JP2000199815A - Color filter and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [Problem] To provide a color filter capable of providing a liquid crystal display device having an optimum liquid crystal layer thickness for each color of a coloring layer and excellent display quality, and a manufacturing method capable of easily manufacturing such a color filter. Provide a way. SOLUTION: The color filter is provided with a colored layer composed of a plurality of colors having different ultraviolet transmittances for each color on one surface of a transparent substrate, and a transparent protective layer formed at least on the colored layer. The thickness of the layer is 360 to 38 of the colored layer.
It is assumed that the color filter is different for each color of the colored layer in accordance with the average value of the ultraviolet transmittance in the region of 0 nm. Forming a colored layer composed of a plurality of different colors,
Forming a coating film using the photosensitive resin composition for a transparent protective layer in the step of covering the coloring layer, exposing the coating film through the coloring layer by irradiating ultraviolet rays from the back surface of the transparent substrate, and developing Then, after the coating film has a desired thickness for each color according to the average value of the ultraviolet transmittance in the region of 360 to 380 nm of the coloring layer, the coating film is cured to form a transparent protective layer. It is manufactured by

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color filter and a method of manufacturing the same, and more particularly to a color filter for a liquid crystal display device having excellent display quality and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, color liquid crystal display devices have attracted attention as flat displays. In general, a color liquid crystal display device includes a color filter including a black matrix and a coloring layer including a plurality of colors (usually, three primary colors of red (R), green (G), and blue (B)); ) Are attached to each other with a predetermined gap, and a liquid crystal material is injected into the gap. Therefore, this gap is the thickness of the liquid crystal layer itself. If the thickness of the liquid crystal layer is uneven, unevenness in brightness and color occurs in the color liquid crystal display device, and display quality is significantly impaired. Is desirably as uniform as possible.

On the other hand, there is a fact that even if the liquid crystal layer is uniform, the transmittance of visible light differs depending on the color (R, G, B) of the pixel of the color filter. Therefore, in order to obtain a uniform and optimal visible light transmittance, it is necessary to optimize the thickness of the liquid crystal layer for each color (R, G, B).

For this reason, a so-called multi-gap color filter has been developed in which the thickness of the colored layer is changed for each of the colors R, G, and B, and the liquid crystal layer is set to a predetermined thickness for each color.

[0005]

However, for example, when a colored layer having a different thickness for each of the R, G, and B colors as described above is formed by a conventionally known pigment dispersion method, the color layer having the smallest thickness is used. There has been a problem that the content of the coloring material in the photosensitive paint used in the formation becomes high, causing background stain, uneven color, poor adhesion to the substrate, and the like.

[0006] Further, a colored layer having a uniform thickness is formed, a coating film is formed on the colored layer by using a photosensitive resin composition for a protective layer, and the coating film is subjected to gradation exposure to obtain a desired layer. There is a method of forming a transparent protective layer having a thickness to form a multi-gap color filter. However, when performing gradation exposure of a coating film by using a photomask for gradation exposure, there is a problem that it is difficult to manufacture a photomask, and when performing gradation exposure of a coating film by step exposure, In addition, there is a problem that the time required for the exposure process becomes long.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and a color filter which enables a liquid crystal display device having an optimum liquid crystal layer thickness for each color of a colored layer and excellent display quality. It is another object of the present invention to provide a manufacturing method capable of easily manufacturing such a color filter.

[0008]

In order to achieve the above object, a color filter according to the present invention comprises a transparent substrate, a colored layer having a plurality of colors formed on one surface of the transparent substrate, and at least A transparent protective layer formed on the colored layer, wherein the colored layer has a different ultraviolet transmittance for each color, and the average value of the ultraviolet transmittance of the colored layer in a range of 360 to 380 nm. The thickness of the transparent protective layer was different for each color of the colored layer.

Further, the color filter of the present invention has a 360
The thickness of the transparent protective layer on the colored layer having a larger average value of the ultraviolet transmittance in the region of ３380 nm is larger, and the colored layer is composed of three colors of red, green and blue. The average value of the ultraviolet transmittance in the region of ３380 nm was the largest in the blue colored layer and the smallest in the red colored layer.

