JPH05249472A - Oriented film - Google Patents

Abstract

PURPOSE:To eliminate the orientation defect of a liquid crystal and to improve bistability by using a vinyl polymer having a specific repeating unit for an oriented film for orienting the encapsulated liquid crystal. CONSTITUTION:The oriented film consisting of the polyimide obtd. by using the diamine expressed by formula is used. In the formula, J denotes a carbamoyl group or ester group; R1 denotes a methyl group or hydrogen atom; R2 and R3 respectively independently denote an alkyl group or perfluoroalkyl group; R4 denotes a hydrogen atom, amino group, imide group, carbonamide group, sulfoneamide group, ureide group or oxycarbonamide group; A denotes methylene, -S-, -CO- or -O-; X1 denotes phenylene or direct bond. The carbamoyl group expressed by J more specifically denotes -CON(R5)- and more preferably denotes- CONH-, -COO-; R5 denotes a substd. or unsubstd. alkyl group or aryl group.

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 a vinyl polymer having an imide residue on its side chain.

[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.

[0006] Of these, F-containing polyimide is often used because of its relatively high contrast.
In general, these polyimides have poor solubility, and when polyimide is used as an alignment film, it is necessary to coat the substrate in the form of polyamic acid and cyclize it with high heat to form a polyimide. However, even with these, the orientation, the high-speed response, the contrast of the liquid crystal display element, the ease of manufacturing, etc. could not be satisfied at the same time.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a vinyl polymer having an imide residue in the side chain which improves the contrast of a liquid crystal display device by sufficiently increasing the pretilt angle of the liquid crystal and does not require a step of polyimidation. The purpose is to provide.

[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 represents a carbamoyl group or an ester group, R ₁ represents a methyl group or a hydrogen atom, R ₂ and R ₃ each independently represent an alkyl group or a perfluoroalkyl group, and R ₄ represents Represents a hydrogen atom, an amino group, an imide group, a carbonamide group, a sulfonamide group, a ureido group or an oxycarbonamide group, A is methylene,
S -, - CO- or an -O-, X ₁ represents a phenylene or a direct bond.

The present invention is characterized in that an F-containing imide structure is introduced into the vinyl polymer side chain.

The present invention is described in detail below. Carbamoyl groups represented by J are specifically -CON (R ₅₎ -
, But preferably -CONH- or -COO-. R ₅ represents a substituted or unsubstituted alkyl group or aryl group.

The alkyl group or perfluoroalkyl group represented by R ₂ and R ₃ may be linear or branched, preferably represents an alkyl group or perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably perfluoro. Represents a methyl group.

The amino group, imide group, carbonamide group, sulfonamide group, ureido group or oxycarbonamide group represented by R ₄ is specifically -N (R ₅ ) R ₆ ,-
N (COR ₅ ) COR ₆ , -N (R ₅ ) COR ₆ , -N
_{(R 5) SO 2 R 6} , -N (R 5) CON (R 6) R 7
Alternatively, it represents -NCOOR ₅ . R ₅ has the same meaning as above,
R ₆ and R ₇ each independently represent a substituted or unsubstituted alkyl group or aryl group. However, R of imide group
₅ and R ₆ may be condensed to represent an alkyl group or an aryl group. Preferred examples of R ₄ are hydrogen atom, amino group,
It is a carbonamide group, a sulfonamide group or an oxycarbonamide group, particularly preferably a hydrogen atom or a carbonamide group.

A preferably represents methylene or --O--, particularly preferably --O--.

X ₁ particularly preferably represents a direct bond.

The polymer of the present invention can be obtained by homopolymerizing the monomer represented by the following general formula (3) or copolymerizing it with any other monomer.

General formula (3)

[0020]

[Chemical 3]

Where J, R ₁ , R ₂ , R ₃ , R ₄ , A,
X ₁ has the same meaning as above.

Specific examples of the monomer represented by the general formula (3) will be given below, but the present invention is not limited thereto.

