JPH0572539A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain a large pretilt angle of a sealed liquid crystal by using an oriented film composed of a polyimide obtd. from a specified diamine compd. and tetracarboxylic acid deriv. CONSTITUTION:This liquid crystal display element consists of two substrates having oriented film and a liquid crystal sealed between these substrates. At least one oriented film is a polyimide oriented film obtd. from at least one kind of diamine compds. expressed by formula I and a tetracarboxylic acid deriv. selected from tetracarboxylic acid, tetracarboxylic acid diester, tetraearboxylic acid tetraester, and tetracarboxylic acid di anhydride. In formula I, X is -CH-, -CS-, -S-, -SO-, -SO2-, or -CH2-, and Y is a bivalent group having a benzene ring. By using the oriented film, a liquid crystal, especially a ferroelectric liquid crystal can be oriented with large pretilt angle which conventionally can be obtd. only in an oriented film formed by oblique vapor deposition of SiO.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a polyimide alignment film.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display element used for a display of a clock, a computer, a word processor or the like has a basic structure in which two transparent electrode substrates each having an alignment film on a transparent electrode have an alignment film. Usually, the structure is such that the liquid crystal is placed inside and the liquid crystal is 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 film inside and enclosing a liquid crystal therebetween. In general, the alignment film is provided because it is necessary to align the liquid crystals in a certain direction, that is, to align the liquid crystals, and thereby the liquid crystal molecules are aligned.

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 response that responds quickly to changes in the electric field, and in response to the applied electric field, either the first optical stable state or the second optical stable state is generated. 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 called bistability). A liquid crystal display device utilizing this has been studied because it can realize high-speed response with a simple structure.

The operating principle of the TN mode utilizes the optical rotatory power of a liquid crystal cell with a twist angle of about 90 degrees. However, if the SBE (super twist birefringence) mode using nematic liquid crystal is used, the steep threshold is achieved. Since the value can be obtained, a large capacity display by high multiplex drive becomes possible. The SBE (super twist birefringence) mode in which such a steep threshold value is obtained utilizes the birefringence of a liquid crystal cell having a twist angle of 180 degrees or more using the above liquid crystal. That is, it is necessary to cause the liquid crystal to be twisted by 180 degrees or more between the upper and lower substrates in the alignment direction. To this end, the liquid crystal molecules are required to have a pretilt angle of 3 to 30 degrees at the substrate electrode interface. Generally, such a pretilt angle is provided by an alignment film. On the other hand, if an alignment film that gives such a pretilt angle is used, generally, the alignment defects of the smectic liquid crystal such as the ferroelectric liquid crystal can be extremely reduced, and the bistability can be improved.

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 aligned liquid crystal molecules is at most 2 degrees. However, a large value cannot be obtained. Further, when an oblique vapor deposition film such as SiO is used as the alignment film, a large pretilt angle can be obtained, but forming the alignment film by vapor deposition has low mass productivity,
It cannot be said that it is advantageous in manufacturing.

As a coating type alignment film material capable of obtaining a large pretilt angle, a polyamic acid composition comprising a component having a fluorine atom in at least one of a carboxylic acid anhydride and a diamine (Japanese Patent Laid-Open No. 62-127827),
Also disclosed is an alignment treatment material for a polyimide resin obtained from a diamine, a tetracarboxylic dianhydride and a specific monoamine (JP-A-62-297819). Further, as a ferroelectric liquid crystal alignment film, a polyimide film obtained by using di-4-aminocyclohexylmethane as a base component and an aromatic tetracarboxylic acid anhydride having one or two benzene rings in the skeleton as an acid component ( JP-A-2-
No. 310524), and fluorine-containing polyimide (Japanese Patent Laid-Open No. 3-25418).

However, when the liquid crystal is oriented by using the above-mentioned orientation film, a large pretilt angle cannot always be obtained, and there is a problem that it tends to change depending on post-treatment conditions such as rubbing treatment.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device having a polyimide alignment film showing a large pretilt angle.

Another object of the present invention is to provide a liquid crystal display device having a polyimide alignment film suitable for multiplex driving.

