JPH1130779A - Liquid crystal orienting agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain a liquid crystal display element provided with liquid crystal oriented films having excellent liquid crystal orientability by incorporating >=1 kind of the polymer selected from a group consisting of polymers having an imide structure and a polymer having a polyamic acid sillyl ester structure. SOLUTION: This liquid crystal orienting agent contains >=1 kind of the polymer 'specific polymer (A)' selected from the group consisting of the polymer having the polyamic acid structure and the polymer having the imide structure obtd. by dehydration ring closure of the polyamic acid and the polymer 'specific polymer (B)' having the polyamic acid sillyl ester structure. The compounding ratio of the specific polymer (A) and the specific polymer (B) is usually 5 to 95 pts.wt., more preferably 10 to 90 pts.wt. specific polymer (A) when the entire part of the polymers is defined as 100 pts.wt. The good liquid crystal orientability, the short time for erasing after-images and excellent preservation stability are obtd. if the liquid crystal display element is formed by using such liquid crystal orienting agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal aligning agent used for forming a liquid crystal alignment film of a liquid crystal display device. More specifically, the present invention relates to a liquid crystal aligning agent having good liquid crystal alignment properties, a short afterimage erasing time of a liquid crystal display element, and excellent storage stability over a long period of time.

[0002]

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

[0003]

However, a liquid crystal display device and the like were manufactured using a conventionally known liquid crystal aligning agent containing a polyamic acid or an imidized polymer having a structure obtained by dehydration and ring closure of the same. In this case, the ionic charges generated during image display (voltage application) and adsorbed on the liquid crystal alignment film are not desorbed from the liquid crystal alignment film even after image erasure (after the voltage application is released), and the liquid crystal after the voltage release is released. The voltage is accumulated in the alignment film, and due to the residual voltage,
There is a problem that an afterimage occurs on the display screen after the release of the voltage application. Further, there is also a problem that the viscosity of the solution changes during storage of the liquid crystal aligning agent, the thickness of the solution varies during printing, and display failure occurs.

[0004] The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a liquid crystal molecule having an excellent alignment property by rubbing treatment. An object of the present invention is to provide a liquid crystal aligning agent capable of providing a liquid crystal display device having a liquid crystal alignment film having the following.
A second object of the present invention is to provide a liquid crystal aligning agent which provides a liquid crystal display element having a short afterimage erasing time. A third object of the present invention is to provide a liquid crystal aligning agent having excellent storage stability.

[0005]

The objects and advantages of the present invention are as follows: (A) (a) a polymer having a polyamic acid structure; and (b) a polymer having an imide structure obtained by dehydrating and ring-closing the polyamic acid. At least one polymer selected from the group consisting of a polymer (hereinafter, also referred to as “specific polymer (A)”) and a polymer (B) having a polyamic acid silyl ester structure (hereinafter, “specific polymer (B) ) ")).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. <Specific polymer (A)> The specific polymer (A) used in the liquid crystal aligning agent of the present invention is obtained by reacting tetracarboxylic dianhydride with a diamine compound in an organic solvent to synthesize a polyamic acid. If necessary, the polyamic acid can be obtained by dehydration ring closure.

Tetracarboxylic dianhydride Examples of the tetracarboxylic dianhydride used in the synthesis of the above polyamic acid include 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,
1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1, 3,3a, 4,
5,9b-Hexahydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b- Hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-
1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,3
-Dione, 1,3,3a, 4,5,9b-hexahydro-7
-Methyl-5 (tetrahydro-2,5-dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione;
1,3,3a, 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,
Aliphatic and alicyclic tetracarboxylic dianhydrides such as 3,5,6-tetracarboxylic dianhydride, compounds represented by the following formulas (I) and (II);

[0008]

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

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

[0011]

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

[0013]

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Diamine Compound Examples of the diamine compound used in the synthesis of the polyamic acid include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane,
4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 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-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl ] Sulfone,
1,4-bis (4-aminophenoxy) benzene, 1,3
-Bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene,
2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2
-Chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-
4,4′-diamino-5,5′-dimethoxybiphenyl,
3,3′-dimethoxy-4,4′-diaminobiphenyl,
1,4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m-phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) ) Phenyl] hexafluoropropane, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 4,4′-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluoro Aromatic diamines such as biphenyl;

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

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

[0017]

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

[0019]

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

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

[0022]

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

[0024]

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

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

[0027]

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

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

[0030]

