JPH095730A - Black matrix substrate and its production - Google Patents

Abstract

PURPOSE: To provide a resin black matrix substrate having a thin film thickness of not impairing the flatness required for the color filters of a liquid crystal display device and high optical density and a process for producing the substrate. CONSTITUTION: A resin layer 2 which is curable by photoirradiation or the photoirradiation and heating, has an ink receptive property and has a thickness of <=2.0μm is formed on a transparent substrate 1 (A) and thereafter, the parts 4a intended to be formed with the transparent parts of the resin layer 2 is cured by the photoirradiation or the photoirradiation and heating (B). Black ink is then applied by an ink jet method on the parts 6a intended to be formed with the light shielding parts of the uncured parts of the resin layer 2 (C) and thereafter, the colored resin layer is cured by the photoirradiation or the photoirradiation and heating, by which the black matrix substrate B formed with the resin layer 2 of a thickness of <=2.0μm arranged with the many transparent parts 4 and light shielding parts 6 formed of ink dots at the peripheral edges of the transparent parts 4 is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black matrix substrate of a color filter used in a color liquid crystal display device which is widely used as a display device of various electronic devices.

[0002]

2. Description of the Related Art Generally, a liquid crystal display device is mounted on a personal computer, a word processor, a car navigation system, a small television, etc., and the demand for it has been increasing in recent years. As the market for liquid crystal display devices expands, the color filters that make up the main part of the device are required to have high-definition, large-scale, high-quality performance, as well as low cost. Is imposed.

A color filter of a liquid crystal display device is formed by arranging a plurality of colored portions having different spectral characteristics, generally red, green and yellow, as pixels on a transparent substrate. The colored portion forming the pixel may be formed by a dyeing method, a pigment dispersion method, an electrodeposition method, a printing method, or the like. Further, a black matrix is provided between each pixel in order to enhance the display contrast.

Normally, a black matrix is manufactured by etching a vapor-deposited film or a sputtered film of metallic chromium formed on the surface of a transparent substrate to form a large number of openings. In addition, in order to reduce the reflection of the black matrix, some methods of manufacturing a resin black matrix as a new black matrix have been proposed.

When forming a resin black matrix,
In order to obtain the optical density required for the black matrix, it is necessary to increase the film thickness. For this reason, there is a problem in that a level difference is generated between the light-shielding portion serving as the black matrix and the opening, and the flatness required for the color filter of the liquid crystal display device cannot be maintained.

Japanese Patent Laid-Open No. 6-265713 is mentioned as one of the methods for producing a resin black matrix in which this point is improved. In JP-A-6-265713, a transparent colored layer is applied to a substrate, a portion to be a black matrix is exposed to ultraviolet light to obtain a dyed portion, and the dyed portion is immersed in black ink to form a black matrix. However, since the dipping method is used, in order to obtain a sufficient optical density, the film thickness of the transparent colored layer needs to exceed 2.0 μm. However, when the film thickness exceeds 2.0 μm, peeling or cracking of the resin layer is likely to occur due to heat treatment in another process, leading to a reduction in yield.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thin film having high flatness and high optical performance that does not impair the flatness required for a color filter of a liquid crystal display device. It is to provide a resin black matrix substrate having a concentration and a method for manufacturing the same.

[0008]

The above objects can be achieved by the following means.

That is, according to the present invention, a resin layer having a thickness of 2.0 μm or less is formed on a transparent substrate by arranging a large number of transparent portions and light-shielding portions formed of ink dots on the periphery of the transparent portions. A black matrix substrate having a gradational optical density, a resin material of the resin layer is an acrylic copolymer resin, and the acrylic copolymer resin is an acrylic copolymer resin. Acid, methyl acrylate, ethyl acrylate, hydroxyethyl methacrylate, N-methylol acrylamide, N-
It is a copolymer resin with at least one or more monomers selected from the group consisting of ethoxymethylacrylamide.

Further, according to the present invention, a resin layer having a thickness of 2.0 μm or less is formed on a transparent substrate by arranging a large number of transparent portions and light-shielding portions formed of ink dots on the periphery of the transparent portions. In the method for producing a black matrix substrate, the following steps (1) to (4), and (1) a thickness 2 which is curable by light irradiation or light irradiation and heating on a transparent substrate and which has ink receptivity A step of forming a resin layer having a thickness of 0.0 μm or less; (2) a step of curing a portion of the resin layer where a transparent portion is to be formed by light irradiation or light irradiation and heating; A method for producing a black matrix substrate, comprising: a step of applying a black ink to a predetermined portion by an inkjet method; and (4) a step of curing the colored resin layer by light irradiation or light irradiation and heating. is there .

