TWI504640B - Liquid crystal alignment agent, liquid crystal alignment film, and liquid crystal display element - 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.

Currently, liquid crystals having display modes such as TN (twisted nematic) type, STN (super twisted nematic) type, VA (vertical alignment) type, IPS (transverse electric field switching) type, and OCB (optical compensation bending) type are known. Display component. In any of these display modes, since the alignment state of the liquid crystal molecules is controlled in the liquid crystal alignment film, the characteristics of the liquid crystal alignment film and the liquid crystal alignment agent constituting the material of the liquid crystal alignment film affect the appearance of the characteristics of the liquid crystal display element.

As a material of the liquid crystal alignment agent, a resin material such as polylysine, polyimine, polyamine or polyester is known, and in particular, a liquid crystal alignment agent containing polyglycolic acid or polyimine is formed. The liquid crystal alignment film is excellent in heat resistance, mechanical strength, affinity with liquid crystal, and the like, and is being used in most liquid crystal display elements (see Patent Documents 1 to 6).

In recent years, research on improvement of display quality represented by high definition of liquid crystal display elements, low power consumption, and the like have been underway, and the range of use of liquid crystal display elements has been expanding. In particular, compared with the conventional liquid crystal display elements, the use of liquid crystal televisions that are supposed to be used under harsher conditions such as brightness and operating time is expanding by eliminating the trend of conventional cathode ray tube televisions.

However, conventional liquid crystal display elements having a liquid crystal alignment film (formed by a liquid crystal alignment agent containing polyglycolic acid or polyimine) have optical stress and heat. In the case of continuous driving for a long period of time in a severe environment such as moisture, the liquid crystal alignment film may be deteriorated, and the electrical characteristics of the liquid crystal cell may be deteriorated, and the display quality may be remarkably deteriorated.

Based on such a situation, it is desired to develop a liquid crystal alignment film which can form a liquid crystal alignment film which can maintain good electrical characteristics even when driving continuously for a long period of time.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 4-156622

[Patent Document 2] Japanese Patent Laid-Open No. 60-107020

[Patent Document 3] Japanese Patent Laid-Open No. 56-91277

[Patent Document 4] US Patent No. 5,958,333

[Patent Document 5] Japanese Patent Laid-Open No. 62-165628

[Patent Document 6] Japanese Patent Laid-Open No. 11-258605

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid crystal alignment film capable of forming a liquid crystal alignment film which is continuously driven for a long time even under severe environments such as light stress, heat, moisture, and the like. Can maintain good electrical properties.

In order to solve the above problems, the following inventions have been proposed: A liquid crystal alignment agent comprising at least one polymer selected from the group consisting of polyacrylic acid and a polyamidene obtained by dehydrating and ring-closing the polyamic acid (hereinafter referred to as "[A] Polymer") and [B] antioxidants.

It is characterized in that the [A] polymer is a polymer obtained by reacting a tetracarboxylic dianhydride with a diamine, and the tetracarboxylic dianhydride contains 1,3,3a,4,5,9b-hexahydro-8-A. 5-(4-hydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5, 9b-hexahydro-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione and 2,4,6,8 At least one selected from the group consisting of tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride, or as a diamine containing at least 1-(4-aminophenyl)-2 ,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine and 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl At least one selected from the group of ketone-1H-indole-6-amines.

By containing the [A] polymer and the [B] antioxidant, the liquid crystal alignment agent can maintain good electrical characteristics even when it is continuously driven for a long period of time under severe environments such as light stress, heat, and moisture.

The [B] antioxidant is preferably a group represented by the following formula (1) or formula (2).

(In the formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, and 1,3-di-terminated oxybutyl group. group or 1,4-oxobutyl side. Further, the formula (1) may be represented by the R ¹ represents an alkyl, aryl, aralkyl, and 1,3-1-oxobutyl sides, One hydrogen atom is removed from the 4-dioxoxybutyl group to become a divalent group, forming a part of the molecular chain.

R ² to R ⁵ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms.

X ¹ is a single bond, a carbonyl group, ^* -(CH ₂ ) _n -O-, ^* -O-, or ^* -CONH-. Here, the linkage indicated by ^* is a moiety indicating a linkage with a piperidine ring. Further, n is an integer of 1 to 4.

X ² to X ⁵ are each independently a single bond, a carbonyl group, ^** -CH ₂ -CO- or ^** -CH ₂ -CH(OH)-. The linkage key represented by ^** is a moiety indicating a bond with a piperidine ring. )

(In the formula (2), R ⁶ is a hydrocarbon group having 4 to 16 carbon atoms in which the hydrocarbon group may have an oxygen atom or a sulfur atom in the carbon chain backbone .a is an integer of 0 to 3 .R ⁷ is a hydrogen atom or a hydrocarbon group having 1 to 16 carbon atoms. When R ⁷ is plural, a plurality of R ^{7 's} may be the same or different.)

[B] Antioxidant The light resistance and high temperature and high humidity resistance can be further improved by the group having the above specific structure.

A liquid crystal alignment film formed of the liquid crystal alignment agent and a liquid crystal display element including the liquid crystal alignment film are suitable for the present invention. The liquid crystal display element can be suitably used in various devices, such as: clocks, handheld game consoles, word processors, notebook computers, car navigation systems, cameras, portable information terminals, digital cameras, mobile phones, various displays, LCD TVs, etc. Display device.

According to the liquid crystal alignment agent of the present invention, a liquid crystal alignment film which maintains good electrical characteristics can be formed even if it is continuously driven for a long period of time under a severe environment such as light stress, heat, or moisture. Therefore, the liquid crystal display element of the present invention including the liquid crystal alignment film can be effectively applied to various devices with less deterioration in display quality, and can be suitably used for, for example, watches, handheld game consoles, word processors, notebook computers, car navigation systems. Display devices such as systems, cameras, portable information terminals, digital cameras, mobile phones, various displays, and LCD TVs.

[Formation of the Invention] <Liquid alignment agent>

The liquid crystal alignment agent of the present invention contains [A] a polymer and [B] an antioxidant. By containing the [A] polymer and the [B] antioxidant, the liquid crystal alignment agent can maintain good electrical characteristics even if it is continuously driven for a long period of time under severe environments such as light stress, heat, and moisture.

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]polymer>

The [A] polymer is at least one polymer selected from the group consisting of polylysine and polyimine which is obtained by dehydration of the polyamic acid. Polylysine as the [A] polymer is obtained by reacting a tetracarboxylic dianhydride with a diamine. Hereinafter, tetracarboxylic dianhydride and diamine will be described in detail.

[tetracarboxylic dianhydride]

Examples of the tetracarboxylic dianhydride include aliphatic tetracarboxylic dianhydride. An alicyclic tetracarboxylic dianhydride or an aromatic tetracarboxylic dianhydride. These tetracarboxylic dianhydrides can be used individually or in combination of 2 or more types.

Examples of the aliphatic tetracarboxylic dianhydride include butane tetracarboxylic dianhydride.

