JPH10325902A - Color filter for liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide color filters for a liquid crystal display device which consist of black matrix layers having sufficiently high optical densities and sufficiently low reflectivity and have good surface flatness as the color filters for the liquid crystal display device. SOLUTION: The color filters 1 for the liquid crystal display device have a transparent glass substrate 10, color filter layers 20 formed in the form of pixels on the transparent glass substrate and the black matrix layers 40 consisting of the black resin compsn. formed between the pixels and in the peripheral parts of the pixels. The black matrix layers 30 packed with the black resin compsn. approximately flush with the pixels are formed within recessed parts 3 of which the bottoms have rough surfaces and which are formed on the transparent glass substrate surfaces between the pixels and in the peripheral parts of the pixels.

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 a liquid crystal display, and more particularly to a color filter for a liquid crystal display having a light-shielding portion (black matrix) between pixels.

[0002]

2. Description of the Related Art Generally, in a color filter for a liquid crystal display device, a black matrix layer serving as a light shielding portion is formed at a predetermined position on a transparent substrate, and then a red (Re) layer is formed on the transparent substrate.
d), green (Green) and blue (Blue) color filter layers are formed in a pixel shape. As a material of the black matrix layer, chromium metal, a photosensitive resin in which a black pigment is dispersed, or the like is used. The photosensitive resin in which the black pigment was dispersed was applied to the coating because the content of the black pigment to be dispersed was limited in terms of its coating suitability, photosensitivity of the coating film, and adhesion of the coating film. At this time, the optical density of the black matrix layer (log ₁₀ I ₀ / I _I , where I ₀ is the amount of incident light and I _I is the amount of transmitted light) is about 2.0 to 2.5 at a film thickness of about 1.0 μm. is there.

In addition, when light from the outside is reflected by the liquid crystal display device when the liquid crystal display device is used, the display quality is degraded. This reflection of light from the outside occurs on the surface and inside of the liquid crystal display device, and is also reflected on the black matrix layer of the color filter. In order to reduce the reflectance of the black matrix layer, a photosensitive resin in which a black pigment is dispersed is used in place of chromium metal, but the reflectance is about 3 to 5%.

In a color filter using a photosensitive resin in which a black pigment is dispersed for a black matrix layer, a color filter layer having a thickness of about 1.4 μm is formed on a black matrix layer having a thickness of about 1.0 μm. Since the pixel peripheral portions overlap, the thickness of the portion from the transparent substrate is about 1.
8 μm. That is, the surface of such a color filter serves as a black matrix layer and has a thickness of about 0.2 μm.
It has poor flatness as compared with a color filter using metallic chromium of m.

[0005]

In order to improve the display quality of a liquid crystal display device, it is desired that the black matrix layer has a higher optical density. An object of the present invention is to provide a color filter for a liquid crystal display device comprising a black matrix layer having a sufficiently high optical density by using a photosensitive resin in which the above-mentioned black pigment is dispersed. Further, in order to improve the display quality of the liquid crystal display device, there is a demand for one in which the reflectance of the black matrix layer is further reduced. It is an object of the present invention to provide a color filter for a liquid crystal display device comprising a black matrix layer having a further reduced reflectance using a photosensitive resin in which the above-mentioned black pigment is dispersed. Another object of the present invention is to provide a color filter for a liquid crystal display device having good surface flatness using a photosensitive resin in which the above-mentioned black pigment is dispersed.

[0006]

Means for Solving the Problems The first invention of the present invention is:
A color for a liquid crystal display device having a transparent glass substrate, a color filter layer formed in a pixel shape on the transparent glass substrate, and a black matrix layer formed of a black resin composition formed between pixels and around the pixels In the filter, the bottom formed on the surface of the transparent glass substrate between the pixels and the periphery of the pixels is filled with a black resin composition substantially flush with the pixels in the rough concave portion, and the black matrix layer is formed. A color filter for a liquid crystal display device.

