JPH10333153A - Liquid crystal orienting agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal orienting agent which gives a liquid crystal orienting film having good liquid crystal orienting property, which hardly produces scratches by rubbing treatment on the surface of the film, and which has excellent durability against cleaning with isopropylalcohol after the rubbing treatment. SOLUTION: This orienting agent contains at least one kind of polymer selected from polymers having a polyamic acid structure and polymers having an imide structure produced by dehydration and ring-closing reaction of the polyamic acid, and an epoxy compd. containing nitrogen atoms. In this method, the average imidization rate of the polymers included in the orienting agent is >=45%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal aligning agent used for forming a liquid crystal alignment film of a liquid crystal display device. More specifically, the liquid crystal alignment is good, and the surface of the liquid crystal alignment film is damaged by a rubbing treatment (hereinafter, referred to as “rubbing”).
The present invention relates to a liquid crystal alignment agent which provides a liquid crystal alignment film which is less likely to cause "rubbing scratches" and has excellent resistance to isopropyl alcohol washing performed after the rubbing treatment.

[0002]

2. Description of the Related Art Conventionally, a sandwich structure is formed by forming a layer of a nematic liquid crystal having a positive dielectric anisotropy between two substrates having a liquid crystal alignment film formed on the surface thereof through a transparent conductive film. A TN type liquid crystal display device having a TN (Twisted Nematic) type liquid crystal cell in which the major axis of the liquid crystal molecules is continuously twisted by 90 degrees from one substrate to the other substrate is known. I have. Orientation of liquid crystal in a liquid crystal display element such as a TN type liquid crystal display element is usually realized by a liquid crystal alignment film provided with an alignment ability of liquid crystal molecules by a rubbing process. Here, as a material of a liquid crystal alignment film constituting a liquid crystal display element, resins such as polyimide, polyamide, and polyester are conventionally known. In particular, polyimide is used in many liquid crystal display devices because of its excellent heat resistance, affinity with liquid crystal, mechanical strength, and the like.

[0003]

However, a liquid crystal display device and the like were manufactured using a conventionally known liquid crystal aligning agent containing a polyamic acid or an imidized polymer having a structure obtained by dehydration and ring closure of the same. In this case, there is a problem that rubbing flaws are easily generated on the surface of the liquid crystal alignment film to be formed, and a display defect due to this is generated. After the rubbing treatment of the liquid crystal alignment film, a cleaning treatment such as immersion in isopropyl alcohol for about 1 minute is performed.
This cleaning has a problem that the liquid crystal alignment of the alignment film is reduced.

[0004] The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a liquid crystal molecule having an excellent alignment property by rubbing treatment. An object of the present invention is to provide a liquid crystal aligning agent capable of providing a liquid crystal display device having a liquid crystal alignment film having the following.
A second object of the present invention is to provide a liquid crystal aligning agent that provides a liquid crystal alignment film that hardly causes rubbing scratches on the surface of the liquid crystal alignment film. A third object of the present invention is to provide a liquid crystal aligning agent having excellent resistance to isopropyl alcohol washing performed after a rubbing treatment.

[0005]

The objects and advantages of the present invention are as follows: (A) (a) a polymer having a polyamic acid structure; and (b) a polymer having an imide structure obtained by dehydrating and ring-closing the polyamic acid. A liquid crystal aligning agent comprising one or more polymers selected from the group consisting of a coalesced compound and (B) a nitrogen atom-containing epoxy compound, wherein the average of the polymers contained in the liquid crystal aligning agent is 45% imidation rate
This is achieved by a liquid crystal alignment agent characterized by the above.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The polymer used for the liquid crystal alignment agent of the present invention,
The polyamic acid can be synthesized by reacting a tetracarboxylic dianhydride with a diamine compound in an organic solvent to synthesize a polyamic acid, and if necessary, dehydrating and ring-closing the polyamic acid.

