JP2001181561A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition excellent in sputtering resistance. SOLUTION: The coating composition comprises a combination of a polymer containing a carboxylic group or an acid anhydride and a compound containing an epoxy group or a polymer containing a carboxylic group and an epoxy group, an organic solvent and a specific imidazole compound, and realizes a protective film excellent in sputtering resistance while maintaining preservation stability equal or superior to conventional compositions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for obtaining a smooth and transparent surface useful for forming a protective film, and particularly to a coating composition for a protective film of a color filter formed on glass or a transparent material.

2. Description of the Related Art In recent years, liquid crystal display elements have been actively applied to electronic devices such as AV devices and personal computers. In particular, demand for a color display is rapidly increasing due to abundant information and the like in addition to good visibility. In general, to obtain a color display, for example, a mosaic or striped color filter on a substrate such as a transparent glass, a staining method,
It is formed by a printing method, a pigment dispersion method, an electrodeposition method, or the like.

[0003] A color filter is usually manufactured to a thickness of about 1 micron, but a submicron step is formed on the surface. In the color STN, this step affects the display crystal quality (uneven color, etc.). Therefore, in order to prevent display unevenness, it is necessary to keep the surface flatness to 0.1 μm or less. In order to obtain such a flat surface, a thermosetting acrylic resin has been applied to the surface of the color filter.

It is necessary to protect the surface of the color filter not only in the liquid crystal display device but also in the solid-state image pickup device. A protective film for protecting the color filter from severe conditions such as high temperature generated when forming by sputtering is required. This protective film is required to be smooth and tough, to be excellent in transparency, and to be excellent in heat resistance and chemical resistance which does not cause discoloration or deterioration for a long time. A thermosetting resin containing an epoxy copolymer has been used to satisfy such requirements.

[0005] Further, many coating compositions for forming a protective film which have hitherto been known are two-parts and are used by mixing them before use. It is desired that the powder be used immediately after mixing. Further, depending on the composition of the coating composition, a sublimate may be generated during curing, and may be crystallized into dust, which may hinder the subsequent production of a liquid crystal panel. Things are desired.

As a conventionally known coating composition for forming such a protective film, for example, Japanese Patent Application Laid-Open No. 9-10033 / 1991
No. 8 discloses that (A) a copolymer having at least 20% by weight of a specific structure having a structure in which an epoxy group is bonded to a main chain of a copolymer via a carbonyl group, and having a weight average molecular weight in terms of polystyrene of 2,000. A coating resin comprising a polymer or copolymer having a molecular weight of 10,000 to 10,000, (B) at least one compound selected from polycarboxylic anhydrides and polycarboxylic acids, and (C) an organic solvent. A composition is described. This specification discloses the addition of an imidazole compound as a curing accelerator.
However, according to the study of the present inventors, these coating compositions have room for improvement in terms of resistance when exposed to the harsh conditions in the sputtering process.

[0007]

SUMMARY OF THE INVENTION The present inventors have now found that a combination of a specific polymer and a cross-linking agent has excellent storage stability, adhesion stability, and flatness, and particularly high temperature generated when an electrode layer is formed by sputtering. (About 150-250 ° C),
Alternatively, it has been found that a coating composition having resistance to severe conditions such as vacuum can be obtained. The present invention
It is based on such knowledge.

Accordingly, the present invention is stable per se,
Another object of the present invention is to provide a coating composition that realizes an excellent protective film.

[0009] More specifically, the present invention relates to a method for producing an electrode layer, which has a storage stability, adhesion, transparency, flatness and the like that are higher than those of a conventional coating composition, and applies sputtering conditions when forming an electrode layer. It is an object of the present invention to provide a coating composition having excellent resistance to odor.

The coating composition according to the present invention comprises (A) a combination of a polymer containing a carboxyl group or an acid anhydride and a compound containing an epoxy group, or a polymer containing a carboxyl group or an epoxy group,
(B) an organic solvent, and (C) at least one kind of an imidazole compound represented by the following general formula (I).

Embedded image (Where R ¹ and R ² are each independently hydrogen or a substituted or unsubstituted alkyl group, R ³ is hydrogen, a substituted or unsubstituted alkyl group, or an aryl group R ⁴ is
Hydrogen, a substituted or unsubstituted alkyl group. )

[0011]

DETAILED DESCRIPTION OF THE INVENTION The coating composition according to the present invention comprises (A) a specific resin component, (B) an organic solvent,
(C) a specific imidazole compound.

