JP2019119848A - Composition for forming cured film, and cured film formation method - Google Patents

Abstract

To provide a composition for forming a cured film containing an epoxy compound (A) and hollow silica (B), capable of forming a cured film while suppressing defects of a surface even when a coated film is formed by using a slit coating method or the like which is likely to cause defects on the surface such as hazy unevenness, stripe unevenness, pin mark, and a cured film formation method using the composition for forming the cured film.SOLUTION: When a cured film is formed 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 kinds of high boiling solvent (SH) having a boiling point under an ambient pressure of 170°C or higher as the solvent (S) are used.SELECTED DRAWING: None

Description

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

Conventionally, various functional films such as an insulating film, a protective film, and an antireflective film are formed by a method of applying various resin compositions in liquid form.
Specifically, a low refractive index film for covering a microlens for an image sensor, a low refractive index film for preventing reflection in a liquid crystal display, an organic EL element or the like is formed into a desired shape using a photosensitive resin composition. It is formed while being patterned.

  As a photosensitive resin composition which can form the patterned cured film which can be used as said low-refractive-index film for reflection prevention, hollow or a porous particle, a photoinitiator, and the polymerizability which has alkali solubility A photosensitive resin composition containing a compound and a particle dispersant has been proposed (Patent Document 1).

JP, 2009-271444, A

If 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, in order to improve the heat resistance, alkali resistance, solvent resistance and the like of the low refractive index film, it may be desired to use an epoxy compound instead of the alkali-soluble polymerizable compound. When the epoxy compound is used in combination with hollow particles, such as, for example, hollow silica, a solvent is used to give the composition a favorable coatability.

  However, when the present inventors examined, when forming a cured film using the composition containing an epoxy compound, hollow silica, and a solvent, haze unevenness, streak unevenness, pin marks on the surface of the cured film. It turned out that such a defect is likely to occur. The occurrence of such a problem is remarkable when employing a coating method such as slit coating.

  The present invention has been made in view of the above problems, and even if a coating film is formed using a slit coating method or the like in which surface defects such as unevenness, streaks, and pin marks are likely to occur, A composition for forming a cured film comprising an epoxy compound (A) and a hollow silica (B) capable of forming a cured film while suppressing surface defects, and a cured film formed using the composition for forming a cured film The purpose is to provide a method.

  The inventors of the present invention use a surfactant (C) in a composition when forming a cured film using a composition containing an epoxy compound (A), hollow silica (B), and a solvent (S). In addition, it is found that the above-mentioned problems can be solved by using, as the solvent (S), one or more high boiling point solvents (SH) having a boiling point of 170 ° C. or higher at atmospheric pressure, and to complete the present invention. It reached.

A first aspect of the present invention comprises an epoxy compound (A), hollow silica (B), surfactant (C), and solvent (S),
It is a composition for cured film formation in which a solvent (S) contains 1 or more types of high boiling point solvents (SH) whose boiling point under atmospheric pressure is 170 degreeC or more.

A second aspect of the present invention is the formation of a coated film by applying the composition for forming a cured film according to the first aspect on a substrate,
Curing the coating film by heating;
And a method of forming a cured film.

  According to the present invention, even when a coating film is formed using a slit coating method or the like in which surface defects such as unevenness, streaks, and pin marks easily occur, curing is performed while suppressing defects on these surfaces. The composition for cured film formation containing an epoxy compound (A) and hollow silica (B) which can form a film, and the cured film formation method using the composition for the said cured film formation can be provided.

«Composition for forming a cured film»
The composition for cured film formation contains an epoxy compound (A), hollow silica (B), surfactant (C), and solvent (S). The solvent (S) contains one or more high boiling point solvents (SH) having a boiling point of 170 ° C. or higher at atmospheric pressure.
After coating by a method such as slit coating, dip coating, spray coating, screen printing coating, etc. using the epoxy compound (A) and the composition for forming a cured film containing hollow silica (B), a coated film is formed In the coated film obtained by curing the coated film, surface defects such as unevenness, streaks, and pin marks tend to occur easily. When the slit coating is performed, particularly when the slit coating is performed at a high coating speed of 120 mm / sec or more, the occurrence of such surface defects is remarkable.
However, in the case of using the above composition for forming a cured film, defects in the surface thereof hardly occur when forming the cured film.

  That is, the composition for forming a cured film containing the above-mentioned predetermined component is applied to the substrate by slit application, and in particular, applied to the substrate by slit application at an application speed of 120 mm / sec or more. , Give a cured film while suppressing surface defects.

<Epoxy Compound (A)>
The composition for cured film formation contains the epoxy compound (A) which has an epoxy group as a component which hardens the composition for high film formation. As an epoxy compound (A), any of a resin containing an epoxy group and an epoxy compound of non-resin type can be used.
An epoxy group-containing resin is preferable as the epoxy compound from the viewpoint of facilitating curing of the coating film comprising the composition for forming a cured film at a low temperature for a short time.

  The epoxy compound (A) may be used together with a known curing agent or curing accelerator, if necessary. The amount of curing agent or curing accelerator used is appropriately determined depending on the type.

The epoxy compound (A) preferably has one or more functional groups selected from the group consisting of a carboxy group, a carboxylic acid anhydride group, a phenolic hydroxyl group, and an amino group.
The carboxy group, the carboxylic anhydride group, the phenolic hydroxyl group, and the amino group all cause a curing reaction with the epoxy group to occur or accelerate the curing reaction of the epoxy group.
Therefore, when the epoxy compound (A) has one or more functional groups selected from the group consisting of a carboxy group, a carboxylic acid anhydride group, a phenolic hydroxyl group, and an amino group, a composition for forming a cured film is used. Even if the curing agent is not contained, the curable crude product can be cured well.

In the case of curing the composition for forming a cured film, as described later, there are cases where a coating film composed of the composition for forming a cured film is placed under reduced pressure conditions. In this case, evaporation or sublimation of the curing agent from the coating film may cause uneven curing or slight roughness on the surface of the cured film.
However, when the composition for forming a cured film does not contain a curing agent, a cured film having a flat and uniformly cured surface is obtained even when the coated film is placed under reduced pressure in the process of the composition for forming a cured film. Easy to form.

The epoxy compound (A) is preferably a copolymer of monomers having unsaturated double bonds. When using the epoxy compound which is this copolymer as an epoxy compound (A), since an epoxy compound is what is called resin, a curable composition is excellent in film forming property.
Moreover, use of the epoxy compound which is a copolymer is also preferable at the point which is easy to adjust the various characteristic of a cured film by selecting suitably the monomer used for preparation of an epoxy compound.

