CN110072946B

CN110072946B - Liquid crystal aligning agent, liquid crystal aligning film, and liquid crystal display element

Info

Publication number: CN110072946B
Application number: CN201780077011.1A
Authority: CN
Inventors: 永井健太郎; 铃木加名子; 名木达哉; 藤枝司
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2016-10-14
Filing date: 2017-10-13
Publication date: 2021-10-15
Anticipated expiration: 2037-10-13
Also published as: TW201829494A; JP6956948B2; JPWO2018070507A1; KR20190070331A; KR102466047B1; WO2018070507A1; CN110072946A; TWI760375B

Abstract

本发明涉及一种聚合物组合物，其含有(A)共聚物，所述共聚物由包含下述单体(A‑1)和单体(A‑2)的单体混合物得到。此处，单体(A‑1)是指，具有1个肉桂酰基部位和2～4个不构成肉桂酰基部位的苯环、且具有聚合性基团的单体，单体(A‑2)是指，具有1个肉桂酰基部位和1个不构成肉桂酰基部位的苯环、且具有聚合性基团的单体(该肉桂酰基部位和苯环任选具有取代基)。进一步本发明涉及一种具有液晶取向膜的基板的制造方法，其具备如下工序：将该组合物涂布于具有横向电场驱动用的导电膜的基板上而形成涂膜的工序；对所得涂膜照射偏振紫外线的工序；和，对所得涂膜进行加热的工序。使用本发明的聚合物组合物的液晶取向剂能以高效率被赋予取向控制能力，余像特性优异，可以提供横向电场驱动型液晶表示元件。The present invention relates to a polymer composition comprising (A) a copolymer obtained from a monomer mixture comprising the following monomers (A-1) and monomers (A-2). Here, the monomer (A-1) refers to a monomer having a cinnamoyl moiety and 2 to 4 benzene rings that do not constitute a cinnamoyl moiety and having a polymerizable group, and the monomer (A-2) It means a monomer having one cinnamoyl moiety and one benzene ring which does not constitute a cinnamoyl moiety and having a polymerizable group (the cinnamoyl moiety and the benzene ring may have a substituent). The present invention further relates to a method for producing a substrate having a liquid crystal aligning film, comprising the steps of: applying the composition to a substrate having a conductive film for lateral electric field driving to form a coating film; a step of irradiating polarized ultraviolet rays; and a step of heating the resulting coating film. The liquid crystal aligning agent using the polymer composition of the present invention can be efficiently imparted with alignment control ability, is excellent in afterimage characteristics, and can provide a lateral electric field driven liquid crystal display element.

Description

Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element

Technical Field

The present invention relates to a novel polymer composition, a liquid crystal alignment film using the same, and a method for producing a substrate having the alignment film. Further, the present invention relates to a novel method for manufacturing a liquid crystal display element having excellent tilt angle characteristics.

Background

Liquid crystal display elements are known as display devices that are lightweight, thin, and consume low power, and have been used for large-sized televisions and the like in recent years, and remarkable progress has been made. The liquid crystal display element is configured by sandwiching a liquid crystal layer between a pair of transparent substrates provided with electrodes, for example. Also, in the liquid crystal display element, an organic film formed of an organic material is used as a liquid crystal alignment film so that the liquid crystal assumes a desired alignment state between the substrates.

That is, the liquid crystal alignment film is a component of the liquid crystal display element, is formed on a surface of the substrate that is in contact with the liquid crystal and holds a role of aligning the liquid crystal in a specific direction between the substrates. Further, the liquid crystal alignment film is sometimes required to have a function of aligning the liquid crystal in a specific direction, for example, a direction parallel to the substrate, and a function of controlling the pretilt angle of the liquid crystal. The ability of such a liquid crystal alignment film to control the alignment of liquid crystals (hereinafter referred to as alignment control ability) is imparted by performing alignment treatment on an organic film constituting the liquid crystal alignment film.

As an alignment treatment method of a liquid crystal alignment film for imparting alignment controllability, a brushing method has been known. The brushing method refers to the following method: with respect to an organic film of polyvinyl alcohol, polyamide, polyimide, or the like on a substrate, the surface thereof is rubbed (brushed) in a constant direction with a cloth of cotton, nylon, polyester, or the like, thereby aligning the liquid crystal in the rubbing direction (brushing direction). This brushing method is used in the production process of a conventional liquid crystal display element because it can easily realize a relatively stable liquid crystal alignment state. As the organic film used for the liquid crystal alignment film, a polyimide-based organic film having excellent reliability such as heat resistance and electrical characteristics is mainly selected.

However, the brush rubbing method of rubbing the surface of a liquid crystal alignment film made of polyimide or the like has a problem of generating dust and static electricity. Further, in recent years, the liquid crystal display element has become more highly transparent, and due to irregularities caused by electrodes on the substrate or switching active elements for driving the liquid crystal, the surface of the liquid crystal alignment film cannot be uniformly rubbed with a cloth, and uniform liquid crystal alignment cannot be achieved in some cases.

Therefore, as another alignment treatment method of a liquid crystal alignment film without brushing, a photo-alignment method has been actively studied.

Various methods are available for the photo-alignment method, but the liquid crystal is aligned by forming anisotropy in an organic film constituting a liquid crystal alignment film by linearly polarized light or collimated light and aligning the liquid crystal according to the anisotropy.

As a main photo-alignment method, a decomposition type photo-alignment method is known. For example, a polyimide film is irradiated with polarized ultraviolet light, and anisotropic decomposition occurs due to the polarization direction dependency of ultraviolet absorption of the molecular structure. Then, the liquid crystal is aligned by the polyimide remaining without decomposition (see patent document 1).

Further, photo-alignment methods based on photo-crosslinking type are also known. For example, when polyvinyl cinnamate is irradiated with polarized ultraviolet light, dimerization reaction (crosslinking reaction) is caused in the double bond portion of 2 side chains parallel to polarized light. Further, the pretilt angle is expressed by irradiating polarized ultraviolet rays in an oblique direction (see non-patent document 1). In addition, when a side chain type polymer having coumarin in a side chain is used, polarized ultraviolet rays are irradiated to cause a photocrosslinking reaction in a coumarin moiety of a side chain parallel to polarization, thereby aligning liquid crystals in a direction parallel to the polarization direction (see non-patent document 2).

As in the above examples, the method of alignment treatment of a liquid crystal alignment film by the photo-alignment method does not require rubbing and does not cause generation of dust or static electricity. Further, the substrate of the liquid crystal display element having irregularities on the surface may be subjected to alignment treatment, and this may be a method of alignment treatment of a liquid crystal alignment film suitable for an industrial production process. In addition, since the photo-alignment method can control the alignment direction by ultraviolet rays, a plurality of regions having different alignment directions (alignment division) are formed in a pixel, and the viewing angle dependence can be compensated for.

On the other hand, the liquid crystal alignment film also exerts a certain constant tilt angle (pretilt angle) to the liquid crystal, and the application of the pretilt angle is becoming an important problem in the development of the liquid crystal alignment film (see patent documents 1 to 4).

Here, it is known that a copolymer obtained from a monomer having a cinnamate structure in a side chain and also having 2 benzene rings exhibits optical orientation (see patent document 5). However, this copolymer has low solubility, and when it is formed into a varnish, it is necessary to use a solvent such as chloroform, which is not industrially used, and it is difficult to apply it as a liquid crystal aligning agent.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication (Kokai) No. Hei 02-223916

Patent document 2: japanese patent laid-open publication (Kokai) No. H04-281427

Patent document 3: japanese patent laid-open publication (Kokai) No. H05-043687

Patent document 4: japanese patent laid-open publication (Kokai) No. Hei 10-333153

Patent document 5: japanese patent laid-open publication No. 2000-212310

Non-patent document

Non-patent document 1: S.Kobayashi et al, Journal of Photopolymer Science and Technology, Vol.8, No.2, pp25-262(1995).

Non-patent document 2: shadt et al, Nature. Vol381,212(1996).

Disclosure of Invention

Problems to be solved by the invention

As described above, the photo-alignment method has a great advantage in that it does not require a rubbing process itself, as compared with a rubbing method which has been industrially used as an alignment treatment method for a liquid crystal display element. In addition, in the photo alignment method, the alignment controllability can be controlled by changing the irradiation amount of polarized light, as compared with the rubbing method in which the alignment controllability is substantially constant by rubbing. However, when the optical alignment method is intended to achieve an alignment controllability comparable to that achieved by the rubbing method, a large amount of polarized light irradiation is required, or stable liquid crystal alignment may not be achieved.