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

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

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

(B) Imidized Polymer The imidized polymer which is a component of the liquid crystal aligning agent of the present invention can be prepared by dehydrating and ring-closing the above polyamic acid. The dehydration ring closure of polyamic acid is
The method is carried out 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. The reaction temperature in the method of heating the polyamic acid of the above (i) is usually 50 to 200.
° C, preferably 60-170 ° C. 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 a polyamic acid solution, the dehydrating agent may be, 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 0.01 to 20 mol per 1 mol of the repeating unit of the polyamic acid. In addition, as a dehydration ring closure 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 0 to 180 ° C,
Preferably it is 10-150 degreeC. 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. Further, the imidized polymer used in the present invention may be a polymer having a low imidation rate.
The imidation rate can be adjusted by controlling the reaction conditions of the dehydration ring closure reaction in the above methods (i) and (ii). Further, by mixing a tetracarboxylic dianhydride, a diamine compound and a diisocyanate compound, and heating and condensing as necessary,
A polymer having a low imidation ratio can also be prepared. Here, the “imidation ratio” is a percentage of the repeating unit having an imide group or an isoimide group in all the repeating units in the polymer.

<Specific Polymer (B)> The specific polymer (B) which is a component of the liquid crystal aligning agent of the present invention comprises (iii) a tetracarboxylic dianhydride and an N, N'-bissilylated diamine compound and And / or a method of reacting an N-silylated diamine compound, or (iv) a method of reacting a polyamic acid with a silylating agent. The N, N'-bissilylated diamine compound and / or N-silylated diamine compound used in the above method (iii) can be obtained by reacting the exemplified diamine compound with a silylating agent. Examples of the silylating agent used in the above reaction include N, O-bistrimethylsilylacetamide, N, O-bistrimethylsilyltrifluoroacetamide, chlorotrimethylsilane,
1,1,3,3,3-hexamethyldisilazane, N-methoxy-N, O-bistrimethylsilylcarbamate,
N-methyl-N-trimethylsilylacetamide, N-
Methyl-N-trimethylsilylheptafluorobutylamide, N-methyl-N-trimethylsilyltrifluoroacetamide, N-trimethylsilylimidazole, N
-Trimethylsilylacetamide, N-trimethylsilyldiethylamine, N-trimethylsilyldimethylamine, chlorodimethylsilane, 1,1,3,3-tetramethyldisilazane, tert-butyldimethylchlorosilane, tert-butyldimethylsilylimidazole, N
-Tert-butyldimethylsilyl-N-methyltrifluoroacetamide, dimethylethylchlorosilane, dimethylethylsilylimidazole, dimethylisopropylchlorosilane, dimethylisopropylsilylimidazole, dimethyl-n-propylchlorosilane, dimethyl-n-propylsilylimidazole, 1,3 -Bischloromethyltetramethyldisilazane, bromomethyldimethylchlorosilane, chloromethyldimethylchlorosilane,
Allyldimethylchlorosilane, N, O-bisdiethylhydrogensilyltrifluoroacetamide, 1-cyanoethyldiethylaminodimethylsilane, dichlorodiethylsilane, 1,3-diphenyltetramethyldisilazane, pentafluorophenyldimethylchlorosilane,
Pantafluorophenyldimethylsilyldiethylamine and the like can be mentioned. Among them, N, O-bistrimethylsilylacetamide, N, O-bistrimethylsilyltrifluoroacetamide, chlorotrimethylsilane, 1,1,1,3,3,3-hexamethyldisilazane, N-methyl-N-trimethylsilyl Acetamide, N-methyl-N-trimethylsilylheptafluorobutylamide, N-methyl-N-trimethylsilyltrifluoroacetamide, N-trimethylsilylimidazole, N-trimethylsilylacetamide, N-trimethylsilyldiethylamine, N-trimethylsilyldimethylamine, 1,1, 3,3-tetramethyldisilazane can be mentioned as a preferred example. Examples of the solvent used in the reaction between the tetracarboxylic dianhydride and the N, N'-bissilylated diamine compound and / or the N-silylated diamine compound include the organic solvents exemplified as those used in the synthesis of polyamic acid. Can be. The silylation rate can be arbitrarily adjusted by allowing the N, N'-bissilylated diamine compound and / or the N-silylated diamine compound and the diamine compound to coexist during the reaction. According to the method (iv), the specific polymer (B) is obtained by adding a silylating agent to the solution of the polyamic acid and stirring. The silylating agent used at this time can be the silylating agent exemplified above. Examples of the solvent used for the reaction include the organic solvents exemplified as those used for the synthesis of the polyamic acid. The synthesis reaction is carried out in an organic solvent
The reaction is usually performed at a reaction temperature of 0 to 100 ° C, preferably 0 to 50 ° C for 0.5 to 48 hours. The specific polymer (B) can be obtained by the above-mentioned methods (iii) and / or (iv).
It is 0 to 100%, preferably 30 to 100%. The term "silylation ratio" as used herein refers to the percentage of silylated repeating units in all the repeating units in the specific polymer (B), expressed in%. In the above method (iii), the N, N'-bissilylated diamine compound and / or the N-silylated diamine compound and an unsilylated diamine are reacted with tetracarboxylic dianhydride to obtain the above ( In the method iv), the silylation rate of the specific polymer (B) can be arbitrarily adjusted by adjusting the amount of the silylating agent to be added. Further, the specific polymer (B) having a silylation ratio of less than 100% may be a polymer in which all or a part of the non-silylated repeating unit is dehydrated and ring-closed.