[0011]

The above object is to provide a liquid crystal display device in which two transparent electrode substrates having an alignment film provided on a transparent electrode are arranged with the alignment film inside and a liquid crystal is sealed between them. At least one of the diamine compounds represented by the following general formula (I) and tetracarboxylic acid, tetracarboxylic acid diester, tetracarboxylic acid tetraester or tetracarboxylic acid dianhydride is selected on at least one of the transparent electrodes. This can be achieved by a liquid crystal display device characterized in that an alignment film made of a polyimide obtained from a tetracarboxylic acid derivative is formed. General formula (I)

[0012]

[Chemical 2]

In the above formula, X is --CO--, --CS--, --S.
-, - SO -, - SO 2 -, - CH 2 - represents, n represents 0
Or represents an integer of 1. Y represents a divalent group having a benzene ring.

The above general formula will be described in detail below. Examples of the specific group of Y in the general formula (I) are:

[Chemical 3]

[0015]

[Chemical 4]

[0016]

[Chemical 5]

[0017]

[Chemical 6]

[0018]

[Chemical 7]

[0019]

[Chemical 8]

[0020]

[Chemical 9]

[0021]

[Chemical 10] Etc.

Preferred embodiments of the liquid crystal display device of the present invention are as follows.

In the general formula (I), X is -CO-, -C.
S -, - S -, - CH 2 - are preferred, particularly preferably -CO -, - CH ₂ - is.

In the general formula (I), Y is particularly preferably a group shown below.

[Chemical 11]

Tetracarboxylic acid derivative used in the present invention
As tetracarboxylic acid, tetracarboxylic acid
Ter, tetracarboxylic acid tetraester and tetracal
Boric acid dianhydride can be used. Tetracarbon
Specific examples of the acid include 1,2,4,5-benzenthene.
Tracarboxylic acid, 3,3 ', 4,4'-diphenyl teto
Lacarboxylic acid, 1,4,5,8-naphthalene tetracal
Examples include boric acid and cyclopentane tetracarboxylic acid.
It Specific examples of tetracarboxylic acid diesters
Is 1,4-dimethoxycarbonyl-2,5-benzene
Dicarboxylic acid, 3,3'-diethoxycarbonyl-4,
4'-diphenyldicarboxylic acid, 1,3-dimethoxyca
Examples include rubonylcyclobutanedicarboxylic acid. Te
Specific examples of the tetracarboxylic acid tetraester include:
1,2,4,5-benzenetetracarboxylic acid tetramethyi
Ester, 3,3 ', 4,4'-diphenyltetraca
Rubonic acid tetraethyl ester, 1,4,5,8, -na
Phthalene tetracarboxylic acid tetramethyl ester, shiku
Lopentane tetracarboxylic acid tetramethyl ester, etc.
Can be mentioned. Specific examples of tetracarboxylic dianhydride and
Then, the tetracarboxylic acid dianhydride shown in Table 1
Can be mentioned. Table 1 Examples of tetracarboxylic dianhydride ───────────────────────────────────── Compound number Tetracarboxylic dianhydride A-1 1,2,4,5-benzenetetracarboxylic dianhydride A-2 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride A-3 3,3 ′, 4,4 ′ -Benzophenone tetracarboxylic acid dianhydride A-4 Bis (3,4-dicarboxyphenyl) ether dianhydride A-5 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride A-5 -6 1,4,5,8-naphthalenetetracarboxylic dianhydride A-7 cyclobutanetetracarboxylic dianhydride A-8 cyclopentanetetracarboxylic dianhydride ───────────── ────────────────────────

The tetracarboxylic acid derivative used in the present invention is preferably tetracarboxylic dianhydride.

Table 2 shows specific examples of the general formula (I) of the present invention, but the present invention is not limited thereto.

Table 2 Specific examples of general formula (I) of the present invention ─────────────────────────────────── ── Compound number Example compound name B-1 2,2-bis [4- (4-aminobenzoyl) phenyl] hexafluoropropane B-2 2,2-bis [4- (4- (4-aminophenoxy) benzoyl) phenyl] hexafluoropropane B -3 2,2-bis [4- (4-aminobenzyl) phenyl] hexafluoropropane B-4 2,2-bis [4- (4- (4-aminophenoxy) benzyl) phenyl] hexafluoropropane B-5 1,4-bis (3-aminobenzoyl) benzene B-6 2,2-bis [4- (4- (2-aminophenoxy) phenylsulfonyl) phenyl] propane B-7 2,2-bis [4- ( 4-Aminophenylthiocarbonyl) phenyl] hexafluoropropane B-8 1,4-bis [4- (2-aminophenoxy) phenylthio] tet Lafluorobenzene B-9 bis [4- (4-aminobenzoyl) phenyl] sulfone B-10 2,2-bis [4- (4-aminophenylthio) -3-fluorophenyl] propane B-11 bis [2 -(4-Aminophenylsulfinyl) -5-fluorophenyl] methane ──────────────────────────────────── ─

A preferred structure of the liquid crystal display device obtained by the manufacturing method of the present invention will be described. FIG. 1 shows a cross-sectional view of an example of the liquid crystal display element of the present invention.

