Liquid crystal alignment agents, liquid crystal alignment films, liquid crystal display elements, diamines and polymers

Abstract

A liquid crystal aligning agent comprising at least one polymer (P) selected from the group consisting of polyimide precursors obtained by using a diamine component including a diamine represented by formula (1), and polyimides which are imidization products of said polyimide precursors. (In the formula, p represents an integer of 0 or 1.)

Description

[Technical Field]

[0001] The present invention relates to a liquid crystal alignment agent, a liquid crystal alignment film obtained from the liquid crystal alignment agent, a liquid crystal display element comprising the liquid crystal alignment film, and novel diamines and polymers suitable for these. [Background technology]

[0002] Liquid crystal display elements are widely used in applications ranging from small devices such as mobile phones and smartphones to relatively large devices such as televisions and monitors. Liquid crystal display elements are generally constructed by arranging a pair of electrode substrates facing each other with a predetermined gap (several μm) between them, and sealing liquid crystal between the electrode substrates. Display is then achieved in the liquid crystal display element by applying a voltage between the transparent conductive films that constitute each electrode on the electrode substrates. These liquid crystal display elements have a liquid crystal alignment film, which is essential for controlling the arrangement of liquid crystal molecules. Patent Document 1 discloses a polyimide alignment film obtained using a diamine compound with a specific structure containing a triazine ring, as a liquid crystal alignment film that allows for easy adjustment of the pre-tilt angle of liquid crystal molecules.

[0003] On the other hand, various driving methods have been developed for liquid crystal display elements, differing in electrode structure and the physical properties of the liquid crystal molecules used. For example, various modes such as TN (Twisted Nematic), STN (Super Twisted Nematic), VA (Vertical Alignment), IPS (In-Plane Switching), and FFS (Fringe Field Switching) are known. VA (Vertical Alignment) liquid crystal display elements have a wide viewing angle, fast response speed, high contrast, and eliminate the need for rubbing during the production process. Therefore, they are widely used, especially in televisions and monitors where there is a high demand for larger displays (Patent Documents 2-3). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2006-511696 [Patent Document 2] Japanese Patent Publication No. 2008-76950 [Patent Document 3] WO2008 / 117615 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Touch panel liquid crystal displays (LCDs) require high durability against external pressure, such as pressure from fingers or pointing devices like pens; in other words, they must be resistant to alignment defects and bright spot defects even when external pressure is applied. Furthermore, tablet and mobile devices are becoming lighter and thinner, which can lead to panel distortion and internal stress during the panel assembly process in LCD manufacturing. Such panel distortion and stress can cause the alignment film to detach from the substrate, resulting in bright spot defects and alignment defects. Therefore, the liquid crystal alignment film must be resistant to substrate detachment. In addition, in tablet and mobile devices, to secure as much display area as possible, the width of the sealant used to bond the substrates of the liquid crystal display elements needs to be narrower than in conventional devices. In such cases, to prevent damage to the liquid crystal display elements, the adhesion (also called bonding) between the liquid crystal alignment film and the sealant needs to be higher than in conventional devices.

[0006] One objective of the present invention is to provide a liquid crystal alignment agent that can produce a liquid crystal alignment film that is less prone to substrate peeling and a liquid crystal display element with high durability against external pressure. Another objective is to provide a liquid crystal alignment agent that can produce a liquid crystal alignment film with high adhesion between the liquid crystal alignment film and the sealant, thereby increasing the strength of the liquid crystal display element. [Means for solving the problem]

[0007] As a result of intensive studies to achieve the above object, the present inventors have found that a liquid crystal aligning agent containing a novel polymer having a specific structure is effective for achieving the above object, and have completed the present invention. The present invention relates to a liquid crystal aligning agent containing at least one polymer (P) selected from the group consisting of a polyimide precursor obtained by using a diamine component containing a diamine represented by the following formula (1) and a polyimide which is an imidized product of the polyimide precursor, a liquid crystal alignment film obtained from the liquid crystal aligning agent, and a liquid crystal display element having the liquid crystal alignment film. [Chemical formula] (In the formula, L is -(CH2) n -O- (n is an integer of 1 to 6), -(CH2) n -C(=O)-NH- (n is an integer of 1 to 6), -(CH2) n -O-C(=O)- (n is an integer of 1 to 6), -(CH2) n -C(=O)-O- (n is an integer of 1 to 6), -O-(CH2) n -O- (n is an integer of 1 to 6), -C(=O)-O-(CH2) n -O- (n is an integer of 1 to 6), -(CH2) m -C(=O)-O-(CH2) n -(m and n are each independently an integer of ① to 6), or -C(=O)-O-(CH2) n -O-C(=O)- (n is an integer of 1 to 6). Any hydrogen atom of the benzene ring bonded to OH may be replaced by a methyl group, a methoxy group, or a halogen atom. p represents an integer of 0 or 1.) Throughout this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and * represents a bond. [Advantages of the Invention]

[0008] Note: In the above translation, ① should be 1 in the original formula content. It seems there was a formatting error in the original text.According to the present invention, there is provided a liquid crystal aligning agent that can obtain a liquid crystal aligning agent in which substrate peeling hardly occurs and a liquid crystal display element having high durability against external pressure. Further, there is provided a liquid crystal aligning agent that can obtain a liquid crystal aligning film having high adhesiveness between the liquid crystal aligning film and the sealant and increasing the strength of the liquid crystal display element. Although the mechanism by which the above effects of the present invention are obtained is not necessarily clear, the following is considered to be a contributing factor. The diamine for obtaining the polymer (P) of the present invention has a structure in which an aromatic ring containing a diamine moiety and a benzene ring having an aromatic hydroxyl group are bonded by a specific linking group. Since the aromatic hydroxyl group has a structure with less steric hindrance and has the effect of enhancing the interaction between the alignment film and the substrate, it is considered that a liquid crystal alignment film in which substrate peeling hardly occurs was obtained. Further, since the polymer (P) has the aromatic hydroxyl group at the side chain portion of the polymer and has a structure with improved flexibility, the reactivity between the aromatic hydroxyl group and the sealant is increased, and it is considered that a liquid crystal alignment film having high seal adhesion and high voltage holding ratio characteristics was obtained. Furthermore, since the specific linking group has a structure containing a hetero atom, an ester group, an amide bond, etc. in the alkyl chain, it is possible to impart appropriate polarity and rigidity to the molecule rather than linking only with an alkyl chain. Therefore, since the rigidity of the product of the aromatic hydroxyl group and the sealant is improved, it is considered that a liquid crystal aligning agent in which substrate peeling hardly occurs can be obtained and a liquid crystal display element having high durability against external pressure can be obtained.

Embodiments for Carrying Out the Invention

[0009] The liquid crystal aligning agent of the present invention contains at least one polymer (P) selected from the group consisting of a polyimide precursor obtained by using a diamine component containing a diamine represented by the above formula (1) (hereinafter also referred to as a specific diamine) and a polyimide which is an imidized product of the polyimide precursor, as described above. Note that the diamine represented by the formula (1) (excluding some diamines) is also an object of the present invention. Further, a polymer obtained by using a diamine component containing the diamine represented by the formula (1) is also an object of the present invention.

[0010] In formula (1) above, L is -(CH2) from the viewpoint of favorably obtaining the effects of the present invention. n -O-(n is an integer between 1 and 6), -(CH2) n -OC(=O)-(n is an integer from 1 to 6), -(CH2) n -C(=O)-O-(n is an integer from 1 to 6) is preferred.

[0011] When p is 0 in formula (1) above, preferred specific examples of the diamine represented by formula (1) include diamines represented by any of the following formulas (d1-1) to (d1-11), and among these, from the viewpoint of suitably obtaining the effects of the present invention, diamines represented by any of (d1-1) to (d1-3) are more preferred. [ka]

[0012] In formula (1) above, when p is 1, a preferred specific example of the diamine represented by formula (1) above is a diamine represented by any of the following formulas (d2-1) to (d2-6), and among these, a diamine represented by any of (d2-1) to (d2-3) is more preferred from the viewpoint of suitably obtaining the effects of the present invention. [ka]

[0013] (Production of polymer (P)) The polymer (P) contained in the liquid crystal alignment agent of the present invention is a polyimide precursor obtained using a diamine component containing the above-mentioned specific diamine, or a polyimide which is an imidized product of the polyimide precursor. Here, the polyimide precursor is a polymer from which a polyimide can be obtained by imidizing a polyamic acid, a polyamic acid ester, etc. The polyamic acid (P'), which is a polyimide precursor of the polymer (P) described above, can be obtained by a polymerization reaction between a diamine component containing the specified diamine and a tetracarboxylic acid component. The specified diamine may be used alone or in combination of two or more types. In this case, the amount of specific diamine used is preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more, relative to the total diamine components.

[0014] The diamine component used in the production of the above polyamic acid (P') may include diamines other than the specified diamine (hereinafter also referred to as "other diamines"). When other diamines are used in combination with the specified diamine, the amount of the specified diamine used relative to the diamine component is preferably 90 mol% or less, and more preferably 80 mol% or less. Examples of other diamines are listed below, but the present invention is not limited to these. The above other diamines may be used individually or in combination of two or more.