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-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1 ,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-di-oxo-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-di-side oxytetrahydro-3-furanyl-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 3,5,6-tricarboxy-2-carboxymethyl Bornane-2:3,5:6-dianhydride, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride, 4,9-dioxo Heterotricyclo[5.3.1.0 ^2,6 ]undecane-3,5,8,10-tetraketone, etc.

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

Other tetracarboxylic dianhydrides, such as the tetracarboxylic dianhydride described in Japanese Patent Application No. 2010-97188, are mentioned.

The tetracarboxylic dianhydride is preferably one containing an alicyclic tetracarboxylic dianhydride. Further, more preferably, it contains 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5 - Bis-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro- 2,5-dioxa-3-furyl)-naphtho[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. Further, it is particularly preferable to contain 1, 3, 3a, 4, 5, 9b-six Hydrogen-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5, 9b-hexahydro-8-methyl-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 2, 4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride. When the above specific compound is used as the tetracarboxylic dianhydride, light resistance and high temperature and high humidity resistance can be further improved.

The above-mentioned particularly preferred 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-di-oxo-3-furyl)-naphtho[1,2-c]furan -1,3-dione, 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho [1,2-c] furan-1,3-dione, 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride It is preferably 10 mol% or more, more preferably 20 mol% to 90 mol%, based on the total tetracarboxylic dianhydride.

[diamine]

Examples of the diamine include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, and a diamine organic decane. These diamines can be used individually or in combination of 2 or more types.

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

Examples of the aliphatic diamine include 1,4-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), and 1,3-bis(aminomethyl)cyclohexane. Wait.

Examples of the aromatic diamine include p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, and 1,5-diaminonaphthalene. , 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,7-di Aminoguanidine, 4,4'-diaminodiphenyl ether, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 9,9-bis(4-aminobenzene) Base, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'- (p-phenylenediphenyl)benzidine, 4,4'-(meta-phenyldiisopropylidene)benzidine, 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)-peripipeline , 1-(4-Aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine, 1-(4-aminophenyl)-2, 3-dihydro-1,3,3-trimethyl-IH-indol-6-amine, 3,5-diaminobenzoic acid, cholesteryloxy-3,5-diaminobenzene, bile Nonyloxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholestyloxy-2,4-diaminobenzene, 3,5 - Diamine benzoic acid cholesteryl ester, 3,5-diamino benzoic acid cholesteryl ester, 3,5-diamino benzoic acid lanostane ester, 3,6-bis(4-aminobenzene) Methoxyoxy)cholestane, 3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzylideneoxy)cyclohexyl-3,5 -diaminobenzoic acid ester, 4-(4'-trifluoromethylbenzylideneoxy)cyclohexyl-3,5-diaminobenzoate, 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)benzene) 4-(4-heptylcyclohexyl)cyclohexane, 2,4-diamino-N,N-diallylaniline, 4-aminobenzylamine, 3-aminobenzylamine and lower Description (3) Compound represented like.

In the above formula (3), R ⁸ is an alkyl group having 1 to 3 carbon atoms, ^* -O-, ^* -COO- or ^* -OCO-. Wherein ^* is a site bonded to a diaminophenyl group. b is 0 or I. c is an integer from 0 to 2. d is an integer from 1 to 20. The two amine groups in the diaminophenyl group are preferably bonded at positions 2, 4 or 3, 5. Further, a and b are preferably both non-zero.

The compound represented by the above formula (3) may, for example, be a compound represented by the following formula.

Examples of the diamine organooxosiloxane include 1,3-bis(3-aminopropyl)-tetramethyldioxane. Examples of the other diamines include diamines and the like described in Japanese Patent Application No. 2010-97188.

As the diamine, those containing an aromatic diamine are preferred. Further, it is more preferred to contain 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine and 1-(4-amino group) At least one selected from the group consisting of phenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indol-6-amine. As a diamine by using The specific compound can further improve light resistance and high temperature and high humidity. As a commercial item of the above-mentioned specific compound, TMDA (made by Nippon Pure Pharmaceuticals) is mentioned, for example. TMDA is 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine and 1-(4-aminophenyl)-2 , a mixture of 3-dihydro-1,3,3-trimethyl-1H-indole-6-amine.

The use ratio of the above-mentioned preferred aromatic diamine is preferably 30% by mole or more, more preferably 50% by mole or more, and particularly preferably 80% by mole or more based on the entire diamine. Further, as the above-mentioned more preferable 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine and 1-(4-amine The proportion of at least one selected from the group consisting of phenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indol-6-amine is preferably relative to all diamines. More than 10% by mole, more preferably 20% by mole to 90% by mole.

Further, the diamine used in the synthesis of the polyamic acid in the VA type alignment film is used as the pretilt component, and it is preferable to contain 5 mol% or more of dodecyloxy-2,4-dithylene based on all diamines. Aminobenzene, tetradecyloxy-2,4-diaminobenzene, pentadecyloxy-2,4-diaminobenzene, hexadecyloxy-2,4-diaminobenzene, ten Octaethoxy-2,4-diaminobenzene, dodecyloxy-2,5-diaminobenzene, tetradecyloxy-2,5-diaminobenzene, pentadecyloxy- 2,5-Diaminobenzene,hexadecyloxy-2,5-diaminobenzene, octadecyloxy-2,5-diaminobenzene, cholesteryloxy-3,5- Diaminobenzene, cholestyloxy-3,5-diaminobenzene, cholestyloxy-2,4-diaminobenzene, cholestyloxy-2,4-diamine Benzobenzene, 3,5-diamino benzoic acid cholesteryl ester, 3,5-diamino benzoic acid lanostane ester, 3,6-bis(4-aminobenzylideneoxy)cholestane ,3,6-bis(4-aminophenoxy)cholestane, 4-(4'-trifluoromethoxybenzylideneoxy)cyclohexyl-3,5-diaminobenzoate 4-(4'-trifluoromethyl Benzyl oxime)cyclohexyl-3,5-diaminobenzoate, 1,1-bis(4-(aminophenylmethyl)phenyl)-4-butylcyclohexane, 1 ,1-bis(4-(aminophenylmethyl)phenyl)-4-heptylcyclohexane, 1,1-bis(4-(aminophenoxymethyl)phenyl)-4- Heptylcyclohexane, 1,1-bis(4-(aminophenylmethyl)phenyl)-4-(4-heptylcyclohexyl)cyclohexane, a compound represented by the above formula (3), and the like, More preferably, it contains 10 mol%.

[Synthesis method of polylysine]

The polyproline in the liquid crystal alignment agent is obtained by reacting the above tetracarboxylic dianhydride with a diamine. The acid anhydride group of the tetracarboxylic dianhydride is preferably 0.2 equivalent to 2 in terms of the use ratio of the tetracarboxylic dianhydride in the synthesis reaction for supplying the polyamic acid with respect to the amine group contained in one equivalent of the diamine. The equivalent weight is more preferably from 0.3 equivalents to 1.2 equivalents.

