JPH08122793A - Orienting agent for liquid crystal - Google Patents

Abstract

PURPOSE: To form a coating film (a material for an oriented film) in which electrostatic charges produced during rubbing can be rapidly removed and scratches due to rubbing treatment are hardly caused, by incorporating a specified polymer. CONSTITUTION: This agent contains at least either a polyamic acid (polymer A) or its imidized polymer. This polyamic acid is produced by the reaction of a diamine compd. expressed by formula II and tetracarboxylic acid dianhydride comprising 70 to 95mol% of dianhydride of a compd. selected from tetracarboxylic acids expressed by formula I or the like and 30 to 5mol% of tetracarboxylic acid dianhydride containing aromatic rings (compd.B). In formula, R<1> is a quadrivalent org. group containing aromatic rings and R<2> is a bivalent org. group. If the proportion of the compd.B is <5mol%, electrostatic charges produced during rubbing in the coating film formed can not be removed rapidly and the surface of the oriented film formed for a liquid crystal is easily damaged with scratches. On the other hand, if the proportion exceeds 30mol%, the orienting agent has inferior storage stability.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid crystal aligning agent used for forming a liquid crystal aligning film of a liquid crystal display device. More specifically, the static electricity generated during the rubbing treatment of the coating film surface can be quickly removed, and the surface of the formed liquid crystal alignment film is less likely to be scratched by the rubbing treatment (hereinafter referred to as “rubbing scratch”). The present invention relates to a liquid crystal aligning agent which can form a liquid crystal display device having excellent liquid crystal aligning property and has excellent storage stability.

[0002]

2. Description of the Related Art Conventionally, a nematic liquid crystal layer having a positive dielectric anisotropy is formed between two substrates each having a liquid crystal alignment film formed on the surface thereof via a transparent conductive film to form a sandwich structure. , A TN type display element having a TN (Twisted Nematic) type liquid crystal cell in which the long axes of the liquid crystal molecules are continuously twisted by 90 degrees from one substrate to the other substrate is known. . Also recently
STN (Super Twisted N) with improved contrast and viewing angle dependence in a TN type display device
An electronic type display device has been developed. In this STN type display element, a nematic liquid crystal substance blended with a chiral agent which is an optically active substance is used as a liquid crystal material, and the long axis of the liquid crystal molecule is continuously 180 to 2 between the substrates.
It utilizes the birefringence effect caused by twisting over 70 degrees.

However, in the liquid crystal display element such as the TN type display element and the STN type display element, the orientation of the liquid crystal is usually
It is realized by a liquid crystal alignment film in which the alignment ability of liquid crystal molecules is given by rubbing treatment. Here, resins such as polyimide, polyamide, and polyester have been conventionally known as the material of the liquid crystal alignment film constituting the liquid crystal display element. In particular, polyimide is used in many liquid crystal display devices because it is excellent in heat resistance, affinity with liquid crystal, mechanical strength and the like.

[0004]

However, static electricity is generated when the resin surface is rubbed, and the static electricity is incorporated into a transparent conductive film which is an electrode for driving the liquid crystal display element or a circuit which drives the liquid crystal display element. There is a problem that the broken transistor will be damaged. Also, rubbing scratches are generated on the surface of the formed liquid crystal alignment film,
There is also a problem in that the rubbing scratches disturb the alignment of the liquid crystal molecules, resulting in defective display of the liquid crystal display element. Therefore, it has been desired to develop a liquid crystal aligning agent that can quickly remove static electricity generated during the rubbing treatment of the coating film surface and can form a coating film that is not easily scratched by rubbing.

The present invention has been made under the above circumstances, and a first object of the present invention is to provide a coating film capable of quickly removing static electricity generated during rubbing treatment. It is to provide a liquid crystal aligning agent capable of forming (alignment film material). A second object of the present invention is to provide a liquid crystal aligning agent which can form a coating film which is less likely to be rubbed by rubbing to prevent rubbing scratches that hinder the liquid crystal aligning property. A third object of the present invention is to provide a liquid crystal aligning agent which can surely impart the aligning ability of liquid crystal molecules by rubbing treatment and can form a liquid crystal display device having excellent liquid crystal aligning property. A fourth object of the present invention is to provide a liquid crystal aligning agent having excellent storage stability.

[0006]

The liquid crystal aligning agent of the present invention comprises:
[A] A dianhydride of at least one compound selected from tetracarboxylic acids represented by the following formulas (1) to (7) [hereinafter also referred to as "compound (A)"] 70 to 95 mol%, and [ B] At least one aromatic ring-containing tetracarboxylic dianhydride represented by the following general formula (I) [also referred to as "compound (B)" hereinafter] 30 to 5 mol% of a tetracarboxylic dianhydride, [C] A polyamic acid [hereinafter also referred to as "polymer P"] obtained by reacting with at least one diamine compound represented by the following general formula (II) [hereinafter also referred to as "compound (C)"], and It is characterized by containing at least one of the imidized polymers [hereinafter also referred to as "polymer Q"].

[0007]

[Chemical 4]

[0008]

Embedded image [In the general formula (I), R ¹ represents a tetravalent organic group containing an aromatic ring. ]

[0009]

[Chemical 6] [In the general formula (II), R ² represents a divalent organic group. ]

The present invention will be described in detail below. The liquid crystal aligning agent of the present invention includes a compound (A) and a compound (B).
The polymer P and / or the polymer Q obtained by reacting the tetracarboxylic dianhydride consisting of the compound (C) with the compound (C) is contained.

