Curable composition, cured product, and method for producing the cured product

Abstract

To provide a curable composition capable of forming a cured product that is highly transparent, with its transparency less prone to decrease due to heating, and also has excellent organic solvent resistance, a cured product of the curable composition, and a method for producing a cured film using the curable composition.SOLUTION: A curable composition contains a polymerizable compound (A), metal oxide fine particles (B) including titanium oxide fine particles (B1), an initiator (C), and a solvent (S). The polymerizable compound (A) used here is a polymerizable fluorene compound (A1) having a radical polymerizable group-containing group, or a cationic polymerizable group-containing group, and also having a fluorene skeleton. The initiator (C) used here is a heat-sensitive initiator (C1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable composition containing a polymerizable compound (A), metal oxide fine particles (B), an initiator (C), and a solvent (S), a cured product of the curable composition, and a method for producing a cured film using the curable composition. [Background technology]

[0002] BACKGROUND ART Curable compositions containing, as a curable component, a cationically polymerizable compound such as an epoxy compound or a radically polymerizable compound having a (meth)acryloyl group or the like have been used in various applications.

[0003] For example, as a cationic polymerization type curable composition, a curable composition containing a fluorene derivative with a specific structure as a photocationically polymerizable compound is known (see Patent Document 1). By using the curable composition described in Patent Document 1, a cured product with a high refractive index can be formed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-283905 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the use of the curable composition described in Patent Document 1 makes it possible to form a cured product with a high refractive index. However, there is a demand for materials with high refractive indexes that have even higher refractive indices. For example, by blending the curable composition described in Patent Document 1 with an inorganic filler such as titanium oxide fine particles, which are used to increase refractive index, it is expected that the refractive index of the cured product will be even higher. However, when the curable composition contains titanium oxide particles, it is difficult to form a cured product that is highly transparent, does not easily lose its transparency when heated, and has excellent organic solvent resistance.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a curable composition capable of forming a cured product that has high transparency, is resistant to deterioration of transparency when heated, and has excellent organic solvent resistance; a cured product of the curable composition; and a method for producing a cured film using the curable composition. [Means for solving the problem]

[0007] The present inventors have found that the above-mentioned problems can be solved by using a polymerizable fluorene compound (A1) having a radically polymerizable group-containing group or a cationically polymerizable group-containing group and a fluorene skeleton as the polymerizable compound (A) and a heat-sensitive initiator (C1) as the initiator (C) in a curable composition containing a polymerizable compound (A), metal oxide fine particles (B) including titanium oxide fine particles (B1), an initiator (C), and a solvent (S). Based on this finding, the present invention has been completed. Specifically, the present invention provides the following.

[0008] A first aspect of the present invention is a polymerizable composition comprising a polymerizable compound (A), metal oxide fine particles (B), an initiator (C), and a solvent (S), the polymerizable compound (A) contains a polymerizable fluorene compound (A1) having a radical polymerizable group-containing group or a cation polymerizable group-containing group and a fluorene skeleton, the metal oxide fine particles (B) contain titanium oxide fine particles (B1); The curable composition includes an initiator (C) that is a heat-sensitive initiator (C1).

[0009] A second aspect of the present invention is a cured product of the curable composition according to the first aspect.

[0010] A third aspect of the present invention provides a method for producing a curable film by applying the curable composition according to the first aspect onto a substrate; Heating the coating film; The method for forming a cured film includes the steps of: [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a curable composition capable of forming a cured product that has high transparency, is resistant to deterioration of transparency when heated, and has excellent organic solvent resistance; a cured product of the curable composition; and a method for producing a cured film using the curable composition. DETAILED DESCRIPTION OF THE INVENTION

[0012] ≪Curable composition≫ The curable composition contains a polymerizable compound (A), metal oxide fine particles (B), an initiator (C), and a solvent (S). The polymerizable compound (A) includes a polymerizable fluorene compound (A1) having a radically polymerizable group-containing group or a cationically polymerizable group-containing group and having a fluorene skeleton. The metal oxide fine particles (B) contain titanium oxide fine particles (B1). The initiator (C) comprises a heat-sensitive initiator (C1). By using such a curable composition, it is possible to form a cured product that is highly transparent, does not easily lose transparency when heated, and has excellent organic solvent resistance.

[0013] Essential and optional components contained in the curable composition will be described below.

[0014] <Polymerizable compound (A)> As described above, the polymerizable compound (A) includes a polymerizable fluorene compound (A1) having a radical polymerizable group-containing group or a cation polymerizable group-containing group and having a fluorene skeleton. The polymerizable compound may also include another polymerizable compound (A2) having a radical polymerizable group-containing group or a cation polymerizable group-containing group and not corresponding to the polymerizable fluorene compound (A1) together with the polymerizable fluorene compound (A1).

[0015] In terms of the refractive index of the cured product, the ratio of the mass of the polymerizable fluorene compound (A1) to the mass of the polymerizable compound (A) is preferably 50 mass% or more, more preferably 70 mass% or more, even more preferably 80 mass% or more, even more preferably 90 mass% or more, particularly preferably 95 mass% or more, and most preferably 100 mass%.

[0016] [Polymerizable fluorene compound (A1)] The polymerizable fluorene compound (A1) has a radically polymerizable group-containing group or a cationically polymerizable group-containing group, and also has a fluorene skeleton.

[0017] The radical polymerizable group-containing group typically includes a group containing an ethylenically unsaturated double bond. As the ethylenically unsaturated double bond-containing group, a vinyl group or an alkenyl group-containing group such as an allyl group is preferred, and a (meth)acryloyl group-containing group is more preferred. Typical examples of the cationically polymerizable group include an epoxy group-containing group, an episulfide group-containing group, an oxetanyl group-containing group, a vinyloxy group-containing group, etc. Among these, the epoxy group-containing group and the vinyloxy group-containing group are preferred. The epoxy group-containing group is preferably an alicyclic epoxy group-containing group or a glycidyl group. The alicyclic epoxy group is an aliphatic cyclic group in which two adjacent carbon atoms as ring constituent atoms in the aliphatic cyclic group are bonded via an oxygen atom. In other words, the alicyclic epoxy group has an epoxy group containing a three-membered ring consisting of two carbon atoms and one oxygen atom on the aliphatic ring.

[0018] In the specification and claims of this application, (meth)acrylic means both acrylic and methacrylic, (meth)acryloyl means both acryloyl and methacryloyl, and (meth)acrylate means both acrylate and methacrylate.

[0019] The number of radical polymerizable group-containing groups or cation polymerizable group-containing groups in the polymerizable fluorene compound (A1) is not particularly limited.The number of radical polymerizable group-containing groups or cation polymerizable group-containing groups in the polymerizable fluorene compound is typically preferably 1 or more and 4 or less, more preferably 2 or more and 4 or less, particularly preferably 2.

[0020] Regarding the polymerizable fluorene compound (A1), even when the polymerizable fluorene compound (A1) has a polycyclic skeleton in which one or more other rings are condensed to a fluorene ring, the polymerizable fluorene compound (A1) is considered to have a fluorene skeleton. Examples of the other rings include a benzene ring, a cyclopentane ring, and a cyclohexane ring.

[0021] The polymerizable fluorene compound (A1) is preferably a compound represented by the following formula (a1), because it is easy to synthesize and obtain, has good polymerization reactivity, and can easily give a cured product with a high refractive index. By using the polymerizable fluorene compound (A1) represented by the following formula (a1) in combination with metal oxide fine particles (B) described below, it is easy to form a cured product with a high refractive index. [ka] (In formula (a1), W 1 and W 2 are each independently represented by the following formula (a2): [ka] is a group represented by In formula (a2), ring Z represents an aromatic hydrocarbon ring, X represents a single bond or a group represented by -S-, and R 1 represents a single bond, an alkylene group having 1 to 4 carbon atoms, or an alkyleneoxy group having 1 to 4 carbon atoms, and R 1 is an alkyleneoxy group, the oxygen atom in the alkyleneoxy group is bonded to the ring Z, and R 2 is a monovalent hydrocarbon group, a hydroxyl group, -OR 4a a group represented by -SR 4bgroups represented by the formula (I), acyl groups, alkoxycarbonyl groups, halogen atoms, nitro groups, cyano groups, mercapto groups, carboxy groups, amino groups, carbamoyl groups, -NHR 4c a group represented by -N(R 4d ) a group represented by the formula (2), a sulfo group, or a monovalent hydrocarbon group, -OR 4a a group represented by -SR 4b groups represented by the formula (I), acyl groups, alkoxycarbonyl groups, -NHR 4c or -N(R 4d At least some of the hydrogen atoms bonded to carbon atoms in the group represented by formula (2) are monovalent hydrocarbon groups, hydroxyl groups, -OR 4a a group represented by -SR 4b groups represented by the formula (I), acyl groups, alkoxycarbonyl groups, halogen atoms, nitro groups, cyano groups, mercapto groups, carboxyl groups, amino groups, carbamoyl groups, -NHR 4c a group represented by -N(R 4d )2, a group substituted with a mesyloxy group or a sulfo group, and R 4a ~R 4d each independently represents a monovalent hydrocarbon group, m represents an integer of 0 or more, and R 3 is a hydrogen atom, a vinyl group, a thiiran-2-ylmethyl group, a glycidyl group, or a (meth)acryloyl group, W 1 and W 2 Both R 3 does not have a hydrogen atom as Ring Y 1 and ring Y 2 represent the same or different aromatic hydrocarbon rings, R represents a single bond, a methylene group which may have a substituent, an ethylene group which may have a substituent and which may contain a heteroatom between two carbon atoms, a group represented by -O-, a group represented by -NH-, or a group represented by -S-, and R 3a and R 3b each independently represents a cyano group, a halogen atom, or a monovalent hydrocarbon group, and n1 and n2 each independently represent an integer of 0 to 4.

[0022] In the above formula (a2), examples of ring Z include a benzene ring, a fused polycyclic aromatic hydrocarbon ring [for example, a fused bicyclic hydrocarbon ring (for example, a C naphthalene ring, etc.] 8-20 Fused bicyclic hydrocarbon rings, preferably C 10-16 Examples of suitable aromatic hydrocarbon rings include fused dicyclic to tetracyclic aromatic hydrocarbon rings such as fused bicyclic hydrocarbon rings, fused tricyclic aromatic hydrocarbon rings (e.g., anthracene ring, phenanthrene ring, etc.). Ring Z is preferably a benzene ring or a naphthalene ring, more preferably a naphthalene ring. In addition, W in formula (a1) 1 and W 2 are each independently a group represented by the following formula (a2), and therefore W 1 and W 2 Each contains the ring Z. 1 Rings Z and W contained in 2 and the rings Z contained in may be the same or different. For example, one ring may be a benzene ring and the other ring may be a naphthalene ring, but it is particularly preferred that both rings are naphthalene rings.

[0023] Also, W 1 and W 2 The substitution position of ring Z bonded via X to the carbon atom to which both of are directly bonded is not particularly limited. For example, when ring Z is a naphthalene ring, the group corresponding to ring Z bonded to the carbon atom may be a 1-naphthyl group, a 2-naphthyl group, etc.

[0024] In the above formula (a2), X independently represents a single bond or a group represented by -S-, and is typically a single bond.

[0025] In the above formula (a2), R 1 Examples of the alkylene groups include a single bond; an alkylene group having 1 to 4 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a propylene group, and a butane-1,2-diyl group; and an alkyleneoxy group having 1 to 4 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, and a propyleneoxy group. 2-4 Alkylene group (especially C such as ethylene group, propylene group, etc.) 2-3 alkylene group); C2-4 Alkyleneoxy group (especially C such as ethyleneoxy group, propyleneoxy group, etc.) 2-3 An alkylene group is preferred, and a single bond is more preferred. 1 When W in formula (a1) is an alkyleneoxy group, the oxygen atom in the alkyleneoxy group bonds to ring Z. 1 and W 2 are each independently a group represented by the following formula (a2), and therefore W 1 and W 2 are divalent groups R 1 Includes: W 1 R included in 1 and W 2 R included in 1 may be the same or different.

