JP2002146276A - Protective film composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a protective film composition which excels in heat resistance, adhesion, and visible light transmittance and, at the same time, can form a protective film having high surface smoothness even when the surface of a base material is not planarized, and has high resistance to liquid crystal staining and excels in high temperature water-vapor resistance on its ITO deposition particularly when used as the protective film for the colored resin film of a liquid crystal display color filter. SOLUTION: This protective film composition comprises, as the essential components, (1) an epoxy resin having at least two functional groups in the molecule, (2) an addition reaction product of a polycarboxylic acid having at least two carboxyl groups in the molecule with a vinyl (thio) ether compound as the curing agent, and (3) a curing catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition for forming a protective film, and more particularly to a composition for a protective film suitable as a protective film on a colored resin film formed on the surface of a glass substrate or the like.

[0002]

2. Description of the Related Art Liquid crystal display elements are immersed in a solvent, an acid, an alkaline solution or the like during the manufacturing process.
When O is formed, the element surface is locally exposed to a high temperature by sputtering. In order to prevent deterioration and damage of the element from such severe conditions, formation of a protective film having resistance thereto is generally performed. Such a protective film has, in addition to the above-mentioned required characteristics, a low degree of liquid crystal contamination, a smoothness, and a good adhesion to a substrate on which the protective film is formed and a layer formed on the protective film. That the visible light transmittance is high so as not to lower the brightness of the liquid crystal display, that there is no change over time such as coloring, whitening, yellowing, impact,
It is required to have toughness to withstand distortion and the like. From the viewpoint of productivity, one of the problems is that the solution is a single solution and that the solution has excellent storage stability.

Acrylic resin, melamine resin, polyimide resin and the like have been proposed as materials for a protective film which have been conventionally used. However, at present, there is no well-balanced material satisfying all required characteristics. It is. For example, an acrylic resin is excellent in visible light transmittance but insufficient in heat resistance, and has a problem that wrinkles and cracks are generated on the film surface during deposition of ITO or the like. Melamine resin has good heat resistance, but has extremely poor adhesion to a glass substrate, and has a problem that cissing easily occurs on the substrate or filter. Although polyimide resin has high heat resistance, it has insufficient transparency and lacks storage stability of the resin, and has poor solubility, and it is said that the organic solvent that can be used becomes a solvent that attacks the color filter. There is such a problem. Also, an acrylic resin having an epoxy group, or a protective film using an epoxy resin and an o-cresol novolac-based curing agent proposed in JP-A-5-140274 and JP-A-5-140267 have been studied. Is insufficient, or the deposition temperature of ITO has been increased in recent years, but there is a problem that the yellowing resistance due to heat during the deposition is poor. Attempts have been made to use an acid anhydride as a curing agent to overcome this yellowing, but there are problems with storage stability due to its reactivity and hygroscopicity. However, there remain problems such as dissolving only in an organic solvent having a problem in safety.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to satisfy the conventional requirements of heat resistance, adhesion, and visible light transmittance, and to provide a case where the substrate surface is not flattened. Even with the formation of a protective film having high surface smoothness, it has excellent liquid crystal contamination resistance and storage stability.
An object of the present invention is to provide a composition for forming a protective film which is excellent in resistance during ITO deposition and liquid crystal contamination when used as a protective film for a colored resin film of a color filter for liquid crystal display.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that an epoxy resin composition satisfying the above-mentioned properties can be obtained at the same time. That is, the present invention relates to (1) (1) an epoxy resin having at least two functional groups in one molecule, and (2) a polycarboxylic acid having at least two carboxyl groups in one molecule as a curing agent. An addition reaction product of a vinyl (thio) ether compound, (3) a composition for a protective film containing a curing catalyst as an essential component, (2) an epoxy resin, (a) a novolak-type epoxy resin, b)
Epoxidized polycondensate of 2,2-bis (hydroxymethyl) -1-butanol and 1,2-epoxy-4-vinylcyclohexane and (c) 2- (4-hydroxyphenyl) -2- {4- [ At least one composition selected from the group consisting of 1,1 bis (4-hydroxyphenyl) ethyl] phenyl} propanetriglycidyl ether, the composition for a protective film according to the above (1), and (3) a carboxylic acid as a curing agent The equivalent value is 0.2 to 0.2 with respect to the epoxy group 1 in the component (1).
The composition for a protective film according to the above (1) or (2), which is 1.8, and (4) the curing agent is an addition reaction product of 1,2,4-benzenetricarboxylic acid and n-propylvinyl ether. The composition for a protective film according to any one of the above (1) to (3), wherein (5) the curing agent is an addition reaction between 1,2,4,5-benzenetetracarboxylic acid and n-propylvinyl ether. The composition for a protective film according to any one of the above (1) to (3), wherein (6) the curing agent is an addition reaction product of naphthalenediic (or tetra) carboxylic acid and n-propyl vinyl ether The composition for a protective film according to any one of the above (1) to (3), wherein (7) the curing catalyst is a heat-latent acid catalyst. The composition for a protective film according to the above item, wherein (8) the curing catalyst comprises a Lewis acid (or base) and The composition for a protective film according to any one of the above (1) to (7), which is a compound obtained from a starting acid (or a base), and (9) the protective film according to the above (1) to (8). The present invention relates to a transparent thin film obtained by using the composition for a liquid.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. Epoxy resin (a) preferably used in the present invention
Is obtained by subjecting orthocresol novolak to glycidyl etherification by an ordinary method, and the epoxy resin (b) is 2,2-bis (hydroxyphenyl)-
The polycondensate obtained by polycondensing 1-butanol and 1,2-epoxy-4-vinylcyclohexane and then oxidizing with a peroxide such as peracetic acid is obtained by epoxidation. The epoxy resin (c) is 2- (4-hydroxyphenyl) -2-
{4- [1,1 bis (4-hydroxyphenyl) ethyl]
Phenyl} propane can be obtained by glycidyl etherification in a usual manner. These epoxy resins (a), (b) and (c) may be used singly or in combination, and furthermore, within a range that does not impair physical properties such as heat resistance, yellowing resistance and transparency. Other epoxy resins, acrylic resins, polyester resins and the like may be mixed.