Further, the color filter of the present invention has a 360
The thickness of the transparent protective layer on the colored layer having a smaller average value of the ultraviolet transmittance in the region of ３380 nm is larger, and the colored layer is composed of three colors of red, green and blue. The average value of the ultraviolet transmittance in the region of ３380 nm was set to be the smallest in the blue coloring layer and the largest in the red coloring layer.

The method of manufacturing a color filter according to the present invention comprises a first step of forming a colored layer composed of a plurality of colors having different ultraviolet transmittances on a transparent substrate on a transparent substrate, wherein a photosensitive resin composition for a transparent protective layer is formed. A coating film is formed so as to cover the coloring layer by using, and the ultraviolet light is irradiated from the back surface of the transparent substrate to expose and develop the coating film via the coloring layer, thereby developing the coloring layer.
A second step of forming a transparent protective layer by forming a coating film of a desired thickness for each color according to the average value of the ultraviolet transmittance in the region of 380 nm and then curing the coating film. Such a configuration was adopted.

In the present invention, the coating film of the photosensitive resin composition for the transparent protective layer formed on the colored layer is exposed to ultraviolet rays from the back surface of the transparent substrate and through the colored layer. Therefore, the amount of exposure of the coating film for each color varies depending on the average value of the ultraviolet transmittance in the region of 360 to 380 nm of the colored layer, and the transparent film having a desired thickness for each color is developed and cured. A protective layer is formed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described below with reference to the drawings. Color Filter Figure 1 of the present invention is a longitudinal sectional view showing an example of a liquid crystal display device using a color filter which is an embodiment of the present invention. In FIG. 1, a liquid crystal display device 1 includes a color filter 11 of the present invention.
And a TFT array substrate 21 with a liquid crystal layer 31 interposed therebetween.

The color filter 11 of the present invention comprises a transparent substrate 12, a black matrix (light-shielding layer) 13 formed on one surface of the transparent substrate 12 in a predetermined pattern, a colored layer 14 of a plurality of colors, and on the colored layer 14. A transparent protective layer 16 and a transparent conductive film 17 formed on the substrate. The coloring layer 14 includes a red coloring layer 14R, a green coloring layer 14G, and a blue coloring layer 14B.
The average value of the ultraviolet transmittance in the region of nm (hereinafter, referred to as “the magnitude of the ultraviolet transmittance”) is different. That is, the magnitude of the ultraviolet transmittance of each color of the colored layer 14 is 14R <14G <14B or 14R>.
It is set so that 14G> 14B.

The transparent protective layer 16 provided on such a colored layer 14 includes colored layers 14R, 14R of each color of the colored layer 14.
G and 14B have a thickness corresponding to the magnitude of the ultraviolet transmittance. In the illustrated example, the thickness of the transparent protective layer 16 is such that the transparent protective layer 16B on the blue colored layer 14B has the largest thickness, and hereinafter the transparent protective layer 16 on the green colored layer 14G.
G and the thickness of the transparent protective layer 16R on the red coloring layer 14R are smaller in this order.

On the other hand, the TFT array substrate 21 is
A display electrode 23 connected to a thin film transistor (not shown) is provided thereon.
4R, 14G, 14B and the corresponding TFT array substrate 2
Positioning is performed so that one display electrode 23 faces the other.

In such a liquid crystal display device 1, the liquid crystal layer 3
1 is not uniform, and each colored layer 14R, 14G, 1
4B, each has an optimum thickness. In the illustrated example, the liquid crystal layer 3 corresponds to the thickness of the transparent protective layers 16R, 16G, 16B on the colored layers 14R, 14G, 14B.
The thicknesses of 1 are TR, TG, and TB, respectively.
The thickness of the liquid crystal layer 31 has been optimized. Therefore, the visible light transmittance of the colored layers 14R, 14G, and 14B of each color constituting the pixels of the color filter 11 is uniform and optimal, and the liquid crystal display device 1 having excellent display quality is provided.
Becomes possible.

