KR20070008422A - Liquid crystal aligning agent and liquid crystal display device - Google Patents

Abstract

A liquid crystal aligning agent is provided to produce a liquid crystal alignment film having high residual DC voltage and good printability without forming print stains and pinholes when applied onto an organic film. The liquid crystal aligning agent for in-plane switching liquid crystal display devices contains a polymer having a repeat unit represented by the following formula 1a and a repeat unit represented by the following formula 1b, a compound having 4 epoxy groups in a molecule, and a functional silane compound. In the formulae, P^1 is a tetravalent organic group, Q^1 is a divalent organic group, P^2 is a tetravalent organic group different from P^1, and Q^2 is a divalent organic group.

Description

Liquid crystal aligning agent and liquid crystal display device {Liquid Crystal Aligning Agent and Liquid Crystal Display Device}

The present invention relates to a liquid crystal aligning agent and a liquid crystal display element. More specifically, it relates to the liquid crystal aligning agent excellent in electrical characteristics and excellent in printability, and the liquid crystal aligning agent for transverse electric field system liquid crystal display elements obtained therefrom.

Conventionally, the layer of the nematic liquid crystal which has positive dielectric anisotropy is formed between two board | substrates with which a liquid crystal aligning film is formed in the surface via a transparent conductive film, and it is set as the cell of a sandwich structure, and the long axis of the said liquid crystal molecule A TN type liquid crystal display device having a TN (Twisted Nematic) type liquid crystal cell in which a) is continuously twisted 90 degrees from one substrate to the other substrate is known.

In addition, the addition of a chiral material achieves a state in which the major axis of the liquid crystal molecules are continuously twisted over 180 degrees between the substrates, and the STN (Super Twisted Nematic) using the birefringence effect generated thereby Nematic) type liquid crystal display elements are also present.

In contrast, the transverse electric field type liquid crystal display element arranges two electrodes for driving a liquid crystal in a comb-tooth shape on one substrate, generates an electric field parallel to the substrate surface, and controls liquid crystal molecules. It was a big feature that a wide viewing angle comparable to a CRT without gray scale inversion or color tone change was obtained without using an optical compensation film. Orientation of the liquid crystal in these liquid crystal display elements is normally expressed by the liquid crystal aligning film in which the rubbing process was performed.

As a material of the liquid crystal aligning film in these liquid crystal display elements, polyimide, polyamide, polyester, etc. are known conventionally. In particular, polyimides are used in many liquid crystal display devices because of their excellent heat resistance, affinity with liquid crystals, mechanical strength, and the like.

In recent years, examination of improvement of display quality, low power consumption, etc., including high-definition of a liquid crystal display element is progressing, The utilization range of a liquid crystal display element is also expanded. In recent years, the range of use of liquid crystal display elements has been expanded as well as in the conventional transmissive type as well as the reflective and semi-transmissive type. Moreover, in order to have flatness on a transparent conductive film, organic films, such as a protective film, are apply | coated and the liquid crystal aligning film is apply | coated therefrom. However, conventional liquid crystal alignment films containing polyimide have poor affinity with organic films such as protective films, are easy to be cratered at the time of coating, and easily cause pinholes. There was a problem of lowering the electrical characteristics.

An object of the present invention includes a polyamic acid and a polyimide which are precursors of a polyimide useful as a liquid crystal aligning film, and a liquid crystal alignment film having a high voltage retention and good printability to organic films such as a protective film and a transverse electric field system having the same. It is providing a liquid crystal display element.

Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention firstly,

(A) a polymer having a repeating unit represented by the following general formula (1a) and a repeating unit represented by the following general formula (1b) (hereinafter referred to as "specific polymer"), a compound having four epoxy groups in a molecule, and a silane coupling agent. It is achieved by the liquid crystal aligning agent made into.

In the formula, P ¹ is a tetravalent organic group, and Q ¹ is a divalent organic group.

In the formula, P ² is a tetravalent organic group different from P ^1, and Q ² is a divalent organic group.

According to the present invention, the above objects and advantages of the present invention are second,

The liquid crystal aligning film formed from the said liquid crystal aligning agent of this invention is provided, It is achieved by the transverse electric field system liquid crystal display element characterized by the above-mentioned.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The liquid crystal aligning agent in this invention contains the polymer which has a repeating unit represented by the said Formula (1a), and a repeating unit represented by the said Formula (1b). The polymer may be a mixture of (1) a polyamic acid having a repeating unit represented by the formula (1a) and a polyimide having a repeating unit represented by the formula (1b), (2) the repeating unit represented by the formula (1a) and the The repeating unit represented by the formula (1b) may be a polymer formed by combining randomly or block-like in the same molecule (hereinafter, referred to as a "partial imidation polymer").

The said polyamic acid is obtained by ring-opening polyaddition of tetracarboxylic dianhydride and a diamine compound, and a polyimide is obtained by dehydrating and closing a polyamic acid normally. Partially imidized polymers can usually be obtained by a method of partially dehydrating and ring-closing a polyamic acid, or by combining an amic acid prepolymer with an imide prepolymer to synthesize a block copolymer.

