JP2002062537A - Liquid crystal aligning agent for stn (supertwisted nematic) liquid crystal display element and stn liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal aligning agent for an STN liquid crystal display element realizing a wide viewing angle and quick response speed with <=4 deg. pretilt angle. SOLUTION: In the liquid crystal aligning agent containing a polyamic acid obtained by reacting a tetracarboxylic acid dianhydride with a diamine and/or an imide polymer obtained by ring closure of the polyamic acid with dehydration, the liquid crystal aligning agent for the STN liquid crystal display element is provided which is characterized by <=15 mol% of the tetracarboxylic acid dianhydride being pyromellitic acid dianhydride, by >=15 mol% of the diamine being 2,2-bis[4-(4-aminophenoxy)phenyl]propane and by retaining <=4 deg. pretilt angle produced by the liquid crystal alignment layer obtained from the liquid crystal aligning agent.

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 for an STN type liquid crystal display device which has excellent liquid crystal alignment properties and can realize a high viewing angle and a fast response speed.

[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. Also,
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 STN (S
There is also an upper Twisted Nematic type liquid crystal display device. 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 the liquid crystal alignment film constituting the 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.

However, recently, liquid crystal display elements have been remarkably developed as high performance display elements with larger size, lighter weight, lower power consumption, etc., and accordingly, the required performance of liquid crystal alignment films has become more severe. I have. However, in the liquid crystal alignment film of a conventionally known polyimide precursor such as polyamic acid or an imide polymer having a structure obtained by dehydration ring closure, the liquid crystal alignment film is used. When a liquid crystal display element is manufactured, there are many liquid crystal display elements having a problem that the liquid crystal alignment ability is excellent and the viewing angle is narrow and the response speed is slow even if the pretilt angle is stable. In particular, these problems are more remarkable in an STN type liquid crystal display device having a twist angle of 180 degrees or more. Therefore, in the STN-type liquid crystal display device, attempts have been made to reduce the pretilt angle, which is usually 6 to 7 °, to, for example, 4 ° or less to improve the viewing angle and the response speed. This is because, by reducing the pretilt angle, light leakage from oblique directions can be reduced, and the interaction between the liquid crystal and the alignment film can be increased. However,
In conventional liquid crystal alignment films for STN-type liquid crystal display devices, when the pretilt angle is reduced, poor alignment of the liquid crystal occurs, and a favorable liquid crystal display device cannot be manufactured.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ST having a pretilt angle of 4 ° or less for realizing a high viewing angle and a high-speed response.
An object of the present invention is to provide a liquid crystal alignment agent for an N-type liquid crystal display device.
Still other objects and advantages of the present invention will become apparent from the following description.

[0005]

SUMMARY OF THE INVENTION The object and advantages of the present invention are to provide a polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine and / or an imidization obtained by dehydrating and ring-closing the polyamic acid. In a liquid crystal aligning agent containing a polymer, 15 mol% or more of tetracarboxylic dianhydride is pyromellitic dianhydride and 15 mol% or more of diamine is 2,2-bis [4-
(4-aminophenoxy) phenyl] propane;
A pre-tilt angle developed by a liquid crystal alignment film obtained from a liquid crystal alignment agent is 4 ° or less;
This is achieved by a liquid crystal alignment agent for a liquid crystal display device.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The liquid crystal aligning agent in the present invention includes tetracarboxylic dianhydride having pyromellitic dianhydride of 15 mol% or more and 2,2-bis [4- (4-aminophenoxy) phenyl] propane of 15 mol% or more. A polyamic acid obtained by reacting with a diamine having and / or an imidized polymer obtained by dehydrating and ring-closing the polyamic acid (hereinafter, the polyamic acid and the imidized polymer are also referred to as “specific polymers”), Usually, it is dissolved in an organic solvent.

<Polyamic Acid> The polyamic acid used in the present invention is obtained by ring-opening polyaddition of a tetracarboxylic dianhydride and a diamine compound.

