JPH0995617A - Composition, color filter and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, containing a polymer, a dye and a specific compound respectively having reactive groups and capable of providing a color filter excellent in spectral characteristics, contrast ratio, processability and chemical and heat resistances, etc., at a low cost. SOLUTION: This composition comprises a polymer having reactive groups, a dye having reactive groups and a compound in order to respectively react and covalently bond the reactive groups of the polymer to the reactive groups of the dye (preferably a compound capable of producing an acid by heating or exposure to radiations). Furthermore, the composition preferably comprises (A) a polymer containing a hemiacetal esterified carboxyl group, (B) a compound having two or more 2-oxazoline groups, (C) a compound capable of producing the acid by exposure to the radiations and (D) a dye having phenolic hydroxyl group or mercapto group.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a photosensitive composition for a color filter, and more particularly to a photosensitive composition for a color filter which can be suitably used for fine color separation of a color sensor, a color solid-state image pickup device, a color display and the like. The present invention relates to a composition, a color filter using the same, and a method for producing the same.

[0002]

2. Description of the Related Art At present, color filters have become an essential component of color devices such as color image pickup devices and color liquid crystal display devices. In particular, in a color liquid crystal display device that is required to have a large screen, the spectral characteristic of the color filter is an important factor that determines the display quality.

A conventional color filter for a liquid crystal display device is
It is manufactured by providing a colored layer on a translucent substrate such as glass by a dyeing method, a pigment dispersion method, a printing method, an electrodeposition method or the like. Colorants used in forming this colored layer are roughly classified into dyes and pigments, and have the following characteristics.

A color filter using a pigment is excellent in heat resistance, light resistance and chemical resistance, but it is known that the display contrast ratio of a color liquid crystal display device is deteriorated due to its depolarizing effect. Further, since the pigment is generally insoluble in a solvent or a polymer system, the composition for a color filter is formed as a dispersion liquid composed of particles of about 0.1 μm, but it is difficult to stabilize the dispersion and it is difficult to remove mixed dust and the like. Have difficulty.

On the other hand, since the dye is soluble in a solvent or a polymer system, the composition for a color filter is stable, and even in the color filter obtained from this, the dye is present at a molecular level, so that the color filter is Has no depolarizing effect and has excellent spectral characteristics. However, compared with pigments, color filters using dyes are inferior in heat resistance, light resistance, and chemical resistance. For example, the heat resistance of a dyeing method color filter in which an ionic bond is formed by dyeing with a water-soluble acid dye or a direct dye is about 180 ° C.

In order to improve the heat resistance, light resistance and chemical resistance,
A method for producing a color filter by dissolving an oil-soluble dye and a disperse dye in a non-photosensitive polyimide precursor solution and performing mask etching with a positive resist after film formation (publication 1-5019).
73, Japanese Patent Publication No. 4-243), positive resist (Japanese Patent Laid-Open No. 12760/1990)
2, JP-A-4-175753, etc., positive resist and cross-linking agent (JP-A-4-283701, JP-A-4-301802, JP-A-6-35183).
It is also known that the dye is dissolved in the resin and directly patterned, but in both cases, the dye is simply dispersed in the resin and is eluted during development, sublimated during heating, and the color filter is It was insufficient in heat resistance and chemical resistance, such as elution when it was dipped in a polar solvent after completion.

On the other hand, it is known that a dye obtained by covalently bonding an acrylic group to a dye and copolymerizing it with another polymerizable monomer has excellent heat resistance and chemical resistance without elution or sublimation. It costs a lot to manufacture,
It is difficult to finely adjust the spectral characteristics of the color filter.

A resist composition comprising a polymer having a phenolic hydroxyl group, a compound having two or more 2-oxazoline groups, and a compound capable of generating an acid upon irradiation with radiation (Japanese Patent Laid-Open No. Hei5-281715). A thermosetting composition comprising a polymer having a carboxyl group blocked with a specific compound, a compound having two or more 2-oxazoline groups, and a heat-latent acid catalyst (Japanese Patent Laid-Open No. 320529) However, none of them is supposed to form a covalent bond with a colorant.

[0009]

As compared with a color filter using a pigment, a color filter using a dye having excellent spectral characteristics, contrast ratio, processability, and chemical resistance and heat resistance comparable to those of a pigment can be easily manufactured at a low cost. The method for producing is not yet known.

The present invention has been made in view of the above problems,
It is an object of the present invention to provide at low cost a color filter having excellent spectral characteristics, contrast ratio, processability, chemical resistance, heat resistance and the like.

