JP2002322244A - Composition for protective coating, method of using the same and use of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for protective coating excellent in adhesion, transparency to visible light and capable of forming a protective coating having a high surface flatness on a substrate having an unplaned surface, exhibiting a high thermal resistance and yellowing resistance and good contamination resistance to liquid crystals and especially excellent in high temperature resistance (yellowing resistance) in vacuum evaporation of ITO in the case of using as a protective coating for a colored resin coating of a color filter for liquid crystal display. SOLUTION: This composition for protective coating includes (1) an epoxy resin having at least two functional groups in a molecule, (2) a polyphenol compound including a cyclic terpene skeleton and (3) an imidazole based hardening accelerator.

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 film (eg, 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.

Conventionally, acrylic resin, melamine resin, polyimide resin and the like have been proposed as a material for a protective film. However, at present, there is no well-balanced material satisfying all required characteristics. 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 when depositing ITO (Indium Tin Oxide) 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 has been studied. There is a problem that the adhesion is insufficient, or the yellowing resistance due to heat during the deposition is inferior with the recent increase in the deposition temperature of ITO. To overcome this yellowing, attempts have been made to use an acid anhydride as a curing agent.
However, there is a problem in storage stability from the viewpoint of reactivity and hygroscopicity, and further, there are problems such as a limited organic solvent to be dissolved and a problem in safety of the solvent.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to satisfy the adhesion performance and the visible light transmission which have been required conventionally.
In addition, it forms a protective film with high surface smoothness even when the substrate surface is not flattened, and has high heat and yellowing resistance and good liquid crystal contamination resistance, especially for color filters for liquid crystal display. An object of the present invention is to provide a composition for forming a protective film, which is excellent in resistance during ITO vapor deposition and liquid crystal contamination resistance when used as a protective film for a resin film.

[0005]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the epoxy resin composition containing a polyhydric phenol compound having a specific skeleton as a curing agent has the above performance. Were simultaneously satisfied, and the present invention was completed. That is, the present invention comprises (1) (i) an epoxy resin having at least two epoxy groups in one molecule, (ii) a polyhydric phenol compound having a cyclic terpene skeleton, and (iii) an imidazole-based curing accelerator. (2) The composition for a protective film according to the above (1), wherein (2) the cyclic terpene skeleton-containing polyhydric phenol compound is a compound obtained by adding two molecules of phenols to one molecule of the cyclic terpene compound. The protective film composition, (3) a compound in which a cyclic terpene skeleton-containing polyhydric phenol compound is obtained by adding two molecules of phenols to one molecule of a cyclic terpene compound,
The composition for a protective film according to the above item (1), which is a compound obtained by further subjecting an aldehyde and / or ketone to a condensation reaction in the presence of an acidic catalyst, (4) the epoxy resin is an alicyclic compound The above (1) to which are multifunctional epoxy resins
(3) The composition for a protective film according to any one of (3), (5).
The phenolic skeleton of the terpene skeleton-containing polyhydric phenol compound is derived from at least one selected from the group consisting of phenol, o-cresol, 2,6-xylenol, and o-allylphenol. (3) The composition for a protective film according to any one of the items (3), (6) the phenol skeleton of the terpene skeleton-containing polyhydric phenol compound is formed from phenol, o-cresol, 2,6-xylenol, and o-allylphenol. The composition for a protective film according to the above item (4), which is derived from at least one member selected from the group consisting of:
The composition for a protective film according to any one of the above items (1) to (3), which is dihydro-1H-pyrrolo- [1,2-a] benzimidazole, and (8) an imidazole-based curing accelerator. , 2,3-dihydro-1H-pyrrolo- [1,2-a]
The composition for a protective film according to the above item (4), which is benzimidazole, (9) the imidazole-based curing accelerator is 2,2.
The composition for a protective film according to the above (5), which is 3-dihydro-1H-pyrrolo- [1,2-a] benzimidazole, wherein (10) the imidazole-based curing accelerator is 2,3-dihydro- The composition for a protective film according to the above (6), which is 1H-pyrrolo- [1,2-a] benzimidazole,
(11) A transparent thin film obtained by using the composition for a protective film according to any one of the above items (1) to (10), and (12) a transparent film described in the above item (11) as a color filter protective film. (13) A method of using the composition for a protective film according to any one of the above (1) to (10) as a protective film of a liquid crystal display element, (14) A) a liquid crystal display device provided with a color filter having a transparent thin film according to the above item (12), (15) (i) an epoxy resin having at least two epoxy groups in one molecule, and (ii)
A cyclic terpene skeleton-containing polyhydric phenol compound and (ii)
i) A composition for a film with high visible light transmittance, comprising an imidazole-based curing accelerator.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the following, "%" and "part" mean "part by mass" and "% by mass", respectively, unless otherwise specified. Examples of the epoxy resin (polyfunctional epoxy resin) having at least two epoxy groups in one molecule in the present invention include a polyfunctional epoxy resin which is a glycidyl etherified product of a polyphenol compound, and a glycidyl etherified product of various novolak resins. Functional epoxy resin,
Alicyclic polyfunctional epoxy resin, aliphatic polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, glycidyl ester polyfunctional epoxy resin, glycidylamine polyfunctional epoxy resin, polyfunctionalized glycidyl of halogenated phenols Epoxy resins and the like can be mentioned. These epoxy resins may be used alone or as a mixture of two or more.