[Tetracarboxylic dianhydride] Examples of the tetracarboxylic dianhydride used in the synthesis of the polyamic acid include butanetetracarboxylic dianhydride and
1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3, 4
-Cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-
Cyclobutanetetracarboxylic dianhydride, 1,2,3,4
-Cyclopentanetetracarboxylic dianhydride, 1,2,
4,5-cyclohexanetetracarboxylic dianhydride, 3,
3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-
Acetic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic 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-5-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 4,5,9b-hexahydro-7-methyl-
5 (tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] -furan-1,3-dione, 1,
3,3a, 4,5,9b-Hexahydro-7-ethyl-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-dione, 1,3, 3
a, 4,5,9b-Hexahydro-8-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3, 3a,
4,5,9b-Hexahydro-5,8-dimethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2 ,
5-dioxotetrahydrofural) -3-methyl-3-
Cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-
Tetracarboxylic dianhydride, the following formulas (I) and (II)
Aliphatic and alicyclic tetracarboxylic dianhydrides such as the compounds represented by

[0008]

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(Wherein, R ¹ and R ³ represent a divalent organic group having an aromatic ring, R ² and R ⁴ represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ⁴ are
Each may be the same or different. )

[0010] Pyromellitic dianhydride, 3,3 ', 4,
4'-benzophenonetetracarboxylic dianhydride, 3,
3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3 , 3 ', 4,4'-biphenylethertetracarboxylic dianhydride, 3,3', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,
4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride,
4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfone dianhydride,
4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′,
4,4′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride,
p-phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis ( (Triphenylphthalic acid) -4,4'-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anne Hydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-
Bis (anhydrotrimellitate), 2,2-bis (4
-Hydroxyphenyl) propane-bis (anhydrotrimellitate) and aromatic tetracarboxylic dianhydrides such as compounds represented by the following formulas (1) to (4). These are used alone or in combination of two or more.

[0011]

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Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl -3-cyclohexene-1,2-dicarboxylic 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) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5- (tetrahydro-2, 5-
Dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2,2,2] -oct-
7-ene-2,3,5,6-tetracarboxylic dianhydride,
Pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-
Biphenylsulfonetetracarboxylic dianhydride, 1,4,
5,8-Naphthalenetetracarboxylic dianhydride, a compound represented by the following formulas (5) to (7) and a compound represented by the above formula (II) among the compounds represented by the above formula (I) Among them, a compound represented by the following formula (8) is preferable from the viewpoint that good liquid crystal alignment can be exhibited, and particularly preferable compounds are 1,2,3,4-cyclobutanetetracarboxylic dianhydride, , 3-Dimethyl-1,2,3,4-
Cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3
a, 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-dione, pyromellitic dianhydride and compounds represented by the following formula (5) can be mentioned.

[0013]

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[Diamine Compound] As the diamine compound used for the synthesis of the above polyamic acid, for example, p-
Phenylenediamine, m-phenylenediamine, 4,
4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,
3'-dimethyl-4,4'-diaminobiphenyl, 4,
4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3
-Dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1, 3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-
Diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-amino Phenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4-bis (4
-Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, , 7-Diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4 '-Diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4'-
(P-phenyleneisopropylidene) bisaniline,
4,4 '-(m-phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-diamino-2, Aromatic diamines such as 2'-bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl;

1,1-methaxylylenediamine, 1,3-
Propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine,
1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine,
Aliphatic and cycloaliphatic diamines such as hexahydro-4,7-methanoindanylene dimethylene diamine, tricyclo [6.2.1.0 2,7] -undecylene dimethyl diamine, 4,4'-methylene bis (cyclohexylamine);

2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino- 2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5
-Triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,
3,5-triazine, 2,4-diamino-6-methoxy-
1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3, 5-
Triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole,
2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8- Diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine and compounds represented by the following formulas (III) and (IV), A diamine having two primary amino groups and a nitrogen atom other than the primary amino groups in the molecule;

[0017]

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Wherein R ⁵ is pyridine, pyrimidine,
X represents a monovalent organic group having a ring structure containing a nitrogen atom selected from triazine, piperidine and piperazine;
Represents a divalent organic group. )

[0019]

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Wherein R ⁶ is pyridine, pyrimidine,
A divalent organic group having a ring structure containing a nitrogen atom selected from triazine, piperidine and piperazine;
Represents a divalent organic group, and a plurality of Xs may be the same or different. )

A monosubstituted phenylenediamine represented by the following formula (V); a diaminoorganosiloxane represented by the following formula (VI):

[0022]

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(Wherein R ⁷ represents —O—, —COO—, —
OCO-, -NHCO-, -CONH- and -CO-
R ⁸ represents a monovalent organic group having a group selected from a steroid skeleton, a trifluoromethyl group and a fluoro group, or an alkyl group having 6 to 30 carbon atoms. )

[0024]

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(Wherein R ⁹ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ^{9 s} may be the same or different, p is an integer of 1 to 3, and q is 1-2
It is an integer of 0. )

Examples include compounds represented by the following formulas (9) to (13). These diamine compounds can be used alone or in combination of two or more.

