JPH09269409A - Photosensitive color composition and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a color resist having high reliability, high sensitivity, high precision and high solubility for an alkali developer by specifying the dissolving rate of the compsn. in a developer except for a solvent. SOLUTION: As for a coloring agent, a pigment is used instead of a dye. The film forming component which constitutes the color resist is designed in such a manner that the dissolving rate of the component compsn. in a developer is 10 to 50mmg per 1l of a developer having 0.1wt.% alkali concn./1min. The amt. of reactive double bond groups in the alkali soluble binder is specified to 1.0×10<-4> to 1.0×10<-2> mol per 1g of the resin. By using the photosensitive resin above described, a photofabrication method can be used for the forming process of a color filter, and a pattern with high precision and good surface smoothness can be easily produced in plural numbers in the same state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive coloring composition (hereinafter simply referred to as a coloring resist) and a color filter used for producing a color filter used in the fields of electronic displays, image sensors for color display and the like. The present invention relates to a color filter most suitable for liquid crystal displays and image sensor applications such as CCDs, and a colored resist used for manufacturing the same.

[0002]

2. Description of the Related Art It is needless to say that a color filter in the structure of a liquid crystal cell has been the most important member of a liquid crystal driven display, especially for displaying a color. The structure is slightly different depending on the type such as TFT, STN and TN, but (1) a black portion (Bk) for light shielding and (2) a red for color display on the glass surface.
(R), Green (G), and Blue (B) matrices, (3) a transparent film holding a color matrix, and a transparent electrode film for driving liquid crystals. Various methods have been devised to form the color matrix layer of these layers.
At present, four types of methods have been put into practical use, roughly classified into a dyeing method, a pigment dispersion method, a printing method, and an electrodeposition method. However, each method has its own problems in quality performance and cost reduction, and its solution is being studied.

[0003]

For example, a color filter by a dyeing method has been put to practical use mainly for use in an image pickup tube. In this method, a dyeable photosensitive film is formed on a glass substrate, pattern exposure is performed through a photomask, and this is developed to form a pattern to be dyed. This is dyed as the first of the three primary colors. After that, a dye-proof treatment is performed, and the process of the second color is started, and the procedure from the formation of the dyeable photosensitive film is repeated to form the pixel patterns of the second color and the third color. Next, in order to protect and flatten the pixel portion, a transparent top coat layer is provided on the surface, and an ITO film for a transparent electrode is formed thereon. As described above, the dyeing method requires a very long color filter forming process.

Further, the dyeable photosensitive film is made by imparting photosensitivity to a natural polymer material such as gelatin or casein with dichromate, but the photosensitive material is limited to a material having dyeability with a dye. However, there is also a problem in light resistance and heat resistance of the dye itself. Further, in the production by the printing method, each pixel is printed by using an ink in which a pigment is dispersed in a thermosetting resin or an ultraviolet curable resin, but it is difficult to form a highly accurate pattern and at the time of printing. However, a problem arises in the surface smoothness of the color filter formed because the mechanical vibration and the like cannot be excluded.

Further, in the electrodeposition method, an ITO film is formed on a glass substrate and patterned. A pigment is dispersed in a transparent and stable polymer having a carboxyl group introduced and dissolved in water. The polymer is negatively charged due to the carboxyl group, and the polymer containing pigment adheres to the patterned ITO film. This is R, G, B 3
Color components are repeated, and a black matrix is formed by Bk. Since the ITO film to which the polymer is attached first is insulated by the polymer, color mixing with other colors does not occur. However, the color filter by this method is excellent in pattern accuracy and film thickness control, but ITO
There are problems that the film forming step is required twice and the degree of freedom in the pixel pattern is low.

As described above, when a color filter is manufactured by the conventional technique, the number of manufacturing steps and the number of processing steps greatly differ depending on the material used. In that sense, it is more advantageous to use a colored resist by the pigment dispersion method than the dyeing method. Conventionally, color filter forming materials using pigments are roughly classified into two types. One of them is to disperse a pigment in a film forming material such as acrylic resin with a dispersant or the like, apply it on a substrate and dry it to form a colored layer, and then apply a positive resist (photosensitive resin) on it. Then, it is dried, exposed using a mask, and then developed to form a resist pattern. By removing the colored layer in the portion where the resist is removed by etching to form a pattern consisting of the colored layer and the resist layer, and then removing the resist on the unnecessary colored layer to complete the colored pattern. is there.

The second method is to add a photopolymerizable monomer and a photopolymerization initiator or a photosensitizer to a composition consisting of a pigment and its vehicle to prepare a colored resist, which is coated, dried, exposed and developed on a substrate. Is performed to form a colored pattern. As the photosensitizer in this case, there are bisazide compounds, diazo compounds and the like, and as the photopolymerization initiator, acetophenone, benzyl dimethyl ketal and the like are used, but since the pigment is contained in the colored resist. In addition, since the pigment absorbs ultraviolet rays even when exposed to light, the colored resist has low sensitivity. Therefore, there is a problem that considerable light energy and light irradiation time are required for complete curing.