A preferred epoxy resin among these polyfunctional epoxy resins is an alicyclic polyfunctional epoxy resin,
In some cases, a preferable effect is given by transparency. Among the alicyclic polyfunctional epoxy resins, an alicyclic polyfunctional epoxy resin in which the aliphatic ring is a cyclohexane ring having 6 carbon atoms is preferable. For example, 2,2-bis (hydroxyphenyl) -1
An epoxy resin made from a compound obtained by polycondensation of -butanol and 1,2-epoxy-4-vinylcyclohexane is one of more preferable ones. A preferred alicyclic polyfunctional epoxy resin having a cyclohexane ring is, for example, EHPE3150 from Daicel Chemical Industries, Ltd.
(Hereinafter referred to as epoxy resin A) and the like. The alicyclic polyfunctional epoxy resin may be used alone or in combination with the other polyfunctional epoxy resins. In some cases, other monofunctional epoxy resins, acrylic resins, polyester resins, and the like may be mixed as long as physical properties such as heat resistance, yellowing resistance, and transparency of the obtained coating film are not impaired.

Specific examples of polyfunctional epoxy resins other than the above-mentioned epoxy resin A are as follows. Examples of the polyfunctional epoxy resin which is a glycidyl etherified product of a polyphenol compound 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-te
rt-butylphenol), 4,4'-butylidene-bis (3-methyl-6-tert-butylphenol),
Trishydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phloroglicinol, phenols having a diisopropylidene skeleton, 1,1-
Examples include phenols having a fluorene skeleton such as di-4-hydroxyphenylfluorene, and polyfunctional epoxy resins that are glycidyl etherified products of polyphenol compounds such as phenolized polybutadiene.

[0009] Polyfunctional epoxy resins which are glycidyl etherified products of various novolak resins include phenol,
Novolak resins made from various phenols such as cresols, ethylphenols, butylphenols, octylphenols, bisphenols such as bisphenol A, bisphenol F and bisphenol S, naphthols, phenol novolak resins containing a xylylene skeleton, dicyclopentadiene skeleton Glycidyl etherified products of various novolak resins such as a phenol novolak resin containing a phenol novolak resin, a phenol novolak resin containing a biphenyl skeleton, and a phenol novolak resin containing a fluorene skeleton.

As the alicyclic polyfunctional epoxy resin, an alicyclic polyfunctional epoxy resin having an aliphatic ring skeleton such as cyclohexane, and as an aliphatic polyfunctional epoxy resin, 1,4-
Glycidyl ethers of polyhydric alcohols such as butanediol, 1,6-hexanediol, polyethylene glycol and pentaerythritol; and heterocyclic polyfunctional epoxy resins include heterocyclic polyfunctional compounds having a heterocyclic ring such as an isocyanuric ring and a hydantoin ring. Epoxy resins and glycidyl ester epoxy resins are epoxy resins composed of carboxylic acid esters such as hexahydrophthalic acid diglycidyl ester, and glycidylamine polyfunctional epoxy resins are epoxy resins obtained by glycidylating amines such as aniline and toluidine. Epoxy resins obtained by glycidylation of halogenated phenols include brominated bisphenol A, brominated bisphenol F, brominated bisphenol S, brominated phenol novolak, and brominated cresol novolak. , Chlorinated bisphenol S, and halogenated phenols glycidylated epoxy resins such as chlorinated bisphenol A.

