JPH09197115A - Color filter and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a color filter with a light shielding film having a sufficiently high concn. to shield light and high thin line precision so as to keep the brightness of the whole of a picture and to obtain a high precision picture. SOLUTION: Picture elements 1 having plural colors are formed on a transparent substrate 3 and a black resin compsn. contg. 10-40wt.% (expressed in term of solid) resin material which is cured by an acid, 5-20wt.% crosslinking agent, 3-10wt.% optical acid generating agent and 20-65wt.% black pigment is applied and dried to form a black resin layer 2. This black resin layer 2 is converted into a black matrix by exposure using the picture elements 1 as a mask from the substrate side, heating, exposure with 40-60mJ/cm<2> UV from the surface and development to obtain the objective color filter having the picture elements 1 and the black matrix on the substrate 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used in a liquid crystal display device or the like, and more particularly to a color filter provided with a black matrix for obtaining contrast and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, color filters have been widely used in the field of liquid crystal display devices. This color filter usually has a plurality of color pixels such as red, green and blue arranged on a transparent substrate. In order to obtain an image with better contrast, it is necessary to form a black black matrix between these pixels. Further, in the active display device, it is possible to remove unnecessary light by using this black matrix, which has an effect of reducing malfunction of the switching element.

As a method of forming a black matrix used for this color filter, (1) a dyeing method of patterning a dyeable synthetic resin and dyeing with a black dye,
(2) A photolithography method in which a radical polymerization type black resist is used for patterning through coating, exposure and development steps, (3) a printing method in which black ink is transferred using an intaglio plate, (4) a metal on a transparent substrate. A vapor deposition method in which a film is vapor deposited and a black matrix is formed by an etching method is known.

However, the above-mentioned prior art has the following problems. In the dyeing method (1), the manufacturing process is complicated, it is difficult to obtain a sufficient density, and it is difficult to obtain panel characteristics such as light resistance and heat resistance. In the photolithography method of (2), since the sensitivity characteristic is low, it takes a long time to expose and the resolution is poor, and it is difficult to obtain the precision of a fine line. The printing method (3) has a smaller number of steps and is simpler than those of (1) and (2), but the accuracy of fine lines and the positional accuracy are poor, and it is not possible to obtain the flatness of the black matrix. It is possible. The vapor deposition method of (4) is very costly and a problem.

Further, as a common problem of the above (1) to (4), since the black matrix is formed after the formation of the plural color pixels, the plural color pixels and the black matrix are overlapped with each other, and the protrusion is formed in that portion. However, the flatness of the color filter is impaired.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and its object is to have a sufficient density to block light and to obtain fine line accuracy. To provide a color filter having a high black matrix and a method for manufacturing the same.

[0007]

In order to solve this problem, the present invention provides a color filter having a plurality of color pixels and a black matrix on a transparent substrate. Provided is a color filter having no matrix overlap.

Further, in the present invention, as the black matrix material, 10 to 40% by weight of a resin material which is cured by an acid as a solid content ratio, 5 to 20% by weight of a crosslinking agent, and 3 to 10% by weight of a photoacid generator. %, And a black resin composition containing 20 to 65% by weight of a black pigment.

According to a third aspect of the present invention, in a method of manufacturing a color filter having a plurality of color pixels and a black matrix on a transparent substrate, after forming the plurality of color pixels, a black resin composition is applied and dried to obtain a black color. A step of forming a resin layer, a step of exposing the black resin layer from the transparent substrate side using a plurality of color pixels as a mask, a step of heating the black resin layer, and a step of developing the black resin layer into a black matrix A method of manufacturing a color filter is provided.

Further, according to a fourth aspect of the present invention, after the exposure is performed and before the heating, 40 to 40% from the black resin layer side is applied.
The method for producing a color filter according to claim 3, wherein the exposure is performed with an ultraviolet ray of 60 mJ / cm ² .

[0011]

Embodiments of the present invention will be described below. The black resin composition used as the black matrix is a black resin composition comprising an acid-curable resin material, a cross-linking agent, a photo-acid generator, a cross-linking agent, and a black pigment.

The resin material which is cured by an acid is a phenol novolac resin, a homopolymer of p-hydroxystyrene, and the copolymer having a p-hydroxystyrene structure is an acrylic acid monomer, a methacrylic acid monomer, styrene, A copolymer with p-hydroxystyrene containing at least one monomer such as maleic acid, fumaric acid and phenylmaleimide can be used. The acrylic acid-based monomer as the copolymerization component can be acrylic acid or methyl acrylate. , Ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, benzyl acrylate and the like can be used. Methacrylic acid-based monomers include methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methacrylic acid. Two
-Hydroxyethyl, benzyl methacrylate and the like can be used.

As the cross-linking agent, methylolated urea, urea resin, methylolated melamine, butyrolized melamine,
It is possible to use methylolated guanamine or alkyl ethers of these compounds. Alkyl ether compounds are more preferable in terms of excellent thermal stability.
The alkyl group of this alkyl ether has 1 to 1 carbon atoms.
An alkyl group of 5 is preferred. Particularly, as the alkyl ether compound, an alkyl ether compound of hexamethylolmelamine, which is excellent in sensitivity, is more preferable.