As described above, when manufacturing a color filter using a colored resist, there are major problems in the length and the yield of the steps in manufacturing and processing. In designing and synthesizing the colored resist, as is clear from the above, the pigment type does not select a resin, and therefore it is more advantageous to use the pigment type colored resist than the dye type. However, in this case,
The solubility of the colored resist in the alkali developing solution in the developing step after exposure is an important issue. That is, considering the effect on the human body, development with a low-concentration alkaline aqueous developer is preferable to development with an organic solvent, and for that purpose, it is necessary to design a colored resist exhibiting sufficient solubility in this aqueous developer. Furthermore, in the color filter manufacturing line, when unnecessary colored resist film developed and peeled during the developing process is re-deposited on the product, the re-adhesion causes color filter defects or defective product in subsequent successive processing steps. It becomes a cause. Also, when the colored resist film peeled off in the development is deposited or adhered in the developing tank and accumulated in the tank,
Cleaning and maintenance of the inside of the tank are required frequently, and it takes a lot of time to clean and maintain the tank, which is a serious problem in productivity.

For the above reasons, the pigment-dispersed colored resist is required to be accurately developed in its constituent material uniformly with respect to the alkaline water-based developer without pattern thinning. Further, as a problem that is posed on the pigment-dispersed colored resist side, it is necessary that the curing sensitivity wavelength on the colored resist side agrees with the exposure light source wavelength used in the production line. That is, in terms of photocuring efficiency, it is necessary to cure the interior of the pigment-dispersed colored resist film with light having a longer wavelength. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a colored resist having high reliability, high sensitivity, high accuracy, and high solubility in an alkali developer, and a color filter. .

[0010]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems. First, a pigment dispersion type colored resist is adopted as a selection for the type of the colored resist. That is, the drawback of the dyeing method is that it is inferior in chemical resistance, heat resistance and light resistance, but these are mainly problems of dyes used for coloring. Therefore, a pigment is used as the colorant instead of the dye. Next, regarding the film-forming components constituting the colored resist, the dissolution rate of those component compositions in the developing solution is
10-500 mg / 0.1 wt% alkali concentration Developer 1
Liter / 1 min. The above film-forming components were designed so that The dissolution rate of the colored resist in the present invention means that a colored resist composition is used to form a coating film having an area of 100 mm × 100 mm and a thickness of 1.0 μm on a glass substrate, and the coating film is kept at room temperature (25 ° C.). After being dried for 15 minutes, prebaked in a clean oven at 90 ° C. for 3 minutes and immersed in a developing solution at a temperature of 23 to 25 ° C. for 1 minute, it means the weight of the colored resist component eluted from the coating film into the developing solution. . Formed in

The dissolution rate of the film-forming components of these resist films is a value obtained as a result of diligent study on the relation with the developing step, and the composition of the film-forming components of the colored resist which satisfies this is a side chain. The main components are an alkali-soluble binder having a reactive double bond group, a pigment, a photopolymerizable monomer and a solvent. This makes it possible to control the development characteristics, achieves high reliability and high resolution for the product, and succeeded in increasing the sensitivity of the colored resist by using an alkali-soluble binder having a reactive double bond group in the side chain. did. The alkali developing solution in the present invention is a developing solution which releases OH ⁻ in the narrow sense because the developing is carried out in an aqueous system. The pH of this alkaline developer is preferably in the range of 7.5 to 12, most preferably 8 to 10, and the alkaline component used is, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, or organic ammonium. Examples thereof include compounds hydrolyzed with tetraethylammonium hydroxide, sulfides, oxides, or weak acid anions (eg, F ⁻ , CN ^−, etc.). Further, a buffer solution in this pH range may be prepared and used as an alkaline developer.

As described above, according to the present invention, the photofabrication method can be applied by using a specific colored resist in the process of producing a color filter using the colored resist, which is highly accurate and has good surface smoothness. It is possible to easily obtain a plurality of different patterns in the same state, and it is possible to obtain a color filter having good heat resistance and environment resistance by using a pigment.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments of the invention. The colored resist of the present invention is a colored resist mainly composed of an alkali-soluble binder having a reactive double bond group in a side chain, a pigment, a photopolymerizable monomer and a solvent, and the dissolution of the composition excluding the solvent in a developer. The speed is 10 to 500 mg / alkali concentration 0.1% by weight developer 1 liter / 1 min. It is characterized by being.

