JP2003073471A - Vertically aligning-type liquid crystal aligner and liquid crystal display element using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vertically aligning-type liquid crystal aligner having excellent vertical alignability, giving short erasing time of an afterimage of a liquid crystal display element, and preferably used for a liquid crystal display element of EVA system or of photo-aligning system photo-aligning by polarized UV-ray irradiation, and a liquid crystal display element using the aligner. SOLUTION: This vertically aligning-type liquid crystal aligner comprises a polyamic acid and/or imidized polymer thereof containing a specific structure diamine.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vertical alignment type liquid crystal aligning agent and a liquid crystal display device using the same. More specifically, the vertical alignment property, the printability, the afterimage erasing time of the liquid crystal display element are short, and the EVA (Electrically tilted Vertical A
The present invention relates to a vertical alignment type liquid crystal aligning agent, which is particularly suitable for a photo alignment vertical alignment type liquid crystal display device in which a liquid crystal alignment film is aligned by irradiating polarized ultraviolet rays.

[0002]

2. Description of the Related Art At present, as a liquid crystal display element, a liquid crystal alignment film made of polyamic acid, polyimide or the like is formed on the surface of a substrate provided with a transparent conductive film to form a liquid crystal display element substrate, and two of them are opposed to each other. A layer of a nematic liquid crystal having a positive dielectric anisotropy is formed in the gap to form a cell having a sandwich structure, and the long axis of the liquid crystal molecules is continuously moved from one substrate to the other substrate. The so-called TN (Twisted Nemati)
A TN type liquid crystal display device having a c) type liquid crystal cell is known. In addition, the contrast is higher than that of the TN type liquid crystal display element, and the STN (Super
A Twisted Nematic) type liquid crystal display element and a vertical alignment type liquid crystal display element have been developed. This S
The TN type liquid crystal display device uses a nematic type liquid crystal blended with a chiral agent which is an optically active substance as a liquid crystal, and the long axis of the liquid crystal molecule is continuously twisted between the substrates over 180 degrees. It utilizes the resulting birefringence effect. For these, "liquid crystal" vo
l. 3 No. EV that controls the orientation direction by devising an electrode structure as described in 4 272 (1999)
Method A, "JpnAppl.phys." Vol36
428 (1997), there is proposed a vertical alignment type liquid crystal display element such as a photo alignment method in which an alignment film is modified by light irradiation to control the alignment direction. These vertical alignment type liquid crystal display elements are excellent in terms of manufacturing process, such as excellent viewing angle and contrast, and no need for rubbing treatment in forming the liquid crystal alignment film. However, the performance is still insufficient as compared with the above-mentioned TN type and STN type liquid crystal display elements, and in particular, the vertical alignment property,
There is a demand for improving the performance of liquid crystal display elements with respect to the afterimage erasing time.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a liquid crystal display device having excellent vertical alignment properties and a short afterimage erasing time.
A vertical alignment type liquid crystal aligning agent suitable for use in a VA type liquid crystal display device and a photo alignment type liquid crystal display device which is optically aligned by irradiation of polarized ultraviolet rays, and a liquid crystal display device using the same. Other objects and advantages of the present invention will be apparent from the following description.

[0004]

According to the present invention, the above objects and advantages of the present invention are achieved by a repeating unit represented by the following formula (I-1) and a repeating unit represented by the following formula (I-2). A vertical alignment type liquid crystal aligning agent comprising a polymer having at least one repeating unit selected from the units (hereinafter, also referred to as “specific polymer”).

[0005]

[Chemical 5]

(In the formula, P ¹ is a tetravalent organic group, and Q ^{1 is}
Is a group represented by the following formula (Q-1) or (Q-2). )

[0007]

[Chemical 6]

(In the formula, P ² is a tetravalent organic group, and Q ²
Is a group represented by the following formula (Q-1) or (Q-2). )

[0009]

[Chemical 7]

(In the formula, X is --O--, --CO--, --COO.
-, -OCO-, -NHCO-, -CONH-, -S
-, A methylene group, a divalent group selected from an alkylene group having 2 to 6 carbon atoms and a phenylene group, and R ¹ represents an alkyl group having 10 to 20 carbon atoms and an alicyclic skeleton having 4 to 40 carbon atoms. A monovalent organic group having or a monovalent organic group having a fluorine atom having 6 or more carbon atoms. )

[0011]

[Chemical 8]

(In the formula, X is --O--, --CO--, --COO.
-, -OCO-, -NHCO-, -CONH-, -S
-, A methylene group, an alkylene group having 2 to 6 carbon atoms and a phenylene group, and R ² is a divalent organic group having an alicyclic skeleton having 4 to 40 carbon atoms. )

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The vertical alignment type liquid crystal aligning agent of the present invention (hereinafter, also simply referred to as “liquid crystal aligning agent”) is formed by dissolving a specific polymer in an organic solvent. The specific polymer is a polyamic acid or an imidized polymer having a structure obtained by dehydration ring closure (imidization) of the polyamic acid. Even if the imidized polymer is a 100% dehydrated ring-closed (imidized) polyimide, it is partially dehydrated ring-closed (imidized).
It may be a polymer prepared by Further, the liquid crystal aligning agent of the present invention may contain both a polyamic acid and an imidized polymer. The polymer component of the liquid crystal aligning agent of the present invention preferably has the repeating unit represented by the above formula (Q-1) in an amount of 5 mol% or more based on all repeating units.

