JP3279757B2 - Liquid crystal alignment agent and liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal aligning agent and a liquid crystal display.
The present invention relates to an indicator element . More specifically, a liquid crystal aligning agent having good liquid crystal alignment and a large pretilt angle and the liquid crystal alignment
The present invention relates to a liquid crystal display device having a liquid crystal alignment film formed using an agent .

[0002]

2. Description of the Related Art Conventionally, a nematic liquid crystal having a positive dielectric anisotropy has a sandwich structure with a substrate having a transparent electrode having a liquid crystal alignment film made of polyimide or the like, and the major axis of the liquid crystal molecules is continuous at 90 degrees between the substrates. 2. Description of the Related Art A liquid crystal display element (TN type display element) having a TN type liquid crystal cell which is twisted likewise is known. The alignment of the liquid crystal in this TN type display element is formed by a liquid crystal alignment film subjected to a rubbing treatment.

[0003] Since the TN type display element has poor contrast and visual dependency, recently, an STN (Super twiste) which is a liquid crystal display element excellent in contrast and visual dependency.
d nematic) Display elements have been developed. The STN display element uses a liquid crystal obtained by blending a chiral agent, which is an optically active substance, with a nematic liquid crystal, and utilizes a birefringence effect generated by continuously twisting the major axis of liquid crystal molecules by 180 degrees or more between substrates. Things.

[0004]

However, the STN
When the display element is manufactured using a liquid crystal alignment film made of polyimide or the like, the liquid crystal alignment film has a small pretilt angle, so that the liquid crystal cannot be twisted by 180 degrees or more between the substrates, and a required display function can be obtained. Have difficulty.

[0005] Therefore, in the case of the current STN display element, it is necessary to use a liquid crystal alignment film formed by obliquely depositing silicon dioxide in order to align the liquid crystal, and the manufacturing process is complicated. There is.

The STN display element uses a substrate on which silicon dioxide is obliquely deposited, or treats the substrate with a fluorine-based surfactant or a coupling agent having a long-chain alkyl group in order to vertically align the liquid crystal. It is necessary. In the case of oblique deposition, there is a problem that the production process is complicated and mass production is not possible, and in the case where a surfactant or a coupling agent is used, reliability is poor.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, to provide a liquid crystal with good orientation, a large pretilt angle,
An object of the present invention is to provide a liquid crystal aligning agent that can be particularly preferably used for a liquid crystal alignment film of an N and SH display element.

[0008]

Means for Solving the Problems As a result of diligent studies on the above problems, it has been found that the orientation of the liquid crystal can be improved by incorporating a diamine having three or more benzene rings and an alkyl group in a side chain into the polymer. It became clear that a stable pretilt angle was obtained without disturbing.

The present invention provides a compound represented by the following general formula (I):

[0010]

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(Here, R ¹ represents a tetravalent organic group.)

A tetracarboxylic dianhydride (hereinafter referred to as "compound I") represented by the following general formula (II):

[0013]

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(Here, R ² and R ⁴ represent a monovalent organic group selected from a methyl group, an ethyl group and a trifluoromethyl group, and these may be the same or different.
R ³ represents a linear and / or branched alkyl group having 1 to 20 carbon atoms. a and c show the integer of 0-4. b shows the integer of 1-4. )

And / or the following general formula (III)

[0016]

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(Here, R ⁵ and R ⁸ represent a monovalent organic group selected from a methyl group, an ethyl group and a trifluoromethyl group, and these may be the same or different.
R ⁶ and R ⁷ each represent a linear and / or branched alkyl group having 1 to 20 carbon atoms, which may be the same or different. R ⁹ represents —O—, —S—, —OCO—, —CO
And a divalent organic group selected from O-, -NHCO-, -CONH-, -CO-, a methylene group and an alkylene group having 2 to 5 carbon atoms. d and g show the integer of 0-4. e, f
Represents an integer of 1 to 4. )

(Hereinafter referred to as "specific polymer I") and / or its imidized polymer (hereinafter referred to as "specific polymer") II ”) , and a solvent
Liquid crystal alignment film containing γ-butyrolactone
And a liquid crystal aligning agent characterized by exhibiting a pretilt angle of 3 to 90 degrees by using the liquid crystal aligning agent.
Liquid crystal display device having a liquid crystal alignment film .