As the above-mentioned pigment, any of the known pigments used in the conventional production of color filters can be used. Specifically, for example, as the organic pigment, phthalocyanine-based, azo-based, condensed azo-based, anthraquinone-based, perinone-perylene-based, indigo-thioindigo-based, isoindolinone-based, azomethine-based, azomethine-azo-based, dioxazine-based, Examples thereof include quinacridone type, aniline black type, triphenylmethane type and carbon black. Among these, particularly preferable pigments include C.I. I. No. 9, C.I.
I. No. 97, C.I. I. No. 122, C.I. I. N
o. 123, C.I. I. No. 149, C.I. I. No. 1
68, C.I. I. No. 177, C.I. I. No. 180,
C. I. No. 192, C.I. I. No. 215 and the like are C.I. I. No. 7, C.I.
I. No. 36 and the like are C.I. as blue.
I. No. 15, C.I. I. No. 22, C.I. I. No.
60, C.I. I. No. 64 and the like.

Furthermore, when spectral correction is performed by combining a plurality of pigments, not by itself, pigments classified as pigments by the following color index, for example, C.I. I. Pigment Yellow 24, C.I. I. Pigment Yellow 31, C.I. I. Pigment Yellow 53,
C. I. Pigment yellow 83, C.I. I. Pigment Orange 43, C.I. I. Pigment Red 105, C.I.
I. Pigment Red 149, C.I. I. Pigment red 176, C.I. I. Pigment Red 177, C.I. I.
Pigment violet 14, C.I. I. Pigment Violet 29, C.I. I. Pigment Blue 15, C.I.
I. Pigment Blue 15: 3, C.I. I. Pigment Blue 22, C.I. I. Pigment Blue 28, C.I. I. Pigment Green 15, C.I. I. Pigment Green 2
5, C.I. I. Pigment Green 36, C.I. I. Pigment Brown 28, C.I. I. Pigment Black 1,
C. I. Pigment Black 7 and the like. Further, in the present invention, these pigments are in the form of dry fine powder,
It can also be used in the form of an aqueous filter cake or an aqueous suspension. The pigment used is a dispersant and / or
Alternatively, it is preferable to carry out dispersion treatment in advance with an alkali-soluble binder having a reactive double bond group in the side chain.

The colored resist of the present invention may further contain a pigment dispersant, if necessary. As the dispersant for the pigment, a wide range of dispersants can be appropriately selected and used. For example, surfactants, pigment intermediates, dye intermediates, solsperse and the like are used. The amount of dispersant used in dispersing the pigment is not particularly limited, but Pigment 1 is preferred.
It is 1 to 10 parts by weight per 00 parts by weight. However, this dispersant must have a function of preventing aggregation of the pigment used in the colored resist and uniformly dispersing the pigment. Therefore, the dispersant itself must not interfere with the physical properties of the color filter produced, and must be selected in consideration of heat resistance and yellowing. Further, in the present invention, in order to treat the pigment, the amount of the alkali-soluble binder having a reactive double bond group in the side chain, which is used together with the dispersant, is preferably about 0 to 40 parts by weight per 100 parts by weight of the pigment. The range of up to 30 parts by weight is more preferable.

The alkali-soluble binder having a reactive double bond group in the side chain used in the present invention has a developability of a coating film of a colored resist forming a pixel in an alkali developing solution,
It acts as a film-forming material, a viscosity modifier for colored resists, and a dispersion stabilizer for pigments. Furthermore, by introducing a reactive double bond group into the side chain of the alkali-soluble binder, the number of double bonds per unit weight of the colored resist is increased, and the contrast between the exposed area and the unexposed area is easily provided. Therefore, high sensitivity and high resolution can be achieved. The alkali-soluble binder having a reactive double bond group in the side chain used in the present invention can be obtained by introducing the double bond group into a known alkali-soluble binder.
For example, a method of reacting a glycidyl group-containing (meth) acrylate compound with an alkali-soluble binder having a carboxyl group such as acrylic acid resin,
Examples include a method of reacting a resin having a hydroxyl group such as a hydroxyacrylic acid ester resin with an isocyanate group-containing (meth) acrylate.

The content of the reactive double bond group as a side chain in the alkali-soluble binder is not particularly limited, but is 1.0 × 10 ^{−4 to} 1.0 × 10 ⁻² per 1 g of the resin.
Mol, more preferably 0.5 × 10 ^{−3 to} 5.0 × 10 ⁻³
It is in the molar range. When the content of the reactive double bond group is less than 1.0 × 10 ⁻⁴ mol per 1 g of the resin, it is difficult to improve the sensitivity by introducing the double bond group, and 1.0 × 10 ⁻⁴ is obtained.
^If it exceeds ^-2 mol, the sensitivity tends to be too high, and in some cases, fringe may occur on the pattern after exposure and development due to the influence of exposure fog due to the narrow marginal zone of the proper exposure value.

