JPH04402A - Color filter manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a color filter (hereinafter abbreviated as CF) used in a liquid crystal display.

[Conventional technology]

Micelle is a method in which pigment particles that are insoluble or sparingly soluble in water are surrounded by a positively charged surfactant through electrolysis to form a micelle colloid, and a thin film of pigment particles is formed on the anode electrode by destroying the micelles through electrolytic oxidation. As an electrolytic method, it has been reported by Saji et al. (J, Al11
．． Chem, Soc, 109.5881 (1987))
, Chem, Lett, 893 (198g), etc.).

We have confirmed that a wide variety of dye thin films can be formed using this film-forming method. (Japanese patent application No. 63-108726, Japanese patent application No. 63-174102).

Therefore, as an application development of its nature, CF for use in liquid crystal displays.
devised a completely new manufacturing method for
0).

[Problem to be solved by the invention]

However, the following problems have been encountered in the application to CF as described above.

Normally, CF is often composed of pigment films of two colors or three colors of R, G, and B. First, a striped two-color coloring pattern is assumed, and in this case, a desired dye film can be easily formed in a predetermined pattern.

This can be done as follows. 1) First, connect only 11 electrode patterns to a transparent substrate on which ITO transparent electrode patterns are formed as shown in Figure 1, and immerse it in an electrolytic solution to perform electrolysis to form a desired dye film. do. 2) Subsequently, the 12 electrodes are connected together and immersed in an electrolytic solution to perform electrolysis to form a desired dye film. By carrying out the procedure described above, a two-color dye pattern can be easily formed. Next, assume a three-color coloring pattern.

However, in this case, it is difficult to easily form a desired dye film in a predetermined pattern. As a three-color colored pattern, it is possible to use a substrate on which a second or triangular ITO transparent electrode pattern is formed, but using a substrate with an ITO pattern in either case has the following problems. This is because it has.

First, let's discuss the problems with using the electrode pattern substrate shown in Figure 2. In the case of alternately forming R, G, and H dye films using the ITO electrode pattern-formed substrate shown in FIG. 2, 21.
22. It is necessary to selectively make each electrode in 23 conductive and the other electrodes non-conductive, but to achieve this, a current-carrying device or the like is used that has electrodes that are in contact at a constant pitch. In addition, it is necessary to perform positioning to bring only predetermined ITO electrodes into contact.

However, the formation pitch of the ITO electrode pattern is 0.5
When the pitch is very narrow (mm or less), it is extremely difficult to create an energizing device that can conduct selectively at such a pitch, and to align the electrodes so that only the electrodes in a predetermined pattern are in contact. . This is the problem with the electrode pattern shown in Figure 2.

Next, we will list some problems in using the electrode pattern substrate shown in FIG. The electrode pattern shown in Figure 3 can be formed by simple electrolytic film formation using a conductive material such as conductive paste, without the use of special equipment and positioning operations as in Figure 2. This is a pattern designed for experimentation.

However, in this case, as can be seen from the pattern shape, if the insulation of the first color pigment film is low, there is a problem in that the second color pigment film is formed on top of it, causing color mixing.

In order to form R, G, and B dye films on this electrode pattern, micelle electrolysis may be performed by bringing the broken line portions 34, 35, and 36 into solid contact with the power source in order. However, as can be seen from FIG. 3, if the insulation of the first color pigment film 31 is not high, when forming the second color pigment film 32, the second color pigment will overlie the first color pigment. There is a problem that a film is formed and color mixture occurs.

In general, dyes for CF are selected based on their spectral characteristics, and many have low insulation properties when subjected to Limicell electrolysis. For this reason, the dye materials that can be used for CF are extremely limited, and a color filter having predetermined spectral characteristics cannot be obtained.

For example, phthalocyanine pigments, which have the best spectral properties, light resistance, and heat resistance and are used in the color filters of current liquid crystal panels, have low insulation properties when deposited by micelle electrolysis, resulting in the shape shown in Figure 3. electrode pattern cannot be used.

