are removed from a host compound as a repeating unit, and a structure in which two hydrogen atoms are removed from a compound containing a boron atom as a repeating unit may be used. . The polymer compound contained in the light-emitting layer includes a structure in which two hydrogen atoms are desorbed from a thermally activated delayed phosphor as a repeating unit, and a structure in which two hydrogen atoms are desorbed from a compound containing a boron atom as a repeating unit. It may be a compound. In addition, the polymer compound contained in the light emitting layer contains a structure in which two hydrogen atoms are desorbed from a host compound as a repeating unit, and a structure in which two hydrogen atoms are desorbed from a thermally activated delayed phosphor is also included as a repeating unit. A polymer compound containing a structure in which two hydrogen atoms have been removed from a compound containing a boron atom as a repeating unit may also be used.

Two or more repeating units may be included in the polymer compound contained in the light-emitting layer and having a structure in which two hydrogen atoms are removed from the host compound. Two or more types of repeating units having a structure in which two hydrogen atoms have been removed from a heat activated delayed phosphor contained in the polymer compound contained in the light emitting layer may be used. Two or more types of repeating units having a structure in which two hydrogen atoms are removed from a compound containing a boron atom, contained in the polymer compound included in the light emitting layer, may be used.

The polymer compound included in the light emitting layer is a repeating unit having a structure in which two hydrogen atoms are removed from a host compound, a repeating unit having a structure in which two hydrogen atoms are removed from a heat activated delayed phosphor, and hydrogen from a compound containing a boron atom. In addition to at least one repeating unit selected from repeating units having a structure in which two atoms are removed, one or more repeating units different from these may be included. As such a repeating unit, a repeating unit including a structure exhibiting hole transport property, a repeating unit including a structure exhibiting electron transport property, a repeating unit not exhibiting hole transport property or electron transport property, and the like can be appropriately selected and employed. As a preferred repeating unit, arylene, heteroarylene, a group bonded by two or more arylenes, a group bonded by two or more heteroarylenes, a group bonded by at least one arylene and at least one heteroarylene, at least ^A group in which one arylene and at least one group represented by -N(R A )- are bonded to each other, a group in which at least one heteroarylene and at least one ^{group represented by -N(R A} )- is bonded, A group in which at least one arylene, at least one heteroarylene, and at least one ^{group represented by -N(R A} )- is bonded can be illustrated. The arylene and heteroarylene referred to herein may be substituted, and examples of the substituent include alkyl having 1 to 30 carbon atoms, aryl having 6 to 22 carbon atoms, and heteroaryl having 5 to 22 ring skeleton members. Moreover, as R ^A , a C1-C30 alkyl, a C6-C22 aryl, and a ring skeleton member number 5-22 heteroaryl can be illustrated. As a specific example of a repeating unit, the following structures are mentioned. The hydrogen atom present in the following structure may be substituted with alkyl having 1 to 30 carbon atoms, aryl having 6 to 22 carbon atoms, heteroaryl having 5 to 22 ring skeleton members, or the like.

The molar ratio of each repeating unit constituting the polymer compound contained in the light emitting layer is not particularly limited. A repeating unit having a structure in which two hydrogen atoms are removed from a host compound, a repeating unit having a structure in which two hydrogen atoms are removed from a thermally activated delayed phosphor, a repeat having a structure in which two hydrogen atoms are removed from a compound containing a boron atom When units are present, each repeating unit can be selected within the range of 0.01 to 100 mol%. In addition, when a repeating unit other than this repeating unit exists, the molar ratio of the repeating unit can be selected within the range of 0.01 to 99.99 mol%.

The polymer compound can be synthesized by a known polymerization reaction. For example, it can be synthesized using a known coupling reaction. That is, a compound in which reactive groups such as a chlorine atom, a bromine atom, an iodine atom, and -OS(=O) ₂ R ^{B are bonded to both ends of the first repeating unit constituting the polymer compound, and at both ends of the second repeating unit.} The target polymer compound can be easily synthesized by reacting a compound in which the reactive groups at both ends of the first repeating unit are bonded with a functional group causing a coupling reaction. The group R ^B is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, or the like. As a functional group causing a coupling reaction with the reactive groups at both ends of the first repeating unit, -B(OR ^C ) ₂ , BF ₃ R ^D , MgR ^E , ZnR ^F , Sn(R ^G ) ₃ can be exemplified. Here, R ^C and R ^G are hydrogen atoms, optionally substituted alkyl, optionally substituted cycloalkyl, and the like, and two or more R ^C or R ^G may be connected to each other to form a cyclic structure. R ^D is Li, Na, K, Rb, Cs, and the like. R ^E and R ^F are a chlorine atom, a bromine atom, or an iodine atom.

It is preferable to perform the coupling reaction in the presence of a catalyst.

As a medium, bis(triphenylphosphine)palladium(II)dichloride, bis(tris-o-methoxyphenylphosphine)palladium(II)dichloride, tetrakis(triphenylphosphine)palladium(0), tris (Dibenzylideneacetone)dipalladium(0), palladium acetate, tetrakis(triphenylphosphine)nickel(0), [1,3-bis(diphenylphosphino)propane)nickel(II)dichloride, bis (1,4-cyclooctadiene) nickel (0), sodium carbonate, potassium carbonate, cesium carbonate, potassium fluoride, cesium fluoride, tripotassium phosphate, tetrabutylammonium fluoride, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, tetrabutyl chloride Ammonium or tetrabutylammonium bromide can be used. By performing the coupling reaction at -100 to 200°C for about 1 to 24 hours, the target polymer compound can be synthesized.

(Other organic layers)

The organic electroluminescent device of the present invention may have one or more organic layers in addition to the light emitting layer. Examples of the organic layer include an electron transport layer, a hole transport layer, an electron injection layer, a hole injection layer, and the like, and may have other organic layers.

Fig. 4 shows an example of a layer structure of an organic electroluminescent device including this organic layer. In FIG. 4, reference numeral 101 denotes a substrate, 102 an anode, 103 a hole injection layer, 104 a hole transport layer, 105 a light-emitting layer, 106 an electron transport layer, 107 an electron injection layer, and 108 a cathode, respectively.

Hereinafter, in the organic electroluminescent device, an organic layer, a cathode and an anode, and a substrate provided in addition to the emission layer will be described.

2-2. Electron injection layer and electron transport layer in organic electroluminescent device

The electron injection layer 107 serves to efficiently inject electrons moving from the cathode 108 into the light emitting layer 105 or into the electron transport layer 106. The electron transport layer 106 serves to efficiently transport electrons injected from the cathode 108 or electrons injected from the cathode 108 through the electron injection layer 107 to the light emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are formed by laminating and mixing one or two or more types of electron transport/injection materials, respectively.

The electron injection/transport layer is a layer responsible for injecting and transporting electrons into the cathode, and preferably has high electron injection efficiency and efficiently transports the injected electrons. For this purpose, it is preferable that the material has high electron affinity, high electron mobility, and further excellent stability, and does not readily generate trapping impurities during manufacture and use. However, in the case of considering the transport balance of holes and electrons, in the case where it plays a role of efficiently preventing holes from flowing from the anode to the cathode side without recombining, the luminous efficiency is improved even if the electron transport ability is not very high. It has the same effect as a material with high electron transport ability. Therefore, the electron injection/transport layer in the present embodiment may also contain a function of a layer capable of effectively preventing the movement of holes.

As a material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107, a compound conventionally used as an electron transport compound in photoconductive materials, an electron injection layer and an electron transport layer of an organic electroluminescent device It can be arbitrarily selected and used from known compounds used in

As a material used for the electron transport layer or the electron injection layer, a compound consisting of an aromatic ring or a heteroaromatic ring consisting of at least one atom selected from carbon, hydrogen, oxygen, sulfur, silicon and phosphorus, a pyrrole derivative and a condensed ring derivative thereof, and It is preferable to contain at least one type selected from metal complexes having electron-accepting nitrogen. Specifically, condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives typified by 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives , Quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, carbazole derivatives and indole derivatives, and the like. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol complexes, and benzoquinoline metal complexes. These materials may be used alone, but may be used in combination with other materials.

In addition, as specific examples of other electron transfer compounds, pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone Derivatives, perylene derivatives, oxadiazole derivatives (1,3-bis[(4-tert-butylphenyl) 1,3,4-oxadiazolyl]phenylene, etc.), thiophene derivatives, triazole derivatives (N- Naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of auxin derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazoles Compound, gallium complex, pyrazole derivative, perfluorinated phenylene derivative, triazine derivative, pyrazine derivative, benzoquinoline derivative (2,2'-bis(benzo[h]quinolin-2-yl)-9,9' -Spirobifluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (tris(N-phenylbenzimidazol-2-yl)benzene, etc.), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives , Oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (1,3-bis(4'-(2,2':6',2"-terpyridinyl))benzene, etc.), naphthyridine derivatives (Bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide, etc.), aldazine derivatives, carbazole derivatives, indole derivatives, phosphor oxide derivatives, bisstyryl derivatives, etc. Can be mentioned.

The above-described materials may be used alone, but may be used in combination with other materials.

Among the aforementioned materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, carbazole derivatives, triazine derivatives, benzimidazole derivatives, Phenanthroline derivatives and quinolinol-based metal complexes are preferred.

2-2-1. Pyridine derivatives

The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), and preferably a compound represented by the formula (ETM-2-1) or (ETM-2-2).

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is 1 to 4 It is an integer.

In the above formula (ETM-2-1), R ¹¹ to ^{R 18} are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably, cycloalkyl having 3 to 12 carbon atoms) Alkyl) or aryl (preferably aryl having 6 to 30 carbon atoms).

In the above formula (ETM-2-2), R ¹¹ and R ¹² are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably, cycloalkyl having 3 to 12 carbon atoms) Alkyl) or aryl (preferably aryl having 6 to 30 carbon atoms), and R ¹¹ and R ¹² may be bonded to form a ring.

In each formula, the "pyridine substituent" is any one of the following formulas (Py-1) to (Py-15), and the pyridine substituents may each independently be substituted with alkyl having 1 to 4 carbon atoms. In addition, the pyridine-based substituent may be bonded to φ in each formula, an anthracene ring, or a fluorene ring through a phenylene group or a naphthylene group.

The pyridine-based substituent is any one of the above formulas (Py-1) to (Py-15), but among these, it is preferably any one of the following formulas (Py-21) to (Py-44).

At least one hydrogen in each pyridine derivative may be substituted with deuterium, and one of the two "pyridine-based substituents" in the above formulas (ETM-2-1) and (ETM-2-2) is an aryl It may be substituted with.

As ^{the "alkyl" for R 11} to ^{R 18} , either straight chain or branched chain may be used, for example, straight chain alkyl having 1 to 24 carbon atoms or branched chain alkyl having 3 to 24 carbon atoms. Preferred "alkyl" is alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). More preferable "alkyl" is C1-C12 alkyl (C3-C12 branched alkyl). A more preferable "alkyl" is alkyl having 1 to 6 carbon atoms (branched chain alkyl having 3 to 6 carbon atoms). Particularly preferred "alkyl" is alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms).

Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethyl Hexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl , n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-eicosyl, etc. have.

As the C1-C4 alkyl substituted with the pyridine-based substituent, the description of the above alkyl can be cited.

Examples of the "cycloalkyl" for R ¹¹ to ^{R 18} include cycloalkyl having 3 to 12 carbon atoms. A preferable "cycloalkyl" is a C3-C10 cycloalkyl. A more preferable "cycloalkyl" is a C3-C8 cycloalkyl. A more preferable "cycloalkyl" is a C3-C6 cycloalkyl. Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, dimethylcyclohexyl, and the like.

The "aryl" in R ¹¹ to ^{R 18} may be monocyclic, may be a condensed ring in which two or more aromatic hydrocarbon rings are condensed, or a linking ring in which two or more aromatic hydrocarbon rings are connected. When two or more aromatic hydrocarbon rings are connected, those connected in a straight chain may be used or may be connected in a branched manner. Preferred aryl is a C6-C30 aryl, a more preferred aryl is a C6-C18 aryl, more preferably a C6-C14 aryl, and particularly preferably a C6-C12 aryl.

Specific examples of aryl include phenyl as monocyclic aryl, biphenylyl (2-biphenylyl, 3-biphenylyl, 4-biphenylyl), and naphthyl (1) condensed bicyclic aryl. -Naphthyl, 2-naphthyl), tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o- Terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl -4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl phosphorus, acenaphthylenyl (acenaphthylene-1-yl, acenaphthylene-3-yl, acenaphthylene-4-yl, acenaphthylene-5 -Yl), fluorenyl (fluoren-1-yl, fluoren-2-yl, fluoren-3-yl, fluoren-4-yl, fluoren-9-yl), phenalenyl (phenalene- 1-yl, phenalen-2-yl), phenanthryl (1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl), quarterphenylyl (5 '-Phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensation 4 Ring-based aryl triphenylene (triphenylen-1-yl, triphenylen-2-yl), pyrenyl (pyren-1-yl, pyren-2-yl, pyren-4-yl), naphthacenyl (naphtha Sen-1-yl, naphthasen-2-yl, naphthasen-5-yl), condensed pentacyclic aryl peryleneyl (perylene-1-yl, perylene-2-yl, perylene-3-yl ), pentacenyl (pentacen-1-yl, pentacen-2-yl, pentacen-5-yl, pentacen-6-yl), and the like.

Preferred "C6-C30 aryl" includes phenyl, naphthyl, phenanthryl, chrysenyl, triphenylenyl, and the like, more preferably phenyl, 1-naphthyl, 2-naphthyl or phenanthryl. For example, phenyl, 1-naphthyl or 2-naphthyl are particularly preferred.

^{R 11} and R ¹² in the above formula (ETM-2-2) may be bonded to form a ring, and as a result, in the 5-membered ring of the fluorene skeleton, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, Cyclohexane, fluorene, indene, or the like may be spiro bonded.

As a specific example of this pyridine derivative, there are the following compounds, for example.

This pyridine derivative can be produced using a known raw material and a known synthesis method.

2-2-2. Phosphine oxide derivatives

The phosphine oxide derivative is, for example, a compound represented by the following formula (ETM-7-1). Details are also disclosed in International Publication No. 2013/079217.

R ⁵ is a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, or heteroaryl having 5 to 20 carbon atoms,

R ⁶ is CN, substituted or unsubstituted alkyl having 1 to 20 carbon atoms, heteroalkyl having 1 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, heteroaryl having 5 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or It is 6-20 aryloxy,

R ⁷ and R ⁸ are each independently a substituted or unsubstituted aryl having 6 to 20 carbon atoms or heteroaryl having 5 to 20 carbon atoms,

R ⁹ is oxygen or sulfur,

j is 0 or 1, k is 0 or 1, r is an integer of 0 to 4, and q is an integer of 1 to 3.

The phosphine oxide derivative may be, for example, a compound represented by the following formula (ETM-7-2).

R ¹ to ^{R 3} may be the same or different, and hydrogen, alkyl group, cycloalkyl group, aralkyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, arylether group, arylthioether group, It is selected from an aryl group, a heterocyclic group, a halogen, a cyano group, an aldehyde group, a carbonyl group, a carboxyl group, an amino group, a nitro group, a silyl group, and a condensed ring formed between an adjacent substituent.

Ar ¹ may be the same or different, an arylene group or a heteroarylene group, and Ar ² may be the same or different, and an aryl group or a heteroaryl group. However, ^{at least one of Ar 1} and Ar ² has a substituent or forms a condensed ring between adjacent substituents. n is an integer of 0 to 3, and when n is 0, there is no unsaturated structure part, and when n is 3, R ¹ does not exist.

Among these substituents, the alkyl group represents, for example, a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group, or a butyl group, and may be unsubstituted or substituted. The substituent in the case of being substituted is not particularly limited, and includes, for example, an alkyl group, an aryl group, a heterocyclic group, and the like, and this point is also common to the following description. In addition, the number of carbon atoms in the alkyl group is not particularly limited, but it is usually in the range of 1 to 20 from the viewpoint of availability and cost.

Further, the cycloalkyl group represents, for example, a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, and adamantyl, which may be unsubstituted or substituted. Although the number of carbon atoms in the alkyl group portion is not particularly limited, it is usually in the range of 3 to 20.

In addition, the aralkyl group represents an aromatic hydrocarbon group via an aliphatic hydrocarbon such as a benzyl group or a phenylethyl group, and both aliphatic hydrocarbons and aromatic hydrocarbons may be unsubstituted or substituted. Although the number of carbon atoms in the aliphatic moiety is not particularly limited, it is usually in the range of 1 to 20.