A second invention of the present invention is that (1) a color filter layer is formed in a pixel shape on a transparent glass substrate,
(2) a step of applying glass corrosive ink thereon using the pixel-like color filter layer as an etching mask, corroding the glass surface between the pixels and around the pixels in a concave shape, and roughening the bottom of the concave portion; Next, a step of applying the black photosensitive resin composition to the entire surface of the transparent glass substrate by removing the glass corrosive ink, and (3) using the color filter layer formed as a pixel as a mask to form a back surface of the transparent glass substrate. (4) a step of dissolving and removing the black photosensitive resin composition in an unexposed portion to form a black matrix layer between pixels and around the pixels;
(5) a step of heating and curing the black matrix layer;
This is a method for manufacturing a color filter for a liquid crystal display device comprising:

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color filter and a method of manufacturing the same according to the present invention will be described below in detail based on one embodiment. FIG. 1 is a plan view showing one embodiment of a color filter for a liquid crystal display device according to the present invention. As shown in FIG. 1, a color filter (1) for a liquid crystal display device has a color filter layer (20) of red (R), green (G), and blue (B) on a transparent glass substrate (10). As a mosaic. A black matrix layer (30) for light shielding is arranged between the pixels in a grid pattern, and a black matrix layer (30) for light shielding is also arranged on the entire periphery of the pixel.

FIG. 2 is a sectional view taken along the line AA 'of one embodiment of the color filter for a liquid crystal display according to the present invention shown in FIG. As shown in FIG. 2, there is a concave portion (3) in the glass surface between the pixels on the transparent glass substrate (10) and around the pixel, and the bottom of the concave portion (3) is rough. . The black matrix layer (30) for shading is formed of a concave portion having a rough bottom and filled with a black resin composition substantially flush with pixels.

FIGS. 3A to 3G are explanatory views showing one embodiment of the manufacturing process of the color filter (1) for the liquid crystal display device according to the present invention, taken along the line AA '. As shown in FIG. 3A, a red (R), green (G), and blue (B) color filter layer (20) is formed on a transparent glass substrate (10).
Are formed as pixels. Next, as shown in FIG. 3B, a glass corrosion ink (2) is applied to the entire surface of the transparent glass substrate (10) on which the pixel-like color filter layers (20) are arranged. Next, as shown in FIG. 3C, the transparent glass substrate (1) coated with the glass corrosion ink (2) was used.
0) is heated to corrode the glass surface between and around the pixels in a concave shape, and roughen the bottom of the concave portion (3).

Next, as shown in FIG. 3 (d), the glass corrosive ink (2) is removed, and as shown in FIG. 3 (e), a black photosensitive resin is formed on the entire surface of the transparent glass substrate (10). Apply composition (4).

Next, as shown in FIG. 3 (f), using the color filter layer (20) formed as a pixel as a mask, the transparent glass substrate (10) is exposed to ultraviolet light (40) from the back side and heated. .

Next, as shown in FIG. 3 (g), the unexposed portions of the black photosensitive resin composition (4) such as on the pixel-like color filter layer (20) are dissolved and removed, and the space between the pixels and around the pixels is removed. The concave portion (3) of the portion is used as a black matrix layer (30), and then cured by heating to obtain a color filter for a liquid crystal display device.

The black matrix layer (30) of the color filter (1) for a liquid crystal display thus obtained.
Has a high optical density. This is because the black matrix layer (30) is formed between the pixels and on the surface of the transparent glass substrate around the pixels, and the bottom is in the concave part (3) having a rough surface.
This is because the black resin composition is formed so as to be substantially flush with the pixels.

The reflectance of the black matrix layer (30) of the color filter (1) for a liquid crystal display thus obtained is low. This is because the bottom of the black matrix layer (30) has a rough surface, and when used in a liquid crystal display device, light from the outside enters from the back side of the transparent glass substrate (10). This is due to irregular reflection.

The surface of the thus-obtained color filter (1) for a liquid crystal display device has a good flatness. This is because the black matrix layer (30) is formed of a black resin composition substantially flush with the pixels.

The transparent glass substrate (10) used in the present invention has sufficient strength, flatness, heat resistance, chemical resistance, light transmittance, etc., and at the same time, a black matrix layer (30) and a color filter layer (20). It is preferable to use a material having a sufficient adhesive force with the like. For example, Corning Co., Ltd., bottom expanded glass, product number 7059, Asahi Glass Co., Ltd., bottom expanded glass, product number AN635, and the like can be given.

As a method for forming the pixel-like color filter layer (20), any method such as a pigment dispersion method, a printing method, an electrodeposition method and an ink-jet method may be used. It is necessary that the filter layer (20) can withstand the glass corrosion ink (2) used in the present invention.