[0027]

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(In the formula, y is an integer of 2 to 12, and z is an integer of 1 to 5.)

Of these, p-phenylenediamine,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenylether, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4
-Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4'-(m-phenylenediene Isopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4′-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, Compounds represented by the above formulas (9) to (13),
2,6-diaminopyridine, 3,4-diaminopyridine,
2,4-diaminopyrimidine, 3,6-diaminoacridine, a compound represented by the following formula (14) among the compounds represented by the above formula (III), and a compound represented by the following formula (IV) among the compounds represented by the above formula (IV) Among the compounds represented by the formula (15) and the compounds represented by the above formula (V), the following formulas (16) to (2)
The compound represented by 1) is preferred.

[0030]

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[Polyamic acid] The ratio of the tetracarboxylic dianhydride and the diamine compound used in the synthesis reaction of the polyamic acid is such that the ratio of the tetracarboxylic dianhydride to the equivalent of the amino group contained in the diamine compound is 1 equivalent. The ratio is preferably such that the acid anhydride group is 0.2 to 2 equivalents, more preferably 0.3 to 1.2 equivalents. The synthesis reaction of the polyamic acid is performed in an organic solvent at a reaction temperature of usually 0 to 150 ° C, preferably 0 to 100 ° C for 1 to 48 hours. The organic solvent is not particularly limited as long as it can dissolve the reactant generated in the reaction. Aprotic polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; Phenolic solvents such as cresol, xylenol, phenol and halogenated phenol can be mentioned. Usually, the amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight based on the total amount of the reaction solution.

The above organic solvents include alcohols, ketones, esters, and the like, which are poor solvents for polyamic acid.
Ethers, halogenated hydrocarbons, hydrocarbons and the like can be used in combination as long as the generated polyamic acid does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol,
Triethylene glycol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol monophenyl ether, ethylene glycol methyl phenyl Ether, ethylene glycol ethyl phenyl ether, 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, ethylene glycol methyl ether acetate, ethylene glycol Lumpur ethyl ether acetate, 4
-Hydroxy-4-methyl-2-pentanone, 2,4-
Pentanedione, 2,5-hexanedione, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxyacetate Methyl-3-methylbutanoate,
Methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3-
Methyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, hydroxymethyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methylmethoxybutanol, ethylmethoxybutanol, methylethoxybutanol, ethylethoxybutanol, tetrahydrofuran, tetrahydrofurfuryl alcohol, tetrahydro -3-furanmethanol, 1,3-dioxolan, 1,3
-Dioxepane, 4-methyl-1,3-dioxolan,
Dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-
Examples thereof include dichlorobenzene, hexane, heptane, octane, benzene, toluene, and xylene. These may be used alone or in combination of two or more.

By the above synthesis reaction, a reaction solution obtained by dissolving the polyamic acid is obtained. Then, the reaction solution is poured into a large amount of a poor solvent to obtain a precipitate, and the precipitate is dried under reduced pressure to obtain a polyamic acid. Further, the polyamic acid can be purified by dissolving the polyamic acid in an organic solvent again and then performing the step of precipitating with a poor solvent once or several times.

[Imidated Polymer] The imidized polymer constituting the liquid crystal aligning agent of the present invention can be prepared by dehydrating and ring-closing the above polyamic acid. The dehydration and ring closure of the polyamic acid can be performed by (i) heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, and heating as necessary. Done by the method. (I) above
The reaction temperature in the method of heating the polyamic acid of
Usually 50 to 200 ° C, preferably 60 to 170 ° C
It is said. When the reaction temperature is lower than 50 ° C., the dehydration ring-closing reaction does not sufficiently proceed, and when the reaction temperature exceeds 200 ° C., the molecular weight of the obtained imidized polymer may decrease. on the other hand,
In the method (ii) of adding a dehydrating agent and a dehydration ring-closing catalyst to the polyamic acid solution, the dehydrating agent may be
For example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 0.01 to 20 mol per 1 mol of the repeating unit of the polyamic acid. As the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the dehydration ring closure reaction, the organic solvents exemplified as those used for the synthesis of polyamic acid can be exemplified. And the reaction temperature of the dehydration ring closure reaction is
Usually, it is 0 to 180 ° C, preferably 10 to 150 ° C. The imidized polymer can be purified by subjecting the reaction solution thus obtained to the same operation as the method for purifying a polyamic acid.

