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

Abstract

This invention provides a liquid crystal alignment agent containing a novel solvent component suitable for a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the film. Furthermore, it provides a liquid crystal display element that improves the coatability of the liquid crystal alignment film's ends, achieving high display characteristics even when used in liquid crystal display elements with large display surfaces. A liquid crystal alignment agent contains a polymer (P) selected from the group consisting of polyimides composed of polyimides and polyimides that are polyimide precursors and amides of the polyimide precursors, and a solvent component containing a compound (a) represented by formula (A).

Description

Technical Field

[0001] This invention relates to a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film. Prior Technology

[0002] In the past, various driving methods have been developed for liquid crystal display elements, including different electrode structures and the physical properties of the liquid crystal molecules used. Examples include known TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), and FFS (Fringe Field Switching) display elements. These liquid crystal display elements have a liquid crystal alignment film to align the liquid crystal molecules. Known materials for the liquid crystal alignment film include, for example, polyamide, polyamide-polyimide precursors, or polymers represented by polyimide.

[0003] VA-type liquid crystal display elements, one of the driving methods for liquid crystal display elements, are known to involve adding a photopolymerizable compound to the liquid crystal composition beforehand, using a polyimide-based vertical alignment film, and applying voltage to the liquid crystal cells while irradiating them with ultraviolet light to accelerate the response speed of the liquid crystal (PSA (Polymer Sustained Alignment) type element) (see, for example, Patent Document 1 and Non-Patent Document 1). Furthermore, it is also known to involve adding a photopolymerizable compound to a polyimide-based vertical liquid crystal alignment agent, and applying voltage to liquid crystal cells having a liquid crystal alignment film obtained from the liquid crystal alignment agent while irradiating them with ultraviolet light to accelerate the response speed of the liquid crystal (SC-PVA type, for example, see Non-Patent Document 2)).

[0004] This refers to a liquid crystal alignment agent used to form a liquid crystal alignment film. The polymer component is dissolved in a solvent. The liquid crystal alignment agent is coated onto a substrate and heated to form a liquid crystal alignment film. Here, the solvent for the liquid crystal alignment agent is an organic solvent with high polymer solubility, such as aprotic polar solvents commonly used, such as N-methyl-2-pyrrolidone and γ-butyrolactone. [Previous Technical Documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2003-307720 [Non-Patent Literature 1] K. Hanaoka, SID 04 DIGEST, pp. 1200-1202 [Non-Patent Literature 2] You-Jin Lee et al., Optics Express, June 8, 2009, Vol.17, Issue 12, pp.10298-10303 Summary of the Invention

[0006] (The problem the invention aims to solve)

[0007] The aforementioned N-methyl-2-pyrrolidone and γ-butyrolactone are not limited to liquid crystal alignment agents and are used in many technical fields, with their usage expected to increase in the future. This could potentially lead to supply shortages, necessitating the exploration of new solvent components suitable for liquid crystal alignment agents.

[0008] Furthermore, in recent years, liquid crystal display elements have been used in applications such as smartphones and tablet computers. However, in these applications, in order to ensure as many display surfaces as possible, the sealant used to bond the substrates of the liquid crystal display elements is located near the ends of the liquid crystal alignment film. Therefore, when the coatability of the liquid crystal alignment film ends decreases, that is, when the area of ​​bulging at the ends of the liquid crystal alignment film (uneven film thickness at the film ends) is large, the contrast at the ends of the liquid crystal alignment film will change, and the display characteristics of the liquid crystal display element will decrease.

[0009] In view of the above, the object of the present invention is to provide a liquid crystal alignment agent containing a new solvent component suitable for a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element using the film. Furthermore, the object is to provide a liquid crystal display element that improves the coatability of the ends of the liquid crystal alignment film, and can still obtain high display characteristics even when used in a liquid crystal display element with a large display surface. (Methods for solving problems)

[0010] This invention is based on this knowledge and insight, and the following are its main points.

[0011] A liquid crystal alignment agent comprising: A polymer (P) selected from at least one polymer (P) of the group consisting of polyimide precursors and polyimides of polyimide precursors, and A solvent component containing compound (a) represented by formula (A)

[0012] [Chemistry 1]

[0013] Furthermore, in this specification, * represents an atomic bond. Boc represents terbutoxycarbonyl. Halogen atoms include fluorine, chlorine, bromine, and iodine. Carbamate protecting groups include terbutoxycarbonyl and 9-pyromethoxycarbonyl. (Effects of the invention)

[0014] By using compound (a) as at least a portion of the solvent component of the liquid crystal alignment agent of the present invention, the coating properties of the polyimide precursor and polyimide can be improved. More specifically, the uniformity of the film thickness at the ends of the obtained liquid crystal alignment film is improved, and high display characteristics can still be obtained even when used in liquid crystal display elements with large display surfaces. Furthermore, the liquid crystal alignment film of the present invention has both high film thickness uniformity and high liquid crystal alignment.

[0015] The mechanism by which the present invention achieves the above-mentioned effects may not be clear, but it is believed to be due to the following reasons. Compound (a) has a higher boiling point and viscosity than N-methyl-2-pyrrolidone, which is mainly used in liquid crystal alignment agents. Furthermore, it has a polarized structure, thus suppressing the precipitation of polyimide precursors and polyimide. Therefore, it is believed that liquid crystal alignment agents using compound (a) do not experience the precipitation of polyimide precursors and polyimide during printing, and the coating size is highly controlled, thereby achieving the above-mentioned effects. Simple Explanation of the Diagram

[0016] [Figure 1] shows the polyimide film printed on the Cr vapor-deposited substrate and the uneven film thickness. [Figure 2] shows the uneven film thickness at the edge of the polyimide film, magnified by an optical microscope of the dashed line area in Figure 1. Implementation

[0017] The following describes the components contained in the liquid crystal alignment agent of the present invention, as well as other components that may be arbitrarily added as needed. <Polymer (P)> The liquid crystal alignment agent of the present invention contains at least one polymer (P) selected from the group consisting of polyimide precursors and polyimides that are amides of the polyimide precursors. Examples of polyimide precursors include polyamide acid and polyamide esters. Furthermore, the tetracarboxylic acid component used to obtain the polymer (P) can be not only tetracarboxylic dianhydride, but also derivatives of tetracarboxylic dianhydride such as tetracarboxylic acid, tetracarboxylic acid dihalides, tetracarboxylic acid dialkyl esters, or tetracarboxylic acid dialkyl ester dihalides.

[0018] (Polyamide) Polyamide (P'), which is the polyimide precursor of the above polymer (P), can be obtained by polymerization of a diamine component and a tetracarboxylic acid component containing a tetracarboxylic acid dianhydride or its derivative.

[0019] (Diamine) The diamine component used in the manufacture of polyacrylic acid (P') can be of various types depending on the purpose. Furthermore, the diamine used in the manufacture of polyacrylic acid (P') can be used alone or in combination of two or more types. Ideal examples of the diamine (hereinafter also referred to as diamine (p)) used in the manufacture of polyacrylic acid (P') can be listed below.

