JP2532758B2 - Alignment control film and liquid crystal element - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment control film for liquid crystal molecules and a liquid crystal element.

[0002]

2. Description of the Related Art As a technique for controlling the orientation of molecules or aggregates thereof, in a liquid crystal device, a synthetic polymer such as polyimide or polyamide is applied on a substrate and dried,
An alignment control film that has been rubbed on its surface with a rubbing treatment to control the alignment is mainly used. As a method of not performing the rubbing treatment, there is an oblique vapor deposition method of silicon oxide or the like.

[0003]

The rubbing treatment, which is one of the methods for controlling the orientation of molecules and the like in a liquid crystal element, is a simple method and can be carried out at low cost. However, a large area and a large number of pixels are required. When the increase is desired, conventional alignment control films such as polyimide and polyamide cannot cope with this, and there is a problem that the alignment uniformity is insufficient. On the other hand, when a protein such as bovine serum albumin is used for the orientation control film, uniform orientation can be realized, but when it is applied to a liquid crystal device using a liquid crystal exhibiting ferroelectricity, the long-term bistability of the orientation direction of the molecule is long. It had a problem of insufficient stability. On the other hand, as a method of aligning the liquid crystal without performing the rubbing treatment, there is an oblique vapor deposition method. A liquid crystal element having good performance can be manufactured by using this method, but there is a problem that the vapor deposition process is complicated, the cost is generally high, and cost reduction is difficult especially in a large area.

[0004]

In order to solve the above problems, the alignment control film of the present invention is a coating film containing a polypeptide mixed with an amine compound as a main component, and the coating film is subjected to an alignment treatment by a rubbing treatment. The liquid crystal element includes the alignment control film having the above characteristics on at least one liquid crystal support plate.

[0005]

In the present invention, the orientation of molecules or aggregates thereof can be favorably achieved by subjecting a coating film containing a polypeptide mixed with an amine compound as a main component to the orientation treatment by rubbing. When this is applied to a liquid crystal element, uniform alignment can be easily realized at low cost over the entire surface of the element. Above all, in a liquid crystal element using a liquid crystal exhibiting ferroelectricity, uniform alignment can be realized at low cost while completely maintaining bistability.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An alignment control film of one embodiment of the present invention and a liquid crystal device using the same will be described below with reference to the drawings. (FIG. 1) is a diagram schematically showing a liquid crystal element using the alignment control film of the present invention. A transparent electrode 12 made of indium / tin oxide is formed on a substrate 11 made of glass or plastic, and an alignment control film 13 is formed on the transparent electrode 12, and then alignment treatment is performed. The liquid crystal support plate 15 was attached, the liquid crystal 16 was injected through the opening, and then the opening was sealed to complete a so-called liquid crystal cell. (Fig. 2)
Is a coating film prepared by using an aqueous solution of poly-L-sodium glutamate mixed with polyoxypropylenediamine (molecular weight 400) as an orientation control film, and the electro-optical characteristics of the ferroelectric liquid crystal cell prepared by the above method are measured. FIG. In FIG. 2, ◯ represents the maximum relative brightness when a voltage is applied and represents the bulk response, and X represents the relative brightness after 1000 line scanning of a series of measurement waveforms, which represents the memory response. It can be seen from 2) that a sharp threshold value and good bistability are exhibited. The structural formula of polyoxypropylenediamine (molecular weight 400) is

[0007]

Embedded image

[0008]

Example 1 1.0 g of sodium poly-L-glutamate was dissolved in 99.0 g of pure water to obtain 1.0
A weight% sodium poly-L-glutamate aqueous solution was prepared. Then, a 1.0 wt% polyoxypropylene diamine (molecular weight 400) aqueous solution 100.
0 g was added and sufficiently stirred to prepare an aqueous solution of sodium poly-L-glutamate mixed with polyoxypropylenediamine.

