CN114080443B

CN114080443B - Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element using same

Info

Publication number: CN114080443B
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: 2024-04-26
Anticipated expiration: 2040-07-02
Also published as: CN114080443A; JPWO2021006182A1; JP7494852B2; WO2021006182A1; TW202116872A; KR20220027945A

Abstract

The invention provides a liquid crystal aligning agent capable of obtaining a liquid crystal alignment film, wherein the liquid crystal alignment film can maintain high voltage retention rate and has excellent reworkability. A liquid crystal aligning agent characterized by comprising the following component (A) and component (B). Component (A): at least one polymer selected from the group consisting of polyimide-based polymers, polyorganosiloxanes, polymers of monomers having polymerizable unsaturated bonds, and cellulose-based polymers. Component (B): a compound having a structure in which two or more rings are bonded directly or via a linking group, or a steroid skeleton, and having 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 having a molecular weight of 2000 or less. ( Wherein R ₂、R_4a、R_4b、R₅、R₆ independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. * Representing 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 a liquid crystal display device, various driving methods have been developed in which the electrode structure, physical properties of liquid crystal molecules used, manufacturing processes, and the like are different. For example, it is known that: TN (TWISTED NEMATIC: twisted nematic), STN (super-TWISTED NEMATIC: super-twisted nematic), VA (VERTICAL ALIGNMENT: vertical alignment), MVA (multi-domain VERTICAL ALIGNMENT: multi-domain vertical alignment), IPS (in-PLANE SWITCHING: in-plane switching) type, FFS (FRINGE FIELD SWITCHING: fringe field switching) type, PSA (polymer-Sustained Alignment: polymer stable alignment) type, and the like.

These liquid crystal display elements include a liquid crystal alignment film for aligning liquid crystal molecules. In view of various good properties such as heat resistance, mechanical strength, and affinity with liquid crystal, a film containing a polymer such as polyamide acid, polyimide, or polysiloxane is generally used as a material of the liquid crystal alignment film.

In recent years, a liquid crystal display device has been increasingly required to have high image quality. For example, a liquid crystal display element capable of maintaining a high voltage holding ratio together with a good liquid crystal alignment property is desired, and patent documents 1 and 2 disclose liquid crystal alignment agents containing specific compounds.

Prior art literature

Patent literature

Patent document 1: international publication (WO) 2016/063134

Patent document 2: japanese patent laid-open publication 2016-200798

Disclosure of Invention

Problems to be solved by the invention

In addition, since the economy of the liquid crystal display element in the production process is also very important, recycling of the element substrate is particularly required. That is, after forming a liquid crystal alignment film on a substrate of an element from a liquid crystal alignment agent, the alignment property and the like are inspected, and as a result, when a defect occurs, it is required to easily remove the liquid crystal alignment film from the substrate, and to recycle the substrate, that is, a so-called rework process.

The conventionally proposed liquid crystal aligning agent is not necessarily sufficient to achieve the above-mentioned 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 is excellent in reworkability; a liquid crystal alignment film obtained from the liquid crystal alignment agent; and a liquid crystal display element using the liquid crystal alignment film.

Solution for solving the problem

As a result of intensive studies, the present inventors have found that the above problems can be solved by using a liquid crystal aligning agent containing specific components, and have completed the present invention.

The present invention has the following gist.

A liquid crystal aligning agent characterized by comprising the following component (A) and component (B).

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

(B) The components are as follows: a compound having a structure in which two or more rings are directly or via a linking group, or a steroid skeleton, 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 having a molecular weight of 2000 or less.

(R ₂、R_4a、R_4b、R₅、R₆ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; independently of each other)

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 is excellent in reworkability and a liquid crystal display element capable of maintaining a high voltage holding ratio can be obtained.

Detailed Description

Component (A)

The liquid crystal aligning agent of the invention comprises at least one polymer (A) selected from the group consisting of polyimide polymer (A-1), polyorganosiloxane (A-2), polymer (A-3) of monomer with polymerizable unsaturated bond and cellulose polymer (A-4), wherein the polyimide polymer (A-1) has at least one repeating unit selected from the group consisting of repeating unit shown in the following formula (1) and repeating unit shown in 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), X ₁ is a tetravalent organic group and Y ₁ is a divalent organic group. R ₁ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and Z ₁₁、Z₁₂ is each independently 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.

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

Specific examples of the alkyl group having 1 to 10 carbon atoms in Z ₁₁、Z₁₂ in the above formula (2) include, in addition to the specific examples of the alkyl group having 1 to 5 carbon atoms shown in the above description of R ₁: hexyl, heptyl, octyl, nonyl, decyl, and the like. Specific examples of the alkenyl group having 2 to 10 carbon atoms in Z ₁₁、Z₁₂ include: ethenyl, propenyl, butenyl, and the like, which may be linear or branched. Specific examples of the alkynyl group having 2 to 10 carbon atoms in Z ₁₁、Z₁₂ include: ethynyl, 1-propynyl, 2-propynyl, and the like.

The above Z ₁₁、Z₁₂ may have a substituent, and examples of the substituent include: halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), hydroxyl group, cyano group, alkoxy group, etc. In terms of few afterimages, Z ₁₁、Z₁₂ is preferably a hydrogen atom or a methyl group.

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

Here, the aromatic tetracarboxylic dianhydride is an acid dianhydride obtained by intramolecular dehydration of four carboxyl groups including at least one carboxyl group 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. However, the structure need not be composed of only a chain hydrocarbon structure, and part of the structure 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 is bonded to an aromatic ring. Further, the structure need not be composed of only an alicyclic structure, and a part thereof may have a chain hydrocarbon structure or an aromatic ring structure.

In terms of obtaining a high voltage holding ratio, X ₁ is preferably a tetravalent organic group selected from the group consisting of the following formulas (4 a) to (4 n), the following formula (5 a), and the following formula (6 a).

Wherein x and y represent 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). Z ¹～Z⁶ each 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.* Representing a bond.

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

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

In terms of obtaining a high voltage holding ratio, X ₁ in the above formula (1) is preferably a tetravalent organic group selected from the group consisting of the above formulas (4 a) to (4 h), (4 j), (4 l), (4 m) and (4 n).

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

As Y ₁ of formula (1), there may be mentioned divalent organic groups derived from diamines. Examples thereof include divalent organic groups derived from aliphatic diamines, alicyclic diamines or aromatic diamines. Specific examples of the aliphatic diamine include: m-xylylenediamine, ethylenediamine, 1, 3-propane diamine, tetramethylenediamine, hexamethylenediamine, and the like; the alicyclic diamine includes: 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-trimethyl-1H-indan-5-amine 1- (4-aminophenyl) -2, 3-dihydro-1, 3-trimethyl-1H-inden-6-amine, 2, 6-diaminopyridine, 3, 4-diaminopyridine, 2, 4-diaminopyrimidine, 3, 6-diaminocarbazole, N-methyl-3, 6-diaminocarbazole, bis (4-aminophenyl) amine, N, N-bis (4-aminophenyl) methylamine, N '-bis (4-aminophenyl) -benzidine, N, N' -bis (4-aminophenyl) -N, N '-dimethylbenzidine, 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, a nitrogen-containing diamine represented by the following formulae (z-1) to (z-19), a carboxyl-containing diamine represented by the following formulae (z-1) to (z-19), 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, diamines of the following formulae (H-1) to (H-16), (H2-1) to (H2-17), and (H3-1) to (H3-4), diamines having a photopolymerizable group at the terminal end such as the following formulae (V2-1) to (V2-13), fluoroalkyl groups having 3 to 20 carbon atoms, alkoxy groups having 3 to 20 carbon atoms, groups having a steroid skeleton having 17 to 51 carbon atoms, diamines of a structure (polycyclic structure) in which two or more rings are bonded directly or via a linking group, diamines having a radical initiating function such as the following formulae (R1) to (R5), diamines having a photopolymerizable group at the terminal end such as the following formulae (V2-1) to (V2-13), diamines having a photoinitiated structure such as the following formulae [0053] of WO2014/080865, diamines having a photoinitiated structure such as the following formulae [ 0050804/0805 ], diamines having a photoinitiated structure such as the following formulae [ 0075 ] of the following formulae (R1) or the following formulae (R5), diamines having a photoinitiated structure such as the following [ 0053/0808 ] of the following formulae (WO 2010805).