The synthesis reaction of poly-proline is preferably carried out in an organic solvent, and in terms of reaction temperature, it is preferably -20 ° C to 150 ° C, more preferably 0 ° C to 100 ° C. In terms of reaction time, it is preferably from 0.1 to 24 hours, more preferably from 0.5 to 12 hours. The organic solvent may, for example, be an aprotic polar solvent, phenol or a derivative thereof, an alcohol, a ketone, an ester, an ether, a halogenated hydrocarbon or a hydrocarbon.

Examples of the aprotic polar solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, and dimethylammonium. , γ-butyrolactone, tetramethyl urea, trimethylamine hexamethyl phosphate, and the like.

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

Examples of the alcohol include methanol, ethanol, and isopropyl alcohol. Cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, and the like.

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

Examples of the ester include ethyl lactate, butyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate, and diethyl oxalate. , diethyl malonate, and the like.

Examples of the ether include diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, and ethylene glycol. Mono-n-butyl ether, ethylene glycol 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 halogenated hydrocarbons include dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, and the like.

Examples of the hydrocarbon include hexane, heptane, octane, benzene, toluene, xylene, isoamylpropionate, isoamylisobutyrate, and diisoamyl ether.

Among these organic solvents, one or more selected from the group consisting of an aprotic polar solvent, phenol and a derivative thereof (the first group of organic solvents) or one or more selected from the first group of organic solvents are preferably used. A mixture of one or more selected from the group consisting of alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons (second group of organic solvents). Use of the second group of organic solvents The ratio is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less based on the total amount of the first group and the second group of organic solvents.

The amount of the organic solvent to be used is preferably 0.1% by mass to 50% by mass based on the total amount of the tetracarboxylic dianhydride and the diamine.

As described above, a reaction solution obtained by dissolving polyamic acid was obtained. The reaction solution may be supplied to the preparation of the liquid crystal alignment agent as it is, or may be supplied to the preparation of the liquid crystal alignment agent after separating the polyamic acid contained in the reaction solution, or may be supplied to the separated polyamic acid after purification. In the preparation of a liquid crystal alignment agent. When polypyridic acid is dehydrated and closed to prepare polyimine, the reaction solution may be supplied to the dehydration ring closure reaction as it is, or the polylysine contained in the reaction solution may be separated and then supplied to the dehydration ring closure reaction. Alternatively, the separated polyamic acid is refined and supplied to the dehydration ring closure reaction. The separation and purification of polylysine can be carried out according to a known method.

[Synthesis method of polyimine]

The polyimine which can be contained in the liquid crystal alignment agent is obtained by dehydrating and ring-closing the polyamic acid and imidating the ruthenium.

Examples of the tetracarboxylic dianhydride and the diamine used in the synthesis of the polyimine include a tetracarboxylic dianhydride and a diamine used in the synthesis of polyamic acid. The type and use ratio of the preferred tetracarboxylic dianhydride and diamine are also the same as in the synthesis of polyamic acid.

The polyimine may be a fully dehydrated ring-closed fully sulfimine of a proline structure having a polylysine of a raw material, or may be only a part of a proline structure and dehydrated and closed, and the proline structure and Part of the quinone imine compound coexisting with the quinone imine ring structure. The ruthenium imidation ratio of the polyimine in the liquid crystal alignment agent is preferably 30% or more, more preferably 50% to 99%, particularly preferably 65% to 99%. The above ruthenium amination ratio is represented by a percentage of the number of ruthenium ring structures relative to the total number of guanidine structure numbers and the number of quinone ring structures of the polyimine. At this time, a part of the quinone ring may be an isoindole ring. The ruthenium amination rate can be known by ¹ H-NMR of polyimine.

In addition, the ruthenium amide ratio in the present specification is obtained by sufficiently drying the polyimine at room temperature under reduced pressure, dissolving it in deuterated dimethyl hydrazine, and using tetramethyl decane as a reference substance. ¹ H-NMR measured at a temperature, and obtained according to the following formula (3).

醯imination rate (%)={1-(A ¹ /A ² )×α}×100 (3)

In the above formula (3), A ¹ is a peak area of protons from the NH group appearing near a chemical shift of 10 ppm, A ² is a peak area from other protons, and α is a precursor of polyimine (polyproline) The ratio of the number of other protons in the proton relative to one NH group.

The dehydration ring closure of the polyamic acid for synthesizing the above polyimine is carried out by heating the poly-proline or by dissolving the poly-proline in an organic solvent, adding a dehydrating agent and dehydrating the solution. A closed loop catalyst is carried out and heated as needed. The latter method is preferred.

Examples of the dehydrating agent include acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. The dehydrating agent is preferably used in an amount of from 0.01 mol to 20 mol with respect to the structural unit of 1 mol of polylysine.

The dehydration ring-closure catalyst may, for example, be a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine. Closed-loop catalysis The amount of the agent to be used is preferably 0.01 mol to 10 mol based on 1 mol of the dehydrating agent used. The organic solvent used for the dehydration ring-closure reaction is exemplified as the organic solvent exemplified as the polylysine synthesis. The reaction temperature for the dehydration ring closure reaction is preferably from 0 ° C to 180 ° C, more preferably from 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 reaction solution may be supplied to the preparation of the liquid crystal alignment agent as it is, or may be supplied to the liquid crystal alignment agent after the dehydration agent and the dehydration ring closure catalyst are removed from the reaction solution, or may be supplied to the liquid crystal alignment agent after separating the polyimine. In the preparation, the isolated polyimine is refined and supplied to the preparation of the liquid crystal alignment agent. The dehydrating agent and the dehydration ring-closure catalyst are removed from the reaction solution, and a method such as solvent replacement can be applied. The separation and purification of the polyimine can be carried out according to a known method.

The polyphthalic acid or polyimine which the liquid crystal alignment agent can contain may be a terminally modified polymer having a molecular weight adjusted. By using the terminal-modified polymer, the effects of the present invention can be prevented, and the coating properties and the like of the liquid crystal alignment agent can be improved. Such a terminal-modified polymer is produced by adding a molecular weight modifier to a polymerization reaction system when synthesizing polyamic acid. The molecular weight modifier may, for example, be a monoanhydride, a monoamine compound or a monoisocyanate compound.

Examples of the monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, and hexadecane. Alkyl succinic anhydride or the like.

Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, and n-decylamine. , n-decylamine, n-undecamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecaneamine, n-octadecylamine, n-dodecylamine, etc. .

The monoisocyanate compound may, for example, be phenyl isocyanate or naphthyl isocyanate.

The use ratio of the molecular weight modifier is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total of the tetracarboxylic dianhydride and the diamine used in the synthesis of the polyamic acid.

The polylysine or polyimine obtained as above is preferably 20 mPa when it is made into a solution having a concentration of 10% by mass. s~800mPa. The solution viscosity of s is more preferably 30 mPa. s~500mPa. s solution viscosity.

In addition, the solution viscosity (mPa.s) of the polymer in the present specification is a polymer solution having a concentration of 10% by mass using a certain solvent, and a value measured at 25 ° C using an E-type rotational viscometer.