As the photoacid generator, a trihalomethyl group-containing triazine derivative is preferably used.
4,6-Tris (trichloromethyl) -s-triazine, 2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2-phenyl-
4,6-bis (trichloromethyl) -s-triazine,
2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4 '-Methoxy-1'-naphthyl)-
4,6-bis (trichloromethyl) -s-triazine,
2- (p-methylthiophenyl) -4,6-bis (trichloromethyl) -s-triazine and the like can be used.

These trihalomethyl group-containing triazine derivatives have an absorption edge near the wavelength of 300 to 400 nm and generate an acid in the light of a longer wavelength region than the conventionally used onium salt, so that they are black. Even when the resin layer is exposed from the transparent substrate side to form a pattern, the pattern can be formed with sufficient sensitivity.

These trihalomethyl group-containing triazine derivatives may be used alone or as a mixture, and the addition amount thereof is 0.5 part by weight based on 100 parts by weight of the acid-curable resin system. To 40 parts by weight are preferred.
This is because when added in excess of 40 parts by weight, the amount of acid generated is too large and the acid diffuses into the unexposed part due to heating after the pattern exposure to cause a crosslinking reaction, which lowers the resolution. Become. When the amount added is less than 0.5 part by weight, the amount of acid generated is insufficient, the crosslinking reaction does not proceed sufficiently, and a pattern cannot be formed.

As the black pigment, a mixture of carbon black, titanium oxide, iron black, aniline black and an organic pigment can be used. Furthermore, in order to improve the dispersibility of the pigment, an acrylic resin, an epoxy resin, or the like can be added as a dispersion medium, if necessary. Further, a polymer dispersant, a derivative of an organic dye, or the like may be added as a dispersant.

Further, as a diluting solvent for improving workability during dispersion, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, diethylene glycol dimethyl ether, cyclohexanone, propylene glycol monomethyl ether,
Propylene glycol monomethyl ether acetate,
You may use organic solvents, such as a lactate ester.

These materials are sufficiently kneaded using a disperser such as a two-roll mill, a three-roll mill, a sand mill and a paint conditioner to give a black resin composition.
The composition ratio includes 10 to 40% by weight of a resin material which is cured by an acid in a solid content ratio, 5 to 20% by weight of a crosslinking agent, 3 to 10% by weight of a photoacid generator, and 20 to 65% by weight of a black pigment. . If the amount of the resin material added by the acid is less than 10% by weight, the sensitivity cannot be obtained and the pattern cannot be formed. If it is more than 40% by weight, the resolution of the pattern cannot be obtained. If the amount of the cross-linking agent is less than 5% by weight, the cross-linking reaction does not proceed and pattern formation cannot be performed. Also 2
If it is more than 0% by weight, the resolution of the pattern cannot be obtained. When the amount of the photo-acid generator added is less than 3% by weight, the amount of acid generated is poor, and the crosslinking reaction does not proceed to form a pattern. On the other hand, when the amount is more than 10% by weight, the amount of generated acid is too large and the acid diffuses into the unexposed portion due to the heating after the pattern exposure to cause a crosslinking reaction to lower the resolution. If the amount of the black pigment added is less than 20% by weight, sufficient light blocking effect cannot be obtained. Also, 6
If it exceeds 5% by weight, pattern formation cannot be performed.

An example of the steps of the manufacturing method of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the black resin composition of the present invention is uniformly applied onto a plurality of color pixels 1 by a spinner method, a bar coating method, a roll coating method, a curtain coating method or the like to form a black resin layer 2. To do.

As the method of forming the multi-color pixels 1, any of the currently practiced methods such as the conventional dyeing method, pigment dispersion method, printing method and electrodeposition method may be used. When the resin layer 2 and the transparent substrate 3 are closely attached,
You may add heat of about 70 to 100 ° C.

Next, as shown in FIG. 2, exposure is performed by irradiating ultraviolet rays from the rear surface of the transparent substrate 3 to generate an acid only in the black resin 2a in the gap portion of the pixels 1 of the plural color pixels. As a light source used for exposure, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or the like is used, but it is preferable that the light source has no output in the visible wavelength range, and a visible light cut filter may be used during exposure.

More preferably, it is 40 from the black resin layer 2 side.
~ 60 mJ / cm^TwoIrradiate with a low exposure amount of ultraviolet rays,
Only the surface of the black resin layer is cured (crosslinked). This
The flatness of the surface of the light-shielding layer is obtained after the development of the black resin layer.
You. Exposure dose is 40 mJ / cm ^TwoThe lower it has no effect,
60 mJ / cm^TwoBlack resin on the multi-color pixel 1 if more
The layer remains.

Next, as shown in FIG. 4, the heating temperature is 90.degree.
At 150 ° C., a catalytic reaction of acid is used to cause a cross-linking reaction of the portion of the black resin 2a to cure it.

