JP2002277880A - Liquid crystal aligning agent for coating resin substrate, and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent for coating a resin substrate, by which a liquid crystal alignment layer superior in liquid crystal alignment performance, pre-tilt angle stability, reliability, rubbing resistance even in the baking treatment at low temperatures can be obtained, and to provide a liquid crystal display element provided with the liquid crystal aligning layer obtained therefrom. SOLUTION: The liquid crystal alignment agent contains an amic acid recurring unit and an imide recurring unit.

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 that is applied to a resin substrate and can be fired at a temperature equal to or lower than the heat resistance temperature of the substrate, and a liquid crystal display device including a liquid crystal aligning film obtained from the liquid crystal aligning agent.

[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. And a TN (Twisted Nematic) liquid crystal cell having a long axis of the liquid crystal molecules twisted continuously by 90 degrees from one substrate to the other substrate. I have.

Further, by adding a chiral agent, a state in which the major axis of the liquid crystal molecules is continuously twisted over 180 degrees between the substrates is achieved, and an STN (Super Twisted Nem) utilizing the birefringence effect generated thereby is achieved.
Atic) type liquid crystal display elements also exist. More recently, a nematic liquid crystal layer having a homeotropic alignment state having negative dielectric anisotropy and a cholesteric liquid crystal layer having a helical axis parallel to the substrate normal are formed between opposing substrates. A guest-host type reflective liquid crystal display device in which a dye is added to a liquid crystal display device has also been developed. Orientation of the liquid crystal in these liquid crystal display elements is usually exhibited by a liquid crystal alignment film subjected to a rubbing treatment. Here, as a material of a liquid crystal alignment film constituting a liquid crystal display element, polyimide, polyamide, polyester, and the like 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.

Recently, the size and weight of liquid crystal display elements have been reduced.
Consideration of power consumption and the like has been advanced, and remarkable development has been achieved as a higher performance display element. In particular, attempts have been made to use a glass substrate that has been conventionally used for the purpose of weight reduction as a resin substrate. However, since the resin substrate has a low heat resistance temperature, the baking treatment for forming the liquid crystal alignment film must be performed at a lower temperature than usual, and at a low baking temperature, the pretilt angle stability and reliability of the liquid crystal alignment film are low. However, there is a problem that rubbing resistance is greatly reduced.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal alignment film having excellent liquid crystal alignment, pretilt angle stability, reliability, and rubbing resistance even in a baking treatment at a low temperature (for example, 150 ° C. or lower). An object of the present invention is to provide a liquid crystal aligning agent for coating a resin substrate and a liquid crystal display element comprising a liquid crystal aligning film obtained therefrom.

[0006]

The object and advantages of the present invention are to provide a polymer having a repeating unit represented by the following formula (I-1) and a repeating unit represented by the following formula (I-2). It is achieved by a liquid crystal aligning agent for coating a resin substrate, characterized by being contained.

[0007]

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Wherein P ¹ is a tetravalent organic group and Q ¹
Is a divalent organic group. )

[0009]

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Wherein P ² is a tetravalent organic group and Q ²
Is a divalent organic group. )

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The liquid crystal aligning agent according to the present invention has the formula (I-1)
And a polymer having a repeating unit represented by the above formula (I-2). The polymer may be a mixture of a polyamic acid having a repeating unit represented by the above formula (I-1) and a polyimide having a repeating unit represented by the above formula (I-2). A polymer in which a repeating unit represented by (I-1) and a repeating unit represented by the above formula (I-2) are bonded in the same molecule in a random or block manner (hereinafter, referred to as "partially imidized Polymer "). The polyamic acid is obtained by ring-opening polyaddition of a tetracarboxylic dianhydride and a diamine compound, and the polyimide is usually obtained by dehydrating and ring-closing a polyamic acid. The partially imidized polymer can be usually obtained by a method of partially dehydrating and cyclizing a polyamic acid or a method of combining an amic acid prepolymer and an imide prepolymer to synthesize a block copolymer.

<Polyamic acid> [Tetracarboxylic dianhydride] The tetracarboxylic dianhydride used in the synthesis reaction of polyamic acid includes, for example, butanetetracarboxylic dianhydride, 1,2,3,4-
Cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Product, 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 acid dianhydride, 3,
5,6-tricarboxynorbornane-2-acetic acid 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, 3
a, 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, 1,3,3a, 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, aliphatic and alicyclic tetracarboxylic dianhydrides such as the compounds represented by the following formulas (I) and (II);

[0013]

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(Wherein, R ¹ and R ^{4 each} represent a divalent organic group having an aromatic ring, R ² and R ^{3 each} represent a hydrogen atom or an alkyl group, and a plurality of R ² and R ³ represent , May be the same or different.)

