TW202122563A - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal element - Google Patents

Abstract

A polymer (A) having structural units derived from at least one monomer selected from the group consisting of a compound represented by formula (1) and a compound represented by formula (2) is included in this liquid crystal alignment agent. In the formulas, of R1 and R2, one of R1 and R2 is a univalent group having a polymerizable group and the other is a hydrogen atom or a univalent organic group, or R1 and R2 are combined with each other to represent a ring structure formed along with the nitrogen atom to which R1 and R2 are bonded. However, the ring structure has a polymerizable carbon-carbon unsaturated bond. In the formulas, A1 is a univalent organic group, and A2 is a hydroxyl group or a univalent organic group. In the formulas, 0 ≤ n1 + n2 ≤ 8 is satisfied.

Description

Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal element, polymer and compound

The invention relates to a liquid crystal alignment agent, a liquid crystal alignment film and a liquid crystal element.

The liquid crystal element includes a liquid crystal alignment film that aligns liquid crystal molecules in a certain direction. Generally, the liquid crystal alignment film is formed by coating a liquid crystal alignment agent obtained by dissolving a polymer component in an organic solvent on a substrate, and preferably heating. As the polymer component of the liquid crystal alignment agent, polyamide acid or soluble polyimide has been used from the past in terms of excellent mechanical strength, liquid crystal alignment, and affinity with liquid crystals.

As a method of imparting liquid crystal alignment ability to a polymer film formed of a liquid crystal alignment agent, a photo-alignment method has been proposed as a technique instead of the rubbing method. The photo-alignment method is a method of irradiating a radiation-sensitive organic film formed on a substrate with polarized or non-polarized radiation to impart anisotropy to the film, thereby controlling the alignment of the liquid crystal.

As a liquid crystal alignment agent for forming a liquid crystal alignment film by a photo-alignment method, there is provided a liquid crystal alignment agent containing a polymer containing a main skeleton different from polyamide acid and soluble polyimide (for example, refer to Patent Document 1 or Patent Document 2). Patent Document 1 discloses a photo-alignment composition containing a reaction product of a polymer having a maleic anhydride structure and a primary amine compound having a photo-alignment group. Patent Document 2 discloses a photo-alignment composition comprising poly(maleimide) and poly(maleimide-styrene) as the main chain and a photosensitive group introduced into the side chain. And a second polymer having a long-chain alkyl group in the side chain. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Korean Patent Publication No. 2015-138548 [Patent Document 2] Japanese Patent No. 2962473

[The problem to be solved by the invention] The angle (pretilt angle) between the long axis of the liquid crystal molecules and the substrate surface greatly affects the display characteristics of the liquid crystal element. The inventors of the present invention have made the following attempt: to control the alignment of the liquid crystal in a manner that the long axis of the liquid crystal molecule is inclined at a moderate angle with respect to the vertical direction (for example, the pretilt angle is 89 degrees or less), thereby obtaining a better Higher-precision liquid crystal elements. However, it is known that when the alignment film material of Patent Document 1 or Patent Document 2 is used to form a liquid crystal alignment film, the long axis of the liquid crystal molecules cannot be sufficiently tilted with respect to the vertical direction, and the pretilt angle is higher than a desired angle.

In addition, in recent years, in the heating step during film formation, it is sometimes required to use a low-boiling point solvent as the solvent component of the liquid crystal alignment agent for the purpose of enabling low-temperature sintering. When the polymer component is not uniformly dissolved in the solvent, uneven coating may occur in the liquid crystal alignment film formed on the substrate, and a flat film may not be formed (poor coating uniformity). In this case, there is a concern that the product yield may be reduced, or display performance such as liquid crystal alignment or electrical characteristics may be affected.

Furthermore, in the case of forming a liquid crystal alignment film by low-temperature baking, the pretilt angle of the liquid crystal alignment film may deviate from the previous high-temperature baking (for example, heat treatment at a temperature of about 230°C to 250°C) And the pretilt angle of the obtained liquid crystal alignment film. Such a deviation in the pretilt angle (hereinafter, also referred to as "post-baking margin") caused by the difference in heating temperature during film formation affects the display quality of the liquid crystal element, so it is desirable to be as small as possible.

The present invention was developed in view of the above situation, and its main purpose is to provide a liquid crystal alignment agent that can form a liquid crystal alignment film with good coating uniformity and excellent pretilt angle characteristics. [Means to solve the problem]

In order to solve the above-mentioned problem, the inventors of the present invention used a polymer having a specific ring structure as a polymer component of the liquid crystal alignment agent. As a result, they found that the above-mentioned problem can be solved. Specifically, according to the present invention, the following means are provided.

（式（1）及式（2）中，R¹ 及R² 表示R¹ 及R² 中的一者為具有聚合性基的一價基、另一者為氫原子或一價有機基，或者R¹ 及R² 彼此結合而與R¹ 及R² 所鍵結的氮原子一起構成的環結構；其中，所述環結構具有聚合性碳-碳不飽和鍵；A¹ 為一價有機基，A² 為羥基或一價有機基；n1及n2分別獨立地為滿足0≦n1+n2≦8的整數）。 [2] 一種液晶配向膜，其是使用所述[1]的液晶配向劑而形成。 [3] 一種液晶元件，包括所述[2]的液晶配向膜。 [4] 一種聚合物，具有源自選自由所述式（1）所表示的化合物及所述式（2）所表示的化合物所組成的群組中的至少一種單量體的結構單元。 [5] 一種化合物，其由所述式（1）表示。 [6] 一種化合物，其由所述式（2）表示。 [發明的效果][1] A liquid crystal alignment agent containing a polymer (A), the polymer (A) having a composition derived from a compound represented by the following formula (1) and a compound represented by the following formula (2) At least one singular structural unit in the group, [化1]

(In formulas (1) and (2), R ¹ and R ² represent that one of R ¹ and R ² is a monovalent group having a polymerizable group, and the other is a hydrogen atom or a monovalent organic group, or R ¹ and R ² are bonded to each other ^{to form a ring structure together with the nitrogen atom to which R 1} and R ² are bonded; wherein the ring structure has a polymerizable carbon-carbon unsaturated bond; A ¹ is a monovalent organic group, A ² is a hydroxyl group or a monovalent organic group; n1 and n2 are each independently an integer satisfying 0≦n1+n2≦8). [2] A liquid crystal alignment film formed using the liquid crystal alignment agent of [1]. [3] A liquid crystal element including the liquid crystal alignment film of [2]. [4] A polymer having a structural unit derived from at least one monomer selected from the group consisting of the compound represented by the formula (1) and the compound represented by the formula (2). [5] A compound represented by the above formula (1). [6] A compound represented by the above formula (2). [Effects of the invention]

By making the liquid crystal alignment agent contain the polymer (A), a liquid crystal alignment agent with good coating uniformity can be obtained. In addition, by using the liquid crystal alignment agent to form a liquid crystal alignment film, the tilt angle of the liquid crystal molecules with respect to the vertical direction can be sufficiently increased, and the deviation of the pretilt angle caused by the difference in heating temperature during film formation can be reduced. That is, according to the liquid crystal alignment agent, a liquid crystal alignment film having excellent pretilt angle characteristics can be formed.

（式（1）及式（2）中，R¹ 及R² 表示R¹ 及R² 中的一者為氫原子或一價有機基、另一者為具有聚合性基的一價基，或者R¹ 及R² 彼此結合而與R¹ 及R² 所鍵結的氮原子一起構成的環結構；其中，所述環結構具有聚合性碳-碳不飽和鍵；A¹ 為一價有機基，A² 為羥基或一價有機基；n1及n2分別獨立地為滿足0≦n1+n2≦8的整數）Hereinafter, matters related to the present invention will be described in detail. "Liquid Crystal Aligning Agent" The liquid crystal aligning agent of the present disclosure contains a polymer (A) derived from a compound represented by the following formula (1) and a compound represented by the following formula (2) The structural unit U1 of at least one monomer (R1) in the group consisting of the compound. [化2]

(In formula (1) and formula (2), R ¹ and R ² represent that one of R ¹ and R ² is a hydrogen atom or a monovalent organic group, and the other is a monovalent group having a polymerizable group, or R ¹ and R ² are bonded to each other ^{to form a ring structure together with the nitrogen atom to which R 1} and R ² are bonded; wherein the ring structure has a polymerizable carbon-carbon unsaturated bond; A ¹ is a monovalent organic group, A ² is a hydroxyl group or a monovalent organic group; n1 and n2 are each independently an integer satisfying 0≦n1+n2≦8)

<Polymer (A)> (Structural unit U1) In the above-mentioned formula (1) and formula (2) ^{, examples of the monovalent organic groups of A 1} and A ² include monovalent hydrocarbon groups having 1 to 40 carbon atoms, At least one methylene group of the hydrocarbon group is substituted with -O-, -CO-, -COO-, -NR ¹⁰ -or -CONR ^10- (wherein R ¹⁰ is a hydrogen atom or a monovalent hydrocarbon group) (hereinafter, also (Referred to as "group α"), a monovalent hydrocarbon group having 1 to 40 carbon atoms, or a group in which at least one hydrogen atom of the group α is substituted with a fluorine atom or a cyano group.

Here, in this specification, the "hydrocarbon group" means a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The "chain hydrocarbon group" refers to a linear hydrocarbon group and a branched hydrocarbon group that do not contain a cyclic structure in the main chain but are composed of only a chain structure. Among them, it may be saturated or unsaturated. The "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic hydrocarbon structure as a ring structure and not containing an aromatic ring structure. Among them, it is not necessary to consist only of the structure of alicyclic hydrocarbons, and those having a chain structure in a part thereof are also included. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it does not need to be composed only of an aromatic ring structure, and a chain structure or a structure of alicyclic hydrocarbon may be included in a part thereof.

When the liquid crystal alignment agent of the present disclosure is used as a polymer composition for forming a photo-alignment film, A ¹ in the formula (1) is preferably a monovalent group having a photo-alignment group. The photo-alignment group possessed by A ¹ is preferably imparted to the film by a photoisomerization reaction, a photodimerization reaction, a photo Fries rearrangement reaction, or a photolysis reaction by light irradiation. Anisotropic functional group.

