JPH086031A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain a liquid crystal display element in which a high pretilt angle is obtd. and uneven luminance or uneven afterimages are hardly produced even when low temp. baking is applied by using an org. oriented film comprising a specified polymerized material. CONSTITUTION:This display element has an org. oriented film between a transparent electrode and a liquid crystal layer. The oriented film consists of a compd. obtd. by the reaction of carboxylic acid and a compd. expressed by an ortho-ortho structure. It is preferable that the org. oriented film contains a diamine compd. having an ortho-ortho structure expressed by formula. In formula, Ri (i=1 to 4) and Rj (j=1 to 4) are independently hydrogen atoms, alkyl groups, cycloalkyl groups, alkoxy groups or halogen atoms and may be same or different. Rm and Rn are independently hydrogen atoms, alkyl groups, halogenated alkyl groups or phenyl groups and may be same or different.

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 using a polymer composed of a diamine having a novel ortho-ortho type structure and a carboxylic acid component as an organic alignment film.

[0002]

2. Description of the Related Art A nematic liquid crystal having a positive dielectric anisotropy is sandwiched on a substrate with a transparent electrode by using an organic alignment film made of polyimide so that the major axis of liquid crystal molecules is twisted by 90 degrees between the substrates. Twisted liquid crystal display elements, super twist liquid crystal display elements with improved contrast and viewing angle dependence, active matrix liquid crystal display elements, etc. have been developed. A super twist liquid crystal display element is one in which the major axis of liquid crystal molecules is twisted by 180 degrees or more between substrates, and an active matrix liquid crystal display element is one in which liquid crystal is driven on an active matrix type electrode substrate. However, the super twist liquid crystal display element and the active matrix liquid crystal display element have problems of scattering (light scattering) domain and edge domain, which are caused by a small pretilt angle when they are manufactured by using an organic alignment film of polyimide. Therefore, various polyimide alignment films having a high pretilt angle have been proposed (Japanese Patent Laid-Open No. 64-64-
25127, JP-A-62-262829, JP-A-63-262620,
JP-A-62-127827, JP-A-62-174725, JP-A-2-2
No. 10328, Japanese Patent Laid-Open No. 2-250033).

[0003]

However, in the super twist liquid crystal display element and the active matrix liquid crystal display element, it is required to increase the production of color display elements and to reduce the cost of the display elements. In order to improve the color fading stability and the yield of liquid crystal display elements, a process material capable of low temperature firing (220 ° C. or lower) is desired. However, the conventional polyimide alignment films have many problems such as difficulty in increasing the pretilt angle when fired at a low temperature, and remarkable occurrence of uneven brightness and residual image afterimage.

An object of the present invention is to provide a liquid crystal display device which has a high pretilt angle and is less likely to have uneven brightness and residual image even after low temperature firing.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors found that a conventional organic alignment film of a polymer using a diamine compound represented by a para-para structure is used. The present invention has been found to be able to solve the above-mentioned problems by making an organic alignment film of a polymer that uses a diamine compound represented by an ortho-ortho structure, which is very different.

In the present invention, the main factors affecting the generation mechanism of the pretilt angle, the uneven brightness, and the residual image phenomenon of the remaining image have not been clarified. Therefore, in order to achieve compatibility with an organic alignment film capable of high pretilt angle, low luminance unevenness and low afterimage by low temperature curing, various diamine compounds were used and analyzed from the relationship with the chemical structure. At that time, the glass transition temperature was lowered for low temperature curing, and the conformational distortion was increased for a high pretilt angle so that the liquid crystal molecules were tilted and adsorbed. An organic alignment film using a diamine compound having a different ortho-ortho structure was reached. As a result, the glass transition temperature of the polymer represented by the ortho-ortho type structure is lower than that of the polymer represented by the conventional para-para type structure, and the distortion of the conformation becomes large, so that the low temperature firing is performed. We have found that a high pretilt angle is possible.
Further, although it is not yet clear about the uneven brightness and the afterimage phenomenon, the residual potential is generated in the element due to the adsorption of the ionic impurities to the alignment film, the frequency fluctuation of the threshold voltage is large, and It is considered that variations in threshold voltage and variations in transmittance occur due to a decrease in AC specific resistance, which causes display unevenness. Therefore, the polymer having the ortho-ortho structure obtained above is used for the alignment film, and the pretilt angle, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance are obtained under the condition of low temperature firing. As a result of the measurement, the characteristics of the liquid crystal display device were improved, the problems to date were achieved, and the present invention was obtained.

That is, the present invention has the general formula [2]

[0008]

Embedded image

(Where Ri (i = 1 to 4) and Rj
(J = 1 to 4) each independently represent hydrogen, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom, which may be the same or different from each other, and Rm
And Rn each independently represent hydrogen, an alkyl group, a halogenated alkyl group or a phenyl group, which may be the same or different from each other) and a diamine compound containing a compound represented by The present invention relates to a liquid crystal display device using the polymer obtained in the organic alignment film. In addition, the organic alignment film of the present invention is formed by applying each precursor, for example, polyimide, polyimide siloxane, polyamide imide, polyhydrazide imide, polyimide isoindoloquinazolinedione, polyamide onto a substrate, and then dehydrating and ring-closing the organic alignment film. And Further, a copolymerization system of a diamine compound represented by the general formula [2] and another diamine compound or a mixture system of polymers can be used for the organic alignment film.

