JPH10212484A - Liquid crystal aligning agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal aligning agent capable of providing a liquid crystal displaying element in which the time required for after-image to be erased after releasing application of voltage is short by compounding a polymer selected from a polyamic acid and its imidated polymer with a specific additive. SOLUTION: This liquid crystal aligning agent comprises (A) a polymer selected from a polyamic acid and its imidated polymer and an additive selected from (B) an isocyanate compound of formula I [R' is mono- or tetrafunctional organic group; (n) is 1-4] (preferably phenylisocyanate) and (C) a diamine compound of formula II (R<2> is a bifunctional organic group) (preferably p- phenylenediamine). 1,2,3,4-Cyclobutanetetracarboxylic dianhydride, etc., is preferably used as tetracarboxylic dianhydride constituting a polyamic acid of the component A and 4,4'-diaminodiphenylmethane, etc., is preferably used as the diamine compound. The liquid crystal aligning agent is preferably obtained by compounding 100 pts.wt. component A with 5-50 pts.wt. component B and 20-40 pts.wt. component C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal alignment agent used for forming a liquid crystal alignment film of a liquid crystal display device, and more particularly, to a liquid crystal alignment device capable of producing a liquid crystal display device having a short afterimage erasing time. Agent.

[0002]

2. Description of the Related Art Conventionally, a sandwich structure is formed by forming a layer of a nematic liquid crystal having a positive dielectric anisotropy between two substrates having a liquid crystal alignment film formed on the surface thereof through a transparent conductive film. TN (Twisted Nematic) in which the major axis of the liquid crystal molecules is continuously twisted by 90 degrees from one substrate to the other substrate.
A TN type liquid crystal display device having a type liquid crystal cell is known. In recent years, the ST has a higher contrast than the TN type liquid crystal display element and has less viewing angle dependence.
N (Super Twisted Nematic) type liquid crystal display devices have been developed. This STN type liquid crystal display element uses a nematic type liquid crystal blended with a chiral agent as an optically active substance as a liquid crystal, and the major axis of the liquid crystal molecule is continuously twisted over 180 degrees between substrates. This makes use of the birefringence effect generated by this. Orientation of liquid crystal molecules in these TN-type liquid crystal display elements and STN-type liquid crystal display elements is generally realized by a liquid crystal alignment film provided with an alignment ability of liquid crystal molecules by rubbing treatment. Here, as a material of the liquid crystal alignment film constituting the liquid crystal display element, conventionally, polyamic acid,
Also, imidized polymers obtained by dehydrating and ring-closing a polyamic acid are known, and these are used in many liquid crystal display devices because of their excellent heat resistance, affinity with liquid crystals, mechanical strength, and the like.

[0003]

However, in the case of a liquid crystal display device manufactured using a conventionally known liquid crystal aligning agent containing a polyamic acid and / or an imidized polymer, the applied voltage was released. There is a problem that an afterimage is generated on a later display screen, and a sufficient contrast cannot be obtained because a long time is required until the afterimage is erased.
In addition, in a case where the liquid crystal display element is driven at a constant frame cycle, it is desirable that the liquid crystal display element has a high voltage holding ratio in order to obtain good contrast. On the other hand, a thin film formed by a liquid crystal alignment agent (a thin film that becomes a liquid crystal alignment film by an alignment process) is required to have high adhesion to a substrate.

The present invention has been made based on the above circumstances. A first object of the present invention is to provide a liquid crystal aligning agent capable of producing a liquid crystal display element having a short time (afterimage erasing time) from the release of voltage application to the elimination of an afterimage. . A second object of the present invention is to provide a liquid crystal aligning agent capable of producing a liquid crystal display element having a high voltage holding ratio. A third object of the present invention is to provide a liquid crystal aligning agent capable of forming a thin film having high adhesion to a substrate.

[0005]

Means for Solving the Problems The liquid crystal aligning agent of the present invention comprises:
At least one polymer selected from a polyamic acid and an imidized polymer thereof; and at least one polymer selected from an isocyanate compound represented by the following general formula (I) and a diamine compound represented by the following general formula (II) And an additive.

[0006]

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[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. <Polymer Component> The liquid crystal aligning agent of the present invention contains a polyamic acid and / or an imidized polymer thereof as a polymer component. The polyamic acid constituting the liquid crystal aligning agent of the present invention can be obtained by reacting a tetracarboxylic dianhydride with a diamine compound, and the imidized polymer is obtained by dehydrating and ring-closing the polyamic acid. Can be.

<Tetracarboxylic dianhydride> The tetracarboxylic dianhydride used for the synthesis reaction of the polyamic acid is not particularly limited. For example, butanetetracarboxylic dianhydride, 1,2,2 3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, hexahydropyromellitic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarboxylic dianhydride Anhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3 , 5-Tricarboxycyclopentylacetic acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 3,5,6
-Tricarboxynorbornane-2-acetic acid dianhydride,
2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-
Methyl-5- (tetrahydro-2,5-dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-
Dione, 1,3,3a, 4,5,9b-hexahydro-
5-ethyl-5- (tetrahydro-2,5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,
3-dione, 1,3,3a, 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,
3,5,6-tetracarboxylic dianhydride, the following formula (1)
[Specific examples are represented by formulas (7) to (9). And a compound represented by the following formula (2) [a specific example of which is represented by formula (10): An aliphatic tetracarboxylic dianhydride and an alicyclic tetracarboxylic dianhydride;

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) 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'-diphenyl ether dianhydride, bis (tri Phenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate), 1,4-butanediol-bis (anhydrotrimeritate) Trimellitate), 1,6-hexanediol-bis (anhydrotrimellitate),
1,8-octanediol-bis (anhydrotrimellitate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate), represented by the following formulas (3) to (6) And aromatic tetracarboxylic dianhydrides such as These are used alone or in combination of two or more.

[0010]

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(Where R^ThreeAnd R^FiveHas an aromatic ring
A divalent organic group represented by^FourAnd R ⁶Is a hydrogen atom
Or an alkyl group. Multiple R^FourAnd R
⁶May be the same or different. )

[0012]

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[0013]

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Of these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid Dianhydride, 1,3,3
a, 4,5,9b-Hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2
-C] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2 ] -Oct-7-ene-2,3,5,6-
Tetracarboxylic dianhydride and pyromellitic dianhydride are preferred, with 1,2,3,3 being particularly preferred.
4-cyclobutanetetracarboxylic dianhydride, 2,3
Examples include 5-tricarboxycyclopentylacetic acid dianhydride and pyromellitic dianhydride.