As the transparent substrate 12 constituting the color filter 11 of the present invention, a rigid material having no flexibility such as quartz glass, Pyrex glass, or a synthetic quartz plate, or a flexible material such as a transparent resin film or an optical resin plate is used. A flexible material having properties can be used. Of these, Corning 7059 glass is a material having a low coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the glass. It is suitable for a color liquid crystal display device for LCD by the method.

The black matrix 13 formed on the transparent substrate 12 is formed by forming a metal thin film of chromium or the like having a thickness of about 1000 to 4000 ° by sputtering, vacuum evaporation, or the like, and patterning the thin film. Forming a resin layer of polyimide resin, acrylic resin, polyvinyl alcohol derivative resin, gelatin resin, etc. containing light-shielding particles such as carbon fine particles and patterning this resin layer; The photosensitive resin layer containing the light-shielding particles may be formed, and the photosensitive resin layer may be formed by patterning.

The coloring layer 14 constituting the color filter 11 of the present invention is composed of a red coloring layer 14R, a green coloring layer 14G, and a blue coloring layer 14B in a mosaic type, a triangle type,
They are arranged in a desired pattern such as a stripe type, a four-pixel arrangement type, or the like. Such a colored layer 14 has a thickness of 0.1.
Each color can be set uniformly within a range of about 5 to 3.0 μm. Further, in consideration of the setting of the thicknesses TR, TG, and TB of the liquid crystal layer 31, as shown in FIG.
A difference may be provided between the thicknesses of R, 14G, and 14B. In this case, it is necessary to set the thickness of the coloring layer within a range in which the content of the coloring material of the photosensitive resin composition to be used becomes high and the background stain, uneven color, poor adhesion to the substrate, and the like do not occur.

The transparent protective layer 16 constituting the color filter 11 of the present invention is formed using a known negative photosensitive resin or positive photosensitive resin. That is, as described later, when the magnitude of the ultraviolet transmittance of each color of the colored layer 14 is 14R <14G <14B, the colored layer 14 can be formed using a known negative-type transparent photosensitive resin. The magnitude of the ultraviolet transmittance of each color of the layer 14 is 14R> 1
When 4G> 14B, it can be formed using a known positive type transparent photosensitive resin. The thickness of the transparent protective layer 16 on the coloring layer 14 can be set in consideration of the liquid crystal material to be used and the like. For example, the thickness of the transparent protective layer 16R on the red coloring layer 14R is about 0 to 2.0 μm, The thickness of the transparent protective layer 16G on the green coloring layer 14G is about 0.2 to 2.5 μm, and the thickness of the transparent protective layer 16B on the blue coloring layer 14B is about 1.5 to 4.0 μm. 16G thickness difference 0.2 ~
The difference in thickness between the transparent protective layers 16G and 16B can be set to about 1.0 μm, and about 0.5 to 1.5 μm.

The transparent conductive film 17 is made of indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO)
And an alloy thereof. The thickness of such a transparent conductive film 17 is preferably about 200 to 2000 °.

Next, a method of manufacturing a color filter according to the present invention will be described with reference to the above-described color filter 11 as an example.

FIG. 3 is a process chart showing an embodiment of the method for manufacturing a color filter of the present invention. In the method for manufacturing a color filter of the present invention, first, as a first step, a red coloring layer 14R having a different ultraviolet transmittance for each color is formed on a transparent substrate 12 having a black matrix 13 in a predetermined pattern shape. The coloring layer 14 in which the layer 14G and the blue coloring layer 14B are arranged is formed (FIG. 3A).
The colored layer 14 can be formed, for example, by a pigment dispersion method using a photosensitive resin composition containing a coloring material in a known negative or positive photosensitive resist, and the like. The setting of the ultraviolet transmittance of each color can be performed by adjusting the content of the ultraviolet absorber in the photosensitive resin composition of each color to be used. Examples of the ultraviolet absorber used include benzotriazole-based, benzophenone-based, benzoate-based, salicylate-based, and cyanoacrylate-based compounds.

The magnitude of the ultraviolet transmittance of the colored layer 14 is 14R <14G <14B, or
14R>14G> 14B.