For example, in the decomposition type photo-alignment method described in patent document 1, it is necessary to irradiate the polyimide film with ultraviolet light from a high-pressure mercury lamp with a power of 500W for 60 minutes or the like, and it is necessary to irradiate a large amount of ultraviolet light for a long time. In addition, in the case of the photo-alignment method of the dimerization type or photoisomerization type, a large amount of ultraviolet irradiation of about several J (joules) to several tens of J may be required. Further, in the photo-alignment method of photo-crosslinking type or photo-isomerization type, thermal stability and photo stability of alignment of liquid crystal are poor, and thus, when a liquid crystal display element is formed, there is a problem that alignment failure occurs and afterimage is displayed.

Therefore, the photo-alignment method is required to achieve stable liquid crystal alignment by increasing the efficiency of alignment treatment, and a liquid crystal alignment film and a liquid crystal alignment agent capable of imparting high alignment controllability to the liquid crystal alignment film with high efficiency are required.

An object of the present invention is to provide: a substrate having a liquid crystal alignment film for a liquid crystal display element, which has excellent tilt angle characteristics and can provide alignment controllability with high efficiency, and a twisted nematic liquid crystal display element and an OCB liquid crystal display element having the substrate.

In addition, in addition to the above object, an object of the present invention is to provide: a twisted nematic liquid crystal display element and an OCB liquid crystal display element having improved tilt angle characteristics, and a liquid crystal alignment film used for the same.

Means for solving the problems

The present inventors have made intensive studies to achieve the above object, and as a result, have made the following inventions.

<1> a polymer composition containing a copolymer of (A) obtained from a monomer mixture comprising the following monomer (A-1) and monomer (A-2).

Monomer (A-1): the monomer is a monomer having 1 cinnamoyl group and 2 to 4 benzene rings not constituting the cinnamoyl group, and having a polymerizable group.

Monomer (A-2): it is a monomer having 1 cinnamoyl moiety and 1 benzene ring not constituting the cinnamoyl moiety and having a polymerizable group.

(the cinnamoyl moiety and the benzene ring may have a substituent.)

<2> the polymer composition according to claim 1, wherein the polymerizable group of the monomer (A-1) and the monomer (A-2) is an acryloyl group or a methacryloyl group.

<3> in <1> above, the component (a) may be a monomer having a polymerizable group bonded to any 1 group selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2).

Wherein A, B, D each independently represents a single bond, -O-, -CH₂-, -COO-, -OCO-, -CONH-or-NH-CO-;

s is an alkylene group having 1 to 12 carbon atoms, and hydrogen atoms bonded thereto are each independently optionally substituted by a halogen group;

t is a single bond or an alkylene group having 1 to 12 carbon atoms, and a hydrogen atom bonded thereto is optionally substituted with a halogen group;

when T is a single bond, B also represents a single bond;

Y₁a 2-valent benzene ring;

P₁、Q₁and Q₂Each independently represents a group selected from the group consisting of a benzene ring and an alicyclic hydrocarbon ring having 5 to 8 carbon atoms;

R₁hydrogen atom, -CN, halogen group, alkyl group with 1-5 carbon atoms, (alkyl group with 1-5 carbon atoms) carbonyl group, cycloalkyl group with 3-7 carbon atoms or alkoxy group with 1-5 carbon atoms;

Y₁、P₁、Q₁and Q₂Wherein each hydrogen atom bonded to the benzene ring is independently optionally substituted by-CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, (an alkyl group having 1 to 5 carbon atoms) carbonyl group, or an alkoxy group having 1 to 5 carbon atoms;

X₁and X₂Each independently represents a single bond, -O-, -COO-or-OCO-;

n1 and n2 are each independently 0, 1 or 2,

X₁when the number of (2), X₁Optionally identical to or different from each other, X₂When the number of (2), X₂Optionally identical or different from each other;

Q₁when the number of (2) is 2, Q₁Optionally identical to or different from each other, Q₂When the number of (2) is 2, Q₂Optionally identical or different from each other;

in the monomer (A-1), Y₁The total number of the benzene rings other than the benzene rings is 2-4;

in the monomer (A-2), Y₁The number of benzene rings other than 1 in total;

the dotted line represents a bond to the polymerizable group.

<4> a method for producing a substrate having a liquid crystal alignment film for a twisted nematic liquid crystal display element and an OCB liquid crystal display element, the method comprising the steps of:

[I] a step of applying the polymer composition described in any one of <1> to <3> above onto a substrate having an electrode for driving a liquid crystal to form a coating film;

[ II ] irradiating the coating film obtained in [ I ] with polarized ultraviolet light from an oblique direction; and the combination of (a) and (b),

and [ III ] a step of heating the coating film obtained in [ II ].

<5> a substrate having a liquid crystal alignment film for a twisted nematic liquid crystal display element and/or an OCB liquid crystal display element, which is produced by the method <4> above.

<6> a twisted nematic liquid crystal display element and an OCB liquid crystal display element, which have the substrate <5> above.

<7> a method for manufacturing a twisted nematic liquid crystal display element and an OCB-mode liquid crystal display element, which comprises the steps of:

preparing the substrate (1 st substrate) according to the above <5 >;

a step of obtaining a2 nd substrate having a liquid crystal alignment film, the liquid crystal alignment film being provided with an alignment control ability by having the following steps [ I ' ], [ II ' ], [ III ' ]: and the number of the first and second groups,

[ IV ] a step of disposing the 1 st and 2 nd substrates so that the liquid crystal alignment films of the 1 st and 2 nd substrates face each other with the liquid crystal interposed therebetween and so that the exposure directions are orthogonal to each other to obtain a liquid crystal display element,

[ I' ] forming a coating film by applying the polymer composition described in any one of the above <1> to <4> onto a2 nd substrate;

a step of irradiating the coating film obtained in [ I' ] with polarized ultraviolet light; and

and [ III '] a step of heating the coating film obtained in [ II' ].

<8> a twisted nematic liquid crystal display element and an OCB liquid crystal display element, which are manufactured by the above <7 >.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided: a substrate having a liquid crystal alignment film which is provided with an alignment controllability at a high efficiency and has excellent tilt angle characteristics, and a twisted nematic liquid crystal display element and an OCB liquid crystal display element having the substrate.

The twisted nematic liquid crystal display element and the OCB liquid crystal display element manufactured by the method of the present invention are imparted with an alignment controllability at high efficiency, and therefore, even if they are continuously driven for a long time, their display characteristics are not impaired.

Detailed Description

The liquid crystal aligning agent used in the production method of the present invention has a photosensitive side chain type polymer (hereinafter, also simply referred to as a side chain type polymer) capable of exhibiting liquid crystallinity, and a coating film obtained by using the liquid crystal aligning agent is a film having a photosensitive side chain type polymer capable of exhibiting liquid crystallinity. The coating film was not subjected to brushing treatment, but was subjected to alignment treatment by polarized light irradiation. After the irradiation with polarized light, a coating film (hereinafter, also referred to as a liquid crystal alignment film) to which an alignment controlling ability is imparted is formed through a step of heating the side chain polymer film. At this time, the minute anisotropy exhibited by the polarized light irradiation becomes a driving force, and the liquid crystalline side chain polymer itself is effectively reoriented by self-assembly. As a result, highly efficient alignment treatment can be realized as a liquid crystal alignment film, and a liquid crystal alignment film having high alignment controllability can be obtained.

Hereinafter, embodiments of the present invention will be described in detail.

< method for producing substrate having liquid crystal alignment film > and < method for producing liquid crystal display element >

Side chain type Polymer (A)

(A) Component (A) is a copolymer (hereinafter, also referred to as a side chain polymer) obtained from a monomer mixture comprising the following monomer (A-1) and monomer (A-2).

Monomer (A-2): is a monomer having 1 cinnamoyl moiety and 1 benzene ring not constituting the cinnamoyl moiety and having a polymerizable group.

(the cinnamoyl moiety and the benzene ring may have a substituent.)

Examples of the substituent include methyl, methoxy, tert-butyl, acetyl, fluoro, cyano and the like.

(A) The side chain type polymer has a main chain to which a side chain having photosensitivity is bonded, and can induce a crosslinking reaction and an isomerization reaction by sensing light. The structure of the side chain having photosensitivity is not particularly limited, and a structure that induces crosslinking reaction by light is preferable. In the above case, even if exposed to external stress such as heat, the achieved alignment controllability can be stably maintained for a long time.

More specific examples of the structure of the side chain polymer of the component (a) include the following structures: the resin composition has a main chain composed of at least 1 selected from the group consisting of a radical polymerizable group such as hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, alpha-methylene-gamma-butyrolactone, styrene, vinyl, maleimide, norbornene and siloxane, and a side chain composed of at least 1 selected from the group consisting of the following formulas (1) and (2).

when T is a single bond, B also represents a single bond;

Y₁a 2-valent benzene ring;

R₁is a hydrogen atom, -CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, (an alkyl group having 1 to 5 carbon atoms) carbonyl group, a cycloalkyl group having 3 to 7 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.