Further, the alkenyl group represents an unsaturated aliphatic hydrocarbon group containing a double bond such as a vinyl group, an allyl group, and a butadienyl group, and may be unsubstituted or substituted. Although the number of carbon atoms of the alkenyl group is not particularly limited, it is usually in the range of 2 to 20.

In addition, the cycloalkenyl group represents an unsaturated alicyclic hydrocarbon group containing a double bond such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexene group, which may be unsubstituted or substituted.

In addition, the alkynyl group represents an unsaturated aliphatic hydrocarbon group containing a triple bond such as an acetylenyl group, and may be unsubstituted or substituted. Although the number of carbon atoms of the alkynyl group is not particularly limited, it is usually in the range of 2 to 20.

Further, the alkoxy group represents an aliphatic hydrocarbon group through an ether bond such as a methoxy group, and the aliphatic hydrocarbon group may be unsubstituted or substituted. Although the number of carbon atoms of the alkoxy group is not particularly limited, it is usually in the range of 1 to 20.

In addition, the alkylthio group is a group in which the oxygen atom of the ether bond of the alkoxy group is substituted with a sulfur atom.

In addition, the aryl ether group represents an aromatic hydrocarbon group through an ether bond such as a phenoxy group, and the aromatic hydrocarbon group may be unsubstituted or substituted. Although the number of carbon atoms in the aryl ether group is not particularly limited, it is usually in the range of 6 to 40.

In addition, the arylthioether group is a group in which the oxygen atom of the ether bond of the aryl ether group is substituted with a sulfur atom.

In addition, the aryl group represents, for example, an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenylyl group, a phenanthryl group, a terphenyl group, and a pyrenyl group. The aryl group may be unsubstituted or substituted. The number of carbon atoms in the aryl group is not particularly limited, but is usually in the range of 6 to 40.

In addition, the heterocyclic group represents, for example, a cyclic structural group having an atom other than carbon such as a furanyl group, a thiophenyl group, an oxazolyl group, a pyridyl group, a quinolinyl group, and a carbazolyl group, which may be unsubstituted. It does not matter if it is substituted. Although the number of carbon atoms in the heterocyclic group is not particularly limited, it is usually in the range of 2 to 30.

Halogen represents fluorine, chlorine, bromine and iodine.

The aldehyde group, the carbonyl group, and the amino group may include groups substituted with aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocycles.

In addition, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocycles may be unsubstituted or substituted.

The silyl group represents, for example, a silicon compound group such as a trimethylsilyl group, and may be unsubstituted or substituted. The number of carbon atoms in the silyl group is not particularly limited, but is usually in the range of 3 to 20. In addition, the number of silicon is usually 1-6.

Condensed rings formed between adjacent substituents are, for example, Ar ¹ and R ² , Ar ¹ and R ³ , Ar ² and R ² , Ar ² and R ³ , R ² and R ³ , Ar ¹ and Ar ² It is a conjugated or non-conjugated condensed ring formed between, etc. Here, when n is 1, a conjugated or non-conjugated condensed ring may be formed by ^{two R 1.} These condensed rings may contain nitrogen, oxygen, and sulfur atoms in the intra-ring structure, or may be condensed with other rings.

As a specific example of this phosphine oxide derivative, there exist the following compounds, for example.

This phosphine oxide derivative can be produced using a known raw material and a known synthesis method.

2-2-3. Pyrimidine derivatives

The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), and preferably a compound represented by the following formula (ETM-8-1). Details are also disclosed in International Publication No. 2011/021689.

Ar is each independently aryl which may be substituted or heteroaryl which may be substituted. n is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2 or 3.

The "aryl" of "the aryl which may be substituted" may be a monocyclic ring, may be a condensed ring in which two or more aromatic hydrocarbon rings are condensed, or a linking ring in which two or more aromatic hydrocarbon rings are connected. When two or more aromatic hydrocarbon rings are connected, those connected in a straight chain may be used or may be connected in a branched manner. As the "aryl", for example, there are aryls having 6 to 30 carbon atoms, preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 20 carbon atoms, and still more preferably an aryl having 6 to 12 carbon atoms. .

Specific examples of aryl include phenyl as monocyclic aryl, biphenylyl (2-biphenylyl, 3-biphenylyl, 4-biphenylyl), and naphthyl (1) condensed bicyclic aryl. -Naphthyl, 2-naphthyl), tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o- Terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl -4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl phosphorus, acenaphthylenyl (acenaphthylene-1-yl, acenaphthylene-3-yl, acenaphthylene-4-yl, acenaphthylene-5 -Yl), fluorenyl (fluoren-1-yl, fluoren-2-yl, fluoren-3-yl, fluoren-4-yl, fluoren-9-yl), phenalenyl (phenalene- 1-yl, phenalen-2-yl), phenanthryl (1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl), quarterphenylyl (5 '-Phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensation 4 Ring-based aryl triphenylene (triphenylen-1-yl, triphenylen-2-yl), pyrenyl (pyren-1-yl, pyren-2-yl, pyren-4-yl), naphthacenyl (naphtha Sen-1-yl, naphthasen-2-yl, naphthasen-5-yl), condensed pentacyclic aryl peryleneyl (perylene-1-yl, perylene-2-yl, perylene-3-yl ), pentacenyl (pentacen-1-yl, pentacen-2-yl, pentacen-5-yl, pentacen-6-yl), and the like.

The "heteroaryl" of the "may be substituted heteroaryl" may be a monocyclic ring, or may be a condensed ring in which one or more heterocycles and one or more heterocycles or one or more aromatic hydrocarbon rings are condensed, or two or more heterocycles. It can also be a linking ring connected by a summon. When two or more heterocycles are connected, those connected in a straight chain may be used or may be connected in a branched manner. As "heteroaryl", for example, there is a C2-C30 heteroaryl, a C2-C25 heteroaryl is preferable, a C2-C20 heteroaryl is more preferable, and a C2-C15 heteroaryl This is more preferable, and C2-C10 heteroaryl is especially preferable. In addition, examples of the heteroaryl include, for example, heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom.

Specific examples of heteroaryl include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, Triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl , Benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteri Denyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxatinyl, thianthrenyl, indolidinyl, and the like.

In addition, the aryl and heteroaryl may be substituted, and each may be substituted with, for example, the aryl or heteroaryl.

As a specific example of this pyrimidine derivative, there are the following compounds, for example.

This pyrimidine derivative can be produced using a known raw material and a known synthesis method.

2-2-4. Triazine derivatives

The triazine derivative is, for example, a compound represented by the following formula (ETM-10), and preferably a compound represented by the following formula (ETM-10-1). Details are described in US Publication No. 2011/0156013.

Ar is each independently aryl which may be substituted or heteroaryl which may be substituted. n is an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 2 or 3.

As the "aryl" of the "optionally substituted aryl", for example, there is an aryl having 6 to 30 carbon atoms, preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 20 carbon atoms, and still more preferably Is a C6-C12 aryl.

Specific examples of aryl include monocyclic aryl phenyl, bicyclic aryl biphenylyl (2-biphenylyl, 3-biphenylyl, 4-biphenylyl), and condensed bicyclic aryl naphthyl (1 -Naphthyl, 2-naphthyl), tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o- Terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl -4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl phosphorus, acenaphthylenyl (acenaphthylene-1-yl, acenaphthylene-3-yl, acenaphthylene-4-yl, acenaphthylene-5 -Yl), fluorenyl (fluoren-1-yl, fluoren-2-yl, fluoren-3-yl, fluoren-4-yl, fluoren-9-yl), phenalenyl (phenalene- 1-yl, phenalen-2-yl), phenanthryl (1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl), quarterphenylyl (5 '-Phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensation 4 Ring-based aryl triphenylene (triphenylen-1-yl, triphenylen-2-yl), pyrenyl (pyren-1-yl, pyren-2-yl, pyren-4-yl), naphthacenyl (naphtha Sen-1-yl, naphthasen-2-yl, naphthasen-5-yl), condensed pentacyclic aryl peryleneyl (perylene-1-yl, perylene-2-yl, perylene-3-yl ), pentacenyl (pentacen-1-yl, pentacen-2-yl, pentacen-5-yl, pentacen-6-yl), and the like.

The "heteroaryl" of the "may be substituted heteroaryl" may be a monocyclic ring, or may be a condensed ring in which one or more heterocycles and one or more heterocycles or one or more aromatic hydrocarbon rings are condensed, or two or more heterocycles. It can also be a linking ring connected by a summon. When two or more heterocycles are connected, those connected in a straight chain may be used or may be connected in a branched manner. As "heteroaryl", for example, there is a C2-C30 heteroaryl, a C2-C25 heteroaryl is preferable, a C2-C20 heteroaryl is more preferable, and a C2-C15 heteroaryl This is more preferable, and C2-C10 heteroaryl is especially preferable. In addition, examples of the heteroaryl include, for example, heterocycles containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen in addition to carbon as a ring constituent atom.

Specific examples of heteroaryl include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, Triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl , Benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteri Denyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxatinyl, thianthrenyl, indolidinyl, and the like.

In addition, the aryl and heteroaryl may be substituted, and each may be substituted with, for example, the aryl or heteroaryl.

As a specific example of this triazine derivative, there are the following compounds, for example.

This triazine derivative can be produced using a known raw material and a known synthesis method.

2-2-5. Benzimidazole derivatives

The benzimidazole derivative is, for example, a compound represented by the following formula (ETM-11).

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is 1 to 4 It is an integer, and the "benzimidazole-based substituent" is the pyridyl group in the "pyridine-based substituent" in the above formulas (ETM-2), (ETM-2-1) and formula (ETM-2-2). It is a substituent substituted with a dazole group, and at least one hydrogen in the benzimidazole derivative may be substituted with deuterium.

^{R 11} in the benzimidazole group is hydrogen, alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 30 carbon atoms, wherein the formula (ETM-2-1) and formula (ETM- ^{The description of R 11} in 2-2) can be cited.

φ is also preferably an anthracene ring or a fluorene ring, and the structure in this case can refer to the description in the above formula (ETM-2-1) or (ETM-2-2), and R in each formula ¹¹ to R ¹⁸ can refer to the description in the above formula (ETM-2-1) or (ETM-2-2). In addition, in the above formula (ETM-2-1) or (ETM-2-2), two pyridine-based substituents are combined, but when replacing them with a benzimidazole-based substituent, both pyridine-based substituents May be substituted with a benzimidazole-based substituent (that is, n=2), one pyridine-based substituent may be substituted with a benzimidazole-based substituent, and the other pyridine-based substituent may be substituted with R ^{11 to R 18} (i.e. n=1). ^{Further, for example, at least one of R 11} to ^{R 18} in the above formula (ETM-2-1) may be substituted with a benzimidazole-based substituent, and “pyridine-based substituent” may be substituted with R ^{11 to R 18} .

Specific examples of this benzimidazole derivative include, for example, 1-phenyl-2-(4-(10-phenylanthracene-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-( 10-(naphthalen-2-yl)anthracene-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalen-2-yl)anthracene-9- Yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 5-(10-(naphthalen-2-yl)anthracene-9-yl)-1,2-diphenyl-1H-benzo[d] Imidazole, 1-(4-(10-(naphthalen-2-yl)anthracene-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10- Di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalen-2-yl)anthracene- 2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalen-2-yl)anthracen-2-yl)-1,2-diphenyl-1H -Benzo[d]imidazole, etc.

This benzimidazole derivative can be produced using a known raw material and a known synthesis method.

2-2-6. Phenanthroline derivatives

The phenanthroline derivative is, for example, a compound represented by the following formula (ETM-12) or (ETM-12-1). Details are described in International Publication No. 2006/021982.

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is 1 to 4 It is an integer.

^{R 11} to ^{R 18} in each formula are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably 6-30 aryl). Further, in the above formula (ETM-12-1), ^{any one of R 11 to R 18} is bonded to φ which is an aryl ring.

At least one hydrogen in each phenanthroline derivative may be substituted with deuterium.

R ¹¹ as alkyl, cycloalkyl and aryl of from ~R ^18, it is possible to cite the above formula ^{(ETM-2) R 11 ~R} 18 of the description. In addition, in addition to the above-described examples, φ has, for example, the following structural formula. In addition, R in the following structural formula is each independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, or terphenylyl.

Specific examples of this phenanthroline derivative include, for example, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9, 10-di(1,10-phenanthrolin-2-yl)anthracene, 2,6-di(1,10-phenanthrolin-5-yl)pyridine, 1,3,5-tri(1,10- Phenanthroline-5-yl)benzene, 9,9'-difluoro-bis(1,10-phenanthroline-5-yl), vasocuproin or 1,3-bis(2-phenyl-1) ,10-phenanthroline-9-yl)benzene.

This phenanthroline derivative can be produced using a known raw material and a known synthesis method.

2-2-7. Quinolinol-based metal complex

The quinolinol-based metal complex is, for example, a compound represented by the following formula (ETM-13).

In the formula, R ¹ to ^{R 6} are hydrogen or a substituent, M is Li, Al, Ga, Be or Zn, and n is an integer of 1 to 3.

Specific examples of the quinolinol-based metal complex include 8-quinolinol lithium, tris(8-quinolinolato)aluminum, tris(4-methyl-8-quinolinolato)aluminum, and tris(5-methyl-8-) Quinolinolato) aluminum, tris (3,4-dimethyl-8-quinolinolato) aluminum, tris (4,5-dimethyl-8-quinolinolato) aluminum, tris (4,6-dimethyl-8 -Quinolinolato)aluminum, bis(2-methyl-8-quinolinolato)(phenolato)aluminum, bis(2-methyl-8-quinolinolato)(2-methylphenolato)aluminum, bis (2-methyl-8-quinolinolato)(3-methylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(4-methylphenolato)aluminum, bis(2-methyl-8 -Quinolinolato)(2-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3-phenylphenolato)aluminum, bis(2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum, bis(2-methyl-8-quinolinolato)(2,3-dimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,6 -Dimethylphenolato) aluminum, bis(2-methyl-8-quinolinolato)(3,4-dimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(3,5-dimethyl Phenolato) aluminum, bis(2-methyl-8-quinolinolato)(3,5-di-tert-butylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,6 -Diphenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,4,6-triphenylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2 ,4,6-trimethylphenolato)aluminum, bis(2-methyl-8-quinolinolato)(2,4,5,6-tetramethylphenolato)aluminum, bis(2-methyl-8-quinoli Norato) (1-naphthorato) aluminum, bis (2-methyl-8-quinolinolato) (2-naphthorato) aluminum, bis (2,4-dimethyl-8-quinolinolato) ( 2-phenylphenolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3-phenylphenolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (4- Phenylphenolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethylphenolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3, 5-di-tert-butylphenolato) alu Minium, bis (2-methyl-8-quinolinolato) aluminum-μ-oxo-bis (2-methyl-8-quinolinolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) ) Aluminum-μ-oxo-bis (2,4-dimethyl-8-quinolinolato) aluminum, bis (2-methyl-4-ethyl-8-quinolinolato) aluminum-μ-oxo-bis (2 -Methyl-4-ethyl-8-quinolinolato) aluminum, bis(2-methyl-4-methoxy-8-quinolinolato) aluminum-μ-oxo-bis(2-methyl-4-methoxy -8-quinolinolato)aluminum, bis(2-methyl-5-cyano-8-quinolinolato)aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinola To) aluminum, bis(2-methyl-5-trifluoromethyl-8-quinolinolato)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolato) Aluminum and bis(10-hydroxybenzo[h]quinoline)beryllium.

This quinolinol-based metal complex can be produced using a known raw material and a known synthesis method.

The electron transport layer or electron injection layer may further contain a material capable of reducing the material for forming the electron transport layer or the electron injection layer. As long as this reducible substance has a certain reducibility, various ones are used. For example, alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, and alkali earth metals. At least one selected from the group consisting of halides, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be preferably used.

Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (work function 2.28 eV), Rb (work function 2.16 eV) or Cs (work function 1.95 eV), or Ca (work function 2.9 eV), Alkaline earth metals, such as Sr (work function 2.0-2.5 eV) or Ba (work function 2.52 eV), are exemplified, and it is particularly preferable that the work function is 2.9 eV or less. Among these, a more preferable reducing substance is an alkali metal of K, Rb or Cs, more preferably Rb or Cs, and most preferable is Cs. These alkali metals have particularly high reducing power, and by adding a relatively small amount to a material forming the electron transport layer or the electron injection layer, the luminance of the organic EL device is improved and the lifespan thereof is increased. In addition, as a reducing material having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable, and in particular, a combination including Cs, for example, Cs and Na, Cs and K, Cs and Rb, or Cs and A combination of Na and K is preferred. By including Cs, the reducing ability can be exhibited efficiently, and by adding it to a material forming the electron transport layer or the electron injection layer, the luminance of light emission in the organic electroluminescent device and the lifespan thereof can be increased.

