JPH0990367A - Liquid crystal orienting agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable production of a liquid crystal display element with a large pretilt angle which has excellent uniformity of film thickness, orientation of the liquid crystal, holding rate of voltage and long-term reliability by incorporating at least either a polyamic acid obtd. by the reaction of a specified tetracarboxylic acid dianhydride and a specified diamine or an imidized polymer prepared by dehydration and ring-closing reaction of the polyamic acid above described. SOLUTION: This orienting agent contains at least either a polyamic acid or an imidized polymer produced by dehydration and ring-closing reaction of the polyamic acid. The polyamic acid is produced by the reaction of tetracarboxylic acid dianhydride expressed by formula I and phenylene diamine expressed by formula II or aromatic diamine expressed by formula III or diamine having a steroid skeleton. In formula I, R<1> is a quadrivalent org. group. In formula II, R<2> is an alkyl group, alkoxy group, or halogen atom and (a) is integers of 0 to 4. In formula III, R<3> , R<4> are alkyl groups, alkoxyl groups, halogen atoms, and (b), (c) are integers of 0 to 3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal aligning agent. More specifically, the present invention relates to a liquid crystal aligning agent which, when used as a liquid crystal aligning film, has excellent film thickness uniformity, good liquid crystal aligning property, excellent voltage holding ratio and long-term reliability, and can provide a liquid crystal display device with a high pretilt angle. .

[0002]

2. Description of the Related Art Conventionally, a layer of a nematic liquid crystal having a positive dielectric anisotropy is formed between substrates with transparent electrodes to form a sandwich structure, and the long axis of the liquid crystal molecule is 90 between the substrates.
There is known a liquid crystal display element (TN type liquid crystal display element) having a TN type liquid crystal cell which is twisted continuously. The liquid crystal alignment in this TN type liquid crystal display element is formed by a liquid crystal alignment film made of polyimide or the like that has been subjected to a rubbing treatment.

[0003]

However, when a TN type liquid crystal display device is manufactured using a conventionally known liquid crystal alignment film made of polyimide or the like, the voltage holding ratio of the liquid crystal display device is low and the long-term reliability is low. There are problems that white spots are generated in the liquid crystal cell during the test, and display defects occur due to the small pretilt angle of the liquid crystal molecules.
Further, the liquid crystal alignment film is usually obtained by applying a liquid crystal alignment agent made of a resin solution onto a substrate and drying, but film thickness unevenness occurs during application of the liquid crystal alignment agent, which affects display characteristics and electrical characteristics. There is also a problem.

An object of the present invention is to provide a novel liquid crystal aligning agent. Another object of the present invention is to provide a high pretilt angle liquid crystal display device which, when used as a liquid crystal alignment film, has excellent film thickness uniformity, good liquid crystal alignment properties, and excellent voltage holding ratio and long-term reliability. To provide an aligning agent.
Other objects and advantages of the present invention will be apparent from the following description.

[0005]

According to the present invention, the above objects and advantages of the present invention are (A) the following general formula (1)

[0006]

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A tetracarboxylic dianhydride represented by the formula (1) wherein R ¹ is a tetravalent organic group (hereinafter referred to as "compound (I)"); and (B) (i) The following general formula (2)

[0008]

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(In the formula (2), R ² is an alkyl group, an alkoxyl group or a halogen atom, and a is an integer of 0 to 4) (hereinafter referred to as "compound (II)") , (Ii) the following general formula (3),
(4), (5), (6) and (7)

[0010]

[Chemical 6]

(In the formulas (3) to (7), R ³ , R ⁴ , R ⁵ ,
R ⁶ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each independently an alkyl group, an alkoxyl group or a halogen atom, R ⁷ is a divalent organic group, b, c, h, i
And j are each independently an integer of 0 to 3, d,
e, f, g and k are each independently an integer of 0 to 4) at least one aromatic diamine selected from the group of compounds (hereinafter, referred to as “compound (III)”), and (Iii) having a steroid skeleton represented by the following general formula (8) H ₂ N—R ¹⁴ —NH ₂ (8) (in the formula (8), R ¹⁴ is a divalent organic group having a steroid skeleton) By subjecting a polyamic acid (hereinafter, referred to as “specific polymer (I)”) and a specific polymer (I) produced by reacting a diamine (hereinafter, referred to as “compound (IV)”) to dehydration ring closure The imidized polymer produced (hereinafter,
It is achieved by a liquid crystal aligning agent characterized by containing at least one of "specific polymer (II)").

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below, and the purpose, constitution, advantages and effects of the present invention will be apparent.

The liquid crystal aligning agent of the present invention contains the specific polymer (I) and / or the specific polymer (II).

<Compound (I)> In the above compound (I) used in the present invention, R ¹ is a tetravalent organic group, preferably an organic group having 4 to 12 carbon atoms.

Specific examples of R ¹ include the following general formula (9-
1) and (9-2)

[0016]

[Chemical 7]

(In the general formula (9-1), R ¹⁵ , R ¹⁶ and R ¹⁷
And R ¹⁸ are each independently a hydrogen atom or a carbon number of 1 to
4 is an alkyl group, m, n and o each independently represent an integer of 0 or 1, and when m, n or o is 0, (CH ₂ ) _m , (CH ₂ ) _n or (CH ₂ ) _o represents a single bond. In formula (9-2), R ¹⁹ represents an alkyl group, an alkoxyl group or a halogen atom, and p represents an integer of 0-4. The group shown by these can be mentioned. Of these, a tetravalent organic group represented by formula (9-1) is preferable.

Examples of the compound (I) having an organic group represented by the general formula (9-1) include 1,2,3,4-
Cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3 Examples include 5,5-tricarboxycyclopentyl acetic acid dianhydride.

