JPH0834923A - Black photosensitive resin composition and manufacture of black matrix - Google Patents

Abstract

PURPOSE:To obtain the composition capable of forming an excellent coating film, having excellent dispersion of pigment and light shielding properties and useful for a black matrix by compounding a photosensitive polymer, a dyeable polymer, a dispersant, a coloring pigment and a black dye. CONSTITUTION:This composition is composed of (A) a photosensitive polymer (preferably, a combination of a binder resin with a photo-crosslinking agent), (B) a dyeable polymer (preferably, casein, glue, polyvinyl alcohol, etc.), (C) a dispersant (e.g. an ionic surfactant, a nonionic surfactant, various kinds of polymers, etc.), (D) a coloring pigment (e.g. an organic pigment or an inorganic pigment; carbon black is not preferable) and (E) a black dye (e.g. Direct fast black D((R), etc., of a direct dye). Further, a black matrix is obtained by coating the composition on a transparent base board, exposing light through a mask of a desired pattern, developing this and coloring the obtained pattern with a black dye.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a black matrix for forming a color filter of a color liquid crystal display device and a photosensitive colored resin composition used for producing the black matrix.

[0002]

2. Description of the Related Art Conventionally, a metal vapor deposition film of aluminum, chromium or the like has been used as a black matrix in a color liquid crystal display device. However, this metal vapor deposition film has a problem that pinholes are likely to occur and that a step is formed between the black matrix portion and other filter portions.

Therefore, in order to solve such a problem, a method of forming a black matrix with an organic film has been proposed.
For example, Japanese Patent Application Laid-Open No. 4-63870 discloses a resist in which a pigment composed of a combination of carbon black and a plurality of different coloring pigments is dispersed. In this resist, a resist coating film is formed on a transparent substrate by a method such as a spin coater, and then a pattern is formed by a photolithography method, similarly to a usual colored color resist.

However, in the above invention, since the pigment is used as the colorant, the pigment concentration must be increased in order to improve the light-shielding property, which deteriorates the coating property and causes the film thickness when the coating film is formed. Distribution tends to occur. Further, in the above-mentioned invention, the pattern is formed by the photolithography method, but since the black matrix has a light-shielding property, the amount of light at the photoreactive site in the coating film is small and the crosslinking efficiency is reduced. If the amount of light required for photocrosslinking cannot be obtained, the pattern will be dissolved during development and peeled off. Further, if the photocrosslinking efficiency is low, the exposure amount required for forming the color filter pattern is large, that is, a considerable exposure time is required. This becomes more remarkable as the light-shielding property of the black matrix becomes higher, that is, the transmittance becomes lower, and such a black color resist requires an exposure amount 3 to 10 times that of the colored color resist. On the contrary, if the transmittance is increased, the photocrosslinking efficiency is certainly improved, but the light-shielding property is lowered, and the improvement of the contrast which is the purpose of the light-shielding color resist is deteriorated.

[0005]

An object of the present invention is to provide a black photosensitive material which does not change the light-shielding property, lowers the pigment concentration in the coating film, and can improve the coating property of the coating film and the dispersibility of the pigment. A resin composition and a method capable of forming a black matrix with a low exposure amount without deteriorating the light-shielding property.

[0006]

As a result of earnest research in view of the above problems, the inventors of the present invention have found that the pigment in the coating film can be used without changing the light-shielding property by using not only a coloring pigment but also a black dye. It was found that the concentration can be kept low and the coating property of the coating film and the dispersibility of the pigment can be improved, and when a black matrix is produced using them, first, a coloring pigment or the like is coated / formed and exposed, Then, the present invention has been completed by finding that the black matrix can be formed with a low exposure amount without lowering the light-shielding property by dyeing with a black dye.

That is, the present invention is a black photosensitive resin composition containing a photosensitive polymer, a dyeable polymer, a dispersant, a color pigment and a black dye.
Further, the present invention, a photosensitive polymer, a dyeable polymer, a photosensitive resin composition containing a dispersant and a color pigment is applied on a transparent substrate, through a mask of a desired pattern, exposure,
It is a method for producing a black matrix, which comprises developing and coloring the obtained pattern with a black dye.