<Terminal-Modified Polymer> The specific polymer (A) and the specific polymer (B) constituting the liquid crystal aligning agent of the present invention.
May be a terminal-modified type having a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified type can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound, or the like to the reaction system when synthesizing the polyamic acid. here,
Examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n- Hexadecyl succinic anhydride may be mentioned. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-
Hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, Examples thereof include n-hexadecylamine, n-heptadecylamine, n-octadecylamine, and n-eicosylamine. In addition, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<Logarithmic viscosity of polymer> Specific polymer (A) and specific polymer (B) constituting the liquid crystal aligning agent of the present invention.
Has a logarithmic viscosity (ηln) value of preferably 0.0
5 to 10 dl / g, more preferably 0.05 to 5 dl
/ G. Here, the value of the logarithmic viscosity (ηln) is obtained by measuring the viscosity at 30 ° C. of a solution having a polymer concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent, It is obtained by the equation shown in (1).

[0038]

(Equation 1)

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention comprises a specific polymer (A) and a specific polymer (B),
The mixing ratio of the specific polymer (A) is usually 5 to 95 parts by weight, preferably 10 to 90 parts by weight, based on 100 parts by weight of the whole polymer. The content ratio of the polymer in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, and the like, but is preferably 0.1 to the entire liquid crystal aligning agent.
The content is in the range of 1 to 20% by weight, more preferably 1 to 10% by weight. That is, a liquid crystal alignment agent composed of a polymer solution is applied to the substrate surface by a printing method, a spin coating method, and the like, and then dried to form a film as an alignment film material. When the content ratio is less than 0.1% by weight, the film thickness of this film may be too small to obtain a good liquid crystal alignment film. Is too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent may be increased, resulting in poor coating characteristics. The organic solvent for dissolving the polymer is not particularly limited as long as it can dissolve the polymer, and examples thereof include the solvents exemplified as those used in the synthesis reaction of polyamic acid and the dehydration ring closure reaction. . 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 liquid crystal aligning agent of the present invention may contain a functional silane-containing compound or an epoxy compound from the viewpoint of improving the adhesion between the polymer and the surface of the substrate to be coated. Examples of such functional silane-containing compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 1
0-trimethoxysilyl-1,4,7-triazadecane,
10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl-3,6-diazanonyl acetate, N-benzyl-3- Aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene)
-3-Aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane and the like can be mentioned. The mixing ratio of these functional silane-containing compounds is usually 20 parts by weight or less, preferably 0.01 to 10 parts by weight, per 100 parts by weight of the polymer.
Parts by weight. Further, as the epoxy group-containing compound,
For example, 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. The compounding ratio of these functional silane-containing compounds and epoxy group-containing compounds is usually 40 parts by weight or less, preferably 0.1 to 30 parts by weight, based on 100 parts by weight of the polymer.

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

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

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

[0044]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The evaluation method for each liquid crystal display device manufactured according to the examples and comparative examples of the present specification will be described below.

[Orientation of Liquid Crystal] The presence or absence of abnormal domains in the liquid crystal cell when the voltage was turned on / off in the liquid crystal display element was observed with a microscope, and the case where there was no abnormal domain was judged as “good”. [Afterimage erasing time] After applying a 15 V DC voltage to the liquid crystal display element for 8 hours, the voltage was turned off, and the time until the afterimage was erased was visually observed. [Storage Stability of Liquid Crystal Alignment Agent] The liquid crystal alignment agent was left in a constant temperature bath at 80 ° C. for 10 hours, and the viscosity of the liquid crystal alignment agent before and after being left was measured using an E-type viscometer.