Specific examples of other epoxy resins that can be used include polyfunctional epoxy resins that are glycidyl etherified polyphenol compounds, polyfunctional epoxy resins that are glycidyl etherified various novolak resins, alicyclic epoxy resins, and heterocyclic epoxy resins. Formula epoxy resin, glycidyl ester epoxy resin, glycidylamine epoxy resin,
Epoxy resins obtained by glycidylation of halogenated phenols are exemplified. Examples of polyfunctional epoxy resins that are glycidyl etherified polyphenol compounds include bisphenol A, bisphenol F, bisphenol S,
4,4′-biphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, tetramethylbisphenol S, dimethylbisphenol S, tetramethyl-4,4′-biphenol, dimethyl-4,4 ′ −
Biphenol, 1- (4-hydroxyphenyl) -2-
[4- (1,1-bis- (4-hydroxyphenyl) ethyl) phenyl] propane, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol),
4,4'-butylidene-bis (3-methyl-6-ter
t-butylphenol), trishydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phloroglicinol, phenols having a diisopropylidene skeleton, phenols having a fluorene skeleton such as 1,1-di-4-hydroxyphenylfluorene, phenol Polyfunctional epoxy resin which is a glycidyl etherified product of a polyphenol compound such as fluorinated polybutadiene. Novolak resin made from various phenols such as phenol, bisphenol A, bisphenol F, bisphenol S, and naphthols, and a phenol resin having a xylylene skeleton Glycidyl etherified products of various novolak resins such as lac resins, phenol novolak resins containing a dicyclopentadiene skeleton, phenol novolak resins containing a biphenyl skeleton, and phenol novolak resins containing a fluorene skeleton; and aliphatic alicyclic epoxy resins such as cyclohexane. Aliphatic epoxy resins having a skeleton and aliphatic epoxy resins of 1,4
-Butanediol, 1,6-hexanediol, polyethylene glycol, glycidyl ethers of polyhydric alcohols such as pentaerythritol, and a heterocyclic epoxy resin having a heterocyclic ring such as an isocyanuric ring and a hydantoin ring; Glycidyl ester-based epoxy resins include epoxy resins composed of carboxylic acids such as hexahydrophthalic acid diglycidyl ester, glycidylamine-based epoxy resins include epoxy resins obtained by glycidylating amines such as aniline and toluidine, and glycidyl-containing halogenated phenols. Brominated bisphenol A, brominated bisphenol F, brominated bisphenol S, brominated phenol novolak, brominated cresol novolak, chlorinated bisphenol S, and halogenated phenols glycidylated epoxy resins such as chlorinated bisphenol A.

The curing agent (c) comprises a compound having at least two carboxyl groups in one molecule and vinyl (thio)
The ether compound is subjected to an addition reaction in the presence of an acid catalyst to obtain a (thio) ester. Here, the vinyl (thio) ether compound means a vinyl ether compound or a vinyl thioether compound, and is not particularly limited as long as the compound has a vinyl group and an ether bond or a thioether bond in one molecule. It may be a cyclic vinyl ether compound or the like.

The compound having at least two carboxyl groups in one molecule includes, for example, aliphatic polycarboxylic acids having 2 to 22 carbon atoms such as succinic acid, adipic acid, azelaic acid and sebacic acid, phthalic acid, isophthalic acid , Terephthalic acid, 1,2,4-benzenetricarboxylic acid, 1,
Aromatic carboxylic acids such as 2,4,5-benzenetetracarboxylic acid and naphthalenediic (or tetra) carboxylic acid; alicyclic polycarboxylic acids such as tetrahydrophthalic acid, hexahydrophthalic acid and methylhexahydrophthalic acid; No.

As the vinyl (thio) ether compound,
For example, aliphatic vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, and the corresponding aliphatic vinyl thioether compounds, Cyclic vinyl ether compounds such as 3,3-dihydrofuran and 3,4-dihydrofuran, and the corresponding cyclic vinyl thioether compounds. As a combination of a compound having at least two carboxyl groups in one molecule and a vinyl (thio) ether compound, an aromatic carboxylic acid and an aliphatic vinyl ether compound are preferable, and 1,2,4-benzenetricarboxylic acid,
1,2,4,5-benzenetetracarboxylic acid or naphthalenedi (or tetra) carboxylic acid and n-propylvinyl ether are particularly preferred.

An acid anhydride-based curing agent, a carboxylic acid-based curing agent, an amine-based curing agent, a phenol-based curing agent, a hydrazide-based curing agent, etc. are used as long as physical properties such as heat resistance and visible light transmittance are not reduced. They can be used in combination.

Specific examples of acid anhydride-based curing agents that can be used include, for example, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol trimellitic anhydride. , Aromatic carboxylic acid anhydrides such as biphenyltetracarboxylic acid anhydride, aliphatic carboxylic acid anhydrides such as azelaic acid, sebacic acid, dodecanedioic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, nadic acid An alicyclic carboxylic anhydride such as an anhydride, a hetic anhydride, and a hymic anhydride can be used.

Specific examples of amine curing agents that can be used include diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenylether, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 1,5-diaminonaphthalene, and m-xylylene. Aromatic amines such as diamine, ethylenediamine, diethylenediamine, isophoronediamine, aliphatic amines such as bis (4-amino-3-methyldicyclohexyl) methane, polyetherdiamine, dicyandiamide,
Guanidines such as-(o-tolyl) biguanide;