The monofunctional epoxy resins which may be used in some cases include alicyclic monofunctional epoxy resins, aliphatic monofunctional epoxy resins, heterocyclic monofunctional epoxy resins,
Examples include glycidyl ester-based monofunctional epoxy resins, glycidylamine-based monofunctional epoxy resins, and monofunctional epoxy resins obtained by glycidylating halogenated phenols.

In the composition of the present invention, it is preferable to use an alicyclic polyfunctional epoxy resin alone as the polyfunctional epoxy resin or to use an alicyclic polyfunctional epoxy resin in combination with another polyfunctional epoxy resin. . Therefore, in a more preferred composition of the present invention, the all polyfunctional epoxy resin (100
Part) the content ratio of the alicyclic polyfunctional epoxy resin in the
It is preferable to contain 100 parts, preferably 40 to 100 parts. The balance is another polyfunctional epoxy resin, the content of which is 0 to 70 parts, preferably 0 to 60 parts. As other preferable polyfunctional epoxy resins to be added to the alicyclic polyfunctional epoxy resin, for example, epoxy resins obtained by glycidyl etherification of a novolak resin, more preferably a substituent (hydroxy group, alkyl group having 1 to 3 carbon atoms, etc.) And a phenol novolak resin using a phenol which may have a phenolic novolak.

In the composition of the present invention, a monofunctional epoxy resin, an acrylic resin, a polyester resin, etc., which may be blended with the polyfunctional epoxy resin as required, may be used for improving the heat resistance, yellowing resistance and transparency of the coating film. There is no particular limitation as long as the physical properties are not substantially reduced, but it is usually in the range of about 0 to 20 parts with respect to 100 parts of the polyfunctional epoxy resin.

The cyclic terpene skeleton-containing polyhydric phenol compound used in the present invention acts as a curing agent, and is not particularly limited as long as it has a cyclic terpene skeleton and two or more phenolic hydroxyl groups in the molecule. Specifically, as described in detail in, for example, Japanese Patent No. 2572293, a cyclic terpene compound is reacted with a phenol to form a cyclic terpene compound in which one molecule of the phenol is added to about 2 molecules of the phenol. Terpene skeleton-containing polyhydric phenol compound, or a compound obtained by condensing it with at least one member selected from the group consisting of aldehydes and ketones in the presence of an acidic catalyst (polyhydric phenol having a high molecular weight cyclic terpene skeleton) Compound) and the like.

Examples of the cyclic terpene compound used as a raw material of the cyclic terpene skeleton-containing polyhydric phenol compound include limonene (formula (1) below), dipentene which is an optical isomer of limonene, and α-type pinene (formula (2) below). ), Β-type pinene (the following formula (3)), α-type terpinene (the following formula (4)), β-type terpinene (the following formula (5)), γ-type terpinene (the following formula (6)), and 3,8-type Methanediene (the following formula (7)), 2,4-type methanediene (the following formula (8)),
Monoterpene compounds such as terpinolene (the following formula (9)) (compounds in which two isoprene units are cyclized and bonded by biosynthesis) are exemplified.

[0016]

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Examples of the phenol to be added to the cyclic terpene compound include phenol, o-cresol,
Examples include unsubstituted phenols such as 2,6-xylenol and o-allylphenol or phenols substituted with an alkyl group having 1 to 3 carbon atoms, an aryl group, a hydroxy group, or the like. Of these, phenol or o-cresol is preferred, and phenol is particularly preferred. The reaction is carried out in the presence of an acid catalyst such as hydrochloric acid, sulfuric acid, phosphoric acid, polyphosphoric acid and boron trifluoride, and usually a solvent such as aromatic hydrocarbons, alcohols and ethers is used.

The cyclic terpene skeleton-containing polyhydric phenol compound thus obtained is presumed to be a mixture of compounds of the following formulas (I) and (II), for example, in the case of a compound obtained by reacting limonene with phenol. Identifying the structure is difficult.