(N represents an integer of 2 to 10.)

(Boc represents t-butoxycarbonyl. The same applies hereinafter.)

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

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

Wherein in the formulae (V2-1) to (V2-13), X ^v1～X^v4、X^p1～X^p8 each independently represents- (CH ₂)_a - (a is an integer of 1 to 15) -CONH-, -NHCO-, -CON (CH ₃)－、－NH－、－O－、－CH₂O－、－CH₂ OCO-, -COO-, or-OCO-, X ^v5 represents-O-, -CH ₂O－、－CH₂ OCO-, -COO-, or-OCO-. X ^V6、X^V7、X^s1～X^s4 each independently represents-O-, -COO-or-OCO-. X _a～X_f represents a single bond, -O-, -NH-, -O- (CH ₂)_m－O－.R^v1～R^v4、R^1a～R^1h) each 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: the tetracarboxylic acid derivative having the structure of X ₁ and the diamine having the structure of Y ₁ are reacted by a known method described in WO 2013/157586.

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

Examples of the blocking agent include: maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxy phthalic anhydride, trimellitic anhydride, and acid monoanhydrides represented by any of the following formulas (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; monoisocyanate compounds such as ethyl isocyanate, phenyl isocyanate and naphthyl isocyanate.

The ratio of the capping agent 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 diamine 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 oxetanyl groups and oxirane groups in the molecule, for example, in terms of imparting a high voltage holding ratio to a liquid crystal display element. Specific examples of the silane compound having an oxetanyl group or an oxirane group include: glycidoxymethyl trimethoxysilane, glycidoxymethyl triethoxysilane, 2-glycidoxyethyl trimethoxysilane, 2-glycidoxyethyl triethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-glycidoxypropyl methyldimethoxy silane, 2- (3, 4-epoxycyclohexyl) ethyl triethoxysilane, and the like.

Examples of the 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-mercaptopropyl triethoxysilane, mercaptomethyl triethoxysilane, 3-aminopropyl trimethoxysilane, and N- (3-cyclohexylamino) propyl trimethoxysilane; alkoxysilanes having an unsaturated bond such as 3- (meth) acryloxypropyl trimethoxysilane, 3- (meth) acryloxypropyl methyl dimethoxy silane, 3- (meth) acryloxypropyl methyl diethoxy silane, and vinyltriethoxy silane; trimethoxysilylpropyl succinic anhydride, and the like.

In the case of a liquid crystal aligning agent used for a TN-type, STN-type or vertical alignment type liquid crystal display element, or in the case of imparting liquid crystal aligning ability to a coating film 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 subjected to hydrolytic condensation to synthesize an epoxy group-containing polymer, and then the obtained epoxy group-containing polymer is reacted with a carboxylic acid having the above-mentioned 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 specific group include: a carboxylic acid having a liquid crystal-oriented 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 17 to 51 carbon atoms and having a steroid skeleton, a group having a structure (polycyclic structure) in which two or more rings are bonded directly or via a linking group, a carboxylic acid having a photo-oriented group such as a cinnamic acid structure, and the like.

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, still more preferably 1000 to 20000.

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

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: (meth) acrylic compounds, conjugated diene compounds, aromatic vinyl compounds, maleimide compounds, and the like. In view of imparting a high voltage holding ratio to the liquid crystal display element, 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 protective isocyanate group in a molecule.

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- (glycidoxymethyl) styrene, 4- (glycidoxymethyl) styrene, and 4-glycidyl- α -methylstyrene; (meth) acrylic compounds such as glycidyl (meth) acrylate, glycidyl α -ethyl acrylate, glycidyl α -n-propyl acrylate, glycidyl α -n-butyl acrylate, 3, 4-epoxybutyl (meth) acrylate, 3, 4-epoxybutyl α -ethyl acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, 6, 7-epoxyheptyl (meth) acrylate, 4-hydroxybutyl glycidyl ether of acrylic acid, 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, alpha-ethacrylic acid, maleic acid, fumaric acid, vinylbenzoic acid, crotonic acid, citraconic acid, mesaconic acid, itaconic acid, 3-maleimide benzoic acid, 3-maleimide propionic acid, maleic anhydride, and the like. Examples of the monomer having an isocyanate group or a blocked isocyanate group include: 2-methacryloxyethyl isocyanate (Karenz MOI, manufactured by Showa electric company), 2- [ (3, 5-dimethylpyrazolyl) carbonylamino ] ethyl methacrylate (Karenz MOI-BP, manufactured by Showa electric company), and the like. Examples of the monomer having an alkoxysilyl group include: 3-methacryloxypropyl trimethoxysilane (Sila-Ace S710, manufactured by JNC Co., ltd.), 3-methacryloxypropyl methyl dimethoxy silane, and the like.

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 them, a group containing a cinnamic acid structure is preferable in terms of high photosensitivity and light-directing property. Specific examples thereof include the following formulas (3-m 1) to (3-m 18).

The monomer used for the polymer (A-3) may be used in combination with a monomer (hereinafter, also referred to as other monomer) having none of the above functional groups. Examples of the other monomer include: (meth) acrylic compounds such as alkyl (meth) acrylate, cycloalkyl (meth) acrylate, benzyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; styrene, methyl styrene, divinylbenzene; 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 oxetanyl group, oxiranyl group, carboxyl group, alkoxysilyl group, cyclic carbonate group, isocyanate group and blocked isocyanate group is preferably 1 mol% or more, more preferably 5 mol% or more, and still more preferably 10 mol% or more, relative to the total amount of the monomers used in the synthesis of the polymer (A-3). In the case of using a photo-alignment group described later in combination, the ratio of the monomer is preferably 90 mol% or less, and more preferably 80 mol% or less.

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

The method for producing the polymer (A-3) is not particularly limited, and a general method for industrially treating the polymer can be used. Specifically, the polymer can be produced by cationic polymerization, radical polymerization, or anionic polymerization of vinyl groups using monomers. Among them, radical polymerization is particularly preferred in view of easiness of reaction control and the like. The polymer (A-3) can be obtained, for example, by polymerizing a monomer in the presence of a polymerization initiator. The polymerization initiator to be used is preferably an azo compound such as 2,2' -azobis (isobutyronitrile), 2' -azobis (2, 4-dimethylvaleronitrile), or 2,2' -azobis (4-methoxy-2, 4-dimethylvaleronitrile). The ratio of the polymerization initiator to be used is preferably 0.01 to 30 parts by mass based on 100 parts by mass of the total monomers used for the reaction. Examples of the organic solvent used include: alcohols, ethers, ketones, amides, esters, hydrocarbon compounds, and the like.

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

Cellulose-based Polymer (A-4) >, and process for producing the same

As a specific example of the polymer (A-4), a polymer having a structural unit represented by the following formula (4-c) can be given.

( R ¹～R⁶ are each independently a hydrogen atom or a monovalent organic group. X is an oxygen atom or a sulfur atom. )

Examples of the monovalent organic group represented by R ¹～R⁶ include: a chain hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, a an aromatic hydrocarbon group having 6 to 15 carbon atoms these groups are selected from the group consisting of-CO-, -COO-, -OCO-and-O-and the like. In terms of availability, R ¹～R⁶ may be a group selected from the group consisting of the following formulas (1 a) to (1 m). In view of imparting a high voltage holding ratio to the liquid crystal display element, at least one of R ¹～R⁶ preferably contains a carboxyl group. For example, the following formulas (1 f), (1 h), (1 i), (1 j) to (1 m) and the like.