The present invention will be described in detail below.

[A] Black Photosensitive Resin Composition The black photosensitive resin composition of the present invention contains a photosensitive polymer, a dyeable polymer, a dispersant, a coloring pigment and a black dye. Hereinafter, each component will be described in detail.

(1) Photosensitive Polymer As the photosensitive polymer in the present invention, a combination of a binder resin and a photocrosslinking agent can be used. As the binder resin, for example, polyvinyl alcohol, polyvinylpyrrolidone, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-
Examples thereof include hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, polyacrylamide and the like.

As the photo-crosslinking agent, diazo compounds, azide compounds and the like are preferably used. The diazo compound in the present invention means a compound having one, preferably two or more diazo salts in one molecule, and preferably an aromatic diazo compound is used. Specific examples of the aromatic diazo compound include p-diazodiphenylamine, 2,5-dimethoxy-4-p-tolylmercaptonbenzenediazonium or 2,5-dimethoxy-4-morpholinobenzenediazonium and formaldehyde condensate. Is mentioned.

The azide compound in the present invention means a compound having one, preferably two or more azide salts in one molecule. The azide compound is usually used in the form of sulfonic acid or sulfonate. Examples of such an azide compound include sodium 4,4-diazidosturbene-2,2'-disulfonate, 2,6-bis (4-azidobenzal) acetone 2-sulfonic acid, and 2,6-bis ( 4-azidobenzal) acetone 2,2′-disulfonic acid,
2,6bis (4-azidobenzal) cyclohexanone-2-2'-disulfonic acid, 2,6bis (4-azidobenzal) methylcyclohexanone-2,2'-disulfonic acid and the like can be mentioned.

The amount of the diazo compound or the azide compound added is preferably large in view of the crosslinking efficiency, but if it is too large, the dispersibility of the pigment is deteriorated. Therefore, it is preferable to add 1 to 30% by weight to the binder resin (solid content). Since these photo-crosslinking agents are highly reactive, it is preferable to add them to the binder resin immediately before they are actually used. The content of the photosensitive polymer in 100 parts by weight of the black photosensitive resin composition is preferably 2 to 25 parts by weight. If it is less than 2 parts by weight, the sensitivity to light is low, and if it exceeds 25 parts by weight, the viscosity increases and the coating property on the substrate decreases.

(2) Dyeable polymer In the present invention, the dyeable polymer means that when a suitable dye (specifically described later) is added, a dye molecule is adsorbed to a specific functional group of the polymer. However, it refers to a polymer that is colored by optical absorption of the dye molecule. Examples of such dyeable polymer include homopolymers or copolymers of casein, glue, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide and the like. In particular, among the above, polyvinyl alcohol, which also functions as a binder resin, polyvinylpyrrolidone,
Polyacrylamide, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are preferred. The content of the dyeable polymer in 100 parts by weight of the black photosensitive resin composition is preferably 5 to 20 parts by weight. If the amount is less than 5 parts by weight, the effect of the present invention is difficult to obtain, and
When it exceeds the weight part, the coating property on the substrate is deteriorated.

(3) Dispersant Examples of the dispersant include ionic surfactants, nonionic surfactants and various polymers. The ionic surfactants include cationic surfactants and anionic surfactants. There are agents and amphoteric surfactants.

Examples of the cationic surfactant include, for example,
Aliphatic amines, quaternary ammonium salts, alkylpyridinium salts and the like can be mentioned. Anionic surfactants include, for example, fatty acid salts, sulfuric acid esters, sulfonates, phosphoric acid esters and the like, and amphoteric surface active agents. Examples of the agent include amino acid salts and the like. Examples of the nonionic surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, and the like.

Further, as the dispersant comprising a polymer,
Alkyd resin, epoxy, epoxy ester, vinyl resin, butyral resin, polyurethane, acrylic resin,
Polyester resin, silicone resin, water-soluble resin, etc. are available. These dispersants may be used as a mixture, or after being dispersed alone, another type may be added and used. For chemical stability, it is preferred to disperse the pigment first with a low molecular weight surfactant and then add the polymer dispersant.