The compound (I) having an organic group represented by the general formula (9-2) is, for example, 3,4-
Dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, 3,4-dicarboxy-6-methyl-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, 3,4-dicarboxy-7-methyl-1,
2,3,4-tetrahydro-1-naphthalene succinic anhydride and the like can be mentioned.

Further, as the other compound (I),
For example, butanetetracarboxylic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid dianhydride, 2,3,
4,5-tetrahydrofuran tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3
-Methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, bicyclo [2,2,2] -oct-7-ene-
Aliphatic dianhydrides such as 2,3,5,6-tetracarboxylic dianhydride or alicyclic dianhydrides;

Pyromellitic dianhydride 3,3 ', 4,4'
-Benzophenone tetracarboxylic acid dianhydride 3,3 ',
4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3 ' , 4,4'-Biphenyl ether tetracarboxylic acid dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilane tetracarboxylic acid dianhydride, 3,3', 4,4'-tetraphenylsilane tetracarboxylic acid Acid 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 acid 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'-diphenylether dianhydride, bis (triphenylphthalic acid) ) -4,4'-Diphenylmethane dianhydride and other aromatic tetracarboxylic dianhydrides can be mentioned.

Of these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,2,3,4-Cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1- Naphthalene succinic anhydride, 3,4-dicarboxy-6-methyl-1,2,3,4-tetrahydro-1-
Naphthalene succinic anhydride, 3,4-dicarboxy-7
-Methyl-1,2,3,4-tetrahydro-1-naphthalene succinic anhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2
-Dicarboxylic acid dianhydride and bicyclo [2,2,2]-
Oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride is preferred, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. Anhydrides are especially preferred. These are 1
They may be used alone or in combination of two or more.

<Compound (II)> Regarding R ² of the above-mentioned general formula (2) relating to the compound (II) used in the present invention, the alkyl group (a) is preferably an alkyl group having 1 to 6 carbon atoms, Alkyl groups of the numbers 1 to 3 are more preferable. Specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group,
Examples thereof include a cyclohexyl group. As the (b) alkoxyl group, an alkoxyl group having 1 to 6 carbon atoms is preferable, and an alkoxyl group having 1 to 3 carbon atoms is more preferable. Specific examples include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, t-butoxy group, n-pentoxy group, n-
Examples thereof include a hexyloxy group and a cyclohexyloxy group. Examples of the halogen atom (c) include chlorine, fluorine, bromine and iodine, and chlorine and fluorine are preferable.

Examples of the compound (II) include 1,2-phenylenediamine, 3-methyl-1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine and 4,5-dimethyl-1,2. -Phenylenediamine,
3-ethyl-1,2-phenylenediamine, 3-methyl-1,2-phenylenediamine, 4-ethyl-1,2-phenylenediamine, 4,5-diethyl-1,2-phenylenediamine, 3-methoxy- 1,2-phenylenediamine, 4-methoxy-1,2-phenylenediamine, 4,5
-Dimethoxy-1,2-phenylenediamine, 3-ethoxy-1,2-phenylenediamine, 4-ethoxy-1,
2-phenylenediamine, 3-chloro-1,2-phenylenediamine, 4-chloro-1,2-phenylenediamine, 3-fluoro-1,2-phenylenediamine, 4-
Fluoro-1,2-phenylenediamine, 1,3-phenylenediamine, 2-methyl-1,3-phenylenediamine, 4-methyl-1,3-phenylenediamine,

5-methyl-1,3-phenylenediamine, 2-ethyl-1,3-phenylenediamine, 4-ethyl-1,3-phenylenediamine, 5-ethyl-1,3
-Phenylenediamine, 2-methoxy-1,3-phenylenediamine, 4-methoxy-1,3-phenylenediamine, 5-methoxy-1,3-phenylenediamine, 4
-Ethoxy-1,3-phenylenediamine, 5-ethoxy-1,3-phenylenediamine, 4-chloro-1,3-
Phenylenediamine, 5-chloro-1,3-phenylenediamine, 4-fluoro-1,3-phenylenediamine, 5-fluoro-1,3-phenylenediamine, 1,4
-Phenylenediamine, 2-methyl-1,4-phenylenediamine, 2,3-dimethyl-1,4-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine,
2,6-dimethyl-1,4-phenylenediamine, 2,3
-Diethyl-1,4-phenylenediamine, 2,5-diethyl-1,4-phenylenediamine, 2,6-ethyl-
1,4-phenylenediamine, 2-methoxy-1,4-phenylenediamine, 2-ethoxy-1,4-phenylenediamine, 2-chloro-1,4-phenylenediamine,
2,3-dichloro-1,4-phenylenediamine, 2,5
-Dichloro-1,4-phenylenediamine, 2,6-dichloro-1,4-phenylenediamine, 2-fluoro-1,
4-phenylenediamine, 2,3-difluoro-1,4-
Examples thereof include phenylenediamine, 2,5-difluoro-1,4-phenylenediamine, and 2,6-difluoro-1,4-phenylenediamine. Of these, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4
-Phenylenediamine, 2-methyl-1,4-phenylenediamine, 2-ethyl-1,4-phenylenediamine, 2-methoxy-1,4-phenylenediamine, 2-
Ethoxy-1,4-phenylenediamine, 2-chloro-
1,4-phenylenediamine and 2-fluoro-1,4
Phenylenediamine is preferred, 1,3-phenylenediamine and 1,4-phenylenediamine are particularly preferred. These can be used alone or in combination of two or more.