（式（3）中，R¹¹ 及R¹² 分別獨立地為氫原子、氟原子、氰基、碳數1～3的烷基、或碳數1～3的氟烷基，R¹³ 為可具有氟原子或氰基的碳數1～10的烷基、可具有氟原子或氰基的碳數1～10的烷氧基、氟原子、或氰基；a為0～4的整數；於a為2以上的情況下，多個R¹³ 為相同的基或不同的基；「*」表示結合鍵）In ^{the case where A 1} has a photoalignment group, specific examples of the photoalignment group include: an azobenzene-containing group containing azobenzene or its derivative as a basic skeleton, a group containing cinnamic acid or Derivatives (cinnamic acid structure) as the basic skeleton of a cinnamic acid structure-containing group, a chalcone-containing group containing chalcone or its derivative as the basic skeleton, a chalcone-containing group containing benzophenone or its derivative as the basic skeleton A benzophenone-containing group with a basic skeleton, a coumarin-containing group containing a coumarin or its derivative as a basic skeleton, a phenyl-containing benzene containing a phenyl benzoate or a derivative thereof as a basic skeleton An acid ester group, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, and the like. In terms of high photosensitivity, among these, the photo-alignment group is preferably a group containing a cinnamic acid structure. Specifically, it is particularly preferable that the group includes a cinnamic acid structure represented by the following formula (3) as a basic skeleton. [化3]

(In formula (3), R ¹¹ and R ¹² are each independently a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 3 carbons, or a fluoroalkyl group having 1 to 3 carbons, and R ¹³ may have A fluorine atom or a C1-C10 alkyl group of a cyano group, a C1-C10 alkoxy group which may have a fluorine atom or a cyano group, a fluorine atom, or a cyano group; a is an integer of 0 to 4; in a In the case of 2 or more, multiple R ¹³ groups are the same group or different groups; "*" indicates a bonding bond)

In the structure represented by the formula (3), in terms of further improving the photoreactivity, it is preferable that both R ¹¹ and R ¹² are hydrogen atoms, or one of them is a hydrogen atom and the other ( Preferably, R ¹² ) is an alkyl group having 1 to 3 carbons. R ^{13 is} preferably an alkyl group having 1 to 5 carbons, more preferably an alkyl group having 1 to 3 carbons. a is preferably 0-2, more preferably 0 or 1.

（式（4）中，X¹ 於鍵結於式（3）中的苯基的情況下，為單鍵、碳數1～3的烷二基、氧原子、硫原子、-CH=CH-、-NH-、-COO-或-OCO-，於鍵結於式（3）中的羰基的情況下，為單鍵、碳數1～3的烷二基、氧原子、硫原子或-NH-；R¹⁴ 及R¹⁵ 分別獨立地為經取代或未經取代的伸苯基、或者經取代或未經取代的伸環己基，R¹⁶ 為苯基或環己基、或者苯基或環己基的至少一個氫原子經碳數1～10的烷基、碳數1～10的烷氧基、至少一個氫原子經氟原子或氰基取代的碳數1～10的取代烷基、至少一個氫原子由氟原子或氰基取代的碳數1～10的取代烷氧基、氟原子、或氰基取代的一價基；r為0～3的整數；於r為2以上的情況下，多個R¹⁵ 為相同的基或不同的基；「*」表示結合鍵）In terms of more appropriately controlling the pretilt angle of the obtained liquid crystal element, it is preferable that one of the two bonding keys "*" in the formula (3) is bonded to have a total of one The group of at least one of the above benzene ring and cyclohexane ring is more preferably bonded to a group having at least one of a total of two or more benzene rings and cyclohexane rings. Specifically, it is preferable that one of the two bonding bonds "*" in the formula (3) is a bonding bond with a group represented by the following formula (4). [化4]

(In formula (4), when X ^{1 is} bonded to the phenyl group in formula (3), it is a single bond, a C1-C3 alkanediyl group, an oxygen atom, a sulfur atom, -CH=CH- , -NH-, -COO- or -OCO-, when bonded to the carbonyl group in formula (3), it is a single bond, a C1-C3 alkanediyl group, an oxygen atom, a sulfur atom or -NH -; R ¹⁴ and R ¹⁵ are each independently substituted or unsubstituted phenylene, or substituted or unsubstituted cyclohexyl, R ¹⁶ is phenyl or cyclohexyl, or phenyl or cyclohexyl At least one hydrogen atom is substituted by an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a substituted alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom or a cyano group, and at least one hydrogen atom A substituted alkoxy group having 1 to 10 carbon atoms, a fluorine atom, or a cyano group substituted by a fluorine atom or a cyano group; r is an integer of 0 to 3; when r is 2 or more, more than one R ¹⁵ is the same base or different bases; "*" indicates a bond)

In the formula (4), the substituent bonded to the ring of the phenylene and cyclohexylene is preferably an alkyl group having 1 to 3 carbon atoms, a fluorine atom or a cyano group. r is preferably 0 or 1. R ^{16 is} preferably a monovalent group in which at least one hydrogen atom of a phenyl group or a cyclohexyl group is substituted with a substituted or unsubstituted alkyl group or an alkoxy group. In this case, the substituted or unsubstituted alkyl group or alkoxy group preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms.

From the viewpoint of making the solubility of the polymer (A) in a solvent more favorable, A ^{2 in} the formulas (1) and (2) is preferably a hydroxyl group or a group "-OR ¹⁷ "(where R ¹⁷ is a monovalent hydrocarbon group having 1 to 10 carbons), more preferably a hydroxyl group or an alkoxy group having 1 to 3 carbons, and still more preferably a hydroxyl group or a methoxy group.

The monomer (R1) has ^{a saturated heterocyclic ring containing -CO-N(A 1} )-CO-, or a structure in which the saturated heterocyclic ring is opened. It is preferable that n1+n2 in said formula (1) and formula (2) is 1 or more, More preferably, it is an integer of 1-6. In terms of obtaining a polymer with more excellent solubility in a solvent, the monomer (R1) is preferably the compound represented by the formula (2), that is, the compound represented by the formula (1) The open loop body.

In the formula (1) and the formula (2), R ¹ and R ² represent that one of R ¹ and R ² is a monovalent group having a polymerizable group, and the other is a hydrogen atom or a monovalent organic group A group or ^{a ring structure in which R 1} and R ² are bonded to each other ^{to form a nitrogen atom to which R 1} and R ² are bonded (hereinafter, also referred to as "ring structure X"). Among them, the ring structure X has a polymerizable carbon-carbon unsaturated bond in the ring. The polymerizable group possessed by one of R ¹ and R ² and the polymerizable carbon-carbon unsaturated bond possessed by the ring structure X can be selected according to the main skeleton of the polymer (A). The polymer (A) can be a polymer produced by the addition polymerization of a monomer (hereinafter, also referred to as "addition polymer (A1)"), or it can be produced by the condensation polymerization of a monomer The polymer (hereinafter, also referred to as "condensation polymer (A2)").

(Addition polymer) The addition polymer (A1) is not particularly limited as long as it is a polymer obtained by using a monomer having a carbon-carbon unsaturated bond-containing group as a polymerizable group. The addition polymer (A1) can be obtained by addition polymerization using a monomer (R1) in which the polymerizable group is a group containing a carbon-carbon unsaturated bond.

（式（5）中，Y¹ 為乙烯基苯基、(甲基)丙烯醯基氧基、(甲基)丙烯醯基胺基、乙烯基、乙烯基氧基、或馬來醯亞胺基，R¹⁸ 為單鍵、碳數1～20的二價烴基，X² 為單鍵、-CO-、*¹ -O-CO-、或*¹ -NH-CO-（其中，「*¹ 」表示與R¹⁸ 的結合鍵）；「*」表示與式（1）或式（2）中的氮原子的結合鍵）In the monomer (R1) used in the synthesis of the addition polymer (A1), one of R ¹ and R ² is a monovalent group having a polymerizable group, and the other is a hydrogen atom or a In the case of a valent organic group, the monovalent group having a polymerizable group is preferably a group represented by the following formula (5). [化5]

(In formula (5), Y ¹ is a vinyl phenyl group, a (meth)acryloyloxy group, a (meth)acryloylamino group, a vinyl group, a vinyloxy group, or a maleimino group , R ¹⁸ is a single bond, a divalent hydrocarbon group with 1 to 20 carbons, and X ² is a single bond, -CO-, * ¹ -O-CO-, or * ¹ -NH-CO- (wherein "* ¹ " Represents the ^{bond with R 18} ); "*" represents the bond with the nitrogen atom in formula (1) or formula (2))

In the monomer (R1) used in the synthesis of the addition polymer (A1), when R ¹ and R ² are combined with each other to form the ring structure X, the ring structure X may be a single ring or multiple Ring (including condensed ring and bridged ring). The ring structure X preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms.

（式中，「*」表示結合鍵）Preferred specific examples of the ring structure X include: monocyclic structures represented by the following formula (x1-1) to formula (x1-4); the following formula (x2-1) to formula (x2- 8) The multi-ring structure, etc. respectively represented. [化6]

(In the formula, "*" represents the combination key)

[化8]

[化9]

[化10]

[化11]

[化12]

[化13]

（式（r1-1）～式（r1-29）中，R²⁰ 為碳數1～10的烷基、碳數1～10的烷氧基、至少一個氫原子經氟原子或氰基取代的碳數1～10的取代烷基、至少一個氫原子由氟原子或氰基取代的碳數1～10的取代烷氧基、氟原子、或氰基；R²¹ 為氫原子或甲基；R²² 為碳數1～10的烷二基）As a specific example of the monomer (R1) used in the synthesis of the addition polymer (A1), the compound represented by the formula (1) includes the following formulas (r1-1) to (r1-29) ) The compound represented by each; the compound represented by the formula (2) includes, for example, the succinimide ring or the compound represented by the following formula (r1-1) to formula (r1-29) Compounds (ring-openers) formed by opening the glutarimide ring, etc. [化7]

[化8]

[化9]

[化10]

[化11]

[化12]

[化13]

(In formulas (r1-1) to (r1-29), R ²⁰ is an alkyl group with 1 to 10 carbons, an alkoxy group with 1 to 10 carbons, and at least one hydrogen atom is substituted with a fluorine atom or a cyano group A substituted alkyl group having 1 to 10 carbons, a substituted alkoxy group having 1 to 10 carbons in which at least one hydrogen atom is replaced by a fluorine atom or a cyano group, a fluorine atom, or a cyano group; R ²¹ is a hydrogen atom or a methyl group; R ²² is an alkanediyl group with 1 to 10 carbons)

（式（R-1）及式（R-2）中，R¹ 、R² 、A¹ 、n1及n2與所述式（1）及式（2）為相同含義）Monomers (R1) can be synthesized according to conventional methods of organic chemistry. As an example, aminoalkanedioic acid (for example, 2-aminobutyric acid, 2-aminoglutaric acid, etc.) can be used in the raw material to synthesize the compound represented by the following formula (R-1), and then make the following The compound represented by the above formula (R-1) is reacted with the compound represented by the following formula (R-2) to obtain the compound represented by the above formula (2). In addition, if necessary, the compound represented by the formula (2) is ring-closed in the presence of a catalyst (for example, zinc chloride, a silylating agent, etc.), whereby the compound represented by the formula (1) can be obtained . However, the synthesis method of the monomer (R1) is not limited to the above-mentioned method. [化14]

(In formula (R-1) and formula (R-2), R ¹ , R ² , A ¹ , n1 and n2 have the same meaning as the above formula (1) and formula (2))

From the viewpoint of making the pretilt angle characteristics (initial pretilt angle and post-baking margin) better, the addition polymer (A1) has a The content of the structural unit U1 is preferably 1 mol% or more, more preferably 2 mol% or more, and still more preferably 5 mol% or more. In addition, the content ratio of the structural unit U1 can be arbitrarily set within the range of 100 mol% or less with respect to all the monomer units included in the addition polymer (A1). In the case of introducing another structural unit different from the structural unit U1, the content of the structural unit U1 is preferably 90 mol% or less relative to all the monomer units of the addition polymer (A1) It is 80 mol% or less, more preferably 60 mol% or less, and particularly preferably 50 mol% or less. Furthermore, the structural unit U1 that the addition polymer (A1) has may be one type, or two or more types.

