CN114080443A

CN114080443A - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element using same

Info

Publication number: CN114080443A
Application number: CN202080049476.8A
Authority: CN
Inventors: 堀隆夫; 大野慎跃; 山本雄介
Original assignee: Nissan Chemical Corp
Current assignee: Nissan Chemical Corp
Priority date: 2019-07-08
Filing date: 2020-07-02
Publication date: 2022-02-22
Anticipated expiration: 2040-07-02
Also published as: JPWO2021006182A1; CN114080443B; KR20220027945A; WO2021006182A1; TW202116872A

Abstract

The invention provides a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film, wherein the liquid crystal aligning film can maintain high voltage conservation rate and has excellent reprocessing performance. A liquid crystal aligning agent characterized by containing the following components (A) and (B). (A) The components: at least one polymer selected from the group consisting of a polyimide polymer, a polyorganosiloxane, a polymer of a monomer having a polymerizable unsaturated bond, and a cellulose polymer. (B) The components: has any of structures or steroid skeletons in which two or more rings are linked directly or via a linking group, and has at least one group represented by the following formulae (b-1) to (b-5) orA compound having a molecular weight of 2000 or less, which has two or more groups represented by the following formula (b-6) as a minimum. (wherein, R₂、R_4a、R_4b、R₅、R₆Each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Denotes a bond. )

Description

Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element using same

Technical Field

The present invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element using the liquid crystal alignment film.

Background

In liquid crystal display elements, various driving methods such as electrode structures, physical properties of liquid crystal molecules to be used, and manufacturing processes have been developed. For example, it is known that: liquid crystal display elements such as TN (twisted nematic) type, STN (super-twisted nematic) type, VA (vertical Alignment) type, MVA (multi-domain vertical Alignment) type, IPS (in-plane switching) type, FFS (fringe field switching) type, and PSA (polymer-stabilized Alignment) type.

These liquid crystal display elements are provided with a liquid crystal alignment film for aligning liquid crystal molecules. A material for the liquid crystal alignment film is generally a film made of a polymer such as polyamic acid, polyimide, or polysiloxane, because of its excellent properties such as heat resistance, mechanical strength, and affinity for liquid crystal.

In recent years, there has been an increasing demand for high image quality of liquid crystal display elements. For example, a liquid crystal display device which can maintain a high voltage holding ratio together with good liquid crystal alignment properties is desired, and patent documents 1 and 2 disclose liquid crystal aligning agents containing specific compounds.

Documents of the prior art

Patent document

Patent document 1: international publication (WO) No. 2016/063834

Patent document 2: japanese patent laid-open publication No. 2016-200798

Disclosure of Invention

Problems to be solved by the invention

Further, since the economical efficiency of the liquid crystal display element in the production process is also very important, the recycling of the element substrate is particularly required. That is, after a liquid crystal alignment film is formed on a substrate of an element by a liquid crystal aligning agent, inspection of alignment property and the like is performed, and as a result, when a defect occurs, it is required to easily perform a so-called rework step of removing the liquid crystal alignment film from the substrate, recovering the substrate, and reusing the substrate.

The liquid crystal aligning agents proposed in the past have not been able to sufficiently satisfy the above-described problems. The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film which can maintain a high voltage holding ratio and has excellent reworkability; a liquid crystal alignment film obtained from the liquid crystal aligning agent; and a liquid crystal display element using the liquid crystal alignment film.

Means for solving the problems

The present inventors have conducted extensive studies and, as a result, have found that the above problems can be solved by using a liquid crystal aligning agent containing specific plural components, and have completed the present invention.

The present invention has the following gist.

A liquid crystal aligning agent characterized by containing the following components (A) and (B).

(A) The components: at least one polymer (A) selected from the group consisting of a polyimide polymer (A-1), a polyorganosiloxane (A-2), a polymer (A-3) of a monomer having a polymerizable unsaturated bond, and a cellulose polymer (A-4).

(B) The components: a compound having a molecular weight of 2000 or less, which has at least one group represented by the following formulae (b-1) to (b-5) or at least two groups represented by the following formula (b-6), in any of a structure or a steroid skeleton in which two or more rings are linked directly or via a linking group.

(. represents a bond, R)₂、R_4a、R_4b、R₅、R₆Each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. )

Effects of the invention

According to the liquid crystal aligning agent of the present invention, a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film which can maintain a high voltage holding ratio and is excellent in reworkability can be obtained.

Detailed Description

< component (A) >

The liquid crystal aligning agent comprises at least one polymer (A) selected from the group consisting of a polyimide polymer (A-1), polyorganosiloxane (A-2), a polymer (A-3) of a monomer having a polymerizable unsaturated bond and a cellulose polymer (A-4), wherein the polyimide polymer (A-1) comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).

< polyimide-based Polymer (A-1) >)

The polyimide-based polymer is preferably a polymer having at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2).

Wherein, in the formulas (1) and (2), X₁Is a tetravalent organic radical, Y₁Is a divalent organic group. R₁Is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, Z₁₁、Z₁₂Each independently represents a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted alkyl groupAn alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms which may have a substituent, a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group.

As R in the above formula (2)₁Specific examples of the alkyl group having 1 to 5 carbon atoms include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl and the like. R is from the viewpoint of easiness of imidation by heating₁Preferably a hydrogen atom or a methyl group.

Z in the above formula (2)₁₁、Z₁₂Specific examples of the alkyl group having 1 to 10 carbon atoms of (A) other than the above-mentioned R₁Specific examples of the alkyl group having 1 to 5 carbon atoms given as examples in the above include: hexyl, heptyl, octyl, nonyl, decyl, and the like. As Z₁₁、Z₁₂Specific examples of the alkenyl group having 2 to 10 carbon atoms include: vinyl, propenyl, butenyl and the like, and these may be linear or branched. As Z₁₁、Z₁₂Specific examples of the alkynyl group having 2 to 10 carbon atoms include: ethynyl, 1-propynyl, 2-propynyl and the like.

Z above₁₁、Z₁₂The substituent optionally having a substituent includes, for example: halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), hydroxyl group, cyano group, alkoxy group, etc. In terms of less afterimage, Z₁₁、Z₁₂Preferably a hydrogen atom or a methyl group.

As the above X₁Examples thereof include tetravalent organic groups derived from at least one selected from the group consisting of tetracarboxylic dianhydrides, tetracarboxylic diesters and tetracarboxylic diester dihalides (hereinafter collectively referred to as tetracarboxylic derivatives). Specific examples thereof include tetravalent organic groups derived from aromatic tetracarboxylic acid dianhydride, aliphatic tetracarboxylic acid dianhydride, alicyclic tetracarboxylic acid dianhydride, or tetracarboxylic acid diester thereof, or tetracarboxylic acid diester dihalide. Y of formula (1)₁Is a divalent organic group derived from a diamine.

The aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of at least one carboxyl group and four carboxyl groups bonded to an aromatic ring. The aliphatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups bonded to a chain hydrocarbon structure. Among them, it is not necessary to constitute only a chain hydrocarbon structure, and a part thereof may have an alicyclic structure or an aromatic ring structure. The alicyclic tetracarboxylic dianhydride is an acid dianhydride which contains at least one carboxyl group bonded to an alicyclic structure and is obtained by intramolecular dehydration of four carboxyl groups. Wherein none of the four carboxyl groups are bonded to an aromatic ring. Further, the alicyclic structure need not be solely formed, and a part thereof may have a chain hydrocarbon structure or an aromatic ring structure.

From the viewpoint of obtaining a high voltage holding ratio, it is preferable that X is₁Is a tetravalent organic group selected from the group consisting of the following formulae (4a) to (4n), the following formula (5a), and the following formula (6 a).

Wherein x and y each represents a single bond, -O-, -CO (═ O) -, an alkylene group having 1 to 5 carbon atoms, a 1, 4-phenylene group, -SO-, or-NRCO- (R represents a hydrogen atom or a methyl group). Z¹～Z⁶Each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring. j. k is 0 or 1. m is an integer of 1 to 5. Denotes a bond.

As a preferable specific example of the formula (4a), a structure represented by any of the following formulae (4 a-1) to (4 a-4) can be mentioned in order to obtain a high voltage holding ratio.

Examples of the alkylene group having 1 to 5 carbon atoms in the formulae (5a) and (6a) include: methylene, ethylene, 1, 3-propylene, 1, 4-butylene, 1, 5-pentylene, and the like.

High electricity is obtainedIn terms of the pressure holding ratio, X in the above formula (1)₁The tetravalent organic group is preferably selected from the group consisting of the above formulas (4a) to (4h), (4j), (4l), (4m) and (4 n).

From the viewpoint of obtaining a high voltage holding ratio, the total content of one or more kinds of repeating units (hereinafter, also referred to as a repeating unit (t)) selected from the group consisting of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is preferably 5 mol% or more, more preferably 10 mol% or more, and particularly preferably 20 mol% or more, based on the total repeating units, and in the formula (1) and the formula (2), X is preferably equal to or greater than X₁Is a tetravalent organic group selected from the group consisting of the above formulas (4a) to (4n), (5a) and (6a), Y₁Is a divalent organic group.

Y as formula (1)₁Divalent organic groups derived from diamines are exemplified. For example, divalent organic groups derived from aliphatic diamines, alicyclic diamines, or aromatic diamines are exemplified. Specific examples of the aliphatic diamine include: m-xylylenediamine, ethylenediamine, 1, 3-propanediamine, tetramethylenediamine, hexamethylenediamine, etc.; examples of the alicyclic diamine include: 1, 4-cyclohexanediamine, 4' -methylenebis (cyclohexylamine), and the like.

Examples of the aromatic diamine include: p-phenylenediamine, 4 '-diaminodiphenylmethane, 4' -diaminobenzophenone, 4 '-diaminodiphenyl ether, 4' -diaminoazobenzene, 1- (4-aminophenyl) -1, 3, 3-trimethyl-1H-indan-5-amine, 1- (4-aminophenyl) -2, 3-dihydro-1, 3, 3-trimethyl-1H-indene-6-amine, 2, 6-diaminopyridine, 3, 4-diaminopyridine, 2, 4-diaminopyrimidine, 3, 6-diaminocarbazole, N-methyl-3, 6-diaminocarbazole, bis (4-aminophenyl) amine, N-bis (4-aminophenyl) methylamine, N '-bis (4-aminophenyl) -benzidine, N' -bis (4-aminophenyl) -N, N '-dimethylbenzidine, 1, 4-bis (4-aminophenyl) -piperazine, 1, 4' -bis (4-aminophenyl) -piperazine, 4- (4-aminophenoxycarbonyl) -1- (4-aminophenyl) piperidine, 4 ' - [4, 4 ' -propane-1, 3-diylbis (piperidine-1, 4-diyl) ] diphenylamine, nitrogen-containing diamines such as the following formulas (z-1) to (z-19), carboxyl-containing diamines such as 3, 5-diaminobenzoic acid, 2 ' -dimethyl-4, 4 ' -diaminobiphenyl, 1, 3-bis (4-aminophenoxy) benzene, 1, 4-bis (4-aminophenoxy) benzene, bis [ 4- (4-aminophenoxy) phenyl ] ether, 4 ' -bis (4-aminophenoxy) biphenyl, 1, 3-bis (3-aminopropyl) -tetramethyldisiloxane, the following formulas (H-1) to (H-16), (H2-1) to (H2-17), (H3-1H 3-4), diamines having an alkyl group having 20 carbon atoms in the side chain, such as the following formulas (V2-1) to (V2-13), A fluoroalkyl group having 3 to 20 carbon atoms, an alkoxy group having 3 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, a diamine having a structure in which two or more rings are connected directly or via a linking group (polycyclic structure), a diamine having a radical-initiating function represented by the following formulae (R1) to (R5), 2- (2, 4-diaminophenoxy) ethyl methacrylate, 2, 4-diamino-N, diamines having a photopolymerizable group at the terminal, such as N-diallylaniline, diamines having a photo-alignment structure, such as those described in [0053] of WO2014/080865, diamines having a carbon-carbon unsaturated bond, such as those described in [0057] of WO2014/080865, diamines having an azobenzene skeleton, such as those described in [0058] of WO2014/080865, and diamines having photoreactivity, such as those described in [0069] to [0072] of WO 2012/086715.