[0015] Aromatic diamines represented by "AXJ" (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, 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-diaminona Phthalene, 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-methylphenyloxy)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]benzeneamine, 1,4-Bis(4-aminophenoxy)benzene, 1,3-Bis(4-aminophenoxy)benzene, 4,4-Bis(4-aminophenoxy)biphenyl, 4,4'-Bis(4-aminophenoxy)diphenyl ether, 1,4-Bis[4-(4-aminophen [(xy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)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]butanediate, 1,6-bis[2-(4-aminophenyl)ethyl]hexanediate, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-amine) (Nobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3-aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate, 4,4'-diaminoazobenzene, diaminotran, 4,4-diaminochalcone, or [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxopropa-1-enyl]phenyl]4-(4,4,4-triflu Diamines having photodirecting groups such as olobutoxy)benzoate or [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4-[4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]propa-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-propa-1-enyl]phenyl]4-(4,4,4-trifluorobutoxy)benzoate, which have a cinnamate structure in their side chains; 2-(2,4-diaminophenoxy)ethyl methacrylate and 2,Diamines having photopolymerizable groups at their termini, such as 4-diamino-N,N-diallylaniline; benzoin or its alkyl ether derivatives, benzyl ketals, acetophenones, acylphosphine oxides, benzophenones, or aminobenzophenones, which exhibit radical polymerization initiator function, as exemplified by 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone and 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate. Diamines containing a radical (hereinafter also referred to as diamines having radical initiation function); diamines having an amide bond such as 4,4'-diaminobenzanilide, diamines having a urea bond such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, 1,3-bis(4-aminophenethyl)urea; 4,4'-sulfonyldianiline, 3,3'-sulfonyldianiline, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-amino Phenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 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 Safluoropropane, 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'-diaminobenzophenone, 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-diaminoacridin, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazole-1-yl)propyl-3,5-diaminobenzamide, 4-[ 4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, 1,4-bis(p-aminobenzyl)piperazine, 4,4'-[4,4'-propane-1,3-diylbis(piperidine-1,4-diyl)]dianiline, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, formula (z-1)~formula (z Diamines represented by -5), 2,5-bis(4-aminophenyl)pyrrole, 4,4'-(1-methyl-1H-pyrrole-2,5-diyl)bis[benzeneamine], 1,4-bis-(4-aminophenyl)-piperazine, 2-N-(4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridine-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5-aminobenzimidazole, 2-(4-aminophenyl)-6-aminobenzimidazole, 5-(1H-benzimidazole-2-yl)benzene-1,3-diamine, and other heterocyclic diamines, or 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-1,4-benzenediamine, N,N Diamines having 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-benzenediamine, which have at least one nitrogen-containing structure selected from the group consisting of a nitrogen-containing heterocycle, a secondary amino group, and a tertiary amino group (hereinafter also referred to as a specific nitrogen-containing structure) (however, they do not have amino groups to which protecting groups that are eliminated by heating and replaced by hydrogen atoms are attached in the molecule); 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-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, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, and 4,4' -Diamines having a carboxyl group such as -diaminodiphenyl ether-3,3'-dicarboxylic acid; 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl)-1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3- Dihydro-1,3,3-trimethyl-1H-inden-6-amine; N1,N4-bis(2-tert-butoxycarbonylamino-4-aminophenyl)adipamide, 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-dimethylethyl ester, Carbamic acid, N,N-[(2,5-diamino-1,3-phenylene )di-3,1-propanediyl]bis-,C,C-bis(1,1-dimethylethyl) 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, carbamic acid, N-[2-(4-aminophenyl)ethyl]-N-[[[2-(4-aminophenyl)ethyl]amino]carbonyl]-,1,Diamines having the group "-N(D)-" (where D represents a protecting group that is removed by heating and replaced by a hydrogen atom, preferably a tert-butoxycarbonyl group), such as 1-dimethylethyl ester, carbamic acid, N-(4-aminophenyl)-N-[[1-(4-aminophenyl)-4-piperidinyl]methyl]-, and 1,1-dimethylethyl ester; Diamines having siloxane bonds, such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and bis(p-aminophenylcarbamoylpropyl)tetramethyldisiloxane; metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), and diamines in which two amino groups are bonded to a group represented by any of the formulas (Y-1) to (Y-167) described in WO2018 / 117239. [ka]

[0016] In the above aromatic diamine (d), A represents a monovalent group in which two primary amino groups are bonded to an 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 -((CH2) a1 -A1) m1 -(a1 is an integer between 1 and 15, A1 represents an oxygen atom or -COO-, and m1 is an integer between 1 and 2. If m1 is 2, multiple a1 and A1 each have the above definition independently.) J represents a monovalent organic group having at least one group selected from the group consisting of alicyclic hydrocarbon groups having 4 to 40 carbon atoms and aromatic hydrocarbon groups having 6 to 40 carbon atoms, wherein at least one of the hydrogen atoms of the alicyclic hydrocarbon group and aromatic hydrocarbon group is substituted with a substituent selected from the group consisting of halogen atoms, halogen atom-containing alkyl groups, halogen atom-containing alkoxy groups, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, alkenyl groups having 3 to 10 carbon atoms, and heteroatom-containing groups in which the carbon-carbon bond of any methylene group of halogen atom-containing alkyl groups, halogen atom-containing alkoxy groups, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, and alkenyl groups having 3 to 10 carbon atoms is interrupted by an oxygen atom. Furthermore, if J is a monovalent organic group having at least two groups selected from the group consisting of alicyclic hydrocarbon groups having 4 to 40 carbon atoms and aromatic hydrocarbon groups having 6 to 40 carbon atoms, then it is sufficient that at least one alicyclic hydrocarbon group or aromatic hydrocarbon group has the substituents exemplified above, and other alicyclic hydrocarbon groups or aromatic hydrocarbon groups of J may be unsubstituted or have substituents other than those exemplified above.

[0017] Examples of halogen atom-containing alkyl groups include halogen atom-containing alkyl groups having 1 to 10 carbon atoms. Examples of halogen atom-containing alkoxy groups include halogen atom-containing alkoxy groups having 1 to 10 carbon atoms.

[0018] Examples of alicyclic hydrocarbon groups of J include cyclobutane rings, cyclopentane rings, cyclohexane rings, cyclodecane rings, and steroid skeletons (e.g., cholestanil group, cholesteryl group, lanostanil group, etc.), while examples of aromatic hydrocarbon groups include benzene rings and naphthalene rings. When J has at least one of a cyclohexane ring and a benzene ring, the group "-XJ" can be represented by, for example, the following structure (S1), and more preferred structures can be represented by the following formulas (S1-1) to (S1-5). [ka] (X 1 This is a single bond, -(CH2) a -(a is an integer from 1 to 15), -CONH-, -CO-N(CH3)-, -NH-, -O-, -COO-, or -((CH2) a1 -A1) m1 -(a1 is an integer between 1 and 15, A1 represents an oxygen atom or -COO-, and m1 is an integer between 1 and 2. If m1 is 2, multiple a1 and A1 each have the above definition independently.) G 1 represents a divalent cyclic group selected from a phenylene group and a cyclohexylene group. Any hydrogen atom on the cyclic group may be substituted with a C1-C3 alkyl group, a C1-C3 alkoxy group, a C1-C3 fluorine-containing alkyl group, a C1-C3 fluorine-containing alkoxy group, or a fluorine atom. m is an integer between 1 and 4. If m is 2 or greater, multiple X 1 , G 1 Each of these has its own independent definition. R 1 This represents a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or an alkoxyalkyl group having 3 to 10 carbon atoms. [ka] (X 1 , R 1 X in the above equation (S1) is 1 , R 1 (This is synonymous with...)

[0019] Specific examples of the above aromatic diamine (d) include diamines represented by the following formulas (d-1) to (d-2). More preferred examples include diamines represented by formulas (d-1) to (d-2) in which the group "-XJ" is one of the above structure (S1) or the above formulas (S1-1) to (S1-5), as well as diamines having a steroid skeleton such as cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, cholestanyl 3,5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane. [ka] (X and J are synonymous with X and J of the aromatic diamine (d) described above, including preferred embodiments. In formula (d-2), the two X and J may be the same or different from each other.)

[0020] As other diamines, from the viewpoint of suitably obtaining the effects of the present invention, the above aromatic diamine (d), p-phenylenediamine, the above diamine having a carboxyl group, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, the above diamine having a photo-orienting group, a diamine having a radical initiation function, a diamine having a photopolymerizable group at its terminus, a diamine having the group "-N(D)-", and the above diamine having a specific nitrogen-containing structure are preferred.

[0021] When other diamines are used in addition to the specified diamines mentioned above, the amount of the other diamines used is preferably 10 to 90 mol%, and more preferably 20 to 80 mol%, relative to the total diamine components used. The amount of the other diamines used is preferably 10 to 90 mol%, and more preferably 20 to 80 mol%, relative to the total diamine components used in the production of polymer (P).

[0022] (Tetracarboxylic acid component) When producing the above polyamic acid (P'), the tetracarboxylic acid component reacted with the diamine component may be not only tetracarboxylic dianhydride, but also a derivative of tetracarboxylic dianhydride such as tetracarboxylic acid, tetracarboxylic dihalide, tetracarboxylic dialkyl ester, or tetracarboxylic dialkyl ester dihalide.