<Diamine Compound> The diamine compound to be subjected to the synthesis reaction of the polyamic acid is not particularly limited. For example, 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, 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 Aromatic diamines such as' -bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl; aromatic diamines having a hetero atom such as diaminotetraphenylthiophene; 1,1-metaxylylenediamine; 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 ] -undesylene 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 the following formula (11)
[A specific example is represented by the formula (20). ]
And a compound represented by the following formula (12) [A specific example is represented by formula (21). A compound having two primary amino groups and a nitrogen atom other than the nitrogen atom constituting the primary amino group in the molecule; mono-substituted phenylenediamines represented by the following formula (13) [specific examples thereof] Into the equation (22)
To (27). A diaminoorganosiloxane represented by the following formula (14); and compounds represented by the following formulas (15) to (19). These diamine compounds can be used alone or in combination of two or more.

[0017]

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[0018] (wherein, R ⁷ represents a divalent organic group, R ⁸
Represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine. )

[0019]

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(In the formula, R ⁹ represents a divalent organic group, and a plurality of R ⁹ may be the same or different.
Reference numeral ¹⁰ denotes a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine. )

[0021]

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(Wherein R ¹¹ represents —O—, —COO—,
OCO-, -NHCO-, -CONH- and -CO-
R ¹² represents a monovalent organic group having at least one group selected from a steroid skeleton, a trifluoromethyl group and a fluoro group, or an alkyl group having 6 to 30 carbon atoms. Show. )

[0023]

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(Wherein, R ¹³ represents a hydrocarbon group having 1 to 12 carbon atoms, and a plurality of R ¹³ may be the same or different. P is an integer of 1 to 3) , Q is an integer of 1 to 20.)

[0025]

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

[0027]

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[0028]

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[0029]

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Of these, p-phenylenediamine,
4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4 ′
-Diaminodiphenyl ether, 4.4 '-(p-phenyleneisopropylidene) bisaniline, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexa Fluoropropane, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl]
Hexafluoropropane, 4,4'-diamino-2,
Preference is given to 2'-bis (trifluoromethyl) biphenyl and 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, particularly preferred are p-phenylenediamine, 4'-diaminodiphenylmethane and 4,
4 '-(p-phenyleneisopropylidene) bisaniline can be mentioned.

<Polyamic Acid> In the synthesis reaction of the polyamic acid constituting the liquid crystal aligning agent of the present invention, the ratio of the tetracarboxylic dianhydride and the diamine compound used is based on 1 equivalent of the amino group contained in the diamine compound. It is preferable that the ratio of the acid anhydride groups of the tetracarboxylic dianhydride be 0.2 to 2 equivalents, more preferably 0.3 to 2 equivalents.
This is a ratio of 1.2 equivalents. The synthesis reaction of the polyamic acid constituting the liquid crystal aligning agent of the present invention is carried out in an organic solvent at a reaction temperature of usually -20 to 150C, preferably 0 to 100C for 1 to 48 hours. The organic solvent is not particularly limited as long as it can dissolve the polyamic acid generated by the reaction. Specifically, aprotic polarities such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide and the like Solvents: phenolic solvents such as m-cresol, xylenol, phenol, halogenated phenol and the like can be mentioned. Usually, the amount of the organic solvent used is preferably such that the total amount of the tetracarboxylic dianhydride and the diamine compound is 0.1 to 30% by weight based on the total amount of the reaction solution.

The above organic solvents include alcohols, ketones, esters, and the like, which are poor solvents for polyamic acid.
Ethers, halogenated hydrocarbons, hydrocarbons and the like can be used in combination as long as the generated polyamic acid does not precipitate. Specific examples of such poor solvents include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol,
Triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, Diethyl malonate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-
Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether,
Ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,1,
Examples thereof include 4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, and xylene. These can 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 having a structural unit represented by the following general formula (III). Can be. In addition, the polyamic acid can be purified by dissolving the polyamic acid in an organic solvent again and then performing a step of precipitating with a poor solvent once or several times.

[0034]

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<Imidated polymer> The imidized polymer constituting the liquid crystal aligning agent of the present invention includes [a] the above-mentioned general formula (III)
And a polymer having a structural unit represented by the following general formula (IV) (hereinafter, referred to as “imide group-containing polyamic acid”), and [b] the following general formula (IV)
100% imidation ratio having only the structural unit represented by
(Hereinafter, referred to as “polyimide”). In the present specification, the “imidation ratio” is a percentage of the number of repeating units forming an imide ring with respect to the total number of repeating units in a polymer.

[0036]

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The imidized polymer constituting the liquid crystal aligning agent of the present invention (imide group-containing polyamic acid and polyimide)
Can be prepared by the following methods (1) to (4). (1) A method for obtaining an imidized polymer by heating the polyamic acid to cause dehydration and ring closure (imidation reaction) of the polyamic acid. (2) A method of dissolving the above polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring-closing catalyst to the solution, and heating if necessary, thereby dehydrating and ring-closing the polyamic acid to obtain an imidized polymer. . (3) A method of reacting a mixture of a tetracarboxylic dianhydride, a diamine compound and a diisocyanate compound to obtain an imide group-containing polyamic acid. (4) A method of reacting a mixture of a tetracarboxylic dianhydride and a diisocyanate compound to obtain a polyimide.

The reaction temperature in the above method (1) is usually from 60 to 300 ° C., preferably from 100 to 250 ° C.
It is said. When the reaction temperature is lower than 60 ° C., the dehydration ring-closing reaction does not sufficiently proceed, and when the reaction temperature exceeds 300 ° C., the molecular weight of the obtained imidized polymer may decrease. In the method (2), an acid anhydride such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is 1.6 to 20 per mol of the repeating unit of the polyamic acid.
Preferably, it is molar. Further, as the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but not limited thereto. The amount of the dehydration ring-closing catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used. In addition, as the organic solvent used for the dehydration ring closure reaction, the organic solvents exemplified as those used for the synthesis of polyamic acid can be exemplified. The reaction temperature of the dehydration ring closure reaction is generally 0 to 180 ° C, preferably 60 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. Examples of the diisocyanate compound used in the above methods (3) and (4) include an aliphatic diisocyanate compound such as hexamethylene diisocyanate; an alicyclic diisocyanate compound such as cyclohexane diisocyanate; diphenylmethane-4,4 ′
-Diisocyanate, diphenyl ether-4,4'-
Diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, 1,2-diphenylethane-p, p '
-Diisocyanate, 2,2-diphenylpropane-
p, p'-diisocyanate, 2,2-diphenyl-
1,1,1,3,3,3-hexafluoropropane-
p, p'-diisocyanate, 2,2-diphenylbutane-p, p'-diisocyanate, diphenyldichloromethane-4,4'-diisocyanate, diphenylfluoromethane-4,4'-diisocyanate, benzophenone-4,4'diisocyanate, Aromatic diisocyanate compounds such as N-phenylbenzoic acid amide-4,4′-diisocyanate can be mentioned, and these can be used alone or in combination of two or more.
In the above methods (3) and (4), a reaction catalyst is not particularly required, and the reaction temperature is usually 50 to 200 ° C, preferably 100 to 160 ° C.