Furthermore, even with highly insulating dye films, as the film thickness becomes thinner, the electrical resistance of the film decreases, which often causes color mixing problems. This is the problem in the case of FIG.

Therefore, from the above, in order to form a colored pattern of the three primary colors, a precise energizing device that selectively conducts only the predetermined electrode patterns described above is used, and precise positioning is performed to bring only the electrodes of the predetermined patterns into contact. This posed a major problem in terms of production technology.

Therefore, the present invention is intended to solve these problems.
The purpose of this is that when producing CF using the micelle electrolysis method, a special energizing jig is used during electrolysis to
The objective is to form only a desired dye film on a predetermined electrode pattern by using a simple current-carrying contact that conducts all at once using a paste-like conductive material, without the need to selectively conduct electricity to the O electrode.

As a means to achieve the above object, after a dye film of one color of R, G, or B is formed on a predetermined electrode pattern, a surfactant is used to form the dye films of the remaining two colors. The molar concentration is at least 115 relative to the dye molar concentration.
The purpose is to use the pigment dye colloid solution prepared above.

[Means to solve the problem]

The method for producing CF of the present invention comprises a micellar colloidal aqueous solution of a dye in which the dye particles are insoluble or sparingly soluble in water, a surfactant charged by electrolysis, and a supporting electrolyte are the basic components, and the dye particles are surrounded by the surfactant. In the CF manufacturing method using the micelle electrolysis method, the micelles are prepared and destroyed by electrolysis, and dye particles are eutectoided on the conductor to form a dye thin film. In order to selectively form the desired pigment film, a micellar colloid aqueous solution in which the molar concentration of the surfactant charged by electrolysis is at least 175 or higher with respect to the pigment molar concentration is used, and a pigment film has already been formed during electrolysis. A desired dye film can be formed on a predetermined ITO electrode pattern without color mixing with the dye film that has already been formed even if electrolytic film formation is performed using a simple current-carrying contact in which the ITO pattern is also energized at the same time. do.

That is, when forming the remaining two colors of dye films after a dye film of either RSG or B is formed on a predetermined electrode pattern of one color, the molar concentration of the surfactant is at least as low as the molar concentration of the dye. A pigment dye colloid solution with a concentration of 175 or higher is used. As a result of intensive efforts, the present inventors have discovered that it is possible to form a film without color mixing by a simple contact method without using a selectively energized contact jig.

Hereinafter, the present invention will be explained in detail using Examples.

〔Example〕

A transparent substrate with a diagonal of 5 inches as shown in Figure 3, on which transparent electrodes of ITO (indium tin oxide) were formed in a striped pattern, was used.

Next, add 1000 r each of the dye colloid solutions shown in Table-1.
Adjusted by +J.

After preparing the dye colloid solutions shown in Table 1, using these solutions and the transparent electrode substrate shown in Figure 3, C consisting of R-G-83 colors was prepared.
I tried to create F. The film formation process was performed as follows. (The combination of liquids and the order of film formation are shown in Table 2.) 1) Connect the broken line part 34 in Figure 3 with a paste-like conductive material, perform electrolysis in the solution shown in Table 1, and form 31 electrode patterns. We attempted to form a dye film as the first color film.

2) Next, connect the broken line part 35 with a paste-like conductive material, and make sure that the activator concentration in Table 1 is 2.0.3. Electrolysis was performed using a solution of OmM, and an attempt was made to form a dye film as a second color film on 32 electrode patterns.

3) Finally, the broken line parts of 36 are connected with a paste-like conductive material, electrolysis is performed using a solution with an activator concentration of 2.0.3゜0mM in Table 1, and the third electrode pattern of 33 is connected. We attempted to form a pigmented film as a colored film.