<Compound (III)> Used in the present invention
Compounds (III) of the above general formulas (3) to (7)
R ^Three~ R⁶And R⁸~ R¹³Is an alkyl group, alkoxyl
A group or a halogen atom, R²Regarding the above
Description of alkyl group, alkoxyl group and halogen atom
Applicable as is, including preferred embodiments and specific examples
Can be. In addition, R in the general formula (5)⁷Is a divalent organic group
And specifically, the following formulas (10-1) to (10-12)

[0027]

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A divalent group represented by can be mentioned.

As a specific example of the compound represented by the general formula (3), 1,5-diaminonaphthalene is preferable. Specific examples of the compound represented by the general formula (4) include 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2 ′, 5,5′-tetrachloro-4,
4'-diaminobiphenyl, 2,2'-dichloro-4,4 '
-Diamino-5,5'-dimethoxybiphenyl, 3,3'-
Dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl and the like are preferred.

Specific examples of the compound represented by the above general formula (5) include 4,4'-diaminodiphenylmethane and 4,4'-diaminodiphenylmethane.
4'-diaminodiphenyl ether, 9,9-bis (4-
Aminophenyl) fluorene, 4,4 ′-(p-phenylene isopropylidene) bisaniline, 4,4 ′-(m-phenylene isopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] propane 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminobenzanilide, 3,4 '
-Diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4 '
-Diaminobenzophenone, 2,2-bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) 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, 4,4'-methylene-bis (2-chloroaniline), 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl]
Hexafluoropropane, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl and the like are mentioned as preferable ones.

As a specific example of the compound represented by the above general formula (6), 2,7-diaminofluorene is preferable. Specific examples of the compound represented by the general formula (7) include 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane and 6-amino-1- (4′-amino. Phenyl) -1,3,3-trimethylindane is preferred. Among the compounds represented by these general formulas (3) to (7),
The compound represented by formula (5), (6) or (7) is more preferable.

Among the compounds represented by the above general formula (5), (6) or (7), 4,4'-diaminodiphenylmethane, 1,5-diaminonaphthalene, 4,4'-
Diaminodiphenyl ether, 2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4 '-(p-phenylene isopropylidene) bisaniline, 4,4'-(m-phenylene isopropylidene) bisaniline 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 5-amino-1-
(4'-Aminophenyl) -1,3,3-trimethylindane and 6-amino-1- (4'-aminophenyl)
-1,3,3-Trimethylindane is preferred. These can be used alone or in combination of two or more.

<Compound (IV)> The compound (IV) used in the present invention is a diamine having a steroid skeleton. Examples of such compound (IV) include the following general formula (11) and general formula (12).

[0034]

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(In the general formulas (11) and (12),
R ²⁰ , R ²³ and R ²⁴ are each independently an alkyl group, an alkoxyl group or a halogen atom, R ²¹ , R ²⁵ and R ²⁶ are each independently a divalent organic group, and R ²² is a steroid. It is a monovalent organic group having a skeleton, R ²⁷ is a divalent organic group having a steroid skeleton, and q is 0 to 3
And r and s are each independently an integer of 0 to 4). As preferred examples, the following formulas (13) to (19)

[0036]

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[0037]

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Examples thereof include compounds represented by the formula (13), formula (14), formula (17) and formula (19). These can be used alone or in combination of two or more.

In producing the specific polymer (I) used in the present invention, the compound (II) is used in an amount of 10 to 70 mol% based on the total diamine, and the compound (III) is used in an amount of 30 to 80 based on the total diamine. The molar ratio of the compound (IV) to be used is preferably 0.5 to 25 mol% based on all diamines. When the proportion of the compound (II) used is less than 10 mol%, it is difficult to obtain a sufficiently high voltage holding ratio, and when it exceeds 70 mol%, the long-term reliability of the liquid crystal display device tends to be poor. When the usage ratio of the compound (III) is less than 30 mol%,
The liquid crystal display element tends to be inferior in long-term reliability.
If it exceeds mol%, it is difficult to obtain a sufficiently high voltage holding ratio. Further, when the usage ratio of the compound (IV) is less than 0.5 mol%, the obtained pretilt angle tends to be small,
If it exceeds 25 mol%, the solubility of the specific polymer in the solvent tends to decrease.

<Synthesis of Specific Polymer (I)> The specific polymer (I) constituting the liquid crystal aligning agent of the present invention includes the tetracarboxylic dianhydride of the above compound (I) and the above compound (I).
It is synthesized by the reaction of I), (III) and (IV) with a diamine compound. The ratio of the compound (I) and the total diamine compound used in the synthesis reaction of the specific polymer (I) is 0.2 to 2 equivalents of the acid anhydride group of the compound (I) per 1 equivalent of the amino group. The amount is preferably 0.3 to 1.2 equivalents.

The compound (I) and the diamine compound are preferably reacted in an organic solvent at a reaction temperature of 0 to 100 ° C. for 1 to 48 hours.

The organic solvent is not particularly limited as long as it can dissolve the polyamic acid produced in the reaction. For example, aprotic polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; m-cresol Examples thereof include phenolic solvents such as xylenol, phenol, and halogenated phenols.

It should be noted that poor organic solvents such as alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons are used in combination with the above-mentioned organic solvent to the extent that the polymer produced does not precipitate. be able to. Examples of the poor solvent include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone. , Methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether,
Ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol-n-hexyl 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 Monobutyl ether,
Diethylene glycol monomethyl ether acetate,
Diethylene glycol monoethyl ether acetate,
Ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol-n-propyl ether acetate, ethylene glycol-i-propyl ether acetate, ethylene glycol-n-butyl ether acetate, ethylene glycol-n-hexyl ether acetate, 4-hydroxy -4-Methyl-2-pentanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy- Methyl 3-methylbutanoate, 3
-Methyl methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o -Dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like can be mentioned. These can be used alone or in combination of two or more.