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

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

  The polyfunctional epoxy compound is not particularly limited as long as it is a difunctional or more epoxy compound. Examples of multifunctional epoxy compounds include bifunctional epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol AD epoxy resin, naphthalene epoxy resin, and biphenyl epoxy resin; Glyceryl ester type epoxy resins such as dimer acid glycidyl ester and triglycidyl ester; Glycidyl amine type epoxy resins such as tetraglycidyl aminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidyl metaxylylene diamine, and tetraglycidyl bisaminomethyl cyclohexane Resin; heterocyclic epoxy resin such as triglycidyl isocyanurate; phloroglycinol triglycidyl ether; trihydroxybiphenyl tri Ricidyl ether, trihydroxyphenylmethane triglycidyl ether, glycerin 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-Epoxypropoxy) phenyl] -1-methylethyl] phenyl] ethyl] phenoxy] trifunctional epoxy resin such as 2-propanol; tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidyl benzophenone, bisresorcinol tetraglycidyl Ether, and tetrafunctional type such as tetraglycidoxybiphenyl Carboxymethyl resins.

  Moreover, an alicyclic epoxy compound is also preferable as a polyfunctional epoxy compound at the point which gives hardened | cured material of high hardness. Specific examples of the alicyclic epoxy compound include 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane and bis (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′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone modified 3, 4-epoxycyclohexene Rumethyl-3 ', 4'-epoxycyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis (3,4-epoxycyclohexanecarboxylate) And epoxy cyclohexahydrophthalic acid dioctyl, and epoxy cyclohexahydrophthalic acid di-2-ethylhexyl, an epoxy resin having a tricyclodecene oxide group, and the following formulas (a01-1) to (a01-5) Compounds are mentioned.

（式（ａ０１−１）中、Ｚ^０１は単結合又は連結基（１以上の原子を有する二価の基）を示す。Ｒ^ａ０１〜Ｒ^ａ０１８は、それぞれ独立に、水素原子、ハロゲン原子、及び有機基からなる群より選択される基である。） Among the specific examples of these alicyclic epoxy compounds, alicyclic epoxy compounds represented by the following formulas (a01-1) to (a01-5) are preferable because they give cured products with high hardness.

(Wherein, in the formula (a01-1), Z ⁰¹ represents a single bond or a linking group (a divalent group having one or more atoms). R ^{a01 to} R a ⁰¹⁸ each independently represent a hydrogen atom, a halogen atom, and A group selected from the group consisting of organic groups)

As the linking group Z ⁰¹ , for example, a divalent hydrocarbon group, —O—, —O—CO—, —S—, —SO—, —SO ₂ —, —CBr ₂ —, —C (CBr ₃ ) _{2 -, - C (CF 3} ) 2 -, and ^{-R a019} -O-CO- 2 divalent group and which are selected from the group consisting of these can be exemplified a plurality bonded group.

  Examples of the divalent hydrocarbon group as the linking group Z include linear or branched alkylene groups having 1 to 18 carbon atoms, and divalent alicyclic hydrocarbon groups. it can. As a linear or branched alkylene group having 1 to 18 carbon atoms, for example, methylene, methylmethylene, dimethylmethylene, dimethylene, trimethylene and the like can be mentioned. Examples of the divalent alicyclic hydrocarbon group include a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a cyclopentylidene group, a 1,2-cyclohexylene group, and a 1,3-disubstituted cycloaliphatic hydrocarbon group. Cycloalkylene groups (including cycloalkylidene groups) such as cyclohexylene group, 1,4-cyclohexylene group, cyclohexylidene group and the like can be mentioned.

R ^{a0 19} is an alkylene group having 1 to 8 carbon atoms, and is preferably a methylene group or an ethylene group.

（式（ａ０１−２）中、Ｒ^ａ０１〜Ｒ^ａ０１８は、水素原子、ハロゲン原子、及び有機基からなる群より選択される基である。Ｒ^ａ０２及びＲ^ａ０１０は、互いに結合してもよい。Ｒ^ａ０１３及びＲ^ａ０１６は互いに結合して環を形成してもよい。ｍ^ａ１は、０又は１である。）

(In the formula (a01-2), R ^{a01 to} R a ⁰¹⁸ 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. R ^a013 and R ^a016 may combine with each other to form a ring, and m ^a1 is 0 or 1.)

（式（ａ０１−２−１）中、Ｒ^ａ０１〜Ｒ^ａ０１２は、水素原子、ハロゲン原子、及び有機基からなる群より選択される基である。Ｒ^ａ０２及びＲ^ａ０１０は互いに結合して環を形成してもよい。） Examples of the alicyclic epoxy compound represented by the above formula (a01-2), corresponds to the compound ^{m a1} is 0 in the formula (a01-2), represented by the following formula (a01-2-1) Compounds are preferred.

(In the formula (a01-2-1), R ^{a01 to} R a ⁰¹² is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. R ^a02 and R ^a010 are bonded to each other to form a ring You may form.)

（式（ａ０１−３）中、Ｒ^ａ０１〜Ｒ^ａ０１０は、水素原子、ハロゲン原子、及び有機基からなる群より選択される基である。Ｒ^ａ０２及びＲ^ａ０８は、互いに結合してもよい。）

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

（式（ａ０１−４）中、Ｒ^ａ０１〜Ｒ^ａ０１２は、水素原子、ハロゲン原子、及び有機基からなる群より選択される基である。Ｒ^ａ０２及びＲ^ａ０１０は、互いに結合してもよい。）

(In formula (a01-4), R ^{a01 to} R a ⁰¹² is 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. )

（式（ａ０１−５）中、Ｒ^ａ０１〜Ｒ^ａ０１２は、水素原子、ハロゲン原子、及び有機基からなる群より選択される基である。）

(In formula (a01-5), R ^{a01 to} R a ⁰¹² is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group.)

In the formulas (a01-1) to (a01-5), when R ^{a01 to} R a ⁰¹⁸ is an organic group, the organic group is not particularly limited as long as the object of the present invention is not ^impaired. Or a group consisting of a carbon atom and a halogen atom, or may be a group containing a halogen atom, an oxygen atom, a sulfur atom, a nitrogen atom, a hetero atom such as a silicon atom, as well as a carbon atom and a hydrogen atom . Examples of the halogen atom include chlorine atom, bromine atom, iodine atom, and fluorine atom.