(n represents an integer of 2 to 10.)

(Boc represents a tert-butoxycarbonyl group; the same applies hereinafter.)

(R represents a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group.)

(R represents a hydrogen atom, a methyl group, or a tert-butoxycarbonyl group

Wherein, in the above formulae (V2-1) to (V2-13), X^v1～X^v4、X^p1～X^p8Each independently represents- (CH)₂)_a- (a is an integer of 1 to 15), -CONH-, -NHCO-, -CON (CH)₃)－、－NH－、－O－、－CH₂O－、－CH₂OCO-, -COO-, or-OCO-, X^v5represents-O-, -CH₂O－、－CH₂OCO-, -COO-, or-OCO-. X^V6、X^V7、X^s1～X^s4Each independently represents-O-, -COO-or-OCO-. X_a～X_fRepresents a single bond, -O-, -NH-, -O- (CH)₂)_m－O－。R^v1～R^v4、R^1a～R^1hEach independently represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. m represents an integer of 1 to 8.

The polyimide-based polymer (a-1) in the present invention can be obtained, for example, as follows: so as to have the above-mentioned X₁Of (2) aTetracarboxylic acid derivatives and compounds having the above Y₁The diamine of the structure (4) is reacted by a known method described in WO 2013/157586.

The polyimide-based polymer (a-1) may be a terminal-modified polymer obtained by using a tetracarboxylic acid derivative and a diamine together with an end-capping agent as described above.

Examples of the blocking agent include: acid monoanhydrides such as maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, and compounds represented by any of the following formulae (m-1) to (m-6); chlorocarbonyl compounds such as di-tert-butyl dicarbonate; monoamine compounds such as aniline, 2-aminophenol, 3-aminophenol, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, and 4-aminobenzoic acid; and monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate, and naphthyl isocyanate.

The amount of the end-capping agent to be used is preferably 40 parts by mole or less, more preferably 30 parts by mole or less, based on 100 parts by mole of the total of the diamines to be used.

< polyorganosiloxane (A-2) >)

The polyorganosiloxane polymer (A-2) can be obtained, for example, by: the hydrolyzable silane compound is preferably hydrolyzed or hydrolyzed/condensed in the presence of an appropriate organic solvent, water, and a catalyst. The hydrolyzable silane compound used for the synthesis of the polymer (a-2) may have at least one functional group selected from the group consisting of an oxetanyl group and an oxirane group in a molecule, for example, from the viewpoint of imparting a high voltage holding ratio to a liquid crystal display device. Specific examples of the silane compound having an oxetanyl group or an oxirane group include: glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltriethoxysilane, etc.

Examples of other silane compounds used for the synthesis of the polymer (A-2) include: alkoxysilanes such as tetramethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and dimethyldiethoxysilane; nitrogen/sulfur-containing alkoxysilanes such as 3-mercaptopropyltriethoxysilane, mercaptomethyltriethoxysilane, 3-aminopropyltrimethoxysilane and N- (3-cyclohexylamino) propyltrimethoxysilane; unsaturated bond-containing alkoxysilanes such as 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropylmethyldiethoxysilane, and vinyltriethoxysilane; trimethoxysilylpropyl succinic anhydride, and the like.

When the polymer (A-2) is used as a liquid crystal aligning agent for TN, STN, or vertical alignment type liquid crystal display elements, or when a coating film is imparted with a liquid crystal aligning ability by a photo-alignment method, a specific group such as a liquid crystal aligning group or a photo-aligning group may be introduced into a side chain of the polymer (A-2). The method for synthesizing the polymer (A-2) having these specific groups in the side chain is not particularly limited, and examples thereof include the following methods: the epoxy group-containing silane compound or a mixture of the epoxy group-containing silane compound and another silane compound is hydrolytically condensed to synthesize an epoxy group-containing polymer, and then the obtained epoxy group-containing polymer is reacted with a carboxylic acid having the specific group. The reaction of the epoxy group-containing polymer with the carboxylic acid can be carried out according to a known method.

Examples of the carboxylic acid having the above-mentioned specific group include: a carboxylic acid having a liquid crystal alignment group such as an alkyl group having 4 to 20 carbon atoms, a fluoroalkyl group having 4 to 20 carbon atoms, an alkoxy group having 4 to 20 carbon atoms, a group having a steroid skeleton having 17 to 51 carbon atoms, a group having a structure (polycyclic structure) in which two or more rings are connected directly or via a linking group, or a carboxylic acid having a photo-alignment group such as a cinnamic acid structure.

The weight average molecular weight (Mw) of the polymer (A-2) in terms of polystyrene, as measured by GPC, is preferably 500 to 100000, more preferably 1000 to 30000, and still more preferably 1000 to 20000.

< Polymer (A-3) > (having a polymerizable unsaturated bond)

The monomer used for polymerization of the polymer (A-3) is not particularly limited as long as it has a polymerizable unsaturated bond. For example, there may be mentioned: a (meth) acrylic compound, a conjugated diene compound, an aromatic vinyl compound, a maleimide compound, and the like. The monomer used for polymerization may have at least one functional group selected from the group consisting of an oxetanyl group, an oxirane group, a carboxyl group, an alkoxysilyl group, a cyclic carbonate group, an isocyanate group, and a protected isocyanate group in the molecule, from the viewpoint of imparting a high voltage holding ratio to the liquid crystal display element.

Examples of the monomer having an oxetanyl group or an oxirane group include: maleimide compounds such as N- (4-glycidyloxyphenyl) maleimide and N-glycidylmaleimide; styrene compounds such as 3- (glycidyloxymethyl) styrene, 4- (glycidyloxymethyl) styrene and 4-glycidyl- α -methylstyrene; (meth) acrylic compounds such as glycidyl (meth) acrylate, glycidyl α -ethylacrylate, glycidyl α -n-propylacrylate, glycidyl α -n-butylacrylate, 3, 4-epoxybutyl (meth) acrylate, 3, 4-epoxybutyl α -ethylacrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, 6, 7-epoxyheptyl (α -ethylacrylate, 4-hydroxybutyl glycidyl acrylate, and (3-ethyloxetan-3-yl) methyl (meth) acrylate.

Examples of the monomer having a carboxyl group include: styrene compounds such as 3-vinylbenzoic acid and 4-vinylbenzoic acid; (meth) acrylic acid, α -ethacrylic acid, maleic acid, fumaric acid, vinylbenzoic acid, crotonic acid, citraconic acid, mesaconic acid, itaconic acid, 3-maleimidobenzoic acid, 3-maleimidopropionic acid, maleic anhydride, and the like. Examples of the monomer having an isocyanate group or a protected isocyanate group include: 2-methacryloyloxyethyl isocyanate (Karenz MOI, manufactured by SHOWA DENKO K.K.), 2- [ (3, 5-dimethylpyrazolyl) carbonylamino ] ethyl methacrylate (Karenz MOI-BP, manufactured by SHOWA DENKO K.K.), and the like. Examples of the monomer having an alkoxysilyl group include: 3-methacryloxypropyltrimethoxysilane (Sila-Ace S710, JNC Co., Ltd.), 3-methacryloxypropylmethyldimethoxysilane, and the like.

Further, the monomer used for polymerization of the polymer (a-3) may have a photo-alignment group, and specific examples of the photo-alignment group include: an azobenzene-containing group containing azobenzene or a derivative thereof as a basic skeleton, a cinnamic acid-containing group containing cinnamic acid or a derivative thereof (cinnamic acid structure) as a basic skeleton, a chalcone-containing group containing chalcone or a derivative thereof as a basic skeleton, a benzophenone-containing group containing benzophenone or a derivative thereof as a basic skeleton, a coumarin-containing group containing coumarin or a derivative thereof as a basic skeleton, a cyclobutane-containing structure containing cyclobutane or a derivative thereof as a basic skeleton, and the like. Among these, a group containing a cinnamic acid structure is preferable as the photo-alignment group in terms of high sensitivity to light. Specific examples thereof include the following formulae (3-m 1) to (3-m 18).

The monomers used for the polymer (A-3) may be used in combination with monomers not having the above-mentioned functional group (hereinafter, also referred to as other monomers). Examples of the other monomers include: (meth) acrylic compounds such as alkyl (meth) acrylate, cycloalkyl (meth) acrylate, benzyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; styrene, methyl styrene, divinyl benzene; 1, 3-butadiene, 2-methyl-1, 3-butadiene; n-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, and the like.

In the synthesis of the polymer (a-3), the proportion of the monomer having at least one functional group selected from the group consisting of an oxetanyl group, an oxirane group, a carboxyl group, an alkoxysilyl group, a cyclic carbonate group, an isocyanate group, and a protected isocyanate group is preferably 1 mol% or more, more preferably 5 mol% or more, and still more preferably 10 mol% or more, based on the total amount of the monomers used in the synthesis of the polymer (a-3). When the photo-alignment groups described later are used in combination, the proportion of the monomer used is preferably 90 mol% or less, and preferably 80 mol% or less.

The content ratio of the monomer having a photo-alignment group is preferably 10 to 99 mol%, more preferably 10 to 95 mol%, and still more preferably 20 to 90 mol% with respect to the total amount of the monomers used for synthesis of the polymer (a-3).

The method for producing the polymer (A-3) is not particularly limited, and a general method for industrial treatment can be used. Specifically, the polymer can be produced by cationic polymerization, radical polymerization, or anionic polymerization of a vinyl group using a monomer. Among them, radical polymerization is particularly preferable in view of ease of reaction control and the like. The polymer (A-3) can be obtained, for example, by polymerizing monomers in the presence of a polymerization initiator. As the polymerization initiator to be used, for example, azo compounds such as 2, 2 ' -azobis (isobutyronitrile), 2 ' -azobis (2, 4-dimethylvaleronitrile), and 2, 2 ' -azobis (4-methoxy-2, 4-dimethylvaleronitrile) are preferable. The proportion of the polymerization initiator used is preferably 0.01 to 30 parts by mass per 100 parts by mass of all monomers used for the reaction. Examples of the organic solvent to be used include: alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like.

The Mw in terms of polystyrene, as measured by Gel Permeation Chromatography (GPC), of the polymer (A-3) is preferably 1000 to 300000, more preferably 2000 to 100000. The molecular weight distribution (Mw/Mn) indicated by the ratio of Mw to the number average molecular weight (Mn) in terms of polystyrene measured by GPC is preferably 10 or less, more preferably 8 or less.

< cellulosic Polymer (A-4) >

Specific examples of the polymer (A-4) include polymers having a structural unit represented by the following formula (4-c).