(A) Resin Component In the present invention, the component (A) includes a polymer containing a carboxyl group or an acid anhydride (hereinafter referred to as a carboxyl group-containing polymer) and a compound containing an epoxy group (hereinafter referred to as an epoxy group-containing compound). Or a polymer containing a carboxyl group and an epoxy group (hereinafter referred to as a carboxyl group-epoxy group-containing polymer).

(I) Component (A) contains a carboxyl group
Combination of polymer and epoxy group-containing compound
In this case, in this case, the epoxy group acts as a crosslinking agent, crosslinks the carboxyl group-containing polymer, and cures the components to form a coating.

Here, the carboxyl group-containing polymer is
It can be arbitrarily selected within a range not to impair the effects of the present invention.

Preferred specific examples of such a polymer include a copolymer of acrylic acid, methacrylic acid, or an ester thereof, and a vinyl aromatic compound. Examples of acrylic acid, methacrylic acid, or esters thereof include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, ethylhexyl methacrylate, phenyl acrylate, and the like. . Examples of the vinyl aromatic compound include styrene, α-methylstyrene, p-methylstyrene and the like.

The copolymer form of the copolymer is not particularly limited, and may be any of a random copolymer obtained by addition polymerization, a block copolymer and the like. Further, the copolymerization method is not particularly limited, and may be performed by a solution polymerization method, an emulsion polymerization method, or the like.

The molecular weight of the carboxyl group-containing polymer is
Although not particularly limited, the weight average molecular weight in terms of styrene is preferably 5,000 to 200,000. The weight average molecular weight of this polymer is 10,000-1.
About 00,000 is preferable. Further, as the chemical properties, the acid value KOH is 10 to 300 mg / g, particularly 30 to 1 mg / g.
The glass transition point is preferably from 50 ° C to 250 ° C.

The addition amount of the carboxyl group-containing polymer in the present invention may be appropriately determined within a range where a good protective film can be realized, but is preferably about 5 to 30% by weight, more preferably 10 to 25% by weight in the coating composition. %
It is about.

In the present invention, it is essential that the epoxy group-containing compound has an epoxy group in order to act as a cross-linking agent, but other compounds may be arbitrarily selected within a range that does not impair the effects of the present invention. it can.

However, as the epoxy group-containing compound, a polyfunctional epoxy group-containing compound containing one or more benzene rings or heterocycles in one molecule and two or more epoxy groups is preferable. According to a more preferred embodiment of the present invention, the epoxy group-containing compound preferably contains a phenyl group and a cyclohexyl group, and more preferably contains at least two phenyl groups.

According to a preferred embodiment of the present invention, a compound containing three or more epoxy functional groups is preferable.

Specific examples of the crosslinking agent include bisphenolacetone diglycidyl ether, phenol novolak epoxy resin, cresol novolak epoxy resin, triglycidyl isocyanate, tetraglycidyldiaminodiphenylene, tetraglycidyl-m-xylenediamine, and tetraglycidyl-1. , 3-Bis (aminoethyl) cyclohexane, tetraphenylglycidyl ether ethane, triphenyl glycidyl ether ethane, bisphenol hexafluoroacetodiglycidyl ether, 1,3-bis (1- (2,3-epoxypropoxy) -1-tri Fluoromethyl-2,2,2-trifluoromethyl) benzene, 4,4-bis (2,3-epoxypropoxy) octafluorobiphenyl, triglycidyl-p-aminophenyl Nord, tetraglycidyl meta-xylene diamine, 2- (4- (2,3-epoxypropoxy) phenyl) -2- (4- (1,1-bis (4-
(2,3-epoxypropoxy) phenyl) ethyl) phenyl) propane, 1,3-bis (4- (1- (4-
(2,3-epoxypropoxy) phenyl) -1- (4
-(1- (4- (2,3-epoxypropoxyphenyl) -1-methylethyl) phenyl) ethyl) phenoxy) -2-propanol and the like.

In the present invention, the amount of the epoxy group-containing compound is not particularly limited, but is preferably about 1 to 50 parts by weight, more preferably 10 to 40 parts by weight, per 100 parts by weight of the carboxyl group-containing polymer. .

(Ii) Component (A) is a carboxyl group—
In the case of an epoxy group-containing polymer, the epoxy group present as a side chain of the polymer reacts with a carboxyl group in the same molecule or another molecule, and is cured to form a coating. Here, the carboxyl group-epoxy group-containing polymer can be arbitrarily selected within a range that does not impair the effects of the present invention.

