TWI554570B - Liquid crystal alignment agent, liquid crystal alignment film and liquid crystal display device - Google Patents

Description

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

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

As liquid crystal display elements, liquid crystal displays of various driving methods typified by a twisted nematic (TN) type, a super twisted nematic type, and a vertical alignment type (VA) type have been developed. element. These liquid crystal display elements have a liquid crystal alignment film as one of main constituent elements. In the liquid crystal display device, the liquid crystal alignment film functions to match the directions of the liquid crystal molecules to a state suitable for the operation mode. As a material of such a liquid crystal alignment film, in view of heat resistance, mechanical strength, affinity with liquid crystal, and the like, polyimine or the like is generally used (refer to Japanese Patent Laid-Open No. Hei 9-197411, Japanese Patent Laid-Open Japanese Patent Publication No. 2003-149648 and Japanese Patent Laid-Open No. 2003-107486.

In recent years, improvement in display quality of a liquid crystal display element has been demanded, and improvement of a driving method and an element structure, and improvement of the liquid crystal alignment film are being performed. especially, With the versatility of smartphones and information displays, the opportunities for use in harsh environments increase, and there is a need for excellent light resistance that maintains electrical characteristics well even when exposed to light stress during long-term operation. Liquid crystal alignment film.

In response to such a request, there has been proposed a technique for improving the ruthenium imidization ratio of a polyimine used in a liquid crystal alignment film (refer to Japanese Laid-Open Patent Publication No. 2010-2501 and Japanese Patent Laid-Open No. 2011-28223). . However, in the current situation where further improvement in display quality is required, the existing technology does not necessarily satisfactorily satisfy the above requirements. Further, in the production step, high coating properties of the liquid crystal alignment agent for forming the liquid crystal alignment film and high reworkability of the defective product are also required.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 9-197411

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-149648

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2003-107486

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2010-2501

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2011-28223

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal alignment element which can form a liquid crystal display element having excellent light resistance and has high coatability and reworkability.

The invention completed to solve the above problem is a liquid crystal alignment agent, which It is characterized by including [A] a compound represented by the following formula (1) (hereinafter, also referred to as "[A] compound"), and [B] a polymer.

In the formula (1), R ¹ is a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a monovalent heterocyclic group having 4 to 20 carbon atoms, or a heterocyclic group of these aromatic hydrocarbon groups and heterocyclic groups. A part or all of a hydrogen atom is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an amine group, a monoalkylamino group, a dialkylamino group, a nitroso group, a fluorenyl group or a thioether group. , decyl, stanol, sulfinate, sulfonate, phosphino, phosphinyl, phosphono group, phosphonato, keto, ester a group substituted with a trifluoromethyl group, a hydroxyl group, a halogen atom, a cyano group, a nitro group, a carboxyl group or a sulfo group. R ² is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 20 carbon atoms. m is an integer from 0 to 2. When m is 2, two R ^{2 's} may be the same or different. n is 1 or 2. When n is 2, two R ^{3 's} may be the same or different. r is an integer from 0 to 12. When r is 2 or more, a plurality of R ^{4 's} may be the same or different.

In addition, another invention completed to solve the problem is a liquid crystal. An alignment film characterized by being formed of the liquid crystal alignment agent.

Further, another invention completed to solve the above problems is a liquid crystal display device comprising the liquid crystal alignment agent.

The present invention can provide a liquid crystal alignment agent which can form a liquid crystal display element having excellent light resistance and has high coatability and reworkability. Therefore, the liquid crystal alignment agent, the liquid crystal alignment film formed of the liquid crystal alignment agent, and the liquid crystal display element including the liquid crystal alignment film can be suitably used for an electronic component capable of maintaining high display quality for a long period of time, a manufacturing process thereof, and the like.

<Liquid alignment agent>

The liquid crystal alignment agent of the present invention contains the [A] compound and the [B] polymer. Further, the liquid crystal alignment agent may contain a [C] solvent as a suitable component. Further, the liquid crystal alignment agent may contain other optional components within the range which does not impair the effects of the present invention. Hereinafter, each component will be described in detail.

[[A] compound]

The compound [A] is a compound represented by the above formula (1). The liquid crystal alignment agent contains the compound of the specific structure [A], whereby the liquid crystal alignment agent is formed The liquid crystal display element maintains excellent light resistance and has high coatability and reworkability.

In the formula (1), R ¹ is a hydrogen atom, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a monovalent heterocyclic group having 4 to 20 carbon atoms, or these aromatic hydrocarbon groups and heterocyclic groups. A part or all of the hydrogen atoms may be an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an amine group, a monoalkylamino group, a dialkylamino group, a nitroso group, a fluorenyl group, or a sulfur group. Ether group, decyl group, stanol group, sulfinate group, sulfonate group, phosphino group, phosphinyl group, phosphinium group, phosphonate group, keto group, ester group, trifluoromethyl group, hydroxyl group, halogen atom, A group substituted with a cyano group, a nitro group, a carboxyl group or a sulfo group. R ² is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom or an alkyl group having 1 to 20 carbon atoms. m is an integer from 0 to 2. When m is 2, two R ^{2 's} may be the same or different. n is 1 or 2. When n is 2, two R ^{3 's} may be the same or different. r is an integer from 0 to 12. When r is 2 or more, a plurality of R ^{4 's} may be the same or different.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by the above R ¹ include a phenyl group, a naphthyl group, an anthracenyl group and the like.

Examples of the monovalent heterocyclic group having 4 to 20 carbon atoms represented by the above R ¹ include a pyridyl group, a pyrimidinyl group, a furyl group, a thienyl group, a tetrahydrofuranyl group, a dioxolyl group, and a benzene group. And oxazol-2-yl, tetrahydropyranyl, pyrrolidinyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, piperidinyl, piperazin ), morpholinyl and the like. Among these groups, a nitrogen-containing heterocyclic group is preferred, and a pyridyl group is more preferred.

Examples of the alkyl group having 1 to 20 carbon atoms which may substitute a part or all of the substituent of the hydrogen atom of the aromatic hydrocarbon group and the heterocyclic group include a methyl group, an ethyl group, a n-propyl group and an isopropyl group. , n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, n-dodecyl, n-pentadecyl, n-nonadecyl and the like.

Examples of the alkoxy group having 1 to 12 carbon atoms as the substituent include a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a butoxy group, and a pentyloxy group.

Examples of the monoalkylamine group as the substituent include a methylamino group, an ethylamino group, a n-propylamino group, a n-butylamino group, and a n-hexylamino group.

Examples of the dialkylamino group as the substituent include a dimethylamino group, a diethylamino group, a di-n-propylamino group, a di-n-butylamino group, an N-methyl-N-cyclohexylamino group, and the like. .

Examples of the halogen atom of the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The R ¹ is preferably a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms or a monovalent heterocyclic group having 4 to 20 carbon atoms, more preferably a monovalent heterocyclic group having 4 to 20 carbon atoms, and further more preferably A nitrogen-containing heterocyclic group is preferred, and a pyridyl group is particularly preferred.

The alkyl group having 1 to 12 carbon atoms represented by the above-mentioned R ² may, for example, be an alkyl group having 1 to 12 carbon atoms in the alkyl group exemplified as the substituent of the above R ¹ . Among these groups, a methyl group, an ethyl group, a n-propyl group, and an isopropyl group are preferable, and a methyl group is more preferable.

Examples of the alkoxy group having 1 to 12 carbon atoms represented by the above R ² include the same groups as the alkoxy group having 1 to 12 carbon atoms exemplified as the substituent of the above R ¹ .

The R ² is preferably an alkyl group having 1 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a n-propyl group or an isopropyl group, and still more preferably a methyl group.

Examples of the halogen atom represented by R ³ and R ⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these halogen atoms, a fluorine atom is preferred.

Examples of the alkyl group having 1 to 20 carbon atoms represented by the above R ³ and R ⁴ include the same groups as those exemplified as the alkyl group having 1 to 20 carbon atoms which is a substituent of the above R ¹ . Base. Among these groups, an alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.

The R ³ and R ^{4 are} preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom.

As the m, 0 or 1 is preferable, and 0 is more preferable.

As the n, it is preferably 2.

As the r, it is preferably 0 to 3, more preferably 0 and 1.

As the compound [A], a compound represented by the following formula is preferable.

The content of the compound [A] is preferably 0.01% by mass to 50% by mass, more preferably 0.1% by mass to 40% by mass, even more preferably 0.5% by mass to 30% by mass, based on the total solid content of the liquid crystal alignment agent. It is preferably 1% by mass to 20% by mass. By setting the content of the [A] compound to the above range, the coating property can be effectively improved.

<Method for synthesizing [A] compound>

The [A] compound can be synthesized by combining known techniques. For example, a method for synthesizing the compound [A] represented by the formula (1-1) includes a method of reacting 3,4-dihydrocoumarin with 3-(aminomethyl)pyridine, and the like. . In addition, as a method of synthesizing the compound [A] represented by the above formula (1-3), a method of reacting 3,4-dihydrocoumarin with 4-aminopyridine or the like can be mentioned. The compound [A] other than these compounds can also be synthesized by a part of the procedure or by changing a part of the procedure.

