JP2009202545A - Ink sheet for heat-sensitive transfer recording, and thermal transfer recording method - Google Patents

Abstract

【選択図】なしAn ink sheet for thermal transfer that provides a full-color image excellent in light fastness is provided.
An ink sheet for thermal transfer recording, wherein the magenta dye contained in the dye-donating layer is a mixture of at least one anthraquinone dye represented by the following general formulas (1) to (4) and an azo dye. .

[Selection figure] None

Description

  The present invention relates to a thermal and thermal transfer recording ink sheet, and more particularly to a thermal and thermal transfer ink sheet capable of forming a recorded image excellent in color density, sharpness and various fastnesses, particularly light fastness.

  In recent years, a material for forming a color image has been mainly used as an image recording material, and specifically, an ink jet recording material, a thermal transfer recording material, an electrophotographic recording material, a transfer halogen. Silver halide photosensitive materials, printing inks, recording pens and the like are actively used. Conventionally, various thermal transfer recordings are known. In thermal transfer recording, a thermal transfer material in which a heat-meltable ink layer is formed on a support (base film) is heated by a thermal head, the ink is melted and recorded on an image receiving material, and on the support. There is a method in which a heat-sensitive transfer material having a dye-donating layer containing a heat-transferable dye is heated by a thermal head to thermally transfer the dye onto the image receiving material. The latter thermal transfer system can change the transfer amount of the dye by changing the energy applied to the thermal head, so that gradation recording is easy and is particularly advantageous for high-color full-color recording. However, the heat transfer dyes used in this method have various limitations, and very few satisfy all the required performance.

  However, the reproduction of a full-color image in the above thermal transfer recording is subtractive color mixing. In such subtractive color mixing, in general, the saturation of magenta greatly affects the color reproduction range. A specific magenta azo dye used in recent years has excellent spectral characteristics such as a high molar extinction coefficient, a sharp absorption curve, and low side absorption. An image formed using this magenta dye is extremely clear and has a high color density. However, there is a problem that the fastness of the formed image, particularly the light fastness, is slightly insufficient.

  Accordingly, the object of the present invention is not only high in magenta color saturation but also color density, sharpness and various fastnesses, particularly light fastness, in thermal transfer recording, particularly thermal transfer recording using a sublimation dye. It is an object to provide a thermal transfer ink sheet and a thermal transfer recording method that give excellent full color images.

  As a result of intensive studies, the present inventors have found that the above problems can be achieved by the following configuration.

(1) An anthraquinone comprising a base sheet and a dye-donating layer formed on one surface of the base sheet, wherein the magenta dye contained in the dye-donating layer is represented by the following general formulas (1) to (4) An ink sheet for thermal transfer recording, wherein the ink sheet is a mixture of at least one type of dye and at least one kind of azo dye represented by the following general formula (5).

Wherein X and Y each independently represent —S—, —O— or —SO ₂ —, and R ¹ , R ² and R ³ each independently represents a substituted or unsubstituted alkyl group, substituted or unsubstituted A cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group, and R ⁴ represents a halogen atom or a cyano group.)

(In the general formula (5), R ⁵ , R ⁶ , R ⁷ and R ⁹ each independently represents a monovalent substituent, R ⁸ represents a hydrogen atom or a monovalent substituent, and n represents 0 to 4) When n is 2 or more, a plurality of R ⁷ may be the same or different from each other, and R ⁵ and R ⁶ may be bonded to each other to form a ring structure. )
(2) A thermal transfer recording method comprising forming an image on an image receiving material having an ink receiving layer containing a polymer on a support, using the thermal transfer recording ink sheet described in (1).

  Thermal transfer that gives a full-color image with excellent color density, sharpness and various fastnesses, especially light fastness, despite the high saturation of the magenta color, by using a mixture of specific dyes according to the present invention A recording ink sheet and a thermal transfer recording method can be provided.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

<Ink sheet for thermal transfer recording>
The ink sheet for thermal transfer recording generally has a structure in which a dye-donating layer is formed on a support, and the dye-donating layer contains a dye.
The ink sheet for thermal transfer recording of the present invention includes at least one of the anthraquinone dyes represented by the general formulas (1) to (4) in the dye donating layer and the azo resin represented by the general formula (5). It contains at least one dye. By using a dye mixture composed of a specific anthraquinone dye and a specific azo dye, the thermal transfer recording ink sheet of the present invention unexpectedly has a magenta color saturation, color density, and sharpness. It has become possible to raise all the elements of lightness and various fastnesses (especially light fastness) to an excellent level.