The compound I used in the present invention is represented by the above formula (I). In the above formula, R ¹ corresponds to the residue obtained by removing the acid anhydride group from compound I.

Examples of the compound I include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-
Tricarboxynorbornane-2-acetic acid dianhydride, 2,
3,4,5-tetrahydrofurantetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5
-(Tetrahydro-2,5-dioxo-3-furanyl)
-Naphtho [1,2-c] -furan-1,3-dione, 5
-(2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-2,
Aliphatic and alicyclic tetracarboxylic dianhydrides such as 3,5,6-tetracarboxylic dianhydride; pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-
Naphthalenetetracarboxylic dianhydride, 3,3 ′, 4
4'-biphenyl ether tetracarboxylic dianhydride,
3,3 ′, 4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4
-Furantetracarboxylic dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride , 4,4'-
Bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenetetracarboxylic 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 ( Aromatic tetracarboxylic dianhydrides such as (triphenylphthalic acid) -4,4'-diphenylmethane dianhydride can be mentioned. Of these, butanetetracarboxylic dianhydride, 1,
2,3,4-cyclobutanetetracarboxylic dianhydride,
2,3,5-tricarboxycyclopentylacetic acid 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, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′,
4,4'-biphenyltetracarboxylic dianhydride is preferred.

The compound II used in the present invention is represented by the above formula (II) and / or the above formula (III). For example, such a compound is obtained by reacting a nitrobenzene compound having one halogen group capable of reacting with a phenolic hydroxyl group in a molecule with a compound having two phenolic hydroxyl groups in a molecule in the presence of an alkaline compound,
Obtained by reducing the nitro group.

Examples of the nitrobenzene compound having one halogen group in the molecule include 4-chloronitrobenzene, 4-bromonitrobenzene, 4-fluoronitrobenzene, 4-iodonitrobenzene, 3-chloronitrobenzene, 3-fluoronitrobenzene, and 3-chloronitrobenzene. Iodonitrobenzene, 2-chloronitrobenzene, 2-bromonitrobenzene, 2-fluoronitrobenzene, 2-iodonitrobenzene, 2-chloro-4-methylnitrobenzene, 4-chloro-3-methylnitrobenzene, 3-
Chloro-2-methylnitrobenzene, 5-chloro-2-
Methyl nitrobenzene, 1-chloro-4-methylnitrobenzene, 2-chloro-4-ethylnitrobenzene, 4
-Chloro-3-ethylnitrobenzene, 3-chloro-2
-Ethylnitrobenzene, 5-chloro-2-ethylnitrobenzene, 1-chloro-4-ethylnitrobenzene,
2-chloro-4-trifluoromethylnitrobenzene,
4-chloro-3-trifluoromethylnitrobenzene,
3-chloro-2-trifluoromethylnitrobenzene,
5-chloro-2-trifluoromethylnitrobenzene,
1-chloro-4-trifluoromethylnitrobenzene and the like can be mentioned.

As the compound having two phenolic hydroxyl groups in the molecule, for example, the following general formula (IV)

[0024]

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(Here, R ¹⁰ represents a linear and / or branched alkyl group having 1 to 20 carbon atoms. H represents an integer of 1 to 4.)

Or the following general formula (V)

[0027]

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(Wherein R ¹¹ and R ¹² are linear or branched alkyl groups having 1 to 20 carbon atoms, which may be the same or different. R ¹³ is ether oxygen, phenylene And a divalent organic group selected from a group and an alkylene group having 1 to 10 carbon atoms.i and j each represent an integer of 1 to 4.)

The following compounds can be mentioned.

As a solvent used for the reaction between the nitrobenzene compound having one halogen group capable of reacting with the phenolic hydroxyl group in the molecule and the compound having two phenolic hydroxyl groups in the molecule, for example, N- Methyl-2-pyrrolidone, N, N-dimethylacetamide,
N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide and the like can be mentioned.