[0023]

[Chemical 4]

[0024]

[Chemical 5]

[0025]

[Chemical 6]

[0026]

[Chemical 7]

The vinyl polymer of the present invention may optionally be copolymerized with a monomer other than formula (3). Examples of such a monomer include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, vinylbenzoic acid, cinnamic acid, vinylbenzenesulfonic acid, 2- (meth) acrylamido-2-methylpropanesulfonic acid, N -Methylsulfonyl (meth) acrylamide, N-ethylsulfonyl (meth) acrylamide, N-phenylsulfonyl (meth) acrylamide, N- (p-methylphenylsulfonyl (meth) acrylamide, alkyl (meth) acrylate, or substituted ( (Meth) alkyl acrylate (for example, methyl (meth) acrylate, ethyl (meth))
Acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, amyl (meth) acrylate, hexyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Ethylhexyl (meth) acrylate, octyl (meth) acrylate, t-octyl (meth) acrylate
, Chloroethyl (meth) acrylate, allyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate
4-hydroxybutyl (meth) acrylate, 2,
2-Dimethyl-3-hydroxypropyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate
G, trimethylolpropane mono (meth) acrylate
G, pentaerythritol mono (meth) acrylate,
Benzyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate
, Furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, etc .: aryl (meth) acrylate (eg phenyl (meth) acrylate, cresyl) (Meth) acrylate, naphthyl (meth) acrylate, etc.): (meth) acrylamides, for example (meth)
Acrylamide, N-alkyl (meth) acrylamide (as the alkyl group, for example, methyl group, ethyl group,
Examples include a propyl group, a butyl group, a t-butyl group, a heptyl group, an octyl group, an ethylhexyl group, a cyclohexyl group, a hydroxyethyl group and a benzyl group. ), N-aryl (meth) acrylamide (as the aryl group,
Examples include phenyl group, tolyl group, nitrophenyl group, naphthyl group and hydroxyphenyl group. ), N, N
-Dialkyl (meth) acrylamide (the alkyl group includes, for example, methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group, cyclohexyl group, etc.), N, N-diaryl (meth) acrylamide (the Examples of the aryl group include a phenyl group), N-methyl-N-phenyl (meth) acrylamide, N-hydroxyethyl-N-methyl (meth) acrylamide, N-2-acetamidoethyl-N-. Acetyl (meth) acrylamide, N- (phenylsulfonyl) (meth) acrylamide, N- (p-methylphenylsulfonyl) (meth) acrylamide and the like: vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethylacetate. , Vinyl diethyl acetate, vinyl ball , Vinyl caproate, vinyl chloracetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinylphenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β- Phenyl butyrate, vinyl cyclohexyl carboxylate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate, etc .: Styrenes such as styrene, alkylstyrenes (eg methylstyrene, dimethylstyrene, trimethyl) styrene,
Ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc.), alkoxy styrene (eg methoxy styrene,
4-methoxy-3-methylstyrene, dimethoxystyrene, etc., halogenostyrene (for example, chlorostyrene,
Dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene,
Trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro-3-trifluoromethylstyrene, etc.): Crotonic acid esters, for example, alkyl crotonic acid (eg, butyl crotonic acid, hexyl crotonic acid, glycerin monochromatic). Tone), etc .: Dialkyl itaconates (eg, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.): Dialkyls of maleic acid or fumaric acid (eg, dimethyl maleate, dibutyl fumarate, etc.): (meta ) Acrylonitrile and the like.

A thermal polymerization reaction, a photopolymerization reaction or the like can be used for synthesizing the polymer of the present invention, but a thermal polymerization reaction is particularly desirable for obtaining the monomer of the present invention. In the thermal polymerization reaction, one or more kinds of the monomer represented by the general formula (3) and optionally the above-mentioned other monomers are used in an arbitrary ratio (preferably, the monomer represented by the general formula (3) is 5 to 5%). 100% by weight, particularly preferably 50-100% by weight
It is desirable to use. ), In any solvent (for example, water, alcohols, ethers, esters, amide solvents or lactones) under heating (heating temperature is preferably 30 to 150 ° C., particularly preferably 50 to 50 ° C.). 10
It is desirable to carry out at 0 ° C. ) Any initiator (for example, potassium persulfate, azobisisobutyronitrile, azobisdimethylvaleronitrile, perbenzoic acid, azobismethylpropionamidine dihydrochloride or dimethylazobisisobutyrate, and the like, monomer As opposed to
It is desirable to use 0.01 to 5% by weight, preferably 0.03 to 1% by weight. ) Can be obtained.