[0019]

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Aldehydes or ketones used in the production of a polyhydric phenol compound having a cyclic terpene skeleton having a high molecular weight include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, and the like.
Examples thereof include aliphatic aldehydes having 1 to 6 carbon atoms such as hydroxybenzaldehyde, acetone, and cyclohexanone, ketones, and benzaldehydes which may have a substituent such as a hydroxy group.

The polyhydric phenol compound having a cyclic terpene skeleton acts as a curing agent in the present invention and is usually used alone, but may be used in combination with another curing agent in some cases. When used in combination, it is preferable to use the cured product within a range that does not deteriorate the physical properties such as heat resistance and yellowing resistance and visible light transmittance. Examples of the curing agent used in combination include an acid anhydride-based curing agent, a carboxylic acid-based curing agent, an amine-based curing agent, a phenol-based curing agent, and a hydrazide-based curing agent.

Specific examples of the acid anhydride-based curing agent include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol trimellitic anhydride, biphenyltetrahydrate Aromatic carboxylic anhydrides such as carboxylic anhydrides, azelaic acid, sebacic acid, anhydrides of aliphatic carboxylic acids such as dodecane diacid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, nadic anhydride, Alicyclic carboxylic acid anhydrides such as het acid anhydride and hymic acid anhydride are exemplified.

Specific examples of the amine curing agent include diaminodiphenylmethane, diaminodiphenylsulfone,
Aromatic amines such as diaminodiphenyl ether, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 1,5-diaminonaphthalene, m-xylylenediamine, ethylenediamine, diethylenediamine, isophoronediamine, bis (4-amino −
Aliphatic amines such as 3-methyldicyclohexyl) methane and polyetherdiamine, dicyandiamide, 1- (o
-Tolyl) guanidines such as biguanide;

Specific examples of the phenolic curing agent include bisphenol A, bisphenol F, bisphenol S, 4,4'-biphenylphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, and tetramethyl Bisphenol 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-tert-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, phenol Resins derived from various phenols such as polybutadiene, phenol, cresols, ethylphenols, butylphenols, octylphenols, bisphenol A, bisphenol F, bisphenol S, and naphthols, phenol novolak resins containing a xylylene skeleton, dicyclopentadiene Phenol novolak resin containing skeleton, phenol novolak resin containing biphenyl skeleton, phenol novolak resin containing fluorene skeleton, fura Various novolak resins such as skeleton containing phenol novolak resin.

Specific examples of the hydrazide-based curing agent include carbodihydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic dihydrazide, suberic dihydrazide, and azelaic acid dihydrazide dihydrazide. Dihydrazide, dodecanediohydrazide, hexadecanediohydrazide, terephthalic dihydrazide, isophthalic dihydrazide, 2,6-naphthoic dihydrazide, 4,4′-bisbenzenedihydrazide, 1,4-naphthoic dihydrazide, 2,6-pyridine dihydrazide, 1,4-cyclohexanedihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid dihydrazide, N, N'-hexamethylenebissemicarbazide, itako Dihydrazide curing agent such as dihydrazide, pyromellitic acid trihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, polyfunctional hydrazide type curing agent such as 1,2,4-benzenetricarboxylic hydrazide.

The curing agent is usually used in an equivalent ratio of the functional group of the curing agent to the epoxy group of the epoxy resin of 0.2 to 1.
8, preferably 0.4 to 1.4, more preferably 0.6
It is used in the range of -1.2.

In the present invention, an imidazole-based curing accelerator is used as a preferred curing accelerator. Other compounds known as catalysts for accelerating the curing of the epoxy resin, such as tertiary amines and phosphines, can be used in combination as long as the physical properties are not impaired. Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole,
-Phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4
-Methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole,
1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,3-dihydro-
1H-pyrrolo- [1,2-a] benzimidazole,
2,4-diamino-6 (2'-methylimidazole (1 ')) ethyl-s-triazine, 2,4-diamino-6 (2'-undecylimidazole (1')) ethyl-
s-Triazine, 2,4-diamino-6 (2′-ethyl, 4-methylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-methylimidazole (1 ′)) Ethyl-s-triazine / isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4 And various imidazole compounds such as -methyl-5-hydroxymethylimidazole or 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole. Among these, a catalyst which preferentially promotes the reaction between an epoxy group and a phenolic hydroxyl group is preferable. For example, 2,3-dihydro-1
H-pyrrolo- [1,2-a] benzimidazole is more preferred.

