JPH01241524A - Liquid crystal electrooptic element - Google Patents

Abstract

PURPOSE:To control a substrate interval constant and uniform by arranging spacer materials which already adsorb silica gel between substrates. CONSTITUTION:The two substrates 1 are arranged opposite each other at the constant interval and liquid crystal 2 is charged in the gap part to constitute the electrooptic element. Then the spacer particles 3 for gap control over the substrates 1 are made to adsorb silica gel previously so as to uniform the gap where the liquid crystal 2 is charged. Cohesion among the particles which is caused by moisture in air or intermolecular force among the particles is prevented and the spacers 10 control the substrate interval. Consequently, the interval between the two substrates can be controlled to the desired uniform interval.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electro-optical device in which a liquid crystal such as a smectine liquid crystal or a nematink liquid crystal is sandwiched between two substrates. In particular, the present invention relates to an electro-optical element having uniform intervals on the order of β.

[Summary of the invention]

In an electro-optical element in which liquid crystals are enclosed in two substrates arranged oppositely at a uniform interval of one order, silica sol is adsorbed to the spacer particles for regulating the distance between the substrates, thereby preventing the spacer particles from agglomerating with each other. To control substrate spacing to be constant and uniform by enabling uniformly distributed arrangement.

[Conventional technology]

A liquid crystal electro-optical device is constructed by forming a driving bridge film and an alignment film for aligning liquid crystal molecules on the surface of a glass substrate, then placing two substrates facing each other at a regular interval, and filling the gap with liquid crystal. ing.

Incidentally, in recent years, a liquid crystal electro-optical element using a ferroelectric liquid crystal exhibiting a chiral smectic C phase has been developed. Chiral smectine liquid crystal has a helical structure in which the liquid crystal molecules are arranged, and by making the substrate spacing narrower than this spiral period, the liquid crystal molecules lose their helical structure and create a bistable state, which increases the strength of the liquid crystal molecules. By applying a voltage due to its dielectric properties, it can be driven by switching between bistable states at high speed.

Furthermore, in recent years, a nematic liquid crystal with positive dielectric constant anisotropy and optically active additives has been sealed between two substrates, and a spiral structure has been created by twisting the crystal by 160° to 270° in the thickness direction. An STN type liquid crystal optical element has been devised. ST
In N-type liquid crystal optical elements, there is a problem in that the background color changes significantly due to a slight change in the product of the thickness d (Q) of the liquid crystal layer and the anisotropy Δn of the refractive index of the liquid crystal.

In order to maintain a uniform distance between the two substrates of these ferroelectric liquid crystal optical elements and STN liquid crystal optical elements, glass fibers, plastic beads, SiOg beads, alumina powder,
As shown in Fig. 3, spacer particles 3 are dispersed and mixed in a liquid such as chlorofluorocarbon, and then sprayed, or as a powder, they are dispersed in the air and distributed on the substrates, and then the two substrates are separated. 1 is pasted together.

[Problem to be solved by the invention]

As shown in FIG. 3, conventional spacer particles 3 often absorb moisture during storage and aggregate together.

In addition, 1- to 31r, which is often used in ferroelectric liquid crystal optical elements,
Since the spacer particles of m are fine, they often aggregate from the beginning due to intermolecular forces between the particles.

Even if the spacer particles 3 that remain agglomerated in this way are placed on the substrates and bonded together, the distance between the substrates will not be the same as the particle diameter of the spacer particles, as shown in FIG. A spiral structure may occur in some parts, or S
In the TN type liquid crystal optical element, there is a problem that uneven background color occurs.

[Means to solve the problem]

The present invention was made in view of the above problems, and aims to make the gap in which the liquid crystal is sealed uniform.By adsorbing silica sol to spacer particles for controlling the substrate spacing in advance, the particles are separated from each other in the air. The feature is that it prevents agglomeration due to moisture and intermolecular forces between particles, and that the spacer regulates the distance between the substrates.

(Function) In this way, by adsorbing the silica sol to the spacer particles, aggregation of the spacer particles does not occur, and since the silica sol particle diameter is less than I/. of the spacer particles, the distance between the two substrates can be set as desired. It is possible to uniformly control the intervals.

〔Example〕

Embodiments will be explained below based on the drawings.

FIG. 1 is a sectional view of an embodiment of a liquid crystal optical element according to the present invention, and FIG. 2 is a diagram of an embodiment of a spacer used therein.

First, the spacer particles 31 will be explained. 10 g of SiOg beads (manufactured by Catalysts Kasei Kogyo Co., Ltd.) with average particle diameters t and sn are mixed in 100 cc of pure water, and the mixture is ultrasonically dispersed for 10 minutes.

