WO2022250007A1

WO2022250007A1 - Liquid crystal aligning agent, liquid crystal alignment film, liquid crystal display element, diamine, and polymer

Info

Publication number: WO2022250007A1
Application number: PCT/JP2022/021080
Authority: WO
Inventors: 美希豊田; 佳和原田; 司藤枝
Original assignee: 日産化学株式会社
Priority date: 2021-05-28
Filing date: 2022-05-23
Publication date: 2022-12-01
Also published as: JPWO2022250007A1; TW202311506A; CN117396803A

Abstract

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

Description

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

The present invention relates to a liquid crystal aligning agent, a liquid crystal aligning film obtained from the liquid crystal aligning agent, a liquid crystal display element comprising the liquid crystal aligning film, and a novel diamine and polymer suitable for them.

Liquid crystal display elements are used in a wide range of applications, from small applications such as mobile phones and smartphones to relatively large applications such as televisions and monitors. A liquid crystal display element is generally constructed by arranging a pair of electrode substrates so as to face each other with a predetermined gap (several μm) and sealing liquid crystal between the electrode substrates. By applying a voltage between the transparent conductive films forming the respective electrodes of the electrode substrate, the display on the liquid crystal display element is performed. These liquid crystal display elements have liquid crystal alignment films that are indispensable for controlling the alignment state of liquid crystal molecules. Patent Document 1 discloses a polyimide alignment film obtained by using a diamine compound having a specific structure containing a triazine ring as a liquid crystal alignment film in which the pretilt angle of liquid crystal molecules can be easily adjusted.

On the other hand, as a liquid crystal display element, various drive systems having different electrode structures, different physical properties of liquid crystal molecules to be used, etc. have been developed. For example, various modes such as TN (Twisted Nematic) method, STN (Super Twisted Nematic) method, VA (Vertical Alignment) method, IPS (In-Plane Switching) method, and FFS (Fringe Field Switching) method are known. .
VA (vertical alignment) liquid crystal display elements have a wide viewing angle, fast response speed, high contrast, and can eliminate the need for rubbing in the production process. It is widely used mainly for monitors and monitors (Patent Documents 2 and 3).

Japanese Patent Publication No. 2006-511696 JP-A-2008-76950 WO2008/117615

A touch panel type liquid crystal display must be highly durable against external pressure such as pressure from a finger or a pointing device such as a pen. is required. In addition, tablet terminals and mobile terminals are becoming lighter and thinner, and in the process of assembling the panels during the manufacture of liquid crystal displays, the panels are more likely to be distorted or subjected to stress inside the panels. Such distortion and stress of the panel cause peeling of the alignment film from the substrate, and cause defective bright spots and defective alignment. Therefore, the liquid crystal alignment film is required to be resistant to substrate peeling. Further, in tablet terminals and mobile terminals, in order to secure as many display surfaces as possible, it is necessary to make the width of the sealant used for bonding the substrates of the liquid crystal display element narrower than before. In such a case, in order to prevent breakage of the liquid crystal display element, it is necessary to increase the adhesiveness (also referred to as adhesion) between the liquid crystal alignment film and the sealant as compared with the prior art.

An object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film that is less prone to substrate peeling and a liquid crystal display element having high durability against external pressure. Another object of the present invention is to provide a liquid crystal aligning agent capable of obtaining a liquid crystal aligning film having high adhesiveness between the liquid crystal aligning film and the sealant and increasing the strength of the liquid crystal display element.

As a result of intensive research to achieve the above objects, the present inventors have found that a liquid crystal aligning agent containing a novel polymer having a specific structure is effective for achieving the above objects. , have completed the present invention.
The present invention provides at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component containing a diamine represented by the following formula (1) and a polyimide that is an imidized product of the polyimide precursor ( P), a liquid crystal alignment film obtained from the liquid crystal alignment agent, and a liquid crystal display element having the liquid crystal alignment film.

(wherein L is -(CH ₂ ) _n -O- (n is an integer of 1 to 6), -(CH ₂ ) _n -C(=O)-NH- (n is 1 to 6 is an integer of ), -(CH ₂ ) _n -OC(=O)- (n is an integer of 1 to 6), -(CH ₂ ) _n -C(=O)-O- (n is an integer of 1 to 6), -O-(CH ₂ ) _n -O- (n is an integer of 1 to 6), -C(=O)-O-(CH ₂ ) _n —O— (n is an integer of 1 to 6), —(CH ₂ ) _m —C(═O)—O—(CH ₂ ) _n — (m and n are each independently 1 to is an integer of 6.), or -C(=O)-O-(CH ₂ ) _n -O-C(=O)- (n is an integer of 1 to 6.) Bonding with OH Any hydrogen atom of the benzene ring may be replaced with a methyl group, a methoxy group, or a halogen atom.p represents an integer of 0 or 1.)
Throughout the present specification, halogen atoms include fluorine, chlorine, bromine, and iodine atoms, and * represents a bond.

ADVANTAGE OF THE INVENTION According to this invention, the liquid crystal aligning agent which can obtain the liquid crystal aligning agent which a board|substrate peeling does not produce easily, and can obtain a liquid crystal display element with high durability with respect to an external pressure is provided. Moreover, the liquid crystal aligning agent which can obtain the liquid crystal aligning film which has high adhesiveness of a liquid crystal aligning film and a sealing agent, and raises the intensity|strength of a liquid crystal display element is provided.
Although the mechanism by which the above effects of the present invention are obtained is not necessarily clear, the following is considered to be one of the reasons. The diamine for obtaining the polymer (P) of the present invention has a structure in which an aromatic ring containing a diamine moiety and a benzene ring having an aromatic hydroxyl group are linked by a specific linking group. The aromatic hydroxyl group has a structure with little steric hindrance and has the effect of enhancing the interaction between the alignment film and the substrate. In addition, since the polymer (P) has the above-mentioned aromatic hydroxyl group in the side chain portion of the polymer and has a structure with improved flexibility, the reactivity between the aromatic hydroxyl group and the sealing agent is increased, resulting in high sealing performance. It is considered that a liquid crystal alignment film having adhesion and high voltage holding characteristics was obtained. Furthermore, since the above-mentioned specific linking group has a structure that includes a hetero atom, an ester group, an amide bond, etc. in the alkyl chain, it has more suitable polarity and rigidity in the molecule than linking only with the alkyl chain. can be given. Therefore, it is considered that the rigidity of the product of the aromatic hydroxyl group and the sealing agent is improved, so that the liquid crystal aligning agent that is less likely to be peeled off from the substrate can be obtained, and the liquid crystal display element having high durability against external pressure can be obtained. .

As described above, the liquid crystal aligning agent of the present invention is a polyimide precursor obtained using a diamine component containing a diamine represented by the above formula (1) (hereinafter also referred to as a specific diamine) and the polyimide precursor It is characterized by containing at least one polymer (P) selected from the group consisting of polyimides which are imidized substances.
The diamine represented by Formula (1) (excluding some diamines) is also the subject of the present invention. A polymer obtained using a diamine component containing the diamine represented by formula (1) is also an object of the present invention.

L in the above formula (1) is —(CH ₂ ) _n —O— (n is an integer of 1 to 6), —(CH ₂ ) _n —, from the viewpoint of suitably obtaining the effects of the present invention. OC(=O)-(n is an integer of 1 to 6) and -(CH ₂ ) _n -C(=O)-O-(n is an integer of 1 to 6) are preferred. .

When p is 0 in the above formula (1), preferred specific examples of the diamine represented by the above formula (1) include diamines represented by any of the following formulas (d1-1) to (d1-11). Among them, diamines represented by any one of (d1-1) to (d1-3) are more preferable from the viewpoint of suitably obtaining the effects of the present invention.

When p is 1 in the above formula (1), preferred specific examples of the diamine represented by the above formula (1) include diamines represented by any of the following formulas (d2-1) to (d2-6). Among them, diamines represented by any one of (d2-1) to (d2-3) are more preferable from the viewpoint of suitably obtaining the effects of the present invention.

(Production of polymer (P))
The polymer (P) contained in the liquid crystal aligning agent of the present invention is a polyimide precursor obtained using a diamine component containing the specific diamine, or a polyimide that is an imidized product of the polyimide precursor. Here, the polyimide precursor is a polymer from which a polyimide can be obtained by imidating polyamic acid, polyamic acid ester, or the like.
A polyamic acid (P′), which is a polyimide precursor of the polymer (P), can be obtained by a polymerization reaction between a diamine component containing the specific diamine and a tetracarboxylic acid component. The specific diamines may be used singly or in combination of two or more.
In this case, the amount of the specific diamine used is preferably 5 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, relative to the total diamine component.

The diamine component used for producing the polyamic acid (P') may contain a diamine other than the specific diamine (hereinafter also referred to as other diamine). When other diamine is used in addition to the specific diamine, the amount of the specific diamine used is preferably 90 mol % or less, more preferably 80 mol % or less, relative to the diamine component. Examples of other diamines are listed below, but the present invention is not limited to these. The other diamines may be used singly or in combination of two or more.

