JP6701668B2 - Liquid crystal aligning agent, liquid crystal aligning film, method for producing liquid crystal aligning film, and liquid crystal element - Google Patents

Description

The present invention relates a liquid crystal aligning agent, a liquid crystal alignment film, the manufacturing method and the liquid crystal element of the liquid crystal alignment film.

  Liquid crystal display devices are widely used in televisions, mobile devices, various monitors and the like. A liquid crystal display device uses a liquid crystal alignment film for controlling the alignment of liquid crystal molecules in a liquid crystal cell. As a method for obtaining an organic film having a liquid crystal alignment regulating force, conventionally, a method of rubbing an organic film, a method of obliquely depositing silicon oxide, a method of forming a monomolecular film having a long-chain alkyl group, and a photosensitive organic film have been used. A method of irradiating a film with light (a photo-alignment method) is known.

  The photo-alignment method can give uniform liquid crystal alignment to the photosensitive organic film while suppressing the generation of static electricity and dust, and can also precisely control the liquid crystal alignment direction. Is being promoted (see, for example, Patent Document 1). Patent Document 1 discloses that a liquid crystal alignment film is formed using a liquid crystal alignment agent containing a polyimide precursor having a cinnamoyl group in the main chain, or polyimide or polyamide.

International Publication No. 2013/161984

  In recent years, large-screen, high-definition liquid crystal televisions have mainly been used, and small display terminals such as smartphones and tablet PCs have become widespread. Specifically, it is important for improving the display quality of the liquid crystal display device that afterimages are less likely to occur (afterimage characteristics) and that the contrast is good (contrast characteristics), and these characteristics are further improved. Is required.

  The present invention has been made in view of the above problems, and an object thereof is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal element having good afterimage characteristics and contrast characteristics.

  As a result of intensive studies to achieve the above-mentioned problems of the conventional technology, the present inventors can solve the above problems by producing a liquid crystal alignment film using a liquid crystal alignment agent containing a compound having a specific structure. Therefore, the present invention has been completed. Specifically, the following means are provided.

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子、ハロゲン原子、ニトロ基、シアノ基又は１価の有機基であり、Ｒ^３は置換基である。Ｘ^１は酸素原子又は−ＮＲ^４−（ただし、Ｒ^４は水素原子又は１価の有機基であり、Ｒ^４が他の基に結合して窒素原子と共に環構造を形成してもよい。）である。Ｒ^３は、他の基に結合して環の少なくとも一部を構成していてもよい。ｎは０〜３の整数である。ｎが２又は３の場合、複数のＲ^３は同じでも異なってもよい。「＊」は結合手を示す。）
［２］上記［１］の液晶配向剤を基板上に塗布して塗膜を形成する工程と、前記塗膜に光照射する工程と、を含む液晶配向膜の製造方法。
［３］上記［１］の液晶配向剤を用いて形成された液晶配向膜。
［４］上記［３］に記載の液晶配向膜を具備する液晶素子。
［５］ポリイミド前駆体、ポリイミド及びポリアミドよりなる群から選ばれる少なくとも一種の重合体であって、かつ上記式（１）で表される部分構造を有する重合体。
［６］下記式（２−１）で表されるジアミン。

（式（２−１）中、Ａ^１は下記式（１−１）で表される基又は下記式（１−２）で表される基であり、Ａ^２は単結合、下記式（１−１）で表される基又は下記式（１−２）で表される基である。Ｒ^５は、Ａ^１が下記式（１−１）で表される基の場合に２価の有機基であり、Ａ^１が下記式（１−２）で表される基の場合に単結合又は２価の有機基である。Ｒ^７は、Ａ^２が下記式（１−１）で表される基の場合に２価の有機基であり、Ａ^２が下記式（１−２）で表される基の場合に単結合又は２価の有機基であり、Ａ^２が単結合の場合に単結合である。Ｒ^６は２価の有機基である。Ｒ^６は２価の有機基である。ただし、下記式（１−１）及び式（１−２）中の「＊１」は、Ｒ^６に結合している。）

（式（１−１）及び式（１−２）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子、ハロゲン原子、ニトロ基、シアノ基又は１価の有機基であり、Ｒ^３は置換基である。Ｘ^１は酸素原子又は−ＮＲ^４−（ただし、Ｒ^４は水素原子又は１価の有機基であり、Ｒ^４が他の基に結合して窒素原子と共に環構造を形成してもよい。）である。ｎは０〜３の整数である。ｎが２又は３の場合、複数のＲ^３は同じでも異なってもよい。「＊１」及び「＊」は結合手を示す。）
［７］下記式（３−１）又は式（３−２）で表される酸二無水物。

（式（３−１）中、Ｒ^５１〜Ｒ^５４は、それぞれ独立に水素原子、ハロゲン原子、ニトロ基、シアノ基又は１価の有機基であり、ｉは０又は１である。Ｒ^５０は、ｉ＝０のときに単結合又は２価の有機基であり、ｉ＝１のときに２価の有機基である。Ｘ^１は、酸素原子又は−ＮＲ^４−（ただし、Ｒ^４は水素原子又は１価の有機基であり、Ｒ^４が他の基に結合して窒素原子と共に環構造を形成してもよい。）である。ただし、ｉ＝１の場合、式中の複数のＸ^１は独立して上記定義を有する。）

（式（３−２）中、Ｒ^５５及びＲ^５６は、それぞれ独立に３価の有機基であり、Ｒ^５７〜Ｒ^６０は、それぞれ独立に水素原子、ハロゲン原子、ニトロ基、シアノ基又は１価の有機基であり、ｋは０又は１である。Ｘ^１は、酸素原子又は−ＮＲ^４−（ただし、Ｒ^４は水素原子又は１価の有機基であり、Ｒ^４が他の基に結合して窒素原子と共に環構造を形成してもよい。）である。ただし、ｋ＝１の場合、式中の複数のＸ^１は独立して上記定義を有する。） [1] A liquid crystal aligning agent containing a compound (X) having a partial structure represented by the following formula (1).

(In the formula (1), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group or a monovalent organic group, and R ³ is a substituent. X ¹ is an oxygen atom. or -NR 4 - ^(. However, R ⁴ is a hydrogen atom or a monovalent organic group, wherein R ⁴ is bonded to another group with the nitrogen atom may form a ring structure) is .R ³ May be bonded to another group to form at least a part of the ring, n is an integer of 0 to 3. When n is 2 or 3, plural R ^{3 s} may be the same or different. Good. "*" indicates a bond.)
[2] A method for producing a liquid crystal alignment film, comprising the steps of applying the liquid crystal aligning agent of the above [1] on a substrate to form a coating film, and irradiating the coating film with light.
[3] A liquid crystal alignment film formed using the liquid crystal alignment agent according to [1] above.
[4] A liquid crystal device comprising the liquid crystal alignment film according to the above [3].
[5] A polymer having at least one kind of polymer selected from the group consisting of a polyimide precursor, polyimide and polyamide, and having a partial structure represented by the above formula (1).
[6] A diamine represented by the following formula (2-1).

(In the formula (2-1), A ¹ is a group represented by the following formula (1-1) or a group represented by the following formula (1-2), A ² is a single bond, and the following formula (1 -1) or a group represented by the following formula (1-2): R ⁵ is a divalent organic group when A ¹ is a group represented by the following formula (1-1). a group, .R ^{7 a 1} is a single bond or a divalent organic group in the case of a group represented by the following formula (1-2), ^{a 2} is represented by the following formula (1-1) Is a divalent organic group, A ² is a single bond or a divalent organic group when A ² is a group represented by the following formula (1-2), and A ² is a single bond. R ⁶ is a divalent organic group, R ⁶ is a divalent organic group, provided that “*1” in the following formulas (1-1) and (1-2) is , Bound to R ^6. )

(In the formulas (1-1) and (1-2), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group or a monovalent organic group, and R ³ is a substituent. X ¹ is an oxygen atom or —NR ⁴ — (wherein R ⁴ is a hydrogen atom or a monovalent organic group, R ⁴ is bonded to another group to form a ring structure with a nitrogen atom). N is an integer of 0 to 3. When n is 2 or 3, a plurality of R ³ 's may be the same or different. "*1" and "*" represent a bond. .)
[7] An acid dianhydride represented by the following formula (3-1) or formula (3-2).

(In formula (3-1), R ^{51 to} R ⁵⁴ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group or a monovalent organic group, and i is 0 or 1. R ⁵⁰ is , A single bond or a divalent organic group when i=0, and a divalent organic group when i=1. X ¹ is an oxygen atom or —NR ⁴ — (wherein R ⁴ is hydrogen. Is an atom or a monovalent organic group, and R ⁴ may be bonded to another group to form a ring structure together with a nitrogen atom), provided that when i=1, plural X's in the formula are represented. ¹ independently has the above definition.)

(In formula (3-2), R ⁵⁵ and R ⁵⁶ are each independently a trivalent organic group, and R ^{57 to} R ⁶⁰ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group or 1 It is a valent organic group and k is 0 or 1. X ¹ is an oxygen atom or —NR ⁴ — (wherein R ⁴ is a hydrogen atom or a monovalent organic group, and R ⁴ is another group. May combine with each other to form a ring structure with a nitrogen atom), provided that when k=1, a plurality of X ¹ 's in the formula independently have the above definitions.)

  With the liquid crystal aligning agent containing the compound (X), it is possible to obtain a liquid crystal element in which an afterimage (particularly, an afterimage due to an AC voltage) is unlikely to occur and which has good contrast characteristics.

The schematic block diagram of a FFS type liquid crystal display element. FIG. 3 is a schematic plan view of a top electrode used for manufacturing a liquid crystal display element by photo-alignment treatment. (A) is a top view of a top electrode, (b) is a partial enlarged view of a top electrode. The figure which shows the drive electrode of 4 systems.

  Hereinafter, each component contained in the liquid crystal aligning agent of the present invention and other components optionally blended as necessary will be described. In the present specification, the term “organic group” means a group containing a hydrocarbon group, and may have a hetero atom in its structure.

<Compound (X)>
The liquid crystal aligning agent of the present invention contains a compound having a partial structure represented by the above formula (1) (hereinafter also referred to as “compound (X)”).
In the above formula (1), examples of the monovalent organic group represented by R ¹ and R ² include an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, Examples thereof include a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an epoxy group, an alkylsilyl group and an alkoxysilyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Here, the alkyl group having 1 to 20 carbon atoms may be linear or branched, and specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group. , Heptyl group, octyl group, nonyl group, decyl group and the like. Examples of the alkoxy group having 1 to 20 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group and the like; examples of the fluoroalkyl group having 1 to 20 carbon atoms include perfluoromethyl group and perfluoromethyl group. Fluoroethyl group, 2,2,2-trifluoroethyl group and the like; Examples of cycloalkyl group having 3 to 20 carbon atoms include cyclopentyl group, cyclohexyl group and methylcyclohexyl group; aryl group having 6 to 20 carbon atoms Examples thereof include a phenyl group and a tolyl group; examples of the aralkyl group having 6 to 20 carbon atoms include a benzyl group and the like.
R ¹ and R ² are preferably a hydrogen atom, a fluorine atom, an alkyl group having 1 to 3 carbon atoms or a fluoroalkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group.

R ^{4 in} —NR ⁴ — is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a protecting group. Examples of the protecting group include a carbamate protecting group, an amide protecting group, an imide protecting group, a sulfonamide protecting group, and the like. A carbamate-based protecting group is preferable, and a t-butoxycarbonyl group is particularly preferable. R ⁴ may be bonded to another group to form a ring structure with the nitrogen atom. Examples of such a ring structure include a piperidine structure and a piperazine structure.
Examples of the substituent of R ³ include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a cyano group, an alkylsilyl group, an alkoxysilyl group, and an ester. Groups and the like. Examples of the ring formed by combining R ³ with another group include an imide ring and an acid anhydride group. n is preferably 0 or 1, and more preferably 0. In addition, the case where "*" in Formula (1) couple|bonds with a hydrogen atom is included. Further, “*” may be bonded to R ³ to form a ring structure such as an acid anhydride group.