Synthesis Example 1 224.17 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride as tetracarboxylic dianhydride
(1.00 mol), 97.33 g (0.90 mol) of p-phenylenediamine as a diamine compound and the formula (2)
42.24 g (0.10 mol) of the compound (0) was dissolved in 1300 g of N-methyl-2-pyrrolidone, and the solution was reacted at 40 ° C. for 6 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product.
Thereafter, the solid is separated, washed with acetone, and dried under reduced pressure for 4 hours.
By drying at 0 ° C. for 15 hours, the logarithmic viscosity (ηl
n) 1.35 dl / g of polyamic acid (Aa-1) 3
33.9 g were obtained. Synthesis Example 2 30.0 g of the polymer (a-1) obtained in Synthesis Example 1 was converted to γ-
Dissolved in 570 g of butyrolactone, 33.3 pyridine
g and 25.8 g of acetic anhydride were added thereto, followed by dehydration ring closure at 110 ° C. for 4 hours. Then, in the same manner as in Synthesis Example 1, by precipitating, separating, washing and drying the reaction product,
Logarithmic viscosity (ηln) 1.36 dl / g, imidization ratio 90
% Of the imidized polymer (Ab-2) was obtained.

SYNTHESIS EXAMPLE 3 In Synthesis Example 1, 1,4-tetracarboxylic dianhydride was used.
3,3a, 4,5,9b-hexahydro-8-methyl-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] furan-1,3-dione 314.3
416.76 g of polyamic acid (Aa-3) having an intrinsic viscosity (ηln) of 1.32 / g was obtained in the same manner as in Synthesis Example 1 except that 0 g (1.00 mol) was used. Thereafter, the polyamic acid (Aa-A) was used instead of the polyamic acid (Aa-I).
3) Using 30.0 g, the reaction temperature in the dehydration ring closure was 8
The logarithmic viscosity (η
In) 1.28 dl / g and 27.5 g of an imidized polymer (Ab-4) having an imidation ratio of 100% were obtained. Synthesis Example 4 In Synthesis Example 1, pyromellitic dianhydride 218.12 g (1.00 mol) as tetracarboxylic dianhydride and 198.27 g (1.00 mol) of 4,4′-diaminodiphenylmethane as diamine compound Was used in the same manner as in Synthesis Example 1 except that the intrinsic viscosity (ηln) was 1.9.
374.8 g of 0 dl / g polyamic acid (Aa-5)
I got

Synthesis Example 5 30.0 g of the polymer (Aa-1) obtained in Synthesis Example 1 was γ
-Butyrolactone in 570 g, added with 16.8 g of N, O-bistrimethylsilylamide and added at 25 ° C.
The reaction was performed for 4 hours. Then, in the same manner as in Synthesis Example 1, by precipitating, separating, washing and drying the reaction product,
Logarithmic viscosity (ηln) 1.06 dl / g, silylation rate 92
% Of polyamic acid silyl ester (B-1) 25.1%
g was obtained. Synthesis Example 6 30.0 g of the polymer (Aa-5) obtained in Synthesis Example 4 was γ
-Butyrolactone in 570 g, added with 7.3 g of N, O-bistrimethylsilylamide and added at 25 ° C. for 24 hours.
Allowed to react for hours. Subsequently, by precipitating, separating, washing and drying the reaction product in the same manner as in Synthesis Example 1, logarithmic viscosity (ηln) 1.56 dl / g, silylation rate 48%
Of polyamic acid silyl ester (B-2) 25.7 g
I got Synthesis Example 7 30.0 g of the polymer (Aa-5) obtained in Synthesis Example 4 was γ
-Butyrolactone in 570 g, added with 14.7 g of N, O-bistrimethylsilylamide and added at 25 ° C.
The reaction was performed for 4 hours. Then, in the same manner as in Synthesis Example 1, by precipitating, separating, washing and drying the reaction product,
Logarithmic viscosity (ηln) 1.46 dl / g, silylation rate 95
% Of polyamic acid silyl ester (B-3) 25.4%
g was obtained. Synthesis Example 8 Pyromellitic dianhydride (218.12 g, 1.00 mol) as tetracarboxylic dianhydride, N, N′-bistrimethylsilyl-4,4′-diamino as N, N′-bissilylated diamine compound Diphenylmethane 322.
48 g (1.00 mol) was dissolved in 1300 g of N-methyl-2-pyrrolidone, and this solution was reacted at 40 ° C. for 6 hours. Next, the obtained reaction solution was poured into a large excess of acetone to precipitate a reaction product. Thereafter, the solid substance was separated, washed with acetone, and dried under reduced pressure at 40 ° C. for 15 hours to obtain a logarithmic viscosity (ηln) of 1.54 dl /.
g of polyamic acid silyl ester (B-4) having a silylation rate of 98% was obtained.