<[B]polymer>

The [B] polymer is not particularly limited as long as it is a polymer, but is preferably at least one selected from the group consisting of polylysine, polyimine, and polyoxyalkylene, and more preferably selected from poly At least one of the group consisting of proline and polyimine. The liquid crystal alignment agent contains the [B] polymer, whereby the liquid crystal alignment film formed of the liquid crystal alignment agent can obtain good liquid crystal alignment by rubbing. Hereinafter, polyamine, polyimine, and polyoxyalkylene will be described in detail.

[polyglycolic acid]

Polylysine is a polymer having a proline structure. The polyphthalic acid contained in the liquid crystal alignment agent of the present invention may be used singly or in combination of two or more kinds.

The polyamic acid can be obtained by reacting a tetracarboxylic dianhydride with a diamine. Further, these tetracarboxylic dianhydrides and diamines may be used alone or in combination of two or more.

Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid include aliphatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aromatic tetracarboxylic dianhydride.

Examples of the aliphatic tetracarboxylic dianhydride include butane tetracarboxylic dianhydride and the like.

Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, and 1, 3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c] Furan-1,3-diketone, 3-oxabicyclo[3.2.1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 5 -(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxyl Base norbornane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride, 4,9- Dioxatricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, and the like.

Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride and the like.

In addition to the tetracarboxylic dianhydride, a tetracarboxylic dianhydride or the like described in Japanese Patent Application No. 2010-97188 may be mentioned.

As the tetracarboxylic dianhydride for synthesizing the polyamic acid, among these tetracarboxylic dianhydrides, those containing an alicyclic tetracarboxylic dianhydride are preferable, and it is more preferable to contain a 2,3,5-tricarboxyl ring. Amyl acetal dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c] Furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphthalene And [1,2-c]furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride, 1,2 , 3,4-cyclobutanetetracarboxylic dianhydride, and more preferably 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 2,4,6,8-tetracarboxybicyclo ring [3.3.0] octane-2,4,6,8-dianhydride. In particular, it is preferred to contain 10 mol% or more of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 2,4,6,8-tetracarboxybicyclo [3.3.0] with respect to all tetracarboxylic dianhydrides. The octane-2,4,6,8-dianhydride, more preferably contains 20 mol% to 100 mol% of 2,3,5-tricarboxycyclopentyl acetic acid relative to all tetracarboxylic dianhydrides. Anhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride.

Examples of the diamine for synthesizing the polyamic acid include an alicyclic diamine, an aromatic diamine, a diamine organic decane, and the like.

Examples of the aliphatic diamine include 1,3-m-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, and hexamethylenediamine. Wait.

Examples of the alicyclic diamine include 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), and 1,3-bis(aminomethyl). Cyclohexane and the like.

Examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, and 1,5-diamino group. Naphthalene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,7- Diamino hydrazine, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminobenzene) , 2, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'- (p-phenylenediphenyl)diphenylamine, 4,4'-(meta-phenyldiisopropylidene)diphenylamine, 1,4-bis(4-aminophenoxy)benzene, 4 , 4'-bis(4-aminophenoxy)biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diamine Acridine, 3,6-diaminocarbazole, N-methyl-3,6-diaminocarbazole, N-ethyl-3,6-diaminocarbazole, N-phenyl-3 ,6-Diaminocarbazole, N,N'-bis(4-aminophenyl)-benzidine, N,N'-bis(4-aminophenyl)-N,N'-dimethyl Benzidine, 1,4-bis-(4-aminophenyl)-piperazine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole- 5-amine, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indol-6-amine, 3,5-diaminobenzoic acid, Cholesteryloxy-3,5-diaminobenzene, cholestyloxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholesteneoxy -2,4-diaminobenzene, cholesteryl 3,5-diaminobenzoate, cholesteryl 3,5-diaminobenzoate, 3,5-diaminobenzoic acid wool甾alkyl ester, 3,6-bis(4-aminobenzylideneoxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-three Fluoromethoxybenzylideneoxy)cyclohexyl-3,5-diaminobenzoate, 4-(4'-trifluoromethylbenzyloxy)cyclohexyl-3,5-diamine Benzoate, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl) )methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1 - bis(4-((aminophenyl)methyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline 4-aminobenzylamine, 3-aminobenzyl , A compound represented by the following formula (2) or the like.

In the formula (2), X ^I is a methylene group, an alkylene group having 2 or 3 carbon atoms, *-O-, *-COO-, or *-OCO-. * indicates a bonding site with a diaminophenyl group. a is 0 or 1. b is an integer from 0 to 2. c is an integer from 1 to 20.

In the formula (2), X ^I is preferably a methylene group, an alkylene group having 2 or 3 carbon atoms, *-O-, *-COO-. The two amine groups in the diaminophenyl group are preferably at the 2, 4 or 3, 5 position relative to X ^I . a and b are preferably not zero at the same time. Further, examples of -C _c H _2c+1 in the formula (2) include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group and n-octyl group. Base, n-decyl, n-decyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecane Base, n-nonadecyl, n-icosyl and the like.

Examples of the aromatic diamine represented by the above formula (2) include a compound represented by the following formula (2-1) to formula (2-3).

Examples of the diaminoorganomethoxy siloxane include 1,3-bis(3-aminopropyl)-tetramethyldioxane, and those described in JP-A-2010-97188. Diamino-based organooxane and the like.

As the diamine, an aromatic diamine is preferred, and a cholesteryl 3,5-diaminobenzoate, cholestyloxy-2,4-diaminobenzene, p-phenylenediamine, 3 is more preferred. , 5-diaminobenzoic acid. Further, as the diamine, it is preferable to contain 30 with respect to all diamines. The aromatic diamine having a molar content of at least mol% or more is more preferably contained in an aromatic diamine of 50 mol% or more, and still more preferably contains an aromatic diamine of 80 mol% or more.

Further, the diamine used in the synthesis of the polyamic acid in the VA type alignment film preferably contains 5 mol% or more of dodecyloxy-2,4 in the diamine with respect to all diamines. -diaminobenzene, tetradecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, cetyloxy-2,4-diaminobenzene , octadecyloxy-2,4-diaminobenzene, dodecyloxy-2,5-diaminobenzene, tetradecyloxy-2,5-diaminobenzene, pentadecyloxy Base-2,5-diaminobenzene, cetyloxy-2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, cholestyloxy-3,5 -diaminobenzene, cholesteneoxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholesteneoxy-2,4-diaminobenzene , 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid cholesteryl ester, 3,5-diaminobenzoic acid lanthanum alkyl ester, 3,6- Bis(4-aminobenzimidyloxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzylideneoxy Cyclohexyl-3,5-diaminobenzoate, 4-(4'-trifluoromethylbenzyloxy)cyclohexyl-3,5-diaminobenzoate, 1,1 - double (4- ((Aminophenyl)methyl)phenyl)-4-butylcyclohexane, 1,1-bis(4-((aminophenyl)methyl)phenyl)-4-heptylcyclohexane Alkane, 1,1-bis(4-((aminophenoxy)methyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-((aminophenyl)methyl) Phenyl)-4-(4-heptylcyclohexyl)cyclohexane and a diamine represented by the above formula (2) as a pretilt component, more preferably containing 10 mol% or more of the diamine as Pretilt composition.

<Synthesis method of polylysine>

Polylysine can be synthesized by reacting a tetracarboxylic dianhydride with a diamine. As the tetracarboxylic dianhydride and diamine, for example, it can be used in the item of the [polyproline] The tetracarboxylic dianhydride and the diamine described above. The ratio of the tetracarboxylic dianhydride to the diamine used for the synthesis reaction of the poly-proline is preferably 1 equivalent to the amine group of the diamine, and the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 equivalents. The acid anhydride group of the tetracarboxylic dianhydride is preferably in a ratio of from 0.3 equivalents to 1.2 equivalents per equivalent of the amine group of the diamine.

The synthesis of polyamic acid is preferably carried out in an organic solvent. The reaction temperature is preferably -20 ° C to 150 ° C, and more preferably 0 ° C to 100 ° C. The reaction time is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours.

Examples of the organic solvent to be used in the synthesis of the polyamic acid include an aprotic polar solvent, a phenol solvent, an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, and a hydrocarbon solvent.

Examples of the aprotic polar solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethylammonium. Γ-butyrolactone, tetramethylurea, hexamethylphosphonium triamine, and the like.

Examples of the phenol solvent include m-cresol, xylenol, and halogenated phenol.

Examples of the alcohol-based solvent include methanol, ethanol, isopropanol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, and ethylene glycol monomethyl ether.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of the ester solvent include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, and ethoxypropionic acid. Ethyl ester, diethyl oxalate, diethyl malonate, and the like.

