JPH03293635A - Production of color filter - Google Patents

Abstract

PURPOSE:To improve liquid crystal driving characteristics by impregnating a material which is made into a conductive material by a post treatment into dyed films after the formation of the dyed films and forming a conductor structure in the dyed films by the post treatment. CONSTITUTION:Org. pigments are dispersed into an aq. micelle soln. of a surfactant having redox reactivity and are made into colloid; thereafter, an electrolysis is effected in the aq. micelle soln. to deposit the org. pigments on a transparent electrode substrate 1 and to form the dyed films 4. The material which is made into the conductive material 5 is impregnated by the post treatment into the dyed films 4 and the conductor structure 6 is formed in the dyed films 4 by the post treatment, by which the dye films 4 are made conductive. The loss of the impressed voltage at the time of liquid crystal driving is eliminated in this way and the color filter sufficiently applicable even to the high-duty driving with a simple matrix type (STN) is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a color filter used in a color display device, and more particularly to a method of manufacturing a color filter used in a liquid crystal display device.

[Conventional technology]

After dispersing the organic pigment in a micellar aqueous solution of a redox-reactive surfactant and turning it into a colloid, electrolysis is performed in the micellar aqueous solution to deposit the organic pigment on a transparent electrode substrate using the anode to form a pigment film. We have invented a method for manufacturing color filters by forming (Japanese Patent Application No. 175610/1983).

However, the above color filter had the following problems.

The dye film of this color filter is formed as a deposited layer of organic pigment particles on a transparent electrode, but when used for a liquid crystal display, it has the great advantage that the transparent electrode can also be used to drive the liquid crystal. There is.

That is, in the case of color filters made using the conventional dyeing method or pigment dispersion method, the pigment film contains, in addition to the dye or pigment, a binder resin for fixing them, so the pigment film becomes relatively thick. Therefore, when such a dye film is formed on a transparent electrode for driving a liquid crystal, there is a problem in that a loss of applied voltage occurs and the driving performance of the liquid crystal decreases. In particular, when a simple matrix type (STN type) liquid crystal panel is driven at a duty of at least 1/200 or more, it is difficult to obtain sufficient drive characteristics. Regarding this point, since the color filter of our invention has a pigment film formed only from organic pigments, it is possible to make the pigment film relatively thin compared to the dyeing method or pigment dispersion method, so the duty is about 1/200. It can be driven satisfactorily. However, it has been found that sufficient driving is still difficult when driving at a high duty of about 1/400 to 1/480. Therefore, in order to solve this problem, it seems easy to simply provide a transparent electrode for driving the liquid crystal on the dye film, but in reality, the manufacturing process is long, high yield cannot be obtained, and the cost is high. There was a problem that it was also uploaded.

[Problem to be solved by the invention]

As mentioned above, the conventional technology has a problem in that it is difficult to apply it to high duty drive in a simple matrix type (STN type).

Therefore, the object of the present invention is to eliminate the applied voltage loss during liquid crystal driving by treating the dye film to conductivity, thereby making the color sufficiently applicable to high-duty driving in a simple matrix type (STN). An object of the present invention is to provide a method for manufacturing a filter.

[Means to solve the problem]

The method for producing a color filter of the present invention involves dispersing an organic pigment in an aqueous solution of a redox-reactive surfactant to form a colloid, and then electrolyzing the organic pigment in the aqueous solution of the latter to transfer the organic pigment onto a transparent electrode substrate. After depositing and forming a pigment film, a material that becomes a conductive substance is impregnated into the pigment film in a post-treatment, and in the post-treatment, a conductive structure is formed in the pigment film to make the pigment film conductive. Features.

The means will be specifically described below.

The color filter of the present invention has a structure in which organic pigment fine particles are deposited to form a film. Therefore, the pigment film is characterized by the presence of many voids between pigment particles.

Therefore, in the present invention, an alkoxide of indium or tin is made into a solution with a certain concentration, hydrolyzed, the resulting solution is impregnated into the voids of the pigment film, and an oxide conductor structure of indium or tin is formed in a matrix between the pigment particles by heat treatment. It is intended to make the dye film electrically conductive.

Examples of the redox-reactive surfactant used in the gap in which the dye film is formed include Ferrocenyl PEG manufactured by Doguchi Chemical Co., Ltd., which has ferrocene introduced into the hydrophobic end group. After dispersing and colloidizing organic pigment fine particles in this surfactant aqueous solution using ultrasonic treatment or the like, electrolysis is performed, and a dye consisting only of organic pigment is deposited by the destruction of micelles on the transparent electrode substrate used as an anode. A film can be formed.

A color filter can be formed by forming a dye film in a fixed pattern consisting of the three primary colors P, G, and H.

Next, this dye film may be impregnated with a material capable of forming a conductor structure in a post-treatment. There are no particular restrictions on the material that can form the conductor structure, but alkoxides such as indium and tin are preferred.