Examples of the basic compound used in the reaction include potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, sodium hydride, potassium metal, sodium metal, pyridine, triethylamine and the like.

Further, during the reaction, a phase transfer catalyst is added,
The reaction may be accelerated.

For the reduction of the reaction product, for example, zinc,
Iron, tin, tin (II) chloride, sodium sulfide (Na ₂
S, Na ₂ S ₂ , Na ₂ S _x ), sodium hydrosulfide, sodium dithionite, ammonium sulfide and the like are advantageously used. Also, for example, palladium-
Using carbon, platinum, Raney nickel, platinum black, rhodium-alumina, platinum sulfide carbon, or the like as a catalyst, reduction can also be performed with hydrogen gas, hydrazine, hydrochloric acid, or the like.

Examples of the solvent for the reduction reaction include alcohols such as ethanol, methanol and 2-propanol;
Ethers such as diethyl ether, methyl ethyl ether and methyl butyl ether, aqueous ammonia, toluene,
Water, tetrahydrofuran, chloroform or dichloromethane is used.

The specific polymer I is obtained by reacting the compound I with the compound II. This reaction is carried out in an organic solvent at a reaction temperature of usually 0 to 150 ° C, preferably 0 to 100 ° C.

In addition to compound II, other diamines can be used in combination to the extent that the effects of the present invention are not lost. Other diamine compounds include, for example, p-phenylenediamine, m-phenylenediamine, 4,4′-
Diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylsulfone, 4,4 '
-Diaminodiphenyl ether, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, 3,4'-
Diaminodiphenyl ether, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone, 4,
4'-diaminobenzophenone, 2,2-bis [4-
(4-aminophenoxy) phenyl] propane, 2,2
-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) hexafluoropropane, 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, 9,9-
Bis (4-aminophenyl) fluorene, 4,4'-methylene-bis (2-chloroaniline), 4,4 '-(m
-Phenylenediisopropylidene) bisaniline, 4,
4 '-(p-phenylenediisopropylidene) bisaniline, 2,2', 5,5'-tetrachloro-4,4'-
Diaminobiphenyl, 2,2'-dichloro-4,4'-
Diamino-5,5'-dimethoxybiphenyl, 3,3 '
Aromatic diamines such as -dimethoxy-4,4'-diaminobiphenyl; aromatic diamines having a hetero atom such as diaminotetraphenylthiophene; 1,1-methaxylylenediamine, 1,3-propanediamine, tetramethylenediamine; Pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro- 4,7-methanoindanylene dimethylene diamine, tricyclo [6,
Aliphatic or alicyclic diamines such as 2,1,0 ^2.7 ] -undecylenedimethyldiamine; the following general formula (VI)

[0037]

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(In the formula, R represents a hydrocarbon group having 1 to 12 carbon atoms such as an alkyl group such as a methyl group, an ethyl group or a propyl group, a cycloalkyl group such as a cyclohexyl group, or an aryl group such as a phenyl group. , P represents 1 to 3 and q represents an integer of 1 to 20). In these, p
Phenylenediamine, 4,4′-diaminodiphenylmethane, 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-bis (4-
Aminophenyl) hexafluoropropane, 4,4'-
(M-phenylenediisopropylidene) bisaniline,
4,4 '-(p-phenylenediisopropylidene) bisaniline is preferred. These can be used alone or in combination of two or more.

The use of such other diamine compound is usually 0 to 90 mol%, preferably 0 to 90 mol%, of all diamine compounds.
~ 80 mol%.

The ratio of the compound I to the total diamine compound is preferably such that the acid anhydride group of the compound I is 0.2 to 2 equivalents, more preferably 1 equivalent of the amino group in the total diamine compound. Is 0.3 to 1.2 equivalents.

The organic solvent used in the reaction includes
There is no particular limitation as long as the specific polymer I generated by the reaction can be dissolved. For example, aprotic polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, tetramethylurea, hexamethylphosphortriamide; Phenolic solvents such as cresol, xylenol, phenol and halogenated phenol can be mentioned. Usually, the amount of the organic solvent used is preferably such that the total amount of the compound I and all the diamine compounds is 0.1 to 30% by weight based on the total amount of the reaction solution.