The amount of the imidazole-based curing accelerator used is usually 0.1 part or more, preferably 0.3 part or more, more preferably 0.5 part or more, per 100 parts of the epoxy resin.
Or more, and 7 parts or less, preferably 5 parts or less, more preferably 4 parts or less, and still more preferably 3.5 parts or less. If the amount of the imidazole-based curing accelerator used is too small, a sufficient crosslinking reaction is unlikely to occur, adversely affecting the heat resistance of the protective film, and if too large, the aging stability, yellowing resistance during curing, and liquid crystal resistance are prevented. Possibility of reducing pollution.

The composition for a protective film of the present invention may optionally contain a coupling agent, a surfactant, an oxidation stabilizer, a light stabilizer, a moisture resistance improver, a thixotropic agent, an antifoaming agent, Additives such as 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-based 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 an aluminum-based coupling agent No. Among these, a silane coupling agent is preferable, and a silane coupling agent having an epoxy group is more 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 amount of coupling agent used is epoxy resin 100
0.1 to 5 parts, preferably about 0.5 to 4 parts, per part. The surfactant is added to improve the suitability for coating the composition for a protective film. For example, a silicone-based surfactant and a fluorine-based surfactant are used, and the amount of the surfactant is usually 0.001 to 0.5 part, preferably 0.08 to 0.3 part, per 100 parts of the epoxy resin. is there.

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, an imidazole-based curing accelerator, and, if necessary, various additives in an organic solvent. In this case, the solid concentration is usually 10% or more, preferably 15% or more, more preferably 20% or more, and 50% or less, preferably 40% or less.
% Or less, more preferably about 35% or less. These concentrations may be appropriately adjusted depending on the epoxy resin composition.
The viscosity at 5 ° C. is 2 to 30 mPa · s, preferably 4
What is necessary is just to prepare so that it may be set to １５15 mPa · s.

Specific examples of the organic solvent include alcohols such as methanol, ethanol, propanol and butanol, preferably lower alcohols having 1 to 4 carbon atoms, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and ethylene glycol. Glycol ethers such as monobutyl ether, propylene glycol monomethyl ether, 3-methoxybutanol and 3-methyl-3-methoxybutanol, preferably having 1 to 4 carbon atoms of alkylene glycol having 1 to 4 carbon atoms
Lower ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, ethylethoxypropio And alkylene glycol ether acetates such as an alkylene glycol, preferably a lower ether acetate having 1 to 4 carbon atoms of an alkylene glycol having 1 to 4 carbon atoms, aromatic hydrocarbons such as toluene and xylene, methyl ethyl ketone, cyclohexanone, cyclopentanone, Ketones such as -hydroxy-4-methyl-2-pentanone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, 2-
Methyl hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl hydroxyacetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, butyl lactate, methyl 3-hydroxypropionate, 3- Ethyl hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate, propyl 2-hydroxy-3-methylbutanoate, ethyl methoxyacetate, propyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, ethoxy Butyl acetate, 2-
Methyl methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, 2-ethoxy Butyl propionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, butyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate,
Esters such as propyl 3-ethoxypropionate and butyl 3-ethoxypropionate, preferably a hydroxy group, a C 1 -C 4 fatty acid which may be substituted with a C 1 -C 4 lower alkyl group. And ethers such as an alkyl ester of 4, and tetrahydrofuran.

Of these, considering the solubility of the epoxy resin, the curing agent, the curing accelerator, the reactivity with the organic solvent, the concentration change over time due to volatilization, the toxicity to the human body, etc., propylene glycol monomethyl ether acetate, C1-C3 alkylene glycols such as propylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, etc.
4, lower ether acetate, propylene glycol monomethyl ether, 3-methoxybutanol, 3-methyl-3-methoxybutanol, and esters are preferred.

The use amount of these organic solvents is not particularly limited, and may be adjusted according to the desired film thickness, surface smoothness, film forming method, and the like to impart coating suitability. The coating film formed by the coating composition of the present invention thus obtained has excellent adhesion to various materials such as glass, wood, metal, and plastic, and has smoothness and heat resistance. Yellowing,
Because of its excellent transparency and toughness, for example, as a protective film or the like, particularly as a coating film (high visible light transmittance coating film) at a place where high visible light transmittance is required, such as an organic EL device or a plasma display panel. Useful. Also,
Further, because of its excellent liquid crystal contamination property, 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 a color filter for liquid crystal display is formed. In this case, the transparent thin film obtained by curing the composition for a protective film of the present invention has a function of effectively preventing ionic impurities eluted from the color filter from contaminating the liquid crystal.