<Compound (A)> The compound (A) used for the synthesis of the polymer P is obtained by dehydrating at least one compound selected from the tetracarboxylic acids represented by the above formulas (1) to (7). It can be manufactured by These can be used alone or in combination of two or more. Of these,
The dianhydride of 3,5-tricarboxycyclopentylacetic acid and the dianhydride of 1,2,3,4-cyclobutanetetracarboxylic acid represented by the formula (4) are formed by a liquid crystal aligning agent prepared using them. It is particularly preferable that the obtained liquid crystal alignment film has a good liquid crystal alignment property for a long period of time.

<Compound (B)> The compound (B) used for the synthesis of the polymer P is a tetracarboxylic dianhydride represented by the above general formula (I), and has an aromatic ring in its molecular structure. Is a compound containing. Examples of the aromatic ring contained in the compound (B) include a benzene ring, a naphthalene ring, an anthracene ring and a pyrene ring. As the compound (B), a compound containing 1 to 9 benzene rings or 1 naphthalene ring in its molecular structure is preferably used.

Specific examples of the compound (B) include pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3',
4,4'-biphenylsulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride, 3,3 ' , 4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3 ', 4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3'
3 ', 4,4'-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic 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'-diphenylether dianhydride, bis (triphenylphthalic acid) ) -4,4'-Diphenylmethane dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -Furan-1,3-dione etc. can be mentioned, and these can be used individually or in combination of 2 or more types.

Of these compounds, pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride. , 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride and 1,3,3a, 4
5,9b-hexahydro-5- (tetrahydro-2,5
-Dioxo-3-furanyl) -naphtho [1,2-c]-
Furan-1,3-dione is particularly preferable because the liquid crystal alignment film formed by the liquid crystal aligning agent prepared by using them has a good liquid crystal aligning property for a long period of time.

In the tetracarboxylic dianhydride used for the synthesis reaction of the polymer P, the proportion of the compound (B) is 5 to 30 mol%, preferably 5 to 20 mol%.
It is said. When the proportion of the compound (B) is less than 5 mol%, in the coating film formed from the obtained liquid crystal aligning agent, the static electricity generated during the rubbing treatment cannot be quickly removed, and The surface of the liquid crystal alignment film formed from the coating film is easily scratched by rubbing. On the other hand, when this ratio exceeds 30 mol%, the liquid crystal aligning agent obtained has poor storage stability. Also, this ratio is 20
When it is at most mol%, it can be stored for a long period of time and has extremely excellent storage stability.

<Compound (C)> The compound (C) used for the synthesis of the polymer P is a diamine compound represented by the above general formula (II).

Specific examples of such a compound (C) include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane and 4,4'-.
Diaminodiphenylethane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 1,5-
Diaminonaphthalene, 3,3'-dimethyl-4,4'-
Diaminobiphenyl, 4,4'-diaminobenzanilide, 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, bis [4-
(4-Aminophenoxy) phenyl] sulfone, 1,4
-Bis (4-aminophenoxy) benzene, 4,4'-
(P-phenylenediisopropylidene) bisaniline,
4,4 ′-(m-phenylenediisopropylidene) bisaniline, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-amino) Phenyl) -10-hydroanthracene, 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,
Aromatic diamines such as 3,3′-dimethoxy-4,4′-diaminobiphenyl; Aromatic diamines having a hetero atom such as diaminotetraphenylthiophene;
1,1-metaxylylenediamine, 1,2-ethylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 1,4- Diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenemethylenediamine, tricyclo [6.
2.1.0 ^2.7 ] -Undecylenedimethyldiamine,
Aliphatic or alicyclic diamines such as 4,4′-methylenebis (cyclohexylamine); and further diaminoorganosiloxanes represented by the following general formula, which may be used alone or in combination of two or more. Can be used. Further, as these diamine compounds, commercially available products may be used as they are, or commercially available products may be re-reduced before use.

[0018]

[Chemical 7] [In the formula, R represents an alkyl group selected from a methyl group, an ethyl group, a propyl group, a cycloalkyl group such as a cyclohexyl group, or a hydrocarbon group having 1 to 12 carbon atoms such as an aryl group such as a phenyl group. . m is an integer of 1 to 3, n is an integer of 1 to 20, and r is an integer of 1 to 3. ]

Of these compounds, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,
4'-diaminodiphenyl ether, 2,2-bis [4
-(4-aminophenoxy) phenyl] propane, 9,
9-bis (4-aminophenyl) fluorene, 2,2-
Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′ −
(M-Phenylenediisopropylidene) bisaniline and the like are particularly preferable because the liquid crystal alignment film formed by the liquid crystal alignment agent prepared using them will have good liquid crystal alignment properties for a long period of time.

<Ratio of Reacting Raw Materials Used> Tetracarboxylic acid dianhydride [compound (A) used in the synthesis reaction of the polymer P]
The compound (B)] and the diamine compound [compound (C)] are used in such a ratio that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 with respect to 1 equivalent of the amino group contained in the diamine compound. The ratio is preferably 2 to 2 equivalents, more preferably 0.3 to 1.4 equivalents. In both cases where the ratio of the acid anhydride group of the tetracarboxylic dianhydride is less than 0.2 equivalents and exceeds 2 equivalents, the molecular weight of the resulting polymer P becomes too small, and the coating property of the liquid crystal aligning agent is low. Will be inferior.

