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

Abstract

Provided is a liquid crystal alignment agent whereby a liquid crystal display element having a low incidence of display defects (line burn-in) is obtained even when negative-type liquid crystal is used as the liquid crystal material.　The present invention provides a liquid crystal alignment agent containing a polymer (A), a polymer (B), and a crosslinkable compound (C).　Polymer (A): A polyimide obtained by imidization of a polyimide precursor that is a product of reaction of a tetracarboxylic acid derivative component and a diamine compound containing a diamine represented by formula (d0) and a diamine represented by formula (dD).　Polymer (B): A polyimide precursor that is a product of reaction of a tetracarboxylic derivative component and a diamine component constituted from a diamine (dD'B) represented by "H-N(R)-YD'-N(R)-H" (YD' representing a divalent organic group having "-N(D')-" in the molecule thereof (where D' represents a protecting group dissociated by heating and replaced with a hydrogen atom), and R being synonymous with R in formula (dD)) and a diamine represented by formula (dB) (excluding the diamine (dD'B). However, the diamine precursor does not have an imide ring structure.　Crosslinkable compound (C): An epoxy-based compound represented by formula (En). (In formula (d0): the two Ar atoms each independently represent a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom on the ring may be substituted with a univalent group; and Lo represents -O-(-Ar'-O-)n- (where n is an integer of 0 to 3, Ar' represents a divalent benzene ring or a biphenyl structure, and any hydrogen atom on the ring may be substituted with a univalent group), -(CH2)n- (where n is an integer of 2 to 18), or a group in which at least a portion of the -CH2- groups of the –(CH2)n- are substituted with any of -O-, -C(=O)-, or -O-C(=O)-. In formula (dD), YD represents a divalent organic group having the group "-N(D)-" in the molecule thereof (where D represents a protecting group dissociated by heating and replaced with a hydrogen atom). In formulae (d0) and (dD), the plurality of R each independently represent a hydrogen atom or a univalent organic group.) (YB represents a divalent organic group that satisfies conditions (1) and (2), and R is synonymous with R in formula (d0.)　Condition (1): Not having a nitrogen-atom-containing structure selected from the group consisting of heterocycles including a nitrogen atom and secondary or higher amino groups (excluding amino groups derived from the group "-N(D')-" (where D' represents a protecting group dissociated by heating and replaced with a hydrogen atom)).　Condition (2): Not having a C6 or higher side-chain group in the molecule thereof. (In formula (En), a is an integer of 2 to 4, Ra is an a-valent organic group, and a bonding sites with N are aliphatic carbon atoms.)

Description

Technical Field

[0001] The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element.

Background Art

[0002] A liquid crystal display element is configured by sandwiching a liquid crystal layer between a pair of transparent substrates provided with electrodes. In the liquid crystal display element, an organic film made of an organic material is used as a liquid crystal alignment film so that the liquid crystal assumes a desired alignment state between the substrates. That is, the liquid crystal alignment film is a constituent member of the liquid crystal display element, is formed on the surface of the substrate sandwiching the liquid crystal that contacts the liquid crystal, and plays a role of aligning the liquid crystal in a certain direction between the substrates. Furthermore, the pretilt angle of the liquid crystal can be controlled by the liquid crystal alignment film. A method of lowering the pretilt angle by mainly selecting the structure of polyimide (see Patent Documents 1 and 2) and the like are known. In recent years, with the improvement in performance of liquid crystal display elements, in addition to applications such as large-screen and high-definition liquid crystal TVs, liquid crystal display elements are used in in-vehicle applications, for example, car navigation systems, meter panels, monitors for surveillance cameras and medical cameras, etc. From the demand for viewing angle characteristics, among the driving methods of liquid crystal molecules, the IPS method and the FFS method, which are excellent in viewing angle characteristics, are being studied, and a polyimide-based liquid crystal alignment film is also proposed for a rubbed alignment film (see Patent Document 3). In addition, in IPS method and FFS method liquid crystal display elements, static electricity is likely to accumulate in the liquid crystal cell, and these accumulated charges affect the display as disturbances in liquid crystal alignment and afterimages, significantly degrading the display quality of the liquid crystal display element. Therefore, there is a need for a liquid crystal alignment film that can reduce the generated charges in a short time and reduce the absolute value of the accumulated charges. In addressing these problems, Patent Document 4 proposes a liquid crystal aligning agent containing a polyamic acid or polyimide having a structural unit having an aromatic tetracarboxylic acid residue and a structural unit having an alicyclic tetracarboxylic acid residue, and Patent Document 5 proposes a liquid crystal aligning agent containing a polyimide precursor having a diphenylamine skeleton. In addition, in recent years, from the perspective of enhancing design characteristics, flexible liquid crystal elements using a PET film or a polycarbonate film as a base material have been studied, and a liquid crystal alignment film material suitable for a low-temperature firing process in which the firing temperature of the substrate when forming the liquid crystal alignment film is less than 200°C has been proposed (see Patent Document 6).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0005] In view of the above circumstances, the object of the present invention is to provide a liquid crystal alignment agent that can produce a liquid crystal display element with a low rate of display defects (line burn-in) even when a negative-type liquid crystal is used as the liquid crystal material. Furthermore, the object is to provide a liquid crystal alignment agent that can produce a liquid crystal alignment film with high liquid crystal alignment stability, a reduced absolute value of accumulated charge, and the ability to reduce the generated charge in a short time. Moreover, the object is to provide a liquid crystal alignment agent that can produce a liquid crystal alignment film in which film abrasion during alignment processing is suppressed in a low-temperature firing process of 200°C or below.

[0006] As a result of various studies to achieve the above objective, the inventors found that a liquid crystal alignment agent with the following configuration is optimal for achieving the above objective, and thus completed the present invention. [Means for solving the problem]

[0007] Thus, the present invention is based on the above findings and has the following gist. A liquid crystal alignment agent characterized by containing the following polymer (A), polymer (B), and crosslinkable compound (C). Polymer (A): Diamine represented by the following formula (d0) and the following formula (d DA polyimide obtained by imidizing a polyimide precursor which is a reaction product of a diamine component containing a diamine represented by Polymer (B): "H-N(R)-Y D’ -N(R)-H" (Y D’ represents a divalent organic group having a group "-N(D')-" (D' represents a protecting group which is eliminated by heating and replaced by a hydrogen atom) in the molecule. R has the same meaning as R in formula (d D ).) A polyimide precursor which is a reaction product of a diamine component composed of a diamine represented by (d D’B ) and a diamine represented by the following formula (d B ) (however, the diamine (d D’B ) is excluded.) and a tetracarboxylic acid derivative component. However, the polyimide precursor does not have an imide ring structure. Crosslinkable compound (C): An epoxy compound represented by the following formula (E n ). [Chemical formula] (In formula (d0), two Ars each independently represent a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom on the ring may be replaced by a monovalent group. L o is -O-(-Ar'-O-) n -(n is an integer from 0 to 3. Ar' represents a divalent benzene ring or a biphenyl structure, and any hydrogen atom on the ring may be replaced by a monovalent group. When there are a plurality of Ar', the plurality of Ar' may be the same or different.), -(CH2) n -(n is an integer from 2 to 18.), or a group in which at least a part of -CH2- of the -(CH2) n - is replaced by any one of -O-, -C(=O)- or -O-C(=O)-. In formula (d D ), Y D represents a divalent organic group having a group "-N(D)-" (D represents a protecting group which is eliminated by heating and replaced by a hydrogen atom) in the molecule. Formula (d0) and formula (d D(In this expression, each R independently represents either a hydrogen atom or a monovalent organic group.) [ka] (Y B R represents a divalent organic group that satisfies the following conditions (1) and (2). R is equivalent to R in the above formula (d0). Condition (1): Does not have a nitrogen atom-containing structure selected from the group consisting of a heterocycle containing a nitrogen atom and a secondary or tertiary amino group (excluding amino groups derived from the group "-N(D')-" (where D' represents a protecting group that is eliminated by heating and replaced by a hydrogen atom)). Condition (2): Does not have side chain groups with 6 or more carbon atoms. [ka] (a is an integer between 2 and 4, R a (It is an α-valent organic group, and the bonding sites with a number of N atoms are aliphatic carbon atoms.)

