JP3049719B2 - Liquid crystal alignment agent and liquid crystal display device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid crystal compounding agent, and more particularly to a liquid crystal aligning agent having a small residual image when driven, and particularly useful for a TN type display device.

[Conventional technology]

Conventionally, a nematic liquid crystal having a positive dielectric anisotropy is
A TN-type display element having a TN-type array cell in which a sandwich structure is used on a substrate with a transparent electrode having a liquid crystal alignment film made of polyimide or the like so that the major axis of liquid crystal molecules is continuously twisted 90 ° between the substrates is known. ing. The alignment of the liquid crystal in this TN type display element is formed by a liquid crystal alignment film subjected to a rubbing process, but since a charge is accumulated on the alignment film surface during driving, even if a new drive signal is input, the previous drive signal is input. There is a problem that an afterimage of a display remains.

[Problems to be solved by the invention]

An object of the present invention is to provide a liquid crystal aligning agent which can be suitably used for a liquid crystal alignment film of a TN type display element having little residual image.

[Means for solving the problem]

A first aspect of the present invention is to provide a compound represented by the general formula (I) (Wherein, R ¹ and R ³ are the same or different divalent aromatic groups, organic groups selected from aliphatic groups and alicyclic groups, a is an integer of 0 or 1, n is 1 to 1000 An integer, R ² is a divalent aliphatic group, and X is a polymer having a repeating structural unit represented by an oxygen atom or a sulfur atom (hereinafter referred to as “polymer (I)”). It relates to a liquid crystal alignment agent.

A second aspect of the present invention is a compound represented by the general formula (II): (Wherein R ⁴ represents a tetravalent organic group and R ⁵ represents a divalent organic group) and / or a general formula (III) (Wherein R ⁶ represents a tetravalent organic group and R ⁷ represents a divalent organic group), a polymer having a repeating structural unit represented by the following formula: The present invention relates to a liquid crystal aligning agent except for ferroelectric liquid crystal, comprising at least one member selected from the group consisting of:

A third aspect of the present invention relates to a liquid crystal display device having a liquid crystal alignment film obtained using the liquid crystal compounding agent according to the first or second aspect.

R ¹ and R in the general formula (I) according to the first aspect of the present invention.
³ is a divalent aromatic group, an organic group selected from an aliphatic group and an alicyclic group, which may be the same or different from each other, for example, as an aromatic group, And the like, and examples of the aliphatic group include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and an isobutylene group. And the like. Among these, an aromatic group or an aliphatic group is preferable, and a methylene group, an ethylene group,
When the n-propylene group or the isopropylene group is an aromatic group, Is preferred.

R ² in the general formula (I) is a divalent aliphatic group;
Examples include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, a butylene group, a perfluoroethylene group, a perfluoroisopropylene group, and the like.
Of these, an ethylene group, an n-propylene group, an isopropylene group, a perfluoroethylene group or a perfluoroisopropylene group is preferred.

Further, the n is a repeating unit of the general formula (I) in the (R ² -X) is from 1 to 1000, preferably 1 to 100. X is an oxygen atom or a sulfur atom.

The polymer (I) used in the first embodiment of the present invention is, for example, a polyamic acid obtained by reacting tricarboxycyclopentyl acetic acid (hereinafter referred to as “TCA”) or a dianhydride thereof with a specific diamine compound in an organic solvent. Obtained by heating the acid, specifically, heating the polyamic acid obtained from 2,3,5-tricarboxycyclopentylacetic acid or its dianhydride and a specific diamine compound as it is in an organic solvent, or It is obtained by a method of performing an imidization reaction in the presence of a dehydrating agent and a basic catalyst.

In the synthesis of the polymer (I), the use ratio of TCA or its dianhydride to a specific diamine compound is 1% of the amino group.
The TCA is preferably 0.2 to 2 moles, more preferably 0.3 to 1.2 moles, per mole.

The reaction between TCA or its dianhydride and a specific diamine compound is carried out by dissolving both in an organic solvent and stirring, and the amount of the organic solvent at this time is usually TCA or its dianhydride and the specific dianhydride. Is used so that the total amount of the diamine compound is 0.1 to 30% by weight. The reaction temperature when the polyamic acid obtained by this reaction is subjected to an imidization reaction in an organic solvent is usually 60 to 200 ° C, preferably 100 to 170 ° C. Below 60 ° C, the progress of the imidization reaction is slow, and
If it exceeds 0 ° C., the molecular weight of the polyimide compound may decrease. The reaction temperature when imidizing in the presence of a dehydrating agent and a basic catalyst is usually 0 to 180 ° C, preferably 60 ° C.
~ 150 ° C. Acid anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride can be used as the dehydrating agent. The amount of the dehydrating agent used is preferably 1.6 to 20 mol per 1 mol of the repeating unit of the polyamic acid. Further, the basic catalyst is not particularly limited,
Tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used. The amount of the basic catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used.

