JPH01284830A - Spacer material spreading device - Google Patents

Abstract

PURPOSE:To shorten the time when a spacer material is spread to a plate by electrifying the spacer material to charge opposite to the polarity of an electrode plate at the time of spreading the spacer material and allowing an electrical attraction to work between the spacer material and the electrode plate. CONSTITUTION:A spacer material 5 is injected into the air in a state that it has been dispersed to a dispersion medium from a nozzle 1, and thereafter, the dispersion medium is evaporated. In this case, the spacer material 5 is electrified to negative at the time of collision with a negative ion in a corona discharge space which has been formed by a discharge pin 2 provided on a substrate. Since an electrode plate 4 is grounded, an electrical attraction works between the spacer material 5 and the electrode plate 4, and the spacer material 5 reaches the substrate 3 placed on the electrode plate 4 in a short time and it is spread since the electrical attraction is applied in addition to the gravity of itself. As for the spacer material, spherical silica whose average diameter is 0.5-5mum is used, and adhesive grains 7 can be injected from the nozzle 1 together with the spacer material 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a spacer material dispersion device used when making a liquid crystal cell, particularly a ferroelectric liquid crystal cell.

[Conventional technology]

Conventionally, in the spacer material dispersion process for ferroelectric liquid crystal elements, a dispersion medium in which spacer materials are dispersed is injected into the atmosphere by means such as a sprayer, the dispersion medium is vaporized, and the spacer particles are naturally dispersed under their own weight. It was lowered, reached the substrate, and was deposited.

However, in the method of letting the spacer material fall naturally onto the substrate, the process of dispersing the spacer material takes a long time.

Particularly in the case of ferroelectric liquid crystals, the spacer material is minute, so the method of letting it fall naturally takes a very long time. for example,
For a spherical fine particle of 5i02 (specific gravity 2.55, diameter 1 μm), the speed when falling naturally in the atmosphere is approximately 8X
10-”cm/s (from Stogokus’ law), and 5
The time required to lower the aircraft by 0 cm was about 100 minutes.

[Summary of the invention]

An object of the present invention is to provide a spraying device that can spray spacer material onto a plate in a shortened time.

Another object of the present invention is to provide a spraying device capable of uniformly distributing spacer material onto a plate.

The present invention comprises a) a spraying means for spraying a spacer material and adhesive particles, b. a charging means for imparting an electric charge to the spacer material and adhesive particles, and a C9-charged spacer material and adhesive particles, and a liquid crystal cell. This is a spacer material dispersion device having means for applying a potential to an electrode disposed behind a constituting plate to generate an electrical attraction between the electrode and the electrode.

[Detailed description of aspects of the invention]

FIG. 1 is an explanatory diagram showing this embodiment. 1 is a nozzle for spraying a dispersion medium in which a spacer material is dispersed; 2 is a plurality of discharge pins provided on a substrate; 3 is a substrate for forming a liquid crystal cell; 4 is an electrode plate; It is a stage for placing. 5 is a spacer material. 6 is a DC high voltage power supply. 7 is an adhesive particle.

In the above configuration, the spacer material 5 is injected into the atmosphere from the nozzle 1 while being dispersed in a dispersion medium (for example, isopropyl alcohol, n-hexane, butane, Freon manufactured by Mitsui-DuPont Fluorochemicals, etc.), and then dispersed. The medium evaporates. The spacer material 5 is negatively charged due to collision with negative ions in the corona discharge space created by the discharge pins 3 provided on the substrate. At this time, since the electrode plate 4 is connected to the ground, an electrical attractive force acts between the spacer material 5 and the electrode plate 4, and the spacer material 5 is attached to the substrate 3 placed on the electrode plate 4. Arrived and dispersed.

Generally speaking, the spacer material 5 is applied to the substrate 3 with a difference of 4 mm per 1 mm.
Y≠-# Dispersed at a rate of 100 to 500 pieces. or,
The spacer material 5 when present in the dispersion medium is generally 0.0
It can be contained in a proportion of 1 wt%.

In addition, the discharge pin 2 of the corona discharger has a voltage of 10 KV to 1
A voltage of 00 KV is applied, and a discharge occurs between the electrode plate 4 connected to the ground. As the voltage at this time, a direct current or a direct current to which an AC bias is applied is used.

Further, in this embodiment, a negative voltage (with respect to the ground) is applied to the discharge pin 2, but the same effect can be obtained by applying a positive voltage (with respect to the ground).

Since the spacer material 5 is subjected to electrical attraction in addition to its own gravity, the spacer material 5 can be lowered in a shorter time compared to a method in which the spacer material 5 is naturally lowered by its own weight. It became possible to reach and complete the adhesion onto the substrate 3. Moreover, it is possible to make the dispersion state uniform. For example, when 10 different locations were observed using a microscope, 300 particles per 1 mm (±
1% error range).

On the other hand, in the case of the method of allowing the object to fall naturally using only its own weight, the error range in similar measurements was ±15%.

Example 2 FIG. 2 is an explanatory diagram showing this example. When the spacer material 5 was attached to the substrate 3 in the same manner as in Example 1 except that the discharge pin 2 was provided inside the nozzle 1, compared to the method of letting the spacer material 5 fall naturally only by its own weight, The spacer material 5 reaches the substrate 3 in a shorter time,
It became possible to complete the attachment.

Example 3 A discharge pin 2 was provided inside the nozzle 1 as shown in FIG. 2 and on the electrode plate 3 as shown in FIG. As a result, it became possible to complete the arrival and attachment of the spacer material 5 onto the substrate 3 in a shorter time than with a method in which the spacer material 5 is allowed to fall naturally using only its own weight.