The compound (X) may be a polymer component that can be the main component of the liquid crystal alignment film, or an additive component that is blended separately from the polymer component. When the compound (X) is a polymer, the compound (X) may have the partial structure represented by the above formula (1) in the main chain of the polymer or in the side chain. May be. Here, the “main chain” of the polymer in the present invention refers to a “stem” portion composed of the longest chain of atoms in the polymer. It should be noted that this "stem" portion is allowed to include a ring structure. Therefore, “having the partial structure represented by the above formula (1) in the main chain of the polymer” means that the partial structure constitutes a part of the main chain. However, it is not excluded that the partial structure represented by the above formula (1) is also present in a portion other than the main chain, for example, a side chain (a portion branched from the “stem” of the polymer).
Of these, the compound (X) is preferably a polymer having a partial structure represented by the above formula (1) from the viewpoint that the effect of exhibiting anisotropy by the photo-alignment method is high, and the compound represented by the above formula (1) It is particularly preferable that the polymer has a partial structure represented by (4) in the main chain.

  The main skeleton when the compound (X) is a polymer is not particularly limited, and examples thereof include polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenyl). Examples of the main skeleton include maleimide) derivatives and poly(meth)acrylates. Among these, at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyamide, polyorganosiloxane, and poly(meth)acrylate from the viewpoint of heat resistance, mechanical strength, affinity with liquid crystal, and the like. It is preferably a polymer, more preferably at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide and polyamide, selected from the group consisting of polyamic acid, polyamic acid ester and polyimide. More preferably, it is at least one polymer. The polymer used for preparing the liquid crystal aligning agent may be only one kind or two or more kinds. (Meth)acrylate is meant to include acrylates and methacrylates.

[Polyamic acid]
The polyamic acid (hereinafter, also referred to as “specific polyamic acid”) as the compound (X) can be obtained, for example, by reacting a tetracarboxylic dianhydride and a diamine. Specifically, [1] a method of polymerizing using a tetracarboxylic dianhydride having a partial structure represented by the above formula (1) (hereinafter, also referred to as “specific tetracarboxylic dianhydride”), [ 2] A method of polymerizing using a diamine having a partial structure represented by the above formula (1) (hereinafter also referred to as "specific diamine"), [3] using the specific tetracarboxylic dianhydride and the specific diamine. And the like, and the like.

(Tetracarboxylic acid dianhydride)
The specific tetracarboxylic acid dianhydride is not particularly limited in its remaining structure as long as it has the partial structure represented by the above formula (1). Preferred is a compound capable of introducing the partial structure represented by the above formula (1) into the main chain of the polymer, and specifically, the compound represented by the above formula (3-1) and the above formula (3-2). It is preferable to use at least one selected from the group consisting of the above compounds.
In the above formula (3-1), as the divalent organic group for R ⁵⁰ , for example, a divalent hydrocarbon group having 1 to 20 carbon atoms, a part of the methylene group contained in the hydrocarbon group is —O—, Examples thereof include a divalent group and a divalent heterocyclic group which are replaced with —CO—, —COO— or —NR ³³ — (R ³³ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). At least one hydrogen atom of the hydrocarbon group may be replaced with a substituent.
Here, the “hydrocarbon group” in the present specification is meant to include a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Among these, the “chain hydrocarbon group” means a straight chain hydrocarbon group or a branched hydrocarbon group which does not include a cyclic structure in the main chain and is composed of only a chain structure. However, it may be saturated or unsaturated. The “alicyclic hydrocarbon group” means a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. However, it does not need to be composed only of the structure of an alicyclic hydrocarbon, and a part thereof having a chain structure is also included. The “aromatic hydrocarbon group” means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, the structure need not be composed of only the aromatic ring structure, and a part thereof may include a chain structure or an alicyclic hydrocarbon structure.

Specific examples of the divalent hydrocarbon group having 1 to 20 carbon atoms of R ⁵⁰ include chain hydrocarbon groups such as methylene group, ethylene group, propanediyl group, butanediyl group, pentanediyl group, hexanediyl group and heptanediyl group. group, octane-diyl group, Nonanjiiru group, a decanediyl group or the like; alicyclic hydrocarbon groups such as a cyclohexylene ^{group, -R} 30 -R ³¹ - (provided ^{that, R 30} is ^{cyclohexylene, R 31} is And the like; as an aromatic hydrocarbon group, for example, a phenylene group, a biphenylene group, a naphthylene group, —Ar ³ —R ³² — (wherein Ar ³ is a phenylene group, a biphenylene group). Group or naphthylene group, and R ³² is an alkanediyl group having 1 to 3 carbon atoms or a cyclohexylene group.) and the like;
Examples of the divalent heterocyclic group for R ⁵⁰ include groups in which two hydrogen atoms have been removed from a nitrogen-containing heterocycle such as piperidine, piperazine and piperidine. Examples of the substituent that the divalent organic group for R ⁵⁰ may have include a halogen atom, an alkoxy group, a hydroxyl group, a carboxyl group, a cyano group and the like. With respect to R ^{51 to} R ⁵⁴ , the description of R ¹ and R ^{2 in} the above formula (1) can be applied. i is preferably 1.

（式（３−１−２９）及び式（３−１−３０）中、Ｒはフッ素原子又はメチル基であり、ｋ１は０〜２の整数である。式中の複数のＲは互いに同じでも異なっていてもよい。）

In the above formula (3-2), examples of the trivalent organic group for R ⁵⁵ and R ⁵⁶ include a group in which three hydrogen atoms have been removed from a benzene ring or a cyclohexane ring. With respect to R ^{57 to} R ⁶⁰ , the description of R ¹ and R ^{2 in} the above formula (1) can be applied. k is preferably 1.
Specific examples of the specific tetracarboxylic acid dianhydride include compounds represented by the above formula (3-1), for example, the following formulas (3-1-1) to (3-1-30) respectively. And the like; as the compound represented by the above formula (3-2), for example, compounds represented by the following formulas (3-2-1) to (3-2-12) and the like can be mentioned. be able to. In addition, the specific tetracarboxylic dianhydride can be used individually by 1 type or in combination of 2 or more types.

(In formula (3-1-29) and formula (3-1-30), R is a fluorine atom or a methyl group, and k1 is an integer of 0 to 2. Even if a plurality of Rs in the formula are the same as each other, It may be different.)

  In the case of the above methods [1] and [3], the tetracarboxylic dianhydride used in the synthesis of the specific polyamic acid may be only the specific tetracarboxylic dianhydride, but is represented by the above formula (1). The tetracarboxylic dianhydride having no such partial structure (hereinafter, also referred to as “other tetracarboxylic dianhydride”) may be used in combination. In addition, in the above method [2], the other tetracarboxylic acid dianhydride is used as the tetracarboxylic acid dianhydride in the synthesis of the specific polyamic acid. Examples of other tetracarboxylic acid dianhydrides include aliphatic tetracarboxylic acid dianhydrides, alicyclic tetracarboxylic acid dianhydrides, and aromatic tetracarboxylic acid dianhydrides.

（式（ＡＮ−２）中、Ｘ^１３及びＸ^１４は、それぞれ独立に、メチレン基から１個の水素原子を取り除いた基又は窒素原子であり、Ｒ^４１は炭素数１〜１０のアルカンジイル基である。式（ＡＮ−３）中、Ｘ^１５及びＸ^１６は、それぞれ独立に、メチレン基から１個の水素原子を取り除いた基又は窒素原子であり、Ｂ^１及びＢ^２は、それぞれ独立にフェニレン基又はピリジニレン基であり、Ｒ^４２は炭素数１〜１０のアルカンジイル基であり、ｍは１〜３の整数である。ただし、ｍが２又は３の場合、複数のＲ^４２は互いに同じでも異なってもよい。）
のそれぞれで表される化合物などを；
脂環式テトラカルボン酸二無水物として、例えば１，２，３，４−シクロブタンテトラカルボン酸二無水物、１，３−ジメチル−１，２，３，４−シクロブタンテトラカルボン酸二無水物、２，３，５−トリカルボキシシクロペンチル酢酸二無水物、５−（２，５−ジオキソテトラヒドロフラン−３−イル）−３ａ，４，５，９ｂ−テトラヒドロナフト［１，２−ｃ］フラン−１，３−ジオン、５−（２，５−ジオキソテトラヒドロフラン−３−イル）−８−メチル−３ａ，４，５，９ｂ−テトラヒドロナフト［１，２−ｃ］フラン−１，３−ジオン、３−オキサビシクロ［３．２．１］オクタン−２，４−ジオン−６−スピロ−３’−（テトラヒドロフラン−２’，５’−ジオン）、５−（２，５−ジオキソテトラヒドロ−３−フラニル）−３−メチル−３−シクロヘキセン−１，２−ジカルボン酸無水物、３，５，６−トリカルボキシ−２−カルボキシメチルノルボルナン−２：３，５：６−二無水物、ビシクロ［３．３．０］オクタン−２，４，６，８−テトラカルボン酸２：４，６：８−二無水物、ビシクロ［２．２．１］ヘプタン−２，３，５，６−テトラカルボン酸２：３，５：６−二無水物、４，９−ジオキサトリシクロ［５．３．１．０^２，６］ウンデカン−３，５，８，１０−テトラオン、１，２，４，５−シクロヘキサンテトラカルボン酸二無水物、ビシクロ［２．２．２］オクト−７−エン−２，３，５，６−テトラカルボン酸二無水物、シクロペンタンテトラカルボン酸二無水物、下記式（ＡＮ−４）

で表される化合物などを； Specific examples of the other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride, the following formula (AN-2) and formula (AN-3).

(In formula (AN-2), X ¹³ and X ¹⁴ are each independently a group in which one hydrogen atom is removed from a methylene group or a nitrogen atom, and R ⁴¹ is an alkanediyl group having 1 to 10 carbon atoms. In formula (AN-3), X ¹⁵ and X ¹⁶ are each independently a group in which one hydrogen atom is removed from a methylene group or a nitrogen atom, and B ¹ and B ² are each independently. It is a phenylene group or a pyridinylene group, R ⁴² is an alkanediyl group having 1 to 10 carbon atoms, and m is an integer of 1 to 3. However, when m is 2 or 3, a plurality of R ^42's are the same as each other. But it may be different.)
A compound represented by each of
As the alicyclic tetracarboxylic dianhydride, for example, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-Tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1 ,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 3-Oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5-(2,5-dioxotetrahydro-3 -Furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, 3,5,6-tricarboxy-2-carboxymethylnorbornane-2:3,5:6-dianhydride, bicyclo[ 3.3.0] Octane-2,4,6,8-tetracarboxylic acid 2:4,6:8-dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetra Carboxylic acid 2:3,5:6-dianhydride, 4,9-dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraone, 1,2,2. 4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, The following formula (AN-4)

A compound represented by

（式（ＡＮ−１）中、Ｘ^１１及びＸ^１２は、それぞれ独立に単結合、酸素原子、硫黄原子、−ＣＯ−、＊−ＣＯＯ−、＊−ＯＣＯ−、＊−ＣＯ−ＮＲ^２１−、＊−ＮＲ^２１−ＣＯ−（ただし、Ｒ^２１は水素原子又は炭素数１〜６の１価の炭化水素基である。「＊」は、Ｒ^２２との結合手を示す。）である。Ｒ^２２は、単結合、炭素数１〜２０の２価の炭化水素基、当該炭化水素基の炭素−炭素結合間に−Ｏ−を含む２価の基、又は窒素含有複素環を有する２価の基である。）
で表される化合物、下記式（ＡＮ−５−１）〜式（ＡＮ−５−４）

のそれぞれで表される化合物などを；それぞれ挙げることができるほか、特開２０１０−９７１８８号公報に記載のテトラカルボン酸二無水物を用いることができる。 As the aromatic tetracarboxylic dianhydride, for example, pyromellitic dianhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, the following formula (AN-1)

(In formula (AN-1), X ¹¹ and X ¹² are each independently a single bond, an oxygen atom, a sulfur atom, —CO—, *—COO—, *—OCO—, *—CO—NR ²¹ —, * ^-NR 21 -CO- ^{(However, R 21} is a monovalent hydrocarbon group having 1 to 6 carbon hydrogen atom or a carbon. "*" ^indicates a bond to ^{R 22.)} is .R ²² is a single bond, a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent group containing —O— between carbon-carbon bonds of the hydrocarbon group, or a divalent group having a nitrogen-containing heterocycle. It is a base.)
A compound represented by the following formula (AN-5-1) to formula (AN-5-4)

In addition to the compounds represented by each of the above; and the like, tetracarboxylic acid dianhydrides described in JP-A-2010-97188 can be used.