The present invention will be described below with reference to the drawings.
FIG. 1 shows the manufacturing process of the black matrix of the present invention, and shows the configuration of the black matrix of the present invention.

The substrate used in the present invention is preferably a translucent substrate, and a glass substrate is generally used. However, it is not limited to a glass substrate as long as it has necessary properties such as transparency and mechanical strength as a liquid crystal color filter.

In FIG. 1A, a resin composition that is curable by light irradiation or light irradiation and heating and has ink receptivity is applied onto a substrate 1, and if necessary, prebaked to form a resin layer. 2 shows a state in which 2 is formed.

The resin layer 2 has a dry film thickness of 2.0 μm or less, preferably 1.8 μm.

As the curable resin composition used in the present invention, any curable resin composition may be used as long as it has ink receptivity and is cured by light irradiation or light irradiation and heating. Examples of the resin include acrylic resins; epoxy resins; silicone resins; cellulose derivatives such as hydroxypropyl cellulose, hydroxyethyl cellulose, methyl cellulose, and carboxymethyl cellulose or modified products thereof, but acrylic resins are preferable, and acrylic resins are particularly preferable. Copolymer resins are preferred. As the acrylic copolymer resin, acrylic acid,
Methyl acrylate, ethyl acrylate, hydroxyethyl methacrylate, N-methylol acrylamide, N
-Copolymers of one or more monomers such as ethoxymethyl acrylamide are preferred. The mixing ratio of these monomers is preferably 5 to 95 mol% with respect to the resin.

As the method for applying the resin composition to the substrate, various application methods such as spin coating, roll coating, and dipping can be used, and are not particularly limited.

Next, pattern exposure is performed on the area other than the black matrix light-shielding area (predetermined transparent area 4a) using the photomask 3 (FIG. 1B), and then the black-matrix light-shielding area 6 is formed. The planned light-shielding portion 6a is colored with black ink (FIG. 1C). Finally, if necessary, the planned light-shielding portion 6a is cured by light irradiation or light irradiation and heating to form the light-shielding portion 6 (FIG. 1D).
The coloring method is performed using an inkjet method. In addition,
Reference numeral 5 in the figure denotes an inkjet head.

As a result, a black matrix substrate 8 is obtained in which the resin layer 2 having a large number of the transparent portions 4 and the light shielding portions 6 formed on the periphery thereof is arranged on the substrate 1.

The ink jet method is different from the dipping method.
It has the following advantages. (1) Since a high-concentration black ink can be directly applied and colored, the resin layer can be thin. (2) The solid component of the black ink that cannot be accommodated in the resin layer is crystallized on the resin layer. By utilizing this, it is possible to improve the light-shielding property. (3) It is possible to give gradation to the optical density in the black matrix by adjusting only the optical density of the black matrix region in contact with the thin film transistor.

Although the black matrix may have a uniform optical density in the light-shielding portion, the optical density may be different for each portion of the light-shielding portion of the black matrix so as to provide gradation. Even if it continuously changes between different optical densities,
It may change intermittently.

FIG. 2A is a partially enlarged view of the display electrode portion of the liquid crystal display device, and a pixel of the liquid crystal display device is constructed by superimposing a black matrix on the electrode portion.

In FIG. 2A, 21 is a display electrode, 22 is a thin film transistor (TFT), 23 is a signal wiring, and 24 is a gate wiring.

FIG. 2B is a partial view showing a black matrix to be superimposed on the display electrode portion shown in FIG. 2A, in which the light shielding portion 27 formed of ink dots is formed on the peripheral portion of the transparent portion 26. is there. The light shielding portion 27 is the high optical density portion 2
8 and the low optical density portion 29 have different optical densities (different shades of light).

When the black matrix is overlaid on the display electrode, the high optical density portion 28 completely covers the TFT 22 and T
By forming a light-shielding layer having the required optical density on the FT22, an excellent light-shielding effect is exhibited.