On the transparent substrates 1a and 1b, the transparent electrodes 2a,
2b and alignment films 3a and 3b are stacked in this order 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 3a and 3b face each other, and the ferroelectric liquid crystal 4 is enclosed between them. The transparent electrodes 2a and 2b are formed on the transparent substrates 1a and 1b, respectively, in the form of a striped display pattern.

As described above, the transparent electrodes 2a and 2b are formed in a stripe shape, and the stripe shapes 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.

The liquid crystal display element of the present invention is provided with the above-mentioned alignment film 3a.
And 3b are formed from a polyimide using the diamine compound of the general formula (I) as a diamine component.
By using this alignment film, it is possible to align the liquid crystal, particularly the ferroelectric liquid crystal, with a large pretilt angle which can be obtained only by the alignment film formed by oblique vapor deposition of SiO 2.

The liquid crystal display device of the present invention is not limited to the one shown in FIG. 1, but all the modes which are carried out for ordinary liquid crystal display devices such as the use of spacers are possible. In particular, the gap between both alignment films (that is, the layer thickness of the liquid crystal layer)
It is preferred that a spacer be used to ensure As the spacer, glass fiber, glass
Beads, plastic beads, metal oxide particles such as alumina and silica are used. The particle size of the spacer is
Depending on the liquid crystal used, alignment film material, setting of the gap, particles used as spacers, etc., 1.2
Generally, it is from 6 μm to 6 μm.

The liquid crystal display device of the present invention can be manufactured, for example, 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 polyimide alignment film of the present invention can be produced by various methods, but preferably a polyamic acid obtained from at least one of the diamine compounds represented by the general formula (I) and a tetracarboxylic acid derivative. It can be obtained by dehydration condensation of some or all of the above.

Regarding the production of the above polyamic acid, the molar ratio of the diamine compound to the tetracarboxylic acid derivative may be any ratio, but preferably the diamine compound / tetracarboxylic acid derivative (mol number / mol number) is 0.50 to 2 .0
Within the range, and particularly preferably 0.83 to 1.2.

Further, regarding the production of the polyamic acid, it may be copolymerized with a diamine compound other than the general formula (I).

The alignment film of the present invention is prepared by dissolving a polyamic acid synthesized from at least one diamine compound represented by the general formula (I) and the above tetracarboxylic acid derivative in a solvent to prepare a coating liquid for forming the alignment film. It is formed by preparing, coating this on a substrate, drying and heat-treating a part or all of the polyimide film.

Synthesis Examples 1 to 3 of the diamine represented by the above general formula (I) are shown below.

Synthesis Example 1 Synthesis of B-1 2,2-bis [4- (4-fluorobenzoyl) phenyl] hexafluoropropane 10.96 g (0.02 mol) and potassium phthalimide 7.8 g (0.042 mol) 2) in 50 ml of dimethylacetamide at 140 ° C.
9.0 g (0.11 mol) of 2,2-bis [4- (4-phthalimidobenzoyl) phenyl] hexafluoropropane obtained by reacting for 4 hours was added to 100 ml of ethanol.
In addition to potassium hydroxide 1.7g (0.03mol), water 1
Stir for 30 minutes at 50 ° C. in the presence of 0 ml, then 12N
Hydrochloric acid (5 ml, 0.06 mol) was added, the mixture was heated under reflux for 2 hours, stirred and then poured into water. The solid obtained by the neutralization treatment was subjected to column chromatography (acetic acid ethyl ester / toluene = 1/2 to silica gel). 1.82g (0.0034mol) of diamine compound B-1 was obtained by refine | purifying by the ().