Specific examples of phenolic curing agents that can be used include bisphenol A, bisphenol F, bisphenol S, 4,4'-biphenylphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, Tetramethylbisphenol S, dimethylbisphenol S, tetramethyl-4,4'-biphenol, dimethyl-4,4'-biphenylphenol, 1- (4-
Hydroxyphenyl) -2- [4- (1,1-bis-
(4-hydroxyphenyl) ethyl) phenyl] propane, 2,2'-methylene-bis (4-methyl-6-te
rt-butylphenol), 4,4'-butylidene-bis (3-methyl-6-tert-butylphenol),
Trishydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phenols having a diisopropylidene skeleton, phenols having a fluorene skeleton such as 1,1-di-4-hydroxyphenylfluorene, phenolated polybutadiene, phenol, cresols, ethyl Phenols, butylphenols,
Novolak resin, phenol novolak resin containing xylylene skeleton, phenol novolak resin containing dicyclopentadiene skeleton, phenol novolak resin containing biphenyl skeleton, phenol novolak resin containing biphenyl skeleton, using various phenols such as octylphenols, bisphenol A, bisphenol F, bisphenol S, and naphthols Various novolak resins, such as a phenol novolak resin containing a furan skeleton and a phenol novolak resin containing a furan skeleton.

Specific examples of hydrazide-based curing agents that can be used include carbodihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, and azelaic acid dihydrazide. Sebacic acid dihydrazide, dodecandiohydrazide, hexadecandiohydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-
Naphthoic acid dihydrazide, 4,4'-bisbenzene dihydrazide, 1,4-naphthoic acid dihydrazide, 2,6-
Pyridine dihydrazide, 1,4-cyclohexane dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide,
Dihydrazide curing agents such as iminodiacetic acid dihydrazide, N, N'-hexamethylenebissemicarbazide, itaconic acid dihydrazide, pyromellitic trihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, 1,2,4-
A polyfunctional hydrazide-based curing agent such as benzenetrihydrazide is exemplified.

The curing agent is usually 0.2 to 1.8 in the equivalent ratio of the curing agent to the epoxy group of the epoxy resin (specifically, the carboxylic acid group equivalent in the curing agent (c)).
Preferably 0.4 to 1.4, more preferably 0.5 to
It is used in the range of 1.0.

The curing catalyst used in the present invention is not particularly limited as long as it is a compound known as a catalyst for accelerating the curing of an epoxy resin, and examples thereof include imidazoles, tertiary amines, and phosphines. Although it may be used, a thermally latent acid catalyst is preferred. Examples of the heat-latent acid catalyst include a compound comprising a Lewis acid and a Bronsted acid or a complex of a Lewis acid and a Bronsted salt, a compound obtained by neutralizing a Lewis acid or a Bronsted acid with a Lewis base, sulfonic acid esters, phosphoric acid Esters, onium compounds, etc. are mentioned, and a compound using a Lewis acid (or base) and a Bronsted acid (or base) as raw materials is preferable.

Examples of the Lewis acid include metal halides such as boron trifluoride and aluminum trichloride, and diethyl ether boron fluoride, trialkyl boron, zinc dioctylate, zinc stearate, tin octylate, calcium stearate and the like. Examples of the Bronsted acid include sulfuric acid, sulfonic acids such as p-toluenesulfonic acid, phosphoric acid, boric acid, carboxylic acids, and derivatives thereof.

The Lewis base used to neutralize the Lewis acid or Bronsted acid is, for example, ammonia, triethylamine, triethanolamine, pyridine, aniline, morpholine, N-methylmorpholine, pyrrolidine, N-methyl. Amines such as imidazole, N,
Amide compounds such as N-dimethylformamide and N-methylpyrrolidone; sulfoxide compounds such as dimethyl sulfoxide; ether compounds such as diethyl ether and tetrahydrofuran; thioether compounds such as dimethyl sulfide; phosphate ester compounds; borate esters Series compounds, carboxylic acid ester compounds, carbonate ester compounds, and trialkylphosphine compounds.

Among these latent heat hardening accelerators, p-toluenesulfonic acid, zinc dioctylate, neutralized product of zinc dioctylate in N-methylmorpholine, neutralized product of zinc dioctylate in triethanolamine, diethyl ether hydrofluoride Boron iodide is preferred.

The amount of the heat latent curing accelerator to be used is usually 0.05 to 100 parts by weight of the epoxy resin.
The amount is 5 parts by weight, preferably 0.1 to 3 parts by weight, more preferably 0.2 to 2 parts by weight. The amount of the curing accelerator used is 0.
If the amount is less than 05 parts by weight, a sufficient crosslinking reaction is unlikely to occur, and the heat resistance of the protective film is adversely affected. If the amount is more than 5 parts by weight, stability over time, yellowing during curing, and liquid crystal contamination may be poor. There is a nature.