<[B]Antioxidants>

The [B] antioxidant is a compound that can capture and decompose peroxy radicals and hydrogen peroxide generated by energy such as ultraviolet rays or heat, thereby suppressing oxidative degradation of substances. When a radical is generated in the [A] polymer by ultraviolet rays or heat, a new radical or a peroxide is generated based on the radical (the peroxide further generates a new radical), which may cause a high The function of the molecular material is reduced. [B] The antioxidant has a function as a radical scavenger which invalidates the radical generated as described above, and as a result, oxidation of the polymer material can be prevented and deterioration thereof can be suppressed.

The [B] antioxidant is preferably a group represented by the above formula (1) or formula (2). [B] an antioxidant having a specific structure as described above and capable of Further improve light resistance and high temperature and high humidity.

In the above formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, or a 1,3-dioxyloxybutyl group. Or 1,4-dihydroxybutyl. Further, the formula (1) may be represented by a group from R ¹ represents an alkyl group, an aryl group, an aralkyl group, removing one side of the 1,3-and 1,4-oxobutyl sides oxobutyl The hydrogen atom becomes a divalent group to form a part of the molecular chain. R ² to R ⁵ are each independently an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. X ¹ is a single bond, a carbonyl group, ^* -(CH ₂ ) _n -O-, ^* -O-, or ^* -CONH-. Here, the linkage indicated by ^* is a moiety indicating a bond with a piperidine ring. In addition, n is an integer of 1 to 4. X ² to X ⁵ are each independently a single bond, a carbonyl group, ^** -CH ₂ -CO- or ^** -CH ₂ -CH(OH)-. Here, the linkage represented by ^** is a moiety indicating a bond with a piperidine ring. In the above formula (2), R ⁶ is a hydrocarbon group having 4 to 16 carbon atoms. The above hydrocarbon group may have an oxygen atom or a sulfur atom in the carbon skeleton chain. a is an integer from 0 to 3. R ⁷ is a hydrogen atom or a hydrocarbon group having 1 to 16 carbon atoms. When R ⁷ is plural, a plurality of R ^{7 's} may be the same or different.

Examples of the alkyl group having 1 to 20 carbon atoms represented by the above R ¹ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a decyl group, and an eleventh group. Alkyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, and the like. Examples of the aryl group having 6 to 20 carbon atoms represented by the above R ¹ include a phenyl group, a 3-fluorophenyl group, a 3-chlorophenyl group, a 4-chlorophenyl group, a 4-isopropylphenyl group, and 4 n-Butylphenyl, 3-chloro-4-methylphenyl, 4-pyridyl, 2-phenyl-4-quinolinyl, 2-(4'-tri-butylphenyl)-4-quinoline A phenyl group, a 2-(2'-phenylthio)-4-quinolyl group or the like. The alkyl group having 1 to 6 carbon atoms represented by the above R ² to R ⁵ may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group. Examples of the aralkyl group having 7 to 13 carbon atoms represented by the above R ¹ to R ⁵ include a benzyl group and a phenethyl group. Examples of the aryl group having 6 to 12 carbon atoms represented by the above R ² to R ⁵ include a phenyl group and the like. The hydrocarbon group having 4 to 16 carbon atoms which may have an oxygen atom or a sulfur atom in the carbon skeleton chain represented by the above R ⁶ may, for example, be a tertiary butyl group, a 1-methylpentadecyl group or an octylmethylthio group. , dodecylmethylthio group and the like. Examples of the hydrocarbon group having 1 to 16 carbon atoms represented by R ⁷ include a methyl group, a tertiary butyl group, a 1-methylpentadecyl group, and an octylmethylthio group.

As the [B] antioxidant, a commercially available product can be used, and examples thereof include a phenol-based antioxidant, an amine-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and a mixed-based compound thereof. These [B] antioxidants may be used alone or in combination of two or more.

As a commercial product of a phenolic antioxidant, for example, ADK STAB AO-20, ADK STAB AO-30, ADK STAB AO-40, ADK STAB AO-50, ADK STAB AO-60, ADK STAB AO-80, ADK STAB AO-330 (above made by ADEKA), IRGANOX 1010, IRGANOX1035, IRGAOX1076, IRGANOX1098, IRGANOX1135, IRGANOX1330, IRGANOX1726, IRGANOX1425, IRGANOX1520, IRGANOX245, IRGANOX259, IRGANOX3114, IRGANOX3790, IRGANOX5057, IRGANOX565, IRGAMOD295 (above made in BASF Japan) )Wait.

Commercially available products of the amine-based antioxidant include, for example, ADK STAB LA-52, LA-57, LA-63, LA-68, LA-72, and LA-77. , LA-81, LA-82, LA-87, LA-402, LA-502 (above made by ADEKA), CHIMASSORB119, CHIMASSORB 2020, CHIMASSORB944, TINUVIN622, TINUVIN123, TINUVIN144, TINUVIN765, TINUVIN770, TINUVIN111, TINUVIN783, TINUVIN791 ( The above is made by BASF in Japan).

Commercially available products of the phosphorus-based antioxidant include, for example, ADK STAB PEP-4C, ADK STAB PEP-8, ADK STAB PEP-36, HP-10, 2112 (above, manufactured by ADEKA), IRGAFOS 168, and GSY-P101 ( The above is manufactured by 堺Chemical Industries), IRGAFOS168, IRGAFOS12, IRGAFOS126, IRGAFOS38, IRGAFOSP-EPQ (above, BASF made in Japan).

The commercially available product of the sulfur-based antioxidant may, for example, be ADK STAB AO-412, ADK STAB AO-503 (above, manufactured by ADEKA), IRGANOX PS 800, IRGANOX PS 802 (above, BASF Japan).

Commercially available products of the mixed antioxidant include, for example, ADK STAB A-611, ADK STAB A-612, ADK STAB A-613, ADK STAB AO-37, ADK STAB AO-15, ADK STAB AO-18, 328 (above is manufactured by ADEKA), TINUVIN 111, TINUVIN 783, TINUVIN 791 (above, manufactured by BASF Japan).

Among these commercially available products, a phenol-based antioxidant and an amine-based antioxidant are preferable. The content ratio of the [B] antioxidant is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and particularly preferably 0.1 parts by mass to 3 parts by mass or less based on 100 parts by mass of the [A] polymer.

<optional ingredients>

In addition to the [A] polymer and the [B] antioxidant, the liquid crystal alignment agent may contain other polymers other than the [A] polymer, a functional decane compound, etc., insofar as the effects of the present invention are not impaired. ingredient. These optional components may be used singly or in combination of two or more. Hereinafter, each component will be described in detail.

[Other polymers]

Other polymers can be used to improve solution properties and electrical properties. As other polymers, for example, polyphthalate, polyester, polyamine, polyoxyalkylene, cellulose derivatives, polyacetal, polystyrene derivatives, poly(styrene-phenyl horse) A quinone imine) derivative, a poly(meth) acrylate, or the like. Further, the content of other polymers may be appropriately determined depending on the purpose.