The following compounds can be mentioned as specific examples of the above specific diamine compound.

_{H 2 N- (CH 2) l} - (CH 2 CH 2 O) n- (CH 2) m-NH 2 ( wherein, l is 0 to 3, n is 1 to 100, m is from 1 to 3 , L, m, and n each represent an integer.), (In the formula, n means an integer of 1 to 100.) (In the formula, p is 0-3, n is 1-100, q is 0-3, and p, n, and q each represent an integer.) These diamine compounds may be used alone or in combination of two or more. Can be used.

The intrinsic viscosity of the obtained polymer (I) [η _inh = lnη _reL /
C, C = 0.5 g / dl, 30 ° C., N-methyl-2-pyrrolidone]
Is usually 0.05 to 10 dl / g, preferably 0.05 to 5 dl / g.

The organic solvent is not particularly limited as long as it can dissolve the polymer produced by the reaction. For example, N-methyl-2
Aprotic polar solvents such as pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide, m-cresol, xylenol, phenol, halogen Phenolic solvents such as activated phenol can be mentioned.

Other common organic solvents are alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, such as 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, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1 , 4-Dichlorobutane, trichloroethane, chlorobenzene, o- Chlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like, can be mixed so as not to precipitate the polymer (I).

In the second embodiment of the present invention, R ⁴ in the general formula (II) and R ⁶ in the general formula (III) are tetravalent organic groups, for example, a residue obtained by removing an acid anhydride from tetracarboxylic dianhydride. Group. R ⁵ in the general formula (II) and R ⁷ in the general formula (III) are divalent organic and are represented by, for example, a residue obtained by removing an amino group from a diamine compound.

The polymer having a repeating structural unit represented by the general formula (II) used in the second aspect of the present invention (hereinafter referred to as “polymer (II)”)
Is reacted with a tetracarboxylic dianhydride and a diamine compound in the above-mentioned organic solvent under the same conditions as for the polymer (I) to form a repeating structural unit represented by the general formula (III). Having a polymer (hereinafter referred to as “polymer (II)
I) ") can be obtained by heating the organic solvent solution of the reaction product of the tetracarboxylic dianhydride and the diamine compound as it is, or by dehydrating and ring-closing with the above-described dehydrating agent and basic catalyst.

Examples of the tetracarboxylic dianhydride, for example, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride Product, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxy-
Norbornane-2-acetic acid dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-cyclohexenedicarboxylic dianhydride, bicyclo [2,2,2] -oct-
Aliphatic and alicyclic tetracarboxylic dianhydrides such as 7-ene-tetracarboxylic dianhydride; pyromellitic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride; 3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride , 3,3 ', 4,4'-biphenylethertetracarboxylic dianhydride, 3,3', 4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ', 4,4'- Tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,
4-furantetracarboxylic dianhydride, 4,4'-bis (3,
4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy)
Diphenylsulfone dianhydride, 4,4'-bis (3,4-dicarbonphenoxy) diphenylpropane dianhydride,
3 ', 4,4'-perfluoroisopropylidenetetracarboxylic dianhydride, 3,3', 4,4'-biphenylethertetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenyl-bis-
(Triphenylphthalic acid) dianhydride, m-phenylene-
Aromas such as bis- (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride A group tetracarboxylic dianhydride is used. Of these, 2,3,5-tricarboxycyclopentylacetic acid dianhydride is particularly preferred.

Examples of the diamine compound include, for example, paraphenylenediamine, metaphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, benzidine, 4,4'-diaminodiphenyl sulfide, and 4,4'-diaminodiphenyl Sulfone, 4,4'-diaminodiphenyl ether, 1,5-diaminonaphthalene,
3,3'-dimethyl-4,4'-diaminobiphenyl, 3,4 '
-Diaminobenzanilide, 3,4'-diaminodiphenyl ether, 3,3'-diaminobenzophenone, 3,4'-
Diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy)
Phenyl] hexafluoropropane, bis [4- (4-
Aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-
Aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydro-anthracene, 9,9-bis (4-aminophenyl) fluorene, 4 , 4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,
4'-diamino-5,5'-dimethoxybiphenyl, 3,3 '
Aromatic diamines such as dimethoxy-4,4'-diaminobiphenyl; aromatic diamines having a heteroatom such as diaminotetraphenylthiophene; 1,1'-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine , Pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4'-dimethylheptamethylenediamine, 1,4-diaminocyclohexane,
Isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanylenediethylenediamine, tricyclo [6.2.1.0 ^2,7 ]-
Aliphatic or cycloaliphatic diamines such as undecylenedimethyldiamine; (Wherein, R ⁸ represents an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, r
Represents an integer of 1 to 3, and s represents an integer of 1 to 20). These can be used alone or in combination of two or more.