[0011]

In order to solve the above problems, the present invention provides a polymer having a reactive group, a dye having a reactive group, a reactive group of the polymer and a reactive group of the dye, respectively. And a compound for forming a covalent bond.

The present invention also relates to a polymer having a reactive group,
A composition comprising a dye having a reactive group and a compound capable of generating an acid when heated or irradiated with radiation.

The present invention also relates to (A) a polymer having a carboxyl group which is hemiacetal-esterified by reacting with a phenolic hydroxyl group or vinyl ether, and (B) a compound having two or more 2-oxazoline groups. And (C) a compound that generates an acid upon irradiation with radiation, and (D) a dye having a phenolic hydroxyl group or a mercapto group.

The present invention also provides a color filter characterized by being obtained by curing the above polymer using each of the above compositions. The present invention also provides a method for producing a color filter, which comprises simultaneously curing the polymer of the above composition and introducing the dye into a side chain.

In the present invention, a step of coating and drying the composition on a substrate, a step of forming the coated and dried composition into a pixel pattern by photolithography, and a heat treatment to fix the pixel pattern. A method for manufacturing a color filter is provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor has conducted extensive studies on a method for easily and inexpensively producing a color filter using a dye having chemical resistance and heat resistance equivalent to those of the above pigments.
The following findings were obtained.

That is, in the color filter obtained by the usual dye dispersion method, the dye is present at the molecular level and is simply dispersed in the resin composition. Even if the crosslink density of the resin is increased, the dye is eluted and sublimated. Etc. had occurred. Therefore, the dye is introduced into the side chain of the resin by a covalent bond to elute the dye,
I found that I could prevent sublimation.

Further, as a method of introducing a dye into the side chain of the resin, a dye having a specific reactive group and a polymer having a specific substituent (reactive group), an oxazoline compound and a photoacid generator are used. By mixing with a compound that reacts and bonds with the reactive group and the substituent, long-term stable storage can be achieved, and furthermore, the dye can be easily introduced into the side chain of the resin by a covalent bond by exposure and heating after exposure. I found it.

Examples of the polymer having a reactive group used in the present invention include a polymer having a phenolic hydroxyl group. Any one containing a phenolic hydroxyl group and soluble in an alkaline developer or an organic solvent may be used. Preferable examples thereof include those that undergo heavy denaturation to form novolac resin, poly (hydroxystyrene) -based resin, and the like.

The above novolak resin is obtained by polycondensing phenols and aldehydes in the presence of an acid catalyst, and examples of phenols include phenol and o.
-Cresol, m-cresol, p-cresol, m-
Ethylphenol, m-butylphenol, 2,3-xylenol, 3,4,5-trimethylphenol, p-
Examples thereof include phenylphenol, hydroquinone, catechol, resorcinol, 1-naphthol, bisphenol A, dihydroxybenzoic acid ester, gallic acid ester, and the like. Examples of aldehydes include formaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, o-hydroxybenzaldehyde, m. -Nitrobenzaldehyde, furfural and the like can be mentioned, but formaldehyde is particularly preferable.

Examples of the acid catalyst include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, p-toluenesulfonic acid, and the like.
The amount is usually 1 × 10 ^{−4 to} 5 × 10 ⁻¹ mol per mol.

The weight average molecular weight of the novolak resin used in the present invention is usually 2,000 to 25,000, preferably 3,500 to 15,000. Two
If it is less than 000, the developability, heat resistance, etc. will be reduced to 25,000.
When it is 0 or more, developability, sensitivity, resolution, etc. are deteriorated.

The poly (hydroxystyrene) -based resin is a homopolymer or copolymer of hydroxystyrenes. Examples of hydroxystyrenes include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, and 3-hydroxystyrene. -Ethyl-4-hydroxystyrene,
3-propyl-4-hydroxystyrene, 3-t-butyl-4-hydroxystyrene, 3-phenyl-4-hydroxystyrene, 2,6-dimethyl-4-hydroxystyrene and the like can be mentioned. The above-mentioned hydroxystyrenes are polymerized alone, or copolymerized with the hydrogenated products of the above-mentioned hydroxystyrenes (usually the hydrogenated product is 70 mol% or less), or other monomers such as styrene, methyl methacrylate, glycidyl methacrylate. The poly (hydroxystyrene) -based resin used in the present invention can be obtained by copolymerization with methacrylamide, methyl vinyl ketone, methacrylonitrile or the like. This weight average molecular weight is usually 5,000-
100,000, preferably 7,000-30,000
It is. When it is less than 5,000, the developability and heat resistance tend to deteriorate, and when it is 100,000 or more, the developability, resolution and coating property tend to deteriorate.