Examples of the ether solvent include diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-isopropyl ether, ethylene glycol-n-butyl ether, and B. Diol dimethyl ether, ethylene glycol ethyl ether acetate, 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, tetrahydrofuran, and the like.

Examples of the hydrocarbon-based solvent include hexane, heptane, octane, benzene, toluene, xylene, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, dichloromethane, and 1 , 2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like.

Among these organic solvents, at least one organic solvent selected from the group consisting of an aprotic polar solvent and a phenol solvent (hereinafter also referred to as "the first group of organic solvents") or the organic The solvent and at least one organic solvent selected from the group consisting of an alcohol solvent, a ketone solvent, an ester solvent, an ether solvent, and a hydrocarbon solvent (hereinafter also referred to as "the second group of organic solvent" )mixture. In the latter case, the use ratio of the organic solvent of the second group is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably the total mass of the organic solvent of the first group and the second group. 30% by mass or less.

The amount (a) to be used as the organic solvent is preferably such an amount that the total mass (b) of the tetracarboxylic dianhydride and the diamine becomes 0.1 mass with respect to the total mass (a+b) of the reaction solution. %~50% by mass.

Furthermore, when synthesizing polylysine, it is also possible to adjust the appropriate molecular weight. The agent is added to tetracarboxylic dianhydride and a diamine to synthesize a polymer which is a terminal modified type. By forming the terminal-modified polymer, the coating property of the liquid crystal alignment agent can be further improved without impairing the effects of the present invention.

Examples of the molecular weight modifier include an acid monoanhydride, a monoamine compound, and a monoisocyanate compound. These molecular weight modifiers may be used alone or in combination of two or more.

Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, and positive Cetyl succinic anhydride and the like.

Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, and n-octylamine.

Examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

The amount of the molecular weight modifier to be used is preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, based on 100 parts by weight of the total of the tetracarboxylic dianhydride and the diamine to be used.

The reaction solution containing the polylysine obtained in the above manner may be directly supplied to the preparation of the liquid crystal alignment agent, or may be supplied to the preparation of the liquid crystal alignment agent after the polyamic acid contained in the reaction solution is isolated. It is also possible to supply the liquid crystal alignment agent after refining the isolated polyamic acid. When polypyridic acid is subjected to dehydration ring closure to form a polyimine, the reaction solution may be directly supplied to a dehydration ring closure reaction, or may be subjected to dehydration after isolating the polylysine contained in the reaction solution. Closed loop Alternatively, the isolated polylysine may be purified and subjected to a dehydration ring closure reaction. The isolation and purification of polylysine can be carried out according to a known method.

[polyimine]

Polyimine is a polymer having a quinone ring structure. The polyimine contained in the liquid crystal alignment agent of the present invention may be used singly or in combination of two or more kinds.

The polyimine can be obtained by subjecting polylysine synthesized as described above to dehydration ring closure to carry out hydrazine imidization.

The polyimine may be a fully hydrazide formed by dehydration ring closure of all of the proline structures of the polyglycolic acid as a precursor thereof, or may be dehydrated only for a part of the proline structure. A closed-loop, partial yttrium imide that has a valeric acid structure and a quinone ring structure. The ruthenium iodide ratio of the polyimine is preferably 30% or more, more preferably 40% to 99%, still more preferably 50% to 99%. The ruthenium imidization ratio is a ratio of the number of quinone ring structures to the total number of guanidine structures and the number of quinone ring structures of the polyimine. Here, a part of the quinone ring may also be an isoindole ring.

<Synthesis method of polyimine]

As a dehydration ring-closure method of poly-proline in the synthesis of polyimine, (1) a method of heating poly-proline, and (2) dissolving poly-lysine in an organic solvent, and obtaining the obtained The method of (2) is more preferably a method in which a dehydrating agent and a dehydration ring-closure catalyst are added to the solution and heated as necessary.

In the method of the above (2), examples of the dehydrating agent include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. As the amount of the dehydrating agent used, relative to The proline structure of the polyaminic acid is 1 mole, preferably 0.01 mole to 20 moles. Examples of the dehydration ring-closure catalyst include tertiary amines such as pyridine, collidine, lutidine, and triethylamine. The amount of the dehydration ring-closure catalyst to be used is preferably 0.01 mol to 10 mol based on 1 mol of the dehydrating agent to be used.

The organic solvent used for the dehydration ring-closure reaction is, for example, the same organic solvent as the organic solvent exemplified as the organic solvent used for the synthesis of polyglycine. The reaction temperature of the dehydration ring closure reaction is preferably 0 ° C to 180 ° C, more preferably 10 ° C to 150 ° C. The reaction time is preferably from 1.0 to 120 hours, more preferably from 2.0 to 30 hours.

The polyiminoimine-containing reaction solution obtained in the above manner may be directly supplied to the preparation of the liquid crystal alignment agent, or may be supplied to the liquid crystal alignment agent after removing the dehydrating agent and the dehydration ring-closing catalyst from the reaction solution, or may be The polyimine is isolated and supplied to the preparation of the liquid crystal alignment agent, and may be supplied to the liquid crystal alignment agent after refining the isolated polyimine. Segregation and purification of polyimine can be carried out according to a known method.

[polyoxyalkylene]

Polyoxyalkylene is a polymer having a decane bond. The polyoxyalkylene is preferably a hydrolysis condensate of a decane compound.