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.

[0016]

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Of these, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 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-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxynorbornane-2-acetic acid 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-7-
Methyl-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- Zeon,
2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, bicyclo [2.2.2] -oct-7-ene-
2,3,5,6-tetracarboxylic dianhydride, cis-3,7
-Dibutylcycloocta-1,5-diene-1,2,5,6
-Alicyclic tetracarboxylic dianhydrides such as tetracarboxylic dianhydride and pyromellitic dianhydride are preferred.

In the repeating unit (amic acid unit) represented by the above formula (I-1), a tetravalent organic group represented by P ¹ and a repeating unit represented by the above formula (I-2) (an imide) (Unit) The tetravalent organic group represented by P ² is a group derived from tetracarboxylic dianhydride. Each of these may be the same or different, but the formula (I-
P ¹ in 1) is preferably a group represented by the following formula (i), and P ² in the formula (I-2) is preferably a group having an alicyclic skeleton. Particularly preferred are groups represented by the following formula (ii).

[0019]

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(Wherein R is a halogen atom, a methyl group or an ethyl group, a is an integer of 0 or 1, b is an integer of 0-5, c and d are an integer of 0-4. is there.)

Specific examples of the preferred tetracarboxylic dianhydride in each repeating unit are as follows. As the tetracarboxylic dianhydride constituting the amic acid unit, 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, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, pyromellitic dianhydride, etc. And the tetracarboxylic dianhydride constituting the imide unit is an alicyclic tetracarboxylic dianhydride, particularly 2,3,5-tricarboxycyclopentylacetic 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-7-methyl-
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 and the like.

[Diamine Compound] Examples of the diamine compound used in the synthesis reaction of the polyamic acid include, 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'-dimethyl-4,4'-diaminobiphenyl, , 2'-Ditrifluoromethyl-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, 1,
4.4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl ] Hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl An aromatic diamine;

1,1-meta-xylylenediamine, 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 [6,2,1,02.7] -undecylenedimethyldiamine, 4,4'-methylenebis (cyclohexylamine);

A monosubstituted phenylenediamine represented by the following formula (III): a diaminoorganosiloxane represented by the following formula (IV):

[0025]

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(Wherein R ⁵ represents —O—, —COO—,
OCO-, -NHCO-, -CONH- and -CO-
And R ⁶ represents a monovalent organic group having a steroid skeleton or a trifluoromethyl group. )

[0027]

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(Wherein R ⁷ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ^{7 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. )

Compounds represented by the following formulas (5) to (9) can be exemplified. These diamine compounds are:
They can be used alone or in combination of two or more.

[0030]

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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, preferred are p
-Phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,
5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 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-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4'-methylenebis (cyclohexylamine), 1,4-bis (4
-Aminophenoxy) benzene, 4,4'-bis (4-
Aminophenoxy) biphenyl, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine, 2,2′-dimethyl-4,4′-diaminobiphenyl, 2, 2′-Ditrifluoromethyl-4,4′-diaminobiphenyl, a diamine represented by the above formula (III), represented by the following formulas (10) to
Examples include the compound represented by (15), the compound represented by the above formula (IV), and the compounds represented by the above formulas (5) to (7).

[0033]

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[Synthesis reaction of polyamic acid] The ratio of the tetracarboxylic dianhydride and the diamine compound used in the synthesis reaction of the polyamic acid is such that tetracarboxylic acid is equivalent to 1 equivalent of the amino group contained in the diamine compound. The ratio in which the acid anhydride group contained in the dianhydride is 0.2 to 2 equivalents is preferable, and the ratio is more preferably 0.3 to 1.4 equivalents. In both cases where the ratio of the acid anhydride groups contained in the tetracarboxylic dianhydride is less than 0.2 equivalent or more than 2 equivalents, the molecular weight of the obtained polymer becomes too small and the application of the liquid crystal aligning agent is performed. The properties may be poor.

The synthesis reaction of the polyamic acid is carried out in an organic solvent at a temperature of usually 0 to 150 ° C., preferably 0 to 100 ° C. If the reaction temperature is 0 ° C or lower, the solubility of the compound in a solvent may be poor, and if it exceeds 150 ° C, the molecular weight of the obtained polymer may decrease.

The organic solvent used for the synthesis of the polyamic acid is not particularly limited as long as it can dissolve the tetracarboxylic dianhydride, the diamine compound and the polyamic acid formed by the reaction. For example, γ-butyrolactone, N Aprotic systems such as -methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, tetramethylurea, hexamethylphosphoryltriamide, 1,3-dimethyl-2-imidazolidinone Polar solvents; phenolic solvents such as m-cresol, xylenol, phenol, halogenated phenol and the like can be mentioned.