[0020] "AXJ" (definitions for A, X, and J are given below) represents aromatic diamines (d), p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl. Aminobiphenyl, 3,3'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, bis(4-aminophenoxy)methane, 1,2-bis(4-aminophenyl)ethane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl)butane, 1,4-bis(4-amino-2-methylphenoxy)butane, 1,4-bis... (3-Aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy)hexane, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3-aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis(3-aminophenoxy)decane, 1,11- bis(4-aminophenoxy)undecane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 3-[2-[2-(4-aminophenoxy)ethoxy]ethoxy]aniline, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthoxy)ethane, 1,2-Bis(6-amino-2-naphthyl)ethane, 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 4'-[2-(4-aminophenoxy)ethoxy]-[1,1'-biphenyl]-4-amine, 1,4-bis[2-(4-aminophenyl)ethyl]succinate, 1,6-bis[2-(4-aminophenyl)ethyl]hexadiate, 1,4-epoxyphenylbis(4-aminobenzoate), 1,4-epoxyphenylbis(3-aminobenzoate), 1,3-epoxyphenylbis(4-aminobenzoate), 1,3-epoxyphenylbis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis... (3-aminophenyl) isophthalate (hereinafter, these diamines are also referred to as diamines (1)); 4,4'-diaminoazobenzene, diaminodiphenylacetylene, 4,4'-diaminochalcone, or [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-sideoxy-prop-1-enyl]phenyl]4-(4,4,4-trifluorobutoxy)benzoate, or [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enyl]oxymethyl]phenyl]phenyl]methoxy]-3-sideoxy-prop-1-enyl]phenyl]4-(4,4,4-trifluorobutoxy] Diamines with photooriented groups, such as aromatic diamines with cinnamic acid ester side chains (represented by benzoic acid esters); diamines with photopolymerizable groups at the ends, such as 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,4-diamino-N,N-diallyl aniline; and diamines with photopolymerizable groups at the ends, such as benzoin or its alkyl ether derivatives (represented by 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone and 2-(4-(2-hydroxy-2-methylpropionic acid)phenoxy)ethyl-3,5-diaminobenzoic acid esters), benzyl ketals, acetophenones, phosphine oxides, diphenyl ketones, or aminodiphenyl ketones, which exhibit free radical polymerization initiator functions (hereinafter also referred to as diamines with free radical polymerization initiator functions). Diamines that begin function on the hydroxyl group. Examples include diamines with amide bonds such as 4,4'-diaminophenylbenzylaniline, 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, and 1,3-bis(4-aminophenylethyl)urea; 4,4'-sulfonylurea, 3,3'-sulfonylurea, bis(4-aminophenyl)silane, etc. bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodiphenylamine, 3,3'-thiodiphenylamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane Ketones, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazol-1-yl)propyl-3,5-diaminobenzyl) acetylamine, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-azolyl]-aniline, 1,4-bis(p-aminobenzyl)piperidine, 4,4'-[propane-1,3-diylbis(piperidine-1,4-diyl)]diphenylamine, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, diamines represented by formulas (z-1) to (z-5), 2,5-bis(4-aminophenyl)pyrrole, 4,4'-(1-methyl-1H-pyrrole-2,5-diyl)bis[aniline], 1,4- Bis-(4-aminophenyl)-piperazine, 2-N-(4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridin-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-6-aminobenzimidazole, 5-(1H-benzimidazole-2-yl)phenyl-1,3-diamine and other heterocyclic diamines, or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-1,4-phenylenediamine, N,N Diamines with a diphenylamine structure, such as '-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-phenylenediamine, are representative of diamines with at least one nitrogen-containing structure (hereinafter also referred to as specific nitrogen-containing structures) selected from the group consisting of nitrogen-containing heterocycles, secondary amine groups, and tertiary amine groups. (However, the molecule does not contain an amine group that has been decoupled by heating and replaced by a hydrogen atom.) 2,4-Diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,Diamines with carboxyl groups, such as 4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 1,2-bis(4-aminophenyl)ethane-3,3'-dicarboxylic acid, and 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid; 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminodiphenylmethane-3,3'-dicarboxylic acid, etc. Aminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-dihydroindene-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine; N,N'-bis(2-tert-butoxycarbonylamino-4-aminophenyl)hexamethylenediamine, 4-amino-N-(2-tert-butoxycarbonylamino-4-aminophenyl)benzamide, carbamic acid, N-[(2,5-diaminophenyl)methyl]-1,1-dimethylethyl ester, carbamic acid, N-[3-(2,5-diaminophenyl)propyl]- 1,1-Dimethyl ethyl ester, N,N-[(2,5-diamino-1,3-epoxyphenyl)di-3,1-propanediyl]bis-C,C-bis(1,1-dimethyl ethyl) ester, N-tert-butoxycarbonyl-N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine, benzoic acid, 4-amino-2-tert-butoxycarbonylamino-1,1'-[(1,1,3,3-tetramethyl-1,3-disiloxanediyl)di-4,1-butanediyl] ester, N-[2-(4-aminophenyl)ethyl]-N-[[[2-(4-aminophenyl)ethyl]amino]carbonyl]-1,1-dimethyl ethyl ester, N-(4-aminophenyl)-N-[[ Diamines containing the group "-N(D)-" (D represents a protecting group that is removed and replaced by a hydrogen atom upon heating, preferably a tert-butoxycarbonyl group) such as 1-(4-aminophenyl)-4-piperidinyl]methyl]-1,1-dimethylethyl ester; 1-dodecyl-2,4-diaminobenzene, 1-tetradecyloxy-2,4-diaminobenzene, 1-pentadecanyloxy-2,4-diaminobenzene, 1-hexadecyloxy-2,4-diaminobenzene, 1-octadecyloxy-2,4-diaminobenzene, 1-dodecyloxy-2,5-diaminobenzene, 1-tetradecyloxy-2,5-diaminobenzene, 1-pentadecanyloxy-2,5-diaminobenzene, 1-hexadecyloxy-2,5-diaminobenzene, 1-octadecyloxy-2,5-diaminobenzene, 1-octadecyloxy-2,4-diaminobenzene, 1-tetadecan ...4-diaminobenzene, 1-tetadecanyloxy-2,4-diaminobenzene, 1-tetadecanyloxy-2,4-diaminobenzene, 1-tetadecanyloxy-2,4-diaminobenzene, 1-tetadecanyloxy-2,4-diaminobenzene, 1-tetadecanyloxy-Aromatic diamines (tn) with long-chain alkyl groups having 12 to 20 carbon atoms, represented by 5-diaminobenzene; diamines with siloxane bonds, such as 1,3-bis(3-aminopropyl)tetramethyldisiloxane and 1,3-bis[3-(p-aminophenylaminomethyl)propyl]tetramethyldisiloxane; diamines with two amino groups bonded by any of the formulas (Y-1) to (Y-167) described in International Publication No. 2018 / 117239, including m-xylene diamine, 1,3-propane diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and diamines with two amino groups bonded by any of the formulas (Y-1) to (Y-167) described in International Publication No. 2018 / 117239.

[0021] [Chemistry 2] In equation (z-2), m can be the same or different.

[0022] In the above aromatic diamine (d), A represents two primary amino groups bonded to a monovalent aromatic group. Specific examples of aromatic groups include benzene rings, naphthalene rings, and biphenyl structures. X represents a single bond, -(CH2)a- (a is an integer from 1 to 15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -COO-, -OCO-, or -(A0)m0-((CH2)a1-A1)m1- (a1 is an integer from 1 to 15, A0 and A1 each independently represent an oxygen atom or -COO-, m0 is an integer of 0 or 1, and m1 is an integer from 1 to 2. When m1 is 2, multiple a1 and A1 independently have the above definitions).

[0023] J represents a monovalent organic group having at least one group selected from the group consisting of alicyclic hydrocarbon groups with 4 to 40 carbon atoms and aromatic hydrocarbon groups with 6 to 40 carbon atoms. However, at least one hydrogen atom of the aforementioned alicyclic hydrocarbon group and aromatic hydrocarbon group is substituted by a substituent (v) of any one of the following: a halogen atom, a halogen-containing alkyl group, a halogen-containing alkoxy group, an alkyl group with 3 to 10 carbon atoms, an alkoxy group with 3 to 10 carbon atoms, and an alkenyl group with 3 to 10 carbon atoms. Any carbon-carbon single bond in these substituents (v) (excluding halogen atoms) may also be interrupted by -O-. Furthermore, in addition to having the aforementioned alicyclic hydrocarbon group and aromatic hydrocarbon group, J may also have at least one group selected from the group consisting of alicyclic hydrocarbon groups and aromatic hydrocarbon groups that are unsubstituted or substituted by substituents other than the aforementioned substituents (v).

[0024] Alkyl groups containing halogen atoms, for example: alkyl groups containing halogen atoms with 1 to 10 carbon atoms.

[0025] Alkoxy groups containing halogen atoms, for example: alkoxy groups containing halogen atoms with 1 to 10 carbon atoms.

[0026] The alicyclic hydrocarbon group J can be listed as cyclobutane ring, cyclopentane ring, cyclohexane ring, cyclodecane ring, steroid skeleton (e.g., cholesteryl, cholesterol, lanosteryl, etc.), etc., and the aromatic hydrocarbon group can be listed as benzene ring, naphthalene ring, etc. When J has at least one of cyclohexane ring and benzene ring, the group "-XJ" is, for example, the following structure (S1), and more ideal structures can be listed as formulas (S1-1) to (S1-5).

[0027] [Chemistry 3]

[0028] X1 represents a single bond, -(CH2)a- (a is an integer from 1 to 15), -CONH-, -CO-N(CH3)-, -NH-, -O-, -COO-, or -(A0)m0-((CH2)a1-A1)m1- (a1 is an integer from 1 to 15, A0 and A1 each independently represent an oxygen atom or -COO-, m0 is an integer of 0 or 1, and m1 is an integer from 1 to 2. When m1 is 2, multiple a1 and A1 each have the above definitions independently).

[0029] G1 represents a divalent cyclic group selected from phenyl and cyclohexyl. Any hydrogen atom on the aforementioned cyclic group may also be replaced by an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorinated alkyl group having 1 to 3 carbon atoms, a fluorinated alkoxy group having 1 to 3 carbon atoms, or a fluorine atom.

[0030] m is an integer from 1 to 4. When m is 2 or more, multiple X1 and G1 can each independently have the above definitions.

[0031] R 1 represents a fluorine atom, an alkyl group containing fluorine atoms with 1 to 10 carbon atoms, an alkoxy group containing fluorine atoms with 1 to 10 carbon atoms, an alkyl group with 3 to 10 carbon atoms, an alkoxy group with 3 to 10 carbon atoms, or an alkoxyalkyl group with 3 to 10 carbon atoms.

[0032] [Chemistry 4]

[0033] X1 and R1 are synonyms with X1 and R1 in the above formula (S1). Specific examples of the above-mentioned aromatic diamines (d) can be listed as diamines represented by formulas (d-1) to (d-2). More ideal specific examples can be listed as diamines represented by formulas (d-1) to (d-2) in which the radical "-XJ" is the above structure (S1) or any of the above formulas (S1-1) to (S1-5), and diamines having a steroid skeleton such as cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-3,5-diaminobenzene, cholesteryloxy-2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, cholesteryl 3,5-diaminobenzoate, lanosteryl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane.

