JPH04342206A - Production of color filter - Google Patents

Abstract

PURPOSE:To improve the adhesion of colored layers and to shorten the process in the process for producing the color filters by a wet electrolysis method on a transparent substrate disposed with transparent electrodes of prescribed patterns. CONSTITUTION:The colored layer consisting of only the org. pigment is firstly formed and transparent electrodeposition polymer bodies are secondly formed within this colored layer and on this layer to improve the adhesion of the colored layer. The color filters consisting of three colors; R, G, B, are produced by continuously repeating the 1st and 2nd stage without the calcination stage of the colored layer. The sufficient washing after film formation is executed by improving the adhesion of the colored layers, by which the contamination of the electrodes not formed with the films is prevented. The production process is thus simplified.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter for use in liquid crystal displays, and more particularly to a method for manufacturing a color filter using a wet electrolytic method.

0002

[Prior Art] Coloring is achieved by colloidally dispersing an organic pigment in a micellar aqueous solution of a redox-reactive surfactant, and then depositing the organic pigment on a substrate by electrolysis in the micellar aqueous solution to form a colored layer. We filed a patent application regarding the filter (Japanese Patent Laid-Open No. 2-24603).

[0003] In this method of manufacturing a color filter, after a colored layer made of an organic pigment is formed by electrolysis, the substrate is lightly washed with water in an overflow type water washing tank, and before the second color film is formed, the first color film is A process of firing the colored layer at a temperature of 100 degrees Celsius or higher was used. The same was true for the third color film formation.

That is, since the colored layer made of organic pigment has only weak adhesion due to physical adsorption, when an attempt was made to remove the electrolyte adhering to the substrate by strong water washing such as shower washing, the colored layer itself peeled off. Furthermore, if a second color film is formed directly after washing with water, the first color colored layer is likely to peel off in the electrolytic solution during the film formation. Therefore, a process was used in which the film was heated and baked before film formation to ensure adhesion.

[0005]

SUMMARY OF THE INVENTION As described above, the prior art has the following problems.

(1) Due to poor adhesion when forming the colored layer,
Sufficient cleaning cannot be performed immediately after film formation. Therefore, the transparent electrode used for forming the second and subsequent colors becomes contaminated due to adhesion and residual electrolyte, which deteriorates the color tone of the second and subsequent colored layers.

(2) Adhesion after forming the colored layer is also weak;
It was necessary to heat and bake the deposition layer every time one color was deposited to improve adhesion. In other words, the process becomes long, which is one of the factors that puts pressure on cost benefits.

SUMMARY OF THE INVENTION Therefore, the present invention has been made to solve the above-mentioned problems.The purpose of the present invention is to enable sufficient cleaning of the substrate each time a colored layer is formed, and to eliminate the need for baking. It is an object of the present invention to provide a method for manufacturing a color filter in a short process in which the formation of a colored layer can be continuously repeated, thereby ensuring strong adhesion of a colored layer without the need for the above steps.

[0009]

[Means for Solving the Problems] The method for producing a color filter of the present invention involves dispersing an organic pigment in a micellar aqueous solution of a redox-reactive surfactant, and then electrolyzing it in the solution to form a color filter on a substrate. In a method for manufacturing a color filter in which a colored layer is formed on a substrate, a predetermined number of transparent electrode layer patterns in a predetermined shape are formed on a substrate, and then the substrate is immersed in a first electrolytic solution to form a specific transparent electrode pattern. A first color colored layer is formed by applying electricity and electrolyzing the substrate, and then immediately immersing the substrate in a transparent polymer solution that can be electrodeposited and electrolyzing it, thereby forming a transparent polymer body in and on the colored layer. The basic process is to form a color layer and clean the substrate, and by continuously repeating this basic process at least three times, a colored layer of a second color and a third color is formed.
It is characterized by forming a colored layer group composed of B3 primary colors.

[0010] That is, by electrodepositing a transparent polymer on the colored layer, adhesion that can withstand strong cleaning of the substrate is ensured, and even if the second and subsequent colors are formed without baking, no film is formed. Adhesion that does not cause peeling during coating is ensured. Therefore, the colored layer can be repeatedly and continuously formed.

[0011] The electrodeposited polymer grows through the gaps between the uncolored organic pigment particles and further covers the entire surface of the colored layer, but it is grown to the extent that the original thickness of the colored layer is not increased too much. It is preferable to form a film.

0012

【Example】

(Example 1) A 30 cm square glass substrate shown in FIG. 1 was used as a color filter substrate for a liquid crystal panel. A transparent electrode 2 made of ITO is formed in a striped pattern on a glass substrate, and a pattern for a current-carrying contact during electrolysis is drawn out at one end of the pattern.