[0026] In the above formula (a2), R 2 Examples of the alkyl group include alkyl groups (e.g., C groups such as methyl, ethyl, propyl, isopropyl, and butyl groups). 1-12 Alkyl groups, preferably C 1-8 Alkyl groups, more preferably C 1-6 alkyl group, cycloalkyl group (cyclohexyl group, etc.) 5-10 Cycloalkyl groups, preferably C 5-8 Cycloalkyl groups, more preferably C 5-6 cycloalkyl groups, etc.), aryl groups (e.g., phenyl, tolyl, xylyl, naphthyl groups, etc.) 6-14 Aryl groups, preferably C 6-10 an aryl group, more preferably C 6-8 aryl group, etc.), aralkyl group (benzyl group, phenethyl group, etc.) 6-10 Aryl-C 1-4 Monovalent hydrocarbon groups such as alkyl groups; hydroxyl groups; alkoxy groups (C groups such as methoxy, ethoxy, propoxy, and butoxy groups) 1-12 Alkoxy groups, preferably C 1-8 Alkoxy groups, more preferably C 1-6 alkoxy groups, etc.), cycloalkoxy groups (cyclohexyloxy groups, etc.) 5-10cycloalkoxy groups, etc.), aryloxy groups (phenoxy groups, etc.) 6-10 aryloxy group), aralkyloxy group (e.g., C 6-10 Aryl-C 1-4 -OR (e.g., alkyloxy group) 4a [wherein R 4a represents a monovalent hydrocarbon group (such as the monovalent hydrocarbon groups exemplified above); an alkylthio group (such as a methylthio group, an ethylthio group, a propylthio group, or a butylthio group); 1-12 Alkylthio groups, preferably C 1-8 Alkylthio groups, more preferably C 1-6 alkylthio groups, cycloalkylthio groups (cyclohexylthio groups, etc.) 5-10 cycloalkylthio groups, arylthio groups (phenylthio groups, etc.) 6-10 arylthio group), aralkylthio group (e.g., C 6-10 Aryl-C 1-4 -SR (e.g., alkylthio group) 4b [wherein R 4b represents a monovalent hydrocarbon group (such as the monovalent hydrocarbon groups exemplified above); an acyl group (such as an acetyl group) 1-6 acyl group, etc.); alkoxycarbonyl group (C such as methoxycarbonyl group) 1-4 Alkoxy-carbonyl group, etc.; halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.); nitro group; cyano group; mercapto group; carboxyl group; amino group; carbamoyl group; alkylamino group (methylamino group, ethylamino group, propylamino group, butylamino group, etc. C 1-12 Alkylamino groups, preferably C 1-8 Alkylamino groups, more preferably C 1-6 alkylamino group, etc.), cycloalkylamino group (cyclohexylamino group, etc.) 5-10 cycloalkylamino group, etc.), arylamino group (phenylamino group, etc. C 6-10 arylamino group), aralkylamino group (e.g., C 6-10 Aryl-C 1-4 -NHR (e.g., alkylamino group) 4c[wherein R 4c represents a monovalent hydrocarbon group (such as the monovalent hydrocarbon groups exemplified above); a dialkylamino group (such as a dimethylamino group, a diethylamino group, a dipropylamino group, or a dibutylamino group); 1-12 alkyl)amino groups, preferably di(C 1-8 alkyl)amino group, more preferably di(C 1-6 alkyl)amino group, dicycloalkylamino group (dicyclohexylamino group, etc.), 5-10 cycloalkyl)amino group, diarylamino group (diphenylamino group, etc.) 6-10 aryl)amino group), diaralkylamino group (e.g., di(C 6-10 Aryl-C 1-4 -N(R alkyl)amino group) 4d )2 [wherein R 4d each independently represents a monovalent hydrocarbon group (such as the monovalent hydrocarbon groups exemplified above); a (meth)acryloyloxy group; a sulfo group; the above monovalent hydrocarbon groups, -OR 4a a group represented by -SR 4b groups represented by the formula (I), acyl groups, alkoxycarbonyl groups, -NHR 4c or -N(R 4d At least some of the hydrogen atoms bonded to carbon atoms in the group represented by formula (2) are the above monovalent hydrocarbon group, hydroxyl group, -OR 4a a group represented by -SR 4b groups represented by the formula (I), acyl groups, alkoxycarbonyl groups, halogen atoms, nitro groups, cyano groups, mercapto groups, carboxyl groups, amino groups, carbamoyl groups, -NHR 4c a group represented by -N(R 4d ) 2, a group substituted with a (meth)acryloyloxy group, a mesyloxy group, or a sulfo group [for example, an alkoxyaryl group (e.g., a C group such as a methoxyphenyl group] 1-4 Alkoxy C 6-10 aryl group), alkoxycarbonylaryl group (e.g., methoxycarbonylphenyl group, ethoxycarbonylphenyl group, etc. 1-4 Alkoxy-carbonyl C 6-10aryl group, etc.)].

[0027] Among these, the representative is R 2 is a monovalent hydrocarbon radical, -OR 4a a group represented by -SR 4b groups represented by the formula (I), acyl groups, alkoxycarbonyl groups, halogen atoms, nitro groups, cyano groups, -NHR 4c a group represented by -N(R 4d ) 2, etc.

[0028] Preferred R 2 Examples of the alkyl group include monovalent hydrocarbon groups [e.g., alkyl groups (e.g., C 1-6 alkyl groups), cycloalkyl groups (e.g., C 5-8 cycloalkyl groups), aryl groups (e.g., C 6-10 aryl groups), aralkyl groups (e.g., C 6-8 Aryl-C 1-2 alkyl group), etc.], alkoxy group (C 1-4 Alkoxy groups, etc. In particular, R 2a and R 2b is an alkyl group [C 1-4 alkyl groups (especially methyl groups), etc.], aryl groups [e.g., C 6-10 It is preferably a monovalent hydrocarbon group (particularly an alkyl group) such as an aryl group (particularly a phenyl group).

[0029] When m is an integer of 2 or more, multiple R 2 may be different from each other or may be the same. 1 R included in 2 and W 2 R included in 2 may be the same or different.

[0030] In the above formula (a2), R 2 The number m can be selected depending on the type of ring Z, and may be, for example, 0 to 4, preferably 0 to 3, and more preferably 0 to 2. 1 m and W in 2The m's in the formula may be the same or different.

[0031] In the above formula (a3), R 3 is a hydrogen atom, a vinyl group, a thiiran-2-ylmethyl group, a glycidyl group, or a (meth)acryloyl group. 1 and W 2 Both R 3 It does not have a hydrogen atom as a The vinyloxy group, the thiiran-2-ylmethyl group, and the glycidyl group are all cationic polymerizable functional groups. Therefore, in the compound represented by formula (a1), R 3 Compounds having a vinyl group, a thiiran-2-ylmethyl group, or a glycidyl group as the cationically polymerizable group are cationically polymerizable compounds. On the other hand, in the compound represented by formula (a1), R 3 As such, a compound having a (meth)acryloyl group is a radically polymerizable compound.

[0032] W 1 R included in 3 and W 2 R included in 3 and may be the same or different, as long as they are not both hydrogen atoms. 1 R included in 3 and W 2 R included in 3 and both are preferably a vinyl group, a thiiran-2-ylmethyl group, or a glycidyl group, and more preferably are the same group selected from the group consisting of a vinyl group, a thiiran-2-ylmethyl group, and a glycidyl group. Also, W 1 R included in 3 and W 2 R included in 3 It is also preferred that both of the groups are (meth)acryloyl groups.

[0033] R 3 As the alkyl group, a vinyl group, a glycidyl group, or a (meth)acryloyl group is preferred because the compound represented by formula (a1) can be easily synthesized and easily obtained. In addition, since the number of types of components contained in the curable composition can be reduced, it is preferable that the compound represented by formula (a1) has only groups selected from a vinyl group, a thiirane-2-ylmethyl group, and a glycidyl group as reactive groups, or has only (meth)acryloyl groups as reactive groups.

[0034] In the above formula (a1), ring Y 1 and ring Y 2 Examples of the aromatic hydrocarbon ring include a benzene ring, a fused polycyclic aromatic hydrocarbon ring [e.g., a fused bicyclic hydrocarbon ring (e.g., a C naphthalene ring, etc.] 8-20 Fused bicyclic hydrocarbon rings, preferably C 10-16 condensed bicyclic hydrocarbon rings, condensed tricyclic aromatic hydrocarbon rings (for example, anthracene ring, phenanthrene ring, etc.), and other condensed dicyclic to tetracyclic aromatic hydrocarbon rings. 1 and ring Y 2 is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring. 1 and ring Y 2 may be the same or different, and for example, one ring may be a benzene ring and the other ring may be a naphthalene ring.

[0035] In the above formula (a1), R represents a single bond, a methylene group which may have a substituent, an ethylene group which may have a substituent and which may contain a heteroatom between two carbon atoms, a group represented by -O-, a group represented by -NH-, or a group represented by -S-, and is typically a single bond. Examples of the substituent include a cyano group, a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom), a monovalent hydrocarbon group [e.g., an alkyl group (e.g., a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, or a t-butyl group], a C 1-6 alkyl groups), aryl groups (phenyl groups, etc.) 6-10 Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, and a silicon atom.

[0036] In the above formula (a1), R 3a and R 3bThe substituents are usually non-reactive substituents such as a cyano group, a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom), a monovalent hydrocarbon group [such as an alkyl group, an aryl group (C such as a phenyl group)], 6-10 Examples of the alkyl group include a cyano group or an alkyl group, and particularly preferably an alkyl group. Examples of the alkyl group include a C aryl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group. 1-6 Alkyl groups (e.g., C 1-4 Examples include alkyl groups, particularly methyl groups. When n1 is an integer of 2 or more, R 3a may be different from each other or may be the same. When n2 is an integer of 2 or more, R 3b may be different from each other or may be the same. 3a and R 3b and may be the same or different. 1 and ring Y 2 R 3a and R 3b The bonding positions (substitution positions) of are not particularly limited. The substitution numbers n1 and n2 are preferably 0 or 1, particularly 0. Note that n1 and n2 may be the same or different.

[0037] Among the compounds represented by the above formula (a1), particularly preferred specific examples include epoxy group-containing fluorene compounds such as 9,9-bis[4-[2-(glycidyloxy)ethoxy]phenyl]-9H-fluorene, 9,9-bis[4-[2-(glycidyloxy)ethyl]phenyl]-9H-fluorene, 9,9-bis[4-(glycidyloxy)-3-methylphenyl]-9H-fluorene, 9,9-bis[4-(glycidyloxy)-3,5-dimethylphenyl]-9H-fluorene, 9,9-bis(6-glycidyloxynaphthalen-1-yl)-9H-fluorene and 9,9-bis(5-glycidyloxynaphthalen-2-yl)-9H-fluorene; and compounds represented by the following formula:

[0038] [ka]

[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049] [ka]

[0050] Among the compounds represented by formula (a1) explained above, the following compounds are particularly preferred. [ka]

[0051] [Other polymerizable compounds (A2)] As described above, the polymerizable compound (A) may contain, in addition to the polymerizable fluorene compound (A1), other polymerizable compounds that do not fall under the category of the polymerizable fluorene compound (A1). The ratio of the mass of the polymerizable fluorene compound (A1) to the mass of the polymerizable compound (A) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 100% by mass.

[0052] When the polymerizable fluorene compound (A1) has only a cationically polymerizable group-containing group, the other polymerizable compound (A2) preferably has only a cationically polymerizable group-containing group. When the polymerizable fluorene compound (A1) has only radically polymerizable group-containing groups, the other polymerizable compound (A2) preferably has only radically polymerizable group-containing groups.

[0053] Examples of the other polymerizable compound (A2) having a cationically polymerizable group-containing group include vinyl ether compounds containing a vinyloxy group, epoxy compounds containing an epoxy group, and episulfide compounds containing an episulfide group. The other polymerizable compound (A2) having a radically polymerizable group-containing group includes a radically polymerizable compound having a radically polymerizable unsaturated double bond. The vinyl ether compound, the epoxy compound, the episulfide compound, and the radical polymerizable compound will be described below.

[0054] (Vinyl ether compounds) The vinyl ether compound is not particularly limited as long as it has a vinyloxy group and is cationic polymerizable. The vinyl ether compound used in combination with the polymerizable fluorene compound (A1) may or may not contain an aromatic group. From the viewpoint of transparency of the cured product, the vinyl ether compound used in combination with the polymerizable fluorene compound (A1) is preferably an aliphatic vinyl ether compound containing no aromatic group. In view of the excellent thermal decomposition resistance of the cured product, the vinyl ether compound used in combination with the polymerizable fluorene compound (A1) is preferably a compound having a vinyloxy group bonded to an aromatic group.