Examples of the decane compound include tetrachloromethane, tetramethoxy decane, tetraethoxy decane, tetra-n-propoxy decane, tetra-isopropoxy decane, and tetra-n-butoxy decane. Tetra-second butoxydecane, trichlorodecane, trimethoxydecane, Triethoxy decane, tri-n-propoxy decane, tri-isopropoxy decane, tri-n-butoxy decane, tri-second butoxy decane, fluorotrichloro decane, fluorotrimethoxy decane, Fluorotriethoxydecane, fluorotri-n-propoxy decane, fluorotri-isopropoxy decane, fluorotri-n-butoxy decane, fluorotri-t-butoxydecane, methyltrichloro decane, Methyl trimethoxy decane, methyl triethoxy decane, methyl tri-n-propoxy decane, methyl tri-isopropoxy decane, methyl tri-n-butoxy decane, methyl tri- Dibutoxydecane, 2-(trifluoromethyl)ethyltrichlorodecane, 2-(trifluoromethyl)ethyltrimethoxydecane, 2-(trifluoromethyl)ethyltriethoxydecane , 2-(trifluoromethyl)ethyltri-n-propoxydecane, 2-(trifluoromethyl)ethyltri-isopropoxydecane, 2-(trifluoromethyl)ethyltri-positive Butoxy decane, 2-(trifluoromethyl)ethyltri-t-butoxydecane, 2-(perfluoro-n-hexyl)ethyltrichlorodecane, 2-(perfluoro-n-hexyl)ethyl Trimethoxydecane, 2-(perfluoro-n-hexyl)ethyltriethoxydecane, 2-(perfluoro-n-hexyl)ethyltri-n-propoxy Alkane, 2-(perfluoro-n-hexyl)ethyltri-isopropoxydecane, 2-(perfluoro-n-hexyl)ethyltri-n-butoxydecane, 2-(perfluoro-n-hexyl)ethyl Tris-t-butoxydecane, 2-(perfluoro-n-octyl)ethyltrichlorodecane, 2-(perfluoro-n-octyl)ethyltrimethoxydecane, 2-(perfluoro-positive Octyl)ethyltriethoxydecane, 2-(perfluoro-n-octyl)ethyltri-n-propoxydecane, 2-(perfluoro-n-octyl)ethyltris-isopropoxydecane , 2-(perfluoro-n-octyl)ethyltri-n-butoxydecane, 2-(perfluoro-n-octyl)ethyltri-t-butoxydecane, hydroxymethyltrichlorodecane, hydroxy Methyl trimethoxy decane, hydroxyethyl trimethoxy decane, hydroxymethyl tri-n-propoxy decane, hydroxymethyl tri-isopropoxy decane, hydroxymethyl tri-n-butoxy decane, hydroxymethyl Tris-t-butoxydecane, 3-(methyl)propenyloxypropyltrichlorodecane, 3-(methyl)propenyloxypropyltrimethoxydecane, 3-(methyl)propene Oxygen Propyltriethoxydecane, 3-(methyl)propenyloxypropyltri-n-propoxydecane, 3-(methyl)propenyloxypropyltris-isopropoxydecane, 3 -(Meth)acryloxypropyltri-n-butoxydecane, 3-(methyl)propenyloxypropyltri-t-butoxydecane, 3-mercaptopropyltrichlorodecane, 3 - mercaptopropyltrimethoxydecane, 3-mercaptopropyltriethoxydecane, 3-mercaptopropyltri-n-propoxydecane, 3-mercaptopropyltris-isopropoxydecane, 3-mercaptopropylpropane Tris-n-butoxydecane, 3-mercaptopropyltri-t-butoxydecane, mercaptomethyltrimethoxydecane, mercaptomethyltriethoxydecane, vinyltrichlorodecane, vinyltrimethoxy Base decane, vinyl triethoxy decane, vinyl tri-n-propoxy decane, vinyl tri-isopropoxy decane, vinyl tri-n-butoxy decane, vinyl tri-second butoxy Decane, allyltrichloromethane, allyltrimethoxydecane, allyltriethoxydecane,allyltri-n-propoxydecane,allyltri-isopropoxydecane, allyl Tris-n-butoxydecane, allyl - a second butoxy decane, phenyl trichloro decane, phenyl trimethoxy decane, phenyl triethoxy decane, phenyl tri-n-propoxy decane, phenyl tri-isopropoxy decane, benzene Tris-n-butoxydecane, phenyltri-t-butoxydecane, methyldichlorodecane, methyldimethoxydecane, methyldiethoxydecane, methyldi-n-propoxy Decane, methyl di-isopropoxy decane, methyl di-n-butoxy decane, methyl di-second butoxy decane, dimethyl dichloro decane, dimethyl dimethoxy decane, two Methyl diethoxy decane, dimethyl di-n-propoxy decane, dimethyl di-isopropoxy decane, dimethyl di-n-butoxy decane, dimethyl di-second butoxide Pyridin, (methyl)[2-(perfluoro-n-octyl)ethyl]dichlorodecane, (methyl)[2-(perfluoro-n-octyl)ethyl]dimethoxydecane, ( Methyl)[2-(perfluoro-n-octyl)ethyl]diethoxydecane, (methyl)[2-(perfluoro-n-octyl) Ethyl]di-n-propoxydecane, (methyl)[2-(perfluoro-n-octyl)ethyl]di-isopropoxydecane, (methyl)[2-(perfluoro-n-octyl) Ethyl]di-n-butoxydecane, (methyl)[2-(perfluoro-n-octyl)ethyl]di-secondbutoxydecane, (methyl)(3-mercaptopropyl) Dichlorodecane, (methyl)(3-mercaptopropyl)dimethoxydecane, (methyl)(3-mercaptopropyl)diethoxydecane, (methyl)(3-mercaptopropyl) Di-n-propoxy decane, (methyl) (3-mercaptopropyl) di-isopropoxy decane, (methyl) (3-mercaptopropyl) di-n-butoxy decane, (methyl) (3-mercaptopropyl)di-second butoxydecane, (methyl)(vinyl)dichlorodecane, (methyl)(vinyl)dimethoxydecane, (methyl)(vinyl) Diethoxydecane, (methyl) (vinyl) di-n-propoxy decane, (methyl) (vinyl) di-isopropoxy decane, (methyl) (vinyl) di-n-butyl Oxaloxane, (meth)(vinyl)di-second butoxydecane, divinyldichlorodecane, divinyldimethoxydecane, divinyldiethoxydecane,divinyldiene - n-propoxy decane, divinyl di-isopropoxy oxime Alkane, divinyldi-n-butoxydecane, divinyldi-second butoxydecane, diphenyldichlorodecane, diphenyldimethoxydecane, diphenyldiethoxydecane, Diphenyldi-n-propoxydecane, diphenyldi-isopropoxydecane, diphenyldi-n-butoxydecane, diphenyldi-secondbutoxydecane, chlorodimethylsilane , methoxy dimethyl decane, ethoxy dimethyl decane, chlorotrimethyl decane, bromotrimethyl decane, iodine trimethyl decane, methoxy trimethyl decane, ethoxy trimethyl decane , n-propoxy trimethyl decane, isopropoxy trimethyl decane, n-butoxy trimethyl decane, second butoxy trimethyl decane, third butoxy trimethyl decane, (chlorine (vinyl) dimethyl decane, (methoxy) (vinyl) dimethyl decane, (ethoxy) (vinyl) dimethyl decane, (chloro) (methyl) diphenyl decane, (methoxy)(methyl)diphenylnonane, (ethoxy)(methyl)diphenylanthracene Alkane, etc. These decane compounds may be used singly or in combination of two or more.

<Synthesis method of polyoxyalkylene>

The polyoxyalkylene can be synthesized, for example, by subjecting the decane compound or the like to hydrolysis condensation. The conditions for carrying out the hydrolysis and condensation are not particularly limited as long as the hydrolysis reaction is converted to a stanol group by at least a part of the decane compound, and the condensation reaction is produced. Implementation.

The water used for the hydrolysis condensation is preferably water obtained by a method such as reverse osmosis membrane treatment, ion exchange treatment, or distillation. By using such purified water, side reactions can be suppressed and the reactivity of hydrolysis can be enhanced. The amount of water used is preferably 0.1 mole to 3 moles, more preferably 0.3 moles to 2 moles, and still more preferably 0.5 moles to 1.5 moles, based on the total amount of the hydrolyzable groups of the decane compound. The amount. Hydrolysis can be achieved by using this amount of water. The reaction rate of the condensation is optimized.

As the solvent which can be used for the hydrolysis condensation, for example, ethylene glycol monoalkyl ether acetate, diethylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, and propionate are preferable. Among these solvents, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, and methyl 3-methoxypropionate are more preferable. 4-hydroxy-4-methyl-2-pentanone (diacetone alcohol).

The hydrolysis condensation reaction is preferably carried out in the presence of a catalyst such as an acid catalyst, a base catalyst or an alkoxide. The amount of the catalyst to be used is preferably 0.2 mol or less, more preferably 0.00001 mol to 0.1 mol, from the viewpoint of promoting the hydrolysis condensation reaction with respect to the monomer 1 mol of the hydrolyzable decane compound.

The reaction temperature and the reaction time in the hydrolysis condensation may be appropriately set, but the reaction temperature is preferably 40 ° C to 200 ° C, and more preferably 50 ° C to 150 ° C. The reaction time is preferably 30 minutes to 24 hours, more preferably 1 hour to 12 hours. By setting such a reaction temperature and reaction time, the hydrolysis condensation reaction can be carried out most efficiently. In the hydrolytic condensation, a hydrolyzable decane compound, water, and a catalyst may be added to the reaction system at one time to carry out the reaction in one stage, or the hydrolyzable decane compound, water, and catalyst may be added to the reaction system in multiple portions. Thereby, the hydrolysis condensation reaction is carried out in a plurality of stages. Further, after the hydrolysis condensation reaction, a dehydrating agent is added, followed by evaporation, whereby water and the produced alcohol can be removed from the reaction system.

As the solution viscosity of the [B] polymer, when a solution having a concentration of 10% by mass is prepared, it is preferably 10 mPa. s~800 mPa. s, more preferably 15 mPa. s~500 mPa. s. Further, the solution viscosity (mPa.s) of the [B] polymer is a concentration prepared for a good solvent (for example, γ-butyrolactone, N-methyl-2-pyrrolidone, etc.) using the [B] polymer. The value measured at 25 ° C using an E-type rotational viscometer was 10% by mass of the polymer solution.

The content of the [B] polymer is preferably 80% by mass or more, and more preferably 90% by mass or more based on the total solid content.

The polystyrene-equivalent weight average molecular weight (Mw) measured by Gel Permeation Chromatography (GPC) as the [B] polymer is preferably 1,000 to 500,000, more preferably 2,000 to 300,000, and Mw is utilized for coagulation. Average number of polystyrene conversions determined by gel permeation chromatography (GPC) The ratio (Mw/Mn) of the sub-quantity (Mn) is preferably 15 or less, more preferably 10 or less. By being in such a range, good alignment and stability of the liquid crystal display element can be ensured.

<[C]solvent>

The liquid crystal alignment agent usually contains a [C] solvent. As the solvent of [C], a solvent which uniformly dissolves or disperses each component such as the [A] compound or the [B] polymer and does not react with each component can be used. Examples of the [C] solvent include an alcohol solvent, a ketone solvent, a guanamine solvent, an ether solvent, and an ester solvent. Further, the [C] solvent may be used singly or in combination of two or more.

Examples of the alcohol-based solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, second butanol, butanol, and n-pentane. Alcohol, isoamyl alcohol, 2-methylbutanol, second pentanol, third pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, second hexanol, 2-ethyl Butanol, second heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, second octanol, n-nonanol, 2,6-dimethyl-4-heptanol, n-nonanol, Twenty-first alcohol, trimethyl decyl alcohol, twenty-tetradecanol, heptadecyl alcohol, decyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol , benzyl alcohol, diacetone alcohol, etc.; as the polyol solvent, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2 , 4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, three Propylene glycol and the like; as the polyol partial ether solvent, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, and B Glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-n-hexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-positive Ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether and the like.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-isobutyl ketone, and methyl group. - n-amyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-isobutyl ketone, trimethyl fluorenone, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, Methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, and the like.

Examples of the amide-based solvent include N,N'-dimethylimidazolidinone, N-methylformamide, N,N-dimethylformamide, and N,N-diethyl. Formamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, N-methyl-2-pyrrolidone, and the like.