The amount of the organic solvent used is preferably such that the total amount of the compound (I) and all the diamine compounds is 0.1 to 30% by weight based on the total amount of the reaction solution.

Further, at the time of synthesizing the specific polymer (I), an end anhydride prepared by adding an acid anhydride having only one anhydride group or a monoamine compound for the purpose of controlling the molecular weight, improving the coating property on a substrate, and the like. The specific polymer (I) of the type and the specific polymer (II) obtained by dehydrating and ring-closing it can also be used in the present invention without any problem.

Examples of the acid anhydrides include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, and n-tetradecylsuccinic anhydride. , N-hexadecylsuccinic anhydride, n-octadecylsuccinic anhydride, and the like.

Examples of the above monoamines 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- Examples thereof include eicosylamine.

<Specific polymer (II)> The specific polymer (II) constituting the liquid crystal aligning agent of the present invention is the specific polymer (I).
Is obtained by heating or by dehydration ring closure in the presence of a dehydrating agent and a dehydration ring closure catalyst. The specific polymer (II) is usually polyimide or polyisoimide. The reaction temperature for dehydration ring closure by heating is preferably 60 to 250 ° C., more preferably 100.
~ 170 ° C.

The reaction for the dehydration ring closure in the presence of the dehydrating agent and the dehydration ring closure catalyst can be carried out in the above-mentioned organic solvent. The reaction temperature is generally 0 to 180 ° C, preferably 60 to 150 ° C. As the dehydrating agent, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. Examples of the dehydration ring-closing catalyst include, but are not limited to, tertiary amines such as pyridine, collidine, lutidine, and triethylamine. The amount of the dehydrating agent used is 1.5 to 1 mol of the repeating unit of the specific polymer (I).
It is preferably 20 mol. Further, the amount of the dehydration ring-closing catalyst used is preferably 0.5 to 10 mols per 1 mol of the dehydrating agent used.

<Specific Polymer (I) and Specific Polymer (I
Intrinsic viscosity of I)> Intrinsic viscosity of specific polymer (I) and specific polymer (II) thus obtained [ηinh =
ln (t / t0) / C, where C = 0.5 g / dl, t
Is the flow rate of the polymer solution, and t0 is the flow rate of N-methyl-2-pyrrolidone. 30 ° C, N-methyl-2-
Measured in pyrrolidone, then measured intrinsic viscosity under the same conditions]
Is usually 0.05 to 10 dl / g, preferably 0.05
５5 dl / g.

<Liquid Crystal Aligning Agent> The liquid crystal aligning agent of the present invention is used as a uniform solution in which the specific polymer (I) and / or the specific polymer (II) described above are dissolved in an organic solvent.

As the organic solvent, the specific polymer (I) is used.
The above-mentioned aprotic solvent, phenolic solvent or the like that can be used during production, or these solvents and the above-mentioned alcohols, ketones, esters, ethers and halogenated hydrocarbons that can be used during production of the specific polymer (II). And a mixed solvent with a poor solvent such as hydrocarbons to the extent that the polymer does not precipitate.

The concentration of the specific polymer (I) and / or the specific polymer (II) in the solution is usually 0.1 to 2
It is 0% by weight, preferably 0.5 to 10% by weight.

The liquid crystal aligning agent of the present invention comprises the specific polymer (I)
And / or a functional silane-containing compound shown below may be contained for the purpose of further improving the adhesion between the specific polymer (II) and the substrate.

Examples of the functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane and 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-
Trimethoxysilylpropyltriethylenetriamine,
10-trimethoxyisyl-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 can be mentioned.

<Production of Liquid Crystal Display Element> A liquid crystal display element 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 a substrate provided with a patterned transparent conductive film by a roll coater method, a spinner method, a printing method or the like, and the temperature is 80 to 250 ° C. Preferably, the coating film is formed by heating at a temperature of 120 to 200 ° C. The thickness of this coating film is usually 0.001 to 1 μm, preferably 0.005 to 0.5.
μm. The liquid crystal aligning agent of the present invention containing the specific polymer (I) forms a coating film which becomes a liquid crystal aligning film by removing the organic solvent after coating, and is further imidized by further heating. It can also be a membrane. The formed coating film is subjected to a rubbing treatment in which a cloth made of synthetic fibers such as nylon and rayon is rubbed in a certain direction with a roll to give the liquid crystal molecule alignment ability to the liquid crystal alignment film. .

As the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of a plastic film such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone or polycarbonate can be used. As the transparent conductive film, NESA film made of SnO2, In ₂ O ₃ -
An ITO film made of SnO ₂ or the like can be used, and 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 aligning agent, a functional silane-containing compound, titanate or the like may be applied in advance on the substrate and the transparent conductive film in order to further improve the adhesion between the substrate and the transparent conductive film and the coating film. it can.

(2) Two substrates with the liquid crystal alignment film formed as described above are prepared, and a gap (cell gap) is formed between the two substrates so that the rubbing directions in the respective liquid crystal alignment films are orthogonal or antiparallel. The liquid crystal cell is sealed by sealing the peripheral portion of the substrate with a sealant, and the filling hole is sealed to form a liquid crystal cell. A liquid crystal display device is obtained by laminating a polarizing plate on the outer surface of the liquid crystal cell such that the polarization direction matches or is orthogonal to the rubbing direction of the liquid crystal alignment film of the substrate.