X₁and X₂Each independently represents a single bond, -O-, -COO-or-OCO-;

n1 and n2 are each independently 0, 1 or 2,

X₁when the number of (2), X₁Optionally identical to or different from each other, X₂Is counted as2 is, X₂Optionally identical or different from each other;

in the monomer (A-2), Y₁The number of benzene rings other than 1 in total;

the dotted line represents a bond to the polymerizable group.

In view of liquid crystal alignment properties and solubility of the side chain type polymer, the content of the side chain derived from (a-1) in the side chain type polymer of the present invention is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, and even more preferably 30 to 70 mol% of the total of the content of the side chain derived from (a-1) and the content of the side chain derived from (a-2).

The side chain polymer of the present invention may contain a side chain other than the above-mentioned side chain derived from (A-1) and side chain derived from (A-2) within a range not to impair the effects of the present invention. When the total content of the photoreactive side chain and the liquid crystalline side chain is less than 100%, the content of the other side chain is the remaining part.

Production of photosensitive side chain type Polymer

The photosensitive side chain polymer capable of exhibiting liquid crystallinity can be obtained by polymerizing a monomer mixture containing at least the monomer (A-1) and the monomer (A-2).

[ monomer (A-1) and monomer (A-2) ]

The photoreactive side chain monomer is a monomer capable of forming a polymer having a photosensitive side chain at a side chain site of the polymer when the polymer is formed.

As the photoreactive group contained in the side chain, the following structure and derivatives thereof are preferable.

As more specific examples of the monomer (A-1) and the monomer (A-2), the following structures are preferred: the photosensitive resin composition has a polymerizable group comprising at least 1 kind selected from the group consisting of a radical polymerizable group such as hydrocarbon, (meth) acrylate, itaconate, fumarate, maleate, α -methylene- γ -butyrolactone, styrene, vinyl, maleimide, norbornene and a trialkoxysilyl group, and a photosensitive side chain having a structure selected from the group consisting of the structures represented by the above formulae (1) and (2).

The polymerizable group is preferably selected from the groups represented by the following formulae PG1 to PG 8. Among them, from the viewpoint of easy control of the polymerization reaction and stability of the polymer, an acryloyl group or methacryloyl group represented by PG1 is preferable. In the formula, the broken line represents a bond with the photosensitive side chain represented by the above formula (1) or (2).

(in the formula PG1, M1 represents a hydrogen atom or a methyl group.)

Examples of the monomer (A-1) include monomers selected from the following formulas A1-1 to A1-7.

(in the formulae A1-1 to A1-7, PG represents a polymerizable group selected from the groups represented by the formulae PG1 to PG8, and s1 and s2 each independently represents the number of methylene groups and is a natural number of 2 to 9.)

Examples of the monomer (A-2) include monomers selected from the following formulas A2-1 to A2-14.

(in the formulae A2-1 to A2-14, PG represents a polymerizable group selected from the groups represented by the formulae PG1 to PG8, and s1 and s2 each independently represents the number of methylene groups and is a natural number of 2 to 9.)

The monomer (A-1) and the monomer (A-2) are commercially available, and may be produced by a method described in, for example, International patent application publication WO 2014/074785.

(A) The side chain type polymer can be obtained by copolymerization of the monomer (A-1) and the monomer (A-2). Further, the monomer may be copolymerized with other monomers within a range not impairing the expression ability of liquid crystallinity.

When the polymerizable groups of the monomers (A-1) and (A-2) are radical polymerizable groups, examples of the other monomers include industrially available monomers capable of radical polymerization.

Specific examples of the other monomer include unsaturated carboxylic acids, acrylate compounds, methacrylate compounds, maleimide compounds, acrylonitrile, maleic anhydride, styrene compounds, vinyl compounds, and the like.

Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, maleic acid, and fumaric acid.

Examples of the acrylate compound include methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, anthryl methyl acrylate, phenyl acrylate, 2,2, 2-trifluoroethyl acrylate, t-butyl acrylate, lauryl acrylate, and palmityl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-adamantyl acrylate, 2-propyl-2-adamantyl acrylate, 8-methyl-8-tricyclodecanyl acrylate, and 8-ethyl-8-tricyclodecanyl acrylate, and the like.

Examples of the methacrylate compound include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, benzyl methacrylate, naphthyl methacrylate, anthryl methyl methacrylate, phenyl methacrylate, 2,2, 2-trifluoroethyl methacrylate, t-butyl methacrylate, lauryl methacrylate, palmityl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methoxyethyl methacrylate, methoxytriethylene glycol methacrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, 3-methoxybutyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-propyl-2-adamantyl methacrylate, and mixtures thereof, 8-methyl-8-tricyclodecyl methacrylate, and 8-ethyl-8-tricyclodecyl methacrylate.

Examples of the vinyl compound include vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

Examples of the styrene compound include styrene, methylstyrene, chlorostyrene, bromostyrene, and the like.

Examples of the maleimide compound include maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide.

The content of the photoreactive side chains represented by (A-1) and (A-2) in the side chain polymer of the present invention is preferably 10 to 100 mol%, more preferably 20 to 100 mol%, and still more preferably 30 to 100 mol%, from the viewpoint of liquid crystal alignment properties.

The method for producing the side chain polymer of the present embodiment is not particularly limited, and a general method which is industrially operated can be used. Specifically, the copolymer can be produced by cationic polymerization, radical polymerization, or anionic polymerization of a vinyl group using the monomers (A-1) and (A-2). Among them, radical polymerization is particularly preferable from the viewpoint of easiness of reaction control and the like.

The conditions of the radical polymerization such as the polymerization initiator, the reaction temperature, and the solvent may be those known in the international patent application publication WO2014/074785 and the like.

[ method for producing polysiloxane ]

When the polymer used as the component (a) in the present invention is a polysiloxane, the method for obtaining the polysiloxane is not particularly limited. In the present invention, the alkoxysilane compound is obtained by condensing an alkoxysilane mixture containing as an essential component a monomer having a trialkoxysilyl group as a polymerizable group in the monomer (A-1) and the monomer (A-2) in an organic solvent. In general, the polysiloxane is obtained by polycondensing such alkoxysilane to form a solution uniformly dissolved in an organic solvent.

In the present invention, an alkoxysilane represented by the following formula (3) may be used in addition to the monomer (A-1) and the monomer (A-2). The alkoxysilane represented by the formula (3) can impart various properties to the polysiloxane, and therefore, one or more kinds thereof can be selected and used depending on the desired properties.

(R⁵)_nSi(OR⁶)_4-n (3)

(R⁵Is a hydrogen atom or a hydrocarbon group of 1 to 6 carbon atoms optionally substituted with a hetero atom, a halogen atom, an amino group, a glycidoxy group, a mercapto group, an isocyanate group or a ureido group, R⁶Is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and n represents an integer of 0 to 3, preferably 0 to 2. )

R of alkoxysilane represented by the formula (3)⁵Is a hydrogen atom or an organic group having 1 to 6 carbon atoms (hereinafter, also referred to as a third organic group). As examples of the third organic group, are: optionally containing an aliphatic hydrocarbon; cyclic structures such as aliphatic rings, aromatic rings, and heterocyclic rings; an unsaturated bond; and an organic group having 1 to 6 carbon atoms, such as a heteroatom including an oxygen atom, a nitrogen atom, a sulfur atom, and the like, and optionally having a branched structure. Further, the organic group is optionally substituted with a halogen atom, an amino group, a glycidoxy group, a mercapto group, an isocyanate group, a ureido group, or the like.

Specific examples of the alkoxysilane represented by the formula (3) include, but are not limited to, these.

In the alkoxysilane of the formula (3), R is⁵Specific examples of the alkoxysilane in the case of a hydrogen atom include trimethoxysilane, triethoxysilane, tripropoxysilane, tributoxysilane and the like.

In the alkoxysilane of the formula (3), R is⁵Specific examples of the alkoxysilane as the third organic group include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, methyltripropoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl aminopropyl) trimethoxysilane, 3- (2-aminoethylaminopropyl) triethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, 2- (2-aminoethylthioethyl) triethoxysilane, and, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, vinyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, gamma-ureidopropyltriethoxysilane, gamma-ureidopropyltrimethoxysilane, gamma-ureidopropyltripropoxysilane, and the like.

The polysiloxane used in the present invention may have one or more kinds of the alkoxysilane represented by the above formula (3) for the purpose of improving adhesion to a substrate, affinity with liquid crystal molecules, and the like, as long as the effects of the present invention are not impaired.

In the alkoxysilane represented by the formula (3), the alkoxysilane in which n is 0 is tetraalkoxysilane. Tetraalkoxysilanes are easily condensed with alkoxysilanes represented by the formulae (1) and (2), and are therefore preferable for obtaining the polysiloxane of the present invention.

As the alkoxysilane in which n in the formula (3) is 0, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane or tetrabutoxysilane is more preferable, and tetramethoxysilane or tetraethoxysilane is particularly preferable.