The specific polymer II used in the present invention is obtained by imidizing the above specific polymer I by heating or in the presence of a dehydrating agent and an imidization catalyst. The reaction temperature for imidization by heating is usually 6
It is 0-200 ° C, preferably 100-170 ° C. If the reaction temperature is lower than 60 ° C., the progress of the reaction is delayed,
When the temperature exceeds ℃, the molecular weight of the specific polymer II may be greatly reduced. The reaction for imidization in the presence of a dehydrating agent and an imidization catalyst can be performed in the above-mentioned organic solvent. The reaction temperature is usually 0 to 180 ° C, preferably 60 to 150 ° C. Acid anhydrides such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride can be used as the dehydrating agent. Further, as the imidation catalyst, for example, tertiary amines such as pyridine, collidine, lutidine, and triethylamine can be used, but are not limited thereto. The amount of the dehydrating agent used is 1.6 to 20 per mol of the repeating unit of the specific polymer I.
Preferably, it is molar. The amount of the imidization catalyst used is preferably 0.5 to 10 mol per 1 mol of the dehydrating agent used.

The organic solvent may be used together with the organic solvent to such an extent that a polymer which produces alcohols, ketones, esters, ethers, halogenated hydrocarbons and hydrocarbons, which are poor solvents, is not precipitated. it can. Examples of such poor solvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethylene glycol monomethyl ether, acetone, methyl ethyl ketone,
Methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, ethyl lactate, diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol i-propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-di Chlorbenzene, hexane, heptane, octane, benzene, toluene, xylene, etc. Can.

The intrinsic viscosity of the specific polymer I or II thus obtained [η _inh = (lnηrel / C, C =
0.5 g / dl, 30 ° C., in N-methyl-2-pyrrolidone, the intrinsic viscosity is measured under the same conditions below] is usually 0.0
It is 5 to 10 dl / g, preferably 0.05 to 5 dl / g.

The liquid crystal aligning agent of the present invention contains specific polymers I and / or II. In order to adjust the molecular weight of these specific polymers and to realize an optimum coatability on a substrate,
A monoamine may be added during the reaction.

As the monoamine used at this time, for example, aniline, cyclohexylamine, n-butylamine,
n-pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n
-Decylamine, n-undecylamine, n-dodecylamine, n-tridecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, n-heptadecylamine, n-octadecylamine, n -Eicosylamine and the like.

The liquid crystal aligning agent of the present invention may contain a functional silane-containing compound for the purpose of improving the adhesion between the specific polymer I and / or II and the substrate.

Examples of the functional silane-containing compound include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminopropyltrimethoxysilane, 2-aminopropyltriethoxysilane, and N- (2-amino Ethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, N-ethoxycarbonyl-3 -Aminopropyltrimethoxysilane, N-ethoxycarbonyl-3-aminopropyltriethoxysilane, N-triethoxysilylpropyltriethylenetriamine, N-trimethoxysilylpropyltriethylenetriamine, 1
0-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-aminopropyltriethoxysilane and the like.

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

First, the liquid crystal aligning agent of the present invention is applied on the transparent conductive film side of the substrate provided with the transparent conductive film by a roll coater method.
Apply by spinner method, printing method, etc., 80-200 ° C,
The coating is preferably formed by heating at a temperature of 120 to 200 ° C. This coating film has a thickness of usually 0.001 to 1 μm, preferably 0.005 to 0.5 μm.

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

As the substrate, a transparent substrate made of, for example, glass such as float glass or soda glass, or a plastic film such as polyethylene terephthalate, polybutylene terephthalate, polyether sulfone, or polycarbonate can be used.

As the transparent conductive film, a NESA film made of SnO ₂ , an ITO film made of In ₂ O ₃ —SnO ₂ and the like can be used. A method using a mask in advance is used.

In applying the liquid crystal aligning agent, in order to further improve the adhesion between the substrate and the transparent conductive film and the coating film,
On the substrate and the transparent conductive film, a functional silane-containing compound, titanate, or the like can be applied in advance.