The polymer containing a carboxyl group which has been converted into a hemiacetal ester by reaction with the vinyl ether used in the present invention is not particularly limited as long as it is soluble in an organic solvent. Acrylic acid, methacrylic acid, half-ester maleic acid, phthalic anhydride, tetrahydrophthalic anhydride, biphenyltetracarboxylic acid and the like in the polymer skeleton in which the carboxyl group has been converted into a hemiacetal ester by reaction with vinyl ether can be mentioned.

Specifically, for example, a copolymer of styrene and acrylic acid, a copolymer of styrene and methacrylic acid, a copolymer of styrene and half-methyl esterified maleic acid,
For the reaction product of the epoxy compound represented by the following (Chemical formula 1) and (meth) acrylic acid

[0026]

Embedded image Examples thereof include polymers obtained by reacting 1,2,3,6-tetrahydrophthalic anhydride and biphenyltetracarboxylic dianhydride with ethyl vinyl ether, isobutyl vinyl ether and the like to be converted into hemiacetal ester.

The weight average molecular weight of this resin is usually 3,000.
0 to 50,000, preferably 5,000 to 30,000
0 and less than 3,000, developability and heat resistance decrease,
When it is 50,000 or more, the developability, resolution, coating property and the like are deteriorated.

The compound (B) having two or more 2-oxazoline groups used in the present invention is 2,2 '.
-Bis (2-oxazoline), 2,2'-ethylenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2,2'-1,4-cyclohexylenebis (2- Oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2,2'-m-phenylenebis (5-methyl-2-oxazoline) ) And other monomers, poly (4- (2-oxazolyl) styrene), 4
Examples thereof include polymers such as a copolymer of-(2-oxazolyl) styrene and acrylonitrile. From the above-mentioned internal solubility, etc., 2,2'-bis (2-oxazoline), 2,2'-
Tetramethylene bis (2-oxazoline), 2,2'-
m-phenylene bis (2-oxazoline), 2,2'-
A copolymer having a weight average molecular weight of 3.000 or less, such as p-phenylenebis (2-oxazoline), is preferable.

These (B) components are used alone or in admixture of two or more, and the blending amount thereof is 100 parts of the (A) component.
It is usually 10 to 110 parts by weight, preferably 30 to 100 parts by weight, based on parts by weight. If the amount is less than 10 parts by weight, the crosslinking reaction does not proceed sufficiently and the pattern shape upon development, film slippage, and dye elution are likely to occur. If the amount is more than 110 parts by weight, the solubility and the coating property are deteriorated. In particular, when the component (A) contains a phenolic hydroxyl group and unreacted hydroxyl group remains after development, a quinone structure is formed by heating at about 200 ° C., and coloration deteriorates the quality as a color filter. It is desirable to react with an oxazoline group.

Examples of the compound (C) which generates an acid upon irradiation with radiation used in the present invention include onium salts and
Haloalkyl group-containing compounds, quinonediazide compounds, β
Examples thereof include a ketosulfone compound, a β-sulfonylsulfone compound, a sulfonate compound, a nitrobenzyl sulfonate compound, and a dinitrobenzyl sulfonate compound.

Of these, onium salts, haloalkyl group-containing compounds, and quinonediazide compounds are particularly preferable from the viewpoint of sensitivity. These (C) components are used alone or in admixture of two or more. The compounding amount is 1 to 70 parts by weight, preferably 3 to 50 parts by weight, relative to 100 parts by weight of the component (A). If it is less than 1 part by weight, the pattern forming ability and covalent bond of the dye are insufficient, and if it exceeds 70 parts by weight, homopolymerization of oxazoline occurs and scum easily occurs, which is not preferable. Examples of the dye (D) having a phenolic hydroxyl group or a mercapto group used in the present invention include the followings.

[0032]

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[0033]

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[0034]

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[0035]

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[0036]

[Chemical 6]

[0037]

[Chemical 7]

[0038]

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[0039]

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[0040]

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[0041]

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The amount of these dyes (D) used is 10 to 200 parts by weight, preferably 20 to 80 parts by weight, based on 100 parts by weight of the component (A). If it is less than 10 parts by weight, the desired spectral characteristics cannot be obtained, and if it exceeds 200 parts by weight, the adhesion and sensitivity of the resist film are deteriorated, which is not preferable.

In the photosensitive composition of the present invention, if necessary, phosphoric acid, diphenyl phosphite, triphenyl phosphite, etc. may be used as a catalyst for accelerating the reaction between the phenolic hydroxyl group or mercapto group and the oxazoline group upon heating. May be added.

