TW201932526A - Cured film formation composition and cured film formation method capable of forming a cured film while suppressing surface defects such as wave shape unevenness, stripe shape unevenness and pin marks - Google Patents

Abstract

The subject of the present invention is to provide a cured film formation composition containing an epoxy compound (A) and hollow silica (B), which is capable of forming a cured film under a condition that surface defects are suppressed, even if a coating film is formed by using a slit coating method or the like where surface defects such as wave shape unevenness, stripe shape unevenness and pin marks are likely to occur, and a cured film formation method using the cured film formation composition. To solve the problem, when forming a cured film by using a composition containing an epoxy compound (A), hollow silica (B), and a solvent (S), a surfactant (C) is added to the composition, and one or more high boiling point solvents (SH) having a boiling point of 170 DEG C or higher under the atmospheric pressure are used as the solvent (S).

Description

Composition for forming a cured film, and method for forming a cured film

The present invention relates to a cured film forming composition containing an epoxy compound (A) and hollow cerium oxide (B), and a cured film forming method using the cured film forming composition.

Various functional films such as an insulating film, a protective film, and an antireflection film are formed by a method of applying various resin compositions in a liquid state.
Specifically, a photosensitive resin composition is used to form a low refractive index film for covering a microlens for an image sensor while forming a desired shape, or an antireflection for use in a liquid crystal display or an organic EL device. Low refractive index film.

As a photosensitive resin composition which can form a patterned cured film which can be used as the low refractive index film for antireflection, it is proposed to contain hollow or porous particles, a photopolymerization initiator, and an alkali-soluble one. A photosensitive resin composition of a polymerizable compound and a particle dispersing agent (Patent Document 1).
[Previous Technical Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2009-271444

[Problems to be solved by the invention]

When the photosensitive resin composition described in Patent Document 1 is used, a low refractive index film having a smooth surface can be formed without any problem.
On the other hand, for the purpose of improving the heat resistance, alkali resistance, solvent resistance, and the like of the low refractive index film, it may be desirable to use an epoxy compound instead of the alkali-soluble polymerizable compound. When an epoxy compound is used in combination with a hollow particle such as hollow ceria, a solvent is used in order to impart better coatability to the composition.

However, the inventors of the present invention have found that when a cured film is formed using an epoxy compound, hollow cerium oxide, and a solvent composition, the surface of the cured film is likely to have wavy unevenness and strip shape. Unevenness and poor condition of pin marks. The occurrence of such a problem is remarkable in a coating method using slit coating or the like.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a coating film by using a slit coating method or the like which is susceptible to surface defects such as wavy unevenness, strip unevenness, and pin marks. The cured film formation composition containing the epoxy compound (A) and the hollow cerium oxide (B) and the cured film formed using the cured film forming composition can be formed by suppressing such surface defects. method.

[Means to solve the problem]

The present inventors have found that when a cured film is formed using a composition containing an epoxy compound (A), hollow cerium oxide (B), and a solvent (S), a surfactant (C) is added to the composition. Further, the above problem can be solved by using one or more high boiling point solvents (SH) having a boiling point of 170 ° C or higher at atmospheric pressure as the solvent (S), and the present invention has been completed.

According to a first aspect of the invention, there is provided a composition for forming a cured film comprising an epoxy compound (A), hollow cerium oxide (B), a surfactant (C), a solvent (S), and a solvent ( S) One or more high boiling point solvents (SH) having a boiling point of 170 ° C or higher at atmospheric pressure.

According to a second aspect of the invention, there is provided a method for forming a cured film comprising: applying a composition for forming a cured film of a first aspect onto a substrate to form a coating film, and curing the coating by heating; membrane.

[Effects of the Invention]

According to the present invention, it is possible to provide a coating film by using a slit coating method which is likely to cause surface defects such as wavy unevenness, strip unevenness, and pin marks, and to suppress such surface defects. At the same time, a composition for forming a cured film containing an epoxy compound (A) and hollow cerium oxide (B) and a method for forming a cured film using the cured film forming composition are formed.

≪hardening film forming composition≫
The composition for forming a cured film contains an epoxy compound (A), hollow cerium oxide (B), a surfactant (C), and a solvent (S). The solvent (S) contains at least one high boiling point solvent (SH) having a boiling point of 170 ° C or higher at atmospheric pressure.
The composition for forming a cured film containing the epoxy compound (A) and the hollow cerium oxide (B) is applied by a method such as slit coating, dip coating, spray coating, screen printing or the like. After the coating film is formed by the cloth, the coating film obtained by curing the coating film is liable to cause surface defects such as wavy unevenness, unevenness of the stripe, and pin marks. When the slit coating is performed, particularly when the slit coating is performed at a coating speed of 120 mm/sec or more, the occurrence of the surface defect is remarkable.
However, when the above-mentioned composition for forming a cured film is used, when a cured film is formed, such surface defects are less likely to occur.

In other words, the composition for forming a cured film containing the specific component described above is applied to the substrate by slit coating, and particularly applied to the substrate by a slit coating at a coating speed of 120 mm/sec or more. A cured film is obtained under the condition of suppressing surface defects.

<epoxy compound (A)>
The composition for forming a cured film contains an epoxy compound (A) having an epoxy group as a component for curing a composition for forming a high film. The epoxy compound (A) is an epoxy group-containing resin and can be used together with a non-resin type epoxy compound.
From the viewpoint of curing the coating film composed of the composition for forming a cured film at a low temperature and for a short period of time, the epoxy compound is preferably an epoxy group-containing resin.

The epoxy compound (A) may be used together with a known hardener or a hardening accelerator as needed. The amount of the hardener or the hardening accelerator to be used is appropriately determined depending on the type thereof.

The epoxy compound (A) preferably has one or more functional groups selected from the group consisting of a carboxyl group, a carboxylic acid anhydride group, a phenolic hydroxyl group, and an amine group.
The carboxyl group, the carboxylic anhydride group, the phenolic hydroxyl group, and the amine group all have a hardening reaction with the epoxy group or a hardening reaction of the epoxy group.
Therefore, when the epoxy compound (A) has one or more functional groups selected from the group consisting of a carboxyl group, a carboxylic anhydride group, a phenolic hydroxyl group, and an amine group, the cured film forming composition does not contain a hardener. It is also possible to harden the hardenable crude material well.

When the cured film forming composition is cured, as described later, the coating film composed of the cured film forming composition may be placed under reduced pressure. At this time, since the hardener is volatilized or sublimated from the coating film, unevenness of hardening occurs, or the surface of the cured film is slightly rough.
However, when the composition for forming a cured film does not contain a curing agent, even when the coating film is placed under reduced pressure, the surface is flat during the process of forming the cured film, and it is easy to form unevenness. Hardened film.

The epoxy compound (A) is preferably a copolymer of a monomer having an unsaturated double bond. When the epoxy compound of the copolymer is used as the epoxy compound (A), the epoxy compound is a so-called resin, and therefore the curable composition is excellent in film formability.
Moreover, the use of the epoxy compound of the copolymer is also preferable from the viewpoint of easily selecting various monomers used for preparation of the epoxy compound and easily adjusting various properties of the cured film.