2-3. Cathode in organic light emitting device

The cathode 108 serves to inject electrons into the light emitting layer 105 through the electron injection layer 107 and the electron transport layer 106.

The material for forming the cathode 108 is not particularly limited as long as it is a material capable of efficiently injecting electrons into the organic layer, but the same material as the material for forming the anode 102 may be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (magnesium-silver alloy, magnesium -Indium alloy, aluminum-lithium alloy such as lithium fluoride/aluminum, etc.) and the like are preferable. In order to improve the device characteristics by increasing the electron injection efficiency, lithium, sodium, potassium, cesium, calcium, magnesium, or an alloy containing these low work function metals is effective. However, this low work function metal is generally unstable in the atmosphere in many cases. In order to improve this point, for example, a method of using an electrode having high stability by doping an organic layer with a trace amount of lithium, cesium or magnesium is known. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide and cesium oxide can also be used. However, it is not limited to these.

In addition, for electrode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, and inorganic substances such as silica, titania and silicon nitride, polyvinyl alcohol, and vinyl chloride , A hydrocarbon-based polymer compound or the like is laminated thereon as a preferred example. The manufacturing method of these electrodes is also not specifically limited as long as it can conduct, such as resistance heating, electron beam evaporation, sputtering, ion plating, and coating.

2-4. Hole injection layer and hole transport layer in organic electroluminescent device

The hole injection layer 103 serves to efficiently inject holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 serves to efficiently transport holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. Each of the hole injection layer 103 and the hole transport layer 104 is formed by laminating and mixing one or two or more types of hole injection and transport materials, or a mixture of a hole injection and transport material and a polymer binder. Further, an inorganic salt such as iron (III) chloride may be added to the hole injection/transport material to form a layer.

As a hole injection/transport material, it is necessary to efficiently inject and transport holes from the anode between electrodes to which an electric field is applied, and it is preferable to have high hole injection efficiency and to efficiently transport the injected holes. To this end, it is preferable that the ionization potential is small, the hole mobility is large, and furthermore, the stability is excellent, and the impurities used as traps are not easily generated during manufacture and use.

As a material for forming the hole injection layer 103 and the hole transport layer 104, a compound conventionally used as a charge transport material for holes in a photoconductive material, a p-type semiconductor, a hole injection layer of an organic electroluminescent device, and Any of the known ones used for the hole transport layer may be selected and used. Specific examples of these are carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine Derivatives (polymers having aromatic tertiary amino in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3 -Methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N ,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl 1,1'-diamine, N ^4, N ^{4 '-} diphenyl -N ^4, N ^4' - bis (9-phenyl -9H- carbazole-3-yl) [1,1'-biphenyl] ^{4,4'-diamine, N 4, N 4, N} 4 ', N 4' - tetrahydro [1,1'-biphenyl] -4-yl) - [1,1'-biphenyl] -4, Triphenylamine derivatives such as 4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, starburstamine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, Copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives or thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (e.g., 1,4,5,8,9,12-hexaazatriphenyl Ene-2,3,6,7,10,11-hexacarbonitrile, etc.), and heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. In polymer systems, polycarbonate, styrene derivatives, and polyvinyls having the above monomers in the side chain Although carbazole, polysilane, and the like are preferable, it is not particularly limited as long as it is a compound capable of forming a thin film necessary for manufacturing a light emitting device, injecting holes from the anode, and transporting holes further.

It is also known that the conductivity of an organic semiconductor is strongly influenced by its doping. Such an organic semiconductor matrix material is composed of a compound having good electron-providing properties or a compound having good electron-accepting properties. For the doping of electron-providing materials, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are used. It is known (e.g., M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)” and J. Blochwitz , M. Pheiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731(1998)). These generate so-called holes by an electron transfer process in an electron-providing base material (hole transport material). Depending on the number of holes and the mobility, the conductivity of the base material varies greatly. As a matrix material having hole transport properties, for example, a benzidine derivative (TPD, etc.) or a starburstamine derivative (TDATA, etc.), or a specific metal phthalocyanine (in particular, zinc phthalocyanine ZnPc, etc.) is known (Japanese Patent Laid-Open Patent Publication No. 2005-167175 publication).

In addition, as a material for forming the hole injection layer 103 and the hole transport layer 104 using the wet film forming method, in addition to the material forming the hole injection layer 103 and the hole transport layer 104 used for the above deposition, Hole-injecting and hole-transporting polymers, hole-injecting and hole-transporting crosslinkable polymers, hole-injecting and hole-transporting polymer precursors, and polymerization initiators may be used. For example, PEDOT:PSS, polyaniline compound (described in Japanese Patent Laid-Open No. 2005-108828, International Publication No. 2010/058776, International Publication No. 2013/042623, etc.), fluorene polymer (Japanese Laid-Open Patent No. 2011-251984, Japanese Laid-Open Patent No. 2011-501449, Japanese Laid-Open Patent No. 2012-533661, etc.), ``Xiaohui Yang, David C. Muller, Dieter Neher, Klaus Meerholz, Organic Electronics, 12, 2253 -2257(2011)'', 「Philipp Zacharias, Malte C. Gather, Markus Rojahn, Oskar Nuyken, Klaus Meerholz, Angew. Chem. Int. Ed., 46, 4388-4392(2007)'', 「Chei-Yen, Yu-Cheng Lin, Wen-Yi Hung, Ken-Tsung Wong, Raymond C. Kwong, Sean C. Xia, Yu-Hung Chen, Chih- I Wu, J. Mater. Chem., 19, 3618-3626 (2009)'', ``Fei Huang, Yen-Ju Cheng, Yong Zhang, Michelle S. Liu, Alex K.- Y. Jen, J. Mater. Chem., 18, 4495-4509(2008)'' 「Carlos A. Zuniga, Jassem Abdallah, Wojciech Haske, Yadong Zhang, Igor Coropceanu, Stephen Barlow, Bernard Kippelen, Seth R. Marder, Adv. Mater., 25, 1739- 1744(2013)'', 「Wen-Yi Hung, Chi-Yen Lin, Tsang-Lung Cheng, Shih-Wei Yang, Atul Chaskar, Gang-Lun Fan, Ken-Tsung Wong, Teng-Chih Chao, Mei- Rurng Tseng, Organic Electronics, 13, 2508-2515 (2012)" and the like.

2-5. Anode in organic light emitting device

The anode 102 serves to inject holes into the light emitting layer 105. In addition, when the hole injection layer 103 and/or the hole transport layer 104 is provided between the anode 102 and the light emitting layer 105, holes are injected into the light emitting layer 105 through these.

Examples of the material for forming the anode 102 include inorganic compounds and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO)) Etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, and nesa glass. Examples of the organic compound include polythiophenes such as poly(3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. In addition, it can be appropriately selected and used from materials used as anodes of organic light emitting devices.

The resistance of the transparent electrode is not limited since it is sufficient to supply sufficient current to emit light from the light emitting element, but it is preferable to have a low resistance from the viewpoint of power consumption of the light emitting element. For example, if the ITO substrate is 300 Ω/□ or less, it functions as a device electrode, but nowadays, it is possible to supply a substrate of about 10 Ω/□. For example, 100 to 5 Ω/□, preferably 50 to 5 Ω. It is particularly preferable to use a low resistance product of /□. Although the thickness of ITO can be arbitrarily selected according to the resistance value, it is usually used between 50 and 300 nm in many cases.

The anode in the organic electroluminescent device may have a bank (partition wall material). When forming an organic electroluminescent device by a wet film forming method, an arbitrary layer can be obtained by dropping each layer-forming composition or a light-emitting layer-forming composition into the bank and drying it.

Photolithography techniques can be used to fabricate the banks. As the bank material that can be used for photolithography, inorganic materials and organic materials can be used, and examples of the inorganic materials include SiNx, SiOx and mixtures thereof, and examples of the organic materials include positive resist materials and negative types. Resist materials can be used. Further, patternable printing methods such as sputtering method, ink jet method, gravure offset printing, reverse offset printing, and screen printing can also be used. In that case, a permanent resist material can also be used. In addition, the bank may have a multilayer structure, and other types of materials may be used.

As organic materials used in the bank, polysaccharides and derivatives thereof, homopolymers and copolymers of ethylenic monomers having hydroxyl, biopolymer compounds, polyacryloyl compounds, polyesters, polystyrenes, polyimides, polyamideimide, poly Etherimide, polysulfide, polysulfone, polyphenylene, polyphenyl ether, polyurethane, epoxy (meth) acrylate, melamine (meth) acrylate, polyolefin, cyclic polyolefin, acrylonitrile-butadiene-styrene copolymer ( ABS), silicone resin, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, polyacetate, polynorbornene, synthetic rubber, polyfluorovinylidene, polytetrafluoroethylene, fluorinated polymers such as polyhexafluoropropylene, A copolymer of a fluoroolefin-hydrocarbon olefin and a fluorocarbon polymer may be exemplified, but the present invention is not limited thereto.

An example is given below as a formation method using an organic material in the bank's photolithography technique. A resin layer is formed by applying a material exhibiting liquid repellency to a composition for forming a functional layer, such as a composition for forming a light emitting layer, to an element substrate on which an electrode is formed, and drying it. By performing an exposure process and a development process with respect to this resin layer using an exposure mask, a bank can be formed on the element substrate on which an electrode was formed. After that, if necessary, steps such as washing/drying with a solvent or UV treatment may be performed in order to spread the composition for forming a functional layer evenly, to remove impurities on the surface of the bank.

2-6 Substrate in organic electroluminescent device

The substrate 101 serves as a support for the organic electroluminescent device 100, and usually quartz, glass, metal, plastic, or the like is used. The substrate 101 is formed in a plate shape, a film shape, or a sheet shape depending on the purpose, and, for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Among them, a glass plate and a plate made of transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferable. In the case of a glass substrate, soda-lime glass, alkali-free glass, or the like is used, and the thickness needs to be sufficient to maintain mechanical strength. For example, it may be 0.2 mm or more. The upper limit of the thickness is, for example, 2 mm or less, and preferably 1 mm or less. As for the material of the glass, since it is preferable that there are few eluted ions from the glass, alkali-free glass is preferable. However, since soda lime glass having a barrier coating such as _{SiO 2 is also commercially available, it can be used.} Further, on the substrate 101, in order to increase the gas barrier property, a gas barrier film such as a dense silicon oxide film may be formed on at least one surface. In particular, a plate, film, or sheet made of a synthetic resin having low gas barrier property is used as the substrate 101. In the case of using as ), it is preferable to form a gas barrier film.

2-7. Manufacturing method of organic electroluminescent device

For each layer constituting the organic electroluminescent device, the material constituting each layer is deposited by a method such as vapor deposition, resistance heating deposition, electron beam deposition, sputtering, molecular lamination, printing, spin coating, cast method, coating method, etc. It can be formed by setting it as a thin film. The film thickness of each layer thus formed is not particularly limited, and can be appropriately set according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured by a crystal oscillation type film thickness measuring device or the like. In the case of forming a thin film using a vapor deposition method, the vapor deposition conditions differ depending on the type of material, the target crystal structure and association structure of the film, and the like. Evaporation conditions are generally the heating temperature of the evaporation crucible + ^{50 to +400 °C, the vacuum degree 10 -6} to 10 ^-3 Pa, the deposition rate 0.01 to 50 nm/sec, the substrate temperature -150 to +300 °C, the film thickness of 2 nm to 5 It is preferable to appropriately select it in the range of µm.

Next, as an example of a method of manufacturing an organic EL device, an anode/hole injection layer/hole transport layer/host compound, a heat-activated delayed phosphor, and a light-emitting layer/electron transport layer/electron injection layer containing a compound having a boron atom/ A method of fabricating an organic electroluminescent device comprising a cathode will be described.

2-7-1. Evaporation method

On a suitable substrate, a thin film of an anode material is formed by a vapor deposition method or the like to prepare an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. On this, a host compound, a thermally activated delayed phosphor, and a compound having a boron atom are co-deposited to form a thin film to form a light emitting layer, an electron transport layer and an electron injection layer are formed on the light emitting layer, and a thin film made of a material for a cathode is deposited. The target organic electroluminescent device is obtained by forming a cathode by forming it by means of an or the like. Further, in the fabrication of the above-described organic electroluminescent device, the fabrication order may be reversed and fabricated in the order of a cathode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, and an anode.

When forming the light emitting layer by the vapor deposition method, it is preferable to select and use a compound represented by formula (ii) or a compound represented by formula (2) as the third component. In particular, it is preferable to select and use a compound in which at least one ^{of R 1} to ^{R 14} in formula (2) is a substituent. As the substituent mentioned here, a preferable substituent in the above-described third component can be adopted. Among them, alkyl having 1 to 24 carbon atoms and diarylamino optionally substituted can be particularly preferably employed. When the light emitting layer is formed by vapor deposition using compounds having these substituents, the corresponding compound not having a substituent, a compound represented by formula (i), a compound represented by formula (iii), or represented by formula (4) Compared to the case where the compound is formed by a vapor deposition method, the external quantum efficiency of the organic electroluminescent device is higher and the characteristics are excellent.

In addition, when forming a light emitting layer by vapor deposition using a compound represented by formula (i) or formula (iii) as the third component, it is preferable to employ a preferred substituent in the third component, and 1 to carbon atoms. It is particularly preferable to use a compound having 24 alkyl or optionally substituted diarylamino. When the light emitting layer is formed by the evaporation method using compounds having these substituents, the external quantum efficiency of the organic electroluminescent device is higher than that of the case formed by the evaporation method using a corresponding compound that does not have a substituent. .

2-7-2. Wet film formation method

In the case of using the composition for forming a light emitting layer, it is formed by using a wet film forming method.

In the wet film forming method, generally, a coating film is formed by going through a coating step of applying a composition for forming a light emitting layer to a substrate and a drying step of removing a solvent from the applied composition for forming a light emitting layer. Depending on the difference in the application process, the spin coater is used as the spin coating method, the slit coater is used as the slit coating method, and the plate is used as gravure, offset, reverse offset, flexo printing, and inkjet printers. The method to be used is called the inkjet method, and the method of spraying with a mist type is called the spray method. The drying process includes methods such as air drying, heating, and vacuum drying. The drying process may be performed only once, or may be performed multiple times using different methods and conditions. Further, for example, different methods may be used in combination, such as firing under reduced pressure.

The wet film forming method is a film forming method using a solution, for example, a partial printing method (ink jet method), a spin coating method, a cast method, a coating method, or the like. Unlike the vacuum deposition method, the wet film deposition method does not require the use of an expensive vacuum deposition apparatus, and can be formed under atmospheric pressure. In addition, the wet film forming method enables a large area or continuous production, leading to a reduction in manufacturing cost.

On the other hand, in the case of comparison with the vacuum evaporation method, lamination is difficult in the wet film forming method. When manufacturing a laminated film using the wet film forming method, it is necessary to prevent the dissolution of the lower layer by the composition of the upper layer, and the composition with controlled solubility, the crosslinking and orthogonal solvent of the lower layer (orthogonal solvent, solvent that does not dissolve each other), etc. Is spoken. However, even if such a technique is used, it may be difficult to use the wet film forming method for coating all films.

2-7-3. Combination of vacuum deposition method and wet film forming method

Thus, in general, a method of fabricating an organic electroluminescent device by using a wet film forming method for only a few layers and vacuum evaporation for the remainder is employed.

For example, the procedure for manufacturing an organic electroluminescent device by partially applying a wet film forming method is shown below.

(Procedure 1) Film formation by vacuum deposition of anode

(Procedure 2) Formation of the hole injection layer by wet film formation method

(Procedure 3) Film formation by the wet film formation method of the hole transport layer

(Procedure 4) Film formation of a composition for forming a light emitting layer containing a host compound, a thermally activated delayed phosphor, and a compound having a boron atom by a wet film forming method

(Procedure 5) Formation of electron transport layer by vacuum evaporation method

(Procedure 6) Formation of electron injection layer by vacuum evaporation method

(Procedure 7) Film formation by vacuum evaporation of the cathode

By passing through this procedure, an organic electroluminescent device consisting of an anode/hole injection layer/hole transport layer/host material, a light-emitting layer/electron transport layer/electron injection layer/cathode comprising a compound having a thermally activated delayed phosphor and a boron atom is obtained. Lose.