[Terminal-Modified Polymer] The polymer constituting the liquid crystal aligning agent used in the present invention may be a terminal-modified polymer having a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified type can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound, or the like to the reaction system when synthesizing the polyamic acid. Here, as the acid monoanhydride,
For example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decyl succinic anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl succinic anhydride And the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine,
n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n
-Dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine and the like. . In addition, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

[Logarithmic Viscosity of Polymer] The polymer constituting the liquid crystal aligning agent used in the present invention has a logarithmic viscosity (ηln) value of preferably 0.05 to 10 dl / g, more preferably 0.05. ~ 5 dl / g. Here, the value of the logarithmic viscosity (ηln) is obtained by measuring the viscosity at 30 ° C. of a solution having a polymer concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent, It is obtained by the equation shown in (1).

[0037]

(Equation 1)

[Epoxy Compound Containing Nitrogen Atom] As the epoxy compound containing a nitrogen atom used in the present invention, for example, N, N-diglycidylaniline, N, N-
Nitrogen-containing epoxy compounds having an aromatic monoamine as a nucleus such as diglycidyl toluidine; an alicyclic monoamine such as N, N-diglycidylcyclohexylamine and N, N-diglycidylmethylcyclohexylamine as a nucleus An epoxy compound containing a nitrogen atom;
N, N ', N'-tetraglycidyl-p-phenylenediamine, N, N, N', N'-tetraglycidyl-m-
Phenylenediamine, N, N, N ', N'-tetraglycidyl-o-phenylenediamine, N, N, N', N '
-Tetraglycidyl-4,4'-diaminodiphenylmethane, N, N, N ', N'-tetraglycidyl-3,
4'-diaminodiphenylmethane, N, N, N ', N'
-Tetraglycidyl-3,3'-diaminodiphenylmethane, N, N, N ', N'-tetraglycidyl-4,
4'-diaminodiphenyl sulfide, N, N, N ',
N'-tetraglycidyl-1,5-diaminonaphthalene, N, N, N ', N'-tetraglycidyl-2,7-
Diaminofluorene, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenyl ether, N,
N, N ', N'-tetraglycidyl-2,2-bis [4
-(4-aminophenoxy) phenyl] propane, N,
N, N ', N'-tetraglycidyl-9,9-bis (4
-Aminophenyl) fluorene, N, N, N ', N'
-Tetraglycidyl-2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, N,
N, N ', N'-tetraglycidyl-2,2-bis (4
-Aminophenyl) hexafluoropropane, N, N,
N ′, N′-tetraglycidyl-4,4 ′-(p-phenylenediisopropylidene) bisaniline, N, N,
N ′, N′-tetraglycidyl-4,4 ′-(m-phenylenediisopropylidene) bisaniline, N, N,
N ', N'-tetraglycidyl-1,4-bis (4-aminophenoxy) benzene, N, N, N', N'-tetraglycidyl-4,4'-bis (4-aminophenoxy) biphenyl and the like An epoxy compound containing a nitrogen atom containing an aromatic diamine as a mother nucleus; N, N, N ', N'-
Tetraglycidyl-m-xylylenediamine, N, N,
N ', N'-tetraglycidyl-p-xylylenediamine, 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane, 1,4-bis (N, N'-diglycidylaminomethyl) cyclohexane , N, N, N ',
N'-tetraglycidyl-1,4-cyclohexanediamine, N, N, N ', N'-tetraglycidyl-1,3
An epoxy compound containing a nitrogen atom having an alicyclic diamine as a mother nucleus such as -cyclohexanediamine, N, N, N ', N'-tetraglycidyl-4,4'-methylenebis (cyclohexylamine); N, N, N ', N'-tetraglycidyl-diaminoethane, N, N, N', N'-
Tetraglycidyl-diaminopropane, N, N, N ',
N'-tetraglycidyl-diaminobutane, N, N,
N ′, N′-tetraglycidyl-diaminopentane,
N, N, N ', N'-tetraglycidyl-diaminohexane, N, N, N', N'-tetraglycidyl-diaminoheptane, N, N, N ', N'-tetraglycidyl-
Examples thereof include an epoxy compound containing a nitrogen atom having an aliphatic diamine such as diaminooctane as a mother nucleus. Among these, epoxy compounds containing a nitrogen atom having an aromatic monoamine as a nucleus, epoxy compounds containing a nitrogen atom having an aromatic diamine as a nucleus, and nitrogen atoms having an alicyclic diamine as a nucleus Epoxy compounds are preferred, N, N-diglycidylaniline,
N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane and 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane are particularly preferred.

