JPS62144141A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To prevent the flaws on the surface of liquid crystal oriented films, nonuniform film thicknesses thereof, delamination of the films and the damage of driving electrodes and the consequent defective orientation and quality deterioration of a display element which are generated in the conventional rubbing method by bringing a monomolecular film formed on a water surface and diamine compd. in an aq. soln. into reaction to form a polyimide film and applying such film to the liquid crystal oriented films. CONSTITUTION:The sticking an forming of the liquid crystal oriented films 4, 4' are executed in the following manner: The compd. expressed by the formu la is synthesized of a pyromellitic dianhydride and octadecylamine. the compd. is dissolved in chloroform and when the soln. is dropped ont ot e aq. soln, the soln. spreads neatly on the water surface. Hydrophilic groups and hydropho bic groups array regularly on the surface. the film spread on the water surface is exerted with pressure in the compressing direction thereof by exerting pres sure onto a float 7 by a weight 6 to form the monomolecular film 9. The diamino diphenyl ether in the aq. sol. and the monomolecular film induce a condensation reaction thereafter and the hydrophobic group part is taken. The formed polyimide film is transferred onto glass.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid crystal alignment film that is a component of a liquid crystal display element.

[Summary of the invention]

This invention relates to liquid crystal orientation U, which is a component of a liquid crystal display element.
Among the materials, when forming a polyimide copolymer, which has strong heat resistance, mechanical strength, and liquid crystal alignment power, on a substrate, a compound represented by the general formula is spread on the surface of water, @completely formed, and then submerged in water in advance. Dissolved general 2Hz N OR4-
By reacting with a diamine compound represented by 0-MHI, a film of the compound represented by the general formula is formed, and by transferring it to a substrate on which a transparent electrode is formed, the surface of the alignment film that was generated by conventional rubbing methods can be improved. It is possible to prevent scratches, uneven film thickness, peeling of the film, damage to the drive electrode, and the resulting poor alignment and quality deterioration of the display element.In addition, it is possible to prevent the expensive and mass-producible materials that are essential for the oblique evaporation method. Since low vacuum equipment is not required, it is possible to form the entire liquid crystal alignment film that is uniform, defect-free, and has good alignment and cylindrical heat resistance 2 at low cost and with high mass productivity.
This makes it possible to fabricate high-quality quasi-crystalline display elements.

[Conventional technology]

Display methods of liquid crystal display elements include (a) twisted nematic ink field effect display method;
(b) Induced birefringence field effect display method, (C) Dynamic scattering display method, (d) Genutohost two-color display method, (e) Orientation vibration display method, etc. The method in (a) has been widely put into practical use.

Conventionally, alignment films for liquid crystal display elements include (a) an obliquely vapor-deposited film such as silicon oxide, (b) a surface treatment film, and a thermosetting polymer such as a linear polymer or an epoxy resin. (C) Rubbed materials such as polyimide, which has good heat resistance, have been used.

[Problem that the invention seeks to solve]

However, all of the above alignment films have the following disadvantages:
had.

(a) The orientation of obliquely deposited films such as silicon oxide differs depending on the liquid crystal used, and some liquid crystals have poor orientation. Also, the viewing angle is also negative? It was inferior, had poor mass productivity, and had problems in terms of cost.

(b) The orientation of surface treatment films, thermosetting polymer films such as linear polymers and epoxy resins decreases when the sealant or sealant is heated to perform sealing or sealing work. .

(C) Although the polyimide pattern has good orientation, problems such as poor orientation and quality deterioration may occur due to scratches on the surface of the alignment film, uneven film thickness, peeling of the film, and damage to the drive electrode due to rubbing.2
It was happening.

Therefore, in order to solve these conventional problems, the entire purpose of the present invention is to obtain a liquid crystal alignment film that is uniform, defect-free, has good alignment properties and heat resistance, and is low-cost and highly mass-producible.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a compound represented by the general formula (for reference, R1 in the formula is 0H3(CH
z), one type of group selected from n=5 to 30, and R3 in the group is 0-1-CF(21-Co-*-801-.

H3 -C-, -ocH2CF? , O-H3) is developed on the entire water surface to form a single molecule @totally formed, and is dissolved in water in advance. However, R4 in the formula is -〇-
+ CFl 2-+ G O-+ O-○-0-
1-o-0-o-0-o-), one type of group selected from the general formula, and a sweet group R3 of
Ke10-, C[(z + CO* -8021H3 -(, -, -0CI(z CHz O-H3, R4 is -o +
, -0H2+, -co +, -0-c-0-.

Liquid crystal alignment (8) is achieved by forming a monomolecular film of one type of group selected from -o -0-o -0-o - and transferring it to a substrate on which a transparent electrode is formed. I am sorry to form this.

[For production]

The liquid crystal alignment film formed as described above is uniform, defect-free, and has good alignment. It is also highly mass-producible. Furthermore, it has excellent heat resistance. This alignment film enables a liquid crystal display element that is inexpensive and has high image quality.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Example 1 FIG. 1 shows a liquid crystal display element. After forming a gold pattern 2.2' on a glass or plastic substrate 1.1', a liquid crystal alignment film 4.4' is entirely attached. Next, seal material 6.
6' was assembled into a display panel, liquid crystal 5 was injected, and the injection port was sealed.

In order to deposit and form the liquid crystal alignment films 4, 4'i shown in FIG. 1, the following procedure was carried out.

The following compound was synthesized from hyromellitic dianhydride and octadecylamine.

This was dissolved in trichloroform and poured into an aqueous solution. The above compound that was dropped spread neatly on the water surface. On the surface of an aqueous solution, hydrophilic and hydrophobic groups are regularly arranged. - ``Figure 2 shows a method of compressing this membrane with an appropriate pressure to form a monomolecular membrane.

A monomolecular film 9 is formed by applying pressure in the direction of membrane compression using a floating float 7 spread out on the water surface and a mole 6.

Thereafter, a condensation reaction occurred between the monomolecular film and the diaminodiphenyl ether NH2-◎-〇-■-NH2 previously included in the aqueous solution, and the hawk water group moieties were removed. The third picture shows the state of this polycondensation reaction. Here, A represents, and B represents diaminodiphenyl ether. The resulting polyimide film, the galanu after the Nesa pattern was formed, was transferred onto glass by repeating dipping and pulling up in a direction perpendicular to the water surface. Assemble it into a liquid crystal panel and inject TN liquid crystal.

This is a liquid crystal display element with excellent display characteristics and heat resistance.

Implementation Problem] 2 The following compound was synthesized from dianhydride 5.3',4.4'-benzophenonetetracarboxylic acid and octadenylamine.

C1 (3 Dissolve this in chloroform and drop it into an aqueous solution,
A monolayer was formed. Then, it reacted with diazunodiphenyl ether that had been pre-impregnated in the aqueous solution, and the hydrophobic group was removed, forming a polyimide film. The material was transferred to Nesa glass, assembled into a liquid crystal panel, and liquid crystal was injected into the entire display element. Both display characteristics and heat resistance were excellent.

〔Effect of the invention〕

As explained above, this invention allows a monomolecular film formed on a water surface to react with a diamine compound in an aqueous solution to produce a polyimide @ completely and apply it to a liquid crystal alignment film, thereby eliminating the effects produced by conventional rubbing methods. Orientation @ surface scratches and uneven film thickness 1. Peeling off, driving tJ! It is possible to prevent damage to the poles and the resulting poor alignment and quality deterioration of display elements.
Furthermore, it is easy to mass produce, and it is possible to form a liquid crystal alignment film that is uniform, defect-free, has good alignment, and high heat resistance, making it possible to manufacture high-quality liquid crystal display elements. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal display element, FIG. 2 is a method for manufacturing a monomolecular film, and FIG. 6 is a diagram showing the state of the l-condensation reaction. 1.1'...Substrate 2.2'...Nesa pattern 3.5'...Seal material 4.4'...Liquid crystal alignment film 5...・・・・・・・・・・LCD 6・・・・・・・・・・Weight 7・・・・・・・・・・Float 8・・・・・・・・・・...Water 9...Monolayer 9a...Hydrophobic group 9b...Hydrophilic group 10... ...Polymer film or higher

Claims (3)

[Claims] (1) In a liquid crystal display element having a liquid crystal layer sandwiched between a pair of substrates on which transparent electrodes are formed, a) a compound represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ is spread on the water surface. b) By reacting with a diamine compound represented by the general formula ▲Mathematical formula, chemical formula, table, etc., which has been previously dissolved in water, c) The general formula ▲Mathematical formula, chemical formula, table, etc. A liquid crystal display element, characterized in that a film of a compound represented by ▼ is formed, and d) this film is transferred to the substrate to form an alignment film. However: R_1 is CH_3(CH_2)_n and n=5~
It is 30. R_2 is one type of group selected from among, and R_3 in the group is -O-, -CH_2-CO-, -
SO_2-, C(CH_3)_2-_1-OCH_2C
It is one type of group among H_2O. R_4: One type of group selected from -O-, -CH_2-, -CO-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼. (2) R_2 in the compound represented by the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼
and R_4 in the diamine compound represented by the general formula ▲There are numerical formulas, chemical formulas, tables, etc.▼ is -O- or -CO-, as described in claim (1) Liquid crystal display element. (3) Claim (1), characterized in that the film of the compound represented by the previous general formula (including mathematical formulas, chemical formulas, tables, etc.) is a monomolecular film on the water surface. liquid crystal display element.