Synthesis Example 2 Synthesis of B-2 4.29 g (0.01 mol) of acid chloride obtained by reacting 2,2-bis (4-carboxyphenyl) hexafluoropropane with thionyl chloride and aluminum chloride 4
To a solution of 60 g of carbon disulfide (0.03 mol) to 5 ml of nitrobenzene, 4-phenoxyacetanilide 4.5 was added.
4 g (0.02 mol) was added, the mixture was heated under reflux for 9 hours, stirred and then poured into dilute hydrochloric acid, and the obtained solid was added to ethanol 100.
After heating and refluxing in 10 ml of 12 ml hydrochloric acid for 13 hours and stirring, the solid obtained by the neutralization treatment by pouring into water was subjected to column chromatography (acetic acid ethyl ester / hexane =
(2/1 to silica gel) to obtain 3.0 g (0.0041 mol) of diamine compound B-2.

Synthesis Example 3 Synthesis of B-3 4.0 g of 2,2-bis [4- (4-fluorobenzoyl) phenyl] hexafluoropropane used in Synthesis Example 1
(0.005 mol) 30 ml of diethylene glycol
2.53 g (0.05 mol) of hydrazine monohydrate,
In the presence of 2.81 g (0.05 g) potassium hydroxide, 2
After stirring at 15 to 225 ° C. for 4 hours, the mixture was poured into water and the extract with chloroform was purified by column chromatography (acetic acid ethyl ester to silica gel) to obtain 1.50 g (0.00292 mol of diamine compound B-3). )Obtained.

Synthesis examples 4 to 7 of polyamic acid are shown below.

Synthesis Example 4 Polyamic Acid; Synthesis of C-1 A solution of 1.50 g (0.00292 mol) of the diamine compound of B-3 in 19.22 g of N-methyl-2-pyrrolidone was added to the tetracarboxylic acid diacid of A-1. Anhydrous 0.636 g (0.
(00292 mol) and stirred at room temperature for 6 hours to obtain 10 wt.
% Polyamic acid; C-1 solution was obtained.

Synthesis Example 5 Synthesis of polyamic acid; C-2 The procedure of Synthesis Example 4 was repeated except that B-1 was used as the diamine compound.

Synthesis Example 6 Synthesis of Polyamic Acid; C-3 The procedure of Synthesis Example 4 was repeated except that B-2 was used as the diamine compound.

Synthesis Example 7 Polyamic acids C-4 to C-23 were obtained according to Synthesis Examples 4 to 6. This is shown in Table 3. Table 3 Synthesis of polyamic acid Polyamic acid Diamine acid anhydride Diamine / acid anhydride (molar ratio) C-4 B-4 A-1 1/1 C-5 B-3 A-1 1 / 1.1 C-6 B-3 A-1 1.1 / 1 C-7 B-5 A-1 1/1 C-8 B-6 A-1 1/1 C-9 B-7 A-1 1.2 / 1 C -10 B-8 A-1 1/1 C-11 B-9 A-1 1 / 1.15 C-12 B-10 A-1 1/1 C-13 B-11 A-1 1/1 C -14 B-3 A-2 1/1 C-15 B-3 A-3 1/1 C-16 B-3 A-4 1/1 C-17 B-3 A-5 1/1 C-18 B-3 A-6 1/1 C-19 B-3 A-7 1/1 C-20 B-3 A-8 1/1 C-21 aB-1 bB-3 A-1 (a / b = 0.5 / 0.5) / 1 C-22 B-3 cA-1 dA-2 1 / (c / d = 0.5 / 0.5) C-23 aB-1 bB-3 cA-1 dA-2 (a / b = 0.5 / 0.5) / (c / d = 0.5 / 0.5) ────────────────────────── ───────────

The coating solution for forming an alignment film is prepared by using the polyamic acid solution obtained above or the polyamic acid obtained by reprecipitation or the like in a suitable form such as pyridine, N-methyl-2-pyrrolidone, dioxane, THF or a glycol derivative. A solution dissolved in a solvent can be prepared. This coating solution contains
In addition to the above components, other polymer such as high molecular weight polymer and organic metal may be added for the purpose of increasing the adhesion to the substrate or adjusting the viscosity of the coating liquid.

The coating liquid for forming an alignment film is coated on a transparent electrode and an exposed substrate by a spin coater or the like, and at room temperature to 150 ° C. under atmospheric pressure or reduced pressure for 1 to 120 minutes (preferably 80 to 120 ° C.). At 10-80 minutes). Next, the coating film is heat-treated at 150 to 300 ° C. under normal pressure or reduced pressure for 0.5 to 3 hours. Heating is the latter one
Only heating at 50 to 300 ° C. for 0.5 to 3 hours is sufficient.
As a result, a polyimide alignment film is formed.