As a method for polycondensing the polysiloxane, a method described in international patent application publication No. WO2010/126108 or the like can be used.

[ recovery of Polymer ]

When the polymer produced is recovered from the reaction solution of the photosensitive side chain type polymer obtained by the above reaction and capable of exhibiting liquid crystallinity, the reaction solution may be introduced into a poor solvent to precipitate the polymer. Examples of the poor solvent used for precipitation include methanol, acetone, hexane, heptane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, ethanol, toluene, benzene, diethyl ether, methyl ethyl ether, and water. The polymer precipitated by being put into the poor solvent may be recovered by filtration and then dried at normal temperature or under reduced pressure or dried by heating. Further, when the operation of re-dissolving the polymer recovered by precipitation in the organic solvent and re-precipitating and recovering is repeated 2 to 10 times, impurities in the polymer can be reduced. Examples of the poor solvent in this case include alcohols, ketones, hydrocarbons, and the like, and the use of 3 or more poor solvents selected from these is preferable because the purification efficiency is further improved.

The molecular weight of the side chain type polymer (A) of the present invention is preferably 2000 to 1000000, more preferably 5000 to 100000, as measured by GPC (Gel Permeation Chromatography) method, in view of the strength of the obtained coating film, the workability at the time of forming the coating film, and the uniformity of the coating film.

< organic solvent >

The organic solvent used in the polymer composition used in the present invention is not particularly limited as long as it is an organic solvent capable of dissolving the resin component. Specific examples thereof are listed below.

Examples thereof include: n, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 2-pyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, dimethyl sulfoxide, tetramethylurea, pyridine, dimethyl sulfone, hexamethylsulfoxide, γ -butyrolactone, 3-methoxy-N, N-dimethylpropionamide, 3-ethoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, 1, 3-dimethyl-imidazolidinone, ethylpentyl ketone, methylnonyl ketone, methyl ethyl ketone, methyl isoamyl ketone, methyl isopropyl ketone, cyclohexanone, ethylene carbonate, propylene carbonate, diethylene glycol dimethyl ether, propylene glycol dimethyl pyrrolidone, propylene glycol dimethyl ether, propylene glycol dimethyl pyrrolidone, propylene glycol dimethyl ether, propylene glycol dimethyl pyrrolidone, propylene glycol, and propylene glycol dimethyl pyrrolidone, and propylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol t-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, and the like. These may be used alone or in combination.

< liquid Crystal Aligning agent >

A liquid crystal aligning agent is applied to the side of the substrate on which the electrodes are formed.

The liquid crystal aligning agent of the present invention is obtained by using the polymer composition of the present invention, and contains (A) a copolymer obtained from a monomer mixture containing the above-mentioned monomer (A-1) and monomer (A-2).

[ preparation of liquid Crystal Aligning agent ]

The liquid crystal aligning agent used in the present invention is preferably prepared as a coating liquid so as to be suitable for forming a liquid crystal alignment film. That is, the liquid crystal aligning agent used in the present invention is preferably prepared as a solution in which a resin component for forming a resin coating is dissolved in an organic solvent. Here, the resin component is a resin component containing the side chain type polymer described above as the component (a). In this case, the content of the resin component is preferably 1 to 20% by mass, more preferably 3 to 15% by mass, and particularly preferably 3 to 10% by mass.

In the liquid crystal aligning agent of the present invention, the resin component may be all side chain type polymers as the component (a), and polymers other than these may be mixed in a range not impairing the liquid crystal aligning ability. In this case, the content of the other polymer in the resin component is 0.5 to 80% by mass, preferably 1 to 50% by mass.

Examples of such other polymers include poly (meth) acrylates, polyamic acids, and polyimides, and examples thereof include polymers other than the side chain type polymer as the component (a).

The polymer composition used in the present invention may contain components other than the side chain type polymer as the component (a) and the organic solvent. Examples thereof include: solvents and compounds for improving film thickness uniformity and surface smoothness when applying a liquid crystal aligning agent; and compounds for improving the adhesion between the liquid crystal alignment film and the substrate, but the present invention is not limited thereto.

Specific examples of the solvent (poor solvent) for improving the film thickness uniformity and the surface smoothness include the following solvents.

Examples thereof include isopropyl alcohol, methoxymethyl amyl alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, butyl carbitol, ethyl carbitol acetate, ethylene glycol monoacetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoacetate, propylene glycol monomethyl ether, propylene glycol tert-butyl ether, dipropylene glycol monomethyl ether, diethylene glycol monoacetate, diethylene glycol dimethyl ether, dipropylene glycol monoacetate monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoacetate monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monoacetate monopropyl ether, 3-methyl-3-methoxybutyl acetate, tripropylene glycol methyl ether, 3-methyl-3-methoxybutanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether, propylene glycol monoacetate, propylene glycol monobutyl ether, diethylene glycol monoacetate monoacid, ethylene glycol monoacid, and the like, Diisopropyl ether, ethyl isobutyl ether, diisobutylene, amyl acetate, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol, n-hexane, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, ethyl pyruvate, methyl 3-methoxypropionate, methyl ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxypropionic acid, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-phenoxy-2-propanol, butyl butyrate, butyl ether, diisobutyl ketone, methylcyclohexene, propyl ether, dihexyl ether, 1-hexanol ether, n-pentane, n-octane, diethyl ether, methyl lactate, ethyl acetate, n-butyl acetate, propylene glycol monoethyl ether acetate, methyl pyruvate, methyl 3-methoxy propionate, methyl propionate, 3-ethoxypropionate, 3-methoxypropionic acid, 3-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-butoxy-2-propanol, 1-2-propanol, and a mixture of the like, And solvents having low surface tension such as propylene glycol monoacetate, propylene glycol diacetate, propylene glycol-1-monomethyl ether-2-acetate, propylene glycol-1-monoethyl ether-2-acetate, dipropylene glycol, 2- (2-ethoxypropoxy) propanol, methyl lactate, ethyl lactate, n-propyl lactate, n-butyl lactate, and isoamyl lactate.

These poor solvents may be used in 1 kind, or may be used in combination of two or more kinds. When the solvent as described above is used, the solvent is preferably 5 to 80% by mass, more preferably 20 to 60% by mass, based on the whole solvent, in order not to significantly reduce the solubility of the whole solvent contained in the polymer composition.

Examples of the compound for improving the film thickness uniformity and surface smoothness include a fluorine-based surfactant, a silicone-based surfactant, and a nonionic surfactant.

More specifically, examples thereof include Eftop (registered trademark) 301, EF303, EF352(TOHKEM PRODUCTS CORPORATION), Megafac (registered trademark) F171, F173, R-30(DIC CORPORATION), Fluorad FC430, FC431(Sumitomo 3M Limited), Asahiguard (registered trademark) AG710 (Asahi Niger Co., Ltd.), Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, and SC106(AGC SEIMI CHEMICAL CO., LTD., Ltd.). The proportion of the surfactant to be used is preferably 0.01 to 2 parts by mass, more preferably 0.01 to 1 part by mass, per 100 parts by mass of the resin component contained in the polymer composition.

Specific examples of the compound for improving the adhesion between the liquid crystal alignment film and the substrate include functional silane-containing compounds described below.

Examples thereof include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, N-aminopropyltriethoxysilane, N-aminopropyltrimethoxysilane, N-aminopropyltriethoxysilane, N-ureidopropyltriethoxysilane, N-ureidopropyltrimethoxysilane, N-ethyltrimethoxysilane, N-ethylmethoxysilane, N-ethyltriethoxysilane, N-ethyltrimethoxysilane, N-propyltriethoxysilane, N-ethyltrimethoxysilane, N-ethylsilylpropyl, N-propyltriethoxysilane, N-ethyltrimethoxysilane, N-propyltriethoxysilane, N-ethyltrimethoxysilane, N-one or one-, 10-trimethoxysilyl-1, 4, 7-triazacyclodecane, 10-triethoxysilyl-1, 4, 7-triazacyclodecane, 9-trimethoxysilyl-3, 6-diaza-nonyl acetate, 9-triethoxysilyl-3, 6-diaza-nonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, n-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, etc.

Further, in order to improve the adhesion between the substrate and the liquid crystal alignment film and to prevent the deterioration of electrical characteristics due to a backlight when the liquid crystal display element is formed, the liquid crystal alignment agent may contain an additive such as a phenolic plastic-based or epoxy-containing compound as described below. Specific examples of the phenolic plastic additive are shown below, but the additive is not limited to this structure.

Specific examples of the epoxy group-containing compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2-dibromoneopentyl glycol diglycidyl ether, 1,3,5, 6-tetraglycidyl-2, 4-hexanediol, N ' -tetraglycidyl-m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N ' -tetraglycidyl-4, 4 ' -diaminodiphenylmethane, and the like.