<Polyamic acid>

Tetracarboxylic dianhydride

As tetracarboxylic dianhydride, for example, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2-dimethyl-1,2,3,4- Cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1,2,3,4-cyclobutanetetracarb Acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3 ', 4,4'-dicyclohexyltetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride , 3,5,6-tricarboxynorbornene-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexa Hydro-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3 , 3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3- Dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan -1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2 -c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naph Earth [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-ethyl-5 (tetrahydro-2,5- Dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione, 5- (2,5-dioxotetrahydrofural) -3 -Methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -octo-7- -2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5 Aliphatic and alicyclic tetracarboxylic dianhydrides such as' -dione) and compounds represented by the following formulas (I) and (II);

<Formula I>

<Formula II>

In formula, R <^1> and R <^3> represents the divalent organic group which has an aromatic ring, R <^2> and R <^4> represents a hydrogen atom or an alkyl group, and ^two or more R <^2> and R <^4> may be same or different, respectively.

Pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfontetracarboxylic 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-furanthate Carboxylic acid dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride , 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl propane dianhydride, 3,3 ', 4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3', 4 , 4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphineoxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride , m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4'-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride , Ethylene glycol -bis (anhydrotrimerate), propylene glycol -bis (anhydrotrimerate), 1,4-butanediol-bis (anhydrotrimerate), 1,6-hexanediol-bis (an Hydrotrimerate), 1,8-octanediol-bis (anhydrotrimerate), 2,2-bis (4-hydroxyphenyl) propane-bis (anhydrotrimerate), formula (1) Aromatic tetracarboxylic dianhydrides, such as the compound represented by (4), are mentioned. These are used individually by 1 type or in combination of 2 or more types.

Among them, butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride , 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 5 -(2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8 -Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5,9b -Hexahydro-5,8-dimethyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, bicyclo [2 , 2,2] -octo-7-ene-2,3,5,6-tetracarboxylic dianhydride, 3-oxabicyclo [3.2.1] octane-2,4-dione-6-spiro- 3 '-(tetrahydrofuran-2', 5'-dione), pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4 '-Biphenylsulfontetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, a compound represented by the following formulas (5) to (7) among the compounds represented by the formula (I) and Among the compounds represented by the above formula (II), the compound represented by the following formula (8) is preferable from the viewpoint of being able to express good liquid crystal alignment, and particularly preferred is 1,2,3,4-cyclobutanetetracarboxylic dianhydride. , 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclo Pentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan- 1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8 -Methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 3-oxabicyclo [3.2.1] octane And a compound represented by -2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione), pyromellitic dianhydride and the following general formula (5).

The tetravalent organic group represented by P ¹ in the repeating unit (amic acid unit) represented by the formula (1a), and the tetravalent organic group represented by P ² in the repeating unit (imide unit) represented by the formula (1b) It is group derived from tetracarboxylic dianhydride. Each of which may be the same or different, but, as preferable examples of P ¹ in the formula (1a) is to be the group represented respectively by the following general formula (i) and (i '). Preferred examples of P ² include groups having an alicyclic skeleton, and particularly preferably groups represented by the following general formulas (ii) and (ii ').

In formula, R is a halogen atom, a methyl group, or an ethyl group, a is an integer of 0 or 1, b is an integer of 0-6, c is an integer of 0-4, d is an integer of 0-5.

When the specific example of the preferable tetracarboxylic dianhydride in each repeating unit is shown, as tetracarboxylic dianhydride which comprises an amic acid unit, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2 -Dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dichloro-1 , 2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4, 5-cyclohexane tetracarboxylic dianhydride and pyromellitic dianhydride, and the like, and examples of the tetracarboxylic dianhydride constituting the imide unit include alicyclic tetracarboxylic dianhydrides, especially 2,3,5 Tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2- c] -furan-1,3- On, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan -1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1, 2 -c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naph Tol [1,2-c] -furan-1,3-dione and 1,3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 (tetrahydro-2,5-dioxo- 3-furanyl) -naphtho [1,2-c] -furan-1,3-dione and the like are preferred, among them 2,3,5-tricarboxycyclopentylacetic dianhydride and 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione and 1,3, 3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione This is more preferable.

[Diamine Compound]

As a diamine compound used for the synthesis | combination of the said polyamic acid, p-phenylenediamine, m-phenylenediamine, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenylethane, 4, 4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4, 4'-diaminodiphenylether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3 , 3-trimethylindane, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenylether, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4- Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] sulfone, 1,4- Bis (4-aminophenoxy) benzene, 1,3-bis (4 -Aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene, 2,7-diaminofluorene, 9,9 -Bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 1,4,4'- (p-phenyleneisopropylidene) bisaniline, 4,4 '-(m-phenyleneisopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy Phenyl] hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl and 4,4'-bis [(4-amino-2-trifluoromethyl Aromatic diamines such as phenoxy] -octafluorobiphenyl;

1,1-methacrylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine , 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindenylenedimethylenediamine, tricyclo [6.2.1.0 ^2,7 ] -undecylene Aliphatic and alicyclic diamines such as dimethyldiamine and 4,4'-methylenebis (cyclohexylamine);

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

<Formula III>

In the formula, R ⁵ represents a monovalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, and X represents a divalent organic group.