The two substrates having the liquid crystal alignment film formed thereon are opposed to each other so that the rubbing directions are orthogonal or antiparallel, the peripheral portion between the substrates is sealed with a sealant, and the liquid crystal is filled. Then, the filling hole is sealed to form a liquid crystal cell, and the liquid crystal display element is formed by bonding both surfaces of the liquid crystal cell such that the polarization directions thereof coincide with or perpendicular to the rubbing direction of the liquid crystal alignment film of the substrate.

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

As the liquid crystal, nematic liquid crystal,
Smectic type liquid crystals, among them, those which form nematic type liquid crystals are preferable. Liquid crystals, dioxane-based liquid crystals, bicyclooctane-based liquid crystals, cubane-based liquid crystals, and the like are used. In addition, these liquid crystals
For example, cholesteric liquid crystals such as cholesteryl chloride, cholesteryl nonaate and cholesteryl carbonate, and trade names C-15 and CB-15 (Merck Lt)
d. ) May be added and used. In addition, ferroelectric liquid crystals such as p-decyloxybenzylidene-p-amino-2-methylbutylcinnamate can be used.

As the polarizing plate used outside the liquid crystal cell, a polarizing plate in which a polarizing film called an H film in which polyvinyl alcohol is stretched and oriented and iodine is absorbed by a cellulose acetate protective film or the H film itself is used. And the like.

[0059]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Incidentally, the measurement of the pretilt angle in the examples is described in [TJ Schffer, et al., J. Appl. Phys., 19 , 2].
(1980)], according to a crystal rotation method using He-Ne laser light.

In the evaluation of the orientation of the liquid crystal cell, the presence or absence of abnormal domains in the liquid crystal cell when the voltage was turned on / off was observed with a polarizing microscope.

Synthesis Example 1 The following formula (VII)

[0063]

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200 g of the compound represented by the formula and 284 g of 4-chloronitrobenzene were dissolved in 5000 g of N, N-dimethylformamide, 150 g of sodium hydroxide was added, and the mixture was reacted at 150 ° C. for 8 hours. The obtained reaction solution was poured into water to precipitate a reaction product. The product was thoroughly washed with water and recrystallized in acetone to obtain a nitro compound (yield 60%).

Synthesis Example 2 100 g of the dinitro compound obtained in Synthesis Example 1 was dissolved in 1000 g of ethanol, 1 g of Pd / C and 50 g of hydrazine monohydrate were added, and the mixture was refluxed for 6 hours. After cooling to room temperature, the precipitate was separated by filtration and recrystallized from ethanol to obtain a compound IIa (yield: 52%).

Synthesis Example 3 44.8 g of 2,3,5-tricarboxycyclopentylacetic acid dianhydride and 103.2 g of compound IIa were dissolved in 1332 g of N-methyl-2-pyrrolidone and reacted at room temperature for 6 hours. The reaction mixture was then poured into a large excess of methanol, causing the reaction product to precipitate. Thereafter, it was washed with methanol and dried under reduced pressure at 40 ° C. for 15 hours to obtain 130.3 g of a specific polymer Ia having an intrinsic viscosity of 1.11 dl / g.

Synthesis Example 4 30.0 g of the specific polymer Ia obtained in Synthesis Example 3 was added to 570
g of γ-butyrolactone, 36.7 g of pyridine and 31.3 g of acetic anhydride were added, and an imidation reaction was carried out at 120 ° C. for 3 hours. Next, the reaction product liquid was precipitated in the same manner as in Synthesis Example 1 to obtain 25.3 g of a specific polymer IIa having an intrinsic viscosity of 1.04 dl / g.

Synthesis Example 5 In Synthesis Example 3, 10.8 g of p-phenylenediamine and 51.6 of compound IIa were used as the diamine compounds.
g), except that the specific polymer Ib was obtained in the same manner as in Synthesis Example 3. Further, an imidization reaction was carried out using this specific polymer Ib in the same manner as in Synthesis Example 4 to obtain an intrinsic viscosity of 1.22 dl / g.
90.3 g of the specific polymer IIb was obtained.