The epoxy resin composition for a protective film of the present invention may contain, if necessary, a coupling agent, a surfactant, an oxidation stabilizer, a light stabilizer, a moisture resistance improver, a thixotropic agent, an antifoaming agent, Additives such as other various resins, tackifiers, antistatic agents, lubricants, and ultraviolet absorbers can also be blended.

Specific examples of the coupling agent that can be used include 3-glycidoxypropyltrimethoxysilane,
-Glycidoxypropylmethyldimethoxysilane, 3-
Glycidoxypropylmethyldimethoxysilane, 2-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl)
3-aminopropylmethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane,
Silanes such as N- (2- (vinylbenzylamino) ethyl) 3-aminopropyltrimethoxysilane hydrochloride, 3-methacryloxypropyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane Coupling agent, isopropyl
(N-ethylaminoethylamino) titanate, isopropyl triisostearoyl titanate, titanium di
(Dioctyl pyrophosphate) oxyacetate, tetraisopropyl di (dioctyl phosphite) titanate, neoalkoxy tri (p-N- (β-aminoethyl)
Titanium coupling agents such as (aminophenyl) titanate, Zr-acetylacetonate, Zr-methacrylate, Zr-propionate, neoalkoxy zirconate, neoalkoxytris neodecanoyl zirconate, neoalkoxytris (dodecanoyl) benzenesulfonyl zirconate , Neoalkoxytris (ethylenediaminoethyl) zirconate, neoalkoxytris (m-aminophenyl) zirconate, ammonium zirconium carbonate, Al-acetylacetonate, Al-methacrylate, zirconium such as Al-propionate, or aluminum-based coupling And a silane coupling agent is preferable. By using the coupling agent, the adhesion to the base material is improved, and a protective film having excellent moisture resistance reliability can be obtained.

The surfactant is added to improve the coating suitability of the composition for a protective film. For example, a silicon-based surfactant and a fluorine-based surfactant are used.
As the amount of addition, based on 100 parts by weight of the epoxy resin,
Usually, it is 0.001 to 0.5 parts by weight.

The composition for a protective film of the present invention can be obtained as a varnish by uniformly dissolving an epoxy resin, a curing agent, a curing catalyst, and, if necessary, various additives in an organic solvent. Specific examples of the organic solvent that can be used include, for example, methanol, ethanol, propanol,
Alcohols such as butanol, glycols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, 3-methoxybutanol, 3-methyl-3-methoxybutanol Ethers, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethylene glycol ether acetates such as ethylethoxypropiolate , Toluene, aromatic hydrocarbons such as xylene, methyl ethyl ketone, Ketones such as clohexanone, cyclopentanone, 4-hydroxy-4-methyl-2-pentanone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl 2-hydroxy-2-methylpropionate, 2-hydroxy- Ethyl 2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, 3 -Butyl hydroxypropionate, propyl 2-hydroxy-3-methylbutanoate, ethyl methoxyacetate, propyl methoxyacetate, methyl ethoxyacetate,
Ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, 2-ethoxy Ethyl propionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, 3-ethoxypropion Esters such as methyl acrylate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, and butyl 3-ethoxypropionate;
Ethers such as tetrahydrofuran;

Among these, considering the solubility of the epoxy resin, the curing agent, the curing catalyst, the reactivity with the organic solvent, the concentration change with time due to volatilization, the toxicity to the human body, etc.
Propylene glycol monomethyl ether acetate,
Propylene glycol monoethyl ether acetate,
Preferred are ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol, and esters.

The amount of the organic solvent used is not particularly limited, and is adjusted according to the desired film thickness, surface smoothness, film forming method, and the like to impart coating suitability.

The protective film formed by the composition of the present invention thus obtained has excellent adhesion to various materials such as glass, wood, metal, plastic and the like, and has smoothness and heat resistance. Because of its excellent transparency and toughness, it is useful as various protective films. It is particularly useful when a protective film is formed on a colored resin film such as a color filter for liquid crystal display or when a smooth layer of the color filter is formed because of its excellent liquid crystal contamination.