[Tetracarboxylic dianhydride] As the tetracarboxylic dianhydride, pyromellitic dianhydride is contained in an amount of 15 mol% or more, preferably 15 to 80 mol%, of all the tetracarboxylic dianhydrides. . Pyromellitic acid 15
By containing at least mol%, a liquid crystal alignment film having good liquid crystal alignment can be obtained even when the pretilt angle is 4 ° or less. In the present invention, it is preferable to further use an alicyclic tetracarboxylic dianhydride as the other tetracarboxylic anhydride. By using an alicyclic tetracarboxylic dianhydride, 80-100
% Of the liquid crystal alignment film having a high voltage holding ratio. The alicyclic tetracarboxylic dianhydride is usually 85 mol% in all the tetracarboxylic dianhydrides.
Hereinafter, the content is preferably 15 to 85 mol%, more preferably 30 to 70 mol%. Examples of the alicyclic tetracarboxylic dianhydride include 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,2
3,4-cyclobutanetetracarboxylic dianhydride, 1,
2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5
-Cyclohexanetetracarboxylic dianhydride, 3,
3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3 , 4,5-Tetrahydrofurantetracarboxylic dianhydride, bicyclo [2.2.2]
-Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, cis-3,7-dibutylcycloocta-
1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-
5 (tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] -furan-1,3-dione,
1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione; 1,3,3a, 4,5,9b-hexahydro-5-
Ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7
-Methyl-5 (tetrahydro-2,5-dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-
Dione, 1,3,3a, 4,5,9b-hexahydro-
7-ethyl-5 (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-c] -furan-1,3
-Dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,
3-dione, 1,3,3a, 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-
Examples include 1,2-dicarboxylic dianhydride, compounds represented by the following formulas (I) and (II), and the like. These may be used alone or in combination of two or more.

[0009]

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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.)

Of these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3, 4-
Tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride Two, three,
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-tetracarboxylic dianhydride, 1,3,3a, 4, 5,9b-
Hexahydro-8-methyl-5 (tetrahydro-2,5
-Dioxo-3-furanyl) -naphtho [1,2-c]-
Furan-1,3-dione, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′- Those containing an acid anhydride such as biphenyl ether tetracarboxylic dianhydride are preferred. More preferably,
2,3,5-tricarboxycyclopentyl acetic 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, 1,2,
4,5-Cyclohexanetetracarboxylic dianhydride is preferred.

The liquid crystal aligning agent of the present invention further comprises, as other tetracarboxylic dianhydrides, aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride; 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 ′
-Biphenyl ether tetracarboxylic dianhydride, 3,
3 ', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3', 4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic acid Dianhydride, 4,4'-bis (3,
4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone 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'-diphenylether dianhydride, bis (triphenylphthalic acid)-
4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,
4-butanediol-bis (anhydrotrimellitate), 1,6-hexanediol-bis (anhydrotrimellitate), 1,8-octanediol-bis (anhydrotrimellitate), 2,2- Aromatic tetracarboxylic dianhydrides such as bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate) and compounds represented by the following formulas (1) to (4) may be used. These are used alone or in combination of two or more.

[0013]

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[Diamine] As the diamine used in the present invention, 2,2-bis [4- (4-aminophenoxy) phenyl] propane is used in an amount of 15 mol% or more, preferably 20 to 100 mol%, of the total diamine. Preferably, the content is 20 to 80 mol%. 2,2-bis [4- (4-
By containing 15% by mole or more of [aminophenoxy) phenyl] propane, a liquid crystal alignment film having good liquid crystal alignment can be obtained even when the pretilt angle is 4 ° or less. In the present invention, other diamines which may be used in combination with 2,2-bis [4- (4-aminophenoxy) phenyl] propane include diaminodiphenyl ether, diaminodiphenylmethane and diamine represented by the above formula (I). At least one diamine obtained is mentioned. These diamine compounds can be used alone or in combination of two or more. By using these diamines, a liquid crystal alignment film having higher reliability can be obtained. Specific examples of the diamine represented by the above formula (I) include the following formulas (I-1) to (I
-6).

[0015]

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[Synthesis 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 the tetracarboxylic acid dianhydride is equivalent to 1 equivalent of the amino group contained in the diamine compound. The ratio is preferably such that the acid anhydride group contained in the anhydride is 0.2 to 2 equivalents, 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 polyamic acid constituting the liquid crystal aligning agent in the present invention is synthesized by reacting a tetracarboxylic dianhydride with a diamine compound. The synthesis reaction of the polyamic acid is carried out in an organic solvent under a temperature condition of usually 0 to 150 ° C, preferably 0 to 100 ° C. Reaction temperature is 0
If the temperature is lower than 0 ° C, the solubility of the compound in a solvent may be poor. If the temperature 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, and 1,3-dimethyl-2-imidazolidinone Polar solvents; phenolic solvents such as m-cresol, xylenol, phenol, halogenated phenol and the like can be mentioned.

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.

The above organic solvents include alcohols, ketones, esters which are poor solvents for polyamic acid,
Ethers, halogenated hydrocarbons, hydrocarbons, etc.,
They can be used together 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, acetic acid Methyl, 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, 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-hydroxy-3-methylbutanoate, methyl 3-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-dichlorobenzene, hexane, heptane, octane , Benzene, toluene, xylene and the like. These can be used alone or in combination of two or more.

By the above synthesis reaction, a polymer solution obtained by dissolving a 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.

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

<Terminal-Modified Polymer> The polyamic acid and / or imidized 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, and the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. The terminal-modified polymer can be synthesized by adding an acid anhydride, a monoamine compound, or a monoisocyanate compound to the reaction system when synthesizing the polyamic acid.

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, N-[(3-trimethoxysilyl) propyl]
Diethylene triamine and the like can be mentioned. Also,
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 formed of a liquid crystal alignment agent composed of the above polyamic acid and / or imidized polymer dissolved and contained in an organic solvent. The liquid crystal aligning agent of the present invention may contain two or more polymers. In that case, the proportion of pyromellitic dianhydride in the total amount of tetracarboxylic dianhydride used is 15 mol% or more, and 2,2-bis [4- (4-aminophenoxy) phenyl] in the total amount of diamine used. Propane ratio is 15 mol%
If it is above, you may mix and use a specific polymer and another polyamic acid and / or imidation polymer. In particular, a specific polymer, polyamic acid, and another imidized polymer may be used as a mixture. 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 concentration of the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, and the like.
It is in the range of 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. Further, the temperature at the time of preparing the liquid crystal alignment agent of the present invention,
Preferably, it is 0 ° C to 200 ° C, more preferably 20 ° C to
60 ° C.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound or an epoxy group-containing compound from the viewpoint of improving the adhesion to the substrate surface. Such functional silane-containing compounds include, for example, 3
-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane,
N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3
-Aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-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-aminopropyltriacetate Ethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-
Aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane and the like can be mentioned.

Examples of the epoxy group-containing compound include, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and 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 preferable ones. . The mixing ratio of these functional silane-containing compounds and epoxy group-containing compounds is preferably 40 parts by weight based on 100 parts by weight of the polymer.
It is not more than 0.1 parts by weight, more preferably 0.1 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) A liquid crystal aligning agent for forming a liquid crystal alignment film of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method, a printing method, and the like. Then, a coating film is formed by heating the application surface. Here, as the substrate, for example, a transparent substrate made of glass such as float glass and soda glass; and plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, and polycarbonate can be used. As the transparent conductive film provided on one surface of the substrate, tin oxide (SnO ₂ )
Film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ )
A TO film or 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 surface of the substrate 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 application of the liquid crystal aligning agent is preferably 80 to 300 ° C, more preferably 120 to 25 ° C.
0 ° C. The liquid crystal aligning agent of the present invention containing a polyamic acid forms a coating film to be an alignment film by removing the organic solvent after coating, but further heats the dehydration ring closure to be further imidized. It can also be a coating film. The thickness of the formed coating film is preferably 0.001 to 1 μm, more preferably 0.01 to 1 μm.
It is 0.5 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 or cotton 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, by partially irradiating the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention with ultraviolet rays as shown in, for example, JP-A-6-222366 and JP-A-6-281937. Processing for changing the pretilt angle, or Japanese Patent Laid-Open No. 5-107544
As shown in the publication, a resist film is partially formed on the surface of the liquid crystal alignment film that has been subjected to the rubbing treatment, and the resist film is removed after performing the rubbing treatment in a direction different from the previous rubbing treatment, By performing a process that changes 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 a liquid crystal into the substrate surface and a cell gap defined by the sealant, and sealing the injection hole. Then, by attaching a polarizing plate to the outer surface of the liquid crystal cell, that is, to the other surface of each substrate constituting the liquid crystal cell, ST ST is obtained.
An N-type liquid crystal display element is obtained.