[0055] Specific preferred examples of the vinyl ether compound include aliphatic vinyl ether compounds such as ethyl vinyl ether, isobutyl vinyl ether, hydroxybutyl vinyl ether, butanediol divinyl ether, cyclohexyl vinyl ether, N-butyl vinyl ether, tert-butyl vinyl ether, triethylene glycol divinyl ether octadecyl vinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, and cyclohexanedimethanol monovinyl ether vinyl phenyl ether; 4-vinyloxytoluene, 3-vinyloxytoluene, 2-vinyloxytoluene, 1-vinyloxy-4-chlorobenzene, 1-vinyloxy aromatic monovinyl ether compounds such as 3-chlorobenzene, 1-vinyloxy-2-chlorobenzene, 1-vinyloxy-2,3-dimethylbenzene, 1-vinyloxy-2,4-dimethylbenzene, 1-vinyloxy-2,5-dimethylbenzene, 1-vinyloxy-2,6-dimethylbenzene, 1-vinyloxy-3,4-dimethylbenzene, 1-vinyloxy-3,5-dimethylbenzene, 1-vinyloxynaphthalene, 2-vinyloxynaphthalene, 2-vinyloxyfluorene, 3-vinyloxyfluorene, 4-vinyloxy-1,1'-biphenyl, 3-vinyloxy-1,1'-biphenyl, 2-vinyloxy-1,1'-biphenyl, 6-vinyloxytetralin, and 5-vinyloxytetralin;1,4-Divinyloxybenzene, 1,3-Divinyloxybenzene, 1,2-Divinyloxybenzene, 1,4-Divinyloxynaphthalene, 1,3-Divinyloxynaphthalene, 1,2-Divinyloxynaphthalene, 1,5-Divinyloxynaphthalene, 1,6-Divinyloxynaphthalene, 1,7-Divinyloxynaphthalene, 1,8-Divinyloxynaphthalene, 2,3-Divinyloxynaphthalene, 2,6-Divinyloxynaphthalene, 2,7-Divinyloxy Examples of aromatic divinyl ether compounds include cinnaphthalene, 1,2-divinyloxyfluorene, 3,4-divinyloxyfluorene, 2,7-divinyloxyfluorene, 4,4'-divinyloxybiphenyl, 3,3'-divinyloxybiphenyl, 2,2'-divinyloxybiphenyl, 3,4'-divinyloxybiphenyl, 2,3'-divinyloxybiphenyl, 2,4'-divinyloxybiphenyl, and bisphenol A divinyl ether. These vinyl ether compounds may be used in combination of two or more kinds.

[0056] (epoxy compounds) Examples of epoxy compounds that can be used together with the polymerizable fluorene compound (A1) include bifunctional epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AD ​​type epoxy resins, naphthalene type epoxy resins, and biphenyl type epoxy resins; novolac epoxy resins such as phenol novolac type epoxy resins, brominated phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, and bisphenol AD ​​novolac type epoxy resins; cycloaliphatic epoxy resins such as epoxidized products of dicyclopentadiene type phenolic resins; aromatic epoxy resins such as epoxidized products of naphthalene type phenolic resins; glycidyl ester type epoxy resins such as dimer acid glycidyl ester and triglycidyl ester; glycidyl aminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidyl metaxylylenediamine, and tetraglycidyl bisaminomethylcyclohexane; amine-type epoxy resins; heterocyclic epoxy resins such as triglycidyl isocyanurate; phloroglucinol triglycidyl ether, trihydroxybiphenyl triglycidyl 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]ethyl]phenyl]propane. trifunctional epoxy resins such as tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidylbenzophenone, bisresorcinol tetraglycidyl ether, and tetraglycidoxybiphenyl; and 1,2-epoxy-4-(2-oxiranyl)cyclohexane adducts of 2,2-bis(hydroxymethyl)-1-butanol.The 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol is commercially available as EHPE-3150 (manufactured by Daicel Corporation).

[0057] Alternatively, an oligomeric or polymeric polyfunctional epoxy compound may be used as the other polymerizable compound (A2). Typical examples of oligomer or polymer type polyfunctional epoxy compounds include phenol novolac type epoxy compounds, brominated phenol novolac type epoxy compounds, orthocresol novolac type epoxy compounds, xylenol novolac type epoxy compounds, naphthol novolac type epoxy compounds, bisphenol A novolac type epoxy compounds, bisphenol AD ​​novolac type epoxy compounds, epoxidized dicyclopentadiene type phenol resins, and epoxidized naphthalene type phenol resins.

[0058] Other examples of epoxy compounds that can be used in combination with the polymerizable fluorene compound (A1) include polyfunctional alicyclic epoxy compounds having alicyclic epoxy groups. When the polymerizable compound (A) contains an alicyclic epoxy compound, it is easy to form a cured product with excellent transparency using the curable composition.

[0059] Specific examples of the alicyclic epoxy compound include 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-meta-dioxane, 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, and trimethylcaprolactone-modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate. epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone-modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, methylenebis(3,4-epoxycyclohexane), di(3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylenebis(3,4-epoxycyclohexanecarboxylate), dioctyl epoxycyclohexahydrophthalate, and di-2-ethylhexyl epoxycyclohexahydrophthalate, epoxy resins having a tricyclodecene oxide group, and compounds represented by the following formulas (a01-1) to (a01-5).

[0060] Among these specific examples of alicyclic epoxy compounds, alicyclic epoxy compounds represented by the following formulae (a01-1) to (a01-5) are preferred because they give cured products with high hardness.

[0061] [ka] (In formula (a01-1), Z 01 R represents a single bond or a linking group (a divalent group having one or more atoms). a01 ~R a018 are each independently a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group.

[0062] Linking group Z 01Examples of the alkyl group include divalent hydrocarbon groups, -O-, -O-CO-, -S-, -SO-, -SO2-, -CBr2-, -C(CBr3)2-, -C(CF3)2-, and -R a019 Examples include a divalent group selected from the group consisting of -O-CO- and a group in which a plurality of such groups are bonded together.

[0063] Linking group Z 01 Examples of the divalent hydrocarbon group include a linear or branched alkylene group having from 1 to 18 carbon atoms and a divalent alicyclic hydrocarbon group. Examples of the linear or branched alkylene group having from 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, a dimethylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group include a cycloalkylene group (including a cycloalkylidene group) such as a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a cyclopentylidene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, a 1,4-cyclohexylene group, and a cyclohexylidene group.

[0064] R a019 is an alkylene group having 1 to 8 carbon atoms, and is preferably a methylene group or an ethylene group.

[0065] [ka] (In formula (a01-2), R a01 ~R a018 R is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. a02 and R a010 may be bonded to each other. a013 and R a016 may be bonded to each other to form a ring. a1 is either 0 or 1.)

[0066] The alicyclic epoxy compound represented by the formula (a01-2) includes m a1is 0, and is preferably a compound represented by the following formula (a01-2-1). [ka] (In formula (a01-2-1), R a01 ~R a012 R is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. a02 and R a010 may be bonded to each other to form a ring.

[0067] [ka] (In formula (a01-3), R a01 ~R a010 R is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. a02 and R a08 may be combined with each other.)

[0068] [ka] (In formula (a01-4), R a01 ~R a012 R is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group. a02 and R a010 may be combined with each other.)

[0069] [ka] (In formula (a01-5), R a01 ~R a012 is a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group.

[0070] In formulas (a01-1) to (a01-5), R a01 ~R a018is an organic group, the organic group is not particularly limited as long as it does not impair the object of the present invention, and may be a hydrocarbon group, a group consisting of carbon atoms and halogen atoms, or a group containing heteroatoms such as halogen atoms, oxygen atoms, sulfur atoms, nitrogen atoms, and silicon atoms in addition to carbon atoms and hydrogen atoms. Examples of halogen atoms include chlorine atoms, bromine atoms, iodine atoms, and fluorine atoms.

[0071] The organic group is preferably a hydrocarbon group, a group consisting of carbon atoms, hydrogen atoms, and oxygen atoms, a halogenated hydrocarbon group, a group consisting of carbon atoms, oxygen atoms, and halogen atoms, or a group consisting of carbon atoms, hydrogen atoms, oxygen atoms, and halogen atoms. 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 to 20, more preferably 1 to 10, and particularly preferably 1 to 5.

[0072] Specific examples of the hydrocarbon group include chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, and n-icosyl; vinyl, 1-propenyl, 2-n-propenyl (allyl), and 1-n-butenyl. chain alkenyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; aryl groups such as phenyl, o-tolyl, m-tolyl, p-tolyl, α-naphthyl, β-naphthyl, biphenyl-4-yl, biphenyl-3-yl, biphenyl-2-yl, anthryl, and phenanthryl; and aralkyl groups such as benzyl, phenethyl, α-naphthylmethyl, β-naphthylmethyl, α-naphthylethyl, and β-naphthylethyl.

[0073] Specific examples of the halogenated hydrocarbon group include halogenated chain alkyl groups such as a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a bromomethyl group, a dibromomethyl group, a tribromomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, a perfluorooctyl group, a perfluorononyl group, and a perfluorodecyl group; halogenated cyclohexyl groups such as a 2-chlorocyclohexyl group, a 3-chlorocyclohexyl group, a 4-chlorocyclohexyl group, a 2,4-dichlorocyclohexyl group, a 2-bromocyclohexyl group, a 3-bromocyclohexyl group, and a 4-bromocyclohexyl group; chloroalkyl groups; halogenated aryl groups such as a 2-chlorophenyl group, a 3-chlorophenyl group, a 4-chlorophenyl group, a 2,3-dichlorophenyl group, a 2,4-dichlorophenyl group, a 2,5-dichlorophenyl group, a 2,6-dichlorophenyl group, a 3,4-dichlorophenyl group, a 3,5-dichlorophenyl group, a 2-bromophenyl group, a 3-bromophenyl group, a 4-bromophenyl group, a 2-fluorophenyl group, a 3-fluorophenyl group, and a 4-fluorophenyl group; halogenated aralkyl groups such as a 2-chlorophenylmethyl group, a 3-chlorophenylmethyl group, a 4-chlorophenylmethyl group, a 2-bromophenylmethyl group, a 3-bromophenylmethyl group, a 4-bromophenylmethyl group, a 2-fluorophenylmethyl group, a 3-fluorophenylmethyl group, and a 4-fluorophenylmethyl group.

[0074] Specific examples of the group consisting of carbon atoms, hydrogen atoms, and oxygen atoms include chain hydroxy alkyl groups such as a hydroxymethyl group, a 2-hydroxyethyl group, a 3-hydroxy-n-propyl group, and a 4-hydroxy-n-butyl group; halogenated cycloalkyl groups such as a 2-hydroxycyclohexyl group, a 3-hydroxycyclohexyl group, and a 4-hydroxycyclohexyl group; a 2-hydroxyphenyl group, a 3-hydroxyphenyl group, a 4-hydroxyphenyl group, a 2,3-dihydroxyphenyl group, a 2,4-dihydroxyphenyl group, a 2,5-dihydroxyphenyl group, and a 2,5-dihydroxyphenyl group. hydroxyaryl groups such as phenyl, 2,6-dihydroxyphenyl, 3,4-dihydroxyphenyl, and 3,5-dihydroxyphenyl; hydroxyaralkyl groups such as 2-hydroxyphenylmethyl, 3-hydroxyphenylmethyl, and 4-hydroxyphenylmethyl; methoxy, ethoxy, n-propoxy, isopropoxy, n-butyloxy, isobutyloxy, sec-butyloxy, tert-butyloxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, and the like. chain alkoxy groups such as n-methyl-n-methyloxy, n-ethyl ... chain alkenyloxy groups such as an oxy group; aryloxy groups such as a phenoxy group, an o-tolyloxy group, an m-tolyloxy group, a p-tolyloxy group, an α-naphthyloxy group, a β-naphthyloxy group, a biphenyl-4-yloxy group, a biphenyl-3-yloxy group, a biphenyl-2-yloxy group, an anthryloxy group, and a phenanthryloxy group; aralkyloxy groups such as a benzyloxy group, a phenethyloxy group, an α-naphthylmethyloxy group, a β-naphthylmethyloxy group, an α-naphthylethyloxy group, and a β-naphthylethyloxy group;Alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, an n-propoxymethyl group, a 2-methoxyethyl group, a 2-ethoxyethyl group, a 2-n-propoxyethyl group, a 3-methoxy-n-propyl group, a 3-ethoxy-n-propyl group, a 3-n-propoxy-n-propyl group, a 4-methoxy-n-butyl group, a 4-ethoxy-n-butyl group, and a 4-n-propoxy-n-butyl group; a methoxymethoxy group, an ethoxymethoxy group, an n-propoxymethoxy group, a 2-methoxyethoxy group, a 2-ethoxyethoxy group, and a 2-n-propoxyethoxy group. alkoxyalkoxy groups such as a 3-methoxy-n-propoxy group, a 3-ethoxy-n-propoxy group, a 3-n-propoxy-n-propoxy group, a 4-methoxy-n-butyloxy group, a 4-ethoxy-n-butyloxy group, and a 4-n-propoxy-n-butyloxy group; alkoxyaryl groups such as a 2-methoxyphenyl group, a 3-methoxyphenyl group, and a 4-methoxyphenyl group; alkoxyaryloxy groups such as a 2-methoxyphenoxy group, a 3-methoxyphenoxy group, and a 4-methoxyphenoxy group; a formyl group, an acetyl group, a propionyl group, aliphatic acyl groups such as benzoyl, butanoyl, pentanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, and decanoyl groups; aromatic acyl groups such as benzoyl, α-naphthoyl, and β-naphthoyl groups; methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, n-butyloxycarbonyl, n-pentyloxycarbonyl, n-hexylcarbonyl, n-heptyloxycarbonyl, n-octyloxycarbonyl, n-nonyloxycarbonyl, and n-decyloxycarbonyl groups; chain alkyloxycarbonyl groups such as an alkyloxy group; aryloxycarbonyl groups such as a phenoxycarbonyl group, an α-naphthoxycarbonyl group, and a β-naphthoxycarbonyl group; aliphatic acyloxy groups such as a formyloxy group, an acetyloxy group, a propionyloxy group, a butanoyloxy group, a pentanoyloxy group, a hexanoyloxy group, a heptanoyloxy group, an octanoyloxy group, a nonanoyloxy group, and a decanoyloxy group; aromatic acyloxy groups such as a benzoyloxy group, an α-naphthoyloxy group, and a β-naphthoyloxy group;

[0075] R a01 ~R a018 are each independently preferably a group selected 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, R a01 ~R a018 More preferably, all of are hydrogen atoms.