(Other structural units) The addition polymer (A1) may have only the structural unit U1, or the structural unit U1 and a structural unit derived from a monomer different from the monomer (R1) (hereinafter, also referred to as "other structural unit") ). The addition polymer (A1) is preferably derived from a compound containing a maleimide structure, a (meth)acrylic compound, a compound containing a styrene structure, a compound containing a maleic anhydride structure, and a cyclic compound. At least one structural unit in the group consisting of olefin compounds serves as the other structural unit.

（式（z-1）及式（z-2）中，R³¹ 、R³² 、R³⁴ 及R³⁵ 分別獨立地為氫原子或甲基；R³³ 及R³⁶ 分別獨立地為一價有機基；「*」表示結合鍵）The maleimine structure-containing compound is not particularly limited as long as it is a compound having a maleimine ring or a ring-opened body thereof. As specific examples of the maleimine structure-containing compound, a compound represented by the following formula (z-1), a compound represented by the following formula (z-2), and the like can be cited. [化15]

(In formula (z-1) and formula (z-2), R ³¹ , R ³² , R ³⁴ and R ³⁵ are each independently a hydrogen atom or a methyl group; R ³³ and R ³⁶ are each independently a monovalent organic group ; "*" means the combination key)

In the above formula (z-1) and formula (z-2) ^{, examples of the monovalent organic group of R 33} and R ³⁶ include: a monovalent hydrocarbon group having 1 to 40 carbon atoms, and at least one methylene group of the hydrocarbon group A group substituted with -O-, -CO-, -COO-, -NR ²⁶ -or -CONR ^26- (wherein R ²⁶ is a hydrogen atom or a monovalent hydrocarbon group) (hereinafter, also referred to as "group β"), A monovalent hydrocarbon group having 1 to 40 carbon atoms or a group in which at least one hydrogen atom of the group β is substituted with a substituent such as a fluorine atom, a cyano group, a carboxyl group, an epoxy group, a hydroxyl group, or a cyclic carbonate group. The ^{monovalent organic group of R 33} and R ³⁶ is preferably a group having a photo-alignment group, a group having a vertical alignment group, or a group having a crosslinkable group. When the ^{monovalent organic group of R 33} and R ³⁶ is a group having a photo-alignment group, the group having a photo-alignment group is preferably a group having a cinnamic acid structure represented by the formula (3).

Here, the "vertical alignment group" is a functional group that imparts a function of inducing a desired pretilt angle to liquid crystal molecules to a coating film formed using a liquid crystal alignment agent. The vertical alignment group exhibits the property of vertically aligning liquid crystal molecules independently of light irradiation. Specific examples of the vertical alignment group include: alkyl groups having 4 to 40 carbons, alkoxy groups having 4 to 40 carbons, fluoroalkyl groups having 4 to 40 carbons, and having two or more rings (preferably 1,4-phenylene and 1,4-cyclohexylene) are bonded via a single bond or a divalent linking group (-O-, -COO-, etc.) with a carbon number of 12 to 50, A group having 17 to 51 carbon atoms with a steroid skeleton, etc.

As an example of a compound containing a maleimide structure, for example, N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, 4-carboxy Phenylmaleimide, 2-methylphenylmaleimide, 4-hydroxyphenylmaleimide, N-dodecylmaleimide, N-cholestyloxy Carbonyl phenyl maleimide, and compounds (ring-opened body) formed by opening the maleimide ring of these compounds, and the like.

The (meth)acrylic compound only needs to have a (meth)acryloyl group, and the remaining structure is not particularly limited. Specific examples of the (meth)acrylic compound include (meth)acrylic acid, α-ethacrylic acid, maleic acid, fumaric acid, itaconic acid, alkyl (meth)acrylate, (meth)acrylic acid, ) Cycloalkyl acrylate, benzyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, glycidyl (meth)acrylate, α-ethyl glycidyl acrylate, α-normal Glycidyl propyl acrylate, glycidyl α-n-butyl acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxybutyl α-ethyl acrylate, (meth)acrylic acid 3,4-Epoxycyclohexyl methyl ester, 6,7-epoxyheptyl (meth)acrylate, 6,7-epoxyheptyl α-ethyl acrylate, 4-hydroxybutyl glycidyl acrylate, ( (3-ethyloxetan-3-yl)methyl meth)acrylate, propylene carbonate (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, and the like.

Examples of the compound containing a styrene structure include styrene, methylstyrene, 4-vinyl-1-glycidyloxymethylbenzene, and 3-vinyl-1-glycidyloxymethylbenzene. , 3-vinyl benzoic acid, 4-vinyl benzoic acid, etc. Examples of the maleic anhydride structure-containing compound include maleic anhydride and citraconic anhydride. Examples of cyclic olefin compounds include cyclobutene, cyclopentyne, cyclohexene, bicyclo[2.2.1]hept-2-ene, and the like.

As other structural units of the addition polymer (A1), in addition to the above, for example, ethylene, vinyl alcohol, (meth)allyl alcohol, 3-methyl-3-butene- Vinyl-containing compounds such as 1-alcohol; conjugated diene compounds such as 1,3-butadiene and 2-methyl-1,3-butadiene, etc. Furthermore, the addition polymer (A1) may have only one kind of other structural units, or may have two or more other structural units.

^{In the case where A 1} in the structural unit U1 is a monovalent group having a photo-alignment group, from the viewpoint of suppressing the pretilt angle exhibited by the liquid crystal alignment film from becoming too high, the addition polymer (A1) Preferably, it has a structural unit U1, and is derived from a compound selected from the group consisting of a maleimide structure-containing compound, a (meth)acrylic acid compound, a styrene structure-containing compound, a maleic anhydride structure-containing compound, and a cyclic olefin A single-weight structural unit (hereinafter, also referred to as "structural unit U2") that is at least one of the group consisting of compounds and does not have a photoalignment group.

When A ¹ is a monovalent group having a photo-alignment group, the content ratio of the structural unit U2 in the addition polymer (A1) relative to all the monomer units possessed by the addition polymer (A1) It is preferably 50 mol% or more, more preferably 55 mol% or more, and still more preferably 60 mol% or more. In addition, relative to all the monomer units of the addition polymer (A1), the content of the structural unit U2 is preferably 99 mol% or less, more preferably 97 mol% or less, and still more preferably 95 mol% %the following. Furthermore, the structural unit U2 possessed by the addition polymer (A1) may be only one type or two or more types.

(Cyclic ether structure and cyclic carbonate structure) In terms of further reducing the deviation of the pretilt angle (post-baking margin) with respect to the difference in the heating temperature (post-baking temperature) during film formation, the addition polymer (A1) is preferably It has a structural unit derived from the following monomer (hereinafter also referred to as "structural unit U3"), the monomer having at least one selected from the group consisting of a cyclic ether structure and a cyclic carbonate structure . As a cyclic ether structure, an oxetane ring structure, an oxetane ring structure, etc. are mentioned, for example. As a cyclic carbonate structure, an ethylene carbonate structure, a propylene carbonate structure, etc. are mentioned, for example. Among these, the structural unit U3 is preferably a structural unit derived from a single body having a cyclic ether structure, and more preferably a structural unit derived from a single body having an oxetane ring structure or an oxetane ring structure. Structural units.

The structural unit U3 is preferably a structural unit derived from at least one selected from the group consisting of a (meth)acrylic acid compound, a maleimide structure-containing compound, and a styrene structure-containing compound. Among these, in terms of the high degree of freedom of monomer selection, it is more preferable to be a structural unit derived from at least one selected from the group consisting of a (meth)acrylic compound and a styrene structure-containing compound.

In the case where the addition polymer (A1) has the structural unit U3, the ratio of the structural unit U3 is preferably 5 mol% or more relative to all the monomer units of the addition polymer (A1). It is 10 mol% or more, more preferably 20 mol% or more. In addition, relative to all the monomer units of the addition polymer (A1), the content of the structural unit U3 is preferably 90 mol% or less, more preferably 85 mol% or less, and still more preferably 70 mol% %the following. Furthermore, the structural unit U3 possessed by the addition polymer (A1) may be only one type or two or more types.

(Reactive functional group) From the viewpoint of further improving the effect of improving the post-baking margin, the addition polymer (A1) preferably has a functional group that reacts with at least one of a cyclic ether structure and a cyclic carbonate structure (hereinafter, also Called "reactive functional group"). Examples of the reactive functional group include a carboxyl group, a hydroxyl group, an isocyanate group, and an amino group, and groups in which these respective groups are protected with a protective group. In terms of good storage stability and high reactivity by heating, among them, the reactive functional group is preferably selected from the group consisting of a carboxyl group and a protected carboxyl group (hereinafter, also referred to as "protected carboxyl group") At least one of the group.

（式（6）中，R⁴¹ 、R⁴² 及R⁴³ 分別獨立地為碳數1～10的烷基或碳數3～20的一價脂環式烴基，或者表示R⁴¹ 與R⁴² 彼此結合而與R⁴¹ 及R⁴² 所鍵結的碳原子一起構成的碳數4～20的二價脂環式烴基或環狀醚基，且R⁴³ 為碳數1～10的烷基、碳數2～10的烯基或碳數6～20的芳基；「*」表示結合鍵）The protected carboxyl group is not particularly limited as long as it is removed by heat and generates a carboxyl group. As a preferable specific example of protecting a carboxyl group, the structure represented by following formula (6), the acetal ester structure of a carboxylic acid, the ketal ester structure of a carboxylic acid, etc. are mentioned. [化16]

(In formula (6), R ⁴¹ , R ⁴² and R ⁴³ are each independently an alkyl group having 1 to 10 carbons or a monovalent alicyclic hydrocarbon group having 3 to 20 carbons, or that R ⁴¹ and R ⁴² are bonded to each other A divalent alicyclic hydrocarbon group or cyclic ether group having 4 to 20 carbon atoms is formed together with the carbon atom to which R ⁴¹ and R ^{42 are bonded, and R 43} is an alkyl group having 1 to 10 carbon atoms and 2 carbon atoms. ～10 alkenyl group or carbon 6-20 aryl group; "*" means bond)

The monomer having a reactive functional group is preferably at least one selected from the group consisting of a (meth)acrylic compound, a maleimide structure-containing compound, and a styrene structure-containing compound. Among these, in terms of the high degree of freedom of monomer selection, it is more preferable to be at least one selected from the group consisting of (meth)acrylic compounds and styrene structure-containing compounds.