The base resin of the alkali-soluble binder having a reactive double bond group in the side chain used in the present invention is not particularly limited as long as it is a known resin as described above. Specific examples include acrylic resins, polyester resins, unsaturated polyester resins, and photosensitive monomers and oligomers having a (meth) acryloyl group. Furthermore, poly (meth) acrylic acid ester or its partial hydrolyzate, polyvinyl acetate or its partial saponification product, polyvinylphenol, phenol novolac, polystyrene, polyvinyl butyral, polychloroprene, polyvinyl chloride, chlorinated polyethylene, chlorinated From copolymerizable monomers such as polypropylene, polyvinylpyrrolidone, copolymers of styrene and maleic anhydride or half esters thereof, and further (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, (meth) acrylonitrile Selected glass transition point is 35
And a copolymer having a temperature of at least ℃.

Of these, a particularly preferred alkali-soluble binder is a copolymer of at least (meth) acrylic acid, styrene, and benzyl (meth) acrylate, in which a reactive double bond group is introduced as a side chain into a copolymer of three or more groups. It was done. The copolymerization ratio of these copolymers is arbitrary, but the preferred range is about 20 to 40 moles of (meth) acrylic acid and about 25 to 4 moles of styrene when the total amount is 100 moles.
5 mol, and benzyl (meth) acrylate about 10 to 50
It is a molar copolymer. The copolymer also has the purpose of stabilizing the pigment in the colored resist together with the above-mentioned dispersant, and its molecular weight is preferably about 10,000 to 70,000. Further, in order to impart appropriate alkali developer resistance, the preferable acid value is in the range of about 60 to 250 mgKOH / g, and more preferably in the range of 110 to 170 mgKOH / g. If the copolymerization ratio and acid value are not well-balanced, pattern resolution will occur after exposure and development, but there will be no resistance to the alkali developing solution, and small wrinkles and cracks will occur on the development pattern surface. The rapid penetration of the liquid may eventually cause the colored resist film to peel off from the glass substrate surface.

The photopolymerizable monomer used in the present invention may be either a radical polymerization type or a cationic polymerization type and is not particularly limited, but a polyfunctional (meth) acrylate monomer is preferably used. Examples of the polyfunctional (meth) acrylate monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth).
Acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyoxyethylene polyoxypropylene di (meth) acrylate, butylene glycol di (meth)
Acrylate, hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Glycerin di (meth) acrylate, glycerin tri (meth) acrylate, diglycerin tetra (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, tetra Examples include trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, sorbitol hexa (meth) acrylate, and these components are used alone or as a mixture.

These polyfunctional (meth) acrylate monomers include at least one trifunctional or higher functional monomer in the polyfunctional (meth) acrylate monomer in an amount of about 30 to 95.
It is preferable to use it in a proportion occupying weight%. Further, these polyfunctional (meth) acrylate monomers include, as reactive diluents, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, ethylhexyl. Monofunctional monomers such as (meth) acrylate, styrene, methylstyrene, N-vinylpyrrolidone can be added.

The photopolymerization initiator used in the present invention preferably has a maximum absorption wavelength in the spectral absorption spectrum from 300 nm to 400 nm. As the photopolymerization initiator corresponding to this, for example, a compound that generates a free radical by the energy of ultraviolet rays, benzoin, benzophenone, benzophenone derivatives such as acetophenone,
Or derivatives such as esters thereof, thioxanthone and thioxanthone derivatives, benzimidazole and imidazole derivatives as nitrogen-containing heterocyclic compounds, chlorosulfonyl and chloromethyl polynuclear aromatic compounds as halogen-containing compounds, chloromethyl heterocyclic compounds, chloromethylbenzophenones , Fluorenones, haloalkanes, redox couples of photoreducible dyes and reducing agents, organic sulfur compounds, peroxides and the like, and these can be used alone or in combination of two or more.

Specific examples of the photopolymerization initiator include 2-dimethoxy-2-phenylacetophenone and 2-ethyl {4.
-(Methylthio) phenyl} -2-morpholino-1-propane, benzoin butyl ether, benzoin isopropyl ether, benzophenone, Michler's ketone,
4,4-diethylaminobenzophenone, chloromethylbenzophenone, 9,10-anthraquinone, 2-methyl-9,10-anthraquinone, chlorosulfonylanthraquinone, chloromethylanthraquinone, 9,10-
Phenanthrenequinone, xanthone, chloroxanthone, thioxanthone, chlorothioxanthone, 2,4-
Examples include diethylthioxanthone, chlorosulfonylxanthone, chloromethylbenzothiazole and the like.