[0076] In formulas (a01-2) to (a01-5), R a01 ~R a018 is R in formula (a01-1) a01 ~R a018 In formula (a01-2) and formula (a01-4), R a02 and R a010 When these are bonded to each other, in formula (a01-2), R a013 and R a016 are bonded to each other, and in formula (a01-3), R a02 and R a08 Examples of the divalent group formed when these groups bond to each other include -CH2- and -C(CH3)2-.

[0077] Among the alicyclic epoxy compounds represented by formula (a01-1), specific examples of suitable compounds include alicyclic epoxy compounds represented by the following formulae (a01-1a), (a01-1b), and (a01-1c), 2,2-bis(3,4-epoxycyclohexane-1-yl)propane [=2,2-bis(3,4-epoxycyclohexyl)propane], etc. [ka]

[0078] Among the alicyclic epoxy compounds represented by formula (a01-2), specific examples of suitable compounds include alicyclic epoxy compounds represented by the following formulae (a01-2a) and (a01-2b). [ka]

[0079] Among the alicyclic epoxy compounds represented by formula (a01-3), specific examples of suitable compounds include S-spiro[3-oxatricyclo[3.2.1.0 2,4 ]octane-6,2'-oxirane] and the like.

[0080] Among the alicyclic epoxy compounds represented by formula (a01-4), specific examples of suitable compounds include 4-vinylcyclohexene dioxide, dipentene dioxide, limonene dioxide, 1-methyl-4-(3-methyloxiran-2-yl)-7-oxabicyclo[4.1.0]heptane, and the like.

[0081] Among the alicyclic epoxy compounds represented by formula (a01-5), a specific example of a suitable compound is 1,2,5,6-diepoxycyclooctane.

[0082] Furthermore, a compound represented by the following formula (a1-I) can be suitably used as the epoxy compound. [ka] (In formula (a1-I), X a1 , X a2 , and X a3 are each independently a hydrogen atom or an organic group which may contain an epoxy group, and X a1 , X a2 , and X a3 The total number of epoxy groups contained in

[0083] The compound represented by the above formula (a1-I) is preferably a compound represented by the following formula (a1-II): [ka] (In formula (a1-II), R a20 ~R a22represents a linear, branched, or cyclic alkylene group, an arylene group, -O-, -C(=O)-, -NH-, or a group consisting of a combination thereof, and may be the same or different. 1 ~E 3 is at least one substituent selected from the group consisting of an epoxy group, an oxetanyl group, an ethylenically unsaturated group, an alkoxysilyl group, an isocyanate group, a blocked isocyanate group, a thiol group, a carboxy group, a hydroxyl group, and a succinic anhydride group, or a hydrogen atom, provided that E 1 , E 2 , and E 3 The total number of epoxy groups contained in

[0084] In formula (a1-II), R a20 and E 1 , R a21 and E 2 , and R a22 and E 3 Preferably, at least two of the groups represented by the formula (b1-IIa) are each a group represented by the following formula (b1-IIa), and more preferably, all of the groups are each a group represented by the following formula (a1-IIa). Preferably, multiple groups represented by formula (a1-IIa) bonded to one compound are the same group. -LC a (a1-IIa) In formula (a1-IIa), L represents a linear, branched, or cyclic alkylene group, an arylene group, —O—, —C(═O)—, —NH—, or a group formed by a combination thereof; a is an oxiranyl group (epoxy group). In formula (a1-IIa), L and C a may be bonded to form a cyclic structure.)

[0085] In formula (a1-IIa), the linear, branched, or cyclic alkylene group represented by L is preferably an alkylene group having from 1 to 10 carbon atoms, and the arylene group represented by L is preferably an arylene group having from 5 to 10 carbon atoms. In formula (a1-IIa), L is preferably a linear alkylene group having from 1 to 3 carbon atoms, a phenylene group, -O-, -C(=O)-, -NH-, or a group formed by a combination thereof, and is preferably at least one of a linear alkylene group having from 1 to 3 carbon atoms, such as a methylene group, and a phenylene group, or a group formed by a combination of any of these with at least one of -O-, -C(=O)-, and NH-.

[0086] In formula (a1-IIa), L and C a Examples of the case where a branched alkylene group and an epoxy group are bonded to form a cyclic structure (a structure having an alicyclic epoxy group) include organic groups represented by the following formulas (a1-IIb) to (a1-IId). [ka] (In formula (a1-IIb), R a23 is a hydrogen atom or a methyl group.

[0087] Examples of the compound represented by formula (a1-II) include, but are not limited to, epoxy compounds having an oxiranyl group or an alicyclic epoxy group. [ka]

[0088] [ka]

[0089] Furthermore, a siloxane compound having two or more glycidyl groups or alicyclic epoxy groups in the molecule (hereinafter also simply referred to as "siloxane compound") can be suitably used as the epoxy compound.

[0090] The siloxane compound is a compound having a siloxane skeleton composed of siloxane bonds (Si—O—Si) and two or more glycidyl groups or alicyclic epoxy groups in the molecule.

[0091] Examples of the siloxane skeleton in the siloxane compound include a cyclic siloxane skeleton and a cage-type or ladder-type polysilsesquioxane skeleton.

[0092] Of the siloxane compounds, compounds having a cyclic siloxane skeleton represented by the following formula (a1-III) (hereinafter, sometimes referred to as "cyclic siloxane") are preferred. [ka]

[0093] In formula (a1-III), R a24 , and R a25 represents a monovalent group or alkyl group containing an epoxy group, provided that x1 R in the compound represented by formula (a1-III) a24 and x1 R a25 At least two of the groups represented by formula (a1-III) are monovalent groups containing an epoxy group. In addition, x1 in formula (a1-III) represents an integer of 3 or more. a24 , R a25 may be the same or different. a24 may be the same or different. a25 may be the same or different. Examples of the alkyl group include linear or branched alkyl groups having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), such as a methyl group, an ethyl group, a propyl group, and an isopropyl group.

[0094] In formula (a1-III), x1 represents an integer of 3 or more, and preferably an integer of 3 or more and 6 or less in terms of excellent crosslinking reactivity when forming a cured film. The number of epoxy groups contained in the siloxane compound molecule is 2 or more, and from the viewpoint of excellent crosslinking reactivity when forming a cured film, 2 to 6 is preferred, and 2 to 4 is particularly preferred.

[0095] The monovalent group containing an epoxy group includes an alicyclic epoxy group and -D A -OR a26 A glycidyl ether group [D A represents an alkylene group, and R a26 represents a glycidyl group] is preferred, an alicyclic epoxy group is more preferred, and an alicyclic epoxy group represented by the following formula (a1-IIIa) or the following formula (a1-IIIb) is even more preferred. A Examples of the (alkylene group) include linear or branched alkylene groups having 1 to 18 carbon atoms, such as methylene, methylmethylene, dimethylmethylene, dimethylene, and trimethylene. [ka] (In the above formula (a1-IIIa) and formula (a1-IIIb), D 1 and D 2 each independently represents an alkylene group, and ms represents an integer of 0 or more and 2 or less.

[0096] In addition to the siloxane compound represented by Formula (a1-III), the curable composition may contain, as the epoxy compound, a compound having a siloxane skeleton, such as an alicyclic epoxy group-containing cyclic siloxane, an alicyclic epoxy group-containing silicone resin described in JP-A-2008-248169, and an organopolysilsesquioxane resin having at least two epoxy functional groups per molecule described in JP-A-2008-19422.

[0097] More specifically, the siloxane compound may be a cyclic siloxane having two or more glycidyl groups in the molecule, as represented by the following formula: Furthermore, as the siloxane compound, for example, commercially available products such as "X-40-2670," "X-40-2701," "X-40-2728," "X-40-2738," and "X-40-2740" (all manufactured by Shin-Etsu Chemical Co., Ltd.) may be used.

[0098] [ka]

[0099] [ka]

[0100] (episulfide compounds) The type of episulfide compound is not particularly limited as long as it does not impair the object of the present invention. Preferred episulfide compounds include compounds in which the oxygen atom in the epoxy group of the above-mentioned epoxy compound is substituted with a sulfur atom.

[0101] (Radical polymerizable compound) The radical polymerizable compound may be a compound having an ethylenically unsaturated group, which may be a monofunctional compound or a polyfunctional compound.

[0102] Examples of monofunctional compounds include (meth)acrylamide, methylol (meth)acrylamide, methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, propoxymethyl (meth)acrylamide, butoxymethoxymethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, (meth)acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, crotonic acid, 2-acrylamido-2-methylpropanesulfonic acid, tert-butylacrylamidosulfonic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl acrylate ... Examples of suitable monofunctional compounds include xyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-(meth)acryloyloxy-2-hydroxypropyl phthalate, glycerin mono(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and half (meth)acrylates of phthalic acid derivatives. These monofunctional compounds can be used alone or in combination of two or more.

[0103] On the other hand, examples of polyfunctional compounds include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexane glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl ester di(meth)acrylate, glycerin triacrylate, glycerin polyglycerin Examples of suitable polyfunctional compounds include ricidyl ether poly(meth)acrylate, urethane (meth)acrylate (i.e., a reaction product of tolylene diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, or the like with 2-hydroxyethyl (meth)acrylate), methylene bis(meth)acrylamide, (meth)acrylamide methylene ether, and a condensation product of a polyhydric alcohol and N-methylol (meth)acrylamide, as well as triacryl formal. These polyfunctional compounds can be used alone or in combination of two or more.

[0104] Among these compounds having an ethylenically unsaturated group, polyfunctional compounds having three or more functional groups are preferred, polyfunctional compounds having four or more functional groups are more preferred, and polyfunctional compounds having five or more functional groups are even more preferred, as they tend to improve the adhesion of the cured product to a substrate and the strength of the curable composition after curing.

[0105] The content of the polymerizable compound (A) in the curable composition is not particularly limited as long as the desired effects are not impaired. The content of the polymerizable compound (A) in the curable composition is, for example, 3% by mass or more and 95% by mass or less, preferably 5% by mass or more and 30% by mass or less in terms of curability, more preferably 5% by mass or more and 29% by mass or less, even more preferably 7% by mass or more and 20% by mass or less, and particularly preferably 7% by mass or more and 15% by mass or less, based on the total mass of the components other than the solvent (S).

[0106] <Metal oxide fine particles (B)> The curable composition contains metal oxide fine particles (B). The metal oxide fine particles (B) contribute to increasing the refractive index of a cured product of the curable composition. The metal oxide fine particles (B) contain titanium oxide fine particles (B1). When the curable composition contains titanium oxide fine particles (B1) as the metal oxide fine particles (B), it becomes easier to highly fill the curable composition with the metal oxide fine particles (B), and as a result, it becomes easier to form a cured product with a high refractive index.

[0107] The metal oxide fine particles (B) may contain, in addition to the titanium oxide fine particles (B1), other metal oxide fine particles (B2) other than the titanium oxide fine particles (B1). Preferred examples of the other metal oxide fine particles (B2) include zirconium oxide fine particles, barium titanate fine particles, and cerium oxide fine particles. The metal oxide fine particles (B) may contain a combination of two or more types of other metal oxide fine particles. The mass ratio of the titanium oxide fine particles (B1) in the metal oxide fine particles (B) is preferably 70 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 100 mass%.

[0108] The average particle size of the metal oxide fine particles (B) is preferably 500 nm or less, and more preferably 2 nm or more and 100 nm or less, from the viewpoint of the transparency of the cured product.

[0109] When the polymerizable compound contains a polymerizable fluorene compound (A1) having a radically polymerizable group-containing group, the surface of the metal oxide fine particles (B) may be modified with an ethylenically unsaturated double bond-containing group. When the surface of the metal oxide fine particles (B) is modified with an ethylenically unsaturated double bond-containing group, the polymerizable fluorene compound (A1) polymerizes with the metal oxide fine particles (B) during the formation of a cured product, and the metal oxide fine particles (B) are fixed in a matrix consisting of a polymer of the polymerizable fluorene compound (A1). Therefore, when the surface of the metal oxide fine particles (B) is modified with an ethylenically unsaturated double bond-containing group, it is particularly easy to suppress the localization of the metal oxide fine particles (B) in the cured product.

[0110] For example, by applying a capping agent containing an ethylenically unsaturated double bond to the surface of metal oxide fine particles (B), metal oxide fine particles (B) can be obtained whose surfaces are modified with ethylenically unsaturated double bond-containing groups via chemical bonds such as covalent bonds.