aromatic diamines represented by "AXJ" (d), p-phenylenediamine, 2,3,5,6-tetramethyl-p-phenylenediamine, 2,5-dimethyl-p-phenylenediamine, m-phenylenediamine, 2,4-dimethyl-m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'- Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4 '-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-bis(trifluoromethyl )-4,4′-diaminobiphenyl, 3,4′-diaminobiphenyl, 4,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,2′-diaminobiphenyl, 2,3′-diaminobiphenyl, 1,5-diaminonaphthalene, 1,6-diaminonaphthalene, 1,7-diaminonaphthalene, 2,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, bis(4-aminophenoxy)methane , 1,2-bis(4-aminophenyl)ethane, 1,2-bis(4-aminophenoxy)ethane, 1,3-bis(3-aminophenyl)propane, 1,4-bis(4-aminophenyl ) butane, 1,4-bis(4-amino-2-methylphenyloxy)butane, 1,4-bis(3-aminophenyl)butane, bis(3,5-diethyl-4-aminophenyl)methane, 1 ,5-bis(4-aminophenoxy)pentane, 1,5-bis(3-aminophenoxy)pentane, 1,6-bis(4-aminophenoxy)hexane, 1,6-bis(3-aminophenoxy) Hexane, 1,7-bis(4-aminophenoxy)heptane, 1,7-bis(3-aminophenoxy)heptane, 1,8-bis(4-aminophenoxy)octane, 1,8-bis(3- aminophenoxy)octane, 1,9-bis(4-aminophenoxy)nonane, 1,9-bis(3-aminophenoxy)nonane, 1,10-bis(4-aminophenoxy)decane, 1,10-bis( 3-aminophenoxy)decane, 1,11-bis(4-aminophenoxy)un Decane, 1,11-bis(3-aminophenoxy)undecane, 1,12-bis(4-aminophenoxy)dodecane, 1,12-bis(3-aminophenoxy)dodecane, 3-[2-[2-( 4-aminophenoxy)ethoxy]ethoxy]benzenamine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl , 4,4′-bis(4-aminophenoxy)diphenyl ether, 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene, 1,2-bis(6-amino-2-naphthyloxy)ethane, 1,2-bis(6-amino-2-naphthyl)ethane, 6-[2-(4-aminophenoxy)ethoxy]-2-naphthylamine, 4′-[2-(4-aminophenoxy)ethoxy]-[ 1,1′-biphenyl]-4-amine, 1,4-bis[2-(4-aminophenyl)ethyl]butanedioate, 1,6-bis[2-(4-aminophenyl)ethyl]hexanedioate art, 1,4-phenylenebis(4-aminobenzoate), 1,4-phenylenebis(3-aminobenzoate), 1,3-phenylenebis(4-aminobenzoate), 1,3-phenylenebis(3- aminobenzoate), bis(4-aminophenyl)terephthalate, bis(3-aminophenyl)terephthalate, bis(4-aminophenyl)isophthalate, bis(3-aminophenyl)isophthalate; 4,4'-diaminoazobenzene , diaminotolan, 4,4-diaminochalcone, or [4-[(E)-3-[2-(2,4-diaminophenyl)ethoxy]-3-oxo-prop-1-enyl]phenyl]4- (4,4,4-trifluorobutoxy)benzoate, or [4-[(E)-3-[[5-amino-2-[4-amino-2-[[(E)-3-[4- [4-(4,4,4-trifluorobutoxy)benzoyl]oxyphenyl]prop-2-enoyl]oxymethyl]phenyl]phenyl]methoxy]-3-oxo-prop-1-enyl]phenyl]4-( 4,4,4-trifluorobutoxy)benzoate, an aromatic diamine having a cinnamate structure in the side chain, and a diamine having a photoalignable group; 2-(2,4-diaminophenoxy)ethyl methacrylate; 2,4-diamino-N,N-diallylaniline 1-(4-(2-(2,4-diaminophenoxy)ethoxy)phenyl)-2-hydroxy-2-methylpropanone, 2-(4-(2 -hydroxy-2-methylpropanoyl)phenoxy)ethyl-3,5-diaminobenzoate, benzoin or alkyl ethers thereof, benzyl ketals, acetophenones, acylphosphine oxides, benzophenones, or aminobenzophenones A diamine having a group that exhibits a radical polymerization initiator function in the molecule (hereinafter also referred to as a diamine having a radical initiation function). ); diamines having an amide bond such as 4,4′-diaminobenzanilide, 1,3-bis(4-aminophenyl)urea, 1,3-bis(4-aminobenzyl)urea, 1,3-bis( diamines having a urea bond such as 4-aminophenethyl)urea; 4,4′-sulfonyldianiline, 3,3′-sulfonyldianiline, bis(4-aminophenyl)silane, bis(3-aminophenyl)silane, dimethyl-bis(4-aminophenyl)silane, dimethyl-bis(3-aminophenyl)silane, 4,4'-thiodianiline, 3,3'-thiodianiline, 3,3'-diaminodiphenyl ether, 3,4'-diamino diphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2'-bis(4-aminophenyl)hexafluoropropane, 2,2'-bis(3-aminophenyl)hexafluoropropane, 2,2'-bis(3-amino-4-methylphenyl)hexafluoro propane, 2,2'-bis(4-aminophenyl)propane, 2,2'-bis(3-aminophenyl)propane, 2,2'-bis(3-amino-4-methylphenyl)propane, 3, 3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 4,4′-diaminobenzophenone, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4 -aminophenyl)benzene, 1,4-bis(4-aminobenzyl)benzene; 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminocarbazole, N-methyl -3,6-diaminocarbazole, 1,4-bis-(4-aminophenyl)-piperazine, 3,6-diaminoacridine, N-ethyl-3,6-diaminocarbazole, N-phenyl-3,6-diamino Carbazole, N-(3-(1H-imidazol-1-yl)propyl-3,5-diaminobenzamide, 4-[4-[(4-aminophenoxy)methyl]-4,5-dihydro-4-methyl- 2-oxazolyl]-benzenamine, 1,4-bis(p-aminobenzyl)piperazine, 4,4′-[4,4′-propane-1,3-diylbis(piperidine-1,4 -diyl)]dianiline, 4-(4-aminophenoxycarbonyl)-1-(4-aminophenyl)piperidine, diamines represented by the following formulas (z-1) to (z-5), 2,5- bis(4-aminophenyl)pyrrole, 4,4′-(1-methyl-1H-pyrrole-2,5-diyl)bis[benzenamine], 1,4-bis-(4-aminophenyl)-piperazine, 2-N-(4-aminophenyl)pyridine-2,5-diamine, 2-N-(5-aminopyridin-2-yl)pyridine-2,5-diamine, 2-(4-aminophenyl)-5 -heterocycle-containing diamines such as aminobenzimidazole, 2-(4-aminophenyl)-6-aminobenzimidazole, 5-(1H-benzimidazol-2-yl)benzene-1,3-diamine, or 4, 4'-diaminodiphenylamine, 4,4'-diaminodiphenyl-N-methylamine, N,N'-bis(4-aminophenyl)-1,4-benzenediamine, N,N'-bis(4-aminophenyl )-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethylbenzidine, or N,N'-bis(4-aminophenyl)-N,N'-dimethyl-1,4 - At least one nitrogen-containing structure selected from the group consisting of nitrogen-containing heterocycles, secondary amino groups and tertiary amino groups (hereinafter referred to as specific nitrogen-containing Also called structure. ) (provided that the molecule does not have an amino group bonded with a protective group that is eliminated by heating and replaced with a hydrogen atom.); 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3, 5-diaminobenzoic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminodiphenylmethane-3-carboxylic acid, 4,4'-diaminodiphenylethane-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diamino biphenyl-2,4'-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-diaminodiphenylethane-3,3'-dicarboxylic acid, and 4,4'-diamino Diamines having a carboxy group such as diphenyl ether-3,3′-dicarboxylic acid; 2,4-diaminophenol, 3,5-diaminophenol, 3,5-diaminobenzyl alcohol, 2,4-diaminobenzyl alcohol, 4,6 -diaminoresorcinol, 4,4'-diamino-3,3'-dihydroxybiphenyl; 4-(2-(methylamino)ethyl)aniline, 4-(2-aminoethyl)aniline, 1-(4-aminophenyl) -1,3,3-trimethyl-1H-indan-5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene-6-amine; N1, N4-bis(2-tert-butoxycarbonylamino-4-aminophenyl)adipamide, 4-amino-N-(2-tert-butoxycarbonylamino-4-aminophenyl)benzamide, carbamic acid, N-[(2, 5-diaminophenyl)methyl]-,1,1-dimethylethyl ester, carbamic acid, N-[3-(2,5-diaminophenyl)propyl]-,1,1-dimethylethyl ester, carbamic acid, N, N-[(2,5-diamino-1,3-phenylene)di-3,1-propanediyl]bis-,C,C-bis(1,1-dimethylethyl) ester, N-tert-butoxycarbonyl- N-(2-(4-aminophenyl)ethyl)-N-(4-aminobenzyl)amine, benzoic acid, 4-amino-2-tert-butoxycarbonylamino-, 1,1'-[(1,1 , 3,3-tetramethyl-1,3-disilo xandiyl)di-4,1-butanediyl]ester, carbamic acid, N-[2-(4-aminophenyl)ethyl]-N-[[[2-(4-aminophenyl)ethyl]amino]carbonyl]-, 1,1-dimethylethyl ester, carbamic acid, N-(4-aminophenyl)-N-[[1-(4-aminophenyl)-4-piperidinyl]methyl]-, 1,1-dimethylethyl ester A group such as “—N(D)—” (D represents a protective group that is eliminated by heating and replaced by a hydrogen atom, preferably a tert-butoxycarbonyl group. );
Diamines having a siloxane bond such as 1,3-bis(3-aminopropyl)-tetramethyldisiloxane, bis(p-aminophenylcarbamoylpropyl)tetramethyldisiloxane; meta-xylylenediamine, 1,3-propanediamine, Tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), the formula described in WO2018/117239 ( Y-1) to a diamine in which two amino groups are bonded to a group represented by any one of (Y-167), etc.

In the aromatic diamine (d) above, A represents a monovalent group in which two primary amino groups are bonded to an aromatic group. Specific examples of aromatic groups include benzene rings, naphthalene rings, and biphenyl structures. X is a single bond, —(CH ₂ ) _a — (a is an integer of 1 to 15), —CONH—, —NHCO—, —CO—N(CH ₃ )—, —NH—, —O -, -COO-, -OCO- or -((CH ₂ ) _a1 -A ₁ ) _m1 - (a1 is an integer of 1 to 15, A ₁ represents an oxygen atom or -COO-, m1 is 1 to is an integer of 2. When m1 is 2, a1 and _A1 each independently have the above definition).
J represents a monovalent organic group having at least one group selected from the group consisting of an alicyclic hydrocarbon group having 4 to 40 carbon atoms and an aromatic hydrocarbon group having 6 to 40 carbon atoms, with the proviso that At least one of the hydrogen atoms of the alicyclic hydrocarbon group and the aromatic hydrocarbon group is a halogen atom, a halogen atom-containing alkyl group, a halogen atom-containing alkoxy group, an alkyl group having 3 to 10 carbon atoms, or 3 carbon atoms. -10 alkoxy groups, alkenyl groups having 3 to 10 carbon atoms, halogen atom-containing alkyl groups, halogen atom-containing alkoxy groups, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, and 3 carbon atoms The carbon-carbon bond of any methylene group of the alkenyl group from 1 to 10 is replaced with a substituent selected from the group consisting of heteroatom-containing groups interrupted by oxygen atoms.
J is a monovalent organic group having two or more at least one group selected from the group consisting of an alicyclic hydrocarbon group having 4 to 40 carbon atoms and an aromatic hydrocarbon group having 6 to 40 carbon atoms. In some cases, at least one alicyclic hydrocarbon group or aromatic hydrocarbon group may have the substituents exemplified above, and the other alicyclic hydrocarbon groups or aromatic hydrocarbon groups of J are It may be unsubstituted or have substituents other than those exemplified above.

