JPH08122790A - Liquid crystal orienting agent - Google Patents

Abstract

PURPOSE: To obtain such an orienting agent for a liquid crystal that when the agent is formed into an oriented film for a liquid crystal, good orienting property of the liquid crystal is obtd., the pretilt angle produced in the liquid crystal is >=3 deg. and the dependence of the pretilt angle on the cleaning process after rubbing is little, by incorporating a specified polymer. CONSTITUTION: This agent contains a polyamic acid (polymer A) and/or a polymer produced by dehydration and ring-closing reaction of the polymer A. The polymer A is obtd. by the reaction of tetracarboxylic acid dianhydride expressed by formula I and diamine compds. expressed by formula II and formula III. In formulae R1 is a quadrivalent org. group, R2 is a bivalent org. group selected from -O-, -COO-, -OCO-, and the like, and R3 is a univalent org. group. However, R3 does not include an anthracene ring nor two or more benzene rings. R4 is a bivalent org. group containing three or more benzene rings and/or at least one anthracene ring. The proportion of the diamine expressed by formula II is 3 to 60mol% of the whole diamines, while the proportion of the diamine expressed by formula II is 10 to 97mol% of the whole diamines.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a liquid crystal aligning agent.
More specifically, the present invention relates to a liquid crystal aligning agent which, when used as a liquid crystal aligning film, has a good liquid crystal aligning property, a large pretilt angle that the liquid crystal develops, and a small dependence on the cleaning step after rubbing.

[0002]

2. Description of the Related Art Conventionally, a nematic liquid crystal having a positive dielectric anisotropy is sandwiched by a substrate with a transparent electrode having a liquid crystal alignment film made of an organic polymer such as polyimide, and the long axis of liquid crystal molecules is arranged between the substrates. A TN type liquid crystal display device is known in which it is twisted continuously by 90 degrees. The liquid crystal orientation in this TN type liquid crystal display element is formed by a rubbing-treated liquid crystal orientation film.

In addition, STN (Super twisted nemati) which is a liquid crystal display device having excellent contrast and viewing angle dependence.
The c) type liquid crystal display element uses a nematic type liquid crystal blended with a chiral agent which is an optically active substance as a liquid crystal, and a birefringence effect produced by continuously twisting the major axis of liquid crystal molecules between the substrates by 180 degrees or more. Is used.
In this case, an alignment film having a high pretilt angle is required in order to twist the liquid crystal between the substrates by 180 degrees or more. further,
Also in the TN type liquid crystal display element described above, a liquid crystal alignment film having a high pretilt angle has been desired in order to suppress display defects due to a reverse tilt phenomenon when a liquid crystal cell is driven.

[0004]

In a liquid crystal alignment film of an organic polymer, a large pretilt angle of, for example, 3 degrees or more is achieved by introducing a long-chain alkyl group into the polymer, and the obtained pretilt angle is obtained. Has a problem that it largely depends on the process, and in particular, it greatly changes due to the cleaning process of the liquid crystal alignment film after rubbing. An object of the present invention is to provide a liquid crystal alignment film which, when used as a liquid crystal alignment film, has good liquid crystal alignment properties, a pretilt angle at which the liquid crystal develops is 3 degrees or more, and a pretilt angle is less dependent on a cleaning step after rubbing. To provide the agent.

[0005]

According to the present invention, (A)
The following formula (1)

[0006]

[Chemical 4]

A tetracarboxylic dianhydride represented by the formula (1) (wherein R ₁ represents a tetravalent organic group) (hereinafter referred to as "compound I") and (B) (i) the following formula (2)

[0008]

Embedded image

(In the formula (2), R ₂ is —O— or —COO.
-, -OCO-, -NHCO-, -CONH- and-
R represents any divalent organic group selected from CO-, R
₃ represents a monovalent organic group, provided that R ₃ does not include an anthracene ring and two or more benzene rings) (hereinafter referred to as “compound II”) and (ii) the following formula (3)

[0010]

[Chemical 6]

(In the formula (3), R ₄ represents a divalent organic group containing three or more benzene rings and / or at least one anthracene ring) (hereinafter referred to as "compound III") A polyamic acid (hereinafter referred to as “polymer (A)”) obtained by reacting with, but the ratio of the diamine represented by the formula (2) is 3 to 6 of all diamines.
0 mol%, and the ratio of the diamine represented by the formula (3) is 10 to 97 mol% of all diamines, and / or a polymer obtained by dehydrating and ring-closing the polymer (A) (hereinafter referred to as “polymer (B ) ”) Is provided to achieve the above object of the present invention.