<Formula IV>

In the formula, R ⁶ represents a divalent organic group having a ring structure containing a nitrogen atom selected from pyridine, pyrimidine, triazine, piperidine and piperazine, X represents a divalent organic group, and a plurality of X May be the same or different.

Mono-substituted phenylenediamines represented by the following general formula (V); Diaminoorganosiloxane represented by the following formula (VI);

<Formula V>

In the formula, R ⁷ represents a divalent organic group selected from -O-, -COO-, -OCO-, -NHCO-, -CONH- and -CO-, and R ⁸ represents a steroid skeleton, a trifluoromethyl group and a fluorine group. The monovalent organic group or the C6-C30 alkyl group which has group chosen from a furnace group is shown.

<Formula VI>

In formula, R <^9> represents a C1-C12 hydrocarbon group, two or more R <^9> may be same or different, p is an integer of 1-3, q is an integer of 1-20.

The compound etc. which are represented by following General formula (9)-(13) are mentioned. These diamine compounds can be used individually or in combination of 2 or more types.

In formula, y is an integer of 2-12 and z is an integer of 1-5.

Among them, p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4, 4'-diaminodiphenylether, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 '-(p-phenylenediisopropylidene) bisaniline, 4,4 '-(m-phenylenediisopropylidene) bisaniline, 1,4-cyclohexanediamine, 4,4'-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4 , 4'-bis (4-aminophenoxy) biphenyl, a compound represented by the above formulas (9) to (13), 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-dia Minopyrimidine, 3,6-diaminoacridine, the compound represented by the following formula (14) among the compounds represented by the formula (III), the above The compound represented by the following general formula (16) to (21) of the compound represented by Formula and Formula V of the formula 15 to the compound of formula IV is preferred.

[Synthesis reaction of polyamic acid]

The use ratio of the tetracarboxylic dianhydride and the diamine compound provided in the synthesis reaction of the polyamic acid is preferably such that the acid anhydride group of the tetracarboxylic dianhydride is 0.2 to 2 equivalents to 1 equivalent of the amino group contained in the diamine compound. More preferably, it is the ratio which becomes 0.3 to 1.2 equivalent.

The synthesis reaction of the polyamic acid is usually carried out in an organic solvent under a temperature condition of -20 to 150 ° C, preferably 0 to 100 ° C. The organic solvent is not particularly limited as long as it can dissolve the polyamic acid synthesized. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, Aprotic polar solvents such as dimethyl sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphospholitriamide; Phenol solvents, such as m-cresol, xylenol, a phenol, and a halogenated phenol, can be illustrated. In addition, it is preferable that the usage-amount (a) of an organic solvent is the quantity which normally becomes 0.1-30 weight% with respect to the total amount (a + b) of the total reaction solution (a) of the total amount of tetracarboxylic dianhydride and a diamine compound. Do.

[Poor Solvent]

In the organic solvent, alcohols, ketones, esters, ethers, halogenated hydrocarbons, hydrocarbons, and the like, which are poor solvents of polyamic acid, can be used in combination without causing precipitation of the resulting polyamic acid. As an example of such a poor solvent, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1, 4- butanediol, triethylene glycol, ethylene glycol monomethyl ether, ethyl lactate, butyl lactate Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate, 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 hair Ethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o- Dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene, etc. are mentioned.

As described above, a reaction solution obtained by dissolving the polyamic acid is obtained. The reaction solution is poured into a large amount of poor solvent to obtain a precipitate, and the precipitate can be dried under reduced pressure to obtain a polyamic acid. In addition, the polyamic acid can be purified by dissolving the polyamic acid again in an organic solvent and then precipitating with a poor solvent once or several times.

<Imidated Polymer>

The imidation polymer which comprises the liquid crystal aligning agent of this invention can be manufactured by dehydrating and ring-closing the said polyamic acid. The dehydration ring closure of the polyamic acid may be carried out by (i) a method of heating the polyamic acid, or (ii) by dissolving the polyamic acid in an organic solvent, adding a dehydrating agent and a dehydration ring closure catalyst to the solution, and heating it as necessary. Is done.

The reaction temperature in the method of heating the polyamic acid of said (i) is 50-200 degreeC normally, Preferably it is 60-170 degreeC. When reaction temperature is less than 50 degreeC, dehydration ring-closure reaction does not fully advance, and when reaction temperature exceeds 200 degreeC, the molecular weight of the imidation polymer obtained may fall.

On the other hand, in the method of adding the dehydrating agent and the dehydrating ring-closure catalyst in the solution of the polyamic acid of the above (ii), for example, acid anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.01-20 mol with respect to 1 mol of repeating units of a polyamic acid. As the dehydration ring closure catalyst, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used, for example. However, it is not limited to these. It is preferable that the usage-amount of a dehydration ring-closure catalyst shall be 0.01-10 mol with respect to 1 mol of dehydrating agents used. Moreover, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid as an organic solvent used for dehydration ring-closure reaction is mentioned. And the reaction temperature of a dehydration ring-closure reaction is 0-180 degreeC normally, Preferably it is 10-150 degreeC. Moreover, the imidation polymer can be refine | purified by performing the same operation as the purification method of a polyamic acid with respect to the reaction solution obtained in this way.