（式（ＡＮ−３−１）〜式（ＡＮ−３−１２）中、ｐは２〜６の整数である。式中の複数のｐは互いに同じでも異なっていてもよい。） In the above formulas (AN-2) and (AN-3), examples of the alkanediyl group having 1 to 10 carbon atoms of R ⁴¹ and R ⁴² include a methylene group, an ethylene group, a propylene group, a butanediyl group, a pentanediyl group, Examples thereof include a hexanediyl group, a heptanediyl group, an octanediyl group, a nonanediyl group and a decanediyl group, which may be linear or branched. B ¹ and B ² are preferably a 1,4-phenylene group or a 2,5-pyridinylene group.
Specific examples of the compound represented by the above formula (AN-2) include, for example, compounds represented by the following formula (a-2), and specific examples of the compound represented by the above formula (AN-3). Examples include, for example, compounds represented by the following formulas (AN-3-1) to (AN-3-12).

(In formula (AN-3-1) to formula (AN-3-12), p is an integer of 2 to 6. A plurality of p in the formula may be the same or different from each other.)

Specific examples of the divalent hydrocarbon group having 1 to 20 carbon atoms of R ^{22 in} the above formula (AN-1) include, for example, methylene group, ethylene group, propylene group, butanediyl group, pentanediyl group, hexanediyl group, heptanediyl. Group, octanediyl group, nonanediyl group, alkanediyl group such as decandiyl group; divalent alicyclic hydrocarbon group such as cyclohexylene group; divalent aromatic hydrocarbon group such as phenylene group and biphenylene group; Can be mentioned. The number of oxygen atoms that may be introduced between the carbon-carbon bonds of the hydrocarbon group may be one, or may be two or more. When R ²² is a divalent group having a nitrogen-containing heterocycle, examples of the nitrogen-containing heterocycle include a pyrrole ring, an imidazole ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a piperidine ring, a piperazine ring and a pyrrolidine ring. Etc.

なお、特定ポリアミック酸の合成に際し、テトラカルボン酸二無水物は１種を単独で又は２種以上組み合わせて使用することができる。 Specific examples of the compound represented by the above formula (AN-1) include, for example, compounds represented by the following formulas (AN-1-1) to (AN-1-27), and the following formula (a- Examples thereof include compounds represented by 1) and compounds represented by the following formula (a-3).

In the synthesis of the specific polyamic acid, the tetracarboxylic dianhydride may be used alone or in combination of two or more.

  As the other tetracarboxylic acid dianhydride, from the viewpoint of electrical characteristics, it is preferable to include at least one selected from the group consisting of an aliphatic tetracarboxylic acid dianhydride and an alicyclic tetracarboxylic acid dianhydride, Specifically, the compound represented by the above formula (a-2), bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic acid 2:3,5:6-dianhydride. 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride Anhydrous, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5 -Dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[3.3.0]octane-2 ,4,6,8-Tetracarboxylic acid 2:4,6:8-dianhydride, 4,4'-diamino-2,2'-dimethylbiphenyl, 1,3-propylene glycol bis(anhydrotrimellitate ) And at least one compound selected from the group consisting of cyclohexanetetracarboxylic dianhydride. The amount of these preferred compounds used (the total amount when two or more types are used) is preferably 10 mol% or more with respect to the total amount of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid. Is more preferably 20 mol% or more, still more preferably 50 mol% or more.

In the above method [1], the proportion of the specific tetracarboxylic dianhydride used is, relative to the total amount of the tetracarboxylic dianhydride used for the synthesis of the specific polyamic acid, from the viewpoint of providing sufficient photoreactivity. It is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more.
The specific tetracarboxylic dianhydride can be synthesized by appropriately combining conventional methods of organic chemistry. For example, a compound having “—C(R ¹ )═C(R ² )—CO—X ¹ —” is reacted with a phthalic acid derivative to give a tetracarboxylic acid having a partial structure represented by the above formula (1). A method of synthesizing an acid and then acidifying the obtained tetracarboxylic acid may be mentioned. However, the method for synthesizing the specific tetracarboxylic dianhydride is not limited to the above.

(Diamine)
The other structure of the specific diamine is not particularly limited as long as it has the partial structure represented by the above formula (1). When an alignment regulating force is applied to a coating film by using a photo-alignment method, the resulting liquid crystal display element has a high effect of reducing AC afterimage (afterimage caused by charge accumulation by applying an AC voltage) and improving contrast. It is preferable to use the compound represented by the above formula (2-1).
In the above formula (2-1), the description of R ^{50 in} the above formula (3-1) can be applied to the divalent organic groups of R ^{5 to} R ⁷ . R ⁵ and R ⁷ are preferably a phenylene group, a biphenylene group, a naphthylene group, a cyclohexylene group, or —Ar ⁴ —COO-* ³ (Ar ⁴ is a phenylene group, a biphenylene group, a naphthylene group or a cyclohexylene group. And "* ³ " represents a bond with the benzene ring in the formula (1). R ⁶ is preferably an alkanediyl group having 1 to 6 carbon atoms, a cyclohexylene group, a phenylene group, a biphenylene group or a naphthylene group. The description of the above formula (1) can be applied to the description of R ¹ , R ² , R ³ and X ^{1 in} the above formula (1-1).

（式（４）中、Ａｒ^１及びＡｒ^２は、それぞれ独立にフェニレン基又はシクロヘキシレン基であり、Ｘ^２は単結合、−ＣＯＯ−又は−ＣＯＮＲ^２０−（Ｒ^２０は水素原子又は１価の有機基である。）である。ｔは１又は２である。ｔ＝２のとき、Ａｒ^２，Ｘ^２は各々独立に上記定義を有する。「＊」は結合手を示す。） The specific diamine is preferably a compound having a partial structure represented by the following formula (4) in the molecule. Having the partial structure represented by the following formula (4) is preferable in that the effect of reducing the occurrence of AC afterimage in the liquid crystal display element can be enhanced.

(In the formula (4), Ar ¹ and Ar ² are each independently a phenylene group or a cyclohexylene group, X ² is a single bond, —COO— or —CONR ²⁰ — (R ²⁰ is a hydrogen atom or a monovalent group. It is an organic group.) t is 1 or 2. When t=2, Ar ² and X ² each independently have the above definition. “*” represents a bond.

（式中、「＊」は結合手を示す。） In the above formula (4), examples of the monovalent organic group for R ²⁰ include an alkyl group having 1 to 6 carbon atoms and a protecting group. Specific examples of the protecting group include t-butoxycarbonyl group, benzyloxycarbonyl group, 1,1-dimethyl-2-haloethyloxycarbonyl group, allyloxycarbonyl group and the like. X ² is preferably a single bond or —COO—. Preferred specific examples of the partial structure represented by the above formula (4) include, for example, 4,4′-biphenylene group, 4,4′-bicyclohexylene group, and the following formulas (4-1) to (4-4). ) And the like.

(In the formula, "*" indicates a bond.)

（式（ｂ−３４）〜式（ｂ−３９）、式（ｂ−４６）〜式（ｂ−５０）中、Ｒはフッ素原子又はメチル基であり、ｋ１は０〜２の整数である。式中の複数のＲ、複数のｋ１は、互いに同じでも異なっていてもよい。式（ｂ−４６）〜式（ｂ−５０）中、ｍは２〜１０の整数である。） Specific examples of the specific diamine include compounds represented by the following formulas (b-1) to (b-53). By using the compound represented by the above formula (2-1) as the specific diamine, a polymer having a partial structure represented by the above formula (1) in the main chain is preferred.

(In formula (b-34) to formula (b-39) and formula (b-46) to formula (b-50), R is a fluorine atom or a methyl group, and k1 is an integer of 0 to 2. A plurality of R's and a plurality of k1's in the formula may be the same or different from each other, and in the formulas (b-46) to (b-50), m is an integer of 2 to 10.)

  When synthesizing the specific polyamic acid, the specific diamines may be used alone or in combination of two or more. The above formulas (b-1), (b-2), (b-7), (b-11), formula (b-12), formula (b-16), formula (b-28) to formula (b). The compound represented by each of formula (-31) and formula (b-50) corresponds to the compound having the partial structure represented by formula (4).

  The specific diamine can be synthesized by appropriately combining conventional methods of organic chemistry. As an example thereof, a dinitro intermediate having a nitro group instead of the primary amino group of the compound represented by the above formula (2-1) is synthesized, and then the nitro group of the obtained dinitro intermediate is appropriately converted. The method of amination using a reduction system is mentioned. The method for synthesizing the dinitro intermediate can be appropriately selected depending on the target compound. For example, it is obtained by using a dehydration condensation reaction between a carboxylic acid having a group corresponding to the above formula (1) and an alcohol, a dehydration condensation reaction between a carboxylic acid having a group corresponding to the above formula (1) and an amine compound, and the like. be able to. The reduction reaction of the dinitro intermediate can be carried out preferably in an organic solvent using a catalyst such as palladium carbon, platinum oxide, zinc, iron, tin or nickel. Examples of the organic solvent used here include ethyl acetate, toluene, tetrahydrofuran, alcohols and the like. However, the procedure for synthesizing the specific diamine is not limited to the above method.

When synthesizing the specific polyamic acid by the method [2] or the method [3], the specific diamine may be used alone, or the diamine having no partial structure represented by the above formula (1) (others Diamine) may be used in combination. In the above method [1], the other diamine is used as the diamine.
Examples of such other diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, and diaminoorganosiloxanes. Specific examples of these include aliphatic diamines such as m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane and 2 , 2'-diamino-N-methyldiethylamine, a compound represented by the following formula (da-6), and the like; as an alicyclic diamine, for example, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine) A compound represented by the following formula (da-9), a compound represented by the following formula (da-10), and the like;

（式（Ｅ−１）中、Ｘ^I及びＸ^IIは、それぞれ独立に、単結合、−Ｏ−、−ＣＯＯ−又は−ＯＣＯ−であり、Ｒ^Ｉは炭素数１〜３のアルカンジイル基であり、Ｒ^ＩＩは単結合又は炭素数１〜３のアルカンジイル基であり、ａは０又は１であり、ｂは０〜２の整数であり、ｃは１〜２０の整数であり、ｄは０又は１である。ただし、ａ及びｂが同時に０になることはない。）
で表される化合物、下記式（ｄａ−１）又は式（ｄａ−２）

で表される化合物などの配向性基含有ジアミン： As the aromatic diamine, for example, dodecanoxydiaminobenzene, tetradecanoxydiaminobenzene, pentadecanoxydiaminobenzene, hexadecanoxydiaminobenzene, octadecanoxydiaminobenzene, cholestanyloxydiaminobenzene, cholesteryloxydiaminobenzene. , Cholestanyl diaminobenzoate, cholesteryl diaminobenzoate, lanostannyl diaminobenzoate, 3,6-bis(4-aminobenzoyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 1,1-bis(4 -((Aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((amino Phenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, N-(2,4-diaminophenyl) -4-(4-heptylcyclohexyl)benzamide, the following formula (E-1)

(In formula (E-1), X ^I and X ^II are each independently a single bond, —O—, —COO— or —OCO—, and R ^I is an alkanediyl group having 1 to 3 carbon atoms. R ^II is a single bond or an alkanediyl group having 1 to 3 carbon atoms, a is 0 or 1, b is an integer of 0 to 2, c is an integer of 1 to 20, and d is It is 0 or 1. However, a and b cannot be 0 at the same time.)
A compound represented by the following formula (da-1) or formula (da-2)

An orienting group-containing diamine such as a compound represented by:

（式（ｄａ−９）〜式（ｄａ−１１）中、ｕは２〜６の整数である。） p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl sulfide, 4-aminophenyl-4'-aminobenzoate, 4,4'-diaminoazobenzene, 1 ,5-bis(4-aminophenoxy)pentane, 1,7-bis(4-aminophenoxy)heptane, bis[2-(4-aminophenyl)ethyl]hexanedioic acid, N,N-bis(4-amino) Phenyl)methylamine, 1,5-diaminonaphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4 '-Diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis[4-(4-aminophenoxy) Phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(p-phenylenediisopropylidene)bisaniline, 1,4-bis(4-aminophenoxy)benzene, 4 ,4'-bis(4-aminophenoxy)biphenyl, 2,6-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 3,6-diaminocarbazole, N-methyl-3,6-diamino Carbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, 1,4-bis-(4-aminophenyl) -Piperazine, 3,5-diaminobenzoic acid, compounds represented by the following formula (da-3) to formula (da-5), formula (da-7) and formula (da-8), and the like;
Examples of the diaminoorganosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; and compounds represented by the following formula (da-11), JP-A-2010- The diamine described in 97188 can be used. As the diamine used for synthesizing the polyamic acid, one kind of these compounds may be used alone or two or more kinds may be appropriately selected and used.

(In the formulas (da-9) to (da-11), u is an integer of 2 to 6.)

In the case of synthesizing the specific polyamic acid by the above method [2], the use ratio of the specific diamine is such that the total amount of diamine used in the synthesis of the specific polyamic acid is from the viewpoint of imparting sufficient photoreactivity to the compound (X). On the other hand, it is preferably 10 mol% or more, more preferably 20 mol% or more, and further preferably 30 mol% or more.
When synthesizing the specific polyamic acid by the above method [3], the total amount of the specific tetracarboxylic dianhydride and the specific diamine is set to 10 mol% or more with respect to the total amount of the monomers used for the synthesis. The amount is preferably 20 mol% or more, more preferably 30 mol% or more.

のそれぞれで表される化合物などの酸一無水物、アニリン、シクロヘキシルアミン、ｎ−ブチルアミンなどのモノアミン化合物、フェニルイソシアネート、ナフチルイソシアネートなどのモノイソシアネート化合物等を挙げることができる。分子量調整剤の使用割合は、使用するテトラカルボン酸二無水物及びジアミンの合計１００重量部に対して、２０重量部以下とすることが好ましい。 (Synthesis of polyamic acid)
The polyamic acid can be obtained by reacting the above-mentioned tetracarboxylic acid dianhydride and diamine together with a molecular weight modifier, if necessary. The ratio of the tetracarboxylic dianhydride and the diamine used for the synthesis reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 with respect to 1 equivalent of the amino group of the diamine. The equivalent ratio is preferable. Examples of the molecular weight modifier include maleic anhydride, phthalic anhydride, itaconic anhydride, and the following formulas (F-1) to (F-4).

Examples thereof include acid monoanhydrides such as compounds represented by the above, monoamine compounds such as aniline, cyclohexylamine and n-butylamine, and monoisocyanate compounds such as phenyl isocyanate and naphthyl isocyanate. The ratio of the molecular weight modifier used is preferably 20 parts by weight or less based on 100 parts by weight of the total tetracarboxylic dianhydride and diamine used.

The synthesis reaction of polyamic acid is preferably carried out in an organic solvent. The reaction temperature at this time is preferably −20° C. to 150° C., and the reaction time is preferably 0.1 to 24 hours. Examples of the organic solvent used in the reaction include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons. Particularly preferred organic solvents are N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol. And at least one selected from the group consisting of halogenated phenols as a solvent, or selected from the group consisting of one or more of these and alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons. It is preferred to use a mixture with one or more of The amount (a) of the organic solvent used is such that the total amount (b) of the tetracarboxylic dianhydride and the diamine becomes 0.1 to 50% by weight based on the total amount (a+b) of the reaction solution. Is preferred.
As described above, a reaction solution obtained by dissolving polyamic acid is obtained. This reaction solution may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid contained in the reaction solution.

[Polyamic acid ester]
The polyamic acid ester as the compound (X) includes, for example, [I] a method of reacting a polyamic acid having a partial structure represented by the above formula (1) with an esterifying agent, and [II] a tetracarboxylic acid diester. It can be obtained by a method of reacting with a diamine, a method of reacting [III] tetracarboxylic acid diester dihalide with a diamine, or the like.
Examples of the esterifying agent used in the method [I] include hydroxyl group-containing compounds (methanol, ethanol, phenol, etc.), acetal compounds (N,N-dimethylformamide diethyl acetal, etc.), halides (methyl bromide, methyl chloride). Etc.) and epoxy group-containing compounds. In the method [II], at least one of a tetracarboxylic acid diester having a partial structure represented by the above formula (1) and a specific diamine is used. In the method [III], at least one of a tetracarboxylic acid diester dihalide having a partial structure represented by the above formula (1) and a specific diamine is used.
The polyamic acid ester contained in the liquid crystal aligning agent may have only an amic acid ester structure, or may be a partial esterified product having both an amic acid structure and an amic acid ester structure. The reaction solution obtained by dissolving the polyamic acid ester may be directly used for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after isolating the polyamic acid ester contained in the reaction solution. Good.

[Polyimide]
The polyimide as the compound (X) can be obtained, for example, by subjecting the polyamic acid as the compound (X) synthesized as described above to dehydration ring closure and imidization. Polyimide may be a completely imidized product obtained by dehydration ring closure of all of the amic acid structure of the precursor polyamic acid, dehydration ring closure of only a portion of the amic acid structure, amic acid structure and imide It may be a partial imidized compound having a ring structure. The imidation ratio of the polyimide used in the reaction is preferably 20% or more, more preferably 30 to 99%. The imidization ratio is a percentage of the ratio of the number of imide ring structures to the total number of amic acid structures and imide ring structures of polyimide. Here, a part of the imide ring may be an isoimide ring.

The dehydration ring closure of the polyamic acid is preferably carried out by a method of heating the polyamic acid or by dissolving the polyamic acid in an organic solvent and adding a dehydrating agent and a dehydration ring closure catalyst to the solution and heating the mixture as necessary. .. Of these, the latter method is preferable.
In the method of adding a dehydrating agent and a dehydration ring-closing catalyst to a solution of polyamic acid, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the amic acid structure of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol with respect to 1 mol of the dehydrating agent used. Examples of the organic solvent used for the dehydration ring closure reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature of the dehydration ring closure reaction is preferably 0 to 180° C., and the reaction time is preferably 1.0 to 120 hours.
In this way, a reaction solution containing polyimide is obtained. This reaction solution may be used as it is for preparing a liquid crystal aligning agent, or may be used for preparing a liquid crystal aligning agent after isolation of polyimide. In addition, the polyimide can also be obtained by imidization of polyamic acid ester.

The polyamic acid, polyamic acid ester, and polyimide as the compound (X) obtained as described above have a solution viscosity of 10 to 800 mPa·s when the solution is a 10% by weight solution. Is preferable, and one having a solution viscosity of 15 to 500 mPa·s is more preferable. In addition, the solution viscosity (mPa·s) of the above-mentioned polymer is based on a polymer solution having a concentration of 10% by weight prepared using a good solvent for the polymer (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.). , A value measured at 25° C. using an E-type rotational viscometer (the same applies to the following polymers).
The polystyrene-equivalent weight average molecular weight (Mw) of the polyamic acid, polyamic acid ester and polyimide of the present invention measured by gel permeation chromatography (GPC) is preferably 1,000 to 500,000, more preferably 2 1,000 to 300,000. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene-equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, and more preferably 10 or less. Within such a molecular weight range, good alignment and stability of the liquid crystal display device can be secured.

[polyamide]
The polyamide as the compound (X) can be obtained by, for example, a method of reacting a dicarboxylic acid with a diamine. Here, the dicarboxylic acid is preferably subjected to reaction with a diamine after acid chloride formation using a suitable chlorinating agent such as thionyl chloride.

The dicarboxylic acid used in the synthesis of the polyamide is not particularly limited, but for example, aliphatic dicarboxylic acids such as oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, and fumaric acid; cyclobutanedicarboxylic acid, cyclohexane Dicarboxylic acids having an alicyclic structure such as dicarboxylic acids; phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-carbonyl Examples thereof include dicarboxylic acids having an aromatic ring such as dibenzoic acid, 4-carboxycinnamic acid, and p-phenylenediacrylic acid. In addition, the dicarboxylic acid can be used individually by 1 type or in combination of 2 or more types.
As the diamine used when synthesizing the polyamide as the compound (X), a polyamide having a partial structure represented by the above formula (1) is obtained by using at least a part of the specific diamine. In addition, at the time of synthesis, you may use together other diamines as needed. The diamine may be used alone or in combination of two or more.

The use ratio of the dicarboxylic acid and the diamine used for the synthesis reaction of the polyamide is preferably such that the carboxyl group of the dicarboxylic acid is 0.2 to 2 equivalents relative to 1 equivalent of the amino group of the diamine. The reaction between the dicarboxylic acid (preferably acid chloride-dicarboxylic acid) and the diamine is carried out in an organic solvent, preferably in the presence of a base. The reaction temperature at this time is preferably 0° C. to 200° C., and the reaction time is preferably 0.5 to 48 hours. As the organic solvent, for example, tetrahydrofuran, dioxane, toluene, chloroform, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone and the like can be preferably used. The amount of the organic solvent used is preferably 400 to 900 parts by weight based on 100 parts by weight of the total amount of dicarboxylic acid and diamine. As the base used in the above reaction, for example, tertiary amines such as pyridine, triethylamine, N-ethyl-N,N-diisopropylamine and the like can be preferably used. The amount of the base used is preferably 2 to 4 mol with respect to 1 mol of the diamine.
As described above, a reaction solution obtained by dissolving polyamide is obtained. This reaction solution may be directly used for preparing the liquid crystal aligning agent, or may be used for preparing the liquid crystal aligning agent after isolating the polyamide contained in the reaction solution.

  The solution viscosity of the polyamide as the compound (X) preferably has a solution viscosity of 10 to 800 mPa·s when the solution has a concentration of 10% by weight, and a solution viscosity of 15 to 500 mPa·s. It is more preferable that the The polystyrene-reduced weight average molecular weight (Mw) of the polyamide measured by GPC is preferably 1,000 to 500,000, and more preferably 5,000 to 300,000.

[Polyorganosiloxane]
The polyorganosiloxane (hereinafter, also referred to as “specific polyorganosiloxane”) as the compound (X) can be obtained, for example, by hydrolyzing and condensing a hydrolyzable silane compound. As an example thereof, for example, [1] a hydrolyzable silane compound (s-1) having a partial structure represented by the above formula (1), or the silane compound (s-1) and other hydrolyzable compounds The method of hydrolyzing and condensing a mixture with the silane compound, [2] a hydrolyzable silane compound having an epoxy group (s-2), or a mixture of the silane compound (s-2) with another silane compound. The epoxy group-containing polyorganosiloxane is synthesized by hydrolysis and condensation, and then the obtained epoxy group-containing polyorganosiloxane and a carboxylic acid having a partial structure represented by the above formula (1) (hereinafter referred to as “specific carboxylic acid”). Also referred to as a).

（式（ｓ−１Ａ）中、Ｒ^８及びＲ^９は、それぞれ独立に炭素数１〜１２のアルキル基又は炭素数６〜１２のアリール基であり、Ｘ^３及びＸ^４は、それぞれ独立に炭素数１〜１２のアルコキシ基又はハロゲン原子である。ｒ１及びｒ２は、それぞれ独立に１又は２である。Ａ^１、Ａ^２、Ｒ^５、Ｒ^６及びＲ^７は上記式（２−１）と同義である。） Examples of the silane compound (s-1) include silane compounds having a partial structure represented by the above formula (1) in the molecular chain, and examples thereof include compounds represented by the following formula (s-1A).

(In the formula (s-1A), R ⁸ and R ⁹ are each independently an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and X ³ and X ⁴ are independently carbon atoms. It is an alkoxy group or a halogen atom of the formulas 1 to 12. r1 and r2 are each independently 1 or 2. A ¹ , A ² , R ⁵ , R ⁶ and R ⁷ are the same as those of the above formula (2-1). Synonymous.)

In the above formula (s-1A), specific examples of the alkyl group and aryl group of R ⁸ and R ⁹ and the alkoxy group of X ³ and X ⁴ are exemplified by R ¹ and R ² of the above formula (1). Among them, those having a corresponding carbon number can be mentioned. The description of the formula (2-1) can be applied to the respective examples and preferable specific examples of A ¹ , A ² , R ⁵ , R ⁶ and R ^{7 in} the formula (s-1A). The compound represented by the above formula (s-1A) can be synthesized by appropriately combining conventional methods of organic chemistry.
In the above synthesis, the use ratio of the silane compound (s-1) is preferably 5 mol% or more, more preferably 10 to 100 mol%, based on the total amount of the monomers used in the synthesis. More preferably, it is 10 to 80 mol %.