As the sealing agent, for example, a curing agent and an epoxy resin containing 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, a liquid crystal that forms a nematic liquid crystal is preferable.
Azoxy liquid crystal, biphenyl liquid crystal, phenylcyclohexane liquid crystal, ester liquid crystal, terphenyl liquid crystal,
Biphenylcyclohexane liquid crystal, pyrimidine liquid crystal,
Dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, and the like are used. In addition to these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate, and chiral agents such as those sold under the trade names C-15 and CB-15 (Merck Ltd.) are added. It can also be used. Furthermore, p-decyloxybenzylidene-p-
Ferroelectric liquid crystals such as amino-2-methylbutyl cinnamate can also be used.

The polarizing plate used for the outer surface of the liquid crystal cell is a polarizing plate in which a polarizing film called an H film in which polyvinyl alcohol is stretched and oriented while absorbing iodine is sandwiched between cellulose acetate protective films, or an H film. Examples thereof include a polarizing plate made of itself.

[0062]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. For each liquid crystal display element produced in the following examples and comparative examples, the liquid crystal orientation of the liquid crystal display element, the voltage holding ratio of the liquid crystal display element, the reliability of the liquid crystal display element, the pretilt angle of the liquid crystal display element, the liquid crystal The film thickness uniformity of the alignment film was evaluated. The evaluation method is as follows.

[Liquid Crystal Orientation of Liquid Crystal Display Element] The presence or absence of an abnormal domain in the liquid crystal display element when a voltage was turned on and off was observed with a polarizing microscope, and when there was no abnormal domain, it was judged to be good. . [Voltage retention of liquid crystal display element] The voltage of 5 V applied to the liquid crystal display element was turned off, and the voltage retention rate after 16.7 msec was measured and evaluated. [Reliability of Liquid Crystal Display Element] The liquid crystal display element was driven at a rectangular wave of 5 V and 60 Hz for 1000 hours in a thermo-hygrostat having a temperature of 80 ° C. and a humidity of 80%, and it was judged that no white spot was generated.

[Pretilt angle of liquid crystal display element] [TJSc
hffer et al., J.Appl.Phys., 19, 2013 (1980)]. [Uniformity of Liquid Crystal Alignment Film] A liquid crystal aligning agent is applied onto a silicon wafer by printing, the substrate is baked at 180 ° C. for 1 hour, 10 measurement points are selected, and the film thickness is measured. The average film thickness was obtained, and the difference between the maximum film thickness and the minimum film thickness was obtained as the film thickness unevenness.

Synthesis Example 1 44.83 g (0.20 mol) of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride and 5.41 g (0.05 mol) of 1,4-phenylenediamine, 4,4'- 27.76 g (0.14 mol) of diaminodiphenylmethane and 5.21 g (0.01 mol) of the compound of the above formula (13) were dissolved in 749 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours. The reaction mixture was then poured into a large excess of methanol, causing the reaction product to precipitate. Then, it was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain 76.3 g of the specific polymer (Ia) having an intrinsic viscosity of 1.13 dl / g.

Synthesis Example 2 40.0 g of the specific polymer (Ia) obtained in Synthesis Example 1 was
The imidization reaction was carried out at 110 ° C. for 4 hours in 800 g of N-methyl-2-pyrrolidone, 35.5 g of pyridine and 27.5 g of acetic anhydride. Then, the reaction product liquid is used in Synthesis Example 1.
Precipitation was performed in the same manner as in (3) to obtain 38.6 g of the specific polymer (IIa) having an intrinsic viscosity of 1.20 dl / g.

Synthesis Example 3 In Synthesis Example 1, 1,6-phenylenediamine was added in an amount of 14.06 g (0.13 mol), 4,4'-diaminodiphenylmethane (11.90 g, 0.06 mol) and the above formula (13). ) The specific polymer (Ib) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound of
Further, this specific polymer (Ib) was used for imidization in the same manner as in Synthesis Example 2 to obtain 38.9 g of the specific polymer (IIb) having an intrinsic viscosity of 1.26 dl / g.

Synthetic Example 4 In Synthetic Example 1, 1,4-phenylenediamine was used as the diamine in an amount of 2.16 g (0.02 mol), 4,4'-diaminodiphenylmethane (33.71 g (0.17 mol)) and the above formula (13). ) The compound (Ic) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound (4) was used, and this specific polymer (Ic) was used in the same manner as in Synthesis Example 2. Imidation was carried out to obtain 38.1 g of the specific polymer (IIc) having an intrinsic viscosity of 1.06 dl / g.

Synthesis Example 5 In Synthesis Example 1, the diamine was changed to 1,4-phenylenediamine (2.16 g, 0.05 mol), 4,4'-diaminodiphenylmethane (33.71 g, 0.17 mol) and the above formula (13). The specific polymer (Id) was obtained in the same manner as in Synthesis Example 1 except that 0.52 g (0.001 mol) of the compound of 4) was used.
Further, this specific polymer (Id) was used for imidization in the same manner as in Synthesis Example 2 to obtain 38.1 g of the specific polymer (IId) having an intrinsic viscosity of 1.29 dl / g.

Synthesis Example 6 In Synthesis Example 1, 1,4-phenylenediamine was used as the diamine in an amount of 2.16 g (0.05 mol), 4,4'-diaminodiphenylmethane (19.83 g) and the above formula (13). The specific polymer (Ie) was obtained in the same manner as in Synthesis Example 1 except that 26.04 g (0.05 mol) of the compound (4) was used.
Further, this specific polymer (Ie) was used for imidization in the same manner as in Synthesis Example 2 to obtain 36.1 g of the specific polymer (IIe) having an intrinsic viscosity of 0.78 dl / g.