<Synthesis of Polymer P> Polymer P constituting the liquid crystal aligning agent of the present invention includes tetracarboxylic dianhydride [compound (A) and compound (B)] and diamine compound [compound (C)]. ] Is synthesize | combined by reaction. The synthesis reaction of the polymer P is carried out in an organic solvent under a temperature condition of usually 0 to 150 ° C, preferably 0 to 100 ° C.

The organic solvent used for synthesizing the polymer P is not particularly limited as long as it can dissolve the polymer P, and for example, γ-butyrolactone, N-methyl-2-
Pyrrolidone, N, N-dimethylformamide, N, N-
Aprotic polar solvents such as dimethylacetamide, dimethylsulfoxide, tetramethylurea and hexamethylphosphotriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenols. As the usage amount (a) of the organic solvent, the total amount (b) of the tetracarboxylic dianhydride and the diamine compound, which are reaction raw materials, is the total amount (a + b) of the reaction solution.
The amount is preferably 0.1 to 30% by weight with respect to the above.

In the organic solvent, the polymer P which produces alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons, which are poor solvents for the polymer P, does not precipitate. It can be used in combination within a range. Specific examples of such a poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, acetone, methyl ethyl ketone, methyl. Isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n −
Butyl ether, ethylene glycol-n-hexyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate , Ethylene glycol methyl ether acetate, ethylene glycol-n
-Propyl ether acetate, ethylene glycol-
i-Propyl ether acetate, ethylene glycol-n-butyl ether acetate, ethylene glycol-n-hexyl ether acetate, 4-hydroxy-
4-methyl-2-pentanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-
Methyl hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4- Dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene,
Examples thereof include toluene and xylene.

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

<Polymer Q> The polymer Q constituting the liquid crystal aligning agent of the present invention is an imidized polymer obtained by subjecting the polymer P, which is a polyamic acid, to an imidization reaction. The imidization reaction is performed by heating the polymer P,
Alternatively, the polymer P is dissolved in an organic solvent, a dehydrating agent and an imidization catalyst are added to this solution, and heating is performed as necessary.

The reaction temperature in the method of heating the polymer P is usually 60 to 200 ° C., preferably 100 to 1
It is set to 70 ° C. When the reaction temperature is lower than 60 ° C, the imidization reaction does not proceed sufficiently, and when the reaction temperature exceeds 200 ° C, the molecular weight of the imidized polymer obtained may be small.

On the other hand, in the method of adding the dehydrating agent and the imidization catalyst to the solution of the polymer P, the dehydrating agent is
For example, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. The amount of the dehydrating agent used is 1.6 per 1 mol of the repeating unit of the polymer P.
It is preferably about 20 mol. Further, as the imidization catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used.
It is not limited to these. The amount of the imidization catalyst used is preferably 0.5 to 10 mol with respect to 1 mol of the dehydrating agent used. As the organic solvent used for the imidization reaction, the organic solvents exemplified as those used for the synthesis of the polymer P can be mentioned. The reaction temperature of the imidization reaction is usually 0 to 180 ° C., preferably 60.
It is set to ~ 150 ° C. Further, the polymer Q can be purified by performing the same operation as in the method for purifying the polymer P on the polymer solution thus obtained.

<Intrinsic Viscosity of Polymer> Intrinsic Viscosity of Polymer P and Polymer Q (30 ° C., N)
-Measured in methyl-2-pyrrolidone. The same applies below. ) Is usually 0.05 to 10 dl / g, preferably 0.05 to 5 dl / g.

<Liquid Crystal Aligning Agent> The liquid crystal aligning agent of the present invention comprises the polymer P and / or the polymer Q contained in an organic solvent. Examples of the organic solvent that constitutes the liquid crystal aligning agent of the present invention include aprotic polar solvents and phenolic solvents exemplified as those used for the synthesis reaction and imidization reaction of the polymer P. Further, the poor solvent exemplified as the one that can be used together during the synthesis of the polymer P can also be appropriately selected and used together.

The concentration of the polymer P and / or the polymer Q in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, influence on the environment, etc., but preferably 1-10.
It is set in the range of% by weight. That is, a liquid crystal aligning agent composed of a polymer solution is applied to the surface of a substrate by a printing method, a spin coating method, etc., and then dried,
A coating film as an alignment film material is formed, but when the polymer concentration is less than 1% by weight, the film thickness of this coating film becomes too small to obtain a good liquid crystal alignment film. .
On the other hand, when the polymer concentration exceeds 10% by weight, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film, and the viscosity of the liquid crystal alignment agent increases to increase coating properties. Will be inferior to.

The polymer P and / or polymer Q constituting the liquid crystal aligning agent of the present invention may be a terminal-modified polymer. This terminal-modified polymer has a controlled molecular weight and can improve the coating properties of the liquid crystal aligning agent without impairing the effects of the present invention. The terminal modified polymer can be synthesized by adding an acid anhydride or a monoamine compound to the reaction system when the polymer P is synthesized.