[Liquid crystal aligning agent] The liquid crystal aligning agent of the present invention is a liquid crystal aligning agent containing the above polymer and an epoxy compound containing a nitrogen atom. It is at least 45%, preferably 50 to 98%, particularly preferably 60 to 98%. 45% average imidization rate
If it is less than 3, when the substrate is washed with isopropyl alcohol, the alignment ability obtained by the rubbing treatment is reduced, and the liquid crystal alignment may be deteriorated. In this specification, the definition of “imidation ratio” is defined as a percentage of the number of repeating units forming an imide ring or an isoimide ring with respect to the total number of repeating units in a polymer,
The “average imidation ratio” is a percentage of the number of repeating units forming an imide ring or an isoimide ring with respect to the total number of repeating units in all the polymers in the liquid crystal aligning agent. As a method for adjusting the average imidation ratio,
1) A method of adjusting the average imidation ratio by adjusting the reaction temperature, the amount of catalyst added, and the like when performing the dehydration and ring-closing reaction of the polyamic acid. 2) Mixing the polyamic acid and the imidized polymer to obtain an average imide. And the method of adjusting the average imidation rate by mixing imidized polymers having different imidation rates, and 3) achieving the effects of the present invention by any method. can do.

The content ratio of the polymer in the liquid crystal aligning agent used in the present invention is selected in consideration of viscosity, volatility and the like.
0% by weight, more preferably 1 to 10% by weight. That is, the liquid crystal alignment agent composed of a polymer solution is applied to the substrate surface by a printing method, a spin coating method, or the like,
Then, by drying this, a film as an alignment film material is formed, and the content ratio of the polymer is 0.1.
When the amount is less than 20% by weight, a good liquid crystal alignment film may not be obtained because the thickness of the film is too small. When the amount exceeds 20% by weight, the film thickness becomes too large. In some cases, it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent is increased, which may result in poor coating characteristics.
The organic solvent for dissolving the polymer is not particularly limited as long as it can dissolve the polymer, and examples thereof include the solvents exemplified as those used in the synthesis reaction of polyamic acid and the dehydration ring closure reaction. . Also,
Poor solvents exemplified as those that can be used together in the synthesis reaction of the polyamic acid can be appropriately selected and used in combination. The content of the nitrogen-containing epoxy compound is 0.01 to 50 parts by weight, preferably 0.1 to 40 parts by weight, per 100 parts by weight of the polymer in the liquid crystal aligning agent.
Parts by weight, particularly preferably 1 to 30 parts by weight. If the content of the epoxy compound is less than 0.01 part by weight, the effect of improving the afterimage characteristics may not be easily exhibited, and if it exceeds 50 parts by weight, the storage stability of the liquid crystal aligning agent may be deteriorated.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound from the viewpoint of improving the adhesiveness between the polymer and the surface of the substrate to be coated. Such functional silane-containing compounds include, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane,
2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyl Triethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-
Triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N -Phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like. The compounding ratio of these functional silane-containing compounds is usually 20 parts by weight or less, preferably 0.01 to 10 parts by weight, based on 100 parts by weight of the polymer.