Intrinsic viscosity of the obtained polymer (II) [η _inh = lnη _reL /
C, C = 0.5 g / dl, 30 ° C., N-methyl-2-pyrrolidone]
Is usually 0.05 to 10 dl / g, preferably 0.05 to 5 dl / g.

Examples of the surfactant of the surfactant-based antistatic agent used in the second embodiment of the present invention include long-chain aliphatic carboxylate, long-chain sulfonate, long-chain benzoate and long-chain benzene sulfonate. Anionic, long-chain aliphatic amine salts, cationic such as long-chain aliphatic quaternary ammonium salts, ethylene oxide adducts, long-chain aliphatic alcohols, long-chain aliphatic amines, long-chain aliphatic amides, and long sugars Examples include nonionic surfactants such as chain aliphatic esters and amphoteric surfactants such as long chain betaine compounds. Among these surfactants, nonionic surfactants are preferred. Commercially available products include Kao's Electrostopper, Estamit, such as 3M's Florard (trade name, the same applies hereinafter).
Examples include UNIOX, Blemmer, Anon, Nonion, and Cation manufactured by NOF Corporation, such as Emulgen, Amit, and Amphitol, and Sunstat, Sanyo Elion, and Chemistat, manufactured by Sanyo Chemicals.

Examples of the polymer charge transfer complex used in the second embodiment of the present invention include, for example, Compounds containing tetracyanoquinodimethane or tetrathiofulvalene in a polymer such as polyvinyl anthracene, polyurethane, polyvinyl pyridine, polystyrene, polyvinyl naphthalene, polyvinyl mesitylene,
Compounds obtained by doping a polymer such as polyacetylphthylene, polyvinylpyrene, polyvinylcarbazole, or polyvinylphenothiazine with iodine, bromine, or tetracyanoquinodimethane; and cationic polymers. Here, examples of the cationic polymer include a polymer containing an onium salt. Among them, a polymer containing a quaternary ammonium salt is preferable. For example And X includes fluorine, chlorine, bromine and iodine.

The timing and method of adding the polymer (II) and / or (III) of the antistatic agent or the polymer charge transfer complex are not particularly limited. For example, after the synthesis of the polymer (II) or (III), In an organic solvent. The amount of these additives is preferably 0.0001 to 100% by weight, more preferably 0.01 to 10% by weight, based on the solid content of the polymer solution.

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

First, a patterned transparent conductive film is provided on a substrate, and the liquid crystal alignment agent of the present invention is applied to the transparent conductive film side of the substrate by a roll coater method, a spinner method, a printing method, and the like.
The coating is formed by heating at a temperature of 80 to 200 ° C. The thickness of this coating film is usually from 0.001 to 1 μm.

The formed coating film is subjected to a liquid crystal alignment treatment by rubbing with a roll around which a cloth made of a synthetic fiber such as nylon is wound, thereby forming a liquid crystal alignment film.

When applying the liquid crystal alignment agent, in order to further improve the adhesiveness between the substrate and the transparent conductive film and the coating film, a silane coupling agent,
A titanium coupling agent or the like can be applied.

As the substrate, a transparent substrate made of glass, such as float glass or soda glass, or a 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 and In ₂ O ₃ -S
An ITO film made of nO ₂ or the like can be used, and the transparent conductive film is patterned by a photo-etching method or a method using a mask in advance.

The two substrates having the liquid crystal alignment film formed thereon are opposed to each other so that the rubbing directions of the liquid crystal alignment films are orthogonal or antiparallel, the peripheral portion between the substrates is sealed with a sealant, and the liquid crystal is filled. The liquid crystal cell is formed by sealing the filling port to form a liquid crystal cell, and bonding the two surfaces of the liquid crystal cell so that the polarization direction matches or is orthogonal to the rubbing direction of the liquid crystal alignment film of each substrate.

The liquid crystal is not particularly limited as long as it has a positive dielectric anisotropy, but is preferably a liquid crystal that forms a nematic liquid crystal, such as a Schiff base liquid crystal, an azoxy liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, and an ester. Liquid crystal, terphenyl liquid crystal, biphenylcyclohexane liquid crystal, pyrimidine liquid crystal, dioxane liquid crystal, bicyclooctane liquid crystal, cubane liquid crystal, and the like.