In the present invention, since the optimization of the thickness of the liquid crystal layer is controlled by the thickness of the transparent protective layer, the thickness of the colored layer 14 is set to 0.1.
It can be formed uniformly in the range of about 5 to 3.0 μm. However, by providing a slight difference in the thickness of the colored layers 14R, 14G and 14B in advance and controlling the thickness of the transparent protective layer, the liquid crystal layer can be formed. The adaptation range of the thickness optimization can be further expanded.

Next, as a second step, first, the colored layer 1
A coating film 15 is formed using the photosensitive resin composition for a transparent protective layer so as to cover No. 4 (FIG. 3B). The photosensitive resin used is a negative photosensitive resin when the magnitude of the ultraviolet transmittance of the coloring layers 14R, 14G, 14B is 14R <14G <14B, and the coloring layers 14R, 14G, 1
The magnitude of the ultraviolet transmittance of 4B is 14R>14G> 14
In the case of B, it is a positive photosensitive resin. Specifically, as the negative photosensitive resin composition, photopolymerizable, crosslinkable acrylic resin, polyimide resin, polyamide resin, epoxy resin, polyester resin,
One or more light-transmitting negative photosensitive resins such as a polyamic acid resin are used, and an antioxidant, a surfactant, an antifoaming agent, a fluorescent brightener, an ultraviolet absorber, and a dispersant are used. ,
What added a viscosity modifier etc. can be used.
Further, as a positive photosensitive resin composition, a mixture of a resin such as a novolak resin, a polyamic acid resin, a maleimide-styrene copolymer, a polyvinyl phenol derivative and a photoacid generator, and a light transmission material such as a polyamic acid derivative One or two or more positive photosensitive resins are used, and an antioxidant, a surfactant, an antifoaming agent, a fluorescent brightener, an ultraviolet absorber, a dispersant, a viscosity modifier, and the like are added thereto. Things can be used.

The thickness of the coating film 15 is uniform, and the thickness of the coating film 15 is set in consideration of the final shape of the transparent protective layer 16 having a desired thickness for each color layer 14R, 14G, 14B. For example, 1.0 to 7.0 μ
It can be set within a range of about m.

Next, ultraviolet rays are irradiated from the back surface of the transparent substrate 12 to expose the coating film 15 via the coloring layer 14 (FIG. 3).
(C)). As a result, the coating film 15 becomes a colored layer 14R, 1
Exposure is performed at an exposure amount corresponding to the magnitude of the ultraviolet transmittance of 4G and 14B. That is, the colored layers 14R, 14G, 14B
Is less than 14R <14G <14B, the negative photosensitive coating film 15 is
The exposure amount becomes maximum on B, and becomes minimum on the red coloring layer 14R. Also, the colored layers 14R, 14G, 14B
Is greater than 14R>14G> 14B, the positive photosensitive coating film 15 is
The exposure amount becomes minimum on B and the exposure amount becomes maximum on the red coloring layer 14R. Therefore, the thickness of the transparent protective layer 16 formed on the blue colored layer 14B is the largest for the transparent protective layer 16 formed by development and curing after exposure, and hereinafter, the transparent protective layer 16G on the green colored layer 14G, The thickness becomes smaller in the order of the transparent protective layer 16R on the red coloring layer 14R (FIG. 3D). Each of the colored layers 14R, 14G,
The thickness of the transparent protective layers 16R, 16G, and 16B on 14B is, for example, 0 to 1.5 μm for the transparent protective layer 16R, 0.5 to 2.0 μm for the transparent protective layer 16G, and 0.5 to 2.0 μm for the transparent protective layer 16B. It can be set in the range of 1.0 to 2.5 μm.

Thereafter, on the transparent protective layer 16 described above, an indium tin oxide (ITO), a zinc oxide (ZnO), a tin oxide (SnO), an alloy thereof, or the like, and an evaporation method, a sputtering method, or a CVD method are used. The transparent conductive film 17 is formed in a predetermined pattern by a known method such as that shown in FIG.
(E)). Thereby, the color filter 11 is obtained.

[0031]

Next, the present invention will be described in more detail with reference to examples.

Example 1 First, a chromium thin film (thickness 1000 mm) was formed on a glass substrate (Corning Co., Ltd., 7059 glass 0.7 mm thick) by a vacuum evaporation method, and a spin coating method was performed on this chromium thin film. Was applied and OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. was applied and dried. Next, a photosensitive resist layer was exposed and developed through a photomask for a black matrix to form a resist pattern, a chromium thin film was etched using the resist pattern as a mask, and the resist pattern was peeled off to form a black matrix. . As the etching solution, an aqueous solution obtained by mixing ceric ammonium nitrate and perchloric acid was used.

On the other hand, using a base photosensitive resin having the following composition, a photosensitive resin composition R for a colored layer of each color having the following composition is provided.
1, G1 and B1 were prepared. These photosensitive resin compositions R1, G1, and B1 can adjust the amount of the ultraviolet absorber to adjust the magnitude of the ultraviolet transmittance (360 to 380 n).
m1) (R1 <G1 <B)
It was set to be 1.

Composition of base photosensitive resin o-cresol novolak epoxy acrylate: 9.5 parts by weight (50% of hydroxyl groups reacted with phthalic anhydride) Dipentaerythritol hexaacrylate: 9.5 parts by weight ( Nippon Kayaku Co., Ltd. DPHA)-Irgacure 907 (Ciba-Geigy) ... 1 part by weight-Irgacure 369 (Ciba-Geigy) ... 2 parts by weight-Ethyl cellosolve acetate ... 80 parts by weight-Benzophenone ... 1 part by weight red Photosensitive resin composition R1 , base photosensitive resin ... 50 parts by weight-Ethyl cellosolve acetate ... 85 parts by weight-Chromophthal Red BRN (manufactured by Ciba Geigy) ... 10 parts by weight-UV absorber ... 5 parts by weight 2-ethylhexyl-2 cyano-3,3'-diphenylacrylate green-sensitive trees Composition G1-based photosensitive resin ... 50 parts by weight of ethyl cellosolve acetate ... 50 parts by weight diglyme ... 35 parts by weight Lionol Green 2Y-301 ... 8 parts by weight (manufactured by Toyo Ink Mfg. Co., Ltd.) Ultraviolet absorber 2.5 parts by weight 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate blue photosensitive resin composition B1 base photosensitive resin 50 parts by weight Ethyl cellosolve acetate 50 parts by weight Diglyme 35 parts by weight・ Chromophthal Blue A3R (Ciba Geigy) 12 parts by weight

Next, the photosensitive resin composition B1 is applied onto the above-mentioned glass substrate by a spin coating method (rotation speed: 600 rpm), dried, exposed to light through a blue colored layer photomask, and developed. Thus, a blue colored layer (thickness: 1.5 μm) was formed. Similarly, a green coloring layer and a red coloring layer were formed using the photosensitive resin composition G1 and the photosensitive resin composition R1 (corresponding to FIG. 3A). Incidentally, the photosensitive region of the initiator contained in the photosensitive resin composition of each color described above is around 405 nm.

With respect to the blue colored layer B, the green colored layer G, and the red colored layer R thus formed, the average value of the transmittance for ultraviolet rays in the wavelength range of 360 to 380 nm was measured with an ultraviolet-visible spectrophotometer. Colored layer B = 5.0-5.5
%, Green coloring layer G = 2.5 to 3.0%, red coloring layer R =
1.0% or less.

Next, a negative photosensitive composition for a transparent protective layer having the following composition was prepared and applied on a glass substrate having a colored layer formed thereon by a spin coating method (at a rotation speed of 500 rpm).
The coating film was formed by drying at 100 ° C. for 5 minutes (FIG. 3)
(Equivalent to (B)).

Photosensitive composition for protective layer : dipentaerythritol hexaacrylate: 40 parts by weight (DPHA manufactured by Nippon Kayaku Co., Ltd.) methyl methacrylate / methacrylic acid / benzyl methacrylate copolymer: 40 parts by weight Irgacure 907 (manufactured by Ciba Geigy) 20 parts by weight 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazole 10 parts by weight Propylene glycol monomethyl ether acetate 250 parts by weight Department