Hereinafter, a specific example of the epoxy compound (A) will be described with respect to a non-resin type epoxy compound and a resin containing an epoxy group.

(non-resin type epoxy compound)
As the non-resin type epoxy compound, various epoxy compounds widely known from the past can be used. The molecular weight of the epoxy compound is not particularly limited. Among the epoxy compounds, a cured film excellent in heat resistance, chemical resistance, mechanical properties, and the like is easily formed, and a polyfunctional epoxy compound having two or more epoxy groups in the molecule is preferable.

The polyfunctional epoxy compound is not particularly limited as long as it is a bifunctional or higher epoxy compound. Examples of the polyfunctional epoxy compound include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, naphthalene epoxy resin, and a bifunctional epoxy resin such as a benzene type epoxy resin; a glycidyl ester type epoxy resin such as a dimer acid glycidyl ester; and a triglycidyl ester; a tetraglycidylamino diphenylmethane or a triglycidyl group; a glycidylamine type epoxy resin such as -p-aminophenol, tetraglycidyl-m-xylenediamine, and tetraglycidyl-diaminomethylcyclohexane; and a triglycidyl isocyanurate Heterocyclic epoxy resin; fluoroethanolamine triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydroxyphenylmethane triglycidyl ether, glycerol triglycidyl ether, 2-[4-(2,3- Epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-(2,3-epoxypropoxy)phenyl]ethyl]phenyl]propane, and 1 ,3-bis[4-[1-[4-(2,3-epoxypropoxy)phenyl]-1-[4-[1-[4-(2,3-epoxyoxypropoxy) 3-functional epoxy resin such as phenyl]-1-methylethyl]phenyl]ethyl]phenoxy]-2-propanol; tetrahydroxyphenyl A tetrafunctional epoxy resin such as ethane tetraglycidyl ether, tetraglycidyl benzophenone, bis resorcinol tetraglycidyl ether, or tetraglycidoxybiphenyl.

Further, from the viewpoint of obtaining a cured product having a high hardness, the alicyclic epoxy compound is also preferable as the polyfunctional epoxy compound. Specific examples of the alicyclic epoxy compound include 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-m-dioxane, and a double (3,4-Epoxycyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, 3,4-epoxy- 6-Methylcyclohexyl-3',4'-epoxy-6'-methylcyclohexanecarboxylate, ε-caprolactone modified 3,4-epoxycyclohexylmethyl-3' , 4'-epoxycyclohexane carboxylate, trimethyl caprolactone modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexane carboxylate, β-Methyl-δ-valerolactone modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, methylenebis(3,4-ring Oxycyclohexane), ethylene glycol bis(3,4-epoxycyclohexylmethyl)ether, ethyl bis(3,4-epoxycyclohexanecarboxylate), epoxy group Dioctyl hexahydrophthalate, and di-2-ethylhexyl epoxide hexahydrophthalate, epoxy resin having a tricyclononene oxide group, or the following formula (a01) -1)~(a01-5) represents a compound.

In the specific example of the alicyclic epoxy compound, an alicyclic epoxy compound represented by the following formulas (a01-1) to (a01-5) is preferable because a cured product having a high hardness is obtained.

(In the formula (a01-1), Z ⁰¹ represents a single bond or a linking group (having a divalent group of one or more atoms). R ^a01 to R ^a018 are each independently selected from a hydrogen atom, a halogen atom, and an organic group. The basis of the group).

The linking group Z ^{01 may,} for example, be selected from the group consisting of a divalent hydrocarbon group, -O-, -O-CO-, -S-, -SO-, -SO ₂ -, -CBr ₂ -, -C(CBr ₃ ) ₂ -, The divalent group and the bond of the group formed by -C(CF ₃ ) ₂ -, and -R ^a019 -O-CO- have such a plurality of bases and the like.

Examples of the divalent hydrocarbon group of the linking group Z include a linear or branched alkyl group having 1 or more and 18 or less carbon atoms, and a divalent alicyclic hydrocarbon group. Examples of the linear or branched chain alkyl group having 1 or more and 18 or less carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, a dimethylene group, and a trimethylene group. Examples of the above-mentioned divalent alicyclic hydrocarbon group include 1,2-cyclopentyl group, 1,3-cyclopentyl group, cyclopentylene group, 1,2-extended cyclohexyl group, and 1,3-cyclohexylene group. a cycloalkyl group (including a cycloalkylene group) such as a 1,4-cyclohexylene group or a cyclohexylene group.

R ^a019 is an alkylene group having 1 or more and 8 or less carbon atoms, preferably a methylene group or an ethylidene group.

In .R group (formula ^{(a01-2), R a01 ~ R} a018 is selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group of the group formed by R ^a010 and ^a02 can also be bonded to each other, and R ^{a016 A013} also .R The rings may be bonded to each other to form a ring. m ^a1 is 0 or 1).

The alicyclic epoxy compound represented by the above formula (a01-2) is preferably a compound represented by the following formula (a01-2-1) corresponding to a compound wherein m ^a1 is 0 in the above formula (a01-2). .

(In the formula (a01-2-1), R ^a01 to R ^a012 are a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. R ^a02 and R ^a010 may be bonded to each other to form a ring).

(In the formula (a01-3), group .R R ^a01 ~ R ^a010 is selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group of the group formed by ^a02 and R ^a08 may be bonded to each other).

(In the formula (a01-4), R ^a01 to R ^a012 are a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. R ^a02 and R ^a010 may be bonded to each other).

(In the formula (a01-5), R ^a01 to R ^a012 are a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group).

In the formula (a01-1) to (a01-5), when R ^a01 to R ^a018 are an organic group, the organic group is not particularly limited ^insofar as it does not inhibit the object of the present invention, and may be a hydrocarbon group or a carbon atom. The group composed of a halogen atom may be a group containing a carbon atom and a hydrogen atom, and a hetero atom such as a halogen atom, an oxygen atom, a sulfur atom, a nitrogen atom or a ruthenium atom. Examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom.

The organic group is preferably a hydrocarbon group; a group formed by a carbon atom, a hydrogen atom, and an oxygen atom; a halogenated hydrocarbon group; a group formed by a carbon atom, an oxygen atom, and a halogen atom; and a carbon atom, a hydrogen atom, An oxygen atom and a group formed by a halogen atom. When the organic group is a hydrocarbon group, the hydrocarbon group may be an aromatic hydrocarbon group, may be an aliphatic hydrocarbon group, or may be a group containing an aromatic skeleton and an aliphatic skeleton. The number of carbon atoms in the organic group is preferably 1 or more and 20 or less, more preferably 1 or more and 10 or less, and particularly preferably 1 or more and 5 or less.

Specific examples of the hydrocarbon group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, N-heptyl, n-octyl, 2-ethylhexyl, n-fluorenyl, n-fluorenyl, n-undecyl, n-tridedecyl, n-tetradecyl, n-pentadecayl, a chain alkyl group of n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-yetyl group, and n-octayl group; vinyl group, 1-propenyl group, 2-n-propylene group a chain-like alkenyl group such as a (allyl) group, a 1-n-butenyl group, a 2-n-butenyl group, and a 3-n-butenyl group; a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Cyclohexyl, and cycloheptyl and the like cycloalkyl; phenyl, o-tolyl, m-tolyl, p-tolyl, α-naphthyl, β-naphthyl, biphenyl-4-yl, biphenyl An aryl group such as -3-yl, biphenyl-2-yl, fluorenyl, and phenanthryl; benzyl, phenethyl, α-naphthylmethyl, β-naphthylmethyl, α-naphthylethyl And an aralkyl group such as β-naphthylethyl.