[0023] The above-mentioned tetracarboxylic dianhydrides or derivatives thereof include acyclic aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, or derivatives thereof. In particular, it is more preferable to include tetracarboxylic dianhydrides or derivatives thereof having at least one substructure selected from the group consisting of a benzene ring, a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure, and even more preferable to include tetracarboxylic dianhydrides or derivatives thereof having at least one substructure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure.

[0024] In liquid crystal display elements, a low voltage holding ratio (VHR) can make it difficult to apply sufficient voltage to the liquid crystal molecules even when voltage is applied. In particular, in automotive applications such as car navigation systems and instrument panels, these elements may be used or left in high-temperature environments for extended periods. In such cases, the decrease in voltage holding ratio becomes more pronounced, and liquid crystal alignment films with a high voltage holding ratio are sometimes required. Furthermore, in liquid crystal display elements, the thinning and enlarging of the substrates used can lead to temperature differences between different parts of the same substrate during firing. In areas that are excessively heated, the liquid crystal alignment film loses its ability to align the liquid crystals, which can result in problems where the resulting liquid crystal display element exhibits partial display defects. Therefore, there is a need for a liquid crystal alignment film that maintains a high ability to align liquid crystals even when exposed to excessive heat. From the viewpoint of obtaining a liquid crystal alignment film having the above-mentioned high voltage retention rate and / or a liquid crystal alignment film that has a high ability to align liquid crystals even when exposed to excessive heating, when producing the above-mentioned polyamic acid (P'), the tetracarboxylic acid component reacted with the diamine component is more preferably an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, or a derivative thereof. In particular, it is even more preferable to include a tetracarboxylic dianhydride or a derivative thereof having at least one substructure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure, and a cyclohexane ring structure. The tetracarboxylic acid components that can be used in the synthesis of polyamic acid (P') preferably include the following tetracarboxylic dianhydrides or their derivatives (hereinafter collectively referred to as specific tetracarboxylic acid derivatives). Furthermore, from the viewpoint of obtaining a liquid crystal alignment film having the above-mentioned high voltage retention rate and / or a liquid crystal alignment film that has a high ability to align liquid crystals even when exposed to excessive heating, the above-mentioned specific tetracarboxylic acid derivative is preferably one of the following acyclic aliphatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, or derivatives thereof. Furthermore, examples of derivatives of the above-mentioned tetracarboxylic dianhydride include the derivatives of the tetracarboxylic dianhydride described above, and the above-mentioned tetracarboxylic dianhydride or its derivative may be used alone or in combination of two or more types.

[0025] 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, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic Dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic acid dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3- Dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]octa-7-en-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0] Alicyclic tetracarboxylic dianhydrides such as octane-2:4,6:8-dianhydride; pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfone 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'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride, 2,2 Aromatic tetracarboxylic dianhydrides such as ',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, ethylene glycol bisanhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-oxydi(1,4-phenylene)bis(phthalic acid) dianhydride, or 4,4'-methylenedi(1,4-phenylene)bis(phthalic acid) dianhydride; and other tetracarboxylic dianhydrides described in Japanese Patent Publication No. 2010-97188.

[0026] Preferred examples of the above-mentioned specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, and 1,3-diflu Oro-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride, 3,3',4,4'-dicyclohexyltetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 5-(2,5-dioxy Sotetrahydrofuran-3-yl)-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellitic dianhydride, 3,3',4,4'-benzopheno These are dianhydrides of tetracarboxylic acid, 3,3',4,4'-biphenylsulfontetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 3,3',4,4'-biphenylethertetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, or derivatives thereof.

[0027] The proportion of the above-mentioned specific tetracarboxylic acid derivative used is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more, based on 1 mole of the total tetracarboxylic acid component used.

[0028] (Synthesis of polyamic acids) The synthesis of polyamic acids is carried out by reacting a diamine component containing the above-mentioned specific diamine with a tetracarboxylic acid component containing the above-mentioned tetracarboxylic dianhydride or a derivative thereof in an organic solvent. The ratio of tetracarboxylic dianhydride to diamine used in the synthesis reaction of polyamic acids is preferably such that the acid anhydride groups of the tetracarboxylic dianhydride are in an amount of 0.2 to 2 equivalents, and more preferably 0.3 to 1.2 equivalents, per 1 equivalent of amino groups of the diamine. Similar to ordinary polycondensation reactions, the closer the equivalent amount of acid anhydride groups of the tetracarboxylic dianhydride is to 1 equivalent, the larger the molecular weight of the resulting polyamic acid. The reaction temperature for the synthesis of polyamic acids is preferably -20 to 150°C, and more preferably 0 to 100°C. The reaction time is preferably 0.1 to 24 hours, and more preferably 0.5 to 12 hours. The synthesis reaction of polyamic acids can be carried out at any concentration, but preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The reaction can be carried out at a high concentration initially, and then the solvent can be added.

[0029] Specific examples of the above organic solvents include 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-imidazolidinone. Furthermore, if the solvent solubility of the polymer is high, 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.

[0030] (Synthesis of polyamic acid SL) Polyamic acid esters can be obtained by known methods, such as [I] reacting the polyamic acid obtained by the above method with an esterifying agent, [II] reacting a tetracarboxylic acid diester with a diamine, or [III] reacting a tetracarboxylic acid dihalide with a diamine.

[0031] (Synthesis of polyimides) Furthermore, polyimides can be obtained by cyclizing (imidizing) polyimide precursors such as the above-mentioned polyamic acid or polyamic acid ester. In this specification, the imidization rate refers to the ratio of imide groups to the total amount of imide groups and carboxyl groups (or their derivatives) derived from tetracarboxylic dianhydride or its derivatives. The imidization rate does not necessarily have to be 100% and can be adjusted as needed depending on the application and purpose.

[0032] Methods for imidizing a polyimide precursor include thermal imidation, which involves heating the polyimide precursor solution directly, and catalytic imidation, which involves adding a catalyst to the polyimide precursor solution.

[0033] The temperature at which the polyimide precursor is thermally imidized in solution is preferably 100 to 400°C, more preferably 120 to 250°C, and it is preferable to remove the water produced by the imidization reaction from the system.

[0034] Catalytic imidation of polyimide precursors can be carried out by adding a basic catalyst and an acid anhydride to a solution of the polyimide precursor and stirring at -20 to 250°C, preferably 0 to 180°C. The amount of basic catalyst is 0.5 to 30 molar times the amount of amic acid groups, preferably 2 to 20 molar times, and the amount of acid anhydride is 1 to 50 molar times the amount of amic acid groups, preferably 3 to 30 molar times. Examples of basic catalysts include pyridine, triethylamine, trimethylamine, tributylamine, or trioctylamine, with pyridine being preferred because it has a suitable basicity for the reaction to proceed. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, or pyromellitic anhydride, with acetic anhydride being preferred because it facilitates purification after the reaction. The imidation rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0035] To recover the polyimide precursor or polyimide from the reaction solution of the polyimide precursor or polyimide, the reaction solution can be placed in a solvent and precipitated. Examples of solvents that can be used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellsolve, 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 atmospheric pressure or reduced pressure. Furthermore, the amount of impurities in the polymer can be reduced by repeating the operation of redissolving the precipitated polymer in an organic solvent and reprecipitating it 2 to 10 times. Examples of solvents used in this process include alcohols, ketones, and hydrocarbons, and it is preferable to use three or more solvents selected from these to further improve the efficiency of purification.

[0036] <End capping agent> In synthesizing the polyimide precursor or polyimide in the present invention, a tetracarboxylic acid component containing tetracarboxylic dianhydride or its derivative, and a diamine component containing the above-mentioned specific diamine, may be used together with a suitable end-sealing agent to synthesize a end-sealed polymer. The end-sealed polymer has the effect of improving the film hardness of the orientation film obtained by the coating film and improving the adhesion characteristics between the sealant and the orientation film. Examples of polyimide precursors and polyimide ends in the present invention include amino groups, carboxyl groups, acid anhydride groups, or groups derived from end-capturing agents described later. Amino groups, carboxyl groups, and acid anhydride groups can be obtained by conventional condensation reactions or by encapsulating the ends using the following end-capturing agents.

[0037] Examples of end-capturing agents include acid anhydrides such as acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic acid anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-(3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, and 4-ethynylphthalic anhydride; dicarbonate diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride, and nicotinic acid chloride; and aniline Examples include monoamine compounds such as n-aminophenol, 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, and n-octylamine; and isocyanates having unsaturated bonds such as ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.

[0038] The proportion of end-capturing agent used is preferably 0.01 to 20 moles, and more preferably 0.01 to 10 moles, per 100 moles of the total diamine components used.

[0039] The weight-average molecular weight (Mw) of the polyimide precursor and polyimide, measured by gel permeation chromatography (GPC), is preferably 1,000 to 500,000, and 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) measured by GPC, is preferably 15 or less, and more preferably 10 or less. This molecular weight range ensures good orientation of the liquid crystal display element.

[0040] (Liquid crystal alignment agent) The liquid crystal alignment agent of the present invention is a liquid composition comprising a polymer (P) and other components used as needed, preferably dispersed or dissolved in a suitable solvent.