  In the thermal transfer recording ink sheet of the present invention, an ink liquid is prepared by dissolving a dye together with a binder resin in a solvent, or by dispersing fine particles in a solvent, and applying the ink liquid onto a support. It can be produced by appropriately drying to form a dye-donating layer.

[Dye-donating layer]
(Dye)
The anthraquinone dyes used in the present invention are dyes represented by the general formulas (1) to (4), and these dyes can be used alone or in a mixture. In particular, a more appropriate magenta color can be obtained by using a mixture of two or more anthraquinone dyes. Examples of the azo dye used in the present invention include dyes represented by the general formula (5), and these dyes can be used alone or as a mixture.

  The anthraquinone dye and azo dye used in the present invention are described in detail below.

(Anthraquinone dyes of general formulas (1) to (4))
Anthraquinone dyes represented by the general formulas (1) to (4) are dyes that have been conventionally used as disperse dyes. These anthraquinone pigments are known pigments such as disperse dyes, and can be obtained from the market and used in the present invention.

In the general formulas (1) and (3), X and Y each independently represent one linking group selected from —S—, —O— or —SO ₂ —.
X is preferably —S— or —O—, and more preferably —O—.
Y is preferably —S— or —O—, and more preferably —O—.

In the general formulas (1) to (3), R ¹ , R ² and R ³ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted Represents an unsubstituted allyl group.

Examples of the alkyl group for R ¹ , R ^2, and R ³ include a linear or branched alkyl group, which may have a substituent. 1-30 are preferable, as for carbon number of an alkyl group, C1-C20 is more preferable, and C1-C10 is especially preferable. Preferred examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, benzyl and 2-ethylhexyl. The group can be mentioned.
The cycloalkyl group in R ^1, R ² and R ^3, preferably a cycloalkyl group having 3 to 30 carbon atoms, more preferably 3 to 7 carbon atoms, 5-6 carbon atoms are particularly preferred. Preferred examples of the cycloalkyl group include a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group.
As the aryl group in R ¹ , R ² and R ³ , a substituted or unsubstituted aryl group having 6 to 30 carbon atoms is preferable, and phenyl group, p-tolyl group, naphthyl group, m-chlorophenyl group, o-hexadeca. A noylaminophenyl group is more preferred, and a substituted or unsubstituted phenyl group is particularly preferred.

R ¹ and R ² are preferably a substituted or unsubstituted aryl group, an alkyl group or an acyl group, more preferably a substituted or unsubstituted aryl group or an alkyl group, and particularly preferably a substituted or unsubstituted phenyl group. It is.
R ³ is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group or an aryl group, more preferably a substituted or unsubstituted branched alkyl group, a substituted or unsubstituted cycloalkyl group, phenyl Particularly preferably a substituted or unsubstituted branched alkyl group or a substituted or unsubstituted cycloalkyl group.

Hereinafter, preferred substituents when R ¹ , R ² and R ³ are substituted will be described in more detail.
The substituents in R ¹ , R ² , and R ³ are not particularly limited, but representative examples include halogen atoms, aliphatic groups [saturated aliphatic groups (alkyl groups, cycloalkyl groups, bicycloalkyl groups, bridged cyclic saturations). A cyclic saturated aliphatic group including a hydrocarbon group or a spiro-saturated hydrocarbon group), an unsaturated aliphatic group (a chain unsaturated fatty acid having a double bond or a triple bond, such as an alkenyl group or an alkenyl group) Group or a cycloalkenyl group, a bicycloalkenyl group, a cyclic unsaturated aliphatic group including a bridged cyclic unsaturated hydrocarbon group or a spiro unsaturated hydrocarbon group)], an aryl group (preferably having a substituent) A phenyl group), a heterocyclic group (preferably, a ring-constituting atom is a 5- to 8-membered ring containing an oxygen atom, a sulfur atom or a nitrogen atom, condensed with an alicyclic ring, an aromatic ring or a heterocyclic ring. ), Cyano group, aliphatic oxy group (typically alkoxy group), aryloxy group, acyloxy group, carbamoyloxy group, aliphatic oxycarbonyloxy group (typically alkoxycarbonyloxy group), aryloxycarbonyloxy group Amino groups [including aliphatic amino groups (typically alkylamino groups), anilino groups and heterocyclic amino groups], acylamino groups, aminocarbonylamino groups, aliphatic oxycarbonylamino groups (typically alkoxycarbonylamino groups), Aryloxycarbonylamino group, sulfamoylamino group, aliphatic (typically alkyl) or arylsulfonylamino group, aliphatic thio group (typically alkylthio group), arylthio group, sulfamoyl group, aliphatic (typically alkyl) ) Or arylsulfinyl group, aliphatic (typically alkyl) or arylsulfonyl group, acyl group, aryloxycarbonyl group, aliphatic oxycarbonyl group (typically alkoxycarbonyl group), carbamoyl group, aryl or heterocyclic azo group, imide Groups, aliphatic oxysulfonyl groups (typically alkoxysulfonyl groups), aryloxysulfonyl groups, hydroxyl groups, nitro groups, carboxyl groups, and sulfo groups, and each group may further have a substituent. Good.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, a chlorine atom and a bromine atom are preferable, and a chlorine atom is particularly preferable.