  Specific examples of the silane compound (s-2) include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropyl. Examples thereof include methyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane. As the silane compound (s-2), one of these may be used alone or in combination of two or more.

Other silane compounds are not particularly limited as long as they are hydrolyzable silane compounds, for example, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Alkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane;
3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(3 -Cyclohexylamino)propyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and the like alkoxysilanes containing nitrogen and sulfur atoms;
3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 6-(meth)acryloyloxyhexyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3- (Meth)acryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane and other unsaturated hydrocarbon-containing alkoxysilanes; trimethoxysilylpropylsuccinic anhydride, etc. Can be mentioned. Other silane compounds may be used alone or in combination of two or more.
In the method [1], the silane compound (s-2) may be used as the other silane compound, and in the method [2], the silane compound (s-1) is used as the other silane compound. May be.

  The hydrolysis/condensation reaction of the silane compound is carried out by reacting one or more of the above-mentioned silane compounds with water, preferably in the presence of a suitable catalyst and an organic solvent. In the hydrolysis/condensation reaction, the amount of water used is preferably 0.5 to 100 mol, and more preferably 1 to 30 mol, based on 1 mol of the silane compound (total amount). Examples of the catalyst used in the hydrolysis/condensation reaction include acids, alkali metal compounds, organic bases, titanium compounds and zirconium compounds. Of these, a tertiary or quaternary organic base is preferred. The amount of the organic base used depends on the type of the organic base, reaction conditions such as temperature and the like, and should be appropriately set, but is preferably 0.01 to 3 times by mole with respect to the total silane compound, More preferably, it is 0.05 to 1 times mol. Examples of the organic solvent used in the hydrolysis/condensation reaction include hydrocarbons, ketones, esters, ethers, alcohols and the like. Of these, it is preferable to use a water-insoluble organic solvent. The proportion of the organic solvent used is preferably 10 to 10,000 parts by weight with respect to 100 parts by weight of all silane compounds used in the reaction.

  The hydrolysis/condensation reaction is preferably carried out, for example, by heating with an oil bath or the like. At that time, the heating temperature is preferably 130° C. or lower, and the heating time is preferably 0.5 to 12 hours. After completion of the reaction, the organic solvent layer separated from the reaction solution is dried with a desiccant, if necessary, and then the solvent is removed, whereby the desired polyorganosiloxane can be obtained. The method of synthesizing the polyorganosiloxane is not limited to the above hydrolysis/condensation reaction, and for example, a method of reacting a hydrolyzable silane compound in the presence of oxalic acid and alcohol may be adopted.

（式（５）中、Ａ^１及びＡ^２は、それぞれ上記式（２−１）と同義である。ただし、上記式（１−１）及び式（１−２）中の「＊１」は、Ｒ^１３に結合する結合手を示す。Ｒ^１２は、Ａ^１が上記式（１−１）で表される基の場合に１価の有機基であり、Ａ^１が上記式（１−２）で表される基の場合に水素原子又は１価の有機基である。Ｒ^１３は２価の有機基である。Ｒ^１４は、Ａ^２が上記式（１−１）で表される基である場合に２価の有機基であり、Ａ^２が上記式（１−２）で表される基である場合に単結合又は２価の有機基である。ｓ及びｒは、それぞれ独立に０又は１である。ただし、式（５）中にカルボキシル基を１個有する。） In the above method [2], the epoxy group-containing polyorganosiloxane obtained by the above reaction is then reacted with a specific carboxylic acid. Thereby, the epoxy group of the epoxy group-containing polyorganosiloxane reacts with the carboxylic acid to obtain a polyorganosiloxane having a partial structure represented by the above formula (1) in the side chain. Specific examples of the specific carboxylic acid include compounds represented by the following formula (5).

(In the formula (5), A ¹ and A ² are respectively synonymous with the formula (2-1). However, “*1” in the formula (1-1) and the formula (1-2) is , R ¹³ is a bond to bond to R ^13. R ¹² is a monovalent organic group when A ¹ is a group represented by the above formula (1-1), and A ¹ is a group represented by the above formula (1-2). ) Is a hydrogen atom or a monovalent organic group, R ¹³ is a divalent organic group, and R ¹⁴ is a group in which A ² is represented by the above formula (1-1). Is a divalent organic group, and A ² is a group represented by the above formula (1-2), is a single bond or a divalent organic group, and s and r are each independently. 0 or 1, provided that the formula (5) has one carboxyl group.)

In the above formula (5), the monovalent organic group represented by R ¹² is, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a part of the methylene group of the hydrocarbon group is —O— or —CO. —, —COO— or —NR ³³ — (R ³³ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) is a monovalent group or a monovalent heterocyclic group. It may have a group. As an example of the divalent organic group of R ¹³ and R ¹⁴ , the description of R ^{5 to} R ^{7 in} the above formula (2-1) can be applied. The description of the above formula (1) can be applied to the description of R ¹ , R ² , R ³ and X ¹ of A ¹ and A ² .

  From the viewpoint of enhancing the effect of reducing the AC afterimage, the specific carboxylic acid preferably further has, in the molecule, the partial structure represented by the above formula (1) and the partial structure represented by the above formula (4). Note that the description of the specific diamine can be applied to the specific preferred examples of the partial structure represented by the above formula (4). In the reaction of the epoxy group-containing polyorganosiloxane and the specific carboxylic acid, the specific carboxylic acids may be used alone or in combination of two or more.

  The content of the partial structure represented by the formula (1) in one molecule of the specific polyorganosiloxane is 3 to 3 with respect to the silicon atom of the specific polyorganosiloxane from the viewpoint of improving the sensitivity to light. The amount is preferably 100 mol %, more preferably 5 to 95 mol %, further preferably 10 to 90 mol %. Therefore, when synthesizing the specific polyorganosiloxane, it is preferable to select the use ratio of the specific carboxylic acid so that the content ratio of the partial structure represented by the above formula (1) falls within the above range.

The specific carboxylic acid can be synthesized by appropriately combining conventional methods of organic chemistry. As one example thereof, for example, a compound represented by "R ¹² -A ¹ -H" and a compound represented by "HO-R ¹³ -A ² -R ¹⁴ -COOM (where M is a protecting group of a carboxyl group)" are represented. The compound can be obtained by, for example, a method of reacting with a compound, preferably in an organic solvent, if necessary in the presence of a catalyst, and then performing deprotection. However, the procedure for synthesizing the specific carboxylic acid is not limited to the above method.

  When synthesizing the specific polyorganosiloxane, the carboxylic acid used for the reaction with the epoxy group-containing polyorganosiloxane may be only the specific carboxylic acid, or other carboxylic acid other than the specific carboxylic acid may be used in combination. Other carboxylic acids are not particularly limited as long as they are carboxylic acids having no partial structure represented by the above formula (1). The other carboxylic acids may be used alone or in combination of two or more.

  The use ratio of the carboxylic acid to be reacted with the epoxy group-containing polyorganosiloxane is preferably 0.001 to 1.5 mol, and 0.01 to 1 mol, based on 1 mol of the total epoxy groups of the polyorganosiloxane. It is more preferable that the amount is 0.0 mol. From the viewpoint of sufficiently obtaining the effect of the present invention, the proportion of the other carboxylic acid used is preferably 80 mol% or less, and 50 mol% or less, based on the total amount of the carboxylic acid reacted with the epoxy group-containing polyorganosiloxane. It is more preferable that the content is not more than %.

The reaction between the epoxy group-containing polyorganosiloxane and the carboxylic acid can be carried out preferably in the presence of a catalyst and an organic solvent. As the catalyst to be used, for example, an organic base, a compound known as a so-called curing accelerator that accelerates the reaction of an epoxy compound, or the like can be used. The use ratio of the catalyst is preferably 100 parts by weight or less, and more preferably 0.01 to 100 parts by weight, based on 100 parts by weight of the epoxy group-containing polyorganosiloxane.
Examples of the organic solvent used in the above reaction include hydrocarbon, ether, ester, ketone, amide, alcohol and the like. Specific examples of particularly preferable solvents include 2-butanone, 2-hexanone, methyl isobutyl ketone, and butyl acetate. The organic solvent is preferably used in such a proportion that the solid content concentration (the ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) is 0.1% by weight or more. The reaction temperature in the above reaction is preferably 0 to 200°C, and the reaction time is preferably 0.1 to 50 hours.

  The specific polyorganosiloxane obtained as described above preferably has a solution viscosity of 1 to 500 mPa·s and a solution of 3 to 200 mPa·s when the solution has a concentration of 10% by weight. More preferably, it has viscosity. The polystyrene-reduced weight average molecular weight (Mw) of the specific polyorganosiloxane measured by GPC is preferably 1,000 to 200,000, more preferably 2,000 to 50,000, and It is more preferably 000 to 20,000.

[Poly(meth)acrylate]
The poly(meth)acrylate (hereinafter also referred to as “specific polymer (M)”) as the compound (X) can be prepared, for example, by the following method [1] or [2];
[1] A (meth)acrylic monomer (m-1) having a partial structure represented by the above formula (1), or the (meth)acrylic monomer (m-1) and other (meth)acrylic monomers. ) A method of polymerizing a mixture with an acrylic monomer in the presence of a polymerization initiator,
[2] Epoxy group-containing (meth)acrylic monomer (m-2), or a mixture of the (meth)acrylic monomer (m-2) and another (meth)acrylic monomer. Is polymerized in the presence of a polymerization initiator, and the resulting polymer (hereinafter, also referred to as “epoxy group-containing poly(meth)acrylate”) and a specific carboxylic acid are reacted with each other,
Etc. can be obtained.

（式（ｍ−１Ａ）中、Ｒ^１０及びＲ^１１は、それぞれ独立に水素原子又はメチル基である。Ａ^１、Ａ^２、Ｒ^５、Ｒ^６及びＲ^７は上記式（２−１）と同義である。） Examples of the (meth)acrylic monomer (m-1) include di(meth)acrylate compounds having a partial structure represented by the above formula (1) in the molecular chain, and include, for example, the following formula (m-1A). And the like.

(In the formula (m-1A), R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a methyl group. A ¹ , A ² , R ⁵ , R ⁶ and R ⁷ are the same as those in the formula (2-1). Synonymous.)

The description of the formula (2-1) can be applied to the respective exemplified and preferred specific examples of A ¹ , A ² , R ⁵ , R ⁶ and R ^{7 in} the formula (m-1A). The compound represented by the above formula (m-1A) can be synthesized by appropriately combining conventional methods of organic chemistry.
In the above synthesis, the use ratio of the monomer (m-1) is preferably 5 mol% or more, more preferably 10 to 100 mol% with respect to the total amount of the monomers used in the synthesis. , 10 to 90 mol% is more preferable.

Specific examples of the (meth)acrylic monomer (m-2) include glycidyl (meth)acrylate, glycidyl α-ethyl acrylate, 3,4-epoxybutyl (meth)acrylate, and (meth)acrylic. Acid 3,4-epoxycyclohexylmethyl, (meth)acrylic acid 6,7-epoxyheptyl, acrylic acid 4-hydroxybutyl glycidyl ether, (meth)acrylic acid (3-ethyloxetane-3-yl)methyl and the like. .. The (meth)acrylic monomer (m-2) can be used alone or in combination of two or more of the above.
Examples of other (meth)acrylic monomers include (meth)acrylic acid, (meth)acrylic acid ω-carboxypolycaprolactone, crotonic acid, α-ethylacrylic acid, maleic acid, fumaric acid, vinylbenzoic acid. Unsaturated carboxylic acids such as: alkyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, (meth ) Methoxyethyl acrylate, N-N-dimethylaminoethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate and the like (meth ) Unsaturated carboxylic acid esters such as acrylic acid esters; unsaturated polycarboxylic acid anhydrides such as maleic anhydride; and the like. As the other (meth)acrylic monomers, one kind may be used alone, or two or more kinds may be used in combination. In the above method [1], a (meth)acrylic monomer (m-2) may be used as the other (meth)acrylic monomer, and in the above method [2], another (meth)acryl monomer is used. A (meth)acrylic monomer (m-1) may be used as the acrylic monomer.