[Liquid crystal display device] A liquid crystal display device obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method. (1) The liquid crystal aligning agent of the present invention is applied to the transparent conductive film side of the substrate on which the patterned transparent conductive film is provided, for example, by a method such as a roll coater method, a spinner method, or a printing method. A film is formed by heating. Here, as the substrate, for example, float glass,
A transparent substrate made of glass such as soda glass, a plastic film of polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, polycarbonate, or the like can be used. As the transparent conductive film provided on one surface of the substrate, NE made of SnO ₂ is used.
An SA film, an ITO film made of In ₂ O ₃ —SnO ₂ , or the like can be used. A photo-etching method, a method using a mask in advance, or the like is used for patterning these transparent conductive films. When applying the liquid crystal alignment agent, a functional silane-containing compound, titanate, or the like may be applied on the substrate and the transparent conductive film in advance to further improve the adhesion between the substrate and the transparent conductive film. it can. The heating temperature is preferably from 80 to 250 ° C, and more preferably from 120 to 200 ° C. The thickness of the film to be formed is usually 0.001 to 1 μm, preferably 0.00.
5 to 0.5 μm.

(2) The formed film is subjected to a rubbing treatment of rubbing in a certain direction with a roll wrapped with a cloth made of a synthetic fiber such as nylon, so that the film is provided with the ability to align liquid crystal molecules. Becomes In addition to the method using a rubbing treatment, a method of irradiating polarized ultraviolet light to the coating surface to impart orientation ability, a uniaxial stretching method, a Langmuir method,
The liquid crystal alignment film can also be formed by a method of obtaining a film by a blow jet method or the like. Note that the formed liquid crystal alignment film is preferably washed with isopropyl alcohol or the like in order to remove fine powder (foreign matter) generated during the rubbing treatment and keep the surface clean. Also,
For example, JP-A-6-222366 and JP-A-6-281 disclose a liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention.
No. 937, a process in which the pretilt angle is changed by partially irradiating ultraviolet rays, or a rubbed liquid crystal, as described in JP-A-5-107544. After partially forming a resist film on the alignment film, performing a rubbing process in a direction different from the preceding rubbing process, removing the resist film, and performing a process of changing the alignment ability of the liquid crystal alignment film. By doing so, it is possible to improve the visibility characteristics of the liquid crystal display element.

(3) Two substrates on which the liquid crystal alignment films are formed as described above are prepared, and the two substrates are separated by a gap so that the rubbing directions of the respective liquid crystal alignment films are orthogonal or antiparallel. (A cell gap), the peripheral portions of the two substrates are bonded together with a sealant, liquid crystal is filled into the surface of the substrate and the cell gap defined by the sealant, and the filling hole is sealed. To form a liquid crystal cell.
Then, a polarizing plate is provided on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell, and the polarization direction thereof coincides with or is orthogonal to the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. Thus, a liquid crystal display element is obtained. As the sealant,
For example, an epoxy resin containing a hardening agent and aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal. Among them, nematic liquid crystals are preferable. For example, Schiff base liquid crystal, azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane Liquid crystal, cubane liquid crystal, and the like are used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, and chiral agents sold under the trade names “C-15” and “CB-15” (manufactured by Merck & Co.) It can also be used by adding it. In addition, ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can be used. Also,
As a polarizing plate used outside the liquid crystal cell, a polarizing plate formed by sandwiching a polarizing film called an H film absorbing iodine with a cellulose acetate protective film or a H film itself while stretching and aligning polyvinyl alcohol is used. And the like.

[0045]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The evaluation method for each liquid crystal display device manufactured by the following Examples and Comparative Examples is described below. [Imidation rate of polymer / average imidation rate of liquid crystal aligning agent]
The polymer or the liquid crystal aligning agent was dried under reduced pressure at room temperature, dissolved in deuterated dimethylsulfoxide, and 1 H-NMR was measured at room temperature using tetramethylsilane as a reference substance, which was determined by the following formula (2). . The imidation ratio of the polyamic acid which was not subjected to the dehydration ring closure reaction was set to 0%.