Finally, an alkaline developer is used to remove the uncrosslinked black resin 2b on the plural color pixels 1 to form a black matrix as shown in FIG.

As described above, in the present invention, a black matrix is formed by using the back exposure method by using the material of the weight% shown as the black matrix material, thereby forming a black matrix on a plurality of color pixels and a black matrix. And the effect of making the black matrix flat by exposing the black resin layer side to ultraviolet rays of 40 to 60 mJ / cm ² immediately after the back exposure. Due to all of these effects, it is not necessary to cure the inside of the black resin layer with a large amount of ultraviolet rays as in the conventional exposure method from the back side of the transparent substrate, and the absorption in the ultraviolet region of multiple color pixels and the optical density of the black resin layer By exposing the back side of the transparent substrate with a small amount of ultraviolet rays, it is possible to form a color filter in which the black matrix does not overlap the pixels of a plurality of colors.

[0027]

EXAMPLE A glass plate having a thickness of 1 mm was used as the transparent substrate 3, and a red pattern R, a green pattern G, and a blue pattern B made of a preliminarily colored polyimide resin were sequentially formed on this surface. The film thickness of these multi-color pixels 1 is 1.5 μm
Met. The composition of the black resin layer provided thereon is shown below.

<Composition of Black Resin Layer> Black pigment: “# 20 Black” manufactured by Mitsubishi Chemical Co., Ltd. 10 g Acid-curable resin: Sumitomo Bakelite Co., Ltd .: “Phenol novolac resin” 5 g Dispersant: Zeneca (stock) ): "Solspers""24000GR" and "5000" are mixed in a ratio of 1: 1 1g Crosslinking agent: Sanwa Chemical Co., Ltd .: "Nikarac MW-30M" 3g Photo acid generator: Midori Kagaku Co., Ltd. : "TAZ-104" 1.9 g The solid content of these black resin compositions is 20% by weight.
The solvent was added so that

This was spun at 940 rpm for 5
It was applied in seconds and heated in an oven at 70 ° C. for 20 minutes. Then, the transparent substrate side was exposed with 100 mJ / cm ² of ultraviolet rays using the plural-color pixels 1 as a mask to form a black resin layer. After that, 50mJ from the black resin layer side
Exposure was carried out with ultraviolet rays of / cm ² . Then, it was heated at 110 ° C. for 1 minute using a hot plate, and development was performed using a 0.5% sodium hydroxide aqueous solution to which a slight amount of a cationic surfactant was added. Finally, it was heated in an oven at 230 ° C. for 1 hour to obtain a color filter.

In the color filter completed as described above, as shown in FIG. 5, the flatness of the surface of each color pattern group was extremely good.

[0031]

As described above, since the black resin composition itself used for the black matrix of the present invention is a highly sensitive resist, it is possible to absorb ultraviolet rays in a plurality of color pixels such as red, green and blue used as a mask. It is not necessary to add additives such as agents and optical brighteners. As a result, even if the light is exposed from the back side of the transparent substrate, a sufficient degree of development is exhibited, the spaces between the plural color pixels are filled, and the black matrix does not overlap the plural color pixels unlike in the conventional case.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a process of an embodiment of a method for manufacturing a color filter of the present invention.

FIG. 2 is an explanatory view showing the steps of an embodiment of the color filter manufacturing method of the present invention.

FIG. 3 is an explanatory view showing a process of an embodiment of a method for manufacturing a color filter of the present invention.

FIG. 4 is an explanatory view showing a process of an embodiment of the color filter manufacturing method of the present invention.

FIG. 5 is an explanatory view showing the steps of an embodiment of the color filter manufacturing method of the present invention.

[Explanation of symbols]

1 ... Multi-color pixel 2 ... Black resin layer 3 ... Transparent substrate 4 ...
Hot plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobumi Takemura 1-5-1 Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inoue Tsuneo Ooki 1-1-5 Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. (72) Inventor Shinichi Kita 1-5-1 Taito, Taito-ku, Tokyo Tokyo Toppan Printing Co., Ltd.

Claims (4)

[Claims] 1. A color filter having a plurality of color pixels and a black matrix on a transparent substrate, wherein the black matrix does not overlap the plurality of color pixels. 2. As the black matrix material, 10 to 40% by weight of a resin material which is cured by an acid as a solid content ratio, 5 to 20% by weight of a crosslinking agent, 3 to 10% by weight of a photoacid generator, and 20 to 20% of a black pigment. The color filter according to claim 1, wherein a black resin composition containing 65% by weight is used. 3. A method of manufacturing a color filter having a plurality of color pixels and a black matrix on a transparent substrate, after forming the plurality of color pixels, 1) applying a black resin composition and drying to form a black resin layer. The step of 2) exposing the black resin layer from the transparent substrate side using the pixels of a plurality of colors as a mask, 3) heating the black resin layer, 4) developing the black resin layer to form a black matrix. And a method for manufacturing a color filter. 4. The method for producing a color filter according to claim 3, wherein after the exposure, before the heating, the exposure is performed by ultraviolet rays of 40 to 60 mJ / cm ² from the black resin layer side. .