When a compound for improving adhesion to a substrate is used, the amount thereof is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resin component contained in the liquid crystal aligning agent. When the amount is less than 0.1 part by mass, the effect of improving the adhesion cannot be expected, and when it is more than 30 parts by mass, the alignment property of the liquid crystal may be deteriorated.

As an additive, a photosensitizing agent may also be used. Preferred are leuco sensitizers and triplet sensitizers.

As photosensitizers, there are aromatic nitro compounds, coumarins (7-diethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin), coumarins, carbonylbiscoumarin, aromatic-2-hydroxyketones, and amino-substituted aromatic-2-hydroxyketones (2-hydroxybenzophenone, mono-or di-p- (dimethylamino) -2-hydroxybenzophenone), acetophenone, anthraquinone, xanthone, thioxanthone, benzanthrone, thiazoline (2-benzoylmethylene-3-methyl-. beta. -naphthothiazoline, 2- (. beta. -naphthoylmethylene) -3-methylbenzothiazoline, 2- (. alpha. -naphthoylmethylene) -3-methylbenzothiazoline, 2- (4-benzimidomethylene) -3-methylbenzothiazoline, 2- (beta-naphthoylmethylene) -3-methyl-beta-naphthothiazoline, 2- (4-benzimidomethylene) -3-methyl-beta-naphthothiazoline, 2- (p-fluorobenzoylmethylene) -3-methyl-beta-naphthothiazoline), oxazoline (2-benzoylmethylene-3-methyl-beta-naphthooxazoline, 2- (beta-naphthoylmethylene) -3-methylbenzoxazolin, 2- (alpha-naphthoylmethylene) -3-methylbenzoxazolin, 2- (4-benzimidomethylene) -3-methylbenzoxazolin, oxazoline, 2- (beta-naphthoylmethylene) -3-methyl-beta-naphthooxazoline, 2- (4-benziylmethylene) -3-methyl-beta-naphthooxazoline, 2- (p-fluorobenzoylmethylene) -3-methyl-beta-naphthooxazoline), benzothiazole, nitroaniline (m-or p-nitroaniline, 2,4, 6-trinitroaniline) or nitroacenaphthylene (5-nitroacenaphthylene), (2- [ (m-hydroxy-p-methoxy) styryl ] benzothiazole, benzoin alkyl ether, N-alkylated phthalein (N-alkyl ketone), acetophenone ketal (2, 2-dimethoxyacetophenone), naphthalene, anthracene (2-naphthalenemethanol, 2-naphthoic acid, naphthoic acid, 9-anthracenemethanol and 9-anthracenecarboxylic acid), benzopyran, azoindolizine, methylcoumarin, and the like.

Preferred are aromatic-2-hydroxyketones (benzophenone), coumarins, carbonyldicoumarins, acetophenones, anthraquinones, xanthones, thioxanthones and acetophenone ketals.

The method for manufacturing a substrate having a liquid crystal alignment film according to the present invention includes the steps of:

[I] a step of applying a liquid crystal aligning agent containing (A) a side chain polymer and an organic solvent onto a substrate having a transparent electrode to form a coating film;

[ II ] irradiating the coating film obtained in [ I ] with polarized ultraviolet light; and

and [ III ] a step of heating the coating film obtained in [ II ].

Through the above steps, a liquid crystal alignment film for a liquid crystal display element to which an alignment control capability is imparted can be obtained, and a substrate having the liquid crystal alignment film can be obtained.

In addition to the substrate (1 st substrate) obtained above, a2 nd substrate was prepared, and a liquid crystal display element was obtained.

The 2 nd substrate was obtained as follows: and a second substrate having a transparent electrode, and a second substrate 2 having a liquid crystal alignment film to which an alignment control ability is imparted by using the steps [ I ] to [ III ] above.

The method for manufacturing a twisted nematic liquid crystal display element and an OCB liquid crystal display element includes the steps of:

[ IV ] the step of obtaining a liquid crystal display element by disposing the 1 st and 2 nd substrates obtained in the above manner such that the liquid crystal alignment films of the 1 st and 2 nd substrates face each other with the liquid crystal interposed therebetween.

Thus, a twisted nematic liquid crystal display element can be obtained.

The respective steps of [ I ] to [ III ] and [ IV ] included in the production method of the present invention will be described below.

< Process [ I ] >

In the step [ I ], a liquid crystal aligning agent containing (A) a side chain polymer and an organic solvent is applied to a substrate having an electrode for driving a liquid crystal to form a coating film.

< substrate >

The substrate is not particularly limited, and when the liquid crystal display element to be manufactured is transmissive, a substrate having high transparency is preferably used. In this case, there is no particular limitation, and a glass substrate, an acrylic substrate, a plastic substrate such as a polycarbonate substrate, or the like can be used.

As the electrode for liquid crystal driving, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or the like is preferable. In the reflective liquid crystal display element, if only one substrate is used, an opaque object such as a silicon wafer may be used, and in this case, a material that reflects light such as aluminum may be used for the electrode.

The method for forming the electrode on the substrate may be a conventionally known method.

The method for applying the liquid crystal aligning agent to a substrate having an electrode for driving liquid crystal is not particularly limited.

As for the coating method, a method using screen printing, offset printing, flexographic printing, inkjet method, or the like is generally industrially used. As other coating methods, there are a dipping method, a roll coating method, a slit coating method, a spin coating method (spin coating method), a spray coating method, and the like, and they can be used according to the purpose.

After coating the liquid crystal aligning agent on the substrate having the electrode for driving liquid crystal, the solvent is evaporated at 50 to 230 ℃, preferably 50 to 200 ℃ for 0.4 to 60 minutes, preferably 0.5 to 10 minutes by a heating means such as a hot plate, a thermal cycle oven or an IR (infrared) oven to obtain a coating film. The drying temperature in this case is preferably within a temperature range lower than the temperature at which the side chain polymer as the component (a) exhibits liquid crystallinity (hereinafter referred to as liquid crystal display temperature).

When the thickness of the coating film is too large, it is disadvantageous in terms of power consumption of the liquid crystal display element, and when the thickness of the coating film is too small, reliability of the liquid crystal display element may be lowered, and therefore, it is preferably 5nm to 300nm, more preferably 10nm to 150 nm.

After the step (I) and before the step (II), a step of cooling the substrate having the coating film formed thereon to room temperature may be provided.

< Process [ II ] >

In the step [ II ], the coating film obtained in the step [ I ] is irradiated with polarized ultraviolet rays from an oblique direction. When polarized ultraviolet rays are irradiated onto the film surface of the coating film, ultraviolet rays polarized by the polarizing plate are irradiated onto the substrate from a certain direction. As the ultraviolet ray to be used, ultraviolet rays having a wavelength in the range of 100nm to 400nm can be used. Preferably, the optimum wavelength is selected by means of a filter or the like according to the type of the coating film used. Further, for example, ultraviolet rays having a wavelength in the range of 290 to 400nm can be selectively used so that the photocrosslinking reaction can be selectively induced. As the ultraviolet rays, for example, light emitted from a high-pressure mercury lamp can be used.

The irradiation amount of the polarized ultraviolet ray depends on the coating film used. The irradiation amount is preferably in the range of 1% to 70%, more preferably in the range of 1% to 50%, of the amount of polarized ultraviolet light that achieves a maximum value of Δ a (hereinafter also referred to as Δ Amax) that is the difference between the ultraviolet absorbance of the coating film in the direction parallel to the polarization direction of the polarized ultraviolet light and the ultraviolet absorbance of the coating film in the direction perpendicular to the polarization direction of the polarized ultraviolet light.

The irradiation direction of the polarized ultraviolet ray is usually 1 ° to 89 °, preferably 10 ° to 80 °, and particularly preferably 20 ° to 70 ° with respect to the substrate. When the angle is too small, the pretilt angle becomes small, and when the angle is too large, the pretilt angle becomes high.

As a method of adjusting the irradiation direction to the above-described angle, there is a method of inclining the substrate itself; and a method of tilting the light source, it is more preferable to tilt the light source itself from the viewpoint of productivity.

The pretilt angle obtained is preferably 1 ° to 20 °, more preferably 2 ° to 15 °, in terms of a pretilt angle suitable for the twisted nematic mode.

In the present invention, the tilt angle may be controlled by adjusting the irradiation amount, the irradiation time, or both in the step [ II ].

< Process [ III ] >

In the step [ III ], the coating film irradiated with the polarized ultraviolet ray in the step [ II ] is heated. The orientation control ability of the coating film can be imparted by heating.

Heating means such as a hot plate, a thermal cycle type oven, or an IR (infrared ray) type oven can be used for heating. The heating temperature may be determined in consideration of the temperature at which the coating film used exhibits liquid crystallinity.