The diamine compound represented by the above general formula [1] used in the present invention has an ortho-ortho type structure, for example, bis [2- (4-aminophenoxy) phenyl] methane, bis [2- (4 -Aminophenoxy) -5-methylphenyl] methane, bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] methane, bis [2-
(4-Aminophenoxy) -3,4,5-trimethylphenyl] methane, bis [2- (4-aminophenoxy)
-3,5,6-trimethylphenyl] methane, bis [2
-(4-Aminophenoxy) -5-ethylphenyl] methane, bis [2- (4-aminophenoxy) -3,5-
Diethylphenyl] methane, bis [2- (4-aminophenoxy) -5-n-propylphenyl] methane, bis [2- (4-aminophenoxy) -5-isopropylphenyl] methane, bis [2- (4- Aminophenoxy)
-3-Methyl-5-isopropylphenyl] methane, bis [2- (4-aminophenoxy) -5-methyl-3-
Isopropylphenyl] methane, bis [2- (4-aminophenoxy) -5-n-butylphenyl] methane, bis [2- (4-aminophenoxy) -5-isobutylphenyl] methane, bis [2- (4- Aminophenoxy)
-5-s-Butylphenyl] methane, bis [2- (4-
Aminophenoxy) -3-methyl-5-t-butylphenyl] methane, bis [2- (4-aminophenoxy)-
5-methyl-3-t-butylphenyl] methane, bis [2- (4-aminophenoxy) -3-methyl-5-octylphenyl] methane, bis [2- (4-aminophenoxy) -3-methyl- 5-nonylphenyl] methane,
Bis [2- (4-aminophenoxy) -5-cyclohexylphenyl] methane, Bis [2- (4-aminophenoxy) -3-methyl-5-cyclohexylphenyl] methane, Bis [2- (4-aminophenoxy) -5-methyl-3-cyclohexylphenyl] methane, bis [2-
(4-Aminophenoxy) -5-methylphenyl] methane, bis [2- (4-aminophenoxy) -3-methyl-5-methylphenyl] methane, 1,1-bis [2-
(4-Aminophenoxy) -5-methylphenyl] ethane, 1,1-bis [2- (4-aminophenoxy)-
3,5-Dimethylphenyl] ethane, 1,1-bis [2
-(4-Aminophenoxy) -5-methylphenyl] propane, 2,2-bis [2- (4-aminophenoxy)]
Phenyl] octane, 1,1-bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] propane,
2,2-bis [2- (4-aminophenoxy) phenyl] decane, 2,2-bis [2- (4-aminophenoxy) phenyl] propane, 2,2-bis [2- (4-aminophenoxy)] Phenyl] dodecane, 2,2-bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] propane, 1,1-bis [2- (4-aminophenoxy) -5-methylphenyl] butane, 1,1-bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] butane, 2,2-bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] butane, 1,
1-bis [2- (4-aminophenoxy) -5-methylphenyl] -3-methylpropane, 1,1-bis [2-
(4-Aminophenoxy) -3,5-dimethylphenyl] -3-methylpropane, 1,1-bis [2- (4-
Aminophenoxy) -5-methylphenyl] cyclopentane, 1,1-bis [2- (4-aminophenoxy)-
3,5-Dimethylphenyl] cyclopentane, 1,1-
Bis [2- (4-aminophenoxy) -5-methylphenyl] cyclohexane, 1,1-bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] cyclohexane, 1,1-bis [2- (4-aminophenoxy)
-5-Methylphenyl] -3,3,5-trimethylcyclohexane, 1,1-bis [2- (4-aminophenoxy) -3,5-dimethylphenyl] -3,3,5-trimethylcyclohexane, 9, 9-bis [2- (4-aminophenoxy) -5-methylphenyl] fluorenone,
9,9-bis [2- (4-aminophenoxy) -3,5
-Dimethylphenyl] fluorenone and the like can be mentioned, and these can be used alone or in combination of two or more. The diamine compound or dihydrazide compound that can be polymerized with the above diamine compound is, for example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenyl ether, 4,
4'-diaminodiphenyl ether-3-carbonamide, 3,3'-diaminodiphenyl ether, 3,3 '
-Diaminodiphenyl ether-4-carbonamide,
4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane,
4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 4,4'-diaminotaphenyl, 1,1-metaxylylenediamine, 1,
4-diaminocyclohexane, isophthalic acid dihydrazide, sebacic acid dihydrazide, succinic acid dihydrazide,
3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dibutyl-4,4'-diaminodiphenylmethane, 3,3'-dibutoxy-4,4'-diaminodiphenylmethane, 2,4-diamino -1-dodecylbenzene, 2,4-diamino-1-octylbenzene,
2,4-diamino-1-octyloxybenzene, 2,
4-diamino-1-methoxymethylenebenzene, 3,
3'-dimethyl-4,4'-diaminodiphenyl ether, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, 2,2-bis [4- ( 4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4
-(4-aminophenoxy) phenyl] pentane, 2,
2-bis [4- (4-aminophenoxy) phenyl] hexane, 2,2-bis [4- (4-aminophenoxy)
Phenyl] octane, 2,2-bis [4- (4-aminophenoxy) phenyl] decane, 2,2-bis [4-
(4-Aminophenoxy) phenyl] tridecane, 2,
2-bis [4- (4-aminophenoxy) phenyl] pentadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] methane, 2,2-bis [4- (4-aminophenoxy) phenyl] Sulfone, 2,2-bis [4
-(4-aminophenoxy) phenyl] ketone, 2,2
-Bis [4- (4-aminophenoxy) phenyl] biphenyl, 2,2-bis [4- (4-aminophenoxy)
Phenyl] cyclohexane, 2,2-bis [4- (4-
Aminophenoxy) phenyl] methylcyclohexane,
2,2-bis [4- (4-aminophenoxy) phenyl] propylcyclohexane, bis [4- (4-aminobenzoyloxy) benzoic acid] propane, bis [4-
(3-Aminobenzoyloxy) benzoic acid] propane,
Bis [4- (4-aminobenzoyloxy) benzoic acid]
Pentane, bis [4- (4-aminobenzoyloxy)
Benzoic acid] octane, bis [4- (4-aminobenzoyloxy) benzoic acid] cyclohexane, bis [4- (4
-Aminobenzoyloxy) benzoic acid] methylcyclohexane, bis [4- (4-aminomethylbenzoyloxy) benzoic acid] propane, bis (4-aminobenzoyloxy) propane, bis (4-aminobenzoyloxy) methane, bis ( 4-aminobenzoyloxy) hexane, bis (4-aminobenzoyloxy) octane,
Bis (4-aminobenzoyloxy) decane, bis (4
-Aminobenzoyloxy) octadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis [4- (2-aminophenoxy) -3,5-dimethylphenyl] hexa Further, diamines such as fluoropropane and 4,4′-bis (4-amino-2-trifluoromethylphenoxy) biphenyl