The content of the dispersant in 100 parts by weight of the black photosensitive resin composition is preferably 0.5 to 40 parts by weight. When it is less than 0.5 part by weight, the dispersibility of the pigment is poor, and when it exceeds 40 parts by weight, the coating property on the substrate is deteriorated.

(4) Coloring Pigment As the coloring pigment, an organic pigment is mainly used, but an inorganic pigment may be used, and both may be used. As the organic pigment, azo lake type, insoluble azo type, condensed azo type, phthalocyanine type, quinacridone type,
There are dioxazine-based, isoindolinone-based, anthraquinone-based, perinone-based, thioindico-based, perylene-based, and the like. Examples of the inorganic pigment include carbon black, titanium oxide, milori blue, cobalt violet, manganese violet, ultramarine blue, navy blue, cobalt blue, cerulean blue and viridian. Carbon black has a high light-shielding property by itself, and it takes a long time to expose the photosensitive composition.
It is preferably not used. In this case, the light-shielding property can be maintained by using a large amount of black dye described below.

The above color pigments can be used alone or in combination. Further, in order to obtain a black color by using the above color pigment, it is preferable to use it in combination with a pigment having a complementary color relationship with each other to obtain a pseudo black color. Examples of complementary colors include red and blue-green, purple and green, and yellow and blue. The content of the pigment in 100 parts by weight of the black photosensitive resin composition is preferably 30 parts by weight or less. If it exceeds 30 parts by weight, dispersion stability deteriorates. The ratio of the pigment to the dispersant is preferably 1: 0.2 to 1:10. Since the photosensitive resin composition of the present invention has a dye in addition to the color pigment, the addition amount of the color pigment can be suppressed to be small and the dispersibility of the pigment can be improved.

(5) Dye The dye used in the present invention, when applied to a pattern obtained by exposing and developing a photosensitive resin composition, exhibits a black color by adsorbing to the dyeable polymer described above. is there. Examples of such black dyes include direct fast black D which is a direct dye, acid first black VLG which is an acid dye, acid black WA which is a 1: 1 type metal complex salt dye, chrome black P2B which is a chrome dye, and chrome. Examples thereof include Black T and Reactive Black B which is a reactive dye.

The preferred combination with the dyeable polymer is a combination of casein or glue with Direct First Black D, polyvinyl alcohol or 2
-A combination of hydroxyethyl methacrylate and Acid First Black VLG or Acid Black WA, a combination of polyacrylamide and Chrome Black P2B or Chrome Black T, and a combination of polyvinyl alcohol and Reactive Black B.

The content of the black dye in the black photosensitive resin composition may be appropriately adjusted so that the coating film has a desired light-shielding property, that is, in accordance with the addition amount of the color pigment.
It is preferably about 20 to 20% by weight, particularly preferably about 3 to 10% by weight.

[B] Method for Manufacturing Black Matrix The method for manufacturing the black matrix of the present invention will be described below.

(1) Preparation of Photosensitive Resin Composition The above-mentioned photosensitive polymer, dyeable polymer, dispersant and color pigment are dispersed in a solvent in a predetermined weight ratio. As the solvent, water, organic solvents such as alcohol, benzene, toluene, cyclohexane, methyl ethyl ketone, acetone, ethyl cellosolve and the like can be used. The dispersion may be carried out by an ordinary method using a three roll mill, a ball mill, a sand mill, a homogenizer, a pigment disperser such as an ultrasonic disperser, or the like. The coloring composition (coloring pigment or a dispersion liquid in which the coloring pigment is dispersed) may be used in a single color, but may be toned with a plurality of coloring compositions in order to exhibit good color characteristics.

(2) Coating of photosensitive resin composition / formation of pattern The photosensitive resin composition obtained as described above is coated on a transparent substrate such as glass by a coating machine such as a spin coater or a roll coater. Apply to form a coating film. At this time, the coating film is formed with a thickness such that the transmittance is higher than the target transmittance in consideration of dyeing later. Specifically, a film thickness (calculated from Lambert-Beer's law) that is 1.5 to 5 times the desired transmittance is preferable. In the photosensitive resin composition of the present invention, since the concentration of the color pigment can be suppressed to a low level, the viscosity is small and the coatability is good.