Glass corrosive ink (2) is composed of fluoride such as calcium fluoride, aluminum fluoride soda and hydrochloric acid,
It is a mixture of acids such as sulfuric acid, and the corrosion surface can be roughened by adding ammonium fluoride. Ammonium fluoride reacts with the glass component to produce microcrystals of ammonium silicofluoride, which adhere to the glass surface and block the contact between the glass corrosive ink and the glass surface, resulting in minute irregularities on the glass surface. It becomes possible to make the corrosion surface rough. As a commercially available product, for example, “Deca-Gl” manufactured by Deca-Products
assign "and the like. Usually, for example, in the case of buffered hydrofluoric acid or the like used for corrosion of a glass material, the bottom surface of the corroded concave portion (3) is less roughened, and a black matrix layer (low reflectance) which is one of the objects of the present invention. 30) cannot be obtained, which is not preferred.

The method for applying the glass corrosive ink (2) is not particularly limited, and may be a dipping method, a spray method, a roll coating method, a spin coating method, a bar coating method, a curtain coating method, etc., as well as screen printing and offset printing. And the like. The transparent glass substrate (10) coated with the glass corrosive ink (2) is heated so that the surface of the transparent glass substrate between the pixels and around the pixels is corroded in a concave shape, and the bottom of the concave portion (3) is roughened. The heating method is not particularly limited, but a hot plate is preferable.

The transparent glass substrate (10) used in the present invention
The black photosensitive resin composition (4) applied and filled in the concave portion (3) is a black photosensitive resin composition comprising a resin-based material, a crosslinking agent, a photoacid generator, and grafted carbon black. Is used.

As the resin material, O which can be a crosslinking point is used.
A polymer compound containing an H group and soluble in an alkaline aqueous solution is used. Examples of the resin material include phenols such as phenol novolak and p-hydroxystyrene, OH groups such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylic acid, methacrylic acid, maleic acid, and fumaric acid. A homopolymer or a copolymer of a monomer containing is used. Examples of monomers that can be used for this copolymerization include styrene, phenylmaleimide, methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, benzyl methacrylate, and the like. . These resin materials are in the range of 7 to 38% by weight, preferably 7 to 20% by weight, based on the weight of the black photosensitive resin composition. If the amount is too small, the photosensitive performance deteriorates, and the pixel shape deteriorates due to aggregation of carbon. , Film strength, adhesion, and the like. If the amount is too large, the light shielding property tends to be insufficient.

Examples of the crosslinking agent include methylolated urea, urea resin, methylolated melamine, butyrolated melamine,
Methylolated guanamine or an alkyl ether of these compounds is used. From the viewpoint of thermal stability, an alkyl ether compound is more preferable. The alkyl group of the alkyl ether is preferably an alkyl group having 1 to 5 carbon atoms. In particular, as this alkyl ether compound, an alkyl etherified product of hexamethylolmelamine is more preferable in terms of photosensitivity. Further, a compound having two or more epoxy groups can also be used. These crosslinking agents are used in an amount of 2 to 30% by weight, preferably 2 to 30% by weight, based on the weight of the black photosensitive resin composition.
It is used in the range of ９9% by weight. If the amount is too small, the sensitivity tends to deteriorate, and if it is too large, the light-shielding properties tend to be insufficient.

As the photoacid generator, a trihalomethyl group-containing triazine derivative or onium salt which has light absorption in the wavelength region of the light source and generates an acid by light absorption is used. For example, trihalomethyl group-containing triazine derivatives include, for example, 2,4,6-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.

Onium salts include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphonate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium-p-toluenesulfonate. 4-methoxyphenylphenyliodonium hexafluorophosphonate, 4-methoxyphenylphenyliodonium hexafluoroarsenate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate,
Methoxyphenylphenyliodonium trifluoroacetate, 4-methoxyphenyliodonium-p-toluenesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (4-tert-butylphenyl) iodonium hexafluorophosphonate, bis ( 4-tert-butylphenyl) iodonium hexafluoroarsenate, bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-tert-
Butylphenyl) iodonium trifluoroacetate, diaryliodonium salts such as bis (4-tert-butylphenyl) iodonium-p-toluenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphonate, triphenylsulfonium hexafluoroarcete Nate,
Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, 4-methoxyphenyldiphenylsulfonium tetrafluoroborate, 4-methoxyphenyldiphenylsulfonium hexafluorophosphonate, 4-methoxyphenyldiphenyl Sulfonium hexafluoroarsenate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium trifluoroacetate, 4-methoxyphenyldiphenylsulfonium-p-trienesulfonate, 4-phenylthiophenyldiphenyltetrafluoroborate, 4-phenylthiophenyldiphenylhexafluorophosphonate, 4- Triarylsulfonium salts such as phenylthiophenyldiphenylhexafluoroarsenate, 4-phenylthiophenyldiphenyltrifluoromethanesulfonate, 4-phenylthiophenyldiphenyltrifluoroacetate, and 4-phenylthiophenyldiphenyl-p-toluenesulfonate; can give.