<Terminal-Modified Polymer> The polymer (polyamic acid and imidized polymer) constituting the liquid crystal aligning agent of the present invention may be a terminal-modified polymer having a controlled molecular weight. By using this terminal-modified polymer, the coating characteristics of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified type can be synthesized by adding a dicarboxylic acid monoanhydride, a monoamine compound, a monoisocyanate compound, or the like to the reaction system when synthesizing the polyamic acid. Here, as the dicarboxylic acid monoanhydride, for example, maleic anhydride, phthalic anhydride, nadic anhydride,
Itaconic anhydride, n-decylsuccinic anhydride, n
-Dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, and n-undecylamine. , N-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n-eicosylamine and the like. Can be. In addition, examples of the monoisocyanate compound include phenyl isocyanate and naphthyl isocyanate.

<Logarithmic Viscosity of Polymer> The polymer (polyamic acid and imidized polymer) constituting the liquid crystal aligning agent of the present invention has a logarithmic viscosity (ηln) of usually 0.05.
To 10 dl / g, preferably 0.05 to 5 dl / g.
g. Here, the value of the logarithmic viscosity (ηln) is N-
Using methyl-2-pyrrolidone as a solvent, the viscosity of a solution having a polymer concentration of 0.5 g / 100 ml was measured at 30 ° C., and the viscosity was determined by the following equation.

[0041]

(Equation 1)

<Additive> The liquid crystal aligning agent of the present invention contains an isocyanate compound represented by the above general formula (I) and / or a diamine compound represented by the above general formula (II) as an additive. It is characterized by points.
According to the liquid crystal alignment agent of the present invention containing the above-described additive as an essential component, the afterimage erasing time can be significantly shortened in the manufactured liquid crystal display device, and a high-contrast image is displayed. It becomes possible. Also,
According to the liquid crystal alignment agent containing the isocyanate compound, in the formed thin film, the adhesion to the substrate can be improved, and according to the liquid crystal alignment agent containing the diamine compound, in the liquid crystal display device to be manufactured, ,
The voltage holding ratio can be increased.

<Isocyanate Compound> Examples of the isocyanate compound constituting the liquid crystal aligning agent of the present invention include 1 to 4
And a derivative thereof having an isocyanate group (NCO). Specific examples of such isocyanate compounds include, for example, monoisocyanate compounds such as ethyl isocyanate and phenyl isocyanate;

Methylene diisocyanate, ethylene diisocyanate, trimethylene diisocyanate, 1-methylethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 2-methylbutane-1,4-diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, 2,2'- Dimethylpentane-1,5-diisocyanate, octamethylene diisocyanate, 2,5-dimethylhexane-1,6-diisocyanate, 2,2
4-trimethylpentane-1,5-diisocyanate,
Nonamethylene diisocyanate, 2,2 ', 4-trimethylhexane diisocyanate, 2,4,4'-trimethylhexane diisocyanate, decamethylene diisocyanate, undecamethylene diisocyanate, dodecamethylene diisocyanate, tridecamethylene diisocyanate, tetradecamethylene diisocyanate, penta Decamethylene diisocyanate, hexadecamethylene diisocyanate, butene diisocyanate,

1,3-butadiene-1,4-diisocyanate, 2-butynylene-1,4-diisocyanate,
Propane hexafluoro-1,3-diisocyanate, butane octafluoro-1,4-diisocyanate, octane hexafluoro-1,8-diisocyanate, cyclopropane
1,2-diisocyanate, cyclopropane-1,2-
Bis (carbonyl isocyanate), cyclobutane-
1,2-bis (methyl isocyanate), cyclohexane-1,2-diisocyanate, cyclohexane-1,
3-diisocyanate, cyclohexane-1,4-diisocyanate, 1-methylcyclohexane-2,4-diisocyanate, 1-ethylcyclohexane-2,4-
Diisocyanate, 4,5-dimethylcyclohexane-
1,3-diisocyanate, 1,2-dimethylcyclohexane-ω, ω′-diisocyanate, 1,4-dimethylcyclohexane-ω, ω′-diisocyanate, isophorone diisocyanate, 1,3,5-trimethyl-2
-Propylcyclohexane-1ω, 2ω-diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethylmethane-4,4′-diisocyanate, dicyclohexyldimethylmethane
4,4′-diisocyanate, 2,2′-dimethyldicyclohexylmethane-4,4′-diisocyanate,
3,3'-dimethyldicyclohexylmethane-4,4 '
-Diisocyanate, 3,3 ', 5,5'-tetramethyldicyclohexylmethane-4,4'-diisocyanate, dimer acid diisocyanate, 2,5-isocyanatomethyltetrahydrofuran, 2,5-isocyanatomethyltetrahydrofuran-5,5' -Ether,
2,2,4,4-tetramethyl-1,3-cyclobutane diisocyanate, 2,2,4,4-tetraethyl-
1,3-cyclobutane diisocyanate, 2,2-dibutyl-2,4-diethyl-1,3-cyclobutane diisocyanate, 2,4-diethyl-2,4-dimethyl-
1,3-cyclobutane diisocyanate,

2,4-dimethyl-2,4-dipropyl-
1,3-cyclobutane diisocyanate, 2,4-diethyl-2,4-dioctyl-1,3-cyclobutane diisocyanate, 2,4-didecyl-1,3-cyclobutane diisocyanate, 2- (γ-isocyanatopropyl) cyclohexyl isocyanate, 5-dimethyl-
1,3-cyclohexylene diisocyanate, carbonyl diisocyanate, methyl ether-ω, ω'-diisocyanate, dipropyl ether-ω, ω'-diisocyanate, ethylene glycol diethyl ether-
1,1′-diisocyanate, 3-methoxyhexamethylene-diisocyanate, 3-butoxyhexamethylene-diisocyanate, propylene glycol dipropyl ether-ω, ω′-diisocyanate, dipropylene glycol dipropyl ether-ω, ω′-diisocyanate, Carboxyethane-1,2-diisocyanate, carboxypropane-1,3-diisocyanate,
Carboxybutane-1,4-diisocyanate, di-
(2-isocyanatocarboxyethyl) ether,
2,2-di (4-isocyanatocarboxyphenyl)
Propane, 1,1,1-diisocyanate-6-acetoxyundecane, 1,1,1-diisocyanateundecane-6-one, bis (2-isocyanatoethyl) carbonate, bis (4-isocyanatophenyl) carbonate, lysine diisocyanate, fumaric Diethyl acid-ω, ω'-diisocyanate, diethyl succinate-
ω, ω'-diisocyanate, diethyl adipate-
ω, ω'-diisocyanate, dimethylsulfone diisocyanate, thiodiethyl diisocyanate, thiodipropyl diisocyanate, 3,3-dinitotopentane-1,5-diisocyanate, 3-nitraza-1,5-
Pentane diisocyanate, 3,6-dinitraza-1,
8-octane diisocyanate, 2-nitraza-1,4
-Butane diisocyanate, 3,10-dinitraza-
1,12-dodecane diisocyanate, 3,7-dinitraza-1,9-nonane diisocyanate, 3,6,9-
Trinitraza-1,1,1-undecane diisocyanate, 2,5-dinitraza-1,6-hexane diisocyanate, 1,3-xylylene diisocyanate, 1,4
-Xylylene diisocyanate,