[Partial imide]

<Imide group containing polyamic acid>

The imide group containing polyamic acid used for this invention has a structure obtained by partially imidating the said polyamic acid, The preferable imidation ratio in the imide group containing polyamic acid used for this invention is 30% or more, More preferably, Is 50% or more. Here, "imidation ratio" shows the ratio of the number of repeating units which form an imide ring with respect to the total number of repeating units in a polymer in%. At this time, part of the imide ring may be an isoimide ring.

As a method for synthesizing an imide group-containing polyamic acid, (i) a method of partially dehydrating and ring-closing by heating the polyamic acid, and (ii) dissolving the polyamic acid in an organic solvent, and dehydrating agent and a dehydrating ring-closure catalyst in this solution A method of partially dehydrating and closing ring synthesis by adding and heating as necessary, or (iii) a method of condensing and synthesizing by mixing tetracarboxylic dianhydride, diamine compound and diisocyanate compound and heating as necessary do.

In the method of (i), the reaction temperature is usually 300 ° C. or lower, preferably 100 to 250 ° C. When reaction temperature exceeds 300 degreeC, the molecular weight of the imide group containing polyamic acid obtained may fall.

On the other hand, as the dehydrating agent used in the method of the above (ii), acid anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride can be used. It is preferable that the usage-amount of a dehydrating agent shall be 0.2-20 mol with respect to 1 mol of repeating units of a polyamic acid. As the dehydration ring closure catalyst, tertiary amines such as pyridine, collidine, lutidine and triethylamine can be used, for example, but not limited thereto. In addition, it is preferable that the usage-amount of an imidation catalyst shall be 0.1-10 mol with respect to 1 mol of dehydrating agents to be used. Moreover, the organic solvent illustrated as what is used for the synthesis | combination of a polyamic acid as an organic solvent used for reaction of dehydration ring closure is mentioned. And the reaction temperature of dehydration ring closure is 0-180 degreeC normally, Preferably it is 60-150 degreeC. Moreover, the imide group containing polyamic acid can be refine | purified by performing the same operation as the purification method of a polyamic acid with respect to the reaction solution obtained in this way.

As a specific example of the diisocyanate compound used by reaction of said (iii), Aliphatic diisocyanate, such as hexamethylene diisocyanate; Cyclohexane-1,2-diisocyanate, 1-methylcyclohexane-2,4-diisocyanate, 1,2-dimethylcyclohexane-ω, ω'-diisocyanate, 1,4-dimethylcyclohexane-ω, ω Alicyclic diisocyanates such as' -diisocyanate, isophorone diisocyanate, 1,3,5-trimethyl-2-propylcyclohexane-1ω, 2ω-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate; Diphenylmethane-4,4'-diisocyanate, 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, 1-methyl-2,4-phenylenediisocyanate, 1-methyl-2,6-phenylenedi Aromatic diisocyanate, such as an isocyanate and the diisocyanate represented by following General formula (22)-(26), is mentioned.

Among them, dicyclohexylmethane-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 1-methyl-2,4-phenylenediisocyanate and 1-methyl-2,6-phenylenedi Isocyanate is mentioned as a preferable thing. These can be used individually or in combination of 2 or more types. In addition, the catalyst of (iii) does not need a catalyst in particular, and reaction temperature is 50-200 degreeC normally, Preferably it is 100-160 degreeC.

[Terminal Formula]

<Polymer of Terminal Modified Type>

The polyamic acid and the imide group-containing polyamic acid may be terminally modified with molecular weight. By using this terminal modified polymer, the coating property of a liquid crystal aligning agent, etc. can be improved, without impairing the effect of this invention. Such terminal-modified form can be synthesized by adding an acid anhydride, a monoamine compound, a monoisocyanate compound and the like to the reaction system when synthesizing the polyamic acid. Here, examples of the acid anhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, n-tetradecylsuccinic anhydride, n-hexadecylsuccinic anhydride, and the like. have. As the monoamine compound, 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 and n- Eicosylamine, etc. are mentioned. Moreover, as a monoisocyanate compound, phenyl isocyanate, naphthyl isocyanate, etc. are mentioned, for example.

Logarithmic viscosity

Logarithmic viscosity of the polymer

The value of the logarithmic viscosity ((eta) _1n ) of the polyamic acid and imide group containing polyamic acid obtained as mentioned above is _0.05-10 dl / g normally, Preferably it is 0.05-5 dl / g.

In the present invention, the value of the logarithmic viscosity (η _1n ) is measured using a N-methyl-2-pyrrolidone as a solvent and the viscosity is measured at 30 ° C for a solution having a concentration of 0.5 g / 100 ml. It is calculated | required by Formula 1.

<Liquid crystal aligning agent>

The liquid crystal aligning agent of this invention is comprised by melt | dissolving and containing the said polymer normally in an organic solvent. Moreover, as a ratio of the repeating unit represented by the said Formula (1a): the repeating unit represented by the said Formula (1b) in the polymer which comprises the liquid crystal aligning agent of this invention, 1: 9-5: 5 are preferable.