Synthesis Example 6 91.6 g of a specific polymer Ic having an intrinsic viscosity of 1.36 dl / g in the same manner as in Synthesis Example 3 except that the acid anhydride was changed to 43.6 g of pyromellitic dianhydride. I got

Synthesis Example 7 Formula (VIII)

[0071]

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In 200 g of 4-chloronitrobenzene was dissolved in 5000 g of N, N-dimethylformamide, 150 g of sodium hydroxide was added, and the mixture was reacted at 150 ° C. for 8 hours. The obtained reaction solution was poured into water to precipitate a reaction product. The product was thoroughly washed with water and recrystallized in acetone to obtain a nitro compound (yield 61%). Thereafter, the nitro compound obtained in the same manner as in Synthesis Example 2 was reduced to obtain compound IIb (yield: 50%).

Synthesis Example 8 In Synthesis Example 3, 10.8 g of p-phenylenediamine and 51.6 of compound IIb were used as the diamine compounds.
g), except that the specific polymer Ib was obtained in the same manner as in Synthesis Example 3, and an imidization reaction was carried out using this specific polymer Id in the same manner as in Synthesis Example 4 to obtain an intrinsic viscosity of 1.12 dl / g.
90.2 g of the specified polymer IId was obtained.

Synthesis Example 9 The following formula (IX)

[0075]

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200 g of the compound represented by the formula and 192 g of 4-chloronitrobenzene were dissolved in 5000 g of N, N-dimethylformamide, 150 g of sodium hydroxide was added, and the mixture was reacted at 150 ° C. for 8 hours. The obtained reaction solution was poured into water to precipitate a reaction product. The product was thoroughly washed with water and recrystallized in acetone to give a nitro compound (63% yield). Thereafter, the nitro compound obtained in the same manner as in Synthesis Example 2 was reduced to obtain compound IIIa (yield: 56%).

Synthesis Example 10 In Synthesis Example 3, 10.8 g of p-phenylenediamine as a diamine compound and 67.
Specific polymer Ib in the same manner as in Synthesis Example 3 except that the amount was 6 g.
Further, an imidization reaction was carried out using this specific polymer Ie in the same manner as in Synthesis Example 4 to obtain an intrinsic viscosity of 1.10 dl /
Thus, 100.2 g of the specific polymer IIe was obtained.

Synthesis Example 11 The following formula (X)

[0079]

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200 g of the compound represented by the formula and 360 g of 4-chloronitrobenzene were dissolved in 5000 g of N, N-dimethylformamide, 150 g of sodium hydroxide was added, and the mixture was reacted at 150 ° C. for 8 hours. The obtained reaction solution was poured into water to precipitate a reaction product. The product was thoroughly washed with water and recrystallized in acetone to obtain a nitro compound (yield 60%). Thereafter, the nitro compound obtained in the same manner as in Synthesis Example 2 was reduced to obtain compound IIIb (yield: 51%).

Synthesis Example 12 In Synthesis Example 3, 10.8 g of p-phenylenediamine as a diamine compound and 48.
Specific polymer Ib in the same manner as in Synthesis Example 3 except that the amount was 8 g.
, And an imidization reaction was carried out using this specific polymer If in the same manner as in Synthesis Example 4 to give an intrinsic viscosity of 1.10 dl /
Thus, 80.2 g of the specific polymer IIf was obtained.

Synthesis Example 13 A specific polymer I having an intrinsic viscosity of 1.40 dl / g was prepared in the same manner as in Synthesis Example 3 except that only 21.6 g of p-phenylenediamine was used as the diamine compound.
50.2 g were obtained.