The heating temperature is preferably within a temperature range at which the side chain polymer exhibits liquid crystallinity (hereinafter referred to as a liquid crystal display temperature). In the case of a film surface such as a coating film, it is expected that the liquid crystal display temperature of the coating film surface is lower than that when the side chain type polymer as the component (a) is observed in the bulk phase (bulk). Therefore, the heating temperature is more preferably within the temperature range of the liquid crystal display temperature on the surface of the coating film. That is, the temperature range of the heating temperature after irradiation with polarized ultraviolet rays is preferably: a temperature in a range having a temperature lower by 10 ℃ than the lower limit of the liquid crystal display temperature range of the side chain polymer to be used as the lower limit and a temperature lower by 10 ℃ than the upper limit of the liquid crystal temperature range as the upper limit. When the heating temperature is lower than the above temperature range, the effect of increasing anisotropy by heat in the coating film tends to be insufficient, and when the heating temperature is too high as compared with the above temperature range, the state of the coating film tends to be close to an isotropic liquid state (isotropic phase), and in this case, it may be difficult to perform reorientation in one direction by self-assembly.

The liquid crystal display temperature is: the side chain type polymer or the surface of the coating film has a temperature not lower than the glass transition temperature (Tg) at which the phase transition from the solid phase to the liquid crystal phase occurs, and not higher than the isotropic phase transition temperature (Tiso) at which the phase transition from the liquid crystal phase to the isotropic phase occurs.

In the present invention, the inclination angle may be controlled by adjusting the heating temperature, the heating time, or both in the step [ III ].

The thickness of the coating film formed after heating may be preferably 5nm to 300nm, more preferably 50nm to 150nm, for the same reason as described in the step [ I ].

By having the above steps, the production method of the present invention can efficiently introduce anisotropy into a coating film. Further, a substrate with a liquid crystal alignment film can be efficiently produced.

< Process [ IV ] >

In the step [ IV ], the liquid crystal display element includes a liquid crystal cell having 2 substrates [ III ] arranged so that the sides of the substrates on which the liquid crystal alignment films are formed face each other, a liquid crystal layer provided between the substrates, and the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention and provided between the substrates and the liquid crystal layer. Examples of the liquid crystal display element of the present invention include various liquid crystal display elements such as a Twisted Nematic (TN) system, a Vertical Alignment (VA) system, an In-Plane Switching (IPS) system, and an OCB (OCB) system.

When an example of manufacturing a liquid crystal cell or a liquid crystal display element is described, the following method can be exemplified: a method of preparing the 1 st substrate and the 2 nd substrate, spreading spacers on the liquid crystal alignment film of one substrate to make the liquid crystal alignment film surface inside, attaching the other substrate so that the ultraviolet exposure directions are orthogonal to each other, injecting liquid crystal under reduced pressure, and sealing; or a method of dropping liquid crystal onto the liquid crystal alignment film surface on which the spacers are dispersed, and then attaching and sealing the substrate. The diameter of the spacer in this case is preferably 1 to 30 μm, more preferably 2 to 10 μm. The spacer diameter determines the distance between the pair of substrates sandwiching the liquid crystal layer, i.e., the thickness of the liquid crystal layer.

The obtained liquid crystal display element is preferably further subjected to annealing treatment for alignment stability. The heating temperature may be a phase transition temperature of the liquid crystal, i.e., preferably 10 to 160 ℃, and more preferably 50 to 140 ℃.

In the method for producing a substrate with a coating film of the present invention, after a coating film is formed by applying the polymer composition onto a substrate, polarized ultraviolet rays are irradiated. Then, by heating, the anisotropy is efficiently introduced into the side chain type polymer film, and a substrate with a liquid crystal alignment film having a liquid crystal alignment control ability is manufactured.

The coating film used in the present invention realizes efficient introduction of anisotropy into the coating film by utilizing the principle of molecular reorientation induced by photoreaction of side chains and self-assembly due to liquid crystallinity. In the production method of the present invention, when the side chain polymer has a structure in which a photocrosslinkable group is a photoreactive group, a liquid crystal display element is produced by forming a coating film on a substrate using the side chain polymer, irradiating the coating film with polarized ultraviolet rays, and then heating the coating film.

Therefore, the coating film used in the method of the present invention can efficiently introduce anisotropy by subjecting the coating film to polarized ultraviolet irradiation and heat treatment in this order, and a liquid crystal alignment film having excellent alignment controllability can be produced.

In addition, the coating film used in the method of the present invention is optimized in the irradiation amount of polarized ultraviolet rays to be irradiated to the coating film and the heating temperature of the heating treatment. This enables efficient introduction of anisotropy into the coating film.

The irradiation amount of polarized ultraviolet ray optimal for efficiently introducing anisotropy into the coating film used in the present invention corresponds to the irradiation amount of polarized ultraviolet ray that optimizes the amount of photocrosslinking reaction or photoisomerization reaction of the photosensitive group in the coating film. When the side chain photosensitive group which undergoes the photocrosslinking reaction or photoisomerization reaction is small as a result of irradiating polarized ultraviolet rays to the coating film used in the present invention, a sufficient photoreactive amount is not obtained. In this case, sufficient self-assembly does not proceed even when heating is performed thereafter. On the other hand, in the coating film used in the present invention, when the photosensitive group of the side chain which undergoes the crosslinking reaction is excessive as a result of irradiating the structure having the photocrosslinkable group with polarized ultraviolet rays, the crosslinking reaction between the side chains proceeds excessively. At this time, the obtained film becomes rigid, and the self-assembly by the subsequent heating may be inhibited.

Therefore, in the coating film used in the present invention, the optimum amount of the photocrosslinking reaction and photoisomerization reaction of the photosensitive group of the side chain due to irradiation with polarized ultraviolet rays is preferably 0.1 to 60 mol%, more preferably 0.1 to 40 mol%, of the photosensitive group of the side chain-type polymer film. When the amount of the photosensitive group of the side chain which is photoreactive is in such a range, self-assembly in the subsequent heat treatment proceeds efficiently, and anisotropy in film formation can be formed efficiently.

In the coating film used in the method of the present invention, the amount of photocrosslinking reaction, photoisomerization reaction, or photofries rearrangement reaction of the photosensitive group in the side chain of the side chain-type polymer film is optimized by optimizing the irradiation amount of the polarized ultraviolet ray. Further, the anisotropy can be efficiently introduced into the coating film used in the present invention together with the subsequent heat treatment. In this case, the appropriate amount of polarized ultraviolet light can be evaluated based on the ultraviolet absorption of the coating film used in the present invention.

That is, with respect to the coating film used in the present invention, ultraviolet absorption in a direction parallel to the polarization direction of the polarized ultraviolet ray and ultraviolet absorption in a direction perpendicular to the polarization direction of the polarized ultraviolet ray after irradiation with the polarized ultraviolet ray were measured. From the measurement result of the ultraviolet absorption, Δ a, which is the difference between the ultraviolet absorbance in the direction parallel to the polarization direction of the polarized ultraviolet ray and the ultraviolet absorbance in the direction perpendicular to the polarization direction of the polarized ultraviolet ray in the coating film, was evaluated. Then, the maximum value of Δ a (Δ Amax) realized in the coating film used in the present invention and the irradiation amount of polarized ultraviolet rays realizing this were obtained. In the production method of the present invention, the amount of polarized ultraviolet light irradiated with a preferred amount in the production of the liquid crystal alignment film can be determined with reference to the amount of polarized ultraviolet light irradiation that achieves Δ Amax.

In the production method of the present invention, the irradiation amount of the polarized ultraviolet ray with which the coating film used in the present invention is irradiated is preferably in the range of 1% to 70%, more preferably in the range of 1% to 50%, of the amount of the polarized ultraviolet ray that realizes Δ Amax. In the coating film used in the present invention, the irradiation amount of polarized ultraviolet light in the range of 1% to 50% of the amount of polarized ultraviolet light that realizes Δ Amax corresponds to the amount of polarized ultraviolet light that causes a photocrosslinking reaction of 0.1% to 20% by mole of the entire photosensitive groups of the side chain-type polymer film.

As described above, in the production method of the present invention, in order to efficiently introduce anisotropy into a coating film, the above-described appropriate heating temperature may be determined based on the liquid crystal temperature range of the side chain polymer. Therefore, for example, when the liquid crystal temperature of the side chain polymer used in the present invention is in the range of 100 to 200 ℃, it is preferable that the heating temperature after irradiation with polarized ultraviolet rays is 90 to 190 ℃. By setting in this way, a greater anisotropy is imparted to the coating film used in the present invention.

By doing so, the liquid crystal display element provided by the present invention exhibits high reliability against external stimuli such as light and heat.

As described above, the substrate for a twisted nematic liquid crystal display element or the liquid crystal display element having the substrate, the substrate for an OCB liquid crystal display element or the liquid crystal display element having the substrate, which are manufactured by the method of the present invention, have excellent reliability, and can be suitably used for a large-screen, high-definition liquid crystal television or the like. Further, the present invention is also useful for liquid crystal antennas, light control elements, and the like.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Examples

Abbreviations used in the examples are as follows.