[0041] The liquid crystal alignment agent of the present invention may contain polymers other than polymer (P). Specific examples of other polymers include at least one polymer (B) selected from the group consisting of polyimide precursors obtained using a diamine component that does not contain the above-mentioned specific diamine and polyimides which are imidized products of the polyimide precursor; and 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. As polymer (B), from the viewpoint of enhancing vertical orientation, at least one polymer selected from the group consisting of polyimide precursors obtained using a diamine component containing the above-mentioned aromatic diamine (d) and imidized products of the polyimide precursor is mentioned. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley), and GSM301 (manufactured by Gifu Ceratek Manufacturing Co., Ltd.). Specific examples of poly(isobutylene-maleic anhydride) copolymers include Isoban-600 (manufactured by Kuraray Co., Ltd.). Specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether maleic anhydride resin, manufactured by Ashland). Other polymers may be used individually or in combination of two or more. The content of other polymers is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and even more preferably 20 to 80 parts by mass, based on 100 parts by mass of the total polymers contained in the liquid crystal alignment agent.

[0042] The liquid crystal alignment agent of the present invention may also contain other components as needed. Examples of such components include at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-1) having at least one substituent selected from epoxy groups, isocyanate groups, oxetane groups, cyclocarbonate groups, blocked isocyanate groups, hydroxyl groups, and alkoxy groups, and a crosslinkable compound (c-2) having a polymerizable unsaturated group, a functional silane compound, a metal chelating compound, a curing accelerator, a surfactant, an antioxidant, a sensitizer, a preservative, and a compound for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film.

[0043] Preferred specific examples of the crosslinkable compounds (c-1) and (c-2) include epoxy compounds in which a tertiary nitrogen atom is bonded to an aromatic carbon atom, such as N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl-2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane; N,N,N',N' -Tetraglycidyl-1,2-diaminocyclohexane, N,N,N',N'-Tetraglycidyl-1,3-diaminocyclohexane, N,N,N',N'-Tetraglycidyl-1,4-diaminocyclohexane, Bis(N,N-diglycidyl-4-aminocyclohexyl)methane, Bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, Bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-Bis(N,N-diglycidylaminomethyl) Epoxy compounds in which a tertiary nitrogen atom is bonded to an aliphatic carbon atom, such as cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis(N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, and 1,3,5-tris(N,N-diglycidylaminomethyl)benzene, as well as triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Corporation). Any epoxy compound; compounds having two or more oxetanyl groups as described in paragraphs

[0170] to

[0175] of Publication No. WO2011 / 132751; compounds having blocked isocyanate groups such as Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.);Compounds having hydroxyl or alkoxy groups such as N,N,N',N'-tetrakis(2-hydroxyethyl)adipoamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxymethylphenyl)propane, and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-compound mixture), glycerin tris(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, and pentaerythritol. Examples include crosslinkable compounds having polymerizable unsaturated groups, such as tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, and hexaethylene glycol mono(meth)acrylate.

[0044] The content of the above crosslinkable compound is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0045] Examples of compounds used to adjust dielectric constant and electrical resistance include monoamines having nitrogen-containing aromatic heterocycles, such as 3-picolylamine. When using monoamines having nitrogen-containing aromatic heterocycles, the amount is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0046] Preferred specific 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-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane. Examples include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane. When using functionalized silane compounds, the amount is preferably 0.1 to 30 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0047] Organic solvents used in the liquid crystal alignment agent of the present invention include, for example, lactone solvents such as γ-valerolactone and γ-butyrolactone; γ-butyrolactam, 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-ethoxypropyl Lactam solvents such as tyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone; amide solvents such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, and tetramethylurea;Cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, 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 cellosolve), ethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, Examples include 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, diisobutylcarbinol (2,6-dimethyl-4-heptanol), diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, and propylene carbonate. Two or more of these can be used in combination.

[0048] Preferred solvent combinations include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2-pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl-4-heptanone, and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol Coal monomethyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl-4-heptanone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, cyclohexanone and ethylene glycol monobutyl ether, cyclohexanone and propylene glycol monobutyl ether, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monobutyl ether, cyclopentanone and propylene glycol monomethyl ether, cyclohexanone and diethylene glycol monoethyl ether, cyclopentanone and diethylene glycol monoethyl ether, cyclohexanone and diisobutyl ketone, cyclopentanone and diisobutyl ketone, methyl isobutyl ketone and propylene glycol monobutyl ether, methyl ethyl ketone and propylene glycol monobutyl ether, cyclohexanone and 4-hydroxy-4-methyl-2-pentanone, cyclopentanone and 4-hydroxy -4-methyl-2-pentanone, cyclohexanone and diethylene glycol diethyl ether, cyclopentanone and diethylene glycol diethyl ether, tetramethylurea and propylene glycol diacetate, N,N-dimethylpropionamide and propylene glycol monobutyl ether, tetramethylurea and propylene glycol monobutyl ether, tetramethylurea and cyclohexanone and propylene glycol monomethyl ether, N,N-dimethylpropionamide and propylene glycol monomethyl ether, N,N-dimethylpropionamide and ethylene glycol monobutyl ether acetate, N,N-dimethylpropionamide and ethylene glycol monobutyl ether, N,N-diethylpropionamide and propylene glycol monomethyl ether, tetramethylurea and propylene glycol monomethyl ether, N,N-dimethylpropionamide and cyclohexanone and diethylene glycol diethyl ether, N,N-diethylformamide and propylene glycol monomethyl ether, N,Examples include N-diethylformamide and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone and n-butyl acetate, cyclopentanone and n-butyl acetate, 4-hydroxy-4-methyl-2-pentanone and ethylene glycol monobutyl ether, cyclohexanone and propylene glycol diacetate, and cyclopentanone and propylene glycol diacetate. The type and content of such solvents are appropriately selected depending on the liquid crystal alignment agent coating apparatus, coating conditions, and coating environment.

[0049] The solid content concentration in the liquid crystal alignment agent (the ratio 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 viscosity, volatility, etc., but is preferably in the range of 1 to 10% by mass. From the viewpoint of forming a uniform and defect-free coating film, 1% by mass or more is preferred, and from the viewpoint of storage stability of the solution, 10% by mass or less is preferred. A particularly preferred polymer concentration is 2 to 8% by mass.

[0050] <Liquid crystal alignment film> The liquid crystal alignment film of the present invention is obtained from the above-mentioned liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used as a horizontal alignment type (TN method, STN method, IPS method, or FFS method, etc.) or a vertical alignment type liquid crystal alignment film. Among the vertical alignment type liquid crystal alignment films, a liquid crystal alignment film used in a vertical alignment type liquid crystal display element such as the VA method or PSA (Polymer Sustained Alignment) method is preferred.

[0051] <Liquid crystal display element> The liquid crystal display element of the present invention comprises the above-mentioned liquid crystal alignment film. The liquid crystal alignment agent of the present invention is preferably used in liquid crystal display elements that have a liquid crystal layer between a pair of substrates equipped with electrodes, and are manufactured by placing a liquid crystal composition containing a polymerizable compound that polymerizes by at least one of active energy rays and heat between the pair of substrates, and polymerizing the polymerizable compound by irradiation with active energy rays and heating while applying a voltage between the electrodes.

[0052] The liquid crystal display element of the present invention can be manufactured, for example, by performing the following steps (1) to (3) or steps (1) to (4) in this order. (1) A step of applying a liquid crystal aligning agent onto at least one of a pair of substrates having a conductive film to form a coating film The liquid crystal aligning agent of the present invention is applied onto one surface of at least one of a pair of substrates provided with a patterned transparent conductive film to form a coating film by an appropriate coating method such as a roll coater method, a spin coating method, a printing method, an inkjet method, or the like. Here, the substrate is not particularly limited as long as it has high transparency, and in addition to a glass substrate and a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. Further, in a reflective liquid crystal display element, if only one of the substrates is used, an opaque material such as a silicon wafer can also be used, and in this case, a material that reflects light such as aluminum can also be used for the electrodes. In addition, when manufacturing an IPS mode or FFS mode liquid crystal display element, a coating film may be formed on one surface of at least one of the substrates using a substrate provided with an electrode made of a transparent conductive film or a metal film patterned in a comb shape and a counter substrate not provided with an electrode.

[0053] (2) A step of baking the coating film After applying the liquid crystal aligning agent, the coating film is baked for the purpose of preventing dripping of the applied aligning agent. Preferably, preheating (prebake) is first performed. The prebake temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The prebake time is preferably 0.25 to 10 minutes, more preferably 0.5 to 5 minutes. Then, it is preferable to perform a heating (postbake) step. This postbake temperature is preferably 80 to 300°C, more preferably 12 to 250°C. The postbake time is preferably 5 to 200 minutes, more preferably 10 to 100 minutes. The film thickness of the film thus formed is preferably 5 to 300 nm, more preferably 10 to 200 nm.

[0054] The coating film formed in steps (1) and (2) above can be used as is as a liquid crystal alignment film, but the coating film may also be subjected to an alignment-imparting treatment. Examples of alignment-imparting treatments include rubbing, in which the coating film is rubbed in a certain direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, or cotton, and photo-alignment, in which the coating film is irradiated with polarized or unpolarized radiation.