Synthesis Example 7 In Synthesis Example 1, 1,3-phenylenediamine was used as the diamine in an amount of 5.41 g (0.05 mol), 4,4'-diaminodiphenylmethane (27.76 g, 0.14 mol) and the above formula (13). ) The specific polymer (If) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound of Example 1) was substituted, and this specific polymer (If) was used in the same manner as in Synthesis Example 2. Imidation was carried out to obtain 37.1 g of the specific polymer (IIf) having an intrinsic viscosity of 0.86 dl / g.

Synthesis Example 8 In Synthesis Example 1, 1,4-phenylenediamine was added in an amount of 5.41 g (0.05 mol) and 4,4'-diaminodiphenylmethane (27.76 g, 0.14 mol) and the above formula (14). ) The compound (Ig) was obtained in the same manner as in Synthesis Example 1 except that the compound (5.23 g (0.01 mol)) was replaced by the same procedure as in Synthesis Example 2 using the specific polymer (Ig). Imidation was carried out to obtain 37.8 g of the specific polymer (IIg) having an intrinsic viscosity of 0.96 dl / g.

Synthetic Example 9 In Synthetic Example 1, diamine was added in an amount of 5,41 g (0.05 mol), 4,4'-diaminodiphenylmethane (27.76 g, 0.14 mol) and the above formula (17). ) Was obtained in the same manner as in Synthesis Example 1 except that the compound (6) (6.43 g (0.01 mol)) was replaced with the specific polymer (Ih), and this specific polymer (Ih) was used in the same manner as in Synthesis Example 2. Imidation was carried out to obtain 37.0 g of the specific polymer (IIh) having an intrinsic viscosity of 0.91 dl / g.

Synthesis Example 10 In Synthesis Example 1, 1,4-phenylenediamine was added in an amount of 5.41 g (0.05 mol) and 4,4'-diaminodiphenylmethane (27.76 g, 0.14 mol) and the above formula (19). ) The compound (Ii) was obtained in the same manner as in Synthesis Example 1 except that the compound (7) was replaced by 7.40 g (0.01 mol), and the specific polymer (Ii) was used in the same manner as in Synthesis Example 2. Imidation was carried out to obtain 37.0 g of the specific polymer (IIi) having an intrinsic viscosity of 0.81 dl / g.

Synthesis Example 11 In Synthesis Example 1, the diamine was replaced by 1,4-phenylenediamine (5.41 g, 0.05 mol), 1,5-diaminonaphthalene (22.12 g, 0.14 mol) and the above formula (1).
3) The specific polymer (Ij) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound was used, and this specific polymer (Ij) was used in the same manner as in Synthesis Example 2. Was imidized to obtain 35.1 g of the specific polymer (IIj) having an intrinsic viscosity of 0.66 dl / g.

Synthesis Example 12 In Synthesis Example 1, diamine was added in an amount of 5,41 g (0.05 mol), 4,4'-diaminodiphenyl ether (28.04 g, 0.14 mol) and the above formula (13). ) The specific polymer (Ik) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound of
Further, this specific polymer (Ik) was imidized in the same manner as in Synthesis Example 2 to obtain 38.1 g of the specific polymer (IIk) having an intrinsic viscosity of 1.26 dl / g.

Synthesis Example 13 In Synthesis Example 1, the diamine was replaced by 1,4-phenylenediamine (5.41 g, 0.05 mol), 2,7-diaminofluorene (27.44 g, 0.14 mol) and the above formula (1).
The specific polymer (Il) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound of 3) was used, and this specific polymer (Il) was used in the same manner as in Synthesis Example 2. Was imidized to obtain 36.1 g of the specific polymer (IIl) having an intrinsic viscosity of 0.86 dl / g.

Synthesis Example 14 In Synthesis Example 1, diamine was added in an amount of 5,41 g (0.05 mol) of 1,4-phenylenediamine and 48.72 g (0.14 mol) of 9,9-bis (4-aminophenyl) fluorene.
And a specific polymer (Im) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound of the above formula (13) was used, and the specific polymer (Im) was further synthesized. Imidization was carried out in the same manner as in Example 2 to give an intrinsic viscosity of 0.7.
36.3 g of 6 dl / g of the specific polymer (IIm) was obtained.

Synthesis Example 15 In Synthesis Example 1, diamine was added in an amount of 5,41 g (0.05 mol) and 4,4 '-(p-phenylene isopropylidene) bisaniline (48.16 g, 0.14).
14 mol) and 5.21 g of the compound of formula (13)
A specific polymer (In) was obtained in the same manner as in Synthesis Example 1 except that the specific polymer (In) was replaced with (0.01 mol).
n) was used for imidization in the same manner as in Synthesis Example 2 to give a specific polymer (IIn) 36.5 having an intrinsic viscosity of 0.77 dl / g.
g was obtained.

Synthesis Example 16 In Synthesis Example 1, diamine was added in an amount of 1,41-phenylenediamine (5.41 g, 0.05 mol) and 4,4 '-(m-phenyleneisopropylidene) bisaniline (48.16 g, 0.14).
14 mol) and 5.21 g of the compound of formula (13)
A specific polymer (Io) was obtained in the same manner as in Synthesis Example 1 except that the specific polymer (Io) was used.
o) was used for imidization in the same manner as in Synthesis Example 2 to give a specific polymer (IIo) 36.1 having an intrinsic viscosity of 0.67 dl / g.
g was obtained.

Synthesis Example 17 In Synthesis Example 1, the diamine was replaced by 1,4-phenylenediamine (5.41 g, 0.05 mol) and 2,2-bis [4-].
(4-Aminophenoxy) phenyl] propane 57.5
4 g (0.14 mol) and the compound of formula (13) above 5.
A specific polymer (Ip) was obtained in the same manner as in Synthesis Example 1 except that 21 g (0.01 mol) was used, and imidization was performed in the same manner as in Synthesis Example 2 using this specific polymer (Ip). , A specific polymer (IIp) having an intrinsic viscosity of 1.29 dl / g
38.1 g was obtained.