As an organic solvent which comprises the liquid crystal aligning agent of this invention, the solvent illustrated as what is used for the synthesis reaction of polyamic acid is mentioned. Moreover, the poor solvent illustrated as what can be used together at the time of the synthesis reaction of polyamic acid can also be selected suitably, and can be used together.

Although solid content concentration in the liquid crystal aligning agent of this invention is selected in consideration of viscosity, volatility, etc., Preferably it is the range of 1 to 10 weight%. That is, although the liquid crystal aligning agent of this invention is apply | coated to the board | substrate surface, and the coating film used as a liquid crystal aligning film is formed, when solid content concentration is less than 1 weight%, the film thickness of this coating film becomes too small and it is difficult to obtain a favorable liquid crystal aligning film. When solid content concentration exceeds 10 weight%, the film thickness of a coating film becomes too large and it is difficult to obtain a favorable liquid crystal aligning film, the viscosity of a liquid crystal aligning agent increases, and application | coating characteristics tend to fall. Moreover, the temperature at the time of manufacturing the liquid crystal aligning agent of this invention becomes like this. Preferably it is 0 degreeC-200 degreeC, More preferably, it is 20 degreeC-60 degreeC.

The liquid crystal aligning agent of this invention contains the compound which has four epoxy groups (henceforth "epoxy group containing compound") in a molecule | numerator at least 2 weight part with respect to 100 weight part of specific polymers.

Examples of the epoxy group-containing compound include 1,3,5,6-tetraglycidyl-2,4-hexanediol, N, N, N ', N',-tetraglycidyl-m-xylenediamine, 1, 3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N, N ', N',-tetraglycidyl-4,4'-diaminodiphenylmethane, N, N, N ', N',-tetraglycidyl-4,4'-diaminodiphenylether, N, N, N ', N',-tetraglycidyl-p-xylenediamine, N, N, N ', N ',-tetraglycidyl-3,4'-diaminodiphenylmethane, N, N, N', N ',-tetraglycidyl-1,3-propanediamine, N, N, N', N ',-tetraglycidyl-4,4'-diaminoheptamethylenediamine, 1,3-bis (N, N-diglycidylaminoethyl) cyclohexane and N, N, N', N ', -Tetraglycidyl-2,2'-dimethyl-4,4'-aminobiphenyl etc. are mentioned as a preferable thing. As content of such an epoxy compound, Preferably it is 2-40 weight part, More preferably, it is 5-30 weight part with respect to 100 weight part of specific polymers contained in an aligning agent.

In addition, the liquid crystal aligning agent of this invention may contain a functional silane containing compound (henceforth a "silane coupling agent"). As a silane coupling agent, what is represented by following General formula (1d) is preferable.

YR ³ SiR _{3 - m} X _m

In the formula, Y is an organic group having an amino group, R ³ is a divalent hydrocarbon group having 1 to 10 carbon atoms, R is an alkyl group having 1 to 5 carbon atoms, and X is represented by an alkoxy group or OCOR ⁵ represented by OR ⁴ An alkoxycarbonyl group (wherein R ⁴ and R ⁵ is an alkyl group having 1 to 10 carbon atoms), and m represents an integer of 1 to 3.

As such a silane coupling agent, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidepropyltrimethoxysilane, 3-ureidepropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilyl Propyltriethylenetriamine, 10-trimethoxysilyl-1,4,7-triadecane, 10-triethoxysilyl-1,4,7-triazadecane, 9-trimethoxysilyl-3,6 -Diazanyl acetate, 9-triethoxysilyl-3,6-diazanyl acetate, N-benzyl-3-aminopropyltrimethoxysilane, N-benzyl-3-amimi Propyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N -Bis (oxyethylene) -3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, methyl 3- [2- (3-trimethoxysilylpropylamino) ethylamino] propionate, and the like Can be mentioned.

The blending ratio of these silane coupling agents is usually 0.01 to 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.5 to 2 parts by weight based on 100 parts by weight of the specific polymer. If it is less than 0.01 weight part, the effect of a printability improvement may become inadequate, and when it exceeds 5 weight part, it may thicken.

<Liquid crystal display element>

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

(1) The liquid crystal aligning agent of this invention is apply | coated to one surface of the board | substrate with which the patterned transparent conductive film is provided by methods, such as a roll coater method, a spinner method, the printing method, and the inkjet method, and then a coating surface is heated. This forms a coating film. Here, as a board | substrate, For example, glass, such as float glass and a soda glass; Transparent substrates containing plastics such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone and polycarbonate can be used. Examples of the transparent conductive film provided on one side of the substrate include an NESA film (registered trademark of PPG Co., Ltd.) containing tin oxide (SnO ₂ ), an ITO film containing indium tin oxide (In ₂ O ₃ -SnO ₂ ), and the like. The transparent conductive film can be used, and the photo-etching method or the method using a preliminary mask is used for patterning of these transparent conductive films. When apply | coating a liquid crystal aligning agent, in order to make adhesiveness of a board | substrate surface, a transparent conductive film, and a coating film more favorable, you may apply | coat a functional silane containing compound, a functional titanium containing compound, etc. previously on the said surface of a board | substrate. The heating temperature after apply | coating a liquid crystal aligning agent is 80-300 degreeC, Preferably it is 120-250 degreeC. In addition, although the liquid crystal aligning agent of this invention containing a polyamic acid forms the coating film used as an oriented film by removing an organic solvent after application | coating, it can also be made into a more imidized coating film by advancing dehydration ring closure by further heating. The film thickness of the coating film formed is normally 0.001-1 micrometer, Preferably it is 0.005-0.5 micrometer.