When the addition polymer (A1) has a structural unit derived from a monomer having a reactive functional group (hereinafter also referred to as "structural unit U4"), it is relative to the addition polymer (A1) For all the monomer units of, the content ratio of the structural unit U4 is preferably 2 mol% or more, more preferably 5 mol% or more, and still more preferably 10 mol% or more. In addition, relative to all the monomer units of the addition polymer (A1), the content of the structural unit U4 is preferably 70 mol% or less, more preferably 60 mol% or less, and still more preferably 50 mol% %the following. Furthermore, the structural unit U4 possessed by the addition polymer (A1) may be only one type or two or more types.

(Optical sensitization structure) The polymer (A) may have a partial structure capable of expressing a photosensitizing function that exhibits a sensitizing effect by light irradiation (hereinafter, also referred to as a "photosensitizing structure"). In the case where the polymer (A) has a photosensitized structure, a liquid crystal alignment film with a smaller deviation in the pretilt angle caused by the difference in heating temperature at the time of film formation can be obtained, which is suitable in this respect. Here, the “photosensitization function” refers to the function of rapidly generating intersystem crossing (intersystem crossing) and transitioning to a triplet excited state after being irradiated with light into a singlet excited state. If it collides with other molecules in this triplet state, it changes the other party to an excited state and restores itself to a basic state.

The photosensitizing structure possessed by the polymer (A) is not particularly limited, and examples thereof include acetophenone structure, benzophenone structure, anthraquinone structure, biphenyl structure, terphenyl structure, carbazole structure, Nitroaryl structure (nitrobenzene structure, 1,3-dinitrobenzene structure, etc.), naphthalene structure, fluorene structure, anthracene structure, 9,10-dihydroanthracene structure, acridine structure, indole structure, 1 ,4-dioxocyclohexa-2,5-diene structure, etc. The polymer (A) preferably has a light-sensitizing structure in the side chain.

In the case where the addition polymer (A1) is a polymer having a photosensitizing structure, the method for obtaining the addition polymer (A1) is not particularly limited, and it is preferable to use a monomer (R1), And the monomer with light-sensitized structure is polymerized. As a specific example of the monomer having a photosensitizing structure, a compound represented by the following formula (9) can be cited. Y ² -L ¹ -Y ³ ... (9) (In formula (9), Y ² is a vinyl phenyl group, a (meth)acryloyloxy group, a (meth)acryloylamino group, a vinyl group, Vinyloxy group or maleimide group, L ¹ is a single bond or divalent linking group, Y ³ is a group with a photosensitizing structure)

In the formula (9), in terms of improving the freedom of monomer selection, Y ^{2 is} preferably a (meth)acryloyloxy group or a (meth)acryloylamino group, more preferably It is (meth)acryloyloxy. The divalent linking group of L ¹ is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms or a group having -O- between the carbon-carbon bonds of the hydrocarbon group. Y ^{3 is} preferably acetophenone structure, benzophenone structure, anthraquinone structure, biphenyl structure, terphenyl structure, carbazole structure, nitroaryl structure, naphthalene structure, fluorene structure, anthracene structure, 9 , 10-Dihydroanthracene structure, acridine structure, indole structure, or 1,4-dioxocyclohexa-2,5-diene structure.

In the case where the addition polymer (A1) has a structural unit derived from a monomer having a photosensitizing structure (hereinafter also referred to as "structural unit U5"), compared to the addition polymer (A1) For all the monomass units of, the ratio of the structural unit U5 is preferably 1 mol% or more, more preferably 2 mol% or more, and still more preferably 3 mol% or more. In addition, with respect to all the monomer units of the addition polymer (A1), the content of the structural unit U5 is preferably 50 mol% or less, more preferably 40 mol% or less, and still more preferably 30 mol% %the following. Furthermore, the structural unit U5 possessed by the addition polymer (A1) may be only one type or two or more types.

The addition polymer (A1) can be obtained by polymerizing the monomer (R1) and other monomers as needed in an organic solvent, preferably in the presence of a polymerization initiator . Examples of the polymerization initiator used include: 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2' -Azo compounds such as azobis(4-methoxy-2,4-dimethylvaleronitrile), nickel catalysts, etc. The use ratio of the polymerization initiator is preferably 0.01 parts by mass to 30 parts by mass relative to 100 parts by mass of all monomers used in the reaction. Examples of the organic solvent used include alcohols, ethers, ketones, amides, esters, and hydrocarbons.

In the polymerization reaction, the reaction temperature is preferably 30°C to 120°C, and the reaction time is preferably 1 hour to 36 hours. The use amount (a) of the organic solvent is preferably such that the total amount (b) of the monomers used in the reaction is 0.1% by mass to 60% by mass relative to the total amount (a+b) of the reaction solution. The reaction solution obtained by dissolving the polymer can be used for the preparation of the liquid crystal alignment agent after the addition polymer (A1) contained in the reaction solution is separated using a known separation method, for example, the separation method is to inject the reaction solution into A method in which the precipitate obtained in a large amount of poor solvent is dried under reduced pressure, a method in which the reaction solution is distilled off under reduced pressure using an evaporator, and the like.

The weight average molecular weight (Mw) of the addition polymer (A1) measured by gel permeation chromatography (GPC) in terms of polystyrene is preferably 1,000 to 300,000, more preferably 2,000 to 100,000. The molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 7 or less, and more preferably 5 or less. Furthermore, the addition polymer (A1) used in the preparation of the liquid crystal alignment agent may be only one type, or two or more types may be combined.

(Condensation polymer) The polycondensate (A2) is not particularly limited as long as it is a polymer obtained by using a monomer having a polycondensation-polymerizable group as a polymerizable group. In terms of the high effect of improving the coating uniformity and pretilt angle characteristics of the obtained liquid crystal alignment film, the polycondensate (A2) is preferably a polyorganosiloxane having a structural unit U1 (hereinafter, also referred to as " Polyorganosiloxane (A)”). The polyorganosiloxane (A) can be formed by using the hydrolyzable silane compound represented by the formula (1) or the formula (2) (hereinafter, also referred to as "specific silane compound") as a monomer (R1) ) Is obtained by the hydrolysis-condensation reaction.

（式（7）及式（8）中，R²³ 為碳數1～20的二價烴基，R²⁴ 及R²⁵ 分別獨立地為碳數1～10的一價烴基，R²⁷ 為氫原子或一價有機基；k為1～3的整數；A¹ 、n1及n2與所述式（1）及式（2）為相同含義） ^{Regarding the specific silane compound, one of R 1} and R ² in the above formula (1) and formula (2) is a monovalent group having a polymerizable group, and the other is a hydrogen atom or a monovalent organic group. The polymerizable group is preferably an alkoxysilyl group. The specific silane compound is preferably at least one selected from the group consisting of a compound represented by the following formula (7) and a compound represented by the following formula (8). [化17]

(In formulas (7) and (8), R ²³ is a divalent hydrocarbon group with 1 to 20 carbons, R ²⁴ and R ²⁵ are each independently a monovalent hydrocarbon group with 1 to 10 carbons, and R ²⁷ is a hydrogen atom or Monovalent organic group; k is an integer of 1 to 3; A ¹ , n1 and n2 have the same meaning as the above formula (1) and formula (2))

[化19]

（所述式（s1-1）～式（s1-10）中，R²³ 、R²⁴ 、R²⁵ 、R²⁷ 及k與所述式（7）為相同含義；R²⁰ 為碳數1～10的烷基、碳數1～10的烷氧基、至少一個氫原子經氟原子或氰基取代的碳數1～10的取代烷基、至少一個氫原子由氟原子或氰基取代的碳數1～10的取代烷氧基、氟原子、或氰基）As a specific example of a specific silane compound, the compound etc. which are respectively represented by following formula (s1-1)-formula (s1-10) are mentioned. [化18]

[化19]

(In the formula (s1-1) to (s1-10), R ²³ , R ²⁴ , R ²⁵ , R ²⁷ and k have the same meaning as in the formula (7); R ²⁰ is carbon number 1-10 Alkyl group, alkoxy group having 1 to 10 carbon atoms, substituted alkyl group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom or cyano group, and carbon number in which at least one hydrogen atom is substituted by a fluorine atom or cyano group 1-10 substituted alkoxy group, fluorine atom, or cyano group)

In the synthesis of polyorganosiloxane (A), as the hydrolyzable silane compound, only a specific silane compound may be used, or a hydrolyzable silane compound other than the specific silane compound may be used in combination (hereinafter, also referred to as "other silane compound") .

Other silane compounds are not particularly limited as long as they can be polycondensed with specific silane compounds. Examples include tetraalkoxysilane compounds such as tetramethoxysilane, methyltriethoxysilane, and dimethyldiethoxysilane. Or alkyl alkoxy silane compounds; cycloalkyl alkoxy silane compounds such as cyclohexyl trimethoxy silane, cyclohexyl methyl dimethoxy silane, etc.; phenyl trimethoxy silane, phenyl triethoxy silane, etc. Aryl alkoxy silane compound; 3-mercaptopropyl triethoxy silane, mercaptomethyl triethoxy silane, 3-aminopropyl trimethoxy silane, N-(3-cyclohexylamino) propyl Nitrogen-sulfur-containing alkoxysilane compounds such as trimethoxysilane; 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxysilane Propylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, etc. Epoxy silane compound; 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(methyl) Acrylicoxypropylmethyldiethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane and other alkoxysilane compounds containing unsaturated bonds; trimethoxysilylpropyl succinate Silane compounds containing acid anhydride groups such as acid anhydrides; Silane compounds containing isocyanate groups such as 3-isocyanate propyl trimethoxysilane, 3-isocyanate propyl triethoxy silane, etc. As other silane compounds, one of these can be used alone or two or more of them can be used in combination. Furthermore, "(meth)acrylic acid" means "acrylic acid" and "methacrylic acid".