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, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate,
Diethyl malonate, diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl 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, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether Le, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, ethylene glycol ethyl ether acetate, 4
-Hydroxy-4-methyl-2-pentanone, ethyl 2-hydroxypropionate, ethyl lactate, methyl lactate,
Butyl lactate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-
Methyl methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3-methyl-3-methoxybutanol, 3-ethyl-3-methoxybutanol, 2-methyl-2-methoxybutanol,
2-ethyl-2-methoxybutanol, 3-methyl-3
-Ethoxybutanol, 3-ethyl-3-ethoxybutanol, 2-methyl-2-ethoxybutanol, 2-ethyl-2-ethoxybutanol, tetrahydrofuran,
Dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-
Examples thereof include dichlorobenzene, hexane, heptane, octane, benzene, toluene, and xylene. These can be used alone or in combination of two or more.

The amount (A) of the organic solvent used is such that the total amount (B) of the tetracarboxylic dianhydride and the diamine compound as the reaction raw materials is 0.1 to 3 with respect to the total amount (A + B) of the reaction solution.
Preferably, the amount is 0% by weight.

By the above synthesis reaction, a polymer solution obtained by dissolving the polyamic acid is obtained. The polymer 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.

<Polyimide> The polyimide constituting the liquid crystal aligning agent of the present invention can be synthesized by the following methods (1) to (3). In addition, a so-called imidation ratio of 10 when a part of the repeating unit of the polyamic acid is dehydrated and ring-closed is 10%.
A polymer having less than 0% is also suitably used for the liquid crystal aligning agent of the present invention. The term "imidation ratio" used herein indicates the percentage of the repeating unit having an imide ring in the repeating units of the entire polymer, expressed as a percentage.

Method (1): A method in which a polyamic acid is heated to effect dehydration and ring closure. The reaction temperature in this method is usually from 60 to 300C, preferably from 100 to 250C. When the reaction temperature is lower than 60 ° C., the imidization reaction does not proceed sufficiently, and when the reaction temperature exceeds 300 ° C., the molecular weight of the obtained polyimide may be small.

Method (2): A method in which a polyamic acid is dissolved in an organic solvent, a dehydrating agent and an imidization catalyst are added to the solution, and the solution is heated if necessary. In this method, as the dehydrating agent, for example, acetic anhydride,
Acid anhydrides such as propionic anhydride and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is preferably 1.6 to 20 mol per 1 mol of the repeating unit of the polyamic acid. Further, as the imidation catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but are not limited thereto. The amount of the imidation catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the imidization reaction, the organic solvents exemplified as those used for the synthesis of the polyamic acid can be exemplified. And the reaction temperature of the imidization reaction is usually 0 to 180 ° C, preferably 60 to 150 ° C.

Method (3): A method in which tetracarboxylic dianhydride and a diisocyanate compound are mixed and condensed. Specific examples of the diisocyanate compound used in this method include: an aliphatic diisocyanate compound such as hexamethylene diisocyanate; an alicyclic diisocyanate compound such as cyclohexane diisocyanate; diphenylmethane-4,4'-diisocyanate, diphenylether-4,4'- Diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, 1,2-diphenylethane-p, p'-diisocyanate, 2,2-diphenylpropane-p, p'-diisocyanate, 2,2-diphenyl-1,1,1,3,3,3-hexafluoropropane-p, p'-diisocyanate, 2,2-diphenylbutane-p, p'-diisocyanate, diphenyl dichloromethane-4,4 ' -Diisocyanates, diphs Aromatic diisocyanate compounds such as nylfluoromethane-4,4′-diisocyanate, benzophenone-4,4′-diisocyanate, and N-phenylbenzoic acid amide-4,4′-diisocyanate can be given, either alone or Two or more can be used in combination. This method does not require a catalyst, and the reaction temperature is usually 50 to 200 ° C., preferably 100 to 160 ° C.
° C. For the polymer solution thus obtained,
The polyimide can be purified by performing the same operation as the method for purifying the polyamic acid.