1,4-diethylbenzol-ω, ω'-
Diisocyanate, m-phenylenebis (isopropylisocyanate), p-phenylenebis (isopropylisocyanate), 1,3-diphenylpropane-1,
3-diisocyanate, 1,4-dimethylnaphthalene-
ω, ω′-diisocyanate, 1,5-dimethylnaphthalene-ω, ω′-diisocyanate, diphenylether-4,4′-bismethylisocyanate, 4,4′-
n-propylbiphenyl-ω, ω'-diisocyanate, anthracene-9,10-diisocyanate, dihydroanthracene-9,10-diisocyanate, bis (2-isocyanatoethyl) terephthalate, bis (2-isocyanatoethyl) isophthalate, bis ( 2-isocyanatoethyl) -p-phenylenediacetate, 4-phenylisocyanate-methylisocyanate, 4-phenylisocyanate-β-ethylisocyanate, 4-phenylisocyanate-α-ethylisocyanate, 4-phenylisocyanate-γ-propylisocyanate, 3-phenyl isocyanate-
γ-propyl isocyanate, 3-phenyl isocyanate-γ-butyl isocyanate, 4-phenyl isocyanate-γ-butyl isocyanate, tetrahydronaphthylene-1,5-diisocyanate, hexahydrobenzidine-4,4′-diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-3,5 -Phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl Tyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene-2,4-diisocyanate, 3-methyl-1 , 5-diethylbenzene-2,
4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate,

1-methyltrifluorobenzene-3,4-
Diisocyanate, 1-chlorobenzene-2,4-diisocyanate, 1,3-dichlorobenzene-2,4-diisocyanate, 1,5-dichlorobenzene-2,4-
Diisocyanate, 1-methyl-5-bromobenzene-
2,4-diisocyanate, 1-trifluoromethylbenzene-2,4-diisocyanate, 2,5-dichlorobenzene-1,4-diisocyanate, 2-trifluoromethylbenzene-1,4-diisocyanate, 2-methyl-6 -Bromobenzene-1,4-diisocyanate, 1
-Nitrobenzene-2,4-diisocyanate, 2-nitrobenzene-1,4-diisocyanate, 1,3,5
-Triisopropylbenzene-2,4-diisocyanate, 2,6-dimethylbenzene-1,4-diisocyanate, 2,6-diethylbenzene-1,4-diisocyanate, 1-methoxybenzene-2,4-diisocyanate, 1-ethoxy Benzene-2,4-diisocyanate, 1,5-dimethoxybenzene-2,4-diisocyanate, 1-propoxybenzene-2,4-diisocyanate, 1-isobutoxybenzene-2,4-diisocyanate, 2-methoxybenzene-1 , 4-diisocyanate, 2,5-dimethoxybenzene-1,4-diisocyanate, 2,5-diethoxybenzene-1,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1- Methyl naphthalene-1 5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1'-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4-diisocyanate, biphenyl-4,4'-diisocyanate , 3,
3'-dimethylbiphenyl-4,4'-diisocyanate, tolidine diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 2-nitrobiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'- Diisocyanate, diphenylmethane-2,2'-diisocyanate, diphenylmethane-
2,4-diisocyanate, 3,3′-dichlorodiphenylmethane-4,4′-diisocyanate, 3,5-dimethyldiphenylmethane-4,4′-diisocyanate,

2,2'-dimethyldiphenylmethane
4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 3-methoxydiphenylmethane-4,4′-diisocyanate,
2,4,6-trimethyldiphenylmethane-3,4'-
Diisocyanate, 2,2 ′, 5,5′-tetramethyldiphenylmethane-4,4′-diisocyanate, 3,
3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-dimethoxydiphenylmethane-
3,3′-diisocyanate, 4,4′-diethoxydiphenylmethane-3,3′-diisocyanate,
2'-dimethyl-5,5'-dimethoxydiphenylmethane-4,4'-diisocyanate, 3,3 ', 5,5'
-Tetraisopropyldiphenylmethane-4,4'-diisocyanate, bis (4-isocyanatophenyl)
Dimethylmethane, bis (3-chloro-4-isocyanatophenyl) dimethylmethane, bis (4-isocyanatophenyl) ditrifluoromethylmethane, bis (4-
Isocyanatephenyl) cyclohexylmethane, bis (4-isocyanatophenyl) -2-nitrophenylmethane, bis (4-isocyanatophenyl) -4-nitrophenylmethane, bis (4-isocyanate-2,
5-dimethylphenyl) phenylmethane, bibenzyl-
4,4'-diisocyanate, bibenzyl-2,4-diisocyanate, bis (4-isocyanatephenyl)
Ethylene, bis (4-isocyanatophenyl) difluoroethylene, fluorene-2,7-diisocyanate, anthraquinone-2,6-diisocyanate, pyrene-3,8-diisocyanate, chrysene-2,8-diisocyanate, diphenylether-2,4- Diisocyanate, diphenyl ether-4,4'-diisocyanate, ethylene glycol diphenyl ether-
4,4′-diisocyanate, 1,3-propylene glycol diphenyl ether-4,4′-diisocyanate, diethylene glycol diphenyl ether-4,
4'-diisocyanate, diphenylcarbonyl-3,
3'-diisocyanate, azodiphenyl-4,4'-
Diisocyanate, 3-methylazidiphenyl 4,4 '
-Diisocyanate, 4-isocyanatophenylazo-4'-naphthyl diisocyanate,