From the viewpoint of making the pretilt angle characteristics (initial pretilt angle and post-baking margin) better, compared to all the unitary units of polyorganosiloxane (A), polyorganosiloxane (A) The content ratio of the structural unit U1 in is preferably 1 mol% or more, more preferably 2 mol% or more, and still more preferably 5 mol% or more. In addition, relative to all the monomer units of the polyorganosiloxane (A), the content of the structural unit U1 is preferably 90 mol% or less, more preferably 80 mol% or less, and still more preferably 60 mol%. Less than ear%. Furthermore, the structural unit U1 possessed by the polyorganosiloxane (A) may be one type or two or more types.

The hydrolysis-condensation reaction is carried out by reacting one or two or more of the hydrolyzable silane compounds with water in the presence of a suitable catalyst and organic solvent. During the reaction, the use ratio of water is preferably 1 mol to 30 mol relative to 1 mol of the silane compound (total amount). Examples of the catalyst used include acids, alkali metal compounds, organic bases, titanium compounds, and zirconium compounds. The amount of the catalyst used varies depending on the type of the catalyst, reaction conditions such as temperature, and the like, and should be appropriately set. For example, it is preferably 0.01 to 3 times mol relative to the total amount of the silane compound. Examples of the organic solvent used include hydrocarbons, ketones, esters, ethers, alcohols, etc. Among these, it is preferable to use a water-insoluble or poorly water-soluble organic solvent. The use ratio of the organic solvent is preferably 10 parts by mass to 10,000 parts by mass relative to 100 parts by mass of the total of the silane compounds used in the reaction.

The hydrolysis-condensation reaction is preferably carried out, for example, by heating in an oil bath or the like. At this time, the heating temperature is preferably 130°C or lower, and the heating time is preferably 0.5 to 12 hours. After the reaction is completed, the organic solvent layer separated from the reaction liquid is dried with a desiccant as needed, and then the solvent is removed, thereby obtaining the target polyorganosiloxane. In addition, the method of synthesizing polyorganosiloxane is not limited to the hydrolysis-condensation reaction. For example, it may be carried out by a method of reacting a hydrolyzable silane compound in the presence of oxalic acid and alcohol.

Regarding the polyorganosiloxane (A), the weight average molecular weight (Mw) in terms of polystyrene measured by GPC is preferably in the range of 100 to 50,000, and more preferably in the range of 200 to 10,000.

In the liquid crystal alignment agent of the present disclosure, from the viewpoint of sufficiently improving the coating property to the substrate and making the pretilt angle characteristics (initial pretilt angle, post-baking margin) excellent, compared with the liquid crystal aligning agent contained For all polymers, the content of the polymer (A) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1% by mass or more. In addition, the content ratio of the polymer (A) can be appropriately set within a range of 100% by mass or less with respect to all the polymers contained in the liquid crystal alignment agent. According to the polymer (A), even if the amount used is reduced, the effect of improving coating uniformity and pretilt angle characteristics can be obtained. From the viewpoint of achieving cost reduction of the liquid crystal alignment agent and sufficient improvement in reliability, the content ratio of the polymer (A) is preferably 90 mass relative to the total amount of the polymer contained in the liquid crystal alignment agent % Or less, more preferably 70% by mass or less, and still more preferably 50% by mass or less.

＜Other ingredients＞ The liquid crystal alignment agent of the present disclosure may contain other components other than the polymer (A) as necessary.

(Other polymers) In the liquid crystal alignment agent of the present disclosure, a polymer (A) and a polymer that does not have a structural unit derived from the monomer (R1) (hereinafter, also referred to as "other polymer") may be contained as a polymer component . Other polymers are not particularly limited, and at least one polymer selected from the group consisting of polyamide acid, polyamide ester, polyimide and polyurea (hereinafter, also referred to as polyurea) can be preferably used. "Polymer (B)"). By using the polymer (B) and the polymer (A) together, the liquid crystal orientation and electrical characteristics of the obtained liquid crystal element can be ensured, which is preferable in this respect. The polymer (B) is more preferably at least one selected from the group consisting of polyamide, polyamide, and polyimide.

When the polymer (B) is polyamide, the polyamide can be obtained by reacting tetracarboxylic dianhydride with a diamine compound. In this case, as the tetracarboxylic dianhydride and the diamine compound, a conventionally known compound used in the synthesis of polyamide acid can be used. The polyamide ester can be obtained, for example, by the following method, etc.: the obtained polyamide acid and an esterification agent (for example, methanol or ethanol, N,N-dimethylformamide diethyl acetal Etc.) A method of reaction; a method of reacting a tetracarboxylic acid diester and a diamine compound in the presence of a suitable dehydration catalyst; a method of making a tetracarboxylic acid diester dihalide and a diamine in the presence of a suitable base The method of carrying out the reaction. Polyimine can be obtained, for example, by dehydrating and ring-closing the obtained polyimide and then imidizing it. The imidization rate of the polyimide is preferably 20% to 90%, more preferably 30% to 80%.

Regarding the polymer (B), the weight average molecular weight (Mw) in terms of polystyrene measured by GPC is preferably 1,000 to 500,000, and more preferably 2,000 to 300,000. The molecular weight distribution (Mw/Mn) is preferably 7 or less, more preferably 5 or less.

When the liquid crystal alignment agent contains the polymer (A) and the polymer (B) as the polymer components, the effect of improving the pretilt angle characteristics of the polymer (A) is sufficiently obtained, and the liquid crystal alignment is good From the viewpoint of, the content ratio of the polymer (B) is preferably set to 100 parts by mass or more with respect to 100 parts by mass of the polymer (A) in the liquid crystal alignment agent. The content ratio of the polymer (B) is more preferably 100 parts by mass to 2000 parts by mass, and still more preferably 200 parts by mass to 1500 parts by mass. Furthermore, as the polymer (B), one kind may be used alone, or two or more kinds may be used in combination.

(Photosensitizer) The liquid crystal alignment agent of the present disclosure preferably contains a compound having a photosensitizing structure (hereinafter, also referred to as "photosensitizer"). The photosensitizer can be a polymer (A) having a structural unit derived from a monomer (R1) and a photosensitizing structure, or other polymers, or an additive separately formulated independently of the polymer components Ingredients (hereinafter, also referred to as "additives (S)"). In addition, the liquid crystal alignment agent may also contain both the polymer (A) and the additive (S). The additive (S) is preferably a compound having a photosensitizing structure and a molecular weight of 1000 or less.

Specific examples of additives (S) include: acetophenone, acetophenone benzyl ketal, 2,2-dimethoxy-2-phenylacetophenone, 3-methylacetophenone, etc. Compounds with acetophenone structure; benzophenone, 4-diethylamino-2-hydroxybenzophenone, 2-hydroxybenzophenone, 4-methylbenzophenone, 3-(4- Benzyl-phenoxy)propyl, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, 4,4'-bis(dimethylamine) Group) benzophenone (Michler's ketone) and other compounds containing benzophenone structure; 3,5-dinitrobenzene, 4-methyl-3,5-dinitrobenzene, 3 -(3,5-Dinitrophenoxy)propyl, 2-methyl-3,5-dinitrobenzene and other compounds containing nitroaryl structure; naphthalene, anthracene, biphenyl, terphenyl, 2 ,3-Benzofluorene, pyrene, perylene, fluorene, anthraquinone and other hydrocarbons; 9,10-dioxo-9,10-dihydroanthracene, 3-(9,10-dioxo-9,10- Dihydroanthracene-2-yl) propyl, 2-oxo-9,10-dihydroanthracene and other anthracene derivatives; triphenylamine, carbazole and other amine-containing compounds; thioxanthone, diethyl Lucanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propane- Sulfur-containing compounds such as 1-ketone; 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzyl)-2,4,4 -Phosphorus-containing compounds such as trimethylpentyl phosphine oxide. In addition, as the additive (S), one kind may be used alone, or two or more kinds may be used in combination.

In the case of using the additive (S) as a photosensitizer, from the viewpoint of further improving the effect of reducing the post-baking margin, relative to 100 parts by mass of the total amount of polymer components in the liquid crystal alignment agent, the liquid crystal The content ratio of the additive (S) in the alignment agent is preferably 0.5 part by mass or more, more preferably 1 part by mass or more. In addition, from the viewpoint of suppressing performance degradation due to excessive addition, the content of the additive (S) is preferably 30 parts by mass or less, and more preferably 20 parts by mass relative to 100 parts by mass of the total amount of polymer components. The following.

(Solvent) The liquid crystal alignment agent of the present disclosure is prepared in the form of a solution-like composition, and the solution-like composition is prepared by dissolving the polymer components and optional components as required, preferably in an organic solvent. Examples of the organic solvent used include aprotic polar solvents, phenolic solvents, alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons. The solvent component may be one of these, or a mixed solvent of two or more.

（式（D-1）中，R¹ 為碳數1～4的烷基或CH₃ CO-，R² 為碳數1～4的烷二基或-(CH₂ CH₂ O)n-CH₂ CH₂ -（其中，n為1～4的整數），R³ 為氫原子或碳數1～4的烷基） [化21]

（式（D-2）中，R⁴ 為碳數1～3的烷二基） [化22]

（式（D-3）中，R⁵ 及R⁶ 分別獨立地為碳數4～8的烷基）As the solvent component of the liquid crystal alignment agent, a compound selected from the group consisting of the compound represented by the following formula (D-1), the compound represented by the following formula (D-2), and the following formula (D-3) can be preferably used At least one solvent in the group consisting of the compounds shown and having a boiling point of 180° C. or less under 1 atmosphere (hereinafter, also referred to as "specific solvent"). By using a specific solvent as at least a part of the solvent component, even in the case of heating during film formation at a low temperature (for example, 200°C or less), a liquid crystal element with excellent liquid crystal alignment and electrical characteristics can be obtained. The words are better. [化20]

(In formula (D-1), R ¹ is an alkyl group with 1 to 4 carbons or CH ₃ CO-, and R ² is an alkanediyl group with 1 to 4 carbons or -(CH ₂ CH ₂ O)n-CH ₂ CH _2- (wherein n is an integer of 1 to 4), R ³ is a hydrogen atom or an alkyl group with 1 to 4 carbon atoms) [Chemical Formula 21]

(In formula (D-2), R ⁴ is an alkanediyl group having 1 to 3 carbons) [Chemical Formula 22]

(In formula (D-3), R ⁵ and R ⁶ are each independently an alkyl group having 4 to 8 carbons)

As a specific example of a specific solvent, the compound represented by the formula (D-1) includes: propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol methyl ethyl ether, 3-methoxy-1 -Butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetic acid Esters, diethylene glycol dimethyl ether, etc.; The compound represented by the formula (D-2) includes cyclobutanone, cyclopentanone, and cyclohexanone; Examples of the compound represented by the formula (D-3) include diisobutyl ketone and the like. Furthermore, as the specific solvent, one kind may be used alone, or two or more kinds may be used in combination.