[0046]

[Number 2] imidization ratio (%) = (1-A 1 / A 2 × α) × 100 ··· (2) A 1: peak area derived from proton of NH group (10pp
m) A ² : peak area derived from other protons α: N in a polymer precursor (polyamic acid)
Number ratio of other protons to one proton of H group

[Orientation of Liquid Crystal] The presence or absence of abnormal domains in the liquid crystal cell when the voltage was turned on / off in the liquid crystal display element was observed with a microscope, and the case where there was no abnormal domain was judged as “good”. [Presence of Rubbing Scratch on Liquid Crystal Alignment Film (Toughness of Film)] IT
Stripe electrode made of O film (interval: 0.7 mm, IT
O film thickness: 2700 °), a liquid crystal aligning agent is applied to the electrode surface of the transparent electrode substrate, and the coating film is dried to a dry film thickness of 0.
A liquid crystal alignment film obtained by forming a film having a thickness of 05 μm and subjecting the surface of the film to a rubbing treatment (processing conditions: push-in length of hair: 0.4 mm, roll rotation speed: 500 rpm, stage moving speed: 1 cm / sec). For, the presence or absence of rubbing scratches such as abrasion of the film surface due to the rubbing treatment was observed. [Isolation resistance to isopropyl alcohol] After rubbing under the above conditions, the substrate was immersed in boiled isopropyl alcohol at room temperature for 10 minutes, and then dried on a hot plate at 100 ° C for 5 minutes. The presence or absence of an abnormal domain in the liquid crystal cell when the voltage was turned on / off in the liquid crystal display element formed using the substrate was observed with a polarizing microscope, and the case where there was no abnormal domain was judged as “good”.

Synthesis Example 1 224.17 g (1.00 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 97.33 g (0.90 mol) of p-phenylenediamine and formula (20)
42.24 g (0.10 mol) of N-methyl-
Dissolve in 1300 g of 2-pyrrolidone and add this solution to 40
The reaction was carried out at 6 ° C. for 6 hours. Next, the obtained reaction solution was poured into a large excess of pure water to precipitate a reaction product. afterwards,
The solid was separated, washed with pure water, and dried under reduced pressure at 40 ° C. for 15 hours to give a logarithmic viscosity (ηln) of 1.35.
dl / g, polymer (A-1) 334 having an imidation ratio of 0%.
9 g were obtained. Synthesis Example 2 30.0 g of the polymer (A-1) obtained in Synthesis Example 1 was γ-
Dissolved in 570 g of butyrolactone, 33.3 pyridine
g and 25.8 g of acetic anhydride were added thereto, followed by dehydration ring closure at 110 ° C. for 4 hours. Then, in the same manner as in Synthesis Example 1, by precipitating, separating, washing and drying the reaction product,
Logarithmic viscosity (ηln) 1.36 dl / g, imidization ratio 90
% Of polymer (A-2) was obtained.

Synthesis Example 3 As the tetracarboxylic dianhydride used in Synthesis Example 1, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl ) -Naphtho [1,2-c] furan-1,3-dione 31
In the same manner as in Synthesis Example 1 except that 4.30 g (1.00 mol) was used, 416.76 g of a polymer (A-3) having an logarithmic viscosity (ηln) of 1.32 / g and an imidation ratio of 0% was obtained. Obtained. After that, the polymer (A-3) 3 was used instead of the polymer (A-1).
Logarithmic viscosity (ηln) in the same manner as in Synthesis Example 2 except that 0.0 g was used and the reaction temperature in the dehydration ring closure was 80 ° C.
1.28 dl / g, a polymer having an imidation ratio of 100% (A-
4) 28.5 g was obtained. Synthesis Example 4 Logarithmic viscosity (ηln) 1.7 was obtained in the same manner as in Synthesis Example 1 except that 108.16 g (1.00 mol) of p-phenylenediamine was used as the diamine compound.
Polymer (A-5) 305.7 with 8 / g and 0% imidation ratio
g was obtained. Synthesis Example 5 In Synthesis Example 4, 218.12 g (1.00 mol) of pyromellitic dianhydride was used as the tetracarboxylic dianhydride.
As a diamine compound, p-phenylenediamine 108.
299.9 g of a polymer (A-6) having an intrinsic viscosity (ηln) of 2.01 / g and an imidation ratio of 0% was obtained in the same manner as in Synthesis Example 1 except that 16 g (1.00 mol) was used. .