[0011]

[Chemical 3]

[0012]

[Chemical 4]

[0013]

[Chemical 5]

[0014]

[Chemical 6]

Examples thereof include diaminosiloxane and the like, and these can be used alone or in combination of two or more kinds.

On the other hand, the carboxylic acid component is, for example, pyromellitic dianhydride, methylpyromellitic dianhydride,
3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-diphenylmethanetetracarboxylic acid Dianhydride, 3,3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride, 3,
3 ', 4,4'-diphenylsulfone tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3', 4,4'-diphenylpropane tetracarboxylic dianhydride Thing 2,2- [4- (3,4-
Dicarboxyphenoxy) phenyl] propane tetracarboxylic dianhydride, 2,2- [4- (3,4-dicarboxyphenoxy) phenyl] hexafluoropropane tetracarboxylic dianhydride, 2,2- [4- ( 3,4-Dicarboxyphenoxy) phenyl] octyltetracarboxylic dianhydride, 2,2- [4- (3,4-dicarboxybenzoyloxy) phenyl] propanetetracarboxylic dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] tridecanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclobutanetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, 1, 4-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid chloride, 4,4'-diph Alkenyl ether dicarboxylic acid,
4,4'-diphenyl ether dicarboxylic acid chloride, 4,4'-diphenylmethane dicarboxylic acid, 4,
4'-diphenylmethanedicarboxylic acid chloride, isophthalic acid, isophthalic acid chloride, isophthalic acid dichloride, terephthalic acid chloride, terephthalic acid dichloride, adipic acid, adipic acid chloride, adipic acid dichloride, stearic acid chloride, stearic acid dichloride and the like, These are 1 or 2
Combinations of more than one species can be used.

Further, the organic alignment film is composed of N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, butyl lactone, cresol, phenol, cyclohexanone,
Dioxane, tetrahydrofuran, butyl cellosolve,
It can be synthesized at −20 to 200 ° C. in a solvent such as butyl cellosolve acetate or acetophenone.

Further, the organic alignment film may be a film in which imidization has progressed, as long as it has solubility other than complete polyamic acid or its derivative. In addition, γ-aminopropyltriethoxysilane, δ-aminopropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and other amino silane coupling agents, epoxy silane coupling agents, and titanates. The coupling agent, aluminum alcoholate, aluminum chelate, zirconium chelate and the like can be mixed or reacted in the varnish. The alignment film can be formed by general spin coating, printing, brush coating, spraying, or the like.