The solvent component of the liquid crystal alignment agent may include only a specific solvent, or may be a mixed solvent of other solvents other than the specific solvent and the specific solvent. As other solvents, for example, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,2-dimethyl-2-imidazolidone, γ-butyrolactone, Highly polar solvents such as γ-butyrolactamide, N,N-dimethylformamide, N,N-dimethylacetamide, etc.; in addition to this, you can also enumerate: 4-hydroxy-4-methyl-2-pentanone, butyl lactate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, diethylene glycol dimethyl ether, diethyl Glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, isoamyl propionate, isobutyric acid Isoamyl ester, diisoamyl ether, ethylene carbonate, propylene carbonate, cyclohexane, octanol, tetrahydrofuran, etc. These can be used individually by 1 type or in mixture of 2 or more types.

Regarding the solvent component contained in the liquid crystal alignment agent, the content ratio of the specific solvent relative to the total amount of the solvent contained in the liquid crystal alignment agent is preferably 20% by mass or more, more preferably 40% by mass or more, and still more preferably 50 Above mass%.

As other components contained in the liquid crystal alignment agent, in addition to the above-mentioned components, for example, functional silane compounds, polyfunctional (meth)acrylates, antioxidants, metal chelate compounds, hardening accelerators, and interfacial activity can be cited. Agents, fillers, dispersants, photosensitizers, etc. The blending ratio of other components can be appropriately selected according to each compound within a range that does not impair the effect of the present disclosure.

The solid content concentration in the liquid crystal alignment agent (the ratio of the total mass of components other than the solvent of the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) can be appropriately selected in consideration of viscosity, volatility, etc., preferably 1 The range of mass% to 10 mass%. When the solid content concentration is 1% by mass or more, a coating film with a sufficient film thickness can be obtained, and a good liquid crystal alignment film can be easily obtained. On the other hand, when the solid content concentration is 10% by mass or less, the film thickness of the coating film will not be too large. In addition, the viscosity of the liquid crystal alignment agent can be made moderate, and the decrease in coating properties can be suppressed. The language is appropriate.

"Liquid Crystal Alignment Film and Liquid Crystal Element" The liquid crystal alignment film of the present disclosure is formed by the liquid crystal alignment agent prepared as described above. In addition, the liquid crystal element of the present disclosure includes a liquid crystal alignment film formed using the liquid crystal alignment agent described above. The operation mode of the liquid crystal in the liquid crystal element is not particularly limited. For example, it can be applied to a twisted nematic (TN) type, a super twisted nematic (STN) type, and a vertical alignment (VA) type. (Including Vertical Alignment-Multi-domain Vertical Alignment (VA-MVA) type, Vertical Alignment-Patterned Vertical Alignment (VA-PVA) type, etc.), coplanar switching (In-Plane Switching, IPS) type, fringe field switching (Fringe Field Switching, FFS) type, Optically Compensated Bend (OCB) type, Polymer Sustained Alignment (PSA) and other modes . The liquid crystal element can be manufactured by a method including the following steps 1 to 3, for example. In step 1, the substrate used varies depending on the desired operation mode. Steps 2 and 3 are common in each operation mode.

<Step 1: Formation of Coating Film> First, a liquid crystal alignment agent is coated on the substrate, preferably by heating the coated surface, thereby forming a coating film on the substrate. As the substrate, for example, a transparent substrate containing the following materials: glass such as float glass and soda glass; polyethylene terephthalate, polybutylene terephthalate, polyether agglomerate, polycarbonate, poly( Alicyclic olefin) and other plastics. As the transparent conductive film provided on one side of the substrate, there can be used: _{NESA film containing tin oxide (SnO 2} ) (registered trademark of PPG Corporation in the United States), indium oxide-tin oxide (In ₂ O ₃ -SnO ₂₎ ) Indium tin oxide (Indium Tin Oxide, ITO) film, etc. In the case of manufacturing TN-type, STN-type or VA-type liquid crystal elements, two substrates provided with patterned transparent conductive films are used. On the other hand, in the case of manufacturing an IPS-type or FFS-type liquid crystal element, a substrate provided with electrodes patterned into a comb-tooth shape and a counter substrate without electrodes are used. The application of the liquid crystal alignment agent to the substrate on the electrode forming surface is preferably performed by a lithographic printing method, a flexographic printing method, a spin coating method, a roll coater method, or an inkjet printing method.

After the liquid crystal alignment agent is applied, for the purpose of preventing dripping of the applied liquid crystal alignment agent, etc., it is preferable to perform preheating (prebaking). The pre-baking temperature is preferably 30°C to 200°C, and the pre-baking time is preferably 0.25 minutes to 10 minutes. Thereafter, for the purpose of completely removing the solvent, etc., a sintering (post-baking) step is implemented. The firing temperature (post-baking temperature) at this time is preferably 80°C to 250°C, more preferably 80°C to 200°C. The post-baking time is preferably 5 minutes to 200 minutes. In particular, in the case of using the prepared liquid crystal alignment agent, the solubility to a low boiling point solvent like a specific solvent is good, and even when the post-baking temperature is set to 200°C or lower, preferably 180°C Hereinafter, when it is more preferably 160°C or less, the deviation of the pretilt angle caused by the difference in the post-baking temperature can be further reduced, which is preferable in this respect. The film thickness of the film thus formed is preferably 0.001 μm to 1 μm.

<Step 2: Orientation processing> In the case of manufacturing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal element, a process (alignment process) for imparting a liquid crystal alignment capability to the coating film formed in the step 1 is performed. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film. In the case of manufacturing a vertical alignment type liquid crystal element, the coating film formed in step 1 can be directly used as a liquid crystal alignment film, but in order to further improve the liquid crystal alignment ability, the coating film can also be subjected to alignment treatment. As the alignment treatment, it is preferable to use a photo-alignment treatment that irradiates a coating film formed on a substrate with light to impart a liquid crystal alignment ability to the coating film.

The light irradiation for photo-alignment can be performed by the following methods: a method of irradiating the coating film after the post-baking step, a method of irradiating the coating film after the pre-baking step and before the post-baking step, A method of irradiating the coating film during the heating process of the coating film in at least any one of the pre-baking step and the post-baking step. As the radiation irradiated to the coating film, for example, ultraviolet rays and visible rays including light with a wavelength of 150 nm to 800 nm can be used. Preferably, it is an ultraviolet ray containing light with a wavelength of 200 nm to 400 nm. When the radiation is polarized light, it may be linearly polarized light or partially polarized light. When the radiation used is linearly polarized light or partially polarized light, the irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination of these directions. The irradiation direction in the case of non-polarized radiation is an oblique direction.

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 cited. The radiation dose is preferably 400 J/m ² to 50,000 J/m ² , more preferably 1,000 J/m ² to 20,000 J/m ² . After light irradiation for imparting alignment ability, it is also possible to apply water, organic solvents (for example, methanol, isopropanol, 1-methoxy-2-propanol acetate, butyl cellosolve, butyl cellosolve, etc.) to the surface of the substrate. Ethyl lactate, etc.) or a mixture of these are processed for cleaning, or a process for heating the substrate.

<Step 3: Construction of the liquid crystal cell> Prepare two substrates on which the liquid crystal alignment film is formed in the manner described above, and arrange the liquid crystal between the two substrates facing each other, thereby manufacturing a liquid crystal cell. When manufacturing a liquid crystal cell, for example, the following method can be cited: the two substrates are arranged facing each other with a gap between the liquid crystal alignment film, and the peripheral parts of the two substrates are bonded together with a sealant, and the surface of the substrate and the sealant are bonded together. The method of filling and filling the liquid crystal into the enclosed cell gap and sealing the injection hole, and the method using the liquid crystal drop (One Drop Fill, ODF) method. As the sealing agent, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used. As the liquid crystal, nematic liquid crystal and smectic liquid crystal can be cited, and among them, nematic liquid crystal is preferred. In the PSA mode, after the liquid crystal cell is constructed, the liquid crystal cell is subjected to light irradiation treatment in a state where a voltage is applied between the conductive films of a pair of substrates.

Then, if necessary, a polarizing plate is attached to the outer surface of the liquid crystal cell to form a liquid crystal element. Examples of the polarizing plate include: a polarizing plate formed by sandwiching a polarizing film called "H film" with a protective film of cellulose acetate, or a polarizing plate including the H film itself. The "H film" is made of polyethylene on one side. The base alcohol is formed by extending the alignment to one side so that it absorbs iodine.

The liquid crystal element of the present disclosure can be effectively applied to various applications, such as clocks, portable game consoles, word processors, notebook personal computers, car navigation systems, camcorders, personal digital assistants (Personal Digital Assistant, PDA). ), digital cameras, mobile phones, smart phones, various monitors, LCD TVs, information displays and other display devices, or dimming films, retardation films, etc. [Example]

Hereinafter, a more specific description will be given with examples, but the present invention is not limited by these examples.

In the following Examples and Comparative Examples, the weight average molecular weight of the polymer was measured by the following method. [Weight average molecular weight of polymer] The weight average molecular weight is a polystyrene conversion value measured by gel permeation chromatography under the following conditions. Column: manufactured by Tosoh Corporation, TSKgelGRCXLII Solvent: Tetrahydrofuran Temperature: 40°C Pressure: 68 kgf/cm ²

[化24]

[化25]

[化26]

The structural formula of the compound used in this example is shown below. In addition, hereinafter, for convenience, the "compound represented by formula (X)" may be abbreviated as "compound (X)" in some cases. [化23]

[化24]

[化25]

[化26]

<Synthesis of Compound> [Synthesis Example 1-1: Synthesis of Compound (MA-2)] Compound (MA-2) was synthesized according to the following scheme. [化27]

Add 13.3 g of aspartic acid and 200 ml of tetrahydrofuran (THF) to the eggplant-shaped flask to dissolve it. 9.81 g of maleic acid was added thereto, and after stirring for 1 hour, the solvent was distilled off using an evaporator. To the obtained solid, 300 ml of toluene, 24.2 g of hexamethyldisilazane, and 27.3 g of zinc chloride were added, and the reaction was carried out at 80°C for 4 hours. After the reaction, the reaction solution was separated and purified twice with hydrochloric acid (1N) and twice with water. Then, the organic layer was concentrated using an evaporator. The obtained solid was crystallized with THF/ethanol/water, thereby obtaining 14.2 g of Intermediate 1. Intermediate 1 was dissolved in THF, and 28.6 g of cinnamate amine represented by the formula (CA) (hereinafter referred to as "compound CA") was added, and the reaction was carried out at 50°C for 1 hour. After the reaction, the solvent was distilled off, thereby obtaining 42.5 g of compound (MA-2).