  As an organic group, a group consisting of a hydrocarbon group, a carbon atom, a hydrogen atom and an oxygen atom, a halogenated hydrocarbon group, a group consisting of a carbon atom, an oxygen atom and a halogen atom, a carbon atom and a hydrogen atom And the group which consists of an oxygen atom and a halogen atom is preferable. When the organic group is a hydrocarbon group, the hydrocarbon group may be an aromatic hydrocarbon group, an aliphatic hydrocarbon group, or 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 group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group , N-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, n-undecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group And linear alkyl groups such as n-heptadecyl, n-octadecyl, n-nonadecyl and n-icosyl; vinyl, 1-propenyl, 2-n-propenyl (allyl), 1-n -Chain-like alkenyl groups such as butenyl group, 2-n-butenyl group and 3-n-butenyl group; cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group And cycloalkyl groups such as cycloheptyl group; phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, α-naphthyl group, β-naphthyl group, β-naphthyl group, biphenyl-4-yl group, biphenyl-3-yl group Aryl group such as biphenyl-2-yl group, anthryl group and phenanthryl group; benzyl group, phenethyl group, α-naphthylmethyl group, β-naphthylmethyl group, α-naphthylethyl group and β-naphthylethyl group And aralkyl groups such as

  Specific examples of the halogenated hydrocarbon group are chloromethyl group, dichloromethyl group, trichloromethyl group, bromomethyl group, dibromomethyl group, tribromomethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, 2, 2 , 2-trifluoroethyl group, pentafluoroethyl group, heptafluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group, perfluorooctyl group, perfluorononyl group, and Halogenated linear alkyl group such as perfluorodecyl group; 2-chlorocyclohexyl group, 3-chlorocyclohexyl group, 4-chlorocyclohexyl group, 2,4-dichlorocyclohexyl group, 2-bromocyclohexyl group, 3-bromocyclohexyl group , And 4- Halogenated cycloalkyl group such as mocyclohexyl group; 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2,3-dichlorophenyl group, 2,4-dichlorophenyl group, 2,5-dichlorophenyl group, 2, 6 -Dichlorophenyl group, 3,4-dichlorophenyl group, 3,5-dichlorophenyl group, 2-bromophenyl group, 3-bromophenyl group, 4-bromophenyl group, 2-fluorophenyl group, 3-fluorophenyl group, 4- Halogenated aryl groups such as fluorophenyl group; 2-chlorophenylmethyl group, 3-chlorophenylmethyl group, 4-chlorophenylmethyl group, 2-bromophenylmethyl group, 3-bromophenylmethyl group, 4-bromophenylmethyl group, 2 -Fluorophenylmethyl group, 3-fluorophenyl Methyl group, a halogenated aralkyl group such as 4-fluorophenyl methyl group.

  Specific examples of the group consisting of carbon atom, hydrogen atom and oxygen atom are hydroxy chain such as hydroxymethyl group, 2-hydroxyethyl group, 3-hydroxy-n-propyl group and 4-hydroxy-n-butyl group Alkyl group; halogenated cycloalkyl group such as 2-hydroxycyclohexyl group, 3-hydroxycyclohexyl group, and 4-hydroxycyclohexyl group; 2-hydroxyphenyl group, 3-hydroxyphenyl group, 4-hydroxyphenyl group, 2, 3 -Hydroxyaryl groups such as dihydroxyphenyl group, 2,4-dihydroxyphenyl group, 2,5-dihydroxyphenyl group, 2,6-dihydroxyphenyl group, 3,4-dihydroxyphenyl group, and 3,5-dihydroxyphenyl group 2-hydroxyphenylmethyl group, 3-hydroxy Hydroxyaralkyl groups such as phenylmethyl group and 4-hydroxyphenylmethyl group; methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butyloxy group, isobutyloxy group, sec-butyloxy group, tert-butyloxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-trioxy group Decyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, n-nonadecyloxy, n-icosyloxy, etc. Linear alkoxy group; vinyloxy group, 1-propenyl group A chain alkenyloxy group such as a cis group, 2-n-propenyloxy group (allyloxy group), 1-n-butenyloxy group, 2-n-butenyloxy group, and 3-n-butenyloxy group; phenoxy group, o-tolyloxy Group, m-tolyloxy group, p-tolyloxy group, α-naphthyloxy group, β-naphthyloxy group, biphenyl-4-yloxy group, biphenyl-3-yloxy group, biphenyl-2-yloxy group, anthryloxy group, And aryloxy groups such as phenanthryloxy groups; benzyloxy groups, phenethyloxy groups, α-naphthylmethyloxy groups, β-naphthylmethyloxy groups, α-naphthylethyloxy groups, β-naphthylethyloxy groups and the like Aralkyloxy group; methoxymethyl group, ethoxymethyl group, n-propoxymethyl group , 2-methoxyethyl group, 2-ethoxyethyl group, 2-n-propoxyethyl group, 3-methoxy-n-propyl group, 3-ethoxy-n-propyl group, 3-n-propoxy-n-propyl group, Alkoxyalkyl groups such as 4-methoxy-n-butyl group, 4-ethoxy-n-butyl group, and 4-n-propoxy-n-butyl group; methoxymethoxy group, ethoxymethoxy group, n-propoxymethoxy group, 2 4-methoxyethoxy group, 2-ethoxyethoxy group, 2-n-propoxyethoxy group, 3-methoxy-n-propoxy group, 3-ethoxy-n-propoxy group, 3-n-propoxy-n-propoxy group, 4- Alkoxy alkoxy such as methoxy-n-butyloxy group, 4-ethoxy-n-butyloxy group, and 4-n-propoxy-n-butyloxy group Groups; alkoxyaryl groups such as 2-methoxyphenyl group, 3-methoxyphenyl group, and 4-methoxyphenyl group; alkoxyaryloxy groups such as 2-methoxyphenoxy group, 3-methoxyphenoxy group, and 4-methoxyphenoxy group Aliphatic acyl groups such as formyl group, acetyl group, propionyl group, butanoyl group, pentanoyl group, hexanoyl group, heptanoyl group, octanoyl group, nonanoyl group, and decanoyl group; benzoyl group, α-naphthoyl group, and β-naphthoyl Aromatic acyl groups such as groups; methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, n-butyloxycarbonyl group, n-pentyloxycarbonyl group, n-hexylcarbonyl group, n-heptyloxycarbonyl group, n -Octyloxy Chain-like alkyloxycarbonyl groups such as rubonyl group, n-nonyloxycarbonyl group and n-decyloxycarbonyl group; and aryloxycarbonyl groups such as phenoxycarbonyl group, α-naphthoxy carbonyl group and β-naphthoxy carbonyl group Aliphatics such as formyloxy group, acetyloxy group, propionyloxy group, butanoyloxy group, pentanoyloxy group, hexanoyloxy group, heptanoyloxy group, octanoyloxy group, nonanoyloxy group, and decanoyloxy group Acyloxy groups; aromatic acyloxy groups such as benzoyloxy group, α-naphthoyloxy group, and β-naphthoyloxy group.