The liquid crystal material used is, for example, 4-substituted phenyl-4'-substituted cyclohexane, 4-substituted cyclohexyl-4'-substituted cyclohexane, 4-substituted phenyl-.
4'-substituted dicyclohexane, 4-substituted dicyclohexyl-4'-substituted diphenyl, 4-substituted-4 "-substituted
Phenyl, 4-substituted biphenyl-4'-substituted cyclohexane, 2- (4-substituted phenyl) -5-substituted pyrimidine, 4-substituted benzoic acid-4'-phenyl ester, 4-
Substituted cyclohexanecarboxylic acid-4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid-4'-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy) benzoic acid-4'-substituted phenyl ester, 4- (4 -Substituted cyclohexyl) benzoic acid-4 '
-Substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid-4'-substituted cyclohexyl ester, 4
-Substituted-4'-substituted biphenyl and the like,
Among these compounds, at least one end of the molecule has an alkyl group, an alkoxy group, an alkoxymethylene group,
A liquid crystal compound having a cyano group, a fluorine group, a difluorine group or a trifluorine group is preferable.

[0020]

The present invention finds an organic alignment film having an ortho-ortho structure by analyzing the glass transition temperature, conformation and the like, and has a high pretilt angle in low temperature firing, frequency characteristics of threshold voltage, residual DC voltage and The objectives were achieved because the characteristics of voltage holding ratio and AC specific resistance could be improved.
That is, by using a polymer having an ortho-ortho structure as an organic alignment film, the glass transition temperature is reduced, the distortion of conformation is expanded, and the adsorption motion of ionic impurities is restricted by the reduction of polarization, and the above characteristics are It is considered that the improvement makes it possible to reduce the display unevenness by reducing the change in the threshold voltage and the change in the transmittance. As a result, an organic alignment film that can be used even in a low temperature firing process can be obtained, and the fading of the color filter and the occurrence of display unevenness are reduced, and a liquid crystal element of high display quality is achieved.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 0.1 mol% of bis [2- (4-aminophenoxy) -5-methylphenyl] methane was dissolved in N-methyl-2-pyrrolidone, and then pyromellitic dianhydride was added. When 05 mol% and 0.05 mol% of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride were added and reacted at 5 ° C for 7 hours, a pale yellow viscous varnish was obtained. The varnish was diluted to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve, and 4% by weight of γ-aminopropyltriethoxysilane was added in a solid content to prepare a composition for a liquid crystal alignment film. . Then IT
After spinner coating on a glass substrate with O transparent electrode, 150
Approximately 600 after calcination at ℃ and heat curing at 220 ℃ for 1 hour
A Å polyimide film was formed. Further, rubbing was performed under the conditions of a cut of 0.3 mm, a rotation speed of 700 rpm, and a feed speed of 1000 mm / min, and after printing an epoxy-based sealant, ZLI-4792 (trade name, manufactured by Merck) was sealed. A liquid crystal cell was produced. To stabilize the liquid crystal cell 1
After aging treatment at 30 ° C. for 1 hour, the pretilt angle was measured by the crystal rotation method. As a result, a high pretilt angle value of 5.6 degrees was shown. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured.
1, 2, and 3 show the frequency characteristic curve of the threshold voltage, the residual DC voltage, and the method of measuring the voltage holding ratio. The frequency characteristics of threshold voltage are 30Hz and 1KH as shown in Fig.1.
It was calculated as the ratio of the threshold voltage of z. The residual DC voltage is
A rectangular wave having an amplitude of 6 V and an offset of 1 V and a frequency of 30 Hz was applied for 30 minutes using the apparatus shown in FIG. 2, and the difference was calculated as the difference between the flicker erasing voltage after application of the DC component and the initial flicker erasing voltage. The voltage holding ratio was measured using the device shown in FIG.
The output signal from the drain was calculated as the ratio of the effective value of the input source signal under the conditions that the output signal from the drain was a signal having an amplitude of 6 V, a rectangular wave of 165 ms with an offset of 0 V, and a pulse width of 35 μs of the gate signal. The alternating current specific resistance was obtained from the resistance component by measuring the impedance at 30 Hz using an LCR meter. The respective results are shown in Table 1.

Next, the above-mentioned alignment film varnish was applied by printing onto a transparent electrode substrate with a color filter, and then prebaked at 150 ° C. and heat-cured at 220 ° C. for 1 hour to form a polyimide film of about 600 Å. Furthermore, in order to set the twist angle of the liquid crystal molecules held between the substrates to 250 degrees, the upper and lower substrates are rubbed at respective angles, and after seal printing between the substrates,
Substituted phenyl-4'-substituted cyclohexane, 4-substituted cyclohexanecarboxylic acid-4'-substituted phenyl ester, 4-substituted cyclohexyl-4'-substituted cyclohexane, 4-substituted phenyl-4'-substituted dicyclohexane,
0.5 wt% of a chiral agent S811 (trade name, manufactured by Merck & Co., Inc.) is added to a liquid crystal component having an alkyl group, a cyano group, a fluorine group and a difluorine group at one end of 4-substituted dicyclohexyl-4'-substituted diphenyl. The added liquid crystal composition was enclosed to prepare a super twist liquid crystal display device. Then, aging treatment (130 ° C., 1 hour) was performed to display a window pattern on the screen, and as a result, a liquid crystal display element in which unevenness in brightness and defective afterimage were reduced was obtained.