Examples of halogen atom-containing alkyl groups include halogen atom-containing alkyl groups having 1 to 10 carbon atoms.
Halogen atom-containing alkoxy groups include, for example, halogen atom-containing alkoxy groups having 1 to 10 carbon atoms.

Examples of the alicyclic hydrocarbon group for J include cyclobutane ring, cyclopentane ring, cyclohexane ring, cyclodecane ring, steroid skeleton (e.g., cholestanyl group, cholesteryl group, lanostanyl group, etc.), and the like. A benzene ring, a naphthalene ring, etc. can be mentioned as a hydrogen group. When J has at least one of a cyclohexane ring and a benzene ring, examples of the group "-XJ" include the following structure (S1), and more preferred structures are the following formulas (S1-1) to (S1-5) can be mentioned.

(X ¹ is a single bond, —(CH ₂ ) _a — (a is an integer of 1 to 15), —CONH—, —CO—N(CH ₃ )—, —NH—, —O—, -COO- or -((CH ₂ ) _a1 -A ₁ ) _m1 - (a1 is an integer of 1 to 15, A ₁ represents an oxygen atom or -COO-, m1 is an integer of 1 to 2 When m1 is 2, a1 and _A1 each independently have the above definition.).
G ¹ represents a divalent cyclic group selected from a phenylene group and a cyclohexylene group. Any hydrogen atom on the cyclic group is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a fluorine-containing alkyl group having 1 to 3 carbon atoms, or a fluorine-containing alkoxy group having 1 to 3 carbon atoms. Alternatively, it may be substituted with a fluorine atom.
m is an integer of 1-4. When m is 2 or more, multiple X ¹ and G ¹ each independently have the above definition.
R ¹ is a fluorine atom, a fluorine atom-containing alkyl group having 1 to 10 carbon atoms, a fluorine atom-containing alkoxy group having 1 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms, an alkoxy group having 3 to 10 carbon atoms, or carbon represents an alkoxyalkyl group of numbers 3 to 10;

(X ¹ and R ¹ have the same definitions as X ¹ and R ¹ in formula (S1) above.)

Specific examples of the aromatic diamine (d) include diamines represented by the following formulas (d-1) and (d-2). More preferred specific examples are the groups of formulas (d-1) to (d-1) to ( diamines represented by d-2), and cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-3,5-diaminobenzene, cholestanyloxy-2,4-diaminobenzene, and 3,5-diaminobenzo diamines having a steroid skeleton such as cholestanyl acid, cholestenyl 3,5-diaminobenzoate, lanostanyl 3,5-diaminobenzoate and 3,6-bis(4-aminobenzoyloxy)cholestane.

(X and J have the same definitions as X and J of the aromatic diamine (d), including preferred embodiments. In the formula (d-2), two X and J may be the same may be different.)

Other diamines include the above aromatic diamine (d), p-phenylenediamine, the above carboxy group-containing diamine, 4,4'-diaminodiphenylmethane, 4,4'- Diaminobenzophenone, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, diamine having photo-orientation group, radical initiation function , a diamine having a terminal photopolymerizable group, a diamine having a group “—N(D)—”, and a diamine having the above specific nitrogen-containing structure are preferred.

When other diamines are used in addition to the specific diamines, the amount of the other diamines used is preferably 10 to 90 mol%, more preferably 20 to 80 mol, based on the total diamine components used. %.
The amount of the other diamine used is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, based on the total diamine components used in the production of the polymer (P).

(Tetracarboxylic acid component)
When producing the polyamic acid (P'), the tetracarboxylic acid component to be reacted with the diamine component is not only tetracarboxylic dianhydride, but also tetracarboxylic acid, tetracarboxylic acid dihalide, tetracarboxylic acid dialkyl ester, or tetracarboxylic acid. Derivatives of tetracarboxylic dianhydrides such as carboxylic acid dialkyl ester dihalides can also be used.

The tetracarboxylic dianhydride or derivative thereof includes an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride, or derivatives thereof. . Among them, it is more preferable to contain a tetracarboxylic dianhydride or a derivative thereof having at least one partial structure selected from the group consisting of a benzene ring, a cyclobutane ring structure, a cyclopentane ring structure and a cyclohexane ring structure, and a cyclobutane ring structure. , a tetracarboxylic dianhydride having at least one partial structure selected from the group consisting of a cyclopentane ring structure and a cyclohexane ring structure, or derivatives thereof.

When a liquid crystal display element has a low voltage holding ratio (VHR), it may be difficult to apply a sufficient voltage to the liquid crystal molecules even if a voltage is applied. In particular, automotive applications such as car navigation systems and meter panels may be used or left in high-temperature environments for long periods of time. In some cases, a liquid crystal alignment film having
In addition, in liquid crystal display elements, due to the influence of thinning and increasing size of the substrates used, temperature differences occur between different parts in the same substrate during firing, and the liquid crystal alignment film in the part that is excessively heated will not release the liquid crystal. The ability to orient is deteriorated, and as a result, there may be a problem that the obtained liquid crystal display element partially causes display defects. Therefore, there is a demand for a liquid crystal alignment film that has a high ability to align liquid crystals even when exposed to excessive heating.
From the viewpoint of obtaining a liquid crystal alignment film having a high voltage holding ratio and/or a liquid crystal alignment film having a high ability to align liquid crystals even when exposed to excessive heating, the polyamic acid (P') is used. When producing, the tetracarboxylic acid component to be reacted with the diamine component is more preferably an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, or a derivative thereof. Among them, it is more preferable to contain a tetracarboxylic dianhydride having at least one partial structure selected from the group consisting of a cyclobutane ring structure, a cyclopentane ring structure and a cyclohexane ring structure, or a derivative thereof.
As the tetracarboxylic acid component that can be used in the synthesis of the polyamic acid (P′), the following tetracarboxylic dianhydrides or derivatives thereof (hereinafter collectively referred to as specific tetracarboxylic acid derivatives) are preferred. .)including.
In addition, from the viewpoint of obtaining a liquid crystal alignment film having a high voltage holding ratio and/or a liquid crystal alignment film having a high ability to orient liquid crystals even when exposed to excessive heating, the specific tetracarboxylic acid The derivative is preferably the following acyclic aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride or derivative thereof.
Examples of the tetracarboxylic dianhydride derivative include the above-described tetracarboxylic dianhydride derivative, and the tetracarboxylic dianhydride or derivative thereof may be used alone, or two More than one species may be used in combination.

Acyclic aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl -1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3 ,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3, 4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride product, 4-(2,5-dioxotetrahydrofuran-3-yl)tetrahydronaphthalene-1,2-dicarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a, 4, 5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydro naphtho[1,2-c]furan-1,3-dione, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2 .2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride alicyclic tetracarboxylic dianhydrides such as products; pyromellitic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenylsulfone Tetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenyl ethertetracarboxylic dianhydride, 3,3′,4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,2 ',3,3'-biphenyltetracarboxylic dianhydride, 4,4'- Bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, ethylene glycol bis-anhydrotrimellitate, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-carbonyldiphthalic acid Fragrances such as anhydride, 4,4'-oxydi(1,4-phenylene)bis(phthalic acid) dianhydride, or 4,4'-methylenedi(1,4-phenylene)bis(phthalic acid) dianhydride group tetracarboxylic dianhydrides; other tetracarboxylic dianhydrides described in JP-A-2010-97188.

Preferred examples of the above specific tetracarboxylic acid derivatives include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl -1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl- 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-difluoro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-bis(trifluoromethyl)-1 , 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3, 3′,4,4′-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5-(2,5-dioxotetrahydrofuran-3-yl)-3a,4, 5,9b-tetrahydronaphtho[1,2-c]furan-1,3-dione, 5-(2,5-dioxotetrahydrofuran-3-yl)-8-methyl-3a,4,5,9b-tetrahydro naphtho[1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2:4,6:8-dianhydride, pyromellit acid dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8- naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3′,4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3′,4, 4′-biphenyltetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, or derivatives thereof.

The proportion of the above-mentioned specific tetracarboxylic acid derivative used is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 50 mol% or more, relative to 1 mol of the total tetracarboxylic acid component used.

(Synthesis of polyamic acid)
A polyamic acid is synthesized by reacting a diamine component containing the specific diamine with a tetracarboxylic acid component containing the tetracarboxylic dianhydride or its derivative in an organic solvent. The ratio of the tetracarboxylic dianhydride and the diamine used in the synthesis reaction of the polyamic acid is such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 per equivalent of the amino group of the diamine. A ratio that provides equivalents is preferred, and a ratio that provides 0.3 to 1.2 equivalents is more preferred. As in ordinary polycondensation reactions, the closer the equivalent of the acid anhydride group in this tetracarboxylic dianhydride to one equivalent, the greater the molecular weight of the resulting polyamic acid.
The reaction temperature in the polyamic acid synthesis reaction is preferably -20 to 150°C, more preferably 0 to 100°C. Also, the reaction time is preferably 0.1 to 24 hours, more preferably 0.5 to 12 hours.
The polyamic acid synthesis reaction can be carried out at any concentration, preferably 1 to 50% by mass, more preferably 5 to 30% by mass. The initial stage of the reaction can be carried out at a high concentration, and then the solvent can be added.

Specific examples of the organic solvent include cyclohexanone, cyclopentanone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone. In addition, when the solvent solubility of the polymer is high, methyl ethyl ketone, cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene Glycol monopropyl ether, diethylene glycol monomethyl ether, or diethylene glycol monoethyl ether can be used

(Synthesis of Polyamic Acid Ester)
Polyamic acid esters are produced by, for example, [I] a method of reacting the polyamic acid obtained by the above method with an esterifying agent, [II] a method of reacting a tetracarboxylic acid diester with a diamine, [III] a tetracarboxylic acid It can be obtained by a known method such as a method of reacting a diester dihalide and a diamine.

(Synthesis of polyimide)
Moreover, a polyimide can be obtained by ring-closing (imidating) a polyimide precursor such as the above polyamic acid or polyamic acid ester. The imidization ratio as used herein means the ratio of imide groups to the total amount of imide groups derived from tetracarboxylic dianhydride or derivatives thereof and carboxy groups (or derivatives thereof). The imidization rate does not necessarily have to be 100%, and can be arbitrarily adjusted according to the application and purpose.