These photoacid generators may be used alone or
You may mix and use. Further, it may be used as a combination of a light absorber and a photoacid generator. The addition amount is preferably 0.5 to 40% by weight based on the resin material. If the amount exceeds 40% by weight, the amount of generated acid is too large, and the acid diffuses into unexposed areas due to heating after exposure to cause a cross-linking reaction, which tends to lower the resolution. On the other hand, when the addition amount is less than 0.5% by weight, the amount of generated acid is small, and the crosslinking reaction does not proceed sufficiently, so that an image tends to be unable to be formed.

As the black pigment, a grafted carbon black is used. The polymer compound used for grafting carbon black has a group which can easily react with a functional group present on the surface of carbon black. Examples include an aziridine group, an oxazoline group, an N-hydroxyalkylamide group, an epoxy group, a thioepoxy group, an isocyanate group, a vinyl group, an acryl group, a methacryl group, a silicon-based hydrolyzable group, an amino group, and the like.
The polymer compound used must have one or more of these groups in the molecule. Particularly in terms of reactivity with functional groups on the carbon black surface, aziridine groups, oxazoline groups, N-hydroxyalkylamide groups, epoxy groups,
A polymer compound having one or more groups selected from a thioepoxy group and an isocyanate group is preferred. More preferably, it is a polymer compound having one or more groups such as an aziridine group, an oxazoline group, and an N-hydroxyalkylamide group.

In the case of reacting carbon black with a polymer compound, substances such as polymer components, monomers, and organic solvents other than the polymer compound may be present in the reaction system as long as the reaction is not inhibited. The polymer compound is 10 to 100% by weight of carbon black, preferably 20 to 6%.
It is necessary to contain 0% by weight. If it is less than 10% by weight, the effect of grafting is small and the film strength tends to decrease. If it is 100% by weight or more, the photosensitivity tends to deteriorate and the optical density tends to decrease. PH 7 as carbon black
Or less, preferably 5 or less. When the pH is 7 or more, there is no grafting effect and the film strength is not improved.

The preparation of the black photosensitive resin composition (4) is as follows.
These materials are kneaded using a dispersing machine such as a roll mill, a roll mill, a sand mill, and a paint conditioner to obtain a black photosensitive resin composition. Further, as a diluting solvent to improve dispersibility, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, diglyme, cyclohexanone,
Organic solvents such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and lactic acid esters may be used.

The method for applying the black photosensitive resin composition (4) is not particularly limited, and may be a dipping method, a spray method, a roll coating method, a spin coating method, a bar coating method, a curtain coating method, etc., or screen printing. And an application method by printing such as offset printing. It is desirable that the applied film thickness is approximately the same as the film thickness of the color filter layer (20) as a pixel after the formation of the black matrix layer (30), so that a flat color filter is formed.

A high-pressure mercury lamp, an ultra-high-pressure mercury lamp, or the like is used as a light source for light exposure from the back surface of the transparent glass substrate (10) coated with the black photosensitive resin composition (4) and dried. When the photosensitive wavelength range of the black photosensitive composition is 400 nm or more, it is preferable to perform exposure through a visible light cut filter. By this exposure, an acid is generated in the black photosensitive resin composition (4) between the pixels and around the pixels.
By subsequent heating at a temperature of 90 ° C. to 150 ° C. for a time period of 15 seconds to 5 minutes, a cross-linking reaction due to the catalytic action of the acid occurs between the pixels of the black photosensitive resin composition (4) and around the pixels. Subsequently, the black photosensitive resin composition (4) in the unreacted portions on the pixels is removed using a developer, and then the black photosensitive resin composition (4) between the pixels and the peripheral portion of the pixels is heat-cured. Thus, a color filter (1) is obtained.

Since the black photosensitive resin composition (4) is composed of a resin material, a crosslinking agent, a photoacid generator and grafted carbon black, an acid is generated from the photoacid generator upon exposure. Then, when a cross-linking reaction occurs due to the catalytic action of the acid by heating, the cross-linking reaction gives a large sensitivity characteristic curve of the photosensitive resin, a hard sensitivity characteristic, steep in a region above a certain exposure amount It has the property of curing the film. Therefore, in the exposure from the back surface of the transparent glass substrate (10), when the exposure amount exceeds a certain amount, the black photosensitive resin composition (4) between the pixels and the peripheral portion of the pixels sharply hardens, and The black photosensitive resin composition (4) hardly hardens.