[0111] There are no particular limitations on the method for bonding a capping agent containing an ethylenically unsaturated double bond to the surface of the metal oxide fine particles (B) via a chemical bond such as a covalent bond. Hydroxyl groups are usually present on the surface of the metal oxide fine particles (B). By reacting these hydroxyl groups with reactive groups of the capping agent, the capping agent is covalently bonded to the surface of the metal oxide fine particles (B). Preferred examples of the reactive group possessed by the capping agent include trialkoxysilyl groups such as trimethoxysilyl group and triethoxyl group; dialkoxysilyl groups such as dimethoxysilyl group and diethoxysilyl group; monoalkoxysilyl groups such as monomethoxysilyl group and monoethoxysilyl group; trihalosilyl groups such as trichlorosilyl group; dihalosilyl groups such as dichlorosilyl group; monohalosilyl groups such as monochlorosilyl group; carboxy group; halocarbonyl groups such as chlorocarbonyl group; hydroxyl group; phosphono group (-P(=O)(OH)2); and phosphate group (-OP(=O)(OH)2).

[0112] The trialkoxysilyl group, dialkoxysilyl group, monoalkoxysilyl group, trihalosilyl group, dihalosilyl group, and monohalosilyl group form a siloxane bond with the surface of the metal oxide fine particles (B). The carboxy group and the halocarbonyl group form a bond represented by (metal oxide -O-CO-) with the surface of the metal oxide fine particles (B). The hydroxyl groups form bonds represented by (metal oxide-O-) with the surfaces of the metal oxide fine particles (B). The phosphono group and the phosphate group form a bond represented by (metal oxide-OP(=O)<) with the surface of the metal oxide fine particles (B).

[0113] In the capping agent, the group that bonds to the reactive group includes a hydrogen atom and various organic groups, which may contain heteroatoms such as O, N, S, P, B, Si, and halogen atoms. Examples of the group that bonds to the reactive group include an alkyl group, which may be linear or branched and may be interrupted by an oxygen atom (-O-), an alkenyl group, which may be linear or branched and may be interrupted by an oxygen atom (-O-), an alkynyl group, which may be linear or branched and may be interrupted by an oxygen atom (-O-), a cycloalkyl group, an aromatic hydrocarbon group, and a heterocyclic group. These groups may be substituted with a substituent such as a halogen atom, an epoxy group-containing group such as a glycidyl group, a hydroxyl group, a mercapto group, an amino group, a (meth)acryloyl group, an isocyanate group, etc. The number of substituents is not particularly limited.

[0114] In addition, the group bonded to the reactive group may be -(SiR b1 R b2 -O-) r -(SiR b3 R b4 -O-) s -R b5 Also preferred is a group represented by R b1 , R b2 , R b3 , and Rb4 are each an organic group which may be the same or different. Suitable examples of the organic group include alkyl groups such as methyl and ethyl groups, alkenyl groups such as vinyl and allyl groups, aromatic hydrocarbon groups such as phenyl, naphthyl and tolyl groups, epoxy group-containing groups such as 3-glycidoxypropyl groups, and (meth)acryloyloxy groups. In the above formula, R b5 Examples of end groups include -Si(CH3)3, -Si(CH3)2H, -Si(CH3)2(CH=CH2), and -Si(CH3)2(CH2CH2CH2CH3). In the above formula, r and s are each independently an integer of 0 to 60. In the above formula, r and s cannot both be 0.

[0115] Specific preferred examples of the capping agent include unsaturated group-containing alkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, 1-hexenyltrimethoxysilane, 1-hexenyltriethoxysilane, 1-octenyltrimethoxysilane, 1-octenyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloylpropyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-methacryloyloxypropyltriethoxysilane; unsaturated group-containing alcohols such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, allyl alcohol, ethylene glycol monoallyl ether, propylene glycol monoallyl ether, and 3-allyloxypropanol; (meth)acrylic acid; and (meth)acrylic acid halides such as (meth)acrylic acid chloride.

[0116] The amount of the capping agent used when bonding the capping agent to the surface of the metal oxide fine particles (B) via a chemical bond such as a covalent bond is not particularly limited. Preferably, a sufficient amount of the capping agent is used to react with almost all of the hydroxyl groups on the surface of the metal oxide fine particles (B).

[0117] The content of the metal oxide fine particles (B) in the curable composition is not particularly limited as long as it does not impair the object of the present invention. The content of the metal oxide fine particles (B) in the curable composition is preferably 50% by mass or more and 98% by mass or less, more preferably 70% by mass or more and 97% by mass or less, and even more preferably 90% by mass or more and 95% by mass or less, based on the mass of the curable composition excluding the mass of the solvent (S). In particular, in terms of a high refractive index of the cured product, the content of titanium oxide fine particles (B1) in the curable composition is preferably 90 mass % or more relative to the mass of the curable composition excluding the mass of the solvent (S).

[0118] <Initiator (C)> The curable composition contains an initiator (C) for curing the polymerizable compound (A). The initiator (C) contains a heat-sensitive initiator (C1). The curable composition contains the polymerizable fluorene compound (A1) and the heat-sensitive initiator (C1) in combination, so that a cured product can be formed that has high transparency, is resistant to deterioration of transparency when heated, and has excellent organic solvent resistance.

[0119] The initiator (C) may contain an initiator other than the heat-sensitive initiator as long as the desired effect is not impaired. The other initiator is typically a photosensitive initiator (C2). The photosensitive initiator (C2) cures the polymerizable compound (A) by exposure to light. In terms of facilitating the attainment of the desired effects described above, the content of the photosensitive initiator (C2) in the curable composition is preferably as small as possible. The content of the photosensitive initiator (C2) is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, even more preferably 0.1 parts by mass or less, and particularly preferably 0.01 parts by mass or less, based on 100 parts by mass of the polymerizable compound (A). It is most preferable that the curable composition does not contain a photosensitive initiator (C2).

[0120] Incidentally, the initiator (C) includes an initiator that is both heat-sensitive and photosensitive. In the specification and claims of the present application, the initiator that is both heat-sensitive and photosensitive is referred to as a heat-sensitive initiator (C1).

[0121] [Thermal Initiator (C1)] When the polymerizable fluorene compound (A1) has a cationically polymerizable group-containing group, the curable composition usually contains a thermal cationic initiator (C1a) as the heat-sensitive initiator (C1). When the polymerizable fluorene compound (A1) has a radically polymerizable group-containing group, the curable composition usually contains a thermal radical initiator (C1b) as the heat-sensitive initiator (C2).

[0122] (Thermal cationic polymerization initiator (C1a))

[0123] As the thermal cationic polymerization initiator (C1a), any thermal cationic polymerization initiator that has been conventionally blended in various cationically polymerizable curable compositions can be used without any particular limitation. Suitable examples of the thermal cationic polymerization initiator (C1a) include diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, triphenylsulfonium tetrafluoroborate, tri-p-tolylsulfonium hexafluorophosphate, tri-p-tolylsulfonium trifluoromethanesulfonate, bis(cyclohexylsulfonyl)diazomethane, bis(tert-butylsulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane, triphenylsulfonium trifluoromethanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-p-toluenesulfonate, and diphenyl-p-phenylthiophenylsulfonium hexafluorophosphate. These may be used in combination of two or more.

[0124] Examples of the thermal cationic polymerization initiator (C1a) include diazonium salt-type initiators such as the AMERICURE series (manufactured by American Can), the ULTRASET series (manufactured by Adeka Corporation), and the WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.); iodonium salt-type initiators such as the UVE series (manufactured by General Electric Co.), the FC series (manufactured by 3M Corporation), UV9310C (manufactured by GE Toshiba Silicones Co., Ltd.), and the WPI series (manufactured by Wako Pure Chemical Industries, Ltd.); and sulfonium salt-type initiators such as the CYRACURE series (manufactured by Union Carbide Corporation), the UVI series (manufactured by General Electric Co.), the FC series (manufactured by 3M Corporation), the CD series (manufactured by Sartomer Corporation), the Optomer SP series (manufactured by Adeka Corporation), the Optomer CP series (manufactured by Adeka Corporation), the San-Aid SI series (manufactured by Sanshin Chemical Industry Co., Ltd.), the CI series (manufactured by Nippon Soda Co., Ltd.), the WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.), and the CPI series (manufactured by San-Apro Co., Ltd.).

[0125] From the viewpoints of the thermosetting property of the curable composition and the transparency of the cured product, it is particularly preferable that the heat-sensitive initiator (C1) contains, as the thermal cationic initiator (C1a), an onium salt having a cation moiety represented by the following formula (c1): R c02 -D + -(R c01 ) u (c1) (In formula (c1), R c01 is a monovalent organic group, D is an element in Groups 15 to 17 of the Periodic Table of Elements (IUPAC notation) with a valence of u, and R c02 is an alkyl group which may have a substituent, or an aralkyl group which may have a substituent, provided that R c02 When R is an alkyl group which may have a substituent, c01 At least one of R is an alkyl group which may have a substituent. u is an integer of 1 to 3, and a plurality of R c01 may be the same or different, and multiple R c01 may be bonded to form a ring together with D.

[0126] D in formula (c1) is an element of Groups 15 to 17 of the Periodic Table of Elements (IUPAC notation) with a valence of u. Among the elements of Groups 15 to 17 of the Periodic Table of Elements (IUPAC notation), preferred elements for D are S (sulfur), Se (selenium), N (nitrogen), I (iodine), and P (phosphorus). Corresponding onium ions include sulfonium ions, ammonium ions, iodonium ions, and phosphonium ions. These are preferred because they are stable and easy to handle. Sulfonium ions and iodonium ions are more preferred because they have excellent cationic polymerization performance.

[0127] In formula (c1), R c01 represents an organic group bonded to D, and R c01 When there are multiple R c01 may be the same or different. c01Examples of the alkyl group include aromatic hydrocarbon groups having 6 to 14 carbon atoms, alkyl groups having 1 to 18 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, and alkynyl groups having 2 to 18 carbon atoms.

[0128] R c01 Examples of the substituents that the aromatic hydrocarbon group, aralkyl group, alkyl group, alkenyl group, and alkynyl group may have include an alkyl group having from 1 to 18 carbon atoms, an alkenyl group having from 2 to 18 carbon atoms, an alkynyl group having from 2 to 18 carbon atoms, an aryl group having from 6 to 14 carbon atoms, a nitro group, a hydroxyl group, a cyano group, an alkoxy group having from 1 to 18 carbon atoms, an aryloxy group having from 6 to 14 carbon atoms, an aliphatic acyl group having from 2 to 19 carbon atoms, an aromatic acyl group having from 7 to 15 carbon atoms, an aliphatic acyloxy group having from 2 to 19 carbon atoms, an aromatic acyloxy group having from 7 to 15 carbon atoms, an alkylthio group having from 1 to 18 carbon atoms, an arylthio group having from 6 to 14 carbon atoms, an amino group in which one or two hydrogen atoms bonded to the nitrogen atom may be substituted with a hydrocarbon group having from 1 to 18 carbon atoms, and a halogen atom.

[0129] When the substituent is a halogenated alkyl group, preferred examples of the halogenated alkyl group include linear halogenated alkyl groups such as a trifluoromethyl group, a trichloromethyl group, a pentafluoroethyl group, a 2,2,2-trichloroethyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a heptafluoro-n-propyl group, a 1,1-difluoro-n-propyl group, a 3,3,3-trifluoro-n-propyl group, a nonafluoro-n-butyl group, a 3,3,4,4,4-pentafluoro-n-butyl group, a perfluoro-n-pentyl group, and a perfluoro-n-octyl group; and branched halogenated alkyl groups such as a hexafluoroisopropyl group, a hexachloroisopropyl group, a hexafluoroisobutyl group, and a nonafluoro-tert-butyl group.

[0130] When the above-mentioned substituent is a halogenated aliphatic cyclic group, preferred examples of the halogenated aliphatic cyclic group include a pentafluorocyclopropyl group, a nonafluorocyclobutyl group, a perfluorocyclopentyl group, a perfluorocyclohexyl group, and a perfluoroadamantyl group.

[0131] When the above-mentioned substituent is an alkoxy group, preferred examples of the alkoxy group include straight-chain alkoxy groups such as a methoxy group, an ethoxy group, an n-propyloxy group, an n-butyloxy group, an n-pentyloxy group, an n-hexyloxy group, an n-octyloxy group, an n-nonyloxy group, an n-decyloxy group, an n-undecyloxy group, an n-dodecyloxy group, an n-tridecyloxy group, an n-tetradecyloxy group, an n-pentadecyloxy group, an n-hexadecyloxy group, an n-heptadecyloxy group, and an n-octadecyloxy group; and branched-chain alkoxy groups such as an isopropyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an isopentyloxy group, a neopentyloxy group, a tert-pentyloxy group, an isohexyloxy group, a 2-ethylhexyloxy group, and a 1,1,3,3-tetramethylbutyloxy group.