Wherein X ⁷ and X ⁸ represent a benzene ring or an alkyl group having 1 to 4 carbon atoms (specifically, methyl, ethyl, n-propyl, isopropyl, butyl, etc.). X ⁹、X¹⁰、X¹¹、X¹²、X¹³ and X ¹⁴ each represent a benzene ring or an alkylene group having 1 to 4 carbon atoms (specifically, methylene, ethylene, n-propylene, isopropylene, butylene, etc.).

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

Component (B)

The component (B) contained in the liquid crystal alignment agent of the present invention has a side chain structure in the molecule, and thus the obtained liquid crystal alignment film has a soft structure in the molecule. Thus, the solubility in the reworking solvent can be improved, and therefore the liquid crystal alignment film of the present invention exhibits high reworkability. Further, since the component (B) has a hydroxyalkyl group at the molecular terminal, a crosslinking reaction occurs between the component (a) and either the component (B) or the component (B), and thus the crosslinking density of the obtained liquid crystal alignment film becomes high. As a result, the impurity components originating from the substrate are easily trapped in the liquid crystal alignment film, and therefore the liquid crystal display element provided with the liquid crystal alignment film exhibits a high voltage holding ratio.

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

The component (B) may be a compound represented by the following formula (3-1) or the following formula (3-2).

Wherein B ₁ represents a structure selected from the group consisting of the following formulas (B-1) to (B-6), and B ₂ represents a structure selected from the following formulas (B-1) to (B-5). L ₁ represents the structure of the following formula (1L-1) or (1L-2). L ₂ represents a single bond, the following formula (2L-1), or a divalent group selected from the group consisting of-CH ₂－、－CH(CH₃)－、－C(CH₃)₂－、－(CH₂)_n - (n represents an integer of 2 to 20) and-NR- (R represents a hydrogen atom or a methyl group) (hereinafter, referred to as a linking group (2 a)). It should be noted that the number of the substrates, any of the above- (CH ₂)_n) -CH ₂ is optionally replaced by-O-, -CH (CH ₃)－、－C(CH₃)₂ -; -CO-or-NR-substituted AL ₁、AL₂ independently represents Cy ₁－Z₁ or Cy ₂ m1 represents an integer of 1 to 4m 2 represents an integer of 1 to 2.Cy ₁ represents a structure in which two or more rings are directly or via a linking group, cy ₂ represents a group having a steroid skeleton, and Z ₁ represents a linear or branched hydrocarbon group having 3 or more carbon atoms.

( Wherein, 1 represents a bond to AL ₁ and 2 represents a bond to B ₁. n1 represents an integer of 1 to 2, and n2 represents an integer of 1 to 4.A ₁₁、A₁₂ each independently represents a single bond, -O-, or a linking group (2 a). Where there are a plurality of a ₁₂, the plurality of a ₁₂ may be the same or different. A ₂₁、A₂₂ each independently represents a linking group (2 a) (-NR-except for). A _s11 represents a single bond, -O-, -CO-, or a linking group (2 a). A _s12 represents a single bond, -CO-, or a linking group (2 a) (-NR-with the exception). )

( Wherein, 1 represents a bond to B ₂ and 2 represents a bond to AL ₂. A _s2 is synonymous with A _s11 described above. )

(Wherein, R ₂、R_4a、R_4b、R₅、R₆ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms independently)

In the above-mentioned Z ₁, the linear or branched hydrocarbon group may be one in which one or more methylene groups not adjacent to each other are oxygen atoms, groups containing oxygen atoms such as CO or CO (=o), groups substituted with sulfur atoms, groups in which hydrogen atoms in methylene groups are substituted with alkoxy groups, halogens, or the like. From the viewpoint of good reworking characteristics, Z ₁ may be: 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, a linear or branched alkyl ester group having 3 to 20 carbon atoms, or the like.

In Cy ₁, the ring constituting the structure in which two or more rings are directly or via a linking group is preferably a benzene ring, naphthalene ring or cyclohexane ring. The number of rings constituting the polycyclic structure is not less than two, preferably 2 to 4. The plurality of rings constituting the polycyclic structure may be the same or different from each other. In the case where 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 trans (2, 6-position) with respect to the 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 the other groups. 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, or an alkoxy group having 1 to 6 carbon atoms.

In Cy ₁, examples of the linking group include: -O-, -CO-, -COO-, -NR ^b－、－CONR^b－(R^b is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protecting group), an alkylene group having 1 to 10 carbon atoms, or a divalent group in which at least one methylene group of an alkylene group having 1 to 10 carbon atoms is substituted with-O-, -CO-, -COO-, -NR ^b -or-CONR ^b -, or the like. Examples of the protecting group for R ^b include urethane protecting groups. Specific examples of the urethane protecting group include t-butoxycarbonyl and 9-fluorenylmethoxycarbonyl.

Among them, the structure represented by the following formula (Rn) is preferable in terms of the above Cy ₁.

In the formula (Rn), X independently represents a single bond or a divalent group exemplified in Cy ₁. m is 2-6. G each independently represents a benzene ring, a naphthalene ring or a cyclohexane ring. * Representing a bond.

The group having a steroid skeleton in Cy ₂ 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, B ₁ is preferably the above formula (B-1), (B-3), (B-5), or (B-6).

For the reason of improving reworkability, the component (B) in the present invention is a compound having a molecular weight of 2000 or less. Among them, the molecular weight is preferably 1800 or less, more preferably 1500 or less, from the viewpoint of improving reworkability. The molecular weight of the compound as the 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 formulas (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) in view of having a 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 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 alignment agent >)

The liquid crystal aligning agent of the present invention contains the component (A) and the 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). The other polymer types 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 the liquid crystal aligning agent takes the form of a coating liquid in terms of forming a uniform film. The liquid crystal aligning agent of the present invention preferably contains the above-mentioned coating liquid containing the component (a) and the component (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. In terms of forming a uniform and defect-free coating film, it is preferably 1% by mass or more, and in terms of storage stability of the solution, it is preferably 10% by mass or less, and particularly preferably 2 to 8% by mass.

The organic solvent contained in the liquid crystal aligning agent is not particularly limited as long as the polymer component is uniformly dissolved. Specific examples thereof include: n, N-dimethylformamide, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethylsulfoxide, γ -butyrolactone, γ -valerolactone, 1, 3-dimethyl-2-imidazolidinone, methylethylketone, cyclohexanone, cyclopentanone, N-dimethylformamide, 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, or γ -butyrolactone is preferable in view 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 solvents, the organic solvent contained in the liquid crystal aligning agent is preferably a solvent (also referred to as a poor solvent) in which the coating property and the surface smoothness of the coating film are improved when the liquid crystal aligning agent is applied. Specific examples of the poor solvent are listed below, but are 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 diethyl 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 monoisopentyl 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, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monoacetate, ethylene glycol diacetate, diethylene glycol monoethyl acetate, diethylene glycol monobutyl ether acetate, 2- (2-ethylhexyl) acetate, ethylene glycol monoacetate, 3-methoxybutyl propionate, 3-methoxyethyl propionate, and the like.

Among them, diisobutyl methanol, 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, 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 according to the application apparatus, application conditions, application environment, and the like of the liquid crystal aligning agent.

The combination of the good solvent and the poor solvent may be mentioned in terms of good printability: n-methyl-2-pyrrolidone and 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 and propylene glycol monobutyl ether; n-methyl-2-pyrrolidone, gamma-butyrolactone, 4-hydroxy-4-methyl-2-pentanone, 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 diisobutyl methanol; n-methyl-2-pyrrolidone, gamma-butyrolactone, dipropylene glycol dimethyl ether; n-methyl-2-pyrrolidone, propylene glycol monobutyl ether, and dipropylene glycol dimethyl ether; n-ethyl-2-pyrrolidone, propylene glycol monobutyl ether, dipropylene glycol dimethyl ether, and the like.