Examples of the ether solvent include diethyl ether, dipropyl ether, dibutyl ether, butyl methyl ether, butyl ethyl ether, diisoamyl ether, hexyl methyl ether, and octane. Examples of the aliphatic-aromatic ethers include anisole and phenylethyl ether; and the cyclic ethers include tetrahydrofuran. , tetrahydropyran, dioxane, and the like.

Examples of the ester solvent include diethyl carbonate and propylene carbonate. Ester ester, methyl acetate, ethyl acetate, γ-valerolactone, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, dibutyl acetate, n-amyl acetate, acetic acid Dipentyl ester, 3-methoxybutyl acetate, methyl amyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate , n-decyl acetate, methyl acetate methyl acetate, ethyl acetate ethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Diethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, ethylene glycol Diacetate, methoxytriethylene glycol acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate , n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate γ- butyrolactone.

The solvent of [C] is preferably an alcohol solvent or a guanamine solvent, and as the alcohol solvent, a polyol partial ether solvent is more preferable, and ethylene glycol mono-n-butyl ether is more preferable. As the guanamine-based solvent, N-methyl-2-pyrrolidone is more preferable.

The content of the solvent of [C] is preferably selected in consideration of viscosity, volatility, etc., but the solid content concentration in the liquid crystal alignment agent (the total mass of components other than the solvent of the liquid crystal alignment agent is in the total mass of the liquid crystal alignment agent) The proportion) is 1% by mass to 10% by mass. When the solid content concentration is less than 1% by mass, the film thickness of the formed liquid crystal alignment film becomes too small to obtain a good liquid crystal alignment film, and when the solid content concentration exceeds 10% by mass, the formed liquid crystal Film thickness of alignment film It is too large to obtain a good liquid crystal alignment film. In addition, when the solid content concentration exceeds 10% by mass, the viscosity of the liquid crystal alignment agent increases and the coatability tends to decrease.

The more preferable range of the solid content concentration differs depending on the method of applying the liquid crystal alignment agent. For example, in the case of using the rotator method, it is more preferably 1.5% by mass to 4.5% by mass. In the case of using the printing method, it is more preferably 3% by mass to 9% by mass, thereby making the solution viscosity 12 mPa. s~50 mPa. The scope of s. In the case of using the inkjet method, it is more preferably 1% by mass to 5% by mass, thereby making the solution viscosity 3 mPa. s~15 mPa. The scope of s.

<Other optional ingredients>

Examples of other optional components which may be contained in the liquid crystal alignment agent include an epoxy group-containing compound, an antioxidant, a polyfunctional (meth) acrylate, and a functional decane compound. Hereinafter, each component will be described.

(epoxy group-containing compound)

The epoxy group-containing compound is a component that enhances adhesion. The liquid crystal alignment agent contains the epoxy group-containing compound, and the liquid crystal alignment film formed of the liquid crystal alignment agent can improve adhesion to the substrate. Further, the epoxy group-containing compound may be used singly or in combination of two or more kinds.

Examples of the epoxy group-containing compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. , neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol diglycidyl ether, trimethylol Propane triglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-double (N, N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N-diglycidyl Base-benzylamine, N,N-diglycidyl-aminomethylcyclohexane, N,N-diglycidyl-cyclohexylamine, an epoxy group as described in International Publication No. 2009/096598 Polyorganosiloxane and the like.

The content of the epoxy group-containing compound is preferably 0 parts by mass to 40 parts by mass, and more preferably 0.1 parts by mass to 30 parts by mass, per 100 parts by mass of all the polymers contained in the liquid crystal alignment agent.

(Antioxidants)

The antioxidant is a component that functions as a radical scavenger or a peroxide decomposer that invalidates peroxy radicals or hydroperoxides generated by energy such as ultraviolet rays or heat. When the liquid crystal alignment agent contains the antioxidant, it is possible to suppress a decrease in electrical characteristics of the liquid crystal display element caused by a peroxy radical or the like. Further, the antioxidant may be used singly or in combination of two or more.

Examples of the antioxidant include a phenol-based antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and a mixed antioxidant. As these antioxidants, the following commercial items can be used, for example.

Examples of the phenolic antioxidant include Adekastab AO-20, Adekastab AO-30, Adekastab AO-40, Adekastab AO-50, Adekastab AO-60, Adekastab AO-80, Adekastab AO-330 (above, Ai Made by ADEKA), IRGANOX1010, IRGANOX1035, IRGAOX 1076, IRGANOX 1098, IRGANOX 1135, IRGANOX 1330, IRGANOX 1726, IRGANOX 1425, IRGANOX 1520, IRGANOX 245, IRGANOX 259, IRGANOX 3114, IRGANOX 3790, IRGANOX 5057, IRGANOX 565, IRGAMOD 295 (above, manufactured by BASF Japan).

Examples of the amine-based antioxidant include Adekastab LA-52, Adekastab LA-57, Adekastab LA-63, Adekastab LA-68, Adekastab LA-72, Adekastab LA-77, Adekastab LA-81, Adekastab LA- 82, Adekastab LA-87, Adekastab LA-402, Adekastab LA-502 (above, manufactured by Eddy), CHIMASSORB119, CHIMASSORB2020, CHIMASSORB944, TINUVIN622, TINUVIN123, TINUVIN144, TINUVIN765, TINUVIN770, TINUVIN111, TINUVIN783, TINUVIN791 (above, Japan Made by BASF).

Examples of the phosphorus-based antioxidant include Adekastab PEP-4C, Adekastab PEP-8, Adekastab PEP-36, HP-10, 2112 (above, manufactured by Eddy), IRGAFOS 168, and GSY-P101 (above, 堺Chemical industry manufacturing), IRGAFOS168, IRGAFOS12, IRGAFOS126, IRGAFOS38, IRGAFOS P-EPQ (above, manufactured by BASF, Japan).

Examples of the sulfur-based antioxidant include Adekastab AO-412, Adekastab AO-503 (above, manufactured by Adeco), IRGANOX PS 800, IRGANOX PS 802 (above, manufactured by BASF, Japan).

As the mixed antioxidant, for example, Adekastab A-611, Adekastab A-612, Adekastab A-613, Adekastab AO-37, Adekastab AO-15, Adekastab AO-18, 328 (above, manufactured by Eddy), TINUVIN111, TINUVIN783, TINUVIN791 (above, manufactured by BASF, Japan) )Wait.

Among these antioxidants, a phenol-based antioxidant and an amine-based antioxidant are preferable.

The content of the antioxidant is preferably 0 parts by mass to 10 parts by mass, more preferably 0 parts by mass to 5 parts by mass, even more preferably 0.1 parts by mass, based on 100 parts by mass of all the polymers contained in the liquid crystal alignment agent. 3 parts by mass.

(polyfunctional (meth) acrylate)

Polyfunctional (meth) acrylate is a component that improves weather resistance. When the liquid crystal alignment agent contains the polyfunctional (meth) acrylate, the weather resistance of the liquid crystal display element can be improved. Further, the polyfunctional (meth) acrylate may be used singly or in combination of two or more kinds.

Examples of the polyfunctional (meth) acrylate include ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, and 1,6-hexanediol. Dimethacrylate, 1,9-nonanediol diacrylate, 1,9-nonanediol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, polypropylene glycol Diacrylate, polypropylene glycol dimethacrylate, bisphenoxyethanol oxime diacrylate, bisphenoxyethanol oxime dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethyl Acrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethylpropyl An enoate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tris(2-propenyl methoxyethyl) phosphate, tris(2-methylpropenyloxyethyl) phosphate, and the like. Further, as the polyfunctional (meth) acrylate, a commercially available product can also be used.

The content of the polyfunctional (meth) acrylate is preferably 0 parts by mass to 100 parts by mass, more preferably 0 parts by mass to 50 parts by mass, based on 100 parts by mass of all the polymers contained in the liquid crystal alignment agent. More preferably, it is 0.1 mass part - 30 mass parts.

(functional decane compound)

The functional decane compound is a component that improves coatability. By containing the functional decane compound in the liquid crystal alignment agent, the coating property of the liquid crystal alignment agent to the substrate can be improved. Further, the functional decane compound may be used singly or in combination of two or more kinds.

Examples of the functional decane compound include 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane, and 2-amino group. Propyltriethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldi Methoxydecane, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxy Carbocarbonyl-3-aminopropyltriethoxydecane, N-triethoxydecylpropyltriethylenetriamine, N-trimethoxydecylpropyltriethylenetriamine, 10-trimethoxydecane Base-1,4,7-triazadecane, 10-triethoxydecyl-1,4,7-triazadecane, 9-trimethoxydecyl-3,6-diaza Mercaptoacetate, 9-trimethoxydecyl-3,6-diazadecyl acetate, 9-triethoxydecyl-3,6- Diazinyl acetate, methyl 9-trimethoxydecyl-3,6-diazepine, methyl 9-triethoxydecyl-3,6-diazepine, N -benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, N- Phenyl-3-aminopropyltriethoxydecane, glycidoxymethyltrimethoxydecane, glycidoxymethyltriethoxydecane, 2-glycidoxyethyltrimethoxydecane 2-glycidoxyethyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethoxydecane, and the like.