(2) The rubbing process which rubs a predetermined surface with the roll which wound the cloth containing fibers, such as nylon, rayon, and cotton, is formed, for example. Thereby, the orientation ability of a liquid crystal molecule is provided to a coating film, and it becomes a liquid crystal aligning film.

Furthermore, the liquid crystal aligning film formed by the liquid crystal aligning agent of this invention is free by partially irradiating the ultraviolet-ray as described in Unexamined-Japanese-Patent No. 6-222366 or Unexamined-Japanese-Patent No. 6-281937, for example. A resist film is partially formed on the surface of the liquid crystal alignment film subjected to the treatment for changing the tilt angle or the rubbing treatment described in JP-A-5-107544, and the rubbing treatment is performed in a direction different from the rubbing treatment previously performed. It is possible to improve the field of view characteristics of the liquid crystal display element by performing a process of removing the resist film and then changing the liquid crystal alignment ability of the liquid crystal alignment film after performing the process.

(3) As described above, two substrates on which a liquid crystal alignment film was formed were prepared, and two substrates were arranged to face each other via a gap (cell spacing) such that the rubbing direction in each liquid crystal alignment film was perpendicular or antiparallel. The liquid crystal cells are injected into and filled with liquid crystals within the cell gap partitioned by the bonding, the substrate surface, and the sealing agent using a sealant at the periphery of the two substrates, and the injection holes are sealed. And a liquid crystal display element is obtained by arrange | positioning a polarizing plate in the outer surface of a liquid crystal cell, ie, the transparent substrate side which comprises a liquid crystal cell.

Here, as the sealant, for example, an epoxy resin containing aluminum oxide spheres as a curing agent and a spacer can be used.

Examples of the liquid crystals include nematic liquid crystals and smectic liquid crystals. Among them, nematic liquid crystals are preferable, and for example, a sieve base liquid crystal, a cyanide liquid crystal, a biphenyl liquid crystal, a phenylcyclohexane liquid crystal, an ester liquid crystal, A terphenyl type liquid crystal, a biphenyl cyclohexane type liquid crystal, a pyrimidine type liquid crystal, a dioxane type liquid crystal, a bicyclooctane type liquid crystal, a cuban type liquid crystal, etc. can be used. In addition, these liquid crystals are, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, or trade names "C-15" and "CB-15" (manufactured by Merck Co., Ltd.). The chiral agent sold etc. can also be added and used. In addition, strong dielectric liquid crystals such as p-decyloxybenzilidene-p-amino-2-methylbutylcinnamate can also be used.

Moreover, as a polarizing plate bonded to the outer surface of a liquid crystal cell, the polarizing plate which inserted the polarizing film called H film | membrane which absorbed iodine with the cellulose acetate protective film, or extending | stretching polyvinyl alcohol, and the polarizing plate containing the H film itself are mentioned.

<Example>

Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these Examples. The voltage retention in the Example and the comparative example was evaluated by the following method.

[Voltage retention rate]

After a voltage of 5 V was applied to the liquid crystal display element at an application time of 60 microseconds and a span of 167 milliseconds, the voltage retention after 167 milliseconds from the release of the application was measured. The measurement apparatus used VHR-1 by Toyo Technica Co., Ltd. The case where the voltage retention was 95% or more was judged as good, and the other cases as defective.

Synthesis Example 1

224.17 g (1.0 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride and 108.14 g (1.0 mol) of p-phenylenediamine as a diamine compound It was dissolved in 4,500 g of pig and reacted at 60 ° C for 6 hours. The reaction solution was then injected in very excess methyl alcohol to precipitate the reaction product. Thereafter, the resultant was washed with methyl alcohol and dried at 40 ° C. for 15 hours under reduced pressure, thereby obtaining 380 g of a polyamic acid having a logarithmic viscosity of 0.75 dl / g. 30 g of the obtained polyamic acid was dissolved in 570 g of N-methyl-2-pyrrolidone, 23.4 g of pyridine and 18.1 g of acetic anhydride were added to dehydrate and ring-close at 110 ° C. for 4 hours, and precipitated and washed in the same manner as described above. And pressure reduction to obtain 18.2 g of a polyimide having a logarithmic viscosity of 0.68 dl / g (this is referred to as "polyimide (A-1)").

Synthesis Example 2

In the synthesis example 1, except having used 198.27 g (1.0 mol) of 4,4'- diamino diphenylmethane as a diamine compound, it carried out similarly to the synthesis example 1, and obtained 390 g of polyamic acids of the logarithmic viscosity of 0.55 dl / g. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and ring-close at 110 DEG C for 4 hours, and precipitated and washed in the same manner as described above. And pressure reduction to obtain 20.5 g of a polyimide having a logarithmic viscosity of 0.49 dl / g (this is referred to as "polyimide (A-2)").