The aqueous solution of poly-L-sodium glutamate mixed with the polyoxypropylenediamine thus prepared was spin-coated on the glass substrate on which the pattern of the transparent electrode was formed at 500 rpm for 10 seconds, and then continuously applied for 2300. Spin coating was carried out for 1 minute at spin / minute. After coating, the coating film was dried in an electric furnace at 110 ° C. for 1 hour, and then the surface of the coating film was rubbed 10 times in the same direction with a rayon cloth to complete an orientation control film. In this way, the glass liquid crystal support plate on which the orientation control film of poly-L-sodium glutamate mixed with polyoxypropylene diamine is formed is used.
As shown in FIG. 3, an acid prepared by dispersing glass fibers having a diameter of 2 μm was used as a spacer / sealing resin 25 on the surface of one support plate (for example, the lower liquid crystal support plate 22) on which the orientation control film was formed, as shown in FIG. Orientation control formed on the upper liquid crystal support plate 21 and the lower support plate 22 after printing an anhydride-curable epoxy resin with a width of 5 mm in the center of one side and a width of 0.2 mm on the other side. The rubbing directions 23 and 24 of the film are parallel and pressure is applied with the orientation control film surfaces facing each other.
It was heated at 0 ° C. for 4 hours to be cured and adhered. After bonding, the liquid crystal is heated to a temperature at which the liquid crystal is isotropic, that is, around 80 ° C., and a commercially available liquid crystal (trade name ZL manufactured by Merck Co.
I-3654). After the injection, the mixture was gradually 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 completed in this way exhibits a good alignment state with little alignment unevenness and rubbing streaks. By applying a voltage, good electro-optical characteristics with bistability ensured are obtained. The stability was maintained for a long period of 1000 hours or more.

(Example 2) 1.0 g of sodium poly-DL-glutamate was dissolved in 99.0 g of pure water, and 1.
A 0% by weight aqueous solution of sodium poly-DL-glutamate was prepared. Then, a 1.0 wt% polyoxypropylene diamine (molecular weight 400) aqueous solution 10 was added to this aqueous solution.
0.0 g was added and sufficiently stirred to prepare a poly-DL-sodium glutamate aqueous solution in which polyoxypropylene diamine (molecular weight 400) was mixed.

A ferroelectric liquid crystal cell prepared by the same operation as in Example 1 using this aqueous solution showed a good alignment state with little alignment unevenness and rubbing streaks, and by applying a voltage,
Bistability was ensured and good electro-optical characteristics were obtained, and bistability was maintained for a long period of 1000 hours or more.

Example 3 1.0 g of sodium poly-D-glutamate was dissolved in 99.0 g of pure water to obtain 1.0
A weight% sodium poly-D-glutamate aqueous solution was prepared. Then, a 1.0 wt% polyoxypropylene diamine (molecular weight 400) aqueous solution 100.
0 g was added and sufficiently stirred to prepare a poly-D-sodium glutamate aqueous solution in which polyoxypropylene diamine (molecular weight 400) was mixed.

A ferroelectric liquid crystal cell produced by using this aqueous solution in the same manner as in Example 1 showed a good alignment state with little alignment unevenness and rubbing streaks.
Bistability was ensured and good electro-optical characteristics were obtained, and bistability was maintained for a long period of 1000 hours or more.

Example 4 1.0 g of sodium poly-DL-aspartate was dissolved in 99.0 g of pure water,
A 1.0 wt% sodium poly-DL-aspartate aqueous solution was prepared. Then 1.0% by weight in this aqueous solution
100.0 g of polyoxypropylene diamine (molecular weight 400) aqueous solution was added and sufficiently stirred to prepare a poly-DL-sodium aspartate aqueous solution in which polyoxypropylene diamine (molecular weight 400) was mixed.

A ferroelectric liquid crystal cell prepared by the same procedure as in Example 1 using this aqueous solution showed a good alignment state with little alignment unevenness and rubbing streaks, and when a voltage was applied,
Bistability was ensured and good electro-optical characteristics were obtained, and bistability was maintained for a long period of 1000 hours or more.

(Example 5) 1.0 g of sodium poly-L-glutamate was dissolved in 99.0 g of pure water to obtain 1.0
A weight% sodium poly-L-glutamate aqueous solution was prepared. Next, 100.0 g of a 1.0 wt% benzylamine aqueous solution was added to this aqueous solution and sufficiently stirred to prepare an aqueous solution of sodium poly-L-glutamate mixed with benzylamine.