[Polyamic acid] <Tetracarboxylic acid dianhydride> As the tetracarboxylic acid dianhydride used in the synthesis of the above polyamic acid, an alicyclic tetracarboxylic acid dianhydride is preferable. Specific examples of the alicyclic tetracarboxylic dianhydride include, for example, 1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,2-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,3-dichloro- 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4 -Cyclopentanetetracarboxylic dianhydride, 1,2,4,5
-Cyclohexanetetracarboxylic dianhydride, 3,3 ',
4,4′-dicyclohexyltetracarboxylic acid dianhydride, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic acid dianhydride, 2,3,
5-tricarboxycyclopentyl acetic acid dianhydride, 3,
5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-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, 1,3,3a, 4,5,9b- Hexahydro-5-methyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-
1,3-dione, 1,3,3a, 4,5,9b-hexahydro-5-ethyl-5 (tetrahydro-2,5-dioxo-
3-furanyl) -naphtho [1,2-c] -furan-1,3
-Dione, 1,3,3a, 4,5,9b-hexahydro-7
-Methyl-5 (tetrahydro-2,5-dioxo-3-
Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-7-ethyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione, 1,3,3a, 4,5,9b-hexahydro-8-methyl-5 (tetrahydro-2,5-dioxo-3- Furanyl) -naphtho [1,2-c] -furan-1,3-dione,
1,3,3a, 4,5,9b-hexahydro-8-ethyl-
5 (tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] -furan-1,3-dione, 1,
3,3a, 4,5,9b-hexahydro-5,8-dimethyl-5 (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] -furan-1,3-dione,
5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, bicyclo [2,2,2] -oct-7-ene-2,
3,5,6-Tetracarboxylic acid dianhydride, 3-oxabicyclo [3,2,1] octane-2,4-dione-6-spiro-3 '-(tetrahydrofuran-2', 5'-dione) And compounds represented by the following formulas (I) and (II).

[0015]

[Chemical 9]

(In the formula, R ³ and R ⁵ represent a divalent organic group having an aromatic ring, R ⁴ and R ⁶ represent a hydrogen atom or an alkyl group, and a plurality of R ⁴ and R ⁶ are present. , Each may be the same or different.)

Other tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides such as butanetetracarboxylic dianhydride; pyromellitic dianhydride, 3,
3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3', 4,4'-dimethyldiphenylsilanetetra Carboxylic dianhydride, 3,
3 ', 4,4'-tetraphenylsilane tetracarboxylic acid dianhydride, 1,2,3,4-furan tetracarboxylic acid dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl Sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ', 4,
4'-perfluoroisopropylidene diphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis ( Triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid)-
4,4′-diphenyl ether dianhydride, bis (triphenylphthalic acid) -4,4′-diphenylmethane dianhydride, ethylene glycol-bis (anhydrotrimellitate), propylene glycol-bis (anhydrotrimellitate) ) 1,4-butanediol-bis (anhydrotrimeritate), 1,6-hexanediol-bis (anhydrotrimeritate), 1,8-octanediol-bis (anhydrotrimeritate), 2,2-
Examples thereof include aromatic tetracarboxylic dianhydrides such as bis (4-hydroxyphenyl) propane-bis (anhydrotrimellitate) and compounds represented by the following formulas (1) to (4). These may be used alone or in combination of two or more.

[0018]

[Chemical 10]

Of the above alicyclic tetracarboxylic acid dianhydrides, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid Dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2, 3,5-Tricarboxycyclopentyl acetic acid dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, cis-3,7-dibutyl Cycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-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] -oct-
7-ene-2,3,5,6-tetracarboxylic dianhydride,
3-Oxabicyclo [3,2,1] octane-2,4-
Dione-6-spiro-3 '-(tetrahydrofuran-
2 ′, 5′-dione), among the compounds represented by the above formula (I), compounds represented by the following formulas (5) to (7) and among the compounds represented by the above formula (II), the following formulas The compound represented by (8) is preferable from the viewpoint of exhibiting good liquid crystal alignment, and particularly preferable is 1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
1,3-Dimethyl-1,2,3,4-cyclobutanetetracarboxylic 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, cis-3,7-dibutylcycloocta-1,5-diene-1,2,5,6-tetracarboxylic dianhydride, Three, five,
6-tricarbonyl-2-carboxynorbornane-
2: 3,5: 6-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, 3-oxabicyclo [3,2,2]
1] Octane-2,4-dione-6-spiro-3'-
(Tetrahydrofuran-2 ′, 5′-dione) and the compound represented by the following formula (5) can be given.

[0020]

[Chemical 11]

Among the other tetracarboxylic acid dianhydrides, butanetetracarboxylic acid dianhydride, pyromellitic acid dianhydride and 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride are preferable. One, three, three ', four,
4'-biphenyl sulfone tetracarboxylic acid dianhydride,
1,4,5,8-naphthalenetetracarboxylic dianhydride and the like can be mentioned. Of these tetracarboxylic acid dianhydrides, the alicyclic tetracarboxylic acid dianhydride is preferably 50 mol% or more based on the total tetracarboxylic acid dianhydride.