Specific examples of the halogenated hydrocarbon group are chloromethyl, dichloromethyl, trichloromethyl, bromomethyl, dibromomethyl, tribromomethyl, fluoromethyl, difluoromethyl, trifluoromethyl, 2 , 2,2-trifluoroethyl, pentafluoroethyl, heptafluoropropyl, perfluorobutyl, and perfluoropentyl, perfluorohexyl, perfluoroheptyl, perfluorooctyl, perfluorodecyl, And a halogenated chain alkyl group such as a perfluorodecyl group; 2-chlorocyclohexyl, 3-chlorocyclohexyl, 4-chlorocyclohexyl, 2,4-dichlorocyclohexyl, 2-bromocyclohexyl, 3-bromocyclo Hexyl, and halogenated cycloalkyl groups such as 4-bromocyclohexyl; 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,3-dichlorophenyl, 2,4-dichlorophenyl , 2,5-dichlorophenyl, 2,6-dichlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4 a halogenated aryl group such as bromophenyl, 2-fluorophenyl, 3-fluorophenyl or 4-fluorophenyl; 2-chlorophenylmethyl, 3-chlorophenylmethyl, 4-chlorophenyl Base, 2-bromophenylmethyl, 3-bromophenylmethyl, 4-bromophenylmethyl, 2-fluorophenylmethyl, 3-fluorophenylmethyl, 4-fluorophenylmethyl, etc. Halogenated aralkyl.

Specific examples of the group formed by a carbon atom, a hydrogen atom, and an oxygen atom are a hydroxyl group such as a hydroxymethyl group, a 2-hydroxyethyl group, a 3-hydroxy-n-propyl group, and a 4-hydroxy-n-butyl group. Chain alkyl; 2-hydroxycyclohexyl, 3-hydroxycyclohexyl, and halogenated cycloalkyl of 4-hydroxycyclohexyl; 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2, 3-dihydroxyphenyl, 2,4-dihydroxyphenyl, 2,5-dihydroxyphenyl, 2,6-dihydroxyphenyl, 3,4-dihydroxyphenyl, and 3,5-dihydroxy Hydroxyaryl group such as phenyl; 2-hydroxyphenylmethyl, 3-hydroxyphenylmethyl, and hydroxyarylalkyl such as 4-hydroxyphenylmethyl; methoxy, ethoxy, n-propyl Oxyl, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n -octyloxy, 2-ethylhexyloxy, n-decyloxy, n-decyloxy, n-undecyloxy, n-tridecyloxy, n-tetradecyloxy, n a chain of -pentadecanyloxy, n-hexadecanyloxy, n-heptadecanyloxy, n-octadecyloxy, n-nonadecanyloxy, and n-icosyloxy Alkoxy; vinyloxy, 1-propene Chain, 2-n-propyleneoxy (allyloxy), 1-n-butenyloxy, 2-n-butenyloxy, and 3-n-butenyloxy, etc. Phenoxy, o-tolyloxy, m-tolyloxy, p-tolyloxy, α-naphthyloxy, β-naphthyloxy, biphenyl-4-oxy, biphenyl-3-oxy An aryloxy group such as a biphenyl-2-oxy group, an anthraceneoxy group, or a phenanthrenyl group; a benzyloxy group, a phenethyloxy group, an α-naphthylmethoxy group, a β-naphthylmethoxy group, and an α- Naphthylethoxy, and aralkoxy such as β-naphthylethoxy; methoxymethyl, ethoxymethyl, n-propoxymethyl, 2-methoxyethyl, 2 -ethoxyethyl, 2-n-propoxyethyl, 3-methoxy-n-propyl, 3-ethoxy-n-propyl, 3-n-propoxy-n-propyl Alkoxyalkyl group such as 4-methoxy-n-butyl, 4-ethoxy-n-butyl, and 4-n-propoxy-n-butyl; methoxymethoxy , ethoxymethoxy, n-propoxymethoxy, 2-methoxyethoxy, 2-ethoxyethoxy, 2-n-propoxyethoxy, 3-methyl Oxy-n-propoxy, 3-ethoxy-n-propoxy, 3-n-propoxy-n-propoxy, 4-methoxy-n-butoxy, 4-B Oxy-n-butoxy, and 4-n Alkoxyalkoxy groups such as -propoxy-n-butoxy; alkoxyaryl groups such as 2-methoxyphenyl, 3-methoxyphenyl, and 4-methoxyphenyl 2-methoxyphenoxy, 3-methoxyphenoxy, and alkoxyaryloxy such as 4-methoxyphenoxy; methyl sulfhydryl, ethyl hydrazino, propyl fluorenyl, butyl fluorenyl An aliphatic sulfhydryl group such as a pentamidine group, a hexyl group, a decyl group, a octyl group, a fluorenyl group, and a fluorenyl group; a benzinyl group, an α-naphthylmethyl group, and a β-naphthylmethyl group; Aromatic fluorenyl; methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, n-butoxycarbonyl, n-pentyloxycarbonyl, n-hexylcarbonyl, n-heptyloxycarbonyl, n-octyloxy a chain alkoxycarbonyl group such as a carbonyl group, an n-methoxycarbonyl group, and an n-methoxycarbonyl group; an aryloxy group such as a phenoxycarbonyl group, an α-naphthyloxycarbonyl group, or a β-naphthyloxycarbonyl group; Carbonyl; methyl methoxy, ethoxycarbonyl, propenyloxy, butyloxy, pentyloxy, hexyloxy, decyloxy, octyloxy, decyloxy, and hydrazine An aliphatic oxime such as an oxy group; an aromatic hydrazine such as a benzyl hydroxy group, an α-naphthylmethoxy group, or a β-naphthylmethoxy group; Groups.

R ^a01 to R ^a018 are each independently a group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 or more and 5 or less carbon atoms, and an alkoxy group having 1 or more and 5 or less carbon atoms. In particular, since it is easy to form a cured film excellent in mechanical properties, it is more preferable that all of R ^a01 to R ^a018 are hydrogen atoms.

In the formulas (a01-2) to (a01-5), R ^a01 to R ^a018 are the same as R ^a01 to R ^a018 in the formula (a01-1). In time, R ^a013 and R ^a016 bonded to each other in formula (a01-2) and formula (a01-4), when R ^a02 and R ^a010 bonded to each other, of formula (a01-2), and formula (a01-3) In the case of the divalent group formed when R ^a02 and R ^a08 are bonded to each other, for example, -CH ₂ - or -C(CH ₃ ) ₂ - may be mentioned.

Among the alicyclic epoxy compounds represented by the formula (a01-1), specific examples of suitable compounds include the following formula (a01-1a), formula (a01-1b), and formula (a01-1c). An alicyclic epoxy compound, or 2,2-bis(3,4-epoxycyclohexane-1-yl)propane [=2,2-bis(3,4-epoxycyclohexyl)propane] Wait.