The thickness of the obtained alignment film is 10 to 800 nm, preferably 20 to 100 nm, although it varies depending on the type of liquid crystal and the alignment film used.

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 polyimide alignment film of the present invention thus formed allows liquid crystals to be aligned with a large pretilt angle. This polyimide alignment film is characterized by using a diamine compound represented by the above general formula (I) as a diamine component of polyimide.

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 form 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 such as those 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.

The liquid crystal display device thus obtained is
The enclosed liquid crystal can be aligned with a large pretilt angle. The pretilt angle of the liquid crystal is preferably 3 to 90 degrees, and particularly preferably 5 to 40 degrees.

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. Furthermore, the liquid crystal display element of the present invention may be provided with a structure such as a reflection plate and a retardation plate, which are provided in a conventional liquid crystal display element, depending on the purpose of use.

[0063]

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

On the above-mentioned insulating layer, 20 parts by weight of C-1 10 wt% N-methylpyrrolidone solution of polyamic acid, diluent for coating liquid (20% N-methylpyrrolidone, 40% ethylene glycol monobutyl ether, diethylene glycol monoethyl ether) 40%) 80 parts by weight of the coating solution prepared was applied by a spinner.

The conditions for the spinner are 2500 rpm.
m., time 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 3 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 pretilt angle of the obtained liquid crystal display device was measured by a crystal rotation method using a polarizing microscope manufactured by Nikon Corporation. The pretilt angle was 17 °.

Example 2 A liquid crystal display device was manufactured in the same manner as in Example 1 except that C-2 polyamic acid was used as the polyamic acid.

The pretilt angle of the obtained liquid crystal display element was measured in the same manner as in Example 1 and it was 5 °.

Example 3 A liquid crystal display device was manufactured in the same manner as in Example 1 except that C-3 polyamic acid was used as the polyamic acid.

The pretilt angle of the obtained liquid crystal display device was measured in the same manner as in Example 1, and it was 5 °.

Example 4 In Example 1, when rubbing with a nylon raised fabric, the rubbing direction with the respective rubbing surfaces inside was changed from anti-parallel 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 device was manufactured in the same manner as in Example 1 except that the number was changed to 1023.

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 5 In Example 4, the liquid crystal was a ferroelectric liquid crystal CS-1023.
To liquid crystal compositions shown in Table 4 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 4. Table 4 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 ───────────────── ─────────────────────

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.

Examples 6 to 27 In Example 4, C shown in Table 1 as the polyamic acid.
A liquid crystal display device was manufactured in the same manner as in Example 4 except that polyamic acids of -2-C-23 were used.

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

[0080]

INDUSTRIAL APPLICABILITY As shown in the above examples, in the liquid crystal display element of the present invention, the diamine compound of the present invention represented by the general formula (I) is used as an alignment film for aligning the enclosed liquid crystal. By using at least one of the polyimides obtained by using as an amine component, the liquid crystal can be aligned with a large pretilt angle that can be obtained only by the alignment film formed by oblique vapor deposition of SiO, and alignment defects are almost eliminated. However, it is possible to obtain an improved bistability. Furthermore, the alignment film of the present invention can be formed by coating, which is advantageous in manufacturing.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a configuration example of a liquid crystal display element of the present invention.

[Explanation of symbols]

 1a, 1b: transparent substrate 2a, 2b: transparent electrode 3a, 3b: alignment film 4: liquid crystal

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 28, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Claims]

[Chemical 1] In the above formula, X is -CO-, -CS-, -S-, -SO-,
Represents --SO _2- , --CH _2- , and Y represents a divalent group having a benzene ring.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

In the above formula, X is --CO--, --CS--, --S.
_{-, - SO -, - SO} 2 -, - CH 2 - , Y represents represents a divalent group having a benzene ring.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