[0008] In this specification, Boc represents a tert-butoxycarbonyl group. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The imidization rate as used herein refers to the proportion of imide groups to the total amount of imide groups and carboxyl groups (or their derivatives) derived from tetracarboxylic dianhydride or its derivatives. [Effects of the Invention]

[0009] By using the liquid crystal alignment agent of the present invention, a liquid crystal display element with a low incidence of display defects (line burn-in) can be obtained even when a negative-type liquid crystal is used as the liquid crystal material. Furthermore, a liquid crystal alignment film can be obtained that exhibits high liquid crystal alignment stability, reduces the absolute value of accumulated charge, and reduces the generated charge in a short time. Moreover, since a liquid crystal alignment film with suppressed film abrasion during alignment processing can be obtained in a low-temperature firing process of 200°C or below, a liquid crystal display element with excellent display quality can be obtained. [Modes for carrying out the invention]

[0010] <Polymer (A)> The liquid crystal alignment agent of the present invention is a diamine represented by the above formula (d0) and the above formula (d D The material contains a polymer (A) which is a polyimide obtained by imidizing a polyimide precursor, which is a reaction product of a diamine component containing a diamine represented by ) and a tetracarboxylic acid derivative component. By adopting the above embodiment, the high-temperature treatment required for thermal imidization is eliminated. Furthermore, because it contains a specific diamine component, the resulting liquid crystal alignment film has high liquid crystal alignment stability and a low incidence of display defects (line burn-in) in the liquid crystal display element. The above polymer (A) is obtained by imidizing a polyimide precursor obtained from a tetracarboxylic acid derivative component containing a tetracarboxylic dianhydride and a diamine component containing a specific diamine. The imidization rate of the polyimide in polymer (A) is preferably 10 to 100% from the viewpoint of reducing the occurrence rate of labeling defects. Furthermore, the lower limit of the imidization rate is preferably 10%, more preferably 20%, even more preferably 50%, and most preferably 70%, while the upper limit of the imidization rate is preferably 100%, more preferably 99%, and even more preferably 95%.Specific examples of materials used in the production of polymer (A) and the production method are described in detail below.

[0011] The diamine component used in the production of polymer (A), which is a polyimide contained in the liquid crystal alignment agent of the present invention, is a diamine represented by the following formula (d0) and the following formula (d D It contains a diamine represented by the following formula (d0) and the following formula (d D Each of the diamines represented by ) may be used individually or in combination of two or more. [ka] (The definitions of each symbol in the formula are the same as above.)

[0012] In the above formula (d0), Ar and L oThe hydrogen atoms on the benzene ring, biphenyl structure, or naphthalene ring of the Ar' contained in may be substituted with, for example, halogen atoms, C1-C10 (more preferably C1-C5) alkyl groups, C2-C10 (more preferably C2-C5) alkenyl groups, C1-C10 (more preferably C1-C5) alkoxy groups, C1-C10 (more preferably C1-C5) fluoroalkyl groups, C2-C10 (more preferably C2-C5) fluoroalkenyl groups, C1-C10 (more preferably C1-C5) fluoroalkoxy groups, hydroxyl groups, C1-C10 (more preferably C1-C5) alkyloxycarbonyl groups, cyano groups, nitro groups, etc.

[0013] The diamine represented by the above formula (d0) is 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, the compounds represented by the following formulas (d0-1) to (d0-10), 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 At least one diamine selected from the group consisting of s(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 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-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, and 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine is preferred. [ka]

[0014] The above formula (d D The diamine represented by ) is preferably, from the viewpoint of suitably obtaining the effects of the present invention, an aromatic diamine having one aromatic ring in the molecule, wherein at least one of the hydrogen atoms on the aromatic ring is replaced by a monovalent group having the group "-N(D)-" (d n1 ), or an aromatic diamine having two aromatic rings in the molecule, wherein the two aromatic rings are a single bond, -CH2-, -C(CH3)2-, -O-, -C(=O)-, -OC(=O)-, -NR-C(=O)- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), -NR- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), or an alkyl group having 2 to 20 carbon atoms A divalent group selected from the group consisting of a kylene group and a divalent group in which any -CH2- of the alkylene group is replaced with -O-, -Si(CH3)2-, -C(=O)-, -OC(=O)-, -NR-C(=O)- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), or -NR- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D") (L n Aromatic diamine linked by (i) any hydrogen atom on the aromatic ring is replaced by a monovalent group having "-N(D)-", or (ii) the above divalent group (L n Aromatic diamines (d) have the group "-N(D)-" and satisfy at least one of the following conditions. n2 Examples of aromatic rings include benzene rings, naphthalene rings, and anthracene rings, with benzene rings and naphthalene rings being preferred, and benzene rings being more preferred. Furthermore, any hydrogen atom on the aromatic ring may be replaced with a monovalent organic group having 1 to 5 carbon atoms containing a hydroxyl group, a C1-C5 alkyl group, a C1-C5 alkoxy group, a carboxyl group, a halogen atom, or a fluorine atom, or with a monovalent organic group in which some of the hydrogen atoms on the C1-C5 alkyl group are replaced with hydroxyl groups.

[0015] The D in the group "-N(D)-" represents a protecting group that is removed by heating and replaced by a hydrogen atom. It is not particularly limited to any organic group that is converted to the group "-NH-" by decomposition and removal by heat. Examples of organic groups D that can be removed by heat include carbamate-type organic groups such as the benzyloxycarbonyl group, 9-fluorenylmethyloxycarbonyl group, allyloxycarbonyl group, and tertiary butoxycarbonyl group (tert-butoxycarbonyl group). However, the tertiary butoxycarbonyl group is particularly preferred from the standpoint of efficient removal by heat, removal at relatively low temperatures, and emission as a harmless gas upon removal.

[0016] The above formula (d D The diamine represented by the following formula (d D -1)~(d D A diamine selected from -7) is preferred. [ka] (Formula(d D -2), formula (d D -6) and formula (d D -7) In this case, R represents a hydrogen atom or a tert-butoxycarbonyl group.

[0017] The preferred content of the diamine represented by the above formula (d0) is preferably 50 to 95 mol%, and more preferably 50 to 90 mol%, relative to the total amount of the diamine component used in the production of polymer (A).

[0018] The above formula (d D The preferred content of the diamine in the polymer (A) is preferably 5 to 50 mol%, and more preferably 10 to 50 mol%, relative to the total amount of the diamine components used in the production of polymer (A).

[0019] The diamine component used in the production of polymer (A) contained in the liquid crystal alignment agent of the present invention can be any of the diamines mentioned above, or any other diamines (hereinafter also referred to as "other diamine 1"), depending on the desired properties of the liquid crystal alignment agent. Each of the above-mentioned other diamines 1 may be used individually or in combination of two or more. Other diamines 1 include 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, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, 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 phenyl, 4,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,2'-diaminobiphenyl, 2,3'-diaminobiphenyl, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-sulfonyldianiline, 3,3'-sulfonyldi Aniline, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 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; diamines having photo-orienting groups such as 4,4'-diaminoazobenzene or diaminotran; diamines having photopolymerizable groups at the terminal, such as 2-(2,4-diaminophenoxy)ethyl methacrylate or 2,4-diamino-N,N-diallylaniline; 1-(4-(2-(2,4-diaminophenoxy) Diamines with radical polymerization initiator functions such as toxy)phenyl)-2-hydroxy-2-methylpropanone and 2-(4-(2-hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate; diamines with amide bonds such as 4,4'-diaminobenzanilide; diamines with urea bonds such as 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, and 1,3-bis(4-aminophenethyl)urea; 2,2'-bis[4-(4-aminophenoxy)phenoxy [L]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoropropane, 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, 1,4-bis (4-aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diaminocarbazole, N-(3-(1H-imidazole-1-yl)propyl-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,[5-dihydro-4-methyl-2-oxazolyl]-benzeneamine, or heterocyclic diamines such as those represented by formulas (z-1) to (z-13) below, or diamines having a diphenylamine structure such as 4,4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4-benzenediamine. Diamines having at least one nitrogen atom-containing structure selected from the group consisting of a heterocyclic ring containing a nitrogen atom, a secondary or tertiary amino group (excluding amino groups derived from the group "-N(D)-" (where D represents a protecting group that is eliminated by heating and replaced by a hydrogen atom); hereinafter also referred to as a specific nitrogen atom-containing structure); 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6-diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl 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' -Diamines having a carboxyl group such as 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenyl ether-3,3'-dicarboxylic acid; 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; cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, 3,Examples include diamines having a steroid skeleton such as cholestanil 5-diaminobenzoate, cholestenyl 3,5-diaminobenzoate, lanostanil 3,5-diaminobenzoate, and 3,6-bis(4-aminobenzoyloxy)cholestane; diamines represented by the following formulas (V-1) to (V-2); diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane; acyclic aliphatic diamines such as metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine; alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, and 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 International Publication No. 2018 / 117239. , [ka] [ka] [ka] (In equation (V-1), m and n are integers from 1 to 3 (where 1 ≤ m + n ≤ 4), and j is an integer of 0 or 1, X 1 is, -(CH2) a -(a is an integer from 1 to 15), -CONH-, -NHCO-, -CO-N(CH3)-, -NH-, -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-, 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. In formula (V-2), X 2 R represents -O-, -CH2O-, -CH2-OCO-, -COO-, or -OCO-. 2 This represents alkyl groups containing fluorine atoms with 1 to 20 carbon atoms, and alkyl groups with 3 to 20 carbon atoms. In the above formula, m, n, X 1 , R 1 If two such entities exist, each independently possesses the above definition.