Synthetic Example 18 In Synthetic Example 1, diamine was added to 1,4-phenylenediamine (5.41 g, 0.05 mol) and 5-amino-1-
37.24 g (0.14 mol) of (4'-aminophenyl) -1,3,3-trimethylindane and the above formula (13)
The specific polymer (Iq) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the above compound was used, and this specific polymer (Iq) was used in the same manner as in Synthesis Example 2. Imidization was performed to obtain 35.1 g of the specific polymer (IIq) having an intrinsic viscosity of 0.59 dl / g.

Synthesis Example 19 In Synthesis Example 1, diamine was added in an amount of 5,41 g (0.05 mol) of 1,4-phenylenediamine and 6-amino-1-.
37.24 g (0.14 mol) of (4'-aminophenyl) -1,3,3-trimethylindane and the above formula (13)
The specific polymer (Ir) was obtained in the same manner as in Synthesis Example 1 except that 5.21 g (0.01 mol) of the compound of Example 2 was used, and the specific polymer (Ir) was used in the same manner as in Synthesis Example 2. Imidization was performed to obtain 35.0 g of the specific polymer (IIr) having an intrinsic viscosity of 0.58 dl / g.

Synthesis Example 20 In Synthesis Example 1, tetracarboxylic acid dianhydride was replaced with cyclobutanetetracarboxylic acid dianhydride 39.22 g (0.20 g).
The specific polymer (Is) having an intrinsic viscosity of 1.22 dl / g was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to 72.1 g.

Synthesis Example 21 In Synthesis Example 1, tetracarboxylic dianhydride was added to 1,3,
3a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-
c] A specific polymer (It) was obtained in the same manner as in Synthesis Example 1 except that 60.05 g (0.20 mol) of furan-1,3-dione was used, and the specific polymer (It) was used. Imidization was carried out in the same manner as in Synthesis Example 2 to give an intrinsic viscosity of 0.8.
36.2 g of a specific polymer (IIt) of 8 dl / g was obtained.

Synthesis Example 22 (Comparative Synthesis Example) In Synthesis Example 1, tetracarboxylic acid dianhydride was replaced with cyclobutanetetracarboxylic acid dianhydride 39.22 g (0.20 g).
Mol) in place of diamine, 20.55 g (0.19 mol) of 1,4-phenylenediamine and 5.21 g (0.01 mol) of the compound of the formula (13), and the same as in Synthesis Example 1. Thus, 58.3 g of a specific polymer (Iu) having an intrinsic viscosity of 1.22 dl / g was obtained.

Synthesis Example 23 (Comparative Synthesis Example) In Synthesis Example 1, tetracarboxylic dianhydride was replaced with cyclobutanetetracarboxylic dianhydride 39.22 g (0.20 g).
37.67 g (0.19 mol) of 4,4′-diaminodiphenylmethane instead of diamine and the above formula (1).
72.3 g of the specific polymer (Iv) having an intrinsic viscosity of 0.97 dl / g was obtained in the same manner as in Synthesis Example 1, except that 5.21 g (0.01 mol) of the compound 3) was used.

Synthesis Example 24 (Comparative Synthesis Example) In Synthesis Example 1, tetracarboxylic acid dianhydride was replaced with cyclobutanetetracarboxylic acid dianhydride 39.22 g (0.20 g).
Mol), and the diamine was replaced with 39.65 g (0.20 mol) of 4,4′-diaminodiphenylmethane, and the specific polymer (Iw) having an intrinsic viscosity of 1.17 dl / g was synthesized in the same manner as in Synthesis Example 1. 72.0 g was obtained.

Example 1 5 g of the specific polymer (Ia) obtained in Synthesis Example 1 was dissolved in γ-butyrolactone to obtain a solution having a solid content concentration of 4% by weight, and the solution was filtered with a filter having a pore size of 1 μm to give a liquid crystal. An aligner solution was prepared. This solution was applied on a transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a printing machine for applying a liquid crystal aligning agent, dried at 180 ° C. for 1 hour, and a coating film having a dry film thickness of 0.05 μm Was formed. A rubbing machine having a roll in which a cloth made of rayon was wrapped around this coating film was subjected to rubbing treatment at a roll rotation speed of 500 rpm and a stage moving speed of 1 cm / sec.

Two substrates on which the liquid crystal alignment film was formed as described above were prepared, and a diameter of 17 was formed on the outer edge of each substrate.
After applying an epoxy resin adhesive containing μm aluminum oxide spheres by screen printing, the two substrates are separated so that the liquid crystal alignment film surfaces of the substrates face each other and the rubbing directions of the liquid crystal alignment films are orthogonal to each other. Then, the outer edge portion was pressure-bonded to the adhesive and the adhesive was cured. Next, a nematic liquid crystal (Me
rck Ltd., ZLI-5081), and then the liquid crystal injection port is sealed with an epoxy adhesive, polarizing plates are placed on both outer sides of the substrate, and the polarization direction of the polarizing plate is the liquid crystal alignment film of each substrate. A liquid crystal display device was manufactured by laminating the liquid crystal display devices so that they were aligned with the rubbing direction.

The liquid crystal display device produced as described above had an excellent liquid crystal orientation, with no abnormal domains being observed in the liquid crystal display device when the voltage was turned on and off. Further, the voltage holding ratio of the liquid crystal display device was measured and found to be a high value of 99.3%. Also, 1000
Even in the reliability test after a lapse of time, white spots did not occur on the liquid crystal display element. Then, the pretilt angle of the liquid crystal display device was measured, and it was a high value of 5.8 °. Furthermore, the average film thickness of the liquid crystal alignment film was 500Å and the coating unevenness was 20Å, and a uniform film thickness was obtained. Table 1 shows the results.