<Partially imidized polymer> The imidation ratio of the partially imidized polymer constituting the liquid crystal aligning agent of the present invention is preferably 10 to 80%, particularly preferably 20 to 80%.
70%. The partially imidized polymer is obtained by the following method (4)
To (5). Method (4): A method of partially dehydrating and cyclizing a polyamic acid. Examples of the method of dehydration ring closure include the method (1) and the method (2) in the method for synthesizing polyimide. (Please describe if the reaction conditions are different. Also, isn't it preferable to use chemical imidization? In that case, I would like to mention that.) Method (5): Amic acid pretreatment A method of obtaining a block copolymer by bonding a polymer and an imide prepolymer. Amic acid prepolymer is the same as the above polyamic acid synthesis method, except that the amount ratio of tetracarboxylic dianhydride and diamine compound is adjusted to a polymer having an amino group or an acid anhydride group at the terminal. Can be obtained. The imide prepolymer is prepared by the above-mentioned method (except that the above amic acid prepolymer is subjected to dehydration and ring closure, or a polymer having an amino group or an isocyanate group at a terminal by adjusting a quantitative ratio of a diisocyanate compound and a diamine compound). It can be obtained by the same method as in 3). A block copolymer can be synthesized by reacting an amino group at each terminal with an acid anhydride group or an amino group and an isocyanate group in these prepolymers.

<Intrinsic Viscosity of Polymer> The intrinsic viscosity of the polymer obtained as described above (measured in N-methyl-2-pyrrolidone at 30 ° C .; the same applies hereinafter) is usually 0.1.
05 to 10 dl / g, preferably 0.05 to 5 dl / g
It is.

<Terminal-Modified Polymer> The polymer constituting the liquid crystal aligning agent of the present invention may be a terminal-modified polymer. The molecular weight of the terminal-modified polymer is controlled,
The coating characteristics of the liquid crystal alignment agent can be improved without impairing the effects of the present invention. The terminal-modified polymer is
When synthesizing a polyamic acid, it can be synthesized by adding an acid anhydride, a monoamine compound, or a monoisocyanate compound to a reaction system.

The acid anhydride to be added to the reaction system for synthesizing the polyamic acid to obtain a terminal-modified polymer includes, for example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic acid Anhydride, n-dodecyl succinic anhydride, n-tetradecyl succinic anhydride, n-hexadecyl succinic anhydride and the like can be mentioned. Examples of the monoamine added to the reaction system include, for example, 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-eicosyl Alkylamines such as amines; 3-aminopropylmethyldiethoxysilane, 3- [N-allyl-N- (2-aminoethyl)] aminopropyltrimethoxysilane, N- (2
-Aminoethyl) -3-aminopropylmethyldimethoxysilane, silyl group-containing amines such as N-[(3-trimethoxysilyl) propyl] diethylenetriamine; 4-aminophenyl-n-butyl ether, 4-aminophenyl-n- Pentyl ether, 4-aminophenyl-n-hexyl ether, 4-aminophenyl-n
-Octyl ether, 4-aminophenyl-n-decyl ether, 4-aminophenyl-n-dodecyl ether, 4-aminophenyl-n-hexadecyl ether,
Examples include aminophenyl alkyl ethers such as 4-aminophenyl-n-octadecyl ether. In addition, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention is usually constituted by dissolving the above polymer in an organic solvent. The ratio of the repeating unit represented by the formula (I-1) to the repeating unit represented by the formula (I-2) in the polymer constituting the liquid crystal aligning agent of the present invention is 9: 1-7: 3 is preferred. Examples of the organic solvent constituting the liquid crystal alignment agent of the present invention include the solvents exemplified as those used in the synthesis reaction of the polyamic acid. In addition, the poor solvents exemplified as those which can be used together in the synthesis reaction of the polyamic acid can be appropriately selected and used in combination.

The solid content of the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility and the like, but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the substrate surface to form a coating film serving as a liquid crystal alignment film. When the solid content concentration is less than 1% by weight, the thickness of the coating film is reduced. It is too small to obtain a good liquid crystal alignment film. If the solids content exceeds 10% by weight, the thickness of the coating film becomes excessively large, making it difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent is increased, so that the coating characteristics are likely to be inferior. The temperature at the time of preparing the liquid crystal aligning agent of the present invention is preferably 0 ° C to 200 ° C, more preferably 20 ° C to 60 ° C.

The liquid crystal aligning agent of the present invention may contain a compound having at least one epoxy group in the molecule (hereinafter, also referred to as “epoxy group-containing compound”) from the viewpoint of improving the adhesion to the substrate surface. preferable. Examples of such an epoxy group-containing compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether,
1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 1,3,5,6
-Tetraglycidyl-2,4-hexanediol, N,
N, N ', N',-tetraglycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N',-tetraglycidyl-4, 4'-diaminodiphenylmethane and the like can be mentioned as preferred.

