JPH0445424A - Orientation control film and ferroelectric liquid crystal element formed by using this film - Google Patents

Abstract

PURPOSE:To increase the area of orientation control of molecules, etc., and to increase the number of picture elements by providing the orientation control films formed of coated films of modified protein on supporting plates. CONSTITUTION:Transparent electrodes 12 are formed on substrates 11 and after the orientation control films 13 are formed thereon, a resin 14 is printed. Two sheets of the liquid crystal supporting plates 15 are stuck to each other and a liquid crystal 16 is injected from an aperture and the aperture is sealed to complete a liquid crystal cell. The control films are formed by subjecting the coated films essentially consisting of the protein to an orientation treatment and further exposing the films to environment of 30 to 60 deg.C and >=70% humidity. Since the protein molecules and assemblage thereof exhibit good orientation, the orientation uniform over the entire surface of the element is attained easily at a low cost if this film is applied to the liquid crystal element. Above all, the uniform orientation is attained at the low cost with the liquid crystal element formed by using a liquid crystal exhibiting a ferroelectric property while the bistability is perfectly maintained over a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an alignment control film suitable for ferroelectric liquid crystals and a ferroelectric liquid crystal element using the same.

Conventional technology In order to control the orientation of molecules and their aggregates in liquid crystal elements, a rubbing process involves applying synthetic polymers such as polyimide or polyamide to a substrate, drying them, and then rubbing the surface with a cloth to control the orientation. Orientation control films that have undergone this process are mainly used.

Problems to be Solved by the Invention In a liquid crystal element, rubbing treatment, which is one of the means for controlling the orientation of molecules, etc., is a simple means and can be carried out at low cost. However, as it became desirable to increase the area and number of pixels, the conventionally used alignment control films made of polyimide, polyamide, and the like could not meet this demand, and the uniformity of alignment was insufficient. In particular, in a liquid crystal element using a liquid crystal exhibiting ferroelectricity, bistability is required in the orientation direction of molecules, and there has been a problem that conventional alignment control films are insufficient in expressing this bistability.

The present invention is intended to solve these problems, and provides an alignment control film that exhibits bistability of ferroelectric liquid crystal suitable for large-area liquid crystal display elements with a large number of pixels, and a ferroelectric liquid crystal element using the same. The purpose is to provide the following.

Means for Solving the Problems In order to solve the problems, the present invention provides the following methods:
An alignment control film formed of a proteinaceous coating film denatured by exposure to an environment with a temperature of 30 to 60°C and a humidity of 70% or more is provided on at least one of the liquid crystal support plates, and a ferroelectric film is provided in the gap between the opposing liquid crystal support plates. It is designed to hold a liquid crystal.

Function The present invention uses an alignment film ms obtained by performing an alignment treatment on a coating film containing protein as a main component, and further exposes the alignment control film to an environment with a temperature of 30 to 60°C and a humidity of 70% or more. Molecules and their aggregates exhibit good orientation. Furthermore, when this alignment film is applied to a liquid crystal device, uniform alignment can be easily achieved over the entire surface of the device at low cost.

In particular, in a liquid crystal element using a liquid crystal exhibiting ferroelectricity, uniform alignment can be achieved at low cost while completely maintaining bistability for a long period of time. The film ms and a liquid crystal element using the same will be explained with reference to the drawings. 1st
The figure shows the structure of a liquid crystal element using the alignment control film of the present invention.As shown in figure 0, a substrate made of glass or plastic, etc.
A transparent electrode 12 made of indium-tin oxide (hereinafter abbreviated as ITO) is formed on top of the transparent electrode 12, an alignment control film 13 is formed on top of the transparent electrode 12, an alignment treatment is performed, a spacer/sealing resin 14 is printed, and two sheets of A liquid crystal support plate 15 was bonded together, liquid crystal 16 was injected through the opening, and the opening was sealed to complete a so-called liquid crystal cell.

(Example 1) 1.0 g of bovine serum albumin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight bovine serum albumin aqueous solution. Next, this aqueous solution was applied to a glass substrate on which an ITO electrode pattern was formed using a spin coater at 500 rpm for 10 minutes.
After spin coating for seconds, spin coating was continued for 1 minute at 2300 rpm. After coating, it was dried at 110° C. for 1 hour. After drying, the surface on which bovine serum albumin 28 was formed was rubbed 10 times in the same direction using a rayon cloth to complete an alignment film ALL. Two glass liquid crystal support plates on which alignment films MW of raw serum albumin were formed in this way were prepared, and as shown in FIG. 2, one of the support plates 2
2 (for example, the lower liquid crystal support plate 22), an acid anhydride-curing epoxy resin in which glass fibers with a diameter of 2 μm are dispersed is applied as a spacer/sealing resin 25 to the surface on which the alignment film M film is formed, in the center of only one side. I left the liquid crystal inlet with a width of 0.2mm and printed around it with a width of 0.2mm. The rubbing directions 23 and 24 of the alignment control films formed on the upper liquid crystal support plate 21 and the lower support plate 22 thus created were parallel to each other, and the surfaces of the alignment control films were placed opposite each other, and pressurized at 140°C. The epoxy resin spacer was cured and bonded by heating for 4 hours.