Further, the photosensitive composition of the present invention may optionally contain an ethylenically unsaturated group-containing compound, a photopolymerization initiator,
A plasticizer, a leveling agent, a defoaming agent, an adhesion promoter, a light stabilizer, an antioxidant and the like can be used. Examples of the ethylenically unsaturated group-containing compound include dipentaerythritol hexa (meth) acrylate and tris ((meth) acryloyloxyethyl) isocyanurate, and examples of the photopolymerization initiator include Irgacure 907 and Irgacure 369.
(Both are trade names of Ciba-Geigy Co., Ltd.), 2,2-bis (0-chlorophenyl) -4,4, '5,5'-tetraphenylbisimidazolyl and the like. Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, and tricresyl, and examples of the defoaming agent and leveling agent include silicone-based, fluorine-based, and alcohol-based compounds. Examples of the adhesion promoter include a silane coupling agent and the like, examples of the light stabilizer include hindered amines, and examples of the antioxidant include an organic phosphorus compound.

The photosensitive composition of the present invention is used as a solution by dissolving or dispersing it in a suitable solvent. Examples of the solvent include methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethyl cellosolve acetate,
Ethyl carbitol, methyl carbitol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, cellosolves such as ethyl 3-ethoxypropionate, esters such as ethyl lactate, acetone, methyl ethyl ketone, methyl isobutyl ketone. , Ketones such as cyclohexanone, γ-butyrolactone, sulfolane,
Examples of polar solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N, N-dimethylimidazolidinone and N-methylpyrrolidone.

A method for producing a color filter using the photosensitive composition of the present invention will be described. First, a photosensitive composition solution of the present invention, which is any one of red, green, blue or yellow, cyan, and magenta, is transferred onto the substrate by spin coating, roll coating, bar coating, or the like to transfer a film. To form. Then, by photolithography means, exposure and post-exposure heating are performed to form a covalent bond between the dye and the oxazoline compound, or the oxazoline compound and the resin, using the acid generated by the light irradiation in the exposed area as a catalyst, and the alkali developer or organic solvent. By developing with a solvent, the unexposed portion is dissolved and removed, and then further baked to further cure, whereby a pixel pattern of the first color is formed. Subsequently, a color filter is completed by similarly forming a pixel pattern using the second color composition solution and the third color composition solution.

When the composition solution of the present invention is ink-jetted or printed, a color filter can be easily formed without the need for a matching mask and development. In the present invention, since the dye forms a covalent bond with the resin via the oxazoline compound, there is almost no dye elution or sublimation after development, after baking and pattern formation, and the obtained color filter maintains high spectral characteristics. However, it has excellent heat, light and chemical resistance.

[0048]

Embodiments will be specifically described below with reference to embodiments. Synthesis Example 1 220 g (1 mol) of pt-butyl carbonyl carbonate styrene, 100 g (1 mol) of methyl methacrylate and 8.2 g (0.05 mol) of azobisisobutyronitrile were dissolved in 200 ml of dioxane to prepare a solution. Keep the temperature at 75 ℃ 2
The reaction was carried out for 4 hours. After the reaction, the reprecipitation treatment was repeated to remove the unreacted monomer, and an approximately 1: 1 copolymer of poly (pt-butyl carbonate styrene-methyl methacrylate) was obtained. Then, this copolymer was hydrolyzed with a weak acid to obtain poly (p-hydroxystyrene-methyl methacrylate). The weight average molecular weight was 12,000.

Synthesis Example 2 162 g (1.5 mol) of m-cresol and 57.8 g of 37% formalin water (0.71 mol of formaldehyde).
Was reacted for 1 hour at 100 ° C. with 0.189 g (1.5 × 10 −3 mol) of oxalic acid dihydrate as a catalyst, and then 3
57.8 g of 7% formalin water, 1.7 oxalic acid dihydrate
0 g (1.35 × 10 −2 mol) was added and the reaction was continued for 2 hours. Then, the unreacted monomer, formaldehyde, water and the like were removed by distillation under reduced pressure of 30 mmHg for 1 hour to obtain a novolac resin (weight average molecular weight 6,200).

Synthesis Example 3 SMA-2625 (1: 1 copolymer of styrene-maleic acid half ester) manufactured by Arco Chemical Co., 234 g (1 mol), ethyl vinyl ether 86.5 g (1.2 mol), hydroquinone monomethyl ether 0.1. 2 g, 35
% Hydrochloric acid (0.1 g) was charged into a four-necked flask equipped with a reflux condenser and a stirrer, and stirred at 50 ° C. The reaction was terminated when the acid value of the mixture became 30 or less, washed with 100 g of a 10% sodium hydrogen carbonate aqueous solution and then repeatedly washed with water, and the organic layer was separated and reprecipitated with methanol to reprecipitate the carboxyl group of maleic acid. A hemiacetal-esterified copolymer was obtained. The weight average molecular weight was 13,000.