Diphenyl sulfide-2,4'-diisocyanate, diphenyl sulfide-4,4'-diisocyanate, 2,2'-dimethylphenyl sulfide
5,5′-diisocyanate, 2,2′-dimethylphenyl disulfide-5,5′-diisocyanate, 3,
3′-dimethyldiphenyldisulfide-6,6′-diisocyanate, 4,4′-dimethyldiphenyldisulfide-5,5′-diisocyanate, 4,4′-dimethyldiphenyldisulfide-3,3′-diisocyanate, 3,3 ′ -Dimethoxydiphenyl disulfide-
4,4'-diisocyanate, diphenylsulfone-
4,4'-diisocyanate, diphenylsulfone-
3,3′-diisocyanate, 4,4′-dichlorodiphenylsulfone-3,3′-diisocyanate,
4'-dimethyldiphenylsulfone-3,3'-diisocyanate, 4,4'-dimethoxydiphenylsulfone-3,3'-diisocyanate, 4,4'-di-t
tert-butyldiphenylsulfone-3,3'-diisocyanate, 4-methyldiphenylsulfone-2,
4-diisocyanate, 2,5-di (CH ₂ NCO) furan, dibenzofuran-2,7-diisocyanate, carbazole-3,6-diisocyanate, 9-ethylcarbazole-3,6-diisocyanate, 1,8-dichloro-carbazole - 3,6-diisocyanate, diphenylboron diisocyanate, di-n-butoxyboron diisocyanate, dimethylaminoboron diisocyanate, diethylaminoboron diisocyanate, dimethylsilicon diisocyanate, di-n-butylsilicon diisocyanate, diphenylsilicon diisocyanate, diethoxysilicon diisocyanate, diphenoxy Silicon diisocyanate, dibutyltin diisocyanate, diphenyltin diisocyanate, triphenylarsenic diisocyanate Salt, tributylantimony diisocyanate, triisobutylantimony diisocyanate, phenyl phosphorus diisocyanate, methoxy phosphorus diisocyanate, ethoxy phosphorus diisocyanate, methyl phosphorus oxide diisocyanate, monochloromethyl phosphorus oxide diisocyanate, ethyl phosphorus oxide diisocyanate, isopropyl phosphorus oxide diisocyanate, benzyl phosphorus oxide diisocyanate, Phenyl phosphorus oxide diisocyanate, butoxy phosphorus oxide diisocyanate, phenoxy phosphorus oxide diisocyanate and the following formulas (28) to (3)
A diisocyanate compound represented by 2);

1-methylbenzol-2,4,6-triisocyanate, 1,3,5-trimethylbenzol-
2,4,6-triisocyanate, naphthalene-1,
3,7-triisocyanate, biphenyl-2,4,
4'-triisocyanate, diphenylmethane-2,
Triisocyanates such as 4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, triphenylmethane, 4,4 ', 4'-triisocyanate, polymeric-diphenylmethane-4,4'-diisocyanate Compounds: 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5′-tetraisocyanate and tetraisocyanate compounds represented by the following formulas (33) to (36): dimers of the above isocyanates, trimers of the above isocyanates, Carbodiimides formed from the above diisocyanate compounds, and oligomers and polymers having isocyanate groups at both terminals represented by the following formulas (37) to (40) can be given. These isocyanate compounds can be used alone or in combination of two or more.

[0052]

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[0053]

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[0054]

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Among these isocyanate compounds, an aromatic isocyanate compound is preferable because a liquid crystal alignment film having excellent heat resistance can be obtained. Specifically, aromatic monoisocyanate compounds such as phenyl isocyanate; diphenylmethane-4,4′-diisocyanate;
Aromatic diisocyanate compounds such as 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate; 4,4′-dimethyldiphenylmethane- 2,2 ',
5,5′-tetraisocyanate and the like are preferred, and particularly preferred are phenyl isocyanate, diphenylmethane-4,4′-diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-
2,6-phenylene diisocyanate can be mentioned.

The content of the isocyanate compound in the liquid crystal aligning agent of the present invention is usually 1 to 100 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the polymer component.
50 parts by weight. When the content of the isocyanate compound is too small, the effect of reducing the afterimage erasing time in the liquid crystal display device to be produced and the effect of improving the adhesion of the formed thin film to the substrate cannot be sufficiently achieved. On the other hand, when an isocyanate compound is excessively added, the liquid crystal alignment property of the obtained liquid crystal alignment film may be reduced.

<Diamine Compound> Examples of the diamine compound constituting the liquid crystal aligning agent of the present invention include the compounds exemplified as those subjected to the synthesis reaction of polyamic acid. Among these diamine compounds, an aromatic diamine compound is preferable because a liquid crystal alignment film having excellent heat resistance is obtained, and particularly preferable are p-phenylenediamine, 4,4′-diaminodiphenylmethane, and 4,4 ′. -(P-phenyleneisopropylidene) bisaniline, 4,4 '-(m-phenyleneisopropylidene) bisaniline, 1,5-diaminonaphthalene,
2,7-diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
4,4'-diaminodiphenyl ether and 4,4 '
-(P-phenyleneisopropylidene) bisaniline.

The content of the diamine compound in the liquid crystal aligning agent of the present invention is usually 1 to 100 parts by weight, preferably 20 to 4 parts by weight, per 100 parts by weight of the polymer component.
0 parts by weight. When the content of the diamine compound is too small, it is impossible to sufficiently reduce the afterimage erasing time and increase the voltage holding ratio in the manufactured liquid crystal display device. On the other hand, when the diamine compound is excessively added, the liquid crystal alignment of the obtained liquid crystal alignment film may be reduced.

<Liquid Crystal Alignment Agent> The liquid crystal alignment agent of the present invention comprises at least one polymer selected from a polyamic acid and an imidized polymer, and at least one additive selected from the above isocyanate compounds and the above diamine compounds. Consists of a solution contained in an organic solvent.
The liquid crystal alignment agent of the present invention is applied to the substrate surface by, for example, a printing method or a spin coating method, and the coating film is dried to remove the organic solvent, thereby forming a thin film as an alignment film material. The organic solvent constituting the liquid crystal aligning agent of the present invention is not particularly limited as long as it can dissolve the polyamic acid and the imidized polymer. For example, the organic solvent used in the synthesis reaction of the polyamic acid is exemplified. Solvents can be mentioned. In addition, the poor solvent exemplified as being able to be used in combination during the synthesis reaction of the polyamic acid can also be appropriately selected and used in combination, and by using the poor solvent in combination, the coating characteristics of the liquid crystal alignment agent are improved. be able to. The content ratio (polymer concentration) of the polymer in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is 0.1 to 20% by weight of the liquid crystal aligning agent.
And more preferably in the range of 1 to 10% by weight. If the content of the polymer is less than 0.1% by weight, the thickness of the formed thin film may be too small to obtain a good liquid crystal alignment film,
If the content exceeds 20% by weight, the thickness of the thin film becomes excessively large, so that it is difficult to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent is increased, so that the coating properties may be poor.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound from the viewpoint of improving the adhesion of the thin film (polymer) to the substrate surface. Examples of such a functional silane-containing compound include 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-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane , N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane, and the like. .