Preferred specific examples of such a polymer include a copolymer of acrylic acid, methacrylic acid or an ester thereof and an epoxy group-containing compound.
Further, a vinyl aromatic compound may be used as a monomer as needed. The acrylic acid, methacrylic acid, or their esters, epoxy group-containing compounds, and vinyl aromatic compounds that can be used as monomers are the same as those described above.

Here, the performance of the formed film also depends on the crosslinked structure, and the crosslinked structure also depends on the ratio of the epoxy group to the carboxyl group or acid anhydride contained in the polymer. Therefore, these ratios in the polymer are restricted to some extent, and the number of epoxy groups per carboxyl group is preferably from 0.1 to 10, more preferably from 0.2 to 1.

The copolymer form of the copolymer is not particularly limited, and may be any of a random copolymer obtained by addition polymerization, a block copolymer and the like. Further, the copolymerization method is not particularly limited, and may be performed by a solution polymerization method, an emulsion polymerization method, or the like.

The addition amount of the carboxyl-epoxy group-containing polymer in the present invention may be appropriately determined within a range where a good protective film can be realized, but is preferably about 5 to 30% by weight, more preferably about 10 to 30% by weight in the coating composition.
About 25% by weight.

The molecular weight of the carboxyl-epoxy group-containing polymer is not particularly limited, but preferably has a weight average molecular weight in terms of styrene of 5,000 to 200,000. The weight average molecular weight of this polymer is 10,
About 000 to 100,000 is preferable. Further, as chemical properties, the acid value KOH is preferably from 10 to 300 mg / g, particularly preferably from 30 to 100 mg / g, and the glass transition point is preferably from 50 ° C to 250 ° C.

(B) Solvent In the present invention, an organic solvent is used as a solvent for dissolving the component (A) and the imidazole compound (C) described below. According to a preferred embodiment of the present invention, the organic solvent comprises
It is preferably selected from the group consisting of propylene glycol, ethylene glycol, lactic acid, butyric acid, acetic acid, formic acid, γ-butyrolactone solvent and mixtures thereof. By utilizing these organic solvents,
The obtained coating composition is stable for about 6 months after preparation, and a uniform coating film without coating unevenness is obtained. As a result, excellent adhesion, flatness, transparency, and durability are obtained. A protective film having excellent wear resistance, stain resistance, and chemical resistance can be obtained.

Specific examples of the organic solvent include glycol ether and acetate solvents such as propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol-t-butyl ether, dipropylene glycol methyl ether, and dipropylene glycol. Propyl ether, tripropylene glycol methyl ether, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, ethylene glycol ethyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, ethylene glycol isopropyl ether, ethylene glycol-n-butyl ether, cellosolve acetate , Methyl celloso Bed acetate, ethyl cellosolve Sete - DOO, diethylene glycol methyl ether,
Diethylene glycol ethyl ether, diethylene glycol butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monoacetate, diethylene glycol monoethyl ether acetate, propylene glycol phenyl ether, propylene glycol ethyl ether acetate, triethylene glycol butyl ether, 3-methyl-3-methoxy Butyl acetate, 3
-Methyl-3-methoxybutanol. Examples of the lactic acid-based solvent include ethyl lactate, methyl lactate, butyl lactate, and pentyl lactate. Examples of the acetic acid-based solvent include butyl acetate, amyl formate, isoamyl acetate, isobutyl acetate, methoxybutyl acetate, and butyl propionate, and examples of the butyric acid-based solvent include isobutyl butyrate, butyl butyrate, and ethyl pyruvate.

Further, according to a preferred embodiment of the present invention,
It is preferable to use propylene glycol methyl ether acetate or a mixed organic solvent containing at least this as the organic solvent. When using a mixed organic solvent containing propylene glycol methyl ether acetate, preferred organic solvents used with propylene glycol methyl ether acetate include propylene glycol, ethylene glycol, lactic acid, butyric acid, acetic acid, formic acid, γ -Butyrolactone solvents and mixtures thereof.

The amount of the organic solvent to be added to the coating composition may be appropriately adjusted depending on the concentration of the polymer other than the solvent, the crosslinking agent, and other additives. %. Here, other additives include an adhesion enhancer, a surfactant, an antioxidant, a thickener, an ultraviolet absorber, a reaction accelerator, and others.

(C) Imidazole compound The coating composition of the present invention comprises an imidazole compound. Here, the imidazole compound is represented by the following general formula (I).