Here, when used as a protective film such as a color filter protective film, coating is usually performed by a spin coating method. The film thickness is usually 0.1 to 10 μm after heat curing.
m, preferably 0.5 to 8 μm. At this time, in order to perform the coating operation efficiently, the viscosity of the composition of the present invention at 25 ° C. is 2 mPa · s or more,
Preferably 4 mPa · s or more, more preferably 5 mPa
S or more and 30 mPa · s or less, preferably 1
The amount of the organic solvent is usually adjusted so as to be 5 mPa · s or less, more preferably 13 mPa · s or less. Drying and curing conditions after application are as follows:
It is necessary to select optimal conditions depending on the type of the solvent. Usually, after pre-baking at 70 to 100 ° C. to remove the solvent, post-baking is performed at 150 to 250 ° C. for 10 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.

The color filter on which the protective film of the present invention (the transparent thin film of the present invention) is formed as described above can be suitably used for a liquid crystal display device and the like. The ordinary liquid crystal display device has a color filter section (an ITO film,
TO patterning), a liquid crystal part, a backlight part, and a polarizing film part. By using a color filter in which the protective film of the present invention is applied to the color filter part, the liquid crystal of the present invention is obtained. It can be a display device.

[0037]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 As a composition for a protective film, a composition (numerical value "parts") shown in the column of Example 1 in Table 1 was dissolved in propylene glycol monoethyl ether acetate to give a solid content of 25%.
% And a viscosity of 5.2 mPa · s (R-type viscometer, measured at 10 rpm) to prepare a composition for a protective film. Next, thickness 0.7
On a glass substrate having a thickness of 2 mm, the composition 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 transparent thin film of the present invention. Table 2 shows the evaluation results of the obtained transparent thin films (the evaluation method will be described later).

Examples 2 to 3 and Comparative Examples 1 to 2 Examples 2 to 3 and Comparative Example 1 in Table 1 were used as compositions for the protective film.
A transparent thin film was prepared in the same manner as in Example 1 except that the compositions shown in the respective columns of Nos. 1 to 2 were used. Table 2 shows the results of these evaluations.

Examples 4 to 6 The composition shown in each column of Examples 1 to 3 of Table 1 was used as a composition for a protective film. Table 3 shows the results of evaluating the protective film obtained in the same manner as in Example 1 except that a colored resin film was formed).

[0041]

[Table 1]

In Table 1, epoxy resin A: a polyfunctional cyclohexane epoxy resin having an epoxy group on a cyclohexane ring (epoxy equivalent: about 180 g / eq) (product name: EHPE3150,
Epoxy resin B: ortho-cresol novolak type epoxy resin (epoxy equivalent: 201 g / eq) (trade name: E)
(OCN-1020-80, manufactured by Nippon Kayaku Co., Ltd.) Curing agent A: Terpene skeleton-containing diphenol (hydroxyl equivalent: 158 g / eq, softening point 120 ° C.) (trade name: YP
-90 (high purity product, manufactured by Yasuhara Chemical Co., Ltd.) Curing agent B: Novolak type terpene skeleton-containing phenolic resin (hydroxyl equivalent: 170 g / eq) (trade name: Epicure MP402FPY, manufactured by Nippon Epoxy Resin Co., Ltd.) Curing agent C: Phenol novolak resin (hydroxyl equivalent: 1
05g / eq) (trade name: HF-1, manufactured by Meiwa Kasei Co., Ltd.) Accelerator A: 2,3-dihydro-1H-pyrrolo- [1,2
-A] Benzimidazole Accelerator B: Triphenylphosphine (Hokuko Chemical's phosphorus-based curing accelerator) Coupling agent: Epoxysilane-based coupling silaace S-510 (manufactured by Ajinomoto Co., Ltd.) Surfactant: Fluorine-based interface Activator Megafac F470
(Dai Nippon Ink Co., Ltd.)