<Diamine> The groups represented by the above formula (Q-1) and the above formula (Q-2) are groups derived from a diamine which synthesizes a polyamic acid. Hereinafter, the diamine having a group represented by the formula (Q-1) or the formula (Q-2) is also referred to as "specific diamine". In the above formula (Q-1), as the alkyl group having 10 to 20 carbon atoms represented by R ¹ , for example, n-decyl group, n-dodecyl group, n-
Pentadecyl group, n-hexadecyl group, n-octadecyl group, n-eicosyl group and the like can be mentioned. Examples of the organic group having an alicyclic skeleton having 4 to 40 carbon atoms, which is represented by R ¹ in the formula (Q-1) and R ² in the formula (Q-2), include, for example, cyclobutane and cyclopentane. , A group having an alicyclic skeleton derived from a cycloalkane such as cyclohexane and cyclodecane; a group having a steroid skeleton such as cholesterol and cholestanol; a group having a bridged alicyclic skeleton such as norbornene and adamantane. Among these, particularly preferably n-
An octadecyl group, a group having an alicyclic skeleton derived from cyclohexane, and a group having a steroid skeleton. The organic group having an alicyclic skeleton may be a group substituted with a halogen atom, preferably a fluorine atom.

Further, the group having a fluorine atom having 6 or more carbon atoms represented by R ¹ in the above formula (Q-1) includes, for example, n-hexyl group, n-octyl group, n-decyl group and the like. A straight-chain alkyl group having 6 or more carbon atoms; an alicyclic hydrocarbon group having 6 or more carbon atoms such as cyclohexyl group and cyclooctyl group; an aromatic hydrocarbon group having 6 or more carbon atoms such as phenyl group and biphenyl group A group in which a part or all of hydrogen atoms in the organic group are substituted with a fluorine atom or a fluoroalkyl group can be mentioned.

Further, the above formula (Q-1) and the above formula (Q
As the divalent organic group represented by X in -2),-
O-, -COO-, -OCO-, -NHCO-, -CO
NH-, -CO-, a methylene group, an alkylene group having 2 to 6 carbon atoms and a phenylene group, and among these, a group represented by -O-, -COO-, or -OCO- is particularly preferable.

Specific examples of the diamine having a group represented by the above formula (Q-1) include dodecanoxy-2,4-diaminobenzene, pentadecanoxy-2,4-diaminobenzene, hexadecanooxy-2,4-diaminobenzene. , Octadecanoxy-2,4-diaminobenzene and compounds represented by the following formulas (9) to (16) can be mentioned as preferable ones.

[0026]

[Chemical 12]

Further, specific examples of the diamine having a group represented by the above formula (Q-2) include the following formulas (17) to (2).
The diamine represented by 1) can be mentioned as a preferable example.

[0028]

[Chemical 13]

In the synthesis of the polyamic acid used in the present invention, another diamine compound may be used in combination to the extent that the effects of the present invention are not impaired. Examples of other diamine compounds include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl sulfide, 4,4′-diamino. Diphenyl sulfone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 4,
4'-diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl)-
1,3,3-trimethylindane, 6-amino-1-
(4'-Aminophenyl) -1,3,3-trimethylindane, 3,4'-diaminodiphenyl ether, 3,3 '
-Diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 2,2-
Bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2 , 2-bis [4- (4-aminophenoxy) phenyl] sulfone,
1,4-bis (4-aminophenoxy) benzene, 1,3
-Bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) -10-hydroanthracene,
2,7-diaminofluorene, 9,9-bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2
-Chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-
4,4'-diamino-5,5'-dimethoxybiphenyl,
3,3'-dimethoxy-4,4'-diaminobiphenyl,
1,4,4 '-(p-phenylene isopropylidene) bisaniline, 4,4'-(m-phenylene isopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) ) Phenyl] hexafluoropropane, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-bis [(4-amino-2-trifluoromethyl) phenoxy] -octafluoro Aromatic diamines such as biphenyl;

1,1-meta-xylylenediamine, 1,3-
Propanediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine,
1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine,
Aliphatic and cycloaliphatic diamines such as hexahydro-4,7-methanoindanylene dimethylene diamine, tricyclo [6.2.1.02,7] -undecylenedimethyl diamine, 4,4'-methylene bis (cyclohexyl amine);

2,3-diaminopyridine, 2,6-diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 5,6-diamino-2,3-dicyanopyrazine, 5,6-diamino- 2,4-dihydroxypyrimidine, 2,4-diamino-6-dimethylamino-1,3,5
-Triazine, 1,4-bis (3-aminopropyl) piperazine, 2,4-diamino-6-isopropoxy-1,
3,5-triazine, 2,4-diamino-6-methoxy-
1,3,5-triazine, 2,4-diamino-6-phenyl-1,3,5-triazine, 2,4-diamino-6-methyl-s-triazine, 2,4-diamino-1,3, 5-
Triazine, 4,6-diamino-2-vinyl-s-triazine, 2,4-diamino-5-phenylthiazole,
2,6-diaminopurine, 5,6-diamino-1,3-dimethyluracil, 3,5-diamino-1,2,4-triazole, 6,9-diamino-2-ethoxyacridine lactate, 3,8- Two primary amino groups in the molecule such as diamino-6-phenylphenanthridine, 1,4-diaminopiperazine, 3,6-diaminoacridine, bis (4-aminophenyl) phenylamine and the primary amino group A diamine having a nitrogen atom other than the following formula (II
Examples thereof include diaminoorganosiloxane represented by I).