  The aliphatic group is a linear, branched or cyclic aliphatic group. As described above, the saturated aliphatic group includes an alkyl group, a cycloalkyl group, and a bicycloalkyl group, and has a substituent. May be. These carbon numbers are preferably 1-30. Examples include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, benzyl and 2-ethylhexyl. Can do. Here, the cycloalkyl group includes a substituted or unsubstituted cycloalkyl group. The substituted or unsubstituted cycloalkyl group is preferably a cycloalkyl group having 3 to 30 carbon atoms. Examples include a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group. Examples of the bicycloalkyl group include a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. Examples include a bicyclo [1.2.2] heptan-2-yl group and a bicyclo [2.2.2] octan-3-yl group. Further, it includes a tricyclo structure having many ring structures.

  The unsaturated aliphatic group is a linear, branched or cyclic unsaturated aliphatic group, and includes an alkenyl group, a cycloalkenyl group, a bicycloalkenyl group, and an alkynyl group. The alkenyl group represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. As the alkenyl group, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms is preferable. Examples include vinyl group, allyl group, prenyl group, geranyl group, and oleyl group. The cycloalkenyl group is preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. Examples include a 2-cyclopenten-1-yl group and a 2-cyclohexen-1-yl group. The bicycloalkenyl group includes a substituted or unsubstituted bicycloalkenyl group. The bicycloalkenyl group is preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. Examples include a bicyclo [2.2.1] hept-2-en-1-yl group and a bicyclo [2.2.2] oct-2-en-4-yl group. The alkynyl group is preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, and examples thereof include an ethynyl group and a propargyl group.

  As the aryl group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms is preferable, and examples thereof include a phenyl group, a p-tolyl group, a naphthyl group, an m-chlorophenyl group, and an o-hexadecanoylaminophenyl group. The phenyl group which may have a substituent is preferable.

  The heterocyclic group is a monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and these may be further condensed. These heterocyclic groups are preferably 5- or 6-membered heterocyclic groups, and the hetero atoms of the ring structure are preferably oxygen atoms, sulfur atoms and nitrogen atoms. More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. The heterocyclic ring in the heterocyclic group includes pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinazoline ring, cinnoline ring, phthalazine ring, quinoxaline ring, pyrrole ring, indole ring, furan ring Benzofuran ring, thiophene ring, benzothiophene ring, pyrazole ring, imidazole ring, benzimidazole ring, triazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, isothiazole ring, benzisothiazole ring, thiadiazole ring, Examples include isoxazole ring, benzisoxazole ring, pyrrolidine ring, piperidine ring, piperazine ring, imidazolidine ring and thiazoline ring.

  The aliphatic oxy group (typically an alkoxy group) includes a substituted or unsubstituted aliphatic oxy group (typically an alkoxy group), and preferably has 1 to 30 carbon atoms. Examples thereof include a methoxy group, an ethoxy group, an isopropoxy group, an n-octyloxy group, a methoxyethoxy group, a hydroxyethoxy group, and a 3-carboxypropoxy group.

  As the aryloxy group, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms is preferable. Examples of the aryloxy group include phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group and the like. Preferably, it is a phenyloxy group that may have a substituent.

  As the acyloxy group, a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, and a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms are preferable. Examples of the acyloxy group include formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group and the like.

  The carbamoyloxy group is preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms. Examples of carbamoyloxy groups include N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octyl A carbamoyloxy group can be exemplified.

  The aliphatic oxycarbonyloxy group (typically an alkoxycarbonyloxy group) preferably has 2 to 30 carbon atoms and may have a substituent. Examples thereof include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a tert-butoxycarbonyloxy group, and an n-octylcarbonyloxy group.

  As the aryloxycarbonyloxy group, a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms is preferable. Examples of the aryloxycarbonyloxy group include a phenoxycarbonyloxy group, a p-methoxyphenoxycarbonyloxy group, and a pn-hexadecyloxyphenoxycarbonyloxy group. Preferable is a phenoxycarbonyloxy group which may have a substituent.

