TWI858148B - Curable composition, cured product, and method for forming cured product - Google Patents

Abstract

The present invention provides a cationic curable curable composition that can suppress the coloring of the cured product during curing and has good curability, a cured product of the curable composition, and a method for forming a cured product using the curable composition. In the curable composition comprising a cationic curing agent (A) and a cationic curing compound (B), a cationic curing agent is used that is a combination of a photoacid generator (A1) composed of an onium salt having a cationic part with a specific structure and a thermal acid generator (A2) having a gallium anion with a specific structure as an anionic part.

Description

Curable composition, cured product, and method for forming cured product

The present invention relates to a curable composition comprising a cationic curing agent (A) and a cationic curable compound (B), a cured product of the curable composition, and a method for forming a cured product using the curable composition.

Conventionally, cationically polymerizable curable compositions containing cationically polymerizable compounds such as epoxy compounds as curable components have been used in various applications.

Such curable compositions, for example, cationic polymerizable thermosetting compositions comprising an alicyclic epoxy compound containing an aromatic ring, a cationic polymerizable compound other than the alicyclic epoxy compound containing an aromatic ring, and a thermal cationic polymerization initiator are known (see Patent Document 1). By using such a curable composition, a cured product having a high glass transition temperature, not easily yellowing even when heated to a high temperature, and excellent substrate adhesion can be formed. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2014-156522

[The problem that the invention wants to solve]

However, the curable composition containing a thermal cationic polymerization initiator as described in Patent Document 1 sometimes requires high temperature and sometimes requires a long time to cure. This undesirable situation can be eliminated by using an onium salt-based photoacid generator. However, when the curable composition containing an onium salt-based photoacid generator and a cationic curable compound is cured by exposure, the cured product sometimes has a problem of coloring during curing.

The present invention was completed in view of the above-mentioned problem. The purpose of the present invention is to provide a curable composition that can suppress the coloring of the cured product when the composition is cured and has good curability, a cured product of the curable composition, and a method for forming a cured product using the curable composition. [Means for solving the problem]

The inventors of the present invention have found that in a curable composition comprising a cationic curing agent (A) and a cationic curing compound (B), the above-mentioned problems can be solved by using a cationic curing agent that combines a photoacid generator (A1) comprising an onium salt having a cationic part with a specific structure and a thermal acid generator (A2) having a gallium-containing anion having a specific structure as an anionic part, thereby completing the present invention. Specifically, the present invention provides the following.

The first aspect of the present invention is a curable composition comprising a cationic curing agent (A) and a cationic curing compound (B), wherein the cationic curing agent (A) comprises a photoacid generator (A1) and a thermal acid generator (A2), wherein the photoacid generator (A1) is an onium salt having a cationic part represented by the following formula (ai), and the thermal acid generator (A2) is an onium salt having an anionic part represented by the following formula (Ai). (In formula (ai), each ^Ra1 is independently a monovalent organic group, ^Ra2 is an element of Group 15 to Group 17 of the Periodic Table of the Elements according to the IUPAC notation with an atomic valence of t, and at least one of ^Ra1 is an aromatic group which may have a substituent) (In formula (Ai), each ^RA1 is independently a phenyl group which may have one or more substituents, or a perfluoroalkyl group).

The second aspect of the present invention is a cured product of the curable composition of the first aspect.

The third aspect of the present invention is a method for forming a hardened product by exposing and heating the hardening composition of the first aspect. [Effect of the invention]

According to the present invention, a cationic curable curable composition that can suppress the coloring of the cured product during curing and has good curability, a cured product of the curable composition, and a method for forming a cured product using the curable composition can be provided. [Embodiments of the invention]

≪Curing composition≫ The curing composition includes a cationic curing agent (A) and a cationic curing compound (B). The cationic curing agent (A) includes a photoacid generator (A1) and a thermal acid generator (A2). The photoacid generator (A1) is an onium salt having a cationic part represented by the following formula (ai). (In formula (ai), each ^Ra1 is independently a monovalent organic group, ^Ra2 is an element of Group 15 to Group 17 of the periodic table of the elements according to IUPAC notation with an atomic valence of t, and at least one of ^Ra1 is an aromatic group which may have a substituent.) The thermal acid generator (A2) is an onium salt having an anion portion represented by the following formula (Ai). (In formula (Ai), each ^RA1 is independently a phenyl group which may have one or more substituents, or a perfluoroalkyl group).

By using the above-mentioned photoacid generator (A1) having a cationic part with a specific structure and the above-mentioned thermal acid generator (A2) having a cationic part with a specific structure in combination, the curability of the curable composition can be improved, and the coloring of the cured product during curing can be suppressed. The reason why the cured product is colored when the cationic curable compound (B) is cured using the onium salt-based photoacid generator (A1) is that the photoacid generator (A1) is decomposed by exposure to light to generate a coloring cause substance. In contrast, when the thermal acid generator (A2) is decomposed by heating, no substance that causes coloring caused by the coloring cause substance generated by the decomposition of the photoacid generator (A1) occurs, or the decomposition product of the thermal acid generator (A2) has some effect on the coloring cause substance, thereby suppressing the coloring of the cured product during curing. In particular, when the cationic curing compound (B) described later is a compound that provides a colorless and transparent cured product, by combining the above-mentioned cationic curing agent (A) and the cationic curing compound (B), a highly colorless and transparent cured product suitable for optical use can be formed.

The following describes the essential or optional components contained in the curable composition.

[Photoacid Generator (A1)] The photoacid generator (A1) is an onium salt having a cationic part represented by the following formula (ai). The anionic part constituting the onium salt of the photoacid generator (A1) is not particularly limited within the range not hindering the purpose of the present invention. (In formula (ai), each ^Ra1 is independently a monovalent organic group, ^Ra2 is an element of Group 15 to Group 17 of the Periodic Table of the Elements according to the IUPAC notation with an atomic valence of t, and at least one of ^Ra1 is an aromatic group which may have a substituent.)

^Ra1 in the formula (ai) of the cation part represents an organic group bonded to ^Ra2 . The organic group is preferably a group containing carbon atoms, and more preferably a group consisting of one or more carbon atoms and one or more atoms selected from the group consisting of H, O, S, Se, N, B, P, Si and halogen atoms. The number of carbon atoms in the group containing carbon atoms is not particularly limited, but is preferably 1 to 50, and more preferably 1 to 20. When ^Ra1 exists in plural, the plural ^Ra1 may be the same or different. As ^Ra1 , there can be mentioned an aryl group (aromatic alkyl group) having 6 to 14 carbon atoms which may have a substituent, an alkyl group having 1 to 18 carbon atoms which may have a substituent, an aralkyl group having 7 to 12 carbon atoms which may have a substituent, an alkenyl group having 2 to 18 carbon atoms which may have a substituent, and an alkynyl group having 2 to 18 carbon atoms which may have a substituent. In the photoacid generator (A1) having a cation represented by the formula (ai) as a cation part, ^Ra1 is preferably an aryl 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.

As the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl of R ^a1 may have, there can be listed an alkyl group having 1 to 18 carbon atoms, a halogenated alkyl group having 1 to 18 carbon atoms, an aliphatic cyclic group having 3 to 18 carbon atoms, a halogenated aliphatic cyclic group having 3 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group having 6 to 14 carbon atoms, a nitro group, a hydroxyl group, a cyano group, a Alkoxy groups, aryloxy groups having 6 to 14 carbon atoms, aliphatic acyl groups having 2 to 19 carbon atoms, aromatic acyl groups having 7 to 15 carbon atoms, aliphatic acyloxy groups having 2 to 19 carbon atoms, aromatic acyloxy groups having 7 to 15 carbon atoms, alkylthio groups having 1 to 18 carbon atoms, arylthio groups having 6 to 14 carbon atoms, amino groups in which 1 or 2 hydrogen atoms bonded to a nitrogen atom may be substituted by a alkyl group having 1 to 18 carbon atoms, and halogen atoms.

Among these substituents, preferred are alkyl groups, halogenated alkyl groups, aliphatic cyclic groups, halogenated aliphatic cyclic groups, alkoxy groups, aryloxy groups, aliphatic acyl groups, aromatic acyl groups, aliphatic acyloxy groups, aromatic acyloxy groups, alkylthio groups, arylthio groups, and amino groups which may be substituted with a alkyl group.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group of R ^a1 may have is an alkyl group, preferred examples of the alkyl group include straight-chain alkoxy groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl and n-octadecyl; and branched-chain alkoxy groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, 2-ethylhexyl and 1,1,3,3-tetramethylbutyl.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl of R ^a1 may have is a halogenated alkyl group, preferred examples of the halogenated alkyl group include straight-chain halogenated alkyl groups such as trifluoromethyl, trichloromethyl, pentafluoroethyl, 2,2,2-trichloroethyl, 2,2,2-trifluoroethyl, 1,1-difluoroethyl, heptafluoro-n-propyl, 1,1-difluoro-n-propyl, 3,3,3-trifluoro-n-propyl, nonafluoro-n-butyl, 3,3,4,4,4-pentafluoro-n-butyl, perfluoro-n-pentyl and perfluoro-n-octyl; and branched-chain halogenated alkyl groups such as hexafluoroisopropyl, hexachloroisopropyl, hexafluoroisobutyl and nonafluoro-tert-butyl.

When the substituent which the aryl, aralkyl, alkyl, alkenyl and alkynyl group represented by R ^a1 may have is an aliphatic cyclic group, preferred examples of the aliphatic cyclic group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and adamantyl.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group as R ^a1 may have is a halogenated aliphatic cyclogroup, preferred examples of the halogenated aliphatic cyclogroup include pentafluorocyclopropyl, nonafluorocyclobutyl, perfluorocyclopentyl, perfluorocyclohexyl and perfluoroadamantyl.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl of R ^a1 may have is an alkoxy group, preferred examples of the alkoxy group include straight-chain alkoxy groups such as methoxy, ethoxy, n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy and n-octadecyloxy; and branched-chain alkoxy groups such as isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentyloxy, neopentyloxy, tert-pentyloxy, isohexyloxy, 2-ethylhexyloxy and 1,1,3,3-tetramethylbutoxy.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl represented by R ^a1 may have is an aryloxy group, preferred examples of the aryloxy group include phenoxy, α-naphthyloxy, β-naphthyloxy, biphenyl-4-yloxy, biphenyl-3-yloxy, biphenyl-2-yloxy, anthracenyloxy and phenanthrenyloxy.

When the substituent which the aryl, aralkyl, alkyl, alkenyl and alkynyl group as R ^a1 may have is an aliphatic acyl group, preferred examples of the aliphatic acyl group include acetyl, propionyl, butyryl, pentyl, hexyl, heptyl and octyl.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group as R ^a1 may have is an aromatic acyl group, preferred examples of the aromatic acyl group include benzoyl, α-naphthoyl, β-naphthoyl, biphenyl-4-ylcarbonyl, biphenyl-3-ylcarbonyl, biphenyl-2-ylcarbonyl, anthracenylcarbonyl and phenanthrenylcarbonyl.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group represented by R ^a1 may have is an aliphatic acyloxy group, preferred examples of the aliphatic acyloxy group include acetyloxy, propionyloxy, butyryloxy, pentyloxy, hexyloxy, heptyloxy and octyloxy groups.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group represented by R ^a1 may have is an aromatic acyloxy group, preferred examples of the aromatic acyloxy group include a benzoyloxy group, an α-naphthyloxy group, a β-naphthyloxy group, a biphenyl-4-ylcarbonyloxy group, a biphenyl-3-ylcarbonyloxy group, a biphenyl-2-ylcarbonyloxy group, anthracenylcarbonyloxy group and phenanthrenylcarbonyloxy group.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group as R ^a1 may have is an alkylthio group or an arylthio group, preferred examples of the alkylthio group or the arylthio group include groups in which the oxygen atom in the preferred groups of the aforementioned alkoxy group or aryloxy group is substituted with a sulfur atom.

When the substituent that the aryl, aralkyl, alkyl, alkenyl and alkynyl group as R ^a1 may have is an amino group that may be substituted by an alkyl group, preferred examples of the amino group that may be substituted by an alkyl group include amino, methylamino, ethylamino, n-propylamino, dimethylamino, diethylamino, methylethylamino, di-n-propylamino and piperidinyl.

When the substituent which the aryl group, aralkyl group, alkyl group, alkenyl group and alkynyl group represented by R ^a1 may have is a halogen atom, preferred examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Among the substituents described above, from the viewpoint of high activity of the photoacid generator (A1), preferred are halogenated alkyl groups having 1 to 8 carbon atoms, halogen atoms, nitro groups, and cyano groups, and more preferred are fluorinated alkyl groups having 1 to 8 carbon atoms.

In formula (ai), when multiple ^Ra1 exists, the multiple ^Ra1 may form a ring together with ^Ra2 . The ring formed by multiple ^Ra1 and ^Ra2 may contain one or more bonds selected from the group consisting of -O-, -S-, -SO-, _-SO2- , -NH-, -CO-, -COO-, and -CONH- in its ring structure.

^Ra2 in formula (ai) is an element of Group 15 to Group 17 of the Periodic Table of the Elements (IUPAC notation) with an atomic valence of t. Furthermore, the element of Group 15 to Group 17 of the Periodic Table of the Elements (IUPAC notation) as ^Ra2 is an element that can stably exist under the manufacturing conditions and storage conditions of the curable composition and the formation conditions of the cured product. ^Ra2 forms an onium ion by bonding with the organic group ^Ra1 . Among the elements of Group 15 to Group 17 of the Periodic Table of the Elements (IUPAC notation), the preferred elements as ^Ra2 are S (sulfur), N (nitrogen), I (iodine), and P (phosphorus). The corresponding onium ions are cobalt ions, ammonium ions, iodine ions, and phosphonium ions. These are preferred because they are stable and easy to handle. From the viewpoint of excellent cationic polymerization performance or crosslinking reaction performance, cobalt ions and iodine ions are preferred, and cobalt ions are particularly preferred. In other words, in the above formula (ai), it is preferred that ^Ra2 is sulfur and t is 2.

Specific examples of the coronium ion include triphenylcoronium, tri-p-tolylcoronium, tri-o-tolylcoronium, tri(4-methoxyphenyl)coronium, 1-naphthyldiphenylcoronium, 2-naphthyldiphenylcoronium, tri(4-fluorophenyl)coronium, tri-1-naphthylcoronium, tri-2-naphthylcoronium, tri(4-hydroxyphenyl)coronium, 4-(phenylthio)phenyldiphenylcoronium, 4-(p-tolylthio)phenyldi-p-tolylcoronium, 4-(4-methoxyphenylthio)phenylbis(4-methoxyphenyl)coronium, 4-(phenylthio)phenylbis(4-fluorophenyl)coronium, 4-(phenylthio)phenylbis(4-methoxyphenyl)coronium, bis[4-(bis(4-fluorophenyl)copperyl]phenyl} sulfide, bis{4-[bis(4-methylphenyl)copperyl]phenyl} sulfide, bis{4-[bis(4-methoxyphenyl)copperyl]phenyl} sulfide, 4-(4-phenylthio)phenyl di-p-tolylcopperyl, [4-(4-biphenylthio)phenyl]-4-biphenylphenylcopperyl, [4-(2-thiathionylthio)phenyl]diphenylcopperyl, bis[4-(diphenylcopperyl)phenyl]sulfide, bis[4-{bis[4-(2-hydroxyethoxy)phenyl]copperyl}phenyl]sulfide, bis{4-[bis(4-fluorophenyl)copperyl]phenyl} sulfide, bis{4-[bis(4-methylphenyl)copperyl]phenyl} sulfide, bis{4-[bis(4-methoxyphenyl)copperyl]phenyl} sulfide, 4-(4-benzoyl-2-chloro 4-(4-phenylthio)phenylbis(4-fluorophenyl)coppermidol, 4-(4-phenylthio)phenylbis(4-fluorophenyl)coppermidol, 4-(4-phenylthio)phenylbis(4-fluorophenyl)coppermidol, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylcoppermidol, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldiphenylcoppermidol, 2-[(di-p-tolyl)coppermidol]thiazonone, 2-[(diphenyl)coppermidol]thiazonone, 4-(9- 4-[4-(4-tert-butylbenzyl)phenylthio]phenyldi-p-tolylcoppermidium, 4-[4-(4-tert-butylbenzyl)phenylthio]phenyldiphenylcoppermidium, 4-[4-(benzoylphenylthio)]phenyldi-p-tolylcoppermidium, 4-[4-(benzoylphenylthio)]phenyldi-p-tolylcoppermidium, 4-[4-(benzoylphenylthio)]phenyldiphenylcoppermidium, 5-(4-methoxyphenyl)selenium, 5-phenylselenium, 5-tolylselenium, 5-(4-ethoxyphenyl)selenium, and 5-(2,4,6-trimethylphenyl) Selenium and other triaryl coroniums; diphenylbenzyl methyl coronium, diphenyl 4-nitrobenzyl methyl coronium, diphenylbenzyl coronium, and diphenylmethyl coronium and other diaryl coroniums; phenylmethylbenzyl coronium, 4-hydroxyphenylmethylbenzyl coronium, 4-methoxyphenylmethylbenzyl coronium, 4-acetylcarbonyloxyphenylmethylbenzyl coronium, 4-hydroxyphenyl (2-naphthylmethyl) methyl coronium, 2-naphthylmethylbenzyl coronium, 2-naphthylmethyl (1-ethoxycarbonyl) ethyl coronium, phenylmethylbenzyl coronium, 4-hydroxyphenyl (2-naphthylmethyl) methyl coronium, 2-naphthylmethylbenzyl coronium, 2-naphthylmethyl (1-ethoxycarbonyl) ethyl coronium, phenylmethylbenzyl coronium, 4-hydroxyphenyl (2-naphthylmethyl) methyl coronium, 2-naphthylmethyl (1-ethoxycarbonyl) ethyl coronium, 4-methylbenzyl coronium, 4-methylbenzyl coronium, 4-hydroxyphenyl (2-naphthylmethyl) methyl coronium, 2-methylbenzyl ... The invention also includes monoaryl coroniums such as 4-hydroxyphenylmethylbenzylmethylcoronium, 4-methoxyphenylmethylbenzylmethylcoronium, 4-acetylcarbonyloxyphenylmethylbenzylmethylcoronium, 2-naphthylmethylbenzylmethylcoronium, 2-naphthyloctadecylbenzylmethylcoronium, and 9-anthrylmethylbenzylmethylcoronium; and trialkyl coroniums such as dimethylbenzylmethylcoronium, benzylmethyltetrahydrothiophenium, dimethylbenzylcoronium, benzyltetrahydrothiophenium, and octadecylmethylbenzylmethylcoronium.

Specific examples of ammonium ions include tetraalkylammonium such as tetramethylammonium, ethyltrimethylammonium, diethyldimethylammonium, triethylmethylammonium, and tetraethylammonium; pyrrolidinium such as N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, and N,N-diethylpyrrolidinium; imidazolium such as N,N'-dimethylimidazolium, N,N'-diethylimidazolium, N-ethyl-N'-methylimidazolium, 1,3,4-trimethylimidazolium, and 1,2,3,4-tetramethylimidazolium; tetrahydropyrimidinium such as N,N'-dimethyltetrahydropyrimidinium; Hydropyrimidinium; phenoline such as N,N'-dimethylphenoline; piperidinium such as N,N'-diethylpiperidinium; pyridinium such as N-methylpyridinium, N-benzylpyridinium, and N-benzoylmethylpyridinium; imidazolium such as N,N'-dimethylimidazolium; quinolium such as N-methylquinolinium, N-benzylquinolinium, and N-benzoylmethylquinolinium; isoquinolinium such as N-methylisoquinolinium; thiazolium such as benzylbenzothiazolium and benzoylmethylbenzothiazolium; acridinium such as benzylacridinium and benzoylmethylacridinium.

Specific examples of the phosphonium ion include tetraarylphosphonium such as tetraphenylphosphonium, tetra-p-tolylphosphonium, tetrakis(2-methoxyphenyl)phosphonium, tetrakis(3-methoxyphenyl)phosphonium, and tetrakis(4-methoxyphenyl)phosphonium; triarylphosphonium such as triphenylbenzylphosphonium, triphenylbenzylmethylphosphonium, triphenylmethylphosphonium, and triphenylbutylphosphonium; and tetraalkylphosphonium such as triethylbenzylphosphonium, tributylbenzylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetrahexylphosphonium, triethylbenzylmethylphosphonium, and tributylbenzylmethylphosphonium.

Specific examples of the iodine ion include diphenyliodine, di-p-tolyliodine, bis(4-dodecylphenyl)iodine, bis(4-methoxyphenyl)iodine, (4-octyloxyphenyl)phenyliodine, bis(4-decyloxy)phenyliodine, 4-(2-hydroxytetradecyloxy)phenylphenyliodine, 4-isopropylphenyl(p-tolyl)iodine, and 4-isobutylphenyl(p-tolyl)iodine.