[0032]

[Chemical 14]

(In the formula, R ⁷ represents a hydrocarbon group having 1 to 12 carbon atoms, a plurality of R ^7's may be the same or different, p is an integer of 1 to 3, and q is 1-2
It is an integer of 0. )

These diamine compounds may be used alone or in combination of two or more.

Of these, p-phenylenediamine,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 1,5-diaminonaphthalene, 2,7-diaminofluorene, 4,4'-diaminodiphenyl ether, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis [4- (4-
Aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4 ′-(p-phenylenediisopropylidene) bisaniline, 4,4 ′-(m-phenylenedipropyi) Ridene) bisaniline, 1,4-cyclohexanediamine, 4,4'-methylenebis (cyclohexylamine), 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, 2 , 6-Diaminopyridine, 3,4-diaminopyridine, 2,4-diaminopyrimidine, 3,6-diaminoacridine and the like are preferable.

The proportion of the specific diamine in the total diamine components in all the polymers contained in the liquid crystal aligning agent of the present invention is preferably 5 mol% or more, more preferably 10 mol%, based on the total amount of diamine components. That is all. If this usage ratio is less than 5 mol%, a sufficient effect may not be obtained in the vertical alignment property.

<Synthesis of polyamic acid> The ratio of tetracarboxylic dianhydride and diamine used in the synthesis reaction of polyamic acid is such that the acid anhydride of tetracarboxylic dianhydride is equivalent to 1 equivalent of amino group of diamine. The basis is 0.2-
A ratio of 2 equivalents is preferable, and 0.3 is more preferable.
It is a ratio of about 1.2 equivalents. The reaction for synthesizing polyamic acid is usually -20 ° C to 150 ° C in an organic solvent.
It is carried out under a temperature condition of 0 ° C, preferably 0 to 100 ° C.

The organic solvent is not particularly limited as long as it can dissolve the polyamic acid to be synthesized. For example, 1-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide. Aprotic polar solvents such as dimethyl sulfoxide, γ-butyrolactone, tetramethylurea and hexamethylphosphortriamide; and phenolic solvents such as m-cresol, xylenol, phenol and halogenated phenol. Further, the amount (α) of the organic solvent used is usually the total amount (β) of the tetracarboxylic dianhydride and the diamine compound, and the total amount (α + β) of the reaction solution.
It is preferable that the amount is 0.1 to 30% by weight with respect to.

The organic solvent includes alcohols, ketones, esters, which are poor solvents for polyamic acid,
Ethers, halogenated hydrocarbons, hydrocarbons and the like can be used in combination so long as the polyamic acid to be produced does not precipitate. Specific examples of such a poor solvent include, for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, 4-hydroxy-4.
-Methyl-2-pentanone, 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 monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran,
Dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-
Examples thereof include dichlorobenzene, hexane, heptane, octane, benzene, toluene and xylene.

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

<Dehydration Ring Closure Reaction> The specific polymer constituting the liquid crystal aligning agent of the present invention can be synthesized by dehydration ring closure of a part or all of the polyamic acid.
In the specific polymer used in the present invention, the proportion of repeating units having an imide ring in all repeating units (hereinafter, also referred to as "imidization ratio") is 40 mol% or more, preferably 5
It is 0 mol% or more. By using a polymer having an imidization ratio of 40 mol% or more, a liquid crystal aligning agent capable of forming a liquid crystal aligning film having a short afterimage erasing time can be obtained.

The dehydration ring closure of the polyamic acid is carried out by (i) heating the polyamic acid or (ii) dissolving the polyamic acid in an organic solvent, and adding a dehydrating agent and a dehydration ring-closing catalyst to this solution, if necessary. It is carried out by a method of heating. The reaction temperature in the method of heating the polyamic acid (i) is preferably 50 to 200 ° C, more preferably 60 to 170 ° C. If the reaction temperature is lower than 50 ° C, the dehydration ring closure reaction may not proceed sufficiently, and if the reaction temperature exceeds 200 ° C, the molecular weight of the imidized polymer obtained may decrease. On the other hand, in the method (ii) of adding a dehydrating agent and a dehydration ring-closing catalyst to the solution of polyamic acid, as the dehydrating agent, for example, an acid anhydride such as acetic anhydride, propionic anhydride, or trifluoroacetic anhydride should be used. You can The amount of the dehydrating agent used depends on the desired imidization ratio, but it is preferably 0.01 to 20 mol per 1 mol of the repeating unit of the polyamic acid. Further, as the dehydration ring-closing catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, triethylamine and the like can be used. However, it is not limited to these. The amount of the dehydration ring-closing catalyst used is preferably 0.01 to 10 mol per 1 mol of the dehydrating agent used. The imidization ratio can be increased as the amount of the dehydrating agent and dehydrating ring-closing agent used increases. Examples of the organic solvent used for the dehydration ring-closing reaction include the organic solvents exemplified as those used for the synthesis of polyamic acid. The reaction temperature for the dehydration ring closure reaction is preferably 0.
˜180 ° C., and more preferably 10˜150 ° C. The specific polymer obtained can be purified by performing the same operation as in the method for purifying a polyamic acid on the reaction solution thus obtained.