Each of R ^{a01 to} R a ⁰¹⁸ is preferably a group selected independently from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms, In particular, it is more preferable that all of R ^{a01 to} R a ⁰¹⁸ be hydrogen atoms because it is easy to form a cured film having excellent mechanical properties.

Wherein ^{(a01-2) ~ (a01-5),} R a01 ~R a018 is the same as ^R a01 ^{to R A018} in formula (a01-1). In the formula (a01-2) and the formula (a01-4), when R ^a02 and R ^a010 are bonded to each other, in the formula (a01-2), the R ^a013 and the R ^a016 are bonded to each other; In a01-3), ^examples of the divalent group formed when R ^a02 and R ^a08 bond to each other include —CH ₂ — and —C (CH ₃ ) ₂ —.

Among the alicyclic epoxy compounds represented by the formula (a01-1), specific examples of suitable compounds include those represented by the following formulas (a01-1a), (a01-1b), and (a01-1c) May include the alicyclic epoxy compounds, 2,2-bis (3,4-epoxycyclohexan-1-yl) propane [= 2,2-bis (3,4-epoxycyclohexyl) propane], etc. it can.

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

Among the alicyclic epoxy compounds represented by the formula (a01-3), specific examples of suitable compounds include Sspiro [3-oxatricyclo [3.2.1.0 ^2,4 ] octane-6. , 2′-oxirane] 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, 1-methyl-4- (3- (3- (3-) Examples include methyl oxirane-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-diepoxycyclooctane and the like.

(Epoxy group-containing resin)
In the case of using an epoxy group-containing resin having an epoxy group, cross-linking due to a polyaddition reaction between epoxy groups occurs between the molecules contained in the resin by using a known curing agent or curing accelerator as needed.

  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 is obtained by introducing an epoxy group to a polymer having a functional group having reactivity such as a hydroxyl group, a carboxyl group, an amino group, etc. using a compound having an epoxy group such as epichlorohydrin, for example. May be Since it is easy to obtain, prepare, adjust the amount of epoxy group in the polymer, etc., as the polymer having an epoxy group, a monomer containing an epoxy group-containing monomer or an epoxy group-containing monomer The polymer obtained by polymerizing the body mixture is preferred.

  Preferred examples of epoxy group-containing resins include phenol novolac epoxy resins, brominated phenol novolac epoxy resins, ortho cresol novolac epoxy resins, bisphenol A novolac epoxy resins, and novolac epoxy resins such as bisphenol AD novolac epoxy resins. Cyclic aliphatic epoxy resins such as epoxidized products of dicyclopentadiene type phenolic resins; and aromatic epoxy resins such as epoxidized compounds of naphthalene type phenolic resins.

  In addition, among epoxy group-containing resins, it is easy to prepare and it is easy to adjust the physical properties of the cured film, so it is possible to use an epoxy group-containing (meth) acrylic acid ester homopolymer or epoxy group. Copolymers of (meth) acrylic acid ester having the following and other monomers are preferred.

  The (meth) acrylic acid ester having an epoxy group is a (meth) acrylic acid ester having an alicyclic epoxy group as described later, even if it is a (meth) acrylic acid ester having a linear aliphatic epoxy group It may be. In addition, the (meth) acrylic acid ester having an epoxy group may contain an aromatic group. Among the (meth) acrylic acid esters having an epoxy group, aliphatic (meth) acrylic acid esters having a linear aliphatic epoxy group and aliphatic (meth) acrylic acid esters having an alicyclic epoxy group are preferable, More preferred are aliphatic (meth) acrylic esters having an alicyclic epoxy group.

  4-glycidyl oxyphenyl (meth) acrylate, 3-glycidyl oxyphenyl (meth) acrylate, 2-glycidyl oxyphenyl (meth) acrylate as an example of (meth) acrylic acid ester which contains an aromatic group and has an epoxy group 4-glycidyl oxyphenyl methyl (meth) acrylate, 3-glycidyl oxyphenyl methyl (meth) acrylate, 2-glycidyl oxyphenyl methyl (meth) acrylate, etc. are mentioned.

  Examples of aliphatic (meth) acrylic acid esters having a linear aliphatic epoxy group include epoxy alkyl (meth) acrylates, and ester groups (-O-CO- such as epoxy alkyl oxyalkyl (meth) acrylates etc. And (meth) acrylic acid esters in which a chain aliphatic epoxy group is bonded to an oxy group (—O—) in the above. The chain-like aliphatic epoxy group which such (meth) acrylic acid ester has may contain one or more oxy groups (-O-) in a chain. The number of carbon atoms in 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) acrylic acid ester having a linear aliphatic epoxy group include glycidyl (meth) acrylate, 2-methyl glycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 6, Epoxyalkyl (meth) acrylates such as 7-epoxyheptyl (meth) acrylate; 2-glycidyloxyethyl (meth) acrylate, 3-glycidyloxy n-propyl (meth) acrylate, 4-glycidyloxy n-butyl (meth) And epoxyalkyloxyalkyl (meth) acrylates such as acrylates, 5-glycidyloxy-n-hexyl (meth) acrylate, 6-glycidyloxy-n-hexyl (meth) acrylate and the like.

  As a specific example of aliphatic (meth) acrylic acid ester which has an alicyclic epoxy group, the compound represented, for example by following formula (a05-1)-(a05-15) is mentioned. Among these, the compounds represented by the following formulas (a05-1) to (a05-5) are preferable, and the compounds represented by the following formulas (a05-1) to (a05-3) are more preferable. Further, in each of these compounds, the bonding site of the oxygen atom of the ester group to an alicyclic ring is not limited to the one shown here, and may contain partial regioisomer.

In the above formulae, R ^a032 represents a hydrogen atom or a methyl group, R ^a033 represents a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms, and R ^a034 represents 1 to 10 carbon atoms. indicates the valency of the hydrocarbon group, t ⁰ is an integer of 0 to 10. As R ^a033 , a linear or branched alkylene group such as a methylene group, an ethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group or a hexamethylene group is preferable. As R ^a034 , for example, a methylene group, an ethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group, a hexamethylene group, a phenylene group and a cyclohexylene group are preferable.