Examples of the photoacid generator (A1) include gallium-containing onium salts having an anion portion represented by the following formula (aii) or boron-containing onium salts having an anion portion represented by the following formula (aiii). (In formula (aii), ^Ra3 , ^Ra4 , ^Ra5 , and ^Ra6 are each independently a alkyl group which may have a substituent, or a heterocyclic group which may have a substituent, and at least one of ^Ra3 , ^Ra4 , ^Ra5 , and ^Ra6 is an aromatic alkyl group which may have a substituent.) (In formula (aiii), ^Ra7 , ^Ra8 , ^Ra9 , and ^Ra10 are each independently a alkyl group which may have a substituent, or a heterocyclic group which may have a substituent, and at least one of ^Ra7 , ^Ra8 , ^Ra9 , and ^Ra10 is an aromatic alkyl group which may have a substituent.)

The number of carbon atoms of the alkyl or heterocyclic group of R ^a3 to R ^a6 in formula (aii) is not particularly limited, and is preferably 1 to 50, more preferably 1 to 30, and particularly preferably 1 to 20. Specific examples of the alkyl group of R ^a3 to R ^a6 include linear or branched alkyl groups, linear or branched alkenyl groups, linear or branched alkynyl groups, aromatic alkyl groups, alicyclic alkyl groups, and aralkyl groups. As mentioned above, at least one of R ^a3 to R ^a6 is an aromatic group that may have a substituent, more preferably three or more of R ^a3 to R ^a6 are aromatic groups that may have a substituent, and particularly preferably all of R ^a3 to R ^a6 are aromatic groups that may have a substituent.

Examples of the substituent that the alkyl group or heterocyclic group of R ^a3 to R ^a6 may have include a halogenated alkyl group having 1 to 18 carbon atoms, a halogenated aliphatic cyclic group having 3 to 18 carbon atoms, a nitro group, a hydroxyl group, a cyano group, an alkoxy group having 1 to 18 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, an aliphatic acyl group having 2 to 19 carbon atoms, an aromatic acyl group having 7 to 15 carbon atoms, an aliphatic acyloxy group having 2 to 19 carbon atoms, an aromatic acyloxy group having 7 to 15 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, an arylthio group having 6 to 14 carbon atoms, an amino group in which one or two hydrogen atoms bonded to a nitrogen atom may be substituted by a alkyl group having 1 to 18 carbon atoms, and a halogen atom. When the alkyl group of R ^a3 to R ^a6 is an aromatic alkyl group, the aromatic alkyl group may be substituted with one or more substituents selected from the group consisting of 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.

When the alkyl group of R ^a3 to R ^a6 has a substituent, the number of the substituent is not particularly limited and may be 1 or 2 or more. When the number of the substituent is plural, the plural substituents may be the same or different.

Preferred specific examples of when R ^a3 to R ^a6 are alkyl groups include straight-chain alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, and n-eicosyl; and branched-chain alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, 2-ethylhexyl, and 1,1,3,3-tetramethylbutyl.

When R ^a3 to R ^a6 are alkenyl or alkynyl, preferred examples include the alkenyl and alkynyl groups described above corresponding to the preferred alkyl groups.

When R ^a3 to R ^a6 are aromatic hydrocarbon groups, preferred examples include phenyl, α-naphthyl, β-naphthyl, biphenyl-4-yl, biphenyl-3-yl, biphenyl-2-yl, anthracenyl and phenanthryl.

When R ^a3 to R ^a6 are alicyclic alkyl groups, preferred examples include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentyl, cyclooctyl, cyclononyl, and cyclodecyl; and cross-linked aliphatic cyclic alkyl groups such as norbornyl, adamantyl, tricyclodecyl, and pinanyl.

When R ^a3 to R ^a6 are aralkyl groups, preferred examples include benzyl, phenethyl, α-naphthylmethyl, β-naphthylmethyl, α-naphthylethyl, and β-naphthylethyl.

When R ^a3 to R ^a6 are heterocyclic groups, preferred examples thereof include thienyl, furanyl, phenylselenoyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidinyl, pyrazinyl, indolyl, benzofuranyl, benzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenoxazinyl, phenazinyl, xanthenyl, thienyl, phenoxathiinyl, phenoxathiinyl, chromanyl, isochromanyl, dibenzothienyl, xanthonyl, tononyl and dibenzofuranyl.

^Ra7 to ^Ra10 in the formula (aiii) can be the same groups as those mentioned above for ^Ra3 to ^Ra6 in the formula (aii).

Preferred specific examples of the anion part represented by the above-described formula (aii) 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-nonafluoroanthracenyl)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)heptafluoroanthracenyl)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 monoperfluorobutyltris(pentafluorophenyl)gallium anion, etc., and the following anions are more preferred.

Furthermore, preferred specific examples of the anion part represented by formula (aiii) 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-nonafluoroanthracenyl)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)heptafluoroanthracenyl)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 monoperfluorobutyltris(pentafluorophenyl)boron anion, etc., and more preferably, the following anions can be listed.

In addition, the preferred specific examples of the cationic part represented by the above-described formula (ai) include iodine ions such as 4-isopropylphenyl (p-tolyl) iodine, 4-isobutylphenyl (p-tolyl) iodine, [4-(2-thioxanthinethio)phenyl] diphenylthiodine, 2-[(di-p-tolyl)thiodine] Copper ions containing a thiothione skeleton such as thiothione, 2-[(diphenyl)copper]thiothione, 4-(9-hydroxy-9H-thiothione-2-yl)thiophenyl-9-hydroxy-9H-thiothione-2-ylphenylcopper; the details are as shown in the cation part of formula (a1) described later; other copper ions are shown below;.

As described above, the photoacid generator (A1) preferably has a cationic part represented by the following formula (a1). When the onium salt of the photoacid generator (A1) has a cationic part represented by the following formula (a1), the sensitivity of the photoacid generator (A1) is excellent. Since the onium salt of the photoacid generator (A1) contains a cationic part represented by the following formula (a1), the curing of the cationic curable compound (B) described later can be easily and well performed.

(In formula (a1), ^R1 and ^R2 independently represent an alkyl group which may be substituted with a halogen atom or a group represented by the following formula (a2); ^R1 and ^R2 are bonded to each other and may form a ring together with the sulfur atom in the formula; ^R3 represents a group represented by the following formula (a3) or a group represented by the following formula (a4); ^A1 represents S, O, or Se, but ^R1 and ^R2 are not both alkyl groups which may be substituted with a halogen atom.)

(In formula (a2), ring ^Z1 represents an aromatic hydrocarbon ring, ^R4 represents an alkyl group which may be substituted with a halogen atom, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, a thienyl group, a thienylcarbonyl group, a furyl group, a furylcarbonyl group, a phenylselenyl group, a phenylselenylcarbonyl group, a heterocyclic aliphatic hydrocarbon group, an alkylsulfinyl group, an alkylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or a halogen atom, and m1 represents an integer greater than or equal to 0.)

(In the formula (a3), R ⁵ represents a hydroxyl group, an alkoxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxylene group, an amino group which may be substituted, a cyano group, a nitro group, or an alkylene group which may be substituted with a halogen atom, or a group represented by the following formula (a5), R ⁶ represents a hydroxyl group, an alkoxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or an alkyl group which may be substituted with a halogen atom, or a group represented by the following formula (a6), ^A2 represents a single bond, S, O, a sulfinyl group, or a carbonyl group, and n1 represents 0 or 1.)

(In formula (a4), ^R7 and ^R8 independently represent a hydroxyl group, an alkoxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic alkyl group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxylene group, an amino group which may be substituted, a cyano group, a nitro group, or an alkylene group which may be substituted with a halogen atom, or a group represented by the following formula (a5); ^R9 and ^R10 independently represent an alkyl group which may be substituted with a halogen atom, or a group represented by the above formula (a2); ^R9 and ^R10 may be bonded to each other to form a ring together with the sulfur atom in the formula; ^A3 represents a single bond, S, O, a sulfinyl group, or a carbonyl group; X ^- represents a monovalent anion, n2 represents 0 or 1, but ^R9 and ^R10 are not both alkyl groups which may be substituted by a halogen atom.)

(In formula (a5), ring ^Z2 represents an aromatic hydrocarbon ring, ^R11 represents an alkyl group which may be substituted with a halogen atom, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or a halogen atom, and m2 represents an integer greater than 0.) (In formula (a6), ring Z ³ represents an aromatic hydrocarbon ring, R ¹² represents an alkyl group which may be substituted with a halogen atom, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, a thienylcarbonyl group, a furylcarbonyl group, a phenylselenylcarbonyl group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or a halogen atom, and m3 represents an integer greater than or equal to 0.)

The cationic part of the cobalt salt represented by the above formula (a1) is characterized in that a methyl group is bonded to a carbon atom adjacent to the carbon atom to which ^A1 is bonded in the benzene ring of the above formula (a1). Since the above position has a methyl group, it is easier to generate protons than conventional cobalt salts, and has a higher sensitivity to active energy rays such as ultraviolet rays.

In the above formula (a1), either R ¹ and R ² is preferably a group represented by the above formula (a2). R ¹ and R ² may be the same or different from each other. In the above formula (a1), when R ¹ and R ² are bonded to each other and form a ring together with the sulfur atom in the formula, the formed ring contains the sulfur atom, preferably a 3-10-membered ring, and more preferably a 5-7-membered ring. The formed ring may be a polycyclic ring, or a polycyclic ring with 5-7 members condensed is preferred. In the above formula (a1), R ¹ and R ² are preferably both phenyl groups. In the above formula (a1), R ³ is preferably a group represented by the above formula (a3). In the above formula (a1), A ¹ is preferably S or O, and more preferably S.

In the above formula (a2), ^R4 is preferably an alkyl group, hydroxyl group, alkylcarbonyl group, thienylcarbonyl group, furylcarbonyl group, phenylselenylcarbonyl group, substituted amino group, or nitro group which may be substituted by a halogen atom, and more preferably an alkyl group, alkylcarbonyl group, or thienylcarbonyl group which may be substituted by a halogen atom. In the above formula (a2), m1 can be selected according to the type of ring ^Z1 , for example, an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably an integer of 0 to 2.

In the above formula (a3), ^R5 is preferably an alkylene group; a hydroxyl group, an amino group which may be substituted, or an alkylene group substituted by a nitro group; or a group represented by the above formula (a5), and more preferably a group represented by the above formula (a5). In the above formula (a3), ^R6 is preferably an alkyl group; a hydroxyl group, an amino group which may be substituted, or an alkylene group substituted by a nitro group; or a group represented by the above formula (a6), and more preferably a group represented by the above formula (a6). In the above formula (a3), ^A2 is preferably S or O, and more preferably S. In the above formula (a3), n1 is preferably 0.