In order to promote this function, a color filter layer as a pixel may contain an ultraviolet absorber in advance. Examples of the ultraviolet absorber include benzophenone derivatives (Michler's ketone, etc.), metal oxides, benzotriazole-based compounds, merocyanine-based compounds, and cromarin-based compounds. Among them, light absorption is excellent, and light absorption of 25% or more even after heat curing. Chromalin-based compounds are preferred as those that maintain the properties.

In order to ensure the removal of the residue of the black photosensitive resin composition (4) on the pixel, the unreacted black photosensitive resin composition (4) on the pixel is removed using a developing solution. Rubbing with a brush or the like may be performed.

Since the black photosensitive resin composition (4) uses grafted carbon black,
When the unreacted black photosensitive resin composition is removed by the developer, the polymer is not eluted as in the conventional method, and the black matrix layer is hard to peel off from the transparent glass substrate.

[0036]

Next, the formation of a color filter for a liquid crystal display device according to the present invention will be specifically described with reference to examples.

<Example 1><Preparation of black photosensitive resin composition> (Step 1) Stirring blade, inert gas introduction pipe, reflux cooling pipe,
A separable flask equipped with a thermometer and a dropping funnel was charged with 80 parts of toluene and 20 parts of methyl ethyl ketone as a solvent, and methyl methacrylate (MMA) 85
Part, 2-hydroxyethyl methacrylate (HEMA)
A mixed solution of 15 parts, 4.3 parts of thioglycolic acid, and 2 parts of azobisisobutyronitrile (AIBN) was continuously dropped over about 4 hours to initiate polymerization. Then 70 ° C
For about 3 hours, and then aged at about 95 ° C. for about 2 hours to complete the polymerization. To 200 parts of the reaction solution, 8.5 parts of glycidyl methacrylate (GMA) (1.3 parts equivalent / COOH), 1.3 parts of tetrabutylammonium bromide as a catalyst, and 0.04 parts of hydroquinone monomethyl ether as a polymerization inhibitor. In addition, reaction temperature 85
The reaction was carried out at ~ 90 ° C for about 10 hours. This was reprecipitated in n-hexane and dried under reduced pressure at 50 ° C. for 2 days to obtain a methacrylate-type MMA-HEMA copolymer macromonomer at one end.

(Step 2) At room temperature, 50 parts of the macromonomer obtained in Step 1, 25 parts of styrene (St),
20 parts of hydroxyethyl methacrylate (HEMA),
5 parts of isopropenyl oxazoline (IPO), 3 parts of azobisisobutyronitrile (AIBN) as an initiator,
It was dissolved in 100 parts of propylene glycol monomethyl ether acetate (PGM-Ac) as a solvent to obtain a polymerizable monomer composition. The same separable flask as used in Step 1 was charged with 50 parts of propylene glycol monomethyl ether acetate (PGM-Ac),
The temperature was raised to C. The polymerizable monomer composition was charged into the dropping funnel over 3 hours while maintaining the temperature at 80 ° C., and the polymerization reaction was continued at the same temperature for about 2 hours. Thereafter, the temperature was raised to 110 ° C. and an aging reaction was performed for about 2 hours to obtain a solution of a polymer compound having an oxazoline group as a reactive group (nonvolatile content: 40%).

(Step 3) 30 parts of carbon black, 22.5 parts of the polymer solution obtained in Step 2 were placed in a separable flask equipped with a stirring blade, a cooling pipe, and a temperature sensor.
97.5 parts of propylene glycol monomethyl ether acetate (PGM-Ac) and 800 parts of zirconia beads were charged. The reaction was carried out at 100 ° C. for 3 hours while stirring at a rotation speed of 600 rpm. After cooling, the beads were separated from the beads to obtain a carbon black graft polymer (GCB) dispersion having a carbon black content of 20%.

(Step 4) To 150 parts of the carbon black graft polymer (GCB) dispersion obtained in Step 3, 3.59 of trimellitic anhydride (MW 192.13) was added.
Part, 1,8-diazabicyclo [5,4,0] as catalyst
-0.09 parts of undecene (DBU) at 80 ° C
At a temperature of about 1 hour to obtain a carbon black graft polymer (GCB) dispersion containing a carboxyl group.

