JPH05216047A - Orineted film - Google Patents

Abstract

PURPOSE:To provide an oriented film consisting of polyimide which eliminates the orientation defects of a sealed liquid crystal and with which a good contrast is obtainable. CONSTITUTION:This oriented film consists of the polyimide obtd. by using diamine expressed by formula. In the formula, J1 and J2 respectively independently denote carbonamide group, sulfone amide group, carbamoyl group, sulfamoyl group, carbonyl group, -O- or -S-; X1 and X2 respectively independently denote hydrogen atom or a substituent on benzene ring; A, D and E respectively independently denote a benzene ring, cyclohexane ring or heterocycle; p denotes 0 or 1: m and n denote an integer from 1 to 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment film made of polyimide having a liquid crystal structure in which the main chain is linked with an oxyalkylene group.

[0002]

2. Description of the Related Art Generally, an alignment film is used for a liquid crystal display element or the like, and is provided because it is necessary to align liquid crystals in a certain direction, that is, to align the liquid crystals. it can. Liquid crystal display devices have been used in displays for clocks, computers, word processors, etc. from the past, but the basic structure is that two transparent electrode substrates with alignment films on transparent electrodes are arranged with the alignment films inside. The liquid crystal is normally enclosed between them. Such a liquid crystal display device transparent electrode is generally formed on the substrate in the form of a display pattern such as a stripe pattern or a grid pattern, and the alignment film is formed on the transparent electrode and the exposed substrate (other than the display pattern). It is provided by coating or vapor deposition on the entire surface. A liquid crystal display element is manufactured by arranging the two transparent electrode substrates with the alignment films inside and enclosing a liquid crystal therebetween.

The mainstream of such a liquid crystal display device is a display in a twisted nematic (TN) mode in which a nematic liquid crystal has a twisted structure. However, this TN type liquid crystal display element is not suitable for high capacity display by high multiplex drive (generally, time division drive used for dot matrix) because the threshold value is not steep. Also, the response speed of the TN type liquid crystal display element is slow,
It has a drawback that it has a limit of milliseconds, which is a big problem when it is used for a television panel or the like that requires high-speed response.

Recently, it has the above-mentioned high-speed responsiveness that responds quickly to changes in the electric field, and responds to the applied electric field to bring about either the first optically stable state or the second optically stable state. Attention has been paid to a ferroelectric liquid crystal which has a property of maintaining its state when no voltage is applied, that is, a memory property (also referred to as bistability). A liquid crystal display device utilizing this has been studied because it can realize high-speed response with a simple structure.

However, when an alignment film made of an organic material such as a polymer, which has been used in the conventional TN mode or the like, is formed on an electrode substrate and subjected to a rubbing treatment, the pretilt angle of the liquid crystal is not sufficiently large, so that a liquid crystal display is obtained. Insufficient device contrast was a major problem.

On the other hand, in recent years, attempts have been made actively in the TN mode to control the orientation by providing a liquid crystal on a polyimide side chain, and these techniques are disclosed in JP-A-2-223918 and 3-1.
07926, ibid 3-179322, ibid 3-179425
It is open to the public. However, even in these cases, it was not possible to simultaneously satisfy the orientation, the high-speed response, the contrast of the liquid crystal display device and the like.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the contrast of a liquid crystal display device by sufficiently increasing the pretilt angle of liquid crystal.

[0008]

The above object has been achieved by using an alignment film made of a polyimide obtained by using a diamine represented by the following general formula (1).

General formula (1)

[0010]

[Chemical 2]

In the formula, J ₁ and J ₂ each independently represent a carbonamido group, a sulfonamide group, a carbamoyl group, a sulfamoyl group, a carbonyl group, —O— or —S—, and X ₁ and X ₂ are each independently. Represents a hydrogen atom or a substituent on the benzene ring, A, D and E each independently represent a benzene ring, a cyclohexane ring or a hetero ring, p
Represents 0 or 1, and m and n represent an integer of 1 to 6.

The present invention is characterized in that a liquid crystal structure is introduced into the polyimide main chain with an oxyalkylene group without deteriorating various properties such as mechanical strength.