<End-Modified Polymer> The specific polymer used in the present invention may be a terminal-modified type polymer having a controlled molecular weight. By using this terminal-modified polymer, the coating properties of the liquid crystal aligning agent can be improved without impairing the effects of the present invention. Such a terminal-modified polymer can be synthesized by adding an acid monoanhydride, a monoamine compound, a monoisocyanate compound or the like to the reaction system when synthesizing the polyamic acid. Here, examples of the acid monoanhydride include maleic anhydride, phthalic anhydride, itaconic anhydride, n-decylsuccinic anhydride, n-dodecylsuccinic anhydride, and n-tetradecylsuccinic anhydride. , N-hexadecyl succinic acid anhydride and the like. Examples of the monoamine compound include aniline, cyclohexylamine, n-butylamine, n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-undecylamine. , N-dodecylamine, n-tridecylamine, n-tetradecylamine,
n-pentadecylamine, n-hexadecylamine, n
-Heptadecylamine, n-octadecylamine, n-
Examples thereof include eicosylamine. Examples of monoisocyanate compounds include phenyl isocyanate and naphthyl isocyanate.

<Logarithmic Viscosity of Polymer> The polyamic acid obtained as described above has a logarithmic viscosity (η _ln ) value of preferably from 0.05 to 10 dl / g, more preferably from 0.0 to 10 dl / g.
It is 05-5 dl / g. The logarithmic viscosity (η
The value of _ln ) is determined by the following formula (i) by measuring the viscosity of a solution having a concentration of 0.5 g / 100 ml using N-methyl-2-pyrrolidone as a solvent at 30 ° C. .

[0045]

[Liquid Crystal Alignment Agent] The liquid crystal alignment agent of the present invention is usually constituted by dissolving and containing the above-mentioned specific polymer in an organic solvent. The temperature when preparing the liquid crystal aligning agent of the present invention,
It is preferably 0 ° C to 200 ° C, more preferably 20 ° C.
C to 60C.

Examples of the organic solvent constituting the liquid crystal aligning agent of the present invention include 1-methyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, N, N-dimethylformamide, N, N-dimethylacetamide, and -Hydroxy-4-methyl-2-pentanone, ethylene glycol monomethyl ether, butyl lactate, butyl acetate,
Methyl methoxy propionate, ethyl ethoxy propionate, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n
-Propyl ether, ethylene glycol-i-propyl ether, ethylene glycol-n-butyl ether (butyl cellosolve), 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 Examples thereof include ether acetate and diethylene glycol monoethyl ether acetate.

The solid content concentration in the liquid crystal aligning agent of the present invention is selected in consideration of viscosity, volatility, etc., but is preferably in the range of 1 to 10% by weight. That is, the liquid crystal aligning agent of the present invention is applied to the surface of a substrate to form a coating film which becomes a liquid crystal aligning film, but when the solid content concentration is less than 1% by weight, the film thickness of this coating film is If it is too small to obtain a good liquid crystal alignment film, and if the solid content concentration exceeds 10% by weight, the film thickness of the coating film becomes too large to obtain a good liquid crystal alignment film. In addition, the viscosity of the liquid crystal aligning agent increases, and the coating characteristics deteriorate.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound and an epoxy compound from the viewpoint of improving the adhesiveness to the substrate surface within a range that does not impair the desired physical properties. Examples of such a functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, N- (2-aminoethyl). -3-
Aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3-aminopropyltrimethoxysilane Silane, N-
Ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 10-trimethoxysilyl-1,4,7
-Triazadecane, 10-triethoxysilyl-1,4,
7-triazadecane, 9-trimethoxysilyl-3,6
-Diazanonyl acetate, 9-triethoxysilyl-
3,6-diazanonyl acetate, N-benzyl-3-
Aminopropyltrimethoxysilane, N-benzyl-3
-Aminopropyltriethoxysilane, N-phenyl-
3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, N-bis (oxyethylene) -3-aminopropyltrimethoxysilane, N-bis (oxyethylene) -3-aminopropyltriethoxy Silane etc. can be mentioned. Examples of such epoxy compounds include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether,
1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, 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, 3- (N
Examples include -allyl-N-glycidyl) aminopropyltrimethoxysilane and 3- (N, N-diglycidyl) aminopropyltrimethoxysilane.

<Liquid Crystal Display Element> A liquid crystal display element obtained by using the liquid crystal aligning agent of the present invention can be produced, for example, by the following method. (1) The liquid crystal aligning agent of the present invention is applied to one surface of a substrate provided with a patterned transparent conductive film by a method such as a roll coater method, a spinner method or a printing method, and then the applied surface is heated. By doing so, a film is formed. Here, as the substrate, for example, a glass such as float glass or soda glass; a transparent substrate made of plastic such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone or polycarbonate can be used. Further, as the transparent conductive film provided on one surface of the substrate, a NESA film made of tin oxide (SnO ₂ ) (registered trademark of PPG Co., USA) and an ITO made of indium oxide-tin oxide (In ₂ O ₃ —SnO ₂ ).
A film or the like can be used, and a photo-etching method or a method using a mask in advance is used for patterning these transparent conductive films. Furthermore, a liquid crystal display element with improved viewing angle dependency can be obtained by forming a protrusion structure on the substrate to define the alignment direction of the liquid crystal or forming a slit in the electrode. When applying the liquid crystal aligning agent, in order to further improve the adhesiveness between the substrate surface and the transparent conductive film and the film of the liquid crystal aligning agent, a functional silane-containing compound, a functional titanium-containing compound or the like is formed on the surface of the substrate. Can also be applied in advance. The heating temperature is 8
The temperature is set to 0 to 250 ° C., preferably 120 to 200 ° C. The film thickness of the formed film is usually 0.001 to 1 μm.
m, and preferably 0.005 to 0.5 μm.
The liquid crystal aligning agent of the present invention forms a film to be a liquid crystal aligning film by removing the organic solvent after coating,
By further heating, dehydration ring closure can proceed to form a partially or completely imidized film.