Here, when used as a color filter protective film, coating is usually performed by a spin coating method. The film thickness is usually applied under the condition of 0.1 to 10 μm, preferably 0.5 to 8 μm after heat curing.
At this time, in order to perform the coating operation efficiently, the viscosity of the composition of the present invention at 25 ° C. is adjusted to be 3 to 30 mPa · s, preferably 5 to 15 mPa · s, usually by the amount of the organic solvent used. . It is necessary to select optimal conditions for the drying and curing conditions after application according to the composition ratio of the components in the composition solution and the type of solvent, but usually, after pre-baking at 70 to 100 ° C. to remove the solvent, 150 10 at ~ 250 ° C
Post-bake for minutes to 1.5 hours to cure. The curing temperature does not need to be constant. For example, the curing may be performed while increasing the temperature. Prebake solvent removal and postbake curing can be performed using an oven, a hot plate, or the like.

[0030]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In Examples and Comparative Examples,% and parts are by weight unless otherwise specified.

Example 1 As a composition for a protective film, a composition (numerical value is "part") shown in the column of Example 1 in (Table 1) was dissolved in propylene glycol monoethyl ether acetate to give a solid content of 35%.
% Of the composition for the protective film was prepared. Next, thickness 0.7
On a glass substrate having a thickness of 2 mm, the resin solution was applied using a spin coater so that the thickness after curing became 2 μm, and prebaked at 100 ° C. for 2 minutes.
The composition was cured at 20 ° C. for 20 minutes to obtain a protective film of the present invention. Table 2 shows the evaluation results of the obtained protective films (the evaluation method will be described later).

Examples 2 to 4, Comparative Examples 1 to 3 Except that the compositions shown in the columns of Examples 2 to 4 and Comparative Examples 1 to 2 of Table 1 were used as the protective film composition. A protective film was formed in the same manner as in Example 1. In Comparative Example 3, a solution was prepared in the same manner as in other Comparative Examples, except that the curing agent used was insoluble in propylene glycol monoethyl ether acetate, and thus 40% was changed to cyclohexanone.
A protective film was obtained. The results of these evaluations are shown in (Table 2).

Examples 5 to 8 The compositions shown in each column of Examples 1 to 4 of Table 1 were used as the protective film composition, and instead of the glass substrate, a finely patterned color filter (the surface of the glass substrate was (Table 3) shows the results of evaluation of the protective film obtained in the same manner as in Example 1 except that a colored resin film was formed).

[0034]

[Table 1]

In Table 1, epoxy resin A: ortho-cresol novolak type epoxy resin (epoxy equivalent: 201 g / eq) epoxy resin B: 2,2-bis (hydroxymethyl)-
Epoxidized product of polycondensate of 1-butanol and 1,2-epoxy-4-vinylcyclohexane (epoxy equivalent: 1
80 g / eq) Epoxy resin C: 2- (4-hydroxyphenyl) -2
-{4- [1,1bis (4-hydroxyphenyl) ethyl] phenyl} propane triglycidyl ether (epoxy equivalent: 211 g / eq) Curing agent A: 1,2,4-benzenetricarboxylic acid and n-
Addition product of propyl vinyl ether (carboxylic acid equivalent: 160 g / eq) Curing agent B: 1,2,4-benzenetricarboxylic anhydride (acid anhydride equivalent: 192 g / eq) Accelerator A: triethanol of zinc dioctylate Amine neutralizer Accelerator B: 2E4MZ-CN (imidazole-based curing accelerator manufactured by Shikoku Chemicals Co., Ltd.) Coupling agent: Epoxysilane-based coupling silaace S-510 (manufactured by Ajinomoto Co., Ltd.) Surfactant: fluorine-based Surfactant Megafac F470
(Dai Nippon Ink Co., Ltd.)