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, these liquid crystals include, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate, and trade names of “C-15”, “C
B-15 "(manufactured by Merck Ltd.) may be used after adding a chiral agent or the like. Also,
As the polarizing plate to be bonded to the outer surface of the liquid crystal cell, a polarizing film called an H film absorbing iodine is stretched and oriented with polyvinyl alcohol, or a polarizing plate or a H film itself sandwiched between cellulose acetate protective films. Polarizing plate.

[0033]

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 of the liquid crystal display device manufactured using the liquid crystal alignment film in Examples and Comparative Examples of the present specification,
The viewing angle, response speed, and orientation were evaluated by the following methods.

(Pretilt angle) "TJ Scheff
er, et. al. , J. et al. Appl. Phys. , Vo
l. 19, 2013 (1980) ", and measured by a crystal rotation method using a He-Ne laser beam. (Viewing angle) Under normal white mode driving, the liquid crystal cell was visually observed while moving the viewpoint from the front to the oblique direction, and the angle at which the drive unit began to be blurred was defined as the viewing angle.

(Response Speed) First, an applied voltage-transmittance characteristic of the liquid crystal cell was measured in a normally white mode, and an applied voltage V _{0 at} which the transmittance became ₀ was obtained. Next, an applied voltage V ₀ was applied to the liquid crystal cell, and a time required until the transmittance became 0 was measured as a response time, and a value having a small value was evaluated as having a high response speed. (Liquid Crystal Orientation) A liquid crystal cell was prepared, and the cell was observed with an optical microscope, and evaluated based on the presence or absence of an alignment defect domain.

Synthesis Example 1 174.5 g (0.8 mol) of pyromellitic dianhydride as tetracarboxylic dianhydride 44.83 g (0.2 mol of 2,3,5-tricarboxycyclopentylacetic dianhydride)
Mol), 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane 410.52
g (1.0 mol) of N-methyl-2-pyrrolidone 450
0 g, 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, wash with methyl alcohol,
By drying at 40 ° C. under reduced pressure for 15 hours, 410 g of a polyamic acid having an logarithmic viscosity of 0.90 dl / g (hereinafter referred to as “polyamic acid (A-1)”) was obtained.

Synthesis Example 2 In Synthesis Example 1, the diamine was replaced with 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane 82.10 g
Synthesis Example 1 except that (0.2 mol) and 158.62 g (0.8 mol) of 4,4′-diaminodiphenylmethane were used.
Polyamic acid having a logarithmic viscosity of 1.51 dl / g in the same manner as described above (hereinafter referred to as “polyamic acid (A-2)”).
80 g were obtained.

Synthesis Example 3 In Synthesis Example 1, diamine was replaced with 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane 82.10 g
(0.2 mol), diaminodiphenyl ether 160.
412 g of a polyamic acid having an logarithmic viscosity of 0.98 dl / g (hereinafter referred to as “polyamic acid (A-3)”) was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to 19 g (0.8 mol).

Synthesis Example 4 In Synthesis Example 1, diamine was replaced with 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane 82.10 g
(0.2 mol), 156.64 g (0.79 mol) of 4,4′-diaminodiphenylmethane, and 5.23 g (0.01 mol) of the diamine represented by the chemical formula (I-1) were synthesized. Logarithmic viscosity 1.87 dl / g as in Example 1.
Of polyamic acid (this is referred to as "polyamic acid (A-
4) ". 398 g).

Synthesis Example 5 In Synthesis Example 1, diamine was replaced with 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane 82.10 g
(0.2 mol), 158.19 g (0.79 mol) of 4,4′-diaminodiphenyl ether, chemical formula (I-1)
In the same manner as in Synthesis Example 1 except that the diamine represented by the formula was 5.23 g (0.01 mol), the logarithmic viscosity was 0.99 dl /.
g of polyamic acid (this is referred to as "polyamic acid (A-
5) ". 367 g).