[Synthesis Example 1-2: Synthesis of Compound (MA-1)] Compound (MA-1) was synthesized according to the following scheme. [化28]

300 ml of toluene, 7.26 g of hexamethyldisilazane, and 8.18 g of zinc chloride were added to 17.9 g of compound (MA-2), and reacted at 80°C for 4 hours. After the reaction, the reaction solution was separated and purified twice with hydrochloric acid (1N) and twice with water. Then, the organic layer was concentrated using an evaporator. The obtained solid was crystallized with THF/ethanol/water, thereby obtaining 7.34 g of compound (MA-1).

[Synthesis Example 1-3: Synthesis of Compound (MA-3)] It was synthesized by the same method as the compound (MA-2) except that the starting material was 3-aminoglutaric acid.

[Synthesis Example 1-4: Synthesis of Compound (MA-4)] Compound (MA-4) was synthesized according to the following scheme. [化29]

While circulating nitrogen gas in a three-necked eggplant-shaped flask, 200 ml of dehydrated THF was added to 13.3 g of aspartic acid to dissolve it. 15.5 g of "Karenz MOI" (manufactured by Showa Denko Co., Ltd.) was added thereto, and the reaction was carried out at 50° C. for 8 hours, and the solvent was distilled off. Then, 300 ml of toluene, 24.2 g of hexamethyldisilazane, 27.3 g of zinc chloride, and 1 g of dibutylhydroxytoluene were added and reacted at 50°C for 8 hours. After the reaction, the reaction solution was separated and purified twice with hydrochloric acid (1N) and twice with water. Then, the organic layer was concentrated using an evaporator. The obtained solid was crystallized with THF/ethanol/water, thereby obtaining 10.0 g of Intermediate 2. Then, the intermediate 2 was dissolved in THF, 14.5 g of compound CA was further added, and the reaction was carried out at 50°C for 1 hour. After the reaction, the solvent was distilled off, thereby obtaining 22.9 g of compound (MA-4).

[Synthesis Example 1-5: Synthesis of Compound (MA-5)] It was synthesized by the same method as the compound (MA-4) except that the starting material was 5-norbornene-2,3-dicarboxylic anhydride.

[Synthesis Example 1-6: Synthesis of Compound (MA-6)] Compound (MA-6) was synthesized according to the following scheme. [化30]

Add 13.3 g of aspartic acid, 10 ml of pyridine, and 150 ml of dehydrated THF to the eggplant-shaped flask, dissolve it and cool in an ice bath. The 4-vinylbenzoic acid chloride dissolved in 50 ml of dehydrated THF was slowly added dropwise thereto, and then reacted for 15 hours. After the reaction, 100 ml of ethyl acetate was added, and liquid separation and purification were performed twice with hydrochloric acid (1N) and twice with water. Then, the organic layer was concentrated using an evaporator. The obtained solid was crystallized with THF/ethanol/water, thereby obtaining 20.3 g of Intermediate 3. The intermediate 3 was dissolved in THF, 32.4 g of compound CA was further added, and the reaction was carried out at 50°C for 1 hour. After the reaction, the solvent was distilled off, thereby obtaining 51.6 g of compound (MA-6).

[Synthesis Example 1-7: Synthesis of Compound (MA-7)] Compound (MA-7) was synthesized according to the following scheme. [化31]

30 ml of toluene, 4.84 g of hexamethyldisilazane, and 5.45 g of zinc chloride were added to 3.46 g of N-allyl aspartic acid, and reacted at 80°C for 4 hours. After the reaction, the reaction solution was separated and purified twice with hydrochloric acid (1N) and twice with water. Then, the organic layer was concentrated using an evaporator. The obtained solid was crystallized with THF/ethanol/water, thereby obtaining 1.68 g of Intermediate 4. The obtained intermediate 4 was dissolved in THF, 4.27 g of compound CA was further added, and the reaction was carried out at 50°C for 1 hour. After the reaction, the solvent was distilled off, thereby obtaining 5.45 g of Intermediate 5. Furthermore, 300 μl of Intermediate 5 and 0.01 M hexachloroplatin (IV) acid hexahydrate solution were dissolved in 20 ml of THF under a nitrogen atmosphere. 1.26 g of trimethoxysilane was slowly added dropwise thereto, and thereafter, it was allowed to react at 70°C for 3 days. After the reaction, the solvent was distilled off and crystallization was performed with THF/ethanol to obtain 3.71 g of compound (MA-7).

＜Synthesis of polymers＞ [Synthesis Example 2-1] Under nitrogen, add 1.71 g (3.00 mmol) of compound (MA-1) as a polymerization monomer, 0.70 g (7.00 mmol) of compound (MB-4), as a radical polymerization initiator in a 100 mL two-necked flask 2,2'-azobis(2,4-dimethylvaleronitrile) 0.10 g (0.41 mmol), 2,4-diphenyl-4-methyl-1-pentene as a chain transfer agent 0.10 g (0.44 mmol), and 15 ml of N-methyl-2-pyrrolidone (NMP) as a solvent, and polymerize at 70°C for 6 hours. After reprecipitation in methanol, the precipitate was filtered and vacuum dried at room temperature for 8 hours, thereby obtaining the target polymer (P-1). The weight average molecular weight Mw measured by GPC-based polystyrene conversion was 30,000, and the molecular weight distribution Mw/Mn was 2.8.

[Synthesis example 2-2~Synthesis example 2-5, Synthesis example 2-7 and Synthesis example 2-8] The types and amounts of monomers used were changed as described in Table 1 below. Except for this point, the polymer (P-2) to the polymer (P-5) were synthesized by the same method as in Synthesis Example 2-1. ), polymer (P-7), polymer (P-8). In addition, in Table 1, the unit of the numerical value of the monomer composition is "mole part".

[Table 1] Synthesis Example No. Single body (R1) Other single body Polymer name MA-1 MA-2 MA-3 MA-4 MA-5 MA-6 MB-1 MB-2 MB-3 MB-4 MB-5 MB-6 MB-7 MB-8 2-1 30 70 P-1 2-2 30 20 50 P-2 2-3 5 50 45 P-3 2-4 30 15 35 20 P-4 2-5 7 3 10 40 40 P-5 2-7 20 40 15 20 5 P-7 2-8 10 25 35 10 20 P-8

[Synthesis Example 2-6] In a reaction vessel including a stirrer, a thermometer, a dropping funnel and a reflux cooling tube, 40 mole parts of compound (MA-7), 20 mole parts of compound (MS-1), and 40 mole parts of compound (MS-2) are charged. Mole parts, 50 g of methyl isobutyl ketone, and 5 g of triethylamine were mixed at room temperature. Then, after 35 g of deionized water was added dropwise using a dropping funnel over a period of 30 minutes, the mixture was mixed under reflux, and at the same time, it was allowed to react at 80° C. for 6 hours. After the reaction, the organic layer was taken out and washed with a 0.2% by mass ammonium nitrate aqueous solution until the washed water became neutral, and then the solvent and water were distilled off under reduced pressure to obtain a viscous transparent liquid. Polyorganosiloxane polymer (P-6). The weight average molecular weight (Mw) of the obtained polymer (P-6) was 11,000.

[Synthesis example 2-9] Dissolve 100 mol parts of 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 100 mol parts of 2,2'-dimethyl-4,4'-diaminobiphenyl in N- In methyl-2-pyrrolidone (NMP), it was made to react at 40 degreeC for 3 hours, and the solution containing the polymer (P-9) which is a polyamide acid of 10 mass% was obtained by this. [Synthesis Example 2-10] Combine 100 mol parts of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 20 mol parts of 3,5-diaminobenzoic acid, and 2,2'-dimethyl-4,4'-bis 80 mole parts of aminobiphenyl was dissolved in NMP and reacted at 40°C for 3 hours to obtain a solution containing 10% by mass of the polymer (P-10) as a polyamide acid.

[Synthesis Example 2-11] In accordance with the procedure of Production Example 2 described in Korean Patent Publication No. 2015-138548, a maleimide resin having a chalcone side chain was synthesized (referred to as "polymer (P-11)"). [Synthesis example 2-12] In accordance with the procedure of Example 1 described in Japanese Patent No. 2962473, a maleimide resin having a cinnamyl group in its side chain was synthesized (referred to as "polymer (P-12)"). [Synthesis Example 2-13] In accordance with the procedure of Production Example 1 described in Japanese Patent Application Laid-Open No. 2015-152743, a styrene resin having a cinnamyl group in a side chain was synthesized (referred to as "polymer (P-13)"). [Synthesis Example 2-14] Following the order of Example 27 described in Japanese Patent No. 5803915, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and acrylic acid (E)-3,5-diaminobenzyl 3- (2-(4-Butoxyphenyl)-1,3-dioxoisoindolin-5-yl) ester to synthesize polyamide acid (set it as "Polymer (P-14)" ).

＜Manufacturing and Evaluation of Liquid Crystal Display Device＞ [Example 1] (1) Preparation of liquid crystal alignment agent In a container containing 100 parts by mass of the polymer (P-1) obtained in Synthesis Example 2-1, cyclopentanone (CPN) and butyl cellosolve (BC) were added as solvents to prepare a solvent composition of CPN /BC=70/30 (mass ratio), a solution with a solid concentration of 3.5% by mass. The solution was filtered with a filter with a pore diameter of 1 μm, thereby preparing a liquid crystal alignment agent (AL-1).

(2) Manufacturing of optical vertical type liquid crystal display element The liquid crystal alignment agent (AL-1) prepared in (1) above was coated on the transparent electrode surface of the glass substrate with transparent electrode containing ITO film by a spinner , Using a hot plate at 80°C for 1 minute pre-baking to form a coating film with a thickness of 0.08 μm. Then, using Hg-Xe lamp and Glan-Taylor prism, irradiated the coating film surface with 313 nm bright line of polarized ultraviolet 200 from a direction inclined 40° from the normal line of the substrate at room temperature. J/m ² . Then, in an oven in which the inside of the warehouse was replaced with nitrogen, heating was performed at 160° C. for 40 minutes (formal sintering) to prepare a liquid crystal alignment film. The same operation is repeated repeatedly to form a pair (two) of substrates on which the liquid crystal alignment film is formed. By screen printing, an epoxy resin adhesive containing alumina balls with a diameter of 3.5 μm was applied to the outer periphery of the surface with the liquid crystal alignment film of one of the two substrates on which the liquid crystal alignment film was formed, and then used The liquid crystal alignment film surfaces of the pair of substrates face each other, and the pair of substrates are crimped so that the projection direction of the optical axis of the ultraviolet rays irradiated to the substrates on the substrate surface becomes antiparallel, and the adhesive is heated at 150°C for 1 hour hardening. Next, after filling the gap between the substrates with nematic liquid crystal (Merck (Merck), MLC-6608) from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy-based adhesive to obtain a liquid crystal cell. Furthermore, in order to remove the flow alignment during liquid crystal injection, the liquid crystal cell was heated at 150° C. and then slowly cooled to room temperature. Secondly, on the outer sides of the substrate in the liquid crystal cell, the polarized light is bonded so that the polarization directions of the polarizing plates are orthogonal to each other and the optical axis of the ultraviolet ray irradiated when the liquid crystal alignment film is formed is at an angle of 45° to the projection direction of the substrate surface. board.