Embedded image (Where R ¹ and R ² are each independently hydrogen or a substituted or unsubstituted alkyl group, R ³ is hydrogen, a substituted or unsubstituted alkyl group, or an aryl group R ⁴ is
Hydrogen, a substituted or unsubstituted alkyl group. Here, when R ^{1 to} R ⁴ are an alkyl group, the number of carbon atoms is preferably independently 1 to 20. Moreover, each may be independently substituted by a substituent. Preferred substituents include a hydroxyl group, a cyano group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted triazinyl group,
Examples include a substituted or unsubstituted alkoxy group.

More specifically, R ¹ and R ² are each independently —H, —CH ₃ , —CH ₂ OH, or —CH ₂
Is preferably OC ₂ H ₄ CN, R ³ is, -H, -
_{CH 3, -C 2 H 5,} -C 11 H 23, -C 17 H 35, -Ph,
R ⁴ is preferably -H, -CH ₃ , -CH
_{2 -Ph, -C 2 H 4 CN} , preferably a -C ₂ H ₄ -DAT. Here, Ph is a phenyl group,
DAT is a 2,4-idiamino-1,3,5-triazin-6-yl group.

The imidazole compounds include, among these, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole,
2-phenyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,
2-dimethylimidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole , 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6
-(2'-methylimidazolyl- (1 '))-ethyl-
s-triazine, 2,4-diamino-6- (2′-undecylimidazolyl) -ethyl-s-triazine, 2,
4-diamino-6- (2′-ethyl-4-methylimidazolyl- (1 ′))-ethyl-s-triazine, 2-phenyl-4,5-dihydroxymethylimidazole,
Preferred are -phenyl-4-methyl-5-hydroxymethylimidazole and 1-cyanoethyl-2-phenyl-4,5-di (2-cyanoethoxy) methylimidazole.

The imidazole compounds can be used alone or in combination of two or more.

The amount of the imidazole compound to be added is generally 0.5 to 40 parts by weight, especially 1.5 to 10 parts by weight, based on 100 parts of the polymer component (A). Is preferred. In addition, the imidazole compound can form a molecular compound with multiple molecules, for example, trimellitic acid. Such molecular compounds include 1-cyanoethyl-2-ethyl-4-methylimidazolium trimellitate, 1-cyanoethyl-2-undecylimidazolium trimellitate and 1-cyanoethyl-2-mellitate.
Phenylimidazolium trimellitate; These molecular compounds can also be used arbitrarily as long as they do not impair the effects of the present invention. In such a case, the amount added should be based on the weight excluding the polymolecule that binds to the imidazole compound.

Formation of Protective Film As a substrate to which the coating composition according to the present invention can be applied, a color filter, a glass, a glass filter,
Black matrix, various polymers (polyimide, polyamide, polyethylene, acrylic resin, etc.), indium titanium oxide, silicon nitride, metal oxides (titanium oxide, silicon oxide, chromium oxide, etc.), metals (aluminum, copper, etc.)
But are not limited to these.

The substrate on which the protective film is formed by the coating composition according to the present invention is used for, for example, semiconductors, flat panel displays, and electronic equipment.
It is not limited to these.

The coating composition according to the present invention can be applied to the above-mentioned substrate and cured by heating to form a protective film.

The method of applying the coating composition is not particularly limited, and for example, a method such as a spin coating method, a roll coating method, and a spraying method can be used. In particular, the spin coating method is useful for forming a uniform film.

The curing conditions for the coating composition according to the present invention may be appropriately determined in consideration of the type of the polymer, the composition of the coating composition, and the like.
It can be cured at a temperature of 0 ° C. for about 20 minutes to 10 hours.

[0044]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 (a) Preparation of coating composition A coating composition comprising the following components was prepared.

Example 1 Comparative Example 1 Polymer ^{* 1} 14% 14% Crosslinking Agent VG3101L ^{* 2} 4.2% 4.2% Surfactant R08 ^{* 3} 0.056% 0.056% Additive 2E4MZ ^{* 4} 3% --- Solvent PGMEA ^{* 5} residue ^{* 1} monomer components are methacrylic acid (14%), 2-hydroxypropyl methacrylate (20%), methyl methacrylate (60%), and n-butyl acrylate (6%) Is a polymer. Styrene-equivalent molecular weight 40,000, acid value KOH150,
Glass transition point 81. ^{* 2} Crosslinking agent (Techmore VG3010L) manufactured by Mitsui Chemicals, Inc., epoxy equivalent 212 g / eq ^{* 3} Surfactant (perfluoroalkyl group-containing oligomer) manufactured by Dainippon Ink Co., Ltd. ^{* 4} Shikoku Chemical Industry Co., Ltd. 2-ethyl-4-methylimidazole ^{* 5} Solvent: propylene glycol methyl ether acetate

(B) Applying the coating composition obtained on the formation of the protective film on a substrate on which a 1.2 μm color filter was formed at 1000 rpm / 5.
The coating was performed under a spin coating condition of 2 seconds, and then dried at 110 ° C. for 1 minute on a hot plate. Then, it was heat-cured on a hot plate at 250 ° C. for 1 hour.