Synthesis Example 3

In Synthesis Example 1, except that 200.24 g (1.0 mol) of 4,4'-diaminodiphenyl ether was used as the diamine compound, in the same manner as in Synthesis Example 1, 390 g of a polyamic acid having a logarithmic viscosity of 0.52 dl / g was obtained. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and ring-close at 110 DEG C for 4 hours, and precipitated and washed in the same manner as described above. And pressure reduction to obtain 18.5 g of a polyimide having a logarithmic viscosity of 0.48 dl / g (this is referred to as "polyimide (A-3)").

Synthesis Example 4

In Synthesis Example 1, the logarithmic viscosity was the same as in Synthesis Example 1, except that 75.69 g (0.7 mol) of p-phenylenediamine and 59.48 g (0.3 mol) of 4,4'-diaminodiphenylmethane were used as the diamine compound. 390 g of 0.56 dL / g polyamic acid was obtained. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and ring-close at 110 DEG C for 4 hours, and precipitated and washed in the same manner as described above. And pressure reduction to obtain 17.5 g of a polyimide having a logarithmic viscosity of 0.50 dl / g (this is referred to as "polyimide (A-4)").

Synthesis Example 5

In Synthesis Example 1, the logarithmic viscosity was the same as in Synthesis Example 1 except that 86.51 g (0.8 mol) of p-phenylenediamine and 40.04 g (0.2 mol) of 4,4'-diaminodiphenyl ether were used as the diamine compound. 390 g of polyamic acid of 0.70 dL / g were obtained. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, and 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and close the ring for 4 hours at 110 ° C. And pressure reduction to obtain 19.8 g of a polyimide having a logarithmic viscosity of 0.61 dl / g (this is referred to as "polyimide (A-5)").

Synthesis Example 6

In Synthesis Example 1, 112.08 g (0.5 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-8-methyl -5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157.14 g (0.5 mol), p-phenylene as a diamine compound Except having used 108.14 g (1.0 mol) of diamines, it carried out similarly to the synthesis example 1, and obtained 390 g of polyamic acids with a logarithmic viscosity of 0.8 dl / g. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, and 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and close the ring for 4 hours at 110 ° C. And pressure reduction to obtain 18.3 g of a polyimide having a logarithmic viscosity of 0.68 dl / g (this is referred to as "polyimide (A-6)").

Synthesis Example 7

Synthesis example 1 except that 86.51 g (0.8 mol) of p-phenylenediamine and 82.1 g (0.2 mol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane were used as the diamine compound. In the same manner as in 1, 390 g of a polyamic acid having a logarithmic viscosity of 0.61 dl / g was obtained. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and ring-close at 110 DEG C for 4 hours, and precipitated and washed in the same manner as described above. And pressure reduction to obtain 19.2 g of a polyimide having a logarithmic viscosity of 0.53 dl / g (this is referred to as "polyimide (A-7)").

Synthesis Example 8

In Synthesis Example 1, 112.08 g (0.5 mol) of 2,3,5-tricarboxycyclopentylacetic dianhydride as tetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5-methyl -5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione 157.14 g (0.5 mol), p-phenylene as a diamine compound Except for using diamine 95.71 g (0.885 mole), bisaminopropyltetramethyldisiloxane 24.85 g (0.1 mole), and 2.793 g (0.03 mole) of aniline as a monoamine, the logarithm viscosity was 0.85 dl / g 390 g of polyamic acids were obtained. 30 g of the obtained polyamic acid is dissolved in 570 g of N-methyl-2-pyrrolidone, and 5.7 g of pyridine and 7.4 g of acetic anhydride are added to dehydrate and close the ring for 4 hours at 110 ° C. And pressure reduction to obtain 18.5 g of a polyimide having a logarithmic viscosity of 0.70 dl / g (this is referred to as "polyimide (A-8)").

Example 1

) 길이 0.4 ㎜로 하였다.(이 기판을 기판 A로 함)100 parts by weight of polyimide (A-1) obtained in Synthesis Example 1 and 10 parts by weight of N, N, N ', N'-tetra-4,4'-glycidyl-diaminodiphenylmethane, and further methyl 0.75 parts by weight of 3- [2- (3-trimethoxysilylpropylamino) ethylamino] propionate was dissolved in γ-butyrolactone / N-methyl-2-pyrrolidone mixed solvent (weight ratio 90/10) After stirring sufficiently as a solution of 4 weight% of solid content concentration, this solution was filtered using the filter of 1 micrometer of pore diameters, and the liquid crystal aligning agent of this invention was manufactured. The liquid crystal aligning agent of this invention manufactured as mentioned above was apply | coated using a spinner on the transparent conductive film containing the ITO film | membrane provided in the comb-tooth shape on one side of the glass substrate of thickness 1mm using a spinner, and it is 1 hour at 180 degreeC. By drying, a film having a dry film thickness of 0.08 mu m was formed. The rubbing process was performed using the rubbing machine which has the roll which wound the cloth made of nylon on the formed coating film surface, and it was set as the liquid crystal aligning film. Here, the rubbing treatment conditions are the rotation speed of the roll 400 rpm, the moving speed of the stage 3 cm / sec, the mother foot indentation (毛 足 狎)

) 0.4 mm in length. (This substrate is referred to as substrate A)

On one side of the glass substrate having a thickness of 1 mm, the liquid crystal aligning agent of the present invention prepared as described above was applied using a spinner, and dried at 180 ° C. for 1 hour to form a film having a dry film thickness of 0.08 μm. . When the board | substrate was observed under the microscope of 20 times magnification, the printing spot and the pinhole were not observed and printability was favorable.