<Liquid Crystal Display Device> A liquid crystal display device obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method.

(1) The liquid crystal aligning agent of the present invention is applied to one surface (the surface on the transparent conductive film side) of the substrate provided with the patterned transparent conductive film by a method such as a roll coater method, a spinner method, or a printing method. And then heating the coating to remove the organic solvent to form a thin film. Here, as the substrate, for example, a transparent substrate made of glass such as float glass or soda glass; or a plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, or polycarbonate can be used. As the transparent conductive film provided on one surface of the substrate, NE made of tin oxide (SnO ₂ ) is used.
An SA film (registered trademark of US PPG), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like can be used. A method using a mask in advance is used. When applying the liquid crystal aligning agent, a functional silane-containing compound, a functional titanium-containing compound, etc. are previously applied on the substrate and the transparent conductive film in order to further improve the adhesion between the substrate surface and the transparent conductive film and the thin film. It can also be applied. The heating temperature of the coating film is usually 80 to 30
0 ° C, preferably 120-250 ° C. The thickness of the formed thin film is usually 0.001 to 1 μm, and preferably 0.005 to 0.5 μm. By further heating the thin film made of polyamic acid and / or imide group-containing polyamic acid,
The dehydration ring closure (imidization) of the amic acid structure can also proceed.

(2) A rubbing treatment is performed in which the formed thin film 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. This allows
The thin film becomes a liquid crystal alignment film provided with the alignment ability of liquid crystal molecules. Also, in addition to the rubbing method, a liquid crystal alignment film may be formed by irradiating the surface of the thin film with polarized ultraviolet rays to impart alignment ability, a uniaxial stretching method, a method of obtaining a thin film by a Langmuir-Blodgett method, or the like. Can also. 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. Further, a liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention is, for example, disclosed in JP-A-6-222366.
JP-A-6-281937 and JP-A-6-281937, a process in which the pretilt angle is changed by partially irradiating ultraviolet rays, or
No. 07544, a resist film is partially formed on a rubbed liquid crystal alignment film, a rubbing process is performed in a direction different from the preceding rubbing process, and then the resist film is removed. Then, by performing a process for changing the alignment ability of the liquid crystal alignment film, the visibility characteristics of the liquid crystal display element can be improved.

(3) Two substrates on which a liquid crystal alignment film is 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. (Cell gap)
The peripheral portions of the two substrates are bonded to each other using a sealant, and liquid crystal is injected and filled into the substrate surface and a cell gap defined by the sealant, and the injection 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. Here, as the sealing agent, for example, an epoxy resin containing an aluminum oxide sphere as a curing agent and a spacer can be used. Examples of the liquid crystal include a nematic liquid crystal and a smectic liquid crystal, and among them, a nematic liquid crystal is preferable, for example, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, and a terphenyl liquid crystal. A liquid crystal, a biphenylcyclohexane-based liquid crystal, a pyrimidine-based liquid crystal, a dioxane-based liquid crystal, a bicyclooctane-based liquid crystal, a cubane-based liquid crystal, or the like can be used. In addition, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate, and chiral agents such as those sold under the trade names "C-15" and "CB-15" (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.
Further, as a polarizing plate bonded to the outer surface of the liquid crystal cell, a polarizing plate in which a polarizing film called an H film absorbing iodine is sandwiched between cellulose acetate protective films while stretching and aligning polyvinyl alcohol, or H A polarizing plate composed of the film itself can be used.

[0065]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the following, “parts” means “parts by weight”.
Shall mean. The measuring method and evaluation method for the liquid crystal aligning agents prepared by the following Examples and Comparative Examples and the manufactured liquid crystal display devices are as follows.

[Adhesion of Thin Film with Liquid Crystal Alignment Agent]
After immersion for a time, according to JIS K 5400, 100 cross-sections were made on the thin film forming surface at 1 mm intervals, and a peel test was performed using an adhesive tape as a test piece. Was measured.

[Afterimage erasing time] After a DC voltage of 10 V was applied to the liquid crystal display element for 1 hour, the application of the voltage was released, the display screen was visually observed, and after the voltage application was released, the display was stopped. The time required until the afterimage of the sample was erased was measured.

[Voltage holding ratio] An application time of 60 μsec,
A voltage of 5 V was applied to the liquid crystal display element in a span of 167 msec, and the holding voltage (V) of the liquid crystal display element was measured 167 msec after the application of the voltage was released.
The retention [(V / 5) × 100] was determined.

[Liquid Crystal Alignment] The presence or absence of abnormal domains when the voltage was turned on / off (applied / canceled) to the liquid crystal display element was observed with a polarizing microscope.

Synthesis Example 1 5.23 g (10 mmol) of diamine represented by the above formula (22), 17.8 g (90 mmol) of 4,4′-diaminodiphenylmethane and 2,
3,5-tricarboxycyclopentylacetic acid dianhydride 2
2.4 g (100 mmol) were dissolved in 450 g of N-methyl-2-pyrrolidone, and this solution was reacted at 60 ° C. for 6 hours. Then, the obtained reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the solid substance was separated, washed with methyl alcohol, and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid having a logarithmic viscosity (ηln) of 0.95 dl / g [this was referred to as “Polymer (a1) ". 40.8 g was obtained.

[Synthesis Example 2] 25.0 g of the polymer (a1) obtained in Synthesis Example 1 was mixed with N-methyl-2-pyrrolidone 45.
The solution was dissolved in 0 g, and 7.0 g of pyridine and 9.1 g of acetic anhydride were added to this solution, followed by heating at 100 ° C. for 3 hours to effect dehydration and ring closure. Then, in the same manner as in Synthesis Example 1,
By performing precipitation, separation, washing and drying of the reaction product, an imide group-containing polyamic acid having a logarithmic viscosity (ηln) of 0.93 dl / g and an imidation ratio of 70% [this is referred to as “Polymer (b1) ". 19.0 g were obtained.

Synthesis Example 3 5.24 g (10 mmol) of diamine represented by the above formula (23), 17.8 g (90 mmol) of 4,4′-diaminodiphenylmethane and 2,
3,5-tricarboxycyclopentylacetic acid dianhydride 2
2.4 g (100 mmol) were dissolved in 450 g of N-methyl-2-pyrrolidone, and this solution was reacted at 60 ° C. for 6 hours. Then, the obtained reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the solid substance was separated, washed with methyl alcohol, and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid having a logarithmic viscosity (ηln) of 0.95 dl / g [this was referred to as “Polymer (a2) ". 40.8 g was obtained.