[0055] In photo-alignment processing, ultraviolet and visible light, including wavelengths of 150 to 800 nm, can be used as radiation to irradiate the coating film. If the radiation is polarized, it may be linearly polarized or partially polarized. Furthermore, if the radiation used is linearly polarized or partially polarized, irradiation may be performed perpendicular to the substrate surface, at an oblique angle, or a combination of these. When irradiating with unpolarized radiation, the irradiation direction should be oblique.

[0056] (3) A process of forming a liquid crystal layer between the pair of substrates to produce a liquid crystal cell. (3-1) When manufacturing a VA type liquid crystal display element As described above, two substrates are prepared, each having a liquid crystal alignment film of the present invention formed on at least one of them, and liquid crystal is placed between the two substrates which are placed opposite each other. Specifically, the following two methods can be used. The first method is a conventionally known method. First, two substrates are placed opposite each other with a gap (cell gap) in between so that their respective liquid crystal alignment films face each other. Next, a sealant is applied to the periphery of the two substrates and they are bonded together. A liquid crystal composition is then injected and filled into the cell gap partitioned by the substrate surface and the sealant, and after contact with the film surface, the injection holes are sealed.

[0057] The second method is called the ODF (One Drop Fill) method. In this method, a UV-curable sealant is applied to a predetermined location on one of two substrates on which a liquid crystal alignment film has been formed, and then liquid crystal composition is dropped onto several predetermined locations on the surface of the liquid crystal alignment film. The other substrate is then bonded together so that the liquid crystal alignment films face each other, and the liquid crystal composition is spread across the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with UV light to cure the sealant. In either method, it is desirable to further remove the flow orientation during liquid crystal filling by heating the liquid crystal composition to a temperature at which it forms an isotropic phase, and then slowly cooling it to room temperature.

[0058] (Liquid crystal composition) The above-mentioned liquid crystal composition is not particularly limited, and any composition containing at least one liquid crystal compound (liquid crystal molecule) can be used, and various liquid crystal compositions with positive or negative dielectric anisotropy can be used. In the following, a liquid crystal composition with positive dielectric anisotropy will also be called a positive-type liquid crystal, and a liquid crystal composition with negative dielectric anisotropy will also be called a negative-type liquid crystal. The above liquid crystal composition may contain liquid crystal compounds having a fluorine atom, a hydroxyl group, an amino group, a fluorine atom-containing group (e.g., a trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocycle, a cycloalkane, a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring, and may also contain compounds having two or more rigid sites (mesogenic skeletons) that exhibit liquid crystallinity within the molecule (e.g., two rigid biphenyl structures, or a bimesogenic compound in which terphenyl structures are linked by alkyl groups). The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase. Furthermore, the above liquid crystal composition may contain additional additives from the viewpoint of improving liquid crystal alignment. Examples of such additives include photopolymerizable monomers such as compounds having polymerizable groups; optically active compounds (e.g., S-811 manufactured by Merck KGaA); antioxidants; ultraviolet absorbers; dyes; defoamers; polymerization initiators; or polymerization inhibitors. Examples of positive-type LCDs include the Merck ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, and MLC-7081. Examples of negative-type LCDs include the MLC-6608, MLC-6609, MLC-6610, or MLC-7026-100, all manufactured by Merck. Furthermore, MLC-3023 manufactured by Merck is an example of a liquid crystal composition containing a polymerizable group, as described later.

[0059] (3-2) When manufacturing a liquid crystal display element using the PSA method The procedure is the same as in (3-1) above, except that a liquid crystal composition containing a polymerizable compound is injected or dropped. Examples of polymerizable compounds include compounds having a mesogenic structure and two or more photopolymerizable or thermally polymerizable groups. Examples of mesogenic structures include structures in which two or more aromatic or aliphatic groups are linked, such as biphenyl structures, terphenyl structures, naphthalene rings, groups obtained by removing two hydroxyl groups from bisphenol A, or fluorine atom-containing structures in which some of the hydrogen atoms in these structures are replaced with fluorine atoms. Specific examples of compounds include 4,4'-dimethacryloxybiphenyl or 3-fluoro-1,1'-biphenyl-4,4'-diyldimethacrylate.

[0060] (3-3) When a coating film is formed on a substrate using a liquid crystal alignment agent containing a polymerizable compound. A method may be adopted in which the liquid crystal display element is manufactured by following the same procedure as in (3-1) above, followed by a step of irradiating with ultraviolet light as described later. According to this method, a liquid crystal display element with excellent response speed can be obtained with a small amount of light irradiation, similar to the case in which the PSA method liquid crystal display element is manufactured. The compound having polymerizable groups may be the compound having polymerizable groups described above, and its content is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of all polymer components. Furthermore, the polymerizable groups may be present in the polymer used as a liquid crystal alignment agent, and examples of such polymers include polymers obtained by using a diamine component containing a diamine having the above-mentioned photopolymerizable groups at its terminals in the reaction.

[0061] (4) Process of irradiating the liquid crystal cell with light The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in (3-2) or (3-3) above. The applied voltage can be, for example, 5 to 50 V DC or AC. As the irradiated light, ultraviolet light and visible light including wavelengths of 150 to 800 nm can be used, but ultraviolet light including wavelengths of 300 to 400 nm is preferred. As the light source for the irradiation light, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, or an excimer laser can be used. The amount of light irradiated is preferably 1,000 to 200,000 J / m 2 More preferably, 1,000 to 100,000 J / m 2 That is the case.

[0062] A liquid crystal display element can then be obtained by laminating a polarizing plate onto the outer surface of the liquid crystal cell. Examples of polarizing plates that can be laminated onto the outer surface of the liquid crystal cell include a polarizing plate made by sandwiching a polarizing film called an "H film," which is made by stretching and oriented polyvinyl alcohol while absorbing iodine, between cellulose acetate protective films, or a polarizing plate made of the H film itself.

[0063] The liquid crystal display element of the present invention can be effectively applied to various devices, for example, it can be used in various display devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smartphones, various monitors, liquid crystal televisions, and information displays. Furthermore, the polymer composition contained in the liquid crystal alignment agent can be used as a liquid crystal alignment film for phase difference films, a liquid crystal alignment film for scanning antennas and liquid crystal array antennas, or a liquid crystal alignment film 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. [Examples]

[0064] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The abbreviations for the compounds and the methods for measuring each property are as follows.

[0065] (Tetracarboxylic acid dianhydride) [ka]

[0066] (Diamine) [ka]

[0067] (solvent) THF: Tetrahydrofuran NMP:N-methyl-2-pyrrolidone BCS: Ethylene glycol monobutyl ether (butyl cellosolve)

[0068] [viscosity] Viscosity was measured using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.) with a sample volume of 1.1 mL, a cone rotor TE-1 (1°34', R24), and a temperature of 25°C. [Measurement of molecular weight] Measurements were performed using a room-temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko Corporation) and columns (GPC KD-803 and GPC KD-805 in series) (manufactured by Showa Denko Corporation) under the following conditions. Column temperature: 50℃ Eluent: N,N-dimethylformamide (additives: lithium bromide monohydrate (LiBr·H2O) 30 mmol / L, anhydrous crystalline phosphoric acid (o-phosphoric acid) 30 mmol / L, tetrahydrofuran (THF) 10 mL / L) Flow rate: 1.0mL / min Standard samples for calibration curve creation: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0069] [Synthesis of specific diamines (DA-1) to (DA-2)] The synthesis methods for the compounds represented by formulas (DA-1) to (DA-2) are described in detail below. Note that the compounds represented by formulas (DA-1) to (DA-2) are novel compounds not previously published in literature.

[0070] < 1 H-NMR measurement> Equipment: Fourier transform superconducting nuclear magnetic resonance (FT-NMR) spectrometers "Varian NMR System 400NB" (manufactured by Varian) 400MHz, "AVANCE III" (manufactured by BRUKER) 500MHz. Solvent: Deuterated dimethyl sulfoxide (DMSO-d6, standard substance: tetramethylsilane).

[0071] <Example 1-1: Synthesis of DA-1> (DA-1-1 synthesis) [ka]

[0072] 3,5-dinitrobenzyl alcohol (19.9 g, 100 mmol), THF (118 g), and triethylamine (12.5 g, 123 mmol) were placed in a 500 mL four-necked flask. After cooling to 5°C in an ice bath, methanesulfonyl chloride (12.5 g, 109 mmol) was added dropwise. After the reaction was complete, the precipitated triethylamine salt was removed by filtration, and the resulting filtrate was concentrated to obtain crude DA-1-1. A mixture of crude DA-1-1 and 2-propanol (68.0 g) was stirred as a slurry at 80°C for 1 hour, then cooled to room temperature, and the crystals were recovered by filtration. The recovered crystals were vacuum-dried at 50°C to obtain DA-1-1 (yield: 20.9 g, 75.6 mmol, yield: 75.6%, yellow solid).

[0073] (DA-1-2 synthesis) [ka]

[0074] DA-1-1 (14.0 g, 50.7 mmol), potassium carbonate (12.4 g, 90.0 mmol), hydroquinone (90.6 g, 823 mmol), and ethanol (362 g) were added to a 1 L four-necked flask and reacted at 45°C for 5 hours. After the reaction, the reaction solution and water (1200 g) were added to a 2 L beaker to precipitate crude DA-1-2. The precipitate was collected by filtration and vacuum-dried at 50°C. Methanol (350 g) and ethanol (190 g) were added to the crude DA-1-2 and heated to 60°C to dissolve. Insoluble matter was removed by filtration, and water (1000 g) was added to the resulting filtrate to precipitate DA-1-2. The precipitated solid was recovered by filtration and vacuum-dried at 50°C to obtain DA-1-2 (yield: 10.0 g, 34.5 mmol, yield: 68.0%, yellow solid).

