JPH1180584A - Carbon black for forming black resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject carbon black that gives a coating solution with a good developing properties by covering carbon black containing different kinds of particles having different average primary particle sizes where the weight ratio of the maximum particle size to the minimum particle size is specified with a resin. SOLUTION: Carbon black that contains 2 or more kinds of carbon blacks different in the average particle size by at least 20 nm and has the weight ratio of the particles having the maximum particle size to those having the minimum particle size of 1/(0.1-10) and pure water are mixed with a homo-mixer to prepare a slurry. Then, the slurry is charged into a vessel equipped with a screw type stirring machine, and an epoxy resin solution in toluene is added gradually under stirring until the carbon black dispersed in water is transferred to the toluene phase, then the carbon black is drained on a wire screen of 60 mesh and dried in a vacuum drier whereby the objective carbon black for forming black resist patterns is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon black for forming a black resist pattern, and more particularly to a carbon black having an insulative surface and excellent dispersibility in preparing a coating solution, and excellent developing characteristics. The present invention relates to a carbon black for forming a black resist pattern which can provide a coating liquid.

[0002]

2. Description of the Related Art Carbon black is utilized for forming black resist patterns of various optical elements by utilizing its excellent blackness. For example, an optical color filter is an optical element suitably used for a color television, a liquid crystal display element, a camera, and the like, and is provided on a surface of a transparent substrate provided with a black resist pattern (black matrix).
Red, green and blue, three different hues, 10-150μ
It is manufactured by forming a color pattern such as an m-width stripe or mosaic with an accuracy of several μm.

[0003] The above-mentioned black matrix is formed by applying a photopolymerizable composition (coating liquid) in which carbon black is dispersed on a transparent substrate, and then performing each of heating, drying, image exposure, development and heat curing. You can do it.

[0004] The above-mentioned color filter is basically formed by applying a photopolymerizable composition (coating solution) in which red, green and blue materials are respectively dispersed on a surface on which a black matrix is formed, and heating the composition. It can be manufactured by sequentially performing drying, image exposure, development, and heat curing to form a pixel image of each color (Japanese Patent Laid-Open No. 2-902).
Counter electrode (transparent electrode) for driving color filter
Is formed in a thin film form on the pixel image surface from ITO or the like.

[0005] In actual production of a color filter, a top coat layer of polyamide, polyimide or the like is provided on the pixel image surface. Such a top coat layer is
It is required for the purpose of electrical insulation between the black matrix and the transparent electrode and enhancement of the smoothness of the pixel image surface.

One of the present inventors has proposed a carbon black obtained by coating with a resin as the above-described carbon black for the black matrix (Japanese Patent Application Laid-Open No. 9-7).
Nos. 1733 and 9-95625 and 9-12
No. 4969). Since the above-mentioned carbon black is coated with a resin, it has features such as an insulating surface and excellent dispersibility in preparing a coating solution. Therefore, the use of the above carbon black can omit the top coat layer in the color filter.

[0007] The black resist pattern is not limited to the above-described black matrix, but may be formed by applying a photopolymerizable composition (coating solution) in which carbon black is dispersed onto a transparent substrate, and then performing image exposure and development. It is formed by performing processing. Therefore, the above-mentioned coating liquid is required to have excellent developing characteristics. Here, the development characteristics are that, at the time of image exposure, ultraviolet rays reach the lower part of the photopolymerizable composition layer on the transparent substrate, and sufficient curing is performed. As a result, during development,
This means that a black resist pattern having a good profile is formed. Such development characteristics can be evaluated based on the length of development time capable of maintaining a pattern having a constant line width during development. In other words, it means that the longer the developing time, the more the curing treatment by the ultraviolet rays is performed.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a carbon black for forming a black resist pattern, the surface of which is made insulative, and which is used when preparing a coating solution. An object of the present invention is to provide the above carbon black which has excellent dispersibility and can provide a coating solution having excellent developing characteristics.

[0009]

As a result of various studies, the present inventors have found that the above object can be easily achieved by using two or more carbon blacks having different average primary particle diameters. Was obtained. The present invention has been completed based on such findings, and the gist of the present invention is that two or more types of carbon black having an average primary particle diameter different from each other by at least 20 nm, a carbon black having a maximum particle diameter and a carbon black having a minimum particle diameter Weight ratio of 1: 0.1 to 10
And carbon black for forming a black resist pattern, wherein each carbon black is coated with a resin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The carbon black for forming a black resist pattern of the present invention is formed by coating with a resin. In the present invention, it is important to use two or more carbon blacks having different average primary particle diameters.

The average primary particle size of the carbon black is usually in the range of 10 to 300 nm. Therefore, the carbon black used in the present invention is selected from those having the above average primary particle size. In the present invention, the difference between the average primary particle diameters of two or more carbon blacks must be 20 nm or more. When the difference between the average primary particle diameters is less than 20 nm, two or more carbon blacks are used. The significance is so weak that a coating liquid having excellent developing characteristics cannot be obtained. In addition, the OD value (optical density) and insulation of a coating film formed from the photopolymerizable composition (coating solution) for forming a black resist pattern are reduced. The difference in the average primary particle diameter is preferably 30 nm or more.

In the present invention, the weight ratio of the maximum particle diameter carbon black (CBmax) to the minimum particle diameter carbon black (CBmin) is at least 1: Must be between 0.1 and 10. The preferred weight ratio of CBmax to CBmin is in the range from 1: 0.5 to 5.

In the present invention, two types of carbon blacks having different average primary particle diameters are usually used.
Carbon black having a particle size distribution having two peaks is used. In this case, the average primary particle diameter of one carbon black is selected from the range of 10 to 40 nm, and the average primary particle diameter of the other carbon black is selected from the range of 45 to 300 nm. Is preferred.

[0014] Two or more types of carbon blacks having different average primary particle diameters are produced in the production process by using a reactor having a plurality of feed oil supply ports to vary the residence time of each feed oil. I can do it. Alternatively, two or more types of carbon blacks having different average primary particle diameters manufactured by changing the residence time of the feedstock oil may be mixed and prepared. The average primary particle diameter can be determined by taking an electron micrograph at a magnification of tens of thousands, measuring thousands of particles, and calculating the average value.

The resin used for coating the above carbon black is not particularly limited, and is disclosed in JP-A-9-71733, JP-A-9-95625 and JP-A-9-124969.
Various resins described in Japanese Patent Application Laid-Open No. H10-208 can be appropriately selected and used. In particular, a polyfunctional epoxy resin described in JP-A-9-124969 is recommended.

Specific examples of the polyfunctional epoxy resin include glycidylamine type epoxy resins (“Sumiepoxy” ELM-100, 120, 434, etc., manufactured by Sumitomo Chemical Co., Ltd.), and triphenylglycidylmethane type epoxy resins (Yuika Shell Epoxy) "Epicoat" 1032H50, 1032
H60 etc.), tetraphenyl glycidyl methane type epoxy resin (“Epicoat” 103 manufactured by Yuka Shell Epoxy)
1), aminophenol-type epoxy resin (“Epicoat” 154, 630 manufactured by Yuka Shell Epoxy), diamide diphenylmethane type epoxy resin (“Epicoat” 604 manufactured by Yuka Shell Epoxy), phenol novolak-type epoxy resin (oiled shell) Epoxy "Epicoat"
152), ortho-cresol type epoxy resin (“Epicoat” 180S65 manufactured by Yuka Shell Epoxy), bisphenol A novolak type epoxy resin (“Epicoat” 157S65, 157S70 manufactured by Yuka Shell Epoxy)
And the like. These epoxy resins are used together with a curing agent and a curing accelerator according to a conventional method.

The amount of the resin coated on the carbon black is generally selected from the range of 5 to 40% by weight as the ratio of the resin to the total amount of the carbon black and the resin.
As the coating method, for example, a method in which a water slurry of carbon black is housed in a container equipped with a screw type stirrer and a resin solution is added little by little under stirring conditions can be adopted. By such a treatment, the carbon black dispersed in the water migrates to the resin solution side and becomes particles of about 1 mm.
Thereafter, draining is performed, and then the solvent and water are removed by vacuum drying, whereby a resin-coated carbon black can be obtained.

The carbon black for forming a black resist pattern of the present invention is used as a photopolymerizable composition in which carbon black is dispersed. Such a photopolymerizable composition,
A photopolymerization initiation system that absorbs light to generate a radical together with carbon black, and a compound (ethylenic compound) having at least one addition-polymerizable ethylenically unsaturated double bond induced by the radical to induce polymerization. It contains. In addition, the above composition contains a dispersant and the like as necessary together with the organic polymer substance (binder resin). Then, the above composition is used as a coating solution prepared with a suitable solvent. The above-mentioned photopolymerization initiation system, ethylenic compound, organic polymer substance and solvent are appropriately selected according to the purpose of the black resist pattern.

In the method for manufacturing a color filter,
After applying the above-mentioned photopolymerizable composition on a transparent substrate, each process of heat drying, image exposure, development, and thermosetting is performed to form a black matrix.

Examples of the coating device include a spinner, a wire bar, a flow coater, a die coater, a roll coater,
A spray or the like is used. The image exposure is performed by guiding a negative matrix pattern mask on the photopolymerizable layer and irradiating an ultraviolet or visible light source through the pattern mask. As the alkali developer, for example, an inorganic alkali agent such as sodium carbonate, potassium carbonate, sodium silicate, potassium silicate, sodium hydroxide, and potassium hydroxide is used.

[0021]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the following examples, the following materials were used.

(1) Preparation of resin-coated carbon black:
A slurry was prepared by mixing 540 g of carbon black having two types of primary average particle diameters shown in Table 1 and 1450 g of pure water at 6,000 rpm for 30 minutes using a homomixer. On the other hand, "Epicoat 63" manufactured by Yuka Shell Epoxy Co., Ltd.
“0” was dissolved in 600 g of toluene to prepare an epoxy resin solution. The above slurry was transferred to a container equipped with a screw type stirrer, and the above epoxy resin solution was added little by little under stirring conditions of about 1,000 rpm. After about 15 minutes, all of the carbon black dispersed in the water was transferred to the toluene side to become particles of about 1 mm. Then, 6
After draining with a 0-mesh wire net, it was dried with a vacuum drier at 70 ° C. for 7 hours to remove water and toluene. The average residual toluene amount in the obtained resin-coated carbon black was 50 ppm, and the average residual water amount was 500 ppm.

[0023]

[Table 1]

(2) Synthesis of Binder Resin: 32 g of trimer of tolylene diisocyanate (“Mitec GP750A” manufactured by Mitsubishi Chemical Corporation: resin solid content of 50% by weight, butyl acetate solution) and dibutyltin dilaurate as a catalyst 0.02 g was dissolved in 47 g of propylene glycol monomethyl ether acetate (PGMEA). Then
Under stirring conditions, polyethylene glycol having a methoxy group at one end (“UNIOX M” manufactured by NOF CORPORATION)
A mixture of 14.4 g of “-1000”: molecular weight of 1,000) and 9.6 g of polypropylene glycol (“Sannicks PP-1000”, manufactured by Sanyo Chemical Industries, Ltd .: molecular weight of 1,000) was dropped at 70 ° C. The reaction was further performed for 3 hours. The reaction was then added to N, N-dimethylamino-
After 1 g of 1,3-propanediamine was added, the mixture was further reacted at 40 ° C. for 1 hour. The amine value of the obtained dispersion resin-containing solution was determined by neutralization titration, and as a result, 14 mgKOH /
g. Further, as a result of obtaining a resin content by a dry-up method of removing a solvent by a hot plate at 150 ° C. for 30 minutes and calculating a resin concentration by a weight change amount,
It was 40% by weight.

(3) Synthesis of polymer dispersant: styrene / acrylic acid resin (acid value 200, molecular weight 5,000) 20
g, p-methoxyphenol 0.2 g, dodecyltrimethylammonium chloride 0.2 g, PGMEA 40 g
Was charged into a flask, 7.6 g of (3,4-epoxycyclohexyl) methyl acrylate was added dropwise, and the mixture was reacted at a temperature of 100 ° C. for 30 hours. Next, the reaction solution was reprecipitated with water, and the recovered resin was dried. The acid value of the obtained resin determined by neutralization titration with KOH was 80.

Examples 1 to 5 and Comparative Examples 1 to 5 50 parts by weight of each of the various resin-coated carbon blacks obtained in the above (1) and the binder resin 5 obtained in the above (2)
Parts by weight (as a solid content) and a solid content concentration of 50
A dispersion was prepared by adding PGMEA so as to obtain a weight%. Next, 50 g of the obtained dispersion liquid was subjected to a preliminary stirring treatment, and then subjected to a dispersion treatment at 25 to 45 ° C for 6 hours by a paint shaker. This dispersion treatment has a diameter of 0.5 m.
m of zirconia beads were used in the same weight ratio as the dispersion. After the dispersion treatment, the dispersion liquid and the beads were separated by a filter.

Next, the above resin-coated carbon black dispersion ink was used and mixed with the components shown in Table 2 to obtain a photopolymerizable composition for a black matrix (coating solution).
Was prepared. The g number in Table 2 is a value as a solid content.

[0028]

(A) 50 g of resin-coated carbon black (b) 2 g of polymerization initiation system 2,2 ′-(o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole Butanediol bisthiopropionate 1 g 4,4'-bis- (diethylamino) benzophenone 1 g 2-mercaptobenzothiazole 1 g (c) Binder resin (see (2) above) 25 g (d) Dipentaerythritol hexaacrylate 15 g (e ) Propylene glycol monomethyl ether acetate (solvent) 300 g (f) Polymer dispersant (see (3) above) 5 g

Next, the above-mentioned photopolymerizable composition for black matrix (coating solution) was applied to a glass substrate (Corning Co., Ltd. “7059”) using a spin coater, and dried at 80 ° C. for 1 minute using a hot plate. It was 1 μm as a result of measuring the film thickness after drying with a stylus type film thickness meter.

Then, after image exposure with a high-pressure mercury lamp through a 20 μm mask, development was performed by immersion in a 0.05% by weight aqueous sodium hydroxide solution at 25 ° C. On this occasion,
The development time required to form and maintain a resist pattern having a width of 20 ± 1 μm corresponding to the mask dimension of 20 μm was measured. The longer the development time, the more the curing by exposure is performed, and the better the developability. Table 3 shows the results.

Separately, the above-mentioned photopolymerizable composition for black matrix (coating solution) is coated on a glass substrate by about 1.0
After coating to a thickness of μm, it was dried to form a coating film, which was subjected to OD value measurement and surface resistance measurement by the following methods. Table 3 shows the results.

(1) Measurement of OD value: The OD value of the dried coating film was measured by a Macbeth reflection densitometer (“RD-914” manufactured by Sakata Inx).

(2) Surface resistance measurement: Surface resistance measuring device ("Histar MCP" manufactured by Dia Instruments Co., Ltd.)
-HT210 "), the surface resistance of the dried coating film was measured.

[0034]

[Table 3]

[0035]

According to the present invention as described above, a carbon black for forming a black resist pattern, which has an insulative surface, has excellent dispersibility in preparing a coating solution, and has excellent developing characteristics. A carbon black as described above is provided which can provide a liquid.

[Procedure amendment]

[Submission date] December 19, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction contents]

(2) Synthesis of polymer dispersant: 32 g of trimer of tolylene diisocyanate (“Mitec GP75OA” manufactured by Mitsubishi Chemical Corporation: resin solid content of 50% by weight, butyl acetate solution) and dibutyl as a catalyst 0.02 g of tindyl laurate was dissolved in 47 g of propylene glycol monomethyl ether acetate (PGMEA). Then
Under stirring conditions, polyethylene glycol having a methoxy group at one end (“UNIOX M” manufactured by NOF CORPORATION)
A mixture of 14.4 g of “-1000”: molecular weight of 1,000) and 9.6 g of polypropylene glycol (“Sannicks PP-1000”, manufactured by Sanyo Chemical Industries, Ltd .: molecular weight of 1,000) was dropped at 70 ° C. The reaction was further performed for 3 hours. The reaction was then added to N, N-dimethylamino-
After 1 g of 1,3-propanediamine was added, the mixture was further reacted at 40 ° C. for 1 hour. The amine value of the obtained dispersion resin-containing solution was determined by neutralization titration, and as a result, 14 mgKOH /
g. Further, as a result of obtaining a resin content by a dry-up method of removing a solvent by a hot plate at 150 ° C. for 30 minutes and calculating a resin concentration by a weight change amount,
It was 40% by weight.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Correction contents]

(3) Synthesis of binder resin: styrene
Acrylic resin (acid value 200, molecular weight 5,000) 20
g, p-methoxyphenol 0.2 g, dodecyltrimethylammonium chloride 0.2 g, PGMEA 40 g
Was charged into a flask, 7.6 g of (3,4-epoxycyclohexyl) methyl acrylate was added dropwise, and the mixture was reacted at a temperature of 100 ° C. for 30 hours. Next, the reaction solution was reprecipitated with water, and the recovered resin was dried. The acid value of the obtained resin determined by neutralization titration with KOH was 80.

Claims (3)

[Claims] Claims: 1. A composition comprising two or more carbon blacks having an average primary particle diameter different by at least 20 nm, wherein the weight ratio of the maximum particle diameter carbon black to the minimum particle diameter carbon black is 1: 0.1 to 10, and A carbon black for forming a black resist pattern, wherein each carbon black is coated with a resin. 2. Carbon black having an average primary particle diameter of 10
The carbon black according to claim 1, wherein the carbon black is selected from the range of from about 300 nm to about 300 nm, and has a difference in average primary particle diameter of 30 nm or more. 3. The carbon black is composed of two kinds having different average primary particle diameters, one of the carbon blacks has an average primary particle diameter of 10 to 40 nm, and the other carbon black has an average primary particle diameter of 45 to 300 nm. The carbon black according to claim 1, wherein the difference in the average primary particle diameter is 30 nm or more.