Synthesis Example 6 In Synthesis Example 1, diamine was replaced with 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane 205.25
g (0.5 mol), 97.16 g (0.49 mol) of 4,4′-diaminodiphenylmethane, and 5.23 g (0.01 mol) of the diamine represented by the chemical formula (I-1), Logarithmic viscosity 1.90 dl / g as in Synthesis Example 1.
Of polyamic acid (this is referred to as "polyamic acid (A-
6) ". ) 356 g were obtained.

Synthesis Example 7 In Synthesis Example 1, tetracarboxylic dianhydride was used except for pyromellitic dianhydride of 174.5 g (0.8 mol) and cyclobutanetetracarboxylic dianhydride of 39.22 g (0.2 mol). Is a logarithmic viscosity of 1.21 d in the same manner as in Synthesis Example 1.
l / g of polyamic acid (this is referred to as "polyamic acid (A
-7) ". ) 420 g were obtained.

Synthesis Example 8 In Synthesis Example 2, the tetracarboxylic dianhydride was changed to a compound other than 174.5 g (0.8 mol) of pyromellitic dianhydride and 39.22 g (0.2 mol) of cyclobutanetetracarboxylic dianhydride. Is a logarithmic viscosity of 1.18 d as in Synthesis Example 3.
l / g of polyamic acid (this is referred to as "polyamic acid (A
-8) ". 485 g).

Synthesis Example 9 In Synthesis Example 3, the tetracarboxylic dianhydride was changed to a compound other than 174.5 g (0.8 mol) of pyromellitic dianhydride and 39.22 g (0.2 mol) of cyclobutanetetracarboxylic dianhydride. Has a logarithmic viscosity of 0.98 d in the same manner as in Synthesis Example 4.
l / g of polyamic acid (this is referred to as "polyamic acid (A
-9) ". ) 420 g were obtained.

Synthesis Example 10 In Synthesis Example 4, the tetracarboxylic dianhydride was changed to a compound other than 174.5 g (0.8 mol) of pyromellitic dianhydride and 39.22 g (0.2 mol) of cyclobutanetetracarboxylic dianhydride. Has a logarithmic viscosity of 0.95 d in the same manner as in Synthesis Example 5.
l / g of polyamic acid (this is referred to as "polyamic acid (A
-10) ". ) 420 g were obtained.

Synthesis Example 11 In Synthesis Example 5, the tetracarboxylic dianhydride was changed to a compound other than 174.5 g (0.8 mol) of pyromellitic dianhydride and 39.22 g (0.2 mol) of cyclobutanetetracarboxylic dianhydride. Has a logarithmic viscosity of 0.99 d in the same manner as in Synthesis Example 6.
l / g of polyamic acid (this is referred to as "polyamic acid (A
-11)). 408 g).

Synthesis Example 12 In Synthesis Example 6, the tetracarboxylic dianhydride was other than pyromellitic dianhydride 174.5 g (0.8 mol) and cyclobutanetetracarboxylic dianhydride 39.22 g (0.2 mol). Has a logarithmic viscosity of 0.97 d in the same manner as in Synthesis Example 7.
l / g of polyamic acid (this is referred to as "polyamic acid (A
-12) ". 398 g).

Synthesis Example 13 In Synthesis Example 1, 109.06 g (0.5 mol) of pyromellitic anhydride and 98.06 g (0.5 mol) of cyclobutanetetracarboxylic dianhydride were used as the tetracarboxylic dianhydride.
485 g of a polyamic acid having a logarithmic viscosity of 0.99 dl / g (hereinafter referred to as “polyamic acid (A-13)”) was obtained in the same manner as in Synthesis Example 1 except that the composition was changed to (mol).

Synthesis Example 14 In Synthesis Example 2, 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 the logarithmic viscosity was 1.
485 g of a 29 dl / g polyamic acid (hereinafter referred to as “polyamic acid (A-14)”) was obtained.