[0075] (DA-1 synthesis) [ka]

[0076] DA-1-2 (9.98 g, 34.4 mmol), THF (120 g), and carbon-supported platinum (3% by mass, 0.500 g) were added to a 500 mL four-necked flask and reacted at room temperature under a hydrogen atmosphere. After the reaction was complete, the carbon-supported platinum was removed by filtration, and the resulting filtrate was concentrated. The precipitated crystals were vacuum-dried at 50°C to obtain DA-1 (yield: 7.71 g, 33.5 mmol, yield: 97.4%, orange solid). The following is shown. 1 Based on the results of 1H-NMR, it was confirmed that this solid is DA-1. 1 H-NMR(500MHz,DMSO-d6):δ(ppm=)8.86(s,1H),6.75(d,2H,J=9.0Hz),6.64(d,2H, J=9.0Hz), 5.83(d,2H,J=1.9Hz), 5.74(t,1H,J=2.0Hz),4.71(br,4H),4.66(s,2H).

[0077] <Example 1-2: Synthesis of DA-2> Diamine DA-2 was synthesized according to the route shown below. [ka]

[0078] (Synthesis of DA-2-1) In a 2000 mL four-necked flask, tetrahydrofuran (361 g), ethyl 3,4-dihydroxybenzoate (90.2 g, 495 mmol), and N,N-diisopropylethylamine (320 g, 2.48 mol) were charged, and chloromethyl methyl ether (MOMCl, 179 g, 2.22 mol) was added dropwise under ice-cooled conditions in a nitrogen atmosphere. After addition, the reaction was carried out at room temperature until the starting materials disappeared. After the reaction was complete, the reaction solution was diluted with ethyl acetate (1350 g), and the organic phase was washed with pure water (720 g). Subsequently, the organic phase was washed twice with 2.0 mol / L hydrochloric acid aqueous solution (720 g) and three times with pure water (720 g). The obtained organic phase was concentrated under reduced pressure to obtain a pale yellow oily crude product. Ethanol (400g) and pure water (274g) were added to the crude product obtained, and then sodium hydroxide (21.8g) was charged in. The mixture was reacted at room temperature for 20 hours to hydrolyze it. After the reaction was complete, 1.0mol / L hydrochloric acid aqueous solution (600mL) was added to the reaction mixture to precipitate crystals, and the slurry was washed with pure water (266g). Subsequently, the filtrate was filtered, washed with pure water and hexane, and dried to obtain DA-2-1 as white crystals (yield: 111g, 458 mmol, yield: 93%).

[0079] (DA-2-2 synthesis) In a 2000 mL four-necked flask, tetrahydrofuran (452 ​​g), 3,5-dinitrobenzyl alcohol (75.2 g, 379 mmol), DA-2-1 (106 g, 438 mmol), 4-dimethylaminopyridine (DMAP, 4.62 g), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC, 94.5 g) were charged and reacted for 4 hours under a nitrogen atmosphere at room temperature. After the reaction was complete, the reaction solution was poured into pure water (810 g) to precipitate crystals, and the filtrate was filtered, washed with pure water, and washed with methanol. Subsequently, the obtained filtrate was slurry-washed with methanol (180 g), filtered, and dried to obtain DA-2-2 (yield: 156 g, 369 mmol, yield: 97%, pale yellow crystals).

[0080] (DA-2-3 synthesis) In a 2000 mL four-necked flask, 195 g of tetrahydrofuran and 327 g of methanol were mixed with 200 g of 4.0 mol / L aqueous hydrochloric acid solution and 131 g of DA-2-2 (310 mmol). The mixture was reacted at 50°C for approximately 12 hours. After the reaction was complete, 1310 g of ethyl acetate and 432 g of toluene were added to the reaction mixture to separate the two phases. After removing the hydrochloric acid phase, the organic layer was washed three times with 400 g of pure water. The organic layer was concentrated under reduced pressure to a total internal weight of 555 g, and 262 g of 2-propanol was added. Crystals were precipitated by stirring under ice cooling. The precipitated crystals were filtered and dried to obtain DA-2-3 (yield: 80.3 g, 240 mmol, yield: 78%, yellow crystals).

[0081] (DA-2 synthesis) In a 1000 mL four-necked flask, 39.2 g (117 mmol) of DA-2-3 and 3.13 g of carbon-supported platinum (supported amount 3% by mass) were charged with 240 g of tetrahydrofuran and 80 g of methanol, and the mixture was reacted for 2 days under a hydrogen atmosphere at 40°C. After the reaction was complete, the mixture was filtered and concentrated under reduced pressure to obtain a total internal weight of 35 g. Subsequently, 120 g of methanol was added to precipitate crystals, which were then filtered and dried to obtain DA-2 (yield: 28.0 g, 102 mmol, yield: 87%, pale yellow crystals). 1 H-NMR(400MHz,DMSO-d6):δ(ppm=)9.60(s,2H),7.38(s,1H),7.32-7.38(m,1H),6.81 (d,1H,J=8.0Hz),5.83(d,2H,J=1.6Hz),5.76-5.77(m,1H),4.96(s,2H),4.78(s,4H)

[0082] [Synthesis of polymers] <Example 2-1> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-1 (0.921 g, 4.00 mmol), DA-3 (1.08 g, 10.0 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.0 mmol), and NMP (27.1 g) were added, and the mixture was stirred at 60°C for 3 hours while supplying nitrogen. Subsequently, CA-2 (1.94 g, 9.90 mmol) and NMP (7.77 g) were added, and the mixture was stirred at 40°C for 3 hours to obtain a polyamic acid solution (1) with a solid content of 20% by mass (viscosity: 680 mPa·s). The Mn of this polyamic acid was 14,360 and the Mw was 49,800.

[0083] <Example 2-2> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-2 (1.10 g, 4.00 mmol), DA-3 (1.08 g, 10.00 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.00 mmol), and NMP (27.8 g) were added, and the mixture was stirred at 60°C for 3 hours while supplying nitrogen. Subsequently, CA-2 (1.93 g, 9.86 mmol) and NMP (7.73 g) were added, and the mixture was stirred at 40°C for 3 hours to obtain a polyamic acid solution (2) with a solid content of 20% by mass (viscosity: 710 mPa·s). The Mn of this polyamic acid was 10,800 and the Mw was 34,800.

[0084] <Example 2-3> In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-1 (1.38 g, 6.00 mmol), DA-3 (0.973 g, 9.00 mmol), CA-2 (2.90 g, 14.8 mmol), and NMP (30.0 g) were added and stirred at 40°C for 3 hours to obtain a polyamic acid solution (3) with a solid content of 15% by mass (viscosity: 450 mPa·s). The Mn of this polyamic acid was 12,100 and the Mw was 28,900.

[0085] <Example 2-4> In a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, DA-2 (1.65 g, 6.00 mmol), DA-3 (0.973 g, 9.00 mmol), CA-2 (2.91 g, 14.8 mmol), and NMP (31.3 g) were added and stirred at 40°C for 3 hours to obtain a polyamic acid solution (4) with a solid content of 15% by mass (viscosity: 520 mPa·s). The Mn of this polyamic acid was 14,500 and the Mw was 32,900.

[0086] <Example 2-5> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-1 (0.691 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-2 (2.90 g, 14.8 mmol), and NMP (24.5 g) were added and stirred at 40°C for 3 hours to obtain a polyamic acid solution (5) (viscosity: 680 mPa·s) with a solid content of 20% by mass. The Mn of this polyamic acid was 11,100 and the Mw was 25,600.

[0087] <Example 2-6> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-2 (0.822 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-2 (2.89 g, 14.8 mmol), and NMP (25.0 g) were added and stirred at 40°C for 3 hours to obtain a polyamic acid solution (6) with a solid content of 20% by mass (viscosity: 640 mPa·s). The Mn of this polyamic acid was 13,400 and the Mw was 32,000.

[0088] <Example 2-7> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-1 (0.691 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-3 (3.23 g, 14.8 mmol), and NMP (25.8 g) were added and stirred at room temperature for 3 hours to obtain a polyamic acid solution (7) with a solid content of 20% by mass (viscosity: 670 mPa·s). The Mn of this polyamic acid was 14,300 and the Mw was 30,900.

[0089] <Example 2-8> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-2 (0.823 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-3 (3.21 g, 14.8 mmol), and NMP (26.2 g) were added and stirred at room temperature for 3 hours to obtain a polyamic acid solution (8) with a solid content of 20% by mass (viscosity: 720 mPa·s). The Mn of this polyamic acid was 15,300 and the Mw was 32,600.

[0090] <Comparative Example 2-1> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-5 (0.553 g, 4.00 mmol), DA-3 (1.08 g, 10.0 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.0 mmol), and NMP (25.7 g) were added, and the mixture was stirred at 60°C for 3 hours while supplying nitrogen. Subsequently, CA-2 (1.91 g, 9.76 mmol) and NMP (7.66 g) were added, and the mixture was stirred at 40°C for 3 hours to obtain a polyamic acid solution (9) with a solid content of 20% by mass (viscosity: 760 mPa·s). The Mn of this polyamic acid was 11,300 and the Mw was 25,880.