The content of the functional decane compound is preferably 0 parts by mass to 2 parts by mass, more preferably 0.02 parts by mass to 0.2 parts by mass, per 100 parts by mass of all the polymers contained in the liquid crystal alignment agent.

<Preparation method of liquid crystal alignment agent>

The liquid crystal alignment agent of the present invention can be obtained by using [A] compound, [B] polymer, optionally [C] solvent, epoxy group-containing compound, antioxidant, polyfunctional (meth) acrylate, functionality Any component such as a decane compound is prepared by mixing in a predetermined ratio. The temperature at the time of preparation is preferably 10 ° C to 50 ° C, more preferably 20 ° C to 30 ° C. Further, the liquid crystal alignment agent may be prepared by mixing the respective components and then filtering by, for example, a filter having a pore size of about 1 μm.

<Liquid alignment film>

The liquid crystal alignment film of the present invention is formed of the liquid crystal alignment agent. Since the liquid crystal alignment film is formed of the liquid crystal alignment agent containing the [A] compound and the [B] polymer, the liquid crystal display element including the liquid crystal alignment film has excellent light resistance.

<Method of Forming Liquid Crystal Alignment Film>

The liquid crystal alignment film can be formed, for example, by the following steps: (1) a step of forming a coating film on a substrate using the liquid crystal alignment agent (hereinafter, also referred to as "step (1)"); (2) The step of rubbing the coating film to form a liquid crystal alignment film (hereinafter, also referred to as "step (2)"). Further, the step (1) differs depending on the driving method of the liquid crystal display element. Hereinafter, the above steps (1) and (2) will be described in detail.

[step 1)]

In this step, the liquid crystal alignment agent of the present invention is applied onto a substrate, and then the coated surface is heated to form a coating film on the substrate.

When the liquid crystal display element is a TN type, STN type or VA type liquid crystal display element, first, two sheets of the substrate on which the patterned transparent conductive film is provided are paired, and then each transparent conductive film on the two substrates The liquid crystal alignment agent is coated on the forming surface.

Examples of the substrate include glass such as float glass and soda glass; and polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, and poly A transparent substrate of plastic such as (alicyclic olefin). Examples of the transparent conductive film include a NESA film containing tin oxide (SnO ₂ ) (registered trademark of PPG Corporation, USA), and indium tin oxide containing indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) (Indium). Tin Oxide, ITO) film, etc. As a method of providing the patterned transparent conductive film, for example, a method of forming a pattern by photolithography after forming a transparent conductive film without a pattern, and a method of forming a transparent conductive film are used. A method of masking a desired pattern. As a coating method of liquid crystal alignment agent

The method is preferably an offset printing method, a spin coating method, a roll coater method, or an inkjet printing method. Further, when the liquid crystal alignment agent is applied, in order to improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, the surface of the substrate on which the coating film is to be formed may be coated with a functional decane compound. Pretreatment of functional titanium compounds and the like.

After the liquid crystal alignment agent is applied, in order to prevent liquid sag or the like of the applied liquid crystal alignment agent, preheating (prebaking) is preferably performed. The prebaking temperature is preferably 30 ° C to 200 ° C, more preferably 40 ° C to 150 ° C, still more preferably 40 ° C to 100 ° C. The prebaking time is preferably 0.25 minutes to 10 minutes, more preferably 0.5 minutes to 5 minutes. Thereafter, the solvent is completely removed, and if necessary, calcination (post-baking) may be carried out for the thermal imidization of the proline structure in the [B] polymer. The post-baking temperature is preferably 80 ° C to 300 ° C, more preferably 120 ° C to 250 ° C. The post-baking time is preferably 5 minutes to 200 minutes, more preferably 10 minutes to 100 minutes. The film thickness of the formed liquid crystal alignment film is preferably 1 nm to 1,000 nm, and more preferably 5 nm to 500 nm.

When the liquid crystal display device is an In-Plane Switching (IPS) type liquid crystal display device, the liquid crystal alignment agent is applied to a conductive film forming surface of a substrate provided with a patterned transparent conductive film, and A coating film is formed by heating each coated surface on one surface of the counter substrate on which the conductive film is not provided. The material of the substrate and the transparent conductive film used at this time, the coating method, the heating conditions after coating, the patterning method of the transparent conductive film, the pretreatment of the substrate, and the preferred film thickness of the formed coating film, The case of the TN type, the STN type, and the VA type liquid crystal display element is the same.

In the case of any of the liquid crystal display elements of the driving type, when the [B] polymer is a polyaminic acid or a ruthenium-based polymer having a quinone ring structure and a proline structure, After the coating film is formed and further heated, the dehydration ring-closure reaction is carried out to prepare a coating film which is further imidized.

[Step (2)]

In this step, a liquid crystal alignment film is formed by the rubbing of the coating film.

When the liquid crystal display element is a TN type, STN type, or IPS type liquid crystal display element, the following rubbing treatment is performed: using, for example, a roll wound with a cloth containing fibers such as nylon, rayon, cotton, etc., in a fixed direction The coating film formed in the step (1) is rubbed. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to become a liquid crystal alignment film.

When the liquid crystal display element is a VA type liquid crystal display element, the coating film formed in the above step (1) can be directly used as the liquid crystal alignment film, but the formed coating film can also be subjected to a rubbing treatment.

With respect to the liquid crystal alignment film formed as described above, the liquid crystal alignment film may have a different liquid crystal alignment ability in each region by irradiating ultraviolet rays to a part of the liquid crystal alignment film. The treatment of the pretilt angle change of the region; or the treatment of removing the resist film in a direction different from the previous rubbing treatment after the resist film is formed on a portion of the surface of the liquid crystal alignment film. In this case, the field of view characteristics of the obtained liquid crystal display element can be improved. Further, a liquid crystal alignment film suitable for a VA type liquid crystal display element can also be suitably used for a polymer sustained alignment (Polymer sustained alignment, PSA) type liquid crystal display element.

<Liquid crystal display element>

The liquid crystal display element of the present invention includes the liquid crystal alignment film. This liquid crystal display element includes a liquid crystal cell, a polarizing plate, and the like which will be described later. Since the liquid crystal display element includes the liquid crystal alignment film formed of the liquid crystal alignment agent, it has excellent light resistance.

The driving method of the liquid crystal display element is not particularly limited, and can be applied to an IPS type, a TN type, an STN type, a Fringe Field Switching (FFS) type, a VA type, and an Optically Compensated Bend (OCB) type. And other driving methods. The liquid crystal display device includes a pair of substrates in which a transparent electrode and a liquid crystal alignment film are sequentially laminated on the surface, and the pair of substrates are disposed opposite to each other, and liquid crystal is filled between the pair of substrates, and the peripheral portion is sealed with a sealant.

<Method of Manufacturing Liquid Crystal Display Element>

For the liquid crystal display element, for example, a pair of substrates on which a liquid crystal alignment film is formed by the steps (1) and (2) can be used, and are formed by the following steps: (3) by facing the opposite direction a step of forming a liquid crystal cell by filling a liquid crystal between a pair of substrates of the liquid crystal alignment film (hereinafter, also referred to as "step (3)"); (4) attaching a polarizing plate to an outer surface of the liquid crystal cell Step (hereinafter, also referred to as "step (4)"). Hereinafter, the above steps (3) and (4) will be described in detail.

[Step (3)]

In this step, the rubbing direction of the liquid crystal alignment film of the two substrates on which the liquid crystal alignment film is formed is orthogonal or antiparallel, and is arranged to face each other with a gap (cell gap), and a sealant is used. The peripheral portion of the substrate is bonded and oriented The filling liquid crystal is injected into the cell gap defined by the surface of the substrate and the sealant, and then the injection hole is sealed to constitute a liquid crystal cell.

Examples of the sealant include an epoxy resin containing a curing agent and an alumina ball as a spacer.

Examples of the liquid crystal include nematic liquid crystal, smectic liquid crystal, and the like. Among these liquid crystals, nematic liquid crystals are preferred. Examples of the nematic liquid crystal include a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, and a terphenyl system. Liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, or the like. Further, a cholesteric liquid crystal such as cholesteryl cholesteryl, cholesteryl phthalate or cholesteryl carbonate may be added to these liquid crystals; for example, as "C-15" and "CB-15" (above, Merck) A chiral agent sold by (Merck); a ferroelectric liquid crystal such as p-oxybenzylidene-p-amino-2-methylbutyl cinnamate or the like.

[Step (4)]

In this step, the polarizing plate is bonded to the outer surface of the formed liquid crystal cell such that the polarizing direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on each of the substrates.

Examples of the polarizing plate include a polarizing plate in which a polarizing film called “H film” is sandwiched by a cellulose acetate protective film, or a polarizing plate including an H film itself. The vinyl alcohol is extended to a polarizing film which absorbs iodine on one side.