(R¹～R⁶Each independently a hydrogen atom or a monovalent organic group. X is an oxygen atom or a sulfur atom. )

As the above-mentioned R¹～R⁶Examples of the monovalent organic group include: a chain hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 15 carbon atoms, a combination of these groups with at least one group selected from the group consisting of-CO-, -COO-, -OCO-, and-O-, and the like. From the viewpoint of availability, R is¹～R⁶The group may be selected from the group consisting of the following formulae (1a) to (1 m). In view of imparting a high voltage holding ratio to a liquid crystal display device, R¹～R⁶At least one of (a) preferably contains a carboxyl group. For example, the following formulae (1f), (1h), (1i), (1j) to (1m), and the like.

Wherein, X⁷And X⁸Represents a benzene ring or an alkyl group having 1 to 4 carbon atoms (specifically, methyl, ethyl, n-propyl, isopropyl, butyl, etc.). X⁹、X¹⁰、X¹¹、X¹²、X¹³And X¹⁴Represents a benzene ring or a carbon atomAnd alkylene groups having a sub-number of 1 to 4 (specifically, methylene, ethylene, n-propylene, isopropylene, butylene, and the like).

The Mn of the polymer (A-4) is preferably 100 to 500000, more preferably 100 to 100000, from the viewpoint of solubility in a solvent and handling as a liquid crystal aligning agent.

< ingredient (B) >

Since the component (B) contained in the liquid crystal aligning agent of the present invention has a side chain structure in the molecule, the liquid crystal alignment film obtained contains a flexible structure in the molecule. This improves the solubility in the reworking solvent, and therefore the liquid crystal alignment film of the present invention exhibits high reworkability. Since the component (B) has a hydroxyalkyl group at the molecular terminal, a crosslinking reaction occurs between the components (a) and (B) or between the components (B), and the crosslinking density of the resulting liquid crystal alignment film is increased. As a result, the impurity components derived from the substrate are easily trapped in the liquid crystal alignment film, and therefore, a liquid crystal display device including the liquid crystal alignment film has a high voltage holding ratio.

When the component (B) has at least one group represented by any of the above formulae (B-1) to (B-5), it may have at least two groups represented by any of the above formulae (B-1) to (B-5) from the viewpoint of imparting a high voltage holding ratio to the liquid crystal display device.

Examples of the component (B) include compounds represented by the following formula (3-1) and compounds represented by the following formula (3-2).

Wherein, B₁Represents a structure selected from the group consisting of the following formulas (B-1) to (B-6), B₂Represents a structure selected from the following formulae (b-1) to (b-5). L is₁The structure of the following formula (1L-1) or (1L-2) is shown. L is₂Represents a single bond, the following formula (2L-1), or is selected from-CH₂－、－CH(CH₃)－、－C(CH₃)₂－、－(CH₂)_nA divalent group (hereinafter referred to as a linking group (2a)) selected from the group consisting of- (n represents an integer of 2 to 20) and-NR- (R represents a hydrogen atom or a methyl group). In addition, the above- (CH)₂)_nAny of-CH₂Optionally substituted by-O-, -CH (CH)₃)－、－C(CH₃)₂-, -CO-or-NR-. AL₁、AL₂Each independently represents a-Cy₁－Z₁or-Cy₂. m1 represents an integer of 1 to 4. m2 represents an integer of 1 to 2. Cy is a Cy-is₁The structure is a structure in which two or more rings are connected directly or via a connecting group. Cy is a Cy-is₂Represents a group having a steroid skeleton. Z₁Represents a linear or branched hydrocarbon group having 3 or more carbon atoms.

(wherein 1 represents Al₁A bonding bond of bonding ` 2 represents a bond with B₁A bonded linkage. n1 represents an integer of 1 to 2, and n2 represents an integer of 1 to 4. A. the₁₁、A₁₂Each independently represents a single bond, -O-, or a linking group (2 a). In A₁₂In the case where there are plural, plural A₁₂May be the same or different. A. the₂₁、A₂₂Each independently represents a linking group (2a) (-except NR-). A. the_s11Represents a single bond, -O-, -CO-, or a linking group (2 a). A. the_s12Represents a single bond, -CO-, or a linking group (2a) (-except NR-). )

(wherein 1 represents a group represented by the formula II and B₂Bonding bond of bonding ` 2 represents bonding with AL₂A bonded linkage. A. the_s2And the above-mentioned A_s11Synonymously. )

(wherein, represents a bond, R₂、R_4a、R_4b、R₅、R₆Each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. )

In the above-mentioned Z₁In the above-mentioned linear or branched hydrocarbon group, one or more methylene groups which are not adjacent to each other in the above-mentioned group may be an oxygen atom, an oxygen atom-containing group such as CO or CO (═ O), a group substituted with a sulfur atom, a group substituted with an alkoxy group or a halogen atom in the methylene group. From the viewpoint of satisfactory reworking properties, Z is₁Examples thereof include: a linear or branched alkyl group having 3 to 20 carbon atoms, a linear or branched fluoroalkyl group having 3 to 20 carbon atoms, a linear or branched alkoxy group having 3 to 20 carbon atoms, or a linear or branched alkyl ester group having 3 to 20 carbon atoms.

In the above Cy₁In the above-mentioned embodiments, the ring constituting the structure in which two or more rings are linked directly or via a linking group is preferably a benzene ring, a naphthalene ring or a cyclohexane ring. The number of rings constituting the polycyclic structure is preferably 2 to 4, as long as two or more rings are present. The plurality of rings constituting the polycyclic structure may be the same or different from each other. When the ring is a benzene ring, the bonding position of the ring is preferably para to other groups. In the case where the ring is a naphthalene ring, the bonding position of the ring is preferably a trans position (2, 6-position) with respect to other groups (amphi position). In the case where the ring is a cyclohexane ring, the bonding position of the ring is 1, 4-position with respect to other groups. Further, any hydrogen atom on the ring may be substituted with a monovalent organic group such as a halogen atom, a hydroxyl group, a carboxyl group, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, a monovalent organic group having 1 to 6 carbon atoms containing a fluorine atom, an alkoxy group having 1 to 6 carbon atoms, or the like.

In the above Cy₁In (b), examples of the linking group include: -O-, -CO-, -COO-, -NR^b－、－CONR^b－(R^bIs the number of hydrogen atoms or carbon atoms1 to 6 alkyl groups or protective groups), an alkylene group having 1 to 10 carbon atoms, or an alkylene group having 1 to 10 carbon atoms, wherein at least one methylene group is replaced by-O-, -CO-, -COO-, -NR^b-or-CONR^bA divalent group formed by substitution, etc. As R^bExamples of the protective group(s) of (2) include urethane-based protective groups. Specific examples of the urethane-based protecting group include a tert-butoxycarbonyl group and a 9-fluorenylmethoxycarbonyl group.

Then Cy mentioned above₁Among them, a structure represented by the following formula (Rn) is preferable.

In the formula (Rn), X's each independently represents a single bond, or Cy₁The divalent groups shown in (1) by way of example. m is 2 to 6. G independently represents a benzene ring, a naphthalene ring or a cyclohexane ring. Denotes a bond.

In the above Cy₂The group having a steroid skeleton in (1) is preferably a group having 17 to 51 carbon atoms, and examples thereof include: cholesteryl, cholestanyl, lanostanyl, and the like.

From the viewpoint of having a high voltage holding ratio, B₁The above formula (b-1), (b-3), (b-5) or (b-6) is preferred.

The component (B) in the present invention is a compound having a molecular weight of 2000 or less for the reason of improving the reworkability. Among them, the molecular weight is preferably 1800 or less, more preferably 1500 or less, from the viewpoint of improving the reworkability. The molecular weight of the compound of component (B) is preferably 100 or more, more preferably 150 or more, from the viewpoint of improving the voltage holding ratio.

The component (B) is preferably a compound represented by the above formula (3-1) in view of having a high voltage holding ratio.

The component (B) is preferably a compound represented by any of the following formulae (B1-1-1) to (B1-1-43), (B1-2-1) to (B1-2-22), (B2-1-1) to (B2-1-18), (B2-2-1) to (B2-2-34), and (B2-3-1) to (B2-3-14), from the viewpoints of high voltage holding ratio and easy synthesis. The compounds (B1-1-1) to (B1-1-43) and (B1-2-1) to (B1-2-22) are more preferable from the viewpoint of having a high voltage holding ratio, and the compounds (B1-1-1), (B1-1-3), (B1-1-4), (B1-1-6), (B1-1-8), (B1-1-9), (B1-1-11), (B1-1-12), (B1-1-14), (B1-1-15), (B1-1-17), (B1-1-18), (B1-1-20), (B1-1-21), (B1-1-23), (B1-1-24) and (B1-1-26) are more preferable from the viewpoint of easy synthesis.

The content of the component (B) is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 35 parts by mass, and particularly preferably 0.5 to 30 parts by mass, per 100 parts by mass of the component (A).

< liquid Crystal Aligning agent >

The liquid crystal aligning agent of the present invention contains the above-mentioned component (A) and component (B). The liquid crystal aligning agent of the present invention may contain other polymers in addition to the polymers (A-1) to (A-4) as the component (A). Examples of the other polymers include: polyesters, polyamides, polyureas, polyacetals, polystyrenes or derivatives thereof, poly (styrene-phenylmaleimide) derivatives, poly (meth) acrylates, and the like.

The liquid crystal aligning agent is used for producing a liquid crystal alignment film, and is in the form of a coating liquid in terms of forming a uniform thin film. The liquid crystal aligning agent of the present invention is also preferably a coating solution containing the above-mentioned components (a) and (B) and an organic solvent. In this case, the content (concentration) of the polymer containing the component (a) in the liquid crystal aligning agent may be appropriately changed according to the setting of the thickness of the coating film to be formed. The content is preferably 1% by mass or more in terms of forming a uniform and defect-free coating film, and is preferably 10% by mass or less, particularly preferably 2 to 8% by mass in terms of storage stability of the solution.

The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as it is an organic solvent in which the polymer component is uniformly dissolved. Specific examples thereof include: n, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ -butyrolactone, γ -valerolactone, 1, 3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, N-dimethyllactamide, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide (collectively referred to as a good solvent), and the like. Among them, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N, N-dimethylpropionamide, 3-butoxy-N, N-dimethylpropionamide, N-dimethyllactamide, or γ -butyrolactone is preferable from the viewpoint of good printability. The good solvent is preferably 20 to 99% by mass, more preferably 20 to 90% by mass, and particularly preferably 30 to 80% by mass of the entire solvent contained in the liquid crystal aligning agent, from the viewpoint of good printability.

In addition to the above-mentioned solvents, the organic solvent contained in the liquid crystal aligning agent is preferably a solvent obtained by mixing a solvent (also referred to as a poor solvent) which improves coatability when the liquid crystal aligning agent is coated and surface smoothness of a coating film. Specific examples of the poor solvent are given below, but the poor solvent is not limited to these examples.

For example, there may be mentioned: diisopropyl ether, diisobutyl methanol (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 glycol monobutyl ether, ethylene glycol monoisoamyl ether, ethylene glycol monohexyl ether, propylene glycol monobutyl ether, 1- (2-butoxyethoxy) -2-propanol, 2- (2-butoxyethoxy) -1-propanol, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether, dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, 1, 2-ethylbutyl ether, 2-ethylbutyl acetate, ethylene glycol monohexyl ether, propylene glycol isoamyl ether, propylene glycol monohexyl ether, propylene glycol mono, Dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, ethyl 2- (2-ethoxyethoxy) acetate, diethylene glycol acetate, propylene glycol diacetate, n-butyl acetate, propylene glycol monoethyl ether 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, diisobutyl ketone (2, 6-dimethyl-4-heptanone), and the like.