[0020] The above formulas (d0) and (d D When using other diamine 1 in addition to the diamine of ), the amount of other diamine 1 used is preferably 5 to 40 mol%, more preferably 10 to 40 mol%, relative to the total diamine components used in the production of polymer (A). Also, the above formulas (d0) and (d D The total diamine content of the polymer (A) is preferably 95 mol% or less, and more preferably 90 mol% or less, relative to the total diamine components used in the production of polymer (A).

[0021] <Tetracarboxylic acid derivatives> The tetracarboxylic acid derivative component used in the production of polymer (A) of the present invention may include not only tetracarboxylic dianhydrides but also their derivatives, such as tetracarboxylic dihalide compounds, tetracarboxylic dialkyl esters, and tetracarboxylic dialkyl ester dihalides. The tetracarboxylic acid derivative component may be a single tetracarboxylic dianhydride or its derivative, or two or more may be used in combination.

[0022] Specific examples of the tetracarboxylic dianhydride or its derivatives include acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, or derivatives thereof. In particular, from the viewpoint of suitably obtaining the effects of the present invention, it is more preferable to include a tetracarboxylic dianhydride or derivative thereof (hereinafter collectively referred to as a tetracarboxylic derivative having a specific substructure) 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 it is even more preferable to include a tetracarboxylic dianhydride or 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. Aromatic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the aromatic ring. Acyclic aliphatic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups bonded to a chain-like hydrocarbon structure. However, they do not need to consist solely of chain-like hydrocarbon structures; they may also contain alicyclic or aromatic ring structures as part of their structure. Alicyclic tetracarboxylic dianhydrides are acidic dianhydrides obtained by intramolecular dehydration of four carboxyl groups, including at least one carboxyl group bonded to the alicyclic structure. However, none of these four carboxyl groups are bonded to an aromatic ring. Furthermore, they do not need to consist solely of alicyclic structures; they may also contain a chain-like hydrocarbon structure or an aromatic ring structure as part of their composition. The tetracarboxylic acid derivative components that can be used in the synthesis of the polymer (A) above preferably include the following tetracarboxylic dianhydrides or their derivatives (hereinafter collectively referred to as specific tetracarboxylic acid derivatives).

[0023] 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] Octane-2:4,6:8-dianhydride and other alicyclic tetracarboxylic dianhydrides; pyromellitic acid 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, Aromatic tetracarboxylic dianhydrides such as 2',3,3'-biphenyltetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, ethylene glycol bisanhydrotrimate, 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.

[0024] More 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-di Fluoro-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-di Xotetrahydrofuran-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.

[0025] The proportion of the tetracarboxylic acid derivative having the above-mentioned specific substructure or the 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, relative to the total tetracarboxylic acid derivative component used.

[0026] <Polymer (B)> The liquid crystal alignment agent of the present invention is "HN(R)-Y D’ -N(R)-H" (Y D’ R represents a divalent organic group having the group "-N(D')-" (where D' represents a protecting group that is removed by heating and replaced by a hydrogen atom) within the molecule. D This is synonymous with R in ). Diamine (d D’B ) and the above formula (d B ) represented by diamine (however, diamine (d D’B It contains polymer (B), which is a polyimide precursor that is a reaction product of a diamine component composed of ( ) and a tetracarboxylic acid derivative component. However, polymer (B) does not have an imide ring structure. The diamine component used in the production of polymer (B) is the above-mentioned diamine (d D’B By including polymer (B), it becomes possible to unevenly distribute polymer (B) within the polyimide layer derived from polymer (A) when forming a liquid crystal alignment film. Therefore, the film strength improvement effect of polymer (B) is enhanced, and film abrasion during alignment processing is suppressed. Furthermore, the diamine component used in the production of polymer (B) is the above formula (d B It contains a diamine represented by ). Here, the diamine (d B The divalent organic group Y contained in ) B It satisfies the above conditions (1) and (2). By adopting the configuration of condition (1), the basicity of the polymer is reduced, and the thermal imidation reaction of polymer (B) is suppressed, making it possible to obtain a liquid crystal alignment film with high film strength. Furthermore, by adopting the configuration of condition (2), the alignment restricting force of the liquid crystal is increased in the IPS method and FFS method, making it possible to improve the alignment stability of the obtained liquid crystal alignment film. Here, a divalent organic group having a nitrogen atom-containing structure selected from the group consisting of a heterocycle containing a nitrogen atom and a secondary or tertiary amino group (excluding amino groups derived from the group "-N(D')-") is given the group "-NHR" (R is the above formula (d BThis is synonymous with R in ). Examples of diamines in which two ) are bonded include diamines having a specific nitrogen atom-containing structure as exemplified in the other diamine 1 of polymer (A) above.

[0027] The above formula (d B The diamines represented by ) are preferably aromatic diamine (I) having one benzene ring; diamine (II-a) having two benzene rings linked by a single bond; and aromatic diamine (II-b) having two benzene rings linked by a divalent group, wherein the divalent group is an oxygen atom or an organic group having 1 to 3 carbon atoms and is bonded to the two benzene rings by the same atom. However, aromatic diamine (I), aromatic diamine (II-a), and aromatic diamine (II-b) are the same as the above diamine (d D’B A diamine other than the above, that satisfies conditions (1) and (2). The above formula (d B A more preferred specific example of a diamine represented by formula (d) described later is MDiamines represented by the above formulas (d0-1) to (d0-10), compounds represented by the above formulas (d0-1) to (d0-10), 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-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, and 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 1,4-bis(4-aminophenyl)benzene, 1,3- Examples include bis(4-aminophenyl)benzene, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 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, diamines having the above photo-directing group, diamines having the above amide bond, diamines having the above urea bond, or 1,4-bis(4-aminobenzyl)benzene.

[0028] The above diamine (d D’B ) Specific examples include the above diamine (d D Examples of diamines include those exemplified in ). The above diamines (d D’B ) may be used individually or in combination of two or more types. Furthermore, specific examples of D' in the base "-N(D')-" include the structures exemplified by D in the base "-N(D)-" above, including preferred embodiments. The above formula (d D’B The preferred content of the diamine in polymer (B) is preferably 5 to 40 mol%, and more preferably 10 to 40 mol%, relative to the total diamine components of the diamine component used in the production of polymer (B).

[0029] The diamine component used in the production of polymer (B) is, from the viewpoint of suitably obtaining the effects of the present invention, the following formula (d M It is preferable that the diamine represented by ) is included. [ka] (L M L represents a single bond, -CH2-, -CO-, -O-, or -C(CH3)2-. M ' is a single bond or -(CH2) m -(m is an integer between 1 and 2). M represents a divalent benzene ring, and any hydrogen atom on the ring may be replaced by a monovalent group. M If multiple Ar M The Rs may be the same or different. Each of the multiple Rs independently represents a hydrogen atom or a monovalent organic group. n is an integer between 0 and 1.

[0030] Ar M The hydrogen atoms on the benzene ring may be substituted with halogen atoms, C1-C5 alkyl groups, C2-C5 alkenyl groups, C1-C5 alkoxy groups, C1-C5 fluoroalkyl groups, C2-C5 fluoroalkenyl groups, C1-C5 fluoroalkoxy groups, hydroxyl groups, C1-C5 alkyloxycarbonyl groups, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, etc.

[0031] The above formula (d MPreferred specific examples of diamines represented by ) include 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, 3-aminobenzylamine, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2-(6-aminonaphthyl)ethylamine, 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'-di Examples include fluoro-4,4'-diaminobiphenyl, 2,2'-ditrifluoromethyl-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, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 4,4'-diaminobenzophenone, and other diamines having the carboxyl group described in Diamine 1. Among these, p-phenylenediamine, m-phenylenediamine, 3-aminobenzylamine, 4-aminobenzylamine, 2-(4-aminophenyl)ethylamine, 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminobenzophenone, and 4,4'-diaminodiphenyl ether are more preferred.

[0032] The above diamine (d M ) may be used individually or in combination of two or more types. The above formula (d M The preferred content of the diamine in polymer (B) is preferably 60 to 95 mol%, and more preferably 60 to 90 mol%, of the total diamine components used in the production of polymer (B).

[0033] The diamine component used in the production of polymer (B) is the above-mentioned diamine (d D’B ) and diamine (d M Other diamines (hereinafter also referred to as other diamine 2) may be used. Specific examples of other diamine 2 include diamine components for obtaining the polymer (A) above, which satisfy conditions (1) and (2) above.

[0034] Specific examples of tetracarboxylic acid derivative components used in the production of polymer (B) include, including preferred examples, compounds similar to those exemplified in polymer (A). More preferably, the tetracarboxylic acid derivative component used in the production of polymer (B) is a tetracarboxylic acid derivative having the specific substructure or a specific tetracarboxylic acid derivative, and most preferably a more preferred example of the specific tetracarboxylic acid derivative. Furthermore, it is preferable that the tetracarboxylic acid derivative having the specific substructure or the specific tetracarboxylic acid derivative be contained in 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more, relative to the total tetracarboxylic acid derivative components used in the production of polymer (B). Furthermore, from the viewpoint of obtaining a liquid crystal alignment film that can reduce the absolute value of accumulated charge while reducing the generated charge in a short time, the tetracarboxylic acid derivative component used in the production of polymer (B) preferably contains the aromatic tetracarboxylic acid dianhydride or its derivative, and among these, a tetracarboxylic acid dianhydride or its derivative having a benzene ring structure is preferred. More preferably, it is an aromatic tetracarboxylic acid dianhydride or its derivative exemplified in the specific tetracarboxylic acid derivatives above. The tetracarboxylic acid derivative component used in the production of polymer (A) and the tetracarboxylic acid derivative component used in the production of polymer (B) may be the same or different.