Example 1 1.5 g of the polymer (A-2) obtained in Synthesis Example 2, 0.5 g of the polymer (A-1) obtained in Synthesis Example 1, and N, N as epoxy compounds , N ', N'-Tetraglycidyl-
0.5 g of 4,4′-diaminodiphenylmethane was dissolved in γ-butyrolactone to obtain a solution having a solid concentration of 4% by weight, and this solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent. The average imidation ratio of this liquid crystal aligning agent was 67.5%. The above-mentioned liquid crystal aligning agent was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal aligning film coating printing machine, and dried on a hot plate at 180 ° C. for 20 minutes to obtain a dry film thickness of 0. A film of 05 μm was formed. A rubbing machine having a roll in which a rayon cloth was wound around the coating film was subjected to a rubbing treatment at a roll rotation speed of 500 rpm, a stage moving speed of 1 cm / sec, and a push-in length of 0.4 mm. When the coating surface was observed, no rubbing damage was observed.
After immersing the alignment film coated substrate in boiling isopropyl alcohol for 1 minute, both substrates were dried on a hot plate at 100 ° C. for 5 minutes. Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 17 μm is screen-printed and applied to each outer edge of the pair of rubbed liquid crystal sandwiching substrates having a liquid crystal alignment film, and then the pair of liquid crystal sandwiching substrates is attached to the liquid crystal alignment film. Overlap and crimp so that the faces are opposed, and the rubbing direction is antiparallel,
The adhesive was cured. Next, a nematic liquid crystal (MLC-5, manufactured by Merck & Co., Ltd.) is placed between the pair of substrates from the liquid crystal injection port.
081), the liquid crystal injection port is sealed with an epoxy-based adhesive, and a polarizing plate is provided on both outer surfaces of the substrate so that the polarizing direction of the polarizing plate matches the rubbing direction of the liquid crystal alignment film of each substrate. To produce a liquid crystal display device. When the orientation of the liquid crystal of the obtained liquid crystal display device was evaluated, the orientation of the liquid crystal was good. Also, after the rubbing treatment, a liquid crystal display element was prepared in the same manner as above except that the liquid crystal display element was immersed in isopropyl alcohol for 10 minutes, and the orientation of the liquid crystal was evaluated. Was good. Table 1 shows the results.

Examples 2 to 7 and Comparative Examples 1 to 3 According to the formulations shown in Tables 1 and 2, the polymer (component (A)) obtained in Synthesis Examples 1 to 5 and the nitrogen-containing epoxy compound [ (B) component], and a liquid crystal aligning agent was prepared in the same manner as in Example 1. Next, a liquid crystal display device was produced in the same manner as in Example 1 using each of the liquid crystal aligning agents thus obtained. For each of the obtained liquid crystal aligning agents, the presence or absence of rubbing scratches on the liquid crystal aligning film, the alignment of the liquid crystal, and the isopropyl alcohol washing resistance were evaluated. The results are shown in Tables 1 and 2.

[0052]

[Table 1]

[0053]

[Table 2]

The compound names of the epoxy compounds in Tables 1 and 2 are as follows. B-1: N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane B-2: 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane b-3: tri Methylol Fluorescent Liquid Ether

[0055]

According to the liquid crystal alignment agent of the present invention, when a liquid crystal display device is used, a liquid crystal alignment film having good liquid crystal alignment properties and hardly causing rubbing scratches on the surface of the liquid crystal alignment film is provided. A liquid crystal alignment film having excellent resistance to isopropyl alcohol washing performed after the treatment is obtained. The liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be suitably used for TN type and STN type liquid crystal display devices, and can be further provided by selecting SH (Super Homeotropic) by selecting a liquid crystal to be used. ) Type, IPS (In-Plane)
Switching) -type, ferroelectric and anti-ferroelectric liquid crystal display devices, etc. further,
The liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be effectively used for various devices, for example, a desk calculator, a wristwatch, a clock, a coefficient display plate, a word processor, a personal computer, a liquid crystal television, and the like. Used for the display device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Matsuki 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd.

Claims (1)

[Claims] 1. One or more polymers selected from the group consisting of (A) (a) a polymer having a polyamic acid structure and (b) a polymer having an imide structure obtained by dehydration and ring closure of the polyamic acid. And (B) a liquid crystal aligning agent containing a nitrogen atom-containing epoxy compound,
An average imidation ratio of a polymer contained in the liquid crystal alignment agent is 45% or more.