Among the alicyclic epoxy compounds represented by the formula (a01-2), specific examples of suitable compounds include the alicyclic epoxy compounds represented by the following formula (a01-2a) and the following formula (a01-2b). .

Among the alicyclic epoxy compounds represented by the formula (a01-3), specific examples of suitable compounds include S. sp. [3-oxatricyclo[3.2.1.0 ^2,4 ]octane-6,2'- Ethylene oxide] and the like.

Among the alicyclic epoxy compounds represented by the formula (a01-4), specific examples of suitable compounds include 4-vinylcyclohexene dioxide, dipentene dioxide, limonene dioxide, and 1- Methyl-4-(3-methyloxiran-2-yl)-7-oxabicyclo[4.1.0]heptane and the like.

Among the alicyclic epoxy compounds represented by the formula (a01-5), specific examples of suitable compounds include 1,2,5,6-dicyclooxycyclooctane and the like.

(Resin containing epoxy resin)
When an epoxy group-containing resin having an epoxy group is used, an addition polymerization reaction between epoxy groups is generated between molecules contained in the resin by using a known curing agent or a curing accelerator or the like as needed. To cross-link.

The epoxy group-containing resin may be a polymer obtained by polymerizing a monomer having an epoxy group or a monomer mixture containing a monomer having an epoxy group. The epoxy group-containing resin may be a polymer having a functional group reactive with a hydroxyl group, a carboxyl group, an amine group or the like, and an epoxy group-containing compound such as epichlorohydrin may be used to introduce an epoxy group. It is easy to obtain, modulate, adjust the amount of epoxy groups in the polymer, etc., and an epoxy group-containing polymer, preferably a monomer having an epoxy group or a monomer containing an epoxy group. A polymer obtained by polymerizing a bulk mixture.

A preferred example of the epoxy group-containing resin includes a phenol novolac type epoxy resin, a brominated phenol novolac type epoxy resin, an o-cresol novolac type epoxy resin, and a bisphenol A novolac type epoxy resin. Resin, phenolic varnish epoxy resin such as bisphenol AD novolac type epoxy resin; cyclic aliphatic epoxy resin such as epoxide of dicyclopentadiene type phenol resin; epoxide of naphthalene type phenol resin Aromatic epoxy resin.

Further, among the epoxy group-containing resins, it is easy to prepare, or the physical properties of the cured film are easily adjusted, and it is preferably a homopolymer having an epoxy group (meth) acrylate or having an epoxy group (A) Copolymer of acrylate with other monomers.

The (meth) acrylate having an epoxy group may be a (meth) acrylate having a chain aliphatic epoxy group or a (meth) acrylate having an alicyclic epoxy group as described later. ester. Further, the (meth) acrylate having an epoxy group may further contain an aromatic group. Among the (meth) acrylates having an epoxy group, an aliphatic (meth) acrylate having a chain aliphatic epoxy group or an aliphatic (meth) acrylate having an alicyclic epoxy group is preferred. An ester; more preferably an aliphatic (meth) acrylate having an alicyclic epoxy group.

Examples of the (meth) acrylate having an aromatic group and having an epoxy group include 4-glycidoxyphenyl (meth)acrylate and 3-glycidoxyphenyl (meth)acrylate. 2-glycidoxyphenyl (meth)acrylate, 4-glycidoxyphenylmethyl (meth)acrylate, 3-glycidoxyphenylmethyl (meth)acrylate, and (methyl) ) 2-glycidoxyphenyl methyl acrylate or the like.

Examples of the aliphatic (meth) acrylate having a chain aliphatic epoxy group include a chain of an epoxy group of (meth)acrylate and an epoxy alkoxylate of (meth)acrylate. The (meth) acrylate of an oxy group (-O-) in which an aliphatic epoxy group is bonded to an ester group (-O-CO-). The chain aliphatic epoxy group which the (meth) acrylate has may contain 1 or a plurality of oxy groups (-O-) in the chain. The number of carbon atoms of the chain aliphatic epoxy group is not particularly limited, but is preferably 3 or more and 20 or less, more preferably 3 or more and 15 or less, and particularly preferably 3 or more and 10 or less.

Specific examples of the aliphatic (meth) acrylate having a chain aliphatic epoxy group include glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, and (meth)acrylic acid. 3,4-epoxybutyl acrylate, (meth)acrylic acid epoxy alkyl ester such as 6,7-epoxyheptyl (meth)acrylate; 2-glycidoxyethyl (meth)acrylate , 3-glycidoxy-n-propyl (meth)acrylate, 4-glycidoxy-n-butyl (meth)acrylate, 5-glycidoxy-n-hexyl (meth)acrylate An (meth)acrylic acid epoxy alkoxyalkyl ester such as an ester or a 6-glycidoxy-n-hexyl (meth)acrylate.

Specific examples of the aliphatic (meth) acrylate having an alicyclic epoxy group include compounds represented by the following formulas (a05-1) to (a05-15). Among these, a compound represented by the following formula (a05-1) to (a05-5) is preferable, and a compound represented by the following formula (a05-1) to (a05-3) is more preferable. Further, with respect to each of these compounds, the bonding site of the oxygen atom of the ester group to the alicyclic ring is not limited to those shown herein, and a part of the positional isomer may be contained.

In the above formula, R ^a032 represents a hydrogen atom or a methyl group, R ^a033 represents a divalent aliphatic saturated hydrocarbon group having 1 or more and 6 or less carbon atoms, and R ^a034 represents a divalent hydrocarbon group having 1 or more and 10 or less carbon atoms, and t ⁰ represents 0. An integer of 10 or more. R ^{a033 is} preferably a linear or branched alkyl group such as methylene, ethyl, propyl, tetramethylene, ethylethyl, pentamethylene or hexamethylene. R ^{a034 is} preferably, for example, a methylene group, an ^exoethyl group, a propyl group, a tetramethylene group, an ^ethylexyl group, a pentamethylene group, a hexamethylene group, a phenylene group, or a cyclohexyl group.

a polymer having an epoxy group, which is a homopolymer of a (meth) acrylate having an epoxy group, and a copolymer of a (meth) acrylate having an epoxy group and another monomer, which may be used. In the polymer of the oxy group, the content of the unit derived from the (meth) acrylate having an epoxy group is preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

When the polymer having an epoxy group is a copolymer of a (meth) acrylate having an epoxy group and another monomer, the other monomer may be an unsaturated carboxylic acid or a (meth)acrylic acid having no epoxy group. Ester, (meth) acrylamide, allyl compound, vinyl ether, vinyl ester, styrene, and the like. These compounds may be used alone or in combination of two or more.

A polymer having an epoxy group, preferably a copolymer of an epoxy group-containing (meth) acrylate and an unsaturated carboxylic acid, from the viewpoint of forming a cured film without using a hardener or a hardening accelerator.

Examples of the unsaturated carboxylic acid include (meth)acrylic acid; decylamine (meth)acrylate; crotonic acid; maleic acid, fumaric acid, citraconic acid, mesaconic acid, isaconic acid, and these dicarboxylic acids. Acid anhydride.