Examples 2 to 21 Using the specific polymer (I) or the specific polymer (II) obtained in Synthesis Examples 2 to 21, a liquid crystal aligning agent was prepared, except that
A liquid crystal display device was manufactured in the same manner as in Example 1. In each example, the liquid crystal orientation of the liquid crystal display element, the voltage holding ratio, the reliability and the pretilt angle, and the film thickness uniformity of the liquid crystal orientation film were evaluated. The results are shown in Table 1.

Comparative Examples 1 to 3 Using the specific polymers (I) obtained in Synthesis Examples 22 to 24,
A liquid crystal display device was produced in the same manner as in Example 1 except that the liquid crystal aligning agent was prepared. In each comparative example, the liquid crystal orientation of the liquid crystal display element, the voltage holding ratio, the reliability and the pretilt angle, and the film thickness uniformity of the liquid crystal orientation film were evaluated. The results are shown in Table 1.

[0094]

[Table 1]

[0095]

According to the liquid crystal aligning agent of the present invention, when a liquid crystal aligning film is formed, the liquid crystal display device has excellent film thickness uniformity, good liquid crystal aligning property, and excellent voltage holding ratio and long-term reliability. A liquid crystal aligning agent capable of giving In addition, a liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention can be used, for example, in Japanese Patent Laid-Open No.
JP-A-222366 and JP-A-6-281937, a process of changing the pretilt angle by irradiating ultraviolet rays, or Japanese Patent Application Laid-Open No. H05-281937.
No. 107544, a resist film is partially formed on the surface of a liquid crystal alignment film subjected to a rubbing treatment, the rubbing treatment is performed in a direction different from the previous rubbing treatment, and then the resist film is removed. By performing a treatment that changes the alignment ability of the liquid crystal alignment film, the visual field characteristics of the liquid crystal display element can be improved.

The liquid crystal display device having a liquid crystal alignment film formed by using the liquid crystal aligning agent of the present invention can be suitably used for a TN type liquid crystal display device, and by selecting a liquid crystal to be used, STN (Super twisted nematic) type, SH (S
It can be suitably used for a liquid crystal display device of upper homeotropic type, ferroelectricity and antiferroelectricity. Furthermore, a liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal aligning agent of the present invention can be effectively used in various devices,
For example, it is used for display devices such as desktop calculators, wrist watches, table clocks, coefficient display boards, word processors, personal computers, and liquid crystal televisions.

The preferred embodiments of the present invention detailed above will be described below. 1. Compound (I) in all diamines used for producing a polyamic acid by reacting with compound (I)
A liquid crystal aligning agent in which the ratio of I) is 10 to 70 mol%, the ratio of compound (III) is 30 to 80 mol%, and the ratio of compound (IV) is 0.5 to 25 mol%. 2. Compound (I) in all diamines used for forming polyamic acid by reacting with compound (I)
A liquid crystal aligning agent having a ratio of I) of 10 to 60 mol%. 3. Compound (I) in the total diamine used for producing polyamic acid by reacting with compound (I)
A liquid crystal aligning agent in which the ratio of II) is 40 to 80 mol%. 4. Compound (I) in the total diamine used for producing a polyamic acid by reacting with compound (I)
A liquid crystal aligning agent having a ratio of V) of 1 to 15 mol%. 5. Compound (III) is 4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 4,4′-diaminodiphenyl ether, 2,7-diaminofluorene, 9,
9-bis (4-aminophenyl) fluorene, 4,4-
(P-phenyleneisoprilopylidene) bisaniline,
4,4 '-(m-phenylene isopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] propane and 5-amino-1- (4'-aminophenyl) -1,3, A liquid crystal aligning agent which is at least one diamine compound selected from 3-trimethylindane. 6. A liquid crystal aligning agent, wherein R ^{1 of the} formula (1) is at least one of tetravalent groups represented by the formulas (9-1) and (9-2). 7. Compound (I) is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3,4-dicarboxy-1,2,3,
A liquid crystal aligning agent which is at least one of 4-tetrahydro-1-naphthalene succinic dianhydride and 2,3,5-tricarboxycyclopentyl acetic acid dianhydride. 8. A liquid crystal aligning agent in which the compound (II) is 1,4-phenylenediamine.

 ──────────────────────────────────────────────────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. (A) The following general formula (1): A tetracarboxylic acid dianhydride represented by the formula (wherein R ¹ is a tetravalent organic group); and (B) (i) the following general formula (2): (In the formula (2), R ² is an alkyl group, an alkoxyl group or a halogen atom, and a is an integer of 0 to 4), (ii) the following general formulas (3), (4) ), (5), (6) and (7) (In the general formulas (3) to (7), R ³ , R ⁴ , R ⁵ , R ⁶ ,
R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ are each independently an alkyl group, an alkoxyl group or a halogen atom, R ⁷ is a divalent organic group, and b, c, h , I and j are each independently an integer of 0 to 3, and d, e, f,
g and k are each independently an integer of 0 to 4), and (iii) at least one aromatic diamine selected from the group of compounds represented by the following general formula (8) H ₂ N—R ¹⁴ — NH ₂ (8) (in the formula (8), R ¹⁴ is a divalent organic group having a steroid skeleton), a polyamic acid produced by reacting with a diamine having a steroid skeleton, and the polyamic acid A liquid crystal aligning agent comprising at least one of imidized polymers formed by dehydration ring closure.