Hereinafter, the present invention will be described in detail, which will make clear the objects, configurations, effects and advantages of the present invention.

Compound I, which is a tetracarboxylic dianhydride used in the present invention, is represented by the above formula (1). In the above formula (1), R ₁ which is a tetravalent organic group corresponds to a residue obtained by removing an anhydride group from tetracarboxylic dianhydride.
Examples of the tetravalent organic group R ₁ in the above formula (1) include an aliphatic group, an aromatic group, and an alicyclic group, and an aliphatic group or an alicyclic group is preferable. Also, R
The carbon number of ₁ is preferably 4 to 14. Specifically, the following formulas (1-1) to (1-6)

[0014]

[Chemical 7]

[In the formula (1-1), R ^{5 to} R ⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and a, b and c independently represent 0 or Indicates an integer of 1. In formula (1-3), R ⁹ represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a halogen atom, and d represents an integer of 0 to 4. In formula (1-4),
R ¹⁰ represents an alkyl group, an alkoxy group or a halogen atom having 1 to 3 carbon atoms of 1 to 3 carbon atoms, e is an integer of 0 to 20. In formula (1-5), R ¹¹ is an oxygen atom and has 1 carbon atom.
To 14 alkyl groups, methylene, C2 to C14 alkylene groups, C2 to C14 alkylidene groups, and C1
To 5 are halogenated alkyl groups, sulfide groups, sulfone groups or ketone groups, and f is an integer of 0 or 1. ]

Examples thereof include groups represented by: Among them, a tetravalent group represented by formula (1-1), (1-3) or (1-6) is preferable.

Examples of the compound I include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4 -Cyclopentanetetracarboxylic acid dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 3,5,6-tricarboxynorbornane-
2-acetic acid dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic acid dianhydride, 1,3,3a, 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 acid dianhydride, bicyclo [2,2,2] -oct-7
Alicyclic tetracarboxylic dianhydrides such as -ene-2,3,5,6-tetracarboxylic dianhydride; pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic acid Dianhydride, 3,3 ', 4,4'-biphenylsulfone tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid Acid dianhydride 3,3 ′, 4,4′-biphenyl ether tetracarboxylic acid dianhydride 3,3 ′,
4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,4'-tetraphenylsilane tetracarboxylic 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'-diphenylether dianhydride, bis (tri Aromatic tetracarboxylic acid dianhydrides such as phenylphthalic acid) -4,4′-diphenylmethane dianhydride can be mentioned.

Of these, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic acid Dianhydride, 1,3,3a, 4,
5,9b-Hexahydro-5-tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 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 the like are preferable, and 1,2,3,4-cyclobutanetetra Carboxylic dianhydride and 2,3,5-tricarboxycyclopentyl acetic acid dianhydride are particularly preferred. These are 1
They may be used alone or in combination of two or more.

The compound II is a mono-substituted phenylenediamine represented by the formula (2). In the formula (2), R ₃ is a monovalent organic group containing neither an anthracene ring nor two or more benzene rings. As a preferable example of the compound II, the following formula (4) having a steroid skeleton in R ₃
(7)

[0020]

Embedded image

[0021]

[Chemical 9]

A diamine represented by:

Examples include 3,5-diamino-4'-trifluoromethylbenzanilide having a trifluoromethylphenyl group for R ₃ and 3,5-diamino-3'-trifluoromethylbenzanilide.

The compound III is represented by the formula (3), and R ₄ in the formula (3) represents a divalent organic group containing three or more benzene rings and / or at least one anthracene ring. As a preferable example of the compound III, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (4
-Aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) -biphenyl, 1,3-bis (4-aminophenoxy) benzene, 9 , 9-bis (4
-Aminophenyl) fluorene, 4.4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-
(M-phenylene isopropylidene) bisaniline,
2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluoro Biphenyl, the following formulas (8) to (14)

[0025]

[Chemical 10]

[0026]

[Chemical 11]

Examples thereof include diamines represented by A more preferable example is 9,9-bis (4
-Aminophenyl) fluorene, 4.4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-
(M-phenylene isopropylidene) bisaniline,
Examples thereof include 4,4′-bis (4-aminophenoxy) -biphenyl and diamines represented by the above formulas (8) to (14).