< methacrylic acid monomer >

MA-1 was synthesized by a synthesis method described in non-patent documents (Macromolecules 2002,35, 706-713).

MA-2 was synthesized by the synthesis method described in British patent GB 2306470B.

MA-3 was synthesized by a synthesis method described in non-patent documents (Macromolecules 2007,40, 6355-6360).

MA-4 was synthesized by the synthesis method described in the pamphlet of International patent application publication No. WO 2014/054785.

MA-5 was synthesized by a synthesis method described in the patent literature (Japanese patent application laid-open No. 9-118717).

MA-6 was purchased from Tokyo chemical industry Co., Ltd and used.

MA-7 was purchased from Tokyo chemical industry Co., Ltd and used.

MA-8 was purchased from Tokyo chemical industry Co., Ltd and used.

MA-9 was purchased from Sigma Aldrich Japan and used.

< organic solvent >

THF: tetrahydrofuran (THF)

NMP: n-methyl-2-pyrrolidone

BCS: butyl cellosolve

BCA: butyl Cellosolve acetate

CHN: cyclohexanone

GBL: gamma-butyrolactone

PGME: propylene glycol monomethyl ether

PGMEA: propylene glycol monomethyl ether acetate

< polymerization initiator >

AIBN: 2, 2' -azobisisobutyronitrile

< Synthesis example 1: methacrylic polymer

MA-1(21 g: 40mmol) and MA-2(26 g: 60mmol) were dissolved in THF (270g), degassed by a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added to conduct further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P1.

With respect to synthesis examples 2 and 3, methacrylate polymer powders P2 and P3 were also produced by the same method as in synthesis example 1 under the conditions shown in table 1.

< Synthesis example 4: methacrylic polymer

MA-3(23 g: 40mmol) and MA-2(26 g: 60mmol) were dissolved in THF (282g), degassed by a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added to conduct further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P4.

With respect to synthesis example 5, a methacrylate polymer powder P5 was also produced in the same manner as in synthesis example 4 under the conditions shown in table 1.

< Synthesis example 6: methacrylic polymer

MA-3(23 g: 40mmol) and MA-4(31 g: 60mmol) were dissolved in THF (310g), degassed by a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added to conduct further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P6.

With respect to synthesis example 7, a methacrylate polymer powder P7 was also produced by the same method as in synthesis example 6 under the conditions shown in table 1.

< Synthesis example 8: methacrylic polymer

MA-1(21 g: 40mmol), MA-2(13 g: 30mmol) and MA-4(9 g: 30mmol) were dissolved in THF (246g), degassed with a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added thereto, followed by further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P8.

With respect to synthesis example 9, a methacrylate polymer powder P9 was also produced by the same method as in synthesis example 8 under the conditions shown in table 1.

< Synthesis example 10: methacrylic polymer

MA-1(21 g: 40mmol), MA-2(26 g: 60mmol) and MA-5(2 g: 20mmol) were dissolved in THF (280g), degassed with a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added thereto, followed by further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P10.

With respect to synthesis example 11, a methacrylate polymer powder P11 was also produced by the same method as in synthesis example 10 under the conditions shown in table 1.

< Synthesis example 12: methacrylic polymer

MA-1(21 g: 40mmol), MA-2(26 g: 60mmol) and MA-7(3 g: 10mmol) were dissolved in THF (283g), degassed with a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added thereto, followed by further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P12.

Methacrylate polymer powders P13 and 14 were prepared in the same manner as in Synthesis examples 13 and 14 except that MA-7 in Synthesis example 12 was replaced with MA-8 and MA-9 under the conditions shown in Table 1.

< Synthesis example 15: methacrylic polymer

MA-3(34 g: 60mmol), MA-2(9 g: 20mmol) and MA-5(6 g: 20mmol) were dissolved in THF (282g), degassed with a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added and further degassed. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P15.

< Synthesis example 16: methacrylic polymer

MA-1(21 g: 40mmol) and MA-5(6 g: 60mmol) were dissolved in THF (154g), degassed by a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added to conduct further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P16.

With respect to synthesis example 17, a methacrylate polymer powder P17 was also produced in the same manner as in synthesis example 16 under the conditions shown in table 1.

< Synthesis example 18: methacrylic polymer

MA-3(46 g: 80mmol) and MA-5(6 g: 20mmol) were dissolved in THF (297g), degassed by a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added to conduct further degassing. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P18.

< Synthesis example 19: methacrylic polymer

MA-2(44 g: 100mmol) was dissolved in THF (251g), degassed with a diaphragm pump, and then AIBN (0.5 g: 3mmol) was added and further degassed. Thereafter, the reaction was carried out at 60 ℃ for 6 hours to obtain a polymer solution of a methacrylic acid ester. The polymer solution was added dropwise to methanol (2000ml), and the resulting precipitate was filtered. The precipitate was washed with methanol and dried under reduced pressure to obtain a methacrylate polymer powder P19.

Methacrylate polymer powder P21 was prepared in the same manner as in Synthesis example 20 except that MA-3 was used instead of MA-2 in Synthesis example 19 under the conditions shown in Table 1.

< preparation of liquid Crystal alignment agent: a1 >, and

NMP (11.4g) was added to the methacrylate polymer powder P1(0.6g) obtained in Synthesis example 1, and the mixture was stirred at room temperature for 1 hour to dissolve the powder. BCS (3.0g) was added to the solution to obtain a polymer solution (A1) having a solid content concentration of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Under the conditions shown in table 1, liquid crystal aligning agents a2, A3, a5, a11, a12, and a16 to a20 were also prepared in the same manner as the liquid crystal aligning agent a 1.

< preparation of liquid Crystal alignment agent: b1 >

NMP (11.4g) was added to the methacrylate polymer powder P16(0.6g) obtained in Synthesis example 1, and the mixture was stirred at room temperature for 1 hour to dissolve the powder. BCS (3.0g) was added to the solution to obtain a polymer solution (B1) having a solid content concentration of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Under the conditions shown in table 1, liquid crystal alignment agents B2, B4, and B5 were also prepared by the same method as that for liquid crystal alignment agent B1.

< preparation of liquid Crystal alignment agent: a4 >, and

NMP (9.9g) was added to the methacrylate polymer powder P3(0.6g) obtained in Synthesis example 1, and the mixture was stirred at room temperature for 1 hour to dissolve the powder. BCA (4.5g) was added to the solution to obtain a polymer solution (A4) having a solid content concentration of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Under the conditions shown in table 1, liquid crystal alignment agents a6, a7, and a13 were also prepared by the same method as liquid crystal alignment agent a 4.

< preparation of liquid Crystal alignment agent: a8 >, and

CHN (11.4g) was added to the methacrylate polymer powder P5(0.6g) obtained in Synthesis example 1 above, and the mixture was dissolved by stirring at a temperature of 50 ℃ for 1 hour. PGME (3.0g) was added to the solution to obtain a polymer solution (A8) having a solid content concentration of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Under the conditions shown in table 1, a liquid crystal aligning agent was produced in the same manner except that PGME of the liquid crystal aligning agent A8 was replaced with PGMEA with respect to the liquid crystal aligning agent a 9.

< preparation of liquid Crystal alignment agent: a10 >, and

CHN (15.0g) was added to the methacrylate polymer powder P5(0.6g) obtained in Synthesis example 1, and the mixture was dissolved by stirring at a temperature of 50 ℃ or lower for 1 hour to obtain a polymer solution (A10) having a solid content of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Under the conditions shown in table 1, liquid crystal alignment agents a15 and a21 were also prepared in the same manner as liquid crystal alignment agent a 10.

< preparation of liquid Crystal alignment agent: a14 >, and

NMP (5.4g) was added to the methacrylate polymer powder P9(0.6g) obtained in Synthesis example 1, and the mixture was stirred at room temperature for 1 hour to dissolve the powder. To the solution were added GBL (4.5g) and BCA (4.5g), to give a polymer solution (A14) having a solid content concentration of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Under the conditions shown in table 1, a liquid crystal aligning agent was produced in the same manner except that BCA of the liquid crystal aligning agent a14 was replaced with BCS for the liquid crystal aligning agent B3.

[ Table 1]

< production of substrate for In-plane orientation (In-plane order parameter) measurement >

The substrate for measuring photoreactivity was prepared by the following procedure using the liquid crystal aligning agent obtained above. A quartz substrate having a size of 40mm × 40mm and a thickness of 1.0mm was used as the substrate. The liquid crystal aligning agent A1 was filtered through a filter having a filter pore size of 1.0 μm, spin-coated on a quartz substrate, and dried on a hot plate at 70 ℃ for 90 seconds to form a liquid crystal alignment film having a film thickness of 100 nm.