The liquid crystal aligning agent of the present invention may contain other components in addition to the component (a), the component (B) and the organic solvent. Examples of the additional component 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); dielectric materials, conductive materials, and the like for adjusting the dielectric constant and resistance of the liquid crystal alignment film.

As the crosslinkable compound, a compound selected from the following compounds may 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 represented by the following formulae (r-1) to (r-3), compounds having a protected isocyanate group represented by the following formulae (bi-1) to (bi-3), compounds described in Japanese patent application laid-open 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 above-mentioned compound is an example of a crosslinkable compound, and is not limited to these. For example, other components than the above can be mentioned: an oxetanyl group-containing compound described in [0170] to [0175] of WO2011/132751, an oxazoline structure-containing compound described in [0115] of Japanese patent application laid-open No. 2007-286597, a Mi acid structure-containing compound described in WO2012/091088, a cyclic carbonate group-containing compound described in WO2011/155577, and compounds disclosed in [0105] to [0116] of WO2015/060357, and the like. 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, more preferably 1 to 15 parts by mass, relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent, in view of exhibiting the objective effect and improving the liquid crystal alignment property.

Examples of the adhesion promoter include: 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-aminopropyl diethoxymethyl silane, 2-aminopropyl trimethoxysilane, 2-aminopropyl triethoxysilane, N- (2-aminoethyl) -3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyldimethoxy silane, 3-ureidopropyl trimethoxysilane, 3-ureidopropyl triethoxysilane, N-ethoxycarbonyl-3-aminopropyl trimethoxysilane, N-ethoxycarbonyl-3-aminopropyl triethoxysilane, N-triethoxysilyl-propyl triethyltriamine, N-trimethoxysilylpropyl triethyltriamine, N-bis (oxypropylene) -3-aminopropyl trimethoxysilane, N-bis (oxypropylene) -3-aminopropyl triethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-epoxypropoxy propylmethyldimethoxy silane, 3-epoxypropoxy propyltrimethoxysilane, 3-epoxypropoxy propyltriethoxysilane, 3-epoxypropoxy-methyldiethoxy silane, 3-epoxypropoxy-triethoxysilane, 3-epoxypropyl-methacryloxy silane, 3-acryloyloxy-methacryloxy silane, 3-diethoxy-methacryloxy silane, 3-acryloyloxy-methoxy-propyl-methyl-propyl-silane, 3-acryloyloxy-ethoxy-3-propyl-ethoxymethyl-silane, silane coupling agents such as tris (3-trimethoxysilylpropyl) isocyanurate, 3-mercaptopropyl methyl dimethoxy silane, 3-mercaptopropyl trimethoxy silane, and 3-isocyanatopropyl triethoxy silane. The amount of the silane coupling agent to be used is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, based on 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 comprises a liquid crystal alignment film formed by using the liquid crystal alignment agent. The operation mode of the liquid crystal display element is not particularly limited, and may 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, etc.), an in-plane switching type (IPS type), an FFS type, an optically compensatory bend type (OCB type: optically Compensated Bend type), and the like.

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

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

First, the liquid crystal aligning agent of the present invention is coated on 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 used as a pair, and a liquid crystal aligning agent is applied to each transparent conductive film forming surface by a preferred offset printing method, spin coating method, roll coater method, or ink jet printing method. As the substrate, for example, glass such as float glass (float glass) or soda glass (soda glass) can be used; transparent substrates made of plastics such as polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, and poly (alicyclic olefin). As the transparent conductive film provided on one surface of the substrate, a NESA film (PPG trademark) made of tin oxide (SnO ₂), an ITO film made of indium oxide-tin oxide (In ₂O₃－SnO₂), or the like can be used.

After the liquid crystal aligning agent is applied, preheating (prebaking) is preferably performed for the purpose of preventing sagging of the applied liquid crystal aligning agent, or the like. The preliminary drying temperature is preferably 30 to 200 ℃, more preferably 40 to 150 ℃, particularly preferably 40 to 100 ℃. After that, the solvent is completely removed, and if necessary, a firing (post-baking) step is performed for the purpose of thermally imidizing the amic acid structure existing in the polymer. 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, more preferably 10 to 100 minutes. The film thickness thus formed is preferably 0.001 to 1. Mu.m, 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 device, a liquid crystal aligning agent is applied to an electrode formation surface of a substrate provided with an electrode formed of a transparent conductive film or a metal film patterned into a comb-teeth type, and a surface of a counter substrate provided with no electrode, respectively, and then each of the applied surfaces is heated to form a coating film. The materials of the substrate and the transparent conductive film, the coating method, the heating condition after the coating, the patterning method of 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 of (1-1A) above. As the metal film, for example, a film made of a metal such as chromium can be used.

In either of the cases (1-1A) and (1-1B), a liquid crystal alignment agent is applied to a substrate, and then an organic solvent is removed to form a coating film which becomes a liquid crystal alignment film. In this case, a coating film having been further imidized may be obtained by further heating after the formation of the coating film to carry out a dehydration ring-closure reaction of the polyamic acid, polyamic acid ester, and polyimide blended in the liquid crystal aligning agent.

[ Procedure (1-2): orientation ability imparting treatment ]

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

In the case where the liquid crystal aligning ability is imparted to the coating film by the photo-alignment treatment, for example, ultraviolet rays or visible rays containing light having a wavelength of 150 to 800nm may be used as the radiation to be irradiated to the coating film. In the case where the radiation is polarized, the radiation may be linearly polarized or partially polarized. In the case where the radiation used is linearly polarized or partially polarized, irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. In the case of irradiation of 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. The ultraviolet light in a preferable wavelength region can be obtained by a method in which a light source is used in combination with a filter, a diffraction grating, or the like, for example. The irradiation amount of the radiation is preferably 10 to 5000mJ/cm ², more preferably 30 to 2000mJ/cm ².

In order to improve the reactivity, the coating film may be irradiated with light while heating the coating film. The heating temperature is usually 30 to 250 ℃, preferably 40 to 200 ℃, more preferably 50 to 150 ℃.

In the case of using ultraviolet rays including light having a wavelength of 150 to 800nm, the light irradiated film obtained in the above step may be used as a liquid crystal alignment film as it is, or the light irradiated film may be baked, washed 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, more preferably 10 to 100 minutes. The firing time may be two or more times. The photo-alignment treatment corresponds to the light irradiation treatment in a state where the liquid crystal layer is not in contact with the liquid crystal layer.

As described above, although the liquid crystal alignment film is formed on the substrate by the liquid crystal alignment agent, when a defect occurs in the liquid crystal alignment film, the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention is excellent in a reworking step 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 from the liquid crystal alignment agent of the present invention has the following advantages in the reworking step. Namely, the method has the following advantages: since the liquid crystal alignment film formed from the liquid crystal alignment agent of the present invention has high solubility in the reworking agent, the variety of solvents that can be used increases, or the temperature of immersion in the solvents decreases, and the immersion time decreases, so that the manufacturing cost can be reduced.

[ Procedure (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 arranged between the two substrates arranged to face each other, thereby manufacturing a liquid crystal cell. Specifically, the following two methods are exemplified.

In the first method, first, a gap (cell gap) is formed so that the liquid crystal alignment films face each other, two substrates are arranged so as to face each other, peripheral portions of the two substrates are bonded to each other with a sealant, liquid crystal is filled into the cell gap partitioned by the substrate surface and the sealant, and then the filling hole is sealed, thereby manufacturing a liquid crystal cell.

The second method is a method called an ODF (One Drop Fill) method. A liquid crystal cell is manufactured by applying, for example, an ultraviolet curable sealant to a predetermined portion of one of two substrates on which a liquid crystal alignment film is formed, dropping liquid crystal to predetermined portions on a surface of the liquid crystal alignment film, bonding the other substrate so that the liquid crystal alignment film faces the other substrate, stretching the liquid crystal over the entire surface of the crystal substrate, and then irradiating the entire surface of the substrate with ultraviolet light to cure the sealant. In either method, it is desirable to further heat the liquid crystal cell to a temperature at which the liquid crystal to be used becomes isotropic, and then slowly cool the liquid crystal cell to room temperature, thereby removing the flow orientation during filling of the liquid crystal.

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

The liquid crystal may be: among them, nematic liquid crystals are preferable, and examples thereof include: schiff base, azo oxide, biphenyl, phenylcyclohexane, ester, terphenyl, diphenylcyclohexane, pyrimidine, dioxane, bicyclooctane, and cubane (cubane) liquid crystal. In addition, for example, cholesteric liquid crystals such as cholesterol chloride, cholesterol nonanoate, and cholesterol carbonate may be added to these liquid crystals; chiral agents such as "C-15", "CB-15" (trade name of MERCK company); ferroelectric liquid crystals such as p-decyloxy benzylidene para-amino-2-methylbutyl cinnamate.

In addition, the liquid crystal may additionally contain an anisotropic dye. For example, black dye (black dye) or color dye (color dye) may be used. The ratio of the anisotropic dye to be used for the liquid crystal is appropriately selected within a range that does not impair the target physical properties, and for example, 0.01 to 5 parts by mass relative to 100 parts by mass of the liquid crystal compound can be appropriately changed as required.

(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) above, except that a photopolymerizable compound of the following formulas (w-1) to (w-5) and the like 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 provided on the pair of substrates. The voltage applied here may be, for example, 5 to 50V dc or ac. Further, as the light to be irradiated, for example, ultraviolet rays or visible rays containing light having a wavelength of 150 to 800nm may be used, but ultraviolet rays containing light having a wavelength of 300 to 400nm are preferable. The irradiation amount of light is preferably 100 to 30000mJ/cm ², more preferably 100 to 20000mJ/cm ².

(1－3C)

In the case of forming a coating film on a substrate using a liquid crystal aligning agent containing a compound having a photopolymerizable group, a liquid crystal cell may be constructed in the same manner as in (1-3A) above, and then a process of irradiating the liquid crystal cell with light in a state where a voltage is applied between conductive films provided on a pair of substrates may be employed, thereby manufacturing a liquid crystal display element. Examples of the additive having a photopolymerizable group include the structures shown by the above formulas (w-1) to (w-5). The blending amount thereof is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, particularly preferably 1 to 15% by mass, relative to the solid content contained in the liquid crystal aligning agent.

The light irradiation to the liquid crystal cell may be performed in a state in which the liquid crystal is driven by applying a voltage, or may be performed in a state in which a low voltage to such an extent that the liquid crystal is not driven is applied. The applied voltage may be, for example, 0.1 to 30V dc or ac. Regarding the condition of the irradiated light, the above description of (1-3B) can be applied. The light irradiation treatment corresponds to the light irradiation treatment in a state of contact with the liquid crystal layer.

Further, the liquid crystal display element of the present invention can be obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell. As the polarizing plate attached to the outer surface of the liquid crystal cell, there may be mentioned: a polarizing plate formed by sandwiching a polarizing film called "H film" in which iodine is absorbed while stretching and orienting polyvinyl alcohol with a cellulose acetate protective film; or a polarizing plate composed of the H film itself.

Examples (example)

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

The following abbreviations of the compounds and the measurement methods of the respective characteristics 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: the compounds represented by the following formulas (DA-1) to (DA-27), respectively.

(Tetracarboxylic dianhydride)

CA-1 to CA-8: the compounds represented by the following formulas (CA-1) to (CA-8), respectively.

(Tetracarboxylic acid diester dihalide)

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

(Monocarboxylic acid chloride)

E-1: and (3) acrylic acid chloride.

(Component B)

B-1 to b-8: compounds represented by the following formulas (b-1) to (b-8)

(Other additives)

C-1 to c-4: the compounds represented by the following formulas (c-1) to (c-4).

F-1: n-alpha- (9-fluorenylmethoxycarbonyl) -N-t-butoxycarbonyl-L-histidine (a compound of formula (F-1)).

S-1: 3-glycidoxypropyl triethoxysilane (a compound of formula (s-1)).

S-2: 3-glycidoxypropyl methyl diethoxysilane (a compound of 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. In the formula (c-4), R represents any one of a hydroxymethyl group and a-CH ₂－O－C₈H₁₇ group. )

[ Viscosity ]

The measurement was performed at 25℃using a type E viscometer TVE-22H (manufactured by eastern machine industry Co., ltd.) with a sample size of 1.1mL and a conical rotor TE-1 (1 DEG 34', R24).

[ Molecular weight ]

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

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

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

< Imidization Rate >)

To an NMR sample tube (NMR standard sample tube, phi 5 (manufactured by Bruhnia Co.), 20mg of polyimide powder was added, and deuterated dimethyl sulfoxide (DMSO-d 6,0.05% TMS (tetramethylsilane) mixture) (0.53 ml) was added, and ultrasonic wave was applied to dissolve it completely. The solution was subjected to proton NMR at 500MHz using an NMR measuring machine (JNW-ECA 500) (manufactured by Japanese electronic data UM Co.). The imidization ratio was determined as follows: the proton derived from the structure which does not change before and after imidization is defined as a reference proton, and the peak integrated value of the proton derived from the NH group of the amic acid which appears in the vicinity of 9.5ppm to 10.0ppm are used to determine the proton by the following formula.

Imidization ratio (%) = (1- α·x/y) ×100

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

[ (Synthesis of component B) ]

Synthesis example (b-1) >

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

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

Subsequently, diethanolamine (3.47 g,33.0 mmol), triethylamine (2.51 g,24.8 mmol) and methylene chloride (30 mL) were added to the other eggplant-shaped flask, and the mixture was stirred under ice-cooling. Then, a solution obtained by dissolving the compound (b-1-1) obtained in the above in methylene chloride (8 mL) was added thereto, followed by stirring. After the completion of the reaction, saturated brine was added to the reaction solution, and the organic layer was taken out and washed with saturated brine. 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, whereby 5.29g of compound (b-1) was obtained.

Synthesis example (b-2) >

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

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

Next, compound (b-2-1) (5.00 g,10.7 mmol), diethanolamine (2.37 g,22.5 mmol), THF (27.27 g), and 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) (6.23 g,22.5 mmol) were added to the eggplant-shaped flask, and the mixture was reacted at room temperature for 5 hours. To the reaction solution was added saturated brine, and the organic layer was removed. 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 manner 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. The compound (b-4-4) was synthesized in the same order as in example 3 of Japanese patent application laid-open No. 2010-285367.

Into a flask, compound (b-4-1) (5.00 g,21.4 mmol) and THF (70 g) were charged to dissolve Compound (b-4-1). On the other hand, subsequently, diethanolamine (4.72 g,44.9 mmol) and 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) (6.23 g,22.5 mmol) were added and stirred at room temperature. To the obtained solution was added saturated brine, and the organic layer was removed. The organic layer was dried over sodium sulfate, and the obtained solution was concentrated under reduced pressure to obtain 5.90g of Compound (b-4-2).

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

Next, to the eggplant-shaped flask were added compound (b-4-3) (3.00 g,9.76 mmol), compound (b-4-4) (4.77 g,9.76 mmol), 4- (4, 6-dimethoxy-1, 3, 5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) (2.77 g,10.0 mmol) and THF (50 g), and the mixture was reacted at room temperature for 5 hours. To the reaction solution was added saturated brine, and the organic layer was removed. The organic layer was dried over sodium sulfate, and the obtained 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 instead 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 tris (hydroxymethyl) aminomethane) was used in place of compound (b-4-3), and trans, trans-4' -pentylbyclohexyl-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 sequence as in Synthesis example 4 of WO 2018/159733. The synthesis was performed in the same manner as in synthesis example (b-2), except that compound (b-7-2) was used instead of compound (b-1-2) for compound (b-7-1). Next, the same procedure as in synthesis example (b-2) was repeated except that (b-7-2) was used in place of (b-2-1) and that tris (hydroxymethyl) aminomethane was used in place of diethanolamine for (b-7).