[0034] [Chemistry 5]

[0035] X and J are synonymous with X and J in the above-mentioned aromatic diamine (d) in the ideal state. In the aforementioned formula (d-2), the two X and J can be the same or different from each other. The aforementioned diamine (p) can be appropriately selected from among the diamines depending on, for example, the driving mode of the manufactured liquid crystal display element. Specifically, by using the aforementioned diamine (1), the aforementioned diamine having a specific nitrogen-containing structure, or the aforementioned diamine having a urea bond, liquid crystal alignment agents suitable for IPS-type and FFS-type liquid crystal display elements can be manufactured. Furthermore, by using the aforementioned diamine (1) and aromatic diamine (tn), liquid crystal alignment agents suitable for TN-type liquid crystal display elements can be manufactured, and by using the aforementioned aromatic diamine (d), liquid crystal alignment agents suitable for VA-type liquid crystal display elements can be manufactured. Furthermore, by using the aforementioned diamine having a free radical initiation function and a diamine with a photopolymerizable group at the end, liquid crystal alignment agents suitable for PSA-type and SC-PVA-type liquid crystal display elements can be manufactured. Furthermore, when imparting photoorientation to polyacrylic acid (P'), the aforementioned diamine with photoorientation groups can be used as the diamine (p). Moreover, when imparting solubility to polyacrylic acid (P'), the aforementioned diamine with carboxyl groups, the aforementioned diamine with the group "-N(D)-", or a diamine (K) containing -Ar-K-Ar- (Ar represents unsubstituted or substituted phenyl groups. K represents -C(CH3)2-, -C(CF3)2-, -O-, or -CH2-. Furthermore, the -Ar-K-Ar- is formed in the direction of the polymer backbone.) can be used. Specific examples of diamines (K) include 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(3-aminophenyl)hexafluoropropane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(3-amino-4-methylphenyl)propane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, etc.

[0036] When using the above-mentioned aromatic diamine (d) as the above-mentioned diamine (p), it is preferable to use 5 to 95 mol% of the total diamine component used to manufacture polyacrylic acid (P'), and 10 to 90 mol% is even more preferable. When using the above-mentioned diamine (1), the above-mentioned diamine having a specific nitrogen-containing structure, or the above-mentioned diamine having a urea bond as the above-mentioned diamine (p), it is preferable to use 5 to 95 mol% of the total diamine component used to manufacture polyacrylic acid (P'), and 10 to 90 mol% is more preferable. When using diamines with photoalignment groups, diamines with free radical initiation functions, or diamines with photopolymerization groups at the ends as the aforementioned diamine (p), it is preferable to use 5 to 60 mol% of the total diamine component used to manufacture polyacrylic acid (P'), and 10 to 60 mol% is even more preferable. When using the above-mentioned diamines having a carboxyl group or the above-mentioned diamines having the group "-N(D)-" as the above-mentioned diamine (p), it is preferable to use 5 to 90 mol% of the total diamine component used to manufacture polyacrylic acid (P'), and 10 to 80 mol% is more preferable.

[0037] (Tetracarboxylic acid dianhydride) The tetracarboxylic dianhydrides that can be used in the synthesis of the aforementioned polyacrylic acid (P') are selected from at least one compound chosen from the group consisting of acyclic aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, and aromatic tetracarboxylic dianhydrides. It is preferable that the tetracarboxylic dianhydride contains at least one substructure chosen from the group consisting of benzene ring, cyclobutane ring, cyclopentane ring, and cyclohexane ring structures; it is even more ideal that the tetracarboxylic dianhydride contains at least one substructure chosen from the group consisting of cyclobutane ring, cyclopentane ring, and cyclohexane ring structures. Furthermore, aromatic tetracarboxylic acid dianhydrides are acid dianhydrides obtained by intramolecularly dehydrating four carboxyl groups, including at least one carboxyl group with an aromatic ring bond. Acyclic aliphatic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecularly dehydrating the four carboxyl groups bonded to a chain hydrocarbon structure. However, they do not necessarily have to consist solely of a chain hydrocarbon structure; some may also possess alicyclic or aromatic ring structures. Alicyclic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded by an alicyclic structure. However, none of these four carboxyl groups are bonded to an aromatic ring. Furthermore, it is not necessary for the structure to be solely alicyclic; a portion of it may also possess a chain hydrocarbon structure or an aromatic ring structure. The tetracarboxylic acid components that can be used in the synthesis of polyacrylic acid (P') are preferably tetracarboxylic dianhydrides or their derivatives (hereinafter collectively referred to as specific tetracarboxylic acid derivatives).

[0038] Furthermore, the aforementioned tetracarboxylic dianhydrides or their derivatives may be used alone or in combination of two or more.

[0039] Acyclic aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, ... Pentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 4-(2,5-di-side-oxytetrahydrofuran-3-yl)tetrahydronaphthyl-1,2-dicarboxylic dianhydride, 5-(2,5-di-side-oxytetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-di-side-oxytetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2. [2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclic [2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8-tetracarboxylic bicyclic [3.3.0]octane-2:4,6:8-dianhydride and other alicyclic tetracarboxylic dianhydrides; benzopyrene dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid Aromatic tetracarboxylic acid dianhydrides include dianhydrides such as 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydrous, ethylene glycol bis(triphenylene) anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid anhydride, 4,4'-carbonyldiphthalic acid anhydride, 4,4'-oxobis(1,4-epoxyphenyl)bis(phthalic acid) dianhydride, or 4,4'-methylenebis(1,4-epoxyphenyl)bis(phthalic acid) dianhydride; in addition, tetracarboxylic acid dianhydrides as described in Japanese Patent Application Publication No. 2010-97188, etc.

[0040] Ideal examples of the aforementioned specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1 3-Difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dicyclohexyl) 5-(2,5-di-tetrahydrotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxylic bicyclo[3.3.0]octane-2:4,6:8-di Anhydride, benzopyrotetracarboxylic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2',3,3'-biphenyl tetracarboxylic dianhydride.

[0041] The ideal proportion of the aforementioned specific tetracarboxylic acid derivatives relative to 1 mol of the total tetracarboxylic acid component used is 10 mol% or more, 20 mol% or more is better, and 50 mol% or more is even better.

[0042] (Synthesis of polyamides) Polyamide can be synthesized by reacting a diamine containing the aforementioned diamine with a tetracarboxylic acid containing the aforementioned tetracarboxylic dianhydride or its derivative in an organic solvent. The ideal ratio of tetracarboxylic dianhydride to diamine in the polyamide synthesis reaction is 0.5 to 2 equivalents of the anhydride group of the tetracarboxylic dianhydride relative to 1 equivalent of the amino group of the diamine, and more preferably 0.8 to 1.2 equivalents. Similar to conventional polycondensation reactions, the closer the equivalent of the anhydride group of the tetracarboxylic dianhydride is to 1 equivalent, the larger the molecular weight of the resulting polyamide.

[0043] In the synthesis of polyacrylic acid, the ideal reaction temperature is -20~150℃, and 0~100℃ is even more ideal. Furthermore, the ideal reaction time is 0.1~24 hours, and 0.5~12 hours is even more ideal.

[0044] The synthesis reaction of polyamide can be carried out at any concentration, preferably 1-50% by mass, more preferably 5-30% by mass. The reaction can be carried out at a high concentration initially, and then additional solvent can be added.

[0045] Specific examples of the aforementioned organic solvents include compound (a), cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, and 1,3-dimethyl-2-imidazolidineone. Furthermore, when the polymer has high solvent solubility, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether can be used.

[0046] (Synthesis of polyamides) Polyamide esters can be obtained by known methods such as: [I] reacting polyamide obtained by the above methods with an esterifying agent, [II] reacting tetracarboxylic acid diester with a diamine, [III] reacting tetracarboxylic acid diester dihalide with a diamine.

[0047] (Synthesis of polyimide) Furthermore, polyimide can be obtained by cyclizing (nitroimizing) the aforementioned polyamide precursors such as polyamides or polyamide esters. Also, the nitroimization rate referred to in this specification is the ratio of nitroimide groups to the total amount of nitroimide groups and carboxyl groups (or their derivatives) derived from tetracarboxylic dianhydride or its derivatives. The nitroimization rate in polyimide is not necessarily 100% and can be adjusted arbitrarily according to the application and purpose. For example, considering the solubility of polyimide, its nitroimization rate can be 30% or more, or 40-99%, or 50-99%.

[0048] Methods for amide-imidizing polyimide precursors include thermal amide-imidization by directly heating a solution of the polyimide precursor or catalytic amide-imidization by adding a catalyst to a solution of the polyimide precursor.

[0049] The temperature at which the polyimide precursor is thermally amided in solution is preferably 100~400℃, more preferably 120~250℃, and it is preferable to drain the water generated by the amided reaction outside the system during the process.

[0050] Catalytic amide formation of polyimide precursors can be achieved by adding an alkaline catalyst and an acid anhydride to a solution of the polyimide precursor, preferably at -20 to 250°C, more preferably at 0 to 180°C with stirring. The amount of alkaline catalyst is preferably 0.5 to 30 moles of the amide group, more preferably 2 to 20 moles, and the amount of acid anhydride is preferably 1 to 50 moles of the amide group, more preferably 3 to 30 moles. Examples of alkaline catalysts include pyridine, triethylamine, trimethylamine, tributylamine, or trioctylamine, among which pyridine is ideal due to its moderate alkalinity that facilitates the reaction. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, or phenylmethyltetrahydroquinone, among which acetic anhydride is preferred because it facilitates purification after the reaction. The amide ratio obtained by catalytic amide imidization can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0051] When recovering the polyimide precursor or polyimide generated from the reaction solution of polyimide precursor or polyimide, the reaction solution is simply added to a solvent to precipitate it. Solvents used for precipitation include methanol, ethanol, isopropanol, acetone, hexane, butylceryl ketone, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated in the solvent can be recovered by filtration and then dried at room temperature or by heating under normal or reduced pressure.

[0052] <End-capping agent> When synthesizing the polyimide precursor and polyimide of this invention, a tetracarboxylic acid component containing tetracarboxylic dianhydride or its derivative, and a diamine component containing the aforementioned diamine, along with a suitable end-sealing agent, can be used to synthesize an end-sealing polymer. The end-sealing polymer has the effect of increasing the film hardness of the alignment film obtained from the coating and improving the adhesion properties between the sealant and the alignment film.