As a polarizing plate used outside the liquid crystal cell, a polarizing plate in which a polarizing film called an H film that absorbs iodine while a polyvinyl alcohol is stretched and oriented is sandwiched by a cellulose acetate protective film, or a polarizing film composed of the H film itself. A plate can be used.

As described above, the liquid crystal display device obtained by using the liquid crystal alignment agent of the present invention exhibits excellent alignment properties, and provides excellent display with little residual image when driven.

The evaluation of the remaining display was performed by applying a DC voltage of 10 V for 30 minutes, and then observing the remaining display when a reverse voltage of 5 V was applied with a microscope.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Synthesis Example 1 2,3,5-Tricarboxycyclopentylacetic acid dianhydride 2
2.4 g of H ₂ N—CH ₂ — (CH ₂ CH ₂ O) ₈ — (CH ₂ ) ₃ —NH ₂ 44.0 g are dissolved in 598 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 5 hours. Was. Then, 39.5 g of pyridine
And 30.6 g of acetic anhydride were added and reacted at 120 ° C. for 5 hours. The reaction solution was poured into a large excess of chloroform, and the reaction product was precipitated, washed with chloroform, and further reduced under reduced pressure.
Drying at 20 ° C. for 20 hours gave a polymer (I).

The intrinsic viscosity of the polymer (I) obtained as described above was measured at 30 ° C. in N-methyl-2-pyrrolidone and found to be 0.42 dl / g.

Synthesis Example 2 2,3,5-Tricarboxycyclopentylacetic acid dianhydride 2
2.4g and 59.2 g was dissolved in 734 g of N-methyl-2-pyrrolidone and reacted at 60 ° C. for 5 hours. Thereafter, imidization and reprecipitation were performed in the same manner as in Synthesis Example 1, and the intrinsic viscosity was 0.70 dl / g (N
-Methylpyrrolidone, 30 ° C.).

Synthesis Example 3 2,3,5-Tricarboxycyclopentylacetic acid dianhydride 2
2.4 g and 19.8 g of 4,4′-diaminodiphenylmethane were added to γ-
It was dissolved in 380 g of butyrolactone and reacted at 60 ° C. for 5 hours. Thereafter, imidization and reprecipitation were carried out in the same manner as in Synthesis Example 1 to give an intrinsic viscosity of 1.30 dl / g (N-methylpyrrolidone, 30
C.) of the polymer (III).

Synthesis Example 4 19.6 g of cyclobutanetetracarboxylic dianhydride and 4,4 ′
19.8 g of diaminodiphenylmethane was added to N-methyl-2.
-Dissolved in 355 g of pyrrolidone and reacted at 20 ° C for 5 hours. Thereafter, reprecipitation was performed in the same manner as in Synthesis Example 1 to obtain a polymer (II) having an intrinsic viscosity of 1.28 dl / g (N-methylpyrrolidone, 30 ° C.).

Synthesis Example 5 21.8 g of pyromellitic anhydride and 19.8 g of 4,4'-diaminodiphenylmethane were combined with N-methyl-2-pyrrolidone in 374 g.
And reacted at 25 ° C. for 5 hours. The reaction solution was reprecipitated in the same manner as in Synthesis Example 1 and had an intrinsic viscosity of 1.58 dl / g (30 ° C., N-
Methyl-2-pyrrolidone) was obtained (comparative polymer).

Example 1 6.12 g of the polymer (I) obtained in Synthesis Example 1 was dissolved in 146.9 g of N-methyl-2-pyrrolidone to prepare a solution having a solid content of 4% by weight. The mixture was filtered with a filter to prepare a liquid crystal aligning agent solution.

This solution was applied to a transparent electrode surface on a glass substrate with a transparent electrode made of an ITO film using a spinner and dried at 180 ° C. for 1 hour to form a coating film having a dry film thickness of 0.05 μm.

A rubbing machine having a roll of nylon cloth wound around the formed coating film, the roll rotation speed is 500 rp.
A rubbing treatment was performed at m and a stage moving speed of 1 cm / sec.

Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 17 μm is screen-printed and applied to the outer edge of each of the pair of rubbed substrates on the side having the liquid crystal alignment film, and then the pair of substrates is rubbed up and down. The adhesive was superposed so as to be orthogonal to each other and pressed to cure the adhesive.

Next, a nematic liquid crystal (ZLI-1132, manufactured by Merck) is filled between the pair of substrates from the liquid crystal injection port, and the liquid crystal injection port is sealed with an epoxy resin adhesive. A polarizing plate was attached to both sides of the substrate such that the polarizing direction of the polarizing plate coincided with the rubbing direction of the liquid crystal alignment film of each substrate, thereby producing a liquid crystal display device.