Next, an ultraviolet ray of 365 nm was irradiated from the back surface of the glass substrate with a super high pressure mercury lamp to 300 mJ / cm ^2.
Irradiated to expose the coating film through the colored layer (FIG. 3C)
Equivalent). Thereafter, the film is immersed in a developer prepared by adding a surfactant to a 0.1% by weight aqueous solution of sodium carbonate for 1 minute to carry out development to remove an uncured portion of the coating film.
Heat treatment was performed at 00 ° C. for 60 minutes to form a transparent protective layer (corresponding to FIG. 3D). The thickness of this transparent protective layer is 2.0 μm on the blue colored layer, 1.0 μm on the green colored layer,
It was 0.3 μm on the red coloring layer. Next, a transparent conductive film of ITO (thickness 1000 °) was formed on the transparent protective layer by a sputtering method to obtain a color filter (FIG. 3).
(Equivalent to (E)).

This color filter can be used for background dirt, color unevenness,
It was good without poor adhesion between the glass substrate and the colored layer.

Further, using the above color filter,
The thickness of the liquid crystal layer was 3.7 μm on the blue coloring layer, 4.7 μm on the green coloring layer, and 5.4 μm on the red coloring layer in FIG.
The liquid crystal display device as shown in was manufactured. The display quality of this liquid crystal display device was excellent.

Example 2 In the same manner as in Example 1, a black matrix was formed on a glass substrate (Corning Co., Ltd., 7059 glass, thickness 0.7 mm). Also, using the same base photosensitive resin as in Example 1, photosensitive resin compositions R2, G2,
B2 was prepared. These photosensitive resin compositions R2, G
2, B2 was set such that the magnitude of the ultraviolet transmittance (average value of the ultraviolet transmittance in the range of 360 to 380 nm) was R2>G2> B2 by adjusting the amount of the ultraviolet absorber added. .

Red photosensitive resin composition R2 , base photosensitive resin: 50 parts by weight Ethyl cellosolve acetate: 85 parts by weight Chromophtal red BRN (manufactured by Ciba Geigy) 10 parts by weight Green photosensitive resin composition G2 , base Photosensitive resin: 50 parts by weight ・ Ethyl cellosolve acetate: 50 parts by weight ・ Diglyme: 35 parts by weight ・ Lionol green 2Y-301: 8 parts by weight (manufactured by Toyo Ink Manufacturing Co., Ltd.) ・ UV absorber: 2.5 parts by weight Part 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate blue photosensitive resin composition B2 · base photosensitive resin ... 50 parts by weight-ethyl cellosolve acetate ... 50 parts by weight-diglyme ... 35 parts by weight-chromophtal blue A3R (Manufactured by Ciba-Geigy) 15 parts by weight UV absorber 10 parts by weight 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate

Next, the photosensitive resin composition B2 is applied on the glass substrate by a spin coating method (rotation speed: 600 rpm), dried, exposed to light through a photomask for a blue colored layer, and developed. Thus, a blue colored layer (thickness: 1.5 μm) was formed. Similarly, a green coloring layer and a red coloring layer were formed using the photosensitive resin composition G2 and the photosensitive resin composition R2 (corresponding to FIG. 3A).

With respect to the blue colored layer B, the green colored layer G, and the red colored layer R thus formed, the average transmittance to ultraviolet rays in the wavelength range of 360 to 380 nm was measured in the same manner as in Example 1. Layer B = 0.5% or less, green coloring layer G = 10-11%, red coloring layer R = 22-23%
Met.

Next, a positive-type photosensitive composition for a transparent protective layer having the following composition was prepared and applied on a glass substrate having a colored layer formed thereon by a spin coating method (at a rotation speed of 500 rpm).
It was dried at 120 ° C. for 4 minutes to form a coating film (FIG. 3
(Equivalent to (B)).