[0053] The polyimide precursor and the ends of the polyimide in this invention are derived, for example, from amino, carboxyl, anhydride, or end-capping agents described below. Amine, carboxyl, and anhydride groups can be obtained through conventional condensation reactions or by sealing the ends using the end-capping agents described below.

[0054] End-capping agents, such as acetic anhydride, maleic anhydride, naphthalic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 4-ethynylphthalic anhydride, etc.; dibutyl dicarbonate, diallyl dicarbonate, etc.; acrylonitrile chloride, methacrylic chloride, etc. Nicotinic acid, chlorocarbonyl compounds, etc.; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, etc.; isocyanates with unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.

[0055] The preferred ratio of the capping agent to the total 100 moles of diamine used is 0.01 to 20 moles, and even better is 0.01 to 10 moles.

[0056] The weight-average molecular weight (Mw) of the polyimide precursor and polyimide, determined by gel permeation chromatography (GPC) based on polystyrene, is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. Furthermore, the molecular weight distribution (Mw / Mn), expressed as the ratio of Mw to the number-average molecular weight (Mn) of polystyrene determined by GPC, is preferably 15 or less, more preferably 10 or less. By falling within this molecular weight range, good alignment of the liquid crystal display element can be ensured.

[0057] (Liquid crystal alignment agent) The liquid crystal alignment agent of the present invention contains a polymer (P) and a compound (a) represented by formula (A) as a solvent component. Liquid crystal alignment agents are used in the fabrication of liquid crystal alignment films. From the perspective of forming a uniform film, a coating solution is preferred. The concentration of the polymer in the liquid crystal alignment agent can be appropriately varied depending on the desired coating thickness. For the purpose of forming a uniform and defect-free coating, a polymer concentration (total concentration of polymer components) of 1% by mass or higher is ideal; considering the storage stability of the solution, 10% by mass or lower is preferred. An ideal polymer concentration is 2-8% by mass. The content of compound (a) can be adjusted appropriately according to the purpose. For example, considering the improvement of printability, the content relative to the total amount of solvent components contained in the liquid crystal alignment agent can be 0.1% by mass or more, or 1% by mass or more, or 5% by mass or more, or 10% by mass or more. Furthermore, regarding the upper limit of the content, considering the printability, the content relative to the total amount of solvent components contained in the liquid crystal alignment agent can be 90% by mass or less, or 85% by mass or less, or 80% by mass or less. Furthermore, compound (a) may sometimes contain impurities such as levoglucosan and levoglucosenone. In such cases, the ideal range for the content ratio of the aforementioned compound (a) specifies the amount of compound (a) containing such impurities. Also, compound (a) may be a single stereoisomer or a mixture containing multiple stereoisomers. Commercially available products of compound (a) include, for example, Cyrene (trademark) manufactured by Merck.

[0058] The solvent used in the preparation of the liquid crystal alignment agent of the present invention may also be other solvents besides compound (a) mentioned above. These other solvents include, for example: lactone solvents such as γ-pentanolide, γ-butyrolactone, and α,α-dimethyl-γ-butyrolactone; γ-butyrolactone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-n-propyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-n-pentyl-2-pyrrolidone, N-(3-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone, N-(4-methoxybutyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, and N-acetyl-ε-caprolactone. Acrylamide solvents such as N-acetylated-2-hexamethyleneimine and N-methyl-ε-caprolactam; acetamide solvents such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionic acid, N,N-dimethylisobutylamide (N,N,2-trimethylpropionic acid), N,N-diethylpropionic acid, N,N-dipropylacetamide, N,N-diisopropylacetamide, N,N-dibutylacetamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropane acetamide, and 3-butoxy-N,N-dimethylpropane acetamide;Tetramethylurea, N,N'-dimethylacrylurea, N-propionic acid, 4-sideoxytetrahydropiperanone (tetrahydro-4H-piperanone), tetramethylene sulfoxide, trimethyl phosphate, triethyl phosphate, trimethylamine hexamethylphosphate, 3-methyl-2-azolidinone, 1,3-dimethyl-2-imidazolidinedione (N,N'-dimethylethylurea), 1,4-diacetylopyridine, cyclohexanone, 3-methylcyclohexanone, 4- Methylcyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol), isopropyl acetate, n-butyl acetate, isobutyl acetate, tributyl acetate, propylene glycol monoethyl ether, cyclohexyl acetate, 4-methyl-2-pentyl acetate, 3-methoxybutyl acetate (3-methoxybutyl acetate), isopropyl lactate, n-butyl lactate, isobutyl lactate, tributyl lactate, isoamyl lactate Lactate), 2-(2-ethoxyethoxy)ethyl acetate (ethylene glycol monoethyl ether), methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl 2-hydroxyisobutyrate (methyl 2-hydroxy-2-methylpropionate), ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl cyrosol), ethylene glycol monoisopentyl ether, ethylene glycol monohexyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol diacetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol diacetate, diethylene glycol dimethyl ether, di... Ethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, diethylene glycol methyl propyl ether, diethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate (2-(2-ethoxyethoxy)ethyl acetate, carbitol acetate), diethylene glycol monobutyl ether acetate (butyl carbitol acetate), dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, 1-(2-butoxyethoxy)-2-propanol, 2-(2-butoxyethoxy)-1-propanol, diisobutylmethanol (2,6-dimethyl-4-heptanol), diisobutyl ketone, isoamyl propionate (Isoamyl) Propionate, isoamyl isobutylate, diisoamyl ether, ethyl acetate, propyl acetate, etc. Two or more of these can be mixed.

[0059] From the viewpoint of improving the solubility of the polymer (P), the solvent component in the liquid crystal alignment agent of the present invention may also contain a solvent selected from the group consisting of γ-valerolactone, γ-butyrolactone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-n-propyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-n-pentyl-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, the above-mentioned acetamide solvents, 1,3-dimethyl-2-imidazolidineone, tetramethylurea, hexamethylphosphoric acid triamine, cyclohexanone, and cyclopentanone (hereinafter collectively referred to as "solvent (1)"). The content of the solvent (1) is preferably 20-99% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20-90% by mass, and especially 30-80% by mass is more ideal.

[0060] From the viewpoint of improving the printability of the liquid crystal alignment agent of the present invention, the solvent component may also contain, selected from 4-hydroxy-4-methyl-2-pentanone, n-butyl acetate, propylene glycol monoethyl ether, cyclohexyl acetate, 4-methyl-2-pentyl acetate, n-butyl lactate, isoamyl lactate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl) Solvents in the group consisting of ceroxanone, dimethyl ethylene glycol, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, diisobutylmethanol, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethyl carbonate, and propyl carbonate (hereinafter collectively referred to as "solvent (2)"). The content of the above solvent (2) is preferably 5 to 70% by mass of the total solvents contained in the liquid crystal alignment agent, more preferably 10 to 60% by mass, and 10 to 50% by mass is even more ideal.

[0061] The liquid crystal alignment agent of the present invention may contain a combination of multiple solvents. For example, a solvent component containing compound (a) and the solvent (1) described above, a solvent component containing compound (a) and the solvent (2) described above, and a solvent component containing compound (a) and the solvent (1) and the solvent (2) described above. Among these, more ideal examples can be given, solvent components containing the following states can be listed. Furthermore, in the following samples, BCS represents ethylene glycol monobutyl ether, PB represents propylene glycol monobutyl ether, DAA represents 4-hydroxy-4-methyl-2-pentanone, DIBK represents diisobutyl ketone, BCA represents ethylene glycol monobutyl ether acetate, PGME represents propylene glycol monomethyl ether, PGMEA represents propylene glycol monomethyl ether acetate, PGA represents propylene glycol diacetate, DEDE represents diethylene glycol diethyl ether, DPM represents dipropylene glycol monomethyl ether, NMP represents N-methyl-2-pyrrolidone, GBL represents γ-butyrolactone, CHN represents cyclohexanone, CPN represents cyclopentanone, 3MDP represents 3-methoxy-N,N-dimethylpropanediamine, 3BDP represents 3-butoxy-N,N-dimethylpropanediamine, DP represents N,N-dimethylpropanediamine, and TMP represents N,N,2-trimethylpropanediamine.