Specific examples of the solvent used in the present invention include alcohol solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol and i-propyl alcohol, cellosolve solvents such as methoxy alcohol and ethoxy alcohol, and methoxy. Carbitol solvents such as ethoxyethanol, ethoxyethoxyethanol, ethyl acetate, butyl acetate, methyl methoxypropionate,
Ethyl ethoxypropionate, ester solvents such as ethyl lactate, acetone, methyl isobutyl ketone, ketone solvents such as cyclohexanone, methoxyethyl acetate, ethoxyethyl acetate, cellosolve acetate solvents such as ethyl cellosolve acetate, methoxyethoxyethyl acetate, ethoxy. Carbitol acetate solvents such as ethoxyethyl acetate, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ether solvents such as tetrahydrofuran, N, N-dimethylformamide,
Aprotic amide solvents such as N, N-dimethylacetamide and N-methylpyrrolidone, lactone solvents such as γ-butyrolactone, unsaturated hydrocarbon solvents such as benzene, toluene, xylene and naphthalene, n-heptane, n-
Examples of the organic solvent include saturated hydrocarbon solvents such as hexane and n-octane. Among these solvents, methoxyethyl acetate, ethoxyethyl acetate, ethyl cellosolve acetate and other cellosolve acetate-based solvents such as ethyl cellosolve acetate, methoxyethoxyethyl acetate, carbitol acetate-based solvents such as ethoxyethoxyethyl acetate, ethylene glycol dimethyl ether. , Ether solvents such as diethylene glycol dimethyl ether and propylene glycol diethyl ether, and ester solvents such as methyl methoxypropionate, ethyl ethoxypropionate and ethyl lactate are preferable.

In the colored resist composition of the present invention, the proportion of the pigment in the colored resist is not particularly limited, but is preferably about 40 to 75% by weight, more preferably about 45 to 75% by weight. When the amount of the pigment is less than about 40% by weight, the coloring power of each pixel is insufficient and it may be difficult to display a clear image. On the other hand, the pigment is about 75
When the content exceeds the weight%, the light transmittance of each pixel may be insufficient. Since various optical properties such as coloring power and translucency change depending on the type, particle size, dispersion state, etc. of the pigment, the usage amount is determined according to the physical properties of the specific pigment selected as R, G, B and Bk. Preferably. The criterion for determining the usage amount is that the light transmittance of the formed pixel is usually about 8
The amount is 0 to 90%. However, in the case of Bk, translucency is not required. As the measurement conditions of the light transmittance of each pixel, a measurement sample is placed between two polarizing plates, and the brightness is obtained when the polarization axes are parallel and when the polarization axes are vertical. The measurement wavelength of the light beam is R
Part is 610 nm, G part is 540 nm, B part is 450 nm
Was measured respectively. Further, regarding Bk, the O.D. D. It was measured as a value. Further, a color filter sample having a film thickness of about 1.5 μm was used.

Further, the amount of the photopolymerizable monomer constituting the colored resist, for example, a polyfunctional (meth) acrylate monomer, is a proportion of preferably about 20 to 60% by weight in the film forming material other than the pigment, More preferably, the proportion is about 30 to 50% by weight. When the polyfunctional (meth) acrylate monomer is less than about 20% by weight, various physical strengths such as adhesive strength and heat resistance of the formed pixel (colored resist film) tend to be insufficient. If the amount of the polyfunctional (meth) acrylate monomer exceeds about 60% by weight, the stability of the colored resist may be reduced and the flexibility of the formed colored resist film may be insufficient. Further, this ratio must be taken into consideration in order to improve the dissolution property in the developing solution. This is because although the pattern is resolved, the monomer curing speed increases and scum and whiskers occur around the pattern.
Further, the same phenomenon occurs if the ratio of the alkali-soluble binder having a reactive double bond group in the side chain and the photosensitive resin is not optimized, and in the worst case, the colored resist film resulting from partial swelling / peeling As a result of various studies, it was found that the adhesion occurred and the accurate pattern formation was hindered.

The amount of the alkali-soluble binder having a reactive double bond group in its side chain is preferably about 5 to 80% by weight in the film-forming material other than the pigment, more preferably about 10%. -60% by weight. When the amount of the alkali-soluble binder having a reactive double bond group in the side chain is less than about 5% by weight, the coating suitability of the colored resist on the substrate is deteriorated, and the formed colored resist film is developed by the alkaline developer. In some cases, the adhesiveness, flexibility, etc. of the formed pixel (colored resist film) may be insufficient due to insufficient properties, while about 8
If it exceeds 0% by weight, the film loss rate after post-baking increases,
In some cases, the hardness of the colored resist film may decrease due to an increase in the amount of uncured material inside the photocurable colored resist film, which may be insufficient.

The amount of the photopolymerization initiator contained in the photosensitive resin is preferably about 5 to 35% by weight in the film forming material other than the pigment, and more preferably about 10 to 30%. It is the ratio which accounts for weight%. When the amount of the photopolymerization initiator is less than about 5% by weight, the sensitivity of the colored resist is lowered and the formed colored resist film is insufficient in heat resistance, hardness and other physical strength. There is. The photopolymerization initiator may be added to the colored resist in which the pigment is sufficiently dispersed from the beginning, but when stored for a relatively long period of time, it is dispersed or dissolved in the colored resist immediately before use. It is preferable. The colored resist of the present invention contains the above-mentioned components as essential components, but for the purposes of coating suitability of the colored resist, sensitivity, adjustment of cross-linking density of the coating, various organic solvents, various polymers, sensitizers, chain transfer agents. Other additives known in the art can be added as necessary.