Examples of the (meth) acrylate having no epoxy group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and amyl (meth)acrylate. a linear or branched alkyl (meth)acrylate such as t-octyl methacrylate; chloroethyl (meth)acrylate; 2,2-dimethylhydroxypropyl (meth)acrylate , 2-hydroxyethyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, phenyl (meth)acrylate, 2-methylphenyl (meth)acrylate, (meth)acrylic acid 3-methylphenyl ester, 4-methylphenyl (meth)acrylate, 2-hydroxyphenyl (meth)acrylate, 3-hydroxyphenyl (meth)acrylate, 4-hydroxybenzene (meth)acrylate Ester, naphthalene-1-(meth)acrylate, naphthalene-2-(meth)acrylate, benzyl (meth)acrylate, furan methyl (meth)acrylate; having a group having an alicyclic skeleton (Meth) acrylate. Among the (meth) acrylates having no epoxy group, a (meth) acrylate having a group having an alicyclic skeleton is preferred.

Among the (meth) acrylates having a group having an alicyclic skeleton, the alicyclic group constituting the alicyclic skeleton may be a single ring or a polycyclic ring. The monocyclic alicyclic group may, for example, be a cyclopentyl group or a cyclohexyl group. Further, examples of the polycyclic alicyclic group include a thiol group, an isoindole group, a tricyclic fluorenyl group, a tricyclic fluorenyl group, and a tetracyclic decyl group.

Examples of the (meth) acrylate having a group having an alicyclic skeleton include compounds represented by the following formulas (a06-1) to (a06-8). Among these, a compound represented by the following formula (a06-3) to (a06-8), more preferably a compound represented by the following formula (a06-3) or (a06-4).

In the above formula, R ^a035 represents a hydrogen atom or a methyl group, R ^a036 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 or more and 6 or less carbon atoms, and R ^a037 represents a hydrogen atom or an alkyl group having 1 or more and 5 or less carbon atoms. . R ^{a036 is} preferably a single bond, a linear or branched alkyl group, such as methylene, ethyl, propyl, tetramethylene, ethyl ethyl, pentamethylene, and hexa methyl. R ^{a037 is} preferably a methyl group or an ethyl group.

Examples of the (meth) acrylamides include (meth) acrylamide, N-alkyl (meth) acrylamide, N-aryl (meth) acrylamide, N, N-di Alkyl (meth) acrylamide, N,N-aryl (meth) acrylamide, N-methyl-N-phenyl (meth) acrylamide, N-hydroxyethyl-N- Base (meth) acrylamide and the like.

Examples of the allyl compound include allyl acetate, allyl hexanoate, allyl octanoate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, Allyl acetate such as allyl acetate, allyl lactate, etc.; allyloxyethanol and the like.

Examples of the vinyl ethers include hexyl vinyl ether, octyl vinyl ether, mercapto vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, and ethoxyethyl vinyl ether. , chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether Aliphatic ethylene such as dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofuran methyl vinyl ether or the like Vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl decyl ether, etc. Aryl ether and the like.

Examples of the vinyl esters include vinyl butyrate, vinyl isobutyrate, trimethyl vinyl acetate, diethyl vinyl acetate, vinyl valerate, vinyl hexanoate, vinyl chloroacetate, and dichloro Vinyl acetate, methoxyvinyl acetate, butoxy vinyl acetate, vinyl phenyl acetate, ethylene vinyl acetate, vinyl lactate, vinyl β-phenylbutyrate, vinyl benzoate, water Vinyl acetate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthate, and the like.

Examples of the styrenes include styrene; methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, Hexyl styrene, cyclohexyl styrene, mercapto styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, ethoxymethyl styrene, etc. Alkylstyrene; alkoxystyrene such as methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene; chlorostyrene, dichlorostyrene, trichlorobenzene Ethylene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodine styrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro A halogenated styrene such as -3-trifluoromethylstyrene.

The molecular weight of the epoxy group-containing resin is not particularly limited as long as it does not inhibit the object of the present invention, and is preferably 3,000 or more and 30,000 or less, more preferably 5,000 or more and 15,000 or less in terms of mass average molecular weight in terms of polystyrene.

The content of the epoxy compound (A) in the composition for forming a cured film is not particularly limited insofar as it does not inhibit the object of the present invention.
The content of the epoxy compound (A) in the composition for forming a cured film is a combination of the mass of the epoxy compound (A) and the mass of the hollow ceria (B) from the viewpoint of easy formation of the cured film. It is preferably 5% by mass or more, and more preferably 10% by mass or more.
Moreover, from the viewpoint of easily forming a cured film having a low refractive index, the content of the epoxy compound (A) in the composition for forming a cured film is relative to the mass of the epoxy compound (A) and the hollow cerium oxide (B). The total mass is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less.

<Hollow cerium oxide (B)>
The curable composition contains hollow ceria (B). The refractive index of the hollow cerium (B) is significantly lower than the refractive index of 1.46 of the conventional cerium oxide. This is because the hollow ceria (B) contains air having a low refractive index of 1.0 inside.
Therefore, by using a hardenable composition containing hollow ceria (B), it is possible to form a cured film having a low refractive index.
The refractive index of the hollow ceria is typically preferably 1.2 or more and 1.3 or less.

The hollow cerium oxide (B) can be used without any particular limitation. The hollow cerium oxide may be a commercially available product or a synthetic product.
Hollow ceria (B) can be used in consideration of the particle diameter or refractive index and is selected from known hollow ceria.

The volume average particle diameter of the hollow ceria (B) is preferably 50 nm or more and 100 nm or less, more preferably 60 nm or more and 80 nm or less.

The content of the hollow cerium oxide (B) in the composition for forming a cured film is not particularly limited insofar as it does not inhibit the object of the present invention. The content of the hollow cerium oxide (B) in the composition for forming a cured film is easy to form a cured film having a low refractive index, and the mass of the epoxy compound (A) and the mass of the hollow cerium oxide (B) In total, it is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more.

<Interfacial Active Agent (C)>
The composition for forming a cured film contains a surfactant (C). When a composition for forming a cured film containing a surfactant (C) and a high-boiling point solvent (SH) to be described later is used, even if it is coated by a slit, surface defects such as unevenness or pin marks are likely to occur. The coating method is applied to the composition for forming a cured film, and it is also easy to form a cured film having no surface defects.
It is considered that the surfactant (C) promotes the leveling of the surface of the coating film in the hardening of the coating film.

The molecular weight of the surfactant (C) is preferably 2,000 or more, and more preferably 3,000 or more, from the viewpoint that the cured film formed on the surface without any trouble is particularly easy. The upper limit of the molecular weight of the surfactant (C) is not particularly limited. Typically, the upper limit of the molecular weight of the surfactant (C) is 50,000 or less.

The type of the surfactant (C) is not particularly limited as long as the desired effect can be obtained, and the surfactant (C) is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic system. Surfactants can be used. The surfactant (C) is preferably a nonionic surfactant from the viewpoint that the effect by the use of the surfactant (C) is excellent.
The nonionic surfactant is preferably, for example, a decane-based surfactant and a fluorine-based surfactant.