(Example 2) Bis [2- (4-aminophenoxy) -3,4,5-trimethylphenyl] methane 0.08 mol% and diaminosiloxane 0.03 shown in Chemical formula 3
After dissolving 02 mol% in N-methyl-2-pyrrolidone,
Add 0.05 mol% of pyromellitic dianhydride and 0.05 mol% of cyclobutanetetracarboxylic dianhydride, and add 1
When the reaction was carried out at 0 ° C for 8 hours, a pale yellow viscous varnish was obtained. The varnish was diluted to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve, and 4% by weight of γ-aminopropyltriethoxysilane was added in a solid content to prepare a composition for a liquid crystal alignment film. . Then ITO
After spinner coating on a glass substrate with a transparent electrode, 150 ℃
Approximately 500Å
The polyimide siloxane film of was formed. Furthermore, 0.3 mm
Rubbing was carried out under the conditions of notches, a rotation speed of 700 rpm, and a feed rate of 1000 mm / min. After printing an epoxy-based sealant, ZLI-4792 (trade name of Merck Ltd.) liquid crystal was enclosed to prepare a liquid crystal cell. . As a result of measuring the pretilt angle by the crystal rotation method after aging treatment at 130 ° C for 1 hour to stabilize the liquid crystal cell, 4.
A high pretilt angle value of 8 degrees was shown. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured. The respective results are shown in Table 1.

[0025]

[Table 1]

Next, the above-mentioned alignment film varnish is applied by printing on a substrate for an active matrix having a color filter, and then calcinated at 150 ° C. and heat-cured at 200 ° C. for 1 hour to form a polyimide siloxane film of about 500 Å. did. Furthermore, in order to make the twist angle of the liquid crystal molecules held on the substrate 90 degrees, the upper and lower substrates are rubbed at each angle,
The active matrix liquid crystal display device was manufactured by performing seal printing between the substrates and enclosing the liquid crystal of Example 1 in the device having a gap of 6.5 μm, and after aging treatment (130 ° C., 1 hour), a window pattern was formed on the screen. A liquid crystal display element in which unevenness in brightness and defective afterimage were reduced even when was displayed was obtained.

(Example 3) 0.1 mol% of 1,1-bis [2- (4-aminophenoxy) phenyl] propane was added to N 2
-After dissolving in methyl-2-pyrrolidone, 0.08 mol% of pyromellitic dianhydride and 0.02 mol% of isophthalic acid dichloride were added and reacted at 5 ° C for 7 hours to obtain a pale yellow viscous varnish. It was The reaction varnish was added to a mixed solution of alcohol and pure water, the precipitate was filtered and dried, and the solvent was dimethylacetamide and butylcellosolve to give 5% by weight.
After being diluted to a concentration, γ-aminopropyltriethoxysilane was added in a solid content of 4% by weight to prepare a composition for liquid crystal alignment film. Then, a glass substrate with an ITO transparent electrode was applied with a spinner, prebaked at 150 ° C., and heat-cured at 210 ° C. for 1 hour to form a polyamideimide film of about 650 Å. Further, rubbing was performed under the conditions of a cut of 0.3 mm, a rotation speed of 700 rpm, and a feed speed of 1000 mm / min. After printing an epoxy sealant, ZLI-4792 was printed.
A liquid crystal cell was manufactured by enclosing a liquid crystal (trade name, manufactured by Merck). After aging treatment at 130 ° C. for 1 hour to stabilize the liquid crystal cell, the pretilt angle was measured by the crystal rotation method. As a result, a high pretilt angle value of 5.0 degrees was shown. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured. The respective results are shown in Table 1.

Next, after coating the alignment film varnish on the transparent electrode substrate by printing, it was calcined at 150 ° C. and heat-cured at 210 ° C. for 1 hour to form a polyamideimide film of about 650 Å. Furthermore, in order to make the twist angle of the liquid crystal molecules held by the substrates 260 degrees, the upper and lower substrates were rubbed at respective angles, and seal printing was performed between the substrates to enclose the liquid crystal of Example 1 in an element having a gap of 6 μm. To produce a super twist liquid crystal display element, and after aging treatment (130 ° C, 1 hour),
A liquid crystal display element was obtained in which unevenness in brightness and afterimage defects were reduced even when a window pattern was displayed on the screen.

(Example 4) 1,1-bis [2- (4-aminophenoxy) -5-methylphenyl] propane
06 mol and 0.04 mol% of isophthalic acid dihydrazide
Was dissolved in N-methyl-2-pyrrolidone, butanetetracarboxylic dianhydride was added in an amount of 0.05 mol% and 3,3 ', 4.
0.05 mol% of 4'-biphenyltetracarboxylic dianhydride was added, and the reaction was carried out at 5 ° C for 7 hours to obtain a pale yellow viscous varnish. After diluting the varnish to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve,
γ-Aminopropyltriethoxysilane was added in a solid content of 4% by weight to prepare a composition for liquid crystal alignment film. Then, after applying a spinner on a glass substrate with an ITO transparent electrode, it was pre-baked at 150 ° C. and heat-cured at 220 ° C. for 1 hour to form a polyhydrazide imide film of about 600 Å. Furthermore, a cut of 0.3 mm, a rotation speed of 700 rpm, 100
Rubbing was performed at a feed rate of 0 mm / min to print an epoxy-based sealant, and then ZLI-4792 (trade name, manufactured by Merck & Co., Inc.) liquid crystal was sealed to prepare a liquid crystal cell. After aging treatment at 130 ° C. for 1 hour to stabilize the liquid crystal cell, the pretilt angle was measured by the crystal rotation method. As a result, a high pretilt angle value of 5.5 degrees was shown. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured. The respective results are shown in Table 1.