Examples of methods for imidizing the polyimide precursor include thermal imidization in which the solution of the polyimide precursor is heated as it is, and catalytic imidization in which a catalyst is added to the solution of the polyimide precursor.

When the polyimide precursor is thermally imidized in the solution, the temperature is preferably 100 to 400° C., more preferably 120 to 250° C., and water produced by the imidization reaction is removed from the system. is preferred.

The catalytic imidization of the polyimide precursor can be carried out by adding a basic catalyst and an acid anhydride to the solution of the polyimide precursor and stirring at -20 to 250°C, preferably 0 to 180°C. The amount of the basic catalyst is 0.5 to 30 times the molar amount of the amic acid group, preferably 2 to 20 times the molar amount, and the amount of the acid anhydride is 1 to 50 times the molar amount of the amic acid group, preferably 3 to 30 times the molar amount. Double. Examples of the basic catalyst include pyridine, triethylamine, trimethylamine, tributylamine, trioctylamine, etc. Among them, pyridine is preferable because it has appropriate basicity for advancing the reaction. Examples of the acid anhydride include acetic anhydride, trimellitic anhydride, and pyromellitic anhydride. Among them, acetic anhydride is preferably used because it facilitates purification after the reaction is completed. The imidization rate by catalytic imidization can be controlled by adjusting the catalyst amount, reaction temperature, and reaction time.

When recovering the generated polyimide precursor or polyimide from the polyimide precursor or polyimide reaction solution, the reaction solution may be put into a solvent to precipitate. Solvents used for precipitation include methanol, ethanol, isopropyl alcohol, acetone, hexane, butyl cellosolve, heptane, methyl ethyl ketone, methyl isobutyl ketone, toluene, benzene, and water. The polymer precipitated by adding it to the solvent can be filtered and recovered, and then dried at room temperature or under heat under normal pressure or reduced pressure. In addition, the impurities in the polymer can be reduced by redissolving the precipitated and recovered polymer in an organic solvent and repeating the operation of reprecipitating and recovering 2 to 10 times. Solvents in this case include, for example, alcohols, ketones, hydrocarbons, and the like, and it is preferable to use three or more kinds of solvents selected from these, because the purification efficiency is further improved.

<Terminal blocking agent>
When synthesizing the polyimide precursor or polyimide in the present invention, a tetracarboxylic acid component containing a tetracarboxylic acid dianhydride or a derivative thereof, and a diamine component containing the specific diamine, together with an appropriate terminal blocking agent end-blocking A stop-type polymer may be synthesized. The end-blocking polymer has effects of improving the film hardness of the alignment film obtained by the coating film and improving the adhesion properties between the sealant and the alignment film.
Examples of the terminal of the polyimide precursor or polyimide in the present invention include an amino group, a carboxyl group, an acid anhydride group, or a group derived from a terminal blocking agent to be described later. An amino group, a carboxyl group, and an acid anhydride group can be obtained by a normal condensation reaction, or can be obtained by terminal blocking using the following terminal blocking agents.

Terminal blockers include, for example, acetic anhydride, maleic anhydride, nadic anhydride, phthalic anhydride, itaconic anhydride, cyclohexanedicarboxylic anhydride, 3-hydroxyphthalic anhydride, trimellitic anhydride, 3-( 3-trimethoxysilyl)propyl)-3,4-dihydrofuran-2,5-dione, 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione, 4-ethynylphthalic anhydride, etc. Acid anhydrides; dicarbonic acid diester compounds such as di-tert-butyl dicarbonate and diallyl dicarbonate; chlorocarbonyl compounds such as acryloyl chloride, methacryloyl chloride and nicotinic acid chloride; aniline, 2-aminophenol, 3-aminophenol, 4 -aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n - monoamine compounds such as heptylamine and n-octylamine; ethyl isocyanate, phenyl isocyanate, naphthyl isocyanate, or having unsaturated bonds such as 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate Isocyanate and the like can be mentioned.

The proportion of the end blocking agent used is preferably 0.01 to 20 mol parts, more preferably 0.01 to 10 mol parts, per 100 mol parts in total of the diamine components used.

The polystyrene equivalent weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of the polyimide precursor and polyimide is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. is. In addition, the molecular weight distribution (Mw/Mn) represented by the ratio of Mw to the polystyrene equivalent number average molecular weight (Mn) measured by GPC is preferably 15 or less, more preferably 10 or less. By having the molecular weight within such a range, it is possible to ensure good orientation of the liquid crystal display element.

(Liquid crystal aligning agent)
The liquid crystal aligning agent of the present invention is a liquid composition in which the polymer (P) and optionally other components are preferably dispersed or dissolved in a suitable solvent.

The liquid crystal aligning agent of the present invention may contain other polymers other than the polymer (P). Specific examples of other polymers include at least one polymer selected from the group consisting of a polyimide precursor obtained using a diamine component that does not contain the specific diamine and a polyimide that is an imidized product of the polyimide precursor. (B), polysiloxane, polyester, polyamide, polyurea, polyorganosiloxane, cellulose derivative, polyacetal, polystyrene derivative, poly(styrene-maleic anhydride) copolymer, poly(isobutylene-maleic anhydride) copolymer , poly(vinyl ether-maleic anhydride) copolymer, poly(styrene-phenylmaleimide) derivative, poly(meth)acrylate, and the like. The polymer (B) is selected from the group consisting of a polyimide precursor obtained using a diamine component containing the aromatic diamine (d) and an imidized product of the polyimide precursor, from the viewpoint of improving vertical alignment. At least one polymer is included. Specific examples of poly(styrene-maleic anhydride) copolymers include SMA1000, SMA2000, SMA3000 (manufactured by Cray Valley), GSM301 (manufactured by Gifu Shellac Manufacturing Co., Ltd.) and the like. Anhydride) copolymers include Isoban-600 (manufactured by Kuraray Co., Ltd.), and specific examples of poly(vinyl ether-maleic anhydride) copolymers include Gantrez AN-139 (methyl vinyl ether anhydride). maleic acid resin, manufactured by Ashland).
Other polymers may be used singly or in combination of two or more. The content of the other polymer is preferably 90 parts by mass or less, more preferably 10 to 90 parts by mass, and further 20 to 80 parts by mass with respect to the total 100 parts by mass of the polymer contained in the liquid crystal aligning agent. preferable.

In addition, the liquid crystal aligning agent of the present invention may contain components other than those mentioned above, if necessary. Examples of the component include a crosslinkable compound (c-1) having at least one substituent selected from an epoxy group, an isocyanate group, an oxetane group, a cyclocarbonate group, a blocked isocyanate group, a hydroxy group and an alkoxy group, and , at least one crosslinkable compound selected from the group consisting of a crosslinkable compound (c-2) having a polymerizable unsaturated group, a functional silane compound, a metal chelate compound, a curing accelerator, a surfactant, an antioxidant , sensitizers, preservatives, and compounds for adjusting the dielectric constant and electrical resistance of the liquid crystal alignment film.

Preferred specific examples of the crosslinkable compounds (c-1) and (c-2) include N,N,N',N'-tetraglycidyl-1,4-phenylenediamine, N,N,N',N' -tetraglycidyl-2,2'-dimethyl-4.4'-diaminobiphenyl, 2,2-bis[4-(N,N-diglycidyl-4-aminophenoxy)phenyl]propane, N,N,N', Epoxy compounds in which a tertiary nitrogen atom is bound to an aromatic carbon atom such as N'-tetraglycidyl-4,4'-diaminodiphenylmethane; N,N,N',N'-tetraglycidyl-1,2-diaminocyclohexane , N,N,N′,N′-tetraglycidyl-1,3-diaminocyclohexane, N,N,N′,N′-tetraglycidyl-1,4-diaminocyclohexane, bis(N,N-diglycidyl-4 -aminocyclohexyl)methane, bis(N,N-diglycidyl-2-methyl-4-aminocyclohexyl)methane, bis(N,N-diglycidyl-3-methyl-4-aminocyclohexyl)methane, 1,3-bis( N,N-diglycidylaminomethyl)cyclohexane, 1,4-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)benzene, 1,4-bis (N,N-diglycidylaminomethyl)benzene, 1,3,5-tris(N,N-diglycidylaminomethyl)cyclohexane, 1,3,5-tris(N,N-diglycidylaminomethyl)benzene, etc. Epoxy compounds in which the tertiary nitrogen atom is bound to an aliphatic carbon atom, epoxy compounds such as triglycidyl isocyanurate such as TEPIC (manufactured by Nissan Chemical Co., Ltd.); Compounds having two or more oxetanyl groups described; Coronate AP Stable M, Coronate 2503, 2515, 2507, 2513, 2555, Millionate MS-50 (manufactured by Tosoh Corporation), Takenate B-830, B-815N, Compounds having blocked isocyanate groups such as B-820NSU, B-842N, B-846N, B-870N, B-874N, B-882N (manufactured by Mitsui Chemicals, Inc.); N,N,N',N'- Tetrakis(2-hydroxyethyl)adipamide, 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethoxy compounds having a hydroxy group or an alkoxy group such as methylphenyl)propane and 2,2-bis(4-hydroxy-3,5-dihydroxymethylphenyl)-1,1,1,3,3,3-hexafluoropropane; Glycerin mono(meth)acrylate, glycerin di(meth)acrylate (1,2-,1,3-body mixture), glycerin tris(meth)acrylate, glycerol 1,3-diglycerolate di(meth)acrylate, pentaerythritol Stall tri(meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, pentaethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, etc.) and a crosslinkable compound having a polymerizable unsaturated group.

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

Compounds for adjusting the dielectric constant and electrical resistance include monoamines having nitrogen-containing aromatic heterocycles such as 3-picolylamine. When using a monoamine having a nitrogen-containing aromatic heterocycle, it is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the polymer component contained in the liquid crystal aligning agent. 20 parts by mass.

Preferred specific examples of functional silane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane. Silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxy silane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxysilane sidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, ethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3- isocyanatopropyltriethoxysilane and the like. When using a functional silane compound, it is preferably 0.1 to 30 parts by mass, more preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer component contained in the liquid crystal alignment agent. .

Examples of the organic solvent used in the liquid crystal aligning agent of the present invention include lactone solvents such as γ-valerolactone and γ-butyrolactone; (n-propyl)-2-pyrrolidone, N-isopropyl-2-pyrrolidone, N-(n-butyl)-2-pyrrolidone, N-(tert-butyl)-2-pyrrolidone, N-(n-pentyl)- lactam solvents such as 2-pyrrolidone, N-methoxypropyl-2-pyrrolidone, N-ethoxyethyl-2-pyrrolidone, N-methoxybutyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone; N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-dimethylpropionamide, N,N-diethylpropionamide, N,N-dimethyllactamide, 3-methoxy-N,N-dimethylpropanamide, Amide solvents such as 3-butoxy-N,N-dimethylpropanamide and tetramethylurea; cyclohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate, 3 -methyl methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol n-propyl Ether, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dimethyl ether, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol diacetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether , diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, diisobutylcarbinol (2,6-dimethyl-4-heptanol), diisobutyl ketone, isoamine propionate, isoamyl isobutyrate, diisopentyl ether, ethylene carbonate, propylene carbonate, and the like. These can be used in combination of two or more.

Preferred solvent combinations include N-methyl-2-pyrrolidone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone and propylene. Glycol monobutyl ether, N-ethyl-2-pyrrolidone and propylene glycol monobutyl ether, N-methyl-2-pyrrolidone, γ-butyrolactone, 4-hydroxy-4-methyl-2-pentanone and diethylene glycol diethyl ether, N-ethyl-2 -pyrrolidone and N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl-4 -heptanone, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and dipropylene glycol monomethyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene Glycol monobutyl ether, N-methyl-2-pyrrolidone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and 2,6-dimethyl -4-heptanone, γ-butyrolactone and 4-hydroxy-4-methyl-2-pentanone and propylene glycol diacetate, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4 -heptanone, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and diisopropyl ether, N-methyl-2-pyrrolidone and γ-butyrolactone and propylene glycol monobutyl ether and 2,6-dimethyl-4-heptanol, N-methyl-2-pyrrolidone and γ-butyrolactone and dipropylene glycol dimethyl ether, N-methyl-2-pyrrolidone and propylene glycol monobutyl ether and dipropylene glycol dimethyl ether, cyclohexanone and ethylene glycol monobutyl ether, cyclohexanone and propylene glycol monobutyl ether, cyclohexanone and propylene glycol monomethyl ether, cyclopentanone and propylene glycol monobutyl ether, cyclopentanone Tantanone and propylene glycol monomethyl ether, cyclohexanone and diethylene glycol monoethyl ether, cyclopentanone and diethylene glycol monoethyl ether, cyclohexanone and diisobutyl ketone, cyclopentanone and diisobutyl ketone, methyl isobutyl ketone and propylene glycol monobutyl ether, methyl ethyl ketone and propylene glycol monobutyl ether , cyclohexanone and 4-hydroxy-4-methyl-2-pentanone, cyclopentanone and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone and diethylene glycol diethyl ether, cyclopentanone and diethylene glycol diethyl ether, tetramethyl urea and propylene glycol diacetate, N,N-dimethylpropionamide and propylene glycol monobutyl ether, tetramethylurea and propylene glycol monobutyl ether, tetramethylurea and cyclohexanone and propylene glycol monomethyl ether, N,N-dimethylpropionamide and propylene glycol monomethyl ether, N,N-dimethylpropionamide and ethylene glycol monobutyl ether acetate, N,N-dimethylpropionamide and ethylene glycol monobutyl ether, N,N-diethylpropionamide and propylene glycol monomethyl ether, tetramethylurea and propylene glycol monomethyl ether, N , N-dimethylpropionamide and cyclohexanone and diethylene glycol diethyl ether, N,N-diethylformamide and propylene glycol monomethyl ether, N,N-diethylformamide and 4-hydroxy-4-methyl-2-pentanone, cyclohexanone and n-butyl acetate , cyclopentanone and n-butyl acetate, 4-hydroxy-4-methyl-2-pentanone and ethylene glycol monobutyl ether, cyclohexanone and propylene glycol diacetate, and cyclopentanone and propylene glycol diacetate. The kind and content of such a solvent are appropriately selected according to the liquid crystal aligning agent coating device, coating conditions, coating environment, and the like.

The solid content concentration in the liquid crystal aligning agent (ratio of the total mass of components other than the solvent of the liquid crystal aligning agent to the total mass of the liquid crystal aligning agent) is appropriately selected in consideration of viscosity, volatility, etc., but preferably It is in the range of 1 to 10% by mass. From the viewpoint of forming a uniform and defect-free coating film, it is preferably 1% by mass or more, and from the viewpoint of storage stability of the solution, it is preferably 10% by mass or less. A particularly preferred polymer concentration is 2 to 8% by weight.

<Liquid crystal alignment film>
The liquid crystal alignment film of the present invention is obtained from the above liquid crystal alignment agent. The liquid crystal alignment film of the present invention can be used for horizontal alignment type (TN system, STN system, IPS system, FFS system, etc.) or vertical alignment type liquid crystal alignment film. As the vertically aligned liquid crystal alignment film, a liquid crystal alignment film used for a vertically aligned liquid crystal display element such as a VA system or a PSA (Polymer Sustained Alignment) system is preferable.

<Liquid crystal display element>
The liquid crystal display element of the present invention comprises the liquid crystal alignment film. The liquid crystal aligning agent of the present invention has a liquid crystal layer between a pair of substrates provided with electrodes, and a liquid crystal composition containing a polymerizable compound polymerized by at least one of active energy rays and heat between the pair of substrates. It is also preferably used for a liquid crystal display element manufactured through a process of polymerizing a polymerizable compound by at least one of irradiation with an active energy ray and heating while placing a substance and applying a voltage between electrodes.

The liquid crystal display device of the present invention can be manufactured, for example, by performing the following steps (1) to (3) or steps (1) to (4) in this order.
(1) A step of applying a liquid crystal aligning agent on at least one of a pair of substrates having a conductive film to form a coating film. A substrate provided with a patterned transparent conductive film. The liquid crystal aligning agent of the present invention is coated on one surface of the substrate by an appropriate coating method such as a roll coater method, a spin coat method, a printing method, an ink jet method, or the like to prepare a coating film. Here, the substrate is not particularly limited as long as it is highly transparent, and in addition to a glass substrate and a silicon nitride substrate, a plastic substrate such as an acrylic substrate or a polycarbonate substrate can also be used. In addition, in a reflective liquid crystal display element, if only one substrate is used, an opaque material such as a silicon wafer can be used, and in this case, a light-reflecting material such as aluminum can be used for the electrodes.
In the case of manufacturing an IPS or FFS liquid crystal display element, a substrate provided with electrodes made of a transparent conductive film or a metal film patterned in a comb shape and a counter substrate provided with no electrodes are used. may be used to form a coating film on one surface of at least one of the substrates.

(2) Step of Baking Coating Film After applying the liquid crystal aligning agent, the coating film is baked for the purpose of preventing dripping of the applied aligning agent. Preferably, preheating (prebaking) is performed first. The prebaking temperature is preferably 30 to 200°C, more preferably 40 to 150°C, and particularly preferably 40 to 100°C. The pre-baking time is preferably 0.25-10 minutes, more preferably 0.5-5 minutes. Then, a heating (post-baking) step is preferably performed. The post-bake temperature is preferably 80-300°C, more preferably 120-250°C. The post-bake time is preferably 5-200 minutes, more preferably 10-100 minutes. The thickness of the film thus formed is preferably 5 to 300 nm, more preferably 10 to 200 nm.

The coating film formed in the above steps (1) and (2) can be used as it is as a liquid crystal alignment film, but the coating film may be subjected to an alignment ability imparting treatment. Alignment imparting treatment includes rubbing treatment in which the coating film is rubbed in a fixed direction with a roll wrapped with a cloth made of fibers such as nylon, rayon, cotton, etc., and photo-alignment treatment in which the coating film is irradiated with polarized or non-polarized radiation. processing and the like.

In the photo-alignment treatment, ultraviolet rays and visible rays including light with a wavelength of 150 to 800 nm, for example, can be used as the radiation to irradiate the coating film. When the radiation is polarized, it may be linearly polarized or partially polarized. Further, when the radiation used is linearly polarized or partially polarized, the irradiation may be performed from a direction perpendicular to the substrate surface, from an oblique direction, or a combination thereof. When non-polarized radiation is applied, the direction of irradiation is oblique.

(3) Step of forming a liquid crystal layer between the pair of substrates to produce a liquid crystal cell (3-1) When manufacturing a VA liquid crystal display element Two substrates having the liquid crystal alignment film of the present invention formed on at least one of them are prepared, and a liquid crystal is arranged between the two substrates facing each other. Specifically, the following two methods are mentioned. The first method is a conventionally known method. First, two substrates are arranged to face each other with a gap (cell gap) interposed therebetween so that the respective liquid crystal alignment films face each other. Next, a sealant is applied to the periphery of the two substrates and attached to each other, and a liquid crystal composition is injected and filled into the cell gap defined by the substrate surface and the sealant to contact the film surface, and then the injection hole is opened. Seal.

The second method is a method called ODF (One Drop Fill) method. A predetermined place on one of the two substrates on which the liquid crystal alignment film is formed is coated with, for example, an ultraviolet light-curing sealant, and a liquid crystal composition is applied to several predetermined places on the surface of the liquid crystal alignment film. drip. Thereafter, the other substrate is attached so that the liquid crystal alignment films face each other, and the liquid crystal composition is spread over the entire surface of the substrate and brought into contact with the film surface. Next, the entire surface of the substrate is irradiated with ultraviolet light to cure the sealant.
In any method, it is desirable to remove the flow orientation at the time of liquid crystal filling by heating the liquid crystal composition to a temperature at which the used liquid crystal composition assumes an isotropic phase and then slowly cooling to room temperature.

(Liquid crystal composition)
The liquid crystal composition is not particularly limited, and various liquid crystal compositions containing at least one liquid crystal compound (liquid crystal molecule) and having positive or negative dielectric anisotropy can be used. In the following description, a liquid crystal composition with a positive dielectric anisotropy is also referred to as a positive liquid crystal, and a liquid crystal composition with a negative dielectric anisotropy is also referred to as a negative liquid crystal.
The above liquid crystal composition contains a fluorine atom, a hydroxy group, an amino group, a fluorine atom-containing group (e.g., trifluoromethyl group), a cyano group, an alkyl group, an alkoxy group, an alkenyl group, an isothiocyanate group, a heterocyclic ring, a cycloalkane, A liquid crystal compound having a cycloalkene, a steroid skeleton, a benzene ring, or a naphthalene ring may be included, and a compound having two or more rigid sites (mesogenic skeleton) exhibiting liquid crystallinity in the molecule (for example, two rigid biphenyl structures or terphenyl structures linked by alkyl groups).
The liquid crystal composition may be a liquid crystal composition exhibiting a nematic phase, a liquid crystal composition exhibiting a smectic phase, or a liquid crystal composition exhibiting a cholesteric phase.
In addition, the liquid crystal composition may further contain an additive from the viewpoint of improving liquid crystal orientation. Such additives include photopolymerizable monomers such as compounds having a polymerizable group; optically active compounds (eg, S-811 manufactured by Merck Co., Ltd.); antioxidants; UV absorbers; dyes; antifoaming agents; polymerization initiators; or polymerization inhibitors.
Positive liquid crystals include ZLI-2293, ZLI-4792, MLC-2003, MLC-2041, and MLC-7081 manufactured by Merck.
Negative liquid crystals include, for example, MLC-6608, MLC-6609, MLC-6610, and MLC-7026-100 manufactured by Merck.
As a liquid crystal composition containing a compound having a polymerizable group, which will be described later, MLC-3023 manufactured by Merck & Co., Ltd. can be mentioned.

(3-2) Production of PSA type liquid crystal display device The procedure of (3-1) above is repeated except that the liquid crystal composition containing a compound having a polymerizable group is injected or dropped. Examples of compounds having a polymerizable group include compounds having a mesogenic structure and two or more photopolymerizable groups or thermally polymerizable groups. The mesogenic structure includes a structure in which two or more aromatic groups or aliphatic groups are linked, such as a biphenyl structure, a terphenyl structure, a naphthalene ring, a group obtained by removing two hydroxy groups from bisphenol A, or any of these A fluorine atom-containing structure in which a part of the hydrogen atoms of the structure are replaced with fluorine atoms can be mentioned. Specific compounds include 4,4'-dimethacryloxybiphenyl or 3-fluoro-1,1'-biphenyl-4,4'-diyl dimethacrylate.

(3-3) When a coating film is formed on a substrate using a liquid crystal aligning agent containing a compound having a polymerizable group After performing the same as in (3-1) above, the liquid crystal through the step of irradiating ultraviolet rays described later. A method of manufacturing a display element may be employed. According to this method, a liquid crystal display device having an excellent response speed can be obtained with a small amount of light irradiation, as in the case of manufacturing the PSA type liquid crystal display device. The compound having a polymerizable group may be a compound having the polymerizable group described above, and the content thereof is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of all polymer components. , more preferably 1 to 20 parts by mass. Further, the polymerizable group may be present in the polymer used for the liquid crystal alignment agent, and such a polymer includes, for example, a diamine component containing a diamine having a photopolymerizable group at the end thereof, which is used in the reaction. The polymer obtained is mentioned.

(4) Step of irradiating the liquid crystal cell with light The liquid crystal cell is irradiated with light while a voltage is applied between the conductive films of the pair of substrates obtained in (3-2) or (3-3) above. The voltage applied here can be, for example, 5 to 50 V direct current or alternating current. As the light for irradiation, for example, ultraviolet light containing light with a wavelength of 150 to 800 nm and visible light can be used, but ultraviolet light containing light with a wavelength of 300 to 400 nm is preferable. A low-pressure mercury lamp, a high-pressure mercury lamp, a deuterium lamp, a metal halide lamp, an argon resonance lamp, a xenon lamp, an excimer laser, or the like can be used as the light source for the irradiation light. The irradiation amount of light is preferably 1,000 to 200,000 J/m ² , more preferably 1,000 to 100,000 J/m ² .

Then, a liquid crystal display element can be obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell. As the polarizing plate to be attached to the outer surface of the liquid crystal cell, a polarizing film called "H film" in which polyvinyl alcohol is stretched and oriented while absorbing iodine is sandwiched between cellulose acetate protective films, or the H film itself. A polarizing plate consisting of

The liquid crystal display device of the present invention can be effectively applied to various devices such as watches, portable games, word processors, notebook computers, car navigation systems, camcorders, PDAs, digital cameras, mobile phones, smart phones, It can be used for various display devices such as various monitors, liquid crystal televisions, and information displays. Further, the polymer composition contained in the liquid crystal aligning agent is a liquid crystal alignment film for a retardation film, a liquid crystal alignment film for a scanning antenna or a liquid crystal array antenna, or a liquid crystal alignment film for a transmission scattering type liquid crystal light control element, Alternatively, it can also be used for applications other than these, such as protective films for color filters, gate insulating films for flexible displays, and substrate materials.

The present invention will be specifically described below with reference to examples, but the present invention should not be construed as being limited to these examples. Abbreviations of compounds and methods for measuring properties are as follows.

(tetracarboxylic dianhydride)

(diamine)

(solvent)
THF: tetrahydrofuran NMP: N-methyl-2-pyrrolidone BCS: ethylene glycol monobutyl ether (butyl cellosolve)

[viscosity]
Measurement was performed using an E-type viscometer TVE-22H (manufactured by Toki Sangyo Co., Ltd.), a sample amount of 1.1 mL (milliliter), a cone rotor TE-1 (1°34', R24), and a temperature of 25°C.
[Measurement of molecular weight]
Room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko), column (GPC KD-803, GPC KD-805 in series) (manufactured by Showa Denko), measured under the following conditions. did.
Column temperature: 50°C
Eluent: N,N-dimethylformamide (as additives, lithium bromide monohydrate (LiBr.H ₂ O) at 30 mmol/L (liter), phosphoric acid/anhydrous crystals (o-phosphoric acid) at 30 mmol/L (liter) L, tetrahydrofuran (THF) is 10 mL/L)
Flow rate: 1.0 mL/min Standard sample for creating a calibration curve: TSK standard polyethylene oxide (molecular weight; 12,000, 4,000 and 1,000) (manufactured by Polymer Laboratories).

[Synthesis of specific diamines (DA-1) to (DA-2)]
Methods for synthesizing the compounds represented by formulas (DA-1) to (DA-2) are detailed below. The compounds represented by the formulas (DA-1) to (DA-2) are novel compounds that have not been disclosed in the literature.

<Measurement of ¹ H-NMR>
Apparatus: Fourier transform superconducting nuclear magnetic resonance apparatus (FT-NMR) "Varian NMR System 400NB" (manufactured by Varian) 400 MHz, "AVANCE III" (manufactured by BRUKER) 500 MHz.
Solvent: deuterated dimethylsulfoxide (DMSO-d ₆ , standard: tetramethylsilane).

<Example 1-1: Synthesis of DA-1>
(Synthesis of DA-1-1)

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

(Synthesis of DA-1-2)

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

(Synthesis of DA-1)

To a 500 mL four-necked flask, DA-1-2 (9.98 g, 34.4 mmol), THF (120 g), and carbon-supported platinum (supported amount 3% by mass, 0.500 g) were added, at room temperature under a hydrogen atmosphere. reacted. After completion of the reaction, carbon-supported platinum was removed by filtration, and the resulting filtrate was concentrated and the precipitated crystals were vacuum-dried at 50° C. to obtain DA-1 (yield: 7.71 g, 33.5 mmol, yield: 97 .4%, orange solid). From the ¹ H-NMR results shown below, this solid was confirmed to be DA-1.
¹ H-NMR (500 MHz, DMSO-d ₆ ): δ (ppm=) 8.86 (s, 1H), 6.75 (d, 2H, J=9.0Hz), 6.64 (d, 2H, J = 9.0 Hz), 5.83 (d, 2H, J = 1.9 Hz), 5.74 (t, 1H, J = 2.0 Hz), 4.71 (br, 4H), 4.66 ( s, 2H).

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

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

(Synthesis of DA-2-2)
In a 2000 mL four-necked flask were added 3,5-dinitrobenzyl alcohol (75.2 g, 379 mmol), DA-2-1 (106 g, 438 mmol), 4-dimethylaminopyridine (DMAP, 4.5 g) in tetrahydrofuran (452 g). 62 g) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC, 94.5 g) were charged and reacted for 4 hours in a nitrogen atmosphere at room temperature. After completion of the reaction, the reaction solution was poured into pure water (810 g) to precipitate crystals, which was then filtered, and the filter cake was washed with pure water and methanol. Subsequently, the obtained filter cake was slurry-washed with methanol (180 g), filtered and dried to obtain DA-2-2 (yield: 156 g, 369 mmol, yield: 97%, pale yellow crystals).

(Synthesis of DA-2-3)
A 2000 mL four-necked flask was charged with 4.0 mol/L hydrochloric acid aqueous solution (200 g) and DA-2-2 (131 g, 310 mmol) in tetrahydrofuran (195 g) and methanol (327 g), and heated at 50° C. to about The reaction was allowed to proceed for 12 hours. After completion of the reaction, ethyl acetate (1310 g) and toluene (432 g) were added to the reaction solution to separate two phases. After removing the hydrochloric acid phase, the organic layer was washed with pure water (400 g) three times. The organic phase was concentrated under reduced pressure to a total internal weight of 555 g, 2-propanol (262 g) was added, and the mixture was stirred under ice cooling to precipitate crystals. Precipitated crystals were filtered and dried to obtain DA-2-3 (yield: 80.3 g, 240 mmol, yield: 78%, yellow crystals).

(Synthesis of DA-2)
A 1000 mL four-necked flask was charged with DA-2-3 (39.2 g, 117 mmol) and carbon-supported platinum (3 mass% supported, 3.13 g) in tetrahydrofuran (240 g) and methanol (80 g), and hydrogen was added. The reaction was carried out for 2 days under heating conditions of 40° C. atmosphere. After completion of the reaction, the total internal weight was adjusted to 35 g by filtering and concentrating under reduced pressure. Subsequently, methanol (120 g) was added to precipitate crystals, which were filtered and dried to obtain DA-2 (yield: 28.0 g, 102 mmol, yield: 87%, pale yellow crystals).
¹ H-NMR (400 MHz, DMSO-d ₆ ): δ (ppm=) 9.60 (s, 2H), 7.38 (s, 1H), 7.32-7.38 (m, 1H), 6 .81 (d, 1H, J = 8.0Hz), 5.83 (d, 2H, J = 1.6Hz), 5.76-5.77 (m, 1H), 4.96 (s, 2H) , 4.78(s, 4H)

[Synthesis of polymer]
<Example 2-1>
DA-1 (0.921 g, 4.00 mmol), DA-3 (1.08 g, 10.0 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.0 mmol) and NMP (27.1 g) were added and stirred at 60° C. for 3 hours while purging with nitrogen. After that, CA-2 (1.94 g, 9.90 mmol) and NMP (7.77 g) were added and stirred at 40° C. for 3 hours to obtain a polyamic acid solution (1) having a solid content concentration of 20% by mass (viscosity : 680 mPa·s). This polyamic acid had an Mn of 14,360 and an Mw of 49,800.