[functional decane compound]

From the viewpoint of further improving the printability of the liquid crystal alignment agent, a functional decane compound may be contained. The functional decane compound may, for example, be 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 2-aminopropyltrimethoxydecane or 2-aminopropyl. Triethoxy decane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxy Baseline, 3-ureidopropyltrimethoxydecane, 3-ureidopropyltriethoxydecane, N-ethoxycarbonyl-3-aminopropyltrimethoxydecane, N-ethoxycarbonyl 3-aminopropyltriethoxydecane, N-triethoxydecylpropyltriamine, N-trimethoxydecylpropyltriamine, 10-trimethoxydecane Base-1,4,7-triazadecane, 10-triethoxydecyl-1,4,7-three Azadecane, 9-trimethoxydecyl-3,6-diazadecyl acetate, 9-triethoxydecyl-3,6-diazaindolyl acetate, N- Benzyl-3-aminopropyltrimethoxydecane, N-benzyl-3-aminopropyltriethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, N-benzene Alkyl-3-aminopropyltriethoxydecane, N-bis(extended oxyethyl)-3-aminopropyltrimethoxydecane, N-bis(exooxyethyl)-3-aminopropyl Triethoxy decane and the like. The use ratio of the functional decane compound is preferably 2 parts by mass or less, more preferably 0.1 part by mass to 1 part by mass, per 100 parts by mass of the [A] polymer.

<Preparation method of liquid crystal alignment agent>

The liquid crystal alignment agent is preferably prepared by dissolving the above [A] polymer, [B] antioxidant, and optional components added as needed in an organic solvent to prepare a solution.

Examples of the organic solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N,N-dimethylformamide, and N,N-dimethyl group. Acetamine, 4-hydroxy-4-methyl-2-pentanone, butyl lactate, butyl acetate, methyl methoxypropionate, ethyl ethoxy propionate, ethylene glycol monomethyl Ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether (butyl race), ethylene glycol dimethyl Ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethyl Glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diisobutyl ketone, isoamyl propionate, isoamyl isobutyrate, diisoamyl ether, carbonic acid Ethyl ester, propyl carbonate and the like. They may be used alone or in combination of two or more.

The solid content concentration of the liquid crystal alignment agent (the ratio of the total mass of the liquid crystal alignment agent excluding the organic solvent to the total mass of the liquid crystal alignment agent) is appropriately selected in consideration of viscosity, volatility, etc., and is preferably 1% by mass. 10% by mass. When the liquid crystal alignment agent is applied to the surface of the substrate and the coating film constituting the liquid crystal alignment film is formed by removing the organic solvent, when the solid content concentration is less than 1% by mass, the film thickness of the coating film is too thin, and it is difficult to obtain a good liquid crystal alignment film. On the other hand, when the solid content concentration exceeds 10% by mass, the coating film thickness is too thick, and it is difficult to obtain a favorable liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent may increase to deteriorate the coating characteristics.

The more preferable solid content concentration range differs depending on the method used when the liquid crystal alignment agent is applied onto the substrate. For example, when it is a spin coating method, it is preferably in the range of 1.5% by mass to 4.5% by mass. When the printing method is used, it is preferably in the range of 3% by mass to 9% by mass, and the solution viscosity is 12 mPa. s~50mPa. The scope of s. When the inkjet method is used, the solid content concentration is preferably in the range of 1% by mass to 5% by mass, and the solution viscosity is preferably 3 mPa. s~15mPa. The scope of s.

The temperature at the time of preparing the liquid crystal alignment agent is preferably from 10 ° C to 50 ° C, more preferably from 20 ° C to 30 ° C.

<Method of Forming Liquid Crystal Alignment Film and Method of Manufacturing Liquid Crystal Display Element>

A liquid crystal alignment film formed of the liquid crystal alignment agent and a liquid crystal display element including the liquid crystal alignment film are suitably included in the present invention. The liquid crystal display element can be applied to various devices, such as: watches, handheld game consoles, word processors, notebook computers, car navigation systems, cameras, portable information terminals, digital cameras, mobile phones, various displays, LCD TVs, etc. Device.

In the liquid crystal alignment film of the present invention, the liquid crystal alignment agent is applied onto a substrate, and then formed on the substrate by heating the coated surface. Further, the liquid crystal display element of the present invention includes the liquid crystal alignment film.

Next, a method of forming the liquid crystal alignment film and a method of manufacturing the liquid crystal display element will be described in detail.

(1-1)

When manufacturing a TN type, STN type or VA type liquid crystal display element, two substrates provided with a patterned transparent conductive film are provided as a pair, and each of the transparent conductive film forming surfaces is preferably plated. The liquid crystal alignment agent of the present invention is applied by a printing method, a spin coating method or an inkjet printing method, and then a coating film is formed by heating each coated surface. As the substrate, for example, glass such as floating glass or soda glass; transparent plastic containing polyethylene terephthalate, polybutylene terephthalate, polyether oxime, polycarbonate, alicyclic olefin, or the like can be used. Substrate. As the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (manufactured by PPG, USA), and composed of indium oxide-tin oxide (In ₂ O ₃ -SnO ₂ ) can be used. ITO film, etc.

The method of obtaining the patterned transparent conductive film may, for example, be a method of forming a pattern by photolithography after forming a transparent conductive film without a pattern, or a method of using a photomask having a desired pattern when forming a transparent conductive film. In the application of the liquid crystal alignment agent, in order to further improve the adhesion between the surface of the substrate and the transparent conductive film and the coating film, pretreatment of a functional decane compound or a functional titanium compound may be performed on the surface on which the coating film is formed on the surface of the substrate. .

After applying the liquid crystal alignment agent, it is preferably used for the purpose of preventing dripping or the like. To carry out preheating (prebaking). The prebaking temperature is preferably from 30 ° C to 200 ° C, more preferably from 40 ° C to 150 ° C, and particularly preferably from 40 ° C to 100 ° C. The time for prebaking is preferably from 0.25 minutes to 10 minutes, more preferably from 0.5 minutes to 5 minutes.

Next, in order to completely remove the solvent, if necessary, baking (post-baking) is performed for the purpose of heat-imidization of poly-proline. The temperature for post-baking is preferably from 80 ° C to 300 ° C, more preferably from 120 ° C to 250 ° C. The time for post-baking is preferably from 5 minutes to 200 minutes, more preferably from 10 minutes to 100 minutes. The film thickness of the coating film to be formed is preferably 0.001 μm to 1 μm, more preferably 0.005 μm to 0.5 μm.

(1-2)

When manufacturing an IPS type liquid crystal display element, it is preferable to form a conductive film forming surface of a substrate having a pattern of a comb-shaped transparent conductive film and a surface of a counter substrate on which a conductive film is not provided, by a plate printing method, The liquid crystal alignment agent of the present invention is applied by a coating method or an inkjet printing method, respectively, and then a coating film is formed by heating each coated surface. The material of the substrate and the transparent conductive film used at this time, the pattern forming method of the transparent conductive film, the pretreatment of the substrate, and the heating method after applying the liquid crystal alignment agent are the same as those of the above (1-1). The film thickness of the formed coating film is the same as that of the above (1-1).

