JPH01265204A - Production of color filter - Google Patents

Abstract

PURPOSE:To uniformize the gaps between color filters and array side substrate by pressing undried ink films via a stock having the surface energy lower than the surface energy of colored ink films. CONSTITUTION:Inks 21, 22, 23 of three primary colors; blue, green and red are printed by using screen printing plates on a glass substrate 24. These colored film ink of the plural colors are pressed in the undried state by a roller 35 via a silicone rubber sheet 36. Since the silicone rubber 36 has the surface energy lower than the surface energy of the colored films, the release property is good and the film surfaces are flattened without impairing picture element shapes. The adjacent colored ink films are similarly pressed and the bleeding of the inks is offset by pressing the films with the roller 35 in such a manner, by which the sharp picture element shapes are maintained and the ink films 31, 32, 33 of blue, green and red are formed. In addition, the surfaces are flattened. The gaps between the color filters and the array side substrate are, therefore, uniformized without impairing the picture element shapes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a color filter used in liquid crystal color displays and the like.

(Prior art) If the colored coating surface of color filters used in liquid crystal color displays etc. is not smoothed, the light transmittance will be impaired due to the light diffusion phenomenon caused by minute irregularities, and the function as a color filter will be lost. descend. In addition, when forming an ITO film by sputtering etc. on a colored ink film formed on a substrate, if the film surface has uneven parts and the film thickness is uneven, sputtering may occur in the thick part of the film. This may result in insufficient coating or wire breakage.

Furthermore, when bonding to the array side substrate, the gap for injecting the liquid crystal becomes non-uniform, causing uneven image display.

Therefore, in color filters manufactured by forming a colored ink film on a glass substrate using a printing method, conventionally, in order to obtain the smoothness and uniformity of the film thickness of the colored ink film, a press heated to a predetermined temperature is used. A roll is directly applied to the surface of the printed colored ink film after printing (after some time has elapsed and the solvent has evaporated to some extent), and the film is heated to near the glass transition point of the colored ink. In addition, as another method,
After printing the first color ink, while the ink is still wet,
pressing the film through a material having a surface energy lower than that of the ink and peeling off the material;
The heat curing method was repeated several times for each color.

(Problems to be Solved by the Invention) In the first method, the thickness of the conventional color filter film is about 5 μm at most, and since the solvent has evaporated to some extent, the fluidity of the ink film is low. If smoothing was attempted using a direct press roller, it would be necessary to apply pressure extremely uniformly. In addition, in the second method, it is easier to obtain flatness because the ink film is pressed in a highly fluid state, but as shown in Figure 4, the pressure causes the ink to overflow to adjacent pixels. This has disadvantages in that a sharp pixel shape cannot be obtained and at the same time the aperture ratio of the pixel is reduced.

(Means for solving the problem) In order to solve the above problem, colored ink films of multiple colors are formed in a pattern on a substrate in an undried state, and then the surface energy of the colored ink film is This problem can also be solved by pressing the coating through a material with lower surface energy. However, when forming colored ink films of multiple colors in an undried state,
In conventional printing methods, when printing the second and subsequent colors, a problem arises in that the undried ink film that has already been printed adheres to the surface of the printing plate that is in contact with the substrate in the non-image area. This problem can be solved by forming the surface of the non-image area that comes into contact with the printed material with a material having a surface energy lower than that of the ink.

(Function) In the present invention, by forming the surface of the printing plate in contact with the printing material in the non-image area with a material with extremely low surface energy and good release properties, all the colored ink films of multiple colors are undried. When forming in this state, printing can be performed without the printed ink film adhering to the surface of the printing plate in contact with the printing material in the non-image area. In addition, by forming all the colored ink films of multiple colors in an undried state, the protrusion of ink that occurs when the colored ink film is pressed through a material with extremely low surface energy can be avoided. They are similarly pressurized and offset to cause the ink to bulge out, making it possible to flatten the coating surface without damaging the sharp pixel shape.

(Effects of the Invention) The present invention can easily smooth out unevenness and irregularities that occur on the surface of the colored ink coating formed on the glass substrate in a color filter manufactured by a printing method, without damaging the pixel shape. Therefore, the gap between the color filter and the array side substrate can be made uniform, and even when sputtering a colored ink film, etc.
An appropriate vapor deposited film can be obtained due to the smoothness of the film, and
The transparency of the color filter and the spectral transmittance characteristics of each color are improved, and the aperture ratio of the pixel is not impaired due to distortion of the pattern shape. For this reason, proper color balance can be obtained even on LCD color displays, etc.
This has a remarkable effect in manufacturing color filters using the printing method.

(Example) As shown in Figure 1, the non-printing area (1
When a solution of low molecular weight polytetrafluoroethylene resin (PTFE) dispersed in an organic solvent was sprayed on the side in contact with the non-printed material of 2) and the solvent was evaporated, P was found to have good mold releasability.
A TFE coating (13) was obtained. When this screen printing plate was used to print on a glass substrate with blue ink of the three primary colors of light, blue, green, and red, sharp pixel shapes were obtained. Next, when the printing plate was shifted by one pixel and green ink was printed, a sharp pixel shape was obtained, and the printed blue ink film did not adhere to the non-image areas of the printing plate. In the same manner, red ink was printed to obtain three types of ink films of blue, green, and red arranged in a predetermined pattern in an undried state on a glass substrate as shown in FIG.

When this colored ink film was pressed with a roller through a silicone rubber sheet, the gaps between adjacent colored ink films were filled and the surface became flat, as shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a screen printing plate. Figure 2 is 3
FIG. 2 is a cross-sectional view of a glass substrate immediately after printing a colored ink film. FIG. 3 is a cross-sectional view of the glass substrate immediately after pressing the colored ink film. FIG. 4 is an explanatory diagram showing the protrusion of ink when a colored ink film is pressed. 11...Pattern image area 12...Non-image area 13...PTFE coating 14.24.3
4...Glass substrate 21.31...Blue ink film 22.32...Green ink film 23,
24... Red ink film 35... Press roller 36... Silicone rubber sheet 41... Ink film before pressing 42... Ink film after pressing patent applicant
Miura Printing Co., Ltd. Figure 3 Figure 4

Claims (2)

[Claims] (1) Colored ink films of multiple colors are formed in a pattern on a substrate using a printing method, and when all of the ink films are undried, printing is performed using a material that has a surface energy lower than that of the colored ink film. A method for manufacturing a color filter, which comprises pressing the film. (2) A printing method characterized in that the surface of the non-image area of the printing plate that comes into contact with the printing medium is formed of a material having a surface energy lower than the surface energy of the colored ink film. A color filter manufacturing method according to claim 1.