The present invention is described in detail below. J ₁
And the carbonamide group, sulfonamide group, carbamoyl group and sulfamoyl group represented by J ₂ are specifically
_{N (R 2) CO -,} - N (R 2) SO 2 -, - CON
(R ₂ )-, -SO ₂ N (R ₂ )-, preferably -NHCO-, -NHSO _2- , -CONH-,-.
Representing the SO ₂ NH-. J ₁ and J ₂ are particularly preferably-
Represents 0-, -NHCO- or -CONH-.

The substituent represented by X ₁ and X ₂ specifically represents an alkyl group, an alkoxy group, a cyano group, a halogen atom or the like, preferably an alkyl group or an alkoxy group. X ₁ and X ₂ particularly preferably represent a hydrogen atom, a methyl group, a perfluoromethyl group or a methoxy group.

A, D and E are each independently a benzene ring,
It represents a cyclohexane ring or a hetero ring, and these rings may be substituted with an F element atom or a cyano group. The heterocycle represents a 5- to 7-membered ring containing a hetero atom such as nitrogen, sulfur and oxygen, and particularly preferably a pyridine ring or a pyrimidine ring.

M and n preferably represent an integer of 1 and 3 to 6, particularly preferably an integer of 3 or 4.

The polyimide of the present invention can be obtained by dehydration condensation of the diamine of the present invention and a polyamic acid obtained from a tetracarboxylic acid anhydride.

Specific examples of the diamine of the present invention will be given below, but it goes without saying that the present invention is not limited thereto.

D-1; 4,4'-bis {3- (4-aminophenoxy) propoxy} biphenylene, D-2; 2
-[4- {3- (4-aminophenoxy) propoxy}
Phenyl] -5- {3- (4-aminophenoxy) propoxy} pyrimidine, D-3; 2- [4- {3- (4-
Aminophenoxy) propoxy} phenyl] -5- {3
-(4-aminophenoxy) propoxy} pyridine, D
-4; 2,5-bis [4- {3- (4-aminophenoxy) propoxy} phenyl] pyrimidine, D-5; 2
5-bis [4- {3- (4-aminophenoxy) propoxy} phenyl] pyridine, D-6; 2- [4- {3-
(4-Aminophenoxy) propoxy} phenyl] -5
-[5- {3- (4-aminophenoxy) propoxy}
Pyrimidin-2-yl] pyridine, D-7; 2,2'-
Bis {3- (4-aminophenoxy) propoxy} biphenylene, D-8; 2,2'-bis {3- (3-aminophenoxy) propoxy} biphenylene, D-9; 4
4'-bis {3- (3-aminophenoxy) propoxy} biphenylene, D-10; 2- [4- {4- (4-
Aminophenoxy) butoxy} phenyl] -5- {4-
(4-Aminophenoxy) butoxy} pyrimidine

D-11; 2,2'-bis [3- {N-
(4-Aminophenyl) carbamoyl} propoxy] biphenylene, D-12; 4,4'-bis [3- {N-
(4-Aminophenyl) carbamoyl} propoxy] biphenylene, D-13; 2,2'-bis {6- (4-aminophenoxy) hexyloxy} biphenylene, D-
14; 2- [4- {3- (4-aminophenoxy) propoxy} phenyl] -5- {6- (4-aminophenoxy) hexyloxy} pyrimidine, D-15; 2- {6
-(4-aminophenoxy) hexyloxy} -2'-
{3- (4-Aminophenoxy) propoxy} biphenylene, D-16; 2- [2- {3- (4-aminophenoxy) propoxy} phenyl] -5- [5- {3- (4
-Aminophenoxy) propoxy} pyrimidin-2-yl] pyridine, D-17; 2,4'-bis {3- (4-
Aminophenoxy) propoxy} biphenylene

Further, the polyimide of the present invention can use diamine other than the present invention in an arbitrary ratio. Specific examples of these are shown below, but of course the present invention is not limited thereto.