[0091] <Comparative Example 2-2> In a 50 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, DA-3 (1.51 g, 14.0 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.0 mmol), and NMP (25.2 g) were added, and the mixture was stirred at 60°C for 3 hours while supplying nitrogen. Subsequently, CA-2 (1.90 g, 9.70 mmol) and NMP (7.61 g) were added, and the mixture was stirred at 40°C for 3 hours to obtain a polyamic acid solution (10) with a solid content of 20% by mass (viscosity: 770 mPa·s). The Mn content of this polyamic acid was 11,290 and the Mw content was 21,800.

[0092] <Comparative Example 2-3> DA-5 (0.829 g, 6.00 mmol), DA-3 (0.973 g, 9.00 mmol), CA-2 (2.90 g, 14.8 mmol), and NMP (26.7 g) were added to a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and the mixture was stirred at 40°C for 3 hours to obtain a polyamic acid solution (11) with a solid content of 15% by mass (viscosity: 460 mPa·s). The Mn of this polyamic acid was 15,200 and the Mw was 23,800.

[0093] <Comparative Example 2-4> DA-3 (1.62 g, 15.0 mmol), CA-2 (2.90 g, 14.8 mmol), and NMP (25.6 g) were added to a 50 mL four-necked flask equipped with a stirring device and a nitrogen inlet tube, and the mixture was stirred at 40°C for 3 hours to obtain a polyamic acid solution (12) with a solid content of 15% by mass (viscosity: 520 mPa·s). The Mn of this polyamic acid was 10,600 and the Mw was 41,000.

[0094] The specifications of the monomer components used in the above examples and comparative examples are shown in Table 1 below.

[0095] [Table 1]

[0096] [Preparation of liquid crystal alignment agent] <Example 3-1> To the polyamic acid solution (1) (4.00 g) obtained in Example 2-1, NMP (8.00 g) and BCS (8.00 g) were added and stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (A-1).

[0097] <Examples 3-2, 3-5 to 3-8, Comparative Examples 3-1, 3-2> Liquid crystal alignment agents (A-2), (A-5) to (A-8), (B-1), and (B-2) for Examples 3-2, 3-5 to 3-8, and Comparative Examples 3-1 and 3-2 were obtained in the same manner as in Example 3-1, except that polyamic acid solutions (2), (5) to (10) were used instead of polyamic acid solution (1).

[0098] <Example 3-3> To the polyamic acid solution (3) (4.00 g) obtained in Example 2-3, NMP (5.00 g) and BCS (6.00 g) were added and stirred at room temperature for 3 hours to obtain liquid crystal alignment agent (A-3).

[0099] <Examples 3-4, Comparative Examples 3-3, 3-4> Liquid crystal alignment agents (A-4), (B-3), and (B-4) for Example 3-4 and Comparative Examples 3-3 and 3-4 were obtained in the same manner as in Example 3-3, except that polyamic acid solutions (4), (11), and (12) were used instead of polyamic acid solution (3). The specifications of the liquid crystal alignment agents obtained in the above examples and comparative examples are shown in Table 2 below.

[0100] [Table 2]

[0101] As described above, no abnormalities such as turbidity or precipitation were observed in the obtained liquid crystal alignment agents (A-1) to (A-8) and (B-1) to (B-4), confirming that they were homogeneous solutions. The obtained liquid crystal alignment agents were used to evaluate rubbing resistance, seal adhesion, voltage retention rate, and vertical alignment.

[0102] [Evaluation of rubbing resistance] The liquid crystal alignment agents (A-1) to (A-8) and (B-1) to (B-4) obtained above were spin-coated onto the ITO surface of a glass substrate with ITO electrodes covering the entire surface, and dried on a hot plate at 70°C for 90 seconds. Then, they were fired in an infrared heating furnace at 230°C for 30 minutes to form a coating with a thickness of 100 nm, obtaining a substrate with a liquid crystal alignment film. This liquid crystal alignment film was rubbed with a rayon cloth (Yoshikawa Chemical Co., Ltd., YA-20R) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 20 mm / sec, pressing length: 0.6 mm). The substrates were observed under a microscope and evaluated as "good" if no streaks due to rubbing were observed on the film surface, and "poor" if streaks were observed. The results are shown in Table 3 below.

[0103] [Preparation of samples for evaluating seal adhesion] The liquid crystal alignment agents (A-1) to (A-8) and (B-1) to (B-4) obtained above were spin-coated onto rectangular transparent electrode-equipped glass substrates measuring 30 mm (length) x 40 mm (width) x 1.1 mm (thickness), dried on a hot plate at 70°C for 90 seconds, and then baked in a hot air circulating oven at 230°C for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm. Two substrates were prepared in this manner. A 4 μm diameter bead spacer was applied to the liquid crystal alignment film surface of one of the substrates, and then a sealant (723K1, manufactured by Kyoritsu Chemical Industry Co., Ltd.) was applied. Next, the liquid crystal alignment film surfaces of the two substrates faced each other, and the substrates were bonded together so that the overlap width was 1 cm. At that time, the amount of sealant dropped was adjusted so that the diameter of the sealant after bonding was 3 mm. After fixing the two bonded substrates with clips, a load of 4 J / cm² was applied at a wavelength of 365 nm. 2 Samples for adhesion evaluation were prepared by irradiating them with ultraviolet light and heat-curing them at 120°C for 1 hour.

[0104] [Evaluation of seal adhesion] Adhesion was evaluated using a desktop precision universal testing machine (AGS-X 500N, Shimadzu Corporation). After fixing the edges of the upper and lower substrates of the obtained evaluation sample, pressure was applied from the upper center of the substrate, and the strength (N) at which peeling occurred was measured. Then, the seal adhesion (N / mm) was evaluated using the value normalized by the measured diameter (mm) of the sealant to the pressure (N). The results are shown in Table 3 below. The strength at which peeling occurred and the measured diameter of the sealant were as follows. Example 3-1: Strength: 16.6N, Diameter: 3.3mm Example 3-2: Strength: 15.4N, Diameter: 3.1mm Example 3-3: Strength: 15.9N, Diameter: 3.2mm • Example 3-4: Strength: 16.6N, Diameter: 3.3mm Examples 3-5: Strength: 14.9N, Diameter: 2.9mm • Example 3-6: Strength: 15.4N, Diameter: 3.1mm • Example 3-7: Strength: 16.4N, Diameter: 3.3mm Example 3-8: Strength: 15.6N, Diameter: 3.1mm Comparative example 3-1: Strength: 12.0N, diameter: 3.1mm Comparative Example 3-2: Strength: 8.6N, Diameter: 3.2mm Comparative example 3-3: Strength: 13.0N, diameter: 3.1mm Comparative example 3-4: Strength: 11.5N, diameter: 3.8mm

[0105] [Fabrication of liquid crystal cells for voltage retention rate evaluation] Liquid crystal cells were fabricated using the liquid crystal alignment agents (A-1) to (A-8) and (B-1) to (B-4) obtained above, following the procedure shown below. The liquid crystal alignment agent was spin-coated onto a glass substrate with ITO electrodes, dried on a hot plate at 70°C for 90 seconds, and then fired in an infrared heating furnace at 230°C for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm. Two substrates with this liquid crystal alignment film were prepared, and a 4 μm diameter bead spacer (JGC Catalysts & Chemicals, brass ball, SW-D1) was applied to the liquid crystal alignment film on one of the substrates, and a thermosetting sealant (Mitsui Chemicals, XN-1500T) was printed on it. Next, the other substrate was bonded to the first substrate with the side of the liquid crystal alignment film facing inward, and the sealant was cured to create an empty cell. Liquid crystal MLC-3023 (Merck) was injected into this empty cell by a vacuum injection method to fabricate a liquid crystal cell. Next, with a DC voltage of 15V applied to this liquid crystal cell, UV light with a wavelength of 325nm or less, passed through a cut filter, is applied from the outside of the liquid crystal cell at a rate of 10J / cm². 2 The cells were irradiated. The UV intensity was measured using an ORC UV-MO3A lamp. Subsequently, in order to deactivate any unreacted polymerizable compounds remaining in the liquid crystal cells, UV light (UV lamp: FLR40SUV32 / A-1) was irradiated for 30 minutes using a Toshiba Lighting & Technology UV-FL irradiation device without applying any voltage. The liquid crystal display elements obtained using the above liquid crystal alignment agents (A-1) to (A-8) and (B-1) to (B-4) all showed uniform liquid crystal alignment.

[0106] [Evaluation of voltage retention rate] Voltage retention rate was measured using a liquid crystal cell designed for evaluating voltage retention rate after UV irradiation. A voltage of 1V was applied for 60μsec in a 60°C hot air circulating oven, and the voltage was measured after 1667msec. The voltage retention rate was calculated based on how long the voltage was retained. A VHR-1 manufactured by Toyo Technica Co., Ltd. was used for measuring the voltage retention rate. A higher value indicates better performance. The results are shown in Table 3 below.