The rubbing process was performed using the rubbing machine which has the roll which wound the cloth made of nylon on the formed coating film surface, and it was set as the liquid crystal aligning film. Here, the rubbing treatment conditions were set at 400 rpm of the roll speed, 3 cm / sec of the moving speed of the stage, and 0.4 mm of the seedling press-in length.

After the epoxy resin adhesive containing 17 micrometers diameter aluminum oxide sphere was apply | coated to the outer edge part of the coating film surface of board | substrate A and B by screen printing, two board | substrates so that the rubbing direction in each liquid crystal aligning film may be antiparallel. Were disposed to face each other via a gap, and the outer edge portions were bonded to each other and pressed to cure the adhesive.

Subsequently, after filling a nematic liquid crystal (MLC-2019 by Merck Co., Ltd.) between a pair of board | substrates from a liquid crystal inlet, the liquid crystal inlet is sealed with an epoxy adhesive, and the polarizing direction of a polarizing plate is carried out on both sides of a board | substrate outside. It bonded together so that it might correspond to the rubbing direction of the liquid crystal aligning film of each board | substrate, and manufactured the liquid crystal display element.

The voltage retention of the obtained liquid crystal display element was evaluated. The voltage retention showed a good value of 95% or more, and contrast unevenness and display defects after voltage application were not observed.

Examples 2 to 8 and Comparative Examples 1 to 3

The polyimides (A-2) to (A-8) obtained in Synthesis Examples 2 to 8, various epoxy group-containing compounds and silane coupling agents were dissolved in a mixed solvent containing γ-butyrolactone as a main component and a solution having a solid content of 4.0%. The liquid crystal aligning agent of this invention is adjusted by filtering this solution with the filter of 1 micrometer of pore diameters, forming a film on the board | substrate similarly to Example 1, and observing the presence or absence of a printing stain and a pinhole, and further liquid crystal display The device was fabricated to evaluate the voltage retention. The results are shown in Table 1.

According to the liquid crystal aligning agent of this invention, when printing and apply | coating to organic films, such as a protective film, the liquid crystal aligning film suitable for the transverse electric field type liquid crystal display element which printability is favorable and excellent in voltage retention is obtained, without print unevenness and pinholes.

Moreover, the liquid crystal display element which has the alignment film formed using the liquid crystal aligning agent of this invention is excellent in the orientation and reliability of a liquid crystal, and can be used effectively for various apparatuses, For example, a table calculator, a wristwatch, a table clock, It is used for display devices, such as a coefficient display board, a word processor, a personal computer, and a liquid crystal television.

Claims (5)

(A) A transverse electric field liquid crystal display device comprising a polymer having a repeating unit represented by the following formula (1a) and a repeating unit represented by the following formula (1b), a compound having four epoxy groups in the molecule, and a functional silane compound Liquid crystal aligning agent. <Formula 1a>

<Formula 1b>

In the formula, P ¹ is a tetravalent organic group, Q ¹ is a divalent organic group, P ² is a tetravalent organic group different from P ^1, and Q ² is a divalent organic group. The liquid crystal aligning agent for a transverse electric field type liquid crystal display device according to claim 1, wherein the compound having four epoxy groups in the molecule is at least one epoxy-containing compound selected from the group consisting of compounds represented by the following general formula (1c).

In the formula, R ² represents a divalent organic group. The liquid crystal aligning agent for a transverse electric field liquid crystal display device according to claim 1, wherein the functional silane compound is a silane coupling agent selected from the group consisting of compounds represented by the following general formula (1d). <Formula 1d> YR ³ SiR _{3 - m} X _m In the formula, Y is an organic group having an amino group, R ³ is a divalent hydrocarbon group having 1 to 10 carbon atoms, R is an alkyl group having 1 to 5 carbon atoms, and X is represented by an alkoxy group or OCOR ⁵ represented by OR ⁴ An alkoxycarbonyl group (wherein R ⁴ and R ⁵ is an alkyl group having 1 to 10 carbon atoms), and m represents an integer of 1 to 3. The tetracarboxylic dianhydride according to any one of claims 1 to 3, wherein the tetracarboxylic dianhydride providing the polymer (A) is 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl. -1,2,3,4-cyclobutanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- ( Tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione or 1,3,3a, 4,5,9b-hexahydro-8- Transverse electric field comprising any one of methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione and pyromellitic anhydride Liquid crystal aligning agent for liquid crystal display elements. The liquid crystal aligning film formed from the liquid crystal aligning agent in any one of Claims 1-4 is provided, The transverse electric field system liquid crystal display element characterized by the above-mentioned.