To obtain the end-modified polymer, the polymer P
As the acid anhydride added to the reaction system when synthesizing,
For example, maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride Examples of the monoamine added to the reaction system include aniline, cyclohexylamine, and the like.
n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n
-Nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n
-Tetradecylamine, n-pentadecylamine, n-
Hexadecyl amine, n-heptadecyl amine, n-octadecyl amine, n-eicosyl amine etc. can be mentioned.

The liquid crystal aligning agent of the present invention is a polymer P and / or
Alternatively, although it contains the polymer Q, a functional silane-containing compound may be contained from the viewpoint of improving the adhesiveness to the substrate surface.

As such a functional silane-containing compound,
For example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3
-Aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N -Triethoxysilylpropyltriethylenetriamine, N
-Trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl Acetate, 9-triethoxysilyl-3,6-
Diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane Ethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N
Examples thereof include -bis (oxyethylene) -3-aminopropyltriethoxysilane. Further, a reaction product of a tetracarboxylic dianhydride and an amino group-containing silane compound described in JP-A-63-291922 may be contained.

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

(1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a transparent conductive film by, for example, a printing method, and then the applied surface is heated to form a coating film. Here, as the substrate, for example, float glass,
A transparent substrate made of glass such as soda glass; plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, and polycarbonate can be used. Examples of the transparent conductive film provided on one surface of the substrate include a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA), an ITO film made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ), and the like. Can be used. For patterning these transparent conductive films, a photo-etching method or a method using a mask in advance is used. As a method for applying the liquid crystal aligning agent, a printing method, a roll coater method, a spinner method, or the like can be used. In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate surface and the transparent conductive film and the coating film, a functional silane-containing compound and a functional titanium-containing compound are formed on one surface of the substrate and the transparent conductive film. It is also possible to apply in advance. The heating temperature is 80 ~
The temperature is set to 200 ° C, preferably 120 to 200 ° C. The thickness of the formed coating film is usually 0.001 to 1 μm.
And preferably 0.005 to 0.5 μm.

(2) The formed coating film surface is rubbed in a certain direction with a roll around which a cloth made of fibers such as nylon, rayon and cotton is wound. As a result, the ability of aligning liquid crystal molecules is imparted to the coating film to form a liquid crystal alignment film.

(3) Two substrates on which the 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 liquid crystal alignment films are orthogonal or antiparallel. Facing each other through (cell gap),
The peripheral portions of the two substrates are bonded together using a sealant, and liquid crystal is injected and filled into the cell gap defined by the substrate surface and the sealant, and the injection holes are 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 that constitutes the liquid crystal cell, and the polarization direction thereof is the same as or orthogonal to the rubbing direction of the liquid crystal alignment film formed on the one surface of the substrate. A liquid crystal display device is obtained by laminating as described above. Here, as the sealant, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal material include nematic liquid crystals and smectic liquid crystals, and among them, nematic liquid crystals are preferable, for example, Schiff base liquid crystals, azoxy liquid crystals, biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals. Liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Also,
In addition to these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate, and cholesteryl carbonate, and trade names "C-15" and "CB-1".
5 ”(manufactured by Merck & Co., Inc.) and the like can also be used by adding a chiral agent and the like. Furthermore, p
Ferroelectric liquid crystals such as-decyloxybenzylidene-p-amino-2-methylbutyl cinnamate can also be used. As a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing film in which a polarizing film called an H film absorbing iodine while sandwiching and stretching polyvinyl alcohol is sandwiched between cellulose acetate protective films, or the H film itself And a polarizing plate made of

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. For each liquid crystal display element manufactured in the following examples and comparative examples, the charge decay characteristics of the liquid crystal alignment film, the occurrence of rubbing scratches in the liquid crystal alignment film, the liquid crystal alignment property, and the storage stability of the liquid crystal alignment agent. The evaluation method of is as follows.

[Charge Attenuation Characteristic of Liquid Crystal Alignment Film] The charged voltage on the surface of the liquid crystal alignment film was measured with time immediately after the rubbing treatment, and the half-life of the charged voltage immediately after the rubbing treatment was determined. The charging voltage was measured with an Honest meter (produced by Kasuga Electric Co., Ltd.).

[Situation of Occurrence of Rubbing Scratch in Liquid Crystal Alignment Film] The surface of the liquid crystal alignment film after the rubbing treatment was observed with an optical microscope (magnification: 100 times) to examine whether or not the rubbing scratch occurred due to the rubbing treatment.

[Alignment of Liquid Crystal] The presence or absence of an abnormal domain in the liquid crystal cell when the voltage was turned on and off was observed with a polarizing microscope, and when there was no abnormal domain, it was determined as “good”.

[Storage Stability of Liquid Crystal Alignment Agent] The liquid crystal alignment agent was stored in a freezer at −15 ° C. for 30 days, and the case where no gel was generated in the liquid crystal alignment agent was determined to be “good”.

Synthesis Example 1 [Polymer (P-1)] 3,8.1 g of 2,3,5-tricarboxycyclopentyl acetic acid dianhydride [Compound (A), 0.17 mol] and pyromellitic dianhydride 6.5 g [compound (B), 0.03
Mol] and 21.6 g of p-phenylenediamine [compound (C), 0.20 mol] were dissolved in 1000 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours. Then, the reaction mixture was poured into a large excess of methanol to precipitate the reaction product. Then, it was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain an intrinsic viscosity of 1.54 d.
1 / g of polyamic acid [this is "polymer (P-1)"
62.9 g was obtained.