(2) When the liquid crystal display element produced by the method of the present invention is a VA type liquid crystal display element, the coating film formed as described above can be used as the liquid crystal alignment film as it is, but it is also used after the following rubbing treatment as desired. can. On the other hand, when a liquid crystal display element other than the VA type is produced, a liquid crystal alignment film is produced by performing a rubbing treatment on the coating film formed as described above.

The rubbing treatment is performed in a predetermined direction with respect to the coating film surface formed as described above, for example, by a roll wound with a cloth made of fibers such as nylon, crepe or cotton. Thereby, the alignment of the liquid crystal molecules can be imparted to the coating film to form a liquid crystal alignment film. Further, with respect to the liquid crystal alignment film formed as described above, a pretilt angle for changing a partial region of the liquid crystal alignment film is performed by irradiating a part of the liquid crystal alignment film as shown in Japanese Patent Laid-Open No. Hei 6-222366, No. Hei 6-281937, for example. After the treatment, or a resist film is formed on a portion of the surface of the liquid crystal alignment film as shown in Japanese Laid-Open Patent No. 5-105544, the treatment is performed after the rubbing treatment is performed in a direction different from the previous rubbing treatment. By having different liquid crystal alignment energies in different regions of the liquid crystal alignment film, the field of view characteristics of the obtained liquid crystal display element can be improved.

(3) Two substrates on which the liquid crystal alignment film has been formed are prepared, and liquid crystal cells are produced by disposing liquid crystal between the two substrates disposed opposite each other. Here, when the coating film is subjected to the rubbing treatment, the two substrates are disposed at a predetermined angle with respect to each other in the rubbing direction of each of the coating films, for example, vertically or anti-parallel. Examples of the production of the liquid crystal cell system include the following two methods.

As a first method, it is a well-known method. First, two liquid crystal alignment films are arranged to face each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are bonded together with a sealant. After the filling liquid crystal is injected into the surface of the substrate and the liquid crystal cell partitioned by the sealant, the liquid crystal cell is produced by closing the injection hole.

As a second method, a method called ODF (One Drop Fill) is applied to apply a UV curable sealing material to a position on one of the two substrates forming the liquid crystal alignment film, and further to liquid. After the liquid crystal is dropped onto the predetermined surface of the film surface, the liquid crystal alignment film is opposed to the other substrate, and the liquid crystal is pressed on the entire surface of the substrate, and then the entire surface of the substrate is irradiated with ultraviolet light to cure the seal. Agent to make liquid crystal cells.

In either method, it is desirable to reheat the liquid crystal cell produced above until the liquid crystal used is at a temperature of the isotropic phase, and then slowly cool to room temperature to remove the flow alignment at the time of liquid crystal injection. Thereby, the liquid crystal display element is obtained by bonding a polarizing plate to the outer surface of the liquid crystal cell.

Examples of the sealant include an epoxy resin containing an alumina ball used as a spacer and a curing agent. Examples of the liquid crystal include a nematic liquid crystal and a matrix liquid crystal. Among them, nematic liquid crystals are preferred. In the case of the VA type liquid crystal cell, a nematic liquid crystal having a negative dielectric anisotropy is preferable. Examples of such a liquid crystal include dicyanobenzene liquid crystal and ruthenium. A liquid crystal, a Schiff base liquid crystal, an oxy azo liquid crystal, a biphenyl liquid crystal, a phenyl cyclohexane liquid crystal, or the like. In the case of a TN type liquid crystal cell or an STN type liquid crystal cell, a nematic liquid crystal having positive dielectric anisotropy is preferred. Examples of such a liquid crystal include biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, ditriphenyl liquid crystal, biphenyl cyclohexane liquid crystal, pyrimidine liquid crystal, and An alkane liquid crystal, a bicyclooctane liquid crystal, a cuba liquid crystal, or the like. Further, for the liquid crystal, for example, a commercially available chiral agent such as cholesteric liquid crystal such as chol chloride, cholesterol phthalate or cholesterol carbonate (manufactured by Merck, C-15, CB-15); A ferroelectric liquid crystal such as oxybenzylidene-p-amino-2-methylbutylcinnamate or the like is used.

As a polarizing plate which is bonded to the outer surface of a liquid crystal cell, vinegar is mentioned. A polarizing plate obtained by sandwiching a polarizing film called "H film" with an acid cellulose protective film, or a polarizing plate made of an H film itself, which is obtained by stretching iodine while stretching the polyvinyl alcohol.

[Examples]

Hereinafter, the present invention will be described in detail based on the examples, but the description based on the examples is not intended to limit the explanation of the present invention.

<[A] Synthesis of Polymers> [Synthesis Example 1]

2,3,5-tricarboxycyclopentyl acetic acid dianhydride (TCA) as tetracarboxylic dianhydride 17.9 g (0.08 mol) and 1,3,3a,4,5,9b-hexahydro-5- (tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione (TDA) 6.0 g (0.02 mol), and as a diamine P-phenylenediamine (PDA) 2.2 g (0.02 mol), 3,5-diamino benzoic acid cholesteryl ester (HCDA) 10.4 g (0.02 mol) and 3,5-diamino benzoic acid ( DAB) 9.1 g (0.06 mol) was dissolved in 182 g of N-methyl-2-pyrrolidone (NMP), and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The obtained polyaminic acid solution has a solution viscosity of 99 mPa. s. Next, 423 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-1) having a ruthenium iodide ratio of about 51% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 55 mPa. s.

[Synthesis Example 2]

18.0 g (0.08 mol) and 1,3,3a of TCA as tetracarboxylic dianhydride 4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-di Ketone (MTDA) 6.3 g (0.02 mol), and PDA 2.2 g (0.02 mol), HCDA 10.5 g (0.02 mol) and DAB 9.2 g (0.06 mol) as diamine were dissolved in 185 g of NMP. The reaction was carried out at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 92 mPa. s. Next, 429 g of NMP was added to the obtained polyamic acid solution, and 8.0 g of pyridine and 10.3 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-2) having a ruthenium iodide ratio of about 48% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 50 mPa. s.

[Synthesis Example 3]

18.0 g (0.08 mol) of TCA as tetracarboxylic dianhydride and 2,4,6,8-tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride (BODA) 5.0 g (0.02 mol), and PDA 2.2 g (0.02 mol), HCDA 10.5 g (0.02 mol) and DAB 9.2 g (0.06 mol) as diamine were dissolved in 179 g of NMP and reacted at 60 ° C. After 6 hours, a solution containing 10% by mass of poly-proline was obtained. The solution viscosity of the obtained polyaminic acid solution is 81 mPa. s. Next, 416 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-3) having a ruthenium iodide ratio of about 50% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. Take a small amount of polypethane The imine solution was added with NMP to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 42 mPa. s.