Table-21; 3-color CF film deposition without color mixing Table-2
As is clear from the above, after a pigment film of one color is formed on a predetermined electrode pattern, when forming pigment films of the remaining two colors, the molar concentration of the surfactant in the pigment colloidal solution is adjusted relative to the molar concentration of the dye. By setting the value to at least 115 or more, it was possible to form a desired dye film on a predetermined electrode pattern without causing color mixing even by electrolysis using a simple current-carrying contact.

[Comparison example]

As a comparative example, we tried to form a three-color film using the colloidal solution shown in Table 1 in the same film-forming process as in the example, but the phthalocyanine dye film mixed colors, and the three-color CF film formation failed. Table 3 shows examples in which this was not achieved.

As is clear from Table 3, after a pigment film is formed on the electrode pattern of one color, when forming the remaining two color pigment films, the molar concentration of the surfactant in the colloidal solution used is relative to the molar concentration of the pigment. If it is less than 115, the color will be mixed with the previously formed phthalocyanine dye film, and an example will be shown in which an electrode pattern with a desired window in a predetermined electrode pattern was selectively achieved by the above film forming process.

Table 2 [Example] Ratio of surfactant molar concentration and color tone (R, G, B) of pigment film when set to 10.

It becomes impossible to form a pigment film. In other words, this has been a problem in the past.

Table 3 [Comparison example] The parentheses in the water solution NO column indicate the ratio of surfactant molar concentration when the dye molar concentration is 10, and the color tone of the dye film (R, G
, B).

As is clear from the above Examples and Comparative Examples, by using a colloidal solution with a composition in which the surfactant molar concentration is 175 or more relative to the dye molar concentration, a predetermined electrode pattern can be formed by electrolysis using a simple current-carrying contact. It became possible to selectively form a desired dye film.

Note that the upper limit of the surfactant molar concentration in the colloidal solution is not necessarily limited to the pigment molar concentration of 371O, but is a molar concentration of 175 or more relative to the pigment molar concentration, and the surfactant is in the aqueous solution. It is sufficient as long as it does not agglomerate. In addition, the surfactant and pigment concentrations are not necessarily limited to the present composition, and the surfactant molar concentration is 175 or more relative to the pigment molar concentration to prevent pigment aggregation, precipitation, poor dispersion, and surface activity. It may be within a range that does not cause aggregation of the agent.

〔Effect of the invention〕

As described above, according to the present invention, CF
When manufacturing, after a dye film of either R or GSB is formed on a predetermined electrode pattern of one color, the molar concentration of the surfactant in the colloidal solution used to form the remaining dye film is set to the molar concentration of the pigment. By making it at least 115 or more, it became possible to selectively form a desired dye film on a predetermined electrode pattern without causing the problem of color mixing due to electrolysis using a simple current-carrying contact. The present invention can be said to be an effective method for mass production due to its simplicity and low cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a transparent electrode pattern when producing a two-color CF using a micelle electrolysis method. FIG. 2 is a diagram showing an example of a transparent electrode pattern when producing three-color CF using the micelle electrolysis method. FIG. 3 is a diagram showing an example of a transparent electrode pattern when producing three-color CF using the micelle electrolysis method. 11... Transparent electrode 12, Φ, 〃 21... Transparent electrode 22, 23, 31, 32, 33, 34, 35, 36, Applicant: Seiko Epson Corporation

Claims (1)

[Claims] 1) The basic components are insoluble or poorly soluble pigment particles, a surfactant that is charged by electrolysis, and a supporting electrolyte,
A color using a micellar electrolysis method in which a micelle colloid aqueous solution of a dye is prepared in which the dye particles are surrounded by the surfactant, the micelles are destroyed by electrolysis, and the dye particles are deposited on a conductor to form a thin dye film. In the filter manufacturing method, the surfactant molar concentration of the micellar colloid aqueous solution is
A method for producing a color filter, characterized in that the molar concentration of a dye is at least 1/5 or more.