2,2-bis [4- (4-aminobenzyl) phenyl] hexafluoropropane, o-phenylenediamine; m-phenylenediamine; p-phenylenediamine; 4,4'-diaminodiphenylpropane;
4,4'-diaminodiphenylethane;4,4'-diaminodiphenylmethane;4,4'-diaminodiphenylsulfide;4,4'-diaminodiphenylsulfone;
3,4'-diaminodiphenyl ether; 3,3'-diaminodiphenyl propane; 3,3'-diaminodiphenylphenyl methane; 3,3'-diaminodiphenyl sulfide; 3,3'-diaminodiphenyl sulfone;
-Diaminodiphenyl ether; 1,5-diaminonaphthalene; 3,3'-dimethylbenzidine;2,2'-dimethylbenzidine;3,3'-dimethoxybenzidine;
2,2 ', 5,5'-Tetrachlorobenzidine; 2,4
-Bis (β-amino-t-butyl) toluene; bis (p
-Β-amino-t-butylphenyl) ether; bis (p-β-methyl-o-aminopentyl) benzene;
1,5-diamino-4-isopropylbenzene; 1,2
-Bis (3-aminopropoxy) ethane; m-xylylenediamine; p-xylylenediamine; 2,4-diaminotoluene; 2,6-diaminotoluene; bis (4-aminocyclohexyl) methane; 3-methylheptamethylene Diamine; 4,4-Dimethylheptamethylenediamine; 2,2'-Dimethylpropylenediamine; 2,11
-Dodecanediamine; Otamethylenediamine; 3-Methoxyhexamethylenediamine; 2,5-Dimethylheptamethylenediamine; 2,5-Dimethylhexamethylenediamine; 3-Methylheptamethylenediamine; 5-Methylnonamethylenediamine; 4,4 '-Diamino-3,
3'-dimethyldicyclohexyl;1,12-octadecanediamine; bis (3-aminopropyl) sulfide; N-methyl-bis (3-aminopropyl) amine;
Hexamethylenediamine; Heptamethylenediamine; 4,4'-Diaminobenzophenone;
Nonamethylenediamine; decamethylenediamine; 2,2
-Bis [4- (4-aminophenoxy) phenyl] propane; 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane; bis (3-aminopropyl) tetramethyldisiloxane; bis (4 -Aminobutyl) tetramethyldisiloxane aromatic diamine,
Aliphatic diamines and siloxane-based diamines. These may use only 1 type and may mix and use 2 or more types.

To obtain the polyimide of the present invention, it is desirable to use tetracarboxylic acid anhydride. Specific examples of these are shown below, but of course the present invention is not limited thereto.

1,2,4,5-benzenetetracarboxylic dianhydride; 1,2,3,4-benzenetetracarboxylic dianhydride; 1,4-bis (2,3-dicarboxyphenoxy) benzene Dianhydride; 1,3-bis (2,3-dicarboxyphenoxy) benzene dianhydride; 1,2,
4,5-naphthalenetetracarboxylic dianhydride; 1,
2,5,6-naphthalenetetracarboxylic dianhydride;
1,4,5,8-Naphthalenetetracarboxylic dianhydride; 2,3,6,7-naphthalenetetracarboxylic dianhydride; 2,6-dichloronaphthalene-1,4,5,8-
Tetracarboxylic acid dianhydride; 2,7-Dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride; 3,
3 ', 4,4'-diphenyltetracarboxylic dianhydride; 2,2', 3,3'-diphenyltetracarboxylic dianhydride; 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl Dianhydride; bis (2,3-dicarboxyphenyl) ether dianhydride; 4,4'-bis (2,3-dicarboxyphenoxy) diphenyl ether dianhydride; 4,4'-bis (3,4- Dicarboxyphenoxy) diphenyl ether dianhydride; bis (3,4
-Dicarboxyphenyl) sulfide dianhydride; 4,
4'-bis (2,3-dicarboxyphenoxy) diphenyl sulfide dianhydride; bis (3,4-dicarboxyphenyl) sulfone dianhydride; 4,4'-bis (2,3
-Dicarboxyphenoxy) diphenylsulfone dianhydride; 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride; 3,3 ', 4,4'
-Benzophenone tetracarboxylic dianhydride; 2,
2 ', 3,3'-benzophenone tetracarboxylic acid dianhydride; 2,3', 3,4'-benzophenone tetracarboxylic acid dianhydride; 4,4-bis (3,4-dicarboxyphenoxy) benzophenone dianhydride Anhydrate; bis (2,3-
Dicarboxyphenyl) methane dianhydride; 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride;
1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride; 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride; 2,2-bis (2,3-dicarboxy) Phenyl) ethane dianhydride; 2,2-bis (3,4)
-Dicarboxyphenyl) ethane dianhydride; 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] propane dianhydride; 4- (2,3-dicarboxyphenoxy-4 '-(3 , 4-dicarboxyphenoxy)
Diphenyl-2,2-propane dianhydride; 2,2-bis [4- (3,4-dicarboxyphenoxy) -3,5-
Dimethylphenyl] propane dianhydride; 2,3,4,5
-Thiophene tetracarboxylic dianhydride; 2,3,4
5-pyrrolidine tetracarboxylic dianhydride; 2,3
5,6-pyrazinetetracarboxylic dianhydride; 1,8,
9,10-phenanthrenetetracarboxylic dianhydride;
3,4,9,10-Perylenetetracarboxylic dianhydride; 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride; 1,3-bis (3,4)
-Dicarboxyphenyl) hexafluoropropane dianhydride; 1,1-bis (3,4-dicarboxyphenyl)
-1-Phenyl-2,2,2-trifluoroethane dianhydride; 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane dianhydride;
1,1-bis [4- (3,4-dicarboxyphenoxy) phenyl] -1-phenyl-2,2,2-trifluoroethane dianhydride; 4,4′-bis [2- (3,4 −
Dicarboxyphenyl) hexafluoroisopropyl]
Diphenyl ether dianhydride; 2,3,5-tricarboxycyclopentyl acetic acid dianhydride; Cyclopentane tetracarboxylic dianhydride; Cyclobutane tetracarboxylic dianhydride; 5- (2,5-dioxotetrahydrofuryl) -3 -Methyl-3-cyclohexene dicarboxylic acid anhydride; bicyclo [2,2,2] -oct-7-ene-
2,3,5,6-tetracarboxylic dianhydride; 3,5
6-tricarboxynorbornane-2-acetic acid dianhydride;
Tetrahydrofuran tetracarboxylic dianhydride. These may use only 1 type and may mix and use 2 or more types.

A preferred structure of the liquid crystal display device using the alignment film of the present invention will be described. A transparent electrode and an alignment film are laminated in this order on a transparent substrate to form two transparent electrode substrates. An insulating layer may be interposed between the transparent electrode and the alignment film, if necessary. The two transparent electrode substrates are arranged so that the alignment films face each other,
In the meantime, the ferroelectric liquid crystal is filled. The transparent electrodes are each formed on the transparent substrate in the form of a striped display pattern.

As described above, the transparent electrodes are formed in stripes, and the stripes are formed so that they are orthogonal to each other. This allows matrix display. Further, the transparent electrode may be formed in a stripe shape only on one side. Further, it is not necessary to have both alignment films, and only one may be provided.

The liquid crystal display device using the alignment film obtained by the manufacturing method of the present invention is not limited to the ones shown above,
All the modes such as the use of a spacer and the like which are performed for a normal liquid crystal display element are possible. In particular, it is preferable to use a spacer in order to secure a gap between both alignment films (that is, a layer thickness of the liquid crystal layer). As the spacer, glass fiber, glass beads, plastic beads, and metal oxide particles such as alumina and silica are used. The particle size of the spacer depends on the liquid crystal used,
The thickness is generally 1.2 μm to 6 μm, though it depends on the material of the alignment film, the setting of the gap, the particles used as the spacer, and the like.

A liquid crystal display device using the alignment film of the present invention is
For example, it can be manufactured as follows.

Examples of the transparent substrate of the present invention include glass such as float glass having good smoothness, polyester such as polyethylene terephthalate and polybutylene terephthalate, epoxy resin, phenol resin, polyimide, polycarbonate, polysulfone, polyether sulfone, Heat-resistant resins such as polyetherimide, acetyl cellulose, polyamino acid ester, aromatic polyamide,
Examples thereof include plastic films formed from polystyrene, polyacrylic acid ester, polymethacrylic acid ester, vinyl-based polymers such as polyacrylamide, polyethylene and polypropylene, fluorine-containing resins such as polyvinylidene fluoride and modified products thereof.

On the above-mentioned substrate, a transparent electrode having a stripe-shaped or lattice-shaped display pattern is formed by a conventional method. As the transparent electrode, for example, indium oxide (I
Examples thereof include n ₂ O ₃ ), tin oxide (SnO ₂ ), and ITO (indium tin oxide).

A color filter and a protective layer may be formed in this order on the surface of the substrate. The alignment film of the present invention is formed on the transparent electrode (and the substrate), for example, as described below.

The alignment film of the present invention is formed by coating a substrate with a polyamic acid obtained from diamine and tetracarboxylic acid anhydride, followed by drying and heat treatment.