2-7-4. Manufacturing example of an organic electroluminescent device by inkjet

Referring to FIG. 6, a method of manufacturing an organic electroluminescent device using an ink jet method on a substrate having a bank will be described. First, the bank 200 is installed on the electrode 120 on the substrate 110. In this case, the coating film 130 can be produced by dropping ink droplets 310 between the banks 200 from the inkjet head 300 and drying them. By repeating this, the next coating film 140, and furthermore, the light emitting layer 150 is produced, and the electron transport layer, the electron injection layer, and the electrode are formed by using a vacuum deposition method. Can be produced.

In order to protect the organic electroluminescent device thus fabricated from moisture or oxygen, it is preferable to cover it with an encapsulation layer (not shown). For example, when moisture or oxygen enters from the outside, the luminous function is impaired, the luminous efficiency decreases, and dark spots (dark spots) that do not emit light occur. In addition, there is a possibility that the light emitting life is shortened. As the sealing layer, for example, an inorganic insulating material such as silicon oxynitride (SiON) having low permeability to moisture or oxygen can be used. Further, the organic electroluminescent element may be sealed by bonding a sealing substrate such as transparent glass or opaque ceramic to the element substrate on which the organic electroluminescent element is formed through an adhesive.

2-8. Application example of organic electroluminescent device

In addition, the present invention can be applied to a display device including an organic electroluminescent device or a lighting device including an organic electroluminescent device.

A display device or lighting device having an organic light emitting device can be manufactured by a known method such as connecting the organic light emitting device according to the present embodiment to a known driving device, and direct current drive, pulse drive, and AC drive It can be driven by appropriately using a known driving method such as.

Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescence (EL) displays (e.g., Japanese Laid-Open Patent Publication No. Hei 10-335066, Japanese Laid-Open Patent Publication No. 2003-321546, Japanese Laid-Open Patent No. 2004-281086, etc.). Further, as the display method of the display, for example, a matrix and/or segment method may be exemplified. In addition, the matrix display and the segment display may coexist in the same panel.

In a matrix, pixels for display are arranged two-dimensionally, such as a grid or a mosaic, and characters or images are displayed as a set of pixels. The shape or size of the pixel is determined according to the application. For example, in PCs, monitors, and television images and characters, a square pixel with a side of 300 μm or less is usually used, and in the case of a large display such as a display panel, a pixel of the order of mm is used for one side. . In the case of monochrome display, pixels of the same color may be arranged, but in the case of color display, red, green, and blue pixels are arranged and displayed. In this case, there are typically a delta type and a stripe type. As a driving method of this matrix, either a line-sequential driving method or an active matrix may be used. The linear sequential driving has the advantage of having a simple structure, but considering the operation characteristics, the active matrix may be excellent, and thus it is necessary to use it separately according to the application.

In the segment method (type), a pattern is formed to display predetermined information, and a determined area is illuminated. For example, there is a display of the time or temperature on a digital clock or thermometer, an operation status display of an audio device or an electronic cooker, and a panel display of an automobile.

Examples of lighting devices include lighting devices such as indoor lighting, backlights for liquid crystal displays, and the like (for example, Japanese Laid-Open Patent No. 2003-257621, Japanese Laid-Open Patent No. 2003-277741, Japanese Laid-open See Patent No. 2004-119211, etc.). The backlight is mainly used for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, and a sign. In particular, as a backlight for a liquid crystal display device, especially for a PC whose thinning is a problem, considering that the conventional method is made of a fluorescent lamp or a light guide plate, it is difficult to reduce the thickness, the backlight using the light emitting device according to the present embodiment is thin. It is characterized by light weight.

3. Composition for forming a light emitting layer

The composition for forming a light-emitting layer of the present invention is a composition for forming a light-emitting layer of an organic light-emitting device by a wet method. The composition for forming a light emitting layer comprises a compound having at least one host compound as a first component, at least one thermally activated delayed phosphor as a second component, and at least one boron atom as a third component, and a fourth It is a composition containing at least one organic solvent as a component. For the host compound, the thermally activated delayed phosphor, and the compound having a boron atom, the compound described in the description of the light emitting layer in the organic EL device can be used.

3-1. Organic solvent

It is preferable that the composition for forming a light emitting layer of the present invention contains at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, it is possible to control and improve film-forming properties, the presence or absence of defects in the coating film, surface roughness, and smoothness. In addition, in the case of film formation using the ink jet method, the meniscus stability in the pinhole of the ink jet head can be controlled, and ejection properties can be controlled and improved. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, it is possible to improve the electrical characteristics, luminescence characteristics, efficiency, and lifetime of the organic electroluminescent device having a light-emitting layer obtained from the composition for forming a light-emitting layer.

3-1-1. Physical properties of organic solvent

The boiling point of at least one organic solvent contained as a fourth component in the composition for forming a light emitting layer is 130 to 350°C, more preferably 140 to 300°C, and even more preferably 150 to 250°C. When the boiling point is higher than 130° C., it is preferable from the viewpoint of ink jet ejection properties. Further, when the boiling point is lower than 350°C, it is preferable from the viewpoint of defects of the coating film, surface roughness, residual solvent and smoothness. From the viewpoints of good ink jet ejection properties, film forming properties, smoothness, and low residual solvent, a configuration containing two or more organic solvents is more preferable. On the other hand, in some cases, a composition obtained in a solid state by removing a solvent from the composition for forming a light emitting layer may be employed in consideration of transportability and the like.

The composition for forming a light emitting layer of the present invention contains a good solvent (GS) and a poor solvent (PS) for at least one of the first component, the second component, and the third component as a fourth component, and a good solvent ( It is particularly preferable that the boiling point (BP _{GS ) of GS) is lower than the boiling point (BP PS} ) of the poor solvent (PS).

By adding a high boiling point poor solvent, the low boiling point good solvent first volatilizes at the time of film formation, and the concentration of the contained substances in the composition and the concentration of the poor solvent increase, thereby promoting rapid film formation. Thereby, a coating film with few defects, small surface roughness and high smoothness can be obtained.

The difference in solubility (S _GS -S _PS ) is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more. The difference in boiling point (BP _PS -BP _GS ) is preferably 10°C or higher, more preferably 30°C or higher, and still more preferably 50°C or higher.

After film formation, the organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating. In the case of heating, it is preferable to perform at a glass transition temperature (Tg) + 30°C or lower, which is the highest among the compounds which are the first component, the second component, and the third component from the viewpoint of improving the coating film-forming properties. Further, from the viewpoint of reducing the residual solvent, it is preferable to heat at the lowest glass transition point (Tg) -30°C or higher among the compounds as the second component and the third component. Even if the heating temperature is lower than the boiling point of the organic solvent, since the film is thin, the organic solvent is sufficiently removed. Further, drying may be performed a plurality of times at different temperatures, or a plurality of drying methods may be used in combination.

3-1-2. Specific examples of organic solvent

Examples of the organic solvent used in the light emitting layer-forming composition include hydrocarbon-based solvents, alkylbenzene-based solvents, phenyl ether-based solvents, alkyl ether-based solvents, cyclic ketone-based solvents, aliphatic ketone-based solvents, monocyclic ketone-based solvents, and diester skeletons. And a fluorine-containing solvent and the like, as specific examples, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexane-2 -Ol, heptan-2-ol, octan-2-ol, decan-2-ol, dodecan-2-ol, cyclohexanol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, terpineol (mixture), ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol iso Propyl methyl ether, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether , Ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, p-xylene, m-xylene, o-xylene , 2,6-lutidine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzo trifluoride, cumene, toluene, 2-chloro-6-fluorotoluene, 2-fluoro Roanisole, anisole, 2,3-dimethylpyrazine, bromobenzene, 4-fluoroanisole, 3-fluoroanisole, 3-trifluoromethylanisole, mesitylene, 1,2,4- Trimethylbenzene, tert-butylbenzene, 2-methylanisole, phenethyl, benzodioxole, 4-methylanisole, sec-butylbenzene, 3-methylanisole, 4-fluoro-3-methylanisole, cymene , 1,2,3-trimethylbenzene, 1,2-dichlorobenzene, 2-fluorobenzonitrile, 4-fluoroveratrol, 2,6-dimethylanisole, n-butylbenzene, 3-fluorobenzonitrile , Decalin (decahydronaphthalene), neopentylbenzene, 2,5 -Dimethylanisole, 2,4-dimethylanisole, benzonitrile, 3,5-dimethylanisole, diphenyl ether, 1-fluoro-3,5-dimethoxybenzene, methyl benzoate, isopentylbenzene, 3, 4-dimethylanisole, o-tolonitrile, n-amylbenzene, veratrol, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoic acid, cyclohexylbenzene, 1-methyl Naphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-bitolyl, dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, trimethoxytoluene, 2,3 -Dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butyloxymethyl)benzene, 1-methyl-4-(pentyloxymethyl)benzene, 1-methyl-4 -(Hexyloxymethyl)benzene, 1-methyl-4-(heptyloxymethyl)benzene, benzylbutyl ether, benzylpentyl ether, benzylhexyl ether, benzylheptyl ether, benzyloctyl ether, nitrobenzene, dimethylnitrobenzene, aminobi Phenyl, diphenylamine, etc. may be mentioned, but the present invention is not limited thereto. In addition, the solvent may be used singly or may be mixed.

As the organic solvent, an alkylbenzene-based solvent, a phenyl ether-based solvent, or a mixed solvent thereof is preferable. Cyclohexylbenzene is preferable as the alkylbenzene-based solvent, and 3-phenoxytoluene is preferable as the phenylether-based solvent. A mixed solvent of cyclohexylbenzene and 3-phenoxytoluene is also preferable. In this case, the mass ratio of both is not particularly limited, but for example, it may be 2:8 to 8:2, and 5:5 to 8:2 is preferable.

3-2. Arbitrary ingredient

The composition for forming a light-emitting layer may contain an optional component within a range that does not impair its properties. As an optional component, a binder, a surfactant, etc. are mentioned.

3-2-1. bookbinder

The composition for forming a light emitting layer may contain a binder. The binder forms a film at the time of film formation, and bonds the obtained film to the substrate. In addition, it serves to dissolve, disperse, and bind other components in the composition for forming a light emitting layer.

Examples of the binder used in the light emitting layer forming composition include acrylic resin, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, acrylonitrile-ethylene-styrene copolymer (AES) resin, and Ionomer, chlorinated polyether, diallylphthalate resin, unsaturated polyester resin, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon (registered trademark), acrylonitrile-butadiene-styrene copolymer Polymer (ABS) resin, acrylonitrile-styrene copolymer (AS) resin, phenol resin, epoxy resin, melamine resin, urea resin, alkyd resin, polyurethane, and copolymers of the above resins and polymers. It is not limited to only.

The binder used in the composition for forming a light emitting layer may be used alone or in combination of a plurality of types.

3-2-2. Surfactants

The composition for forming a light-emitting layer may contain, for example, a surfactant for controlling the uniformity of the film surface of the composition for forming a light-emitting layer, the hydrophilicity and liquid repellency of the film surface. Surfactants are classified into ionic and nonionic from the structure of a hydrophilic group, and further classified into alkyl, silicone, and fluorine based on the structure of a hydrophobic group. Further, from the structure of the molecule, it is classified into a monomolecular system having a relatively small molecular weight and a simple structure, and a polymer system having a large molecular weight and side chains or branches. Further, from the composition, it is classified into a single system, a mixed system in which two or more types of surfactants and a base material are mixed. As surfactants that can be used in the composition for forming a light emitting layer, all types of surfactants can be used.

As a surfactant, for example, Polyflow No. 45, Polyflow KL-245, Polyflow No. 75, Polyflow No. 90, Polyflow No. 95 (brand name, manufactured by Kyoeisha Chemicals Co., Ltd.), Disperbyk 161, Disperbyk 162, Disperbake 163, Disperbake 164, Disperbake 166, Disperbyk Perbake 170, Disperbake 180, Disperbake 181, Disperbake 182, BYK300, BYK306, BYK310, BYK320, BYK330, BYK342, BYK344, BYK346 (brand name, manufactured by Big Chemistry Japan Co., Ltd.), KP-341 , KP-358, KP-368, KF-96-50CS, KF-50-100CS (brand name, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH- 40 (brand name, manufactured by Seimi Chemical Co., Ltd.), FTERGENT 222F, Ptagent 251, FTX-218 (brand name, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF -601, EFTOP EF-801, EFTOP EF-802 (brand name, manufactured by Mitsubishi Materials), Megapack F-470, Megapack F-471, Megapack F-475, Megapack R-08, Megapack F -477, Megapack F-479, Megapack F-553, Megapack F-554 (trade name, manufactured by DIC Corporation), fluoroalkylbenzenesulfonate, fluoroalkylcarboxylate, fluoroalkylpolyoxyethylene ether , Fluoroalkylammonium iodide, fluoroalkylbetaine, fluoroalkylsulfonate, diglycerin tetrakis (fluoroalkylpolyoxyethylene ether), fluoroalkyltrimethylammonium salt, fluoroalkylaminosulfonate, polyoxyethylene Nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene laurylamine, sorbitan laurate, sorbitan palmi Tate, sorbitan stearate, sorbitanoleate, sorbitan fatty acid ester, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitanolate, poly Oxyethylene naphthyl ether, alkylbenzenesulfonate and alkyldiphenylether There are redisulfonic acid salts. Surfactants may be used alone or in combination of two or more.

3-3. Composition and physical properties of the composition for forming a light emitting layer

In the composition for forming a light-emitting layer of the present invention, as a first component, a second component, and a third component, a compound that satisfies at least one of excellent solubility, film-forming properties, wet coating properties, thermal stability, and in-plane orientation properties. Choose In addition, from the viewpoint of excellent solubility, film forming property, wet coating property, and in-plane orientation, C1-C24 alkyl, diarylamino, C5-C24 cycloalkyl, C6-C24 aryl, and C5-24 It is preferable to select a compound substituted with a heteroaryl.

As the first component, it is preferable to select a phosphorus compound having in the molecule phenylene, triazine, pyridine, carbazole, dibenzofuran or dibenzothiophene having a substituent at the m position. As the second component, a compound having alkyl or cycloalkyl in the molecule is preferable from the viewpoint of solubility and film-forming properties, and from the viewpoint of efficiency, a rod-shaped molecule having high ovality is preferable, for example, A compound having oxadiazole, thiadiazole and triazole in a molecule is preferable, and it is preferable to select the formula 2PXZ-TAZ. As the third component, a compound having alkyl or cycloalkyl in the molecule is preferable from the viewpoint of solubility and film-forming properties, and from the viewpoint of efficiency, a rod-shaped molecule having high ovality is preferable. For example, formula (2) The compound represented by is preferably B2N4-0230/S-M1, B2N4-0220/S-M1, B2N4-0211/S-M1, BN2BNO-0230/S-M1, and B2O2N2-0220/S-M1 compound It is preferable to choose.

The content of each component in the composition for forming a light emitting layer of the present invention is not particularly limited, but the content of the first component is preferably 40% by mass based on the total mass of the first component, the second component, and the third component. It is -98.999 mass %, More preferably, it is 50 mass%-97.99 mass %, More preferably, it is 60 mass%-94.9 mass %. The content of the second component is 1% by mass to 60% by mass, more preferably 2% by mass to 50% by mass, further preferably It is 5 mass%-30 mass %. The content of the third component is preferably 0.001% by mass to 30% by mass, more preferably 0.01 to 20% by mass, further preferably Is 0.1 to 10% by mass. If it is the above-described range, it is preferable, for example, from the point that concentration quenching can be prevented.

In addition, when the composition for forming a light emitting layer of the present invention contains an organic solvent, the content of each component of the first component, the second component, and the third component is as follows: each component in the composition for forming a light emitting layer has good solubility, storage stability, and film-forming properties. , And good quality film quality of the coating film obtained from the composition for forming a light-emitting layer, and good ejection property when using the inkjet method, good electrical properties, light-emitting properties of an organic electroluminescent device having a light-emitting layer produced using the composition, In terms of efficiency and lifespan, you can decide. For example, from the above point of view, with respect to the total mass of the first component, the second component, and the third component of the composition for forming a light emitting layer, the first component is 40 to 98.999 mass%, and the second component is 1 mass% to 60%. The mass% and the third component are preferably 0.001 mass% to 30 mass%. More preferably, with respect to the total mass of the first component, the second component, and the third component of the composition for forming a light emitting layer, the first component is 50% by mass to 97.99% by mass, and the second component is 2% by mass to 50% by mass. And the third component is 0.01% by mass to 20% by mass. More preferably, the first component is 60% by mass to 94.9% by mass and the second component is 5% by mass to 30% by mass with respect to the total mass of the first component, the second component, and the third component of the composition for forming a light emitting layer. , The third component is 0.1% by mass to 10% by mass.