The polyamic acid used in the present invention can be obtained by reacting compound I with compound II and compound III. Such a reaction is usually performed in an organic solvent at 0 to 150.
C., preferably 0-100.degree. C., at a reaction temperature.

The compound II and the compound III are used in an amount of 3 to 60 mol%, preferably 5 to 50 mol%, relative to the total amount of all diamine compounds used.
More preferably, it is 10 to 30 mol%, and compound III
Is 10 to 97 mol%, preferably 20 to 90 mol%. The pretilt angle can be increased by making the use ratio of these satisfy the above range, and the IP after rubbing can be increased.
It is possible to reduce the fluctuation of the pretilt angle due to A cleaning.

In addition to Compound II and Compound III, other diamines can be used in combination to the extent that the effects of the present invention are not lost. Other diamine compounds include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 3,5-diaminobenzoic acid, 4,4′-diaminodiphenylethane,
4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 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, 4,4'-diaminobenzanilide, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-
Diaminobenzophenone, 4,4'-diaminobenzophenone, 2,7-diaminofluorene, 2,2-bis (4
-Aminophenyl) hexafluoropropane, 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'-diamino-2,
Aromatic diamines such as 2'-bis (trifluoromethyl) biphenyl;

Aromatic diamine having a hetero atom such as diaminotetraphenylthiophene; 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octa Methylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenemethylenediamine, tricyclo [ 6, 2,
1,02.7] -Undecylenedimethyldiamine, 4,4 '
An aliphatic or alicyclic diamine such as methylenebis (cyclohexylamine);

The following equation (15)

[0033]

[Chemical 12]

(In the formula (15), plural R ^5's are each independently exemplified by an alkyl group such as a methyl group, an ethyl group, a propyl group, a cycloalkyl group such as a cyclohexyl group, or an aryl group such as a phenyl group. 1 to 12 carbon atoms
Represents a hydrocarbon group of, 1 is an integer of 1 to 3, m is 1 to 20
Is an integer) of diaminoorganosiloxane.

Among these, p-phenylenediamine,
4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4 '
-Diaminodiphenyl ether, 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 4,4'-diamino-
Aromatic diamines such as 2,2'-bis (trifluoromethyl) biphenyl are preferred. Particularly preferred is p-phenylenediamine, 4,4'-diaminodiphenylmethane. These can be used alone or in combination of two or more.

The proportion of the other diamine used is usually 0 to 80 mol%, preferably 0 to 60 mol%, based on all diamine compounds used.

The ratio of the compound I and the total diamine compound used is preferably 0.2 to 2 equivalents of the acid anhydride group of the tetracarboxylic dianhydride based on 1 equivalent of the amino group in the total diamine compound. More preferably, it is 0.3 to 1.2 equivalents.

The organic solvent is not particularly limited as long as it can dissolve the polymer (A) produced in the reaction.
For example, aprotic polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; m-cresol Examples thereof include phenolic solvents such as xylenol, phenol, and halogenated phenols.

It should be noted that, in the organic solvent, a polymer that produces alcohols, ketones, esters, ethers, halogenated hydrocarbons, and hydrocarbons, which are poor solvents for the polymer (A), does not precipitate. It can be used together to some extent. Examples of such a poor solvent include 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 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, Examples thereof include 2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene and xylene.

The amount of the organic solvent used is usually 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 polymer (B) used in the liquid crystal aligning agent of the present invention is usually polyimide or polyisoimide, and the above polymer (A) is heated or in the presence of a dehydrating agent and a dehydration ring-closing catalyst. Obtained by dehydration ring closure. The reaction temperature for dehydration ring closure by heating is
It is usually 60 to 250 ° C, preferably 100 to 170 ° C. The reaction for dehydration ring closure in the presence of a dehydrating agent and a dehydration ring-closing catalyst can be carried out in the organic solvent, and the reaction temperature is usually 0 to 180 ° C, preferably 60 to
It is 150 ° C. As the dehydrating agent, acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used. Further, as the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but the catalyst is not limited thereto. The amount of the dehydrating agent used is preferably 1.6 to 20 mol per 1 mol of the repeating unit of the polymer (A). Further, the amount of the dehydration ring-closing catalyst used is preferably 0.5 to 10 mol with respect to 1 mol of the dehydrating agent used.

The intrinsic viscosity (η _inh = ln (t / t _o ) / of the polymers (A) and (B) thus obtained is
c, provided that c = 0.5 g / dl, 30 ° C., N-methyl-
Measured in 2-pyrrolidone solvent, where, t is a falling rate, t _o of the polymer solution is flow-down speed of N- methyl-2-pyrrolidone. Hereinafter, η _inh measured under the same conditions is referred to as “intrinsic viscosity”. ) Is preferably 0.05 to 10 dl /
g, more preferably 0.05 to 5 dl / g.

It is also possible to add an acid anhydride, a monoamine compound or the like at the time of synthesizing the polymer (A) for the purpose of controlling the molecular weight of the polymer and improving the coating property on the substrate. The terminal-modified polymers (A) and (B) can also be used as the liquid crystal aligning agent of the present invention without any problems.

Here, as the acid anhydride for terminal modification,
Examples thereof include maleic anhydride and phthalic anhydride.

As the monoamine for terminal modification,
For example, aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-
Heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine , N-heptadecylamine, n-octadecylamine, n-eicosylamine and the like.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound shown below for the purpose of further improving the adhesiveness between the polymer (A) and / or the polymer (B) and the substrate. it can.

Examples of the functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane and N- (2-amino). Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 1
0-trimethoxyisyl-1,4,7-triazadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6-diazanonyl acetate, 9-triethoxysilyl- 3,6-diazanonyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3 -Aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxysilane and the like can be mentioned. -Tetracarboxylic dianhydride and amino group-containing silane compound described in JP-A-291922 And the like can be used in the reaction.

Further, the liquid crystal aligning agent of the present invention may contain various thermosetting crosslinking agents in order to further stabilize the pretilt angle and improve the film strength. As the thermosetting crosslinking agent, a polyfunctional epoxy group-containing compound is effective, and bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, cyclic aliphatic epoxy resin, glycidyl ester type epoxy resin, glycidyl Diamine-based epoxy resin,
A heterocyclic epoxy resin, an epoxy group-containing acrylic resin, etc. can be used.

Commercially available products of such polyfunctional epoxy group-containing compounds include, for example, Epolite 400E and 3002.
(Manufactured by Kyoeisha Oil and Fat Chemical Co., Ltd.), Epicoat 828,
No. 152, epoxy novolac 180S (produced by Yuka Shell Epoxy Co., Ltd.) and the like.

Further, when the compound containing a polyfunctional epoxy group is used, a base catalyst such as 1-benzyl-2-methylimidazole may be added for the purpose of efficiently causing a crosslinking reaction.

The liquid crystal aligning agent of the present invention can be dissolved in a solvent to form a uniform solution. The above-mentioned solvent is not particularly limited as long as it can dissolve the polymer (A) and / or the polymer (B) and various additives, and the organic solvent used during the polymerization of the polymer (A) is usually used. To be done.
Further, the solution concentration at this time is usually 0.1 to 1 in terms of solid content concentration.
It is 20% by weight.

The liquid crystal display device obtained by using the liquid crystal aligning agent of the present invention can be manufactured, for example, by the following method.

First, the liquid crystal aligning agent of the present invention is applied to the transparent conductive film side of the substrate provided with the transparent conductive film by the roll coater method,
Apply by spinner method, printing method, etc.
Preferably, the coating film is formed by heating at a temperature of 120 to 200 ° C. This coating film has a thickness of usually 0.001-1 μm, preferably 0.005-0.5 μm. The formed coating film is made into a liquid crystal alignment film by performing a rubbing treatment with a roll around which a cloth made of synthetic fiber such as nylon is wound. After that, the alignment film is washed with isopropyl alcohol for the purpose of removing dust generated during rubbing.