  The amino group includes an amino group, an aliphatic amino group (typically an alkylamino group), an arylamino group, and a heterocyclic amino group. The amino group is preferably a substituted or unsubstituted aliphatic amino group having 1 to 30 carbon atoms (typically an alkylamino group) or a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms. Examples of amino groups include, for example, amino group, methylamino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group, hydroxyethylamino group, carboxyethylamino group, sulfoethylamino group, 3,5-Dicarboxyanilino group, 4-quinolylamino group and the like can be mentioned.

  As the acylamino group, a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, and a substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms are preferable. Examples of the acylamino group include formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, 3,4,5-tri-n-octyloxyphenylcarbonylamino group, and the like.

  As the aminocarbonylamino group, a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms is preferable. Examples of the aminocarbonylamino group include carbamoylamino group, N, N-dimethylaminocarbonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group and the like. The term “amino” in this group has the same meaning as “amino” in the aforementioned amino group.

The aliphatic oxycarbonylamino group (typically an alkoxycarbonylamino group) preferably has 2 to 30 carbon atoms and may have a substituent. Examples thereof include a methoxycarbonylamino group, an ethoxycarbonylamino group, a tert-butoxycarbonylamino group, an n-octadecyloxycarbonylamino group, and an N-methyl-methoxycarbonylamino group.
The aryloxycarbonylamino group is preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms. Examples of the aryloxycarbonylamino group include phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group, and the like. The phenyloxycarbonylamino group which may have a substituent is preferable.

  The sulfamoylamino group is preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms. Examples of the sulfamoylamino group include a sulfamoylamino group, an N, N-dimethylaminosulfonylamino group, and an Nn-octylaminosulfonylamino group.

  The aliphatic (typically alkyl) or arylsulfonylamino group is a substituted or unsubstituted aliphatic sulfonylamino group having 1 to 30 carbon atoms (typically an alkylsulfonylamino group), substituted or unsubstituted having 6 to 30 carbon atoms. Of the arylsulfonylamino group (preferably a phenylsulfonylamino group which may have a substituent) is preferable. Examples thereof include a methylsulfonylamino group, a butylsulfonylamino group, a phenylsulfonylamino group, a 2,3,5-trichlorophenylsulfonylamino group, and a p-methylphenylsulfonylamino group.

  The aliphatic thio group (typically an alkylthio group) is preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an n-hexadecylthio group.

  As the arylthio group, a substituted or unsubstituted arylthio group having 1 to 30 carbon atoms is preferable. Examples of the arylthio group include a phenylthio group, a 1-naphthylthio group, and a 2-naphthylthio group.

  The sulfamoyl group is preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms. Examples of the sulfamoyl group include N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfa group. A moyl group, an N- (N′-phenylcarbamoyl) sulfamoyl) group, and the like.

  Examples of the aliphatic (typically alkyl) or arylsulfinyl group include substituted or unsubstituted aliphatic sulfinyl groups having 1 to 30 carbon atoms (typically alkylsulfinyl groups), 6 to 30 substituted or unsubstituted arylsulfinyl groups ( A phenylsulfinyl group which may have a substituent is preferable. Examples thereof include a methylsulfinyl group, an ethylsulfinyl group, a phenylsulfinyl group, and a p-methylphenylsulfinyl group.

  Examples of the aliphatic (typically alkyl) or arylsulfonyl group include a substituted or unsubstituted aliphatic sulfonyl group having 1 to 30 carbon atoms (typically an alkylsulfonyl group), a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms (typically an alkylsulfonyl group) A phenylsulfonyl group which may have a substituent is preferable. For example, methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p-toluenesulfonyl group and the like can be mentioned.

  Examples of the acyl group include a formyl group, a substituted or unsubstituted aliphatic carbonyl group having 2 to 30 carbon atoms (typically an alkylcarbonyl group), and a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms (preferably a substituent). And a heterocyclic carbonyl group bonded to the carbonyl group at a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms. Examples thereof include acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl group and the like.

  As the aryloxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms is preferable. Examples of the aryloxycarbonyl group include phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, p-tert-butylphenoxycarbonyl group and the like. A phenyloxycarbonyl group which may have a substituent is preferable.

  The aliphatic oxycarbonyl group (typically an alkoxycarbonyl group) preferably has 2 to 30 carbon atoms and may have a substituent. Examples thereof include methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, n-octadecyloxycarbonyl group and the like.