The alignment film of the present invention can be formed by dehydration condensation of the precursor polyamic acid as described above. An example of synthesizing the polyamic acid that is the precursor of the present invention will be described below.

Synthesis Example 1 Polyamic acid 1 (PA-1)
Synthesis of 1,3-dibromopropane; 121 g, 4,4'-dihydroxybiphenylene; 18.6 g, N, N-dimethylacetamide; 200 ml and potassium carbonate; 28.0
g was stirred at 85 ° C. for 1 hour. Ethyl acetate; 500 ml
And water; 600 ml was added and the ethyl acetate layer was extracted,
Concentration and column purification gave 4,4′-bis (3-bromopropoxy) biphenylene; 15.5 g.

4.4'-Bis (3-bromopropoxy) biphenylene; 13.6 g, 4-nitrophenol;
7 g, N, N-dimethylacetamide; 100 ml and potassium carbonate; 18.5 g were stirred at 85 ° C. for 1 hour.
Ethyl acetate; 100 ml and water; 150 ml were added to extract the ethyl acetate layer, and then the precipitated crystals were filtered to 4,
12.1 g of 4'-bis {3- (4-nitrophenoxy) propoxy} biphenylene; was obtained.

4,4'-bis {3- (4-nitrophenoxy) propoxy} biphenylene; 11.0 g, reduced iron; 20.0 g, ammonium chloride 0.3 g, water; 20
200 ml of isopropanol and 50 ml of N, N-dimethylacetamide were stirred at 80 ° C. for 5 hours and then cooled to 20 ° C. After filtering the precipitated crystals,
The crystals were recrystallized from N, N-dimethylacetamide / methanol to obtain 5.1 g of D-1; 4,4'-bis {3- (4-aminophenoxy) propoxy} biphenylene.

D-1; 4.84 g and N-methyl-2-
While stirring 40 ml of pyrrolidone at 25 ° C., 2.18 g of pyromellitic dianhydride was added. After stirring for 6 hours, P
A solution of A-1 in N-methyl-2-pyrrolidone was obtained.

Synthesis Example 2 Polyamic acid 2 (PA-2)
Synthesis of PA-2 An N-methyl-2-pyrrolidone solution of PA-2 was obtained in the same manner as in Synthesis Example 1 except that D-2 was used instead of D-1.

Synthesis Example 3 According to Synthesis Examples 1 and 2, polyamic acid 3 (PA-3) to polyamic acid 20 (PA-20) were obtained. This is shown in Table 1. Table 1 Synthesis of polyamic acid 3 to 20 ----------------------- Polyamic acid diamine (D ) Acid anhydride (E) D / E (molar ratio) -------------------------------------------- PA-3 D-1 E-2 1/1 PA-4 D-1 E-1 / E-2 1 / 0.5 / 0.5 PA-5 D-1 / D-27 E-1 0.5 /0.5/1 PA-6 D-1 / D-28 E-1 0.5 / 0.5 / 1 PA-7 D-1 / D-29 E-1 0.5 / 0.5 / 1 PA-8 D-2 E-1 1/1 PA-9 D-3 E-1 1/1 PA-10 D-4 E-2 1/1 PA-11 D-5 E-1 1/1 PA- 12 D-6 E-1 1/1 PA-13 D-7 E-1 1/1 PA-14 D-8 -1 1/1 PA-15 D-2 E-2 1/1 PA-16 D-1 / D-2 E-1 0.5 / 0.5 / 1 PA-17 D-11 E-1 1 / 1 PA-18 D-7 E-2 1/1 PA-19 D-1 / D-7 E-1 0.5 / 0.5 / 1 PA-20 D-14 E-1 1/1 --- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

D-27, D-28, D-29, E- in the table
1 and E-2 represent the following compounds. D-27; 2,2-
Bis- [4 (4-aminobenzyl) phenyl] hexafluoropropane D-28; α- (4-aminophenoxy) -N- (3-
Aminophenyl) tetradecanoic acid amide D-29; 2,2-bis- [4 (4-aminophenoxy) phenyl] hexafluoropropane E-1; 1,2,4,5-benzenetetracarboxylic dianhydride E- 2; 1,4,5,8-naphthalenetetracarboxylic dianhydride

The coating liquid for forming an alignment film may be prepared by mixing the polyimide obtained above with a suitable solvent such as pyridine, N-methyl-2-pyrrolidone, dioxane, THF or a glycol derivative. In addition to the above-mentioned components, other high molecular polymer or organometal may be added to the coating liquid for the purpose of increasing adhesion to the substrate or adjusting the viscosity of the coating liquid.