Among the poor solvents, diisobutylcarbinol, propyleneglycol monobutyl ether, propyleneglycol diacetate, diethyleneglycol diethyl ether, dipropyleneglycol monomethyl ether, dipropyleneglycol dimethyl ether, 4-hydroxy-4-methyl-2-pentanone, ethyleneglycol monobutyl ether acetate, or diisobutyl ketone is preferable from the viewpoint of good printability.

The poor solvent is preferably 1 to 80% by mass, more preferably 10 to 80% by mass, and particularly preferably 20 to 70% by mass of the entire solvent contained in the liquid crystal aligning agent. The kind and content of the solvent are appropriately selected depending on the coating apparatus, coating conditions, coating environment, and the like of the liquid crystal aligning agent.

The combination of the good solvent and the poor solvent includes, from the viewpoint of good printability: n-methyl-2-pyrrolidone with ethylene glycol monobutyl ether; n-methyl-2-pyrrolidone, gamma-butyrolactone, and ethylene glycol monobutyl ether; n-methyl-2-pyrrolidone, gamma-butyrolactone and propylene glycol monobutyl ether; n-ethyl-2-pyrrolidone with propylene glycol monobutyl ether; n-methyl-2-pyrrolidone, γ -butyrolactone, 4-hydroxy-4-methyl-2-pentanone, and diethylene glycol diethyl ether; n-methyl-2-pyrrolidone, gamma-butyrolactone, propylene glycol monobutyl ether, and diisobutyl ketone; n-methyl-2-pyrrolidone, gamma-butyrolactone, propylene glycol monobutyl ether, and diisopropyl ether; n-methyl-2-pyrrolidone, gamma-butyrolactone, propylene glycol monobutyl ether, and diisobutylcarbinol; n-methyl-2-pyrrolidone, gamma-butyrolactone and dipropylene glycol dimethyl ether; n-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether; and combinations of N-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether.

The liquid crystal aligning agent of the present invention may additionally contain other components in addition to the component (a), the component (B), and the organic solvent. Examples of additional components include: an adhesion promoter for improving adhesion between the liquid crystal alignment film and the substrate and adhesion between the liquid crystal alignment film and the sealing material; a compound for improving the strength of the liquid crystal alignment film (hereinafter, also referred to as a crosslinkable compound); a dielectric material or a conductive material for adjusting the dielectric constant or resistance of the liquid crystal alignment film.

As the crosslinkable compound, a compound selected from the following compounds may also be used: n, N, N ', N ' -tetraglycidyl m-xylylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N ' -tetraglycidyl-4, 4 ' -diaminodiphenylmethane, N, N, N ', N ' -tetraglycidyl-p-phenylenediamine, compounds having an oxirane group such as the following formulae (r-1) to (r-3), compounds having a protected isocyanate group such as the compounds described in the following formulae (bi-1) to (bi-3) and Japanese patent application laid-open publication No. 2016-200798, hydroxyalkylamide compounds represented by the following formulae (hd-1) to (hd-8), or compounds represented by the following formulae (e-1) to (e-8).

The compound is an example of a crosslinkable compound, and is not limited to these. For example, components other than the above may be mentioned: examples of the oxetanyl group-containing compound include compounds having an oxetanyl group described in [0170] to [0175] of WO2011/132751, compounds having an oxazoline structure described in [0115] of Japanese patent application laid-open No. 2007-286597, compounds having a meldrum acid structure described in WO2012/091088, compounds having a cyclocarbonate group described in WO2011/155577, and compounds disclosed in [0105] to [0116] of WO 2015/060357. Two or more kinds of crosslinkable compounds may be used in combination.

The content of the crosslinkable compound in the liquid crystal aligning 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 aligning agent, from the viewpoint of achieving the intended effects and improving the liquid crystal alignment properties.

Examples of the adhesion promoter 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, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, N-ureidopropyltrimethoxysilane, N-methyl-ethyl-3-hydroxy-methyl-3-ethyl-3-aminopropyltriethoxysilane, N-ureidopropyltrimethoxysilane, N-ureidopropyltriethoxysilane, N-ethyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilane, N-triethoxy-silyltriethylenetriamine, N-tris (oxyethylene) -3-hydroxy-propyltrimethoxysilane, N-3-ethyltrimethoxysilane, N-bis (oxyethylene) -3-ethyltriethoxysilane, N-butyltrimethoxysilane, N-butyltrimethoxysilane, N-one, N-one, N-one, one or, Vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris (3-trimethoxysilylpropyl) isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc, Silane coupling agents such as 3-isocyanatopropyltriethoxysilane. The amount of the silane coupling agent used is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, from the viewpoint of improving the liquid crystal alignment property.

< liquid crystal alignment film/liquid crystal display element >

The liquid crystal display element of the present invention includes a liquid crystal alignment film formed using the liquid crystal aligning agent. The operation mode of the liquid crystal display element is not particularly limited, and the liquid crystal display element can be applied to various operation modes such as a TN type, an STN type, a vertical alignment type (including a VA-MVA type, a VA-PVA type, and the like), an in-plane switching type (IPS type), an FFS type, and an Optically Compensated Bend type (OCB type).

The liquid crystal display element of the present invention can be manufactured by, for example, the following steps (1-1) to (1-3). The process (1-1) uses a substrate differently depending on the desired operation mode. The operation modes of the step (1-2) and the step (1-3) are common.

[ Process (1-1): formation of coating film ]

First, the liquid crystal aligning agent of the present invention is applied to a substrate, and then the coated surface is heated, thereby forming a coating film on the substrate.

(1－1A)

For example, in the case of manufacturing a TN-type, STN-type, or VA-type liquid crystal display element, first, two substrates provided with a patterned transparent conductive film are placedThe liquid crystal aligning agent is applied to the surface on which each of the transparent conductive films is formed by, preferably, an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method. As the substrate, for example, a glass such as float glass (float glass) or soda glass (soda glass); and transparent substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, and poly (alicyclic olefin). As the transparent conductive film provided on one surface of the substrate, tin oxide (SnO) can be used₂) The NESA film (trademark of PPG corporation) was formed of indium oxide-tin oxide (In)₂O₃－SnO₂) And an ITO film formed therefrom.

After the liquid crystal aligning agent is applied, it is preferable to perform preliminary heating (prebaking) for the purpose of preventing the liquid of the applied liquid crystal aligning agent from sagging. The pre-drying temperature is preferably 30-200 ℃, more preferably 40-150 ℃, and particularly preferably 40-100 ℃. Thereafter, the solvent is completely removed, and a firing (post-baking) step is performed for the purpose of thermally imidizing the amic acid structure present in the polymer, if necessary. The firing temperature (post-baking temperature) at this time is preferably 80 to 300 ℃, more preferably 120 to 250 ℃. The post-baking time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The film thickness formed in this way is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5. mu.m.

(1－1B)

In the case of manufacturing an IPS-type or FFS-type liquid crystal display element, a liquid crystal aligning agent is applied to an electrode forming surface of a substrate provided with electrodes formed of a transparent conductive film or a metal film patterned into a comb-tooth shape and a surface of an opposing substrate not provided with the electrodes, and then the respective applied surfaces are heated to form a coating film. The materials of the substrate and the transparent conductive film used in this case, the coating method, the heating conditions after coating, the method for patterning the transparent conductive film or the metal film, the pretreatment of the substrate, and the preferable film thickness of the formed coating film are the same as those in the above (1-1A). As the metal film, for example, a film made of metal such as chromium can be used.

In both cases (1-1A) and (1-1B), the coating film to be the liquid crystal alignment film is formed by applying the liquid crystal alignment agent to the substrate and then removing the organic solvent. In this case, the coating film may be further heated after the formation of the coating film to cause a dehydration ring-closure reaction of the polyamic acid, polyamic acid ester, and polyimide blended in the liquid crystal aligning agent to proceed, thereby forming a further imidized coating film.

[ Process (1-2): orientation ability imparting treatment

In the case of producing a TN-type, STN-type, IPS-type, or FFS-type liquid crystal display element, the coating film formed in the above-described step (1-1) is subjected to a treatment for imparting liquid crystal aligning ability. Examples of the orientation ability imparting treatment include: a brush-polishing process of rubbing a coating film in a certain direction by a roll obtained by winding a cloth made of fibers such as nylon, rayon, and cotton; and photo-alignment treatment in which the coating film is irradiated with polarized or unpolarized radiation. On the other hand, in the case of a VA-type liquid crystal display device, the coating film formed in the step (1-1) may be used as it is as a liquid crystal alignment film, or the coating film may be subjected to an alignment ability imparting treatment.

When the coating film is provided with liquid crystal aligning ability by photo-alignment treatment, ultraviolet rays or visible rays including light having a wavelength of 150 to 800nm can be used as the radiation to be irradiated to the coating film. When the radiation is polarized, the radiation may be linearly polarized or partially polarized. When the radiation to be used is linearly polarized or partially polarized, the irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. In the case of irradiating unpolarized radiation, the direction of irradiation is regarded as an oblique direction.

As the light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, or the like can be used. Ultraviolet rays in a preferred wavelength range can be obtained by a method of using a light source in combination with, for example, a filter, a diffraction grating, or the like. The irradiation dose of the radiation is preferably 10 to 5000mJ/cm²More preferably 30 to 2000mJ/cm²。

In addition, in order to improve the reactivity, the light irradiation of the coating film may be performed while heating the coating film. The heating temperature is usually 30 to 250 ℃, preferably 40 to 200 ℃, and more preferably 50 to 150 ℃.

In the case of using ultraviolet rays containing light having a wavelength of 150 to 800nm, the light irradiation film obtained in the above step may be used as it is as a liquid crystal alignment film, or the light irradiation film may be subjected to firing, washing with water or an organic solvent, or a combination thereof. The firing temperature at this time is preferably 80 to 300 ℃, more preferably 80 to 250 ℃. The firing time is preferably 5 to 200 minutes, and more preferably 10 to 100 minutes. The number of firing may be two or more. The photo-alignment treatment herein corresponds to a treatment of light irradiation in a state of not being in contact with the liquid crystal layer.

As described above, the liquid crystal alignment film is formed on the substrate by the liquid crystal aligning agent, but when the liquid crystal alignment film is defective, the liquid crystal alignment film formed by the liquid crystal aligning agent of the present invention is excellent in a reworking process of removing the liquid crystal alignment film from the substrate and recycling the substrate.

That is, the reworking step is performed by immersing the substrate having the liquid crystal alignment film in a solvent, preferably at 20 to 100 ℃, and then removing the substrate with pure water, and the liquid crystal alignment film formed of the liquid crystal alignment agent of the present invention has the following advantages in the reworking step. Namely, the following advantages are provided: the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention has high solubility in a reworking agent, and therefore, the number of types of solvents that can be used is increased, or the temperature for immersion in the solvent is reduced, and the immersion time is reduced, so that the manufacturing cost can be reduced.

[ Process (1-3): construction of liquid Crystal cell

(1－3A)

As described above, two substrates on which liquid crystal alignment films are formed are prepared, and liquid crystal is disposed between the two substrates disposed to face each other, thereby manufacturing a liquid crystal cell. Specifically, the following two methods are listed.