  As the polymer having an epoxy group, either a homopolymer of an (meth) acrylic acid ester having an epoxy group or a copolymer of a (meth) acrylic acid ester having an epoxy group and another monomer is used 70 mass% or more is preferable, and, as for content of the unit derived from the (meth) acrylic acid ester which has an epoxy group in the polymer which has an epoxy group, 80 mass% or more is more preferable, and 90 mass % Or more is particularly preferred.

  When the polymer having an epoxy group is a copolymer of (meth) acrylic acid ester having an epoxy group and another monomer, the other monomer has an unsaturated carboxylic acid or an epoxy group. And (meth) acrylic acid esters, (meth) acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes and the like. These compounds can be used alone or in combination of two or more.

  The polymer having an epoxy group is a copolymer of an epoxy group-containing (meth) acrylic acid ester and an unsaturated carboxylic acid in that a cured film can be formed without using a curing agent or a curing accelerator. Is preferred.

  Examples of unsaturated carboxylic acids include (meth) acrylic acid; (meth) acrylic acid amide; crotonic acid; maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, anhydrides of these dicarboxylic acids.

  Examples of (meth) acrylates having no epoxy group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, amyl (meth) acrylate, t-octyl (meth) acrylate and the like Linear or branched alkyl (meth) acrylate; chloroethyl (meth) acrylate, 2,2-dimethylhydroxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, trimethylolpropane mono (meth) acrylate, phenyl (Meth) acrylate, 2-methylphenyl (meth) acrylate, 3-methylphenyl (meth) acrylate, 4-methylphenyl (meth) acrylate, 2-hydroxyphenyl (meth) acrylate, 3-hydroxyphenyl (meth) a Lilate, 4-hydroxyphenyl (meth) acrylate, naphthalen-1-yl (meth) acrylate, naphthalen-2-yl (meth) acrylate, benzyl (meth) acrylate, furfuryl (meth) acrylate; group having an alicyclic skeleton And (meth) acrylic acid esters. Among (meth) acrylic esters having no epoxy group, (meth) acrylic esters having a group having an alicyclic skeleton are preferable.

  In the (meth) acrylic acid ester having a group having an alicyclic skeleton, the alicyclic group constituting the alicyclic skeleton may be monocyclic or polycyclic. Examples of the monocyclic alicyclic group include a cyclopentyl group and a cyclohexyl group. In addition, examples of the polycyclic alicyclic group include norbornyl group, isobornyl group, tricyclononyl group, tricyclodecyl group, tetracyclododecyl group and the like.

  Examples of the (meth) acrylic acid ester having a group having an alicyclic skeleton include compounds represented by the following formulas (a06-1) to (a06-8). Among these, the compounds represented by the following formulas (a06-3) to (a06-8) are preferable, and the compounds represented by the following formula (a06-3) or (a06-4) are more preferable.

In the above formulas, 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 to 6 carbon atoms, and R ^a037 represents a hydrogen atom or the number of carbon atoms 1 or more and 5 or less alkyl groups are shown. R ^a036 is preferably a single bond or a linear or branched alkylene group such as a methylene group, an ethylene group, a propylene group, a tetramethylene group, an ethylethylene group, a pentamethylene group or a hexamethylene group. As R ^a037 , a methyl group or an ethyl group is preferable.

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

  Examples of allyl compounds include allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate and other allyl esters; allyloxyethanol; Etc.

  Examples of vinyl ethers are hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethyl butyl vinyl ether, hydroxy Aliphatic vinyl ethers such as ethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether; vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4 -Dichlorofe And the like; ethers, vinyl naphthyl ether, vinyl aryl ethers such as vinyl anthranyl ether.

  Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl barrate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxy acetate, vinyl butoxy acetate, vinyl Examples include phenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenyl butyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate and the like.

  Examples of styrenes include styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene Alkylstyrenes such as ethoxymethylstyrene and acetoxymethylstyrene; alkoxystyrenes such as methoxystyrene, 4-methoxy-3-methylstyrene and dimethoxystyrene; chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromo Styrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoro Methylstyrene, halostyrenes such as 4-fluoro-3-trifluoromethyl styrene; and the like.

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

The content of the epoxy compound (A) in the composition for forming a cured film is not particularly limited as long as the object of the present invention is not impaired.
The content of the epoxy compound (A) in the composition for forming a cured film is the total of the mass of the epoxy compound (A) and the mass of the hollow silica (B), from the viewpoint that the formation of the cured film is easy. 5 mass% or more is preferable, and 10 mass% or more is more preferable.
In addition, the content of the epoxy compound (A) in the composition for forming a cured film is the mass of the epoxy compound (A) and the mass of the hollow silica (B) from the viewpoint of easily forming a cured film having a low refractive index. 50 mass% or less is preferable with respect to the sum, 30 mass% or less is more preferable, and 20 mass% or less is especially preferable.

<Hollow silica (B)>
The curable composition comprises hollow silica (B). The refractive index of hollow silica (B) is significantly lower than that of ordinary silica 1.46. This is because the hollow silica (B) internally contains air exhibiting a low refractive index of 1.0.
For this reason, a cured film having a low refractive index can be formed by using the curable composition containing hollow silica (B).
The refractive index of hollow silica is typically preferably 1.2 or more and 1.3 or less.

As the hollow silica (B), conventionally known ones can be used without particular limitation. The hollow silica may be a commercially available product or a synthetic product.
The hollow silica (B) can be selected from known hollow silicas in consideration of the particle diameter and the refractive index.

  50 nm or more and 100 nm or less are preferable, and, as for the volume average particle diameter of hollow silica (B), 60 nm or more and 80 nm or less are more preferable.

  The content of the hollow silica (B) in the composition for forming a cured film is not particularly limited as long as the object of the present invention is not impaired. The content of the hollow silica (B) in the composition for forming a cured film is the sum of the mass of the epoxy compound (A) and the mass of the hollow silica (B), from the viewpoint of easily forming a cured film having a low refractive index. On the other hand, 50 mass% or more is preferable, 70 mass% or more is more preferable, and 80 mass% or more is especially preferable.

<Surfactant (C)>
The composition for cured film formation contains surfactant (C). In the case of using a composition for forming a cured film that contains a combination of a surfactant (C) and a high boiling point solvent (SH) described later, a coating method that easily causes surface defects such as unevenness and pin marks such as slit coating Thus, even if the composition for forming a cured film is applied, it is easy to form a cured film without defects on the surface.
It is considered that the surfactant (C) promotes the leveling of the coating film surface during curing of the coating film.

  The molecular weight of the surfactant (C) is preferably 2000 or more, more preferably 3000 or more, from the viewpoint that formation of a cured film having no defects on the surface 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 50000 or less.