  As the carbamoyl group, a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms is preferable. Examples of the carbamoyl group include carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl group and the like.

  Examples of the aryl or heterocyclic azo group include phenylazo, 4-methoxyphenylazo, 4-pivaloylaminophenylazo, 2-hydroxy-4-propanoylphenylazo group, and the like.

  Examples of the imide group include an N-succinimide group and an N-phthalimide group.

  The aliphatic oxysulfonyl group (typically an alkoxysulfonyl group) preferably has 1 to 30 carbon atoms and may have a substituent. For example, a methoxysulfonyl group, an ethoxysulfonyl group, an n-butoxysulfonyl group, and the like can be given.

  The aryloxysulfonyl group preferably has 6 to 10 carbon atoms and may have a substituent. For example, a phenoxysulfonyl group, 1 naphthyloxysulfonyl group, etc. can be mentioned.

In addition to these, there are a hydroxyl group, a cyano group, a nitro group, a sulfo group, and a carboxyl group.
Each of these groups may further have a substituent, and examples of such a substituent include the above-described substituents.

In the general formula (4), R ⁴ represents a halogen atom or a cyano group.
R ⁴ is preferably a chlorine atom or a cyano group, and more preferably a chlorine atom.

(Azo dye represented by the general formula (5))
The azo dye represented by the general formula (5) (pyrazolylazoaniline dye) is a dye having a sulfonyl group introduced as a substituent at the 1-position of pyrazole. The azo dye having such a characteristic structure is only an example described in US Pat. No. 3,515,715 as a synthetic intermediate, and a coloring composition relating to the azo dye having this characteristic structure It has never been known that it can be suitably applied to thermal transfer recording ink sheets, thermal transfer recording methods, color toners, inkjet inks, color filters, and the like.
This azo dye can be synthesized by the method described in the aforementioned US Pat. No. 3,515,715.

In the general formula (5), R ⁵ and R ⁶ each independently represents a monovalent substituent.
R ⁵ and R ⁶ are not particularly limited, but R ⁵ and R ⁶ are typically bonded to each other to form an aliphatic group (for example, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group). Group), aryl group, heterocyclic group, acyl group, aryloxycarbonyl group, aliphatic oxycarbonyl group (for example, alkoxycarbonyl group), carbamoyl group, and each group further has a substituent. Also good. The preferred range of each group is the same as the range given as an example of the substituent in R ¹ , R ² and R ³ . In addition, examples of the substituent for R ⁵ and R ⁶ include the substituents mentioned as the substituents for R ¹ , R ² , and R ³ .
R ⁵ and R ⁶ may combine with each other to form a ring structure. The ring structure is preferably a 5- to 7-membered ring structure, and more preferably a 5- to 6-membered ring structure. Specific examples of the ring structure formed by R ⁵ , R ⁶ and the nitrogen atom to which they are bonded include a pyrrolidine ring, a piperidine ring, and a morpholine ring, and a piperidine ring or a morpholine ring is preferable.
R ⁵ and R ⁶ are preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted allyl group, or a cycloalkyl group, more preferably a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, substituted or An unsubstituted allyl group, particularly preferably a substituted or unsubstituted alkyl group having 2 to 4 carbon atoms, or a substituted or unsubstituted allyl group.

In the general formula (5), R ⁷ represents a substituent. The substituent in R ⁷ is not particularly limited, but typical examples include the substituents mentioned in the examples of substituents in R ¹ , R ² , and R ³ . For example, you may have the substituent mentioned in the example of the substituent in said R < ¹ >, R < ² >, R < ³ >). The preferred range of each group is the same as the range given as an example of the substituent in R ¹ , R ² and R ³ .
R ⁷ is preferably a substituted or unsubstituted acylamino group, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, or an aryloxy group having 6 to 10 carbon atoms, more preferably a substituted or unsubstituted carbon number. An acylamino group having 1 to 8 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 8 carbon atoms, and particularly preferably an acetylamino group.
The substitution position of R ⁷ is not particularly limited, but is preferably ortho or meta relative to the azo group, and more preferably ortho.

In the general formula (5), R ⁸ represents a hydrogen atom or a substituent. The substituent for R ⁸ is the same as the examples of the substituent for R ⁷ .
R ⁸ is preferably a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a phenyl group, particularly preferably tert. -A butyl group.