In the above formula (a4), ^R7 and ^R8 are independently preferably an alkylene group; a hydroxyl group, an amino group which may be substituted, or an alkylene group substituted with a nitro group; or a group represented by the above formula (a5), more preferably a group represented by the above formula (a5). ^R7 and ^R8 may be the same or different from each other. In the above formula (a4), either ^R9 and ^R10 are preferably a group represented by the above formula (a2). ^R9 and ^R10 may be the same or different from each other. In the above formula (a4), when ^R9 and ^R10 are bonded to each other and form a ring together with the sulfur atom in the formula, the formed ring contains the sulfur atom, and is preferably a 3-10-membered ring, and more preferably a 5-7-membered ring. The formed ring may be a polycyclic ring, or a polycyclic ring in which 5-7-membered rings are condensed is preferred. In the above formula (a4), ^A3 is preferably S or O, more preferably S. In the above formula (a4), n2 is preferably 0.

In the above formula (a5), R ¹¹ is preferably an alkyl group which may be substituted by a halogen atom, a hydroxyl group, an amine group which may be substituted, or a nitro group, and more preferably an alkyl group which may be substituted by a halogen atom. In the above formula (a5), m2 can be selected according to the type of ring Z ² , for example, an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably an integer of 0 to 2.

In the above formula (a6), R ¹² is preferably an alkyl group, hydroxyl group, alkylcarbonyl group, thienylcarbonyl group, furylcarbonyl group, phenylselenylcarbonyl group, substituted amino group, or nitro group which may be substituted by a halogen atom, and more preferably an alkyl group, alkylcarbonyl group, or thienylcarbonyl group which may be substituted by a halogen atom. In the above formula (a6), m3 can be selected according to the type of ring Z ³ , for example, an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably an integer of 0 to 2.

The counter anion of the cationic part represented by the above formula (a1) is a monovalent anion corresponding to the acid generated by irradiating the zirconium salt having the cationic part represented by the formula (a1) with active energy rays (visible light, ultraviolet rays, electron beams, X-rays, etc.). The counter anion of the cationic part represented by the formula (a1) is preferably the anionic part represented by the above formula (aii) and the anionic part represented by the formula (aiii). Furthermore, the counter anion of the cation part represented by formula (a1) is preferably a monovalent polyatomic ^anion , and more preferably an anion represented by _MYa- ^, ( _Rf ) _{bPF6 -b-} ^{, Rx1cBY4} _{- c-} , ^Rx1cGaY4 - _c-, ^Rx2SO3- _, ( ^{Rx2SO2 ) 3C- ,} or ( ^Rx2SO2 ) _2N- . Furthermore, the counter ^anion of the cation part represented by formula ( _a1 ) _may be a halogen anion, and for example, fluoride ion, chloride ion, bromine ion, iodine ion _, etc. may be mentioned.

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

Rf represents an alkyl group (preferably an alkyl group having 1 to 8 carbon atoms) in which 80 mol% or more of the hydrogen atoms are substituted by fluorine atoms. As the alkyl group of Rf, there can be listed linear alkyl groups (methyl, ethyl, propyl, butyl, pentyl and octyl groups), branched alkyl groups (isopropyl, isobutyl, sec-butyl and tert-butyl groups) and cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl groups). In Rf, the ratio of hydrogen atoms of these alkyl groups to be substituted by fluorine atoms is preferably 80 mol% or more, more preferably 90% or more, and particularly preferably 100% according to the molar number of hydrogen atoms in the original alkyl group. When the ratio of substitution by fluorine atoms is within this range, the photosensitivity of the cobalt salt (Q) is better. ^Particularly preferred _{Rf include CF3-} , _CF3CF2- , ( _CF3 ⁾ _2CF- ^, _{CF3CF2CF2- , CF3CF2CF2CF2- , ( CF3 ) 2CFCF2-} , _CF3CF2 ( _CF3 ⁾ _CF- and ( _CF3 ) _3C- ^. The Rf's are independent of ^{each other} and _may be the same or different.

P represents a phosphorus atom, and F represents a fluorine atom.

R ^x1 represents a phenyl group in which a portion of hydrogen atoms is substituted by at least one element or electron withdrawing group. Examples of such one element include halogen atoms, such as fluorine atoms, chlorine atoms, and bromine atoms. Examples of electron withdrawing groups include trifluoromethyl, nitro, and cyano groups. Among these, a phenyl group in which at least one hydrogen atom is substituted by a fluorine atom or a trifluoromethyl group is preferred. The c R ^x1 groups are mutually independent and may be the same or different from each other.

B represents a boron atom, and Ga represents a gallium atom.

^Rx2 represents an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. The alkyl group and the fluoroalkyl group may be linear, branched, or cyclic. The alkyl group, the fluoroalkyl group, or the aryl group may be unsubstituted or may have a substituent. Examples of the substituent include a hydroxyl group, an amino group which may be substituted (for example, the groups exemplified in the following description of the above formulae (a2) to (a6)), a nitro group, and the like. In addition, the carbon chain in the alkyl group, the fluoroalkyl group, or the aryl group represented by ^Rx2 may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom. In particular, the carbon chain in the alkyl or fluoroalkyl group represented by ^Rx2 may also have a divalent functional group (e.g., an ether bond, a carbonyl bond, an ester bond, an amine bond, an amide bond, an imide bond, a sulfonyl bond, a sulfonylamide bond, a sulfonylimide bond, a carbamate bond, etc.). When the alkyl, fluoroalkyl or aryl group represented by ^Rx2 has the above-mentioned substituents, heteroatoms, or functional groups, the number of the above-mentioned substituents, heteroatoms, or functional groups may be one or more.

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 from 4 to 6. b is preferably an integer from 1 to 5, more preferably an integer from 2 to 4, and particularly preferably 2 or 3. c is preferably an integer from 1 to 4, and more preferably 4.

Examples of the anion represented by MY _a ^- include anions represented by SbF ₆ ^- , PF ₆ ^- or BF ₄ ^- .

The anion represented by (Rf) _b PF _6-b ^- includes (CF ₃ CF ₂ ) ₂ PF ₄ ^- , (CF ₃ CF ₂ ) ₃ PF ₃ ^- , ((CF ₃ ) ₂ CF) ₂ PF ₄ ^- , ((CF ₃ ) ₂ CF) ₃ PF ₃ ^- , (CF ₃ CF ₂ CF ₂ ) ₂ PF ₄ ^- , (CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ^- , ((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ^- , ((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ^- , (CF ₃ CF ₂ CF ₂ CF ₂ ) ₂ PF ₄ ^- or (CF ₃ CF ₂ CF ₂ CF ₂ ) ₃ PF ₃ ^-, etc. Among them, (CF ₃ CF ₂ ) ₃ PF ₃ ^- , (CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ^- , ((CF ₃ ) ₂ CF) ₃ An anion represented by PF ₃ ^- , ((CF ₃ ) ₂ CF) ₂ PF ₄ ^- , ((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ^- , or ((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ^- .

The anion represented by ^Rx1cBY4 _{-c- is} preferably ^Rx1cBY4 _-c- ⁽ wherein ^Rx1 represents a phenyl group _in which at least one part of ^the hydrogen atoms is substituted by a halogen atom or _an electron-withdrawing group, Y represents a halogen atom, ^and c represents an _integer of ₁ to ₄ ). Examples of the anion include ( _C6F5 ) _4B- ^, ( _{( CF3} ⁾ _2C6H3 ⁾ _{4B- , ( CF3C6H4 ) 4B- , ( C6F5 )} ^2BF2- _{, C6F5BF3-} or ( _C6H3F2 ⁾ _4B- . Among them, an anion represented by (C ₆ F ₅ ) ₄ B ^- or ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ^- is preferred.

Examples of the anion _{represented by} ^{Rx1cGaY4 -} _c- include ( _C6F5 ) ^4Ga- , (( _CF3 ) _2C6H3 ) _{4Ga- , ( CF3C6H4} ⁾ _{4Ga- ,} ( _C6F5 ⁾ _2GaF2- , _C6F5GaF3- ^, or ( _C6H3F2 ) _{4Ga- . Among} these _{, anions} represented _{by ( C6F5 ) 4Ga-} ^{or (} ₍ ^CF3 _{) 2C6H3} ⁾ _{4Ga- are preferred .}

Examples of the anion represented by R ^x2 SO ₃ ^- include trifluoromethanesulfonic acid anion, pentafluoroethanesulfonic acid anion, heptafluoropropanesulfonic acid anion, nonafluorobutanesulfonic acid anion, pentafluorophenylsulfonic acid anion, p-toluenesulfonic acid anion, benzenesulfonic acid anion, camphorsulfonic acid anion, methanesulfonic acid anion, ethanesulfonic acid anion, propanesulfonic acid anion and butanesulfonic acid anion. Among these, trifluoromethanesulfonic acid anion, nonafluorobutanesulfonic acid anion, methanesulfonic acid anion, butanesulfonic acid anion, camphorsulfonic acid anion, benzenesulfonic acid anion or p-toluenesulfonic acid anion is preferred.

Examples of the anion represented by (R ^x2 SO ₂ ) ₃ C ^- include (CF ₃ SO ₂ ) ₃ C ^- , (C ₂ F ₅ SO ₂ ) ₃ C ^- , (C ₃ F ₇ SO ₂ ) ₃ C ^- , and (C ₄ F ₉ SO ₂ ) ₃ C ^- .

Examples of the anion represented by (R ^x2 SO ₂ ) ₂ N ^- include (CF ₃ SO ₂ ) ₂ N ^- , (C ₂ F ₅ SO ₂ ) ₂ N ^- , (C ₃ F ₇ SO ₂ ) ₂ N ^- or (C ₄ F ₉ SO ₂ ) ₂ N ^- .

As monovalent polyatomic anions, in addition to anions represented by _MYa- ^, (Rf) _{bPF6 -b-} ^{, Rx1cBY4 -} _c- , _{Rx1cGaY4-c-, Rx2SO3-, ( Rx2SO2} ⁾ _3C- ^, _or ^{( Rx2SO2} ) _2N- ^, _perhalide ^ions ( _ClO4- ^, _BrO4- ^, _etc. ) ^, halogenated sulfonate ions ( _FSO3- , _ClSO3- ^, etc. ⁾ , sulfate ions ( ^CH3SO4- _{, CF3SO4-} , HSO4- _, ^etc. ), carbonate ions ( _HCO3- ^, _CH3CO3- ^, etc.), _aluminate ions ( _AlCl4- ^, _AlF4- ^{, etc.} ), hexafluorobismuth ion (BiF4-, etc. ₎ can ^{be used} _{. 6} ^- ), carboxylate ions (CH ₃ COO ^- , CF ₃ COO ^- , C ₆ H ₅ COO ^- , CH ₃ C ₆ H ₄ COO ^- , C ₆ F ₅ COO ^- , CF ₃ C ₆ H ₄ COO ^-, etc.), aryl borate ions (B(C ₆ H ₅ ) ₄ ^- , CH ₃ CH ₂ CH ₂ CH ₂ B(C ₆ H ₅ ) ₃ ^-, etc.), thiocyanate ions (SCN ^- ) and nitrate ions (NO ₃ ^- ), etc.