Further, the liquid crystal aligning agent of the present invention may contain a functional silane-containing compound. Examples of such functional silane-containing compounds 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-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-aminop Pills triethoxysilane, N-
Phenyl-3-aminopropyltrimethoxysilane, N
-Phenyl-3-aminopropyltriethoxysilane,
Examples thereof include N-bis (oxyethylene) -3-aminopropyltrimethoxysilane and N-bis (oxyethylene) -3-aminopropyltriethoxysilane.

The compounding ratio of the epoxy group-containing compound and the functional silane-containing compound is preferably 40 parts by weight or less, more preferably 0.1 part by weight, based on 100 parts by weight of the polymer.
1 to 30 parts by weight.

<Liquid crystal display element> The liquid crystal display element of the present invention can be manufactured, for example, by the following method. (1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate on which a patterned transparent conductive film is provided by, for example, a roll coater method, a spinner method, a printing method, and the like, and then the coated surface is heated. To form a coating film. Here, a resin substrate is used as the substrate. Specifically, a transparent substrate made of a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, or polycarbonate can be used. Particularly preferably, a transparent substrate made of polyethersulfone is used. As the transparent conductive film provided on one surface of the substrate, NES made of tin oxide (SnO ₂ ) is used.
A film (registered trademark of US PPG), ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like can be used. A photo-etching method or a method using a mask in advance is used for patterning these transparent conductive films. In applying the liquid crystal aligning agent, a functional silane-containing compound, a functional titanium-containing compound, etc. are applied in advance to the substrate surface and the surface of the substrate in order to further improve the adhesion between the transparent conductive film and the coating film. You can also. The heating temperature after the application of the liquid crystal alignment agent is a temperature lower than the heat resistance temperature of the resin substrate, preferably 80 to 160 ° C, more preferably 120 to 150 ° C. Incidentally, the polymer having an amic acid unit in the liquid crystal alignment agent of the present invention,
After the coating film is formed, further heating may cause dehydration ring closure to proceed, resulting in a more imidized coating film. The thickness of the formed coating film is preferably 0.001 to 1 μm, more preferably 0.005 to 0.5 μm.

(2) A rubbing treatment is performed in which the formed coating film surface is rubbed in a certain direction with a roll around which a cloth made of a fiber such as nylon, rayon, cotton or the like is wound. Thereby, the alignment ability of the liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film. Further, the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention, for example, as disclosed in JP-A-6-222366 and JP-A-6-281937,
A process of changing the pretilt angle by partially irradiating ultraviolet rays, or Japanese Patent Application Laid-Open No. Hei 5-10754.
No. 4, as described in Japanese Patent Application Laid-Open Publication No. 4 (1999) -1995, a resist film is partially formed on a rubbed liquid crystal alignment film surface, and the rubbing process is performed in a direction different from the previous rubbing process, and then the resist film is removed. By performing a process for changing the liquid crystal alignment ability of the liquid crystal alignment film, the visibility characteristics of the liquid crystal display element can be improved.

(3) Two substrates on each of which a liquid crystal alignment film is formed as described above are prepared, and the two substrates are arranged to face each other with a gap (cell gap) therebetween. A liquid crystal cell is formed by bonding using a sealant, injecting and filling liquid crystal into the substrate surface and into a cell gap defined by the sealant, and sealing the injection hole. Then, a liquid crystal display element is obtained by attaching a polarizing plate to the outer surface of the liquid crystal cell, that is, the other surface side of each substrate constituting the liquid crystal cell.

Here, as the sealing agent, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal, for example, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal,
Terphenyl-based liquid crystal, biphenylcyclohexane-based liquid crystal, pyrimidine-based liquid crystal, dioxane-based liquid crystal, bicyclooctane-based liquid crystal, cubane-based liquid crystal, and the like can be used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, cholesteryl carbonate, and the product name "C-15"
A chiral agent such as that sold as "CB-15" (manufactured by Merck) may be added for use.
Further, as a polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing plate or an H film in which a polarizing film called an H film absorbing iodine is sandwiched by a cellulose acetate protective film while stretching and aligning polyvinyl alcohol. A polarizing plate composed of itself can be mentioned.

[0057]

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 pretilt angle stability, reliability, and rubbing resistance of the liquid crystal display elements in Examples and Comparative Examples were evaluated by the following methods.

(Pretilt Angle Stability) A liquid crystal display element of antiparallel alignment (a combination of two substrates so that the liquid crystal alignment directions are antiparallel) was prepared, and a liquid crystal display element was prepared at room temperature.
The pre-tilt angle was measured for each of the specimens kept at 120 ° C. for 1 hour, and the value obtained by subtracting the pre-tilt angle at 120 ° C. from the pre-tilt angle at room temperature was calculated as the pre-tilt angle reduction degree. Was measured. The smaller the pretilt angle reduction degree,
Good pretilt angle stability. Note that the pretilt angle was measured by a crystal rotation method.