Synthesis Example 2 [Polymer (Q-1)] 30.0 g of the polymer (P-1) obtained in Synthesis Example 1 was converted into γ-
Dissolved in 570 g of butyrolactone, 21.6 g of pyridine and 16.74 g of acetic anhydride were added to this solution, and 1
An imidation reaction was caused by heating at 20 ° C. for 3 hours. Then, the reaction product solution was precipitated in the same manner as in Synthesis Example 1 to obtain 28.0 g of an imidized polymer having an intrinsic viscosity of 1.45 dl / g [this is referred to as "polymer (Q-1)"]. .

Synthesis Example 3 [Polymer (P-2), Polymer (Q
-2)] Synthesis example except that the amount of the compound (A) used was changed to 42.6 g (0.19 mol) and the amount of the compound (B) used was changed to 2.2 g (0.01 mol). A polyamic acid [this is referred to as "polymer (P-2)"] was obtained in the same manner as in 1. Then, instead of the polymer (P-1), the polymer (P-
An imidization reaction was performed in the same manner as in Synthesis Example 2 except that 2) was used, and the intrinsic viscosity was 1.36 dl / g [this is referred to as "polymer (Q-2)"] 27. .2g
I got

Synthesis Example 4 [Polymer (P-3), Polymer (Q
-3)] Synthesis example except that the amount of the compound (A) used was changed to 35.8 g (0.16 mol) and the amount of the compound (B) used was changed to 8.7 g (0.04 mol). A polyamic acid [this is referred to as "polymer (P-3)"] was obtained in the same manner as in 1. Then, instead of the polymer (P-1), the polymer (P-
Imidization reaction was carried out in the same manner as in Synthesis Example 2 except that 3) was used, and the intrinsic viscosity was 1.56 dl / g [this is referred to as "polymer (Q-3)"] 27. 0.3 g
I got

Synthesis Example 5 [Polymer (P-4), Polymer (Q
-4)] As the compound (C), 4,6′-diaminodiphenylmethane (39.6 g, 0.20 mol) was used, and a polyamic acid was prepared in the same manner as in Synthesis Example 1. 4) ”. Then, the polymer (P-
The imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-4) was used instead of 1), and the intrinsic viscosity was 1.
38 dl / g imidized polymer [this is referred to as "polymer (Q-
4) ”] was obtained.

Synthesis Example 6 [Polymer (P-5), Polymer (Q)
-5)] As the compound (A), 1,3,4-cyclopentanetetracarboxylic dianhydride 35.7 g (0.17 mol)
A polyamic acid [this is referred to as "polymer (P-5)"] was obtained in the same manner as in Synthesis Example 1 except that the above was used. Then, an imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-5) was used instead of the polymer (P-1), and the intrinsic viscosity was 0.98 dl / g. 26.3 g of a combined product (referred to as "polymer (Q-5)") was obtained.

Synthesis Example 7 [Polymer (P-6), Polymer (Q
-6)] The same procedure as in Synthesis Example 1 was carried out except that 36.0 g (0.17 mol) of 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride was used as the compound (A) [polyamic acid [ This is referred to as "polymer (P-6)".
Then, an imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-6) was used instead of the polymer (P-1), and the intrinsic viscosity was 1.02 dl / g. 26.8 g of a combined product (hereinafter referred to as "polymer (Q-6)") was obtained.

Synthesis Example 8 [Polymer (P-7)] Except that 33.3 g (0.17 mol) of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was used as the compound (A). In the same manner as in Synthesis Example 1, 59.5 g of a polyamic acid having an intrinsic viscosity of 1.22 dl / g [this is referred to as "polymer (P-7)"] was obtained.

Synthesis Example 9 [Polymer (P-8), Polymer (Q
-8)] The same procedure as in Synthesis Example 1 was repeated except that 33.7 g (0.17 mol) of butanetetracarboxylic dianhydride was used as the compound (A).
8) ”. Then, an imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-8) was used instead of the polymer (P-1), and the intrinsic viscosity was 0.86 dl.
25.8 g of an imidized polymer (hereinafter referred to as "polymer (Q-8)") was obtained.

Synthesis Example 10 [Polymer (P-9), Polymer (Q-9)] As compound (A), 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene- 1,
2-Dicarboxylic acid dianhydride 44.9 g (0.17 mol)
A polyamic acid [this is referred to as "polymer (P-9)"] was obtained in the same manner as in Synthesis Example 1 except that the above was used. Then, an imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-9) was used instead of the polymer (P-1), and the intrinsic viscosity was 1.16 dl / g. 25.7 g of a combined product (referred to as "polymer (Q-9)") was obtained.

Synthesis Example 11 [Polymer (P-10), Polymer (Q-10)] As the compound (A), bicyclo [2.2.2] -oct-7-ene-2,3,5,5. 6 tetracarboxylic acid dianhydride 42.2 g (0.17 mol) was used in the same manner as in Synthesis Example 1 except for using polyamic acid [this was referred to as "polymer (P-
10) ”. Then, Synthesis Example 2 except that the polymer (P-10) was used instead of the polymer (P-1)
The imidization reaction is carried out in the same manner as, and the intrinsic viscosity is 1.06.
dl / g imidized polymer [this is referred to as "polymer (Q-1
0) ”] was obtained.