Using this substrate, a colored layer of the first color was formed by electrolysis. In forming the first color film, using the R electrolytic solution shown in Table 1, immersing the substrate in this solution,
A red colored layer was formed by electrolysis. At this time, only the ITO electrode pattern indicated by 4 on the substrate was selectively energized, and a colored layer was formed only on this electrode.

[0014]

[Table 1]

[0015] Electrolysis at this time was carried out for 15 minutes by applying 0.8 V between the counter electrode substrate and the counter electrode substrate which were also immersed in the electrolytic solution.

After the electrolysis, the substrate is immediately immersed in the electrodeposited polymer solution, and only the same ITO electrode as above is energized.
Electrolysis was performed at 3V for 1 minute. The electrodeposited polymer solution contains water,
A solution (manufactured by Shimizu Co., Ltd.) in which acrylic acid and melamine were dissolved at a concentration of 10% in an alcoholic solvent was used. Immediately after electrolysis, the substrate was removed from the electrolytic solution and rinsed with water under a powerful shower for 1 minute. At this time, no damage such as peeling was observed in the formed colored layer, and a uniform red colored layer could be formed, and there was no electrolyte residue on the undeposited electrodes. I was able to confirm the effect.

Next, by immediately selectively energizing the ITO electrode 5, using the electrolytic solution G shown in Table 1,
0.5V was applied and electrolysis was performed for 10 minutes. After electrolysis, no peeling of the previously formed red colored layer was observed, so it was immediately immersed in an electrodeposited polymer solution and heated at 3V and 50°C.
Electrolysis was performed for seconds. Immediately after electrolysis, the board was removed from the electrolyte and washed with a strong shower. At this time, there was no peeling or other damage to the green colored layer that had been formed and the red colored layer that had been formed previously, and no electrolyte residue was observed on the unformed electrode.

[0018] Then, by immediately selectively energizing the ITO electrode 6, using the electrolytic solution B in Table 1, 0.5
V, electrolysis was performed for 10 minutes. At this time, the 2
No peeling or the like was observed in the colored layer of the seeds. Subsequently, it was immediately immersed in an electrode polymer solution and electrolyzed at 2.5 V for 1 minute. Although the substrate was washed with strong shower water, there was no damage to any of the colored layers formed, confirming the effect of the present invention.

On the other hand, the cross section of the formed colored layer was observed using a SEM (S-900 manufactured by Hitachi, Ltd.). As a result, it was found that the electrodeposited polymer body was found to grow between the deposited pigment particles, and was also formed on the surface of the pigment film with a thickness of only 0.05 to 0.1 micron. This was confirmed. That is, the film thickness of only the pigment layer of each colored layer (red (0.8 micron),
It was also confirmed that green (0.7 microns) and blue (0.6 microns) films could be formed with almost no increase by controlling the electrolytic conditions. Therefore, it was confirmed that this manufacturing method can be applied without impairing the advantages of the color filter, which is that the colored layer is thin and a sufficient color tone can be ensured.

(Example 2) The process was similar to the above, but shower washing and ultrasonic cleaning were used in combination after polymer electrodeposition, but ultrasonic washing could also be applied for at least 1 minute without any problem.
Sufficient adhesion of the colored layer was confirmed.

(Example 3) A polyester-melamine resin was used as the electrodeposited polymer, but similar effects were confirmed.

[0022]

Effects of the Invention As described above, according to the present invention, sufficient adhesion to the colored layer can be ensured, so that contamination of uncoated electrodes can be prevented by sufficient cleaning after film formation, and the baking process can be eliminated. A significant effect on the process was confirmed.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the present invention in an example.

[Explanation of symbols]

1 Color filter substrate 2 ITO transparent electrode 3 Boundary line immersed in electrolyte 4 I selectively energized when forming the first color
TO electrode 5 I selectively energizes when forming the second color
TO electrode 6 I selectively energizes when forming the third color
TO electrode

Claims (1)

[Claims] 1. A method for producing a color filter, in which a colored layer is formed on a substrate by dispersing an organic pigment in a micellar aqueous solution of a surfactant having redox reactivity and then electrolyzing the solution in the solution. After forming a predetermined number of transparent electrode layer patterns in a predetermined shape on the substrate, the substrate is immersed in a first electrolytic solution, and only specific transparent electrode patterns are energized and electrolyzed to form a colored layer of the first color. The basic process is to immediately immerse the substrate in a transparent polymer solution that can be electrodeposited and electrolyze it to form a transparent polymer body in and on the colored layer, and then to wash the substrate. By continuously repeating the basic process at least three times, colored layers of the second and third colors are formed.
A method for producing a color filter, comprising forming a colored layer group composed of B3 primary colors.