After bonding, the liquid crystal cell was left in a high temperature (35°C, 85%) environment for 7 days, and then the liquid crystal cell was left in a high temperature (35°C, 85%) environment for 7 days.

85%), the liquid crystal material is heated to the temperature at which the liquid crystal exhibits isotropy, that is, around 80°C.
654) was added to the soup. After injection, it was slowly cooled to room temperature and the opening was sealed with a commercially available acid anhydride-curable epoxy resin to complete a ferroelectric liquid crystal cell.

The ferroelectric liquid crystal cell thus completed exhibited a good alignment state with no alignment unevenness, and upon application of a voltage, good electro-optical properties with ensured bistability were obtained. moreover,
This bistability was maintained without deterioration even after more than 100 hours had passed.

(Example 2) 1.0 g of ovalbumin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight aqueous ovalbumin solution. A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Example 1. The completed ferroelectric liquid crystal cell showed a good alignment state with no alignment unevenness, and good electro-optical properties were obtained. Furthermore, this bistability was maintained without deterioration even after more than 100 hours had passed.

(Example 3) 100 g of rabbit serum albumin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight rabbit serum albumin aqueous solution. A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Example 1. The completed ferroelectric liquid crystal cell showed a good alignment state with no alignment unevenness, and good electro-optical properties were obtained.

Furthermore, this bistability was maintained without deterioration even after more than 100 hours had passed.

(Example 4) Dissolve 0.5 g of hemoglobin in 99.5 g of pure water,
A 0.5% by weight aqueous hemoglobin solution was prepared.

A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Example 1. The completed ferroelectric liquid crystal cell is
A good alignment state with no alignment unevenness was exhibited, and good electro-optical properties were obtained. Furthermore, this bistability was maintained without deterioration even after more than 100 hours had passed.

(Example 5) 1.0 g of chymotrypsin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight chymotrypsin aqueous solution. A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Example 1. The completed ferroelectric liquid crystal cell showed a good alignment state with no alignment unevenness, and good electro-optical properties were obtained. Furthermore, this bistability was maintained without deterioration even after more than 100 hours had passed.

(Example 6) Dissolve 1.0 g of cytochrome in 99.0 g of pure water,
A 1.0% by weight aqueous cytochrome solution was prepared.

A ferroelectric liquid crystal cell was produced by the method shown in Example 1 using a rice aqueous solution. The completed ferroelectric liquid crystal cell is
A good alignment state with no alignment unevenness was exhibited, and good electro-optical properties were obtained. Furthermore, this bistability was maintained without deterioration even after more than 100 hours had passed.

(Comparative Example 1) 1.0 g of bovine serum albumin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight bovine serum albumin aqueous solution. Next, this aqueous solution was spin-coated on a glass substrate on which an ITO electrode pattern was formed at 500 rpm for 10 seconds using a spin coater, and then continuously coated at 2300 rpm for 1 minute.

After coating, it was dried for 1 hour in an electric furnace at 110°C.

After drying, the surface on which the bovine serum albumin coating was formed was rubbed 10 times in the same direction using a rayon cloth to complete an orientation control film. Two glass liquid crystal support plates on which the alignment control film of raw serum albumin is formed are prepared in this way, and as shown in FIG. As a spacer/sealing resin 25, an acid anhydride-curing epoxy resin containing glass fibers with a diameter of 2 μm is printed, leaving a liquid crystal injection port with a width of 5 mm in the center of one side, and printing with a width of 0.2 mm on the other periphery. did. Rubbing treatment direction 2 of the alignment control film formed on the upper liquid crystal support plate 21 and the lower support plate 22 thus produced
3.24 were parallel and the orientation control film surfaces faced each other, pressure was applied, and the epoxy resin spacer was cured and bonded by heating at 140° C. for 4 hours. After bonding, the liquid crystal cell is heated to 10℃.
, After being left in an environment with 30% humidity for 7 days, the temperature was 10"C9.
In an environment with a humidity of 30%, the liquid crystal is heated to a temperature at which it exhibits isotropy, that is, around 80°C, and a commercially available liquid crystal 16 (manufactured by Merck & Co., trade name: ZL I 36) is formed by capillary action from the opening.
54) was injected. After injection, it was slowly cooled to room temperature and the opening was sealed with a commercially available acid anhydride-curable epoxy resin to complete a ferroelectric liquid crystal cell. Although bistability of the ferroelectric liquid crystal cell thus completed was ensured by voltage application, the bistability deteriorated within 24 hours.

(Comparative Example 2) 1.0 g of ovalbumin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight aqueous ovalbumin solution. A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Comparative Example 1. The completed ferroelectric liquid crystal cell is
Although bistability was ensured by voltage application, the bistability deteriorated within 24 hours.

(Comparative Example 3) 1.0 g of rabbit serum albumin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight rabbit serum albumin aqueous solution. A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Comparative Example 1. Although bistability of the completed ferroelectric liquid crystal cell was ensured by voltage application, the bistability deteriorated within 24 hours.

(Comparative Example 4) Dissolve 0.5g of hemoglobin in 99.5g of pure water,
A 0.5% by weight aqueous hemoglobin solution was prepared.

A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Comparative Example 1. The completed ferroelectric liquid crystal cell is
Although bistability was ensured by voltage application, the bistability deteriorated within 24 hours.

(Comparative Example 5) 1.0 g of chymotrypsin was dissolved in 99.0 g of pure water to prepare a 1.0% by weight chymotrypsin aqueous solution. A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Comparative Example 1. Although bistability of the completed ferroelectric liquid crystal cell was ensured by voltage application, the bistability deteriorated within 24 hours.

(Comparative Example 6) Dissolve 1.0g of cytochrome in 99.0g of pure water,
A 1.0% by weight aqueous cytochrome solution was prepared.

A ferroelectric liquid crystal cell was produced using this aqueous solution by the method shown in Comparative Example 1. The completed ferroelectric liquid crystal cell is
Although bistability was ensured by voltage application, the bistability deteriorated within 24 hours.

In the above example, the environment during leaving the ferroelectric liquid crystal cell and injecting the liquid crystal was set at a temperature of 30 to 60°C and a humidity of 70°C.
Similar results were obtained when the ratio was changed within a range of % or more.

Further, in the above examples, similar results were obtained when myoglobin, myogen, heme erythtin, ferritin, immunoglobulin, insulin, and nuclease were used as the orientation control membrane.

In addition, in the above example, the surface of the protein formed on the transparent electrode was rubbed, but in the present invention, the surface of the protein formed on the silicon oxide etc. formed on the transparent electrode to prevent short circuits was rubbed. It can also be applied when

Effects of the Invention As is clear from the description of the embodiments above, according to the present invention, a liquid crystal alignment control film is created by applying an alignment treatment to a coating film containing protein as a main component, and the alignment control film is further heated at a temperature of 3.
By exposing it to an environment of 0 to 60°C and humidity of 70% or more, it becomes possible to control the orientation of protein molecules and their aggregates.

Furthermore, when this alignment control film is applied to a liquid crystal element,
Uniform alignment can be easily achieved over the entire surface of a liquid crystal element at low cost. Among liquid crystal elements that use ferroelectric liquid crystals, liquid crystal elements that completely maintain the bistability of ferroelectric liquid crystals for a long period of time have been developed. The effect is that it can be realized.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a liquid crystal element according to an embodiment of the present invention, and FIG. 2 is a plan view of an alignment control film and a ferroelectric liquid crystal element of the present invention. 11...Substrate, 12...Transparent electrode layer,
13...Alignment control film, 14...Spacer/sealing resin, 15...Liquid crystal support plate, 16.
...Liquid crystal, 21... Upper liquid crystal support plate, 2
2...Lower liquid crystal support plate, 23...Rubbing direction of upper liquid crystal support plate, 24...Rubbing direction of lower liquid crystal support plate, 25... ...Spacer and seal resin.

Claims (4)

[Claims] (1) An alignment control film in which a paint containing protein as a main component is applied to a liquid crystal support plate, and this paint film is exposed to an environment with a temperature of 30 to 60°C and a humidity of 70% RH or more. (2) Claim (1) in which the alignment control film is subjected to alignment treatment.
The orientation control film described above. (3) A pair of opposing liquid crystal support plates each having an alignment control film containing protein as a main component, which has been subjected to an alignment treatment on at least one of the substrates, and which has been exposed to an environment of a temperature of 30 to 60°C and a humidity of 70% RH or more. A ferroelectric liquid crystal element that uses an alignment control film that holds liquid crystal material in the gap. (4) A ferroelectric liquid crystal element using the alignment control film according to claim (3), wherein the liquid crystal substance held in the gap between the opposing liquid crystal support plates exhibits ferroelectricity.