Next, the above-mentioned alignment film varnish was applied by printing onto a substrate for an active matrix having a color filter, and then calcinated at 150 ° C. and heat-cured at 220 ° C. for 1 hour to form a polyhydrazide imide film of about 650 Å. Formed. Further, in order to make the twist angle of the liquid crystal molecules held on the substrate 90 degrees, the upper and lower substrates are rubbed at respective angles, and seal printing is performed between the substrates to form a device having a gap of 6.5 μm in Example 1. An active matrix liquid crystal display device is manufactured by encapsulating liquid crystal, and then subjected to aging treatment (130 ° C., 1
After a lapse of time, a liquid crystal display device was obtained in which unevenness in brightness and defective afterimage were reduced even when a window pattern was displayed on the screen.

Example 5 0.09 mol% of 1,1-bis [2- (4-aminophenoxy) phenyl] octane and 0.01 mol% of 4,4'-diaminodiphenyl ether-3-carbonamide were added to N. After dissolution in -methyl-2-pyrrolidone, 0.05 mol% of 2,3,6,7-naphthalenetetracarboxylic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride. When 05 mol% was added and reacted at 20 ° C. for 7 hours, a pale yellow viscous varnish was obtained. The varnish was diluted to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve, and then 5% by weight of γ-aminopropyltriethoxysilane was added in a solid content to prepare a composition for a liquid crystal alignment film. . Then I
After spinner coating on a glass substrate with a TO transparent electrode, 15
Approximately 40 after calcination at 0 ℃ and heat curing at 220 ℃ for 2 hours
A 0Å polyimide isoindoloquinazolinedione film was formed. Further, rubbing is performed under the conditions of a cut of 0.3 mm, a rotation speed of 700 rpm, and a feed speed of 1000 mm / min, and after printing an epoxy type sealant, ZLI-4792.
A liquid crystal cell was manufactured by enclosing a liquid crystal (trade name, manufactured by Merck). After aging treatment at 130 ° C. for 1 hour to stabilize the liquid crystal cell, the pretilt angle was measured by the crystal rotation method. As a result, a high pretilt angle value of 4.4 degrees was shown. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured. The respective results are shown in Table 1.

Next, the above-mentioned alignment film varnish was applied by printing onto a transparent electrode substrate with a color filter, pre-baked at 150 ° C. and heat-cured at 220 ° C. for 1 hour to obtain a polyimide isoindoloquinazolinedione film of about 400 Å. Was formed. Further, in order to set the twist angle of the liquid crystal molecules held by the substrates to 230 degrees, the upper and lower substrates are rubbed at respective angles, seal printing is performed between the substrates, and the liquid crystal of Example 1 is sealed in an element having a gap of 6 μm. A super twisted liquid crystal display device was manufactured by aging, and after aging treatment (130 ° C., 1 hour), a liquid crystal display device in which uneven brightness and afterimage defects were reduced even when a window pattern was displayed on the screen was obtained.

Example 6 Bis [2- (4-aminophenoxy) -5-propylphenyl] methane 0.1 mol%
Was dissolved in N-methyl-2-pyrrolidone, 0.07 mol% of isophthalic acid dichloride and 0.03 mol% of terephthalic acid dichloride were added, and the mixture was reacted at 0 ° C. for 3 hours to give a pale yellow viscous varnish. The reaction varnish was added to a mixed solution of alcohol and pure water, the precipitate was filtered and dried, and the solvent was dimethylacetamide and butylcellosolve to give 5% by weight.
After diluting to a concentration, γ-aminopropyltriethoxysilane was added in a solid content of 4% by weight to prepare a composition for liquid crystal alignment film. Then, after applying a spinner on a glass substrate with an ITO transparent electrode, it was pre-baked at 150 ° C. and heat-cured at 190 ° C. for 1 hour to form a polyamide film of about 450 Å.
Furthermore, a cut of 0.3 mm, a rotation speed of 700 rpm, 10
Rubbing was performed at a feed rate of 00 mm / min to print an epoxy-based sealant, and then ZLI-4792 (trade name, manufactured by Merck & Co., Inc.) liquid crystal was sealed to prepare a liquid crystal cell. After aging treatment at 130 ° C. for 1 hour to stabilize the liquid crystal cell, the pretilt angle was measured by the crystal rotation method. As a result, a high pretilt angle value of 4.2 ° was shown. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured. The respective results are shown in Table 1.