The colored resist of the present invention contains the above-mentioned components and a suitable organic solvent, for example, paint shaker, bead mill, sand grind mill, ball mill,
It can be obtained by dispersing using a disperser such as an attritor mill or a two roll mill. The obtained colored resist is in the state of a coating liquid or an ink in which an organic solvent is a medium, and may be diluted by adding an organic solvent immediately before use if necessary.

A method of forming a color filter pattern using the above colored resist may be a conventionally known method, for example, the colored resists of R, G, B and Bk are spun on a transparent substrate in an appropriate order. Coat, low-speed rotation coater, roll coater, knife coater, etc. for full surface coating, or by various printing methods for full surface printing or slightly larger area than the pattern, and pre-dry the photomask to bring it into close contact. A high pressure mercury lamp is used to expose and print the pattern. Then, development and washing are carried out, and post-baking is carried out if necessary, whereby a color filter pattern can be formed.

[0032]

Next, the present invention will be described more specifically with reference to examples. In the following, "parts" and "%" are based on weight unless otherwise specified. Example 1-Pigment (carbon black, MA-8 manufactured by Mitsubishi Chemical) 10.0 parts-Dispersant (Disperbyk 161 (manufactured by Big Chemie)) 1.0 part-Polyethylene glycol monomethyl ether acetate (PEGMEA) 70.0 parts The components were mixed, kneaded and dispersed with a two-roll mill, etc., and further diluted with PEGMEA solvent and dispersed with a paint shaker or bead mill to obtain a pigment dispersion liquid.

84.0 parts of the above pigment dispersion (black) benzyl methacrylate-styrene-acrylic acid copolymer (copolymerization ratio 1: 1: 1, molecular weight about 30,000, molecular weight distribution: Mw / Mn = 1. 7) Glycidyl methacrylate 0.1% adduct (solid content 40%, 3-methoxybutyl acetate solution) (double bond content 0.7 × 10 ⁻³ mol / g) 5.0 parts trimethylolpropane Triacrylate (manufactured by Nippon Kayaku) 9.0 parts-Irgacure 369 (manufactured by Ciba Geigy) 3.0 parts-Butyl cellosolve 40.0 parts The above components are mixed, and a diluting solvent such as butyl cellosolve is added to the mixture to prepare a paint shaker or a paint shaker. The colored resist of the present invention was dispersed by a bead mill.

The fact that glycidyl methacrylate was added to the benzyl methacrylate-styrene-acrylic acid copolymer was measured by measuring the IR spectrum of the resin solution after addition, and the absorption (1250) derived from the symmetrical expansion and contraction of the epoxy ring was measured.
It was confirmed by the disappearance of (cm ^-1 ). Also, the fact that a double bond group is introduced means that the IR of the resin solution is the same.
In the spectrum, the absorption (16
50 cm ⁻¹ ) was expressed, and after the produced resin was dissolved in acetone, it was quantified by a titration method using a potassium permanganate solution and an iodine addition method (iodine value). Pigment dispersed particle size in the colored resist was dispersed to be less than 0.7μm in d _50. The particle size and the particle size distribution were confirmed using a Microtrac UPA particle size analyzer manufactured by Nikkiso Co., Ltd. Further, a colored resist of the present invention having each hue was obtained by the same formulation as above except that only the pigment was changed. The pigment in each of the colored resists is particularly red (pigment name: CI Pigment Red 177) is 0.5.
The dispersion was performed such that the green color (pigment name: CI Pigment Green 36) was 0.35 μm or less, and the blue color (pigment name: CI Pigment Blue 15: 6) was 0.3 μm or less.

On the other hand, as a transparent substrate, low expansion glass (manufactured by Corning) is washed with a neutral detergent, washed with water, degreased,
An ozone and light washed product was prepared. The colored resists of the respective colors were applied on the glass substrate by a spin coating method so as to have a thickness of 1.0 μm. The film thickness was measured by a stylus type deck tack device. After applying each color resist, pre-baking is performed at about 100 ° C. for 3 minutes in a CR dryer, and then 200 to 2000 mJ / by an aligner through a mask having a fine line pattern.
The exposure amount was changed to cm ² , and the R, G, B, and Bk patterns were printed, respectively.