The synthetic examples and specific examples of the polymer of the present invention will be given below, but the present invention is not limited thereto.

[Synthesis Example 1; Polymer of the present invention: P-1]
2,2-Bis- [4 (4-aminophenoxy) phenyl] hexafluoropropane; 17.8 g, 4-nitrophthalic anhydride; 13.3 g and 150 ml of toluene at 30 ° C. with stirring, N, N-dimethylacetamide 20.
ml was added. After stirring for 30 minutes, 0.5 g of p-toluenesulfonic acid was added, and then water was azeotropically removed under reflux of toluene for 5 hours. The crystals precipitated under ice cooling are filtered,
24 g of the desired nitro compound was obtained.

23 g of the nitro compound, 30 g of reduced iron,
Ammonium chloride; 0.2 g, H ₂ O; 20 ml, NN
40 ml of dimethylformamide and 150 ml of isopropyl alcohol were stirred under reflux for 5 hours. After filtering the insoluble matter while hot, ice-cooling and the precipitated crystals were filtered to obtain 15 g of the desired amine compound.

The above amine compound; 14 g, pyridine; 3 m
Acetyl chloride (1.81 g) was added dropwise while stirring 1, 20 ml of N, N-dimethylacetamide and acetonitrile (80 ml) at 20 ° C. After stirring for 30 minutes, acetonitrile was concentrated, ethyl acetate; 50 ml was added,
After filtering the precipitated insoluble matter, column purification was performed on silica gel to obtain 3.2 g of the desired amide compound.

2.1 g of the above amide compound, pyridine;
While stirring 4 ml, 5 ml of N, N-dimethylacetamide and 15 ml of acetonitrile at 20 ° C., 0.37 g of methacrylic acid chloride was added dropwise. The precipitated crystals were filtered to obtain 2.1 g of the objective monomer: M-1;

2.0 g of M-1 and 18.7 g of N, N-dimethylacetamide were added with stirring at 80 ° C., and 5 mg of azobisisobutyronitrile was added 4 times every hour. After stirring for 3 hours, the polymer of the present invention: N-1, N-dimethylacetamide solution of P-1: solid content concentration;
9% was obtained.

[Synthesis Example 2; Polymer of the present invention: P-2]
M-1; 1.0 g, methyl methacrylate; 0.5 g and N, N-dimethylacetamide 10.0 g with stirring at 80 ° C., azobisisobutyronitrile; 4 mg to 1
It was added four times every hour. After the addition, the mixture was stirred for 3 hours to obtain a polymer of the present invention: P-2, N, N-dimethylacetamide solution: solid content concentration; 13.3%.

[Synthesis Example 3; Polymer of the present invention: P-3 to
20] The monomers were changed according to Synthesis Example 1 or 2 to obtain the polymers of the present invention: P-3 to 20 shown in the table below.

Table Polymers of the present invention: Synthesis of P-3 to 20 --------------------. Polymer Monomer Monomer Monomer D / E / G Initiator Solvent Temperature Time Mar D-E-G (weight ratio) (° C) (hr) ---------- −−−−−−−−−−−−−−− P-3 M-1−−100 / 0/0 Q-1 T-1 80 6 P-4 M−2−− 100/0/0 Q -1 T-1 80 6 P-5 M-3-0-100 / 0/0 Q-1 T-1 80 6 P-6 M-6--100 / 0/0 Q-1 T-1 80 6 P -7 M-14 --100 / 0/0 Q-2 T-1 70 7 P-8 M-15 --100 / 0/0 Q-2 T-1 90 5 P-9 M-19 --100 / 0/0 Q-2 T-1 80 6 P-10 M-20 --100 / 0/0 Q-2 T-1 80 P-11 M-21 --100 / 0/0 Q-1 T-2 80 6 P-12 M-10 --100 / 0/0 Q-1 T-3 80 6 P-13 M-1 M- 20-50 / 50/0 Q-1 T-1 85 6 P-14 M-1 M-6-50 / 50/0 Q-2 T-1 80 6 P-15 M-6 M-19-50 / 50/0 Q-2 T-1 80 7 P-16 M-1 BA-90 / 10/0 Q-1 T-1 80 6 P-17 M-1 MMA BA 50/30/20 Q-2 T- 1 80 8 P-18 M-1 M-6 MMA 50/30/20 Q-1 T-1 80 4 P-19 M-1 M-6 BA 50/30/20 Q-1 T-1 80 6 P -20 M-1 M-6 EA 50/30/20 Q-2 T-1 80 6 ----------------------------. −−−−−−