(example 1)

The coated surface was irradiated with 313nm ultraviolet rays (80 mJ/cm) through a polarizing plate²Then, the substrate was heated on a hot plate at 120 ℃ for 20 minutes to obtain a photoreactive substrate with a liquid crystal alignment film.

Substrates for in-plane orientation degree measurement were also prepared in examples 2 to 21 and comparative examples 1 to 5 under the conditions shown in table 2 in the same manner as in example 1.

< measurement of degree of in-plane orientation >

In order to measure the optical anisotropy of the liquid crystal alignment film using the substrate with a liquid crystal alignment film prepared in the above, S, which is the degree of in-plane alignment, was calculated from the absorbance of polarized light according to the following equation. The highest value in the irradiation dose range is used as the calculation value.

In addition, an ultraviolet-visible near-infrared analyzer U-3100PC manufactured by Shimadzu corporation was used for the measurement of absorbance.

Here, A_paraDenotes the absorbance in the direction parallel to the direction of the irradiated polarized UV, A_perDenotes the absorbance in the direction perpendicular to the direction of the polarized UV of the irradiation. A. the_largeThe absorbance, A, is larger than the absorbance in the parallel and perpendicular directions_smallThe absorbance is smaller when the absorbance in the parallel direction is compared with the absorbance in the perpendicular direction. The closer the absolute value of the in-plane orientation degree is to 1, the more uniform the orientation state is.

[ Table 2]

As shown in Table 2, it was found that the liquid crystal aligning agents of examples 1 to 21 all had a high degree of alignment in the direction parallel to the polarized UV direction. The reason why the alignment was not carried out in the parallel direction in comparative examples 1 and 2 is presumably because the introduced amount of the photosensitive group was small and the alignment by isomerization was dominant over dimerization.

< production of liquid Crystal cell >

The liquid crystal aligning agent (A1) was filtered through a 0.45 μm filter, spin-coated on a glass substrate with a transparent electrode, and dried on a hot plate at 70 ℃ for 90 seconds to form a liquid crystal alignment film having a film thickness of 100 nm.

(example 15)

The coated surface was tilted by 40 degrees, and the substrate was irradiated with 313nm ultraviolet radiation at 80mJ/cm through a polarizing plate²Thereafter, the substrate was heated on a hot plate at 140 ℃ for 20 minutes to obtain a substrate with a liquid crystal alignment film. After preparing 2 substrates with such liquid crystal alignment films and providing a spacer of 4 μm on the liquid crystal alignment film surface of one substrate, the substrates were combined so that the brushing directions of the 2 substrates were parallel to each other, and the liquid crystal injection port was left and the periphery was sealed to prepare an empty cell having a cell gap of 4 μm. Liquid crystal MLC-2003 (manufactured by Merck) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed to obtain an antiparallel liquid crystal cell. After heating at 120 ℃ for 30 minutes, the pretilt angle was measured for the liquid crystal cell.

Under the conditions shown in Table 3, liquid crystal cells were prepared and pretilt angles were measured in the same manner as in example 1 for examples 16 to 42 and comparative examples 6 to 10.

[ Table 3]

As shown in Table 3, the pretilt angle of the liquid crystal suitable for the twisted nematic mode was obtained in any of the cases where the liquid crystal aligning agents of examples 22 to 42 were used. The reason why the pretilt angle is not exhibited in comparative examples 6 and 7 is presumably because no tilt is exhibited in the uniaxial direction. In comparative example 9, although a good tilt angle was exhibited, the obtained liquid crystal alignment film was cloudy. In comparative example 10, no tilt angle suitable for the twisted nematic mode was shown.

A substrate for in-plane alignment degree measurement was prepared using the liquid crystal aligning agent a10 in the same manner as in example 1 under the conditions shown in table 4. Then, according to the above examples, the alignment degree and the pretilt angle were measured, and the results are shown in table 4: the pretilt angle can be adjusted depending on the amount of polarized ultraviolet radiation and the actual firing conditions.

[ Table 4]

< preparation of liquid Crystal alignment agent: a22 >, and

NMP (8.4g) was added to the methacrylate polymer powder P15(0.6g) obtained in Synthesis example 15, and the mixture was stirred at room temperature for 1 hour to dissolve the powder. BCS (6.0g) was added to the solution to obtain a polymer solution (A22) having a solid content concentration of 4.0 wt%. The polymer solution becomes a liquid crystal aligning agent which is directly used for forming a liquid crystal alignment film.

Using this alignment agent a22, the alignment degree and pretilt angle were measured in the same manner. The results show that the pretilt angle is 9.9 ° which is most suitable for the OCB mode, as shown in table 5.

[ Table 5]

Claims

1. A polymer composition comprising (A) a copolymer obtained from a monomer mixture comprising the following monomer (A-1) and monomer (A-2),

Monomer (A-1): a monomer having one cinnamoyl moiety and 2 to 4 benzene rings that do not constitute a cinnamoyl moiety, and having a polymerizable group;

Monomer (A-2): It is a monomer having one cinnamoyl moiety and one benzene ring which does not constitute a cinnamoyl moiety and having a polymerizable group,

The cinnamoyl moiety and the benzene ring optionally have substituents,

The monomer (A-1) and the monomer (A-2) are any selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2). A monomer having a polymerizable group bonded to one of its groups,

In the formula, A, B and D each independently represent a single bond, -O-, -CH ₂ -, -COO-, -OCO-, -CONH- or -NH-CO-;

S is an alkylene group having 1 to 12 carbon atoms, and the hydrogen atoms bonded thereto are each independently optionally substituted by a halogen group;

T is a single bond or an alkylene group with 1 to 12 carbon atoms, and the hydrogen atom bonded to them is optionally substituted by a halogen group;

When T is a single bond, B also represents a single bond;

Y ₁ is a divalent benzene ring;

P ₁ , Q ₁ and Q ₂ are each independently a group selected from the group consisting of a benzene ring and an alicyclic hydrocarbon ring having 5 to 8 carbon atoms;

R ₁ is a hydrogen atom, -CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, a (alkyl group having 1 to 5 carbon atoms) carbonyl group, a cycloalkyl group having 3 to 7 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. alkoxy;

In Y ₁ , P ₁ , Q ₁ and Q ₂ , the hydrogen atoms bonded to the benzene ring are each independently optionally -CN, a halogen group, an alkyl group having 1 to 5 carbon atoms, (a group having 1 to 5 carbon atoms) Alkyl) carbonyl, or alkoxy substitution with 1 to 5 carbon atoms;

X ₁ and X ₂ each independently represent a single bond, -O-, -COO- or -OCO-;

n1 and n2 are each independently 0, 1 or 2,

When the number of X ₁ becomes 2, X ₁ is optionally the same or different from each other, and when the number of X ₂ becomes 2, X ₂ is optionally the same or different from each other;

When the number of Q ₁ becomes 2, Q ₁ is optionally the same or different from each other, and when the number of Q ₂ becomes 2, Q ₂ is optionally the same or different from each other;

In the monomer (A-1), the total number of benzene rings other than Y ₁ is 2 to 4;

In the monomer (A-2), the total number of benzene rings other than Y ₁ is 1;

The dotted line represents the linkage to the polymerizable group.

2 . The polymer composition according to claim 1 , wherein the polymerizable group of the monomer (A-1) and the monomer (A-2) is an acryloyl group or a methacryloyl group. 3 .

3. The manufacturing method of the board|substrate which has a liquid crystal aligning film which obtains the said liquid crystal aligning film provided with the orientation control ability by including the following steps:

[I] a step of applying the polymer composition according to any one of claims 1 to 2 on a substrate having an electrode for driving liquid crystal to form a coating film;

[II] a step of irradiating polarized ultraviolet rays from an oblique direction to the coating film obtained in [I]; and,

[III] A step of heating the coating film obtained in [II].

The board|substrate which has a liquid crystal aligning film manufactured by the method of Claim 3.

5 . A twisted nematic liquid crystal display element having the substrate according to claim 4 .

6. A method for producing a twisted nematic liquid crystal display element, comprising the following steps to obtain the twisted nematic liquid crystal display element:

the process of preparing the substrate according to claim 4, that is, the first substrate;

The process of obtaining the 2nd board|substrate which has a liquid crystal aligning film by having the following [I'], [II'], [III'] process to obtain the said liquid crystal aligning film provided with the orientation control ability: and,

[IV] A liquid crystal display element is obtained by arranging the first and second substrates to face each other so that the liquid crystal aligning films of the first and second substrates face each other with the liquid crystal interposed therebetween, and the ultraviolet exposure directions are orthogonal to each other. process,

[I'] a step of applying the polymer composition according to any one of claims 1 to 2 on a second substrate to form a coating film;

[II'] a step of irradiating polarized ultraviolet rays to the coating film obtained in [I']; and

[III'] A step of heating the coating film obtained in [II'].

7 . A twisted nematic liquid crystal display element produced by the method of claim 6 .