JPH0675372A - Production of photosensitive coloring composition and color filter, and color filter - Google Patents

Abstract

(57) [Summary] [Object] To provide a highly reliable and highly sensitive photosensitive coloring composition, a color filter, and a method for producing the same. [Structure] A photosensitive coloring composition comprising an acrylic resin, a pigment, a dispersant, a photopolymerizable monomer, a photopolymerization initiator and a solvent, wherein the photopolymerization initiator comprises a mixture of a benzophenone compound and an imidazole compound. Coloring composition. And a step of forming the colored resin layer on the entire surface by using the photosensitive coloring composition, a step of exposing and photocuring, and a step of forming a colored resin layer by developing and leaving it in a pattern to form a color filter. . [Effect] A photosensitive coloring composition having high sensitivity was obtained even with a coloring composition containing a dye, and the exposure time could be shortened significantly.

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 for a color liquid crystal display or a color video camera, and more specifically to a photosensitive coloring composition used for producing the color filter.

[0002]

2. Description of the Related Art Conventionally, the following methods (1) and (2) are known for color filters using pigments. (1) A pigment is dispersed in an acrylic resin with a dispersant (referred to as a coloring composition), a glass substrate is coated with the coloring composition and dried, and then a photosensitive resist material (positive resist such as AZ) is coated. After drying and exposure using a mask, development is carried out to form a resist pattern, and the unpatterned portion of the resist is removed by etching to obtain a pattern of a colored product. After that, the unnecessary resist is peeled off to complete the pattern (see JP-A-60-237403).

(2) A method of forming a colored pattern by adding a photosensitizer or a photopolymerization initiator and a photopolymerizable monomer to a colored composition to sensitize it, coating it on a substrate, drying it, exposing it to light and developing it. (JP-A-2-144502, JP-A2-1)
81704).

In this case, the photosensitizer includes bisazide compounds and diazo compounds, and the photopolymerization initiators such as acetophenone and benzyldimethylketal are used. Even if it is exposed, it has low sensitivity because the dye absorbs ultraviolet rays. Therefore, a considerably large amount of exposure and exposure time are required for pattern formation.

[0005]

The problems of the present invention are the following two. In the manufacturing method of (1), since the coloring composition itself has no photosensitivity, it is necessary to coat the positive resist, pattern it, and then etch it, and finally remove the unnecessary positive resist, which requires a long process and a high yield. It is disadvantageous in manufacturing, such as down. In the manufacturing method of (2), since the acrylic resin contains a dye, the sensitivity is low, and a considerable exposure amount is required.

The present invention has been made by paying attention to such a problem, and its object is to provide a highly reliable and highly sensitive photosensitive coloring composition, and as a result thereof. The present invention provides a color filter and a manufacturing method thereof.

[0007]

The present invention has been made to solve the above-mentioned problems, and uses both a benzophenone compound and an imidazole compound as a photopolymerization initiator to be added to a coloring composition. As a result, even in a coloring composition containing a dye, high sensitivity was successfully achieved and the problems of the prior art were solved.

That is, in order to mix the acrylic resin and the pigment well, they are kneaded well by using two rolls,
Chip it. Then, the chip is dissolved using a dispersant and a solvent to prepare a paste. A photopolymerizable monomer and a photosensitizer are added to this paste to obtain a photosensitive coloring composition.

The acrylic resin used at this time is 3 to 5 out of alkyl acrylates or alkyl methacrylates such as acrylic acid, methacrylic acid, methyl acrylate and methyl methacrylate, cyclic acrylates and methacrylates, hydroxyethyl acrylates and methacrylates. A resin synthesized to have a molecular weight of about 5,000 to 100,000 using about several kinds of monomers is used.

As the pigment, C.I.
I. No. 9, 97, 122, 123, 149, 16
8, 177, 180, 192, 215, etc. green (Gr
ee) as C.I. I. No. 7, 36, blue (Bl
ue) include C.I. I. No. 15, 22, 60, 64
Is commonly used. A wide range of dispersants such as surfactants, pigment intermediates, dye intermediates, and solsperses are used.

The composition ratio at the time of dispersion is not particularly limited, but the amount of the pigment added to the acrylic resin for dispersion is about 50 to 150 parts by weight, and the dispersant is 1% of the pigment.
It is about 10 parts by weight. Further, for the spectral adjustment of the color filter, arbitrary pigments are mixed and adjusted at 2-3 points.