When the amount of the surfactant (C) in the composition for forming a cured film is 100 parts by mass or less based on the total amount of the epoxy compound (A) and the amount of the hollow cerium oxide (B), it is preferably 0.01. The mass part is 10 parts by mass or less, more preferably 0.05 parts by mass or more and 5 parts by mass or less, and particularly preferably 0.1 part by mass or more and 3 parts by mass or less.

<Solvent (S)>
The composition for forming a cured film contains a solvent (S). The solvent (S) contains at least one high boiling point solvent (SH) having a boiling point of 170 ° C or higher at atmospheric pressure.
When a composition for forming a cured film containing the surfactant (C) and the high-boiling solvent (SH) is used in combination, even if it is coated by a slit, surface defects such as unevenness or pin marks are likely to occur. The coating method is applied to the composition for forming a cured film, and it is also easy to form a cured film having no surface defects.

When the coating film composed of the composition for forming a cured film contains a high boiling point solvent (SH), even if most of the solvent (S) is removed from the coating film during the curing of the coating film, a certain amount The high boiling point solvent (SH) also remains in the coating film. As a result, the leveling of the surface of the coating film during hardening proceeds due to the influence of the remaining high boiling point solvent (SH). It is considered that for such a reason, a cured film having a smooth and uneven surface is formed.

The boiling point of the high boiling point solvent (SH) at atmospheric pressure is preferably 250 ° C or lower, more preferably 230 ° C or lower. At this time, when the coating film of the cured film formation composition is heated and cured, the residual amount of the high boiling point solvent (SH) in the cured film is extremely small, and it is easy to form a high-quality cured film.

The surface tension of the high boiling point solvent (SH) contained in the solvent (S) at 25 ° C is preferably 27 dyn/cm or more from the viewpoint of easily forming a cured film having a smooth and uneven surface. The surface boiling point of the high boiling point solvent (SH) at 25 ° C is more preferably 28 dyn / cm or more, particularly preferably 30 dyn / cm or more. By using the high boiling point solvent (SH) exhibiting the surface tension, the surface of the coating film can be smoothly leveled in the curing of the coating film.
Further, the solvent (S) preferably contains only an organic solvent having a surface tension of 25 dyn/cm or more, preferably 26 dyn/cm or more, more preferably 27 dyn/cm or more at 25 °C.
At this time, in the hardening of the coating film, it is easy to perform the leveling of the surface of the coating film particularly well.

The SP value ((cal/cm ³ ) ^1/2 , fedor) of one or more high boiling point solvents (SH) contained in the solvent (S) is preferably 9.0 or more and 12.5 or less.
It is presumed that the affinity of the high-boiling point solvent (SH) to the cerium oxide particles (B) is good, and the surface level of the coating film is somewhat affected.

The solvent (S) preferably contains one or more kinds of low boiling point solvents (SL) having a boiling point of less than 170 ° C at atmospheric pressure. When the low-boiling solvent (SL) is used together with the high-boiling solvent (SL), when the solvent (S) is removed by the coating film composed of the composition for forming a free-curing film, the low-boiling solvent (SL) and the high-boiling solvent (SH) ) is volatilized in sequence. Therefore, the solvent (S) does not volatilize strongly from the coating film. As a result, it is easy to form a cured film while preventing defects such as unevenness or roughness of the surface of the cured film.

Further, the low boiling point solvent (SL) preferably contains one or more first low boiling point solvents (SL1) having a boiling point of 80 ° C or higher and less than 130 ° C at atmospheric pressure, and a boiling point of 130 ° C or higher at atmospheric pressure. And less than one or more kinds of the second low boiling point solvent (SL2) at 170 °C.
When the low boiling point solvent (SL) contains two or more kinds of solvents having different boiling points, it is easier to form a cured film while preventing defects such as unevenness or roughness on the surface of the cured film.

Specific examples of the high boiling point solvent (SH) include benzyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, and diethylene glycol single -n-butyl ether (butyl carbitol), triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, diethylene glycol diethyl ether, dipropylene glycol monomethyl ether (DPM) , dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, N-methyl-2-pyrrolidone, 1,4-butyl Diol diacetate, diethylene glycol mono-n-butyl ether acetate, 1,6-hexanediol diacetate, ε-caprolactone, 1,3-butanediol diacetic acid Ester, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol methyl-n-butyl ether, γ-butyrolactone, dipropylene glycol methyl-n-propyl Ethyl ether, 3-methoxybutyl acetate, ethylene glycol monobutyl ether acetate, and propylene glycol diacetate.
The solvent (S) may be combined with two or more kinds of such high boiling point solvents (SH).

Among the above-mentioned high-boiling point solvents (SH), benzyl alcohol or diethylene glycol mono-n-butyl ether is preferable because it is easy to obtain a viewpoint or a composition for forming a cured film which is easy to prepare a coating property. Butyl carbitol), dipropylene glycol monomethyl ether (DPM), 1,4-butanediol diacetate, diethylene glycol mono-n-butyl ether acetate, 1,6-hexane Alcohol diacetate, ε-caprolactone, 1,3-butanediol diacetate, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol Base-n-butyl ether, γ-butyrolactone, dipropylene glycol methyl-n-propyl ether, 3-methoxybutyl acetate, ethylene glycol monobutyl ether acetate, and propylene glycol II Acetate.

Specific examples of suitable first low boiling point solvent (SL1) having a boiling point of 80 ° C or higher and less than 130 ° C under atmospheric pressure include ethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME), and acetic acid n. -propyl, isopropyl acetate, isobutyl acetate, ethyl butyrate, n-butyl acetate, and methyl ethyl ketone.
The solvent (S) may be combined with two or more kinds of the first low-boiling solvent (SL1).

Specific examples of suitable second low boiling point solvent (SL2) having a boiling point of 130 ° C or higher and less than 170 ° C under atmospheric pressure include ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, and propylene glycol. Monoethyl ether, propylene glycol mono-n-propyl ether, 3-methoxybutanol, diethylene glycol dimethyl ether (diethylene glycol dimethyl ether), ethylene glycol monomethyl ether acetate , ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, n-amyl formate, isoamyl acetate, n-butyl propionate, n-propyl butyrate, isopropyl butyrate Base, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, 3-heptanone, N,N-dimethylformamide, N,N-dimethyl Indoleamine, 2-heptanone, cyclopentanone, and cyclohexanone.
The solvent (S) may be combined with two or more kinds of the second low boiling point solvents (SL2).

The amount of the solvent (S) used in the composition for forming a cured film is not particularly limited insofar as it does not inhibit the object of the present invention. The amount of the solvent (S) to be used is determined in accordance with the film thickness of the cured film formed, and the viscosity of the composition for forming a cured film is appropriately determined in accordance with the appropriate viscosity of the coating method.

The solid content concentration of the composition for forming a cured film is, for example, 1% by mass or more and 50% by mass or less, preferably 2% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 20% by mass or less. The solvent (S) is used in a manner.
When the coating method is a slit coating, the solid content concentration of the cured film-forming composition is 1% by mass or more and 15% by mass or less, preferably 2% by mass or more and 12% by mass or less, and more preferably 3% by mass. The solvent (S) is used in the above 10 mass% or less.