[0035] From the viewpoint of suitably obtaining the effects of the present invention, the content ratio of polymer (A) to polymer (B) is preferably 10 / 90 to 90 / 10 in mass ratio of [polymer (A)] / [polymer (B)], more preferably 20 / 80 to 90 / 10, and even more preferably 20 / 80 to 80 / 20.

[0036] <Methods for producing polymer (A) and polymer (B)> Polyimide precursors, such as polyamic acid or polyamic acid esters, used in the production of polymers (A) and (B) contained in the liquid crystal alignment agent of the present invention can be synthesized, for example, by the following method.

[0037] (Synthesis of polyamic acids) The synthesis of polyamic acids is carried out by reacting a diamine component containing the above-mentioned diamine with a tetracarboxylic acid derivative 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 the proportion of 0.5 to 2 equivalents, and more preferably 0.8 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.

[0038] 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, solvents such as 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.

[0039] (Synthesis of polyamic acid esters) 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.

[0040] (Synthesis of polyimides) Polyimide can be obtained by ring-closing (imidization) the above-mentioned polyimide precursor. Methods for imidizing the polyimide precursor include thermal imidization, in which the solution of the polyimide precursor is heated directly, and catalytic imidization, in which a catalyst is added to the solution of the polyimide precursor.

[0041] The temperature used for thermal imidization of polyimide precursors in solution is typically 100 to 400°C, preferably 120 to 250°C, and it is preferable to remove the water produced by the imidization reaction from the system.

[0042] 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 a temperature preferably of -20 to 250°C, more preferably of 0 to 180°C. The amount of basic catalyst is preferably 0.5 to 30 molar times, more preferably 2 to 20 molar times, of the amic acid groups, and the amount of acid anhydride is preferably 1 to 50 molar times, more preferably 3 to 30 molar times, of the amic acid groups. Examples of basic catalysts include pyridine and triethylamine. Examples of acid anhydrides include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. The imidation rate by catalytic imidation can be controlled by adjusting the amount of catalyst, reaction temperature, and reaction time.

[0043] To recover the polyimide precursor or polyimide from the reaction solution of the polyimide precursor or polyimide, the reaction solution can be added to 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.

[0044] 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.

[0045] <End capping agent> In synthesizing the polyimide precursor or polyimide in the present invention, a tetracarboxylic acid derivative component containing tetracarboxylic dianhydride or its derivative, and a diamine component containing the above-mentioned 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 liquid crystal alignment film obtained by the coating film and improving the adhesion between the sealant and the alignment 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.

[0046] 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.

[0047] 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.

[0048] <Liquid crystal alignment agent> The liquid crystal alignment agent of the present invention contains polymer (A) and polymer (B) and a crosslinkable compound (C) described later. In addition to polymer (A) and polymer (B), the liquid crystal alignment agent of the present invention may also contain other polymers. Examples of other polymers include polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene or its derivatives, poly(styrene-phenylmaleimide) derivative, and poly(meth)acrylate. Other polymers may be used individually or in combination of two or more. The content of other polymers is preferably 30 parts by mass or less, more preferably 1 to 25 parts by mass, and even more preferably 1 to 20 parts by mass, based on 100 parts by mass of the total polymers contained in the liquid crystal alignment agent.

[0049] Liquid crystal alignment agents are used to produce liquid crystal alignment films, and from the viewpoint of forming a uniform thin film, they take the form of a coating solution. In the liquid crystal alignment agent of the present invention, it is preferable that it is in the form of a coating solution containing the polymer component and an organic solvent as described above.

[0050] The organic solvent contained in the above coating solution is not particularly limited as long as it uniformly dissolves the polymer components, and examples include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyllactamide, N,N-dimethylpropionamide, tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ-butyrolactone, γ-valerolactone, 1,3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, and cyclopentanone. Examples include 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, N-(n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)-2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, and N-cyclohexyl-2-pyrrolidone (collectively referred to as "good solvents"). Among these, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, or γ-butyrolactone are preferred. The content of good solvent is preferably 20 to 99% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass.

[0051] Furthermore, the organic solvent contained in the liquid crystal alignment agent is preferably a mixed solvent that includes, in addition to the above-mentioned solvent, a solvent (also called a poor solvent) that improves the coatability and surface smoothness of the coating film when applying the liquid crystal alignment agent. Specific examples of poor solvents used in combination are listed below, but are not limited to these. The content of the poor solvent is preferably 1 to 80% by mass of the total solvent contained in the liquid crystal alignment agent, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass. The type and content of the poor solvent are appropriately selected depending on the coating apparatus, coating conditions, and coating environment of the liquid crystal alignment agent.

[0052] Examples of poor solvents include diisopropyl ether, diisobutyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, 4-hydroxy-4-methyl-2-pentanone, diethylene glycol methyl ethyl ether, diethylene glycol dibutyl ether, 3-ethoxybutyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, ethylene glycol monoacetate, ethylene glycol diacetate, propylene carbonate, ethylene carbonate, ethylene glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, and 1-(2-butoxyethoxy)-2-propanol , 2-(2-butoxyethoxy)-1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, 2-(2-ethoxyethoxy)ethyl acetate, diethylene Examples include glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether acetate, cyclohexyl acetate, 4-methyl-2-pentyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, n-butyl lactate, isoamyl lactate, diethylene glycol monoethyl ether, and diisobutyl ketone (2,6-dimethyl-4-heptanone).

[0053] Among these, diisobutylcarbinol, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, or diisobutyl ketone are preferred.

[0054] Preferred solvent combinations of good and poor solvents 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-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, and N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether. Glycol diacetate, N,N-dimethyllactamide and diisobutyl ketone, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monobutyl ether Propyl ether, N-ethyl-2-pyrrolidone and ethyl 3-ethoxypropionate and diethylene glycol monopropyl ether, N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate, N-ethyl-2-pyrrolidone and dipropylene glycol dimethyl ether, N,N-dimethyllactamide and ethylene glycol monobutyl ether, N,N-dimethyllactamide and propylene glycol diacetate, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether, N-ethyl-2 - Pyrrolidone and diethylene glycol monoethyl ether and butyl cellosolve acetate, N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether and butyl cellosolve acetate, N,N-dimethyllactamide and diethylene glycol diethyl 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-ethyl-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 diisobutyl ketone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol 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, N-ethyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol dimethyl ether, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and diisobutyl ketone, 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 diisobutyl ketone, N-methyl-2- Roridone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisobutylcarbinol, 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, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and dipro Pyrene glycol monomethyl ether, N-ethyl-2-pyrrolidone and diethylene glycol diethyl ether and dipropylene glycol monomethyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and propylene glycol diacetate, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether and diisobutyl ketone, N-ethyl-2-pyrrolidone and γ-butyrolactone and diisobutyl ketone, N-ethyl-2-pyrrolidone and N,N-dimethyllactamide and diisobutyl ketone,N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether and ethylene glycol monobutyl ether acetate, γ-butyrolactone and ethylene glycol monobutyl ether acetate and dipropylene glycol dimethyl ether, N-ethyl-2-pyrrolidone and ethylene glycol monobutyl ether acetate and propylene glycol dimethyl ether, N-methyl-2-pyrrolidone and 4-methyl-2-pentyl acetate and ethylene glycol monobutyl ether, N-ethyl-2-pyrrolidone and cyclohexyl acetate and diacetone alcohol, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monomethyl ether, N-methyl-2-pyrrolidone and cyclohexanone and propylene glycol monomethyl ether, tetramethylurea and 4-hydroxy-4-methyl-2-pentanone, tetramethylurea and propylene glycol diacetate, N Examples include 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, 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,N-diethylformamide and 4-hydroxy-4-methyl-2-pentanone, and N,N-diethylformamide and propylene glycol monomethyl ether.

[0055] <Crosslinkable compound (C)> The liquid crystal alignment agent of the present invention contains the above-mentioned crosslinkable compound (C). In this embodiment, the crosslinking reaction with the epoxy crosslinking agent proceeds during firing, thereby suppressing the thermal imidation reaction, i.e., the thermal imidation reaction of the imide precursor contained in the polymer (B) component. As a result, the resulting liquid crystal alignment film has a reduced imidized structure, thus providing a liquid crystal alignment film that can reduce the absolute value of accumulated charge while simultaneously reducing the generated charge in a short time. The content of the crosslinkable compound (C) in the liquid crystal alignment agent of the present invention is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent. Specific examples of the above crosslinkable compound (C) include 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, and bis(N,N-diglycidyl-3-methyl -4-aminocyclohexyl)methane, 1,3-bis(N,N-diglycidylaminomethyl)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, 1,3,5-tris(N,N-diglycidylaminomethyl)benzene, the following formula (E N -1)~(E N Examples include compounds represented by -5). The crosslinkable compound (C) may be used alone or in combination of two or more.