As the substrate, for example, a transparent substrate made of glass such as float glass or soda glass, plastic film such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone or polycarbonate can be used. As the transparent conductive film, a NESA film made of SnO ₂ , In ₂ O
_An ITO film made of _3- SnO ₂ or the like can be used,
For the patterning of these transparent conductive films, a photo-etching method, a method using a mask in advance, or the like is used.
When applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate and the transparent conductive film and the coating film, a functional silane-containing compound, a functional titanium compound, etc. are applied in advance on the substrate and the transparent conductive film. You can also do it.

The substrates on which the liquid crystal alignment film is formed are made to face each other so that the rubbing directions of the liquid crystal alignment films are orthogonal or antiparallel, and the peripheral portion between the substrates is sealed with a sealant to fill the liquid crystal. Then, the filling hole is sealed to form a liquid crystal cell, and the liquid crystal display element is obtained by laminating the both sides of the liquid crystal cell so that the polarization directions thereof coincide with or are orthogonal to the rubbing direction of the liquid crystal alignment film of the substrate.

As the sealant, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used. The liquid crystal is preferably a nematic liquid crystal, a smectic liquid crystal, and among them, a liquid crystal forming a nematic liquid crystal, for example, a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, a terphenyl liquid crystal. Liquid crystals, biphenylcyclohexane-based liquid crystals, pyrimidine-based liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals and the like are used. 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-
15 (Merck Ltd.) and the like can also be used by adding a chiral agent and the like.
Furthermore, p-decyloxybenzylidene-p-amino-2
Ferroelectric liquid crystals such as methylbutyl cinnamate can also be used. The polarizing plate used on the outside of the liquid crystal cell is a polarizing plate in which a polarizing film called an H film absorbing iodine while sandwiching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films, or a polarizing film consisting of the H film itself. A plate etc. can be mentioned.

[0057]

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. In the following description, the specific polymer I means a polyamic acid, and the specific polymer II means the dehydrated ring-closing polymer.

The measurement of the pretilt angle in the examples is as follows.
[TJ Schffer, et al., J. Appl. Phys., 19 , 2013 (1
980)], and a crystal rotation method using a He—Ne laser beam. In addition, the orientation of the liquid crystal cell was evaluated by observing the presence or absence of alignment failure in the liquid crystal cell when the voltage was turned on and off with a polarizing microscope, and judged good when there was no alignment failure.

Synthesis Example 1 16.3 g (0.0724 mol) of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 11.31 g (0.0217 mol) of a diamine represented by the formula (4) as a diamine and 4 17.46 g (0.0507 mol) of 4,4 '-(p-phenylene isopropylidene) bisaniline was added to N
-Methyl-2-pyrrolidone dissolved in 405 g, 60 ° C
And reacted for 6 hours. The reaction mixture was then 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 a specific polymer I (Ia) having an intrinsic viscosity of 0.87 dl / g.
40.25 g was obtained.

Synthesis Example 2 40.00 g of the specific polymer I (Ia) obtained in Synthesis Example 1
To 800 g of N-methyl-2-pyrrolidone and pyridine
28.63 g and acetic anhydride 22.17 g were added, and 110
After dehydration and ring closure at 4 ° C. for 4 hours. Then, the reaction product solution was precipitated, washed and dried in the same manner as in Synthesis Example 1 to obtain 35.75 of a specific polymer II (IIa) having an intrinsic viscosity of 0.85 dl / g.
g was obtained.

Synthesis Example 3 In Synthesis Example 1, tetracarboxylic acid dianhydride was added to 22.
70 g (0.1013 mol) of formula (4) as diamine
5.27 g (0.0101 mol) of the diamine represented by
10.4 g (0.0304 mol) of 4,4 '-(p-phenyleneisopropylidene) bisaniline, and p-
Specific polymer I (Ib) was prepared in the same manner as in Synthesis Example 1 except that the amount of phenylenediamine was 6.57 g (0.0608 mol).
This specific polymer I (Ib) was used to carry out dehydration ring closure in the same manner as in Synthesis Example 2 to give an intrinsic viscosity of 0.98 dl /
36.00 g of the specific polymer II (IIb) was obtained.