Next, the above-mentioned alignment film varnish was applied by printing onto a transparent electrode substrate having a color filter, and then calcinated at 150 ° C. and heat-cured at 190 ° C. for 1 hour to form a polyamide film of about 450 Å. Further, in order to set the twist angle of the liquid crystal molecules held by the substrates to 220 degrees, the upper and lower substrates are rubbed at respective angles, seal printing is performed between the substrates, and the liquid crystal of Example 1 is sealed in an element having a gap of 6 μm. To produce a super twist liquid crystal display element, and to perform aging treatment (1
After 1 hour at 30 ° C., a liquid crystal display device was obtained in which unevenness in brightness and defective afterimage were reduced even when a window pattern was displayed on the screen.

Example 7 Bis [2- (4-aminophenoxy) -5-ethylphenyl] methane 0.06 mol%
And 0.04 mol% of 4,4'-diaminodiphenylmethane were dissolved in N-methyl-2-pyrrolidone, and then 0.05 mol% of pyromellitic dianhydride and 3,3 ', 4,4'-
Biphenyltetracarboxylic dianhydride (0.05 mol%) was added, and the mixture was reacted at 5 ° C. for 7 hours to obtain a pale yellow viscous varnish. The varnish was diluted to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve, and 4% by weight of γ-aminopropyltriethoxysilane was added in a solid content to prepare a composition for a liquid crystal alignment film. . Then I
After spinner coating on a glass substrate with a TO transparent electrode, 15
Approximately 60 after calcination at 0 ℃ and heat curing at 220 ℃ for 1 hour
A 0Å polyimide film was formed. Further, rubbing is performed under the conditions of a cut of 0.3 mm, a rotation speed of 700 rpm, and a feed speed of 1000 mm / min, and after printing an epoxy type sealant, ZLI-4792 (trade name of Merck Ltd.) liquid crystal is sealed. A liquid crystal cell was produced. Then, after aging treatment at 130 ° C. for 1 hour to stabilize the liquid crystal cell, the pretilt angle was measured by the crystal rotation method.
A high pretilt angle value of 4.4 degrees was shown. Furthermore, the frequency characteristics of the threshold voltage of the liquid crystal cell manufactured under the above conditions,
The residual DC voltage, voltage holding ratio, and AC resistivity at low frequencies were measured. The respective results are shown in Table 1.

Next, the above-mentioned alignment film varnish was applied by printing on a transparent electrode substrate having a color filter, and then prebaked at 150 ° C. and heat-cured at 220 ° C. for 1 hour to form a polyimide film of about 600 Å. Further, the upper and lower substrates were rubbed at respective angles in order to make the twist angle of the liquid crystal molecules held by the substrates 240 degrees, and seal printing was performed between the substrates to form a device with a gap of 6 μm on the liquid crystal of Example 1. After encapsulation, a super twist liquid crystal display device was produced, and after aging treatment (130 ° C., 1 hour), a liquid crystal display device in which unevenness in brightness and afterimage defects were reduced even when a window pattern was displayed on the screen was obtained. (Comparative Example 1) 0.1 mol% of bis [4- (4-aminophenoxy) phenyl] propane was dissolved in N-methyl-2-pyrrolidone, and then 0.07 mol% of pyromellitic dianhydride was dissolved.
Then, 0.03 mol% of 3,3 ', 4,4'-benzophenone tetracarboxylic acid dianhydride was added, and the mixture was reacted at 5 ° C for 7 hours to obtain a viscous tan varnish. The varnish was diluted to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve, and 4% by weight of γ-aminopropyltriethoxysilane was added in a solid content to prepare a composition for a liquid crystal alignment film. . Then, after applying a spinner on a glass substrate with an ITO transparent electrode, pre-baking at 150 ° C., 220
It was heated and cured at ℃ for 1 hour to form a polyimide film of about 600 liters. Further, rubbing was performed under the conditions of a cut of 0.3 mm, a rotation speed of 700 rpm, and a feed speed of 1000 mm / min, and after printing an epoxy sealant, ZLI-479 was used.
A liquid crystal cell was prepared by enclosing 2 (trade name, manufactured by Merck) liquid crystal. After that, in order to stabilize the liquid crystal cell, 1 at 130 ℃
After the time aging treatment, the pretilt angle was measured by the crystal rotation method, and the value of the pretilt angle was 2.8 degrees. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under the above conditions were measured. The respective results are shown in Table 1.

Next, the above-mentioned alignment film varnish was applied by printing onto a transparent electrode substrate having a color filter, and then prebaked at 150 ° C. and heat-cured at 220 ° C. for 1 hour to form a polyimide film of about 600 Å. Further, the upper and lower substrates were rubbed at respective angles in order to make the twist angle of the liquid crystal molecules held by the substrates 240 degrees, and seal printing was performed between the substrates to form a device with a gap of 6 μm on the liquid crystal of Example 1. After encapsulating, a super twist liquid crystal display device was produced, and after aging treatment (130 ° C., 1 hour), when a window pattern was displayed on the screen, there was obtained a liquid crystal display device in which unevenness in brightness and display defects of residual image occurred.