[Synthesis Example 4] 25.5 g of the polymer (a2) obtained in Synthesis Example 3 was mixed with N-methyl-2-pyrrolidone 45.
0 g, and to this solution were added 7.2 g of pyridine and 9.2 g of acetic anhydride, followed by heating at 100 ° C. for 3 hours to effect dehydration and ring closure. Then, in the same manner as in Synthesis Example 1,
By precipitating, separating, washing and drying the reaction product, an imide group-containing polyamic acid having a logarithmic viscosity (ηln) of 0.93 dl / g and an imidation ratio of 70% [this is referred to as “Polymer (b2) ". 19.5 g were obtained.

Synthesis Example 5 5.23 g (10 mmol) of the diamine represented by the above formula (22), 17.8 g (90 mmol) of 4,4′-diaminodiphenylmethane and 21.8 g of pyromellitic dianhydride (100 mmol) was dissolved in 450 g of N-methyl-2-pyrrolidone, and the solution was reacted at 25 ° C. for 6 hours. Then, the obtained reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the solid substance was separated, washed with methyl alcohol, and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid having a logarithmic viscosity (ηln) of 1.50 dl / g [this was referred to as “Polymer (a3) ". ]
37.8 g were obtained.

[Synthesis Example 6] 6.43 g (10 mmol) of the diamine represented by the above formula (15), 17.8 g (90 mmol) of 4,4'-diaminodiphenylmethane, and 21.8 g of pyromellitic dianhydride (100 mmol) was dissolved in 450 g of N-methyl-2-pyrrolidone, and the solution was reacted at 25 ° C. for 6 hours. Then, the obtained reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the solid substance was separated, washed with methyl alcohol, and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid having a logarithmic viscosity (ηln) of 0.80 dl / g [this was referred to as “Polymer (a4) ". ]
38.8 g were obtained.

Synthesis Example 7 4.22 g (10 mmol) of the diamine represented by the above formula (26), 17.8 g (90 mmol) of 4,4′-diaminodiphenylmethane and 21.8 g of pyromellitic dianhydride (100 mmol) was dissolved in 450 g of N-methyl-2-pyrrolidone, and the solution was reacted at 25 ° C. for 6 hours. Then, the obtained reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the solid substance was separated, washed with methyl alcohol, and dried under reduced pressure at 40 ° C. for 15 hours to obtain a polyamic acid having a logarithmic viscosity (ηln) of 1.80 dl / g [this was referred to as “Polymer (a5) ". ]
38.2 g were obtained.

Synthesis Example 8 41.0 g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (10
0 mmol) and 19.6 g of pyromellitic dianhydride (9
0 mmol) and 7.52 g (10 mmol) of the tetracarboxylic dianhydride represented by the above formula (3) are dissolved in 450 g of N-methyl-2-pyrrolidone.
The reaction was carried out at 6 ° C. for 6 hours. Then, the obtained reaction solution was poured into a large excess of methyl alcohol to precipitate a reaction product. Thereafter, the solid matter was separated, washed with methyl alcohol, and dried at 40 ° C. under reduced pressure for 15 hours to obtain a polyamic acid having a logarithmic viscosity (ηln) of 1.60 dl / g [this was referred to as “Polymer (a6) ". ] 62.0 g
I got

[Synthesis Example 9] 25.5 g of the polymer (a1) obtained in Synthesis Example 1 was mixed with N-methyl-2-pyrrolidone 45.
Then, 29.2 g of pyridine and 22.6 g of acetic anhydride were added to this solution, and the solution was heated at 100 ° C. for 3 hours to effect dehydration and ring closure. Next, a polyimide having a logarithmic viscosity (ηln) of 0.89 dl / g and an imidation ratio of 100% [this was obtained by performing precipitation, separation, washing, and drying of the reaction product in the same manner as in Synthesis Example 1. "Polymer (c
1) ". 17.5 g was obtained.

Example 1 (1) Preparation of Liquid Crystal Alignment Agent: According to the recipe shown in Table 1, 100 parts of the polymer (a1) obtained in Synthesis Example 1 and dicyclohexylmethane-4,4′-diisocyanate 20 Was dissolved in γ-butyrolactone to form a solution having a polymer concentration of 4% by weight, and this solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent of the present invention.

(2) Production of liquid crystal display element: The present invention prepared as described above was applied to one surface (the surface on the transparent electrode side) of a glass substrate (1 mm thick) provided with a transparent electrode made of an ITO film. Apply the liquid crystal aligning agent using a spinner,
By heating the coating film at 180 ° C. for 1 hour, a thin film having a dry film thickness of 800 ° was formed. Table 1 shows the measurement results of the adhesiveness of the thin film. The surface of the thin film thus formed is subjected to a rubbing treatment using a rubbing machine having a roll wound with a nylon cloth, thereby imparting liquid crystal molecule alignment ability to the thin film and thereby aligning the liquid crystal. A film was formed. Here, the rubbing treatment conditions were as follows: the number of rotations of the roll was 500 rpm, and the moving speed of the stage was 1 cm / sec. After preparing two substrates on which the liquid crystal alignment film was formed as described above, an epoxy resin-based adhesive containing aluminum oxide spheres having a diameter of 17 μm was applied to the outer edge of each substrate by a screen printing method. The two substrates were opposed to each other with a gap therebetween so that the rubbing directions of the respective liquid crystal alignment films were antiparallel, and the outer edges were brought into contact with each other and pressed to cure the adhesive. Next, the nematic liquid crystal “MLC-2001” (manufactured by Merck) is injected and filled into the cell gap defined by the adhesive on the surface and the outer edge of the substrate, and then the injection hole is sealed with an epoxy-based adhesive. Thus, a liquid crystal cell was formed. Thereafter, a polarizing plate is attached on the outer surface of the liquid crystal cell, that is, on the other surface of each of the substrates constituting the liquid crystal cell so that the polarization direction matches the rubbing direction of the liquid crystal alignment film formed on one surface of the substrate. Thus, a liquid crystal display device was manufactured. With respect to the liquid crystal display device manufactured as described above, the afterimage erasing time and the voltage holding ratio were measured, and the liquid crystal orientation was evaluated. Table 1 shows the above results.