Synthesis example (b-8) >

Compound (b-8) was obtained in the same manner as in Synthesis example (b-4), except that tris (hydroxymethyl) aminomethane) was used in place 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 sequence as in example 4 of japanese patent application laid-open No. 2011-70161.

[ Synthesis of Polymer (A) ]

Synthesis example 1 >

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

To this polyamic acid solution (40 g), NMP was added to dilute it to 6.5 mass%, and acetic anhydride (7.06 g) and pyridine (2.19 g) were added as imidization catalysts, and reacted at 80℃for 4 hours. The reaction solution was poured into methanol (463 g), 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 ratio: 74%).

NMP (18.0 g) was added to the obtained polyimide powder (2.0 g), M-1 was added so as to be 1 mass% with respect to the polyimide solid content, 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 (1.20 g,4.80 mmol), DA-8 (1.46 g,9.59 mmol), DA-9 (1.74 g,7.18 mmol), DA-7 (2.74 g,7.20 mmol), and NMP (28.58 g) were dissolved in a four-necked flask equipped with a stirring device and a nitrogen inlet tube, and reacted at 60℃for 2 hours. Then, CA-5 (1.05 g,4.81 mmol) and NMP (4.19 g) were added and reacted at room temperature for 4 hours, and further CA-3 (2.78 g,14.18 mmol) and NMP (11.1 g) were added and reacted at room temperature for 4 hours to obtain a polyamic acid solution.

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

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

Synthesis example 3 >

DA-2 (5.86 g,24.0 mmol), DA-10 (5.46 g,16.0 mmol), DA-4 (1.73 g,16.0 mmol), DA-1 (7.69 g,24.0 mmol) and NMP (194 g) were added to a four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring while nitrogen was fed. CA-1 (17.1 g,76.4 mmol) was added while stirring the diamine solution, 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 was 12400, mw was 33000).

To this polyamic acid solution (225 g) was added NMP to dilute it to 9.0 mass%, and acetic anhydride (17.1 g) and pyridine (3.54 g) were added as imidization catalysts, and reacted at 55℃for 3 hours. The reaction solution was poured into methanol (1111 g), and the obtained 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 ratio: 66%).

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

Synthesis example 4 >

DA-5 (5.73 g,20.0 mmol) and NMP (115 g) were added to a 5L four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring while nitrogen was fed. While stirring the diamine solution under water cooling, CA-3 (2.94 g,15.0 mmol) was added, NMP (19.1 g) was added, and the mixture was stirred under nitrogen at 23℃for 1 hour. Next, DA-3 (11.9 g,40.0 mmol) and DA-11 (6.01 g,40.0 mmol) were weighed, NMP (72 g) was added thereto, and the mixture was dissolved by stirring while nitrogen was being fed. CA-3 (15.9 g,81.0 mmol) was added while stirring the diamine solution under water cooling, NMP was added so that the solid content 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 a 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 stirring device was set in a nitrogen atmosphere, and DA-4 (2.80 g,25.9 mmol), DA-2 (1.58 g,6.47 mmol), NMP (111 g) and pyridine (6.18 g,78.1 mmol) as bases were added and stirred to dissolve the materials. Then, CE-1 (9.89 g,30.4 mmol) was added while stirring the diamine solution, and the mixture was reacted at 15℃until it was used. After stirring overnight, E-1 (0.38 g,4.21 mmol) was added and reacted at 15℃for 4 hours. The resulting polyamic acid ester solution was poured into 1230g of water with stirring, and the white precipitate was collected by filtration, followed by 5 times washing with 1230g of isopropyl alcohol (IPA) and drying, whereby 10.2g (yield: 83.0%) of a white polyamic acid ester powder (Mn: 20786, mw: 40973) was obtained.

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

Synthesis example 6 >

DA-8 (0.46 g,3.00 mmol), DA-13 (3.00 g,15.0 mmol), DA-14 (2.56 g,12.0 mmol), NMP (11.0 g) and GBL (8.10 g) were added to a four-necked flask equipped with a stirrer and a nitrogen inlet tube, and dissolved by stirring while nitrogen was fed. CA-6 (4.76 g,24.0 mmol) was added to the diamine solution while stirring, GBL (10.9 g) was added thereto, and the mixture was stirred at room temperature for 2 hours. Next, GBL (10.8 g) was added thereto and stirred, and then CA-5 (1.31 g,6.01 mmol) was added thereto, GBL (14.3 g) was added thereto and stirred at room temperature for 24 hours. The resulting solution of 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 the polyamic acid, NMP: gbl=20:80 in terms of the mixing ratio of NMP to GBL, and NMP and GBL were added so as to be 15 mass% in the solid content concentration, whereby a solution of polyamic acid (PAA-I-6) was obtained.

Synthesis examples 7 to 11, 14 to 20 >, and

By using the diamine, the tetracarboxylic acid derivative and the organic solvent shown in Table 1 below, the same procedure as in the above synthesis example was followed to obtain solutions of polyimide (PI-V-V-8), (PI-V-9), (PI-I-11), (PI-V-19) and (PI-V-20), polyamic acid (PAA-I-7), (PAA-I-10), (PAA-V-14) to (PAA-V-16), (PAA-I-17) and (PAA-I-18) shown in Table 1 below.

In table 1, the numerical values in brackets indicate the blending ratio (molar parts) of each compound 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 blending ratio (molar parts) of each compound to 100 molar parts of the total amount of diamine used for synthesis. The blocking agent represents a blending ratio (molar parts) with respect to 100 molar parts of the total amount of diamine used for synthesis. The organic solvents are represented by the blending ratio (parts by mass) of each organic solvent 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

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

Synthesis example 13 >

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

Example 1 >

[ Preparation of liquid Crystal alignment agent ]

The solution of polyimide (PI-V-1) obtained in synthesis example 1 and the solution of polyimide (PI-V-2) obtained in synthesis example 2 were used, diluted with NMP and BCS, and then the compounds (b-1) and (b-2) were added so as to be 1 part by mass and 5 parts by mass, respectively, with respect to 100 parts by mass of the total polymer, and stirred at room temperature. Then, the obtained solution was filtered by a filter having a pore size of 0.5 μm, whereby a liquid crystal aligning agent (V1) was obtained in which the component ratio (solid content conversion mass ratio) of the polymer was (PI-V-1): (PI-V-2) =30:70, the solvent composition ratio (mass ratio) was NMP: bcs=60:40, the polymer solid content concentration was 4.5%, the compounding ratio of the compound (b-1) was 1 part by mass and the compounding ratio of the compound (b-2) was 5 parts by mass (see table 2-1 below). It was confirmed that no abnormalities such as turbidity and precipitation were observed in the liquid crystal aligning agent, and the liquid crystal aligning agent was a uniform solution.

Examples 2 to 50 and comparative examples 1 to 6>, respectively

Liquid crystal aligning agents (V2)～(V11)、(I12－P)～(I29－P)、(I30－U)～(I37－U)、(V38)～(V43)、(I44－P)～(I47－P)、(V48－P)～(V49－P)、(I50－U)、(R－V1)～(R－V2)、(R－I3－P)、(R－I4－U)、(R－V5)～(R－V6). table 2-1 to table 2-4 were obtained in the same manner as in example 1 except that the polymers and additives shown in the following tables 2-1 to 2-4 were used, and 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 was represented by the numerical values in brackets for the polymers and additives. The organic solvents are represented by the blending ratio (parts by mass) of each organic solvent to 100 parts by mass of the total amount of the organic solvents used for preparing the liquid crystal aligning agent.