A method for impregnating the dye film with the precursor of the conductor structure is to apply the solution to the dye film, and may be carried out by immersing the substrate on which the dye film is formed in the solution. However, in this case, since the entire surface of the substrate is coated with the precursor, there arises an inconvenience that the transparent electrode patterns end up being electrically connected to each other. Therefore, if a protective film is coated between each transparent electrode in advance, then the entire substrate is coated with a conductive precursor, and the precursor is treated to become conductive, and then the previously formed protective film is stripped. , no conductor structure is formed between each transparent electrode, and short circuits between the electrodes can be prevented.

A good method for forming this protective film is to use a resist material that can be first hardened and then stripped using an organic solvent or weak alkali. Alternatively, the electrodes may be selectively formed between the electrodes with high precision using offset printing or the like.

〔Example〕

(Example 1) After forming an ITO film on a 30 cm square glass substrate, the ITO film was processed into a striped transparent electrode consisting of 1920 stripes with a width of 100 μm using photolithography on a rectangular area of approximately 10 inches diagonally. . Each stripe has 2
They were arranged with a gap of 5 μm. In addition, the ends of the striver patterns were processed into a shape that allows the drive IC to be mounted.

Next, the entire substrate was coated with a photocurable resin and processed by photolithography so that the resin film remained only between the ITO patterns. Tokyo Ohka Kogyo (
A positive resist 0FPR-800 manufactured by Co., Ltd. was used. (
Figure 1(a)) Next, R,
A dye film of 01B was formed. Pigment film is 640 per color
Using a book pattern, selective conduction electrolytic film formation was performed so that R, G, and B were arranged alternately. (FIG. 1(b)) The composition of the electrolytic solution shown in Table 1 was used. Electrolysis was performed for each dye film by constant voltage electrolysis at 0.5 V (vs. 5CE). Each pigment film has R (0.9 μm)
, G (0.9 μm), and B (0°9 μm).

*1 *2 Surfactant with redox reactivity Ferrocenyl PEG (manufactured by Doguchi Kagaku) Supporting electrolyte Li2SO4 The dye film was baked at 120° C. for 30 minutes after each color film was formed to improve adhesion.

Next, the substrate on which this dye film was formed was 5n (i-OC3H7
)4 (manufactured by Lichemical Co., Ltd.) in a 5 wt% ethanol solution. A small amount of water was added to this ethanol solution, and 5n(i-OC3H))4 was previously hydrolyzed and used. This operation impregnated the tin oxide precursor into the pigment film, while also coating the entire substrate. (FIG. 1(C)) Thereafter, this substrate was baked at 120° C. for 30 minutes.

Subsequently, the photocurable resin coated between the ITO patterns was immersed in acetone and stripped.

(FIG. 1(d)) Subsequently, this substrate was further baked at 200° C. for 1 hour to form a matrix of tin oxide within the dye film, thereby completing a color filter.

An STN type color panel was created by using this color filter and passing through a predetermined liquid crystal panel manufacturing process. 1
As a result of driving at a duty of /400, the dye film became conductive, and the liquid crystal driving characteristics were dramatically improved, showing characteristics equivalent to those of a structure without color filters.

(Example 2) In Example 1, each dye film was formed to have the same thickness, resulting in a color filter that was slightly unsatisfactory in terms of color tone. Therefore, when electrolytically forming the dye film, the pigment and transparent resin are eutectoid to ensure a sufficient color tone, and to ensure that the liquid crystal cell gap does not differ between each dye, and the thickness of each dye film is constant. Ta. The thickness of each eutectoid film is 1.2 μm.
The pigment was deposited in the necessary amount to develop a sufficient color tone, and the amount of transparent resin deposited was controlled in order to make the film thickness the same for each pigment film.

As the conductive material used in Example 2, the same material as in Example 1 was used. All other manufacturing methods were the same as in Example 1, and the liquid crystal panel was also created in the same manner.

As a result, we have been able to dramatically improve liquid crystal drive performance and create liquid crystal panels with satisfactory dark gray tones.

〔Effect of the invention〕

As described above, the present invention has made it possible to manufacture a color filter that dramatically improves liquid crystal driving characteristics. It has been found that the present invention is particularly effective when applied to color filters for high-denity drive simple matrix type liquid crystal panels, but it can also be similarly applied to the creation of color filters for MIM active matrix type liquid crystal panels. I think the same effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the method for manufacturing a color filter of the present invention. Glass substrate photocurable resin transparent electrode pigment film conductive material precursor 6 eye/pigment film + conductive material or more

Claims (2)

[Claims] (1) After dispersing and colloidizing an organic pigment in a micellar aqueous solution of a surfactant having redox reactivity, electrolysis is performed in the micellar aqueous solution to deposit the organic pigment on a transparent electrode substrate to form a pigment film. The method for producing a color filter is characterized in that after forming the pigment film, a material that becomes a conductive substance is impregnated into the pigment film in a post-treatment, and a conductive structure is formed in the pigment film in the post-treatment. A method for manufacturing a color filter. (2) The method for manufacturing a color filter according to claim 1, characterized in that a metal alkoxide such as indium or tin is used as the material that becomes a conductive substance in post-treatment.