(Reliability) A liquid crystal display element was placed in a constant temperature bath at 70 ° C., and a drive waveform generator “Function / arbitrary wa
veform generator "(Hewlett-Packard)
After 24 hours of continuous driving, the presence or absence of contrast unevenness and display defects was visually checked, and those in which these were not recognized were evaluated as “good”.

(Rubbing resistance) A liquid crystal aligning agent was coated on a polyethersulfone substrate having an ITO film thickness of 1500 ° and fired. The roll rotation speed was 1,000 rpm, the stage moving speed was 70 mm / sec, and the hair press-in length was 0.5 mm. Rubbing was carried out under the conditions, and the presence or absence of scratches and peeling on the surface was observed with an optical microscope. Those in which these were not observed were evaluated as “good”.

Synthesis Example 1 224.17 g (0.5%) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride
Mol) and 1,3,3a, 4,5,9b-hexahydro-
5-methyl-5 (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] -furan-1,3-
157.14 g (0.5 mol) of dione, 94.62 g (0.875 mol) of p-phenylenediamine as a diamine compound, 32.02 g (0.2%) of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl 1 mol) and 3,6
6.43 g (0.01 mol) of -bis (4-aminobenzoyloxy) cholestan (the compound represented by the above formula (5)), and 4.04 g (0.015 mol) of 4-aminophenyloctadecyl ether as a monoamine. N-methyl-
It was dissolved in 4500 g of 2-pyrrolidone and reacted at 60 ° C. for 6 hours. Then, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the resultant was washed with methyl alcohol and dried under reduced pressure at 40 ° C. for 15 hours to obtain 410 g of polyamic acid having an intrinsic viscosity of 0.87 dl / g. 30 g of the obtained polyamic acid was dissolved in 570 g of N-methyl-2-pyrrolidone, and 23.4 g of pyridine and 18.1 g of acetic anhydride were added thereto.
At 4 ° C. for 4 hours, followed by precipitation, washing, and reduced pressure in the same manner as described above to obtain a polyimide having a logarithmic viscosity of 0.80 dl / g and an imidation ratio of 100% (this is referred to as “polyimide (A-
1) ") 17.5 g was obtained.

Synthesis Example 2 224.17 g (0.5%) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride
Mol) and 1,3,3a, 4,5,9b-hexahydro-
5-methyl-5 (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] -furan-1,3-
157.14 g (0.5 mol) of dione, 94.62 g (0.875 mol) of p-phenylenediamine as a diamine compound, 24.85 g of bisaminopropyltetramethyldisiloxane (compound represented by the above formula (IV)) (0.1
Mol) and 3,6-bis (4-aminobenzoyloxy) cholestan (compound represented by the above formula (5)) 6.
43 g (0.01 mol) and 4.04 g (0.015 mol) of 4-aminophenyloctadecyl ether as a monoamine were dissolved in 4500 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. Then, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. After that, it is washed with methyl alcohol, and the pressure is reduced to 40 ° C.
For 15 hours at a logarithmic viscosity of 0.82 d.
370 g of 1 / g polyamic acid were obtained. 30 g of the obtained polyamic acid was mixed with N-methyl-2-pyrrolidone 570.
g of pyridine, 23.4 g of pyridine and 18.2 g of acetic anhydride.
1 g was added, and the mixture was dehydrated and ring-closed at 110 ° C. for 4 hours.
As a result, 18.5 g of a 1 / g polyimide having an imidation ratio of 100% (hereinafter referred to as "polyimide (A-2)") was obtained.

Synthesis Example 3 As a tetracarboxylic dianhydride, 224.2 g (0.05) of 2,3,5-tricarboxycyclopentylacetic dianhydride
Mol) and 1,3,3a, 4,5,9b-hexahydro-
5-methyl-5 (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] -furan-1,3-
298.57 g (0.95 mol) of dione, 83.81 g (0.7 g) of p-phenylenediamine as a diamine compound
75 mol) 2,2'-ditrifluoromethyl-4,4 '
-Diaminobiphenyl (64.04 g, 0.2 mol) and 3,6-bis (4-aminobenzoyloxy) cholestan (compound represented by the above formula (5)), 6.43 g (0.4%).
01 mol) and 4.04 g (0.015 mol) of 4-aminophenyloctadecyl ether as a monoamine were dissolved in 4500 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 6 hours. Then, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. afterwards,
After washing with methyl alcohol and drying under reduced pressure at 40 ° C. for 15 hours, 410 g of a polyamic acid having a logarithmic viscosity of 0.85 dl / g was obtained. The obtained polyamic acid 3
0 g was dissolved in 570 g of N-methyl-2-pyrrolidone, 23.4 g of pyridine and 18.1 g of acetic anhydride were added, and the mixture was dehydrated and ring closed at 110 ° C. for 4 hours. 15.1 g of a polyimide having a viscosity of 0.83 dl / g and an imidation ratio of 100% (hereinafter referred to as "polyimide (A-3)") was obtained.