A cell can be created by overlapping the substrate 3 with the spacer material 5 sprinkled on the other substrate. At this time, the substrate 3 on which the spacer material 5 has been sprayed and the other substrate are preliminarily coated with a transparent conductive film to serve as an electrode and an alignment control film (furthermore, an insulating film is provided between the transparent conductive film and the alignment control film). is provided.

FIG. 3 is a cross-sectional view of a ferroelectric liquid crystal cell prepared by using a substrate 3 on which spacer material 5 is spread. In FIG. 3, reference numeral 31 indicates the other substrate, and transparent electrodes 32A and 32B are provided on the substrates 31 and 3, respectively, and insulating films 33A and 33B are provided thereon, respectively (500 to 5000
5i02 membrane, preferably 800 to 3000 people thick;
A TiO2 film, etc.) is provided, and an alignment control film (10 to 1000 films, preferably 50 films to
A rubbed polyimide film, a polyvinyl alcohol film, a polyamide film, etc., with a thickness of 500 mm is provided.

The distance between the substrates 31 and 3 is preferably set to be sufficiently thin to control the formation of a helical alignment structure of the ferroelectric smectic liquid crystal 35 disposed therebetween. For this purpose, the diameter size of the spacer material 5 is generally set to 0.5 μm or more.
The thickness is set to 5 μm, preferably about 1.0 to 2.0 μm. Furthermore, crossed Nicol polarizers 36A and 36B are arranged on both sides of this ferroelectric liquid crystal cell 30. This ferroelectric smectic liquid crystal cell 30 is manufactured by Clark et al.
4367924.

Spherical silica can be used as the spacer material 5 used in the present invention. This spherical silica can be obtained by contacting an alcoholic solution of an alkyl silicate with aqueous ammonia. Alkyl silicate is orthosilicic acid (
H4SiO4) alkyl ester with the general formula Si (O
R) 4; R Represented by an alkyl group such as methyl, ethyl, propyl, butyl, amyl, etc. Ethyl silicate and propyl silicate are preferably used. Examples of the alcohol used include methanol, ethanol, and propatool. It is also possible to contain n-hexane, heptane, toluene, xylene, etc. in this alcohol at a weight ratio of 0.01 to 5 per liter of alcohol.

Further, in a preferred embodiment of the present invention, the above-mentioned spacer material 5
At the same time, adhesive particles 7 can be sprayed from the nozzle l. In the cell created by using the substrate 3 on which the adhesive particles 7 are sprinkled together with the spacer material 5, since the two substrates are firmly bonded while maintaining the distance provided by the spacer material 5, the ferroelectric liquid crystal due to the impact Orientation destruction (
(causing sandy texture) can be prevented.

The adhesive particles 7 contain an epoxy compound containing two or more epoxy groups in the molecule and a curing agent. Examples of epoxy compounds include bisphenol A with glycidyl ether at both ends, diglycidyl ether of polyethylene glycol, polyglycidyl ether of phenol novolak type compound, N, N, N', N'-
Tetraglycidyl-m-xylene diamine and the like can be used. Examples of curing agents include dicyandiamide, imidazoles, Lewis acid complexes, phenols, phenol novolacs, polyvinylphenols, carboxylic acids, acid anhydrides, acidic polyesters, styrene-maleic acid copolymers, and polyamines. In particular, phenolic curing agents such as phenol novolaks and polyvinylphenols are preferred.

The above curing agent is used in an amount of 0.05 per equivalent of the epoxy compound.
-1 equivalent can be used.

Moreover, the above-mentioned adhesive particle 7 is one piece of the spacer material 5 [Effects of the Invention] As explained above, the present invention charges the spacer material to a charge opposite to the polarity of the electrode plate when the spacer material is sprayed. This causes an electrical attraction to act between the spacer material and the electrode plate.

As a result, the spacer material can reach and adhere to the substrate placed on the electrode plate in a short time, compared to the conventional example.
In addition to reducing the time required for the spacer dispersion process,
It has an excellent effect of being able to form a uniformly dispersed state.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the device of the present invention. FIG. 2 is a sectional view of another device of the invention. FIG. 3 is a cross-sectional view of a ferroelectric liquid crystal cell produced using the apparatus of the present invention. Patent applicant Canon Co., Ltd.

Claims (6)

[Claims] (1) a. Spraying means for jetting the spacer material and adhesive particles; b. Charging means for applying an electric charge to the spacer material and adhesive particles; and c. The charged spacer material and adhesive particles constitute a liquid crystal cell. A spacer material dispersing device comprising means for applying a potential to an electrode disposed behind a plate for generating an electrical attraction between the electrode and the electrode. (2) The spraying device according to claim 1, wherein the charging means is a corona generator. (3) The spraying device according to claim 1, wherein the spacer material is spherical silica having an average diameter of 0.5 μm to 5 μm. (4) The spraying device according to claim 1, wherein the adhesive particles are granules containing an epoxy compound and a curing agent. (5) Claim 4, wherein the curing agent is a phenolic curing agent.
Spraying equipment. (6) a. Spraying means equipped with a nozzle for jetting spacer material and adhesive particles; b. Corona discharger for imparting electric charge to the spacer material and adhesive particles, the electrodes for generating corona discharge. ,
a corona discharger disposed inside the nozzle; and c. a potential for creating an electrical attraction between the charged spacer material and adhesive particles and the electrode disposed behind the plate for forming the liquid crystal cell. 2. The dispersing device according to claim 1, further comprising means for applying a substance to said electrode.