A ferroelectric liquid crystal cell prepared by the same procedure as in Example 1 using this aqueous solution showed a good alignment state with little alignment unevenness and rubbing streaks.
Bistability was ensured and good electro-optical characteristics were obtained, and bistability was maintained for a long period of 1000 hours or more.

Example 6 1.0 g of sodium poly-L-glutamate was dissolved in 99.0 g of pure water to obtain 1.0
A weight% sodium poly-L-glutamate aqueous solution was prepared.

Next, 100.0 g of 1.0% by weight decamethylenediamine aqueous solution was added to this aqueous solution and sufficiently stirred to prepare an aqueous solution of sodium poly-L-glutamate mixed with decamethylenediamine.

A ferroelectric liquid crystal cell prepared by the same procedure as in Example 1 using this aqueous solution showed a good alignment state with little alignment unevenness and rubbing streaks.
Bistability was ensured and good electro-optical characteristics were obtained, and bistability was maintained for a long period of 1000 hours or more.

The ferroelectric liquid crystal is not limited to ZLI-3654. Further, an insulating layer may be formed on one surface or both surfaces of the transparent electrode layer for the purpose of preventing a short circuit between the upper and lower substrates, and the orientation control film may be formed on the insulating layer.

The orientation control film is not limited to the above-mentioned sodium polyglutamate and sodium polyaspartate, and various polypeptides such as polyalanine and polylysine may be used.

The amine compound added to the orientation control film is polyoxypropylenediamine (molecular weight 4
00), benzylamine, and decamethylenediamine, an amine compound such as cyclohexylamine, phenylethylamine, phenylpropylamine, and benzylethanolamine may be used.

Comparative Example 1 1.0 g of sodium poly-L-glutamate was dissolved in 99.0 g of pure water to obtain 1.0
A weight% sodium poly-L-glutamate aqueous solution was prepared. A ferroelectric liquid crystal cell produced using this aqueous solution by the same operation as in Example 1 exhibited bistability when a voltage was applied, but the bistability deteriorated within 24 hours.

Comparative Example 2 1.0 g of sodium poly-DL-aspartate was dissolved in 99.0 g of pure water,
A 1.0 wt% sodium poly-DL-aspartate aqueous solution was prepared.

A ferroelectric liquid crystal cell prepared by the same procedure as in Example 1 using this aqueous solution showed bistability when a voltage was applied, but the bistability deteriorated within 24 hours.

[0028]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a liquid crystal alignment control film is formed by subjecting a coating film containing a polypeptide mixed with an amine compound as a main component to an alignment treatment by rubbing to align molecules or aggregates thereof. Can be controlled. When this is applied to a ferroelectric liquid crystal device, uniform alignment can be easily realized at low cost over the entire surface of the device, and stable memory property can be secured for a long period of time.

[Brief description of drawings]

FIG. 1 is a schematic view of a liquid crystal element of the present invention.

FIG. 2 is an electro-optical characteristic diagram of a ferroelectric liquid crystal cell.

FIG. 3 is a schematic plan view of a ferroelectric liquid crystal element using an alignment control film and an alignment control method of the present invention.

[Explanation of symbols]

 11 Substrate 12 Transparent Electrode Layer 13 Alignment Control Film 14 Spacer and Seal Resin 15 Liquid Crystal Support Plate 16 Liquid Crystal 21 Upper Liquid Crystal Support Plate 22 Lower Liquid Crystal Support Plate 23 Rubbing Treatment Direction of Upper Liquid Crystal Support Plate 24 Rubbing Treatment of Lower Liquid Crystal Support Plate Direction 25 Spacer and sealing resin

Claims (4)

(57) [Claims] 1. An orientation control film, which is a coating film containing a polypeptide mixed with an amine compound as a main component, wherein the surface of the coating film is subjected to an alignment treatment. 2. The alignment control film according to claim 1, wherein a rubbing method is used as an alignment treatment method. 3. A pair of liquid crystal support plates facing each other on at least one substrate, which has an alignment control film obtained by subjecting a coating film containing a polypeptide mixed with an amine compound as a main component to an alignment treatment by a rubbing method. A liquid crystal element characterized by holding a liquid crystal substance therein. 4. The liquid crystal device according to claim 3, wherein the liquid crystal substance held in the space facing the liquid crystal support plate exhibits ferroelectricity.