(2) A liquid crystal aligning ability is imparted to the surface of the formed coating film. As the method, for example, a method of rubbing in which a cloth made of fibers such as nylon, rayon, and cotton is rubbed in a certain direction with a roll, or a coating surface is irradiated with polarized ultraviolet rays, an ion beam, an electron beam, or the like, and oriented. A method of imparting the ability is preferably used. Alternatively, the liquid crystal alignment film can be formed by a method of obtaining a film by a uniaxial stretching method, a Langmuir-Blodgett method, or the like. It is preferable to wash the formed liquid crystal alignment film with isopropyl alcohol or the like in order to remove fine powder (foreign matter) generated during the rubbing treatment to keep the surface clean. Further, a treatment for changing the pretilt angle by partially irradiating the surface of the formed liquid crystal alignment film with an ultraviolet ray, an ion beam, an electron beam or the like (for example, JP-A-6-222366 and JP-A-6-28193).
Japanese Patent Laid-Open No. 7-168187, Japanese Patent Laid-Open No. 8-168187
No. 234207), a resist film is partially formed on the surface of the formed liquid crystal alignment film, a rubbing process is performed in a direction different from the previous rubbing process, and then the resist film is removed to perform liquid crystal alignment. The viewing angle characteristics of the manufactured liquid crystal display device can be improved by performing a treatment that changes the orientation ability of the film (see, for example, Japanese Patent Application Laid-Open No. 5-107544).

(3) Two substrates on which the liquid crystal alignment film is formed as described above are prepared, and they are arranged opposite to each other with a gap (cell gap) therebetween, and the peripheral portions of the two substrates are sealed with a sealant. Liquid crystal is injected and filled into the cell gap defined by the bonding, the substrate surface and the sealant, and the injection hole is sealed to form a liquid crystal cell. Then, on the outer surface of the liquid crystal cell, that is, on the other surface side of each substrate constituting the liquid crystal cell,
A liquid crystal display device can be obtained by laminating a polarizing plate.

Here, as the sealant, for example, a curing agent and an epoxy resin containing aluminum oxide spheres as a spacer can be used. Examples of the liquid crystal include nematic type liquid crystal and smectic type liquid crystal, and among them, nematic type liquid crystal is preferable, for example, Schiff base type liquid crystal, azoxy type liquid crystal,
Biphenyl liquid crystals, phenylcyclohexane liquid crystals, ester liquid crystals, terphenyl liquid crystals, biphenylcyclohexane liquid crystals, pyrimidine liquid crystals, dioxane liquid crystals, bicyclooctane liquid crystals, cubane liquid crystals, and the like can be used. Further, to these liquid crystals, for example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, and chiral agents such as those sold under the trade names "C-15" and "CB-15" (manufactured by Merck). It is also possible to use by adding such as. Further, as a polarizing plate to be attached to the outer surface of a liquid crystal cell, a polarizing film or an H film in which a polarizing film called an H film that absorbs iodine while stretching and aligning polyvinyl alcohol is sandwiched between cellulose acetate protective films A polarizing plate composed of itself can be mentioned.

The liquid crystal aligning agent of the present invention can be suitably used for EVA type liquid crystal display devices. EVA mode means "liquid crystal" vol. 3 No. 4 272 (1999
(Year), a vertical alignment mode in which the alignment direction is controlled by devising the electrode structure and providing slits is shown. The slit may be formed on each of the TFT substrate side and the color filter side. Also,
The liquid crystal aligning agent of the present invention is "Jpn Appl.
s. It can be suitably used for a vertical alignment type liquid crystal display device of a photo-alignment system by irradiation with polarized ultraviolet light as disclosed in "Vol 36428 (1997). Polarized ultraviolet light used in the liquid crystal display device is linearly polarized. It is preferably ultraviolet light.

[0055]

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. [Method for measuring imidization ratio of specific polymer] The polymer was dried under reduced pressure at room temperature, then dissolved in deuterated dimethyl sulfoxide, and tetramethylsilane was used as a standard substance at room temperature for 1H-
The NMR was measured and determined by the formula shown in the following formula (ii).