Next, the photosensitive resin coating film thus formed is irradiated with ultraviolet rays through a mask having a predetermined pattern. The exposure amount is about 200 to 2000 mJ / cm ² .
When carbon black was not used as the color pigment in the photosensitive resin composition, the exposure amount was 400
It is about mJ / cm ^2, which is much shorter than the case where carbon black is used.

When the photosensitive resin thus exposed through the mask is developed, a pattern is formed only on the exposed portion, and the portion covered by the mask is washed away. As the developing solution, an aqueous developing solution such as dilute acetic acid aqueous solution or malic acid aqueous solution, or an alkaline developing solution such as sodium carbonate aqueous solution or potassium carbonate aqueous solution may be used.

(3) Dyeing The coating film pattern obtained as described above is dyed with a black dye. Dyeing may be carried out by a conventional method, and usually the substrate may be immersed in the dye. The immersion time may be adjusted so that the coating film has a desired light-shielding property. Specifically, it is preferably 3 to 20 minutes, particularly preferably 5 to 10 minutes.

When an acid dye is used as the dye, it is preferable to appropriately adjust pH and temperature in consideration of dyeing efficiency. The pH is preferably 3 to 5 so that the physical properties of the coating film formed do not change, and is preferably around 4. The temperature is preferably 20 to 50 ° C, and particularly preferably 25 to 35 ° C.
Acids that can be used to adjust the pH include acetic acid, citric acid, malic acid, tartaric acid, and the like, and salts include ammonium sulfate, ammonium sulfonate, ammonium nitrate, and the like.

The black matrix obtained as described above has a sufficient light shielding property due to the color pigment and the dye.

[0032]

By using the photosensitive resin composition of the present invention, the pigment concentration in the coating film can be suppressed to a low level,
The coating property of the coating film can be improved without lowering the light-shielding property. Further, according to the method for producing a black matrix of the present invention, the coating film can be dyed with a dye after exposure to obtain a desired light-shielding property, so that the transmittance of the coating film during exposure is high (the light-shielding property is low). ) It can be maintained and the amount of UV irradiation required for exposure can be reduced.

[0033]

The present invention will be described in more detail below with reference to examples, but these examples do not limit the scope of the present invention.

Example 1 In this example, the coatability of the photosensitive resin composition was examined as follows. Acid dye PC-Black 205D (Nippon Kayaku Co., Ltd.) as a black dye
Manufactured by Dainippon Ink Co., Ltd. and Fastogen Super Violet RVS (manufactured by Dainippon Ink Co., Ltd.) as the blue and purple pigments, respectively. Time dispersion was performed. At this time, 2 mmφ glass beads were used as the medium. PC-Black 205D 5% by weight Fastogen Blue TGR 6% by weight Fastogen Super Violet RVS 4% by weight Polyoxyethylene alkylphenyl ether 5% by weight Water 80% by weight Then, 100 parts by weight of the above colored resin composition was added with 2-hydroxyethylmethacrylate. 45 parts by weight of a 10% aqueous solution was added, and further 1 part by weight of p-diazodiphenylamine was added.

The black resin composition thus obtained was evaluated for light-shielding property and coating property. The light-shielding property was measured by measuring the transmittance. Maximum transmittance is 0.8
It was 1.5% in visible light (700 nm). A yield value is used as a representative numerical value representing the coating property. This yield value is a value obtained by extrapolating the shear stress to a shear rate of 0 by changing the shear rate of viscosity, and this value is The larger the value, the higher the thixotropy and the poorer the coating property, so that the film thickness distribution is likely to occur.

The yield value is the E-type viscometer (manufactured by TOKIMEC Co., Ltd.)
Was used to measure the viscosity and the Casson plot was used.
As a result, the yield value was 10 mPa.

Comparative Example 1 A black resin composition was prepared in the same manner as in Example 1 except that the same amount of carbon black (MA 100, manufactured by Mitsubishi Kasei Co., Ltd.) was used instead of the black dye.
The maximum transmittance and the yield value of the obtained composition were determined in the same manner as in Example 1. The results were 1.5% and 100%, respectively.
It was mPa. When the yield value is large as described above, the coating property is poor and a film thickness distribution is generated when the substrate is coated.