Synthesis Example 15 In Synthesis Example 3, 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), except that the logarithmic viscosity was 1.
420 g of a polyamic acid having 11 dl / g and an imidation ratio of 0% (this is referred to as "polyamic acid (A-15)")
I got

Synthesis Example 16 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 the logarithmic viscosity was 0.1 in the same manner as in Synthesis Example 5.
420 g of 98 dl / g polyamic acid (this is referred to as "polyamic acid (A-16)") was obtained.

Synthesis Example 17 In Synthesis Example 5, 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 the logarithmic viscosity was 1.
400 g of 02 dl / g polyamic acid (this is referred to as “polyamic acid (A-17)”) was obtained.

Synthesis Example 18 In Synthesis Example 6, 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), except that the logarithmic viscosity was 0.1 in the same manner as in Synthesis Example 7.
398 g of a 99 dl / g polyamic acid (hereinafter referred to as “polyamic acid (A-18)”) was obtained.

Synthesis Example 19 In Synthesis Example 1, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 110.06 g of cyclohexanetetracarboxylic dianhydride.
408 g of a polyamic acid having a logarithmic viscosity of 1.05 dl / g (hereinafter referred to as “polyamic acid (A-19)”) was obtained in the same manner as in Synthesis Example 1 except that the amount was 0.5 mol.

Synthesis Example 20 In Synthesis Example 2, tetracarboxylic dianhydride was replaced with tetramellitic dianhydride and pyromellitic anhydride 109.06.
g (0.5 mol) and 110.06 g (0.5 mol) of cyclohexanetetracarboxylic dianhydride in the same manner as in Synthesis Example 3 except that a polyamic acid having a logarithmic viscosity of 1.05 dl / g (this was referred to as “polyamic acid”). Acid (A-20) ") was obtained 411 g.

Synthesis Example 21 In Synthesis Example 3, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 110.06 g of cyclohexanetetracarboxylic dianhydride.
391 g of a polyamic acid having a logarithmic viscosity of 1.02 dl / g (hereinafter referred to as “polyamic acid (A-21)”) was obtained in the same manner as in Synthesis Example 4 except that the amount was 0.5 mol.

Synthesis Example 22 In Synthesis Example 4, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 110.06 g of cyclohexanetetracarboxylic dianhydride.
388 g of a polyamic acid having an logarithmic viscosity of 0.92 dl / g (hereinafter referred to as “polyamic acid (A-22)”) was obtained in the same manner as in Synthesis Example 5 except that the amount was 0.5 mol.

Synthesis Example 23 In Synthesis Example 5, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 110.06 g of cyclohexanetetracarboxylic dianhydride.
(0.5 mol), and 392 g of a polyamic acid having an logarithmic viscosity of 1.08 dl / g (hereinafter referred to as “polyamic acid (A-23)”) was obtained in the same manner as in Synthesis Example 5.

Synthesis Example 24 In Synthesis Example 6, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 110.06 g of cyclohexanetetracarboxylic dianhydride.
(0.5 mol), and 402 g of a polyamic acid having a logarithmic viscosity of 1.02 dl / g (this is referred to as “polyamic acid (A-24)”) was obtained in the same manner as in Synthesis Example 6.

Synthesis Example 25 In Synthesis Example 1, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 1,2
-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride 112.10 g (0.5 mol) except that polyamic acid having an logarithmic viscosity of 0.88 dl / g was prepared in the same manner as in Synthesis Example 7. Is referred to as "polyamic acid (A-2)
5) ". 392 g).

Synthesis Example 26 In Synthesis Example 2, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 1,2
-A polyamic acid having an logarithmic viscosity of 1.09 dl / g was prepared in the same manner as in Synthesis Example 1 except for using 112.10 g (0.5 mol) of -dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. Is referred to as "polyamic acid (A-2)
6) ". 390 g).

Synthesis Example 27 In Synthesis Example 3, tetracarboxylic dianhydride was replaced with tetramellitic dianhydride and pyromellitic anhydride 109.06.
g (0.5 mol) and 1,2-dimethyl-1,2,3,
4-cyclobutanetetracarboxylic dianhydride 112.1
389 g of a polyamic acid having a logarithmic viscosity of 1.11 dl / g (hereinafter referred to as “polyamic acid (A-27)”) was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to 0 g (0.5 mol).