Table 2 Example Comparative Example 1 2 3 4 1 2 3 Adhesion 100/100 ← ← ← ← ← ← Yellowing 230 ° C ○ ◎ ◎ ◎ ○ ○ ○ 240 ° C △ ○ ○ ○ △ ○ ○ ○ ○ ○ ○ × × ○ Storage stability ○ ○ ○ ○ ○ ○ ×

[0037]

In Tables 2 and 3, the evaluation methods and criteria are as follows. In Tables 2 and 3, ← means “same as left”.

1. Adhesion test JIS K for the protective film obtained in Examples or Comparative Examples
According to -5400 (1900) 8.5.2, using a cutter knife as a protective film, apply 11 scratches to the cloth at 1 mm intervals to form 100 grids (a), and then peel off with Cellotape (registered trademark). And the number of remaining grids (b) is calculated as b /
Indicated by a.

2. Heat resistance test The obtained protective film was left in an oven at 230 ° C and 240 ° C for 30 minutes, respectively, and the yellowing of the protective film was visually determined. The criterion is compared to the coating before leaving at high temperature,
◎ indicates no change, ○ indicates almost no change, Δ indicates a little yellow coloration but can be used, and x indicates yellowed color and cannot be used.

3. Liquid crystal contamination test The obtained protective film was scraped off with a cutter knife, and 50 m
g was weighed into 50 g of standard liquid crystal, and after standing at 100 ° C. for 72 hours, the specific resistance of the supernatant liquid crystal was measured. It was shown.

4. Storage stability The obtained composition for a protective film was put in a 100 g plastic bottle, sealed, and allowed to stand in a 40 ° C atmosphere for 72 hours. The change in viscosity was measured.
What increased in the above was evaluated as x.

[0043]

The composition for a protective film of the present invention is excellent in heat resistance, adhesiveness, transparency and liquid crystal contamination resistance, and has high stability over time, which is advantageous for protection of a colored resin film. In particular, the reliability of a color liquid crystal display device can be improved.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J036 AF06 AJ08 AK09 DA04 DA09 DB22 GA20 JA01 4J038 DB051 DB071 DB261 HA126 HA376 HA416 HA476 JA35 JA36 JB01 JB32 JB39 JC13 JC24 JC37 KA03 KA04 NA01 NA12 NA14 NA26 PC03

Claims (9)

[Claims] (1) an epoxy resin having at least two functional groups in one molecule; and (2) a polycarboxylic acid having at least two carboxyl groups in one molecule and vinyl (thio) as a curing agent. ) Addition products of ether compounds, (3)
A composition for a protective film, comprising a curing catalyst as an essential component. 2. An epoxy resin comprising: (a) a novolak type epoxy resin; and (b) 2,2-bis (hydroxymethyl).
Epoxidized product of a polycondensate of -1-butanol and 1,2-epoxy-4-vinylcyclohexane, and (c) 2-
The protective film according to claim 1, which is at least one member selected from the group consisting of (4-hydroxyphenyl) -2- {4- [1,1bis (4-hydroxyphenyl) ethyl] phenyl} propanetriglycidyl ether. Composition. 3. The method according to claim 1, wherein the carboxylic acid equivalent value of the curing agent is the component (1).
The composition for a protective film according to claim 1, wherein the ratio is 0.2 to 1.8 with respect to the epoxy group 1 in the protective film. 4. The composition for a protective film according to claim 1, wherein the curing agent is an addition reaction product of 1,2,4-benzenetricarboxylic acid and n-propyl vinyl ether. 5. The composition for a protective film according to claim 1, wherein the curing agent is an addition reaction product of 1,2,4,5-benzenetetracarboxylic acid and n-propyl vinyl ether. object. 6. The composition for a protective film according to claim 1, wherein the curing agent is an addition reaction product of naphthalenediic (or tetra) carboxylic acid and n-propyl vinyl ether. 7. The composition for a protective film according to claim 1, wherein the curing catalyst is a heat-latent acid catalyst. 8. The composition for a protective film according to claim 1, wherein the curing catalyst is a compound using a Lewis acid (or a base) and a Bronsted acid (or a base) as raw materials. 9. A transparent thin film obtained by using the composition for a protective film according to claim 1.