[0056] [ka]

[0057] The liquid crystal alignment agent of the present invention may additionally contain components other than polymers (A), (B), and crosslinkable compound (C) (hereinafter also referred to as additive components). Examples of such additive components include adhesion aids to improve the adhesion between the liquid crystal alignment film and the substrate, and the adhesion between the liquid crystal alignment film and the sealant, compounds other than the crosslinkable compound (C) to improve the strength of the liquid crystal alignment film (hereinafter also referred to as other crosslinkable compounds), dielectric or conductive materials to adjust the dielectric constant and electrical resistance of the liquid crystal alignment film, and imidization accelerators.

[0058] Other crosslinkable compounds mentioned above include crosslinkable compound (C1), which is a compound having an oxiranil group other than crosslinkable compound (C); crosslinkable compound (C2), which is a compound having at least one substituent selected from an oxetanyl group, a blocked isocyanate group, an oxazoline group, a cyclocarbonate group, a hydroxyl group, and an alkoxy group; and crosslinkable compound (C3), which is a compound having a polymerizable unsaturated group.

[0059] Specific examples of the above crosslinkable compound (C1) include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromo neopentyl glycol diglycidyl ether, 1,3,5,6-tetraglycidyl-2,4-hexanediol, bisphenol A type epoxy resins such as jER828 (manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins such as jER807 (manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A type epoxy resins such as YX-8000 (manufactured by Mitsubishi Chemical Corporation), and biphenyl skeleton-containing epoxy resins such as YX6954BH30 (manufactured by Mitsubishi Chemical Corporation). , phenol novolac type epoxy resins such as EPPN-201 (manufactured by Nippon Kayaku Co., Ltd.), (o,m,p-) cresol novolac type epoxy resins such as EOCN-102S (manufactured by Nippon Kayaku Co., Ltd.), triglycidyl isocyanurates such as TEPIC (manufactured by Nissan Chemical Corporation), alicyclic epoxy resins such as Celoxide 2021P (manufactured by Daicel Chemical Industries, Ltd.), N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N'-tetraglycidyl Examples include lysidyl-2,2'-dimethyl-4.4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, tetrakis(glycidyloxymethyl)methane, as well as compounds described in paragraph

[0037] of Japanese Patent Publication No. 10-338880 and compounds described in International Publication No. 2017 / 170483. Specific examples of the above crosslinkable compounds (C2) and (C3) include compounds having two or more oxetanyl groups as described in paragraphs

[0170] to

[0175] of International Publication No. 2011 / 132751; Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (all manufactured by Tosoh Corporation), Takenate B-830, B-815N, B-8 Compounds having a blocked isocyanate group such as 20NSU, B-842N, B-846N, B-870N, B-874N, B-882N (all manufactured by Mitsui Chemicals, Inc.); 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(5-methyl-2-oxazoline), 1,2,4-tris-(2-oxazolinyl-2)-benzene, Epocross (Japan) Compounds having an oxazoline group, such as those manufactured by Catalysts Inc.; compounds having a cyclocarbonate group as described in paragraphs

[0025] to

[0030] and

[0032] of International Publication No. 2011 / 155577; compounds having a hydroxyl or alkoxy group, 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, and glycerol Examples include 1,3-diglycerolate di(meth)acrylate, pentaerythritol 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.

[0060] The above compounds are examples of crosslinkable compounds and are not limited to these. For example, other components disclosed on pages 53

[0105] to 55

[0116] of International Publication No. 2015 / 060357 may be included. Furthermore, two or more crosslinkable compounds may be combined.

[0061] The content of the crosslinkable compounds (C1) to (C3) in the liquid crystal alignment agent of the present invention is preferably 0.5 to 20 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal alignment agent.

[0062] Examples of the adhesion aids mentioned above 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, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxy Examples of functional silane compounds include propyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris(3-trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-isocyanatetopropyltriethoxysilane. When using a functional silane compound, its content 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.

[0063] 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 0.5 to 15% by mass, more preferably 1 to 10% by mass. The preferred range of solid content concentration varies depending on the method used to coat the substrate with the liquid crystal alignment agent. For example, in the case of the spinner method, a solid content concentration in the range of 1.5 to 4.5 mass% is particularly preferred. In the case of the printing method, a solid content concentration in the range of 3 to 9 mass% is particularly preferred, resulting in a solution viscosity in the range of 12 to 50 mPa·s. In the case of the inkjet method, a solid content concentration in the range of 1 to 5 mass% is particularly preferred, resulting in a solution viscosity in the range of 3 to 15 mPa·s.

[0064] <Liquid crystal alignment film / Liquid crystal display element> 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 for horizontal alignment type or vertical alignment type (VA type) liquid crystal alignment films, but is particularly suitable for horizontal alignment type liquid crystal display elements such as IPS type or FFS type. The liquid crystal display element of the present invention comprises the above-mentioned liquid crystal alignment film. The liquid crystal display element of the present invention can be manufactured, for example, by a method including the following steps (1) to (3). (1) Process of applying liquid crystal alignment agent onto the substrate The liquid crystal alignment agent of the present invention is applied to one surface of a substrate on which a patterned transparent conductive film is provided, using an appropriate coating method such as a roll coater, spin coat, printing, or inkjet method. The substrate is not particularly limited as long as it is a highly transparent substrate, and in addition to glass substrates and silicon nitride substrates, plastic substrates such as acrylic substrates and polycarbonate substrates can also be used. Furthermore, in reflective liquid crystal display elements, an opaque material such as a silicon wafer can be used for only one side of the substrate, and in this case, a light-reflecting material such as aluminum can be used for the electrodes. In addition, when manufacturing IPS or FFS type liquid crystal display elements, a substrate on which electrodes made of a comb-shaped patterned transparent conductive film or metal film are provided and a counter substrate on which no electrodes are provided are used. (2) Process of firing the coating film After coating with a liquid crystal alignment agent, preheating (pre-bake) is preferably performed first to prevent dripping of the coated liquid crystal alignment agent. The pre-bake temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The pre-bake time is preferably 0.25 to 10 minutes, and more preferably 0.5 to 5 minutes. Then, it is preferable to perform a further heating (post-bake) step. The post-bake temperature is preferably 80 to 200°C, and more preferably 120 to 180°C. The post-bake time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The film thickness of the film formed in this way is preferably 5 to 300 nm, and more preferably 10 to 200 nm.

[0065] The coating film formed in step (1) or (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.

[0066] 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. (3) Process for manufacturing liquid crystal cells Two substrates with liquid crystal alignment films formed on them as described above are prepared, and liquid crystal is placed between the two substrates which are placed opposite each other. Specifically, the following two methods can be used. In the first method, the two substrates are first placed opposite each other with a gap (cell gap) in between so that their respective liquid crystal alignment films face each other. Next, the periphery of the two substrates is bonded together using a sealant, and the liquid crystal composition is 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.

[0067] 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 over 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. When a rubbing treatment is performed on the coating film, the two substrates are positioned opposite each other so that the rubbing directions in each coating film are at a predetermined angle to each other, for example, orthogonal or antiparallel. As a sealant, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and spacer can be used. The liquid crystal composition is not particularly limited, and is a composition containing at least one liquid crystal compound (liquid crystal molecule), and examples include a liquid crystal composition exhibiting a nematic phase (hereinafter also called a nematic liquid crystal), a liquid crystal composition exhibiting a smectic phase, and a smectic liquid crystal composition, among which nematic liquid crystals are preferred. In addition, various liquid crystal compositions with positive or negative dielectric anisotropy can be used. Hereinafter, 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). Furthermore, the above liquid crystal composition may further contain 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, MLC-3019, and MLC-7081. Examples of negative-type LCDs include the MLC-6608, MLC-6609, MLC-6610, MLC-7026, or MLC-7026-100, all manufactured by Merck. Another example of a liquid crystal containing a polymerizable compound is MLC-3023 manufactured by Merck.

[0068] Then, a liquid crystal display element can be obtained by laminating a polarizing plate to the outer surface of the liquid crystal cell as needed. Examples of polarizing plates to be laminated to 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.

[0069] The liquid crystal alignment film of the present invention can be applied to a variety of applications other than the liquid crystal alignment film used in the above-mentioned applications. For example, it can be used as a liquid crystal alignment film for phase difference films, for scanning antennas and liquid crystal array antennas, or for transmission-scattering type liquid crystal dimming elements. Furthermore, it can also be used in applications other than liquid crystal alignment films, such as protective films (e.g., protective films for color filters), spacer films, interlayer insulating films, anti-reflective films, wiring coating films, anti-static films, and motor insulating films (gate insulating films for flexible displays).