Synthesis Example 12 [Polymer (P-11), Polymer (Q-11)] As the compound (B), 9.7 g of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride was obtained. A polyamic acid [this is referred to as "polymer (P-11)"] was obtained in the same manner as in Synthesis Example 1 except that 0.03 mol) was used. Then, instead of the polymer (P-1), the polymer (P-1
An imidization reaction was conducted in the same manner as in Synthesis Example 2 except that 1) was used, and the intrinsic viscosity was 1.46 dl / g [this is referred to as "polymer (Q-11)"] 27. .9
g was obtained.

Synthesis Example 13 [Polymer (P-12), Polymer (Q-12)] As the compound (B), 8.8 g (3,3 ', 4,4'-biphenyltetracarboxylic dianhydride) A polyamic acid [this will be referred to as "polymer (P-12)"] was obtained in the same manner as in Synthesis Example 1 except that 0.03 mol) was used. Then, an imidization reaction was carried out in the same manner as in Synthesis Example 2 except that the polymer (P-12) was used instead of the polymer (P-1), and the intrinsic viscosity was 1.53 dl / g. 28.3 g of a combined product (referred to as "polymer (Q-12)") was obtained.

Synthetic Example 14 [Polymer (P-13), Polymer (Q-13)] As the compound (B), 8.0 g (0.04) of 1,4,5,8-naphthalenetetracarboxylic dianhydride was obtained. A polyamic acid [this is referred to as "polymer (P-13)"] was obtained in the same manner as in Synthesis Example 1 except that (03 mol) was used. Then
An imidization reaction was carried out in the same manner as in Synthesis Example 2 except that the polymer (P-13) was used instead of the polymer (P-1),
28.0 g of an imidized polymer having an intrinsic viscosity of 1.23 dl / g [this is referred to as "polymer (Q-13)"] was obtained.

Synthesis Example 15 [Polymer (P-14), Polymer (Q-14)] As the compound (B), 8.0 g (0.2%) of 2,3,6,7-naphthalenetetracarboxylic dianhydride was obtained. A polyamic acid [this is referred to as "polymer (P-14)"] was obtained in the same manner as in Synthesis Example 1 except that (03 mol) was used. Then
An imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-14) was used instead of the polymer (P-1),
28.0 g of an imidized polymer having an intrinsic viscosity of 1.22 dl / g [this is referred to as "polymer (Q-14)"] was obtained.

Synthesis Example 16 [Polymer (P-15), Polymer (Q-15)] As the compound (B), 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2, 5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,
A polyamic acid [this is referred to as "polymer (P-15)"] was obtained in the same manner as in Synthesis Example 1 except that 9.0 g (0.03 mol) of 3-dione was used. Then, the polymer (P
The imidization reaction was carried out in the same manner as in Synthesis Example 2 except that the polymer (P-15) was used instead of -1), and the intrinsic viscosity was 1.21 dl / g. It is referred to as “combined (Q-15)”].

Synthesis Example 17 [Polymer (P-16), Polymer (Q-16)] As the compound (B), 9.7 g (3,3 ', 4,4'-benzophenone tetracarboxylic acid dianhydride) A polyamic acid [this is referred to as "polymer (P-16)"] was obtained in the same manner as in Synthesis Example 8 except that 0.03 mol) was used. Then, instead of the polymer (P-1), the polymer (P-1
Imidization reaction was carried out in the same manner as in Synthesis Example 2 except that 6) was used, and the intrinsic viscosity was 1.25 dl / g [this is referred to as "polymer (Q-16)"] 61. .4
g was obtained.

Synthesis Example 18 [Polymer (P-17), Polymer (Q-17)] As the compound (B), 8.8 g (3,3 ', 4,4'-biphenyltetracarboxylic dianhydride) Polyamic acid [this is referred to as "polymer (P-17)"] was obtained in the same manner as in Synthesis Example 8 except that 0.03 mol) was used. Then, an imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-17) was used instead of the polymer (P-1), and the intrinsic viscosity was 1.33 dl / g. 60.5 g of a combined product (referred to as "polymer (Q-17)") was obtained.

Synthesis Example 19 [Polymer (P-18), Polymer (Q-18)] As the compound (B), 1,4,5,8-naphthalenetetracarboxylic dianhydride 8.0 g (0. A polyamic acid [this is referred to as "polymer (P-18)"] was obtained in the same manner as in Synthesis Example 8 except that (03 mol) was used. Then
An imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-18) was used instead of the polymer (P-1),
60.1 g of an imidized polymer having an intrinsic viscosity of 1.21 dl / g [this is referred to as "polymer (Q-18)"] was obtained.

Synthesis Example 20 [Polymer (P-19), Polymer (Q-19)] As the compound (B), 2,3,6,7-naphthalenetetracarboxylic dianhydride 8.0 g (0. A polyamic acid [this is referred to as "polymer (P-19)"] was obtained in the same manner as in Synthesis Example 8 except that (03 mol) was used. Then
An imidization reaction was performed in the same manner as in Synthesis Example 2 except that the polymer (P-19) was used instead of the polymer (P-1),
60.7 g of an imidized polymer having an intrinsic viscosity of 1.15 dl / g [this is referred to as "polymer (Q-19)"] was obtained.