Example 1 The polymer Ia obtained in Synthesis Example 3 was converted to γ-butyrolactone 7
The solution was dissolved in 2 g to obtain a solution having a solid content of 4% by weight, and this solution was filtered through a filter having a pore size of 1 μm to prepare a liquid crystal aligning agent solution. This solution was applied to a transparent electrode surface on a glass substrate with a transparent electrode made of an ITO film and the number of rotations was 3000.
The solution was applied using a spinner at 3 rpm and dried at 180 ° C. for 1 hour to form a coating film having a dry film thickness of 0.05 μm. Using a rubbing machine having a roll in which a nylon cloth is wound around the coating film, the number of rotations of the roll is 500 r.
Rubbing treatment was performed at pm and a stage moving speed of 1 cm / sec. Next, an epoxy resin adhesive containing aluminum oxide spheres having a diameter of 17 μm is screen-printed and applied to each outer edge of the pair of rubbed substrates having the liquid crystal alignment film, and then the pair of substrates face each other. As described above, the rubbing directions were superposed so that the rubbing directions were antiparallel, and the adhesive was hardened. Next, after filling a nematic liquid crystal (ZLI-1565, 2293, manufactured by Merck) between a pair of substrates from the liquid crystal injection port, the liquid crystal injection port is sealed with an epoxy-based adhesive, and both sides on the outside of the substrate are sealed. The polarizing plates were adhered so that the polarizing direction of the polarizing plates coincided with the rubbing direction of the liquid crystal alignment films of the respective substrates, thereby producing a liquid crystal display device. The orientation of the obtained liquid crystal display element was good, and the pretilt angle when the liquid crystal was ZLI-1565, 2293 was 89.
$ 88.

Examples 2 to 7 In Example 1, Synthesis Examples 4, 5, 6, 8, 10, and 12
Specific polymers IIa, IIb, Ic, IId obtained in
A liquid crystal display device was manufactured in the same manner as in Example 1 except that IIe and IIf were used, and the orientation and pretilt angle of the liquid crystal display device were measured. The results are shown in Table 1.

[0085]

[Table 1]

Comparative Example 1 Except that the specific polymer Ig obtained in Synthesis Example 13 was used,
When a liquid crystal display device was manufactured and evaluated in the same manner as in Example 1, the orientation of the obtained liquid crystal display device was good, but the pretilt angle when the liquid crystal was ZLI-1565, 2293 was used. Was measured, and each was 0.9
{, 1.1}.

[0087]

According to the liquid crystal aligning agent of the present invention, the alignment is good and the liquid crystal alignment is stable without disturbing the alignment of the liquid crystal.
A pretilt angle of up to 90 degrees is exhibited, and a liquid crystal alignment film suitable for STN or SH display devices is obtained. Further, the liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent of the present invention, by selecting the liquid crystal to be used,
It can also be suitably used for SBE display elements, ferroelectric display elements, and anti-ferroelectric display elements. Further, a liquid crystal display device having an alignment film formed using the liquid crystal alignment agent of the present invention is excellent in liquid crystal alignment and reliability, and can be effectively used in various devices, for example, a desk calculator, a wristwatch, a clock, and a coefficient. It is used for display devices such as display boards, word processors, personal computers, and liquid crystal televisions.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Nobuo Bessho 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. JP-A-63-205640 (JP, A) JP-A-4-304234 (JP, A) JP-A-3-6528 (JP, A) JP-A-58-72924 (JP, A) JP-A-4-157424 (JP, A) JP-A-3-293325 (JP, A) JP-A-4-6529 (JP, A) JP-A-2-287324 (JP, A) JP-A-1-28282 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1337

Claims (2)

(57) [Claims] 1. A compound represented by the following general formula (I) (Where R ¹ represents a tetravalent organic group) and a tetracarboxylic dianhydride represented by the following general formula (II): (Here, R ² and R ⁴ each represent a monovalent organic group selected from a methyl group, an ethyl group, and a trifluoromethyl group, which may be the same or different. R ³ has 1 carbon atom.
And represents up to 20 linear and / or branched alkyl groups. a,
c shows the integer of 0-4. b shows the integer of 1-4. ) Containing a polymer obtained by reacting with the diamine compound represented by the formula (1) and / or its imidized polymer, and γ-butyrolactone as a solvent, and exhibiting a pretilt angle of 3 to 90 degrees by the obtained liquid crystal alignment film. it a liquid crystal aligning agent characterized that, in the general formula (II), R ³
A liquid crystal aligning agent, wherein at least one of the alkyl groups represented by formula (I) is a linear and / or branched alkyl group having 8 carbon atoms. 2. A liquid crystal display device having a liquid crystal alignment film formed using the liquid crystal alignment agent according to claim 1 .