[0132] When the above-mentioned substituent is an aryloxy group, preferred examples of the aryloxy group include a phenoxy group, an α-naphthyloxy group, a β-naphthyloxy group, a biphenyl-4-yloxy group, a biphenyl-3-yloxy group, a biphenyl-2-yloxy group, an anthryloxy group, and a phenanthryloxy group.

[0133] When the above-mentioned substituent is an aliphatic acyl group, preferred examples of the aliphatic acyl group include an acetyl group, a propanoyl group, a butanoyl group, a pentanoyl group, a hexanoyl group, a heptanoyl group, and an octanoyl group.

[0134] When the above-mentioned substituent is an aliphatic acyl group, preferred examples of the aliphatic acyl group include an acetyl group, a propanoyl group, a butanoyl group, a pentanoyl group, a hexanoyl group, a heptanoyl group, and an octanoyl group.

[0135] When the above-mentioned substituent is an aromatic acyl group, preferred examples of the aromatic acyl group include a benzoyl group, an α-naphthoyl group, a β-naphthoyl group, a biphenyl-4-ylcarbonyl group, a biphenyl-3-ylcarbonyl group, a biphenyl-2-ylcarbonyl group, an anthrylcarbonyl group, and a phenanthrylcarbonyl group.

[0136] When the above-mentioned substituent is an aliphatic acyloxy group, preferred examples of the aliphatic acyloxy group include an acetyloxy group, a propanoyloxy group, a butanoyloxy group, a pentanoyloxy group, a hexanoyloxy group, a heptanoyloxy group, and an octanoyloxy group.

[0137] When the above-mentioned substituent is an aromatic acyloxy group, preferred examples of the aromatic acyloxy group include a benzoyloxy group, an α-naphthoyloxy group, a β-naphthoyloxy group, a biphenyl-4-ylcarbonyloxy group, a biphenyl-3-ylcarbonyloxy group, a biphenyl-2-ylcarbonyloxy group, an anthrylcarbonyloxy group, and a phenanthrylcarbonyloxy group.

[0138] When the above-mentioned substituent is an alkylthio group or an arylthio group, preferred examples of the alkylthio group or arylthio group include groups in which the oxygen atom in the above-mentioned groups suitable as the alkoxy group or aryloxy group is substituted with a sulfur atom.

[0139] When the above-mentioned substituent is an amino group which may be substituted with a hydrocarbon group, suitable examples of the amino group which may be substituted with a hydrocarbon group include an amino group, a methylamino group, an ethylamino group, an n-propylamino group, a dimethylamino group, a diethylamino group, a methylethylamino group, a di-n-propylamino group, and a piperidino group.

[0140] When the above-mentioned substituent is a halogen atom, suitable examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0141] Among the substituents described above, halogenated alkyl groups having 1 to 8 carbon atoms, halogen atoms, nitro groups, and cyano groups are preferred because they have high activity as a thermal cationic initiator (C1a), and fluorinated alkyl groups having 1 to 8 carbon atoms are more preferred.

[0142] In formula (c1), R c01 If there are multiple R c01 may form a ring together with D. c01 and D may contain, in the ring structure, one or more bonds selected from the group consisting of -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, and -CONH-.

[0143] In formula (c1), R c02 Specific examples of the alkyl group as the aryl group include linear alkyl groups having from 1 to 18 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-octyl group, an n-decyl group, an n-dodecyl group, an n-tetradecyl group, an n-hexadecyl group, and an n-octadecyl group; branched alkyl groups having from 3 to 18 carbon atoms, such as an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, an isohexyl group, and an isooctadecyl group; and cycloalkyl groups having from 3 to 18 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a 4-decylcyclohexyl group.

[0144] In formula (c1), R c02 is an alkyl group which may have a substituent, R c01 At least one of them is an alkyl group which may have a substituent.

[0145] In formula (c1), R c02 Specific examples of the aralkyl group as the aryl group include lower alkyl groups substituted with an aryl group having 6 to 10 carbon atoms, such as a benzyl group, a 1-naphthylmethyl group, and a 2-naphthylmethyl group.

[0146] In formula (c1), R c02 Specific examples of substituted aralkyl groups as the above include lower alkyl groups substituted with an aryl group having 6 to 10 carbon atoms, which may have a substituent, such as a 2-methylbenzyl group.

[0147] In formula (c1), R c02 is preferably an aralkyl group which may have a substituent, and more preferably a cation moiety represented by the following formula (c1-1):

[0148] [ka] (In formula (c1-1), R c01 , D, and u are the same as those in formula (c1). c03 is a monovalent organic group, v is an integer of 0 to 5, and a plurality of R c03 may be the same or different.)

[0149] In formula (c1-1), R c03 The monovalent organic group as R is preferably an alkyl group, and R in formula (c1) c02 Examples of the alkyl groups include the same alkyl groups as those listed in 1. Preferably, v is 0 or 1.

[0150] Specific examples of the cation moiety represented by formula (c1) or formula (c1-1) are as follows: In the following specific examples, D' is an S atom or an Se atom, and preferably an S atom. [ka]

[0151] The anion moiety that forms the onium salt together with the cation moiety represented by formula (c1) is not particularly limited as long as the onium salt having the cation moiety represented by formula (c1) acts as a thermal cationic initiator (C1a). From the viewpoints of the curability of the curable composition and the transparency of the cured product, it is preferable that the onium salt having the cation moiety represented by formula (c1) has an anion moiety consisting of a gallium-containing anion.

[0152] Suitable counter anions of the cation moiety represented by formula (c1) include the anion moieties represented by formula (ci) and formula (aii) described below. [ka] (In formula (ci), R c1 , R c2 , R c3 , and R c4 are each independently a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent, and R c1 , R c2 , R c3 , and R c4 At least one of the groups is an aromatic hydrocarbon group which may have a substituent. [ka] (In formula (cii), R c5 , R c6 , R c7 , and R c8 are each independently a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent, and R c5 , R c6 , R c7 , and R c8At least one of the groups is an aromatic hydrocarbon group which may have a substituent.

[0153] R in formula (ci) c1 ~R c4 The number of carbon atoms in the hydrocarbon group or heterocyclic group is not particularly limited, but is preferably 1 or more and 50 or less, more preferably 1 or more and 30 or less, and particularly preferably 1 or more and 20 or less.

[0154] R c1 ~R c4 Specific examples of the hydrocarbon group as the alkyl group include a linear or branched alkyl group, a linear or branched alkenyl group, a linear or branched alkynyl group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and an aralkyl group. As mentioned above, R c1 ~R c4 At least one of R is an aromatic group which may have a substituent; c1 ~R c4 More preferably, three or more of R are aromatic groups which may have a substituent, c1 ~R c4 It is particularly preferred that all of the groups are aromatic groups which may have a substituent.

[0155] R c1 ~R c4 The substituent that the hydrocarbon group or heterocyclic group may have is, in formula (c1), R c01 The substituents are the same as the substituents that may be substituted on the aromatic hydrocarbon group, aralkyl group, alkyl group, alkenyl group, and alkynyl group.

[0156] R c1 ~R c4 When the hydrocarbon group as the aromatic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group may be substituted with one or more substituents selected from the group consisting of alkyl groups having from 1 to 18 carbon atoms, alkenyl groups having from 2 to 18 carbon atoms, and alkynyl groups having from 2 to 18 carbon atoms.

[0157] R c1 ~R c4When the hydrocarbon group has a substituent, the number of the substituents is not particularly limited and may be 1 or more than 2. When the number of the substituents is more than one, the more than one substituents may be the same or different.

[0158] R c1 ~R c4 When is an alkyl group, preferred specific examples include straight-chain alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, and an n-icosyl group; and branched-chain alkyl groups such as an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, an isohexyl group, a 2-ethylhexyl group, and a 1,1,3,3-tetramethylbutyl group.

[0159] R c1 ~R c4 When is an alkenyl group or an alkynyl group, preferred examples include alkenyl groups and alkynyl groups corresponding to the above-mentioned groups preferred as the alkyl group.

[0160] R c1 ~R c4 When is an aromatic hydrocarbon group, preferred examples include a phenyl group, an α-naphthyl group, a β-naphthyl group, a biphenyl-4-yl group, a biphenyl-3-yl group, a biphenyl-2-yl group, an anthryl group, and a phenanthryl group.

[0161] R c1 ~R c4When is an alicyclic hydrocarbon group, preferred examples include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group; and bridged alicyclic hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group, and a pinanyl group.

[0162] R c1 ~R c4 When is an aralkyl group, preferred examples include a benzyl group, a phenethyl group, an α-naphthylmethyl group, a β-naphthylmethyl group, an α-naphthylethyl group, and a β-naphthylethyl group.

[0163] R c1 ~R c4 When is a heterocyclic group, preferred examples thereof include a thienyl group, a furanyl group, a selenophenyl group, a pyranyl group, a pyrrolyl group, an oxazolyl group, a thiazolyl group, a pyridyl group, a pyrimidyl group, a pyrazinyl group, an indolyl group, a benzofuranyl group, a benzothienyl group, a quinolyl group, an isoquinolyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, an acridinyl group, a phenothiazinyl group, a phenazinyl group, a xanthenyl group, a thianthrenyl group, a phenoxazinyl group, a phenoxathiinyl group, a chromanyl group, an isochromanyl group, a dibenzothienyl group, a xanthonyl group, a thioxanthonyl group, and a dibenzofuranyl group.

[0164] R c1 ~R c4 Among the substituents that the hydrocarbon group or heterocyclic group may have as the substituent, halogenated alkyl groups having from 1 to 8 carbon atoms, halogen atoms, nitro groups, and cyano groups are preferred, and fluorinated alkyl groups having from 1 to 8 carbon atoms are more preferred, in terms of high activity of the thermal cationic initiator (C1a).

[0165] R in formula (aii) a5 ~R a8 As for R in formula (ai), a1 ~R a4 Examples of the groups include the same groups as those described above.

[0166] Preferable specific examples of the anion moiety represented by formula (ci) described above include: tetrakis(4-nonafluorobiphenyl)gallium anion, tetrakis(1-heptafluoronaphthyl)gallium anion, tetrakis(pentafluorophenyl)gallium anion, tetrakis(3,4,5-trifluorophenyl)gallate anion, tetrakis(2-nonaphenylbiphenyl)gallium anion, tetrakis(2-heptafluoronaphthyl)gallium anion, tetrakis(7-nonafluoroanthryl)gallium anion, tetrakis(4'-(methoxy)octafluorobiphenyl)gallium anion, tetrakis(2,4,6-tris(trifluoromethyl)phenyl)gallium anion, tetrakis(3,5-bis(trifluoromethyl)phenyl)gallium anion, tetrakis(2,3-bis(pentafluoroethyl)naphthyl)gallium anion, tetrakis(2-isopropoxy-hexafluoronaphthyl)gallium anion, tetrakis(9,10-bis(heptafluoropropyl)heptafluoroanthryl)gallium anion, tetrakis(9-nonafluorophenanthryl)gallate anion, tetrakis(4-[tri(isopropyl)silyl]-tetrafluorophenyl)gallium anion, tetrakis(9,10-bis(p-tolyl)-heptafluorophenanthryl)gallium anion, tetrakis(4-[dimethyl(t-butyl)silyl]-tetrafluorophenyl)gallium anion, monophenyltris(pentafluorophenyl)gallium anion, and Examples thereof include monoperfluorobutyltris(pentafluorophenyl)gallium anion, and more preferably, the following anions are listed. [ka]

[0167] Specific examples of the anion moiety represented by formula (cii) include: tetrakis(4-nonafluorobiphenyl)boron anion, tetrakis(1-heptafluoronaphthyl)boron anion, tetrakis(pentafluorophenyl)boron anion, tetrakis(3,4,5-trifluorophenyl)boron anion, tetrakis(2-nonaphenylbiphenyl)boron anion, tetrakis(2-heptafluoronaphthyl)boron anion, tetrakis(7-nonafluoroanthryl)boron anion, tetrakis(4'-(methoxy)octafluorobiphenyl)boron anion, tetrakis(2,4,6-tris(trifluoromethyl)phenyl)boron anion, tetrakis(3,5-bis(trifluoromethyl)phenyl)boron anion, tetrakis(2,3-bis(pentafluoroethyl)naphthyl)boron anion, tetrakis(2-isopropoxy-hexafluoronaphthyl)boron anion, tetrakis(9,10-bis(heptafluoropropyl)heptafluoroanthryl)boron anion, tetrakis(9-nonafluorophenanthryl)boron anion, tetrakis(4-[tri(isopropyl)silyl]-tetrafluorophenyl)boron anion, tetrakis(9,10-bis(p-tolyl)-heptafluorophenanthryl)boron anion, tetrakis(4-[dimethyl(t-butyl)silyl]-tetrafluorophenyl)boron anion, monophenyltris(pentafluorophenyl)boron anion, and Examples thereof include monoperfluorobutyltris(pentafluorophenyl)boron anion, and more preferably, the following anions are listed. [ka]

[0168] In addition, other monovalent polyatomic anions are also suitable as counter anions of the cation moiety represented by formula (c1), and MY a - , (Rf) b PF 6-b - , R x1 c BY 4-c - , R x1 c Gay 4-c - , R x2 SO3 - , (R x2 SO2)3C - , or (R x2 SO2)2N - The counter anion of the cation moiety represented by formula (c1) may be a halogen anion, such as a fluoride ion, a chloride ion, a bromide ion, or an iodide ion.

[0169] M represents a phosphorus atom, a boron atom, or an antimony atom. Y represents a halogen atom (preferably a fluorine atom).

[0170] Rf represents an alkyl group in which 80 mol % or more of the hydrogen atoms are substituted with fluorine atoms (preferably an alkyl group having 1 to 8 carbon atoms). Examples of alkyl groups that are substituted with fluorine atoms include linear alkyl groups (methyl, ethyl, propyl, butyl, pentyl, octyl, etc.), branched alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, etc.), and cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.). The ratio of hydrogen atoms in these alkyl groups substituted with fluorine atoms in Rf is preferably 80 mol % or more, more preferably 90% or more, and particularly preferably 100%, based on the number of moles of hydrogen atoms possessed by the original alkyl group. When the substitution ratio with fluorine atoms is within these preferred ranges, the photosensitivity of the sulfonium salt (Q) is further improved. Particularly preferred Rf are CF3-, CF3CF2 - , (CF3)2CF - , CF3CF2CF2 - , CF3CF2CF2CF2 - , (CF3)2CFCF2 - , CF3CF2(CF3)CF - and (CF3)3C - The b Rfs are independent of each other and may be the same or different.

[0171] P represents a phosphorus atom, and F represents a fluorine atom.

[0172] R x1 represents a phenyl group in which a portion of the hydrogen atoms has been substituted with at least one element or electron-withdrawing group. Examples of such an element include halogen atoms, such as fluorine, chlorine, and bromine atoms. Examples of electron-withdrawing groups include trifluoromethyl, nitro, and cyano groups. Of these, a phenyl group in which at least one hydrogen atom has been substituted with a fluorine atom or a trifluoromethyl group is preferred. c R x1 are independent of each other and therefore may be the same or different from each other.

[0173] B represents a boron atom, and Ga represents a gallium atom.

[0174] R x2 represents an alkyl group having from 1 to 20 carbon atoms, a fluoroalkyl group having from 1 to 20 carbon atoms, or an aryl group having from 6 to 20 carbon atoms, and the alkyl group and fluoroalkyl group may be linear, branched, or cyclic, and the alkyl group, fluoroalkyl group, or aryl group may be unsubstituted or may have a substituent. Examples of the substituent include a hydroxy group, an optionally substituted amino group, a nitro group, etc. Also, R x2 The carbon chain in the alkyl group, fluoroalkyl group or aryl group represented by the formula (I) may have a heteroatom such as an oxygen atom, a nitrogen atom or a sulfur atom. x2 The carbon chain in the alkyl group or fluoroalkyl group represented by the formula (I) may have a divalent functional group (for example, an ether bond, a carbonyl bond, an ester bond, an amino bond, an amide bond, an imide bond, a sulfonyl bond, a sulfonylamido bond, a sulfonylimide bond, a urethane bond, etc.). R x2 When the alkyl group, fluoroalkyl group, or aryl group represented by the formula (I) has the above-mentioned substituent, hetero atom, or functional group, the number of the above-mentioned substituent, hetero atom, or functional group may be one or more.

[0175] S represents a sulfur atom, O represents an oxygen atom, C represents a carbon atom, and N represents a nitrogen atom. a represents an integer of 4 or more and 6 or less. b is preferably an integer of 1 or more and 5 or less, more preferably an integer of 2 or more and 4 or less, and particularly preferably 2 or 3. c is preferably an integer of 1 or more and 4 or less, and more preferably 4.

[0176] MY a - The anion represented by is SbF6 - , PF6 - Or BF4 - Examples of the anion include anions represented by the following formula:

[0177] (Rf) b PF 6-b - The anion represented by (CF3CF2)2PF4 - , (CF3CF2)3PF3 - , ((CF3)2CF)2PF4 - , ((CF3)2CF)3PF3 - , (CF3CF2CF2)2PF4 - , (CF3CF2CF2)3PF3 - , ((CF3)2CFCF2)2PF4 - , ((CF3)2CFCF2)3PF3 - , (CF3CF2CF2CF2)2PF4 - or (CF3CF2CF2CF2)3PF3 - Among these, anions represented by (CF3CF2)3PF3 - , (CF3CF2CF2)3PF3 - , ((CF3)2CF)3PF3 - , ((CF3)2CF)2PF4 - , ((CF3)2CFCF2)3PF3 - or ((CF3)2CFCF2)2PF4 - Anions represented by the following formula are preferred.

[0178] R x1 c BY 4-c - The anion represented by the formula R x1 c BY 4-c - (In the formula, R x1 represents a phenyl group in which at least a portion of the hydrogen atoms are substituted with a halogen atom or an electron-withdrawing group, Y represents a halogen atom, and c represents an integer of 1 or more and 4 or less. For example, (C6F5)4B - , ((CF3)2C6H3)4B - , (CF3C6H4)4B - , (C6F5)2BF2 -, C6F5BF3 - or (C6H3F2)4B - Among these, anions represented by (C6F5)4B - or ((CF3)2C6H3)4B - Anions represented by the following formula are preferred.

[0179] R x1 c Gay 4-c - The anion represented by the formula is (C6F5)4Ga - , ((CF3)2C6H3)4Ga - , (CF3C6H4)4Ga - , (C6F5)2GaF2 - , C6F5GaF3 - or (C6H3F2)4Ga - Among these, (C6F5)4Ga - or ((CF3)2C6H3)4Ga - Anions represented by the following formula are preferred.

[0180] R x2 SO3 - Examples of the anion represented by the formula (I) include a trifluoromethanesulfonate anion, a pentafluoroethanesulfonate anion, a heptafluoropropanesulfonate anion, a nonafluorobutanesulfonate anion, a pentafluorophenylsulfonate anion, a p-toluenesulfonate anion, a benzenesulfonate anion, a camphorsulfonate anion, a methanesulfonate anion, an ethanesulfonate anion, a propanesulfonate anion, and a butanesulfonate anion. Among these, a trifluoromethanesulfonate anion, a nonafluorobutanesulfonate anion, a methanesulfonate anion, a butanesulfonate anion, a camphorsulfonate anion, a benzenesulfonate anion, or a p-toluenesulfonate anion is preferred.

[0181] (R x2 SO2)3C - The anion represented by (CF3SO2)3C- , (C2F5SO2)3C - , (C3F7SO2)3C - or (C4F9SO2)3C - Examples of the anion include anions represented by the following formula:

[0182] (R x2 SO2)2N - The anion represented by (CF3SO2)2N - , (C2F5SO2)2N - , (C3F7SO2)2N - or (C4F9SO2)2N - Examples of the anion include anions represented by the following formula:

[0183] Monovalent polyatomic anions include MY a - , (Rf) b PF 6-b - , R x1 c BY 4-c - , R x1 c Gay 4-c - , R x2 SO3 - , (R x2 SO2)3C - or (R x2 SO2)2N - In addition to the anions represented by - , BrO4 - etc.), halogenated sulfonate ions (FSO3 - , ClSO3 - etc.), sulfate ions (CH3SO4 - , CF3SO4 - , HSO4 - etc.), carbonate ions (HCO3 - , CH3CO3 - etc.), aluminate ions (AlCl4 - , AlF4 - etc.), hexafluorobismuthate ion (BiF6 - ), carboxylate ion (CH3COO - , CF3COO- , C6H5COO - , CH3C6H4COO - , C6F5COO - , CF3C6H4COO - etc.), aryl borate ions (B(C6H5)4 - , CH3CH2CH2CH2B(C6H5)3 - etc.), thiocyanate ion (SCN - ) and nitrate ions (NO3 - ) etc. can be used.

[0184] Among these anions, MY is the most effective in cationic polymerization. a - , (Rf) b PF 6-b - , R x1 c BY 4-c - , R x1 c Gay 4-c - and (R x2 SO2)3C - The anion represented by SbF6 is preferred. - , PF6 - , (CF3CF2)3PF3 - , (C6F5)4B - , ((CF3)2C6H3)4B - , (C6F5)4Ga - , ((CF3)2C6H3)4Ga - and (CF3SO2)3C - is more preferred, and R x1 c BY 4-c - is more preferable.

[0185] The content of the thermal cationic polymerization initiator (C1a) in the curable composition is not particularly limited as long as the curing of the curable composition proceeds satisfactorily. To facilitate satisfactory curing of the curable composition, the content is typically, relative to 100 parts by mass of the polymerizable compound (A), preferably 0.001 to 30 parts by mass, more preferably 0.01 to 15 parts by mass, and particularly preferably 0.1 to 13 parts by mass. Alternatively, the content of the thermal cationic polymerization initiator (C1a) is, for example, 0.001 to 5% by mass, preferably 0.01 to 3% by mass, and more preferably 0.1 to 1% by mass, based on the total mass of the components excluding the solvent (S).

[0186] (Thermal radical initiator (C1b)) The thermal radical initiator (C1b) is not particularly limited as long as it is a compound that generates radicals upon heating and can cause a polymerization reaction between radically polymerizable group-containing groups. As the thermal radical initiator (C1b), for example, one or more selected from the group consisting of organic peroxides, azo compounds, benzoin compounds, benzoin ether compounds, acetophenone compounds, and benzopinacol are preferably used.

[0187] Preferable specific examples of the thermal radical initiator (C1b) include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), peroxyketals (2,2-bis(tert-butylperoxy)butane, 1,1-bis(tert-butylperoxy)cyclohexane, etc.), hydroperoxides (tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide (Perbutyl (registered trademark) D (manufactured by NOF Corporation) and di-tert-hexyl peroxide (Perhexyl (registered trademark) D (manufactured by NOF Corporation))), diacyl peroxides (isobutyryl peroxide, lauroyl peroxide, benzoyl peroxide, etc.), peroxydicarbonates (diisopropyl peroxydicarbonate, etc.), peroxyesters (tert organic peroxides such as 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis[2-methylpropionamidine]di ... azo compounds such as 2,2'-azobis[2-methyl-N-(2-propenyl)propionamidine] dihydrochloride, 2,2'-azobis(2-methylpropionamide), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(2-methylpropane), 2,2'-azobis(2,4,4-trimethylpentane), and dimethyl 2,2'-azobis(2-methylpropionate), etc.

[0188] The content of the thermal radical initiator (C1b) is preferably from 0.01 to 50 parts by mass, more preferably from 0.1 to 30 parts by mass, more preferably from 0.3 to 15 parts by mass, and particularly preferably from 0.1 to 13 parts by mass, relative to 100 parts by mass of the polymerizable compound (A). Alternatively, the content of the thermal radical initiator (C1b) is, for example, from 0.001 to 5% by mass, preferably from 0.01 to 3% by mass, and more preferably from 0.1 to 1% by mass, relative to the total mass of the components excluding the solvent (S). It is particularly preferably 0 parts by mass or less. By setting the content of the thermal radical initiator (C1b) within the above range, the curable composition can be easily cured satisfactorily.

[0189] <Curing accelerator (D)> The curable composition may contain a curing accelerator (D). When the curable composition contains the curing accelerator (D), the curability of the curable composition and the properties of the cured product are good.

[0190] Examples of the curing accelerator (D) include urea compounds, tertiary amines and their salts, imidazoles and their salts, phosphine compounds and their derivatives, carboxylic acid metal salts, Lewis acids, Bronsted acids and their salts, and tetraphenylboron salts.

[0191] Specific preferred examples of the curing accelerator (D) include tertiary amines such as 1,8-diazabicyclo(5,4,0)undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; phosphine compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine; and tetraphenylboron salts of tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, and N-methylmorpholine tetraphenylborate.

[0192] Among the curing accelerators (D) described above, phosphine compounds and derivatives thereof, and tetraphenylboron salts are preferred. Among the specific examples, triphenylphosphine and triphenylphosphinetriphenylborane are preferred.

[0193] The amount of the curing accelerator (D) used is not particularly limited as long as the desired effect is not impaired. The amount of the curing accelerator (D) used is preferably 0.5 parts by mass or more and 8 parts by mass or less, more preferably 1.5 parts by mass or more and 6 parts by mass or less, and particularly preferably 3 parts by mass or more and 4.5 parts by mass or less, based on 1 part by mass of the initiator (C).

[0194] <Other ingredients> The curable composition may contain additives such as surfactants, thermal polymerization inhibitors, antifoaming agents, silane coupling agents, resins (thermoplastic resins, alkali-soluble resins, etc.), inorganic fillers other than the metal oxide fine particles (B), and organic fillers, as needed. Any of these additives may be used. Examples of surfactants include anionic, cationic, and nonionic compounds. Examples of thermal polymerization inhibitors include hydroquinone and hydroquinone monoethyl ether. Examples of antifoaming agents include silicone and fluorine-based compounds.