Synthesis Example 4 196.12 g (1.0 mol) of cyclobutanetetracarboxylic dianhydride as tetracarboxylic dianhydride and 212 g of 2,2′-dimethyl-4,4′-diaminobiphenyl (1) as diamine compound 2.0 mol) with N-methyl-2-
It was dissolved in 4500 g of pyrrolidone and reacted at 60 ° C. for 6 hours. Then, the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the resultant is washed with methyl alcohol and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid having a logarithmic viscosity of 0.90 dl / g (this is referred to as “polyamic acid (B-1)”).
0 g was obtained.

Synthesis Example 5 In Synthesis Example 4, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 98.06 g (0.5 mol) of cyclobutanetetracarboxylic dianhydride.
Mol), and a polyamic acid having a logarithmic viscosity of 0.93 dl / g (this was referred to as “polyamic acid”) in the same manner as in Synthesis Example 4 except that the diamine compound was changed to 2,0.2 g (1.0 mol) of 4,4′-diaminodiphenyl ether. Acid (B-2) ").

Synthesis Example 6 Synthesis Example 1 was the same as Synthesis Example 1 except that 96.24 g (0.89 mol) of p-phenylenediamine was used except for 4-aminophenyloctadecyl ether which was a monoamine.
An imide prepolymer was synthesized in the same manner as described above, and dissolved in N-methyl-2-pyrrolidone to obtain a solution having a solid content of 10% by weight. Further, the polyamic acid (B-2) obtained in Synthesis Example 5 was used as an amic acid prepolymer,
Similarly, it was dissolved in N-methyl-2-pyrrolidone to obtain a solution having a solid content of 10% by weight. Next, 200 g of the imide prepolymer solution and 800 g of the amic acid prepolymer were mixed and stirred for 2 hours, and then the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. afterwards,
After washing with methyl alcohol and drying at 40 ° C. under reduced pressure for 15 hours, a partially imidized polymer having a logarithmic viscosity of 0.95 dl / g and an imidation ratio of 25% (this is referred to as “polymer (C-1)”) 100 g).

Synthesis Example 7 Synthesis Example 2 was the same as Synthesis Example 2, except that 4-aminophenyloctadecyl ether, which was a monoamine, was used and 96.24 g (0.89 mol) of p-phenylenediamine was used.
An imide prepolymer was synthesized in the same manner as described above, and dissolved in N-methyl-2-pyrrolidone to obtain a solution having a solid content of 10% by weight. Further, using the polyamic acid (B-1) obtained in Synthesis Example 4 as an amic acid prepolymer,
Similarly, it was dissolved in N-methyl-2-pyrrolidone to obtain a solution having a solid content of 10% by weight. Next, 200 g of the imide prepolymer solution and 800 g of the amic acid prepolymer were mixed and stirred for 2 hours, and then the reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. afterwards,
After washing with methyl alcohol and drying under reduced pressure at 40 ° C. for 15 hours, a partially imidized polymer having a logarithmic viscosity of 0.93 dl / g and an imidation ratio of 25% (this is referred to as “polymer (C-2)”) 100 g).