Photosensitive coating solution for protective layer・ Polyvinylphenol resin protected with t-butoxycarbonyl group (t-BOC): 10 parts by weight ・ Hexamethoxymethylolated melamine: 10 parts by weight ・ Ethyl lactate: 50 parts by weight -Photoacid generator (TAZ-104 manufactured by Midori Kagaku KK) ... 10 parts by weight-Propylene glycol monomethyl ether acetate ... 150 parts by weight

Next, ultraviolet light of 365 nm was irradiated from the back surface of the glass substrate using a super-high pressure mercury lamp to 500 mJ / cm ^2.
Irradiated to expose the coating film via the colored layer (FIG. 3C)
Equivalent). Then, 1.0% by weight of aqueous potassium hydroxide solution
Immersed in a developer prepared by adding a surfactant to the mixture for 1.5 minutes to perform development, and further, the entire surface was irradiated with ultraviolet rays (300 mJ / cm ² ) using a low-pressure mercury lamp.
Heat treatment was performed at 0 ° C. for 60 minutes to form a transparent protective layer (corresponding to FIG. 3D). The thickness of the transparent protective layer was 1.7 μm on the blue coloring layer, 0.7 μm on the green coloring layer, and 0.05 μm on the red coloring layer. Next, a transparent conductive film of ITO (thickness: 1000 Å) was formed on the transparent protective layer by a sputtering method to obtain a color filter (FIG. 3).
(Equivalent to (E)).

This color filter is used for background dirt, color unevenness,
It was good without poor adhesion between the glass substrate and the colored layer.

Further, using the above color filter,
The thickness of the liquid crystal layer was 3.7 μm on the blue coloring layer, 4.7 μm on the green coloring layer, and 5.4 μm on the red coloring layer in FIG.
The liquid crystal display device as shown in was manufactured. The display quality of this liquid crystal display device was excellent.

(Comparative Example) First, using the same base photosensitive resin as in Example 1, photosensitive resin compositions R ', G', and B 'for the colored layers having the following compositions were prepared.

Red photosensitive resin composition R ' , base photosensitive resin: 50 parts by weight-Ethyl cellosolve acetate ... 85 parts by weight-Chromophthal Red BRN (manufactured by Ciba Geigy) ... 10 parts by weight Green photosensitive resin composition G' -Base photosensitive resin ... 75 parts by weight-Ethyl cellosolve acetate ... 50 parts by weight-Ziglyme ... 35 parts by weight-Lionol Green 2Y-301 ... 8 parts by weight (Toyo Ink Mfg. Co., Ltd.) Blue photosensitive resin composition B ' Base photosensitive resin 100 parts by weight Ethyl cellosolve acetate 50 parts by weight Diglyme 35 parts by weight Chromophtal blue A3R (manufactured by Ciba-Geigy) 12 parts by weight

Next, a glass substrate (Corning Co., Ltd. 7)
059 glass (thickness: 0.7 mm), a photosensitive resin composition B ′ is applied by a spin coating method (rotation speed: 400 rpm), dried, exposed through a blue coloring photomask, developed, and colored blue. A layer (thickness 3.2 μm) was formed.
Similarly, a green colored layer (2.2 μm in thickness) and a blue colored layer (1.5 μm in thickness) are formed using the photosensitive resin composition G ′ and the photosensitive resin composition R ′, and the thickness is set for each color. Colored layers having different structures were formed.

Next, a coating solution for a protective layer having the following composition is applied by a spin coating method (rotational speed: 700 rpm) and dried, and then a colored layer is formed using an ultra-high pressure mercury lamp through a photomask. Only the region and its peripheral part were irradiated with ultraviolet rays at 100 mJ / cm ² .

Coating solution for protective layer : dipentaerythritol hexaacrylate: 40 parts by weight (DPHA manufactured by Nippon Kayaku Co., Ltd.) methyl methacrylate / methacrylic acid / benzyl methacrylate copolymer: 40 parts by weight Irgacure 907 (Ciba Geigy) 20 parts by weight-2,2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazole ... 10 parts by weight -Propylene glycol monomethyl ether acetate ... 400 parts by weight

Thereafter, development is carried out by immersing in a developing solution prepared by adding a surfactant to a 0.1% by weight aqueous solution of sodium carbonate for 1.5 minutes, followed by a heat treatment at 200 ° C. for 60 minutes to obtain a transparent protective layer. Was formed. An ITO transparent conductive film (thickness: 100) was formed on this transparent protective layer by sputtering.
0 °) was formed to obtain a color filter for comparison.