The type of surfactant (C) is not particularly limited as long as desired effects can be obtained. As surfactant (C), anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants Any of the surfactants can be used. As surfactant (C), a nonionic surfactant is preferable from the point which the effect by use of surfactant (C) is excellent.
As a nonionic surfactant, a siloxane-type surfactant and a fluorine-type surfactant are preferable, for example.

  The amount of surfactant (C) used in the composition for forming a cured film is 0.01 mass when the total of the amount of epoxy compound (A) and the amount of hollow silica (B) is 100 parts by mass. A part or more and 10 mass parts or less are preferable, 0.05 mass part or more and 5 mass parts or less are more preferable, 0.1 mass part or more and 3 mass parts or less are especially preferable.

<Solvent (S)>
The composition for cured film formation contains a solvent (S). The solvent (S) contains one or more high boiling point solvents (SH) having a boiling point of 170 ° C. or higher at atmospheric pressure.
When using the composition for cured film formation which combines the above-mentioned surfactant (C) and high-boiling-point solvent (SH), the coating method which surface defects, such as a nonuniformity and a pin mark, like slit application tend to produce easily Thus, even if the composition for forming a cured film is applied, it is easy to form a cured film without defects on the surface.

  When the coating film made of the composition for forming a cured film contains a high boiling point solvent (SH), a slight amount of high amount of solvent may be removed even if most of the solvent (S) is removed from the coating film in the process of curing the coating film. The boiling point solvent (SH) remains in the coating film. If it does so, leveling of the coating film surface under hardening will advance under the influence of the high boiling point solvent (SH) which remains. For these reasons, it is believed that a cured film having a smooth, uniform and preferable surface is formed.

  250 degreeC or less is preferable and, as for the boiling point under atmospheric pressure of high boiling point solvent (SH), 230 degrees C or less is more preferable. In this case, when the coating film of the composition for forming a cured film is heated and cured, the remaining amount of the high boiling point solvent (SH) in the cured film is extremely reduced, and a high quality cured film is easily formed.

It is preferable that the surface tension at 25 ° C. of the high boiling point solvent (SH) contained in the solvent (S) be 27 dyn / cm or more in terms of easily forming a cured film having a smooth and preferable surface without unevenness. . The surface tension 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 a high boiling point solvent (SH) exhibiting such surface tension, leveling of the surface of the coating film can be favorably advanced during curing of the coating film.
The solvent (S) preferably contains only an organic solvent having a surface tension at 25 ° C. of 25 dyn / cm or more, preferably 26 dyn / cm or more, more preferably 27 dyn / cm or more.
In this case, during the curing of the coating film, the leveling of the surface of the coating film tends to proceed particularly well.

The SP values ((cal / cm ³ ) ^1/2 , Fedor) of one or more high boiling point solvents (SH) contained in the solvent (S) are all 9.0 or more and 12.5 or less preferable.
The good affinity of the high boiling point solvent (SH) to the silica particles (B) is presumed to have some positive effect on the leveling of the coated film surface.

  The solvent (S) preferably comprises one or more low boiling point solvents (SL) having a boiling point below 170 ° C. at atmospheric pressure. When the low boiling point solvent (SL) is used together with the high boiling point solvent (SH), the low boiling point solvent (SL) and the high boiling point solvent are used when removing the solvent (S) from the coating film comprising the composition for forming a cured film. (SH) volatilizes sequentially. Thus, the solvent (S) does not evaporate rapidly from the coating film. As a result, it is easy to form a cured film while preventing the occurrence of defects such as unevenness and roughness on the surface of the cured film.

The low boiling point solvent (SL) has 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, and a boiling point of 130 ° C. or more at 170 ° C. or more. It is preferred to include one or more second low boiling point solvents (SL2) which are less than ° C.
When the low boiling point solvent (SL) contains two or more solvents having different boiling points, it is further easy to form a cured film while preventing the occurrence of defects such as unevenness and 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, diethylene glycol mono-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-butanediol diacetate Diethylene glycol mono-n-butyl ether acetate, 1,6-hexanediol diacetate, ε-caprolactone, 1,3-butylene glycol diacetate, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol methyl-n- Butyl ether, γ-butyrolactone, dipropylene glycol methyl-n-propyl ether, 3-methoxybutyl acetate, ethylene glycol monobutyl ether acetate, and propylene glycol diacetate can be mentioned.
The solvent (S) may contain two or more of these high boiling point solvents (SH) in combination.

  Among the above-mentioned high boiling point solvents (SH), benzyl alcohol, diethylene glycol mono-n-butyl ether (butyl carbyl ether Toll), dipropylene glycol monomethyl ether (DPM), 1,4-butanediol diacetate, diethylene glycol mono-n-butyl ether acetate, 1,6-hexanediol diacetate, ε-caprolactone, 1,3-butylene glycol diacetate , Diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, diethylene glycol methyl-n-butyl ether, γ-butyrolactone, dipropylene glycol methyl-n-propyl ether, 3-metho X-butyl acetate, ethylene glycol monobutyl ether acetate, and propylene glycol diacetate are preferred.

Preferred specific examples of the first low boiling point solvent (SL1) having a boiling point of 80 ° C. or more and less than 130 ° C. under atmospheric pressure include ethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME), n-propyl acetate, and acetic acid Isopropyl, isobutyl acetate, ethyl butyrate, n-butyl acetate, methyl ethyl ketone and the like can be mentioned.
The solvent (S) may contain two or more of these first low boiling point solvents (SL1) in combination.

Preferred specific examples of the second low boiling point solvent (SL2) having a boiling point of 130 ° C. or more and less than 170 ° C. under atmospheric pressure include ethylene glycol monoethyl ether, ethylene glycol n-propyl ether, propylene glycol monoethyl ether Propylene glycol mono-n-propyl ether, 3-methoxybutanol, diethylene glycol dimethyl ether (diglyme), ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, n-pentyl formate, isopentyl acetate, propionic acid n-butyl, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, 3-hepta Emissions, N, N-dimethylformamide, N, N- dimethylacetamide, 2-heptanone, cyclopentanone, and cyclohexanone.
The solvent (S) may contain two or more of these second low boiling point solvents (SL2) in combination.

  The amount of the solvent (S) used in the composition for forming a cured film is not particularly limited as long as the object of the present invention is not impaired. The amount of the solvent (S) used is appropriately determined so that the viscosity of the composition for forming a cured film is an appropriate viscosity according to the application method, taking into consideration the thickness of the cured film to be formed, etc. .