Imidization ratio (%) = (1−A ¹ / A ² × α) × 100 (ii) A ¹ : proton-derived peak area of NH group (10 pp
m) A ² : other proton-derived peak area α: N in the polymer precursor (polyamic acid)
Ratio of number of other protons to one proton of H group

[Method for producing liquid crystal display element] Production of liquid crystal display element: (1) EVA type cell As shown in FIG. 1, two glass substrates each having an ITO pattern were used as model elements corresponding to the EVA method. Print the liquid crystal aligning agent on each for 1 minute at 80 ℃, then 1
A coating film having a dry film thickness of 600 angstrom was formed by drying at 80 ° C. for 1 hour. After applying an epoxy resin-based adhesive containing aluminum oxide spheres having a particle diameter of 3.5 μm to the outer edge portion of one substrate by a screen printing method, as shown in FIG. 1, slits of each substrate are alternately arranged. The two substrates were stuck together in the following positional relationship. Negative liquid crystal MLC6608 manufactured by Merck Co., Ltd. is injected and filled in the cell gap defined by the adhesive on the surface and the outer edge of the substrate, and then the injection hole is sealed with an epoxy adhesive to provide a vertically aligned liquid crystal display device. Was produced. (2) Photo-alignment type cell As a model element corresponding to the vertical photo-alignment system, a liquid crystal aligning agent is printed on each of two glass substrates with ITO,
A coating film having a dry film thickness of 600 angstrom was formed by drying at 0 ° C. for 1 minute and then at 180 ° C. for 1 hour. Further, using a mercury lamp on each substrate, 3
Mainly the wavelength of 65nm and the linearly polarized ultraviolet rays from the film surface 45
Irradiation was performed for 3 minutes at an irradiation intensity of 1.0 J / cm ² from the direction of °. After applying an epoxy resin adhesive containing aluminum oxide spheres with a particle size of 3.5 μm to the outer edge of one substrate by screen printing, the light irradiation direction to each substrate is 180 ° (anti-parallel). I stuck them together so that MLC6608 is injected in the same manner as the EVA type cell,
The inlet was sealed to produce a vertical alignment type liquid crystal display device.

[Vertical orientation] When the voltage is OFF and AC 1
The liquid crystal display device at 2 V (peak-peak) was observed under crossed Nicols. [Voltage holding ratio] After applying a voltage of 5 V to the liquid crystal display element for a duration of 60 microseconds and a span of 167 milliseconds,
The voltage holding ratio was measured 167 milliseconds after the application was released.
As a measuring device, VHR-1 manufactured by Toyo Technica Co., Ltd. was used.

[Afterimage erasing time of liquid crystal display element] DC3.0V, AC6.0V (peak-peak) in the liquid crystal display element
After applying a rectangular wave of 30 Hz and 3.0 V superposed with each other at an ambient temperature of 70 ° C. for 20 hours, the voltage was turned off and the time until the afterimage was erased was measured by visual observation.

<Synthesis of Specific Polymer> Synthesis Examples 1 to 7 1-Methyl-2-pyrrolidone having the composition shown in Table 1 was added in the order of diamine and tetracarboxylic dianhydride, and the solid content concentration was 20%. The reaction was carried out at 60 ° C. for 6 hours to obtain a polyamic acid having an inherent viscosity shown in Table 1.

[0061]

[Table 1] Numbers in parentheses are mol% TCAAH: 2,3,5-tricarboxycyclopentylacetic acid dianhydride CB: 1,2,3,4-cyclobutanetetracarboxylic acid anhydride MTDA: 1,3,3a, 4,5. 9b-hexahydro-5
-8-Methyl- (tetrahydro-2,5-dioxo-3
-Furanyl) -naphtho [1,2-C] furan-1,3-dione PDA: p-phenylenediamine ODA: octadecanoxy-2,4-diaminobenzenediamine: diaminediamine represented by formula (9): formula (9) Diamine represented by 10): diamine represented by formula (13)

Synthetic Examples 8 to 17 The polyamic acid obtained in Synthetic Examples 1 to 7 was converted into 1-methyl-
Dilute to a solid content concentration of 5% with 2-pyrrolidone, add pyridine and acetic anhydride as catalysts shown in Table 2, and
The specific polymer was synthesized by stirring at 0 ° C. for 4 hours.
By reprecipitating this polymer solution with diethyl ether, a white powder of a polymer (imidized polymer) was obtained.
The imidization ratio of the obtained specific polymer is also shown in Table 2.
In addition, in Table 2, pyridine / anhydride (double mole) = 1.0 /
1.0 means that 1.0 mol of pyridine and 1.0 mol of acetic anhydride are added to 1.0 mol of the amide bond in the polyamic acid.

[0063]

[Table 2]

Synthetic Examples 18 to 27 1-Methyl-2-pyrrolidone having the composition shown in Table 3 was added in the order of diamine and tetracarboxylic dianhydride, and reacted at a solid content concentration of 20% and 60 ° C. for 6 hours. Thus, a polyamic acid having a logarithmic viscosity shown in Table 3 was obtained.

[0065]

[Table 3] Numbers in parentheses are mol% TDA: 1,3,3a, 4,5,9b-hexahydro-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-C] furan-1,3-dione TNA: 3,5,6-tricarbonyl-2-carboxynorbornane-2: 3,5: 6-dianhydride CHA: represented by formula (1) Acid anhydride DDE: 4,4′-diaminodiphenyl ether diamine: diamine diamine represented by formula (10): diamine diamine represented by formula (21): diamine diamine represented by formula (17): formula Diamine represented by (16)

Synthesis Examples 28 to 34 The obtained polyamic acid was diluted with 1-methyl-2-pyrrolidone to a solid content concentration of 5%, pyridine and acetic anhydride were added as catalysts shown in Table 4, and the mixture was heated at 110 ° C. for 4 hours. The specific polymer was synthesized by stirring. By reprecipitating this polymer solution with diethyl ether, a white powder of a polymer (imidized polymer) was obtained. Table 4 also shows the imidization ratio of the obtained specific polymer. In Table 4, pyridine / acid anhydride (molar) = 1.0 / 1.0 means 1.0 mol of pyridine and 1.0 mol of acetic anhydride with respect to 1.0 mol of amide bond in polyamic acid. Means to add.