The coating liquid for forming an alignment film is coated on the transparent electrode and the exposed substrate by a spin coater or the like, and at room temperature to 150 ° C. under normal pressure or reduced pressure for 1 to 120 minutes (preferably 80 to 120 ° C.). At 10-80 minutes). Next, the coating film may be heat-treated at 150 to 300 ° C. under normal pressure or reduced pressure for 0.5 to 3 hours. The heating may be only the subsequent heating at 150 to 300 ° C. for 0.5 to 3 hours.

The thickness of the obtained alignment film varies depending on the type of liquid crystal and alignment film used, but is 10 to 800 nm, preferably 20 to 200 nm.

The alignment film provided on the transparent electrode substrate (and the protective layer) is preferably rubbed with a synthetic fiber such as nylon, polyester or polyacrylonitrile, or a natural fiber such as cotton or wool.

The liquid crystal can be stably aligned by the alignment film of the present invention thus formed. This alignment film is characterized by using the polyimide having the oxyalkylene group in its side chain.

A transparent substrate manufactured as described above,
Two transparent electrode substrates composed of a transparent electrode and an alignment film are made to face each other with their alignment films inside so as to form a cell. The size of this gap, that is, the cell gap is preferably about 0.5 μm to 6 μm.

Next, the following liquid crystal (preferably ferroelectric liquid crystal) is injected into this cell, sealed, and then gradually cooled to prepare a liquid crystal display element.

The liquid crystal used in the present invention is preferably a liquid crystal that can be used in the SBE mode or a ferroelectric liquid crystal, but a ferroelectric liquid crystal is particularly preferable.

The liquid crystal having ferroelectricity is specifically a chiral smectic C phase (SmC ^* ) or H phase (Sm
H ^* ), I phase (SmI ^* ), J phase (SmJ ^* ), K phase (SmK ^* ), G phase (SmG ^* ) or F phase (Sm)
It is a liquid crystal having F ^* ). For example, all known ferroelectric liquid crystals as described in "High-speed liquid crystal technology" (published by CMC) p. 127-161 can be used in the present invention.

Specific liquid crystal compositions include CS-1018, CS-1023 and CS- manufactured by Chisso Corporation.
1025, CS-1026, DO manufactured by Roddick Co., Ltd.
F0004, DOF0006, DOF0008, ZLI-4237-000, ZLI-4237- manufactured by Merck & Co., Inc.
100, ZLI-4654-100, ZLI-2293
And so on. There is no problem even if a dichroic dye, a viscosity reducing agent, or the like which dissolves in the liquid crystal is added to these liquid crystals.

In the liquid crystal display device manufactured as described above, polarizing plates may be provided on both substrates of the cell depending on the purpose of use. An insulating layer, a color filter, a protective layer, etc. may be provided between the transparent electrode and the alignment film. Further, the liquid crystal display device using the alignment film obtained by the manufacturing method of the present invention may be provided with a structure provided in a conventional liquid crystal display device such as a reflection plate and a retardation plate depending on the purpose of use.

[0052]

EXAMPLES Examples of the present invention will be described below. However, the present invention is not limited to this embodiment.

Example 1 Indium-tin oxide (ITO) transparent electrodes were formed in stripes (electrode width: 100 μm, gap between electrodes: 15 μm) on two 1.1 mm thick glass substrates. ..

On these two glass substrates with transparent electrodes,
An insulating layer having a layer thickness of 100 nm was formed by depositing SiO 2.

A 3% N-methyl-2-pyrrolidone solution of the polyamic acid PA-1 of the present invention was applied onto the insulating layer by a spinner. Spinner conditions are 2500 rpm.
pm, time 30 seconds. After coating, it was dried at 250 ° C. for 1 hour to form a polyimide alignment film.

Both surfaces of this coating film were rubbed with a nylon raised cloth, and two glass plates were so placed that the rubbing surfaces were inside and the rubbing directions were antiparallel and the electrode patterns were orthogonal. A cell having a cell gap of 2 μm was prepared by stacking with a 3 μm spacer interposed therebetween. Liquid crystal ZLI-2293 manufactured by Merck Ltd. is placed in this cell.
It was injected at 00 ° C and gradually cooled to room temperature at a rate of about 2 ° C / min.