As is clear from the results of Example 1 and Comparative Example 1, the black resin composition prepared by using the dye and the pigment is the black resin composition prepared by using only the pigment so as to have the same light-shielding property. The yield value is very low compared to
Excellent coatability.

(Example 2) Three kinds of organic pigments (black: carbon black (MA 100, manufactured by Mitsubishi Kasei Co., Ltd.), blue: phthalocyanine blue (Fastogen Blue TGR, Dainippon Ink)
Co., Ltd., purple: Dioxazine violet (Fastogen
Super Violet RVS, manufactured by Dainippon Ink and Chemicals, Inc.) was dispersed in water using the nonionic surfactant polyoxyethylene alkylphenyl ether at the following compounding ratios. Organic pigment 20% by weight Polyoxyethylene alkylphenyl ether 5% by weight Water 75% by weight To the resulting pigment dispersion, 10% aqueous solution of 2-hydroxyethyl methacrylate (HEMA), polyoxyethylene alkylphenyl ether and water, The following composition ratios were added. Pigment dispersion 8% by weight Polyoxyethylene alkylphenyl ether 2% by weight HEMA 8% by weight Water 82% by weight Each of the resulting colored pastes has a ratio (weight ratio) of black: blue: purple of 1: 3: 1. As mixed. To impart photosensitivity to this colored composition, 10% by weight (based on HEMA) of p-diazodiphenylamine was added.

The above-mentioned photosensitive resist was applied to a non-alkali glass substrate by a spin coater. At this time, the film thickness was 0.8 μm, and the maximum transmittance in visible light (700 nm) was 4.0%. Further, there was no film thickness distribution, and a good coating film could be formed. For the obtained coating film,
Prebaking was carried out at 50 ° C. for 3 minutes, and then exposure was carried out at 300 mJ / cm ² by a high pressure mercury lamp through a fine test pattern showing the resolution (1 minute). After exposure, 1%
Development was carried out with an aqueous solution of apple acid.

The obtained pattern was formed well without flowing even in the fine 10 μm line due to the development. Next, the black pixels were dyed under the following conditions. Dye PC-Black205D (manufactured by Nippon Kayaku Co., Ltd.) 1.0% aqueous solution pH 4.0 (adjusted with 50% acetic acid aqueous solution) Liquid temperature 60 ° C immersion 10 minutes The maximum transmittance of the coating film after dyeing is 700 nm. It was 0.5%.

(Comparative Example 2) A black matrix having the same light-shielding properties as the black matrix produced in Example 2 was produced without dyeing. Ie 700 nm
The film thickness of the black photosensitive resin composition similar to that in Example 2 was formed so that the maximum transmittance in 0.5% was 0.5% (1.5 μm).
m), prebaking and exposing (300
mJ / cm ² ) and then developed.

It was found that the obtained pattern flowed due to insufficient exposure and the crosslinking reaction was insufficient. Then, when the exposure amount was increased up to the point where the 10 μm line of the test pattern was formed without flowing, it was found that such an exposure amount was 1500 mJ / cm ² . As is clear from the above results, the black matrix produced by using the dye and the pigment can be well formed even with a small amount of ultraviolet irradiation.

[0044]

According to the present invention, the following effects can be obtained. Since the black dye is also used as the light-shielding agent, the coating property on the substrate is improved as compared with the case where only the pigment is used, and as a result, a coating film having no film thickness distribution can be obtained. Since a black dye is used, compared to the case of using only a pigment,
A coating film with a thin film pressure can be obtained even with the same light-shielding property, which is advantageous when incorporated into a liquid crystal module. Since it is possible to reduce the irradiation amount of ultraviolet rays in manufacturing the black matrix, it is possible to save irradiation time and electricity consumption.

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Claims (2)

[Claims] 1. A black photosensitive resin composition comprising a photosensitive polymer, a dyeable polymer, a dispersant, a color pigment and a black dye. 2. A photosensitive resin composition containing a photosensitive polymer, a dyeable polymer, a dispersant and a coloring pigment is applied onto a transparent substrate, exposed through a mask having a desired pattern, and developed to obtain the composition. A method for producing a black matrix, which comprises coloring the formed pattern with a black dye.