Synthesis Example 4 In Synthesis Example 1, tetracarboxylic acid dianhydride was added to 19.
80 g (0.0883 mol) of formula (4) as diamine
9.20 g (0.0177 mol) of the diamine represented by
12.17 g (0.0353 mol) of 4,4 '-(p-phenyleneisopropylidene) bisaniline, and p-
3.82 g (0.0353 mol) of phenylenediamine,
Specific Polymer I (I
c) was obtained, and this specific polymer I (Ic) was used for dehydration ring closure in the same manner as in Synthesis Example 2 to give an intrinsic viscosity of 0.91d.
36.23 g of specific polymer II (IIc) of 1 / g was obtained.

Synthesis Example 5 In Synthesis Example 1, tetracarboxylic dianhydride was added to 15.
80 g (0.0705 mol) of formula (4) as diamine
In the same manner as in Synthesis Example 1 except that the diamine represented by the formula was 11.01 g (0.0212 mol) and 4,4′-bis (4-aminophenoxy) -biphenyl was 18.18 g (0.0493 mol). A specific polymer I (Id) was obtained, and the specific polymer II (Id) was subjected to dehydration ring closure in the same manner as in Synthesis Example 2 to give a specific polymer II (IId) 35.g having an intrinsic viscosity of 0.88 dl / g. 66 g were obtained.

Synthesis Example 6 In Synthesis Example 1, tetracarboxylic dianhydride was added to 22.
33 g (0.0996 mol) of formula (4) as diamine
5.19 g (0.0100 mol) of the diamine represented by
Same as Synthesis Example 1 except that 11.4 g (0.0299 mol) of 4,4'-bis (4-aminophenoxy) -biphenyl and 6.46 g (0.0567 mol) of p-phenylenediamine were used. To obtain the specific polymer I (Ie),
Further, this specific polymer I (Ie) was subjected to dehydration ring closure in the same manner as in Synthesis Example 2 to obtain 35.12 g of a specific polymer II (IIe) having an intrinsic viscosity of 0.92 dl / g.

Synthesis Example 7 In Synthesis Example 1, tetracarboxylic acid dianhydride was added to 19.
78 g (0.0882 mol) of formula (1 as diamine
4.60 g (0.0088 mol) of the diamine represented by 4) and 14.90 g (0.0) of the compound represented by the formula (4).
265 mol), and 5.7 p-phenylenediamine.
A specific polymer I (If) was obtained in the same manner as in Synthesis Example 1 except that 3 g (0.0529 mol) was used, and dehydration ring closure was carried out in the same manner as in Synthesis Example 2 using this specific polymer I (If). , A specific polymer II having an intrinsic viscosity of 0.99 dl / g (II
f) 35.60 g were obtained.

Synthesis Example 8 In Synthesis Example 1, tetracarboxylic acid dianhydride was added to 22.
63 g (0.1010 mol) of formula (4) as diamine
5.26 g (0.0101 mol) of the diamine represented by
Add 9,9-bis (4-aminophenyl) fluorene to 10.
A specific polymer I (Ig) was obtained in the same manner as in Synthesis Example 1 except that 56 g (0.0303 mol) and p-phenylenediamine of 6.55 g (0.0606 mol) were used. (Ig) was subjected to dehydration ring closure in the same manner as in Synthesis Example 2 to obtain 35.90 g of a specific polymer II (IIg) having an intrinsic viscosity of 0.91 dl / g.

Synthesis Example 9 In Synthesis Example 1, tetracarboxylic acid dianhydride was added to 16.
36 g (0.0730 mol) of formula (4) as diamine
7.60 g (0.0146 mol) of the diamine represented by
21.04 g (0.05) of the diamine represented by the formula (12)
Specific Polymer I (Ih) was obtained in the same manner as in Synthesis Example 1, except that the specific polymer I (Ih) was used for dehydration ring closure in the same manner as in Synthesis Example 2 to give an intrinsic viscosity of 0. 0.85 dl / g of specific polymer II (IIh) 34.55
g was obtained.