In this color filter, in particular, by increasing the thickness of the blue coloring layer, color unevenness due to deterioration of the film thickness distribution,
Poor adhesion to the glass substrate occurred, and it could not be used as a color filter for a liquid crystal display device.

[0058]

As described above in detail, according to the present invention, a color filter is provided on one surface of a transparent substrate with a colored layer composed of a plurality of colors having different ultraviolet transmittances for each color, and at least on the colored layer. The transparent protective layer is formed, and the thickness of the transparent protective layer is different for each color of the colored layer corresponding to the magnitude of the ultraviolet transmittance of the colored layer, and is manufactured using such a color filter. In such a liquid crystal display device, the optimal thickness of the liquid crystal layer can be set for each color of the colored layer, and a liquid crystal display device with excellent display quality can be realized. The color filter of the present invention is obtained by forming a colored layer of a plurality of colors having different ultraviolet transmittances for each color on a transparent substrate in a first step, and a photosensitive resin composition for a transparent protective layer in a second step. Forming a coating film so as to cover the colored layer by using an object;
The coating film is exposed and developed through the colored layer by irradiating ultraviolet rays from the back surface of the transparent substrate, and the coating film is formed into a desired thickness for each color according to the magnitude of the ultraviolet transmittance of the colored layer. Is hardened to form a transparent protective layer, so that there is no occurrence of background contamination, color unevenness, poor adhesion to the substrate, etc. due to thickening of the colored layer, and a photo for gradation exposure. Since a mask and a complicated exposure step are not required, a color filter can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a liquid crystal display device using a color filter according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment of the color filter of the present invention.

FIG. 3 is a process chart showing one embodiment of a method for manufacturing a color filter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 11 ... Color filter 12 ... Transparent substrate 13 ... Black matrix 14 (14R, 14G, 14B) ... Coloring layer 15 ... Coating film for a transparent protective layer 16 ... Transparent protective layer 17 ... Transparent conductive film 31 ... Liquid crystal layer

Continued on the front page F term (reference) 2H048 BA45 BA48 BB02 BB07 BB37 BB44 2H091 FA02Y FA35Y FB02 FB04 FB12 FC01 FC02 FC05 FC10 FC23 FD24 GA01 GA03 GA16 KA04 LA12 LA16 5G435 AA00 AA17 BB12 CC09 CC12 EE33 GG07 H07

Claims (6)

[Claims] 1. A transparent substrate comprising: a transparent substrate; a colored layer having a plurality of colors formed on one surface of the transparent substrate; and a transparent protective layer formed on at least the colored layer. Have a different ultraviolet transmittance, and 360
A color filter, wherein the thickness of the transparent protective layer is different for each color of the colored layer so as to correspond to the average value of the ultraviolet transmittance in the region of -380 nm. 2. The color filter according to claim 1, wherein the thickness of the transparent protective layer on the colored layer having a larger average value of the ultraviolet transmittance in the range of 360 to 380 nm is larger. 3. The coloring layer is composed of three colors of red, green and blue, and the average value of the ultraviolet transmittance of the coloring layer in the range of 360 to 380 nm is the largest in the blue coloring layer and the smallest in the red coloring layer. 3. The method according to claim 2, wherein
The color filter according to 1. 4. The color filter according to claim 1, wherein the thickness of the transparent protective layer on the colored layer having a smaller average value of the ultraviolet transmittance in the range of 360 to 380 nm is larger. 5. The colored layer is composed of three colors of red, green and blue, and the average value of ultraviolet transmittance of the colored layer in the range of 360 to 380 nm is smallest in the blue colored layer and largest in the red colored layer. 5. The method according to claim 4, wherein
The color filter according to 1. 6. A first step of forming a colored layer of a plurality of colors having different ultraviolet transmittances for each color on a transparent substrate, wherein the colored layer is covered with a photosensitive resin composition for a transparent protective layer. A coating film is formed on the substrate, and the coating film is exposed and developed through the colored layer by irradiating ultraviolet rays from the back surface of the transparent substrate, and the average value of the ultraviolet transmittance of the colored layer in the range of 360 to 380 nm is increased. A second step of forming a transparent protective layer by curing the coating film after forming the coating film to a desired thickness for each color in accordance with the color filter.