<Example 2-2>
DA-2 (1.10 g, 4.00 mmol), DA-3 (1.08 g, 10.00 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.00 mmol) and NMP (27.8 g) were added and stirred at 60° C. for 3 hours while purging with nitrogen. Then, CA-2 (1.93 g, 9.86 mmol) and NMP (7.73 g) were added and stirred at 40° C. for 3 hours to give a polyamic acid solution (2) with a solid content concentration of 20% by mass (viscosity : 710 mPa·s) was obtained. This polyamic acid had an Mn of 10,800 and an Mw of 34,800.

<Example 2-3>
DA-1 (1.38 g, 6.00 mmol), DA-3 (0.973 g, 9.00 mmol), CA-2 (2.90 g, 14.8 mmol) and NMP (30.0 g) were added and stirred at 40° C. for 3 hours to obtain a polyamic acid solution (3) with a solid concentration of 15% by mass (viscosity: 450 mPa·s). This polyamic acid had an Mn of 12,100 and an Mw of 28,900.

<Example 2-4>
DA-2 (1.65 g, 6.00 mmol), DA-3 (0.973 g, 9.00 mmol), CA-2 (2.91 g, 14.8 mmol) and NMP (31.3 g) were added and stirred at 40° C. for 3 hours to obtain a polyamic acid solution (4) with a solid concentration of 15% by mass (viscosity: 520 mPa·s). This polyamic acid had an Mn of 14,500 and an Mw of 32,900.

<Example 2-5>
DA-1 (0.691 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-2 (2.90 g, 14.8 mmol) and NMP (24.5 g) were added and stirred at 40° C. for 3 hours to obtain a polyamic acid solution with a solid concentration of 20% by mass ( 5) (Viscosity: 680 mPa·s) was obtained. This polyamic acid had an Mn of 11,100 and an Mw of 25,600.

<Example 2-6>
DA-2 (0.822 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-2 (2.89 g, 14.8 mmol) and NMP (25.0 g) were added and stirred at 40 ° C. for 3 hours to obtain a polyamic acid solution with a solid content concentration of 20% by mass. (6) (viscosity: 640 mPa·s) was obtained. This polyamic acid had an Mn of 13,400 and an Mw of 32,000.

<Example 2-7>
DA-1 (0.691 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-3 (3.23 g, 14.8 mmol) and NMP (25.8 g) were added and stirred at room temperature for 3 hours to obtain a polyamic acid solution with a solid concentration of 20% by mass ( 7) (Viscosity: 670 mPa·s) was obtained. This polyamic acid had an Mn of 14,300 and an Mw of 30,900.

<Example 2-8>
DA-2 (0.823 g, 3.00 mmol), DA-3 (0.811 g, 7.50 mmol), DA-4 (1.71 g, 4.50 mmol), CA-3 (3.21 g, 14.8 mmol) and NMP (26.2 g) were added and stirred at room temperature for 3 hours to obtain a polyamic acid solution with a solid concentration of 20% by mass ( 8) (Viscosity: 720 mPa·s) was obtained. This polyamic acid had an Mn of 15,300 and an Mw of 32,600.

<Comparative Example 2-1>
DA-5 (0.553 g, 4.00 mmol), DA-3 (1.08 g, 10.0 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.0 mmol) and NMP (25.7 g) were added and stirred at 60° C. for 3 hours while purging with nitrogen. Then, CA-2 (1.91 g, 9.76 mmol) and NMP (7.66 g) were added and stirred at 40° C. for 3 hours to give a polyamic acid solution (9) with a solid content concentration of 20% by mass (viscosity : 760 mPa·s) was obtained. This polyamic acid had an Mn of 11,300 and an Mw of 25,880.

<Comparative Example 2-2>
DA-3 (1.51 g, 14.0 mmol), DA-4 (2.28 g, 6.00 mmol), CA-1 (2.50 g, 10.0 mmol) and NMP (25.2 g) were added, and the mixture was stirred at 60°C for 3 hours while purging with nitrogen. After that, CA-2 (1.90 g, 9.70 mmol) and NMP (7.61 g) were added and stirred at 40 ° C. for 3 hours to give a polyamic acid solution (10) with a solid content concentration of 20% by mass (viscosity : 770 mPa·s). This polyamic acid had an Mn of 11,290 and an Mw of 21,800.

<Comparative Example 2-3>
DA-5 (0.829 g, 6.00 mmol), DA-3 (0.973 g, 9.00 mmol), CA-2 (2.90 g, 14.8 mmol) and NMP (26.7 g) were added and stirred at 40° C. for 3 hours to obtain a polyamic acid solution (11) with a solid concentration of 15% by mass (viscosity: 460 mPa·s). This polyamic acid had an Mn of 15,200 and an Mw of 23,800.

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

Table 1 below shows the specifications of the monomer components used in the above examples and comparative examples.

[Preparation of Liquid Crystal Aligning Agent]
<Example 3-1>
NMP (8.00 g) and BCS (8.00 g) were added to the polyamic acid solution (1) (4.00 g) obtained in Example 2-1 and stirred at room temperature for 3 hours to obtain a liquid crystal aligning agent. (A-1) was obtained.

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

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

<Example 3-4, Comparative Examples 3-3, 3-4>
Example 3-4, Comparative Example 3- Liquid crystal aligning agents (A-4), (B-3) and (B-4) of 3 and 3-4 were obtained. Specifications of the liquid crystal aligning agents obtained in the above Examples and Comparative Examples are shown in Table 2 below.

In the liquid crystal aligning agents (A-1) to (A-8) and (B-1) to (B-4) obtained as described above, no abnormality such as turbidity or precipitation was observed, and the solution was uniform. One thing has been confirmed. Using the obtained liquid crystal aligning agent, rubbing resistance, seal adhesion, voltage holding ratio and vertical alignment were evaluated.

[Evaluation of rubbing resistance]
The liquid crystal aligning agents (A-1) to (A-8) and (B-1) to (B-4) obtained above were spin-coated onto the ITO surface of a glass substrate having an ITO electrode over the entire surface. and dried on a hot plate at 70° C. for 90 seconds. After that, it was baked in an infrared heating furnace at 230° C. for 30 minutes to form a coating film having a thickness of 100 nm, thereby obtaining a substrate with a liquid crystal alignment film. This liquid crystal alignment film was rubbed with a rayon cloth (YA-20R manufactured by Yoshikawa Kako Co., Ltd.) (roller diameter: 120 mm, roller rotation speed: 1000 rpm, moving speed: 20 mm/sec, pushing length: 0.6 mm). The substrate was observed with a microscope, and evaluation was performed by defining "good" when streaks due to rubbing were not observed on the film surface and "bad" when streaks were observed. The results are shown in Table 3 below.

[Preparation of seal adhesion evaluation sample]
The liquid crystal aligning agents (A-1) to (A-8) and (B-1) to (B-4) obtained above are combined into a rectangular transparent electrode-attached glass having a length of 30 mm, a width of 40 mm, and a thickness of 1.1 mm. Each substrate was spin-coated, dried on a hot plate at 70° C. for 90 seconds, and then baked in a hot air circulating oven at 230° C. for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm.
Two substrates thus obtained were prepared, and a bead spacer with a diameter of 4 μm was applied on the liquid crystal alignment film surface of one of the substrates, and then a sealant (723K1 manufactured by Kyoritsu Chemical Industry Co., Ltd.) was applied. Then, these substrates were bonded together so that the liquid crystal alignment film surfaces of the substrates faced each other and the overlapping width of the substrates was 1 cm. At that time, the dropping amount of the sealant was adjusted so that the diameter of the sealant after bonding was 3 mm. After fixing the two laminated substrates with a clip, they were irradiated with ultraviolet rays of 4 J/cm ² in terms of wavelength of 365 nm, and thermally cured at 120° C. for 1 hour to prepare a sample for adhesion evaluation.

[Evaluation of seal adhesion]
Adhesion was evaluated using a desktop precision universal tester (AGS-X 500N manufactured by Shimadzu Corporation). After the edges of the upper and lower substrates of the obtained evaluation sample were fixed, the substrates were pushed in from the upper central portion, and the peeling strength (N) was measured. Then, the seal adhesion (N/mm) was evaluated using a value obtained by normalizing the pressure (N) with the measured diameter (mm) of the sealant. The results are shown in Table 3 below. The peeling strength and the measured diameter of the sealant were as follows.
・Example 3-1: strength: 16.6 N, diameter: 3.3 mm
・Example 3-2: strength: 15.4 N, diameter: 3.1 mm
・Example 3-3: strength: 15.9 N, diameter: 3.2 mm
・Example 3-4: Strength: 16.6 N, diameter: 3.3 mm
・Example 3-5: strength: 14.9 N, diameter: 2.9 mm
・Example 3-6: strength: 15.4 N, diameter: 3.1 mm
・Example 3-7: Strength: 16.4 N, diameter: 3.3 mm
・Example 3-8: strength: 15.6 N, diameter: 3.1 mm
・Comparative Example 3-1: Strength: 12.0 N, Diameter: 3.1 mm
・Comparative Example 3-2: Strength: 8.6 N, Diameter: 3.2 mm
・Comparative Example 3-3: Strength: 13.0 N, Diameter: 3.1 mm
・Comparative Example 3-4: Strength: 11.5 N, Diameter: 3.8 mm

[Preparation of liquid crystal cell for voltage holding rate evaluation]
Using the liquid crystal aligning agents (A-1) to (A-8) and (B-1) to (B-4) obtained above, liquid crystal cells were produced in the following procedure. A liquid crystal aligning agent was spin-coated on a glass substrate with ITO electrodes, dried on a hot plate at 70° C. for 90 seconds, and then baked in an infrared heating furnace at 230° C. for 20 minutes to form a liquid crystal alignment film having a thickness of 100 nm. . Two substrates with this liquid crystal alignment film are prepared, and a bead spacer with a diameter of 4 μm (manufactured by Nikki Shokubai Kasei Co., Ltd., Shinshikyu, SW-D1) is applied on one of the liquid crystal alignment films, and a thermosetting sealant ( XN-1500T manufactured by Mitsui Chemicals, Inc.) was printed. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was turned inside, and after bonding with the previous substrate, the sealant was cured to prepare an empty cell. Liquid crystal MLC-3023 (manufactured by Merck) was injected into this empty cell by a vacuum injection method to prepare a liquid crystal cell. Next, while a DC voltage of 15 V was applied to the liquid crystal cell, 10 J/cm ² of UV was irradiated from the outside of the liquid crystal cell through a cut filter with a wavelength of 325 nm or less. The UV illuminance was measured using UV-MO3A manufactured by ORC. Then, for the purpose of deactivating the unreacted polymerizable compound remaining in the liquid crystal cell, UV (UV lamp: FLR40SUV32/ A-1) was irradiated for 30 minutes. All of the liquid crystal display elements obtained using the liquid crystal aligning agents (A-1) to (A-8) and (B-1) to (B-4) exhibited uniform liquid crystal alignment.