For the development, an automatic developing device is used, and an unexposed portion of the colored resist is exposed by an alkaline aqueous solution (KOH aqueous solution is used, KOH concentration is 0.1% aqueous solution, pH 8.5, developer temperature 23 to 25 ° C.). After the membrane was dissolved, it was washed with water. Development showed a homogeneous dissolution type (similar in all hues). Furthermore, the dissolution rate of this colored resist film was 110 mg per minute for 1 liter of the developing solution. After confirming the fine pattern lines with a microscope, post baking was performed at 200 ° C. for 60 minutes. Regarding Bk, the sensitivity was about 250 mJ / cm ² . The fine lines of the pattern had no scum and the edge shape was normal, and the resolution was as follows for each color. Red is 1.0 μm, green is 1.5 μm
m and blue were 1.2 μm and black was 2.5 μm, and the line and space pattern was resolved. Furthermore, it was confirmed that the film reduction rate after post-baking was 10% or less.

Example 2 As an alkali-soluble binder having a reactive double bond group in the side chain, a benzyl methacrylate-styrene-acrylic acid copolymer (copolymerization ratio 1: 1: 1, molecular weight about 3)
10,000, molecular weight distribution: Mw / Mn = 1.7) glycidyl methacrylate 0.3% adduct (solid content 40%, 3-methoxybutylacetate solution, double bond content 2.3 × 1)
A colored resist of the present invention was prepared in the same manner as in Example 1 except that 0 to ³ mol / g) was used, and the development characteristics, resolution, and sensitivity (UV exposure amount required for film curing) were evaluated. The double bond content was also quantified in the same manner as in Example 1.

Example 3 As an alkali-soluble binder having a reactive double bond group in its side chain, a benzyl methacrylate-styrene-acrylic acid copolymer (copolymerization ratio 1: 1: 1, molecular weight about 3).
10,000, molecular weight distribution: Mw / Mn = 1.7) glycidyl methacrylate 0.5% adduct (solid content 40%, 3-methoxybutyl acetate solution, double bond content 3.9 × 1)
A colored resist of the present invention was prepared in the same manner as in Example 1 except that 0 to ³ mol / g) was used, and the development characteristics, resolution, and sensitivity (UV exposure amount required for film curing) were evaluated. The double bond content was also quantified in the same manner as in Example 1.

Example 4 As an alkali-soluble binder having a reactive double bond group in the side chain, a benzyl methacrylate-styrene-acrylic acid-2-hydroxyethyl methacrylate copolymer (copolymerization ratio 1: 1: 1: 0. 1, molecular weight of about 30,000, molecular weight distribution: Mw / Mn = 1.7) 0.1% methacrylic isocyanate adduct (solid content 40%, 3-methoxybutyl acetate solution, double bond content 0.7 × 10) ^-3 mol / g) except that the colored resist of the present invention was prepared in the same manner as in Example 1 and evaluated for development characteristics, resolution, and sensitivity (UV exposure amount required for film curing). The fact that methacryl isocyanate is added to the benzyl methacrylate-styrene-acrylic acid-2-hydroxyethyl methacrylate copolymer means that the IR spectrum of the resin solution after the addition is measured, and that the N = C = O group undergoes antisymmetric stretching. It was confirmed by the disappearance of the absorption (2250 cm ⁻¹ ) derived from it. The double bond content was also quantified in the same manner as in Example 1.

Example 5 As an alkali-soluble binder having a reactive double bond group in the side chain, a benzyl methacrylate-styrene-acrylic acid-2-hydroxyethyl methacrylate copolymer (copolymerization ratio 1: 1: 1: 0. 3, molecular weight about 30,000, molecular weight distribution: Mw / Mn = 1.7) 0.3% acrylic isocyanate adduct (solid content 40%, 3-methoxybutylacetate solution, double bond content 2.3 × 10) ^-3 mol /
A colored resist of the present invention was prepared in the same manner as in Example 1 except that g) was used, and the development characteristics, resolution, and sensitivity (UV exposure amount required for film curing) were evaluated. The double bond content was also quantified in the same manner as in Example 1. As a comparative example, a colored resist was prepared using a resin having no double bond in the side chain, and the characteristics of the colored resist were evaluated in the same manner.

Comparative Example 1 Benzyl methacrylate-styrene-acrylic acid copolymer (copolymerization ratio 1: 1: 1, molecular weight about 30,000, molecular weight distribution: Mw / Mn = 1.7, solid content 40%, 3-methoxy) A colored resist of Comparative Example was prepared in the same manner as in Example 1 except that a butyl acetate solution) was used, and the development characteristics, resolution, and sensitivity (UV exposure amount required for film curing) were evaluated. Comparative Example 2 Benzyl methacrylate-styrene-acrylic acid-2-
Hydroxyethyl methacrylate copolymer (copolymerization ratio 1: 1: 1: 0.3, molecular weight about 30,000, molecular weight distribution: Mw
/Mn=1.7, solid content 40%, 3-methoxybutylacetate solution), except that a colored resist of Comparative Example was prepared in the same manner as in Example 1, and the development characteristics, resolution, sensitivity (film curing) The amount of UV exposure required) was evaluated. The above results are shown in Table 1 below.