The content of each component in the composition for forming a light-emitting layer of the present invention includes good solubility, storage stability, and film-forming properties of each component in the composition for forming a light-emitting layer, and the quality of the coating film obtained from the composition for forming a light-emitting layer, and the inkjet method. It may be determined from the viewpoints of good discharge properties when using, and good electrical properties, light-emitting properties, efficiency, and lifespan of an organic electroluminescent device having a light-emitting layer produced using the composition. For example, from the above point of view, the first component is 0.0998 mass% to 4.0 mass% with respect to the total mass of the light-emitting layer-forming composition, and the second component is 0.0001 mass% to 2.0 mass% with respect to the total mass of the light-emitting layer-forming composition. The mass%, the third component is preferably 0.0001 mass% to 2.0 mass% with respect to the total mass of the light-emitting layer-forming composition, and the fourth component is preferably 90.0 mass% to 99.9 mass% with respect to the total mass of the light-emitting layer-forming composition.

More preferably, the first component is 0.17% by mass to 4.0% by mass relative to the total mass of the light-emitting layer-forming composition, and the second component is 0.03% by mass to 1.0% by mass, based on the total mass of the light-emitting layer-forming composition. The three components are 0.03 mass% to 1.0 mass% with respect to the total mass of the light emitting layer-forming composition, and the fourth component is 93.0 mass% to 99.77 mass% with respect to the total mass of the light emitting layer-forming composition. More preferably, the first component is 0.25% by mass to 2.5% by mass with respect to the total mass of the light-emitting layer-forming composition, and the second component is 0.05% by mass to 0.5% by mass with respect to the total mass of the light-emitting layer-forming composition. The three components are 0.05 mass% to 0.5 mass% with respect to the total mass of the light emitting layer-forming composition, and the fourth component is 96.5 mass% to 99.1 mass% with respect to the total mass of the light emitting layer-forming composition. In other preferred embodiments, the first component is 0.095 mass% to 4.0 mass% with respect to the total mass of the light-emitting layer-forming composition, and the second component is 0.003 mass% to 1.0 mass% with respect to the total mass of the light-emitting layer-forming composition. The third component is 0.002 mass% to 1.0 mass% with respect to the total mass of the light-emitting layer-forming composition, and the fourth component is 92.0 mass% to 99.9 mass% with respect to the total mass of the light-emitting layer-forming composition.

The composition for forming a light-emitting layer can be prepared by appropriately selecting and performing stirring, mixing, heating, cooling, dissolving, and dispersing the above-described components by a known method. Further, after preparation, filtration, degassing (also referred to as degassing), ion exchange treatment, and inert gas replacement/encapsulation treatment may be appropriately selected and performed.

As the viscosity of the composition for forming a light-emitting layer, those having a high viscosity provide good film-forming properties and good ejection properties when an inkjet method is used. On the other hand, those with low viscosity are easy to form a thin film. In consideration of this, the viscosity of the composition for forming a light emitting layer is preferably 0.3 mPa·s to 3 mPa·s at 25°C, and more preferably 1 mPa·s to 3 mPa·s. In the present invention, the viscosity is a value measured using a conical flat plate rotational viscometer (cone plate type).

As the surface tension of the composition for forming a light-emitting layer, a low one provides good film-forming properties and a coating film without defects. On the other hand, good inkjet ejection properties are obtained with higher ones. In view of this, the viscosity of the composition for forming a light emitting layer is preferably 20 mN/m to 40 mN/m, and more preferably 20 mN/m to 30 mN/m, as for the viscosity of the composition for forming a light emitting layer. In the present invention, the surface tension is a value measured using a hanging method.

[Example]

Hereinafter, the present invention will be described in detail by examples. Materials, treatment contents, treatment procedures, etc. shown below can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the specific examples shown below.

Hereinafter, examples of synthesis of the compounds used in the examples are shown.

1. Synthesis of compounds

Synthesis Example (1)

Compound (ED1): N ⁷ ,N ⁷ ,N ¹³ ,N ¹³ ,5,9,11,15-octaphenyl-5,9,11,15-tetrahydro-5,9,11,15-tetraaza- Synthesis of 19b,20b-diboradinaphtho[3,2,1-de:1',2',3'-jk]pentacene-7,13-diamine

[Step 1]

Under nitrogen atmosphere, 1,3-dibromobenzene (25.0g, 106mmol), aniline (20.3ml, 223mmol), tris (dibenzylideneacetone) 2 palladium (0) (Pd ₂ (dba) ₃ ) (971 mg, 1.06mmol), 2,2'-bis(diphenylphosphino)-1,1'-binapthyl (BINAP: 1.98g, 3.18mmol), NaOtBu (25.5g, 265mmol) and toluene (400ml) flask Was heated to 110°C and stirred for 18 hours. The reaction solution was cooled to room temperature, filtered using silica gel (eluent: toluene), and the solvent was distilled off under reduced pressure to obtain a crude product. After dissolving the obtained crude product in toluene, an appropriate amount was distilled off under reduced pressure, and then reprecipitated by adding hexane to obtain N ¹ ,N ³ -diphenylbenzene-1,3-diamine (16.5 g, yield 60%) as a white solid. Obtained as.

The structure of the obtained compound was confirmed by NMR spectrum.

¹ H-NMR (400MHz, CDCl ₃ ): δ=5.63 (s, 2H), 6.60 (dd, 2H), 6.74 (t, 1H), 6.90 (t, 2H), 7.06 (d, 4H), 7.12 ( t, 1H), 7.24 (dt, 4H).

[Step 2]

Under nitrogen atmosphere, 1,3-dibromo-5-chlorobenzene (8.11g, 30mmol), diphenylamine (10.1g, 60mmol), Pd ₂ (dba) ₃ (550mg, 0.6mmol), 2-dicyclo 80 flasks containing hexylphenylphosphino-2',6'-dimethoxydiphenyl (SPhos: 0.493g, 1.2mmol), sodium tert-butoxydo (NaOtBu) (8.60g, 90mmol) and toluene (300ml). It heated to degreeC and stirred for 15 hours. The reaction solution was cooled to room temperature, filtered using silica gel (eluent: toluene), and the solvent was distilled off under reduced pressure to obtain a crude product. After dissolving the obtained crude product in toluene, a saturated solution was prepared by distilling off under reduced pressure, and then reprecipitated by adding hexane, and 5-chloro-N ¹ ,N ¹ ,N ³ ,N ³ -tetraphenylbenzene-1,3 -Diamine (5.66 g, yield 43%) was obtained as a white solid.

The structure of the obtained compound was confirmed by NMR spectrum.

¹ H-NMR (400 MHz, CDCl ₃ ): δ=6.56 (d, 2H), 6.64 (t, 1H), 7.00 (t, 4H), 7.05 (d, 8H), 7.21 (dd, 8H).

[Step 3]

In a nitrogen atmosphere, N ¹ ,N ³ -diphenylbenzene-1,3-diamine (1.34 g, 5.1 mmol) synthesized in the first step, 5-chloro-N ¹ ,N ¹ ,N synthesized in the second step ³ ,N ³ -Tetraphenylbenzene-1,3-diamine (4.80g, 11mmol), Pd ₂ (dba) ₃ (0.140g, 0.15mmol), tri-tert-butylphosphine (60.7mg, 0.30mmol), A flask containing NaOtBu (1.47 g, 15 mmol) and toluene (200 ml) was heated to 110°C and stirred for 8 hours. The reaction solution was cooled to room temperature, filtered using silica gel (eluent: toluene), and the solvent was distilled off under reduced pressure to obtain a crude product. By washing the obtained crude product in the order of hexane and methanol, N ¹ ,N ^1′ -(1,3-phenylene)bis(N ¹ ,N ³ ,N ³ ,N ⁵ ,N ⁵ -pentaphenylbenzene-1 ,3,5-triamine) (4.80 g, yield 87%) was obtained as a white solid.

The structure of the obtained compound was confirmed by NMR spectrum.

¹ H-NMR (400 MHz, CDCl ₃ ): δ=6.38 (d, 4H), 6.41 (t, 2H), 6.58 (dd, 2H), 6.70 (t, 1H), 6.88-6.90 (m, 14H), 6.85 (t, 1H), 6.99 (d, 16H), 7.08-7.15 (m, 20H).

[Step 4]

N ¹ ,N ^1′ -(1,3-phenylene)bis(N ¹ ,N ³ ,N ³ ,N ⁵ ,N ⁵ -pentaphenylbenzene-1,3,5-triamine) (3.24 g, 3.0 mmol) and orthodichlorobenzene (400 ml) were added boron tribromide (1.13 ml, 12 mmol) at room temperature under a nitrogen atmosphere. After completion of the dropwise addition, the temperature was raised to 180°C and stirred for 20 hours. Then, it cooled to room temperature again, and N-diisopropylethylamine (7.70 ml, 45 mmol) was added, and it stirred until heat generation was cooled. Then, under reduced pressure at 60 degreeC, the reaction solution was distilled off, and the crude product was obtained. The obtained crude product was washed in the order of acetonitrile, methanol, and toluene, purified by silica gel column chromatography (eluent: toluene), and the crude product was recrystallized twice with o-dichlorobenzene, and then 1× 1.17 g of compounds (ED1) were obtained by performing sublimation purification at 440°C under a reduced pressure of 10 ^{-4 mmHg.}

The structure of the obtained compound was confirmed by NMR spectrum.

¹ H-NMR (400 MHz, CDCl ₃ ): δ=5.72 (s, 2H), 5.74 (s, 2H), 5.86 (s, 1H), 6.83 (d, 2H), 6.88-6.93 (m, 12H), 7.05(t, 8H), 7.12-7.19(m, 6H), 7.24-7.26(m, 4H), 7.05(d, 4H), 7.12(dd, 8H), 7.12-7.19(m, 6H), 7.32( d, 4H), 7.38 (dd, 2H), 7.42 (t, 2H), 7.46 (dd, 2H), 7.47 (dd, 4H), 9.30 (d, 2H), 10.5 (s, 1H).

¹³ C-NMR (101MHz, CDCl ₃ ): 99.5(2C+2C), 103.4(1C), 116.8(2C), 120.0(2C), 123.1(4C), 125.3(8C), 127.1(2C), 127.6(2C) , 128.5(8C), 129.6(4C), 129.8(4C), 130.2(4C+2C), 130.3(4C), 135.0(2C), 142.1(2C), 142.5(2C), 143.3(1C), 146.8(4C) , 147.9 (2C+2C), 148.0 (2C), 150.1 (2C), 151.1 (2C).

Synthesis Example (2)

Compound (1-41): 2,12-di-tert-butyl-5,9-bis(4-(tert-butyl)phenyl)-7-methyl-5,9-dihydro-5,9-diaza Synthesis of -13b-boranaphtho[3,2,1-de]anthracene

Compound (1-41) was synthesized according to the method described in "Synthesis Example (32)" of International Publication No. 2015/102118.

Hereinafter, in Synthesis Example (1-2) to Synthesis Example (1-4), and Synthesis Example (1-9) to Synthesis Example (1-14), the same method as in Synthesis Example (1-1) described above was used. , Each compound was synthesized.

Synthesis Example (3)

Compound (1-31): 2,12-di-tert-butyl-5,9-bis(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-diaza-13b-bora Synthesis of naphtho[3,2,1-de]anthracene

Synthesis Example (4)

Compound (1-53): 2,12-di-tert-butyl-5,9-bis(4-(tert-butyl)phenyl)-7-(9H-carbazol-9-yl)-5,9- Synthesis of dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene

Synthesis Example (5)

Compound (1-37): 3,12-di-tert-butyl-9-(4-(tert-butyl)phenyl)-5-(3,5-di-tert-butylphenyl)-5,9-di Synthesis of hydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene

Synthesis Example (6)

Compound (1-46): 3,12-di-tert-butyl-9-(4-(tert-butyl)phenyl)-5-(3,5-di-tert-butylphenyl)-7-methyl-5 Synthesis of ,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene

Compound (1-46) was synthesized according to the method described in "Synthesis Example (32)" of International Publication No. 2015/102118.

Synthesis Example (7)

Compound (1-50): 2,12-di-tert-butyl-N,N,5,9-tetrakis(4-(tert-butyl)phenyl)-5,9-dihydro-5,9-dia Synthesis of za-13b-boranaphtho[3,2,1-de]anthracene-7-amine

Compound (1-50) was synthesized according to the method described in "Synthesis Example (32)" of International Publication No. 2015/102118.

Synthesis Example (8)

Compound (1-49): 2,12-di-tert-butyl-5,9-bis(4-(tert-butyl)phenyl)-N,N-diphenyl-5,9-dihydro-5,9 -Synthesis of diaza-13b-boranaphtho[3,2,1-de]anthracene-7-amine

Compound (1-49) was synthesized according to the method described in "Comparative Synthesis Example (1)" of JP 2016-88927 A.

Synthesis Example (9)

Compound of formula (1-340): 15,15-dimethyl-N,N-diphenyl-15H-5,9-dioxa-16b-boranedeno[1,2-b]naphtho[1,2, Synthesis of 3-fg] anthracene-13-amine

Compound (1-340) was synthesized according to the method described in "Synthesis Example (4)" of International Publication No. 2017/126443.

Synthesis Example (10)

Compound of formula (1-351): 5-([1,1'-biphenyl]-4-yl)-15,15-dimethyl-N,N,2-triphenyl-5H,15H-9-oxa- Synthesis of 5-aza-16b-boranedeno[1,2-b]naphtho[1,2,3-fg]anthracene-13-amine

Compound (1-351) was synthesized according to the method described in "Synthesis Example (5)" of International Publication No. 2017/126443.

2. Evaluation of basic physical properties

Preparation of the sample

When evaluating the absorption characteristics and luminescence characteristics (fluorescence and phosphorescence) of the compound to be evaluated, only the compound to be evaluated was thinned and evaluated, or the compound to be evaluated was dispersed in an appropriate matrix material to form a thin film.

When only the compound to be evaluated was thinned and evaluated, the compound was vacuum-deposited on a glass substrate to a thickness of 30 to 100 nm to obtain a sample.

Commercially available PMMA (polymethyl methacrylate) was used as a matrix material for dispersing the compound to be evaluated in an appropriate matrix material. In this example, after dissolving PMMA and the compound to be evaluated in toluene, a 10 nm-thick thin film was formed on a quartz transparent support substrate (10 mm×10 mm) by spin coating to prepare a sample. The concentration of the sample was 1% by mass.

Evaluation of absorption and emission characteristics

Measurement of the absorption spectrum of the sample was performed using an ultraviolet-visible near-infrared spectrophotometer (Shimazu Corporation, UV-2600). In addition, the fluorescence spectrum and phosphorescence spectrum of the sample were measured using a spectrophotometer (Hitachi Hi-Tech Co., Ltd. product, F-7000).

For the measurement of the fluorescence spectrum, photoluminescence was measured by excitation at room temperature with an appropriate excitation wavelength around 340 nm. For the measurement of the phosphorescence spectrum, the sample was measured in a state immersed in liquid nitrogen (temperature 77 K) using an attached cooling unit. In order to observe the phosphorescence spectrum, the delay time from irradiation of excitation light to the start of measurement was adjusted using an optical chopper. The sample was excited with an appropriate excitation wavelength to measure photoluminescence.

For each compound of the third component, the Stokes shift was determined from the difference between the peak top of the absorption spectrum and the peak top of the emission spectrum at room temperature.

In addition, the fluorescence quantum yield (PLQY) was measured using an absolute PL quantum yield measuring device (manufactured by Hamamatsu Photonics Co., Ltd., C9920-02G).

Further, by continuously applying a direct current, the time until the starting light intensity reached 50% of the initial stage was measured, and the device life (LT50) was evaluated.