Synthesis Example 21 [Polymer (P-20), Polymer (Q-20)] As the compound (B), 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2, 5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,
A polyamic acid [this is referred to as "polymer (P-20)"] was obtained in the same manner as in Synthesis Example 8 except that 9.0 g (0.03 mol) of 3-dione was used. Then, the polymer (P
The imidization reaction was carried out in the same manner as in Synthesis Example 2 except that the polymer (P-20) was used instead of -1), and the intrinsic viscosity was 1.05 dl / g. This is referred to as “combined (Q-20)”].

Synthesis Example 22 [Polymer (P-21), Polymer (Q-21)] The amount of the compound (A) used was changed to 31.4 g (0.14 mol), and the compound (B) was used. The amount is 13.1 g (0.06
A polyamic acid [this is referred to as "polymer (P-21)"] was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to "mol". Then, instead of the polymer (P-1), the polymer (P-
Imidization reaction was carried out in the same manner as in Synthesis Example 2 except that 21) was used, and the intrinsic viscosity was 1.66 dl / g [this is referred to as "polymer (Q-21)"] 28. ．
3 g were obtained.

Synthesis Example 23 [Polymer (p-22), Polymer (q-22)] The amount of the compound (A) used was changed to 44.8 g (0.20 mol), and the compound (B) was used. The same procedure as in Synthesis Example 1 was carried out except that no polyamic acid ([polymer (p-
22) ”. Then, Synthesis Example 2 except that the polymer (p-22) was used instead of the polymer (P-1)
Imidization reaction is carried out in the same manner as above, and the intrinsic viscosity is 1.36.
dl / g imidized polymer [this is referred to as "polymer (q-2
2) ”] was obtained.

Synthesis Example 24 [Polymer (p-23), Polymer (q-23)] The amount of the compound (A) used was changed to 22.4 g (0.10 mol), and the compound (B) was used. 21.8 g (0.10
A polyamic acid [this is referred to as "polymer (p-23)"] was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to "mol". Then, instead of the polymer (P-1), the polymer (p-
Imidization reaction was carried out in the same manner as in Synthesis Example 2 except that 23) was used, and the intrinsic viscosity was 1.77 dl / g [this is referred to as "polymer (q-23)"] 28. ．
7 g were obtained.

Synthesis Example 25 [Polymer (p-24), Polymer (q-24)] The amount of the compound (A) used was changed to 29.1 g (0.13 mol), and the compound (B) was used. The amount of 15.3 g (0.07
A polyamic acid [this is referred to as "polymer (p-24)"] was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to "mol". Then, instead of the polymer (P-1), the polymer (p-
Imidization reaction was performed in the same manner as in Synthesis Example 2 except that 24) was used, and the intrinsic viscosity was 1.78 dl / g [this is referred to as "polymer (q-24)"] 28. ．
4 g was obtained.

Synthesis Example 26 [Polymer (p-25), Polymer (q-25)] The amount of the compound (A) used was 43.7 g (0.195 mol).
And the amount of the compound (B) used was 1.1 g (0.00
Polyamic acid [this is referred to as "polymer (p-25)"] in the same manner as in Synthesis Example 1 except that the amount was changed to 5 mol).
I got Then, instead of the polymer (P-1), the polymer (p
-25) was used, and an imidization reaction was carried out in the same manner as in Synthesis Example 2 to give an imidized polymer having an intrinsic viscosity of 1.34 dl / g [this will be referred to as "polymer (q-25)"]. Two
7.1 g was obtained.

Example 1 (1) Preparation of Liquid Crystal Alignment Agent The polymer (P-1) obtained in Synthesis Example 1 was treated with N-methyl-2.
-Pyrrolidone was dissolved to obtain a solution having a solid content concentration of 4% by weight, and this solution was filtered with a filter having a pore size of 1 µm to prepare the liquid crystal aligning agent of the present invention. The storage stability results of this liquid crystal aligning agent are shown in Table 1.

(2) Preparation of liquid crystal display device The liquid crystal aligning agent of the present invention was applied onto a transparent conductive film made of an ITO film provided on one surface of a glass substrate using a printing machine for applying a liquid crystal alignment film, A coating film having a dry film thickness of 0.05 μm was formed by drying at 180 ° C. for 1 hour.

The formed coating film surface is subjected to a rubbing treatment using a rubbing machine having a roll around which a cloth made of rayon is wrapped, thereby imparting the alignment ability of liquid crystal molecules to the coating film to prepare a liquid crystal alignment film. did. Here, the rubbing treatment conditions were that the rotation number of the roll was 500 rpm, the moving speed of the stage was 1 cm / sec, and the length of pushing in the hair was 0.4 mm. Table 1 shows the results of the charge decay characteristics of this liquid crystal alignment film and the occurrence of rubbing scratches.

Two substrates on which the liquid crystal alignment film was formed as described above were prepared, and an epoxy resin containing aluminum oxide spheres having a diameter of 17 μm was applied by screen printing to the outer edge of each substrate, and then each of them was applied. Two substrates were arranged so as to oppose each other with a gap so that the rubbing directions in the liquid crystal alignment film were orthogonal to each other, and the outer edges were brought into contact with each other and pressure-bonded to cure the adhesive.