In order to give gradation to the black matrix, there are a method of changing the dye density of the ink jet and a method of changing the dot density.

The other structure of the black matrix substrate is as described above.

[0027]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited thereto. The present invention also includes modifications and substitutions of the constituent elements with known techniques within the scope of achieving the object of the present invention.

Example 1 On a surface-polished non-alkali glass, a photosensitive resin composition made of an acrylic copolymer having the following composition was applied to form a photosensitive resin. Specifically, the photosensitive resin composition was applied by a spinner and then baked at 90 ° C. for 20 minutes to form a photosensitive resin layer having a film thickness of 1 μm.

Photosensitive resin composition: Terpolymer of methyl methacrylate, hydroxyethyl methacrylate, and N-methylol acrylamide (monomer weight composition ratio 2: 3: 5) Average molecular weight about 20,000 10 parts by weight Triphenylsulfone 0.3 parts by weight of hexafluoroantimolyte and 89.7 parts by weight of ethyl cellosolve Further, a part of the photosensitive resin layer is exposed through a photomask so that the area other than the area where the black matrix is to be exposed is exposed, 1 minute at 120 ℃ on a hot plate,
Heat treatment was performed. Through this step, the photosensitive resin layer was partially cured. The photosensitive resin layer of the uncured portion is colored with a black ink having the composition shown below by an inkjet method, and baked at 90 ° C. for 20 minutes and at 200 ° C. for 60 minutes to form a black matrix colored black. Formed.

Black ink composition: Carbon black (Mitsubishi Kasei MCF-88) 5 parts by weight Polyvinylpyrrolidone 0.8 parts by weight Ethylene glycol 10 parts by weight Isopropyl alcohol 3 parts by weight Glycerin 5 parts by weight Water 76.8 Parts by Weight The polyvinylpyrrolidone used here also functions as a dispersant for carbon black, which is a black pigment.

When a color filter was produced using the black matrix substrate thus formed, it showed excellent flatness, and the liquid crystal display device using this color filter showed excellent display contrast.

[0032]

The black matrix substrate of the present invention can be formed of a resin black matrix having a thin film thickness that does not impair the flatness required for a color filter of a liquid crystal display device and having a high optical density. Further, it is possible to manufacture in a simple process, and it is possible to reduce the manufacturing cost.

[Brief description of drawings]

1A to 1D are process diagrams showing a production example of a black matrix substrate of the present invention.

FIG. 2A is an enlarged partial view of a pixel, and FIG.
FIG. 3 is an enlarged partial view showing an example of the black matrix of the present invention for superimposing on the pixel of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Resin layer 3 Photomask 4 Transparent part 4a Transparent part planned part 5 Inkjet head 6 Light-shielding part 6a Light-shielded part planned part 8 Black matrix substrate

Front page continued (72) Inventor Satoshi Yamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A thickness of 2.0 formed by arranging a large number of transparent portions and light-shielding portions formed of ink dots on the periphery of the transparent portions.
A black matrix substrate, characterized in that a resin layer having a thickness of not more than μm is formed on a transparent substrate. 2. The black matrix substrate according to claim 1, wherein the black matrix forms an optical density having gradation. 3. The black matrix substrate according to claim 1, wherein the resin material of the resin layer is an acrylic copolymer resin. 4. The acrylic copolymer resin is acrylic acid,
Methyl acrylate, ethyl acrylate, hydroxyethyl methacrylate, N-methylol acrylamide, N
The black matrix substrate according to claim 3, which is a copolymer resin with at least one monomer selected from the group consisting of ethoxymethyl acrylamide. 5. A thickness 2.0 formed by arranging a large number of transparent portions and light-shielding portions formed of ink dots on the periphery of the transparent portions.
In the method for manufacturing a black matrix substrate having a resin layer of not more than μm formed on a transparent substrate, the following steps (1) to (4), (1) curing the transparent substrate by light irradiation or light irradiation and heating. Possible thickness 2.0 with ink receptivity
a step of forming a resin layer having a thickness of μm or less, (2) a step of curing a transparent portion formation planned portion of the resin layer by light irradiation or light irradiation and heating, (3) a light shielding portion formation plan of an uncured portion of the resin layer And a step of (4) curing the colored resin layer by light irradiation or light irradiation and heating. 4. A method for producing a black matrix substrate, comprising: