JPH1160989A - Carbon black for forming black resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain carbon black for forming a black resist pattern, excellent in dispersibility in preparation of a photopolymerizable composition for forming a black resist pattern, consequently providing a photopolymerizable composition excellent in developing characteristics. SOLUTION: This carbon black for forming a black resist pattern is dispersed into a photopolymerizable composition comprising at least a compound (ethylenic compound) containing at least one ethylenic unsaturated double bond to be subjected to addition polymerization to induce a polymerization by a radical, an organic polymer substance (binder resin) and a polymer dispersant and used. The carbon black is obtained by coating carbon black with a polyfunctional epoxy resin and further at least one component of the constituent component of the photopolymerizable composition or a resin having compatibility with the component.

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 an excellent developing property because the surface is made insulative and excellent in dispersibility when preparing a coating solution. The present invention relates to a carbon black for forming a black resist pattern capable of providing a coating liquid of the formula (1).

[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.

The present inventor has proposed carbon black obtained by coating with a polyfunctional epoxy resin as the carbon black for the black matrix as described above (Japanese Patent Application Laid-Open No. 9-124969). Since such a resin-coated carbon black has an insulating surface,
The top coat layer in the color filter can be omitted. In particular, the above carbon black is
By using a polyfunctional epoxy resin having good wettability with the resin, the resin coating is uniformly performed even on the microscopic portion of the carbon black particles, so that the carbon black is excellent as the carbon black for the above-mentioned black matrix.

[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, it is required that the above-mentioned coating solution has excellent developing characteristics in which carbon black is well dispersed. Here, the developing property means that at the time of image exposure, ultraviolet rays reach the lower part of the photopolymerizable composition layer on the transparent substrate and are sufficiently cured, and as a result, during development, a black profile having a good profile is obtained. It means that a resist pattern 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.

The above-mentioned carbon black obtained by coating with a polyfunctional epoxy resin has excellent properties in terms of insulation and the like, but the carbon black is dispersed in a photopolymerizable composition (coating solution). The dispersibility required in the preparation is not always sufficient.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide excellent dispersibility in preparing a photopolymerizable composition for forming a black resist pattern. An object of the present invention is to provide a carbon black for forming a black resist pattern capable of providing a photopolymerizable composition having excellent developing characteristics.

[0010]

As a result of various studies, the present inventors have found that the constituents of the photopolymerizable composition are further provided on a carbon black epoxy resin coating layer coated with a polyfunctional epoxy resin. It has been found that the above object can be easily achieved by providing the second coating layer according to the above.

The present invention has been completed based on the above-mentioned findings, and the gist of the present invention is to provide a compound having at least one addition-polymerizable ethylenically unsaturated double bond whose polymerization is induced by radicals (ethylenically unsaturated double bond). A black resist pattern forming carbon black used by being dispersed in a photopolymerizable composition containing at least a compound), an organic polymer substance (binder resin) and a polymer dispersant, and coated with a polyfunctional epoxy resin. The carbon black for forming a black resist pattern is characterized in that the carbon black is further coated with at least one component of the photopolymerizable composition or a resin compatible with the component.

[0012]

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 two layers. The first coating layer is made of a polyfunctional epoxy resin. The second coating layer is a component of the photopolymerizable composition, that is, a compound (ethylenic compound) having at least one addition-polymerizable ethylenically unsaturated double bond whose polymerization is induced by a radical; It is composed of a molecular substance (binder resin) or a polymer dispersant, or a resin compatible with the component.

As a specific example of the above polyfunctional epoxy resin, a glycidylamine type epoxy resin (“Sumi Epoxy” ELM-100, 120, 434 manufactured by Sumitomo Chemical Co., Ltd.)
Etc.), triphenylglycidylmethane-type epoxy resin ("Epicoat" 1032H5 manufactured by Yuka Shell Epoxy)
0, 1032H60, etc.), tetraphenylglycidyl methane type epoxy resin (“Epicoat” 1031 manufactured by Yuka Shell Epoxy), aminophenol type epoxy resin (“Epicoat” 154, 63 manufactured by Yuka Shell Epoxy)
0), diamide diphenylmethane type epoxy resin (“Epicoat” 604, manufactured by Yuka Shell Epoxy), phenol novolak type epoxy resin (“Epicoat” 152, manufactured by Yuka Shell Epoxy), orthocresol type epoxy resin (Yukai Shell Epoxy) "Epicoat" 180S
65), bisphenol A novolak type epoxy resin (“Epicoat” 157S6 manufactured by Yuka Shell Epoxy)
5, 157S70).

The components (ethylenic compound, binder resin, polymer dispersant) of the above photopolymerizable composition are appropriately selected according to the purpose of the black resist pattern. Therefore, a resin compatible with any of the above components is also appropriately selected. In the present invention, a binder resin or a polymer dispersant is preferably used for the second coating layer.

The coating amounts of the first layer coating resin and the second layer coating resin are not particularly limited, but if the resin coating layer is too thick, the photopolymerizable composition for forming a black resist pattern ( The OD value (optical density) of the coating film formed from the coating liquid) may decrease. Therefore, the ratio of the total coating component (resin) to the total amount of the carbon black and the total coating component (resin) is preferably 40% by weight or less.

The ratio of the first layer coating layer to the second layer coating layer is not particularly limited, but the insulating property and the insulating property of the coating film formed from the photopolymerizable composition (coating solution) for forming a black resist pattern can be improved. The following ranges are preferable from the viewpoint of the dispersibility of the resin-coated carbon black when the coating liquid is formed. That is, the coating amount of the first layer coating resin is 5 to 30% by weight as the ratio of the first layer coating resin to the carbon black and the first layer coating resin, and the coating amount of the second layer coating resin is carbon black. The ratio of the resin for coating the second layer to black and the resin for coating the second layer is preferably in the range of 5 to 20% by weight.

Resin for coating the first layer (polyfunctional epoxy resin)
As a coating method, for example, a method in which a water slurry of carbon black is contained 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 an epoxy resin-coated carbon black can be obtained.

As a method of coating the resin for coating the second layer (such as a component of the photopolymerizable composition), any method such as a tumbling spraying method and an immersion method can be adopted. The same method as the method of coating is preferred.

In the present invention, it is preferable that the second coating layer composed of the components of the photopolymerizable composition is formed at a stage where the gel fraction of the polyfunctional epoxy resin of the first coating layer is 20 to 90%. The reason is that after the gel fraction of the polyfunctional epoxy resin exceeds 90%, the wettability of the components of the photopolymerizable composition is reduced, and it becomes difficult to form the second coating layer. . When the gel fraction of the polyfunctional epoxy resin is less than 20%, there is a problem in handleability when forming the second coating layer. In addition, when the gel fraction is less than 20%, the coating of the polyfunctional epoxy resin for insulating properties becomes insufficient, so that the coating formed from the photopolymerizable composition (coating solution) for forming a black resist pattern is formed. The insulation of the film may be reduced. The preferred gel fraction of the polyfunctional epoxy resin when forming the second coating layer is 30 to 70%.

The above gel fraction is such that the total oxygen content is 15 m
g / g or more and the ratio of total oxygen content / specific surface area is 0.1 mg
/ M ² or more, and the drying temperature at the time of the coating treatment of the polyfunctional epoxy resin is 40 to 13
In addition to the temperature of 0 ° C., it can be easily obtained by appropriately adjusting the draining conditions before the drying treatment and the arrangement of the resin-coated carbon black in the drying step, particularly, the layer thickness (height) and the like. That is, the functional groups (-OH, = CO, -COOH, etc.) of the carbon black defined by the total oxygen amount are as follows:
It acts as a curing agent for epoxy resin. Therefore, the gel fraction of the polyfunctional epoxy resin can be controlled by adjusting the amount of the functional group defined by the above two parameters and various curing conditions (factors).

The above gel fraction can be measured, for example, as follows. First, 10 g of epoxy resin-coated carbon black and 200 ml of tetrahydrofuran (THF) were weighed and placed in a 500 ml beaker, and stirred with a stirrer for 5 hours to completely dissolve the dissolved components.
Filter through a 6 mesh wire mesh. Next, the obtained filtrate was dried at 70 ° C. to completely remove THF, and then the residue (T
(Epoxy resin eluted with HF). The amount of the epoxy resin in the epoxy resin-coated carbon black is denoted by A, the epoxy resin eluted with THF is denoted by B, and [(A-
B) / A] × 100 (%) is used to calculate the gel fraction.

The amount of the above-mentioned oxygen functional group is a volatile component composition, the amount of a hydroxyl group or a carbonyl group is CO, and the amount of a carboxyl group is C.
It can be quantified by each measurement of O ₂ . The above-mentioned total oxygen amount means a value converted from CO and CO ₂ . In addition, the composition and amount of the volatile matter were determined by collecting a certain amount of dry carbon black in a heat-resistant sample tube, reducing the pressure to 10 ⁻² mmHg, and then placing the sample tube in an electric furnace heated to 950 ° C. It can be obtained by collecting the total amount of volatile components which are put in and desorbed in 30 minutes in a tank and subjected to gas chromatography analysis. The amounts of CO and CO ₂ can be calculated based on the results of gas chromatography analysis.

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,
It contains a photopolymerization initiation system and the like in addition to an ethylenic compound, an organic polymer substance (binder resin), and a polymer dispersant, and is used as a coating solution prepared with an appropriate solvent. The carbon black for forming a black resist pattern of the present invention exhibits excellent dispersibility when preparing the above-mentioned photopolymerizable composition, and gives a photopolymerizable composition having excellent developing characteristics.

In the method for producing 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.

The coating device includes 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.

[0026]

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.

(1) Preparation of resin-coated carbon black:
540 g of carbon black having a total oxygen amount of 30.0 mg / g and a ratio of total oxygen amount / specific surface area of 0.28 and 1450 g of pure water
Was mixed with a homomixer at 6,000 rpm for 30 minutes to prepare a slurry. On the other hand, 60 g of "Epicoat 630" manufactured by Yuka Shell Epoxy Co., Ltd.
To prepare an epoxy resin solution. A binder resin solution was prepared by dissolving 60 g of a binder resin described below in a mixed solvent of 360 g of toluene and 240 g of propylene glycol monomethyl ether acetate.

<Coating with Epoxy Resin> First, the above slurry was transferred to a container equipped with a screw type stirrer,
Under the stirring condition of 000 rpm, the above epoxy resin solution was added little by little. After about 15 minutes, all of the carbon black dispersed in the water was transferred to the toluene side, and about 1 m
m particles. Then, use a 60 mesh wire mesh for about 1
After draining for 0 minutes, width 30cm, length 70c
m, and transferred to a stainless steel vat having a height of 10 cm. At this time, the bat was filled with the resin-coated carbon black. And it dried at 70 degreeC with the vacuum dryer for 7 hours. The measurement result of the gel fraction of the epoxy resin coating layer of the obtained epoxy resin-coated carbon black was 60%.

<Coating with Binder Resin for Photopolymerizable Composition> Next, the above carbon black particles (about 1 mm)
And 1,450 g of pure water with a homomixer for 6,0
A slurry was prepared by mixing at 00 rpm for 30 minutes.
Then, a binder resin coating layer was formed on the epoxy resin coating layer by the same operation as above using the binder resin solution. The average residual toluene amount in the obtained resin-coated carbon black was 50 ppm, and the average residual water amount was 500 ppm.

(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.

Example 1 50 parts by weight of resin-coated carbon black and 5 parts by weight (as a solid content) of the binder resin obtained in the above (2) were mixed, and PGMEA was added so that the solid content concentration became 50% by weight. Thus, a dispersion was prepared. Then, the obtained dispersion 50
g was pre-stirred and then treated with a paint shaker.
The dispersion treatment was performed at 25 to 45 ° C. for 6 hours. For this dispersion treatment, zirconia beads having a diameter of 0.5 mm were used in the same weight ratio as the dispersion liquid. 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 1 to obtain a photopolymerizable composition for a black matrix (coating solution).
Was prepared. The number of grams in Table 1 is a value as a solid content.

[0034]

(A) 50 g of resin-coated carbon black (b) polymerization initiation system (1) 2,2 ′-(o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′- Biimidazole 2 g (2) Butanediol bisthiopropionate 1 g (3) 4,4'-bis- (diethylamino) benzophenone 1 g (4) 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 (“7059” manufactured by Corning Incorporated) by a spin coater, and dried at 80 ° C. for 1 minute on a hot plate. As a result of measuring the film thickness after drying with a stylus type film thickness meter, it was 1 μm.

Next, after image exposure with a high-pressure mercury lamp through a 20 μm mask, development was carried out 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 following methods were used to evaluate the dispersibility of the photopolymerizable composition for a black matrix and to measure the surface resistance of the coating film. Table 3 shows the results.

(1) Evaluation of dispersibility: The above-mentioned photopolymerizable composition for black matrix (coating solution) was coated on a glass substrate to a thickness of about 0.5 mm, and dried to form a coating film. After embedding the coating film with epoxy resin, cut out a slice of about 800 mm thick with an ultra microtome,
Observation was performed using an electron microscope at a magnification of 5000, and the evaluation was performed based on the following three criteria.

[0039]

[Table 2] ・ ・ ・: Aggregates of almost less than 0.1 μm ○: Aggregates of 0.1 to 1 μm △: Aggregates of almost more than 1 μm

(2) Surface resistance measurement: The dried coating film obtained in the above evaluation of the dispersibility was used as a measurement sample, and a surface resistance measurement device (manufactured by Co., Ltd.)
"Histar MCP-HT2" manufactured by Dia Instruments
01 ") was used to measure the surface resistance.

Comparative Example 1 A photopolymerizable composition for a black matrix was prepared in the same manner as in Example 1 except that the coating with the binder resin was omitted and the gel fraction of the epoxy resin coating layer was changed to 100%. A product (coating solution) was prepared, and development characteristics and dispersibility were evaluated and surface resistance was measured. Table 3 shows the results.

Comparative Example 2 A photopolymerizable composition for black matrix (coating solution) was prepared in the same manner as in Example 1 except that the coating with the epoxy resin was omitted. Evaluation and surface resistance measurement were performed. Table 3 shows the results.

[0043]

[Table 3]

[0044]

According to the present invention described above, the dispersibility during the preparation of the photopolymerizable composition for forming a black resist pattern is excellent, and as a result, a black polymer which can provide a photopolymerizable composition having excellent developing characteristics can be obtained. A carbon black for forming a resist pattern is provided.

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[Procedure amendment]

[Submission date] December 19, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

(2) Synthesis of polymer dispersant: Tolylene diisocyanate trimer ("Mitec GP750A" manufactured by Mitsubishi Chemical Corporation; resin solid content 50% by weight, butyl acetate solution) 32 g 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] 0031

[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 compound (ethylenic compound) having at least one ethylenically unsaturated double bond capable of being polymerized by radicals, an organic polymer substance (binder resin), and a polymer dispersant. A black resist pattern-forming carbon black used by being dispersed in a photopolymerizable composition containing at least one component of the above photopolymerizable composition after coating with a polyfunctional epoxy resin. Or carbon black for forming a black resist pattern, which is coated with a resin compatible with the component. 2. The method according to claim 1, wherein the second coating layer composed of the constituents of the photopolymerizable composition is formed at a stage where the gel fraction of the polyfunctional epoxy resin of the first coating layer is 20 to 70%. Carbon black. 3. The coating amount of the first layer coating resin is 5 to 30% by weight as the ratio of carbon black and the first layer coating resin to the first layer coating resin, and the coating amount of the second layer coating resin is The carbon black according to claim 1, wherein the ratio of the second layer coating resin to the carbon black and the second layer coating resin is in the range of 5 to 20% by weight.