When a voltage was applied to the obtained liquid crystal display device, a favorable display with no residual image was obtained.

Example 2 A liquid crystal display device was produced in the same manner as in Example 1 using the polymer (II) obtained in Synthesis Example 2. When a voltage was applied to the obtained liquid crystal display device, a favorable display with no residual image was obtained.

Example 3 4.21 g of the polymer (III) obtained in Synthesis Example 3 was dissolved in 101.3 g of γ-butyrolactone, and 0.042 g of a surfactant-based antistatic agent Blenmer PE350 manufactured by NOF Corporation was added. A liquid crystal aligning agent solution was prepared in the same manner as described above. Further, a liquid crystal display device was manufactured in the same manner as in Example 1, and a voltage was applied to the device. As a result, a good display with no residual image was obtained.

Example 4 3.58 g of the polymer (II) obtained in Synthesis Example 4 was dissolved in 85.9 g of N-methyl-2-pyrrolidone, and 0.036 g of a surfactant-based antistatic agent Blenmer PE350 manufactured by NOF Corporation was added. In the same manner as in Example 1, a liquid crystal aligning agent solution was prepared.
Further, a liquid crystal display device was manufactured in the same manner as in Example 1, and a voltage was applied to the device. As a result, a good display with no residual image was obtained.

Example 5 4.22 g of the polymer (III) obtained in Synthesis Example 3 was dissolved in 101.3 g of γ-butyrolactone to obtain a cationic polymer of poly-N-methyl-4-vinylpyridinium iodide.
84 g was added, and a liquid crystal aligning agent solution was prepared in the same manner as in Example 1. Further, a liquid crystal display device was manufactured in the same manner as in Example 1, and a voltage was applied to the device. As a result, a good display with no residual image was obtained.

Example 6 3.58 g of the polymer (II) obtained in Synthesis Example 4 was dissolved in 85.9 g of N-methyl-2-pyrrolidone, and the cationic polymer of poly-N-methyl-4-vinylviridinium iodide 0.72 g was dissolved. g was added and a liquid crystal alignment film solution was prepared in the same manner as in Example 1. Further, a liquid crystal display device was manufactured in the same manner as in Example 1, and a voltage was applied to the device. As a result, a good display with no residual image was obtained.

Comparative Example 1 A liquid crystal display device was produced in the same manner as in Example 1 using the polymer obtained in Synthesis Example 5. When a voltage was applied to the obtained liquid crystal display device, only an unclear display was obtained with many residual images.

Comparative Example 2 A liquid crystal aligning agent solution was prepared in the same manner as in Example 4 except that no antistatic agent was added. When a voltage was applied to the obtained liquid crystal display device, only an unclear display was obtained with many residual images.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to the liquid-crystal aligning agent of this invention, the liquid-crystal aligning film which is excellent in liquid-crystal aligning property and has few afterimages of a display is suitable especially for TN type display elements.

Further, by using the liquid crystal aligning agent of the present invention, it is possible to suppress electrostatic breakdown of the electrode due to static electricity generated during rubbing.

Further, a liquid crystal display element having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention is excellent in the alignment and reliability of the liquid crystal, for example, a desk calculator, a wristwatch, a clock,
It is particularly useful for display devices such as coefficient display boards, word processors, personal computers, and liquid crystal televisions.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasuaki Yokoyama 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-3-92824 (JP, A) JP-A Heisei 2-153321 (JP, A) JP-A-3-95522 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1337

Claims (3)

(57) [Claims] 1. The compound of the general formula (I) (Wherein, R ¹ and R ³ are the same or different divalent aromatic groups, organic groups selected from aliphatic groups and alicyclic groups, a is an integer of 0 or 1, n is 1 to 1000 An integer, R ² represents a divalent aliphatic group, and X represents an oxygen atom or a sulfur atom.) A liquid crystal aligning agent comprising a polymer having a repeating structural unit represented by the following formula: 2. A compound of the general formula (II) (Wherein R ⁴ represents a tetravalent organic group and R ⁵ represents a divalent organic group) and / or a general formula (III) (Wherein, R ⁶ represents a tetravalent organic group and R ⁷ represents a divalent organic group) to a polymer having a repeating structural unit represented by the following formula: A liquid crystal aligning agent except for ferroelectric liquid crystal, comprising at least one selected from complexes. 3. A liquid crystal display device having a liquid crystal alignment film obtained by using the liquid crystal alignment agent according to claim 1.