(C) The protective film obtained in the test for evaluating the sputter resistance of the protective film was subjected to a sputter treatment under the following sputtering conditions, and the surface of the treated film was observed and evaluated. Sputtering conditions (1) Temperature: 200 ° C., current: 0.48 A · DC, time: 5 minutes (2) Temperature: 250 ° C., current: 0.48 A · DC, time: 5 minutes (3) Temperature: 250 ° C. Current: 0.48 A DC, time: 10 minutes The obtained results were as follows. Table 1 Sputtering conditions Example 1 Comparative Example 1 (1) No wrinkles on the surface, no cracks No wrinkles on the surface, no cracks (2) No wrinkles on the surface, no cracks Wrinkles on the surface (3) No wrinkles on the surface, no wrinkles on the surface Yes

Example 2-6 Evaluation was carried out in the same manner as in Example 1 except that the following imidazole compound was used instead of the imidazole compound. Example 2 1-cyanoethyl-2-methylimidazole Example 3 1-cyanoethyl-2-ethyl-4-methylimidazole Example 4 1-cyanoethyl-2-undecylimidazolium trimellitate Example 5 2,4-diamino -6- (2'-undecylimidazolyl) -ethyl-s-triazine Example 6 2-Phenyl-4-methyl-5-hydroxymethylimidazole In Example 2-6, the same results as in Example 1 were obtained. Was done.

Continued on the front page (72) Inventor Junichi Fukuzawa 2-28-8 Honkomagome, Bunkyo-ku, Tokyo Bunkyo Green Court Center Office 9th floor Inside Clariant Japan Co., Ltd. (72) Inventor Takamasa Harada Ogasa, Shizuoka Prefecture 3810 Chihama, Higashi-cho, Gunma F-term (reference) 4J038 CC021 CC022 CC071 CC072 CG031 CG032 CG141 CG142 CH031 CH032 CH041 CH042 CH071 CH072 CJ031 CJ032 DB051 DB052 DB061 DB062 JA0732 KA06 MA13 MA14 NA01 NA12 NA14 NA26

Claims (7)

[Claims] 1. A combination of (A) a polymer containing a carboxyl group or an acid anhydride and a compound containing an epoxy group,
Alternatively, a coating composition comprising a polymer containing a carboxyl group and an epoxy group, (B) an organic solvent, and (C) at least one imidazole compound represented by the following general formula (I). Embedded image (Where R ¹ and R ² are each independently hydrogen or a substituted or unsubstituted alkyl group, R ³ is hydrogen, a substituted or unsubstituted alkyl group, or an aryl group R ⁴ is
Hydrogen, a substituted or unsubstituted alkyl group. ) 2. The composition according to claim 1, wherein said component (A) has a weight average molecular weight in terms of styrene of 5,000 to 200,000 and an acid value of KOH of 10 to 10.
300 mg / g, and glass transition point 50 ° C to 250 ° C
And a polymer comprising a carboxyl group or an acid anhydride and a polyfunctional epoxide group-containing compound comprising one or more benzene rings or heterocycles and comprising two or more epoxy groups. The coating composition according to claim 1, which is a combination. 3. The coating composition according to claim 1, wherein the polymer is a copolymer of acrylic acid, methacrylic acid, or an ester thereof, and an aromatic vinyl compound. 4. The epoxide group-containing compound according to claim 1, wherein said compound contains at least three epoxide groups.
4. The coating composition according to any one of 3. 5. The method according to claim 1, wherein the organic solvent is propylene glycol, ethylene glycol, lactic acid, butyric acid, acetic acid,
The solvent is selected from the group consisting of formic acid, γ-butyrolactone solvent, and mixtures thereof.
A coating composition according to any one of the preceding claims. 6. The coating composition according to claim 1, wherein the organic solvent is propylene glycol methyl ether acetate or a mixture of propylene glycol methyl ether acetate and another organic solvent. 7. An imidazole compound represented by the general formula (I) is 2-methylimidazole, 2-ethyl-4-
The coating composition according to any one of claims 1 to 6, wherein the coating composition is methylimidazole, 1-benzyl-2-methylimidazole, and 2-phenyl-4-methylimidazole.