Evaluation of fluorescence lifetime (delayed fluorescence)

The fluorescence lifetime was measured at 300K using a fluorescence lifetime measuring device (manufactured by Hamamatsu Photonics Co., Ltd., C11367-01). Specifically, in the maximum emission wavelength measured with an appropriate excitation wavelength, a light-emitting component having a fast fluorescence life and a late light-emitting component were observed. In the fluorescence lifetime measurement at room temperature of a general organic electroluminescent material that emits fluorescence, a late luminescent component involving a triplet component derived from phosphorescence is rarely observed due to deactivation of the triplet component by heat. When a late luminescent component is observed in the compound to be evaluated, triplet energy with a long excitation life is transferred to singlet energy by thermal activation, indicating that it is observed as delayed fluorescence. Here, the fluorescence lifetime of delayed fluorescence was measured as Tau (Delay).

Calculation of E(S, Sh), E(T, Sh), E(S, PT), E(T, PT) and ΔE(ST)

_{The singlet excitation energy level E(S, Sh) is from the wavelength B Sh} (nm) at the intersection of the base line and the tangent line passing through the shoulder on the peak short wavelength side of the fluorescence spectrum, E(S, Sh)=1240/B _Sh Calculated as. _{In addition, the triplet excitation energy level E(T, Sh) is from the wavelength C Sh} (nm) at the intersection of the base line and the tangent line passing through the shoulder on the peak short wavelength side of the phosphorescence spectrum, E(T, Sh)=1240/ It was calculated as _{C Sh.} In addition, the maximum peak emission wavelength of the fluorescence spectrum was also measured. In this specification, the singlet excitation energy level of the first component is E(1, S, Sh), the singlet excitation energy level of the second component is E(2, S, Sh), and the singlet excitation energy of the third component The level is E(3, S, Sh), the triplet excitation energy level of the first component is E(1, T, Sh), the triplet excitation energy level of the second component is E(2, T, Sh), and The three-component triplet excitation energy level is expressed as E(3, T, Sh).

ΔE(ST) is the energy difference between E(S, Sh) and E(T, Sh). It is defined as ΔE(ST)=E(S, Sh)-E(T, Sh). In addition, ΔE(ST) is, for example, "Purely organic electroluminescent material realizing 100% conversion from electricity to light", H. Kaji, H. Suzuki, T. Fukushima, K. Shizu, K. Katsuaki, S. Kubo , T. Komino, H. Oiwa, F. Suzuki, A. Wakamiya, Y. Murata, C. Adachi, Nat. Commun. It can also be calculated by the method described in 2015, 6, 8476. In this specification, ΔE(ST) of the first component is ΔE(1, ST, Sh), ΔE(ST) of the second component is ΔE(2, ST, Sh), and ΔE(ST) of the third component is ΔE It is denoted by (3, ST, Sh).

The results of measuring the basic physical properties of the compounds of the first component used in Examples and Comparative Examples are summarized in the following table.

[Table 1]

The results of measuring the basic physical properties of the compounds of the second component used in Examples and Comparative Examples are summarized in the following table.

[Table 2]

The results of measuring basic physical properties for the compounds of the third component used in Examples and Comparative Examples are summarized in the following table. In the table, it was suggested that R-BD2 could not observe the phosphorescence spectrum, and that E(3, T, Sh) was very low. In addition, "N.D." in the table shows that it is not measured.

[Table 3]

[Table 4]

In the table below, the results of measuring the maximum peak emission wavelength of the fluorescence spectrum of the main compounds are shown.

[Table 5]

3. Fabrication of organic electroluminescent device

An organic light-emitting device was fabricated, and a voltage was applied to measure current density, luminance, chromaticity, and external quantum efficiency. As a configuration of the produced organic electroluminescent device, first, the following configuration A (Table 1) was selected and evaluated. Configuration A is a configuration suitable for a thermally activated delayed fluorescence material. Configuration A is a device configuration that can expect high efficiency shown in the literature (Adv. Mater. 2016, 28, 2777-2781). However, the application of the compound of the present invention is not limited to this configuration, and the film thickness and material of each layer can be appropriately changed according to the basic physical properties of the compound of the present invention.

<Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4>

A glass substrate (manufactured by Optoscience Co., Ltd.) of 26 mm x 28 mm x 0.7 mm in which ITO formed into a film with a thickness of 200 nm by sputtering was polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Choshu Industrial Co., Ltd.), and NPD, TcTa, mCP, first component (mCBP), and second component (compounds listed in the table below) ), a tantalum evaporation boat containing the third component (ED1) and TSPO1, respectively, and an aluminum nitride evaporation boat containing LiF and aluminum, respectively.

Each of the following layers was sequentially formed on the ITO film of the transparent support substrate. The vacuum bath is reduced to 5×10 ^-4 Pa, first, NPD is heated to evaporate to a thickness of 40 nm, and then, TcTa is heated to evaporate to a thickness of 15 nm to form a two-layer hole injection transport layer. did. Next, mCP was heated and vapor-deposited to have a film thickness of 15 nm to form an electron blocking layer. Next, the first component, the second component, and the third component described in the following table were simultaneously heated to co-deposit so as to have a film thickness of 20 nm to form a light emitting layer. The deposition rate was adjusted so that the mass ratio of the first component, the second component, and the third component became the ratios shown in the following table. Next, TSPO1 was heated and vapor-deposited to have a film thickness of 30 nm to form an electron transport layer. The deposition rate of each of the above layers was 0.01 to 1 nm/sec. Thereafter, LiF was heated to evaporate at a deposition rate of 0.01 to 0.1 nm/sec so that the film thickness became 1 nm, and then, aluminum was heated to evaporate to a film thickness of 100 nm to form a cathode, thereby obtaining an organic electroluminescent device. At this time, the deposition rate of aluminum was adjusted to be 1 nm to 10 nm/sec.

[Table 6]

For each organic electroluminescent device of Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4, DC voltage was applied with an ITO electrode as an anode and an aluminum electrode as a cathode, and the fluorescence peak wavelength , Half-value width and external quantum efficiency were measured. The results are shown in the table below. In addition, the relationship between E(S, Sh) and the relationship between E(T, Sh) in the following table shows the magnitude relationship between the energy levels of the first component, the second component, and the third component. For example, E(1, S, Sh)>E(2, S, Sh)>E(3, S) is displayed as "1>2>3" in the relationship of E(S, Sh). , Sh).

[Table 7]

As for the emission color, Examples 1-1 to 1-3, Comparative Examples 1-3, and Comparative Example 1-4 are deep blue (deep blue), and Comparative Example 1-1 is light blue (sky blue) to greenish blue ( Greenish blue), and Comparative Example 1-2 was blue (blue).

Comparing Examples 1-1 to 1-3 with Comparative Examples 1-1 to 1-4, E(1, S, Sh) ≥ E(2, S, Sh) ≥ E(3, S, Sh) When the first component, the second component, and the third component satisfying the relationship were combined and used for the light emitting layer, it was confirmed that the color tone was good, the half value width was narrow, and the external quantum yield was increased. When the third component was not used in the emission layer, the half-value width was widened, resulting in a decrease in external quantum efficiency, and when the second component was not used in the emission layer, the external quantum efficiency decreased. In addition, it was confirmed that the properties provided according to the structure of the second component used in the light emitting layer were different, and Example 1-1 using 2PXZ-TAZ having a D-A-D type structure provided the highest external quantum efficiency.

<Examples 1-4 to 1-11 and Comparative Example 1-5>

Organic electroluminescent devices of Examples 1-4 to 1-11 and Comparative Example 1-5 were manufactured in the same manner as in Example 1-1, except that the materials described in the following table were used. In Examples 1-4, 1-5, and 1-5, the compound of the third component was changed, and in Examples 1-6 to 1-11, the compound of the first component was changed.

[Table 8]

For each organic light emitting device of Examples 1-4 to 1-11 and Comparative Example 1-5, DC voltage was applied with an ITO electrode as an anode and an aluminum electrode as a cathode in the same manner as in Example 1-1. , Fluorescence peak wavelength, half value width, and external quantum efficiency were measured. The results are shown in the table below.

[Table 9]

In Examples 1-4 to 1-11 and Comparative Example 1-5, both of E(1, S, Sh) ≥ E(2, S, Sh) ≥ E(3, S, Sh) Although the first component, the second component, and the third component are combined and used in the light emitting layer, compared to Comparative Example 1-5 using R-BD2, which is a compound that does not have a boron atom as the third component, it has a boron atom as the third component. Examples 1-4 to 1-11 using the compound had a small half width and high external quantum efficiency.

In addition, than in Example 1-5 in which RD-3, which is a compound of formula (i), was used as the third component, RD-1 or ED1, which is a compound of formula (ii) corresponding to a dimer of formula (i), was used as a third The half width of Example 1-11 was smaller than Example 1-4 and Example 1-6 used as a component, and it showed more preferable characteristics. In addition, in Examples, Example 1- than Example 1-4 and Example 1-6 in which E(1, T, Sh)>E(3, T, Sh)>E(2, T, Sh) 11, compared with Example 1-5 in which E(1, T, Sh)>E(2, T, Sh)>E(3, T, Sh), the half-value width was smaller and the external quantum efficiency was equal or higher. Particularly, when ED1 having a structure substituted with a diarylamino group was used as the third component, it was confirmed that the half-value width was particularly small, so that the external quantum efficiency was high, and the characteristics as an organic electroluminescent device were even more excellent.

<Examples 1-12 to 1-15 and Comparative Example 1-6>

Organic electroluminescent devices of Examples 1-4 to 1-11 and Comparative Example 1-5 were manufactured in the same manner as in Example 1-1, except that the materials described in the following table were used. In these specific examples, the compound of the second component was changed.

[Table 10]

For each organic electroluminescent device of Examples 1-12 to 1-15 and Comparative Example 1-6, DC voltage was applied with an ITO electrode as an anode and an aluminum electrode as a cathode in the same manner as in Example 1-1. , Fluorescence peak wavelength, half value width, and external quantum efficiency were measured. The results are shown in the table below.

[Table 11]

Example in which the first component, the second component, and the third component satisfying the relationship of E(1, S, Sh)≥E(2, S, Sh)≥E(3, S, Sh) are combined as a light emitting layer 1-12 to 1-15 have a half-value width compared to Comparative Example 1-6, which does not satisfy the relationship E(1, S, Sh)≥E(2,S,Sh)≥E(3,S, Sh). It was narrow and the external quantum yield was high. In addition, the results of Examples 1-12 to 1-15 show that even if the type of the second component is changed, good properties are maintained.

<Examples 1-16 to 1-26>

Using the materials listed in the table below, the same procedure as in Example 1-1 was used, except that the electron transport layer was formed by forming two layers of an electron transport layer 1 having a thickness of 10 nm and an electron transport layer 2 having a thickness of 20 nm. Organic electroluminescent devices of 1-16 to 1-26 were manufactured. The electron transport layer 2 of Example 1-23 was formed by heating BPy-TP2 and Liq to evaporate with a film thickness of 20 nm so that each ratio is 7:3 in terms of mass ratio. In addition, the electron transport layer 2 of Example 1-24 was formed by heating SF3-TRZ and Liq to evaporate with a film thickness of 20 nm so that the respective ratios were 7:3 in terms of mass ratio.

[Table 12]

For each of the fabricated organic light emitting devices of Examples 1-16 to 1-26, in the same manner as in Example 1-1, a direct current voltage was applied with an ITO electrode as an anode and an aluminum electrode as a cathode, and the fluorescence peak wavelength, half value The width and external quantum efficiency were measured, and the device life (LT50) was also measured. The results are shown in the table below.

[Table 13]

In Examples 1-16 to 1-26, it was confirmed that the organic electroluminescent device in which two electron transport layers were formed also exhibited good characteristics. In addition, it was confirmed that any organic electroluminescent device has a sufficient device life.

<Examples 1-27 to 1-55 and Comparative Example 1-7>

An organic electroluminescent device of Configuration B of Examples 1-27 to 1-55 and Comparative Example 1-7 was manufactured in the same manner as in Examples 1-14 except that the materials described in the following table were used. In Examples 1-27 to 1-55, various compounds represented by formula (ii) were used as the third component and evaluated.

[Table 14]

For each organic light emitting device of Examples 1-27 to 1-55 and Comparative Example 1-7, DC voltage was applied with an ITO electrode as an anode and an aluminum electrode as a cathode in the same manner as in Example 1-16. , Fluorescence peak wavelength, half value width, external quantum efficiency, and device life (LT50) were measured. The results are shown in the table below.

[Table 15]

In Examples 1-27 to 1-55 and Comparative Example 1-7, the first component satisfying E(1, S, Sh) ≥ E(2, S, Sh) ≥ E(3, S, Sh) , The second component and the third component are combined and used in the light-emitting layer, but a compound having a boron atom as a third component is used as a third component, compared to Comparative Example 1-7 using R-BD2, a compound not having a boron atom as a third component. Examples 1-27 to 1-55 used had a small half-width, high external quantum efficiency, and long device life.

Examples 1-27 to 1-38 and 1-40 to 1-55 all satisfy the relational expression of E(1, T, Sh)> E(3, T, Sh) ≥ E(2, T, Sh) Therefore, the device life was long and the external quantum efficiency was high. On the other hand, among the organic electroluminescent devices of E(1, T, Sh)>E(2, T, Sh)>E(3, T, Sh), in Example 1-39, ΔE(3, ST, Sh) is Since it was sufficiently low as 0.08 eV, the half-value width was small and the external quantum efficiency was high. On the other hand, in Comparative Example 1-7, phosphorescence emission from R-BD2, which is the third component, was not recognized, and ΔE(3, ST, Sh) was large, so the half-value width was large and the external quantum efficiency was low. All of Examples 1-27 to 1-55 have a structure represented by formula (ii). Since the skeleton of formula (i) has a dimerized multimeric skeleton and the skeleton has a symmetrical type, it is considered to exhibit good properties.

<Examples 1-56 to 1-72 and Comparative Example 1-8>

An organic electroluminescent device of Configuration B of Examples 1-56 to 1-72 and Comparative Example 1-8 was manufactured in the same manner as in Examples 1-14 except that the materials described in the following table were used. In Examples 1-56 to 1-72, various compounds represented by formula (i) were used as the third component and evaluated.

[Table 16]

For each organic light emitting device of Examples 1-56 to 1-72 and Comparative Example 1-8, DC voltage was applied with an ITO electrode as an anode and an aluminum electrode as a cathode in the same manner as in Example 1-16. , Fluorescence peak wavelength, half value width, external quantum efficiency, and device life (LT50) were measured. Measurement of Examples 1-56 to 1-66 and Comparative Examples 1-8 where E(3, T, Sh) is less than 0.3 eV and ΔE(2, ST, Sh) is greater than ΔE(3, ST, Sh) The results are shown in the table below. In addition, for the measurement results of Examples 1-67 to 1-72 where E(3, T, Sh) is 0.3 eV or more and ΔE(3, ST, Sh) is greater than ΔE(2, ST, Sh), It is shown in the table mentioned later.

[Table 17]

As a result, the first component, the second component, and the third component satisfying the relationship E(1, S, Sh) ≥ E (2, S, Sh) ≥ E (3, S, Sh) are combined to form a light emitting layer. While the device life (LT50) of Examples 1-56 to 1-72 is long, the relationship of E(1, S, Sh)≥E(2, S, Sh)≥E(3, S, Sh) is satisfied. It was confirmed that the device life (LT50) of Comparative Examples 1-8, which was not performed, was short.

The half width of Examples 1-56 to 1-72 was within the range of 22 to 30 nm, the external quantum efficiency was within the range of 12.0 to 16.8%, and the device life (LT50) was within the range of 82 to 116 hours. Although all are good characteristics, the above-described Examples 1-27 to 1-55 showed more favorable characteristics. This is, rather than using a compound having a structure represented by formula (i) as a third component, using a compound having a structure multimerized by formula (i) as in formula (ii) as a third compound, It shows that the characteristics become even more favorable.

This tendency is to classify the compound of the third component used in Examples 1-27 to 1-72 by the structure of the basic skeleton, and average the data of half value width, external quantum efficiency, and device life (LT50) for each basic skeleton. Thus, it is also clear from Fig. 8 as a graph. In FIG. 8, half-width, external quantum efficiency, and device life (LT50) are averaged for each compound having basic skeletons of B2N2O2, BN2, BN2/BNO, BN2/BON, BONf, BOnN, BN2, and BON. The graphed results are shown in order. B2N2O2, B2N4, B2O2N2, BN2, BN2/BNO, BN2/BON, BONf, BOnN, BN2, and BON representing the basic skeleton are included as part of the abbreviations of each compound of the third component referred to in this specification. Fig. 7 also shows the result of graphing the average of the Tau (Delay) and Stokes shifts of the compounds having each of these basic skeletons. 7 and 8, it can be seen that the small Tau (Delay) tends to have a long device life LT50, a narrow half-value width, and a high external quantum efficiency. The compound represented by formula (ii) has a smaller Tau (Delay) than the compound represented by formula (i), and the organic electroluminescent device using the compound represented by formula (ii) as a third component has better properties. have. Among the compounds represented by formula (ii), compounds having a basic skeleton of B2N4 are particularly preferred.