[0062] Compound (a) with BCS, Compound (a) with GBL with BCS, Compound (a) with trimethyl phosphate with BCS, Compound (a) with triethyl phosphate with BCS, Compound (a) with PB, Compound (a) with GBL with PB, Compound (a) with NMP with PB, Compound (a) with DAA, Compound (a) with GBL with DAA, Compound (a) with DAA and BCS, Compound (a) with N,N-dimethylisobutylamide with DAA, Compound (a) with NMP with DAA, Compound (a) with N-ethyl-2-pyrrolidone with DAA, Compound (a) with N,N-dimethyllactamide Compound (a) with DAA, compound (a) with trimethyl phosphate with DAA, compound (a) with triethyl phosphate with DAA, compound (a) with DAA and 3MDP, compound (a) with DAA and 3BDP, compound (a) with DIBK, compound (a) with GBL and DIBK, compound (a) with γ-valerol and DIBK, compound (a) with DIBK and 3MDP, compound (a) with DIBK and 3BDP, compound (a) with DIBK and DAA, compound (a) with DIBK and PB, compound (a) with DEDE, compound (a) with GBL and DEDE, compound (a) with 1,3-Dimethyl-2-imidazolidineone with DEDE, compound (a) with NMP with DEDE, compound (a) with N-butyl-2-pyrrolidone with DEDE, compound (a) with DEDE with DAA, compound (a) with DEDE with DIBK, compound (a) with DEDE with BCS, compound (a) with DEDE with butyl lactate, compound (a) with NMP with GBL with PB with DIBK, compound (a) with DPM, compound (a) with DPM with DAA, compound (a) with PB with DPM, compound (a) with PGA, compound (a) with PGA with DAA, compound (a) with PGA with PB, compound (a) with diisopropyl ether, compound (a) with PB Compound (a) with diisopropyl ether, compound (a) with diisopentyl ether, compound (a) with NMP with diisopentyl ether, compound (a) with N-ethyl-2-pyrrolidone with diisopentyl ether, compound (a) with N-butyl-2-pyrrolidone with diisopentyl ether, compound (a) with diisobutylmethanol, compound (a) with diisobutylmethanol and DIBK, compound (a) with diisobutylmethanol and PB, compound (a) with dipropylene glycol dimethyl ether, compound (a) with dipropylene glycol dimethyl ether and PB, compound (a) with diethylene glycol ethyl methyl ether, compound (a) with diethylene glycol ethyl methyl ether and DIBK, compound (a) with diethylene glycol ethyl methyl ether and PB, compound (a) with diethylene glycol ethyl propyl ether, compound (a) with diethylene glycol ethyl butyl ether Compound (a) with CPN and PGME, Compound (a) with CPN and PB, Compound (a) with CPN and diethylene glycol monoethyl ether, Compound (a) with CPN and PGA, Compound (a) with CPN and DIBK, Compound (a) with CPN and n-butyl acetate, Compound (a) with CHN and n-butyl acetate, Compound (a) with CHN and BCS, Compound (a) with CHN and PGME, Compound (a) with tetramethylurea and PGMEA, Compound (a) with CHN and PB, Compound (a) with CHN and diethylene glycol monoethyl ether, Compound (a) with CHN and DIBK, Compound (a) with methyl isobutyl ketone and PB, Compound (a) with methyl ethyl ketone and PB, Compound Compound (a) with CPN and DAA, Compound (a) with CPN and DEDE, Compound (a) with CHN and DAA, Compound (a) with CHN and DEDE, Compound (a) with CHN and PGA, Compound (a) with tetramethylurea and PGME, Compound (a) with tetramethylurea and PGA, Compound (a) with tetramethylurea and PB, Compound (a) with tetramethylurea and CHN and PGME, Compound (a) with DP and PGME, Compound (a) with DP and PGMEA, Compound (a) with DP and PB, Compound (a) with DP and BCS, Compound (a) with DP and DEDE, Compound (a) with N,N-diethylmethylamine and PGME, Compound (a) with N,Compounds (a) and (a) are: N-diethylmethylamine with DAA, (a) and N,N-diethylpropionic acid with PGME, (a) and TMP with PGME, (a) and TMP with PGMEA, (a) and TMP with PB, (a) and TMP with BCS, (a) and TMP with DEDE, (a) and BCA, (a) and BCS with BCA, (a) and ethyl 3-ethoxypropionate, (a) and GBL with ethyl 3-ethoxypropionate, (a) and CHN with ethyl 3-ethoxypropionate, (a) and propionyl carbonate with ethyl 3-ethoxypropionate, (a) and DP with ethyl 3-ethoxypropionate, (a) and tetramethylurea with ethyl 3-ethoxypropionate, and (a) and trimethyl phosphate with ethyl 3-ethoxypropionate, etc.

[0063] The liquid crystal alignment agent of the present invention may also contain other components other than those described above, as needed. These components include, for example: polymers (Q) other than the polymer (P) described above; at least one crosslinking compound selected from the group consisting of a crosslinking compound (c-1) having at least one substituent selected from epoxy, oxacyclobutane, oxazolinyl, cyclocarbonate, capped isocyanate, hydroxyl, and alkoxy groups, and a crosslinking compound (c-2) having a polymerizable unsaturated group; functional silane compounds; metal chelate compounds; curing accelerators; surfactants; antioxidants; sensitizers; preservatives; and compounds used to adjust the dielectric constant and resistance of the liquid crystal alignment film.

[0064] Other specific examples of polymers (Q) include polymers selected from the group consisting of polysiloxanes, polyesters, polyamides, polyureas, polyorganosiloxanes, cellulose derivatives, polyacetals, polystyrene derivatives, poly(styrene-maleic anhydride) copolymers, poly(isobutylene-maleic anhydride) copolymers, poly(vinyl ether-maleic anhydride) copolymers, poly(styrene-phenylmaleimide) derivatives, and poly(meth)acrylates. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley), and GSM301 (manufactured by GIFUSHELLAC). Specific examples of poly(isobutylene-maleic anhydride) copolymers include ISOBAM-600 (manufactured by Kuraray). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by ASHLAND).

[0065] Other polymers (Q) may be used alone or in combination of two or more. The content of other polymers (Q) should ideally be less than 50 parts by mass relative to the total number of polymers in the liquid crystal alignment agent (100 parts by mass), preferably 1 to 50 parts by mass, and even more preferably 5 to 40 parts by mass. Ideal examples of the aforementioned cross-linking compounds (c-1) and (c-2) can be listed below.

[0066] Compounds containing epoxy groups include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, 2,2-dibromonepentyl glycol diglycidyl ether, 1,3,5,6-tetracyclooxypropyl-2,4-hexanediol, bisphenol A type epoxy resins such as EPIKOTE 828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as EPIKOTE 807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), and YX6... Epoxy resins containing a biphenyl backbone, such as 954BH30 (manufactured by Mitsubishi Chemical Co., Ltd.); phenolic resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.); cresol-phenolic resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.) (ortho, meta, para) cresol-phenolic resins; tetra(epoxypropoxymethyl)methane; N,N,N',N'-tetracyclooxypropyl-1,4-phenylenediamine; N,N,N',N'-tetracyclooxypropyl-2,2'-dimethyl-4,4'-diaminobiphenyl; 2,2-bis[4-(N,N-dicyclooxypropyl-4-aminophenoxy)phenyl]propane; N,N,N',N'-tetracyclooxypropyl Compounds containing tertiary nitrogen atoms and aromatic carbon atoms, such as N,N,N',N'-tetracyclooxypropyl-1,2-diaminocyclohexane, N,N,N',N'-tetracyclooxypropyl-1,3-diaminocyclohexane, N,N,N',N'-tetracyclooxypropyl-1,4-diaminocyclohexane, bis(N,N-dicyclooxypropyl-4-aminocyclohexyl)methane, bis(N,N-dicyclooxypropyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-dicyclooxypropyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis(N,N-dicyclooxypropylaminomethyl)cyclohexane, 1, Compounds of tertiary nitrogen atom and aliphatic carbon atom bonded by tertiary nitrogen atom and aliphatic carbon atom, such as 4-bis(N,N-dicyclooxypropylaminomethyl)cyclohexane, 1,3-bis(N,N-dicyclooxypropylaminomethyl)benzene, 1,4-bis(N,N-dicyclooxypropylaminomethyl)benzene, 1,3,5-tris(N,N-dicyclooxypropylaminomethyl)cyclohexane, 1,3,5-tris(N,N-dicyclooxypropylaminomethyl)benzene, isocyanurate compounds such as tricyclooxypropyl isocyanate produced by Nissan Chemical Co., Ltd., compounds described in paragraph

[0037] of Japanese Patent Application Publication No. 10-338880, and compounds described in International Patent Publication No. 2017 / 170483, etc.; Compounds containing oxetane include 1,4-bis{[(3-ethyl-3-oxetane)methoxy]methyl}benzene (ARON OXETANEOXT-121(XDO)), di[2-(3-oxetane)butyl] ether (ARON OXETANEOXT-221(DOX)), 1,4-bis[(3-ethyloxetane-3-yl)methoxy]benzene (HQOX), 1,3-bis[(3-ethyloxetane-3-yl)methoxy]benzene (RSOX), 1,2-bis[(3-ethyloxetane-3-yl)methoxy]benzene (CTOX), and compounds containing two or more oxetanes as described in paragraphs

[0170] to

[0175] of International Publication No. 2011 / 132751, etc. Compounds containing an acezoline group include compounds such as 2,2'-bis(2-acezoline), 2,2'-bis(4-methyl-2-acezoline), polymers and oligomers containing an acezoline group from EPOCROS (trade name, manufactured by Nippon Shokubai Co., Ltd.), and compounds described in paragraph

[0115] of Japanese Patent Application Publication No. 2007-286597; Compounds having a cyclic carbonate group include N,N,N',N'-tetratetra[(2-sideoxy-1,3-dioxolane-4-yl)methyl]-4,4'-diaminodiphenylmethane, N,N'-di[(2-sideoxy-1,3-dioxolane-4-yl)methyl]-1,3-phenylenediamine, and compounds described in paragraphs

[0025] to

[0030] and

[0032] of WO2011 / 155577, etc. Compounds having capped isocyanate groups include CORONATEAP Stable M, CORONATE2503, 2515, 2507, 2513, 2555, MILLIONATEMS-50 (all manufactured by Tosoh Corporation), TAKENATEB-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals Corporation), compounds having two or more protected isocyanate groups as described in paragraphs

[0046] to

[0047] of Japanese Patent Application Publication No. 2014-224978, and compounds having three or more protected isocyanate groups as described in paragraphs

[0119] to

[0120] of WO2015 / 141598, etc. Compounds having hydroxyl and alkoxy groups include N,N,N',N'-tetra(2-hydroxyethyl)hexamethylenediamine, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane, compounds described in paragraph

[0058] of International Publication No. 2015 / 072554, Japanese Patent Application Publication No. 2016-118753, compounds described in Japanese Patent Application Publication No. 2016-200798, and compounds described in International Publication No. 2010 / 074269, etc. Crosslinkable compounds with polymerizable unsaturated groups include glycerol mono(meth)acrylate, glycerol di(meth)acrylate (a mixture of 1,2- and 1,3-dimeth)acrylate, glycerol tri(meth)acrylate, glycerol 1,3-diglyceric acid di(meth)acrylate, neopentyl tert-ol tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, etc.

[0067] The content of the crosslinking group-containing compounds (c-1) and (c-2) in the liquid crystal alignment agent of the present invention is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the total polymer components contained in the liquid crystal alignment agent, more preferably 0.1 to 20 parts by mass, and even more preferably 1 to 10 parts by mass.

[0068] Compounds used to adjust dielectric constant and resistance include monoamines such as 3-pyridinemethylamine, which have nitrogen-containing aromatic heterocycles. When using monoamines with nitrogen-containing aromatic heterocycles, it is preferable to use 0.1 to 30 parts by mass relative to 100 parts by mass of polymer components contained in the liquid crystal alignment agent, and more preferably 0.1 to 20 parts by mass.

[0069] Ideal examples of functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureopropyltrimethoxysilane, 3-ureopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-epoxypropoxypropylmethyldimethoxysilane. 3-Epoxypropoxypropyltrimethoxysilane, 3-Epoxypropoxypropylmethyldiethoxysilane, 3-Epoxypropoxypropyltriethoxysilane, p-Styrenetrimethoxysilane, 3-Methylpropoxypropylmethyldiethoxysilane, 3-Methylpropoxypropylmethyldiethoxysilane, 3-Methylpropoxypropylmethyldiethoxysilane, 3-Methylpropoxypropyltriethoxysilane, 3-Propylenepropoxypropyltrimethoxysilane, Tris(3-(trimethoxysilyl)propyl)isocyanurate, 3-Mercaptopropylmethyldiethoxysilane, 3-Mercaptopropyltrimethoxysilane, 3-Isocyanatepropyltriethoxysilane, etc. When using functional silane compounds, it is preferable to use 0.1 to 30 parts by mass relative to 100 parts by mass of polymer components contained in the liquid crystal alignment agent, and more preferably 0.1 to 20 parts by mass.

[0070] The concentration of solid components in the liquid crystal alignment agent (the proportion of the total mass of components other than the solvent in the liquid crystal alignment agent to the total mass of the liquid crystal alignment agent) is appropriately selected considering factors such as viscosity and volatility, and is preferably 1 to 10% by mass. The ideal range of solid component concentration varies depending on the method used to coat the liquid crystal alignment agent onto the substrate. For example, when using spin coating, a solid component concentration of 1.5 to 4.5% by mass is particularly preferred. When using printing, a solid component concentration of 3 to 9% by mass is preferred to achieve a solution viscosity of 12 to 50 mPa·s. When using inkjet printing, a solid component concentration of 1 to 5% by mass is preferred to achieve a solution viscosity of 3 to 15 mPa·s.

[0071] <Liquid crystal alignment film> The liquid crystal alignment film of this invention is obtained from the aforementioned liquid crystal alignment agent. The liquid crystal alignment film of this invention can be a horizontally aligned or vertically aligned liquid crystal alignment film. Among vertically aligned liquid crystal alignment films, those used in VA-type, PSA-type, or SC-PVA-type vertically aligned liquid crystal display elements are preferred. Furthermore, the liquid crystal alignment agent of this invention can be used in liquid crystal alignment films for phase retardation films, liquid crystal alignment films for scanning antennas, liquid crystal array antennas, or liquid crystal alignment films for transmission-scattering type liquid crystal dimming elements, or for other applications, such as protective films for color filters, gate insulating films for flexible displays, and substrate materials.

[0072] Liquid crystal display element The liquid crystal display element of the present invention includes the above-described liquid crystal alignment film. The liquid crystal alignment agent of the present invention, having a liquid crystal layer between a pair of substrates having electrodes, and by disposing a liquid crystal composition containing a polymerizable compound that polymerizes due to at least one of active energy rays and heat between the pair of substrates, and by applying a voltage between the electrodes while simultaneously applying at least one of active energy irradiation and heating to polymerize the polymerizable compound, can also ideally be used as a liquid crystal display element.

[0073] The liquid crystal display element of the present invention can be manufactured by, for example, performing the following steps (1) to (3) or steps (1) to (4) in sequence. (1) The step of coating a liquid crystal alignment agent onto at least one of a pair of substrates having a conductive film to form a coating film. On one side of at least one of a pair of substrates having a patterned transparent conductive film, the liquid crystal alignment agent of the present invention is coated using a suitable coating method, such as roll coating, spin coating, printing, or inkjet coating, to form a coating film. Here, the substrate is not particularly limited to any substrate with high transparency; it can also be used simultaneously with glass substrates, silicon nitride substrates, acrylic substrates, polycarbonate substrates, or other plastic substrates. Furthermore, if the reflective liquid crystal display element is only one substrate, an opaque material such as a silicon wafer can be used, and the electrodes can be made of light-reflecting materials such as aluminum. (2) The step of calcining the coating film. After the liquid crystal alignment agent is coated, the coating is calcined to prevent dripping of the coated alignment agent. Pre-heating (pre-baking) is preferred. The pre-baking temperature is preferably 30-200°C, more preferably 40-150°C, and even more preferably 40-100°C. The pre-baking time is preferably 0.25-10 minutes, more preferably 0.5-5 minutes. A post-baking step is then performed. The post-baking temperature is preferably 80-300°C, more preferably 120-250°C. The post-baking time is preferably 5-200 minutes, more preferably 10-100 minutes. The film thickness formed in this manner is ideally 5-300 nm, and more preferably 10-200 nm.

[0074] The coating formed by the above steps (1) and (2) can be used directly as a liquid crystal alignment film, or the coating can be subjected to alignment capability imparting treatment. Alignment capability imparting treatment can include friction treatment, which involves rubbing the coating in a certain direction with a roller wrapped with a cloth made of fibers such as nylon, silk, or cotton, and photoalignment treatment, which involves irradiating the coating with polarized or unpolarized radiation.

[0075] In photoalignment processing, the radiation used to irradiate the coating can be, for example, ultraviolet light or visible light containing wavelengths of 150-800 nm. When the radiation is polarized, it can be linearly polarized or partially polarized. Furthermore, when using linearly polarized or partially polarized radiation, irradiation can be performed perpendicular to the substrate surface, obliquely, or a combination thereof. When irradiating unpolarized radiation, the irradiation direction is set to oblique. (3) Step of forming a liquid crystal layer between the above-mentioned pair of substrates to fabricate a liquid crystal cell. (3-1) When manufacturing VA-type liquid crystal display elements As described above, two substrates are prepared in which at least one of the two substrates forms the liquid crystal alignment film of the present invention, and liquid crystal is disposed between the two opposing substrates. Specifically, the following two methods can be listed. The first method is a conventionally known method. First, the two substrates are arranged facing each other with gaps (cell gaps) separated by each liquid crystal alignment film surface. Then, a sealant is applied to the periphery of the two substrates and they are bonded together. After the liquid crystal composition is injected into the cell gaps separated by the substrate surface and the sealant and comes into contact with the film surface, the injection hole is sealed. There are no special restrictions on the liquid crystal composition mentioned above. Various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy can be used. Furthermore, liquid crystal compositions with positive dielectric anisotropy are also referred to as positive liquid crystals, and liquid crystal compositions with negative dielectric anisotropy are also referred to as negative liquid crystals. The aforementioned liquid crystal composition may also contain liquid crystal compounds having fluorine atoms, hydroxyl groups, amino groups, fluorine-containing groups (e.g., trifluoromethyl), cyano groups, alkyl groups, alkoxy groups, alkenyl groups, isothiocyanate groups, heterocyclic groups, cycloalkanes, cycloalkenes, steroid skeletons, benzene rings, or naphthyl rings. It may also contain compounds with two or more rigid sites exhibiting liquid crystal properties (mesogen skeletons) within the molecule (e.g., rigid biphenyl structures, or biphenyl structures linked by alkyl groups in a double mesosome skeleton). The liquid crystal composition may be a nematic phase liquid crystal composition, a lamellar phase liquid crystal composition, or a cholesterol phase liquid crystal composition. Furthermore, in order to improve the alignment of the liquid crystal, additives may be added to the above-mentioned liquid crystal composition. Such additives include photopolymerizable monomers such as compounds with polymerizable groups; optically active compounds (e.g., S-811 manufactured by Merck); antioxidants; ultraviolet absorbers; pigments; defoamers; polymerization initiators; or polymerization inhibitors. Positive LCDs include those manufactured by Merck such as ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, MLC-3019, and MLC-7081. Negative liquid crystal displays include MLC-6608, MLC-6609, MLC-6610, MLC-6882, MLC-6886, MLC-7026, MLC-7026-000, MLC-7026-100, and MLC-7029 manufactured by Merck. Furthermore, in PSA mode, liquid crystals containing compounds with polymerizable groups can be exemplified by Merck's MLC-3023.

[0076] The second method is called the ODF (One Drop Fill) method. A UV-curable sealant, for example, is applied to predetermined areas on one of the two substrates on which the liquid crystal alignment film has already been formed. Then, liquid crystal composition is dropped onto predetermined points on the surface of the liquid crystal alignment film. Next, the other substrate is bonded together with the liquid crystal alignment film faces facing each other, pressing the liquid crystal composition onto the entire substrate so that it contacts the film surface. Finally, the entire substrate is irradiated with UV light to harden the sealant.

[0077] In either case, the liquid crystal composition is heated further until it reaches the temperature of the isotropic phase, and then slowly cooled to room temperature to remove the flow alignment during liquid crystal filling for a more ideal result. (3-2) Manufacturing of liquid crystal display elements using the PSA method Except for injecting or dropping a liquid crystal composition containing a compound with a polymerizable group, the process is the same as described in (3-1). The compound with a polymerizable group is, for example, a compound having a liquid crystal precursor structure and two or more photopolymerizable or thermally polymerizable groups. Examples of liquid crystal precursor structures include structures formed by the linkage of two or more aromatic or aliphatic groups, such as biphenyl structures, terphenyl structures, naphthalene rings, groups with two hydroxyl groups removed from bisphenol A, or structures where one of the hydrogen atoms is replaced by a fluorine atom. Specific examples of compounds include 4,4'-dimethylpropenyloxybiphenyl, or 3-fluoro-1,1'-biphenyl-4,4'-dimethyldimethacrylate. (3-3) Case where a coating is formed on a substrate using a liquid crystal alignment agent containing a compound with polymerizable groups (SC-PVA method) Alternatively, a method similar to (3-1) above, followed by ultraviolet irradiation as described later, can be used to manufacture a liquid crystal display element. Using this method, similar to manufacturing a PSA-type liquid crystal display element, a liquid crystal display element with excellent response speed can be obtained with a low light irradiation amount. The compound having a polymerizable group can also be a compound having the aforementioned polymerizable group, and its content relative to 100 parts by mass of the total polymer component is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass. Furthermore, the aforementioned polymerizable group can be possessed by the polymer used as a liquid crystal alignment agent, such as a polymer obtained by using a diamine component containing a diamine terminally having the aforementioned photopolymerizable group in the reaction. (4) Steps for irradiating liquid crystal cells The liquid crystal cells are irradiated by applying a voltage between the conductive films on the substrate as obtained in either (3-2) or (3-3) above. The applied voltage can be, for example, DC or AC of 5-50V. The irradiated light can be, for example, ultraviolet light or visible light containing wavelengths of 150-800nm, but ultraviolet light containing wavelengths of 300-400nm is preferred. The light source can be, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonant lamp, a xenon lamp, or an excimer laser. The irradiation intensity is preferably 1,000-200,000 J / m², more preferably 1,000-100,000 J / m².

[0078] Furthermore, a liquid crystal display element can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. Examples of polarizing plates attached to the outer surface of the liquid crystal cell include: polarizing plates made of a polarizing film called "H film" by extending polyvinyl alcohol to absorb iodine through a cellulose acetate protective film clamping the edges, or polarizing plates composed of the H film itself.

[0079] The liquid crystal display element of this invention can be effectively applied to various devices, such as: clocks, portable game consoles, word processors, laptops, navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various screens, LCD TVs, information displays, and other display devices. [Example]

[0080] The following examples illustrate the present invention in detail, but the invention is not limited to these examples. The abbreviations of the compounds and the methods for determining their properties are as follows. (solvent) NMP: N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether Cyrene:(1S,5R)-6,8-dioxabicyclo[3.2.1]oct-4-one (compound(a))

[0081] [Chemistry 6]

[0082] (Tetracarboxylic acid dianhydride) CA-1~CA-2: Each is a compound represented by the formula (CA-1)~(CA-2).

[0083] [Chemistry 7]

[0084] (Diamine) DA-1~DA-2: Each is a compound represented by the formula (DA-1)~(DA-2).

[0085] [Chemistry 8]

[0086] <Determination of Molecular Weight> The following room-temperature GPC (gel permeation chromatography) apparatus was used to determine and calculate Mn and Mw as conversion values ​​for polyethylene glycol and polyethylene oxide. GPC apparatus: SSC-7200 (manufactured by SSC); columns: GPC KD-803 and GPC KD-805 (manufactured by Showa Denko Corporation) in series; column temperature: 50°C; dissolution solution: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr·H₂O) 30 mmol / L, anhydrous phosphoric acid crystals (orthophosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L); flow rate: 1.0 mL / min. Standard samples for the preparation of the calibration curve: TSK standard polyethylene oxide (molecular weight; about 900,000, 150,000, 100,000 and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight; about 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratory Corporation).

[0087] <Determination of acetilimation rate> 20 mg of polyimide powder was placed into an NMR (nuclear magnetic resonance) sample tube (NMR standard sampling tube, φ5 (manufactured by Kusano Science Co., Ltd.)), and 1.0 mL of deuterated dimethyl monoxide ([D6]-DMSO, 0.05% tetramethylsilane (TMS) mixture) was added. The solution was then dissolved completely by ultrasound. Proton NMR was measured at 500 MHz using a Fourier transform superconducting nuclear magnetic resonance (FT-NMR) device, "AVANCE III" (manufactured by BRUKER Co., Ltd.).

[0088] The (chemical) acetilimation rate is determined by using a proton from a structure that remains unchanged before and after acetilimation as a reference proton. The cumulative peak value of this proton, and the cumulative peak value of protons from the NH group of acetic acid appearing around 9.5~10.0 ppm, are calculated using the following formula. In the formula, x represents the cumulative peak value of protons from the NH group of acetic acid, y represents the cumulative peak value of the reference proton, and α represents the proportion of reference protons relative to one proton from the NH group of acetic acid in polyacetic acid (acetilimation rate 0%).

[0089] Acrylimide rate (%) = (1 - α·x / y) × 100

[0090] [Polymer Synthesis] <Synthesis example 1> DA-1 (5.09 g, 11.7 mmol), DA-2 (4.15 g, 27.3 mmol), CA-2 (7.32 g, 29.3 mmol), and NMP (66.2 g) were added to a 100 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube. The mixture was stirred at 80 °C for 3 hours while introducing nitrogen gas. After cooling to room temperature, CA-1 (1.87 g, 9.54 mmol) and NMP (7.49 g) were added, and the mixture was stirred at 40 °C for 18 hours to obtain a polyacrylic acid solution. NMP (103g), acetic anhydride (10.8g), and pyridine (3.34g) were added to the polyamide solution (50.0g) obtained above. The mixture was stirred at room temperature for 30 minutes, then reacted at 80°C for 5 hours. This reaction solution was then added to methanol (587g), and the precipitate was obtained by filtration. The precipitate was washed with methanol and dried under reduced pressure at 60°C to obtain polyimide (SPI-1) powder. The polyimide powder had an imidization rate of 81%, with Mn of 12,502 and Mw of 36,348.

[0091] [Preparation of Liquid Crystal Alignment Agents] <Example 1> 8.00 g of NMP was added to 2.00 g of polyimide (SPI-1) powder and stirred at 70°C for 15 hours to dissolve it, thus obtaining a polyimide solution. The polyimide solution was then diluted with Cyrene and BCS and stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-1) with a polymer solids to solvent mass ratio (polymer solids:Cyrene:NMP:BCS) of 6:30:24:40.

[0092] <Example 2> Cyrene (11.3g) was added to 2.00g of polyimide (SPI-1) powder and stirred at 70°C for 15 hours to dissolve it, thus obtaining a polyimide solution. The above polyimide solution was diluted with Cyrene and BCS and stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-2) with a mass ratio of polymer solids to solvents (polymer solids:Cyrene:BCS) of 6:54:40.

[0093] <Comparative Example 1> 11.3 g of NMP was added to 2.00 g of polyimide (SPI-1) powder and stirred at 70 °C for 15 hours to dissolve it, thus obtaining a polyimide solution. The polyimide solution was then diluted with NMP and BCS and stirred at room temperature for 2 hours to obtain a liquid crystal alignment agent (AL-3) with a polymer solid component to solvent mass ratio (polymer solid component: NMP: BCS) of 6:54:40.

[0094] Table 1 shows the specifications of each liquid crystal alignment agent prepared above.

[0095] [Table 1] Liquid crystal alignment agent Polyimide Solid content concentration [wt%] Solvent composition [wt%] Cyrene NMP BCS Example 1 AL-1 SPI-1 6 30 twenty four 40 Example 2 AL-2 SPI-1 6 54 - 40 Comparative Example 1 AL-3 SPI-1 6 - 54 40

[0096] [Evaluation of print quality] The liquid crystal alignment agents AL-1 to AL-3 obtained in Examples 1 to 2 and Comparative Example 1 were filtered through filters with a pore size of 1.0 μm and then flexographically printed on a cleaned Cr vapor-deposited substrate using an alignment film printing machine (Angstromer, manufactured by Nippon Shinsei Printing Co., Ltd.) to conduct printability tests. Specifically, approximately 1.0 mL of liquid crystal alignment agent was added to an anilox roller, and after five idle cycles, printing was performed on a Cr vapor-deposited substrate (100 mm x 100 mm, 1.0 mm thickness) under the conditions of a printing set size of 80 mm x 80 mm and a printing pressure of 0.2 mm. The printed substrate was placed on a hot plate at 70°C for 90 seconds to temporarily dry the coating, and the film condition was observed. The film thickness unevenness at the edges was observed visually and with an optical microscope (Nikon "ECLIPSE ME600") at 50x magnification. For the evaluation criteria, the largest film thickness unevenness at the edge of the printed coating was selected. If the width of this largest film thickness unevenness was less than 1.5 mm, it was rated as "○", and if it was larger, it was rated as "×". More specifically, in the polyimide film (Figure 1) already printed on the Cr vapor-deposited substrate, the area with the largest film thickness unevenness (the dotted line area in Figure 1) was selected, and the length of point A in Figure 2, obtained by observing the polyimide film at 50x magnification using an optical microscope, was measured. The length of point A corresponds to the width of the aforementioned film thickness unevenness. The results are shown in Table 2.