The content of the high boiling point solvent (SH) in the solvent (S) is not particularly limited insofar as it does not inhibit the object of the present invention. The content of the high boiling point solvent (SH) is preferably 2% by mass or more and 60% by mass or less, more preferably 2% by mass or more and 50% by mass or less, and still more preferably 3% by mass based on the mass of the solvent (S). % or more is 30% by mass or less, and particularly preferably 5% by mass or more and 25% by mass or less.
In the solvent (S), the content of the low boiling point solvent (SL) is preferably 40% by mass or more and 98% by mass or less, more preferably 50% by mass or more and 98% by mass or less based on the mass of the solvent (S). More preferably, it is 70% by mass or more and 97% by mass or less, and particularly preferably 75% by mass or more and 95% by mass or less.

When the low boiling point solvent (SL) contains the first low boiling point solvent (SL1) and the second low boiling point solvent (SL2), the content ratio of both of the low boiling point solvents (SL) is not particularly limited.
In this case, the content of the first low boiling point solvent (SL1) in the low boiling point solvent (SL) is preferably 20% by mass or more and 90% by mass or less, more preferably 30% by mass or more and 90% by mass or less, and still more preferably 40% by mass or more and 80% by mass or less.

<Other ingredients>
The fat composition for forming a cured film may contain various additives as needed. Examples of the additives include an adhesion promoter, an antioxidant, a dispersant, an aggregation preventing agent, and an antifoaming agent.

The components for forming a cured film are produced by uniformly mixing the components described above in a desired composition.

When the cured film formation composition described above is used, it is preferred to form a cured film having a refractive index of 1.30 or less when the cured film is formed by the following cured film formation condition 1.

<Cured film formation condition 1>
The composition for forming a cured film was applied at a coating speed (bracket speed) of 100 mm/sec using a slit coater at 6 吋, and a coating film having a film thickness of 1000 nm was formed in a size of 10 cm × 10 cm.
After the formed coating film was allowed to stand under reduced pressure of 20 Pa for 10 seconds, the glass substrate was placed on a hot plate, and the coated film was heated at 100 ° C for 2 minutes. Next, the glass substrate was heated to 230 ° C, and the coated film was heated at the same temperature for 20 minutes.

In the case of using the cured film formation composition described above, it is preferred to form a cured film having a haze value of 1% or less when the cured film is formed by the following cured film formation condition 2.

<Cured film formation condition 2>
On the glass substrate having a size of 680 mm × 880 mm, a composition for forming a cured film was applied at a coating speed (bracket speed) of 180 mm/sec using a slit coater to form a coating film having a film thickness of 1000 nm.
After the formed coating film was allowed to stand under reduced pressure of 20 Pa for 10 seconds, the glass substrate was placed on a hot plate, and the coated film was heated at 100 ° C for 2 minutes. Next, the glass substrate was heated to 230 ° C, and the coated film was heated at the same temperature for 20 minutes.

By using the composition for forming a cured film described above, it is possible to form a cured film having a low refractive index on the surface without any problem. The cured film is suitably used for various applications such as a low refractive index film for covering a microlens for an image sensor, or a low refractive index film for antireflection in a liquid crystal display or an organic EL device.

≪hardening film formation method≫
The method for forming a cured film includes a method of forming a coating film by applying the composition for forming a cured film onto a substrate, and curing the coating film by heating.

In the formation of the coating film, a coating method such as slit coating, dip coating, spin coating spray coating, screen printing or the like is preferably used. Among these methods, it is preferable to apply a slit from the viewpoint of uniformly forming a film in a plane on a square substrate having a panel size.
When slit coating is performed, it is possible to apply a substrate having a cured film at a high throughput, and it is preferable to apply it at a coating speed of 120 mm/sec or more.

As described above, when the composition containing the epoxy compound (A) and the hollow ceria (B) is applied under the above conditions to form a cured film, the surface tends to be wavy uneven, strip uneven, and inserted. Bad condition of needle marks.
However, when the composition for forming a cured film is used, even if a coating film is formed by slit coating or the like, a cured film can be formed while suppressing surface defects.

The film thickness of the coating film is not particularly limited, and is, for example, preferably 50 nm or more and 5000 nm or less, and particularly preferably 100 nm or more and 2000 nm or less.

The coating film formed in this manner is then hardened by heat.
When the coating film is heated, it is preferred to temporarily place the coating film under reduced pressure. At least a part of the solvent (S) in the coating film is removed by placing the coating film under reduced pressure.
The temperature in the environment under reduced pressure is, for example, a temperature of from 0 ° C to 50 ° C, preferably from 10 ° C to 30 ° C.
The degree of vacuum in the environment under reduced pressure is not particularly limited, and is, for example, 1 Pa or more and 300 Pa or less, preferably 10 Pa or more and 200 Pa or less.
By the solvent (S) being gently removed from the coating film under the above-described reduced pressure conditions, it is easy to form a cured film under the condition of suppressing surface defects.

The coating film formed as described above is arbitrarily placed under reduced pressure, and then heated and hardened. The heating conditions are not particularly limited as long as the curing of the coating film proceeds satisfactorily.
The heating of the coating film is preferably, for example, a preliminary heating at a temperature in a range of from about 60 ° C to about 150 ° C, and a temperature in a range of from about 150 ° C to about 250 ° C after preliminary heating. Formal heating is carried out.
The time for preliminary heating is not particularly limited, and is typically 30 seconds or longer and 10 minutes or shorter, preferably 1 minute or longer and 5 minutes or shorter.
The time of the main heating is not particularly limited, and is typically 5 minutes or longer and 60 minutes or shorter, preferably 10 minutes or longer and 30 minutes or shorter.

According to the method described above, it is possible to form a cured film satisfactorily under conditions in which surface irregularities such as wavy unevenness, strip unevenness, and pin marks are suppressed.

[Examples]

The examples are shown below to more specifically illustrate the invention. The scope of the invention is not limited to the embodiments.

[Examples 1 to 14, and Comparative Examples 1 to 4]
In the examples and comparative examples, the epoxy compound (A) (component (A)) was the following A-1 and A-2.
A-1: 42% by mass of a unit derived from glycidyl methacrylate, 42% by mass of a unit derived from 3,4-epoxycyclohexylmethyl methacrylate, and 16 units derived from methacrylic acid Acrylic copolymer composed of mass%
A-2: an acrylic polymer composed of 80% by mass of a unit derived from glycidyl methacrylate and 20% by mass of a unit derived from 4-hydroxyphenyl methacrylate

In the examples and comparative examples, the hollow ceria (B) (component (B)) was a hollow ceria particle having a volume average particle liquid of 60 nm.