[Synthesis Example 4]

22.5 g (0.1 mol) of TCA as tetracarboxylic dianhydride, and 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl- as diamine Mixture of 1H-indole-5-amine and 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indole-6-amine (TMDA) 10.7 g (0.04 mol) and HCDA 10.5 g (0.02 mol) and DAB 6.1 g (0.04 mol) were dissolved in 199 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of polyglycine. The solution viscosity of the obtained polyaminic acid solution is 80 mPa. s. Next, 462 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-4) having a ruthenium iodide ratio of about 44% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 66 mPa. s.

[Synthesis Example 5]

TCA 18.0 g (0.08 mol) and TDA 6.0 g (0.02 mol) as tetracarboxylic dianhydride, and TMDA 5.3 g (0.02 mol) and HCDA 10.5 g (0.02 mol) and DAB as diamines 9.2 g (0.06 mol) was dissolved in 196 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 84 mPa. s. Next, 455 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and the mixture was allowed to stand at 110 ° C for 4 hours. Dehydration ring closure reaction. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-5) having a ruthenium iodide ratio of about 49% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 52 mPa. s.

[Synthesis Example 6]

TCA 17.9 g (0.08 mol) and MTDA 6.3 g (0.02 mol) as tetracarboxylic dianhydride, and TMDA 5.3 g (0.02 mol) as diamine, HCDA 10.4 g (0.02 mol) and DAB 9.1 g (0.06 mol) was dissolved in 196 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 75 mPa. s. Next, 455 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-6) having a ruthenium iodide ratio of about 47% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 49 mPa. s.

[Synthesis Example 7]

17.8 g (0.08 mol) and BODA 5.0 g (0.02 mol) of TCA as tetracarboxylic dianhydride, and 5.3 g (0.02 mol) of HCDA as diamine, HCDA 10.4 g (0.02 mol) and DAB 9.1 g (0.06 mol) was dissolved in 190 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 85 mPa. s. Next, 442 g of the obtained polyamic acid solution was added. NMP, 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-7) having a ruthenium iodide ratio of about 56% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution of polypyrene at a concentration of 10% by mass, and the viscosity of the solution was determined to be 50 mPa. s.

[Synthesis Example 8]

TCA 20.1 g (0.09 mol) and TDA 3.0 g (0.01 mol) as tetracarboxylic dianhydride, and 2.2 g (0.02 mol), HCDA 10.4 g (0.02 mol) and DAB as PDA of diamine. 9.1 g (0.06 mol) was dissolved in 179 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 112 mPa. s. Next, 416 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-8) having a ruthenium iodide ratio of about 52% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 69 mPa. s.

[Synthesis Example 9]

20.2 g (0.09 mol) and MTDA 3.1 g (0.01 mol) of TCA as tetracarboxylic dianhydride, and 2.2 g (0.02 mol) of PDA as diamine, HCDA 10.5 g (0.02 mol) and DAB 9.1 g (0.06 mol) was dissolved in 181 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of polyaminic acid. The solution viscosity of the obtained polyaminic acid solution is 120mPa. s. Next, 419 g of NMP was added to the obtained polyamic acid solution, and 8.0 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-9) having a ruthenium iodide ratio of about 49% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 75 mPa. s.

[Synthesis Example 10]

20.2 g (0.09 mol) and BODA 2.5 g (0.01 mol) of TCA as tetracarboxylic dianhydride, and 2.2 g (0.02 mol) of PDA as diamine, HCDA 10.5 g (0.02 mol) and DAB 9.1 g (0.06 mol) was dissolved in 178 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 119 mPa. s. Next, 413 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-10) having a ruthenium iodide ratio of about 49% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 68 mPa. s.

[Synthesis Example 11]

22.4 g (0.1 mol) of TCA as tetracarboxylic dianhydride, and 2.7 g (0.01 mol) of TMDA as diamine, 10.5 g (0.02 mol) of HCDA, and 10.7 g (0.07 mol) of DAB were dissolved in In 185 g of NMP, the reaction was carried out at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. Acquired The solution viscosity of the proline solution is 101mPa. s. Next, 429 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-11) having a ruthenium iodide ratio of about 53% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 59 mPa. s.

[Synthesis Example 12]

22.4 g (0.1 mol) of TCA as tetracarboxylic dianhydride, and 2.6 g (0.02 mol) of PDA as diamine, 10.4 g (0.02 mol) of HCDA, and 9.1 g (0.06 mol) of DAB were dissolved in In 176 g of NMP, the reaction was carried out at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 102 mPa. s. Next, 410 g of NMP was added to the obtained polyamic acid solution, and 7.9 g of pyridine and 10.2 g of acetic anhydride were added, and a dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-12) having a ruthenium iodide ratio of about 47% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 56 mPa. s.

[Synthesis Example 13]

22.3 g (0.1 mol) of TCA as tetracarboxylic dianhydride, and 3.9 g (0.02 mol) of 4,4'-diaminodiphenylmethane as diamine, HCDA 5.2 g (0.01 mol) , cholesteryloxy-2,4-diaminobenzene 4.9g (0.01 Mole) and DAB 9.1 g (0.06 mol) were dissolved in 182 g of NMP, and reacted at 60 ° C for 6 hours to obtain a solution containing 10% by mass of poly-proline. The solution viscosity of the obtained polyaminic acid solution is 117 mPa. s. Next, 423 g of NMP was added to the obtained polyamic acid solution, and 10.2 g of pyridine and 13.2 g of acetic anhydride were added, and the dehydration ring-closure reaction was carried out at 110 ° C for 4 hours. After the dehydration ring closure reaction, a solvent containing 15% by mass of a polyamidimide (A-13) having a ruthenium iodide ratio of about 67% was obtained by subjecting the solvent in the system to a solvent replacement with a new NMP. A small amount of the obtained polyimine solution was added and NMP was added to prepare a solution having a polyamidene concentration of 10% by mass, and the measured solution viscosity was 70 mPa. s.

<Preparation of liquid crystal alignment agent>

The [B] antioxidant used in the preparation of each liquid crystal alignment agent is as follows.

<[B]Antioxidants>

B-1: IRGANOX1010FF (phenolic antioxidant)

B-2: ADK STAB LA-72 (Amine Antioxidant)

B-3: TINUVIN622LD (Amine Antioxidant)

B-4: IRGAFOS12 (phosphorus antioxidant)

B-5: IRGANOX PS 800FL (sulfur antioxidant)

B-6: ADK STAB AO-40 (phenolic antioxidant)

[Example 1]

NMP and ethylene glycol-mono-n-butyl ether are added to a solution containing 100 parts by mass of the polyimine (A-1) as the [A] polymer, and 3 parts by mass of the above-mentioned (B) antioxidant is added ( B-1) and fully stirred, and the solvent composition is NMP: ethylene glycol-mono-n-butyl ether = 60:40 (mass ratio), solid A solution having a body component concentration of 3.0% by mass. This solution was filtered using a filter having a pore size of 1 μm to prepare a liquid crystal alignment agent.