Synthesis Example 28 In Synthesis Example 4, tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 1,2
-A polyamic acid having an logarithmic viscosity of 1.09 dl / g was prepared in the same manner as in Synthesis Example 1 except for using 112.10 g (0.5 mol) of -dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. Is referred to as "polyamic acid (A-2)
8) ". 392 g).

Synthesis Example 29 In Synthesis Example 5, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 1,2
-A polyamic acid having a logarithmic viscosity of 1.07 dl / g was prepared in the same manner as in Synthesis Example 1 except that -dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride was 112.10 g (0.5 mol). Is referred to as "polyamic acid (A-2)
9) ". ) 355 g were obtained.

Synthesis Example 30 In Synthesis Example 6, the tetracarboxylic dianhydride was obtained by adding 109.06 g (0.5 mol) of pyromellitic anhydride and 1,2
-A polyamic acid having a logarithmic viscosity of 1.02 dl / g was prepared in the same manner as in Synthesis Example 1 except for using 112.10 g (0.5 mol) of -dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride. To "Polyamic acid (A-3)
0) ". 367 g).

Synthesis Example 31 As a tetracarboxylic dianhydride, 224.17 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride (1
Mol), 107.06 g (0.99 mol) of p-phenylenediamine as a diamine compound, and 5.23 g (0.01 mol) of a diamine represented by the chemical formula (I-1) in 4500 g of N-methyl-2-pyrrolidone It was dissolved 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 an logarithmic viscosity of 0.90 dl / g and an imidation ratio of 0% was obtained. 30 g of the polyamic acid obtained here 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 closed at 110 ° C. for 4 hours. After washing and decompression, polyimide having a logarithmic viscosity of 0.85 dl / g and an imidation ratio of 100% (this is referred to as “polyimide (B-1)”) is 17.5.
g was obtained.

Synthesis Example 32 In Synthesis Example 31, diamine was replaced with 196.29 g (0.99 mol) of 4,4′-diaminodiphenylmethane and 5.23 g (0.01 mol) of the diamine represented by the chemical formula (I-1). A polyimide having a logarithmic viscosity of 1.16 dl / g and an imidation ratio of 100% (this is referred to as “polyimide (B-2)”) is the same as in Synthesis Example 31.
g was obtained.

Comparative Synthesis Example 1 As a diamine compound, p-phenylenediamine
Polyamic acid having a logarithmic viscosity of 1.01 dl / g (similar to Synthesis Example 1 except that 73 g (0.95 mol) and 26.15 g (0.05 mol) of the diamine represented by the chemical formula (I-1) were used) This is referred to as “polyamic acid (A-31).” 276 g was obtained.

Comparative Synthesis Example 2 190.23 g (0.95 mol) of 4,4'-diaminodiphenyl ether as a diamine compound and 26.15 g (0.15 mol) of a diamine represented by the chemical formula (I-1)
In the same manner as in Synthesis Example 14 except that the amount was 0.05 mol), 300 g of a polyamic acid having an logarithmic viscosity of 1.02 dl / g (this is referred to as “polyamic acid (A-32)”) was obtained.

Comparative Synthesis Example 3 As a diamine compound, 190.23 g (0.95 mol) of 4,4′-diaminodiphenyl ether was used as a diamine, and 26.15 g (0.25 g) of a diamine represented by the chemical formula (I-1).
234 g of a polyamic acid having a logarithmic viscosity of 1.14 dl / g (hereinafter referred to as “polyamic acid (A-33)”) was obtained in the same manner as in Synthesis Example 21 except that the amount was changed to 05 mol).

Comparative Synthetic Example 4 The logarithmic viscosity was 1. in the same manner as in Synthetic Example 1 except that 196.12 g (1 mol) of cyclobutanetetracarboxylic dianhydride was used instead of tetracarboxylic dianhydride.
415 g of 08 dl / g polyamic acid (hereinafter referred to as “polyamic acid (A-34)”) was obtained.