The liquid crystal display element formed in the manner described can be effectively applied to various devices such as a clock, a portable game machine, a word processor, a notebook personal computer, a car navigation system, a camcorder, and a personal digital assistant ( Personal Digital Assistant (PDA), digital camera, mobile phone, smart phone, various monitors, LCD TVs, information displays and other display devices.

[Examples]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. The method of measuring each physical property value is shown below.

[Solid viscosity of polymer solution]

[B] The solution viscosity (mPa.s) of the polymer solution was measured by adjusting the concentration of the [B] polymer to 10% by mass using a predetermined solvent, and measuring it at 25 ° C using an E-type rotational viscometer.

[醯imination rate]

The solution of polyimine is put into pure water, and the obtained precipitate is sufficiently dried under reduced pressure at room temperature, and then dissolved in deuterated dimethyl hydrazine, and tetramethyl decane is used as a reference substance. The ¹ H-NMR spectrum was measured at room temperature. From the obtained ¹ H-NMR spectrum, the oxime imidization ratio (%) of the polyimine was determined by the following formula (i).

In the mathematical formula (i), A1 appears near a chemical shift of 10 ppm. The peak area of the proton derived from the NH group. A2 is the peak area derived from other protons. α is the ratio of the number of protons of the other protons to the NH group in the precursor of the polymer (polyglycolic acid).

<[A] Synthesis of Compounds>

[Synthesis Example 1] (Synthesis of Compound (A-1))

As shown in the following scheme (3-1), 3,4-dihydrocoumarin 11.0 mmol (1.63 g), 3-aminomethylpyridine 10.0 mmol (1.08 g) and tetrahydrofuran 10 ml It was mixed and stirred under reflux conditions of 80 ° C for 3 hours. Then, after concentrating the reaction liquid to 5 ml, 30 ml of hexane was added thereto, and the precipitate was filtered, washed with hexane, and dried to obtain a reaction product represented by the following scheme (3-1). Compound (A-1) 9.87 mmol (2.53 g).

[Synthesis Example 2] (Synthesis of Compound (A-2))

As shown in the following scheme (3-2), 3,4-dihydrocoumarin 11.0 mmol (1.63 g), 4-aminomethylpyridine 10.0 mmol (1.08 g) and tetrahydrofuran 10 ml It was mixed and stirred under reflux conditions of 80 ° C for 3 hours. Then, after concentrating the reaction liquid to 5 ml, 30 ml of hexane was added thereto, and the precipitate was filtered, washed with hexane, and dried to obtain a reaction product represented by the following scheme (3-2). Compound (A-2) 9.65 mmol (2.47 g).

[Synthesis Example 3] (Synthesis of Compound (A-3))

As shown in the following scheme (3-3), 3,4-dihydrocoumarin 20.0 mmol (2.96 g), 4-aminopyridine 30.0 mmol (2.82 g) and dioxane 3 mL It was mixed and stirred under reflux conditions of 100 ° C for 24 hours. Then, the formation of the compound (A-3) represented by the reaction product of the following scheme (3-3) was confirmed by Thin Layer Chromatography (TLC), and then purified by silica gel column chromatography. The compound (A-3) represented by the reaction product of the following scheme (3-3) was obtained 18.5 mmol (4.48 g).

<[B] Synthesis of Polymers>

The tetracarboxylic dianhydride and the diamine used for the synthesis of the [B] polymer are shown below.

[tetracarboxylic dianhydride]

B1-1: 2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA)

[diamine]

B2-1: cholesteryl 3,5-diaminobenzoate (HCDA)

B2-2: cholestyloxy-2,4-diaminobenzene (HCODA)

B2-3: p-phenylenediamine (PDA)

B2-4: 3,5-diaminobenzoic acid (DAB)

[Synthesis Example 4] (Synthesis of Polymer (B-1))

(b1-1) 0.1 mol (22.40 g) as tetracarboxylic dianhydride, and (b2-1) 0.02 mol (10.45 g), (b2-2) 0.01 mol (4.94 g) as diamine And (b2-3) 0.07 mol (7.56 g) was dissolved in N-methyl-2-pyrrolidone 181 g, and reacted at 60 ° C for 6 hours, thereby obtaining 20% by mass of polyglycine. Solution. A small amount of this solution was separated and added, and N-methyl-2-pyrrolidone was added to adjust the concentration of the polyaminic acid solution to 10% by mass to a solution viscosity of 68 mPa. s.

Then, 421 g of N-methyl-2-pyrrolidone was added to the obtained 20% by mass solution of poly-proline, and 7.9 g of pyridine as a dehydration ring-closure catalyst and 10.2 g of acetic anhydride as a dehydrating agent were added, and then at 110 The dehydration ring closure reaction was carried out for 4 hours at °C. After the dehydration ring closure reaction, the solvent in the system is solvent-substituted with a new N-methyl-2-pyrrolidone (by the solvent displacement operation, the pyridine and acetic anhydride for the dehydration ring-closure reaction are removed to the outside of the system. Thus, a solution containing 26% by mass of the polymer (B-1) of the polyimine having a ruthenium iodide ratio of 51% was obtained. A small amount of this solution was separated and added, and N-methyl-2-pyrrolidone was added to adjust the concentration of the polyimine to 10% by mass. The solution viscosity was 50 mPa. s.

[Synthesis Example 5] (Synthesis of Polymer (B-2))

A polymer containing a polyimine having a ruthenium imidization ratio of 74% was obtained in the same manner as in Synthesis Example 4 except that the amount of the pyridine and acetic anhydride to be used was changed as shown in the following Table 1. Solution of (B-2). Furthermore, the reaction solution is The N-methyl-2-pyrrolidone was added in such a manner that the total amount of the tetracarboxylic dianhydride and the diamine became 20% by mass based on the total amount of the reaction solution.

[Synthesis Example 6] (Synthesis of Polymer (B-3))

(b1-1) 0.1 mol (22.40 g) as tetracarboxylic dianhydride, and (b2-1) 0.02 mol (10.45 g), (b2-2) 0.01 mol (4.95 g) as diamine And (b2-4) 0.07 mol (10.64 g) was dissolved in N-methyl-2-pyrrolidone 194 g, and reacted at 60 ° C for 6 hours, thereby obtaining 20% by mass of polyglycine. Solution. A small amount of this solution was separated and added, and N-methyl-2-pyrrolidone was added to adjust the polyamine concentration to 10% by mass. The solution viscosity was 67 mPa. s.

Then, 450 g of N-methyl-2-pyrrolidone was added to the obtained 20% by mass solution of poly-proline, and 7.9 g of pyridine as a dehydration ring-closure catalyst and 10.2 g of acetic anhydride as a dehydrating agent were added, and then at 110 The dehydration ring closure reaction was carried out for 4 hours at °C. After the dehydration ring-closure reaction, the solvent in the system was subjected to solvent replacement with a new N-methyl-2-pyrrolidone, thereby obtaining a polymer (B-3) containing a polyamidimide having a ruthenium iodide ratio of 52%. 26% by mass of solution. A small amount of this solution was separated and added, and N-methyl-2-pyrrolidone was added to adjust the concentration of the polyimine to 10% by mass. The solution viscosity was 49 mPa. s.

[Synthesis Example 7] (Synthesis of Polymer (B-4))

A polymer containing a polyimine having a ruthenium iodide ratio of 73% was obtained in the same manner as in Synthesis Example 6, except that the amount of the pyridine and acetic anhydride to be used was changed as shown in the following Table 1. Solution of (B-4). Furthermore, the reaction solution is converted to a total mass of tetracarboxylic dianhydride and diamine relative to the total amount of the reaction solution. It was prepared by adding N-methyl-2-pyrrolidone in %.

In Table 1, the numerical value of the tetracarboxylic dianhydride shows the usage ratio (mol%) of the compound of the kind described in Table 1 with respect to the total amount of tetracarboxylic dianhydride used for synthesis. The numerical value of the diamine indicates the use ratio (mol%) of the compound of the kind described in Table 1 with respect to the total amount of the diamine used for the synthesis. The values of pyridine as a dehydration ring-closure catalyst and acetic anhydride as a dehydrating agent indicate the ratio (mol%) of pyridine and acetic anhydride to the number of methionine units of the obtained polyamic acid, respectively. The physical property values of the obtained polymers are shown together in Table 1. Further, "-" in Table 1 indicates that the compound was not formulated.

<Preparation of liquid crystal alignment agent>

The components other than the [A] compound and the [B] polymer used for the preparation of the liquid crystal alignment agent are shown below.

[[C]solvent]

NMP: N-methyl-2-pyrrolidone

BC: ethylene glycol-mono-n-butyl ether

[Epoxy group-containing compound]

G-1: N, N, N', N'-tetraglycidyl-m-xylylenediamine

[Example 1]

(1) Preparation of liquid crystal alignment agent for evaluation of coatability

To the solution containing 100 parts by mass of (B-1) as the [B] polymer, 5 parts by mass of (A-1) as the [A] compound, and N-methyl-2- as a solvent of [C] Pyrrolidone (NMP) and ethylene glycol mono-n-butyl ether (BC) were used to obtain a solution having a solvent of [C]: NMP: BC = 50:50 (mass ratio) and a solid concentration of 6.5% by mass. This solution was filtered using a filter having a pore size of 1 μm to prepare a liquid crystal alignment agent for coating property evaluation (hereinafter, the liquid crystal alignment agent for coating property evaluation is also referred to as "liquid crystal alignment agent A").