Synthesis Example 10 In Synthesis Example 1, tetracarboxylic dianhydride was added to 22.
45 g (0.1001 mol) of formula (4) as diamine
5.22 g (0.0100 mol) of the diamine represented by
10.83 g (0.03 g) of the diamine represented by the formula (12)
00 mol), and p-phenylenediamine 5.22.
A specific polymer I (Ii) was obtained in the same manner as in Synthesis Example 1 except that g (0.0601 mol) was used, and dehydration ring closure was carried out in the same manner as in Synthesis Example 2 using this specific polymer I (Ii). , A specific polymer II having an intrinsic viscosity of 0.89 dl / g (II
i) 33.60 g were obtained.

Synthesis Example 11 In Synthesis Example 1, tetracarboxylic dianhydride was added to 22.
73 g (0.1014 mol) of formula (4) as diamine
5.28 g (0.0101 mol) of the diamine represented by
10.41 g (0.03) of the diamine represented by the formula (13)
03 mol) and 6.58 p-phenylenediamine.
A specific polymer I (Ij) was obtained in the same manner as in Synthesis Example 1 except that g (0.0610 mol) was used, and dehydration ring closure was performed using this specific polymer I (Ij) in the same manner as in Synthesis Example 2. , A specific polymer II having an intrinsic viscosity of 0.82 dl / g (II
j) 36.00 g was obtained.

Synthetic Example 12 (Comparison) In Synthetic Example 1, tetracarboxylic acid dianhydride was added to 28.
58 g (0.1275 mol) of formula (4) as diamine
3.32 g (0.0064 mol) of the diamine represented by
And 13.10 g (0.12 g) of p-phenylenediamine.
Except that the specific polymer I (Ik) was obtained in the same manner as in Synthesis Example 1 and the specific polymer I (Ik) was subjected to dehydration ring closure in the same manner as in Synthesis Example 2 to give an intrinsic viscosity of 0. Specific polymer II (IIk) 36.11 of 0.98 dl / g
g was obtained.

Synthetic Example 13 (Comparative) In Synthetic Example 1, tetracarboxylic acid dianhydride was added to 27.
66 g (0.1234 mol) of formula (4) as diamine
3.21 g (0.0123 mol) of the diamine represented by
The same procedure as in Synthesis Example 1 was repeated except that 2.13 g (0.0062 mol) of 4,4 '-(p-phenyleneisopropylidene) bisaniline and 12.01 g (0.1049 mol) of p-phenylenediamine were used. Specific polymer I (Il)
This specific polymer I (Il) was used for dehydration ring closure in the same manner as in Synthesis Example 2 to give an intrinsic viscosity of 0.95 dl /
33.43 g of the specific polymer II (IIl) was obtained.

Synthesis Example 14 (Comparative) In Synthesis Example 1, tetracarboxylic acid dianhydride was added to 25.
02 g (0.1116 mol), 4,4'-as diamine
1 part of (p-phenylene isopropylidene) bisaniline
A specific polymer I (Im) was obtained in the same manner as in Synthesis Example 1 except that 1.53 g (0.0355 mol) and p-phenylenediamine of 8.45 g (0.0781 mol) were used. The compound I (Im) was dehydrated and ring-closed in the same manner as in Synthesis Example 2 to obtain 36.76 g of the specific polymer II (IIm) having an intrinsic viscosity of 0.91 dl / g.

Example 1 6 g of the polymer II (IIa) obtained in Synthesis Example 1 was dissolved in 120 g of γ-butyrolactone to obtain a solution having a solid content concentration of about 5% by weight, and this solution was filtered with a filter having a pore size of 1 μm. Then, a liquid crystal aligning agent solution was prepared. This solution is
On a glass substrate with a transparent electrode consisting of an O film, the transparent electrode surface was coated with a spinner at a rotation speed of 3000 rpm for 3 minutes and dried at 180 ° C. for 1 hour to give a dry film thickness of 0.05 μm.
m coating film was formed. With a rubbing machine having a roll in which a nylon cloth is wrapped around this coating film, the roll foot pressing length is 0.6 mm, and the rotation speed of the roll is 500 rp.
The rubbing process was performed at m and a stage moving speed of 1 cm / sec. After that, cleaning was performed by each of the following methods. (A) Immerse in IPA and ultrasonically clean for 5 minutes (b) Clean by exposing to IPA vapor for 20 minutes