Example 1 The polyamic acid (A-1) obtained in Synthesis Example 1 was
-Methyl-2-pyrrolidone / γ-butyrolactone / butyrosolve solvent (weight ratio: 45: 5: 50), and 20 parts by weight of N, N, N ′, N ',-tetraglycidyl-4,4'
-Diaminodiphenylmethane was added to make a solution having a solid content of 4% by weight, and this solution was filtered using a filter having a pore size of 1 µm to prepare a liquid crystal aligning agent of the present invention. Applying the liquid crystal alignment agent to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal alignment film coating printer,
The coating was dried on a hot plate at 230 ° C. for 10 minutes to form a coating having a dry average film thickness of 500 °. A rubbing treatment was carried out by a rubbing machine having a roll around which a cloth made of rayon was wound. After immersing the substrate coated with the alignment film in water for 1 minute, both substrates were dried on a hot plate at 100 ° C. for 5 minutes. Next, a pair of rubbed liquid crystal sandwiching substrates is coated with an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 5.5 μm on each outer edge of the liquid crystal sandwiching substrate having a liquid crystal alignment film. The adhesive was cured by overlapping the surfaces so as to face each other and pressing. Next, a nematic liquid crystal (ZLI-229, manufactured by Merck & Co., Ltd.) is placed between the pair of substrates from the liquid crystal injection port.
After filling in 3), seal the liquid crystal injection port with an acrylic photo-curing adhesive, and attach polarizing plates to both outer surfaces of the substrate.
A liquid crystal display device was manufactured. The pretilt angle was 3.5 °, the viewing angle was 150 °, and the response speed was 100 ms.

Examples 2 to 32 and Comparative Examples 1 to 4 In the same manner as in Example 1, except that the polymers shown in Tables 1 and 2 were used instead of the polyamic acid (A-1), A liquid crystal aligning agent was obtained, and a liquid crystal display device was manufactured and evaluated. The results are shown in Tables 1 and 2. Example 3
In 1 and 32, the mixing ratio of the polyamic acid and the polyimide was 8: 2 in terms of the polymerization ratio.

[0074]

[Table 1]

[0075]

[Table 2]

[0076]

According to the liquid crystal alignment film of the present invention, in the case of a liquid crystal display device, an STN type liquid crystal display device having a high viewing angle and excellent high-speed response without alignment defect can be produced. Furthermore, the liquid crystal display device having the liquid crystal alignment film of the present invention can be effectively used for various devices, for example, a desk calculator,
Used for display devices such as watches, clocks, coefficient display boards, word processors, personal computers, and liquid crystal televisions.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H090 HB08Y HB09Y HB10Y KA08 MA10 4J043 PA05 PA06 PA19 PB07 PB08 PB14 PB15 PC015 PC016 PC135 PC136 QB31 RA05 RA34 RA35 SA01 SA06 SA46 SA49 SA54 SA61 SA63 SB03 TA43 TA70 TA71 UB121 UA121 VA022 VA102 XA03 YA07 YA08 ZA41 ZA51 ZB23

Claims (4)

[Claims] 1. A liquid crystal aligning agent comprising a polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine and / or an imidized polymer obtained by dehydrating and ring-closing the polyamic acid. , 15 mol% or more of tetracarboxylic dianhydride is pyromellitic dianhydride, and 15 mol% or more of diamine is 2,2-bis [4
-(4-aminophenoxy) phenyl] propane, wherein a pretilt angle exhibited by a liquid crystal alignment film obtained from a liquid crystal alignment agent is 4 ° or less, S
Liquid crystal aligning agent for TN type liquid crystal display devices. 2. The liquid crystal aligning agent for an STN-type liquid crystal display element according to claim 1, wherein the liquid crystal alignment agent is obtained by using an alicyclic tetracarboxylic dianhydride as the tetracarboxylic dianhydride. 3. The STN according to claim 1, wherein the STN is obtained by using, as the diamine, at least one diamine selected from diaminodiphenyl ether, diaminodiphenylmethane, and a diamine represented by the following formula (1). Liquid crystal alignment agent for liquid crystal display devices. Embedded image (Wherein, R ¹ represents —O—, —COO—, —OCO—,
NHCO -, - CONH- and -CO- represents a divalent organic group selected from, R ² represents a monovalent organic group having a steroid skeleton or a trifluoromethyl group. ) 4. An ST comprising a liquid crystal alignment film obtained from the liquid crystal alignment agent according to claim 1.
N-type liquid crystal display element.