Example 1 2.0 g of the polymer (Ab-2) obtained in Synthesis Example 2 and 8.0 g of the polymer (B-1) obtained in Synthesis Example 6 were dissolved in γ-butyrolactone. A solution having a solid content concentration of 4% by weight was filtered through a filter having a pore diameter of 1 μm to prepare a liquid crystal aligning agent. The above-mentioned liquid crystal aligning agent was applied to the transparent electrode surface of a glass substrate with a transparent electrode made of an ITO film using a liquid crystal aligning film coating printing machine, and dried on a hot plate at 180 ° C. for 20 minutes to obtain a dry film thickness of 0. A film of 05 μm was formed. A rubbing machine having a roll in which a rayon cloth is wound around the coating film is used.
The rubbing treatment was performed at 0 rpm, at a stage moving speed of 1 cm / sec, and at a push-in length of 0.4 mm. After immersing the substrate coated with the alignment film in isopropyl alcohol 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 each having a liquid crystal alignment film with an outer edge having a diameter of 17
After applying a screen-printed epoxy resin adhesive containing aluminum oxide balls with a thickness of μm, a pair of liquid crystal sandwiching substrates are overlaid so that the liquid crystal alignment film surfaces face each other and the rubbing directions are antiparallel, and then bonded by pressure. The agent was cured. Next, a nematic liquid crystal (MLC-5081 manufactured by Merck) is filled between the pair of substrates from the liquid crystal injection port, and the liquid crystal injection port is sealed with an epoxy-based adhesive. Were bonded so that the polarization direction of the polarizing plate coincided with the rubbing direction of the liquid crystal alignment film of each substrate, to produce a liquid crystal display device. When the orientation of the liquid crystal and the afterimage elimination of the obtained liquid crystal display element were evaluated, the orientation of the liquid crystal was good and the afterimage elimination time was 1.3.
The value was as small as seconds. When the storage stability of the liquid crystal alignment agent was examined, the initial viscosity was 40 cP, 8
The viscosity after standing at 0 ° C. for 10 hours was 39 cP, and it was confirmed that the composition had excellent storage stability. Table 1 shows the results.

Examples 2 to 7, Comparative Examples 1 to 3 Polymers (component (A)) and polymers (component (B)) obtained in Synthesis Examples 1 to 8 according to the formulations shown in Tables 1 and 2.
And a liquid crystal aligning agent was prepared in the same manner as in Example 1.
Next, a liquid crystal display device was produced in the same manner as in Example 1 using each of the liquid crystal aligning agents thus obtained. With respect to each of the obtained liquid crystal aligning agents, the alignment of the liquid crystal, the afterimage erasing time, and the storage stability were evaluated. The results are shown in Tables 1 and 2.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

According to the liquid crystal aligning agent of the present invention, when a liquid crystal display device is used, a liquid crystal aligning agent having good liquid crystal alignment properties, a short afterimage erasing time, and excellent storage stability over a long period of time can be obtained. Can be The liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be suitably used for TN type and STN type liquid crystal display devices, and can be further provided by selecting SH (Super Homeotropic) by selecting a liquid crystal to be used. ) Type,
It can also be suitably used for IPS (In-Plane Switching) type, ferroelectric and antiferroelectric liquid crystal display devices. Further, a liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention can be effectively used for various devices, for example, a desk calculator, a wristwatch, a clock, a coefficient display plate, a word processor, a personal computer, and a liquid crystal. Used for display devices such as televisions.

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

Claims (1)

[Claims] 1. One or more polymers selected from the group consisting of (A) (a) a polymer having a polyamic acid structure and (b) a polymer having an imide structure obtained by dehydration and ring closure of the polyamic acid. And (B) a polymer having a polyamic acid silyl ester structure.