[0070] 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. [Examples]

[0071] The present invention will be further described with reference to the following examples, but the present invention is not limited to these. The abbreviations for the compounds and the methods for measuring each property below are as follows. (Diamine) [ka]

[0072] (Tetracarboxylic acid dianhydride) [ka]

[0073] (Crosslinkable compound) [ka]

[0074] (Adhesion enhancer) [ka]

[0075] (Terminal encapsulant) [ka]

[0076] (organic solvent) NMP:N-methyl-2-pyrrolidone GBL: γ-Butyrolactone BCS: Butyl cellosolve (ethylene glycol monobutyl ether)

[0077] <Measurement of Imidification Rate> 20 mg of polyimide powder was placed in an NMR sample tube (NMR sampling tube standard, φ5 (manufactured by Kusano Science Co., Ltd.)), and 0.53 mL of deuterated dimethyl sulfoxide (DMSO-d6, 0.05% TMS (tetramethylsilane) mixture) was added. The solution was then completely dissolved by sonication. The 500 MHz proton NMR of this solution was measured using an NMR analyzer (JNW-ECA500) (manufactured by JEOL Datum Corporation). The imidation rate was determined by using the following formula, with a reference proton derived from a structure that does not change before and after imidation, and the sum of the peak values ​​of this proton and the sum of the proton peaks derived from the NH group of the amide acid that appears around 9.5 ppm to 10.0 ppm. Imidization rate (%) = (1 - α·x / y) × 100 In the above formula, x is the integrated value of proton peaks derived from the NH group of the amide acid, y is the integrated value of the reference proton peaks, and α is the ratio of the number of reference protons to one NH group proton of the amide acid in the case of a polyamide acid (imidization rate of 0%).

[0078] [Synthesis of polymers] <Synthesis Example 1> In a 300 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 8.60 g (35.2 mmol) of DA-2, 5.34 g (9.59 mmol) of DA-4, and 7.65 g (19.1 mmol) of DA-3 were weighed out. NMP was added to achieve a solid content concentration of 12% by mass, and the mixture was stirred while supplying nitrogen to dissolve the compounds. While stirring this diamine solution under water cooling, 9.32 g (41.6 mmol) of CA-1 was added, and NMP was added to achieve a solid content concentration of 15% by mass. The mixture was stirred at 40°C under a nitrogen atmosphere for 3 hours. Furthermore, 2.82 g (14.3 mmol) of CA-2 was added, and NMP was added to achieve a solid content concentration of 15% by mass. The mixture was stirred at 23°C under a nitrogen atmosphere for 4 hours to obtain polyamic acid solution (PAA-A-1). 80.0 g of the polyamic acid solution (PAA-A-1) obtained above was taken into a 300 mL Erlenmeyer flask containing a stirring bar, and 70.0 g of NMP, 6.97 g of acetic anhydride, and 1.80 g of pyridine were added. The mixture was stirred at room temperature for 30 minutes, and then reacted at 55°C for 3 hours. This reaction solution was added to 560 g of methanol, and the resulting precipitate was filtered off. After washing the precipitate with methanol, it was dried under reduced pressure at 60°C to obtain polyimide powder. The imidization rate of this polyimide was 75%. 9.00 g of the polyimide powder was placed in a 300 mL Erlenmeyer flask containing a stirring bar, 36.0 g of NMP was added, and the mixture was stirred at 50°C for 20 hours to dissolve, obtaining a polyimide (PI-A-1) solution with a solid content of 20% by mass. Table 1 shows the types and amounts of diamine and tetracarboxylic acid derivatives used, the presence or absence of E-1, and the imidization rate when preparing the solution of polyimide (PI-A-1) obtained in Synthesis Example 1.

[0079] <Synthesis Example 2> In a 200 mL four-necked flask equipped with a stirrer and a nitrogen inlet tube, 8.04 g (40.2 mmol) of DA-1, 4.36 g (10.9 mmol) of DA-3, and 12.2 g (21.9 mmol) of DA-4 were weighed out, and 98.4 g of NMP was added. The mixture was stirred while supplying nitrogen to dissolve the compounds. While stirring this diamine solution under water cooling, 9.40 g (47.4 mmol) of CA-3 was added, followed by 37.6 g of NMP, and the mixture was stirred at 50°C under a nitrogen atmosphere for 2 hours. Further, 4.65 g (23.7 mmol) of CA-2 was added, followed by 18.6 g of NMP, and the mixture was stirred at 23°C under a nitrogen atmosphere for 2 hours to obtain a polyamic acid solution (PAA-A-2). 100 g of the polyamic acid solution obtained was taken into a 200 mL Erlenmeyer flask containing a stirring bar, 1.24 g (5.68 mmol) of E-1 was added, and the mixture was stirred at 40°C for 15 hours to obtain a solution of end-capped polyamic acid (PAA-A-3). 100 g of the above (PAA-A-3) solution was taken into a 200 mL Erlenmeyer flask containing a stirring bar, and 66.7 g of NMP, 14.2 g of acetic anhydride, and 4.70 g of pyridine were added. The mixture was stirred at room temperature for 30 minutes, and then reacted at 60°C for 4 hours. This reaction solution was added to 650 g of methanol, and the resulting precipitate was filtered off. After washing the precipitate with methanol, it was dried under reduced pressure at 80°C to obtain polyimide powder (imidization rate: 89%). Furthermore, 9.60 g of this polyimide powder was taken into a 100 mL Erlenmeyer flask containing a stirring bar, 70.4 g of NMP was added, and the mixture was stirred at 70°C for 24 hours to dissolve, obtaining a polyimide (PI-A-2) solution with a solid content of 12% by mass. Table 1 shows the types and amounts of diamine and tetracarboxylic acid derivatives used, the presence or absence of E-1, and the imidization rate when preparing the solution of polyimide (PI-A-2) obtained in Synthesis Example 2.

[0080] <Synthesis Example 3> In a 1 L four-necked flask equipped with a stirrer and a nitrogen inlet tube, 38.26 g (96.0 mmol) of DA-3 and 44.41 g (224.0 mmol) of DA-8 were weighed out. 606.2 g of NMP was added to achieve a solid content concentration of 12% by mass, and the mixture was dissolved by stirring while supplying nitrogen. While stirring this diamine solution under water cooling, 48.32 g (246.4 mmol) of CA-2 and 166.1 g of NMP were added, and the mixture was stirred under a nitrogen atmosphere and water cooling for 2 hours. Furthermore, 18.83 g (64.0 mmol) of CA-4 was added, followed by 76.6 g of NMP, and the mixture was stirred at 50°C under a nitrogen atmosphere for 15 hours to obtain a polyamic acid (PAA-B-1) solution with a solid content concentration of 15% by mass.

[0081] <Synthesis Examples 4-7> Using the diamine and tetracarboxylic acid derivatives shown in Table 2 below, and following the same procedure as in Synthesis Example 3 using the same organic solvent, solutions of the polyamic acids (PAA-B-2) to (PAA-B-5) shown in Table 2 below were obtained.

[0082] <Synthesis Example 8> In a 1 L four-necked flask equipped with a stirrer and a nitrogen inlet tube, 39.65 g (200.0 mmol) of DA-8 and 42.66 g (200.0 mmol) of DA-5 were weighed out. 603.6 g of NMP was added to achieve a solid content concentration of 12% by mass, and the mixture was dissolved by stirring while supplying nitrogen. While stirring this diamine solution under water cooling, 74.52 g (380.0 mmol) of CA-2 and 285.1 g of NMP were added, and the mixture was stirred under a nitrogen atmosphere and water cooling for 4 hours to obtain a polyamic acid (PAA-B-6) solution with a solid content concentration of 15% by mass. Table 2 shows the types and amounts of diamine and tetracarboxylic acid derivatives used when preparing the solution of polyamic acid (PAA-B-6) obtained in Synthesis Example 8.

[0083] [Table 1]

[0084] [Table 2]

[0085] [Preparation of liquid crystal alignment agent] <Examples 1-4, Comparative Examples 1-5> In 200 mL Erlenmeyer flasks, the polyamic acid and polyimide solutions obtained in Synthesis Examples 1-8 were weighed out in the amounts shown in Table 3 below. While stirring, NMP, GBL, a 10% by mass NMP solution containing a crosslinking compound, a 1% by mass GBL solution containing an adhesion promoter, and BCS were added in that order, and the mixture was stirred at room temperature for 2 hours to obtain liquid crystal alignment agents (1)-(9).

[0086] [Table 3]

[0087] [Fabrication of FFS-type liquid crystal display elements] A liquid crystal cell was fabricated that incorporates a configuration of a fringe field switching (FFS) mode liquid crystal display element. First, a substrate with electrodes was prepared. The substrate was a glass substrate measuring 30 mm x 35 mm and with a thickness of 0.7 mm. On the substrate, an ITO electrode with a solid pattern was formed as the first layer, constituting the counter electrode. On top of the first layer counter electrode, a SiN (silicon nitride) film deposited by CVD was formed as the second layer. The second SiN film used had a thickness of 500 nm, which functioned as an interlayer insulating film. On top of the second SiN film, a comb-shaped pixel electrode formed by patterning the ITO film was placed as the third layer, forming two pixels, the first and second pixels. The size of each pixel was 10 mm vertically and approximately 5 mm horizontally. At this time, the first layer counter electrode and the third layer pixel electrode were electrically insulated by the action of the second layer SiN film.