[Examples 2 to 23 and Comparative Examples 1 to 9]

The liquid crystal alignment agent was prepared in the same manner as in Example 1 except that the type and content of the components to be formulated were the same as those described in Table 1. In addition, "-" in Table 1 indicates that the component is not used.

<Formation of liquid crystal alignment film>

On the transparent electrode surface of the glass substrate with the transparent electrode including the ITO film having a thickness of 1 mm, each liquid crystal alignment agent was applied by a spin coater, and prebaked on a hot plate at 80 ° C for 1 minute, followed by Post-baking was carried out at 210 ° C for 30 minutes to form a liquid crystal alignment film having a film thickness of about 80 nm.

<Manufacture of liquid crystal display element>

The formation of the above liquid crystal alignment film was repeated to obtain a pair of (two pieces) substrates having a liquid crystal alignment film. Next, an epoxy resin adhesive having an alumina ball having a diameter of 5.5 μm is applied onto the outer edge of a block of the liquid crystal alignment film having the pair of substrates, and then the liquid crystal alignment film surface is pressed against the film, and the adhesive is hardened. . Next, a nematic liquid crystal (manufactured by Merck, MLC-6608) was filled between the pair of substrates by a liquid crystal injection port, and then the liquid crystal injection port was sealed with an acrylic photocurable adhesive to produce a liquid crystal cell. In addition, this operation is repeated to fabricate another pair of liquid crystal cells.

<evaluation>

The following evaluation was performed on the liquid crystal alignment film formed above and the produced liquid crystal display element. The results are shown together in Table 1.

[light resistance]

After a pair of liquid crystal cells manufactured above were applied with a voltage of 5 V at an application time of 60 μsec and an interval of 167 msec at 70 ° C, the voltage retention rate after 167 msec from the release of application was measured by VHR-1 manufactured by TOYO Corporation. . This value is taken as the initial voltage holding ratio (VH ₁ ) (%). Next, the liquid crystal cells after the initial voltage holding ratio were measured and irradiated with light for 1,000 hours using a weather resistant test chamber using a carbon arc as a light source. The liquid crystal cell after the light irradiation was again measured for the voltage holding ratio by the same method as described above. This value is taken as the voltage holding ratio (VH ₂ ) (%) after light irradiation. The amount of decrease in voltage holding ratio ΔVHR (%) is obtained by the following formula as light resistance.

△VHR(%)=VH ₁ -VH ₂

When ΔVHR is less than 2.5%, it is judged that the light resistance is excellent, and when it is 2.5% or more and less than 5.0%, it is judged that the light resistance is good, and when it is 5.0% or more, it is judged that the light resistance is not good.

[High temperature and high humidity resistance]

After the other pair of liquid crystal cells produced above were applied with a voltage of 5 V at an application time of 60 μsec and an interval of 167 msec at 70 ° C, the voltage retention after 167 msec from the start of the application was measured by VHR-1 manufactured by TOYO Corporation. rate. This value is used as the initial voltage holding ratio (VH ₃ ) (%). Next, the liquid crystal cell after the initial voltage holding ratio was measured and stored in an oven set to 60° C. and a humidity of 90% for 500 hours, and then the voltage holding ratio was measured again by the same method as described above. This value is taken as a voltage holding ratio (VH ₄ ) (%) after high temperature and high humidity resistance. The amount of decrease in voltage holding ratio ΔVHR' (%) is obtained by the following equation as high temperature and high humidity resistance.

△VHR'(%)=VH ₃ -VH ₄

When ΔVHR is less than 3.0%, it is judged that it is excellent in high temperature and high humidity resistance, and When it is 3.0% or more and less than 5.0%, it is judged that the high temperature and high humidity resistance are good, and when it is 5.0% or more, it is judged that the high temperature and high humidity resistance are unacceptable.

As is apparent from the results of Table 1, the liquid crystal alignment agent of the present invention can form a liquid crystal alignment film which maintains good electrical characteristics even when it is continuously driven for a long period of time under the harsh environment of light stress, heat and moisture.

[Industrial availability]

According to the liquid crystal alignment agent of the present invention, it is possible to form a liquid crystal alignment film which can maintain good electrical characteristics even when it is continuously driven for a long period of time under a severe environment such as light stress, heat or moisture. Therefore, the liquid crystal display element of the present invention including the liquid crystal alignment film has a small reduction in display quality, and can be effectively applied to various devices, such as a timepiece, a handheld game machine, a word processor, a notebook computer, a car navigation system, Display devices such as cameras, portable information terminals, digital cameras, mobile phones, various displays, and LCD TVs.

Claims (4)

A liquid crystal alignment agent comprising [A] at least one polymer selected from the group consisting of polylysine and a polyamidene obtained by dehydration of the polyglycolic acid, and [B] an antioxidant. The polymer [A] is a polymer obtained by reacting a tetracarboxylic dianhydride with a diamine, and contains, as a tetracarboxylic dianhydride, a 1,3,3a,4,5,9b-hexahydro-8-methyl group. 5-(4-hydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5, 9b-hexahydro-5-(tetrahydro-2,5-di-oxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione and 2,4,6,8 At least one selected from the group consisting of tetracarboxybicyclo[3.3.0]octane-2,4,6,8-dianhydride, or as a diamine containing at least 1-(4-aminophenyl)-2 ,3-dihydro-1,3,3-trimethyl-1H-indole-5-amine and 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl At least one selected from the group of ketone-1H-indole-6-amines. The liquid crystal alignment agent of claim 1, wherein the [B] antioxidant has a group represented by the following formula (1) or formula (2): In the formula (1), R ¹ is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, or a 1,3-di-butyloxybutyl group or a 1,4-di- oxybutyl group, and the group represented by the formula (1) may also be an alkyl group, an aryl group, an aralkyl group, a 1,3-di- oxybutyl group and 1,4 represented by R ¹ . - removing one hydrogen atom from the two sides of the oxybutyl group to form a divalent group to form a part of the molecular chain; and R ² to R ⁵ are each independently an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 12 carbon atoms; Or an aralkyl group having a carbon number of 7 to 13; X ¹ is a single bond, a carbonyl group, ^* -(CH ₂ ) _n -O-, ^* -O-, or ^* -CONH-, wherein the linkage represented by ^* is a site bonded to a piperidine ring; further, n is an integer of 1 to 4; and X ² to X ⁵ are each independently a single bond, a carbonyl group, ^** -CH ₂ -CO- or ^** -CH ₂ -CH ( OH)-, wherein the linkage represented by ^** is a moiety representing a bond to the piperidine ring; In the formula (2), R ⁶ is a hydrocarbon group having 4 to 16 carbon atoms, wherein the above hydrocarbon group may have an oxygen atom or a sulfur atom in the carbon skeleton chain; a is an integer of 0 to 3; and R ⁷ is a hydrogen atom or a carbon number. hydrocarbon group of 1 to 16, wherein when a plurality of R ^7, a plurality of R ⁷ may be the same or different. A liquid crystal alignment film formed of a liquid crystal alignment agent according to claim 1 or 2. A liquid crystal display element comprising the liquid crystal alignment film of claim 3 of the patent application.