[Evaluation of voltage holding ratio]
A voltage retention rate was measured using a liquid crystal cell for voltage retention rate evaluation after UV irradiation. A voltage of 1 V was applied for 60 μsec in a hot air circulating oven at 60° C., the voltage was measured after 1667 msec, and how much voltage was retained was calculated as a voltage retention rate. VHR-1 manufactured by Toyo Technica Co., Ltd. was used to measure the voltage holding rate. The higher the value, the better. The results are shown in Table 3 below.

[Preparation of Liquid Crystal Cell for Vertical Alignment Evaluation]
Using the liquid crystal aligning agents (A-5) to (A-8) obtained above, a liquid crystal cell was produced in the following procedure.
A liquid crystal aligning agent was spin-coated on the ITO surface of an ITO electrode substrate on which an ITO electrode pattern with a pixel size of 100 μm × 300 μm and a line/space of 5 μm was formed. C. for 20 minutes in an infrared heating furnace to form a liquid crystal alignment film with a thickness of 100 nm. Also, a glass substrate with an ITO electrode was spin-coated, dried on a hot plate at 70° C. for 90 seconds, and then baked in an infrared heating furnace at 230° C. for 20 minutes to form a liquid crystal alignment film with a thickness of 100 nm. These conditions for forming the liquid crystal alignment film are hereinafter referred to as "normal conditions".
A liquid crystal alignment film having a thickness of 100 nm was prepared in the same manner as the normal conditions except that the baking conditions for each of the above substrates were changed to 60 minutes in an infrared heating furnace at 230 ° C. as the severe conditions for evaluating the vertical alignment properties of the liquid crystal alignment film. formed.
Two substrates with a liquid crystal alignment film prepared under normal conditions are prepared, and a bead spacer with a diameter of 4 μm (manufactured by Nikki Shokubai Kasei Co., Ltd., Shinshikyu, SW-D1) is applied on one of the liquid crystal alignment films, and heat cured. A flexible sealant (XN-1500T, manufactured by Mitsui Chemicals, Inc.) was printed. Next, the surface of the other substrate on which the liquid crystal alignment film was formed was turned inside, and after bonding with the previous substrate, the sealant was cured to prepare an empty cell. Liquid crystal MLC-3023 (manufactured by Merck) was injected into this empty cell by a vacuum injection method to prepare a liquid crystal cell. Next, while a DC voltage of 15 V was applied to the liquid crystal cell, 10 J/cm ² of UV was irradiated from the outside of the liquid crystal cell through a cut filter with a wavelength of 325 nm or less. The UV illuminance was measured using UV-MO3A manufactured by ORC. Then, for the purpose of deactivating the unreacted polymerizable compound remaining in the liquid crystal cell, UV (UV lamp: FLR40SUV32/ A-1) was irradiated for 30 minutes.
A liquid crystal cell was produced and UV irradiation was performed in the same manner, except that a substrate with a liquid crystal alignment film produced under severe conditions was used.
All of the liquid crystal display elements obtained using the liquid crystal aligning agents (A-5) to (A-8) exhibited uniform liquid crystal alignment.

[Evaluation of Vertical Alignment]
Using Axostep (manufactured by Optoscience), the pretilt angle of the liquid crystal display element produced above was measured. The difference in pretilt angle between the normal condition (20 minutes) and the severe condition (60 minutes) (normal condition−severe condition=Δpretilt) was calculated. The smaller the Δpretilt, the better the vertical orientation of the liquid crystal alignment film. Table 3 shows the results.

As shown in Table 3, the examples using the liquid crystal alignment film obtained from the liquid crystal alignment agent containing the specific diamine as the diamine component used the liquid crystal alignment film obtained from the liquid crystal alignment agent containing no specific diamine as the diamine component. It exhibited excellent rubbing resistance and high seal adhesion as compared with the comparative example. In addition, the liquid crystal alignment film obtained from the liquid crystal alignment agent using the alicyclic acid dianhydride as the tetracarboxylic acid component has a high voltage holding ratio and good verticality as compared with the case where the aromatic acid dianhydride is used. showed orientation.

Claims

Containing at least one polymer (P) selected from the group consisting of a polyimide precursor obtained using a diamine component containing a diamine represented by the following formula (1) and a polyimide that is an imidized product of the polyimide precursor A liquid crystal aligning agent characterized by:

(wherein L is -(CH 2 ) n -O- (n is an integer of 1 to 6), -(CH 2 ) n -C(=O)-NH- (n is 1 to 6 is an integer of ), -(CH 2 ) n -OC(=O)- (n is an integer of 1 to 6), -(CH 2 ) n -C(=O)-O- (n is an integer of 1 to 6), -O-(CH 2 ) n -O- (n is an integer of 1 to 6), -C(=O)-O-(CH 2 ) n —O— (n is an integer of 1 to 6), —(CH 2 ) m —C(═O)—O—(CH 2 ) n — (m and n are each independently 1 to is an integer of 6.), or -C(=O)-O-(CH 2 ) n -O-C(=O)- (n is an integer of 1 to 6.) Bonding with OH Any hydrogen atom of the benzene ring may be replaced with a methyl group, a methoxy group, or a halogen atom.p represents an integer of 0 or 1.)
The liquid crystal aligning agent according to claim 1, wherein the diamine represented by the formula (1) is a diamine represented by any one of the following formulas (d1-1) to (d1-11).
The liquid crystal aligning agent according to claim 1, wherein the diamine represented by the formula (1) is a diamine represented by any one of the following formulas (d2-1) to (d2-6).
The polymer (P) contains the diamine component, an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, an aromatic tetracarboxylic dianhydride, or a derivative thereof. The liquid crystal aligning agent according to claim 1, which is obtained by a polymerization reaction of a tetracarboxylic acid component.
The polymer (P) is a polymerization of the diamine component and a tetracarboxylic acid component containing an acyclic aliphatic tetracarboxylic dianhydride, an alicyclic tetracarboxylic dianhydride, or a derivative thereof. The liquid crystal aligning agent according to claim 1, obtained by reaction.
The liquid crystal aligning agent according to claim 1, wherein the amount of the diamine represented by the formula (1) used when obtaining the polymer (P) is 5 mol% or more with respect to the total diamine component.
The liquid crystal aligning agent according to claim 1, wherein the diamine component further contains an aromatic diamine (d) represented by "AXJ".
(A represents a monovalent group in which two primary amino groups are bonded to an aromatic group. X is a single bond, —(CH 2 ) a — (a is an integer of 1 to 15), -CONH-, -NHCO-, -CO-N(CH 3 )-, -NH-, -O-, -COO-, -OCO- or -((CH 2 ) a1 -A 1 ) m1 -(a1 is is an integer of 1 to 15, A 1 represents an oxygen atom or —COO—, and m1 is an integer of 1 to 2. When m1 is 2, a plurality of a1 and A 1 are each independently defined above ).
J represents a monovalent organic group having at least one group selected from the group consisting of an alicyclic hydrocarbon group having 4 to 40 carbon atoms and an aromatic hydrocarbon group having 6 to 40 carbon atoms, with the proviso that At least one of the hydrogen atoms of the alicyclic hydrocarbon group and the aromatic hydrocarbon group is a halogen atom, a halogen atom-containing alkyl group, a halogen atom-containing alkoxy group, an alkyl group having 3 to 10 carbon atoms, or 3 carbon atoms. -10 alkoxy groups, alkenyl groups having 3 to 10 carbon atoms, halogen atom-containing alkyl groups, halogen atom-containing alkoxy groups, alkyl groups having 3 to 10 carbon atoms, alkoxy groups having 3 to 10 carbon atoms, and 3 carbon atoms The carbon-carbon bond of any methylene group of the alkenyl group from 1 to 10 is replaced with a substituent selected from the group consisting of heteroatom-containing groups interrupted by oxygen atoms. )
A liquid crystal alignment film obtained from the liquid crystal alignment agent according to any one of claims 1 to 7.
A liquid crystal display element comprising the liquid crystal alignment film according to claim 8.
A method for manufacturing a liquid crystal display device, comprising performing the following steps (1) to (3) in this order.
Step (1): A step of applying the liquid crystal aligning agent according to any one of claims 1 to 7 onto at least one of a pair of substrates having a conductive film to form a coating film. Step (2). : Step of baking the coating film Step (3): Step of forming a liquid crystal layer between the pair of substrates to produce a liquid crystal cell
11. The method of manufacturing a liquid crystal display element according to claim 10, further comprising performing the following step (4) after steps (1) to (3).
Step (4): Step of irradiating the liquid crystal cell with light
A diamine represented by the following formula (1).

(wherein L is -(CH 2 ) n -O- (n is an integer of 1 to 6), -(CH 2 ) n -C(=O)-NH- (n is 1 to 6 is an integer of ), -(CH 2 ) n -OC(=O)- (n is an integer of 1 to 6), -(CH 2 ) n -C(=O)-O- (n is an integer of 1 to 6), -O-(CH 2 ) n -O- (n is an integer of 1 to 6), -C(=O)-O-(CH 2 ) n —O— (n is an integer of 1 to 6), —(CH 2 ) m —C(═O)—O—(CH 2 ) n — (m and n are each independently 1 to is an integer of 6.), or -C(=O)-O-(CH 2 ) n -O-C(=O)- (n is an integer of 1 to 6.) Bonding with OH Any hydrogen atom of the benzene ring may be replaced with a methyl group, a methoxy group, or a halogen atom.p represents an integer of 0 or 1. However, when p is 0, L is -(CH 2 ) represents a group other than n -C(=O)-NH- (n is an integer of 1 to 6).)
The diamine of claim 12, wherein p is 1.
A polymer obtained using a diamine component containing the diamine according to claim 12 or 13.
The polymer according to claim 14, which is a polyimide precursor obtained by a polycondensation reaction of the diamine component and the tetracarboxylic acid component or an imidized product thereof.