(2) Preparation of liquid crystal alignment agent for evaluation of reworkability and light resistance

In the preparation of the liquid crystal alignment agent of the above (1), the solid content concentration of the solution before the filtration is set to 4.0% by mass, and the operation is performed in the same manner as the preparation of the liquid crystal alignment agent of the above (1). In the liquid crystal alignment agent for evaluation of reworkability and light resistance (hereinafter, the liquid crystal alignment agent for evaluation of reworkability and light resistance is also referred to as "liquid crystal alignment agent B").

[Example 2 to Example 7 and Comparative Example 1 to Comparative Example 8]

The operation was carried out in the same manner as in Example 1 except that the compound [A], the [B] polymer, the [C] solvent and the epoxy group-containing compound to be blended were each shown in the following Table 2. The liquid crystal alignment agent A and the liquid crystal alignment agent B of each of the examples and the comparative examples.

<Manufacture of liquid crystal display element>

[Embodiment 8]

The liquid crystal alignment agent B of Example 1 was coated on a transparent conductive film containing an ITO film on one surface of a glass substrate having a thickness of 1 mm, and heated on a hot plate at 80 ° C for 1 minute. Then, it was heated on a hot plate at 230 ° C for 30 minutes, thereby forming a liquid crystal alignment film having a film thickness of about 80 nm. This operation was repeated to fabricate a substrate having a desired number of liquid crystal alignment films.

Then, for a pair of substrates having the liquid crystal alignment film, an epoxy resin adhesive having an alumina ball having a diameter of 3.5 μm is applied to each of the outer edges of the surface having the liquid crystal alignment film, and then each liquid crystal is used. The alignment film faces are laminated in a manner to be crimped, and the adhesive is hardened. Then, a negative liquid crystal (MLC-6608, manufactured by Merck) is filled between the pair of substrates from the liquid crystal injection port, and then the liquid crystal injection port is sealed with an acrylic photocurable adhesive, and the polarizing plate is bonded to both sides of the substrate. Thus, a vertical alignment type liquid crystal display element was fabricated.

[Example 9 to Example 14 and Comparative Example 9 to Comparative Example 16]

A liquid crystal alignment agent to be used was used in the same manner as in Example 8 except that the liquid crystal alignment agents used in Examples 2 to 7 and Comparative Examples 1 to 8 were used to form a vertical alignment type liquid crystal display. element.

<evaluation>

Each of the prepared liquid crystal alignment agents and the produced liquid crystal display element were evaluated by the following method. The results regarding the coatability and the reworkability in the following evaluation results are shown in Table 2, and the results regarding the light resistance are shown in Table 3.

[Coating property]

Using a liquid crystal alignment film printer (Angstromer form "S40L-532", manufactured by Japan Photo Printing), the amount of the liquid crystal alignment agent applied to the anilox roll is 20 drops (about 0.2 g). Each liquid crystal alignment agent A was applied on the surface of a transparent electrode of a glass substrate with a transparent electrode including an ITO film. Further, in the same type of printing press, the amount of dropping is usually 30 round trips (about 0.3 g), and here, printing conditions are set to be stricter than usual.

Then, the substrate on which the liquid crystal alignment agent A was applied was heated (prebaked) on a hot plate at 80 ° C for 1 minute, and then heated on a hot plate at 180 ° C for 10 minutes (post-baking) to form A film with a film thickness of 80 nm.

The coating film was observed with a microscope having a magnification of 20 times, and the coated liquid crystal alignment agent was investigated for cissing and coating unevenness. At this time, when shrinkage cavities and coating unevenness were not observed, the coatability was evaluated as "excellent (A)", and when shrinkage or coating unevenness was slightly observed, the coatability was evaluated as "good (B)" When the shrinkage cavities or coating unevenness were clearly observed, the coatability was evaluated as "poor (C)".

[Reworkability]

Each of the liquid crystal alignment agents B was coated on a transparent conductive film containing an ITO film on one surface of a glass substrate having a thickness of 1 mm, and pre-baked at 100 ° C for 90 seconds on a hot plate. A coating film having a film thickness of about 80 nm was formed. This operation was repeated to produce three substrates with a coating film.

Then, the obtained substrate was stored in a dark room at 25 ° C in a nitrogen atmosphere, and taken out after 12 hours, 24 hours, and 72 hours, respectively, and at 40 ° C. The beaker was added with N-methyl-2-pyrrolidone (NMP) for 2 minutes. Thereafter, the substrate was taken out from the beaker, washed several times with ultrapure water, and water droplets on the surface were removed by air blowing, and the remaining state of the coating film on the substrate was observed using an optical microscope. In this case, when the coating film was not left in the substrate for 72 hours in the dark room, the reworkability was evaluated as "excellent (A)", and in the case of the substrate having a storage time of 48 hours, In the case where the coating film can be peeled off, the reworkability is evaluated as "quite good (B)", and in the case of a substrate having a storage time of 24 hours, when the coating film can be peeled off, the reworkability is evaluated as " Good (C)", when the coating film could not be peeled off even if the substrate was stored for 12 hours, the reworkability was evaluated as "defect (D)".

[light resistance]

At a temperature of 60 ° C, a voltage of 5 V was applied to each of the liquid crystal display elements immediately after fabrication with an application time of 60 μsec and a span of 167 msec, and then a measuring device (VHR-1, Dongyang Teknikika (TOYO) was used. (manufactured by Corporation)) The voltage holding ratio after 167 milliseconds after the release of the application was measured. This voltage holding ratio is set to the initial voltage holding ratio VH ₁ (%).

Then, each of the liquid crystal display elements was subjected to light irradiation for 1,000 hours using a weather meter using a carbon arc as a light source. The voltage holding ratio was measured by the same method as described above for the liquid crystal display element after light irradiation. This voltage holding ratio was defined as a voltage holding ratio VH ₂ (%) after light irradiation.

In this case, the VH _{VH. 1} minus the reduced voltage holding ratio is defined as the obtained ₂ △ VHR, and the △ VHR as a light resistance index. When ΔVHR is 4.0 or less, the light resistance can be evaluated as good, and when ΔVHR exceeds 4.0, the light resistance can be evaluated as poor.

As shown in Table 2 and Table 3, the light resistance of the liquid crystal display element of the examples was It is good, and the coating property and the reworkability of the liquid crystal alignment agent used for it are good. On the other hand, at least one of light resistance, coatability, and reworkability of the comparative example was inferior.

(industrial availability)

The present invention can provide a liquid crystal alignment agent which can form a liquid crystal display element having excellent light resistance and has high coatability and reworkability. Therefore, the liquid crystal alignment agent, the liquid crystal alignment film formed of the liquid crystal alignment agent, and the liquid crystal display element including the liquid crystal alignment film can be suitably used for an electronic component capable of maintaining high display quality for a long period of time, a manufacturing process thereof, and the like.

Claims (5)

A liquid crystal alignment agent comprising [A] a compound represented by the following formula (1), and [B] a polymer, In the formula (1), R ¹ is a monovalent nitrogen-containing heterocyclic group having 4 to 20 carbon atoms, or a part or all of hydrogen atoms of the nitrogen-containing heterocyclic group are alkane having 1 to 20 carbon atoms. Base, alkoxy group having 1 to 12 carbon atoms, amine group, monoalkylamino group, dialkylamino group, nitroso group, fluorenyl group, thioether group, decyl group, decyl alcohol group, sulfinic acid group, sulfonate a group substituted with an acid group, a phosphino group, a phosphinyl group, a phosphonium group, a phosphonate group, a ketone group, an ester group, a trifluoromethyl group, a hydroxyl group, a halogen atom, a cyano group, a nitro group, a carboxyl group or a sulfo group; R ² is an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms; and each of R ³ and R ^{4 is} independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 20 carbon atoms; m is 0 to 2 Integer; when m is 2, 2 R ² may be the same or different; n is 1 or 2; when n is 2, 2 R ³ may be the same or different; r is an integer of 0-12 When r is 2 or more, a plurality of R ^{4 's} may be the same or different. The liquid crystal alignment agent according to claim 1, wherein the [B] polymer is at least one selected from the group consisting of polyproline, polyimine, and polyoxyalkylene. . The liquid crystal alignment agent according to claim 2, wherein: the [B] The polymer is at least one selected from the group consisting of polylysine and polyimine. A liquid crystal alignment film comprising a liquid crystal alignment agent as described in claim 1, claim 2, or a liquid crystal alignment agent according to claim 3. A liquid crystal display element comprising the liquid crystal alignment film according to item 4 of the patent application.