In the first method, first, two substrates are arranged to face each other with a gap (cell gap) therebetween so that the liquid crystal alignment films face each other, the peripheral portions of the two substrates are bonded to each other with a sealant, a liquid crystal is injected into the cell gap defined by the substrate surfaces and the sealant and filled in the cell gap, and then the injection hole is sealed, thereby manufacturing a liquid crystal cell.

The second method is a method called an ODF (One Drop Fill) method. For example, a uv-curable sealant is applied to a predetermined portion of one of two substrates on which a liquid crystal alignment film is formed, liquid crystal is dropped onto predetermined portions of the liquid crystal alignment film surface, the other substrate is bonded to the liquid crystal alignment film surface so as to face the liquid crystal alignment film, the liquid crystal is spread over the entire surface of the crystal substrate, and then the entire surface of the substrate is irradiated with uv light to cure the sealant, thereby producing a liquid crystal cell. In either case, it is desirable that the flow alignment during filling of the liquid crystal is removed by heating the produced liquid crystal cell to a temperature at which the liquid crystal used becomes isotropic and then slowly cooling the liquid crystal cell to room temperature.

As the sealant, for example, an epoxy resin containing a curing agent and alumina balls as spacers can be used.

Examples of the liquid crystal include: nematic liquid crystals, smectic liquid crystals, and the like, among which nematic liquid crystals are preferable, and examples thereof include: schiff base (schiff base), azoxy group, biphenyl group, phenylcyclohexane group, ester group, terphenyl group, diphenylcyclohexane group, pyrimidine group, dioxane group, bicyclooctane group, cubane (cubane) group liquid crystal. In addition, cholesteric liquid crystals such as cholesteric liquid crystals including, for example, cholesteryl chloride, cholesteryl nonanoate, and cholesteryl carbonate; a chiral agent such as "C-15" or "CB-15" (trade name of MERCK); ferroelectric liquid crystals such as p-decyloxybenzylidene p-amino-2-methylbutyl cinnamate and the like.

In addition, the liquid crystal may additionally contain an anisotropic dye. For example, a black dye (black dye) or a color dye (color dye) may be used. The ratio of the anisotropic dye to the liquid crystal is appropriately selected within a range not impairing the objective physical properties, and may be appropriately changed as needed, for example, from 0.01 to 5 parts by mass per 100 parts by mass of the liquid crystal compound.

(1－3B)

In the case of a PSA type liquid crystal display element, a liquid crystal cell is constructed in the same manner as in (1-3A) except that a photopolymerizable compound such as the following formulae (w-1) to (w-5) is injected or dropped together with a liquid crystal.

The liquid crystal cell is irradiated with light in a state where a voltage is applied between the conductive films of the pair of substrates. The voltage applied here may be, for example, 5 to 50V DC or AC. The light to be irradiated may be, for example, ultraviolet light or visible light including light having a wavelength of 150 to 800nm, but preferably ultraviolet light including light having a wavelength of 300 to 400 nm. The dose of light irradiation is preferably 100 to 30000mJ/cm²More preferably 100 to 20000mJ/cm²。

(1－3C)

When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound having a photopolymerizable group, a method of manufacturing a liquid crystal display element may be employed in which a liquid crystal cell is constructed in the same manner as in (1-3A) above, and then, the liquid crystal cell is irradiated with light in a state where a voltage is applied between conductive films provided on a pair of substrates. Examples of the additive having a photopolymerizable group include those exemplified by the above formulae (w-1) to (w-5). The amount of the liquid crystal aligning agent is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, and particularly preferably 1 to 15% by mass, based on the solid content of the liquid crystal aligning agent.

Light irradiation to the liquid crystal cell may be performed in a state where a voltage is applied to drive the liquid crystal, or may be performed in a state where a low voltage is applied to the extent that the liquid crystal is not driven. The applied voltage may be, for example, 0.1 to 30V DC or AC. The above (1-3B) can be applied to the conditions of the light to be irradiated. The light irradiation treatment here corresponds to a treatment of light irradiation in a state of being in contact with the liquid crystal layer.

The liquid crystal display element of the present invention can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. Examples of the polarizing plate attached to the outer surface of the liquid crystal cell include: a polarizing plate which is formed by sandwiching a polarizing film called "H film" which absorbs iodine while extending and orienting polyvinyl alcohol with a cellulose acetate protective film; or a polarizing plate composed of the H film itself.

[ examples ]

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

The following abbreviations for the compounds and the methods for measuring the respective properties are as follows. The compound (c-1) was synthesized according to the method described in synthesis example 3 of Japanese patent application laid-open No. 2008-052260.

(diamine)

DA-1 to DA-27: are represented by the following formulae (DA-1) to (DA-27).

(tetracarboxylic dianhydride)

CA-1 to CA-8: are compounds represented by the following formulae (CA-1) to (CA-8).

(tetracarboxylic acid diester dihalide)

CE-1: a compound represented by the following formula (CE-1).

(monocarboxylic acid chloride)

E-1: acryloyl chloride.

(component B)

b-1 to b-8: are compounds represented by the following formulae (b-1) to (b-8), respectively

(other additives)

c-1 to c-4: are compounds represented by the following formulae (c-1) to (c-4).

F-1: n- α - (9-fluorenylmethyloxycarbonyl) -N-t-butoxycarbonyl-L-histidine (compound of formula (F-1)).

s-1: 3-glycidoxypropyltriethoxysilane (compound of formula (s-1)).

s-2: 3-glycidoxypropylmethyldiethoxysilane (compound of the formula (s-2)).

M-1: 3-aminomethylpyridine.

(organic solvent)

NMP: n-methyl-2-pyrrolidone, GBL: gamma-butyrolactone.

BCS: butyl cellosolve, DIBK: diisobutyl ketone.

NEP: n-ethyl-2-pyrrolidone, DAA: diacetone alcohol.

PC: propylene carbonate, DME: dipropylene glycol dimethyl ether.

DPM: dipropylene glycol monomethyl ether.

PB: propylene glycol monobutyl ether.

PGDAC: propylene glycol diacetate.

DEDE: diethylene glycol diethyl ether.

GVL: gamma valerolactone, DML: n, N-dimethyl lactamide.

EEP: 3-Ethoxypropionic acid ethyl ester.

(Fmoc represents 9-fluorenylmethoxycarbonyl group-in the formula (c-4), R represents a hydroxymethyl group or-CH₂－O－C₈H₁₇Any of the above groups. )

[ viscosity ]

The measurement was carried out at 25 ℃ using an E-type viscometer TVE-22H (manufactured by Toyobo industries Co., Ltd.), a sample volume of 1.1mL and a conical rotor TE-1 (1 ℃ C., 34', R24).

[ molecular weight ]

Mn and Mw were calculated from values converted from polyethylene glycol and polyethylene oxide by measurement using a normal temperature GPC (gel permeation chromatography) apparatus.

GPC apparatus: shodex (GPC-101), column: shodex (GPC KD-803, GPC KD-805 connected in series), column temperature: 50 ℃, eluent: n, N-dimethylformamide (as additive, lithium bromide monohydrate (LiBr. H)₂O) 30mmol/L, phosphoric acid/anhydrous crystals (O-phosphoric acid) 30mmol/L, Tetrahydrofuran (THF) 10mL/L), flow rate: 1.0 mL/min.

Calibration curve preparation standard sample: TSK Standard polyethylene oxide manufactured by Tosoh corporation (Mw: about 900000, 150000, 100000, 30000); and polyethylene glycol (peak top molecular weight (Mp) about 12000, 4000, 1000) manufactured by Polymer Laboratory. For the measurement, in order to avoid overlapping of peaks, two samples, i.e., a sample obtained by mixing four kinds of 900000, 100000, 12000, and 1000 and a sample obtained by mixing three kinds of 150000, 30000, and 4000, were measured.

< imidization ratio >

To an NMR sample tube (. phi.5 (manufactured by Softweed scientific Co.)) was added 20mg of polyimide powder, and to this tube was added 0.53ml of deuterated dimethyl sulfoxide (DMSO-d 6, 0.05% TMS (tetramethylsilane) mixture), followed by completely dissolving the mixture with ultrasonic waves. The proton NMR of the solution at 500MHz was measured by an NMR spectrometer (JNW-ECA 500) (manufactured by electronic DATUM, Japan). The imidization ratio was determined as follows: the proton derived from a structure which does not change before and after imidization was determined as a reference proton, and the peak integral value of the proton derived from an NH group of amic acid appearing in the vicinity of 9.5ppm to 10.0ppm were used to obtain the proton from the following formula.

Imidization ratio (%) - (1-. alpha.x/y). times.100

In the above formula, x is a peak integrated value of a proton derived from an NH group of amic acid, y is a peak integrated value of a reference proton, and α is a ratio of the number of reference protons to the number of protons of one NH group of amic acid in the case of polyamic acid (imidization ratio of 0%).

[ (Synthesis of component B ]

< Synthesis example (b-1) >

Compound (b-1) was synthesized according to the route shown below.

In an eggplant-shaped flask, compound (b-1-1) (5.00g, 16.5mmol), toluene (19.64g), thionyl chloride (5.90g, 49.5mmol) and N, N-Dimethylformamide (DMF) were charged by a Pasteur tube, stirred at room temperature, and then heated to 70 ℃ to react for 6 hours under a nitrogen atmosphere. The reaction solution was concentrated under reduced pressure, whereby compound (b-1-2) was obtained.

Subsequently, diethanolamine (3.47g, 33.0mmol), triethylamine (2.51g, 24.8mmol) and dichloromethane (30mL) were added to the other eggplant-shaped flask, and the mixture was stirred under ice-cooling. Next, a solution prepared by dissolving the compound (b-1-1) obtained in the above step in methylene chloride (8mL) was added thereto, and the mixture was stirred overnight. After the reaction, a saturated saline solution was added to the reaction solution, the organic layer was taken out, and the organic layer was further washed with a saturated saline solution. The obtained organic layer was dried over sodium sulfate, and the obtained solution was concentrated under reduced pressure. The precipitated solid was washed with heptane to obtain 5.29g of compound (b-1).

< Synthesis example (b-2) >

Compound (b-2) was synthesized according to the route shown below.

5-Aminoisophthalic acid (11.97g, 66.1mmol) and N, N-dimethylacetamide (DMAc) (111.97g) were added to an eggplant-shaped flask and stirred. Subsequently, a solution prepared by dissolving compound (b-1-2) (21.21g, 66.1mmol) in toluene (28.00g) was dropped into the eggplant-shaped flask, and the temperature was raised to 60 ℃. After reaction under nitrogen atmosphere, the reaction solution was poured into a mixed solution of ethanol (80mL) and water (400mL) to precipitate a solid. The obtained solid was recovered and dried to obtain 31.07g of the compound (b-2-1).

Next, compound (b-2-1) (5.00g, 10.7mmol), diethanolamine (2.37g, 22.5mmol), THF (27.27g) and 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) (6.23g, 22.5mmol) were added to the eggplant-shaped flask and reacted at room temperature for 5 hours. Saturated brine was added to the reaction solution, and the organic layer was taken out. The organic layer was dried over sodium sulfate, and acetonitrile was added to the obtained solution to precipitate a solid. The obtained solid was recovered and dried to obtain 3.57g of compound (b-2).

< Synthesis example (b-3) >

Compound (b-3) was obtained in the same procedure as in Synthesis example (b-2) except that ethanolamine was used instead of diethanolamine.