In the general formula (5), R ⁹ represents a substituent. The substituent is not particularly limited, but representative examples include the substituents mentioned in the examples of substituents in R ¹ , R ² and R ³ , and each group is further substituted (for example, R ¹ , R above) ² and the substituents mentioned in the example of the substituent in R ³ .
R ⁹ is preferably an aliphatic group (typically an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group), aryl group, heterocyclic group, amino group [amino group, aliphatic amino group (typical As an alkylamino group), an anilino group and a heterocyclic amino group]], more preferably an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an amino group, particularly preferably , An alkyl group having 1 or 2 carbon atoms, a phenyl group, or an alkylamino group having 2 to 10 carbon atoms.

N in General formula (5) represents the integer of 0-4. When n is 2 or more, the plurality of R ⁷ may be the same as or different from each other.
n is preferably 0 to 3, more preferably 0 to 2, and particularly preferably 0 to 1.

  Specific examples of the anthraquinone dyes represented by the general formulas (1) to (4) of the present invention and the azo dyes represented by the general formula (5) are shown below, but they can be used in the present invention. The anthraquinone dyes of the formulas (1) to (4) and the azo dyes represented by the general formula (5) are not limitedly interpreted by the following specific examples.

  The anthraquinone dyes represented by the general formulas (1) to (4) and the azo dye represented by the general formula (5) in the dye-donating layer are different depending on each specific dye selected. Specifically, it is preferably used in a mass ratio of 5 to 95:95 to 5. A ratio of anthraquinone dye of 95% or less is preferable because a sufficient color density can be maintained and color reproducibility is good. On the other hand, if the ratio of the anthraquinone dye is 5% or more, sufficient light fastness is maintained, which is preferable.

(Binder resin)
The binder resin that can be used in the dye-donating layer of the ink sheet for thermal transfer recording of the present invention is particularly high as long as it has high heat resistance and does not prevent the dye compound from moving to the image receiving material when heated. The type is not limited. For example, what is described in paragraph number 0049 of JP-A-7-137466 can be given as a preferred example. As the solvent for forming the dye-donating layer, a conventionally known solvent can be appropriately selected and used, and those described in Examples of JP-A-7-137466 can be preferably used.

(Method for forming dye-donating layer)
In the present invention, a method in which an ink liquid in which a dye is dissolved in a solvent together with a binder resin is applied and dried to form a dye-donating layer can be preferably used. The dye-donating layer is applied by a general method such as roll coating, bar coating, gravure coating, or gravure reverse coating.
The content of the dye mixture in the dye-donating layer is 0.03 to 1.0 g / m ² (in terms of solid content, hereinafter the coating amount in the present invention is a numerical value in terms of solid content unless otherwise specified). Preferably, 0.1 to 0.6 g / m ² is more preferable. Moreover, it is preferable that 10-90 mass% of pigment mixtures are contained in a dye layer, and it is more preferable that 30-65 mass% is contained. Further, the thickness of the dye-donating layer is preferably 0.2 to 5 μm, and more preferably 0.4 to 2 μm.

[Support]
As the support for the thermal transfer recording ink sheet of the present invention, any conventionally used support for an ink sheet can be appropriately selected and used. For example, the material described in paragraph No. 0050 of JP-A-7-137466 can be preferably used. The thickness of the support is preferably 2 to 30 μm.

[Functional layer]
The ink sheet for thermal transfer recording of the present invention may have a layer other than the dye-donating layer as long as the effect of the present invention is not excessively inhibited. For example, it may have an intermediate layer between the support and the dye-donating layer, or it may have a back layer on the support surface opposite to the dye-donating layer (hereinafter also referred to as “back surface”). There may be. Examples of the intermediate layer include an undercoat layer and a diffusion prevention layer (hydrophilic barrier layer) for preventing diffusion of the dye in the direction of the support. Examples of the back layer include a heat resistant slip layer, and can prevent adhesion of the thermal head to the ink sheet.

<Thermal transfer recording material>
The ink sheet for thermal transfer recording of the present invention can be applied to a thermal transfer recording material capable of full color image recording. The thermal transfer recording material includes a cyan ink sheet containing a heat diffusible cyan dye capable of forming a cyan image, a magenta ink sheet containing a heat diffusible magenta dye capable of forming a magenta image, and a yellow image. It is preferable that a yellow ink sheet containing a heat-diffusible yellow dye that can be formed is sequentially coated on a support. In addition, an ink sheet containing a black image forming substance may be further formed as necessary.
As a cyan ink sheet containing a heat-diffusible cyan dye capable of forming a cyan image, for example, those described in JP-A-3-103477 and JP-A-3-150194 are preferably used. it can. As a yellow ink sheet containing a heat diffusible yellow dye capable of forming a yellow image, for example, those described in JP-A-1-225559 can be preferably used.