In the examples and comparative examples, the following surfactants C-1 to C-4 were used as the surfactant (C) (component (C)).
C-1: Fluorine-based surfactant (PF-656, manufactured by OMNOVA), molecular weight 1500
C-2: a siloxane-based surfactant (polyester-modified polydimethyl siloxane, BYK-310 BYK) molecular weight 4000
C-3: a siloxane-based surfactant (Granol 440, manufactured by Kyoeisha Chemical Co., Ltd.), molecular weight 5,300
C-4: Fluorine-based surfactant (APX-4082B, manufactured by Kyoeisha Chemical Co., Ltd.) Molecular Weight 20000

In the examples and comparative examples, SL1-1 as the first low boiling point solvent (SL1), SL2-1 and SL2-2 as the second low boiling point solvent (SL2), and a high boiling point solvent were used ( SH-1, SH-2 and SH-3 below SH).
SL1-1: Propylene glycol monomethyl ether
SL2-1: 3-methoxybutanol
SL2-2: Propylene glycol monomethyl ether acetate
SH-1: Benzyl alcohol
SH-2: dipropylene glycol monomethyl ether
SH-3: diethylene glycol mono-n-butyl ether (butyl carbitol)
SH-4: propylene glycol diacetate

The amount (parts by mass) of the epoxy compound (A) and the hollow cerium oxide (B) described in Tables 1 to 3, and the types and amounts (parts by mass) of the surfactants described in Tables 1 to 3 ( C), dissolved and dispersed in a solvent (S), and the solid content concentrations shown in Tables 1 to 3 were prepared to prepare a composition for forming a cured film of each of Examples and Comparative Examples. The solvent (S) is a mixed solvent of the compositions described in Tables 1 to 3.

Using the obtained composition for forming a cured film, the occurrence of unevenness in the cured film and the generation of pin marks were evaluated by the following methods.
On the glass substrate having a size of 680 mm × 880 mm, a composition for forming a cured film was applied at a coating speed (bracket speed) of 180 mm/sec using a slit coater to form a coating film having a film thickness of 1000 nm.
After the formed coating film was allowed to stand under reduced pressure of 20 Pa for 10 seconds, the glass substrate was placed on a hot plate, and the coated film was heated at 100 ° C for 2 minutes. Next, the glass substrate was transferred to a hot plate at 230 ° C, and the coated film was heated for 20 minutes.
When the surface of the coating film formed by the microscope was observed, and unevenness such as unevenness of the wave shape and unevenness of the stripe was observed, the evaluation of the unevenness was ×. On the other hand, when unevenness was not observed, the evaluation of the unevenness was ○.
Further, the evaluation of the pin trace when the pin trace was observed by microscopic observation was ×. On the other hand, when the pin trace was not observed, the evaluation of the pin trace was ○.

A cured film was formed under the above-described cured film formation condition 1, and the refractive index of the formed cured film was measured. The measurement results of the refractive index are shown in Tables 1 to 3.

Further, a cured film was formed under the above-described cured film formation condition 2, and the haze value of the formed cured film was measured. In addition, the haze value was not measured about the composition for forming a cured film of Comparative Examples 1, 2, and 4.
When the haze value is 1% or less, it is evaluated as ○, and when it is more than 1%, it is evaluated as ×. The evaluation results are shown in Tables 1 to 3.

As is clear from Tables 1 and 2, the epoxy compound (A), the hollow cerium oxide (B) and the solvent (S) are further contained, and the surfactant (C) is further contained, and the boiling point at atmospheric pressure is 170 ° C or higher. When one or more high boiling point solvents (SH) are used as the composition for forming a cured film of the example of the solvent (S), the cured film can be favorably formed by suppressing unevenness of the surface or generation of pin marks.
On the other hand, as is clear from Table 3, when a composition for forming a cured film of a comparative example containing no high boiling point solvent (SH) or surfactant (C) is used, unevenness or pin marks tend to occur on the surface of the cured film. At least one party.

Claims (17)

A composition for forming a cured film, comprising an epoxy compound (A), hollow ceria (B), a surfactant (C), and a solvent (S), and The solvent (S) contains at least one high boiling point solvent (SH) having a boiling point of 170 ° C or higher at atmospheric pressure. The composition for forming a cured film according to claim 1, wherein the high boiling point solvent (SH) has a boiling point of 250 ° C or less at atmospheric pressure. The composition for forming a cured film of claim 1 which is applied to a substrate by slit coating to obtain a cured film. The composition for forming a cured film according to claim 3, which is used for slit coating at a coating speed of 120 mm/sec or more. The composition for forming a cured film according to any one of claims 1 to 4, wherein the solvent (S) contains at least one low-boiling solvent (SL) having a boiling point of less than 170 ° C at atmospheric pressure. The composition for forming a cured film according to claim 5, wherein the low boiling point solvent (SL) is one or more first low boiling point solvents (SL1) having a boiling point of 80 ° C or more and less than 130 ° C at atmospheric pressure. It is composed of one or more second low boiling point solvents (SL2) having a boiling point of 130 ° C or higher and less than 170 ° C at atmospheric pressure. The composition for forming a cured film according to any one of claims 1 to 4, wherein one or more of the high boiling point solvents (SH) have an SP value of 9.0 or more and 12.5 or less. The composition for forming a cured film according to any one of claims 1 to 4, wherein the molecular weight of the surfactant (C) is 2,000 or more. The composition for forming a cured film according to any one of claims 1 to 4, wherein the epoxy compound (A) has one selected from the group consisting of a carboxyl group, a carboxylic anhydride group, a phenolic hydroxyl group, and an amine group. The above functional groups. The composition for forming a cured film according to any one of claims 1 to 4, wherein the epoxy compound (A) is a copolymer of a monomer having an unsaturated double bond. The composition for forming a cured film according to any one of claims 1 to 4, wherein the hollow ceria (B) has a volume average particle diameter of 50 nm or more and 100 nm or less. The cured film formation composition according to any one of claims 1 to 4, wherein when the cured film is formed by the following cured film formation condition 1, a cured film having a refractive index of 1.30 or less is obtained; <Cured film formation condition 1> Applying a composition for forming a cured film at a coating speed (support speed) of 100 mm/sec using a slit coater to form a coating film having a film thickness of 1000 nm in a size of 10 cm × 10 cm; After the formed coating film was allowed to stand under reduced pressure of 20 Pa for 10 seconds, the glass substrate was placed on a hot plate, and the coated film was heated at 100 ° C for 2 minutes, and then the glass substrate was heated to 230 ° C. The coated film was heated at the same temperature for 20 minutes. The composition for forming a cured film according to any one of claims 1 to 4, wherein when the cured film is formed by the following cured film formation condition 2, a cured film having a haze value of 1% or less is obtained; <Cured film formation condition 2> Coating a composition for forming a cured film on a glass substrate having a size of 680 mm × 880 mm at a coating speed (scaffold speed) of 180 mm/sec using a slit coater to form a coating film having a film thickness of 1000 nm; After the formed coating film was allowed to stand under reduced pressure of 20 Pa for 10 seconds, the glass substrate was placed on a hot plate, and the coated film was heated at 100 ° C for 2 minutes, and then the glass substrate was heated to 230 ° C. The coated film was heated at the same temperature for 20 minutes. A method of forming a cured film, comprising A coating film is formed by applying the composition for forming a cured film according to any one of claims 1 to 13 to a substrate, and The coating film is hardened by heating. The method for forming a cured film according to claim 14, which comprises removing at least a part of the solvent (S) contained in the coating film by placing the coating film under reduced pressure before the curing. The method for forming a cured film according to claim 14 or 15, wherein the formation of the coating film is carried out by a slit coating method. The method for forming a cured film according to claim 16, wherein the coating speed when the coating film is formed by slit coating is 120 mm/sec or more.