[ Table 2-1]

[ Table 2-2]

[ Tables 2 to 3]

[ Tables 2 to 4]

[ Evaluation of reworkability of liquid Crystal alignment agent ]

The liquid crystal aligning agent obtained in the above was coated on an ITO substrate by spin coating. After drying on a heating plate at 60℃for 1 minute and 30 seconds, firing was performed in a hot air circulating oven at 230℃for 20 minutes, whereby a coating film having a film thickness of 100nm was formed. Then, the prepared substrate was immersed in NMP heated to 35 ℃ or 50 ℃ for 5 minutes, and then washed with running water for 20 seconds with ultrapure water. The case of immersing in NMP at 35℃for 5 minutes was regarded as "good", the case of immersing in NMP at 50℃for 5 minutes was regarded as "good", and the case of immersing in NMP at 50℃for 5 minutes was regarded as "bad".

[ Production and evaluation of liquid Crystal display element ]

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

Two glass substrates (longitudinal: 40mm, transverse: 30mm, thickness: 1.1 mm) with ITO electrodes were prepared; the washing was performed with pure water and isopropyl alcohol. Next, the liquid crystal aligning agents (V1) to (V11), (V38) to (V43) and (R-V1) to (R-V2), (R-V5) to (R-V6) which were filtered by a filter having a pore diameter of 1.0 μm were spin-coated on the respective ITO surfaces, and were subjected to a heating treatment at 70 ℃ for 90 seconds on a hot plate and a heating treatment at 230 ℃ for 30 minutes in a heat cycle type cleaning oven, 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, sanjing chemical Co., ltd.). Next, the other substrate was bonded to the previous substrate with the surface on the side on which the liquid crystal alignment film was formed as the inner side, and then the sealing material was cured to produce a blank. Liquid crystal cell was prepared by injecting liquid crystal MLC-3023 (trade name manufactured by MERCK company) into empty cells using liquid crystal aligning agents (V1) to (V2), (V5) to (V11), (V38) to (V43) and (R-V1) by a reduced pressure injection method.

Then, a DC voltage of 15V was applied to the obtained liquid crystal cell, and an ultraviolet irradiation device using a high-pressure mercury lamp as a light source was used to irradiate ultraviolet light having passed through a bandpass filter having a wavelength of 365nm at 10J/cm ² in a state where all pixel regions were driven, thereby obtaining a liquid crystal display element for evaluation. The measurement of the amount of ultraviolet irradiation was performed by connecting UV-M03A manufactured by ORC company to a UV-35 light receiver.

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

1-2. Evaluation of liquid Crystal display element

[ Evaluation of Voltage holding Rate ]

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

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

First, a glass substrate with electrodes (vertical: 30mm, horizontal: 50mm, thickness: 0.7 mm) was prepared. An ITO electrode having a dense pattern, which constitutes a counter electrode, is formed as a first layer on a substrate. A SiN (silicon nitride) film formed by a CVD method is formed as a second layer on the opposite electrode of the first layer. The SiN film of the second layer had a film thickness of 500nm and was used as an interlayer insulating film. On the SiN film of the second layer, a comb-tooth-shaped pixel electrode formed by patterning the ITO film is arranged as the third layer, and two kinds of pixels, that is, 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 is electrically insulated from the pixel electrode of the third layer by the SiN film of the second layer.

The pixel electrode of the third layer has a comb-like shape formed by arranging a plurality of electrode elements in a "< symbol" shape, the center portion of which is bent at an inner angle of 160 °. The width of each electrode element in the short dimension direction was 3. Mu.m, and the interval between the electrode elements was 6. Mu.m. Each pixel is divided up and down by a bent portion at the center thereof, and has a first region on the upper side and a second region on the lower side of the bent portion.

Subsequently, the liquid crystal aligning agents (I12-P) to (I29-P), (I44-P) to (I47-P) and (R-I3-P) were filtered by a filter having a pore diameter of 1.0. Mu.m, and then, the liquid crystal aligning agents were applied by spin coating to the electrode-equipped substrate and the glass substrate having a columnar spacer having a height of 4. Mu.m and having an ITO film formed on the back surface thereof.

The coating films obtained from the liquid crystal aligning agents (I12-P) to (I29-P) and (R-I3-P) were dried on a heating plate at 80℃for 5 minutes, and then baked in a hot air circulating oven at 230℃for 20 minutes, to obtain polyimide films having a film thickness of 100 nm. Then, the coated surface was irradiated with a linear polarized 254nm ultraviolet light having an extinction ratio of 26:1 of 500mJ/cm ² via a polarizing plate, followed by firing in a hot air circulation oven at 230℃for 30 minutes, to obtain a substrate with a liquid crystal alignment film having a film thickness of 100 nm. The liquid crystal alignment film formed on the electrode substrate is aligned so that the direction of the inner corners of the pixel bent portions is perpendicular to the alignment direction of the liquid crystal, and the liquid crystal alignment film formed on the substrate having the columnar spacers is aligned so that the alignment direction of the liquid crystal on the electrode substrate coincides with the alignment direction of the liquid crystal on the substrate having the columnar spacers when the liquid crystal cell is manufactured.

The coating film obtained from the liquid crystal aligning agents (I44-P) to (I47-P) was dried on a heating plate at 80℃for 5 minutes, and then, a linearly polarized 254nm ultraviolet ray having an extinction ratio of 26:1 of 500mJ/cm ² was irradiated to the coating film surface via a polarizing plate, followed by firing in a hot air circulating oven at 230℃for 30 minutes, whereby a substrate with a liquid crystal aligning film having a film thickness of 100nm was obtained.

Next, a sealant was printed on one of the above-mentioned glass substrates with a liquid crystal alignment film, and the other substrate was bonded so that the liquid crystal alignment film faces faced each other, and the sealant was cured to produce a blank. The liquid crystal MLC-3019 (manufactured by MERCK Co.) was injected into the empty cell by vacuum injection, and the injection port was sealed to obtain an FFS-driven liquid crystal display element. Then, the obtained liquid crystal cell was heated at 120℃for 1 hour, left standing for one hour, and the liquid crystal display element was observed by a polarization microscope, and as a result, uniform alignment was confirmed for any liquid crystal.

2-2. Evaluation of liquid Crystal display element

[ Evaluation of Voltage holding Rate ]

Two glass substrates (length: 40mm, width: 30mm, thickness: 1.1 mm) with ITO electrodes 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 2-1. Bead spacers (manufactured by Nitro catalyst Co., ltd., silk, SW-D1) having a diameter of 4 μm were coated on the liquid crystal alignment film surface of one substrate.

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

3-1. Manufacturing of FFS type liquid crystal display element using brush rubbing orientation

First, liquid crystal aligning agents (I30-U) to (I37-U), (I50-U) and (R-I4-U) which were filtered by a filter having a pore size of 1.0 μm were applied to each surface of a pair of glass substrates similar to 2-1 using an inkjet coater (HIS-200, manufactured by Hitachi Plant Technologies). The coating was performed under the following conditions: the coating area was 70X 70mm, the nozzle pitch was 0.423mm, the scan pitch was 0.5mm, the coating speed was 40 mm/sec, and the coating was left for 60 seconds from coating to drying. Then, the polyimide film was 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. The polyimide film was brushed (roll diameter: 120mm, roll rotation speed: 500rpm, moving speed: 30mm/sec, pressing length: 0.3mm, brushing direction: direction inclined by 10 ° with respect to 3 IZO comb electrodes) with rayon cloth, and then subjected to ultrasonic irradiation in pure water for 1 minute to clean and 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 are set as a group, a sealant is printed on the substrates in a form of remaining liquid crystal injection ports, and the other substrate is bonded in a mode that the liquid crystal alignment film faces are opposite and the brushing directions are antiparallel. Then, the sealant was cured to prepare a dummy cell having a cell gap of 4 μm. The liquid crystal MLC-7026-100 (manufactured by MERCK Co.) was injected into the empty cell by vacuum injection, and the injection port was sealed to obtain an FFS mode liquid crystal display element. Then, the obtained liquid crystal display element was heated at 120℃for 1 hour, left at 23℃for one minute, and then used for evaluation of afterimage evaluation. The obtained liquid crystal display element was observed by a polarization microscope, and as a result, uniform alignment was confirmed in any liquid crystal.