[0067]

[Table 4]

Examples 1 to 10 The specific polymers obtained in Synthesis Examples 8 to 17 were prepared in a solvent composition (weight ratio) as shown in Table 5 to a solid content concentration of 6.0%, and the vertical alignment type of the present invention was prepared. A liquid crystal aligning agent was obtained. A liquid crystal display device was produced using this liquid crystal aligning agent, and various evaluations were performed. The results are shown in Table 5.

[0069]

[Table 5] NMP: N-methyl-2-pyrrolidone BC: Butyl cellosolve

Examples 11 to 27, Comparative Example 1 As Example 11, 95 g of the specific polymer (Synthesis Example 29)
And 5 g of an additive (N, N, N ', N'-tetraglycyl-4,4'-diaminodiphenylmethane, abbreviated as EP hereinafter) as a solvent (NMP: BC = 5: 5)
(The weight ratio), and the solid content concentration was adjusted to 6.0% to obtain the vertical alignment type liquid crystal aligning agent of the present invention. Using this liquid crystal aligning agent, the above MVA type liquid crystal display device was produced and various evaluations were performed. The results are shown in Table 6. Example 11
Similarly to the above, the specific polymer, the additive and the solvent were mixed in the proportions shown in Tables 6 to 7 to prepare a liquid crystal aligning agent, and the respective properties were evaluated. All the results are summarized in Tables 6-7.

[0071]

[Table 6] Silane: N-glycidyl-N, N-bis [3- (methyldimethoxysilyl) propyl] amine NMP: N-methyl-2-pyrrolidone BC: Butyl cellosolve BL: γ-butyrolactone

[0072]

[Table 7]

Example 28 The specific polymer solution was prepared in the same manner as in Example 11 to prepare an EVA type cell. The liquid crystal alignment of the obtained EVA type cell was good, and no alignment abnormalities such as domains were generated according to ON / OFF of the voltage. The voltage holding ratio of the cell is 99.
3%, afterimage erasing time was 40 seconds. Example 29 A specific polymer solution was prepared in the same manner as in Example 11 to prepare a photo-alignment type cell. The liquid crystal alignment of the obtained photo-alignment type cell was good, and alignment abnormalities such as domains did not occur in response to voltage ON and OFF. The voltage holding ratio of the cell is 98.
3%, afterimage erasing time was 95 seconds.

[0074]

According to the present invention, the vertical orientation is good,
A liquid crystal aligning agent and a liquid crystal display device suitable for an alignment method (EVA, optical alignment, etc.) having a short afterimage erasing time can be obtained. Furthermore, the liquid crystal display device provided with the liquid crystal alignment film formed by using the liquid crystal aligning agent of the present invention can be effectively used in various devices. For example, in addition to direct-view personal computer monitors, liquid crystal televisions, etc. Are used for the transmissive and reflective display devices.

[Brief description of drawings]

FIG. 1 shows a schematic diagram of an EVA type liquid crystal cell used in an example of the present invention.

[Explanation of symbols]

1 Color filter side electrode (ITO) 2 Liquid crystal alignment film 3 Pixel electrode (ITO) 4 Liquid crystal molecules 5 Alignment control means (slit)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H090 HB08Y HC06 KA05 KA08                       MA01 MB01                 4J043 PA02 PA04 QB31 RA08 RA34                       SA06 SB01 SB02 TA21 TA22                       TB01 TB02 UA012 UA022                       UA032 UA082 UA121 UA122                       UA132 UA622 UA632 UB012                       UB121 UB151 UB161 UB221                       UB281 UB402 XA13 XB26                       XB27 XB35 ZA55 ZB23

Claims (2)

[Claims] 1. A polymer containing a repeating unit represented by the following formula (I-1) and at least one repeating unit selected from the repeating units represented by the following formula (I-2). A vertical alignment type liquid crystal aligning agent characterized by: [Chemical 1] (In the formula, P ¹ is a tetravalent organic group, and Q ¹ is the following formula (Q
-1) or a group represented by (Q-2). ) [Chemical 2] (In the formula, P ² is a tetravalent organic group, and Q ² is the following formula (Q
-1) or a group represented by (Q-2). ) [Chemical 3] (In the formula, X is -O-, -CO-, -COO-, -OCO.
-, -NHCO-, -CONH-, -S-, a methylene group, a divalent group selected from an alkylene group having 2 to 6 carbon atoms and a phenylene group, and R ¹ has 10 to 20 carbon atoms.
1 having an alkyl group of 4 to 40 carbon atoms
1 having a valent organic group or a fluorine atom having 6 or more carbon atoms
It is a valent organic group. ) [Chemical 4] (In the formula, X is -O-, -CO-, -COO-, -OCO.
-, -NHCO-, -CONH-, -S-, a methylene group, a divalent group selected from an alkylene group having 2 to 6 carbon atoms and a phenylene group, and R ² is an alicyclic group having 4 to 40 carbon atoms. It is a divalent organic group having a formula skeleton. ) 2. A liquid crystal display device, comprising a liquid crystal alignment film obtained from the vertical alignment type liquid crystal aligning agent according to claim 1.