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 17 μm was applied by screen printing to the outer edges of the pair of rubbing-treated substrates having the liquid crystal alignment film, and then the pair of substrates was placed on the liquid crystal alignment film surface. Were opposed to each other, and the rubbing directions were antiparallel to each other. Then, after filling a nematic liquid crystal (MLC-2001, manufactured by Merck & Co., Inc.) between the pair of substrates through the liquid crystal inlet, the liquid crystal inlet is sealed with an epoxy adhesive, and a polarizing plate is provided on both sides of the substrate. Were laminated so that the polarization direction of the polarizing plate coincided with the rubbing direction of the liquid crystal alignment film of each substrate, to manufacture a liquid crystal display element. The orientation of the obtained liquid crystal display element was good, and the pretilt angle was measured and found to be 5.2 degrees in the unwashed state, 5.1 degrees in the washing method (a), and (b).
At that time, it was 5.1 degrees, and the pretilt angle dependency due to cleaning was small.

Examples 2 to 13 and Comparative Examples 1 to 3 Example 1 except that the specific polymer described in Table 1 and Table 2 was used in place of the specific polymer II (IIa) in Example 1. A liquid crystal display device was produced in the same manner as in. The measurement results of the alignment property of the liquid crystal display element and the dependency of the pretilt angle on the cleaning method are shown in Tables 1 and 2 including Example 1.
It was shown to.

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[Table 1]

[0077]

[Table 2]

[0078]

According to the liquid crystal aligning agent of the present invention, when a liquid crystal aligning film is formed, the liquid crystal aligning property is good, the pretilt angle that the liquid crystal develops is 3 degrees or more, and the pretilt angle after rubbing Since there is little dependency on the cleaning process, STN
Alternatively, a liquid crystal alignment film suitable for TN type display can be obtained. Further, the liquid crystal display device having the liquid crystal alignment film formed by using the liquid crystal aligning agent of the present invention can be suitably used for SH (Super Homeotropic) display devices and ferroelectric display devices by selecting the liquid crystal to be used. be able to. Furthermore, a liquid crystal display device having an alignment film formed by using the liquid crystal aligning agent of the present invention is excellent in liquid crystal alignment and reliability,
It can be effectively used for various devices, and is used for display devices such as desk calculators, wrist watches, table clocks, coefficient display boards, word processors, personal computers, and liquid crystal televisions.

The preferred embodiments of the liquid crystal aligning agent of the present invention described in detail above will be additionally described below. 1. A liquid crystal aligning agent wherein compound II (diamine compound represented by general formula (2)) is at least one selected from diamines represented by formulas (4), (5), (6) and (7). 2. A liquid crystal aligning agent in which the ratio of the compound II is 5 to 50 mol% of all diamines. 3. The ratio of compound II is 10 to 30 mol% of all diamines.
Is a liquid crystal aligning agent. 4. Compound III (diamine compound represented by general formula (3)) is represented by formula (8), (9), (10), (11), (1
A liquid crystal aligning agent which is at least one selected from the diamines represented by 2), (13) and (14). 5. A liquid crystal aligning agent in which the proportion of compound III is 20 to 90 mol% of all diamines.

Front page continuation (72) Inventor Toshinori Nishikawa, 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. Rubber Co., Ltd.

Claims (1)

[Claims] 1. (A) The following formula (1): (In the formula (1), R ₁ represents a tetravalent organic group) and (B) (i) the following formula (2): (In the formula (2), R ₂ is —O—, —COO—, or —OCO.
-, -NHCO-, -CONH- and -CO- represent any divalent organic group, R ₃ represents a monovalent organic group, provided that R ₃ represents an anthracene ring and 2 or more groups. A diamine compound represented by (not containing a benzene ring) and (ii) the following formula (3): (In the formula (3), R ₄ represents a divalent organic group containing three or more benzene rings and / or at least one anthracene ring), a polyamic acid obtained by reacting with a diamine compound, The proportion of the diamine represented by the formula (2) is 3 to 60 mol% of the total diamine, and the proportion of the diamine represented by the formula (3) is 10 to 10 of the total diamine.
A liquid crystal aligning agent comprising 97 mol% and / or a polymer obtained by dehydration ring closure of the polyamic acid thereof.