[0195] <Solvent (S)> The curable composition contains a solvent (S) for the purpose of adjusting the coating property and viscosity. An organic solvent is typically used as the solvent (S). The type of organic solvent is not particularly limited as long as it can uniformly dissolve or disperse the components contained in the curable composition.

[0196] Suitable examples of organic solvents that can be used as the solvent (S) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-butyl ... (Poly)alkylene glycol monoalkyl ethers such as dipropylene glycol monomethyl ether and tripropylene glycol monoethyl ether; (poly)alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; alkyl lactate esters such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate;Other esters such as ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-3-methyl methyl carbonate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-pentyl formate, isopentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutanoate; aromatic hydrocarbons such as toluene and xylene; and amides such as N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These organic solvents may be used alone or in combination of two or more kinds.

[0197] The amount of the solvent (S) used in the curable composition is not particularly limited. In terms of the coatability of the curable composition, the amount of the solvent (S) used is, for example, preferably 30% by mass or more and 99.9% by mass or less, and more preferably 50% by mass or more and 98% by mass or less, based on the total amount of the curable composition.

[0198] By using a curable composition containing the essential or optional components described above, a cured product with a high refractive index can be formed. Therefore, the curable composition can be preferably used for forming high refractive index materials and high refractive index films, which have conventionally been used in various applications. For example, when the above-described curable composition is used, a cured product can be formed having a refractive index of 1.70 or more, preferably 1.75 or more, more preferably 1.80 or more, even more preferably 1.85 or more, and most preferably 1.90 or more.

[0199] <Method for producing curable composition> The curable composition can be produced by uniformly mixing the components described above in a predetermined ratio. Examples of mixing devices that can be used to produce the curable composition include a two-roll mill and a three-roll mill. If the viscosity of the curable composition is sufficiently low, the curable composition may be filtered using a filter with openings of a desired size, as needed, to remove insoluble foreign matter.

[0200] <Method for producing cured product> The method for producing the cured product is not particularly limited as long as it is a method that can cure the curable composition molded into a desired shape. Specific examples of methods for producing a cured product include: forming the curable composition into a predetermined shape; a step of heating the molded curable composition; The method includes the steps of:

[0201] The shape of the molded body is not particularly limited, but a film is preferred because it allows heat to be applied uniformly to the molded body.

[0202] A typical example of a method for producing a cured product as a cured film will be described below. To form a cured film, first, The curable composition is applied onto a substrate to form a coating film, and then the coating film is heated to cure the coating film. A cured film is formed by the above method.

[0203] The substrate is not particularly limited, but a transparent substrate such as a glass substrate or a light-transmitting resin substrate is preferred in order to take advantage of the high refractive index and excellent optical properties of the cured film to be formed, such as high light transmittance.

[0204] Examples of coating methods include methods using contact transfer type coating devices such as roll coaters, reverse coaters, and bar coaters, and non-contact type coating devices such as spinners (rotary coating devices), slit coaters, and curtain flow coaters. Alternatively, the viscosity of the curable composition may be adjusted to an appropriate range, and then the curable composition may be applied by a printing method such as an inkjet method or a screen printing method to form a coating film patterned into a desired shape.

[0205] Next, if necessary, volatile components such as the solvent (S) are removed to dry the coated film. The drying method is not particularly limited, but examples thereof include a method of drying under reduced pressure at room temperature using a vacuum dryer (VCD). The coating film obtained as described above is heated to obtain a cured film.

[0206] The curing temperature is not particularly limited as long as the curing of the curable composition proceeds well. Typically, the curing temperature is preferably 100°C or higher and 250°C or lower. In particular, the curing temperature is more preferably 120°C or higher and 175°C or lower in terms of the resulting cured film exhibiting excellent optical reliability. When taking into consideration the flatness of the cured film as described in JP 2020-037190 A, the curing temperature is preferably 120°C or higher and 175°C or lower. The heating time is not particularly limited, and is typically preferably from 1 minute to 10 minutes, more preferably from 2 minutes to 5 minutes.

[0207] The cured product formed as described above, particularly the cured film, is preferably used as an optical component in optical applications such as various display panels. [Example]

[0208] The present invention will be explained in more detail below by showing examples, but the scope of the present invention is not limited to these examples.

[0209] [Examples 1 to 9 and Comparative Examples 1 to 12] In the examples and comparative examples, the following compounds A1 to A4 were used as the polymerizable compound (A). [ka]

[0210] In the examples and comparative examples, titanium oxide microparticles (particle size measured by TEM: approximately 7 nm) synthesized by a known hydrothermal method and capped using methoxy(triethyleneoxy)propyltrimethoxysilane as a capping agent were used as metal oxide microparticles (B).

[0211] In the examples and comparative examples, the following initiator C1 was used, which acted as a thermal cationic initiator (C1a), the following initiator C2 acted as a thermal radical initiator (C1b), and the following sulfonium salt C3 acted as a photoinitiator (C2) represented by the following formula: C1: An onium salt comprising a cation moiety represented by the above formula (c1-c1) and an anion moiety represented by the above formula (ci-a1), where D' is a sulfur atom. C2: Permec N (manufactured by Nippon Oil & Fats Co., Ltd., methyl ethyl ketone peroxide) [ka]

[0212] 9 to 29 parts by mass of a polymerizable compound (A) of the type shown in Table 1, 70 to 90 parts by mass of titanium oxide microparticles (B1) as metal oxide microparticles (B), and 1 part by mass of an initiator (C) of the type shown in Table 1 were uniformly dissolved and dispersed in a solvent (S) to a solids concentration of 10% by mass, to obtain curable compositions for each of the Examples and Comparative Examples. The amounts of the polymerizable compound (A) and the titanium oxide fine particles (B1) used were the parts by mass shown in Table 1. As the solvent (S), a 1:1 (mass ratio) mixed solvent of tripropylene glycol monomethyl ether and dipropylene glycol monomethyl ether was used.

[0213] Using the obtained curable compositions of each Example and Comparative Example, the refractive index of the cured film, the transmittance of the cured film, the optical reliability (heat resistance) of the cured film, and the organic solvent resistance of the cured film were measured according to the following methods. The measurement results and evaluation results are shown in Table 1.

[0214] <Refractive index measurement> In Examples 1 to 9 and Comparative Examples 4 to 12, the curable composition was first applied to a silicon wafer using a spin coater to form a coating film of the curable composition, and the resulting coating film was heated at 120°C for 2 minutes to obtain a cured film with a thickness of 0.2 μm. For the curable compositions of Comparative Examples 1 to 3, instead of heating, a high-pressure mercury lamp was used to expose the curable compositions to an integrated exposure of 5 J / cm 2 . 2 Cured films were obtained in the same manner as in Examples 1 to 9 and Comparative Examples 4 to 12, except that the coating film was exposed to light so as to become The refractive index of the resulting cured film was measured using a rotary compensator type high-speed spectroscopic ellipsometer manufactured by JA Woollam Japan, and the refractive index of the cured film at a wavelength of 520 nm was determined.

[0215] <Transmittance evaluation> The transmittance of the cured film formed in the same manner as in the measurement of the refractive index was measured using a Vista Spectrophotometer manufactured by Hunterlab Co., Ltd. Based on the measured transmittance value, the transmittance was evaluated according to the following criteria. ◎: 95% or more 〇: 90% or more but less than 95% ×: Less than 90%.

[0216] <Evaluation of optical reliability (heat resistance)> The cured film formed in the same manner as in the refractive index measurement was further heated at 175°C for 2 minutes, and then the transmittance was measured using a Vista Spectrophotometer manufactured by Hunterlab. Based on the measured transmittance value of the heated cured film, the optical reliability (heat resistance) was evaluated according to the following criteria. ◎: 95% or more 〇: 90% or more but less than 95% ×: Less than 90%.

[0217] <Evaluation of organic solvent resistance> A cured film was formed on a silicon wafer in the same manner as in measuring the refractive index. The mass W1 of the silicon substrate with the cured film was measured. The silicon substrate with the cured film was immersed in propylene glycol monomethyl ether acetate (PGMEA) at room temperature for 2 minutes. After the immersion, the wafer was dried, and the mass W2 of the silicon substrate with the cured film was measured. The measured W1 and W2 were used to calculate the remaining film ratio according to the following formula: In the formula, W0 is the mass of the silicon wafer. Remaining film rate (mass%)=(W2-W0) / (W1-W0)×100 Based on the calculated film remaining rate, the organic solvent resistance was evaluated according to the following criteria. ◎: 95% or more 〇: 90% or more but less than 95% ×: Less than 90%.

[0218] [Table 1] *1: The ratio of the mass of TiO2 fine particles (B1) to the mass of the solid content of the curable composition.

[0219] Examples 1 to 9 show that by using a curable composition containing the above-mentioned polymerizable fluorene compound (A1) as the polymerizable compound (A), titanium oxide fine particles (B1) as the metal oxide fine particles (B), a heat-sensitive initiator (C1) as the initiator (C), and a solvent (S), it is possible to form a cured product that has a high refractive index, high transparency, is resistant to deterioration of transparency when heated, and has excellent organic solvent resistance. On the other hand, when the curable compositions of Comparative Examples 1 to 12 were used, which did not contain the polymerizable fluorene compound (A1) as the polymerizable compound (A) or did not contain the heat-sensitive initiator (C1) as the initiator (C), it was not possible to form a cured product that had high transparency, was resistant to deterioration of transparency when heated, and had excellent organic solvent resistance.

Claims

1. A polymerizable compound (A), metal oxide fine particles (B), an initiator (C), and a solvent (S), the polymerizable compound (A) contains a polymerizable fluorene compound (A1) having a radical polymerizable group-containing group or a cation polymerizable group-containing group and a fluorene skeleton, the metal oxide fine particles (B) contain titanium oxide fine particles (B1), The initiator (C) comprises a heat-sensitive initiator (C1), the surfaces of the titanium oxide fine particles (B1) are not modified with an organic group containing a conjugated aromatic skeleton having 7 or more carbon atoms, and are capped using methoxy(triethyleneoxy)propyltrimethoxysilane as a capping agent; The curable composition, wherein the polymerizable fluorene compound (A1) comprises a compound represented by the following formula (a1): 【Chemistry 1】 (In formula (a1), W １ and W ２ are each independently represented by the following formula (a2): 【Chemistry 2】 is a group represented by In formula (a2), ring Z represents a naphthalene ring, X represents a group represented by a single bond, and R １ represents a single bond, an alkylene group having 1 to 4 carbon atoms, or an alkyleneoxy group having 1 to 4 carbon atoms; R １ is an alkyleneoxy group, the oxygen atom in the alkyleneoxy group is bonded to the ring Z, and R ２ represents a monovalent hydrocarbon group, m represents an integer of 0 or more, and R ３ is a glycidyl group or a (meth)acryloyl group, W １ and W ２ Both are R ３ does not have a hydrogen atom as Ring Y １ and Ring Y ２ represent the same aromatic hydrocarbon ring, R represents a single bond, and n1 and n2 independently represent an integer of 0 to 4.

2. 2. The curable composition according to claim 1, wherein the curable composition contains the titanium oxide fine particles (B1) in an amount of 90 mass% or more relative to the mass of the curable composition minus the mass of the solvent (S).

3. the polymerizable fluorene compound (A1) has the cationically polymerizable group-containing group, The curable composition according to claim 1 or 2, wherein the heat-sensitive initiator (C1) comprises an onium salt having a cation moiety represented by the following formula (c1) as a thermal cationic initiator (C1a): R ｃ０２ -D ＋ -(R ｃ０１ ) ｕ ・・・(c1) (In formula (c1), R ｃ０１ is any one of an aromatic hydrocarbon group having 6 to 14 carbon atoms, an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, and an alkynyl group having 2 to 18 carbon atoms, D is an element in Groups 15 to 17 of the Periodic Table of Elements (IUPAC notation) with a valence of u, and R ｃ０２ is an alkyl group which may have a substituent, or an aralkyl group which may have a substituent, provided that R ｃ０２ is an alkyl group which may have a substituent, R ｃ０１ At least one of R is an alkyl group which may have a substituent. u is an integer of 1 to 3, and a plurality of R ｃ０１ may be the same or different, and multiple R ｃ０１ may be bonded to form a ring together with D.

4. The curable composition according to claim 3 , wherein the onium salt has an anion moiety comprising a gallium-containing anion.

5. the polymerizable fluorene compound (A1) has the radical polymerizable group-containing group, 3. The curable composition according to claim 1, wherein the heat-sensitive initiator (C1) comprises, as a thermal radical polymerization initiator (C1b), one or more types selected from the group consisting of organic peroxides, azo compounds, benzoin compounds, benzoin ether compounds, acetophenone compounds, and benzopinacol.

6. A cured product of the curable composition according to any one of claims 1 to 5.

7. Applying the curable composition according to any one of claims 1 to 5 onto a substrate to form a coating film; heating the coating film; A method for forming a cured film comprising the steps of:

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