The photopolymerizable monomer includes bifunctional, trifunctional and polyfunctional monomers, and as the bifunctional monomer,
There are 1,6-hexadiol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, etc., and as trifunctional monomers, trimethylolpropane triacrylate, pentaerythritol acrylate, tris (2-hydroxyethyl). ) There are isocyanates and the like, and as the polyfunctional monomer, there are ditrimethylolpropane tetraacrylate, dipentaerythritol penta, hexaacrylate, etc., and these monomers are available from Showa High Polymer Co., Ltd., Toa Gosei Co. There are commercial products such as stocks. Although the addition amount of the photopolymerizable monomer is not particularly limited, it is about 20 to 150 parts by weight of the acrylic resin for dispersion.

As the solvent, toluene, xylene, ethyl cellosolve, ethyl cellosolve acetate, diglyme, cyclohexanone or the like is used. However, since it depends on the monomer composition of the resin, the photopolymerizable monomer, the photopolymerization initiator, etc., a single solvent or a plurality of solvents may be used. The solvent of the composition is appropriately selected.

Further, according to the present invention, as the benzophenone compound as the photopolymerization initiator, benzophenone, chlorobenzophenone, hydroxybenzophenone,
4,4'-Dimethylaminobenzophenone, 4,4 '
-Diethylaminobenzophenone etc., especially 4,
4'-diethylaminobenzophenone is preferred.

Further, the imidazole compound is 2
-(2,3-Dichlorophenyl) -4,5-diphenyl-imidazole dimer, 2- (2,3-dichlorophenyl) -4,5-bis (3-methoxyphenyl) -imidazole dimer, 2- ( 2,3-dichlorophenyl)
-4,5-bis (4-methoxyphenyl) -imidazole dimer, 2- (2,3-dichlorophenyl) -4,
5-bis (4-chlorophenyl) -imidazole dimer, 2- (2,3-dichlorophenyl) -4,5-di (2-furyl) -imidazole, 2,2'-bis (2
-Chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1-2'-biimidazole and the like, especially 2,
2'-bis (2-chlorophenyl) -4,5,4 ',
5'-Tetraphenyl-1-2'-biimidazole is preferred.

The addition amount of the photopolymerization initiator is not particularly limited, but the addition amount of the benzophenone compound and the imidazole compound is 5 to 50 parts by weight, preferably 10 parts by weight of the benzophenone compound and the photopolymerizable monomer. ~ 30
The weight part and the imidazole compound are added in a proportion of 5 to 40 parts by weight, preferably 5 to 20 parts by weight of the acrylic resin for dispersion.

The method for producing the color filter in the present invention is described in JP-A-3-53201 and JP-A-2-199.
403, JP-A-2-199404, and JP-A-2-1445
02 etc.

[0018]

In the present invention, the sensitivity is increased by using both the benzophenone compound and the imidazole compound as the photopolymerization initiator in the coloring composition. Furthermore, the exposure time can be greatly shortened in the manufacturing process of the color filter, and a great effect such as improvement in productivity and quality is obtained as compared with the conventional technology.

[0019]

EXAMPLE A method of forming a color filter of three colors of red, green and blue on a glass substrate based on the method of the present invention will be described.

Example 1 A: Preparation of Photosensitive Coloring Composition Acrylic resin (20 parts of methacrylic acid, 10 parts of methyl methacrylate, 55 parts of butyl methacrylate, 15 parts of hydroxyethyl methacrylate and 15 parts of ethyl cellosolve 300)
g), 0.75 parts of azobisisobutylnitrile was added under a nitrogen atmosphere, and the acrylic resin obtained by the reaction at 70 ° C. for 5 hours was diluted with ethyl cellosolve to a resin concentration of 10%. To 90.1 g of this diluted resin, 9.0 g of a pigment and 0.9 g of a dispersant were added and sufficiently kneaded with a three-roll mill to prepare red, green and blue colored resins.

To 100 g of each colored resin, 0.4 g of trimethylolpropane triacrylate (monomer) 0.02 g of photopolymerization initiator Michler's ketone, 2- (2,3-dichlorophenyl) -4,5-diphenyl-imidazole dimer 0.01 g was added and well stirred to obtain a photosensitive coloring composition.

B: Preparation of Color Filter First, a blue photosensitive coloring composition 2 was spin-coated (1100 rpm, 40 sec) on a transparent substrate 1 such as glass.
And dried. After prebaking at 70 ° C. for 20 minutes, a 5% solution of polyvinyl alcohol was coated to form an oxygen barrier film 3. After drying at 70 ° C. for 20 minutes, exposure (15 mJ / cm ² ) was performed using a predetermined mask. After development with a 2.5% aqueous sodium carbonate solution, the product was thoroughly washed with water. The pigment adhering to the substrate was removed by rubbing with a soft sponge. Further, it was washed with water and dried, and then baked at 230 ° C. for 1 hour to form a pattern.

In the same manner, a green photosensitive coloring composition 4 and a red photosensitive coloring composition 5 were formed. At this time, the film thickness of each color is 1.2 μm and the exposure amount is 20 for green and 20 for red.
It was 10 mJ / cm ² .

<Comparative Example 1> In the same manner as in Example 1, blue, green and red colored resins were prepared. For 100 g of each colored resin,
Trimethylolpropane triacrylate (monomer)
0.4 g and 0.02 g of a photopolymerization initiator (Irgacure 907 manufactured by Ciba-Geigy) were added and well stirred to obtain a photosensitive coloring composition.

Thereafter, in the same manner as in Example 1, a pattern was formed in the order of blue, green and red to obtain a color filter. The exposure of each color is blue: 1200, green: 2300, red: 1000
It was mJ / cm ² .

FIG. 4 shows a spectral characteristic diagram of the blue photosensitive coloring matter of Example 1. FIG. 5 shows a spectral characteristic diagram of the blue photosensitive coloring matter of Comparative Example 1. As a result, the number of steps of the bright line having a wavelength of 365 nm was 1 in Comparative Example 1 and was 8, and the number of steps was 40.
The number of steps of the 5 nm bright line was 0 in Comparative Example 1 was 4, and the number of steps of the bright line of 365 nm wavelength was 0 in Comparative Example 1 was 1, thus significantly improving the sensitivity. I understand.

[0027]

The photosensitive coloring composition of the present invention has a very high sensitivity even in a coloring composition containing a dye by introducing both a benzophenone compound and an imidazole compound into the composition as a photopolymerization initiator. A highly photosensitive colored composition was obtained. Furthermore, the exposure time in the manufacturing process of the color filter can be significantly shortened, and a large effect such as improvement in productivity and quality can be obtained as compared with the conventional technology.

[0028]

[Brief description of drawings]

FIG. 1 is a sectional view showing a state before exposure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state after pattern formation according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a state after completion of the embodiment of the present invention.

FIG. 4 is a spectral characteristic diagram of a blue photosensitive colored material according to an example of the present invention.

FIG. 5 is a spectral characteristic diagram of a conventional blue photosensitive coloring matter.

[Explanation of symbols]

 1 Transparent Substrate 2 Blue Photosensitive Coloring Composition 3 Oxygen Barrier Film 4 Green Photosensitive Coloring Composition 5 Red Photosensitive Coloring Composition

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area G03F 7/038

Claims (3)

[Claims] 1. A photosensitive coloring composition comprising an acrylic resin, a pigment, a dispersant, a photopolymerizable monomer, a photopolymerization initiator and a solvent, wherein the photopolymerization initiator is a mixture of a benzophenone compound and an imidazole compound. A photosensitive coloring composition comprising: 2. An acrylic resin, a pigment, a dispersant, and
A step of forming a photosensitive coloring composition comprising a photopolymerizable monomer, a photopolymerization initiator which is a mixture of a benzophenone compound and an imidazole compound, and a solvent on the entire surface, and a photosensitive coloring of the exposed portion by pattern exposure on the substrate. A method for producing a color filter, which comprises a step of photocuring a composition and a step of forming a colored resin layer by leaving a photosensitive colored composition that has been developed and photocured in a pattern. 3. An acrylic resin, a pigment, a dispersant, and
A color filter provided with a pattern of a colored resin layer obtained by photocuring a photosensitive coloring composition comprising a photopolymerizable monomer, a photopolymerization initiator which is a mixture of a benzophenone compound and an imidazole compound, and a solvent.