<Thermal transfer recording method>
When the thermal transfer recording method of the present invention is performed using the thermal transfer recording ink sheet of the present invention, a heating means such as a thermal head and an image receiving material are used in combination. In other words, thermal energy is applied from the thermal head to the ink sheet in accordance with the image recording signal, and the dye in the portion to which the thermal energy is applied moves to the image receiving material and is fixed, thereby recording an image. The image receiving material usually has a structure in which an ink receiving layer containing a polymer is provided on a support. As the configuration and materials used of the image receiving material, for example, those described in paragraph numbers 0056 to 0074 of JP-A-7-137466 can be preferably used.

[Image receiving material]
In the thermal transfer recording method of the present invention, it is more preferable to use a thermal transfer image receiving sheet as the image receiving material. The heat-sensitive transfer image-receiving sheet has at least one ink receiving layer (hereinafter also simply referred to as a receiving layer) on a support, and a heat insulating layer (porous) is provided between the support and the receiving layer. Layer), a gloss control layer, a white background adjustment layer, a charge control layer, an adhesive layer, a primer layer, and the like may be formed. An undercoat layer may be provided between these functional layers and the support. It is a preferred embodiment to have at least one heat insulating layer between the support and the receiving layer.
The receptor layer and these intermediate layers are preferably formed by simultaneous multilayer coating, and a plurality of intermediate layers can be provided as necessary.
A curl adjustment layer, a writing layer, and a charge adjustment layer may be formed on the back side of the support. Each layer on the back side of the support can be applied by a general method such as roll coating, bar coating, gravure coating, or gravure reverse coating.

(Receptive layer)
The thermal transfer image-receiving sheet has at least one receiving layer containing a thermoplastic receiving polymer capable of receiving a dye. The receiving polymer used in the receiving layer is not particularly limited as long as it does not excessively inhibit the effects of the present invention, and those conventionally used as a polymer for a known thermal transfer image-receiving sheet can be used. . The receptor layer can be formed by applying an organic solvent as appropriate and applying it onto a support, followed by drying as appropriate. Alternatively, it can be formed by applying the polymer latex on a support in addition to an aqueous coating solution and drying it appropriately.

(Support)
The support for the heat-sensitive transfer image-receiving sheet is not particularly limited, and known coated paper, laminated paper, and synthetic paper can be used.

<Printers and copiers>
The thermal transfer recording method of the present invention can be used in printers, copiers and the like using the thermal transfer recording method. As the means for applying thermal energy at the time of thermal transfer, any conventionally known means for applying can be used. For example, recording is performed by a recording device such as a thermal printer (for example, product name, video printer VY-100, manufactured by Hitachi, Ltd.). By controlling the time, the intended purpose can be sufficiently achieved by applying thermal energy of about 5 to 100 mJ / mm ² .

The features of the present invention will be described more specifically with reference to the following examples.
The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. In Examples, “part” or “%” is based on mass unless otherwise specified.

[Example 1]
<Preparation of thermal transfer recording ink sheet>
Using a 6.0 μm thick polyester film (Lumirror, trade name, manufactured by Toray Industries, Inc.) with a heat-resistant slip treatment applied to the back surface by thermosetting acrylic resin (thickness 1 μm) on the front side of the film The following dye composition for forming a dye-donating layer was applied and formed by wire bar coating so that the thickness when dried was 1 μm, and ink sheet 1 was prepared.

(Coating composition for forming dye-donating layer)
Illustrative compound (1-1) 2.0 parts by mass Illustrative compound (5-1) 2.0 parts by mass Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
90 parts by mass of methyl ethyl ketone / toluene (1/1)

  Next, the ink of the present invention was prepared in the same manner as the production of the ink sheet 1 except that the exemplified compound (1-1) and the exemplified compound (5-1) were respectively changed to the dyes described in Tables 6 to 8 below. Sheets 2 to 36 and comparative ink sheets 37 to 53 were prepared. In addition, in the following Tables 6-8, the usage-amount of each pigment | dye represents a mass part.

<Production of image receiving material>
Synthetic paper (YUPO FPG200, trade name, manufactured by YUPO Corporation, thickness 200 μm) is used as a support, and a white intermediate layer-forming coating composition and a receiving layer-forming coating composition having the following composition are placed on one side in this order. Application was performed by a coater. The amount of each coating was such that the white intermediate layer was 1.0 g / m ² and the receiving layer was 4.0 g / m ² during drying, and the drying was performed at 110 ° C. for 30 seconds.