[0042]

[Table 1]

From the above results, the use of an alkali-soluble binder having a reactive double bond group in the side chain as a constituent material of the colored resist gives a markedly higher sensitivity than the case of using a resin containing no double bond. It turned out to improve. Further, based on these results, the dissolution rate of each colored resist was determined according to the method defined above, and the results shown in the following table were obtained.

[0044]

[Table 2]

Comparative Example 3 (Influence of Double Bond Group Content) In the preparation of the colored resist in Example 1, the copolymerization ratio of the benzyl methacrylate-styrene-acrylic acid-2-hydroxyethyl methacrylate copolymer was changed. Without changing the double bond group content, a colored resist was prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0046]

[Table 4] Overall Evaluation Criteria ⊚: Good substrate adhesion and sensitivity, lines and spaces of 10 μm or less are resolved. ◯: Substrate adhesion and sensitivity are good, and part of the resolution pattern of 15 to 10 μm line and space is missing. Δ: Substrate adhesion is slightly weak, and part of the 20 μm line-and-space resolution pattern is lost. X: The pattern is not resolved and a film peeling phenomenon occurs.

Comparative Example 4 (Influence of Average Dissolution Rate) In the preparation of the colored resist in Example 1, a copolymerization ratio of benzyl methacrylate-styrene-acrylic acid-2-hydroxyethyl methacrylate copolymer (B: S:
A: H molar ratio) (the amount of double bond groups does not change),
A colored resist was prepared in the same manner as in Example 1, evaluated in the same manner as in Example 1, and the alkali concentration was 0.1% (pH
The average dissolution rate of the colored resist film in 1 liter of the developing solution (8-10) was determined. The results are shown in Table 4.

[0048]

[Table 4] Comprehensive Evaluation Criteria ⊚: The resolution pattern is good, the developing method is uniform dissolution, and the image line is not thin. ◯: Fine line is seen in part of the resolution pattern. (Triangle | delta): The image line of a resolution pattern becomes thin, and a part of the pattern is damaged due to a decrease in the substrate adhesion. X: No resolution pattern is possible.

[0049]

According to the present invention, the use of a photosensitive resin makes it possible to apply the photofabrication method to the color filter production process, and it is possible to easily form a plurality of patterns with high precision and good surface smoothness in the same state. It is possible to obtain a color filter having good heat resistance and environment resistance by using a pigment.
Also, since it uses a resin containing a reactive double bond,
The sensitivity is significantly improved, and a color filter having a high resolution can be obtained with a small exposure amount. A color filter can be manufactured by applying the photolithography method, and a liquid crystal color display having high quality and high durability can be obtained. Further, the colored resist of the present invention is 0.1
It is a colored resist that has a high dissolution rate even in a low-concentration aqueous alkaline developer having a concentration of not more than%, and is pattern-formed by a dissolution developing type.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G03F 7/027 511 G03F 7/027 511

Claims (10)

[Claims] 1. A photosensitive coloring composition containing an alkali-soluble binder having a reactive double bond group in a side chain, a pigment, a photopolymerizable monomer and a solvent as a main component, and the composition excluding the solvent to a developer. Dissolution rate is 10-500 mg
/ Alkali concentration 0.1% by weight developer 1 liter / 1 mi
n. A photosensitive coloring composition, wherein 2. The content of the reactive double bond group in the alkali-soluble binder is 1.0 × 10 ⁻⁴ to 1 g of the resin.
The photosensitive coloring composition according to claim 1, which is 1.0 × 10 ^-2 mol. 3. The photosensitive coloring composition according to claim 1, wherein the alkali-soluble binder is an acrylic resin having a carboxyl group. 4. An alkali-soluble binder is a resin in which a reactive double bond group is introduced into a copolymer of at least 3 series consisting of at least (meth) acrylic acid, styrene and benzyl (meth) acrylate. ~ Any one of 3
The photosensitive coloring composition according to the item. 5. The acid value of the alkali-soluble binder is 60.
It is-250 mgKOH / g, The photosensitive coloring composition of any one of Claims 1-4. 6. The photosensitive coloring composition according to claim 1, wherein the alkali-soluble binder has a molecular weight of 10,000 to 70,000. 7. The photosensitive coloring according to any one of claims 1 to 6, wherein the photopolymerizable monomer contains at least one or more trifunctional or higher functional (meth) acrylate monomer and a photopolymerization initiator. Composition. 8. The photopolymerization initiator has a spectral absorption spectrum of 3
It has a maximum absorption wavelength in 00-400 nm.
The photosensitive coloring composition according to any one of 1. 9. The photosensitive coloring composition according to claim 1, wherein at least a part of the surface of the pigment is coated with an alkali-soluble binder and / or a dispersant. 10. A color filter in which red, green and blue pixels and / or a black matrix are provided on a transparent substrate, and a transparent electrode layer is further provided on the surface, wherein the pixels and / or the black matrix are claimed. Item 10. A color filter formed from the photosensitive coloring composition according to any one of items 1 to 9.