Among these anions, from the viewpoint of cationic polymerization performance, anions represented by _MYa- ^, (Rf ⁾ _{bPF6 -b-} ^{, Rx1cBY4} _{-c- ,} ^Rx1cGaY4 _{-c- and} ⁽ _Rx2SO2 ^{) 3C-} _are preferred; SbF6- ^, _PF6- , _{( CF3CF2 )3PF3-} ^, _{( C6F5} ⁾ _4B- , _{( (} ^CF3 ₎ 2C6H3 _{)4B-, (C6F5 )} ^4Ga- _{, ( (} ^CF3 _{) 2C6H3} ⁾ _4Ga- and _{(CF3SO2 ) 3C- are more} ^{preferred ;} _and ^Rx1cBY4 _{-c- is even} more preferred.

In the above formulae (a2), (a5), and (a6), the aromatic hydrocarbon ring may be a benzene ring, a condensed polycyclic aromatic hydrocarbon ring [e.g., a condensed bicyclic hydrocarbon ring (e.g., a C _8-20 condensed bicyclic hydrocarbon ring such as a naphthalene ring, preferably a C _10-16 condensed bicyclic hydrocarbon ring), a condensed tricyclic aromatic hydrocarbon ring (e.g., anthracene ring, phenanthrene ring, etc.), or a condensed bicyclic to tetracyclic aromatic hydrocarbon ring]. The aromatic hydrocarbon ring is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.

In the above formulae (a1) to (a6), the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the above formulae (a1) to (a6), examples of the alkyl group include a straight-chain alkyl group having 1 to 18 carbon atoms (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl), a branched-chain alkyl group having 3 to 18 carbon atoms (isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, and isooctadecyl), and a cycloalkyl group having 3 to 18 carbon atoms (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and 4-decylcyclohexyl). In particular, in the above formulae (a1), (a2), and (a4) to (a6), the alkyl group which may be substituted by a halogen atom refers to an alkyl group and an alkyl group substituted by a halogen atom. Examples of the alkyl group substituted by a halogen atom include the above-mentioned straight-chain alkyl group, branched-chain alkyl group, or cycloalkyl group in which at least one hydrogen atom is substituted by a halogen atom (monofluoromethyl group, difluoromethyl group, trifluoromethyl group, etc.). Among the alkyl groups which may be substituted by a halogen atom, R ¹ , R ² , R ⁹ , or R ¹⁰ is particularly preferably a trifluoromethyl group, and R ⁴ , R ⁶ , R ¹¹ , or R ¹² is particularly preferably a methyl group.

In the above formulae (a2) to (a6), examples of the alkoxy group include straight-chain or branched alkoxy groups having 1 to 18 carbon atoms (methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, hexyloxy, decyloxy, dodecyloxy, and octadecyloxy, etc.).

In the above formulae (a2) to (a6), the alkyl group in the alkylcarbonyl group may be the above-mentioned straight-chain alkyl group having 1 to 18 carbon atoms, branched-chain alkyl group having 3 to 18 carbon atoms, or cycloalkyl group having 3 to 18 carbon atoms. As the alkylcarbonyl group, there may be mentioned straight-chain, branched-chain or cyclic alkylcarbonyl groups having 2 to 18 carbon atoms (acetyl, propionyl, butyryl, 2-methylpropionyl, heptyl, 2-methylbutyryl, 3-methylbutyryl, octyl, decyl, dodecanoyl, octadecanoyl, cyclopentyl, cyclohexyl, etc.).

In the above formulae (a3) to (a6), examples of the arylcarbonyl group include arylcarbonyl groups having 7 to 11 carbon atoms (such as benzoyl and naphthoxyl).

In the above formulae (a2) to (a6), examples of the alkoxycarbonyl group include linear or branched alkoxycarbonyl groups having 2 to 19 carbon atoms (methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, tert-butoxycarbonyl, octyloxycarbonyl, tetradecyloxycarbonyl, and octadecyloxycarbonyl).

In the above formulae (a3) to (a6), examples of the aryloxycarbonyl group include aryloxycarbonyl groups having 7 to 11 carbon atoms (such as phenoxycarbonyl and naphthoxycarbonyl).

In the above formulae (a3) to (a6), examples of the arylthiocarbonyl group include arylthiocarbonyl groups having 7 to 11 carbon atoms (such as phenylthiocarbonyl and naphthylthiocarbonyl).

In the above formulae (a2) to (a6), examples of the acyloxy group include linear or branched acyloxy groups having 2 to 19 carbon atoms (acetyloxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, octylcarbonyloxy, tetradecylcarbonyloxy, and octadecylcarbonyloxy).

In the above formulae (a3) to (a6), the arylthio group includes an arylthio group having 6 to 20 carbon atoms (phenylthio, 2-methylphenylthio, 3-methylphenylthio, 4-methylphenylthio, 2-chlorophenylthio, 3-chlorophenylthio, 4-chlorophenylthio, 2-bromophenylthio, 3-bromophenylthio, 4-bromophenylthio, 2-fluorophenylthio, 3-fluorophenylthio, 4-fluorophenylthio, 2-hydroxyphenylthio, 4-hydroxyphenylthio, 2-methoxyphenylthio, 4-methoxyphenylthio, 1-naphthylthio, 2-naphthylthio, 4-[4-(phenylthio)benzoyl]phenylthio, 4-[4-(phenylthio)phenoxy]phenylthio, 4-[4-(phenylthio)phenoxy]phenylthio, [0063] The following are examples of the group consisting of 4-(4-(2-methylthiobenzyl)phenylthio, 4-(p-methylbenzyl)phenylthio, 4-(p-ethylbenzyl)phenylthio, 4-(p-isopropylbenzyl)phenylthio, and 4-(p-tert-butylbenzyl)phenylthio) and the like.

In the above formulae (a2) to (a6), examples of the alkylthio group include linear or branched alkylthio groups having 1 to 18 carbon atoms (methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio, sec-butylthio, tert-butylthio, pentylthio, isopentylthio, neopentylthio, tert-pentylthio, octylthio, decylthio, dodecylthio, and isooctadecylthio).

In the above formulae (a3) to (a6), examples of the aryl group include aryl groups having 6 to 10 carbon atoms (phenyl, tolyl, dimethylphenyl, naphthyl, etc.).

In the above formula (a2), the heterocyclic aliphatic alkyl group includes heterocyclic alkyl groups having 2 to 20 (preferably 4 to 20) carbon atoms (pyrrolidinyl, tetrahydrofuranyl, tetrahydrothienyl, piperidinyl, tetrahydropyranyl, tetrahydrothiapyranyl, morpholinyl, etc.).

In the above formulae (a3) to (a6), the heterocyclic alkyl group includes a heterocyclic alkyl group having 4 to 20 carbon atoms (thienyl, furanyl, phenylselenoyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidinyl, pyrazinyl, indolyl, benzofuranyl, benzothiophenyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, carbazole, acridinyl, phenothiazinyl, il), phenazinyl, (xanthenyl), thianthrenyl, phenoxazinyl, phenoxathiinyl (phenoxathiinyl, chromanyl, isobenzodihydropyranyl, dibenzothienyl, xanthonyl, thioxanthonyl and dibenzofuranyl, etc.), etc.

In the above formulae (a3) to (a6), examples of the aryloxy group include aryloxy groups having 6 to 10 carbon atoms (such as phenoxy and naphthoxy).

In the above formulae (a2) to (a6), examples of the alkylsulfinyl group include linear or branched sulfinyl groups having 1 to 18 carbon atoms (methylsulfinyl, ethylsulfinyl, propylsulfinyl, isopropylsulfinyl, butylsulfinyl, isobutylsulfinyl, sec-butylsulfinyl, tert-butylsulfinyl, pentylsulfinyl, isopentylsulfinyl, neopentylsulfinyl, tert-pentylsulfinyl, octylsulfinyl, and isooctadecylsulfinyl).

In the above formulae (a3) to (a6), examples of the arylsulfinyl group include arylsulfinyl groups having 6 to 10 carbon atoms (phenylsulfinyl, tolylsulfinyl, naphthylsulfinyl, etc.).

In the above formulae (a2) to (a6), examples of the alkylsulfonyl group include linear or branched alkylsulfonyl groups having 1 to 18 carbon atoms (methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, isobutylsulfonyl, sec-butylsulfonyl, tert-butylsulfonyl, pentylsulfonyl, isopentylsulfonyl, neopentylsulfonyl, tert-pentylsulfonyl, octylsulfonyl, octadecylsulfonyl, etc.).

In the above formulae (a3) to (a6), examples of the arylsulfonyl group include arylsulfonyl groups having 6 to 10 carbon atoms (phenylsulfonyl, tolylsulfonyl (p-toluenesulfonyl), and naphthylsulfonyl).

In the above formulae (a2) to (a6), examples of the hydroxyl (poly) alkoxyl group include a hydroxyl (poly) alkoxyl group represented by HO(AO) _q - (wherein AO independently represents an ethoxyl group and/or a propoxyl group, and q represents an integer of 1 to 5).

In the above formulae (a2) to (a6), the amino group which may be substituted may include amino group ( _-NH2 ) and substituted amino groups having 1 to 15 carbon atoms (methylamino, dimethylamino, ethylamino, methylethylamino, diethylamino, n-propylamino, methyl-n-propylamino, ethyl-n-propylamino, n-propylamino, isopropylamino, isopropylmethylamino, isopropylethylamino, diisopropylamino, phenylamino, diphenylamino, methylphenylamino, ethylphenylamino, n-propylphenylamino, and isopropylphenylamino).

In the above formulae (a3) and (a4), the alkylene group includes a linear or branched alkylene group having 1 to 18 carbon atoms (methylene group, 1,2-ethylene group, 1,1-ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, butane-1,4-diyl group, butane-1,3-diyl group, butane-1,2-diyl group, butane-1,1-diyl group, butane-2,2-diyl group, butane-2,3-diyl group , pentane-1,5-diyl, pentane-1,4-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, 2-ethylhexane-1,6-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, and hexadecane-1,16-diyl, etc.).