Example 1 100 parts by weight of the resin of Synthesis Example 1, 60 parts by weight of 2,2'-m-phenylenebis (2-oxazoline), 2- (4'-
Methoxy-1′-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine 10 parts by weight, (D
After dissolving 30 parts by weight of the dye of -7) in 500 parts by weight of cyclohexanone, it was filtered through a membrane filter having a pore size of 0.2 μm to prepare a photosensitive composition solution. This solution was applied onto a glass substrate using a spinner and then prebaked at 90 ° C. for 5 minutes to form a resist film having a thickness of 1.5 μm. Then, 200 mJ / exposure was performed with i-line through a mask, and heating was performed at 120 ° C. for 2 minutes. After that, it was developed with a 1% potassium hydroxide aqueous solution at 23 ° C. for 1 minute, washed with ultrapure water for 30 seconds, and heated at 200 ° C. for 30 minutes, whereby a red resist pattern was formed in a good shape. The residual film rate was 90%. After pre-baking, development, after-baking, further immersing in N-methylpyrrolidone for 5 minutes, heating at 200 ° C. for 5 minutes, and then measuring spectrophotometry to determine the color difference (ΔEab *) based on the chromaticity after pre-baking. The measured results are shown in Table 1.

[0052]

[Table 1]

It was found that all the color differences were small and the dyes were covalently bonded. Example 2 Instead of the resin of Synthesis Example 1 of Example 1, the resin of Synthesis Example 2 was used.
Instead of the dye of (D-7), 30 parts by weight of the dye of (D-6), 30 parts by weight of the dye of (D-8), 1,2 of 2,3,4-trihydroxybenzophenone instead of triazine.
-A naphthoquinonediazide-4-sulfonic acid ester (average esterification rate: 87%) was used in the same manner as in Example 1, but a good green pattern was obtained and the color difference was also good.

Comparative Example 1 The same procedure as in Example 2 was carried out except that 2,2′-m-phenylenebis (2-oxazoline) in Example 2 was not used, but after development, after baking, immersion and heating. Subsequent elution and sublimation of the dye was very large, leaving only a very pale green pattern.

Comparative Example 2 The same procedure as in Example 2 was carried out except that hexamethoxymethylolated melamine was used instead of 2,2'-m-phenylenebis (2-oxazoline) in Example 2, and the dye was eluted.・ Sublimation was quite large.

Example 3 Instead of the resin of Synthesis Example 1 of Example 1, the resin of Synthesis Example 3 was used,
Instead of the dye of (D-7), 40 parts by weight of the dye of (D-10), 10 parts by weight of the dye of (D-9), poly (2,0'-m-phenylenebis (2-oxazoline)) (4
-(2-Oxazolyl) styrene) (weight average molecular weight 1,500) was used in the same manner as in Example 1 to obtain a good pattern and a good color difference.

[0057]

EFFECTS OF THE INVENTION The photosensitive composition for a color filter of the present invention is excellent in heat resistance and chemical resistance because the dye is covalently bonded, so that the dye hardly elutes or sublimes.

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Claims (6)

[Claims] 1. A polymer having a reactive group, a dye having a reactive group, and a compound for reacting the reactive group of the polymer with the reactive group of the dye to form a covalent bond. Composition. 2. A composition comprising a polymer having a reactive group, a dye having a reactive group, and a compound capable of generating an acid upon heating or irradiation with radiation. 3. (A) a polymer containing a carboxyl group hemiacetal esterified by reacting with a phenolic hydroxyl group or vinyl ether, and (B) a compound having two or more 2-oxazoline groups, A composition comprising C) a compound that generates an acid upon irradiation with radiation and (D) a dye having a phenolic hydroxyl group or a mercapto group. 4. A color filter obtained by using the composition according to claim 1, 2 or 3 and curing the polymer. 5. A method for producing a color filter, which comprises curing the polymer according to claim 1, 2 or 3 and at the same time introducing the dye into a side chain. 6. A step of coating and drying the composition according to claim 1, 2 or 3 on a substrate, a step of forming the coated and dried composition into a pixel pattern by photolithography, and a heat treatment. A method of manufacturing a color filter, characterized in that the pixel pattern is fixed thereby.