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

The content of the high boiling point solvent (SH) in the solvent (S) is not particularly limited as long as the object of the present invention is not impaired. 2 mass% or more and 60 mass% or less are preferable with respect to the mass of a solvent (S), 2 mass% or more and 50 mass% or less are more preferable, and, as for content of high boiling point solvent (SH), 3 mass% or more and 30 mass % Or less is more preferable, and 5% by mass or more and 25% by mass or less is particularly preferable.
The content of the low boiling point solvent (SL) in the solvent (S) is preferably 40% by mass to 98% by mass, and more preferably 50% by mass to 98% by mass, with respect to the mass of the solvent (S). 70 mass% or more and 97 mass% or less are more preferable, and 75 mass% or more and 95 mass% or less are particularly preferable.

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 in the low boiling point solvent (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 to 90% by mass, more preferably 30% by mass to 90% by mass, and 40% by mass. % Or more and 80 mass% or less are more preferable.

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

  The composition for forming a cured film is produced by uniformly mixing each component described above with a desired composition.

When using the composition for cured film formation demonstrated above, Preferably, when a cured film is formed according to the following cured film formation conditions 1, the cured film which becomes 1.30 or less in refractive index is formed.
<Curing film formation condition 1>
The composition for forming a cured film is applied to a 6 inch silicon substrate using a slit coater at a coating speed (gantry speed) of 100 mm / sec to form a coated film with a film thickness of 1000 nm with a size of 10 cm × 10 cm.
After the formed coating film is placed under a reduced pressure condition of 20 Pa for 10 seconds, the glass substrate is placed on a hot plate, and the coating film is heated at 100 ° C. for 2 minutes. Next, the glass substrate is heated to 230 ° C., and the coating film is heated at the same temperature for 20 minutes.

Moreover, when using the composition for cured film formation demonstrated above, Preferably, when a cured film is formed on the following cured film formation conditions 2, the cured film which becomes 1% or less in haze value is formed.
<Curing film formation condition 2>
The composition for forming a cured film is coated on a 680 mm × 880 mm glass substrate at a coating speed (gantry speed) of 180 mm / sec using a slit coater to form a coated film with a film thickness of 1000 nm.
After the formed coating film is placed under a reduced pressure condition of 20 Pa for 10 seconds, the glass substrate is placed on a hot plate, and the coating film is heated at 100 ° C. for 2 minutes. Next, the glass substrate is heated to 230 ° C., and the coating film is 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 with no defects on the surface. The cured film is suitably used for various applications such as a low refractive index film covering a microlens for an image sensor, a low refractive index film for preventing reflection in a liquid crystal display, an organic EL element and the like.

«Method for forming cured film»
The cured film formation method is
Formation of a coating film by applying the composition for forming a cured film described above on a substrate;
Curing of the coating film by heating,
Is a method that includes

In the formation of the coating film, as the coating method, methods such as slit coating, dip coating, spin coating spray coating, screen printing coating and the like are preferably used. Among these methods, slit coating is preferred in that the film can be formed uniformly in the surface with a rectangular substrate of panel size.
When slit coating is performed, it is preferable to perform coating at a coating speed of 120 mm / sec or more in that a substrate provided with a cured film can be produced with high throughput.

As described above, when a composition containing an epoxy compound (A) and hollow silica (B) is applied under the above conditions to form a cured film, the surface may be uneven, uneven, or pin marks. Problems are likely to occur.
However, when using the above-mentioned composition for cured film formation, even if it forms a coating film by slit application etc., a cured film can be formed, controlling a fault of the surface.

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

The coating film thus formed is then subjected to curing by heating.
When heating a coating film, it is preferable to put the coating film under reduced pressure conditions once. By placing the coating film under reduced pressure conditions, at least a part of the solvent (S) in the coating film is removed.
The temperature of the depressurized atmosphere is, for example, 0 ° C. or more and 50 ° C. or less, preferably 10 ° C. or more and 30 ° C. or less, that is, a temperature near room temperature.
The degree of vacuum of the reduced pressure atmosphere is not particularly limited, but is, for example, 1 Pa or more and 300 Pa or less, preferably 10 Pa or more and 200 Pa or less.
By gently removing the solvent (S) from the coating film under the above-described reduced pressure conditions, it is easy to form a cured film while suppressing surface defects.

The coating film formed as described above is optionally heated and cured after being placed under reduced pressure conditions. The heating conditions are not particularly limited as long as curing of the coating film proceeds well.
The heating of the coating film is divided into, for example, preheating at a temperature in the range of about 60 ° C. to 150 ° C. and main heating at a temperature in the range of about 150 ° C. to 250 ° C. performed after preheating. Preferably it is done.
The preheating time is not particularly limited, but is typically 30 seconds to 10 minutes, preferably 1 minute to 5 minutes.
Although the time of the main heating is not particularly limited, it is typically 5 minutes or more and 60 minutes or less, preferably 10 minutes or more and 30 minutes or less.

  According to the method described above, a cured film can be favorably formed while suppressing surface defects such as haze, streaks and pin marks.

  Hereinafter, the present invention will be more specifically described by way of examples. The scope of the present invention is not limited to these examples.

[Examples 1 to 14 and Comparative Examples 1 to 4]
In an Example and a comparative example, following A-1 and A-2 were used as an epoxy compound (A) (component (A)).
A-1: Acrylic copolymer A comprising 42% by mass of units derived from glycidyl methacrylate, 42% by mass of units derived from 3,4-epoxycyclohexylmethyl methacrylate, and 16% by mass of units derived from methacrylic acid -2: Acrylic polymer comprising 80% by mass of units derived from glycidyl methacrylate and 20% by mass of units derived from 4-hydroxyphenyl methacrylate

  In Examples and Comparative Examples, hollow silica particles having a volume average particle liquid of 60 nm were used as the hollow silica (B) (component (B)).

In Examples and Comparative Examples, the following C-1 to C-4 were used as the surfactant (C) (component (C)).
C-1: Fluorosurfactant (PF-656, manufactured by OMNOVA) Molecular weight: 1,500
C-2: Siloxane based surfactant (polyester modified polydimethylsiloxane, BYK-310 by Big Chemie Co., Ltd.) molecular weight 4000
C-3: Siloxane based surfactant (Granol 440, manufactured by Kyoeisha Chemical Co., Ltd.) molecular weight 5300
C-4: fluorinated surfactant (APX-4082B, manufactured by Kyoeisha Chemical Co., Ltd.) molecular weight 20000

In Examples and Comparative Examples, SL1-1 below as the first low boiling point solvent (SL1), SL2-1 and SL2-2 below as the second low boiling point solvent (SL2), as high boiling point solvents (SH) The following SH-1, SH-2 and SH-3 were used.
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 epoxy compound (A) and the hollow silica (B) of the amount (parts by mass) described in Tables 1 to 3 and the surfactant (C) of the type and the amount (parts by mass) described in Tables 1 to 3 Were dissolved and dispersed in a solvent (S) so as to have a solid content concentration described in Tables 1 to 3 to prepare compositions for forming a cured film of Examples and Comparative Examples. As a solvent (S), the mixed solvent of the composition as described in Table 1-Table 3 was used.