Next, nematic liquid crystal “ZLI-5081” (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 filled with an epoxy adhesive. A liquid crystal cell was constructed by sealing with. Next, a polarizing plate is attached to the outer surface of the liquid crystal cell, that is, the other surface of each substrate constituting the liquid crystal cell so that the polarization direction matches the rubbing direction of the liquid crystal alignment film formed on the one surface of the substrate. Thus, a liquid crystal display element was produced. Table 1 shows the results of the orientation of the liquid crystal in this liquid crystal display device.

<Examples 2 to 22> According to the formulations shown in Table 1 below, each of the polymers P and Q obtained in Synthesis Examples 2 to 22 was used, and Example 1 was used.
The liquid crystal aligning agent of the present invention was prepared in the same manner as in (1). Then, using each of the liquid crystal aligning agents thus obtained, a liquid crystal display device was produced in the same manner as in Example 1 (2). In each example, the charge attenuation characteristics of the liquid crystal alignment film, the occurrence of rubbing scratches in the liquid crystal alignment film, the liquid crystal alignment property, and the storage stability of the liquid crystal alignment agent were evaluated. The results are shown in Table 1.

Comparative Example 1 Using the polymer (q-22) obtained in Synthesis Example 23, a liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 (1). Then, using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1 (2). The evaluation results in Comparative Example 1 are shown in Table 1.

Comparative Example 2 Using the polymer (q-23) obtained in Synthesis Example 24, a liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 (1). Then, using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1 (2). The evaluation results in Comparative Example 2 are shown in Table 1.

Comparative Example 3 Using the polymer (q-24) obtained in Synthesis Example 25, a liquid crystal aligning agent for comparison was prepared in the same manner as in Example 1 (1). Then, using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1 (2). Table 1 shows the evaluation results in Comparative Example 3.

Comparative Example 4 A comparative liquid crystal aligning agent was prepared in the same manner as in Example 1 (1) using the polymer (q-25) obtained in Synthesis Example 26. Then, using this liquid crystal aligning agent, a liquid crystal display element was produced in the same manner as in Example 1 (2). The evaluation results in Comparative Example 4 are shown in Table 1.

[0080]

[Table 1]

[0081]

EFFECTS OF THE INVENTION According to the liquid crystal aligning agent of the present invention, a coating film (alignment film material) capable of quickly removing static electricity generated during rubbing treatment and less likely to be scratched by rubbing is formed. be able to. Moreover, the coating film to which the orientation ability of the liquid crystal molecules is given by the rubbing treatment becomes a liquid crystal orientation film having excellent liquid crystal orientation and can be suitably used for various liquid crystal display elements. Moreover, the liquid crystal aligning agent of the present invention has excellent storage stability.

The liquid crystal aligning agent of the present invention can form a coating film (alignment film material) capable of quickly removing static electricity generated during rubbing treatment. Also,
Such a coating film is unlikely to be scratched by rubbing, and the coating film to which the alignment ability of the liquid crystal molecules is given by the rubbing treatment becomes a liquid crystal alignment film, and this liquid crystal alignment film is a liquid crystal display device excellent in liquid crystal alignment property. Configure.

Further, in the liquid crystal display device provided with the liquid crystal alignment film formed of the liquid crystal aligning agent of the present invention, SH type can be selected by selecting the type of liquid crystal material to be injected and filled between the substrates.
(Super Homeotropic), ferroelectricity,
It can also be suitably used as an antiferroelectric liquid crystal display device.

Furthermore, the liquid crystal display device provided with the liquid crystal alignment film formed of the liquid crystal aligning agent of the present invention has excellent liquid crystal alignment and reliability, and can be effectively used in various devices. It is preferably used as a display device for computers, wrist watches, table clocks, counting display boards, word processors, personal computers, liquid crystal televisions, and the like.

The preferred embodiments of the present invention will be listed below. (A) A liquid crystal aligning agent in which the proportion of the compound (B) in the tetracarboxylic dianhydride used in the reaction is 5 to 20 mol%.

(B) The compound (A) is the dianhydride of 2,3,5-tricarboxycyclopentyl acetic acid represented by the above formula (1) and / or 1,2,3 represented by the above chemical formula (4). Liquid crystal aligning agent which is a dianhydride of 4,4-cyclobutanetetracarboxylic acid.

(C) The compound (B) is pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid. Acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride and 1,3,3a, 4
5,9b-hexahydro-5- (tetrahydro-2,5
-Dioxo-3-furanyl) -naphtho [1,2-c]-
A liquid crystal aligning agent which is at least one selected from the group consisting of furan-1,3-dione.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Tadahiko Udagawa 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd. (72) Inventor Yasushi Matsuki 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. [A] 70 to 95 mol% of a dianhydride of at least one compound selected from tetracarboxylic acids represented by the following formulas (1) to (7), and [B] the following general formula ( I) a tetracarboxylic dianhydride consisting of 30 to 5 mol% of at least one aromatic ring-containing tetracarboxylic dianhydride, and [C] at least one diamine represented by the following general formula (II). A liquid crystal aligning agent comprising at least one of a polyamic acid obtained by reacting with a compound and an imidized polymer thereof. Embedded image Embedded image [In the general formula (I), R ¹ represents a tetravalent organic group containing an aromatic ring. ] [Chemical 3] [In the general formula (II), R ² represents a divalent organic group. ]