(3) Evaluation of pretilt angle Regarding the liquid crystal display element manufactured in (2), according to the non-patent literature (TJ Scheffer et. al.) "J. Appl. Phys." Vol. 19, No. 2013 Page (vo. 19, p2013) (1980)), the value of the tilt angle of liquid crystal molecules with respect to the substrate surface is measured by the crystal rotation method using He-Ne laser light, and the value is set as a preset value. inclination. At this time, when the pretilt angle is less than 89.0°, it is set as "good (○)", and when the pretilt angle is 89.0° or more, it is set as "bad (×)". As a result, in this example, the pretilt angle was evaluated as "good (○)".

(4) Evaluation of coating uniformity The liquid crystal alignment agent (AL-1) prepared in (1) above was coated on the glass substrate using a spinner, and after pre-baking on a hot plate at 80°C for 1 minute, the inside of the library was replaced with nitrogen. Heat (post-baking) in an oven at 200°C for 1 hour to form a coating film with an average film thickness of 0.1 μm. The surface of the obtained coating film was observed by an atomic force microscope (AFM), and the center average roughness (Ra) was measured to evaluate the uniformity of the coating film surface. The case where Ra is 5 nm or less is evaluated as "good (○)" for coating uniformity, the case where Ra is greater than 5 nm and less than 10 nm is evaluated as "acceptable (△)", and the case where Ra is 10 nm or more is evaluated It is "bad (×)". As a result, in this example, it was evaluated as "available (△)".

(5) Evaluation of the deviation characteristics of the pretilt angle (post-baking margin) relative to the difference in post-baking temperature According to the method of (2), the liquid crystal alignment film was produced by different post-baking temperatures (150° C. and 200° C.), and the pretilt angles of the obtained two liquid crystal display elements were measured respectively. The difference Δθ between the pretilt angle θ200 of the liquid crystal display element whose post-baking temperature is set to 200°C and the pretilt angle θ150 of the liquid crystal display element whose post-baking temperature is set to 150°C (=| θ200-θ150|) to evaluate the deviation characteristics of the pretilt angle with respect to the difference in post-baking temperature. It can be said that the smaller the Δθ, the smaller the deviation of the pretilt angle with respect to the difference in the post-baking temperature, and the better it is. The pretilt angle is measured according to the non-patent literature (TJ Scheffer et. al.) "J. Appl. Phys." Vol. 19, p. 2013 (vo. 19, p In the method described in 2013) (1980)), the value of the tilt angle of liquid crystal molecules with respect to the substrate surface is measured by the crystal rotation method using He-Ne laser light, and this value is set as the pretilt angle [°]. In the evaluation, the case where Δθ is 0.1° or less is regarded as "excellent (◎)", the case where Δθ is greater than 0.1° and 0.2° or less is regarded as "good (○)", and the case where Δθ is greater than 0.2° and less than 0.5° If Δθ is 0.5° or more, set it as "possible (△)", and set Δθ to be 0.5° or more as "defect (×)". As a result, in this example, it was evaluated as "available (△)".

[Example 2 to Example 11, Comparative Example 1 to Comparative Example 4] The formulation of the liquid crystal alignment agent was changed as in Table 2 below, and except for this point, the liquid crystal alignment agent was prepared in the same manner as in Example 1. In addition, using each of the prepared liquid crystal alignment agents, an optical vertical type liquid crystal display device was manufactured in the same manner as in Example 1, and various evaluations were performed in the same manner as in Example 1. These results are shown in Table 2 below. In addition, in Example 3 to Example 11 and Comparative Example 1 to Comparative Example 4, two types of polymers were blended. In Example 11, an additive (photosensitizer) was blended in the liquid crystal alignment agent.

[Table 2] Polymer composition additive Solvent Evaluation 1 2 Composition (mass ratio) Coating uniformity Pretilt angle Baking margin Example 1 P-1 (100) CPN/BC=70/30 △ ○ △ Example 2 P-2 (100) CPN/BC=70/30 ○ ○ △ Example 3 P-2 (20) P-9 (100) MB/BC=70/30 ○ ○ △ Example 4 P-3 (1) P-9 (100) CPN/BC=70/30 ○ ○ ○ Example 5 P-4 (15) P-9 (100) NMP/BC=50/50 ○ ○ ○ Example 6 P-5 (40) P-9 (100) NMP/BC=50/50 ○ ○ ○ Example 7 P-6 (5) P-9 (100) EDM/BC=70/30 ○ ○ ○ Example 8 P-7 (3) P-10 (100) NMP/BC=50/50 ○ ○ ◎ Example 9 P-8 (8) P-10 (100) PGME/BC=50/50 ○ ○ ◎ Example 10 P-3 (14) P-10 (100) Add-1 (5) NMP/BC=50/50 ○ ○ ◎ Comparative example 1 P-11 (10) P-9 (100) NMP/BC=50/50 X × (High tilt angle) X Comparative example 2 P-12 (15) P-9 (100) NMP/BC=50/50 X × (High tilt angle) ○ Comparative example 3 P-13 (8) P-9 (100) NMP/BC=50/50 X × (High tilt angle) ○ Comparative example 4 P-14 (12) P-9 (100) NMP/BC=50/50 ○ × (High tilt angle) X

In Table 2, the numerical values in parentheses in the column of polymer components and additives indicate the blending ratio (unit: parts by mass) of each compound. The abbreviation of the solvent is as follows. PGME: Propylene Glycol Monomethyl Ether EDM: Diethylene Glycol Methyl Ether CPN: Cyclopentanone MB: 3-Methoxy-1-butanol NMP: N-methyl-2-pyrrolidone BC: γ-butyrolactone

As shown in Table 2, in Examples 1 to 10 prepared as a liquid crystal alignment agent containing polymer (A), the pretilt angle is less than 89 degrees, compared with Comparative Example 1 to which does not contain polymer (A) Compared with Example 4, the tilt angle of the liquid crystal molecules with respect to the vertical direction can be sufficiently increased. In addition, in Examples 1 to 11, the deviation of the pretilt angle due to the difference in the post-baking temperature was small. In particular, in Example 8 and Example 9 where a polymer with a light-sensitizing structure was blended, and Example 10 where an additive with a light-sensitizing structure was blended, the post-baking margin was evaluated as "excellent". Especially excellent. Furthermore, the coating uniformity of the liquid crystal alignment agents of Examples 1 to 10 is also good. In addition, it was found that by using the ring-opening body as the single body (R1), the coating uniformity can be improved. From these results, it was found that by using the polymer (A), a liquid crystal alignment film with good coating uniformity and excellent pretilt angle characteristics can be formed.

no

Claims (11)

A liquid crystal alignment agent comprising a polymer (A) derived from a compound represented by the following formula (1) and a compound represented by the following formula (2) At least one unitary structural unit in

(In formulas (1) and (2), R ¹ and R ² represent that one of R ¹ and R ² is a monovalent group having a polymerizable group, and the other is a hydrogen atom or a monovalent organic group, or R ¹ and R ² are bonded to each other ^{to form a ring structure together with the nitrogen atom to which R 1} and R ² are bonded; wherein the ring structure has a polymerizable carbon-carbon unsaturated bond; A ¹ is a monovalent organic group, A ² is a hydroxyl group or a monovalent organic group; n1 and n2 are each independently an integer satisfying 0≦n1+n2≦8). The liquid crystal alignment agent according to claim ¹ , wherein the A 1 is a monovalent group having a photo-alignment group. The liquid crystal alignment agent according to claim 1 or claim 2, further comprising a polymer (B) selected from the group consisting of polyamide acid, polyamide ester, polyimide and polyimide At least one of the group consisting of urea. The liquid crystal alignment agent according to claim 1 or 2, wherein the polymer (A) has a structural unit derived from a monomer having a cyclic ether structure and a cyclic carbonic acid At least one of the group consisting of an ester structure. The liquid crystal alignment agent according to claim 1 or claim 2, wherein the polymer (A) has a structural unit derived from a monomer having a carboxyl group and a protected carboxyl group. At least one of the group. The liquid crystal alignment agent according to claim 1 or claim 2, which contains a compound having a partial structure as the polymer (A) or an additive component, and the partial structure is capable of showing sensitization by light irradiation The function of light sensitization. A liquid crystal alignment film, which is formed using the liquid crystal alignment agent according to any one of claims 1 to 6. A liquid crystal element, comprising the liquid crystal alignment film according to claim 7. A polymer having a structural unit derived from at least one monomer selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2),

(In formulas (1) and (2), R ¹ and R ² represent that one of R ¹ and R ² is a monovalent group having a polymerizable group, and the other is a hydrogen atom or a monovalent organic group, or R ¹ and R ² are bonded to each other ^{to form a ring structure together with the nitrogen atom to which R 1} and R ² are bonded; wherein the ring structure has a polymerizable carbon-carbon unsaturated bond; A ¹ is a monovalent organic group, A ² is a hydroxyl group or a monovalent organic group; n1 and n2 are each independently an integer satisfying 0≦n1+n2≦8). A compound represented by the following formula (1),

(In formula (1), R ¹ and R ² represent that one of R ¹ and R ² is a monovalent group having a polymerizable group, the other is a hydrogen atom or a monovalent organic group, or R ¹ and R ² A ring structure formed by bonding to each other and ^{the nitrogen atom bonded to R 1} and R ² ; wherein the ring structure has a polymerizable carbon-carbon unsaturated bond; A ¹ is a monovalent organic group, and A ² is a hydroxyl group or A monovalent organic group; n1 and n2 are each independently an integer satisfying 0≦n1+n2≦8). A compound represented by the following formula (2),

(In formula (2), R ¹ and R ² represent that one of R ¹ and R ² is a monovalent group having a polymerizable group, the other is a hydrogen atom or a monovalent organic group, or R ¹ and R ² A ring structure formed by bonding to each other and ^{the nitrogen atom bonded to R 1} and R ² ; wherein the ring structure has a polymerizable carbon-carbon unsaturated bond; A ¹ is a monovalent organic group, and A ² is a hydroxyl group or A monovalent organic group; n1 and n2 are each independently an integer satisfying 0≦n1+n2≦8).