Example 1 The polyimide (A-1) obtained in Synthesis Example 1 and the polyamic acid (B-1) obtained in Synthesis Example 4 were converted to polyimide: polyamic acid = 20: 80 (weight ratio). Thus, a solution having a solid content of 4% by weight was dissolved in an N-methyl-2-pyrrolidone / γ-butyrolactone mixed solvent (weight ratio: 30/70), and this solution was filtered using a filter having a pore size of 1 μm. A liquid crystal alignment agent of the present invention was prepared. The above-mentioned liquid crystal aligning agent was applied to IT using a printing machine for coating a liquid crystal alignment film.
Apply to the transparent electrode surface of a polyether sulfone substrate with a transparent electrode made of O film, and place on a hot plate at 150 ° C for 9
After drying for 0 minutes, a film having a dry average film thickness of 500 ° was formed. Using a rubbing machine having a roll in which a rayon cloth is wound around the coating, the number of rotations of the roll is 400 r.
Rubbing treatment was performed at pm, a stage moving speed of 3 cm / sec, and a hair foot pushing length of 0.4 mm. The liquid crystal alignment film-coated substrate was immersed in isopropyl alcohol for 1 minute, and then dried on a hot plate at 100 ° C. for 5 minutes.
Next, an epoxy resin adhesive containing aluminum oxide spheres with a diameter of 5.5 μm is applied to the outer edges of the pair of substrates coated with the liquid crystal alignment film having the liquid crystal alignment film, and then stacked such that the liquid crystal alignment film surfaces face each other. They were pressed together and the adhesive was cured. Next, after filling a nematic liquid crystal (MLC-6221 manufactured by Merck) between the substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an acrylic photocuring adhesive,
A polarizing plate was stuck on both outer surfaces of the substrate to produce a liquid crystal display device. The pretilt angle stability and reliability of the obtained liquid crystal display device were evaluated. Table 1 shows the results. Further, rubbing resistance was evaluated using the above liquid crystal aligning agent. The results are shown in Table 1.

Examples 2 to 6, Comparative Examples 1 and 2 In the same manner as in Example 1 except that the polymers shown in Table 1 were used, a liquid crystal aligning agent was prepared, and a liquid crystal display device was prepared. went. Table 1 shows the results.

Examples 7 to 8 Using the polymers shown in Table 1, N, N, N ', N'-tetraglycidyl-4,4'-diaminodiphenylmethane was added as an epoxy group-containing compound to 100 parts by weight of the polymer. 1 for
A liquid crystal aligning agent was prepared, a liquid crystal display element was prepared, and each evaluation was performed in the same manner as in Example 1 except that the addition was performed so as to be 0 parts by weight. The results are shown in Table 1.

[0071]

[Table 1]

[0072]

According to the liquid crystal aligning agent of the present invention, when a liquid crystal display device using a resin substrate is manufactured, a liquid crystal display device exhibiting high pretilt angle stability, excellent in reliability and rubbing resistance is manufactured. TN type liquid crystal display device, S
It can be suitably used to form various liquid crystal display elements such as a TN type liquid crystal display element, a reflection type liquid crystal display element, and a vertical alignment type liquid crystal display element (SH type, MVA type, etc.). The liquid crystal display element of the present invention can be effectively used for various devices, and is suitably used as a display device such as a desktop calculator, a wristwatch, a clock, a mobile phone, a counting display, a word processor, a personal computer, and a liquid crystal television. Can be used.

Continued on front page F-term (reference) 2H090 HB07Y KA05 KA08 MB01 4J002 CD012 CD122 CM041 EL026 FD200 FD202 FD206 GP00 4J043 PA02 PA08 PA09 PA19 PB21 PB22 PB23 QB15 QB26 QB31 RA35 SA02 SA06 SA42 SA43 SA45 SA46 SA52 SA54 SA52 SA52 SA54 TA22 TA43 TA67 TA68 TA69 TA72 TB01 TB02 UA012 UA022 UA032 UA041 UA042 UA051 UA061 UA062 UA081 UA082 UA121 UA122 UA131 UA132 UA141 UA151 UA152 UA161 UA162 UA182 UA232 UA241 UA251 UA261 UA262 UA622 UB011 UB012 UB061 UB062 UB121 UB122 UB131 UB132 UB151 UB152 UB161 UB162 UB241 UB281 UB282 UB301 UB302 UB352 UB382 VA041 WA09 XA03 XA14 XA15 XA16 XA17 XA18 XA19 XB06 XB07 XB09 YA06 YA08 ZA23 ZB03 ZB21 ZB23

Claims (4)

[Claims] 1. A resin substrate coating comprising a polymer having a repeating unit represented by the following formula (I-1) and a repeating unit represented by the following formula (I-2): Liquid crystal aligning agent. Embedded image (In the formula, P ¹ is a tetravalent organic group, and Q ¹ is a divalent organic group.) (In the formula, P ² is a tetravalent organic group, and Q ² is a divalent organic group.) 2. In the formula (I-2) of claim 1, P ²
The liquid crystal aligning agent for resin substrate coating according to claim 1, wherein is a group derived from alicyclic tetracarboxylic dianhydride. 3. The liquid crystal aligning agent for coating a resin substrate according to claim 1, comprising a compound having at least one epoxy group in a molecule. 4. A liquid crystal display device comprising a liquid crystal alignment film obtained by applying and drying the liquid crystal alignment agent according to claim 1 on a resin substrate.