[0088] The third layer of pixel electrodes had a comb-like shape, with multiple electrode elements, each 3 μm wide and bent at an internal angle of 160° in the center, arranged parallel to each other at intervals of 6 μm. Each pixel had a first region and a second region, separated by lines connecting the bent portions of the multiple electrode elements.

[0089] Comparing the first and second regions of each pixel, it was found that the formation directions of the electrode elements of the pixel electrodes constituting them were different. Specifically, using the direction connecting the bent portions of the multiple electrode elements as a reference, in the first region of the pixel, the electrode elements of the pixel electrodes were formed at an 80° clockwise angle, while in the second region of the pixel, the electrode elements of the pixel electrodes were formed at an 80° counterclockwise angle. In other words, the first and second regions of each pixel were configured such that the direction of the rotational movement (in-plane switching) of the liquid crystal induced by the voltage applied between the pixel electrode and the counter electrode was opposite to that of the first and second regions of the pixel.

[0090] Next, the liquid crystal alignment agents (1) to (9) were filtered through a filter with a pore size of 1.0 μm, and then applied to the prepared electrode-equipped substrate by spin coating. After drying on a hot plate at 80°C for 5 minutes, the film was baked in an IR oven at 150°C for 20 minutes to obtain a polyimide film with a thickness of 60 nm. This polyimide film was subjected to rubbing alignment treatment with a rayon cloth (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 30 mm / sec, pressing length: 0.3 mm, rubbing direction: 180° to the direction connecting the bent portions of the multiple electrode elements of the third layer pixel electrode), then washed with ultrasonic irradiation in pure water for 1 minute, and water droplets were removed with an air blower. After that, it was dried at 80°C for 15 minutes to obtain a substrate with a liquid crystal alignment film. In addition, a glass substrate with a columnar spacer with a height of 4 μm and ITO electrodes formed on the back surface was treated in the same manner as above to obtain a substrate with a liquid crystal alignment film that had undergone alignment treatment. These two substrates with liquid crystal alignment films were used as a pair. A sealant (Mitsui Chemicals XN-1500T) was printed on one of the substrates, leaving a liquid crystal injection port. The other substrate was then bonded to the first substrate with the liquid crystal alignment film surfaces facing each other and the rubbing directions opposite each other. Subsequently, a heat treatment was performed at 150°C for 60 minutes to cure the sealant, creating an empty cell with a cell gap of 4 μm. Negative liquid crystal MLC-7026-100 (Merck) was injected into this empty cell using a reduced-pressure injection method, and the injection port was sealed to obtain an FFS-type liquid crystal cell. The obtained liquid crystal cell was then heated at 120°C for 1 hour, left overnight at 23°C, and used for evaluation of liquid crystal alignment.

[0091] [Creation of liquid crystal cells for voltage retention measurement] After filtering each of the liquid crystal alignment agents (1) to (9) through a 1.0 μm filter, they were applied by spin coating to an electrode-equipped substrate (a glass substrate measuring 30 mm wide x 40 mm long with a thickness of 1.1 mm, on which a rectangular ITO electrode measuring 10 mm wide x 40 mm long and 35 nm thick was formed). After drying on a 50°C hot plate for 5 minutes, the substrate was baked in a 150°C IR oven for 20 minutes to form a coating with a thickness of 60 nm, thereby obtaining a substrate with a liquid crystal alignment film. This liquid crystal alignment film was subjected to rubbing alignment treatment with a rayon cloth (YA-20R manufactured by Yoshikawa Chemical Co., Ltd.) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 30 mm / sec, pressing length: 0.3 mm), then washed with ultrasonic irradiation in pure water for 1 minute, water droplets were removed with an air blower, and then dried at 80°C for 15 minutes to obtain a substrate with a liquid crystal alignment film. Two substrates with the above-mentioned liquid crystal alignment film were prepared. A 4 μm spacer was scattered on the liquid crystal alignment film surface of one substrate, and then a sealant (Mitsui Chemicals XN-1500T) was printed on top of it. The other substrate was then bonded to the first substrate with the rubbing direction in the opposite direction and the film surfaces facing each other. The substrate was then heated at 150°C for 60 minutes to cure the sealant and create an empty cell. Negative liquid crystal MLC-7026-100 (Merck) was injected into this empty cell by a reduced-pressure injection method, and the injection port was sealed to obtain a liquid crystal cell. Subsequently, the obtained liquid crystal cell was heated at 120°C for 1 hour and left overnight at 23°C to obtain a liquid crystal cell for voltage retention rate measurement.

[0092] [evaluation] 1. Evaluation of orientation stability under long-term AC drive The liquid crystal cell used was fabricated using the FFS method described above. This liquid crystal cell is used with a high-brightness backlight with a surface temperature of 50°C (light source: LED, brightness: 20,000 cd / m²). 2 A ±10V AC voltage was applied at a frequency of 60Hz for 168 hours. After that, the pixel electrode and counter electrode of the liquid crystal cell were short-circuited and left at room temperature for one day. After a period of waiting, the liquid crystal cell was placed between two polarizing plates positioned so that their polarization axes were perpendicular to each other. With no voltage applied, the backlight was turned on, and the positioning angle of the liquid crystal cell was adjusted so that the brightness of the transmitted light was minimized. Then, the rotation angle Δ was calculated when the liquid crystal cell was rotated from the angle at which the second region of the first pixel was darkest to the angle at which the first region was darkest. Similarly, for the second pixel, the second and first regions were compared, and the same angle Δ was calculated. The stability of the liquid crystal alignment was evaluated by defining an angle Δ of less than 0.4° as "good" and an angle Δ of 0.4° or greater as "poor". The evaluation results are shown in Table 4.

[0093] 2. Measurement of the relaxation time of accumulated charge A liquid crystal cell, fabricated in the same manner as described above (fabrication of an FFS-type liquid crystal display element), was placed between two polarizing plates arranged so that their polarization axes were orthogonal. With the pixel electrode and the counter electrode short-circuited to the same potential, an LED backlight was shone from below the two polarizing plates, and the angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured on the two polarizing plates was minimized. Next, the VT curve (voltage-transmittance curve) was measured while applying an AC voltage of 60 Hz to this liquid crystal cell, and the AC voltage at which the relative transmittance was 23% was calculated as the driving voltage. In the afterimage evaluation, an AC voltage at a frequency of 60 Hz, which resulted in a relative transmittance of 23%, was applied to drive the liquid crystal cell, while simultaneously applying a DC voltage of 1 V and driving it for 120 minutes. After that, only the DC voltage was stopped, and the cell was driven for another 15 minutes using only the AC voltage. If the relative transmittance relaxed to 25% or less within 10 minutes of stopping the application of DC voltage, it was defined as "good." If it took more than 10 minutes for the relative transmittance to decrease to 25% or less, it was defined as "poor." The afterimage evaluation according to the method described above was performed under temperature conditions where the liquid crystal cell temperature was 40°C. The evaluation results are shown in Table 4.

[0094] 3. Evaluation of charge accumulation amount by AC drive A liquid crystal cell, fabricated in the same manner as described above (fabrication of an FFS-type liquid crystal display element), was placed between two polarizing plates arranged so that their polarization axes were orthogonal. With the pixel electrode and the counter electrode short-circuited to the same potential, an LED backlight was shone from below the two polarizing plates, and the angle of the liquid crystal cell was adjusted so that the brightness of the LED backlight transmitted light measured on the two polarizing plates was minimized. Next, the VT curve (voltage-transmittance curve) was measured while applying an AC voltage of 60 Hz to this liquid crystal cell, and the AC voltage at which the relative transmittance was 23% was calculated as the driving voltage. In the afterimage evaluation, an AC voltage with a frequency of 60 Hz, which resulted in a relative transmittance of 100%, was applied to drive the liquid crystal cell for 60 minutes. Subsequently, an AC voltage with a relative transmittance of 23% was applied, and the applied voltage that minimized display flicker was measured while sweeping the DC voltage. The absolute value of this applied voltage that minimized display flicker was defined as the charge accumulation amount. If this value exceeded 100 mV, it was defined as "poor," and if it was 100 mV or less, it was defined as "good." The afterimage evaluation according to the method described above was performed under temperature conditions where the liquid crystal cell temperature was 40°C. The evaluation results are shown in Table 4.