(Comparative Example 2) 0.1 mol% of bis [4- (4-aminophenoxy) phenyl] methane was added to N-methyl-
After dissolution in 2-pyrrolidone, pyromellitic dianhydride.
05 mol% and isophthalic acid dichloride 0.05 mol% were added, and the mixture was reacted at 0 ° C. for 3 hours to obtain a pale yellow viscous varnish. The reaction varnish was added to a mixed solution of alcohol and pure water, the precipitate was filtered and dried, and the varnish was diluted to a concentration of 5% by weight with a solvent of dimethylacetamide and butylcellosolve, and then γ-aminopropyltriethoxysilane. 4% by weight of solid content was added to prepare a composition for liquid crystal alignment film. Then, after applying a spinner on a glass substrate with an ITO transparent electrode, it was pre-baked at 150 ° C. and heat-cured at 190 ° C. for 1 hour to form a polyamideimide film of about 600 Å. Further, rubbing was performed under the conditions of a cut of 0.3 mm, a rotation speed of 700 rpm, and a feed speed of 1000 mm / min. After printing an epoxy sealant, ZLI-4792 was printed.
A liquid crystal cell was manufactured by enclosing a liquid crystal (trade name, manufactured by Merck). Then, after aging treatment at 130 ° C. for 1 hour to stabilize the liquid crystal cell, the pretilt angle was measured by the crystal rotation method. As a result, the pretilt angle value was 3.2 degrees. Further, the frequency characteristics of the threshold voltage, the residual DC voltage, the voltage holding ratio, and the AC specific resistance at low frequencies of the liquid crystal cell manufactured under these conditions were measured. The respective results are shown in Table 1.

Next, after the coating of the alignment film varnish on the active matrix electrode substrate with the color filter, 1
Approximately 6 after calcination at 50 ℃ and heat curing at 190 ℃ for 1 hour.
A 00Å polyamide-imide film was formed. Furthermore, in order to make the twist angle of the liquid crystal molecules held by the substrates 90 degrees, the upper and lower substrates were rubbed at respective angles, and seal printing was performed between the substrates to enclose the liquid crystal of Example 1 in an element having a gap of 6 μm. An active matrix liquid crystal display device was produced by aging, and after aging treatment (130 ° C., 1 hour), when a window pattern was displayed on the screen, a liquid crystal display device in which unevenness in brightness and defective display of an image residue were generated was obtained.

[0040]

The organic alignment film used in the liquid crystal display device of the present invention has the following characteristics: high pretilt angle in low temperature firing, frequency dependence of threshold voltage, residual DC voltage, voltage holding ratio, AC specific resistance. Both improve. As a result, a liquid crystal display device with less color filter fading and display unevenness can be achieved, and finally display quality and product yield can be greatly improved.

[Brief description of drawings]

FIG. 1 is a frequency characteristic diagram of threshold voltage.

FIG. 2 is an explanatory diagram of a residual DC voltage measuring system.

FIG. 3 is an explanatory diagram of a voltage holding ratio measurement system.

[Explanation of symbols]

1, 10 ... Constant temperature bath, 2 ... Polarizing plate, 3, 11 ... Unit element, 4 ... Backlight, 5 ... Pulse generator, 6,
9 ... DC power supply, 7 ... Photodiode, 8, 13 ... Oscilloscope, 12 ... Buffer amplifier.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Naoki Kikuchi 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Division

Claims (11)

[Claims] 1. A liquid crystal display device in which a liquid crystal is sandwiched between a pair of substrates having transparent electrodes, at least one of which is transparent,
A liquid crystal display device comprising an organic alignment film made of a polymer obtained by reacting a diamine compound represented by an ortho-ortho structure and a carboxylic acid between the transparent electrode and the liquid crystal layer. 2. The organic alignment film according to claim 1, wherein the organic alignment film has the general formula [1] (In the formula, Ri (i = 1 to 4) and Rj (j = 1 to 4)
Each independently represent hydrogen, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom, which may be the same or different from each other, and Rm and Rn each independently represent hydrogen, an alkyl group or a halogenated alkyl. Group or phenyl group, which may be the same or different from each other), and a liquid crystal display device containing a diamine compound having an ortho-ortho structure. 3. The liquid crystal display device according to claim 1, wherein the organic alignment film is polyimide. 4. The liquid crystal display device according to claim 1, wherein the organic alignment film is polyimide siloxane. 5. The liquid crystal display device according to claim 1, wherein the organic alignment film is polyamideimide. 6. The liquid crystal display device according to claim 1, wherein the organic alignment film is polyhydrazide imide. 7. The liquid crystal display device according to claim 1, wherein the organic alignment film is polyimide isoindoloquinazolinedione. 8. The liquid crystal display device according to claim 1, wherein the organic alignment film is polyamide. 9. The copolymerization system of a diamine compound represented by Chemical Formula 1 and another diamine compound or a mixed system of polymers according to claim 2, 3, 4, 5, 6, 7 or 8. Is a liquid crystal display device. 10. Claims 1, 2, 3, 4, 5, 6, 7, 8
Alternatively, in 9 above, the liquid crystal display element is a super twist liquid crystal display element formed of the organic alignment film. 11. Claims 1, 2, 3, 4, 5, 6, 7, 8
Or the active matrix liquid crystal display element according to 9, wherein the liquid crystal display element is formed of the organic alignment film.