< Synthesis example (b-4) >

Compound (b-4) was synthesized according to the following route. Note that the compound (b-4-4) was synthesized in the same order as in example 3 of japanese patent application laid-open No. 2010-285367.

Compound (b-4-1) (5.00g, 21.4mmol) and THF (70g) were charged into an eggplant-shaped flask to dissolve compound (b-4-1). In contrast, diethanolamine (4.72g, 44.9mmol) and 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) (6.23g, 22.5mmol) were added and stirred at room temperature. To the resulting solution was added saturated saline, and the organic layer was taken out. The organic layer was dried over sodium sulfate, and the resulting solution was concentrated under reduced pressure to obtain 5.90g of compound (b-4-2).

Next, compound (b-4-2) (5.00g, 12.3mmol) and 160mL of 4N hydrochloric acid/ethyl acetate were added to the eggplant-shaped flask, and the mixture was stirred at room temperature for 4 hours. Then, the solvent was distilled off from the stirred solution under reduced pressure to obtain 3.50g of compound (b-4-3).

Next, compound (b-4-3) (3.00g, 9.76mmol), compound (b-4-4) (4.77g, 9.76mmol), 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) (2.77g, 10.0mmol) and THF (50g) were charged into an eggplant-shaped flask and reacted at room temperature for 5 hours. Saturated brine was added to the reaction solution, and the organic layer was taken out. The organic layer was dried over sodium sulfate, and the resulting solution was concentrated under reduced pressure to obtain 5.00g of compound (b-4).

< Synthesis example (b-5) >

Compound (b-5) was obtained in the same manner as in Synthesis example (b-4) except that diethanolamine was used in place of compound (b-4-3).

< Synthesis example (b-6) >

Compound (b-6) was obtained in the same manner as in Synthesis example (b-4) except that trihydroxymethylaminomethane was used in place of compound (b-4-3) and trans, trans-4' -pentyldicyclohexyl-4-carboxylic acid was used in place of compound (b-4-4).

< Synthesis example (b-7) >

Compound (b-7) was synthesized according to the following route. The compound (b-7-1) was synthesized in the same order as in Synthesis example 4 of WO 2018/159733. The compound (b-7-2) was synthesized in the same manner as in synthesis example (b-2) except that the compound (b-7-1) was used in place of the compound (b-1-2). Next, the compound (b-7) was synthesized in the same manner as in Synthesis example (b-2) except that (b-7-2) was used in place of compound (b-2-1) and trihydroxymethylaminomethane was used in place of diethanolamine.

< Synthesis example (b-8) >

Compound (b-8) was obtained in the same manner as in Synthesis example (b-4) except that trihydroxymethylaminomethane was used instead of compound (b-4-3).

< Synthesis example (c-3) >

Compound (c-3) was obtained in the same manner as in Synthesis example (b-4) except that monoethanolamine was used instead of compound (b-4-3).

< Synthesis example (c-4) >

Compound (c-4) was synthesized in the same order as in example 4 of japanese patent application laid-open publication No. 2011-70161.

[ Synthesis of Polymer (A) ]

< Synthesis example 1 >

CA-2 (2.25g, 8.99mmol), DA-6 (2.97g, 8.99mmol), DA-7 (3.43g, 9.01mmol) and NMP (34.6g) were added to a four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved therein, followed by reaction at 60 ℃ for 4 hours. Then, CA-3 (1.75g, 8.92mmol) and NMP (6.99g) were added thereto, and the mixture was reacted at 40 ℃ for 4 hours to obtain a polyamic acid solution.

To the polyamic acid solution (40g) was added NMP to dilute the solution to 6.5 mass%, and acetic anhydride (7.06g) and pyridine (2.19g) were added as imidization catalysts to react at 80 ℃ for 4 hours. The reaction solution was poured into methanol (463g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain a polyimide powder (Mn: 12500, Mw: 38500, imidization rate: 74%).

NMP (18.0g) was added to the obtained polyimide powder (2.0g), M-1 was added so that the content of the polyimide solid was 1 mass%, and the mixture was stirred at 70 ℃ for 12 hours to dissolve the polyimide powder, thereby obtaining a polyimide (PI-V-1) solution having a solid content concentration of 10%.

< Synthesis example 2 >

CA-2 (1.20g, 4.80mmol), DA-8 (1.46g, 9.59mmol), DA-9 (1.74g, 7.18mmol), DA-7 (2.74g, 7.20mmol) and NMP (28.58g) were charged into a four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved therein, followed by reaction at 60 ℃ for 2 hours. Then, CA-5 (1.05g, 4.81mmol) and NMP (4.19g) were added thereto and reacted at room temperature for 4 hours, and CA-3 (2.78g, 14.18mmol) and NMP (11.1g) were further added thereto and reacted at room temperature for 4 hours to obtain a polyamic acid solution.

To the polyamic acid solution (40g) was added NMP to dilute the solution to 6.5 mass%, and acetic anhydride (8.90g) and pyridine (2.76g) were added as imidization catalysts to react at 80 ℃ for 4 hours. The reaction solution was poured into methanol (472g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried under reduced pressure at 100 ℃ to obtain a polyimide powder (Mn: 13000, Mw: 39000, imidization rate: 74%).

To the obtained polyimide powder, NMP was added so that the solid content concentration became 10 mass%, M-1 was added so that the solid content became 1 mass% with respect to the polyimide, and the mixture was stirred at 70 ℃ for 12 hours to dissolve the mixture, thereby obtaining a polyimide (PI-V-2) solution.

< Synthesis example 3 >

DA-2 (5.86g, 24.0mmol), DA-10 (5.46g, 16.0mmol), DA-4 (1.73g, 16.0mmol), DA-1 (7.69g, 24.0mmol) and NMP (194g) were charged into a four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved with stirring while feeding nitrogen. While stirring the diamine solution, CA-1 (17.1g, 76.4mmol) was added, NMP was further added so that the solid content concentration became 12 mass%, and the mixture was stirred at 40 ℃ for 24 hours to obtain a polyamic acid solution (viscosity: 549 mPas, Mn of polyamic acid 12400, Mw of 33000).

NMP was added to the polyamic acid solution (225g) to dilute the solution to 9.0 mass%, and acetic anhydride (17.1g) and pyridine (3.54g) were added as an imidization catalyst to react at 55 ℃ for 3 hours. The reaction solution was poured into methanol (1111g), and the resulting precipitate was filtered off. The precipitate was washed with methanol and dried at 60 ℃ for 12 hours to obtain a polyimide powder (Mn: 11000, Mw: 28000, imidization rate: 66%).

NMP was added to the obtained polyimide powder so that the solid content concentration became 15 mass%, and the mixture was stirred at 70 ℃ for 24 hours to dissolve the NMP, thereby obtaining a polyimide (PI-I-3) solution.

< Synthesis example 4 >

DA-5 (5.73g, 20.0mmol) and NMP (115g) were charged into a 5L four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring while feeding nitrogen. While the diamine solution was stirred under water cooling, CA-3 (2.94g, 15.0mmol) was added, NMP (19.1g) was added, and the mixture was stirred under nitrogen atmosphere at 23 ℃ for 1 hour. Then, DA-3 (11.9g, 40.0mmol) and DA-11 (6.01g, 40.0mmol) were measured, NMP (72g) was added thereto, and the mixture was dissolved by stirring while transporting nitrogen. While stirring the diamine solution under water cooling, CA-3 (15.9g, 81.0mmol) was added, NMP was added so that the solid content concentration became 15 mass%, s-1 was added so that the solid content became 1 mass% with respect to the polyamic acid, and the mixture was stirred at 23 ℃ for 6 hours under nitrogen atmosphere to obtain a solution of polyamic acid (PAA-I-4, Mn: 12000, Mw: 30000).

< Synthesis example 5 >

A500 mL four-necked flask equipped with a stirrer was placed under a nitrogen atmosphere, DA-4 (2.80g, 25.9mmol), DA-2 (1.58g, 6.47mmol), NMP (111g), and pyridine (6.18g, 78.1mmol) as a base were added, and the mixture was stirred and dissolved. CE-1 (9.89g, 30.4mmol) was added while stirring the diamine solution, and then reacted at 15 ℃ until evening-out. After stirring evening, E-1 (0.38g, 4.21mmol) was added and the reaction was allowed to proceed for 4 hours at 15 ℃. The obtained polyamic acid ester solution was poured into 1230g of water while stirring, and white precipitates were collected by filtration, followed by 5 times of washing with 1230g of isopropyl alcohol (IPA) and drying to obtain 10.2g (yield: 83.0%) of a white polyamic acid ester powder (Mn: 20786, Mw: 40973).

GBL was added to the obtained polyamic acid ester powder so that the solid content concentration became 10 mass%, and the mixture was stirred at room temperature for 24 hours to dissolve the GBL, thereby obtaining a solution of polyamic acid ester (PAE-I-5).

< Synthesis example 6 >

DA-8 (0.46g, 3.00mmol), DA-13 (3.00g, 15.0mmol), DA-14 (2.56g, 12.0mmol), NMP (11.0g) and GBL (8.10g) were charged into a four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring while feeding nitrogen. While the diamine solution was stirred, CA-6 (4.76g, 24.0mmol) was added, GBL (10.9g) was added, and the mixture was stirred at room temperature for 2 hours. After GBL (10.8g) was added thereto and the mixture was stirred, CA-5 (1.31g, 6.01mmol) and GBL (14.3g) were added thereto and the mixture was stirred at room temperature for 24 hours. The solution of the obtained polyamic acid (Mn: 14200, Mw: 30110) had a viscosity of 2041 mPas.

Then, s-2 was added so as to be 1 mass% with respect to the solid content of polyamic acid, NMP and GBL were added so that the mixing ratio of NMP and GBL was 20: 80 in terms of the mass ratio and the solid content concentration was 15 mass%, and a solution of polyamic acid (PAA-I-6) was obtained.

< Synthesis examples 7 to 11, 14 to 20 >

By using the diamines, tetracarboxylic acid derivatives, and organic solvents shown in Table 1 below, solutions of the polyimides (PI-V-V-8), (PI-V-9), (PI-I-11), (PI-V-19), and (PI-V-20), the polyamic acids (PAA-I-7), (PAA-I-10), (PAA-V-14), (PAA-V-16), (PAA-I-17), and (PAA-I-18) shown in Table 1 below were obtained in the same order as in the above synthesis examples.

In table 1, the numerical values in parentheses represent the mixing ratio (molar parts) of each compound with respect to 100 molar parts of the total amount of the tetracarboxylic acid derivatives used for synthesis, with respect to the tetracarboxylic acid component. The diamine acid component represents the mixing ratio (molar part) of each compound to 100 molar parts of the total amount of diamines used for synthesis. The end-capping agent is a blending ratio (molar part) based on 100 molar parts of the total amount of diamines used for synthesis. The organic solvent represents a blending ratio (parts by mass) of each organic solvent with respect to 100 parts by mass of the total amount of the organic solvents used for synthesis.

[ Table 1]

[ Synthesis of other Polymer ]

< Synthesis example 12 >

A reactive polyorganosiloxane polymer was obtained by using 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS) according to the method described in Japanese patent application laid-open No. 2018-54761 [0091 ]. Next, a polymer of polyorganosiloxane represented by the following formula (P-S1) was obtained according to the method described in [0093] of Japanese patent application laid-open No. 2018-54761. The numerical values (70, 20, 10) in the formula (P-S1) represent the use ratio (molar parts) of each compound to the total of the silane compounds used for the synthesis.