(Step 5) 300 parts of the GCB dispersion obtained in Step 3, 12 parts of polyhydroxystyrene (MW5000) as a resin material, and 5 parts of “Nikkalac MW-30M” manufactured by Sanwa Chemical Co. as a crosslinking agent. Parts, 5 parts of "TAZ-104" manufactured by Midori Kagaku Co., Ltd. as a photoacid generator, 172 parts of propylene glycol monomethyl ether acetate (PGM-Ac) as a solvent, and 500 g of glass beads in a glass bottle. The mixture was dispersed for about 2 hours to prepare a black photosensitive resin composition.

<Preparation of Color Filter Layer> A low-expansion glass manufactured by Corning Co., Ltd., product number 7059 was used as a transparent glass substrate (10), and on this transparent glass substrate (10), a product made by Fuji Hunt Electronics Technology Co., Ltd. was used. A color mosaic resist, product number CBV7000, was coated by spin coating to a thickness of 1.5 μm. 90
° C, after drying for about 30 minutes, exposure amount 200
(MJ / cm ² ), developed, and heated to obtain a first color pixel-like color filter layer (blue). Next, using a color mosaic resist, product number CGY7000, spin coating is performed so that the film thickness becomes 1.5 μm, and after drying, exposure, development, and heating are performed in the same manner as in the first color to form a pixel-like color filter of the second color. A layer (green) was obtained. Further, using a color mosaic resist, product number CRY7000, a third color pixel-like color filter layer (red) was similarly obtained.

<Preparation of Concave Portion> On the thus obtained transparent glass substrate (10) on which the pixel-like color filter layer (20) is formed, a glass corrosive ink (viscosity, solid content, etc.) is adjusted. 2) was uniformly applied by a bar coating method. Deca-Pro as the glass corrosion ink (2)
Duca-Glasstech manufactured by Ducts was used. The applied film thickness is about 50 μm. Next, this transparent glass substrate was heated using a hot plate at about 45 ° C. for about 20 minutes, so that the glass surfaces between and around the pixels were corroded in a concave shape, and the bottom surface of the concave portion (3) was roughened. . Next, the glass corrosion ink (2) was washed away with water to obtain a transparent glass substrate having a concave portion having a roughened bottom surface.

<Preparation of Black Matrix Layer>
The black photosensitive resin composition (4) is applied on a transparent glass substrate having a concave portion with a roughened bottom surface by a spinner, and the black photosensitive resin composition is applied to the concave portions between pixels and around the pixels. Was filled. About 70 ° using a hot plate
C. After heating for about 1 minute to evaporate the solvent, the entire surface was exposed from the back surface of the transparent glass substrate using the above-mentioned pixels as a mask at an exposure of 150 mJ / cm ² by a 3 kW ultra-high pressure mercury lamp. Next, it was heated at about 90 ° C. for about 1 minute using a hot plate. Next, using a 1.25% aqueous solution of sodium hydroxide, the substrate was developed for about 30 seconds by spraying a shower while rotating the substrate, thereby removing the unreacted black photosensitive resin layer on the pixel. Subsequently, the mixture was cured by heating in a hot air circulation oven at about 230 ° C. for about 1 hour to obtain a black matrix layer (30).

<Performance of Color Filter> The optical density of the black matrix layer of the color filter thus obtained showed a high value of 4.0 or more. The depth of the concave portion (3) on which the black matrix layer was formed was about 1.25 μm. The bottom surface was roughened to have a surface roughness Ra of about 600 °. The reflectance (excluding the reflection on the glass surface) measured from the rear surface of the transparent glass substrate showed a low value of 0.4% in the wavelength range of 400 to 700 nm. FIG. 4 shows this reflectance. Also,
The flatness of the surface of the color filter was as good as about ± 0.2 μm. When the thus obtained color filter for a liquid crystal display device was used in a liquid crystal display device, good display quality could be obtained.

<Example 2> As the transparent glass substrate (10), low expansion glass manufactured by Corning Co., Ltd., product number 7059
Was used to form a pixel-like color filter layer (20) so as to have a film thickness of 1.2 μm by a printing method. The printing ink of each color contained a chrominic compound as an ultraviolet absorber in advance, and the pixel-like color filter layer had a function of cutting ultraviolet rays. The amount added in the ink was adjusted to about 10% of the solid content. The glass corrosive ink (2) is uniformly applied to the transparent glass substrate on which the pixel-like color filter layer is formed by using a bar coating method, and the concave portion (3) roughened in the same manner as in Example 1. Was obtained. Next, a black matrix layer (30) was produced using the black photosensitive resin composition (4) in the same manner as in Example 1. The color filter for a liquid crystal display device thus obtained has substantially the same optical density, reflectance, and flatness as those of Example 1, and when used in a liquid crystal display device, obtains good display quality. Was completed.

Example 3 A transparent glass substrate (10) was manufactured by Corning Co., Ltd., low expansion glass, part number 7059.
Was used to form a pixel-like color filter layer (20) so as to have a film thickness of 1.2 μm by an inkjet method. In the same manner as in Example 2, the ink of each color contained a UV absorber in advance. In the same manner as in Example 1, a concave portion (3) was produced using the glass corrosion ink (2), and a black matrix layer (30) was produced using the black photosensitive resin composition (4). The thus-obtained color filter (1) for a liquid crystal display had the same characteristics as in Example 1.

<Comparative Example 1> A transparent glass substrate (10) was used.
Using a positive resist (manufactured by Hoechst: part number “AZ1350”) on this transparent glass substrate at a pitch of 100
A stripe pattern having a thickness of 90 μm and a line width of 90 μm was formed. Subsequently, the transparent glass substrate was heated at a liquid temperature of 23 ° C.
Buffered hydrofluoric acid (manufactured by Hashimoto Kasei Co., Ltd .: Part number "LAL80")
0 ") for about 30 minutes to corrode the transparent glass substrate,
After washing with water, the resist was immersed in dimethyl sulfoxide for about 30 seconds to remove the positive resist, thereby obtaining a transparent glass substrate having a concave portion (3). The depth of the concave portion obtained at this time is about 3
μm.

Next, in the same manner as in Example 1, the black photosensitive resin composition (4) was spread using a spatula,
The black photosensitive resin composition on the transparent glass substrate was scraped off using a doctor made by S. Subsequently, the mixture was heated and cured at about 230 ° C. for about 60 minutes using a clean oven to form a black matrix layer (30). Next, on the transparent glass substrate having the black matrix layer formed thereon, a color photosensitive resin composition, color mosaic resist manufactured by Fuji Hunt Electronics Technology Co., Ltd., product number C
A pixel-shaped color filter layer (20) having a film thickness of 1.5 μm was sequentially formed by photolithography using RY7000, CGY7000, and CBV7000. Although the optical density of the black matrix layer of the color filter thus obtained was 4.0 or more, the reflectance was 1.6%.
The reflectance was higher than that of Example 1. FIG. 4 shows this reflectance.

<Comparative Example 2> A transparent glass substrate (10) was used.
On the transparent glass substrate, two layers of chromium oxide and chromium metal were deposited for the purpose of reducing the reflectance. The thickness of these two layers was about 0.2 μm. A positive resist (manufactured by Hoechst: product number "AZ135")
0 ") to form a stripe pattern having a pitch of 100 μm and a line width of 10 μm. This substrate was immersed in a solution of a mixture of ceric ammonium nitrate and perchloric acid, and chromium in a portion where a pixel-like color filter layer was formed was removed by etching to expose a transparent glass portion. After washing with water, the positive resist was peeled off to obtain a black matrix layer made of chromium.

Next, on the transparent glass substrate on which the black matrix layer is formed, as a colored photosensitive resin composition, a color mosaic resist manufactured by Fuji Hunt Electronics Technology Co., Ltd., product numbers CRY7000, CGY7
000, CBV7000 using photolithography method,
A pixel-shaped color filter layer having a thickness of 1.5 μm was formed. The optical density of the color filter thus obtained was 4.0 or higher, but the reflectivity was 2.5%. Further, since two layers of chromium were formed by a vapor deposition method, a color filter was produced. The cost of manufacturing the filters was high.