[0097] [Making of Liquid Crystal Cells] Using the liquid crystal alignment agent obtained above, liquid crystal cells were fabricated according to the following procedure. The liquid crystal alignment agent was spin-coated onto a glass substrate (3cm wide × 4cm long) with an ITO electrode. After drying on a hot plate at 70°C for 90 seconds, it was calcined in an infrared furnace at 230°C for 20 minutes to form a liquid crystal alignment film with a thickness of 100nm. Two substrates with the liquid crystal alignment film were prepared. On one substrate, 4μm diameter bead spacers (made by Nichibukai Chemical Co., Ltd., silk balls, SW-D1) were coated onto the liquid crystal alignment film. A thermosetting sealant (made by Mitsui Chemicals Co., Ltd., XN-1500T) was printed around the liquid crystal injection port. Then, the side of the other substrate with the formed liquid crystal alignment film was used as the inner side, and it was bonded to the first substrate. The sealant was then hardened to create a void. Liquid crystal MLC-3023 (made by Merck) was injected into this void using a depressurized injection method to form a liquid crystal cell. Then, with a DC voltage of 15V applied to the liquid crystal cell, UV light of 10J / cm², having passed through a cutoff filter with a wavelength below 325nm, was irradiated from the outside of the liquid crystal cell. The UV illuminance was measured using an ORC UV-MO3A photometer. Afterwards, to deactivate any unreacted polymeric compounds remaining in the liquid crystal cell, UV light (UV lamp: FLR40SUV32 / A-1) was applied for 30 minutes without voltage application using a TOSHBA LIGHTECH UV-FL irradiation device.

[0098] [Evaluation of Liquid Crystal Orientation] The liquid crystal alignment of the liquid crystal display element was observed using a polarizing microscope (Nikon's "ECLIPSE E600WPOL") to confirm whether the liquid crystal was vertically aligned. Based on the evaluation criteria, a rating of "○" was given when no defects due to liquid crystal flow or bright spots due to alignment defects were observed; a rating of "×" was given when defects due to liquid crystal flow or bright spots due to alignment defects were observed. The evaluation results are shown in Table 2.

[0099] [Table 2] Printability Liquid crystal alignment Example 1 〇 〇 Example 2 〇 〇 Comparative Example 1 ╳ 〇

[0100] As shown in Table 2, Examples 1-2, which used liquid crystal alignment agents containing compound (a) represented by formula (A) above, showed better printability and no problems with liquid crystal alignment characteristics compared to Comparative Example 1, which used a liquid crystal alignment agent without compound (a).

[0101] Furthermore, the entire contents of the specification, scope of the patent application, drawings and abstract of Japanese Patent Application No. 2021-142711, filed on September 1, 2021, are hereby incorporated and cited as disclosures of this invention.

[0102] none

Claims

1. A liquid crystal alignment agent comprising: a polymer (P) selected from the group consisting of at least one polyimide composed of a polyimide precursor and a polyimide derivative thereof, and a solvent component comprising a compound (a) represented by formula (A).

2. The liquid crystal alignment agent as claimed in claim 1, wherein, The content of compound (a) is 5% by mass or more relative to the total amount of solvent components contained in the liquid crystal alignment agent.

3. The liquid crystal alignment agent as requested in item 1 or 2, wherein, The polymer (P) is obtained by the polymerization reaction of a diamine component and a tetracarboxylic acid component containing a tetracarboxylic acid dianhydride.

4. The liquid crystal alignment agent as requested in item 1 or 2, wherein, The polymer (P) is obtained by polymerization of a diamine component and a tetracarboxylic acid component containing a tetracarboxylic acid dianhydride, wherein the tetracarboxylic acid dianhydride is selected from at least one compound selected from acyclic aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, and aromatic tetracarboxylic acid dianhydride.

5. The liquid crystal alignment agent as claimed in claim 3, wherein, The tetracarboxylic acid component contains a tetracarboxylic dianhydride having at least one substructure selected from the group consisting of a benzene ring, a cyclobutane ring, a cyclopentane ring, and a cyclohexane ring.

6. The liquid crystal alignment agent as requested in item 1 or 2, wherein, The solvent component further contains a selection from γ-valerolactone, γ-butyrolactone, 1,3-dimethyl-2-imidazolidineone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-n-propyl-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-n-butyl-2-pyrrolidone, N-tert-butyl-2-pyrrolidone, N-n-pentyl-2-pyrrolidone, N-(3-methoxypropyl)-2-pyrrolidone, N-(2-ethoxyethyl)-2-pyrrolidone, N-(4-methoxybutyl)-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N,N Solvents belonging to the group consisting of dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionic acid, N,N-dimethylisobutylamide (N,N,2-trimethylpropionic acid), N,N-diethylpropionic acid, N,N-dipropylacetamide, N,N-diisopropylacetamide, N,N-dibutylacetamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropionic acid, 3-butoxy-N,N-dimethylpropionic acid, tetramethylurea, hexamethylphosphonic triamine, cyclohexanone, and cyclopentanone.

7. The liquid crystal alignment agent as requested in item 1 or 2, wherein, The solvent component further contains, selected from 4-hydroxy-4-methyl-2-pentanone, n-butyl acetate, propylene glycol monoethyl ether, cyclohexyl acetate, 4-methyl-2-pentanyl acetate, n-butyl lactate, and isoamyl lactate. Solvents comprising the group consisting of methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol n-propyl ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl ceroxox), ethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, diisobutylmethanol, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, ethyl carbonate, and propyl carbonate.

8. The liquid crystal alignment agent of claim 3 contains an aromatic diamine (d) represented by "AXJ" as the diamine component, where A represents a monovalent group with two primary amino groups bonded to an aromatic group, and X represents a single bond, -(CH2)a-, -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -COO-, -OCO-, or -(A0)m0-((CH2)a1-A1)m1-, wherein, 'a' is an integer from 1 to 15, 'a1' is an integer from 1 to 15, 'A0' and 'A1' independently represent an oxygen atom or -COO-, 'm0' is an integer from 0 to 1, 'm1' is an integer from 1 to 2, and when 'm1' is 2, multiple 'a1' and 'A1's independently have the above definitions. J represents a monovalent organic group having at least one group selected from the group consisting of alicyclic hydrocarbon groups with 4 to 40 carbon atoms and aromatic hydrocarbon groups with 6 to 40 carbon atoms, wherein at least one hydrogen atom of the aforementioned alicyclic hydrocarbon group and aromatic hydrocarbon group is substituted by a substituent (v) of any one of a halogen atom, an alkyl group containing a halogen atom, an alkoxy group containing a halogen atom, an alkyl group with 3 to 10 carbon atoms, an alkoxy group with 3 to 10 carbon atoms, and an alkenyl group with 3 to 10 carbon atoms, and any carbon-carbon single bond in such substituent (v) may be interrupted by -O-, except for the halogen atom. In addition to having the alicyclic hydrocarbon group and aromatic hydrocarbon group, J may also have at least one group selected from the group consisting of alicyclic hydrocarbon groups and aromatic hydrocarbon groups that are unsubstituted or substituted by substituents other than the substituent (v).

9. The liquid crystal alignment agent as claimed in claim 8, wherein, In this aromatic diamine (d), the group "-XJ" has the following structure (S1): X1 represents a single bond, -(CH2)a-, -CONH-, -CO-N(CH3)-, -NH-, -O-, -COO-, or -(A0)m0-((CH2)a1-A1)m1-, where a is an integer from 1 to 15, a1 is an integer from 1 to 15, A0 and A1 each independently represent an oxygen atom or -COO-, m0 is an integer of 0 or 1, m1 is an integer from 1 to 2, when m1 is 2, multiple a1 and A1 each independently have the above definitions, G1 represents a divalent cyclic group selected from phenyl and cyclohexyl, and any hydrogen atom on the cyclic group can also be replaced by an alkyl group with 1 to 3 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a fluorinated alkyl group with 1 to 3 carbon atoms, a fluorinated alkoxy group with 1 to 3 carbon atoms, or a fluorine atom. When m is an integer from 1 to 4, and m is 2 or more, multiple X1 and G1 can be independently defined as above. R1 represents a fluorine atom, an alkyl group containing fluorine atoms with 1 to 10 carbon atoms, an alkoxy group containing fluorine atoms with 1 to 10 carbon atoms, an alkyl group with 3 to 10 carbon atoms, an alkoxy group with 3 to 10 carbon atoms, or an alkoxyalkyl group with 3 to 10 carbon atoms.

10. The liquid crystal alignment agent as claimed in claim 8, wherein, The aromatic diamine (d) is a diamine represented by the following formulas (d-1) to (d-2), where X and J are defined as in claim 8. In formula (d-2), the two X and J may be the same or different from each other.

11. The liquid crystal alignment agent as claimed in claim 1 or 2 is used in the formation of a horizontally aligned or vertically aligned liquid crystal alignment film, a liquid crystal alignment film for a phase difference film, a liquid crystal alignment film for a scanning antenna, a liquid crystal array antenna, or a liquid crystal alignment film for a transmission-scattering type liquid crystal dimming element.

12. A liquid crystal alignment film obtained from a liquid crystal alignment agent as claimed in any one of claims 1 to 11.

13. A liquid crystal display element comprising a liquid crystal alignment film as claimed in claim 12.

14. A method for manufacturing a liquid crystal display element, comprising performing the following steps (1) to (3) in sequence: Step (1): applying a liquid crystal alignment agent as claimed in any one of claims 1 to 11 onto at least one of a pair of substrates having a conductive film to form a coating film; Step (2): calcining the coating film; Step (3): forming a liquid crystal layer between the pair of substrates to create a liquid crystal cell.

15. The method for manufacturing a liquid crystal display element as claimed in claim 14 further includes, after steps (1) to (3), performing the following step (4): irradiating the liquid crystal cell with light.

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