Synthesis Example 3 Synthesis of B-3 2,2-bis [4- (4-phthalimidobenzoyl) phenyl] hexafluoropropane used in Synthesis Example 1
0 g (0.0051 mol) of diethylene glycol 30
In the presence of 2.53 g (0.05 mol) of hydrazine monohydrate and 2.81 g (0.05 mol) of potassium hydroxide in ml, 100 ° C. for 1 hour, 150 ° C. for 1 hour, 180 ° C.
After stirring for 4 hours at room temperature, the mixture is poured into water and the extract with chloroform is purified by column chromatography (chloroform to silica gel) to give 1.
Obtained 50 g (0.00292 mol). Diamine compound B
The melting point of -3 was 92 to 94 ° C. ─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 30, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

Synthesis Example 7 Polyamic acids C-4 to C-23 were obtained according to Synthesis Examples 4 to 6. This is shown in Table 3.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0064

[Correction method] Change

[Correction content]

Examples 1 to 10 Indium-tin oxide (ITO) transparent electrodes were formed into stripes (electrode width: 100 μm, gap between electrodes: 15 μm) on two 1.1 mm thick glass substrates. Formed.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0066

[Correction method] Change

[Correction content]

On the insulating layer, 20 parts by weight of a 10 wt% polyamic acid N-methyl-2-pyrrolidone solution of C-1 or C-18, a diluent for coating liquid (N-methyl-2-pyrrolidone 20%, ethylene Glycol monobutyl ether 40%, diethylene glycol monoethyl ether 4
0%) 80 parts by weight of the coating solution prepared was applied by a spinner.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0067

[Correction method] Change

[Correction content]

The condition of the spinner is that the number of revolutions is 2500 rpm.
p. m. The time was 30 seconds. After coating, the polyimide alignment film was formed by drying at a heating temperature shown in Table 5 for 1 hour.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0068

[Correction method] Change

[Correction content]

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 the cells with a 2 μm spacer interposed therebetween. Liquid crystal composition A shown in Table 4 was added to this cell at 110 ° C.
, And kept at 110 ° C. for 30 minutes and gradually cooled to room temperature over about 2 hours.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0069

[Correction method] Change

[Correction content]

Table 5 shows the results of measuring the pretilt angle of the obtained liquid crystal display element by a crystal rotation method using a polarizing microscope manufactured by Nikon Corporation.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0070

[Correction method] Change

[Correction content]

Example 11 A liquid crystal display device was manufactured in the same manner as in Example 1 except that C-2 polyamic acid was used as the polyamic acid. Shown in.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0072

[Correction method] Change

[Correction content]

Example 12 A liquid crystal display device was manufactured in the same manner as in Example 1 except that C-3 polyamic acid was used as the polyamic acid. Shown in.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0074

[Correction method] Change

[Correction content]

Examples 13 to 16 In each of Examples 2 to 3 and 8 to 9, during rubbing treatment with a nylon raised fabric, the rubbing direction was changed from antiparallel to the same direction with each rubbing surface facing inward. A liquid crystal display device was manufactured in the same manner as in Examples 2 to 3 and 8 to 9 except that the liquid crystal composition A shown in Table 4 was changed to a ferroelectric liquid crystal CS-1023 manufactured by Chisso Corporation. did.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0076

[Correction method] Change

[Correction content]

Examples 17 to 20 In each of Examples 13 to 16, the liquid crystal was changed from the ferroelectric liquid crystal CS-1023 to the liquid crystal composition B shown in Table 6 below.
[Phase transition temperature (° C.) C ^* 58.0A83.4N ^* 89.
31Iso], and a liquid crystal display device was manufactured in the same manner as in each of Examples 13 to 16.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0078

[Correction method] Change

[Correction content]

Examples 21 to 41 In Examples 17, except that the polyamic acids of C-2 to C-17 and C-19 to C-23 shown in Table 3 were used and the heating and drying temperature was 295 ° C. A liquid crystal display device was manufactured in the same manner as in Example 17.

Claims (1)

[Claims] 1. In a liquid crystal display device in which liquid crystal is sealed between two substrates having an alignment film, at least one of the alignment films and at least one diamine compound represented by the following general formula (I) A liquid crystal display device comprising an alignment film made of a polyimide obtained from a tetracarboxylic acid derivative selected from carboxylic acid, tetracarboxylic acid diester, tetracarboxylic acid tetraester or tetracarboxylic dianhydride. General formula (I): In the above formula, X is -CO-, -CS-, -S-, -SO-,
Represents --SO _2- , --CH _2- , and n represents an integer of 0 or 1. Y represents a divalent group having a benzene ring.