The cobalt salt having a cationic part represented by formula (a1) can be synthesized, for example, according to the following scheme. Specifically, 1-fluoro-2-methyl-4-nitrobenzene represented by formula (b1) is reacted with a compound represented by formula (b2) in the presence of a base such as potassium hydroxide to obtain a nitro compound represented by formula (b3), and then reduced in the presence of reducing iron to obtain an amine compound represented by formula (b4). This amine compound is reacted with a nitrite (e.g., sodium nitrite) represented by MaNO ₂ (wherein Ma represents a metal atom, such as an alkali metal atom such as a sodium atom) to obtain a diazo compound. Next, this diazo compound is mixed with a cuprous halide represented by CuX' (wherein X' represents a halogen atom such as a bromine atom. The same shall apply hereinafter) and a hydrogen halide represented by HX' to react to obtain a halide represented by the following formula (b5). A Grignard reagent is prepared from this halide and magnesium. Next, this Grignard reagent is reacted with a sulfoxide compound represented by the following formula (b6) in the presence of trimethylsilyl chloride to obtain a cobalt salt represented by the following formula (b7). Furthermore, by reacting this zirconia salt with a salt represented by Mb ⁺ X" ^- (wherein Mb ⁺ represents a metal cation, for example, an alkali metal cation such as a potassium ion, and X" ^- is a monovalent anion represented by X ^- (but excluding halogen anions)) to perform salt exchange, a zirconia salt represented by the following formula (b8) can be obtained. In the following formulas (b2) to (b8), R ¹ to R ³ and A ¹ are the same as those in the above formula (a1).

＜Illustration＞

Specific examples of the cationic part represented by the above formula (a1) include the following cationic parts. Specific examples of the anionic part relative to the cationic part represented by the above formula (a1) include the anionic parts listed above and the anionic parts known in the past. The cobalt salt having the cationic part represented by the above formula (a1) can be synthesized according to the above diagram (in the diagram, ^X- represents an anion), and if necessary, the cationic part can be combined with the desired anionic part by salt exchange, especially preferably with the anionic part represented by the above formula (aii) or the anionic part represented by the above formula (aiii).

Among the above-mentioned preferred cationic moieties, a cationic moiety represented by the following formula is more preferred.

[Thermal Acid Generator (A2)] The thermal acid generator (A2) is an onium salt having an anion part represented by the following formula (Ai). (In formula (Ai), each R ^A1 is independently a phenyl group which may have one or more substituents, or a perfluoroalkyl group.)

The four R ^A1s in formula (Ai) are phenyl groups which may have one or more substituents, or perfluoroalkyl groups. When R ^A1 is a phenyl group, the substituents which the phenyl group may have are not particularly limited within the scope not hindering the purpose of the present invention. Preferred examples of the substituents which the phenyl group may have include a perfluoroalkyl group, a perfluoroalkoxy group, a nitro group, a cyano group, an acyl group, and a halogen atom. When the phenyl group as R ^A1 has multiple substituents, the multiple substituents may be the same or different.

The number of carbon atoms of the perfluoroalkyl group as a substituent on the phenyl group is preferably 1 to 8, and more preferably 1 to 4. Specific examples of the perfluoroalkyl group as a substituent on the phenyl group include straight-chain perfluoroalkyl groups such as trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, perfluoropentyl, and perfluorooctyl, branched perfluoroalkyl groups such as heptafluoroisopropyl, nonafluoroisobutyl, nonafluoro-sec-butyl, and nonafluoro-tert-butyl, and perfluorocycloalkyl groups such as perfluorocyclopropyl, perfluorocyclobutyl, perfluorocyclopentyl, and perfluorocyclohexyl.

The number of carbon atoms of the perfluoroalkoxy group as a substituent on the phenyl group is preferably 1 to 8, and more preferably 1 to 4. Specific examples of the perfluoroalkoxy group as a substituent on the phenyl group include straight-chain perfluoroalkoxy groups such as trifluoromethoxy, pentafluoroethoxy, heptafluoropropoxy, nonafluorobutoxy, perfluoropentyloxy, and perfluorooctyloxy, or branched perfluoroalkoxy groups such as heptafluoroisopropoxy, nonafluoroisobutoxy, nonafluoro-sec-butoxy, and nonafluoro-tert-butoxy.

Examples of the halogen atom as a substituent on the phenyl group include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

When ^RA1 is a perfluoroalkyl group, preferred examples of the perfluoroalkyl group are the same as the specific examples of the perfluoroalkyl group as a substituent on the phenyl group.

From the viewpoint of the cationic polymerization performance of the thermal acid generator (A2), it is preferred that at least one of ^RA1 is a phenyl group substituted with one or more groups selected from the group consisting of a perfluoroalkyl group and a fluorine atom, and it is more preferred that all of ^RA1 are phenyl groups substituted with one or more groups selected from the group consisting of a perfluoroalkyl group and a fluorine atom.

Preferred examples of ^RA1 include pentafluorophenyl, trifluorophenyl, tetrafluorophenyl, (trifluoromethyl)phenyl, bis(trifluoromethyl)phenyl, (pentafluoroethyl)phenyl, bis(pentafluoroethyl)phenyl, fluoro(trifluoromethyl)phenyl, fluorobis(trifluoromethyl)phenyl, fluoro(pentafluoroethyl)phenyl, fluorobis(pentafluoroethyl)phenyl, pentachlorophenyl, trichlorophenyl, tetrachlorophenyl, (trichloromethyl)phenyl, bis(trichloromethyl)phenyl, (pentachloroethyl)phenyl, bis(pentachloroethyl)phenyl, chloro(trichloromethyl)phenyl, chlorobis(trichloromethyl)phenyl, chloro(pentachloroethyl)phenyl, chlorobis(pentachloroethyl)phenyl, nitrophenyl, cyanophenyl, and acetylphenyl. Among these, pentafluorophenyl and bis(trifluoromethyl)phenyl are preferred, and pentafluorophenyl is more preferred.

Preferred specific examples of the anion part represented by formula (Ai) include the following anions.

The cationic part which constitutes the onium salt as the thermal acid generator (A2) together with the anionic part represented by the above formula (Ai) is preferably a cationic part represented by the following formula (Aii).

(In formula (Aii), R ^A01 is a monovalent organic group, D is an element of Group 15 to Group 17 of the Periodic Table of the Elements (IUPAC notation) with an atomic valence of u, and R ^A02 is an alkyl group which may have a substituent or an aralkyl group which may have a substituent. However, when R ^A02 is an alkyl group which may have a substituent, at least one of R ^A01 is an alkyl group which may have a substituent. u is an integer of 1 to 3, and multiple R ^A01s may be the same or different, and multiple R ^A01s may form a ring together with D by bonding.)

D in formula (Aii) is an element of Group 15 to Group 17 of the Periodic Table of Elements (IUPAC notation) with an atomic valence of u. In addition, D is the same as ^Ra2 in the aforementioned formula (ai). D forms an onium ion by bonding with an organic group R ^A01 and a benzyl group which may be substituted by R ^A02 . Preferred elements of Group 15 to Group 17 of the Periodic Table of Elements (IUPAC notation) are S (sulfur), N (nitrogen), I (iodine), and P (phosphorus). The corresponding onium ions are cobalt ions, ammonium ions, iodine ions, and phosphonium ions, which are stable and easy to use, and therefore preferred. From the viewpoint of excellent cationic polymerization performance or crosslinking reaction performance, cobalt ions and iodine ions are more preferred, and cobalt ions are even more preferred.

In formula (Aii), ^RA01 represents an organic group bonded to D. When ^RA01 exists in plural, the plural ^RA01 may be the same or different. The organic group is preferably a group containing carbon atoms, more preferably a group consisting of 1 or more carbon atoms and 1 or more atoms selected from the group consisting of H, O, S, Se, N, B, P, Si, and halogen atoms. The number of carbon atoms in the group containing carbon atoms is not particularly limited, but is preferably 1 or more and 50 or less, more preferably 1 or more and 20 or less. Examples of ^RA01 include aromatic alkyl groups having 6 or more and 14 or less carbon atoms, alkyl groups having 1 or more and 18 or less carbon atoms, alkenyl groups having 2 or more and 18 or less carbon atoms, and alkynyl groups having 2 or more and 18 or less carbon atoms. As the aromatic hydrocarbon group, alkyl group, alkenyl group, and alkynyl group for R ^A01 , the same groups as those mentioned above for R ^a1 in formula (ai) can be listed. When R ^A01 is an aromatic hydrocarbon group, it may have a substituent, and the substituent may include a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an optionally substituted silyl group, an optionally substituted amine group, and a halogen atom. In formula (Aii), when ^RA01 exists in plural numbers, the plural ^RA01s may form a ring together with D. The ring system formed by the plurality of ^RA01 and D may contain one or more bonds selected from the group consisting of -O-, -S-, -SO-, -SO ₂ -, -NH-, -CO-, -COO-, and -CONH- in its structure. In the formula (Aii), specific examples of the alkyl group of ^RA02 include a linear alkyl group having 1 to 18 carbon atoms, such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl; a branched alkyl group having 3 to 18 carbon atoms, such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, and isooctadecyl; and a cycloalkyl group having 3 to 18 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and 4-decylcyclohexyl. In the formula (Aii), when ^RA02 is an alkyl group which may have a substituent, at least one of ^RA01 is an alkyl group which may have a substituent. In the formula (Aii), specific examples of the aralkyl group of ^RA02 include lower alkyl groups substituted with an aryl group having 6 to 10 carbon atoms, such as benzyl, 1-naphthylmethyl, and 2-naphthylmethyl. In the formula (Aii), specific examples of the aralkyl group having a substituent of ^RA02 include lower alkyl groups substituted with an aryl group having 6 to 10 carbon atoms, such as 2-methylbenzyl. In the formula (Aii), ^RA02 is preferably an aralkyl group which may have a substituent, and more preferably a cationic moiety represented by the following formula (Aiii).

(In formula (Aiii), R ^A01 is a monovalent organic group, D is an element with an atomic valence of u in Groups 15 to 17 of the Periodic Table of the Elements of IUPAC notation, R ^A03 is a monovalent organic group, u is an integer of 1 to 3, and v is an integer of 0 to 5.)