In the above table, MMA represents methyl methacrylate, BA represents butyl acrylate, EA represents ethyl acrylate, Q-1 represents azobisisobutyronitrile, and Q-2 represents dimethylazobisisobutyrate. , T-1 represents NN-dimethylacetamide, T-2 represents NN-dimethylformamide, and T-3 represents N-methyl-2-pyrrolidone.

In the above table, the initiators are P-15 to P-17.
Is 2% by weight of the total amount of monomer and 1.5 in other cases
Weight percent was used.

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 as to be 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 above-mentioned ones,
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, transparent electrodes having a stripe-shaped or lattice-shaped display pattern are 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 applying the solution of the polymer obtained in the present invention onto a substrate, drying and heating.

The coating solution for forming an alignment film may be prepared by mixing the solution of the polymer 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 applied on the transparent electrode and the exposed substrate by a spin coater or the like, and at normal temperature to 150 ° C. under normal pressure or reduced pressure for 1 to 120 minutes (preferably normal temperature 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. Heating is performed at room temperature to 150 ° C. for 1 to 120 minutes or 150 to 3 after.
Heating at 00 ° C. for 0.5 to 3 hours may be sufficient.

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

The alignment film provided on the transparent electrode substrate (and 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 a vinyl polymer having an imide structure 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 slowly 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 ^* ) and 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, 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.

[0059]

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

Example 1 Transparent electrodes of indium-tin oxide (ITO) 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.

On the insulating layer, the polymer of the present invention: P-
1 of 3% N-methyl-2-pyrrolidone solution was applied with a spinner. Spinner conditions are 2500 rpm.
The time was 30 seconds. After coating, the polyimide alignment film was formed by drying at 200 ° C. for 1 hour.

Both surfaces of this coating film were rubbed with a nylon brushed cloth, and two glass plates were placed so 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.

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. The pretilt angle of the liquid crystal display device was 7 °.

Example 2 A liquid crystal display device was manufactured in the same manner as in Example 1 except that the polymer P-1 was changed to P-2.

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 1, 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.

When the alignment state of the obtained liquid crystal display device 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 4 In Example 3, the liquid crystal was the 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 5-14 In Example 4, the polymer P-1 was replaced with P-2, 3, 4,
A liquid crystal display device was manufactured in the same manner as in Example 4 except that 5, 6, 7, 10, 13, 18, and 19 were used.

When the alignment states of all the obtained liquid crystal display elements were 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 in all cases.

[0073]

INDUSTRIAL APPLICABILITY As shown in the above embodiments, according to the present invention, by using a vinyl polymer having an imide structure as a side chain in the alignment film for aligning the enclosed liquid crystal, the alignment of the liquid crystal is improved. It is possible to obtain a product having almost no defects and improved bistability. Further, the present invention does not require heat treatment at a high temperature and is advantageous in manufacturing. 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 composed of a vinyl polymer having a repeating unit represented by the following general formula (1): General formula (1) In the formula, J represents a carbamoyl group or an ester group, and R ₁
Represents a methyl group or a hydrogen atom, R ₂ and R ₃ each independently represents an alkyl group or a perfluoroalkyl group, and R ₄ represents a hydrogen atom, an amino group, an imide group, a carbonamido group, a sulfonamide group, a ureido group. Represents a group or an oxycarbonamide group, A is methylene, -S-, -CO-
Or represents -O-, X ₁ represents a phenylene or a direct bond.