3-2. Evaluation of liquid Crystal display element

[ Evaluation of Voltage holding Rate ]

The same procedure as in 2-2 was followed 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 mode liquid crystal display element using photo-alignment

Two glass substrates similar to 1-1 were prepared, and a liquid crystal alignment agent (V48-P) or (V49-P) was spin-coated on each substrate, followed by a heating treatment at 80℃for 90 seconds on a hot plate, and a heating treatment at 200℃for 40 minutes in a heat-cycle type cleaning oven, to obtain an ITO substrate with a liquid crystal alignment film having a film thickness of 100 nm.

Then, the substrate was exposed to linearly polarized UV light at an incident angle of 40 ° with respect to the normal of the substrate surface. The exposure applied was set at 20mJ/cm ². After exposure, a cassette having two substrates is assembled such that the exposed alignment layer faces the inside of the cassette, and the substrates are aligned such that the alignment directions are parallel to each other. Subsequently, liquid crystal MLC-7067 (manufactured by MERCK Co.) was injected. Then, annealing was performed at about 90℃for 10 minutes, and the mixture was cooled to room temperature and then used for evaluation of afterimage evaluation. The obtained liquid crystal display element was observed by a polarization microscope, and as a result, uniform alignment was confirmed in any liquid crystal.

4-2. Evaluation of liquid Crystal display element

[ Evaluation of Voltage holding Rate ]

The liquid crystal display element produced in 4-1 was allowed to stand in an oven at 80℃for 200 hours under irradiation of an LED lamp, then allowed to stand at room temperature, and naturally cooled to room temperature. The 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 show the results of evaluation of the liquid crystal aligning agents according to the examples of the present invention, and examples 51 to 56 show the results of evaluation of the liquid crystal aligning agents according to the comparative examples.

TABLE 3

Industrial applicability

The liquid crystal aligning agent of the present invention is useful for forming a liquid crystal alignment film in various liquid crystal display elements such as a vertical alignment type and FFS driving type. The liquid crystal display element provided with the liquid crystal aligning agent of the present invention can be effectively used for various devices, for example, various display devices such as a clock, a portable game machine, a word processor, a notebook computer, a car navigation system, a video camera (cam camera), a PDA, a digital camera, a mobile phone, a smart phone, various monitors, a liquid crystal television, and an information display. The present invention is not limited to the above, and may be applied to a liquid crystal alignment film for a phase difference film, a scanning antenna, a liquid crystal alignment film for a liquid crystal array antenna, a liquid crystal alignment film for a liquid crystal light adjusting element for a transmission scattering type, or applications other than these, for example, a protective film for a color filter, a gate insulating film for a flexible display, and a substrate material.

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

Claims

1. A liquid crystal aligning agent comprising the following component (A) and component (B),

(A) The components are as follows: at least one polymer selected from the group consisting of polyimide-based polymers, polyorganosiloxanes, polymers of monomers having polymerizable unsaturated bonds, and cellulose-based polymers,

(B) The components are as follows: has any one of a structure and a steroid skeleton in which two or more rings are directly or via a linking group, and has at least one group represented by the following formulas (b-1) to (b-5) or at least two groups represented by the following formula (b-6), has a molecular weight of 2000 or less, and is a compound represented by the following formula (3-1) or formula (3-2),

Wherein R ₂、R_4a、R_4b、R₅、R₆ independently represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, represents a bond,

Wherein B ₁ represents a structure selected from the formulae (B-1) to (B-6); b ₂ represents a structure selected from the formulae (B-1) to (B-5); l ₁ represents the following formula (1L-1) or (1L-2); l ₂ represents a single bond, the following formula (2L-1), or a divalent group selected from the group consisting of-CH ₂－、－CH(CH₃)－、－C(CH₃)₂－、－(CH₂)_n -wherein n represents an integer of 2 to 20, and-NR-wherein R represents a hydrogen atom or a methyl group, and wherein the divalent group is hereinafter referred to as a linking group (2 a); it should be noted that the number of the substrates, any CH ₂ of said- (CH ₂)_n -is optionally substituted by-O-, -CH (CH ₃)－、－C(CH₃)₂ -, -CO-or-NR-; AL ₁、AL₂ represents each independently-Cy ₁－Z₁ or Cy ₂, m1 represents an integer of 1 to 4, m2 represents an integer of 1 to 2, cy ₁ represents a structure in which two or more rings are linked directly or via a linking group, cy ₂ represents a group having a steroid skeleton, Z ₁ represents a linear or branched hydrocarbon group having 3 or more carbon atoms,

Wherein, 1 represents a bond to AL ₁ and 2 represents a bond to B ₁; n1 represents an integer of 1 to 2, and n2 represents an integer of 1 to 4; a ₁₁、A₁₂ each independently represents a single bond, -O-, or a linking group (2 a); where a ₁₂ is present in plural, plural a ₁₂ may be the same or different; a ₂₁、A₂₂ each independently represents a linking group (2 a) other than-NR-; a _s11 represents a single bond, -O-, -CO-, or a linking group (2 a); a _s12 represents a single bond, -CO-, or a linking group (2 a) other than-NR-,

Wherein, 1 represents a bond to B ₂, 2 represents a bond to AL ₂, and a _s2 is synonymous with a _s11.

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

The polyimide polymer (A-1) has 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 X ₁ represents a tetravalent organic group; y ₁ represents a divalent organic group; r ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; z ₁₁、Z₁₂ independently represents a hydrogen atom, an optionally substituted C1-10 alkyl group, an optionally substituted C2-10 alkenyl group, an optionally substituted C2-10 alkynyl group, a t-butoxycarbonyl group, or a 9-fluorenylmethoxycarbonyl group.

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

X ₁ is a tetravalent organic group selected from the group consisting of the following formulas (4 a) to (4 n), the following formula (5 a) and the following formula (6 a),

Wherein x and y represent a single bond, -O-, -CO-, -COO-, an alkylene group having 1 to 5 carbon atoms, 1, 4-phenylene, -SO-, or-NRCO-, wherein R represents a hydrogen atom or a methyl group; z ¹～Z⁶ each 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 0 or 1; m is an integer of 1 to 5; * Representing a bond.

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

In the formula (1) and the formula (2), X ₁ is a tetravalent organic group selected from the group consisting of the formulas (4 a) to (4 n), (5 a) and the formula (6 a), and Y ₁ is a divalent organic group.

5. The liquid crystal aligning agent according to claim 1, wherein,

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

6. The liquid crystal aligning agent according to claim 1 or 5, wherein,

The Z ₁ 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.

7. The liquid crystal aligning agent according to claim 1 or 5, wherein,

The Cy ₁ is represented by the following formula (Rn),

In the formula (Rn), X independently represents a single bond, -O-, -CO-, -COO-, -NR ^b－、－CONR^b -, an alkylene group having 1 to 10 carbon atoms, or a divalent group in which at least one methylene group of the alkylene group having 1 to 10 carbon atoms is replaced with-O-, -CO-, -COO-, -NR ^b -or-CONR ^b -, R ^b in-CONR ^b -is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protecting group; m is 2 to 6; g each independently represents a benzene ring, naphthalene ring, or cyclohexane ring, and x represents a bond.

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

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

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

The component (A) contains a polyimide-based polymer, and at least one polymer selected from the group consisting of a polyorganosiloxane, a polymer of a monomer having a polymerizable unsaturated bond, and a cellulose-based polymer.

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

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

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

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

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

The liquid crystal aligning agent contains an organic solvent, and contains 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, gamma-butyrolactone, gamma-valerolactone, 1, 3-dimethyl-2-imidazolidinone, methyl ethyl ketone, cyclohexanone, cyclopentanone, N-dimethylformamide, 3-methoxy-N, N-dimethylpropionamide and 3-butoxy-N, N-dimethylpropionamide as the organic solvent.

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

The liquid crystal aligning agent further comprises at least one poor solvent selected from the group consisting of diisobutyl methanol, 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.

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

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