[0043]

[Table 2]

[0044]

[Table 3]

The evaluation methods and criteria in Tables 1 to 3 are as follows. 1. Heat resistance test (coating yellowing 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, and × indicates yellowing, which is unusable. 2. Liquid crystal stain resistance test The obtained protective film was scraped off with a cutter knife,
g was weighed in 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. Indicated as ×. In the above measurement, the specific resistance value (A) of the supernatant liquid crystal and the specific resistance value (B) after heating only the liquid crystal in the same manner were measured. 2 is also shown. 2. Retention rate = (A / B) × 100 (%) Glass transition temperature measurement In Table 1, of Examples 1 to 3 and Comparative Examples 1 and 2, the composition excluding the solvent was kneaded with a hot roll, and after transfer molding, post-curing was performed at 220 ° C for 20 minutes. DMA: Differential Mechani
Glass transition temperature (Tg) by cal Analysis (Toyo Seiki Co., Ltd., Rheograph Solid, heating rate 2 ° C / min)
Was measured. At this time, the transfer molding conditions were 175
C., 5 minutes. s

[0046]

Industrial Applicability The composition for a protective film of the present invention is excellent in transparency and resistance to liquid crystal contamination and has a particularly high heat resistance, which is advantageous for protection of a colored resin film. In this case, the reliability can be improved.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4J036 AA01 AB01 AB02 AB03 AB13 AB15 AC01 AC06 AD01 AD04 AD05 AD08 AF01 AF06 AF07 AF08 AF10 AK03 DB05 DB10 DB21 FA04 JA01 4J038 DA082 DB051 DB071 DB091 DB131 DB151 DB261 DB291 JA64 JB32 KA03 NA05 NA10 NA12 NA14 NA19 PB08

Claims (15)

[Claims] 1. An epoxy resin having (1) an epoxy resin having at least two epoxy groups in one molecule, (2) a polyhydric phenol compound having a cyclic terpene skeleton, and (3) an imidazole-based curing accelerator. Protective film composition. 2. The protective film composition according to claim 1, wherein the cyclic terpene skeleton-containing polyhydric phenol compound is a compound obtained by adding two molecules of phenols to one molecule of the cyclic terpene compound. 3. A cyclic terpene skeleton-containing polyhydric phenol compound is further subjected to a condensation reaction of a compound obtained by adding two molecules of phenols to one molecule of a cyclic terpene compound in the presence of an acidic catalyst with aldehydes and / or ketones. The composition for a protective film according to claim 1, which is a compound obtained by the above method. 4. The composition for a protective film according to claim 1, wherein the epoxy resin is an alicyclic epoxy resin. 5. The phenolic skeleton of the terpene skeleton-containing polyhydric phenol compound is phenol, o-cresol, 2,
It is derived from at least one selected from the group consisting of 6-xylenol and o-allylphenol.
4. The composition for a protective film according to any one of 3. 6. A terpene skeleton-containing polyhydric phenol compound wherein the phenol skeleton is phenol, o-cresol,
The composition for a protective film according to claim 4, wherein the composition is derived from at least one selected from the group consisting of 6-xylenol and o-allylphenol. 7. The composition for a protective film according to claim 1, wherein the imidazole-based curing accelerator is 2,3-dihydro-1H-pyrrolo- [1,2-a] benzimidazole. object. 8. The composition for a protective film according to claim 4, wherein the imidazole-based curing accelerator is 2,3-dihydro-1H-pyrrolo- [1,2-a] benzimidazole. 9. The composition according to claim 5, wherein the imidazole curing accelerator is 2,3-dihydro-1H-pyrrolo- [1,2-a] benzimidazole. 10. The method according to claim 1, wherein the imidazole-based curing accelerator is 2,3-
The composition for a protective film according to claim 6, which is dihydro-1H-pyrrolo- [1,2-a] benzimidazole. 11. A transparent thin film obtained by using the composition for a protective film according to any one of claims 1 to 10. 12. The transparent thin film according to claim 11, which is used as a color filter protective film. 13. A method of using the composition for a protective film according to any one of claims 1 to 10 as a protective film for a liquid crystal display device. 14. A liquid crystal display device comprising a color filter having the transparent thin film according to claim 12. 15. An epoxy resin having (i) an epoxy resin having at least two epoxy groups in one molecule, (ii) a polyhydric phenol compound having a cyclic terpene skeleton, and (iii) an imidazole-based curing accelerator. For high visible light transmittance films.