< synthetic example 13 >

A reactive polyorganosiloxane polymer was obtained by using 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane (ECETS) according to the method described in Japanese patent application laid-open No. 2018-54761 [0091 ]. Next, a polymer of polyorganosiloxane represented by the following formula (P-S2) was obtained according to the method described in [0093] of Japanese patent application laid-open No. 2018-54761. The numerical values (70, 30) in the formula (P-S2) represent the use ratio (molar parts) of each compound to the total of the silane compounds used for the synthesis.

< example 1 >

[ preparation of liquid Crystal Aligning agent ]

The solution of the polyimide (PI-V-1) obtained in Synthesis example 1 and the solution of the polyimide (PI-V-2) obtained in Synthesis example 2 were diluted with NMP and BCS, and further, the compounds (b-1) and (b-2) were added in amounts of 1 part by mass and 5 parts by mass, respectively, based on 100 parts by mass of the total polymer, and the mixture was stirred at room temperature. Then, the obtained solution was filtered through a filter having a pore diameter of 0.5 μm, whereby a liquid crystal aligning agent (V1) having a polymer component ratio (solid content equivalent mass ratio) of (PI-V-1): (PI-V-2): 30: 70, a solvent composition ratio (mass ratio) of NMP: BCS of 60: 40, a polymer solid content concentration of 4.5%, a compound (b-1) compounding ratio of 1 part by mass, and a compound (b-2) compounding ratio of 5 parts by mass was obtained (see table 2-1 below). It was confirmed that the liquid crystal aligning agent was a uniform solution without any abnormality such as turbidity and precipitation.

< examples 2 to 50, comparative examples 1 to 6 >

Liquid crystal aligning agents (V2) to (V11), (I12-P) to (I29-P), (I30-U) to (I37-U), (V38) to (V43), (I44-P) to (I47-P), (V48-P) to (V49-P), (I50-U), (R-V1) to (R-V2), (R-I3-P), (R-I4-U), and (R-V5) to (R-V6) were obtained in the same manner as in example 1, except that the polymers and additives shown in tables 2-1 to 2-4 below were used. In tables 2-1 to 2-4, the numerical values in parentheses represent the blending ratio (parts by mass) of each polymer component or additive to 100 parts by mass of the total of the polymer components used for preparing the liquid crystal aligning agent, respectively, for the polymer and the additive. The organic solvent represents a blending ratio (parts by mass) of each organic solvent with respect to 100 parts by mass of the total amount of organic solvents used for preparing the liquid crystal aligning agent.

[ Table 2-1 ]

[ tables 2-2 ]

[ tables 2 to 3]

[ tables 2 to 4]

[ evaluation of reworkability of liquid Crystal alignment agent ]

The liquid crystal alignment agent obtained above was applied to an ITO substrate by spin coating. After drying on a hot plate at 60 ℃ for 1 minute and 30 seconds, the film was baked in a hot air circulating oven at 230 ℃ for 20 minutes to form a coating film having a thickness of 100 nm. Then, the substrate thus produced was immersed in NMP heated to 35 ℃ or 50 ℃ for 5 minutes, and then washed with running water for 20 seconds using ultrapure water. The coating film was "excellent" when immersed in NMP at 35 ℃ for 5 minutes without leaving a coating film, was "good" when immersed in NMP at 50 ℃ for 5 minutes without leaving a coating film, and was "poor" when immersed in NMP at 50 ℃ for 5 minutes with a coating film remaining.

[ production and evaluation of liquid Crystal display device ]

1-1. Production of vertical alignment type liquid crystal display element

Preparing two glass substrates (longitudinal: 40mm, transverse: 30mm, thickness: 1.1mm) with ITO electrodes; washing was performed with pure water and isopropanol. Then, liquid crystal aligning agents (V1) to (V11), (V38) to (V43) and (R-V1) to (R-V2) and (R-V5) to (R-V6) filtered through a filter having a pore diameter of 1.0 μm were spin-coated on each ITO surface, and heat treatment was performed on a hot plate at 70 ℃ for 90 seconds and a thermal cycle type cleaning oven at 230 ℃ for 30 minutes to obtain an ITO substrate having a film with a film thickness of 100 nm.

Next, the periphery was coated with a sealant (XN-1500T, manufactured by Mitsui chemical Co., Ltd.). Next, the other substrate was bonded to the former substrate with the surface on which the liquid crystal alignment film was formed as the inner side, and then the sealing material was cured to produce an empty cell. Liquid crystal MLC-3023 (trade name manufactured by MERCK corporation) was injected into empty cells using liquid crystal alignment agents (V1) to (V2), (V5) to (V11), (V38) to (V43), and (R-V1) by a reduced pressure injection method to produce liquid crystal cells.

Then, a direct current voltage of 15V was applied to the obtained liquid crystal cell, and 10J/cm of the liquid crystal was irradiated with ultraviolet light using a high-pressure mercury lamp as a light source in a state where all pixel regions were driven²The ultraviolet light passed through a band-pass filter having a wavelength of 365nm was used to obtain a liquid crystal display element for evaluation. The UV-35 light receiver was connected to UV-M03A manufactured by ORC, and used for measuring the amount of ultraviolet light.

Liquid crystal MLC-6608 (trade name manufactured by MERCK corporation) was injected into empty cells using liquid crystal alignment agents (V3) to (V4) and (R-V2) and (R-V5) to (R-V6) by a reduced pressure injection method to obtain liquid crystal display elements for evaluation. The obtained liquid crystal display element was observed with a polarization microscope, and as a result, uniform alignment was observed in any liquid crystal.

1-2. Evaluation of liquid Crystal display element

[ evaluation of Voltage holding ratio ]

The liquid crystal display element produced in 1-1 was left to stand in an oven at 80 ℃ under irradiation of an LED lamp for 200 hours, then left to stand at room temperature, and was naturally cooled to room temperature. Then, after applying a voltage of 1V at 60 ℃ for an application time of 60 microseconds and a time span of 1667 milliseconds, the voltage holding ratio was measured after 1000 milliseconds from the release of the application. As the measuring apparatus, TOYO Corporation was used.

2-1. Production of FFS type liquid crystal display element using photo-alignment

First, a glass substrate with electrodes (length: 30mm, width: 50mm, thickness: 0.7mm) was prepared. An ITO electrode having a dense pattern constituting a counter electrode is formed as a first layer on a substrate. On the counter electrode of the first layer, a SiN (silicon nitride) film formed by a CVD method is formed as a second layer. The SiN film of the second layer has a film thickness of 500nm and functions as an interlayer insulating film. On the SiN film of the second layer, a comb-shaped pixel electrode formed by patterning an ITO film is disposed as a third layer, and two kinds of pixels, i.e., a first pixel and a second pixel, are formed. The size of each pixel is 10mm long and about 5mm wide. At this time, the counter electrode of the first layer and the pixel electrode of the third layer are electrically insulated by the SiN film of the second layer.

The pixel electrode of the third layer has a comb-tooth shape in which a plurality of "< symbol" -shaped electrode elements each having a central portion bent at an internal angle of 160 ° are arranged. The width of each electrode element in the short dimension direction was 3 μm, and the interval between the electrode elements was 6 μm. Each pixel is divided vertically at a central bent portion into a boundary, and has a first region above the bent portion and a second region below the bent portion.

Then, the liquid crystal alignment agents (I12-P) to (I29-P), (I44-P) to (I47-P) and (R-I3-P) were filtered through a filter having a pore diameter of 1.0 μm, and then applied to the substrate with electrodes and a glass substrate having a column spacer with a height of 4 μm on the back surface thereof, on which an ITO film was formed, by spin coating.

The coating films obtained from the liquid crystal alignment agents (I12-P) to (I29-P) and (R-I3-P) were dried on a hot plate at 80 ℃ for 5 minutes and then baked in a hot air circulating oven at 230 ℃ for 20 minutes to obtain a polyimide film having a film thickness of 100 nm. Then, the coated film was irradiated with 500mJ/cm of light through a polarizing plate²The linearly polarized ultraviolet ray having a wavelength of 254nm and an extinction ratio of 26: 1 was then baked in a hot air circulating oven at 230 ℃ for 30 minutes to obtain a substrate having a liquid crystal alignment film with a film thickness of 100 nm. It is to be noted thatThe liquid crystal alignment film formed on the electrode-attached substrate is subjected to alignment treatment so that the direction of the inner angle of the pixel bending portion is orthogonal to the alignment direction of the liquid crystal, and the liquid crystal alignment film formed on the substrate having the columnar spacer is subjected to alignment treatment so that the alignment direction of the liquid crystal on the electrode-attached substrate coincides with the alignment direction of the liquid crystal on the substrate having the columnar spacer when a liquid crystal cell is manufactured.

The coating films obtained from the liquid crystal alignment agents (I44-P) to (I47-P) were dried on a hot plate at 80 ℃ for 5 minutes, and then the coating films were irradiated with 500mJ/cm of light through a polarizing plate²The linearly polarized ultraviolet ray having a wavelength of 254nm and an extinction ratio of 26: 1 was then baked in a hot air circulating oven at 230 ℃ for 30 minutes to obtain a substrate having a liquid crystal alignment film with a film thickness of 100 nm.

Next, a sealant was printed on one of the pair of glass substrates with the liquid crystal alignment film, the other substrate was bonded so that the liquid crystal alignment film faces each other, and the sealant was cured to produce an empty cell. Liquid crystal MLC-3019 (manufactured by MERCK) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed, thereby obtaining an FFS-driven liquid crystal display element. Then, the obtained liquid crystal cell was heated at 120 ℃ for 1 hour, placed overnight, and the liquid crystal display element was observed with a polarizing microscope, and as a result, uniform alignment was observed in all liquid crystals.

2-2. Evaluation of liquid Crystal display element

[ evaluation of Voltage holding ratio ]

Two glass substrates (length: 40mm, width: 30mm, thickness: 1.1mm) each having an ITO electrode were prepared, and a liquid crystal alignment film having a film thickness of 100nm was formed on the ITO surface in the same manner as in the above-mentioned 2-1. A bead-like spacer (a filament ball, manufactured by Nikkiso Co., Ltd., SW-D1) having a diameter of 4 μm was coated on the liquid crystal alignment film surface of one of the substrates.

Next, the periphery was coated with a sealant (XN-1500T, manufactured by Mitsui chemical Co., Ltd.). Next, the other substrate was bonded to the former substrate with the surface on which the liquid crystal alignment film was formed as the inner side, and then the sealing material was cured to produce an empty cell. The empty cell was filled with liquid crystal MLC-3019 (trade name manufactured by MERCK) by a reduced pressure injection method to produce a liquid crystal display element. Next, the liquid crystal display element was left to stand in an oven at 80 ℃ under irradiation of an LED lamp for 200 hours, then left to stand at room temperature, and naturally cooled to room temperature. Then, evaluation was performed in the same order as in 1-2 above. The evaluation results are shown in table 3.

