JPH03256023A - Production of liquid crystal element - Google Patents

Abstract

PURPOSE:To obtain a good display grade by allowing a minute ice group to collide with a silicon oxide film formed on the principal planes of the first and second substrates at a specified incident angle, opposing the principal planes of the first and second substrates to each other, sealing both substrates with a specified gap in between and then injecting a liq. crystal composition into the gap. CONSTITUTION:A silicon oxide film is formed on the principal planes of the first and second substrates 1 and 2. Water is then atomized by an ultrasonic atomizer to obtain solid ice grains, the grain group is blown against the silicon oxide film at an angle of about 30 deg., clear nitrogen is blown against the substrate which is dried, and the silicon oxide layers 5 and 6 are obtained as the oriented film. The principal planes of the substrates 1 and 2 are opposed to each other and sealed with a specified gap in between, and then a specified liq. crystal composition for SBE is injected into the gap to obtain a liq. crystal element, namely a panel. Consequently, the liq. crystal molecule is oriented with good reproducibility at a low cost, and a liq. crystal element having a good display grade is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a liquid crystal element, particularly a method for aligning liquid crystal molecules.

BACKGROUND OF THE INVENTION A liquid crystal molecule alignment film is essential for liquid crystal displays.

As the alignment film, an inorganic obliquely evaporated film, a polymer resin film rubbed with cloth, etc. is used (
For example, see the literature ``Basics and Applications of Liquid Crystal Electronics'' (edited by Akio Sasaki), and polyimide is mainly used as the polymer resin.

Liquid crystal elements such as the SBE (super twisted bias fringe effect) method, which has a structure in which a nematic liquid crystal is twisted by more than 90 degrees, which has been attracting attention in recent years, are
A tilted orientation having a shake/tilt angle of .degree. or more is desired.

An organic polymer material that can obtain a tilted orientation with a pre-tilt angle of about 5° or more has been developed, and from the viewpoint of cost, an orientation method by rubbing the material is used in production.

In addition, the alignment method is an important issue in liquid crystal devices using an interface stabilization mode using ferroelectric liquid crystals or a mode close to homeotropy. is desired.

Problems to be Solved by the Invention However, in the conventional rubbing method for organic polymer films, there are problems such as changes in the shake/tilt angle of liquid crystal molecules over time after forming a liquid crystal element, and poor reproducibility. Ta. In addition, this process has problems such as easy generation of dust, difficulty in meeting the requirements for dust-free manufacturing sites, and strict management of the rubbing cloth.

Additionally, the oblique evaporation method requires large equipment costs, which significantly increases manufacturing costs.

In view of these points, the present invention aims to provide a method for manufacturing a liquid crystal element that can orient liquid crystal molecules with good reproducibility and at low cost and has good display quality.

Means for Solving the Problems In order to achieve the above object, the present invention includes a process of forming a silicon oxide film on the main surfaces of the first and second substrates, and a process of forming a microscopic ice group on the silicon oxide film at a predetermined incident angle. The process of colliding the liquid crystal composition and the process of injecting the liquid crystal composition into the gap formed after the main surfaces of the first and second substrates are faced to each other and sealed with a predetermined gap maintained are performed in this order.

Operation In the essential part of the present invention, that is, the method for aligning liquid crystal molecules, the cost of the device is small, and this does not significantly increase the manufacturing cost.

Among the contents of the present invention, a method for aligning liquid crystal molecules will be described.

A silicon oxide film is formed on the main surfaces of the first and second substrates.

This may be done by means such as vapor deposition or sputtering, or by applying an organic silicone resin using a spinner or the like and heat-treating it. However, better results will be obtained if the resulting silicon oxide film is slightly softer. After obtaining a mist consisting of microscopic water droplets at room temperature, it is cooled with liquid nitrogen or the like to obtain solid microscopic ice, which is sprayed at a predetermined angle onto the silicon oxide film on the substrate. By doing so, microscopic grooves are formed in the silicon oxide film or polymers in the silicon oxide film are oriented.

The liquid crystal molecules are aligned along the grooves or aligned polymers.