In formula (Aiii), the monovalent organic group of ^RA03 is preferably a group containing carbon atoms, more preferably a group consisting of 1 or more carbon atoms and 1 or more atoms selected from the group consisting of H, O, S, Se, N, B, P, Si, and halogen atoms. The number of carbon atoms in the group containing carbon atoms is not particularly limited, but is preferably 1 or more and 50 or less, and more preferably 1 or more and 20 or less. The monovalent organic group of ^RA03 is particularly preferably an alkyl group. As the alkyl group of ^RA03 , the same groups as those listed for ^RA02 in formula (Aii) can be listed. v is preferably 0 or 1. As described with respect to formula (Aii), D is sulfur, and the cation represented by formula (Aiii) is preferably a galvanic ion. In other words, D is sulfur, and u is preferably 2. Specific examples of the cation part represented by formula (Aii) or formula (Aiii) are listed below. In the following specific examples, D' is a S atom or a Se atom, preferably a S atom.

The content of the cationic curing agent (A) in the curable composition is preferably from 0.01 to 5 parts by mass, more preferably from 0.05 to 3 parts by mass, and particularly preferably from 0.1 to 2 parts by mass, based on 100 parts by mass of the cationic curing compound (B), from the viewpoint of the balance between curability and physical properties of the cured product.

Furthermore, the cationic hardener (A) may contain a cationic hardener other than the photoacid generator (A1) and the thermal acid generator (A2) within the range not hindering the purpose of the present invention. The total ratio of the mass of the photoacid generator (A1) and the mass of the thermal acid generator (A2) relative to the mass of the cationic hardener (A) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass.

Furthermore, from the viewpoint of more easily suppressing the coloring of the cured product during curing, the ratio of the mass of the photoacid generator (A1) to the total mass of the photoacid generator (A1) and the mass of the thermal acid generator (A2) is preferably 50 mass% or less, more preferably 30 mass% or less. The lower limit is not particularly limited, but from the viewpoint of chemical resistance or step margin, it is preferably 10 mass% or more, more preferably 15 mass% or more, and even more preferably 20 mass% or more.

<Cationic curing compound (B)> The cationic curing compound (B) may be any of various compounds known in the art. The cationic curing compound (B) is cured by the cationic curing agent (A) (B) to form a cured product with good solvent resistance, and coloring of the cured product can be suppressed.

An example of a preferred cationic curable compound is a compound represented by the following formula (b1). (In formula (b1), ^W1 and ^W2 are each independently a group represented by the following formula (b2): In formula (b2), ring Z represents an aromatic hydrocarbon ring, ^XB represents a single bond or a group represented by -S-, ^RB1 represents a single bond, an alkylene group having 1 to 4 carbon atoms, or an alkoxyene group having 1 to 4 carbon atoms. When ^RB1 is an alkoxyene group, the oxygen atom in the alkoxyene group is bonded to ring Z, and ^RB2 represents a monovalent alkyl group, a hydroxyl group, a group represented by -OR ^4a , a group represented by -SR ^4b , an acyl group, an alkoxycarbonyl group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, an amino group, a carbamoyl group, a group represented by -NHR ^4c , a group represented by -N(R ^4d ) ₂ , a sulfonic acid group, or a monovalent alkyl group, a group represented by -OR ^4a , a group represented by -SR ^4b , an acyl group, an alkoxycarbonyl group, -NHR wherein at least a part of the hydrogen atoms bonded to the carbon atoms contained in the group represented by ^-OR4a , ^-SR4b, an acyl group, an alkoxycarbonyl group, ^a halogen atom, a nitro group, a cyano group, an alkyl group, a _carboxyl group, an amino group, an aminoformyl group, a group represented by -NHR4c, -N( ^{R4d )} ₂ , a methanesulfonyloxy group, or a sulfonic acid group is substituted, ^R4a to ^R4d independently represent a monovalent hydrocarbon group, m represents an integer greater than 0, ^R3 is a hydrogen atom, a vinyl group, a thioethane- ² -ylmethyl group, or a glycidyl group, neither ^W1 nor ^W2 has a hydrogen atom as ^R3 , and Ring ^Y1 and Ring Y2 are ² represents the same or different aromatic hydrocarbon rings, R is a single bond, a methyl group which may have a substituent, an ethyl group which may have a substituent and may contain a heteroatom between two carbon atoms, a group represented by -O-, a group represented by -NH-, or a group represented by -S-, R ^3a and R ^3b independently represent a cyano group, a halogen atom, or a monovalent hydrocarbon group, and n1 and n2 independently represent an integer greater than or equal to 0 and less than or equal to 4.)

In the above formula (b2), examples of ring Z include benzene ring, condensed polycyclic aromatic hydrocarbon rings [e.g., condensed bicyclic hydrocarbon rings (e.g., C _8-20 condensed bicyclic hydrocarbon rings such as naphthyl ring, preferably C _10-16 condensed bicyclic hydrocarbon rings), condensed tricyclic aromatic hydrocarbon rings (e.g., anthracene ring, phenanthrene ring, etc.), and condensed 2 to 4-ring aromatic hydrocarbon rings], etc. Ring Z is preferably a benzene ring or a naphthyl ring, and more preferably a naphthyl ring. In formula (b1), ^W1 and ^W2 are each independently a group represented by the following formula (b2), and thus ^W1 and ^W2 each contain a ring Z. The ring Z contained in ^W1 and the ring Z contained in ^W2 may be the same or different, for example, one of the rings may be a benzene ring and the other may be a naphthyl ring, and it is particularly preferred that either of the rings is a naphthyl ring.

Furthermore, the substitution position of the ring Z bonded to the carbon atom to which both ^W1 and ^W2 are directly bonded via ^XB is not particularly limited. For example, when the ring Z is a naphthyl ring, the group corresponding to the ring Z bonded to the carbon atom may be 1-naphthyl, 2-naphthyl, etc.

In the above formula (b2), X and ^B independently represent a single bond or a group represented by -S-, and are typically a single bond.

In the above formula (b2), R ^B1 may be, for example, a single bond; an alkylene group having 1 to 4 carbon atoms such as a methylene group, an ethylene group, a propylene group (-CH ₂ CH ₂ CH ₂ -), a propylene group (-CH ₂ CH(CH ₃ )-), a butane-1,2-diyl group, etc.; an alkoxyene group having 1 to 4 carbon atoms such as a methoxyene group, an ethoxyene group, a propoxyene group (-CH ₂ CH(CH ₃ )-O-), preferably a single bond; a C _2-4 alkylene group (particularly a C _2-3 alkylene group such as an ethylene group and a propylene group); and a C _2-4 alkoxyene group (particularly a C _2-3 alkylene group such as an ethoxyene group and a propoxyene group), more preferably a single bond. When R ^B1 is an alkoxyene group, the oxygen atom in the alkoxyene group is bonded to ring Z. In formula (b1), ^W1 and ^W2 are each independently a group represented by formula (b2), and therefore ^W1 and ^W2 each include a divalent group ^RB1 . ^RB1 contained in ^W1 and ^RB1 contained in ^W2 may be the same or different.

In the above formula (b2), R ^B2 includes, for example, a monovalent hydrocarbon group such as an alkyl group (for example, a C _1-12 alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, etc., preferably a C _1-8 alkyl group, more preferably a C _1-6 alkyl group, etc.), a cycloalkyl group (a C _5-10 cycloalkyl group such as cyclohexyl, preferably a C _5-8 cycloalkyl group, more preferably a C _5-6 cycloalkyl group, etc.), an aryl group (for example, a C _6-14 aryl group such as phenyl, tolyl, xylyl, naphthyl, etc., preferably a C _6-10 aryl group, more preferably a C _6-8 aryl group, etc.), an aralkyl group (a C _6-10 aryl-C _1-4 alkyl group such as benzyl, phenethyl, etc.); a hydroxyl group; an alkoxy group (a C 5-10 cycloalkyl group such as methoxy, ethoxy, propoxy, butoxy, etc.); [0047] The present invention further comprises a group represented by -OR 4a such as a C _1-12 alkoxy group, preferably a C _1-8 alkoxy group, more preferably a C _1-6 alkoxy group, etc.), a cycloalkyloxy group (a C _5-10 cycloalkyloxy group such as cyclohexyloxy group, etc.), an aryloxy group ( ^{a C 6-10 aryloxy group such as phenoxy group, an aralkyloxy group (for example, a C 6-10 aryl-C 1-4 alkoxy group such as benzyloxy group), etc. [wherein R 4a} _{represents a monovalent} ^alkyl group (the monovalent alkyl group exemplified above, etc.)]; an alkylthio group (a C _1-12 alkylthio group such as methylthio, ethylthio, propylthio, butylthio, preferably a C _1-8 alkylthio group, more preferably a C _1-6 alkylthio group, etc.), a cycloalkylthio group (a C _5-10 cycloalkylthio group such as cyclohexylthio group, etc.), an arylthio group (a C 6-10 [ ₀₀₆₁ ] The present invention also includes a group represented by -SR ^4b such as a C _{6-10 arylthio group), an aralkylthio group (for example, a C 6-10} aryl-C _1-4 alkylthio group such as a benzylthio group) [wherein R ^4b represents a monovalent alkyl group (the monovalent alkyl group exemplified above, etc.)]; an acyl group (a C _1-6 acyl group such as an acetyl group, etc.); an alkoxycarbonyl group (a C _1-4 alkoxy-carbonyl group such as a methoxycarbonyl group, etc.); a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.); a nitro group; a cyano group; a hydroxyl group; a carboxyl group; an amino group; a carbamoyl group; an alkylamino group (a C _1-12 alkylamino group such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, etc., preferably a C _1-8 alkylamino group, more preferably a C [wherein R _{4c represents a monovalent alkyl group (the monovalent alkyl groups exemplified above)]; a dialkylamino group (di(C 1-12 alkyl} )amino group such as dimethylamino, diethylamino, ^{dipropylamino} , dibutylamino, preferably di(C _1-8 alkyl)amino group, more preferably ^di (C _1-6 alkyl)amino group, etc.); a dicycloalkylamino group (di(C _1-8 alkyl) _amino group such as dicyclohexylamino group, etc.); a dicyclohexylamino group (di(C _1-10 alkyl)amino group such as dicyclohexylamino group, etc.); a dicycloalkylamino group (di(C _1-10 alkyl)amino group such as dicyclohexylamino group, etc.); a group represented by _{-N(R 4d} ) 2 such as a di(C _6-10 aryl)amino group (such as a diphenylamino group), a diaralkylamino group (such as a di(C _6-10 aryl- ^C _1-4 alkyl)amino group) [wherein R ^4d independently represents a monovalent alkyl group (such as the monovalent alkyl group exemplified above) _] ; a (meth)acryloyloxy group; a sulfonic acid group; at least a part of the hydrogen atoms bonded to the carbon atoms contained in the above-mentioned monovalent alkyl group, the group represented by -OR ^4a , the group represented by -SR ^4b , the acyl group, the alkoxycarbonyl group, the group represented by -NHR ^4c , or the group represented by -N(R ^4d ) ₂ is substituted by the above-mentioned monovalent alkyl group, the hydroxyl group, the group represented by -OR ^4a , the group represented by -SR ^A group represented by -NHR ^4c , a group represented by -N(R ^4d ) ₂ , a (meth)acryloyloxy group, a methanesulfonyloxy group, or a group substituted by a sulfonic acid group [for example, an alkoxyaryl group (for example, a C _1-4 alkoxy C _6-10 aryl group such as methoxyphenyl), an alkoxycarbonylaryl group (for example, a C _1-4 alkoxy-carbonyl C _6-10 aryl group such as methoxycarbonylphenyl and ethoxycarbonylphenyl, etc.)] and the like.