Silica sol (“Sn” manufactured by Nissan Chemical Co., Ltd.) was added to this dispersion liquid.
owtsx"N) is added and subjected to ultrasonic dispersion for another 30 minutes. After that, it is suction filtered and dried under reduced pressure at 40°C for 48 hours to adsorb the silica sol, forming spacer particles 31.
get.

An epoxy resin adhesive is printed to a thickness of about 110 Ir around the surface of a glass substrate having a transparent electrode film and a rubbed polyimide film on the surface. The SiOg beads on which the silica sol has been adsorbed are dispersed in a Freon and alcohol wet solution, and then dispersed at a density of about 300 beads/-. The other substrate is stacked on top of this and heated and bonded together while applying pressure, and a liquid crystal exhibiting a chiral smectic C phase ("C5-101" manufactured by Chisso Corporation) is sealed inside, and the substrate is separated from the substrate by 1.5M. A dielectric liquid crystal optical element was obtained.

FIGS. 3 and 4 are cross-sectional views of a liquid crystal optical element in the state of conventional Si0g beads and when these SlO□ beads are used as spacer particles.

In the conventional method, the spacer particles aggregate as shown in Figure 3, and the liquid crystal optical element manufactured using this method has a 4.
As shown in the figure, the substrate spacing is not kept uniform.

Figures 1 and 2 are cross-sectional views of a liquid crystal optical element when silica sol is adsorbed onto Si0g beads and when these 5iOz beads are used as spacer particles.In this way, each spacer particle is aggregated. The distance between the substrates is uniform, and the thickness of the liquid crystal optical element manufactured using this material is such that the diameter of the silica sol particles is equal to that of the spacer particles.
Eight. Since the diameter is less than 1, the diameter is approximately the same as the spacer particle diameter.

(Example 2) ゛ 10 g of plastic beads with an average particle size of 6.3n (“Micro Pearl” manufactured by Blockbuster Fine Chemical Co., Ltd.)
was mixed with 100 cc of pure water and subjected to ultrasonic dispersion for 10 minutes.

Silica sol (“Sn” manufactured by Nissan Chemical Co., Ltd.) was added to this dispersion liquid.
owtex"N) was added and further subjected to ultrasonic dispersion for 30 minutes. After that, the mixture was suction-filtered and dried under reduced pressure at 25° C. for 48 hours to obtain spacer particles on which silica sol was adsorbed.

An epoxy resin adhesive is printed to a thickness of about 3 On around the surface of a glass substrate having a transparent electrode film and a rubbed polyimide film on the surface. The plastic beads on which the silica sol has been adsorbed are dispersed in a mixture of Freon and alcohol, and then scattered at a density of about 100 beads/-. The other substrate is stacked on top of this and heated and bonded together while applying pressure. Nematic liquid crystal (manufactured by Dainippon Ink Co., Ltd.) which has positive dielectric anisotropy and optically active additives inside this
70922-11) to obtain an STN type liquid crystal optical element with a uniform background color and a substrate spacing of 6.4n.

Note that even when glass fibers were subjected to the same treatment as described above and used, uniform spacing could be obtained without agglomeration. Furthermore, even if the above-mentioned spacer on which silica sol is adsorbed is mixed into a sealant, it can be uniformly dispersed and mixed without agglomeration. It is possible to obtain a large gap.

〔Effect of the invention〕

According to the present invention, spacer particles do not agglomerate and it is possible to keep the distance between two substrates constant and uniform to the diameter of the spacer particles, making it possible to easily manufacture ferroelectric liquid crystal optical elements and STN type liquid crystal optical elements. The effect is great.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a liquid crystal optical element manufactured using spacer particles to which silica sol is adsorbed, Fig. 2 is a state diagram when silica sol is adsorbed to spacer particles according to an embodiment of the present invention, and Fig. 3 is a FIG. 4, a state diagram of conventional spacer particles, is a cross-sectional view of a overnight crystal optical element manufactured using conventional spacer particles. More than 10,000 people, this is my first hit! 1 of 1, 11, 11, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2,

Claims (2)

[Claims] (1) A liquid crystal electro-optical element in which a spacer material is arranged in the gap between the substrates to ensure a uniform gap, characterized in that the spacer material to which silica sol is adsorbed is arranged between the substrates. A liquid crystal electro-optical device. (2) Consists of the steps of mixing a spacer with a solution and applying ultrasound to disperse it in the solution, adding silica sol to this solution and applying ultrasound, and extracting and drying the spacer material. A method for manufacturing a spacer material for a liquid crystal electro-optical element, characterized in that: