JPS59189322A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain a controlling film for orientation having good regulating power for orientation, electrical insulating property and mechanical strength with a relatively thin film thickness by dispersing fine powder of an oxide in an org. high polymer film thereby forming the controlling film for orientation. CONSTITUTION:Fine powder of SiO2 having 50-200Angstrom grain size is mixed with an org. solvent in which a polyimide high polymer is dissolved to prepare a coating liquid. Such liquid is printed by a printing method such as stamping on an electrode substrate 1 and is calcined. A controlling film consisting of the fine powder 7 of the oxide dispersed in the org. high polymer film 6 of polyimide is thus obtd. The surface which is in contact with a liquid crystal is the film 6 according to such structure and therefore the regulating power for orientation is strong. The controlling film for orientation has the pulverous powder 7 of the oxide in the film 6 and has therefore good mechanical and electrical insulating properties. Since the film 6 and the powder 7 are not divided to two layers, the formation of the film to a thin thickness over the entire part is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a liquid crystal display element, and particularly to improvement of an alignment control film formed on an electrode substrate.

[Background of the invention]

As shown in FIG. 1, the liquid crystal display element is made up of two transparent electrode substrates 11l facing each other, the periphery of which is adhered with a sealing material 2, and a liquid crystal 3 sealed inside.

Further, on the opposing surfaces of the electrode substrates 1, 1, as shown in FIGS. 2 and 3, a transparent electrode 4 is formed, and an alignment control film is formed thereon using an inorganic solid material 5 such as 5ins, polyimide, etc. An organic polymer film 6 is formed.

However, although the thermal rod 1 insulating layer 5 has high mechanical strength, it is inferior in orientation regulating force and electrical insulation. On the contrary, the organic polymer film 6 has good alignment regulating power and electrical insulation, but has low mechanical strength.

Therefore, in order to compensate for the drawbacks of both, a method is known in which an inorganic insulating film 5 and an organic polymer film 6 are laminated as shown in FIG. 8g4. However, this structure has the disadvantage that the overall film thickness is large, and therefore the voltage applied from the outside drops across this thick alignment control film, resulting in deterioration of electro-optical characteristics.

[Purpose of the invention]

An object of the present invention is to provide a liquid crystal display element having an alignment control film that is relatively thin and has good alignment control ability, electrical insulation, and mechanical strength.

[Summary of the invention]

The present invention is characterized in that the alignment control film is formed by dispersing fine oxide powder in an organic polymer film.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 5 and 6. Note that the same members as in FIGS. 1 to 4 are denoted by the same reference numerals, and the reference numeral 89 is omitted. The alignment control film has a structure in which fine powder 7 of direct compound is dispersed in organic polymer pancreas 6.

Such a structure is obtained as follows. A coating solution is prepared by mixing SiO2 fine powder with a particle size of 50 to 20 tJ into an organic solvent in which a polyimide polymer is dissolved. Apply this coating liquid to an electrode substrate using a printing method such as a stamp method! Print on top and bake. In this case, a control film is formed by dispersing fine oxide powder 7 in a polyimide-based organic polymer film 6.

According to this structure, the surface in contact with the liquid crystal is an organic polymer film 6
Therefore, the orientation regulating force is strong. Furthermore, since the alignment control film has fine oxide powder 7 in the organic polymer film 6, it has good mechanical and electrical insulation properties. Furthermore, since the organic polymer film 6 and the fine powder 7 are not divided into two parts, the overall film thickness can be made thinner.

〔Effect of the invention〕

According to the present invention, it is possible to obtain an orientation control film which has a relatively thin film thickness and has good orientation regulating power, electrical insulation properties, and tangential strength. That is, since the I old () is thin, there is little deterioration in the optical characteristics of the old (I). In addition, since the alignment regulating force and electrical insulation properties are good, the quality is improved. It also has high mechanical strength, so
There are fewer Iji vortices in the alignment control film, and quality is improved from this point as well. Since the film thickness of the effective polymer cavity for orienting the liquid crystal is small, the tilt angle of the liquid crystal molecule alignment is small and the electro-optical properties are improved.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a liquid crystal display element, Figures 2, 3, and 4.
Each figure is a sectional view of a conventional alignment control film, FIG. 5 is a sectional view of an alignment control film showing an embodiment of the present invention, and No. 6-1 is an enlarged view of section A in FIG. 1... Electrode substrate, 2... Seal material, 3...
LCD, 4...transparent'! 7' Pole 1.6...Organic polymer film, 7...Fine powder. -3= 1Figure 4-

Claims (1)

[Claims] In a liquid crystal display element in which two 'electrode substrates on which electrodes and an alignment control film are formed are sealed with a sealing material and a liquid crystal is sealed inside, the alignment control film is composed of fine powder of oxide in an organic polymer film. A liquid crystal display element made by dispersing.