Based on the measurement results of Examples 1-27 to 1-55 in which the compound represented by formula (ii) with a small Tau (Delay) was used as the third component, the type and half width of the substituent substituted in the basic skeleton, and the external quantum The relationship between efficiency and device life (LT50) is graphed and shown in FIG. 10. 9 shows a graph of the average value of Tau (Delay) and Stokes shift for each substituent group. In FIGS. 9 and 10, a compound substituted with carbazolyl (Cz), diphenylamino (DPA), both diphenylamino and fluorine atoms (DPA&F), phenyl (Ph), and tert-butyl (tBu). It is divided and graphed. In addition, diphenylamino (DPA) and phenyl (Ph) include those substituted with alkyl. 9 and 10, the compound substituted with diphenylamino (DPA) has a small Tau (Delay) and a Stokes shift, a long device life (LT50), a narrow half-value width, and an external quantum efficiency. high. However, DPA&F in which a fluorine atom is substituted together with diphenylamino is not as long as the device life (LT50) is substituted with diphenylamino alone. As a substituent, diphenylamino (DPA) exhibits particularly excellent effects in improving device characteristics, and carbazolyl (Cz), phenyl (Ph), and tert-butyl (tBu) also exhibit favorable effects.

11 shows the types of substituents substituted in the basic skeleton and the average and half values of Stokes shift based on the measurement results of Examples 1-56 to 1-66 in which the compound represented by formula (i) was used as a third component. It is a graph of the relationship with the average value of the width. It was confirmed that the Stokes shift of the compound substituted with phenyl (Ph) was small and the half value width was narrow. In particular, the effect of the phenyl group having an alkyl substituted ortho position was excellent.

7 shows that the Stokes shift between BONf and BOnN, which are compounds represented by formula (i), is small. Since both BONf and BOnN have a somewhat large ΔE(3, ST, Sh) of more than 0.3 eV, Examples 1-67 to 1-72 using these compounds as the third component are E(1, T, Sh)>E (2, T, Sh)>E(3, T, Sh), and also ΔE(3, ST, Sh)>ΔE(2, ST, Sh). For such Examples 1-67 to 1-72, the Stokes shift of the third component and the evaluation results of the device characteristics are shown in the following table. The results in the following table show a tendency that a small Stokes shift leads to a longer device life (LT50). From this, even in the case of the relationship E(1, T, Sh)> E(2, T, Sh)> E(3, T, Sh), if a compound having a small Stokes shift is used as the third component, the device It has been shown that the properties become good.

[Table 18]

4. Composition for forming a light-emitting layer

Next, in order to explain the present invention in more detail, specific examples of the composition for forming a light emitting layer of the present invention and evaluation results thereof are shown, but the present invention is not limited to these specific examples.

<Examples 2-1 to 2-32>

The composition for light-emitting layer formation was prepared by mixing and stirring the 1st component, the 2nd component, the 3rd component, and the 4th component shown in the following table in the ratio shown in the table. In the table, Tol used as the fourth component is toluene, DHNp is decahydronaphthalene, 3PxT is 3-phenoxytoluene, c6B is cyclohexylbenzene, Anis is anisole, Xyl is xylene (mixture), 1MNp is 1- Methylnaphthalene, 8B is n-octylbenzene, DPE is diphenyl ether, and 4FAnis is 4-fluoroanisole.

[Table 19]

The following evaluation was performed about each prepared composition for light-emitting layer formation.

(1) solubility evaluation

In order to evaluate the usefulness as an ink composition for inkjet coating, the solubility was evaluated by confirming the turbidity and precipitation of each composition for forming a light emitting layer. It was set as "OK" that there was no turbidity and no precipitation, and "NG" that cloudy or precipitation occurred.

(2) Evaluation of film forming properties

Regarding the composition for forming a light emitting layer which is "OK" in the evaluation of solubility, the film-forming properties of the film obtained after spin coating film formation or inkjet printing were evaluated in the following procedure. After film formation, a film with pinholes or precipitation or non-uniformity is ``x'', a pinhole or compound with no precipitation and non-uniformity is ``○'', and there is no pinhole or compound precipitation and non-uniformity, and has high smoothness (Ra<5nm ) Is indicated by “◎”.

(Spin coating)

A glass substrate having a thickness of 0.5 mm and a size of 28 x 26 mm was irradiated with irradiation energy of 1000 mJ/cm ² (low pressure mercury lamp (254 nanometers)) to perform UV-O ₃ treatment. Next, 0.3 to 0.6 mL of the ink composition was dripped on the glass, and spin coating (slope, 5 seconds → 500 to 5000 rpm, 10 seconds → slope, 5 seconds) was performed. Further, it was dried for 10 minutes on a hot plate at 120°C.

(Inkjet)

Using an ink jet, it was ejected into a pixel of 100 ppi and dried at 100°C.

The ink jet ejection stability was also evaluated immediately after the start of ink jet ejection and after continuous operation for 24 hours, respectively. The poor discharge stability was set to "x", the good one was set to "○", and the very good one was set to "⊚".

The evaluation results are as shown in the following table. In addition, about Examples 2-27, 2-31, 2-32, and 2-33, the viscosity and the surface tension were also published.

[Table 20]

Comparative Example 2-2 in which the compound R-BD2 having no boron atom was used as the third component was poor in solubility, and the subsequent evaluation was not possible. Further, even in the case of a compound having a boron atom, the solubility of Comparative Example 2-1 using unsubstituted R-BD1 was poor due to its high molecular weight. On the other hand, Examples 2-1 to 2-33 using a compound having a boron atom, which is an unsubstituted R-BD3 having a small molecular weight or a compound having a substituent even if the molecular weight is large, have all of solubility, film forming properties, and inkjet ejection stability. It was good.

5. Organic electroluminescent device manufactured using the composition for forming a light emitting layer

Next, an organic electroluminescent device obtained by coating and forming an organic layer will be described. When forming the light-emitting layer, a composition for forming a light-emitting layer was used.

Synthesis of XLP-101

First, according to the method described in Japanese Patent Laid-Open No. 2018-61028, XLP-101, which is a polymer hole transport compound, was synthesized by the following reaction. A copolymer in which M5 or M6 is bonded next to M4 is obtained, and each unit is estimated to be 40:10:50 (molar ratio) from the input ratio. And, in the following formula, Bpin is pinacolatoboril.

PEDOT:PSS solution

A commercially available PEDOT:PSS solution (Clevios(TM) P VP AI4083, an aqueous dispersion of PEDOT:PSS, manufactured by Heraeus Holdings) was used.

Preparation of OTPD solution

OTPD (LT-N159, manufactured by Luminescence Technology Corp) and IK-2 (photo cationic polymerization initiator, manufactured by San Apro) were dissolved in toluene to prepare an OTPD solution having an OTPD concentration of 0.7% by mass and an IK-2 concentration of 0.007% by mass. did.

Preparation of XLP-101 solution

XLP-101 was dissolved in xylene at a concentration of 0.6% by mass to prepare a 0.6% by mass XLP-101 solution.

Preparation of PCz solution

PCz (polyvinylcarbazole) was dissolved in dichlorobenzene to prepare a 0.7% by mass PCz solution.

<Example 3-1>

A PEDOT:PSS solution was spin-coated on a glass substrate on which ITO was deposited to a thickness of 150 nm, followed by firing on a hot plate at 200°C for 1 hour to form a PEDOT:PSS film having a thickness of 40 nm (hole injection layer). Next, the OTPD solution was spin-coated, dried on a hot plate at 80° C. for 10 minutes, exposed to an exposure intensity of ^{100 mJ/cm 2} with an exposure machine, and fired on a hot plate at 100° C. for 1 hour to obtain a film thickness insoluble in the solution. A 30 nm OTPD film was formed (hole transport layer). Next, the composition for forming a light-emitting layer prepared in Example 2-19 was spin-coated and fired on a hot plate at 120° C. for 1 hour to form a light-emitting layer having a thickness of 20 nm.

The produced multilayer film is fixed to the substrate holder of a commercially available evaporation apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum evaporation boat containing 2CzBN and BPy-TP2, a molybdenum evaporation boat containing LiF, A tungsten vapor deposition boat containing aluminum was mounted. After reducing the pressure in the vacuum bath to 5×10 ⁻⁴ Pa, 2CzBN was heated to evaporate to a thickness of 10 nm to form an electron transport layer 1. Next, BPy-TP2 was heated and vapor-deposited to have a film thickness of 20 nm to form an electron transport layer 2. The deposition rate at the time of forming the electron transport layer was 1 nm/sec. Thereafter, LiF was heated to evaporate at a deposition rate of 0.01 to 0.1 nm/sec so that the film thickness was 1 nm. Next, aluminum was heated and vapor-deposited so as to have a film thickness of 100 nm to form a cathode. In this way, an organic electroluminescent device was obtained.

<Example 3-2>

An organic electroluminescent device was obtained in the same manner as in Example 3-1. Then, the hole transport layer was spin-coated with the XLP-101 solution and fired on a hot plate at 200° C. for 1 hour to form a film having a thickness of 30 nm.

<Example 3-3>

An organic electroluminescent device was manufactured in the same procedure as in Example 3-1, except that the composition for forming a light-emitting layer prepared in Example 2-2 was used instead of the composition for forming a light-emitting layer prepared in Example 2-19. Then, the hole transport layer was spin-coated with the XLP-101 solution and fired on a hot plate at 200° C. for 1 hour to form a film having a thickness of 30 nm.

<Example 3-4>

An organic electroluminescent device was manufactured in the same procedure as in Example 3-1, except that the composition for forming a light-emitting layer prepared in Example 2-18 was used instead of the composition for forming a light-emitting layer prepared in Example 2-19. Then, the hole transport layer was spin-coated with the XLP-101 solution and fired on a hot plate at 200° C. for 1 hour to form a film having a thickness of 30 nm.

<Comparative Example 3-1>

An organic electroluminescent device was manufactured in the same procedure as in Example 3-4, except that the composition for forming a light-emitting layer prepared in Comparative Example 2-2 was used instead of the composition for forming a light-emitting layer prepared in Example 2-18.

<Example 3-5>

An organic electroluminescent device was obtained in the same manner as in Example 3-1. Then, the hole transport layer was spin-coated with a PCz solution and fired on a hot plate at 120° C. for 1 hour to form a film having a thickness of 30 nm.

[Table 21]

It was confirmed that an organic electroluminescent device can be manufactured by using the composition for forming a light emitting layer of the present invention. R-BD3, which is a compound containing boron, has excellent solubility, light emission is observed in an organic electroluminescent device manufactured using a wet film forming method, a peak wavelength is blue, a half value width is also small, and a color tone is excellent. In addition, when comparing Example 3-2 and Example 3-4, a device using an emitting dopant having a substituent has excellent external quantum efficiency.

6. Composition containing high molecular compound

The composition for forming a light emitting layer of the present invention may contain a polymer compound or a crosslinkable compound. Further, the organic electroluminescent device of the present invention may contain a polymer compound or a crosslinkable compound.

<Example 4-1>

By the method described in International Patent Publication No. WO2019/004248, a polymer including a structure having a host as a first component and a boron atom as a third component can be synthesized.

The polymer is a polymer containing a first component and a third component in a molecule. The composition for forming a light-emitting layer of the present invention is obtained by adding the second component, a thermally activated delayed phosphor.

<Example 4-2>

By the method described in International Patent Publication No. WO2019/004248, a polymer including a structure of a host as a first component and a thermally activated delayed phosphor as a second component can be synthesized.

The polymer is a polymer comprising a first component and a second component in a molecule. The composition for forming a light-emitting layer of the present invention is obtained by adding a compound having a boron atom as a third component.

<Example 4-3>

By the method described in International Patent Publication No. WO2019/004248, a polymer including a structure having a host as a first component, a thermally activated delayed phosphor as a second component, and a boron atom as a third component can be synthesized.

<Example 4-4>

By the method described in International Patent Publication No. WO2019/004248, a polymer including a structure having a host as a first component and a boron atom as a third component can be synthesized. The composition for forming a light-emitting layer of the present invention is obtained by adding the second component, a thermally activated delayed phosphor.

<Example 4-5>

By the method described in International Patent Publication No. WO2019/004248, a polymer including a structure having a host as a first component and a boron atom as a third component can be synthesized. The composition for forming a light-emitting layer of the present invention is obtained by adding the second component, a thermally activated delayed phosphor.

Further, as the first component, the second component, or the third component added to the polymer, a single molecule that can be used as the first component, the second component, or the third component in the present invention can be employed.

100: organic light emitting device
101: substrate
102: anode
103: hole injection layer
104: hole transport layer
105: light-emitting layer
106: electron transport layer
107: electron injection layer
108: cathode

Claims (42)

An organic electroluminescent device having a light emitting layer,
The light-emitting layer,
As a first component, at least one host compound, and
As a second component, at least one thermally activated delayed phosphor,
As a third component, it contains a compound having at least one boron atom,
The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the first component is E(1, S, Sh), and the peak short wavelength side of the fluorescence spectrum of the second component The excitation singlet energy level obtained from the shoulder is E(2, S, Sh), and the excitation singlet energy level obtained from the shoulder at the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh). When doing, satisfying the following relational expression (1),
The first component may be contained as a polymer compound having a structure in which two hydrogen atoms of the host compound are removed as a repeating unit,
The second component may be contained as a polymer compound having a structure in which two hydrogen atoms of the thermally activated delayed phosphor are desorbed as a repeating unit,
The third component may be included as a polymer compound having a structure in which two hydrogen atoms of the compound having boron atoms are removed as a repeating unit, and may be included as an organic electroluminescent device:
Relation (1): E(1, S, Sh)≥E(2, S, Sh)≥E(3, S, Sh). The method of claim 1,
As the third component, comprising at least one of a compound represented by any one of the following formulas (i), (ii), and (iii), and a multimeric compound having a plurality of structures represented by the following formula (i) , Organic light emitting device:

(In the above formula (i),
Ring A, Ring B, and Ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,
Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl or alkyl,
X ¹ and X ² are each independently O, NR, >CR ₂ , S or Se, and R of NR and R of >CR ₂ are optionally substituted aryl, optionally substituted heteroaryl, optionally substituted cyclo Alkyl or alkyl, and R of NR may be bonded to at least one selected from the A ring, B ring and C ring by a linking group or a single bond, and,
At least one hydrogen in the compound or structure represented by formula (i) may be substituted with cyano, halogen or deuterium)

(In the above formula (ii),
A ring, B ring, C ring, and D ring are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,
Y is B (boron),
X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR, >CR ₂ , >S or >Se, and R of >NR and R of >CR ₂ are optionally substituted aryl , Heteroaryl which may be substituted, cycloalkyl which may be substituted, or alkyl which may be substituted, and R of >NR is at least selected from the A ring, B ring, C ring and D ring by a linking group or a single bond. May be combined with one,
R ¹ and R ² are each independently hydrogen, alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, aryl having 6 to 12 carbon atoms, heteroaryl or diarylamino having 2 to 15 carbon atoms (however, aryl is 6-12 aryl), and
At least one hydrogen in the compound represented by formula (ii) may be substituted with cyano, halogen or deuterium)

(In the above formula (iii),
Ring A, Ring B, and Ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen in these rings may be substituted,
Y ¹ is B, P, P=O, P=S, Al, Ga, As, Si-R or Ge-R, and R of Si-R and Ge-R is aryl or alkyl,
X ¹ , X ² and X ³ are each independently O, NR, >CR ₂ , S or Se, and R of NR and R of >CR ₂ are optionally substituted aryl, optionally substituted heteroaryl, substituted May be cycloalkyl or alkyl, and R of NR may be bonded to at least one selected from the A ring, B ring and C ring by a linking group or a single bond, and,
At least one hydrogen in the compound or structure represented by formula (iii) may be substituted with cyano, halogen or deuterium). The method according to claim 1 or 2,
As the third component, an organic light emitting device comprising at least one compound represented by any one of the following formulas (1), (2), (3), and (4):