[0107] [Fabrication of liquid crystal cells for vertical alignment evaluation] Liquid crystal cells were fabricated using the liquid crystal alignment agents (A-5) to (A-8) obtained above, following the procedure shown below. A liquid crystal alignment agent was spin-coated onto the ITO surface of an ITO electrode substrate, which had an ITO electrode pattern with a pixel size of 100 μm × 300 μm and line / space of 5 μm. After drying on a 70°C hot plate for 90 seconds, it was fired in a 230°C infrared heating furnace for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm. Similarly, a liquid crystal alignment film with a thickness of 100 nm was formed by spin-coating an ITO electrode-attached glass substrate, drying on a 70°C hot plate for 90 seconds, and then firing in a 230°C infrared heating furnace for 20 minutes. These conditions for forming the liquid crystal alignment films will be referred to as "normal conditions" below. As a severe condition for evaluating the vertical alignment of the liquid crystal alignment film, a 100 nm thick liquid crystal alignment film was formed on each of the above substrates under the same conditions as normal, except that the firing conditions were changed to 60 minutes in an infrared heating furnace at 230°C. Two substrates with liquid crystal alignment films, fabricated under normal conditions, were prepared. A 4 μm diameter bead spacer (JGC Catalysts & Chemicals, brass ball, SW-D1) was applied to the liquid crystal alignment film on one of the substrates, and a thermosetting sealant (Mitsui Chemicals, XN-1500T) was printed onto it. Next, the other substrate was bonded to the first substrate with the liquid crystal alignment film facing inward, and the sealant was cured to create an empty cell. Liquid crystal MLC-3023 (Merck) was injected into this empty cell using a reduced-pressure injection method to create a liquid crystal cell. Then, with a DC voltage of 15V applied to this liquid crystal cell, UV light with a wavelength of 325 nm or less was applied from the outside of the liquid crystal cell at a rate of 10 J / cm² through a cut filter. 2The cells were irradiated. The UV intensity was measured using an ORC UV-MO3A. Subsequently, in order to deactivate any unreacted polymerizable compounds remaining in the liquid crystal cells, UV light (UV lamp: FLR40SUV32 / A-1) was irradiated for 30 minutes using a Toshiba Lighting & Technology UV-FL irradiation device without applying any voltage. Except for using a substrate with a liquid crystal alignment film fabricated under harsh conditions, the liquid crystal cells were fabricated and UV irradiation was performed in the same manner. Furthermore, all liquid crystal display elements obtained using the above liquid crystal alignment agents (A-5) to (A-8) exhibited uniform liquid crystal alignment.

[0108] [Evaluation of vertical orientation] The pre-tilt angle of the liquid crystal display element fabricated above was measured using Axostep (OptoScience Co., Ltd.). The difference in pre-tilt angle between normal conditions (20 minutes) and harsh conditions (60 minutes) (normal conditions - harsh conditions = Δpre-tilt) was calculated. A smaller Δpre-tilt indicates better vertical alignment of the liquid crystal alignment film. The results are shown in Table 3.

[0109] [Table 3]

[0110] As shown in Table 3, the examples using liquid crystal alignment films obtained from liquid crystal alignment agents containing a specific diamine as the diamine component showed superior rubbing resistance and high seal adhesion compared to the comparative examples using liquid crystal alignment films obtained from liquid crystal alignment agents that did not contain a specific diamine as the diamine component. Furthermore, the liquid crystal alignment films obtained from liquid crystal alignment agents using alicyclic acid dianhydrides as the tetracarboxylic acid component showed higher voltage retention and better vertical alignment compared to the case using aromatic acid dianhydrides.

Claims

1. A liquid crystal alignment agent characterized by containing at least one polymer (P) selected from the group consisting of a polyimide precursor obtained using a diamine component containing a diamine represented by the following formula (1) and a polyimide which is an imidized product of the polyimide precursor. 【Chemistry 1】 (In the formula, p represents an integer of 0 or 1.) When p is 0, L represents -(CH 2) n -O- (where n is an integer from 1 to 6), -(CH 2) n -C(=O)-NH- (where n is an integer from 1 to 6), or -O-(CH 2) n -O- (where n is an integer from 1 to 6). When p is 1, L represents -(CH 2 ) n -O- (where n is an integer from 1 to 6), -(CH 2 ) n -C(=O)-NH- (where n is an integer from 1 to 6), -(CH 2 ) n -O-C(=O)- (where n is an integer from 1 to 6), -(CH 2 ) n -C(=O)-O- (where n is an integer from 1 to 6), -O-(CH 2 ) n -O- (where n is an integer from 1 to 6), -C(=O)-O-(CH 2 ) n -O- (where n is an integer from 1 to 6), or -(CH 2 ) m -C(=O)-O-(CH 2 ) n- (where m and n are independently integers from 1 to 6). Any hydrogen atom of the benzene ring bonded to the OH group may be replaced with a methyl group, a methoxy group, or a halogen atom.

2. The liquid crystal alignment agent according to claim 1, wherein the diamine represented by formula (1) is a diamine represented by any of the following formulas (d1-1) to (d1-6) and (d1-9) to (d1-10). 【Chemistry 2】

3. The liquid crystal alignment agent according to claim 1, wherein the diamine represented by formula (1) is a diamine represented by any of the following formulas (d2-1) to (d2-4) and (d2-6). 【Transformation 3】

4. The liquid crystal aligning agent according to claim 1, wherein the polymer (P) is obtained by a polymerization reaction of the diamine component and a tetracarboxylic acid component containing an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride, or a derivative thereof.

5. The liquid crystal alignment agent according to claim 1, wherein the polymer (P) is obtained by a polymerization reaction of the diamine component and a tetracarboxylic acid component containing an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, or a derivative thereof.

6. The liquid crystal alignment agent according to claim 1, wherein the amount of the diamine represented by formula (1) used to obtain the polymer (P) is 5 mol% or more of the total diamine component.

7. The liquid crystal alignment agent according to claim 1, wherein the diamine component further comprises an aromatic diamine (d) represented by "A-X-J". (A represents a monovalent group in which two primary amino groups are bonded to an aromatic group. X represents a single bond, -(CH ２ ) ａ - (a is an integer from 1 to 15), -CONH-, -NHCO-, -CO-N(CH ３ )-, -NH-, -O-, -COO-, -OCO- or -((CH ２ ) ａ１ -A １ ) ｍ１ - (a1 is an integer from 1 to 15, A １ represents an oxygen atom or -COO-, and m1 is an integer between 1 and 2. When m1 is 2, a plurality of a1 and A １ each independently have the above definition.) are represented. J represents a monovalent organic group having at least one group selected from the group consisting of alicyclic hydrocarbon groups having 4 to 40 carbon atoms and aromatic hydrocarbon groups having 6 to 40 carbon atoms, wherein at least one of the hydrogen atoms in the alicyclic hydrocarbon group and aromatic hydrocarbon group is substituted with a substituent selected from the group consisting of halogen atoms, halogen atom-containing alkyl groups, halogen atom-containing alkoxy groups, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, alkenyl groups having 3 to 10 carbon atoms, and heteroatom-containing groups in which the carbon-carbon bond of any methylene group of a halogen atom-containing alkyl group, halogen atom-containing alkoxy group, alkyl group having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, and alkenyl groups having 3 to 10 carbon atoms is interrupted by an oxygen atom.

8. A liquid crystal alignment film obtained from a liquid crystal alignment agent according to any one of claims 1 to 7.

9. A liquid crystal display element comprising the liquid crystal alignment film described in claim 8.

10. A method for manufacturing a liquid crystal display element, comprising performing the following steps (1) to (3) in this order. Step (1): A step of applying the liquid crystal alignment agent according to any one of claims 1 to 7 onto at least one of a pair of substrates having a conductive film to form a coating film. Step (2): A step of firing the coating film. Step (3): A step to produce a liquid crystal cell by forming a liquid crystal layer between the pair of substrates.

11. A method for manufacturing a liquid crystal display element according to claim 10, further comprising performing the following step (4) after steps (1) to (3). Step (4): Step of irradiating the liquid crystal cell with light.

12. A diamine represented by the following formula (1). 【Chemistry 4】 (In the formula, p represents an integer of 0 or 1.) If p is 0, L represents -(CH 2) n -O- (where n is an integer from 1 to 6), or -(CH 2) n -C(=O)-NH- (where n is an integer from 1 to 6). When p is 1, L represents -(CH 2 ) n -O- (where n is an integer from 1 to 6), -(CH 2 ) n -C(=O)-NH- (where n is an integer from 1 to 6), -(CH 2 ) n -O-C(=O)- (where n is an integer from 1 to 6), -(CH 2 ) n -C(=O)-O- (where n is an integer from 1 to 6), -O-(CH 2 ) n -O- (where n is an integer from 1 to 6), -C(=O)-O-(CH 2 ) n -O- (where n is an integer from 1 to 6), or -(CH 2 ) m -C(=O)-O-(CH 2 ) n- (where m and n are independently integers from 1 to 6). Any hydrogen atom of the benzene ring bonded to the OH group may be replaced with a methyl group, a methoxy group, or a halogen atom.

13. The diamine according to claim 12, wherein p is 1.

14. A polymer obtained using a diamine component containing the diamine described in claim 12 or 13.

15. The polymer according to claim 14, wherein the polymer is a polyimide that is a polyimide precursor or an imidized product thereof obtained by a polycondensation reaction between the diamine component and the tetracarboxylic acid component.

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