<Examples 2 to 12> According to the formulation shown in Table 1, 100 parts of each of the polymers obtained in Synthesis Examples 1 to 9
Each of the isocyanate compounds was dissolved in γ-butyrolactone to form a solution having a polymer concentration of 4% by weight, and the obtained solution was filtered through a filter having a pore size of 1 μm in the same manner as in Example 1 to obtain a liquid crystal of the present invention. An alignment agent was prepared, a thin film was formed using the liquid crystal alignment agent, and a liquid crystal display device having the thin film was manufactured. Table 1 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display device, and the results of evaluating the liquid crystal orientation of the liquid crystal display device.

Example 13 An organic solvent was removed from a coating film by heating a coating film of a liquid crystal aligning agent formed on one surface of a glass substrate at 250 ° C. for 1 hour.
A thin film composed of an imide group-containing polyamic acid (imidation ratio: 99%) was formed in the same manner as in Example 4 except that the dehydration and ring closure of the polymer constituting the coating film were advanced, and a liquid crystal display having the thin film An element was manufactured. Table 1 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display device, and the results of evaluating the liquid crystal orientation of the liquid crystal display device.

Example 14 According to the formulation shown in Table 2,
100 parts of the polymer (a1) obtained in Synthesis Example 1,
The present invention was carried out in the same manner as in Example 1 except that 20 parts of 4′-diaminodiphenylmethane was dissolved in γ-butyrolactone to obtain a solution having a polymer concentration of 4% by weight, and this solution was filtered through a filter having a pore size of 1 μm. Was prepared, a thin film was formed using the liquid crystal aligning agent, and a liquid crystal display device having the thin film was manufactured. Table 2 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display element, and the results of evaluating the liquid crystal orientation of the liquid crystal display element.

<Examples 15 to 25> In accordance with the formulation shown in Table 2, 100 parts of each of the polymers obtained in Synthesis Examples 1 to 9 and each of the diamine compounds were dissolved in γ-butyrolactone, and the polymer concentration was adjusted. A liquid crystal aligning agent of the present invention was prepared in the same manner as in Example 14 except that a 4% by weight solution was obtained, and the obtained solution was filtered with a filter having a pore size of 1 μm. A liquid crystal display device having the thin film was manufactured. Table 2 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display element, and the results of evaluating the liquid crystal orientation of the liquid crystal display element.

<Comparative Example 1> According to the formulation shown in Table 2, 100 parts of the polymer (a1) obtained in Synthesis Example 1 was dissolved in γ-butyrolactone to obtain a solution having a polymer concentration of 4% by weight.
A liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 except that the obtained solution was filtered through a filter having a pore size of 1 μm, and a thin film was formed using the liquid crystal aligning agent. Was prepared. Table 2 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display element, and the results of evaluating the liquid crystal orientation of the liquid crystal display element.

Comparative Example 2 According to the formulation shown in Table 2, 100 parts of the polymer (b1) obtained in Synthesis Example 2 and 20 parts of benzene were dissolved in 2500 parts of γ-butyrolactone to give a polymer concentration of 4 parts. Weight% solution, and this solution was
A liquid crystal aligning agent for comparison was prepared and a thin film was formed with the liquid crystal aligning agent in the same manner as in Example 1 except that the mixture was filtered with a filter of m, thereby producing a liquid crystal display device having the thin film. Table 2 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display element, and the results of evaluating the liquid crystal orientation of the liquid crystal display element.

Comparative Example 3 According to the formulation shown in Table 2, 100 parts of the polymer (a2) obtained in Synthesis Example 3 and 20 parts of diphenyl ether were dissolved in 2500 parts of γ-butyrolactone to give a polymer concentration of 4 parts. % By weight, and a liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 except that the solution was filtered through a filter having a pore size of 1 μm, and a thin film was formed using the liquid crystal aligning agent. A liquid crystal display device having the above was manufactured. Table 2 shows the results of measuring the adhesion of the formed thin film, the results of measuring the afterimage elimination time and the voltage holding ratio of the manufactured liquid crystal display element, and the results of evaluating the liquid crystal orientation of the liquid crystal display element.

[0088]

[Table 1]

[Isocyanate compounds in Table 1] x1: dicyclohexylmethane-4,4'-diisocyanate x2: diphenylmethane-4,4'-diisocyanate x3: 1-methyl-2,4-phenylene diisocyanate x4: 1-methyl- 2,6-phenylene diisocyanate x5: ethyl isocyanate x6: phenyl isocyanate x7: hexamethylene diisocyanate x8: cyclohexane-1,2-diisocyanate x9: 1-methylcyclohexane-2,4-diisocyanate x10: 1,2-dimethylcyclohexane-ω , Ω'-Diisocyanate

[0090]

[Table 2]

[Diamine compounds in Table 2] y1: p-phenylenediamine y2: 4,4′-diaminodiphenylmethane y3: 4,4 ′-(p-phenyleneisopropylidene)
Bisaniline y4: 4,4 '-(m-phenyleneisopropylidene)
Bisaniline y5: 1,5-diaminonaphthalene y6: 2,7-diaminofluorene y7: 2,2-bis (4-aminophenyl) hexafluoropropane y8: 2,2-bis [4- (4-aminophenoxy) phenyl ] Propane y9: 4,4'-diaminodiphenyl ether y10: 4,4 '-(p-phenyleneisopropylidene)
Bisaniline

[Comparative additives in Table 2] h1: benzene h2: diphenyl ether

[0093]

According to the liquid crystal alignment agent of the present invention, a liquid crystal display device having a short afterimage erasing time can be manufactured. Further, according to the liquid crystal alignment agent of the present invention containing an isocyanate compound, a thin film and a liquid crystal alignment film having high adhesion to a substrate can be formed. Further, according to the liquid crystal alignment agent of the present invention containing a diamine compound, a liquid crystal display device having a high voltage holding ratio can be manufactured. The liquid crystal display device provided with the liquid crystal alignment film formed by the liquid crystal alignment agent of the present invention is not only a TN type liquid crystal display device but also a STN (S
Upper Twisted Nematic (SHM) type liquid crystal display device, SH (Super Homeotropic)
Liquid crystal display device, IPS (In-Plane-Switt)
(Ching) type liquid crystal display element, ferroelectric liquid crystal display element, antiferroelectric liquid crystal display element, and various other liquid crystal display elements. The liquid crystal display element can be effectively used for various devices, and can be suitably used as a display device such as a desk calculator, a wristwatch, a clock, a counting display, a word processor, a personal computer, and a liquid crystal television.

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

Claims (1)

[Claims] An at least one polymer selected from a polyamic acid and an imidized polymer thereof, and an isocyanate compound represented by the following general formula (I) and a diamine compound represented by the following general formula (II) A liquid crystal aligning agent comprising at least one selected additive. Embedded image