(In the above formula (1),
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diaryl Boryl, alkyl, cycloalkyl, alkoxy or aryloxy, which may also be substituted with aryl, heteroaryl or alkyl, and adjacent groups among ^{R 1} to ^{R 3} , R ⁴ to ^{R 7} and R ⁸ to ^{R 11} They may be bonded to each other to form an aryl ring or a heteroaryl ring together with the a ring, b ring, or c ring, and the formed ring is at least one selected from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy. May be substituted, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,
X ¹ and X ² are each independently >O, >NR or >CR ₂ , wherein R of >NR and R of >CR ₂ are aryl, heteroaryl, cycloalkyl or alkyl, and these are aryl, heteroaryl, cyclo It may be substituted with at least one selected from alkyl and alkyl,
However, X ¹ and X ² are not _{>CR 2} at the same time,
And,
At least one hydrogen in the compound and structure represented by formula (1) may be substituted with cyano, halogen or deuterium)

(In the above formula (2),
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently hydrogen, aryl, Heteroaryl, diarylamino, diarylboryl, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio or alkyl substituted silyl, wherein At least one hydrogen may be substituted with aryl, heteroaryl or alkyl, ^{and adjacent groups of R 5} to ^{R 7} and R ¹⁰ to ^{R 12} are bonded to each other to form an aryl ring or heteroaryl ring together with the b ring or d ring. May be formed, and at least one hydrogen in the formed ring is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, aryl May be substituted with thio, heteroarylthio or alkyl substituted silyl, at least one hydrogen in these may be substituted with aryl, heteroaryl or alkyl,
Y is B (boron),
X ¹ , X ² , X ³ and X ⁴ are each independently >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl of 6 to 12 carbon atoms, 2 to 15 carbon atoms Of heteroaryl, C3-C12 cycloalkyl, or C1-C6 alkyl, and R of >NR and R of >CR ₂ are -O-, -S-, -C(-R) _2- Or may be bonded to at least one selected from the a ring, b ring, c ring and d ring by a single bond, and _{R of -C(-R) 2} -is hydrogen or alkyl having 1 to 6 carbon atoms,
However, X ¹ , X ² , X ³ and X ⁴ are not _{>CR 2} at the same time,
And,
At least one hydrogen in the compound represented by formula (2) may be substituted with cyano, halogen or deuterium)

(In the above formula (3),
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁹ , R ¹⁰ and R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diaryl boryl, alkyl, cycloalkyl , Alkoxy or aryloxy, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl, and adjacent groups among ^{R 1} to ^{R 3} , R ⁴ to ^{R 6} and R ⁹ to ^{R 11} May be bonded to form an aryl ring or heteroaryl ring together with the a ring, b ring or c ring, and the formed ring is substituted with at least one selected from aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy May be, these may also be substituted with at least one selected from aryl, heteroaryl, cycloalkyl and alkyl,
X ¹ , X ² and X ³ are each independently >O, >NR, or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl, cycloalkyl or alkyl, and these are aryl, It may be substituted with at least one selected from heteroaryl and alkyl,
However, X ¹ , X ² and X ³ are not _{>CR 2} at the same time,
And,
At least one hydrogen in the compound and structure represented by formula (3) may be substituted with cyano, halogen or deuterium)

(In the above formula (4),
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are each independently hydrogen, aryl, Heteroaryl, diarylamino, diarylboryl, alkyl, cycloalkyl, alkoxy or aryloxy, and these may also be substituted with at least one selected from aryl, heteroaryl and alkyl, and R ¹ to ^{R 3} , R ^{Adjacent groups of 4} to ^{R 7} , R ⁸ to ^{R 10} and R ¹¹ to ^{R 14 may be} bonded to each other to form an aryl ring or heteroaryl ring together with the a ring, b ring, c ring or d ring, and the formed ring is aryl , Heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy and aryloxy may be substituted with at least one, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,
X is >O, >NR or >CR ₂ , and R of >NR and R of >CR ₂ are aryl, heteroaryl or alkyl, and these may be substituted with at least one selected from aryl, heteroaryl and alkyl ,
L is a single bond, >CR ₂ , >O, >S or >NR, and _{R in >CR 2} and >NR are each independently hydrogen, aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryl Oxy, these may also be substituted with at least one selected from aryl, heteroaryl and alkyl,
However, X and L are not _{>CR 2 at the same time,}
And,
At least one hydrogen in the compound and structure represented by formula (4) may be substituted with cyano, halogen or deuterium). The method of claim 3,
As said third component, it contains at least one compound represented by any one of said formula (1), formula (2), and formula (4),
In the above formula (1), X ¹ and X ² are each independently >O or >NR,
In the above formula (2), X ¹ , X ² , X ³ and X ⁴ are each independently >O or >NR,
In the formula (4), X is >O and >NR, and L is a single bond. The method according to claim 3 or 4,
As the third component, at least one compound represented by any one of formulas (1), (2), formula (3), and formula (4) is included, and the valency constituting the ring present in the compound, Selected from aryl, heteroaryl, diarylamino, diarylboryl, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio and alkyl substituted silyl An organic electroluminescent device that is substituted with at least one. The method of claim 5,
As the third component, at least one compound represented by the formula (2) is included, and the valency constituting the ring present in the compound is aryl, heteroaryl, diarylamino, diarylboryl, diheteroarylamino , Arylheteroarylamino, alkyl, cycloalkyl, alkoxy, aryloxy, heteroaryloxy, arylthio, heteroarylthio and alkyl substituted silyl, which are also substituted with at least one selected from aryl, heteroaryl, cycloalkyl and alkyl An organic electroluminescent device which may be substituted with at least one selected from. The method according to any one of claims 1 to 6,
An organic electroluminescent device, wherein the third component includes a partial structure represented by the following formula:
However, the hydrogens in the partial structure may each independently be substituted with aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy or aryloxy, and these may also be selected from aryl, heteroaryl, cycloalkyl and alkyl. It may be substituted with at least one of them.

. The method according to any one of claims 3 to 6,
An organic electroluminescent device, wherein the compound represented by any one of formulas (1) to (4) has any of the following partial structures:

(In the partial structural formula,
Me represents methyl, tBu represents tert-butyl, the broken line represents the bonding position,
However, hydrogen in the partial structural formula,
Each independently may be substituted with aryl, heteroaryl, diarylamino, alkyl, alkoxy or aryloxy, and hydrogen in the aryl may also be substituted with aryl, heteroaryl or alkyl, and hydrogen in the heteroaryl May also be substituted with aryl, heteroaryl or alkyl, and hydrogen in the diarylamino may also be substituted with aryl, heteroaryl or alkyl). The method according to any one of claims 3 to 8,
The compound represented by any one of the above formulas (1) to (4) is sp ^{3 carbon, sp 2} carbon atom bonded to the m position or p position with respect to the boron atom, or nitrogen substituted with the p position with respect to boron An organic electroluminescent device having any one of the atoms. The method of claim 3,
An organic electroluminescent device, wherein the compound represented by formula (2) is the following compound:

. The method of claim 4,
An organic electroluminescent device, wherein the compound represented by formula (2) is the following compound:

. The method according to any one of claims 1 to 11,
The organic electroluminescent device, wherein the first component is a compound having at least one selected from carbazole and furan as a partial structure. The method according to any one of claims 1 to 12,
The organic electroluminescent device, wherein the first component contains at least one compound represented by any one of the following formulas (H1), (H2), and (H3):

(In the above formulas (H1), (H2) and (H3), L ¹ is an arylene having 6 to 24 carbon atoms, a heteroarylene, a heteroarylene arylene, or an arylene heteroarylene arylene,
At least one hydrogen in the compound represented by each of the above formulas may be substituted with alkyl, cyano, halogen or deuterium having 1 to 6 carbon atoms). The method according to any one of claims 1 to 13,
The second component, as a partial structure, carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, An organic electroluminescent device having at least one selected from oxadiazole, thiadiazole, and benzophenone. The method according to any one of claims 1 to 14,
An organic electroluminescent device, wherein the second component contains at least one compound represented by any one of the following formulas (AD1), (AD2), and (AD3):

(In the above formula (AD1), formula (AD2) and formula (AD3),
M is each independently a single bond, -O-, >N-Ar or >CAr ₂ ,
J is each independently an arylene having 6 to 18 carbon atoms, and the arylene may be substituted with at least one selected from phenyl, alkyl having 1 to 6 carbon atoms, and cycloalkyl having 3 to 12 carbon atoms,
Each Q is independently =C(-H)- or =N-,
Ar is each independently hydrogen, aryl having 6 to 18 carbon atoms, heteroaryl having 6 to 18 carbon atoms, alkyl having 1 to 6 carbon atoms, or cycloalkyl having 3 to 12 carbon atoms, and at least one of the aryl and heteroarylene Hydrogen may be substituted with phenyl, C1-C6 alkyl or C3-C12 cycloalkyl,
m is 1 or 2,
n is an integer of 2 to (6-m),
At least one hydrogen in the compound represented by each of the above formulas may be substituted with halogen or deuterium). The method according to any one of claims 1 to 14,
An organic electroluminescent device, wherein the second component contains at least one compound represented by the following formula (DAD1):
(D ¹ -L ¹ )nA ¹ (DAD1)
(In the formula (DAD1), D ¹ is a donor group, L ¹ is a single bond or a conjugated linking group, A ¹ is an acceptor group, n is 2 or more, and A ¹ is less than or equal to the maximum number that can be substituted. Integer). The method of claim 16,
An organic electroluminescent device, wherein the second component contains at least one compound represented by the following formula (DAD2):
D ² -L ² -A ² -L ³ -D ³ (DAD2)
(In the formula (DAD2), D ² and D ³ are each independently a donor group, L ² and L ³ are each independently a single bond or a conjugated linking group, and A ² is an acceptor group). The method of claim 15,
In the above formulas (AD1), (AD2) and (AD3),
M is each independently a single bond, -O- or >N-Ar,
J is each independently phenylene, the phenylene may be substituted with alkyl having 1 to 4 carbon atoms,
Each Q is independently =N-,
Ar is each independently hydrogen or phenyl, and the phenyl may be substituted with phenyl or alkyl having 1 to 4 carbon atoms,
m is 1 or 2,
n is an integer of 4 to (6-m),
Organic electroluminescent device. The method according to any one of claims 1 to 18,
The organic electroluminescent device, wherein the crossover speed between inverse terms of the second component is 10 ⁵ s ^{-1 or more.} The method according to any one of claims 1 to 19,
An organic electroluminescent device having a delayed fluorescence lifetime of the third component of 0.05 μsec to 40 μsec. The method according to any one of claims 1 to 19,
An organic electroluminescent device having a delayed fluorescence lifetime of the third component of 0.05 μsec to 20 μsec. The method according to any one of claims 1 to 21,
An organic electroluminescent device wherein a Stokes shift calculated from a difference between a peak top of a fluorescence spectrum of the third component and a peak top of an absorption spectrum of the third component is 14 nm or less. The method according to any one of claims 1 to 21,
An organic electroluminescent device wherein a Stokes shift calculated from a difference between a peak top of a fluorescence spectrum of the third component and a peak top of an absorption spectrum of the third component is 10 nm or less. The method according to any one of claims 1 to 23,
The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component The energy level is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the phosphorescence spectrum of the third component When the excitation triplet energy level obtained from the shoulder on the peak short wavelength side of is E(3, T, Sh), the singlet triplet energy difference (ΔE(2, ST, Sh) and ΔE(3 , ST, Sh)) is in the following relationship, an organic light-emitting device:
ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)≤0.50eV
ΔE(3, ST, Sh)=E(3, S, Sh)-E(3, T, Sh)≤0.20eV. The method according to any one of claims 1 to 24,
The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component The energy level is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the phosphorescence spectrum of the third component When the excitation triplet energy level obtained from the shoulder on the peak short wavelength side of is E(3, T, Sh), the singlet triplet energy difference (ΔE(2, ST, Sh) and ΔE(3 , ST, Sh)) in the following relationship, an organic light-emitting device:
ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)
ΔE(3, ST, Sh)=E(3, S, Sh)-E(3, T, Sh)
ΔE(2, ST, Sh)≥(3, ST, Sh). The method according to any one of claims 1 to 25,
An organic electroluminescent device having a singlet triplet energy difference (ΔE(2, ST, Sh)) of the second component in the following relationship:
ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh)≤0.30eV. The method according to any one of claims 1 to 26,
An organic electroluminescent device having a singlet triplet energy difference (ΔE(2, ST, Sh)) of the second component in the following relationship:
ΔE(2, ST, Sh)=E(2, S, Sh)-E(2, T, Sh) ≤ 0.15 eV. The method according to any one of claims 1 to 27,
The excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the second component is E(2, S, Sh), and the excitation triplet obtained from the shoulder on the peak short wavelength side of the phosphorescence spectrum of the second component The energy level is E(2, T, Sh), the excitation singlet energy level obtained from the shoulder on the peak short wavelength side of the fluorescence spectrum of the third component is E(3, S, Sh), and the phosphorescence spectrum of the third component When the excitation triplet energy level obtained from the shoulder on the peak short wavelength side of is E(3, T, Sh), they are in the following relationship:
E(2, S, Sh)≥E(3, S, Sh)
E(2, T, Sh) ≤ E(3, T, Sh). The method according to any one of claims 1 to 28,
An organic electroluminescent device wherein a Stokes shift calculated from a difference between a peak top of a fluorescence spectrum of the third component and a peak top of an absorption spectrum of the third component is 10 nm or less. The method according to any one of claims 1 to 29,
The organic electroluminescent device, wherein the third component is contained as a polymer compound having a group from which two hydrogen atoms of the compound having boron atoms are removed as a repeating unit. The method of claim 30,
An organic electroluminescent device, wherein a polymer compound having a group obtained by desorbing two hydrogen atoms of the boron atom as a repeating unit is a repeating unit obtained by desorbing two hydrogen atoms of the host compound. The method of claim 30 or 31,
An organic electroluminescent device, wherein a polymer compound having a group obtained by desorbing two hydrogen atoms of the boron atom as a repeating unit is a repeating unit obtained by desorbing two hydrogen atoms of the delayed phosphor. A display device comprising the organic electroluminescent device according to any one of claims 1 to 32. A lighting device comprising the organic electroluminescent device according to any one of claims 1 to 32. A composition for forming a light-emitting layer for coating and forming a light-emitting layer of an organic light-emitting device,
A composition for forming a light-emitting layer comprising at least one organic solvent as a fourth component in addition to the first component, the second component, and the third component according to any one of claims 1 to 32 (however, the above The third component is not the following compound):

. The method of claim 35,
The composition for forming a light-emitting layer, wherein the boiling point of at least one organic solvent in the fourth component is 130°C to 350°C. The method of claim 35 or 36,
The fourth component includes a good solvent (GS) and a poor solvent (PS) for at least one of the first component, the second component, and the third component of the compound, and the good solvent (GS) The boiling point (BP _{GS ) is lower than the boiling point (BP PS} ) of the poor solvent (PS), a composition for forming a light emitting layer. The method according to any one of claims 35 to 37,
The first component is 0.0998% by mass to 4.0% by mass based on the total mass of the composition for forming a light emitting layer,
The second component is 0.0001% by mass to 2.0% by mass based on the total mass of the composition for forming a light emitting layer,
The third component is 0.0001% by mass to 2.0% by mass based on the total mass of the composition for forming a light emitting layer,
The fourth component is 90.0% by mass to 99.9% by mass based on the total mass of the composition for forming a light emitting layer,
A composition for forming a light emitting layer. An organic electroluminescent device having a light emitting layer formed using the composition for forming a light emitting layer according to any one of claims 35 to 38. A compound wherein at least one hydrogen of the compound represented by formula (ii) according to claim 2 is substituted with the following partial structure (B), chlorine, bromine, or iodine:

(In the partial structure (B), R ⁴⁰ and R ⁴¹ are alkyl which may be bonded with a total of 2 to 10 carbon atoms, and the broken line is a bonding site with other structures). A repeating unit including a structure in which two hydrogen atoms are removed from a compound having a boron atom, a repeating unit including a structure in which two hydrogen atoms are removed from a thermally activated delayed phosphor, and two hydrogen atoms are removed from a host compound A polymer compound comprising at least two repeating units selected from repeating units containing one structure. At least one type of repeating unit including a structure obtained by desorbing two hydrogen atoms from a compound having a boron atom, at least one type of repeating unit including a structure obtained by removing two hydrogen atoms from a thermally activated delayed phosphor, and a host A polymer compound containing at least one of a repeating unit containing a structure obtained by removing two hydrogen atoms from a compound.

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