The alignment state of the obtained liquid crystal display element was observed, and a good alignment state without zigzag defects was obtained. Further, when the above liquid crystal display device was driven by multiplex, good contrast was obtained.

Example 2 In Example 1, polyamic acid PA-1 was replaced with PA-2.
A liquid crystal display element was manufactured in the same manner as in Example 1 except that the above was changed.

When the alignment state of the obtained liquid crystal display element was observed, a good alignment state without zigzag defects was obtained. Further, when the above liquid crystal display device was driven by multiplex, good contrast was obtained.

Example 3 In Example 2, when rubbing with a nylon raised cloth, the rubbing direction with the respective rubbing surfaces inside was changed from antiparallel to the same direction, and the spacer was set to 3
Change from μm to 2 μm, and change the liquid crystal to ZL made by Merck.
Ferroelectric liquid crystal CS- manufactured by Chisso Corporation from I-2293
A liquid crystal display element was manufactured in the same manner as in Example 2 except that the number was changed to 1023.

The alignment state of the obtained liquid crystal display element was observed, and a good alignment state without zigzag defects was obtained. Further, when the above liquid crystal display device was driven by multiplex, good contrast was obtained.

Example 4 In Example 3, the liquid crystal was a ferroelectric liquid crystal CS-1023.
To the liquid crystal compositions shown in Table 2 below (phase transition temperature (° C) C
^* 58.0A83.4N ^* 89.3Iso], except that the liquid crystal display element was manufactured in the same manner as in Example 3. Table 2 Liquid crystal composition ------------------------------------- Compound composition ratio (wt%) 5- Heptyl-2- (4-octyloxyphenyl) 11 pyrimidine 5-nonyl-2- (4-octyloxyphenyl) 11 pyrimidine 5-heptyl-2- (4-nonyloxyphenyl) 11 pyrimidine 5-octyl-2- ( 4-octyloxyphenyl) 22 pyrimidine 5-hexyl-2- (4-pentylbiphenylyl-4′-) 8 pyrimidine 5-heptyl-2- (4-pentylbiphenylyl-4′-) 8 pyrimidine 5-octyl- 2- (4-heptylbiphenylyl-4′-) 8 pyrimidine 5-nonyloxy-2- (4-heptylphenyl) pyrimidine 15 5-octyl-2- [4-((2S) -2-ph Oro 5 octyloxy) phenyl] pyrimidine 5-((2S) -2-methylbutyl) -2- (4-heptyl 1 biphenylyl-4 ′-) pyrimidine ---------- −−−−−−−−−−−−−−−−−−−−

When the alignment state of the obtained liquid crystal display element was observed, a good alignment state without zigzag defects was obtained. Further, when the above liquid crystal display device was driven by multiplex, good contrast was obtained.

Examples 5 to 12 In Example 4, polyamic acid PA-2 was replaced with PA-
A liquid crystal display device was manufactured in the same manner as in Example 4 except that 1, 3, 4, 8, 12, 13, 17, 18, and 19 were used.

When the alignment states of all the obtained liquid crystal display elements were observed, all were in good alignment without zigzag defects. Further, when the above liquid crystal display device was driven by multiplex, good contrast was obtained in all cases.

[0066]

INDUSTRIAL APPLICABILITY As shown in the above embodiments, according to the present invention, a polyimide having a structure in which a liquid crystal structure is connected to the main chain with an oxyalkylene group is used as an alignment film for aligning the enclosed liquid crystal. It is possible to obtain a liquid crystal having almost no alignment defects and improved bistability. Further, the alignment film of the present invention gives good contrast and is extremely useful as a liquid crystal display device.

Claims (1)

[Claims] 1. An alignment film made of a polyimide obtained by using a diamine represented by the following general formula (1). General formula (1) In the formula, J ₁ and J ₂ each independently represent a carbonamide group, a sulfonamide group, a carbamoyl group, a sulfamoyl group, a carbonyl group, —O— or —S—, and X ₁ and X ₂ are each independently a hydrogen atom. Or a substituent on the benzene ring, A, D and E each independently represent a benzene ring, a cyclohexane ring or a hetero ring, p represents 0 or 1, and m and n represent an integer of 1 to 6.