(White intermediate layer forming coating composition)
Polyester resin (Byron 200, trade name, manufactured by Toyobo Co., Ltd.) 10 parts by weight Optical brightener (Uvitex OB, trade name, manufactured by Ciba Geigy) 1 part by weight Titanium oxide 30 parts by weight Methyl ethyl ketone / toluene (1/1) 90 parts by mass

(Coating composition for receiving layer formation)
100 parts by weight of vinyl chloride-vinyl acetate resin (Solvine A, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Amino-modified silicone 5 parts by mass (X22-3050C, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
Epoxy-modified silicone 5 parts by mass (X22-300E, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
Methyl ethyl ketone / toluene (= 1/1) 400 parts by mass Benzotriazole UV absorber 5 parts by mass (Tinuvin 900, trade name, manufactured by Ciba Specialty Chemicals)

<Evaluation of image recording test and thermal transfer recording ink sheet>
The ink sheet 1 obtained as described above and the image receiving material are overlapped so that the dye-donating layer and the image-receiving layer are in contact with each other, and a thermal head is used from the back side of the dye-donating material, and the output of the thermal head is 0. When printing is performed under the conditions of .25 W / dot, pulse width of 0.15 to 15 milliseconds, and dot density of 6 dots / mm, and a magenta dye is imaged on the image receiving layer of the image receiving material, transfer unevenness A clear image recording without any problem was obtained. Next, an image recording test was conducted in the same manner except that the ink sheet 1 was changed to ink sheets 2 to 53, respectively.

(Clarity)
The obtained magenta image of each image was visually evaluated in four stages of A (very clear), B (clear), C (slightly unclear), and D (unclear). The results are shown in Tables 6-8 below.

(Color density)
The status A reflection density at a solid density (100% halftone density) of each image obtained is measured, and the reflection density is A (very good) when the reflection density is 1.8 or more, and B ( Good), 1.0 to less than 1.6, the transferability was evaluated in 3 stages of C (a level acceptable for practical use). The results are shown in Tables 6-8 below.

(Light fastness)
Next, each recorded thermal transfer image-receiving material thus obtained was irradiated with Xe light (17000 lux) for 7 days, and the light stability (light fastness) of the color image was examined. The status A reflection density after irradiation of the portion showing the status A reflection density 1.0 is measured, and the stability is expressed as a residual ratio (percentage) with respect to the reflection density 1.0 before irradiation of A (90% or more and less than 100%). , B (80% or more and less than 90%) and C (less than 80%). The results are shown in Tables 6-8 below.

As a result of the above-mentioned image recording test, by using a mixture of the anthraquinone dye and the azo dye of the present invention, the color density, sharpness, and various fastnesses, in particular, despite the high saturation of magenta color, Ink sheets 1 to 36 that give images with excellent light fastness were obtained. On the other hand, among the two types of dyes of the present invention, in the case of the ink sheets 37 to 49 using only the anthraquinone colorant, the sharpness and color density were significantly inferior to the ink sheet of the present invention. In addition, in the case of the ink sheets 50 to 53 using only the azo dye, the light fastness was inferior to the ink sheet of the present invention.
In addition, since the light fastness test result was unexpectedly high at 90% or more in the above stability, the thermal transfer recording ink sheet of the present invention was unexpectedly excellent in ink aging stability and stored for a long time. It turns out that the nature is high.
Furthermore, it has been found that the thermal transfer recording method of the present invention is a method excellent in color density, sharpness, and various fastness properties, particularly light fastness properties.

Claims (2)

A magenta dye comprising a base sheet and a dye-donating layer formed on one surface of the base sheet, and the magenta dye contained in the dye-donating layer is an anthraquinone dye represented by the following general formulas (1) to (4) An ink sheet for thermal transfer recording, which is a mixture of at least one kind and at least one kind of azo dye represented by the following general formula (5).

Wherein X and Y each independently represent —S—, —O— or —SO ₂ —, and R ¹ , R ² and R ³ each independently represents a substituted or unsubstituted alkyl group, substituted or unsubstituted A cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group, and R ⁴ represents a halogen atom or a cyano group.)

(In the general formula (5), R ⁵ , R ⁶ , R ⁷ and R ⁹ each independently represents a monovalent substituent, R ⁸ represents a hydrogen atom or a monovalent substituent, and n represents 0 to 4) When n is 2 or more, a plurality of R ⁷ may be the same or different from each other, and R ⁵ and R ⁶ may be bonded to each other to form a ring structure. )   A thermal transfer recording method comprising forming an image on an image receiving material having an ink receiving layer containing a polymer on a support, using the thermal transfer recording ink sheet according to claim 1.