[0095] 4. Evaluation of voltage retention stability under backlighting A voltage of 1V was applied to the aforementioned liquid crystal cell for voltage retention measurement at a temperature of 60°C for 60 μsec. The voltage was measured after 167 msec, and the voltage retention rate was calculated to determine how long the voltage was retained. This was defined as the initial voltage retention rate. Next, as a backlight tolerance test, this liquid crystal cell was subjected to a high-brightness backlight with a surface temperature of 50°C (light source: LED, brightness: 20,000 cd / m²). 2 The cells were left for 168 hours under irradiation. The voltage retention rate of these liquid crystal cells was measured in the same manner as above. This was defined as the voltage retention rate after the durability test. The voltage retention rate of the backlight was evaluated as follows: if the difference between the initial value and the value after the durability test was less than 5%, it was considered "good," and if it was 5% or more, it was considered "poor." The evaluation results are shown in Table 4.

[0096] 5. Evaluation of rubbing resistance Liquid crystal alignment agents (1) to (9) were applied to ITO substrates by spin coating. After drying on a 60°C hot plate for 1 minute and 30 seconds, they were baked in a 150°C IR oven for 20 minutes to form a coating with a thickness of 100 nm. Subsequently, this liquid crystal alignment film was rubbed twice consecutively with a rayon cloth (YA-20R, manufactured by Yoshikawa Chemical Co., Ltd.) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, movement speed: 20 mm / sec, indentation length: 0.5 mm). When the surface of the film was observed with a confocal laser microscope, films with scratches were defined as "defective," and those without scratches were defined as "good." The evaluation results are shown in Table 4.

[0097] The evaluation results for the liquid crystal display elements using each of the liquid crystal alignment agents described in Examples 1-4 and Comparative Examples 1-5 are shown in Table 4 below. [Table 4] [Industrial applicability]

[0098] The liquid crystal alignment agent of the present invention is useful for forming liquid crystal alignment films in a wide range of liquid crystal display elements, such as those using IPS drive systems and FFS drive systems.

[0099] Furthermore, the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2021-078636, filed on May 6, 2021, are incorporated herein by reference as disclosure of the present invention.

Claims

1. A liquid crystal alignment agent characterized by containing the following polymer (A), polymer (B), and crosslinkable compound (C). Polymer (A): The following formula (d ０ Diamines represented by the following formula (d Ｄ A polyimide obtained by imidizing a polyimide precursor, which is a reaction product of a diamine component containing a diamine represented by ) and a tetracarboxylic acid derivative component. Polymer (B): “H-N(R)-Y Ｄ’ -N(R)-H”(Y Ｄ’ R represents a divalent organic group having the group "-N(D')-" (where D' represents a protecting group that is removed by heating and replaced by a hydrogen atom) within the molecule. Ｄ This is synonymous with R in ). (d Ｄ’Ｂ ) and the following formula (d Ｂ ) represented by diamine (however, diamine (d Ｄ’Ｂ A polyimide precursor is a reaction product of a diamine component composed of (excluding ), and an acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, aromatic tetracarboxylic dianhydride, or derivative thereof, wherein the alicyclic tetracarboxylic dianhydride is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, or a tetracarboxylic derivative component having at least one substructure selected from the group consisting of a cyclopentane ring structure and a cyclohexane ring structure. However, the polyimide precursor does not have an imide ring structure. Crosslinkable compound (C): An epoxy compound represented by the following formula (E ｎ ). 【Chemistry 1】 (Formula (d ０ In the above, the two Ar groups each independently represent a divalent benzene ring, a biphenyl structure, or a naphthalene ring, and any hydrogen atom on the ring may be replaced by a monovalent group. L ｏ ha-O-(-Ar'-O-) ｎ - (n is an integer from 0 to 3. Ar' represents a divalent benzene ring, a biphenyl structure, and any hydrogen atom on the ring may be replaced by a monovalent group. If there are multiple Ar's, the multiple Ar's may be the same or different.), - (CH ２ ) ｎ - (n is an integer between 2 and 18), or the - (CH ２ ) ｎ - of - CH ２ This represents a group in which at least a portion of the hyphen is replaced with either -O-, -C(=O)-, or -O-C(=O)-. Formula (d Ｄ ) during, Y Ｄ This represents a divalent organic group that has the group "-N(D)-" (where D represents a protecting group that is removed by heating and replaced by a hydrogen atom) within its molecule. Formula (d ０ ) and formula (d Ｄ (In this expression, each R independently represents either a hydrogen atom or a monovalent organic group.) 【Chemistry 2】 (Y Ｂ R represents a divalent organic group that satisfies the following conditions (1) and (2). R is the same as in the above formula (d ０ This is synonymous with R. Condition (1): It does not have a nitrogen atom-containing structure selected from the group consisting of a heterocycle containing a nitrogen atom and a secondary or tertiary amino group (excluding amino groups derived from the group "-N(D')-" (where D' represents a protecting group that is eliminated by heating and replaced by a hydrogen atom)). Condition (2): Does not have side chain groups with 6 or more carbon atoms. 【Transformation 3】 (a is an integer between 2 and 4, R ａ (This is an α-valent organic group, and the bonding sites with a number of N atoms are aliphatic carbon atoms.)

2. The liquid crystal alignment agent according to claim 1, wherein the imidization rate of polyimide in the polymer (A) is 10 to 100%.

3. In the polymer (B), the diamine component is of the following formula (d Ｍ A liquid crystal alignment agent according to claim 1 or 2, comprising a diamine represented by ). 【Chemistry 4】 (L Ｍ This is a single bond, -CH ２ -, -CO-, -O-, or -C(CH ３ ) ２ Represents -. L Ｍ ' is a single bond or - (CH ２ ) ｍ - (where m is an integer between 1 and 2). Ar Ｍ Ar represents a divalent benzene ring, and any hydrogen atom on the ring may be replaced by a monovalent group. Ｍ If there are multiple Ar Ｍ The Rs may be the same or different. Each of the multiple Rs independently represents a hydrogen atom or a monovalent organic group. n is an integer between 0 and 1.

4. The above formula (d ０ The liquid crystal alignment agent according to any one of claims 1 to 3, wherein the content of the diamine represented by ) is 50 to 95 mol% of the total components of the diamine used in the production of polymer (A).

5. The above formula (d Ｄ The liquid crystal alignment agent according to any one of claims 1 to 4, wherein the content of the diamine represented by ) is 5 to 50 mol% relative to the total components of the diamine used in the production of polymer (A).

6. The liquid crystal alignment agent according to any one of claims 1 to 5, wherein the tetracarboxylic acid derivative component used in the production of polymer (A) contains an acyclic aliphatic tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a derivative thereof.

7. The liquid crystal alignment agent according to claim 6, wherein the tetracarboxylic acid derivative component used in the production of polymer (A) contains a tetracarboxylic dianhydride or a derivative 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.

8. The above formula (d ０ The diamine represented by the following formula (d ０ -1) to (d ０ Compounds represented by -10), 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-A The liquid crystal aligning agent according to any one of claims 1 to 7, wherein the diamine is at least one selected from the group consisting of minophenoxy)dodecane, 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-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, and 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine. 【Transformation 5】

9. The above formula (d Ｄ A diamine represented by ) is an aromatic diamine having one aromatic ring in its molecule, wherein at least one of the hydrogen atoms on the aromatic ring is replaced by a monovalent group having the group "-N(D)-" (d ｎ１ ), or an aromatic diamine having two aromatic rings in the molecule, wherein the two aromatic rings are bonded together by a single bond, -CH ２ -, -C(CH ３ ) ２ -, -O-, -C(=O)-, -O-C(=O)-, -NR-C(=O)- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), -NR- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), an alkylene group having 2 to 20 carbon atoms, and any -CH group of the alkylene group. ２ - is -O-, -Si(CH ３ ) ２ A divalent group selected from the group consisting of -, -C(=O)-, -O-C(=O)-, -NR-C(=O)- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), or -NR- (where R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group, or the group "-D"), (L ｎ Aromatic diamine linked by (i) any hydrogen atom on the aromatic ring is replaced by a monovalent group having "-N(D)-", or (ii) the above-mentioned divalent group (L ｎ Aromatic diamines (d) that have the group "-N(D)-" satisfy at least one of the following conditions ｎ２ A liquid crystal alignment agent according to any one of claims 1 to 8.

10. The liquid crystal alignment agent according to any one of claims 1 to 9, wherein the content ratio of polymer (A) to polymer (B) is 10 / 90 to 90 / 10 in mass ratio of [polymer (A)] / [polymer (B)].

11. The crosslinkable compound (C) is 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- Minocyclohexyl methane, 1,3-bis(N,N-diglycidylaminomethyl)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, 1,3,5-tris(N,N-diglycidylaminomethyl)benzene, and the following formula (E Ｎ -1) to (E Ｎ A liquid crystal alignment agent according to any one of claims 1 to 10, which is at least one selected from the group consisting of compounds represented by (-5). 【Transformation 6】

12. A liquid crystal alignment agent according to any one of claims 1 to 11, further comprising a crosslinking compound other than the crosslinking compound (C) and / or an adhesion aid.

13. A liquid crystal alignment film obtained from a liquid crystal alignment agent according to any one of claims 1 to 12.

14. The liquid crystal alignment film according to claim 13, which is of the horizontal alignment type.

15. A liquid crystal display element comprising the liquid crystal alignment film according to claim 13 or 14.

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