After the aforementioned solid micro-ice particles collide with the silicon oxide film on the substrate, they can be vaporized naturally, or the aforementioned substances can be easily removed from the substrate by blowing nitrogen gas or clean air on them, or by slightly heating them. removed.

As will be understood from this, no dust is generated, which greatly contributes to improving production yields and the like. In fact, it also serves as cleaning after conventional rubbing.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a liquid crystal element obtained according to an embodiment of the present invention. In the same figure, 1.2 is, for example,
A first substrate made of transparent glass and jF! 2 boards, 3,
4 is a rectangular transparent conductive electrode made of, for example, an ITO film on the main surface; 5 and 6 are silicon oxide films as alignment films; and 7 is a liquid crystal layer.

After coating the glass substrates 1 and 2 with conductive electrodes 3 and 4 microfabricated on their main surfaces with ZQ-3 resin, an organic silicone resin manufactured by Catalyst Kasei, using a spinner,
A silicon oxide film is obtained by heating at C for 60 minutes. This film contains a considerable amount of organic groups and has very low hardness.

Next, the water is atomized using an atomizer that uses ultrasonic waves.

The fog particles are probably in liquid form at this time.

By passing this through a pipe cooled with liquid nitrogen, it becomes solid ice particles. Make sure it is sufficiently cooled. The particles are blasted onto the silicon oxide film at an angle of about 30' (the angle between the substrate surface and the direction of incidence of the particles) using an improved sand blasting device. The speed of spraying is close to the speed of sound.

Thereafter, clean nitrogen is blown onto the substrate and the substrate is dried to obtain a silicon oxide layer 5.6 as an alignment film. Next, the main surfaces of the first substrate 1 and the second substrate 2 are made to face each other and sealed with a predetermined gap maintained, and then a specific liquid crystal composition for SBE is injected into the gap formed to form a liquid crystal element, i.e. Get the panel.

Six liquid crystal elements were manufactured using the above method under each single condition, and the pre-tilt angles were measured using a magnetic field method.

The results show that when microscopic ice is sprayed onto a silicon oxide film,
30.2±0.4°, in the conventional case (rubbing method)
The average angle was about 0.5°, and the distribution ranged from 0° to about 5°. The display characteristics of the liquid crystal element of this example were uniform and excellent in reproducibility.

Also, after applying ZQ-3 resin. Heat treatment was performed at 200° C. for about 1 hour to obtain a silicon oxide film. Do this as described above,
Similar effects were obtained when obtaining panels.

In addition, the other sample was coated with ZQ-3 resin and then heat treated at 150°C for about 1 hour to obtain a silicon oxide film, after which micro ice groups were allowed to collide with this silicon oxide film as described above.
After that, it was thoroughly dried and further heat-treated at 200°C for 1 hour.
A panel was obtained in the same manner as above. In this case as well, the effects of the present invention were significantly exhibited.

Although twist mode has been described in this embodiment, the present invention can also be applied to liquid crystal elements using ferroelectric liquid crystal in interface stabilization mode and near-homeotropic mode, especially in the orientation of liquid crystal molecules. It is valid.

To obtain a controlled tilt orientation that is close to homeotropic, the angle between the substrate surface and the direction of incidence of the particle group must be precisely adjusted to approximately 9
An alignment film is obtained by making the angle close to 0° or by making this angle precisely about 0° in combination with vertical alignment agent application.

Effects of the Invention As described above, the present invention provides excellent alignment of liquid crystal molecules, and as a result, a liquid crystal element with good display quality can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a liquid crystal element obtained according to an embodiment of the present invention. 1...First substrate, 2...Second substrate, 3
．． 4... Conductive electrode, 5.6... Silicon oxide layer, 7... Liquid crystal layer.

Claims (1)

[Claims] A process of forming a silicon oxide film on the main surfaces of the first substrate and the second substrate, a process of colliding the silicon oxide film with microscopic ice at a predetermined incident angle, and a process of forming a silicon oxide film on the main surfaces of the first substrate and the second substrate. A method for manufacturing a liquid crystal element, comprising the steps of: placing the surfaces facing each other and sealing with a predetermined gap maintained, and then injecting a liquid crystal composition into the gap formed in this order.