3-1. Fabrication of FFS-type liquid crystal display element using brush-rubbing alignment

First, liquid crystal alignment agents (I30-U) to (I37-U), (I50-U), and (R-I4-U) filtered through a filter having a pore size of 1.0 μm were applied to the surfaces of a pair of glass substrates similar to those of the above-mentioned substrate No. 2-1 by using an ink jet applicator (HIS-200, manufactured by Hitachi Plant Technologies). The coating was carried out under the following conditions: the coating area was 70X 70mm, the nozzle pitch was 0.423mm, the scanning pitch was 0.5mm, the coating speed was 40 mm/sec, and the film was left for 60 seconds from coating to drying. Then, the film was dried on a hot plate at 80 ℃ for 5 minutes, and then fired in a hot air circulation oven at 230 ℃ for 20 minutes to obtain a polyimide film having a film thickness of 100 nm. This polyimide film was brushed with rayon cloth (roll diameter: 120mm, roll rotation speed: 500rpm, moving speed: 30mm/sec, pressing length: 0.3mm, brushing direction: direction inclined at 10 ° to 3-layer IZO comb electrode), and then cleaned by ultrasonic irradiation in pure water for 1 minute to remove water droplets. Then, the substrate was dried at 80 ℃ for 15 minutes to obtain a substrate with a liquid crystal alignment film. The two substrates with the liquid crystal alignment films were set as one set, and a sealant was printed so that a liquid crystal injection port remained on the substrates, and the other substrate was bonded so that the liquid crystal alignment films were opposed to each other and the brushing direction was antiparallel. Then, the sealant was cured to prepare an empty cell having a cell gap of 4 μm. Liquid crystal MLC-7026-100 (manufactured by MERCK corporation) was injected into the empty cell by a reduced pressure injection method, and the injection port was sealed, thereby obtaining an FFS liquid crystal display element. Then, the resulting liquid crystal display element was heated at 120 ℃ for 1 hour and placed at 23 ℃ after evening for evaluation of afterimage evaluation. The obtained liquid crystal display element was observed with a polarization microscope, and as a result, uniform alignment was observed in any liquid crystal.

3-2. Evaluation of liquid Crystal display element

[ evaluation of Voltage holding ratio ]

Evaluation was performed in the same manner as in 2-2, except that the same liquid crystal alignment film as in 3-1 was used and the liquid crystal was MLC-7026-100. The evaluation results are shown in table 3.

4-1. Fabrication of VA-type liquid crystal display element using photo-alignment

Two glass substrates identical to those of 1-1 above were prepared, and each of the liquid crystal alignment agents (V48-P) and (V49-P) was spin-coated on the substrate, and heat-treated on a hot plate at 80 ℃ for 90 seconds and 200 ℃ for 40 minutes in a thermal cycle type cleaning oven to obtain an ITO substrate with a liquid crystal alignment film having a film thickness of 100 nm.

Next, the substrate was exposed to linearly polarized UV light at an incident angle of 40 ° with respect to the perpendicular direction of the substrate surface. The exposure amount applied was set to 20mJ/cm². After exposure, a cartridge having two substrates was assembled so that the exposed alignment layers faced the inside of the cartridge, and the substrates were adjusted so that the alignment directions were parallel to each other. Next, liquid crystal MLC-7067 (manufactured by MERCK corporation) was injected. Then, annealing was performed at about 90 ℃ for 10 minutes, and after cooling to room temperature, evaluation was performed for afterimage evaluation. The obtained liquid crystal display element was observed with a polarization microscope, and as a result, uniform alignment was observed in any liquid crystal.

4-2. Evaluation of liquid Crystal display element

[ evaluation of Voltage holding ratio ]

The liquid crystal display element produced in the above 4-1 was allowed to stand in an oven at 80 ℃ under irradiation of an LED lamp for 200 hours, then allowed to stand at room temperature, and naturally cooled to room temperature. Evaluation was performed in the same order as in 1-2 above. The evaluation results are shown in table 3. In table 3, examples 1 to 50 are the evaluation results of the liquid crystal aligning agent of the examples of the present invention, and examples 51 to 56 are the evaluation results of the liquid crystal aligning agent of the comparative examples.

[ Table 3]

Industrial applicability

The liquid crystal aligning agent of the present invention is useful for forming liquid crystal alignment films in various liquid crystal display devices such as a vertical alignment type liquid crystal display device and an FFS drive type liquid crystal display device. The liquid crystal display element including the liquid crystal aligning agent of the present invention can be effectively used in various devices, for example, various display devices such as clocks, portable game machines, word processors, notebook computers, car navigation systems, camcorders (camcorders), PDAs, digital cameras, cellular phones, smart phones, various monitors, liquid crystal televisions, and information displays. The liquid crystal alignment film is not limited to the above, and may be used for a liquid crystal alignment film for a retardation film, a liquid crystal alignment film for a scanning antenna, a liquid crystal array antenna, a liquid crystal alignment film for a transmission/scattering type liquid crystal light control element, or other applications, for example, a protective film for a color filter, a gate insulating film for a flexible display, and a substrate material.

All the contents of the specification, claims, drawings and abstract of japanese patent application No. 2019-127053, which was filed on 7/8/2019, are incorporated herein by reference as disclosure of the specification of the present invention.

Claims

1. A liquid crystal aligning agent characterized by containing the following components (A) and (B),

(A) the components: at least one polymer selected from the group consisting of a polyimide polymer, a polyorganosiloxane, a polymer of a monomer having a polymerizable unsaturated bond, and a cellulose polymer,

(B) the components: a compound having a molecular weight of 2000 or less, which has at least one group represented by the following formulae (b-1) to (b-5) or at least two groups represented by the following formula (b-6), and which has any one of a structure in which two or more rings are linked directly or via a linking group and a steroid skeleton,

wherein R is₂、R_4a、R_4b、R₅、R₆Each independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and represents a bond.

2. The liquid crystal aligning agent according to claim 1,

the polyimide-based polymer is a polymer (A-1) having at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2),

wherein, X₁Represents a tetravalent organic group; y is₁Represents a divalent organic group; r₁Represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; z₁₁、Z₁₂Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may be substituted, an alkenyl group having 2 to 10 carbon atoms which may be substituted, an alkynyl group having 2 to 10 carbon atoms which may be substituted, a tert-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group.

3. The liquid crystal aligning agent according to claim 2,

said X₁Is a tetravalent organic group selected from the group consisting of the following formulae (4a) to (4n), the following formula (5a) and the following formula (6a),

wherein x and y represent a single bond, -O-, -CO-, -COO-and a carbon atom number1-5 alkylene, 1, 4-phenylene, -SO-, or-NRCO-, wherein R represents a hydrogen atom or a methyl group; z¹～Z⁶Each independently represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a chlorine atom or a benzene ring; j. k is an integer of 0 or 1; m is an integer of 1 to 5; denotes a bond.

4. The liquid crystal aligning agent according to claim 3,

the total content of one or more kinds of repeating units selected from the group consisting of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is 5 mol% or more based on the total repeating units, and in the formula (1) and the formula (2), X is₁Is a tetravalent organic group selected from the group consisting of the formulas (4a) to (4n), (5a) and the formula (6a), Y₁Is a divalent organic group.

5. The liquid crystal aligning agent according to any one of claims 1 to 4,

the component (B) is a compound represented by the following formula (3-1) or the following formula (3-2),

wherein, B₁Represents a structure selected from the formulae (b-1) to (b-6); b is₂Represents a structure selected from the formulae (b-1) to (b-5); l is₁Represents the following formula (1L-1) or (1L-2); l is₂Represents a single bond, the following formula (2L-1), or is selected from-CH₂－、－CH(CH₃)－、－C(CH₃)₂－、－(CH₂)_nand-NR-a divalent group of the group consisting of₂)_nIn the formula (I), n represents an integer of 2 to 20, and in the formula (NR), R represents a hydrogen atom or a methyl group, and the divalent group is hereinafter referred to as a linking group (2 a); in addition, the- (CH) is₂)_nAny of-CH₂Optionally substituted by-O-, -CH (CH)₃)－、－C(CH₃)₂-, -CO-or-NR-; AL₁、AL₂Each independently represents a-Cy₁－Z₁or-Cy₂(ii) a m1 represents an integer of 1 to 4; m2 represents an integer of 1 to 2; cy is a Cy-is₁Denotes a structure in which two or more rings are linked directly or via a linking group, Cy₂Represents a group having a steroid skeleton; z₁Represents a linear or branched hydrocarbon group having 3 or more carbon atoms,

wherein 1 represents Al₁A bonding bond of bonding ` 2 represents a bond with B₁A bonded linkage; n1 represents an integer of 1 to 2, and n2 represents an integer of 1 to 4; a. the₁₁、A₁₂Each independently represents a single bond, -O-, or a linking group (2 a); in A₁₂In the case where there are plural, plural A₁₂May be the same or different; a. the₂₁、A₂₂Each independently represents a linking group (2a) other than-NR-; a. the_s11Represents a single bond, -O-, -CO-, or a linking group (2 a); a. the_s12Represents a single bond, -CO-, or a linking group other than-NR- (2a),

wherein 1 represents and B₂Bonding bond of bonding ` 2 represents bonding with AL₂Bonded linkage of A_s2And A_s11Synonymously.

6. The liquid crystal aligning agent according to claim 5,

the component (B) is a compound represented by the formula (3-1).

7. The liquid crystal aligning agent according to claim 5 or 6,

z is₁The alkyl group is a linear or branched alkyl group having 3 to 20 carbon atoms, a linear or branched fluoroalkyl group having 3 to 20 carbon atoms, a linear or branched alkoxy group having 3 to 20 carbon atoms, or a linear or branched alkyl ester group having 3 to 20 carbon atoms.

8. The liquid crystal aligning agent according to any one of claims 5 to 7,

the Cy is₁Represented by the following formula (Rn),

in the formula (Rn), X independently represents a single bond, -O-, -CO-, -COO-, -NR^b－、－CONR^b-, alkylene group having 1 to 10 carbon atoms, or alkylene group having 1 to 10 carbon atoms, at least one methylene group being substituted by-O-, -CO-, -COO-, -NR^b-or-CONR^b-a divalent group substituted by-CONR^bIn (A) R^bIs a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protecting group; m is 2-6; g independently represents a benzene ring, a naphthalene ring or a cyclohexane ring, and represents a bonding bond.

9. The liquid crystal aligning agent according to any one of claims 1 to 8,

the component (B) is a compound represented by any one of the following formulae (B-1) to (B-8),

10. the liquid crystal aligning agent according to any one of claims 1 to 9,

the component (A) contains a polyimide-based polymer and at least one polymer selected from the group consisting of polyorganosiloxanes, polymers of monomers having polymerizable unsaturated bonds, and cellulose-based polymers.

11. The liquid crystal aligning agent according to any one of claims 1 to 9,

the component (A) contains a polyimide-based polymer and a polyorganosiloxane.

12. The liquid crystal aligning agent according to any one of claims 1 to 11,

the content of the component (B) is 0.1 to 40 parts by mass per 100 parts by mass of the component (A).

13. The liquid crystal aligning agent according to claim 1 to 12,

the liquid crystal aligning agent includes an organic solvent including at least one good solvent selected from the group consisting of N, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, γ -butyrolactone, γ -valerolactone, 1, 3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, N-dimethyllactamide, 3-methoxy-N, N-dimethylpropionamide, and 3-butoxy-N, N-dimethylpropionamide as the organic solvent.

14. The liquid crystal aligning agent according to claim 13,

the liquid crystal aligning agent further comprises at least one poor solvent selected from the group consisting of diisobutyl carbinol, 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 acetate, and diisobutyl ketone.

15. A liquid crystal alignment film obtained from the liquid crystal aligning agent according to any one of claims 1 to 14.

16. A liquid crystal display device comprising the liquid crystal alignment film according to claim 15.