Using the obtained compositions for forming a cured film, the occurrence of unevenness and the generation of pin marks in the cured film were evaluated by the following method.
The composition for forming a cured film was coated on a glass substrate having a size of 680 mm × 880 mm using a slit coater at a coating speed (gantry speed) of 180 mm / sec to form a coated film having a film thickness of 1000 nm.
The formed coating film was placed under a reduced pressure condition of 20 Pa for 10 seconds, then the glass substrate was placed on a hot plate and the coating film was heated at 100 ° C. for 2 minutes. Then, the glass substrate was transferred onto a hot plate at 230 ° C., and the coated film was heated for 20 minutes.
The surface of the formed coating film was observed with a microscope, and the unevenness was evaluated as x when unevenness such as unevenness or streaks was observed. On the other hand, when the unevenness was not observed, the evaluation of the unevenness was taken as ○.
Moreover, when a pin trace was observed by microscopic observation, evaluation of the pin trace was set to x. On the other hand, when no pin trace was observed, the evaluation of the pin trace was rated as ○.

  A cured film was formed under the above-described cured film forming condition 1 and the refractive index of the formed cured film was measured. Tables 1 to 3 show the measurement results of the refractive index.

Moreover, the cured film was formed on the above-mentioned cured film formation conditions 2, and the haze value of the formed cured film was measured. In addition, the measurement of haze value was not performed about the composition for cured film formation of Comparative Examples 1, 2, and 4.
The case where the haze value was 1% or less was evaluated as ○, and the case where the haze value was more than 1% was evaluated as x. The evaluation results are shown in Tables 1 to 3.

From Tables 1 and 2, it contains an epoxy compound (A), hollow silica (B) and a solvent (S), and further contains a surfactant (C), and as a solvent (S) under atmospheric pressure In the case of using the composition for forming a cured film of the example containing one or more kinds of high boiling point solvents (SH) having a boiling point of 170 ° C. or higher, the curing is favorably performed while suppressing the occurrence of unevenness and pin marks on the surface. It can be seen that a film can be formed.
On the other hand, according to Table 3, when using the composition for forming a cured film of the comparative example which does not contain the high boiling point solvent (SH) or the surfactant (C), at least one of unevenness or pin marks is generated on the surface of the cured film. I understand that it is easy.

Claims (17)

An epoxy compound (A), hollow silica (B), surfactant (C), and solvent (S),
The composition for cured film formation in which the said solvent (S) contains 1 or more types of high boiling point solvent (SH) whose boiling point under atmospheric pressure is 170 degreeC or more.   The composition for cured film formation of Claim 1 whose boiling point under the atmospheric pressure of the said high boiling point solvent (SH) is 250 degrees C or less.   The composition for cured film formation of Claim 1 or 2 which is apply | coated to a board | substrate by slit application and gives a cured film.   The composition for cured film formation of Claim 3 used in the slit application use with the application 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 one or more low boiling point solvents (SL) having a boiling point of less than 170 ° C at atmospheric pressure. object.   The low boiling point solvent (SL) has one or more first low boiling point solvents (SL1) having a boiling point of 80 ° C. to less than 130 ° C. at atmospheric pressure, and a boiling point of 130 ° C. to 170 ° C. at atmospheric pressure The composition for cured film formation of Claim 5 which consists of one or more 2nd low boiling point solvent (SL2) which is less than.   The composition for cured film formation of any one of Claims 1-6 whose SP values of one or more types of said high boiling point solvent (SH) are all 9.0 or more and 12.5 or less.   The composition for cured film formation of any one of Claims 1-7 whose molecular weight of the said surfactant (C) is 2000 or more.   The epoxy compound (A) has at least one functional group selected from the group consisting of a carboxy group, a carboxylic acid anhydride group, a phenolic hydroxyl group, and an amino group. The composition for cured film formation as described in-.   The composition for cured film formation of any one of Claims 1-9 whose said epoxy compound (A) is a copolymer of the monomer which has an unsaturated double bond.   The composition for cured film formation of any one of Claims 1-10 which is 50 nm-100 nm of the volume average particle diameter of the said hollow silica (B). The composition for cured film formation of any one of Claims 1-11 which gives a cured film which becomes 1.30 or less in refractive index when a cured film is formed according to the following cured film formation conditions 1.
<Curing film formation condition 1>
The composition for forming a cured film is applied to a 6 inch silicon substrate using a slit coater at a coating speed (gantry speed) of 100 mm / sec to form a coated film with a film thickness of 1000 nm with a size of 10 cm × 10 cm.
After the formed coating film is placed under a reduced pressure condition of 20 Pa for 10 seconds, the glass substrate is placed on a hot plate, and the coating film is heated at 100 ° C. for 2 minutes. Next, the glass substrate is heated to 230 ° C., and the coating film is heated at the same temperature for 20 minutes. The composition for cured film formation according to any one of claims 1 to 12, which gives a cured film having a haze value of 1% or less when the cured film is formed under the following cured film forming condition 2.
<Curing film formation condition 2>
The composition for forming a cured film is coated on a 680 mm × 880 mm glass substrate at a coating speed (gantry speed) of 180 mm / sec using a slit coater to form a coated film with a film thickness of 1000 nm.
After the formed coating film is placed under a reduced pressure condition of 20 Pa for 10 seconds, the glass substrate is placed on a hot plate, and the coating film is heated at 100 ° C. for 2 minutes. Next, the glass substrate is heated to 230 ° C., and the coating film is heated at the same temperature for 20 minutes. Formation of a coating film by apply | coating the said composition for cured film formation of any one of Claims 1-13 on a board | substrate,
Curing the coating film by heating;
And a method of forming a cured film.   The cured film formation method according to claim 14 including removal of at least one copy of said solvent (S) contained in said coating film by putting said coating film on decompression conditions before said hardening.   The method for forming a cured film according to claim 14, wherein the formation of the coating film is performed by a slit coating method.   The cured film forming method according to claim 16, wherein a coating speed in forming the coating film by slit coating is 120 mm / sec or more.