Comparative Example 3 <Preparation of Black Photosensitive Resin Composition> 20 parts by weight of methacrylic acid, 10 parts by weight of methyl methacrylate, 55 parts by weight of butyl methacrylate and 15 parts by weight of hydroxyethyl methacrylate were added to 300 parts by weight of ethyl cellosolve. Dissolve, under nitrogen atmosphere azobisisobutyronitrile 0.7
5 parts by weight were added, and 100 g of an acrylic resin obtained by reacting at 70 ° C. for 5 hours, 90 g of carbon black,
3 g by adding 10 g of Solsperse # 5000 as a dispersant
This roll was sufficiently kneaded to produce a black resin composition. Alonix M310 manufactured by Toyo Gosei Co., Ltd. was added to 100 g of the black resin composition as a photopolymerizable monomer.
g, 5 g of Irgacure 907 manufactured by Ciba-Geigy as a photopolymerization initiator, and the solid content was adjusted to 15% with ethyl cellosolve.
% To obtain a black photosensitive resin composition.

<Preparation of Black Matrix Layer> A low-expansion glass manufactured by Corning Co., Ltd., product number 7059 was used as a transparent glass substrate (10), and the black glass obtained as described above was formed on the transparent glass substrate (10). Using a photosensitive resin composition, a film thickness of 1.0 μm, a pitch of 100 μm, and a line width of 10 μm
An m-shaped striped black matrix layer was formed.

<Preparation of Color Filter Layer> Next, on the transparent glass substrate on which the black matrix layer was formed,
A pixel-shaped color filter layer having a film thickness of 1.5 μm was sequentially formed by a photolithography method using a color mosaic resist, product number CRY7000, CGY7000, and CBV7000 manufactured by Fuji Hunt Electronics Technology Co., Ltd. as a colored photosensitive resin composition. The optical density of the black matrix layer of the color filter thus obtained was about 3.0, and the reflectivity was 1.6%, all of which were inferior to Example 1. Also, the overlapping part of the black matrix layer and the color filter layer as pixels
In the case of a liquid crystal display device having a thickness of about 0.7 μm thicker than the black matrix layer, poor alignment of the alignment film in this portion occurred partially. In the case of a liquid crystal display device, the display quality was inferior to that of Example 1.

[0055]

According to the present invention, the black matrix layer comprises:
Since the bottom formed on the surface of the transparent glass substrate between the pixels and around the pixels is filled with the black resin composition substantially flush with the pixels in the rough concave portion, the optical density is 4. A color filter for a liquid crystal display device comprising a high black matrix layer of 0 or more can be obtained. In addition, since the bottom of the black matrix layer has a rough surface, light from the outside when used in a liquid crystal display device is irregularly reflected at the bottom of the rough surface, and a liquid crystal display device comprising a black matrix layer having a low reflectance. Color filter is obtained. Further, since the black matrix layer is formed of a black resin composition substantially flush with the pixels, a color filter for a liquid crystal display device having a surface with good flatness can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a color filter for a liquid crystal display device according to the present invention.

FIG. 2 is a sectional view taken along line AA ′ of one embodiment of the color filter for a liquid crystal display device according to the present invention shown in FIG.

FIGS. 3A to 3G show one embodiment of a manufacturing process of a color filter for a liquid crystal display device according to the present invention, FIG.
It is explanatory drawing represented by A 'cross section.

FIG. 4 is a diagram showing the reflectance of a black matrix layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Color filter for liquid crystal display devices 2 ... Glass corrosive ink 3 ... Concave part 4 ... Black photosensitive resin composition 10 ... Transparent glass substrate 20 ... Pixel-shaped color filter layer 30 ... Black matrix layer 40 ... Ultraviolet exposure R ... Red Filter pixel G: Green filter pixel B: Blue filter pixel

Claims (2)

[Claims] 1. A transparent glass substrate, a color filter layer formed in a pixel shape on the transparent glass substrate, and a black matrix layer made of a black resin composition formed between pixels and around the pixels. In the color filter for a liquid crystal display device, the bottom formed on the surface of the transparent glass substrate between pixels and around the pixels is filled with a black resin composition substantially flush with the pixels in a concave portion having a rough surface. A color filter for a liquid crystal display device, comprising a layer. (1) A color filter layer is formed in a pixel shape on a transparent glass substrate, and a glass corrosive ink is applied on the color filter layer using the pixel color filter layer as an etching mask. (2) Next, the glass corrosion ink is removed, and a black photosensitive resin composition is applied to the entire surface of the transparent glass substrate. (3) using the color filter layer formed as a pixel as a mask, exposing to ultraviolet light from the back side of the transparent glass substrate and heating, and (4) dissolving and removing the unexposed portion of the black photosensitive resin composition. And
A method for producing a color filter for a liquid crystal display device, comprising: a step of forming a black matrix layer between pixels and a peripheral portion of the pixel; and (5) a step of heating and curing the black matrix layer.