  At the time of polymerization, a monomer other than the (meth)acrylic monomer may be used. Examples of other monomers include conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene; aromatic vinyl compounds such as styrene, methylstyrene and divinylbenzene; The proportion of the other monomer used is preferably 30 mol% or less, and more preferably 20 mol% or less, based on the total amount of the monomers used for synthesizing the poly(meth)acrylate.

  The polymerization reaction using the (meth)acrylic monomer is preferably carried out by radical polymerization. Examples of the polymerization initiator used in the polymerization reaction include 2,2′-azobis(isobutyronitrile), 2,2′-azobis(2,4-dimethylvaleronitrile) and 2,2′-azobis(4 Azo compounds such as -methoxy-2,4-dimethylvaleronitrile) are preferred. The proportion of the polymerization initiator used is preferably 0.01 to 50 parts by weight with respect to 100 parts by weight of all the monomers used in the reaction. The polymerization reaction is preferably carried out in an organic solvent. Examples of the organic solvent used in the reaction include alcohols, ethers, ketones, amides, esters, hydrocarbon compounds and the like, with diethylene glycol methyl ethyl ether and propylene glycol monomethyl ether acetate being preferred. The amount (a) of the organic solvent used is such that the total amount (b) of the monomers used in the reaction is 0.1 to 50% by weight based on the total amount (a+b) of the reaction solution. Is preferred. The reaction temperature is preferably 30°C to 120°C, and the reaction time is preferably 1 to 36 hours.

In the above method [2], the epoxy group-containing poly(meth)acrylate obtained by the above reaction is then reacted with a specific carboxylic acid. Thereby, the epoxy group of the epoxy group-containing poly(meth)acrylate reacts with the carboxylic acid to obtain a poly(meth)acrylate having a partial structure represented by the above formula (1) in the side chain. .
As a specific example of the specific carboxylic acid, the description of the specific polyorganosiloxane can be applied. In the reaction, the specific carboxylic acid may be used alone, or another carboxylic acid other than the specific carboxylic acid may be used in combination. The proportion of the carboxylic acid to be reacted with the epoxy group-containing poly(meth)acrylate may be 0.001 to 0.95 mol based on 1 mol of the total epoxy groups of the epoxy group-containing poly(meth)acrylate. Preferably, it is more preferably 0.01 to 0.9 mol.

  The reaction between the epoxy group-containing poly(meth)acrylate and the carboxylic acid can be preferably carried out in the presence of a catalyst and an organic solvent. Among them, a quaternary ammonium salt is preferable as the catalyst. The amount of the catalyst used is preferably 100 parts by weight or less, more preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the epoxy group-containing poly(meth)acrylate. As the organic solvent used in the reaction, the examples of the organic solvent that can be used in the polymerization of the (meth)acrylic monomer can be applied, and among them, an ester is preferable. The organic solvent is preferably used in such a proportion that the solid content concentration (the ratio of the total weight of components other than the solvent in the reaction solution to the total weight of the solution) is 0.1% by weight or more. The reaction temperature is preferably 0 to 200° C., and the reaction time is preferably 0.1 to 50 hours.

Thus, a solution containing poly(meth)acrylate as the compound (X) can be obtained. This reaction solution may be used as it is for the preparation of the liquid crystal aligning agent, or may be used for the preparation of the liquid crystal aligning agent after isolating the poly(meth)acrylate contained in the reaction solution.
With respect to poly(meth)acrylate, the polystyrene-equivalent number average molecular weight (Mn) measured by GPC improves the liquid crystal alignment of the liquid crystal alignment film to be formed and secures the stability of the liquid crystal alignment over time. From this viewpoint, it is preferably 250 to 500,000, more preferably 500 to 100,000, and further preferably 1,000 to 50,000.

<Other ingredients>
The liquid crystal aligning agent of the present invention contains the compound (X) as described above, but may contain other components as necessary. For example, the liquid crystal aligning agent of the present invention may contain a polymer other than the above compound (X) for the purpose of improving solution characteristics and electric characteristics. Such other polymer is a polymer having no partial structure represented by the above formula (1), and its main skeleton is not particularly limited. Specifically, for example, polyamic acid, polyimide, polyamic acid ester, polyorganosiloxane, polyester, polyamide, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate and the like as the main skeleton Examples of the polymer include Among these, at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester, polyimide, polyorganosiloxane, poly(meth)acrylate and polyamide is preferable. When another polymer is added to the liquid crystal aligning agent, the mixing ratio is preferably 90 parts by weight or less based on 100 parts by weight of the total amount of the polymers contained in the liquid crystal aligning agent, The amount is more preferably 80 parts by weight, further preferably 0.1 to 70 parts by weight.

  As other components, additives usually used for preparing a liquid crystal aligning agent can be used. As the additives other than the above, for example, a compound having at least one epoxy group in the molecule, a functional silane compound, a compound having a photopolymerizable group, a photosensitizer, having at least one oxetanyl group in the molecule Examples thereof include compounds, antioxidants, surfactants and dispersants. The blending ratio of these can be appropriately selected according to the compound.

<Solvent>
The liquid crystal aligning agent of the present invention is prepared as a liquid composition in which the above-mentioned specific compound and other components used as necessary are dispersed or dissolved in a suitable solvent.
Examples of the organic solvent used include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, N,N-dimethylacetamide, 4-hydroxy-4-methyl-2-pentanone, Ethylene glycol monomethyl ether, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether , Ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone , Isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate and the like. These may be used alone or in admixture of two or more.

The liquid crystal aligning agent in the present invention may contain only one kind of polymer as a polymer component, or may contain two or more kinds of polymers. In the case of containing two or more kinds of polymers, for example, the following [1] to [3] are exemplified.
[1] A polymer (hereinafter, also referred to as “specific polymer”) as the compound (X) and another polymer, and the specific polymer and the other polymer are polyamic acid, polyamic acid ester and An embodiment in which at least one selected from polyimide is used.
[2] An embodiment containing a plurality of specific polymers, and the plurality of specific polymers is at least one selected from polyamic acid, polyamic acid ester, and polyimide.
[3] An embodiment containing a specific polymer and another polymer, wherein the specific polymer is polyorganosiloxane, and the other polymer is at least one selected from polyamic acid, polyamic acid ester and polyimide.

（式（６）及び式（７）中、Ｒ^６１は４価の有機基であり、Ｒ^６２は２価の有機基であり、Ｘ^６１及びＸ^６２は、それぞれ独立に水酸基又は１価の有機基である。ただし、Ｒ^６１及びＲ^６２は、次の（ｉ）及び（ｉｉ）の少なくとも一方を満たす。（ｉ）Ｒ^６１が、上記式（３−１）又は上記式（３−２）で表される化合物から２つの酸無水物基を取り除いた残基である。（ｉｉ）Ｒ^６２が、上記式（２−１）で表される化合物から２つの１級アミノ基を取り除いた残基である。）
Ｘ^６１及びＸ^６２の１価の有機基は、１価の炭化水素基又は桂皮酸構造を有する基が好ましい。 The compound (X) is at least one compound selected from the group consisting of polyamic acid, polyamic acid ester, and polyimide, and is a compound represented by the above formula (2-1) and a compound represented by the above formula (3-1). It is preferably a polymer having a partial structure derived from at least one compound selected from the group consisting of the compound represented and the compound represented by the formula (3-2). That is, a polymer having at least one selected from the group consisting of the partial structure represented by the following formula (6) and the partial structure represented by the following formula (7) is preferable.

(In Formula (6) and Formula (7), R ⁶¹ is a tetravalent organic group, R ⁶² is a divalent organic group, and X ⁶¹ and X ⁶² are independently a hydroxyl group or a monovalent organic group. However, R ⁶¹ and R ⁶² satisfy at least one of the following (i) and (ii): (i) R ⁶¹ is the above formula (3-1) or the above formula (3-2). It is a residue obtained by removing two acid anhydride groups from the compound represented by: (ii) R ⁶² is a residue obtained by removing two primary amino groups from the compound represented by the formula (2-1). It is a base.)
The monovalent organic group of X ⁶¹ and X ⁶² is preferably a monovalent hydrocarbon group or a group having a cinnamic acid structure.

The reason why the effect of improving the afterimage characteristics and the contrast characteristics of the liquid crystal display element is obtained when the liquid crystal aligning agent containing the compound (X) is used is not clear, but one hypothesis is that, for example, polarized radiation In the molecular chain of the compound (X) in which the long axis direction of the molecular chain is parallel to the polarization direction, the “—CR ¹ ═CR ² —CO—” portion in the above formula (1) becomes cis-form. It is presumed that isomerization and further cyclization proceeded to break the molecular chain (see scheme A below). As a result, it was speculated that anisotropy was developed in the direction perpendicular to the polarization direction, and the coating film was provided with sufficient liquid crystal alignment ability, and as a result, the afterimage characteristics and the contrast characteristics of the liquid crystal display element could be improved. It

  The solid content concentration (ratio of the total weight of components other than the solvent of the liquid crystal aligning agent to the total weight of the liquid crystal aligning agent) in the liquid crystal aligning agent of the present invention is appropriately selected in consideration of viscosity, volatility and the like. , Preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent in the present invention is applied to the surface of the substrate as described later and preferably heated to form a coating film which is a liquid crystal alignment film or a coating film which becomes a liquid crystal alignment film. At this time, if the solid content concentration is less than 1% by weight, the film thickness of the coating film becomes too small, and it becomes difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes excessively large, and it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases and the coating property deteriorates. There is a tendency. The temperature for preparing the liquid crystal aligning agent is preferably 10 to 50°C, more preferably 20 to 30°C.

<Liquid crystal alignment film and liquid crystal element>
A liquid crystal alignment film can be manufactured by using the liquid crystal aligning agent described above. Further, the liquid crystal element of the present invention comprises a liquid crystal alignment film formed using the above liquid crystal alignment agent. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited, and various operations such as TN type, STN type, VA type (including VA-MVA type, VA-PVA type, etc.), IPS type, FFS type, OCB type, etc. Can be applied to any mode.

The liquid crystal element of the present invention can be manufactured, for example, by steps including the following steps (1-1) to (1-3). In the step (1-1), the substrate used differs depending on the desired operation mode. Steps (1-2) and (1-3) are common to each operation mode.
[Step (1-1): Formation of coating film]
First, the liquid crystal aligning agent of the present invention is applied onto a substrate, and then the applied surface is heated to form a coating film on the substrate.
(1-1A) For example, when manufacturing a TN type, STN type or VA type liquid crystal display device, first, a pair of two substrates provided with a patterned transparent conductive film is formed, and each transparent conductive film is formed. The liquid crystal aligning agent of the present invention is applied onto each surface, preferably by an offset printing method, a spin coating method, a roll coater method or an inkjet printing method. As the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, poly (alicyclic olefin) can be used. As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ) and the like are used. Can be used.

  After applying the liquid crystal aligning agent, preheating (prebaking) is preferably carried out for the purpose of preventing liquid dripping of the applied liquid crystal aligning agent. The prebake temperature is preferably 30 to 200° C., and the prebake time is preferably 0.25 to 10 minutes. Then, a baking (post-baking) step is carried out for the purpose of completely removing the solvent and, if necessary, thermal imidization of the amic acid structure present in the polymer. The baking temperature (post-baking temperature) at this time is preferably 80 to 300° C., and the post-baking time is preferably 5 to 200 minutes. The film thickness of the film thus formed is preferably 0.001 to 1 μm.

  (1-1B) When manufacturing an IPS-type or FFS-type liquid crystal display element, an electrode formation surface of a substrate provided with electrodes made of a comb-shaped patterned transparent conductive film or a metal film, and electrodes are provided. The liquid crystal aligning agent of the present invention is applied to one surface of the counter substrate which is not formed, and then the applied surface is heated to form a coating film. The materials of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the coating film formed are as described above. It is the same as (1-1A). As the metal film, for example, a film made of a metal such as chromium can be used.

  In any of the above (1-1A) and (1-1B), a liquid crystal alignment film or a coating film to be a liquid crystal alignment film is formed by removing the organic solvent after applying the liquid crystal alignment agent on the substrate. It At this time, by further heating after forming the coating film, a dehydration ring-closing reaction of the polyamic acid, polyamic acid ester and polyimide blended in the liquid crystal aligning agent of the present invention may proceed to give a more imidized coating film.

[Step (1-2): Alignment ability imparting treatment]
When manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display device, a treatment for imparting a liquid crystal aligning ability to the coating film formed in the step (1-1) is performed. As a result, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. As the orientation ability imparting treatment, for example, a rubbing treatment of rubbing the coating film in a certain direction with a roll wound with a cloth made of fibers such as nylon, rayon, and cotton, photo-alignment for irradiating the coating film with polarized or unpolarized radiation Examples include processing. From the photoreactivity of the compound (X), the point that uniform liquid crystal orientation can be imparted to the coating film while suppressing the generation of static electricity and dust, and the point that the liquid crystal orientation direction can be precisely controlled, It is preferable to use the photo-alignment method.

The light irradiation in the photo-alignment treatment is [1] a method of irradiating the coating film after the post-baking step, [2] a method of irradiating the coating film after the pre-baking step and before the post-baking step, [3] ] It can be performed by a method of irradiating the coating film during heating of the coating film in at least one of the pre-baking step and the post-baking step. Of these, the method [1] or [2] is preferable because the effect of improving the afterimage characteristics and the contrast characteristics of the liquid crystal display element is high. As the radiation for irradiating the coating film, for example, ultraviolet rays and visible rays containing light having a wavelength of 150 to 800 nm can be used. The radiation may be polarized or unpolarized. As the light source used, for example, a low pressure mercury lamp, a high pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, etc. can be used. The irradiation dose of radiation is preferably 100 to 50,000 J/m ² , and more preferably 300 to 20,000 J/m ² . The coating film may be irradiated with light while heating the coating film in order to increase the reactivity. The temperature at the time of heating is usually 30 to 250°C, preferably 40 to 200°C, and more preferably 50 to 150°C.

  It should be noted that the liquid crystal alignment film after the rubbing treatment is further processed by irradiating a part of the liquid crystal alignment film with ultraviolet rays to change the pretilt angle of a part of the liquid crystal alignment film, A resist film may be formed on each part and then a rubbing process may be performed in a direction different from that of the previous rubbing process, and then the resist film may be removed so that the liquid crystal alignment film has different liquid crystal aligning ability for each region. .. In this case, it is possible to improve the visibility characteristics of the obtained liquid crystal display element. The liquid crystal alignment film suitable for a VA type liquid crystal display element can also be suitably used for a PSA (Polymer sustained alignment) type liquid crystal display element. After irradiating the coating film on the substrate with light, the substrate surface may be washed with, for example, water, an organic solvent, or a mixture thereof. Examples of the organic solvent include alcohols (methanol, ethanol, etc.), 1-methoxy-2-propanol, 1-methoxy-2-propanol acetate, butyl cellosolve, ethyl lactate, diacetone alcohol, methyl 3-methoxypropionate, 3- Examples thereof include ethyl ethoxypropionate, propyl acetate, butyl acetate, cyclohexyl acetate and the like. By such washing, it becomes possible to remove the low molecular weight component generated by the light irradiation. After washing, heat treatment may be performed as necessary to remove the solvent used. Further, after the light irradiation of the coating film on the substrate, a treatment of further heating the coating film may be performed in order to remove the low molecular weight components. The heating temperature at this time is preferably in the range of 150 to 300°C, and more preferably in the range of 200 to 290°C. The heating time is preferably 5 to 60 minutes, more preferably 5 to 15 minutes.

[Step (1-3): Construction of Liquid Crystal Cell]
(1-3A) A liquid crystal cell is manufactured by preparing two substrates on which a liquid crystal alignment film is formed as described above, and disposing a liquid crystal between the two substrates that are opposed to each other. In order to manufacture a liquid crystal cell, for example, two substrates are arranged to face each other with a gap (cell gap) so that the respective liquid crystal alignment films face each other, and the peripheral portion of the two substrates is sealed with a sealant. By bonding, filling the liquid crystal into the cell gap defined by the substrate surface and the sealant, and then sealing the injection hole, applying the sealant on one substrate, and then applying the sealant on the surface of the liquid crystal alignment film. After dropping the liquid crystal at a predetermined number of locations, the other substrate is attached so that the liquid crystal alignment films face each other, the liquid crystal is spread over the entire surface of the substrate, and then the sealing agent is cured.

  As the sealant, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic liquid crystal and smectic liquid crystal, and among them, nematic liquid crystal is preferable, for example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenylcyclohexane liquid crystal. Liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, and the like can be used. These liquid crystals include, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate; chiral agents such as those sold under the trade names "C-15" and "CB-15" (manufactured by Merck); Ferroelectric liquid crystal such as p-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate may be added and used.

  Then, a polarizing plate is attached to the outer surface of the liquid crystal cell to obtain the liquid crystal display element of the present invention. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing plate in which a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented to absorb iodine and sandwiched between cellulose acetate protective films or the H film itself is used. A polarizing plate consisting of

  INDUSTRIAL APPLICABILITY The liquid crystal display device of the present invention can be effectively applied to various uses, for example, watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, It can be used for various display devices such as various monitors, liquid crystal televisions, information displays, and light control films. The liquid crystal element formed by using the liquid crystal aligning agent of the present invention can also be applied to a retardation film.

  Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

In the following examples, the weight average molecular weight Mw of the polymer was measured by the following method. In the following, the compound represented by the formula A may be simply referred to as “compound A”.
[Weight average molecular weight Mw of polymer]: It is a polystyrene conversion value measured by GPC under the following conditions.
Column: Tosoh Corp., TSKgelGRCXLII
Solvent: Tetrahydrofuran Temperature: 40°C
Pressure: 68 kgf/cm ²

<Synthesis of compound>
[Example 1-1: Synthesis of compound (b-1)]
Compound (b-1) was synthesized according to the following scheme 1.

5.0 g of 4-nitrosalicylaldehyde was dissolved in 200 ml of N,N-dimethylformamide, and this solution was cooled to 0°C. 8.15 g of imidazole and 9.02 g of t-butyldimethylchlorosilane were added thereto, and the mixture was stirred at room temperature for 16 hours. Then, pure water was added and extraction was performed with ethyl acetate. The organic layer was concentrated to obtain 8.0 g of intermediate (b-1-1) with a purity of 99%.
The obtained intermediate (b-1-1) (8.0 g) and malonic acid (5.92 g) were dissolved in pyridine (50 ml), and piperidine (5.6 ml) was added thereto, followed by stirring at 80°C for 5 hours. After allowing the reaction solution to cool to room temperature, 50 ml of ethyl acetate was added, and then 50 ml of hydrochloric acid was added to separate it. After separating again with pure water, this was concentrated to obtain 8.0 g of Intermediate (b-1-2) with a purity of 99%.
The obtained intermediate (b-1-2) (8.0 g) was added to thionyl chloride (30 ml), N,N-dimethylformamide was added in a catalytic amount, and then the mixture was stirred at 80°C for 1 hr. The reaction solution was concentrated, and the residue was dissolved in 80 ml of tetrahydrofuran (this solution was used as reaction solution (A)). Separately from this, 4.8 g of 4-amino-4′-nitrobiphenyl and 4.6 g of triethylamine were added to 40 ml of tetrahydrofuran, which was cooled to 0° C. and stirred for 5 minutes. Then, the reaction solution (A) was slowly added dropwise to this solution. After completion of the dropping, the reaction was completed by stirring at room temperature for 4 hours. After adding 300 ml of ethyl acetate and 100 ml of tetrahydrofuran and separating the solution with hydrochloric acid, an aqueous solution of sodium carbonate and pure water, this was concentrated, and 10.5 g of the intermediate (b-1-3) was obtained with a purity of 99%. Obtained.
10.5 g of the obtained intermediate (b-1-3) was dissolved in 80 ml of tetrahydrofuran, 30 ml of a 1 mol/L tetrahydrofuran solution of tetrabutylammonium fluoride was added thereto, and the mixture was stirred at room temperature for 2 hours. Then, 100 ml of ethyl acetate was added, the solution was separated with pure water, and then concentrated to obtain 8.0 g of an intermediate (b-1-4) with a purity of 99%.
8.0 g of the obtained intermediate (b-1-4) and 7.9 g of zinc powder were added to 100 ml of tetrahydrofuran, and 5.9 g of acetic acid was further added. Then, it stirred at 60 degreeC for 5 hours. The reaction solution was allowed to cool to room temperature, 150 ml of ethyl acetate was added, and the solution was separated with pure water, and then concentrated to obtain 6.2 g of compound (b-1) in 99% purity.

[Example 1-2: Synthesis of compound (b-2)]
A compound (b-2) was obtained by the same method as in Example 1-1, except that methylmalonic acid was used instead of malonic acid in the second step of Scheme 1 in Example 1-1.
[Example 1-3: Synthesis of compound (b-4)]
Compound (b) was synthesized in the same manner as in Example 1-1 except that 4-amino-4′-nitrobiphenyl was changed to 4-nitroaniline in the third step of Scheme 1 of Example 1-1. -4) was obtained.
[Example 1-4: Synthesis of compound (b-9)]
In the third step of Scheme 1 of Example 1-1, 4-amino-4′-nitrobiphenyl was changed to 1,4-cyclohexanediamine, and the equivalent number of the charged amount of 1,4-cyclohexanediamine was changed to Example 1 Compound (b-9) was obtained by the same method as in Example 1-1, except that the charged amount of 4-amino-4′-nitrobiphenyl of -1 was halved.
[Example 1-5: Synthesis of compound (b-12)]
In the second step of scheme 1 of Example 1-1, malonic acid was changed to methylmalonic acid, and in the third step of scheme 1, 4-amino-4′-nitrobiphenyl was replaced with 4-hydroxy-4′-nitro. Compound (b-12) was obtained by the same method as in Example 1-1 except that biphenyl was used.

<Synthesis of polymer>
[Example 2-1: Synthesis of polymer (A-1)]
Dissolve 100 mol parts of 4,4′-oxydiphthalic anhydride as a tetracarboxylic acid dianhydride and 100 mol parts of a compound (b-1) as a diamine in N-methyl-2-pyrrolidone (NMP), and heat the mixture at 60° C. Was reacted for 6 hours to obtain a solution containing 20% by weight of polyamic acid. The weight average molecular weight Mw of the obtained polyamic acid (polymer (A-1)) was 45,000.
[Examples 2-2 to 2-8 and Synthesis examples 1-1 and 1-2]
Polyamic acid (polymers (A-2) to (A-8)) was prepared in the same manner as in Example 2-1 except that the types and amounts of the tetracarboxylic dianhydride and diamine used were changed as shown in Table 1 below. And polymers (B-1) and (B-2)) were respectively synthesized.

In Table 1, the values in parentheses for tetracarboxylic dianhydride and diamine represent the ratio [mol part] of each compound to 100 mol parts of the total tetracarboxylic dianhydride used in the synthesis of the polymer. The abbreviations in Table 1 have the following meanings.
<Tetracarboxylic acid dianhydride>
a-1: 4,4′-oxydiphthalic anhydride a-2: the compound represented by the above formula (a-2) a-3:1,3-propylene glycol bis(anhydrotrimellitate) (the above formula (Compound represented by (a-3))
a-4: 1,2,3,4-cyclobutanetetracarboxylic dianhydride a-5:4,4'-(hexafluoroisopropylidene)diphthalic anhydride a-6: pyromellitic dianhydride a- 7:1,2,4,5-cyclohexanetetracarboxylic dianhydride <diamine>
b-1: compound represented by the above formula (b-1) b-2: compound represented by the above formula (b-2) b-4: compound represented by the above formula (b-4) b- 9: Compound represented by the above formula (b-9) b-12: Compound represented by the above formula (b-12) c-1: Compound represented by the following formula (c-1) c-2: Compound represented by the following formula (c-2) c-3: p-phenylenediamine c-4: N,N-bis(4-aminophenyl)methylamine

[Example 3-1]
1. Preparation of Liquid Crystal Alignment Agent NMP and butyl cellosolve (BC) were added to a solution containing the polymer (A-1) obtained in Example 2-1 as a polymer component, and the mixture was sufficiently stirred to give a solvent composition of NMP. :BC=70:30 (weight ratio), and a solution having a solid content concentration of 3.0% by weight was prepared. A liquid crystal aligning agent was prepared by filtering this solution using a filter having a pore size of 0.45 μm.

2. Production of Optical FFS Type Liquid Crystal Display Element An FFS type liquid crystal display element 10 shown in FIG. 1 was produced. First, a bottom electrode 15 having no pattern, a silicon nitride film as an insulating layer 14, and a comb-shaped patterned top electrode 13 are formed in this order on a glass substrate 11a having an electrode pair on one side, and an electrode. The opposite glass substrate 11b not provided with is paired, and the surface of the glass substrate 11a having the transparent electrode and the one surface of the opposite glass substrate 11b are each subjected to the above 1. The liquid crystal aligning agent prepared in 1. was applied using a spinner to form a coating film.
A schematic plan view of the top electrode 13 used is shown in FIG. 2(a) is a top view of the top electrode 13, and FIG. 2(b) is an enlarged view of a portion C1 surrounded by a broken line in FIG. 2(a). In this example, the line width d1 of the electrodes was 4 μm, and the distance d2 between the electrodes was 6 μm. Further, as the top electrode 13, four-system drive electrodes of an electrode A, an electrode B, an electrode C and an electrode D were used (FIG. 3). The bottom electrode 15 acts as a common electrode that acts on all four drive electrodes, and each of the four drive electrode regions serves as a pixel region.
After forming the coating film by the spinner, the coating film was pre-baked on a hot plate at 80° C. for 1 minute. Then, each surface of the coating film was irradiated with polarized ultraviolet rays of 5,000 J/m ² using a Hg-Xe lamp and a Glan-Taylor prism to obtain a pair of substrates having a liquid crystal alignment film. At this time, the irradiation direction of the polarized ultraviolet rays is from the substrate normal direction, and the polarization plane direction is set so that the direction of the line segment projecting the polarized surface of the polarized ultraviolet rays on the substrate is the direction of the double-headed arrow in FIG. 2B. After setting, light irradiation processing was performed. After irradiation with light, heating (post-baking) was performed at 230° C. for 1 hour in an oven in which the inside of the chamber was replaced with nitrogen to form a coating film having an average film thickness of 0.1 μm.

Next, after applying an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 3.5 μm by screen printing to the outer periphery of the surface of one of the substrates having the liquid crystal alignment film, the liquid crystal alignment film faces of the pair of substrates were applied. They were opposed to each other, and they were superposed and pressure-bonded so that the polarization planes of polarized ultraviolet rays were parallel to each other, and the adhesive was thermoset at 150° C. for 1 hour. Next, a liquid crystal "MLC-7028" manufactured by Merck & Co., Inc. was filled in the substrate gap from the liquid crystal injection port, and then the liquid crystal injection port was sealed with an epoxy resin adhesive. Then, in order to remove the flow orientation at the time of liquid crystal injection, this was heated to 150° C. and then gradually cooled to room temperature. Next, a FFS type liquid crystal display device was manufactured by bonding polarizing plates to both outer surfaces of the substrate. At this time, one of the polarizing plates was attached so that its polarization direction was parallel to the projection direction of the polarization plane of the polarized ultraviolet light of the liquid crystal alignment film onto the substrate surface, and the other one had the polarization direction first. The polarizing plate was attached so as to be orthogonal to the polarization direction of the polarizing plate.
Further, by performing the above-described series of operations while changing the ultraviolet irradiation amount before post-baking in the range of 100 to 10,000 J/m ² , respectively, three or more liquid crystal display elements having different ultraviolet irradiation amounts can be obtained. Manufactured.

3. Evaluation of liquid crystal display device 2. The following evaluation (1) was performed using the liquid crystal display element manufactured in. In addition, except for the point that the polarizing plates were not stuck together, the above 2. A liquid crystal display device (a liquid crystal cell in which a polarizing plate is not attached) was manufactured by performing the same operation as in (1), and the following (2) was evaluated. Regarding the evaluation result, the best result was selected from three or more liquid crystal display elements having different ultraviolet irradiation doses and used for evaluation of the liquid crystal display element.
(1) Evaluation of AC afterimage characteristics 2. The FFS type liquid crystal display element manufactured in 1. was placed in an environment of 25° C. and 1 atm. The bottom electrode was used as a common electrode for all four drive electrodes, and the potential of the bottom electrode was set to 0V potential (ground potential). While the electrodes B and D were short-circuited to the common electrode and 0 V was applied, a synthetic voltage composed of an AC voltage of 5 V was applied to the electrodes A and C for 100 hours. Immediately after 100 hours, a voltage of AC 1.5 V was applied to all of the electrodes A to D. Then, from the time when a voltage of AC 1.5 V is started to be applied to all of the electrodes A to D, the driving stress application region (pixel regions of the electrodes A and C) and the driving stress non-application region (electrodes B and D). The time until it becomes impossible to visually confirm the difference in luminance from the pixel area) is defined as the afterimage erasing time Ts. It should be noted that the shorter this time is, the less likely the afterimage will occur. When the afterimage erasing time Ts was less than 30 seconds, it was "good (O)", when it was 30 seconds or more and less than 120 seconds, it was "OK", and when it was 120 seconds or more, it was "Bad (x)". )”, the liquid crystal display device of this example was evaluated as “good” in afterimage characteristics.

(2) Evaluation of contrast after driving stress The liquid crystal display device manufactured in 1. was driven for 30 hours at an alternating voltage of 10 V, and then a device in which a polarizer and an analyzer were arranged between a light source and a light amount detector was used, and the minimum relative value represented by the following formula (1) was used. The transmittance (%) was measured.
Minimum relative transmittance (%)=(β−B ⁰ )/(B ¹⁰⁰ −B ⁰ )×100 (1)
(In Formula (1), B ⁰ is a blank transmission amount of light under crossed Nicols. B ¹⁰⁰ is a blank transmission amount of light under para Nicols. β is a polarizer under crossed Nicols. The liquid crystal display element is sandwiched between the analyzers to minimize the amount of light transmission.)
The black level in the dark state is represented by the minimum relative transmittance of the liquid crystal display element, and the smaller the black level in the dark state, the better the contrast. Those with a minimum relative transmittance of less than 0.5% are considered "good (○)" and those with a minimum relative transmittance of 0.5% or more and less than 1.0% are considered "acceptable (△)" and those of 1.0% or more are evaluated. It was defined as “poor (x)”. As a result, the contrast evaluation of this liquid crystal display element was judged to be “good”.

[Examples 3-2 to 3-7 and Comparative Example 1]
Liquid crystal aligning agents were prepared with the same solvent ratio and solid content concentration as in Example 3-1 except that the type of polymer used was changed as shown in Table 2 below. Further, a liquid crystal display element was manufactured in the same manner as in Example 3-1 using each liquid crystal aligning agent, and various evaluations were performed using the obtained liquid crystal display element. The results are shown in Table 2 below. In Table 2, the value in parentheses in the polymer column indicates the blending ratio [parts by weight] of each polymer to 100 parts by weight in total of the polymer components used in the preparation of the liquid crystal aligning agent.
[Example 3-8]
A liquid crystal aligning agent was prepared with the same solvent ratio and solid content concentration as in Example 3-1 except that the type of the polymer used was changed to the polymer (A-8). A liquid crystal display device was manufactured in the same manner as in Example 3-1 except that the liquid crystal aligning agent prepared in this example was used and that the photo-alignment treatment with polarized ultraviolet light was performed after post-baking. Various evaluations were performed using the obtained liquid crystal display element. The results are shown in Table 2 below.

  With respect to the liquid crystal display device manufactured using the liquid crystal aligning agent containing the compound (X), the evaluations of the AC afterimage characteristics and the contrast characteristics were “good” or “good” in each of the examples. (Example 3-1 to Example 3-8). Further, when a diamine having a polycyclic structure such as a biphenyl structure is used, or by using a diamine having a structure in which a plurality of partial structures represented by the above formula (1) are connected, the effect of improving the AC afterimage characteristics is improved. Was found to be high (Example 3-1 to Example 3-5, Example 3-7). On the other hand, the liquid crystal aligning agent of the comparative example not containing the compound (X) was inferior to those of the examples in AC afterimage characteristics and contrast characteristics.

[Example 3-9]
The types of polymers to be used are two types, polymer (A-3) and polymer (A-8), and the blending ratio of each polymer is polymer (A-3):polymer (A-8)= A liquid crystal aligning agent was prepared with the same solvent ratio and solid content concentration as in Example 3-1, except that the ratio was 50:50 (weight ratio). Further, instead of performing the irradiation with polarized ultraviolet rays and post-baking in this order after using the liquid crystal aligning agent prepared in this example, post-baking is first performed at 230° C. for 30 minutes, and then polarization is performed. Example 3 above except that it was irradiated with ultraviolet rays, then immersed in ethyl lactate at 25°C for 3 minutes, rinsed with isopropanol for 1 minute, and then dried in an oven at 80°C in which the interior of the chamber was replaced with nitrogen for 10 minutes. A liquid crystal display element was manufactured in the same manner as in Example 1, and various evaluations were performed in the same manner as in Example 3-1. As a result, in this example, both the AC afterimage characteristics and the contrast characteristics were evaluated as “good”.

[Example 3-10]
The types of polymers to be used are two types, that is, the polymer (A-7) and the polymer (B-2), and the blending ratio of each polymer is polymer (A-7):polymer (B-2)= A liquid crystal aligning agent was prepared with the same solvent ratio and solid content concentration as in Example 3-1 except that the ratio was 20:80 (weight ratio). Further, instead of performing the irradiation with polarized ultraviolet rays and post-baking in this order after using the liquid crystal aligning agent prepared in this example, post-baking is first performed at 230° C. for 30 minutes, and then polarization is performed. Example 3-1: A liquid crystal display device was manufactured in the same manner as in Example 3-1 except that it was heated for 10 minutes in an oven at 230°C in which the inside of the chamber was replaced with nitrogen, after being irradiated with ultraviolet rays. Various evaluations were performed in the same manner as in. As a result, in this example, both the AC afterimage characteristics and the contrast characteristics were evaluated as “good”.

  10... Liquid crystal display element, 11a, 11b... Glass substrate, 12... Liquid crystal alignment film, 13... Top electrode, 14... Insulating layer, 15... Bottom electrode, 16... Liquid crystal layer.

Claims (5)

Compound (X) which is a polymer obtained by using a compound represented by the following formula (2-1), which is at least one polymer selected from the group consisting of polyamic acid, polyamic acid ester and polyimide Liquid crystal aligning agent contained.

(In the formula (2-1), A ¹ is a group represented by the following formula (1-1) or a group represented by the following formula (1-2), A ² is a single bond, and the following formula (1 -1) or a group represented by the following formula (1-2): R ⁵ is a divalent organic group when A ¹ is a group represented by the following formula (1-1). a group, .R ^{7 a 1} represents a single bond or a divalent organic group in the case of a group represented by the following formula (1-2), ^{a 2} is represented by the following formula (1-1) Is a divalent organic group, A ² is a single bond or a divalent organic group when A ² is a group represented by the following formula (1-2), and A ² is a single bond. R ⁶ is a divalent organic group, provided that “*1” in the following formulas (1-1) and (1-2) is bonded to R ^6. )

(In the formulas (1-1) and (1-2), R ¹ and R ² are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group or a monovalent organic group, and R ³ is a substituent. X ¹ is an oxygen atom or —NR ⁴ — (wherein R ⁴ is a hydrogen atom or a monovalent organic group, R ⁴ is bonded to another group to form a ring structure with a nitrogen atom). N is an integer of 0 to 3. When n is 2 or 3, a plurality of R ³ 's may be the same or different. "*1" and "*" represent a bond. .) The liquid crystal aligning agent according to claim 1, wherein the compound represented by the formula (2-1) has a partial structure represented by the following formula (4) in the molecule.

(In formula (4), Ar ¹ and Ar ² are each independently a phenylene group or a cyclohexylene group, X ² is a single bond, —COO— or —CONR ²⁰ — (R ²⁰ is a hydrogen atom or a monovalent group. It is an organic group.) t is 1 or 2. When t=2, Ar ² and X ² each independently have the above definition. “*” represents a bond.   A method for producing a liquid crystal alignment film, comprising the steps of applying the liquid crystal alignment agent according to claim 1 or 2 onto a substrate to form a coating film, and irradiating the coating film with light.   A liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1.   A liquid crystal device comprising the liquid crystal alignment film according to claim 4.

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