Among them, ^RB2 can be typically a monovalent hydrocarbon group, a group represented by ^-OR4a , a group represented by ^-SR4b , an acyl group, an alkoxycarbonyl group, a halogen atom, a nitro group, a cyano group, a group represented by ^-NHR4c , a group represented by -N( ^R4d ) ₂ , or the like.

Preferred R ^B2 includes monovalent alkyl groups [e.g., alkyl (e.g., C _1-6 alkyl), cycloalkyl (e.g., C _5-8 cycloalkyl), aryl (e.g., C _6-10 aryl), aralkyl (e.g., C _6-8 aryl-C _1-2 alkyl)], alkoxy (C _1-4 alkoxy), etc. In particular, R ^2a and R ^2b are preferably monovalent alkyl groups (especially alkyl) such as alkyl [C _1-4 alkyl (especially methyl)], aryl [e.g., C _6-10 aryl (especially phenyl)], etc.

When m is an integer greater than or equal to 2, the RB2 in the plurality of R ^B2 may be the same or different from each other. Also, the ^RB2 in ^W1 and the ^RB2 in ^W2 may be the same or different.

In the above formula (b2), the number m of ^RB2 can be selected according to the type of ring Z, for example, from 0 to 4, preferably from 0 to 3, and more preferably from 0 to 2. In addition, m in ^W1 and m in ^W2 may be the same or different.

In the above formula (a3), ^R3 is a hydrogen atom, a vinyl group, a thiirane-2-ylmethyl group, or a glycidyl group. In addition, neither ^W1 nor ^W2 has a hydrogen atom as ^R3 . Vinyloxy, thiirane-2-ylmethyl group, and glycidyl group are all cationically polymerizable functional groups. Therefore, the compound represented by formula (b1) is a cationically polymerizable compound having 1 or 2 cationically polymerizable functional groups. When ^R3 contained in ^W1 and ^R3 contained in ^W2 are not hydrogen atoms, they may be the same or different. ^R3 contained in ^W1 and R3 contained in ^W2 are preferably both vinyl, thioethane-2-ylmethyl, or glycidyl, and more preferably both are the same group selected from the group consisting of vinyl, thioethane-2-ylmethyl, and glycidyl. ^{R3 is} preferably vinyl or glycidyl because the compound represented by formula (b1) can be easily synthesized or obtained.

In the above formula (b1), examples of ring ^Y1 and ring ^Y2 include benzene ring, condensed polycyclic aromatic hydrocarbon ring [e.g., condensed bicyclic hydrocarbon ring (e.g., _C8-20 condensed bicyclic hydrocarbon ring such as naphthyl ring, preferably _C10-16 condensed bicyclic hydrocarbon ring), condensed tricyclic aromatic hydrocarbon ring (e.g., anthracene ring, phenanthrene ring, etc.), etc. condensed bicyclic to tetracyclic aromatic hydrocarbon ring], etc. Ring ^Y1 and ring ^Y2 are preferably benzene ring or naphthyl ring, more preferably benzene ring. In addition, ring Y ¹ and ring Y ² may be the same or different. For example, one of the rings may be a benzene ring and the other may be a naphthyl ring.

In the above formula (b1), R represents a single bond, a methyl group which may have a substituent, an ethyl group which may have a substituent and 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. Here, as the substituent, for example, a cyano group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a monovalent alkyl group [for example, an alkyl group (methyl, ethyl, propyl, isopropyl, butyl, t-butyl, etc. C _1-6 alkyl), an aryl group (phenyl, etc. C _6-10 aryl)], etc., and as the heteroatom, for example, an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, etc., etc., can be listed.

In the above formula (b1), R ^3a and R ^3b are usually non-reactive substituents, for example, cyano, halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, etc.), monovalent alkyl groups [for example, alkyl groups, aryl groups (C _6-10 aryl groups such as phenyl groups), etc.], preferably cyano or alkyl groups, particularly preferably alkyl groups. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, t-butyl and other C _1-6 alkyl groups (for example, C _1-4 alkyl groups, especially methyl groups), etc. When n1 is an integer greater than 2, R ^3a may be different from or the same to each other. When n2 is an integer greater than 2, R ^3b may be different from or the same to each other. In addition, R ^3a and R ^3b may be the same or different. The bonding positions (substitution positions) of R ^3a and R ^3b of ring Y ¹ and ring Y ² are not particularly limited. Preferred substitution numbers n1 and n2 are 0 or 1, particularly 0. n1 and n2 may be the same or different from each other.

The compound represented by the above formula (b1) has excellent optical and thermal properties and has a cationic polymerizable functional group, so it has high reactivity. In particular, when ring ^Y1 and ring ^Y2 are benzene rings and R is a single bond, the compound represented by the above formula (b1) has a fluorene skeleton and has more excellent optical and thermal properties. In addition, the compound represented by the above formula (b1) provides a hardened material with high hardness and is preferably used as a base component in a composition.

Among the compounds represented by the above formula (b1), particularly preferred specific examples include fluorene compounds containing an epoxide group 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 formulae.

Among the compounds represented by the formula (b1) described above, the following compounds are particularly preferred.

Preferred examples of cationically polymerizable compounds other than the compound represented by formula (b1) include vinyl ether compounds containing vinyloxy groups, epoxy compounds containing epoxy groups, and cyclosulfide compounds containing cyclosulfide groups. The vinyl ether compounds, epoxy compounds, and cyclosulfide compounds are described below.

(Vinyl ether compound) The vinyl ether compound used as the cationic curable compound (B) other than the compound represented by formula (b1) is not particularly limited as long as it is a compound having a vinyloxy group and being cationically polymerizable. The vinyl ether compound used in combination with the compound represented by formula (b1) may contain an aromatic group or may contain an aromatic group. From the viewpoint of good heat decomposition resistance of the cured product, the vinyl ether compound used in combination with the compound represented by formula (b1) is preferably a compound having a vinyloxy group bonded to an aromatic group.

Preferred specific examples of the vinyl ether compound that can be used together with the compound represented by formula (b1) include vinylphenyl ether, 4-vinyloxytoluene, 3-vinyloxytoluene, 2-vinyloxytoluene, 1-vinyloxy-4-chlorobenzene, 1-vinyloxy-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-vinyloxytetrahydronaphthalene, and Aromatic monovinyl ether compounds such as 5-vinyloxytetrahydronaphthalene; 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 Aromatic divinyl ether compounds such as ethyleneoxynaphthalene, 2,7-dievinyloxynaphthalene, 1,2-dievinyloxyfluorene, 3,4-dievinyloxyfluorene, 2,7-dievinyloxyfluorene, 4,4'-dievinyloxybiphenyl, 3,3'-dievinyloxybiphenyl, 2,2'-dievinyloxybiphenyl, 3,4'-dievinyloxybiphenyl, 2,3'-dievinyloxybiphenyl, 2,4'-dievinyloxybiphenyl, and bisphenol A divinyl ether. These vinyl ether compounds may be used in combination of two or more.

(Epoxy compounds) Examples of epoxy compounds of the cationic curable compound (B) other than the compound represented by formula (b1) 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; phenol novolac type epoxy resins, brominated phenol novolac type epoxy resins, o-cresol novolac epoxy resins, bisphenol A novolac type epoxy resins, and Novolac epoxy resins such as bisphenol AD novolac epoxy resins; epoxides of dicyclopentadiene phenol resins and other epoxides; aromatic epoxy resins such as epoxides of naphthyl phenol resins; glycidyl ester-type epoxy resins such as dimer acid glycidyl ester and triglycidyl ester; glycidyls such as tetraglycidylaminodiphenylmethane, triglycidyl-p-aminophenol, tetraglycidyl-m-xylenediamine, and tetraglycidylbisaminomethylcyclohexane amine type epoxy resin; heterocyclic epoxy resin such as triglycidyl isocyanurate; phloroglucinol triglycidyl ether, trihydroxybiphenyl triglycidyl ether, trihydroxyphenylmethane triglycidyl ether, glycerol triglycidyl ether, 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-(2,3-epoxypropoxy)phenyl]ethyl]phenyl]propane, and 1,3-bis[4-[1-[4-(2,3-epoxypropoxy) trifunctional epoxy resins such as [1-[4-[1-[4-(2,3-epoxypropoxy)phenyl]-1-methylethyl]phenyl]ethyl]phenoxy]-2-propanol; tetrafunctional epoxy resins such as tetrahydroxyphenylethane tetraglycidyl ether, tetraglycidyl benzophenone, bisresorcinol tetraglycidyl ether, and tetraglycidyl propoxybiphenyl; 1,2-epoxy-4-(2-epoxyethyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol. 2,2-Bis(hydroxymethyl)-1-butanol-1,2-epoxy-4-(2-epoxyethyl)cyclohexane adduct is commercially available as EHPE-3150 (manufactured by DAICEL Corporation).

Furthermore, oligomer or polymer type multifunctional epoxy compounds can also be used as the cationic curable compound (B). Typical examples include phenol novolac type epoxy compounds, brominated phenol novolac type epoxy compounds, o-cresol 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, epoxides of dicyclopentadiene type phenol resins, epoxides of naphthol type phenol resins, etc.

Other examples of suitable epoxy compounds include polyfunctional alicyclic epoxy compounds having an alicyclic epoxy group. When the cationic curable compound (B) contains an alicyclic epoxy compound, a cured product having excellent transparency can be easily formed using the curable composition.

Specific examples of the alicyclic epoxy compounds include 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-m-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, trimethylcaprolactone-modified 3,4-epoxycyclohexylmethyl- 3',4'-Epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone-modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, methylenebis(3,4-epoxycyclohexane), ethylene glycol bis(3,4-epoxycyclohexylmethyl)ether, ethylenebis(3,4-epoxycyclohexanecarboxylate), epoxycyclohexahydrophthalate dioctyl, epoxycyclohexahydrophthalate di-2-ethylhexyl, an epoxy resin having a triethylene oxide decenyl group, or a compound represented by the following formula (b01-1) to (b01-5).

Specific examples of these alicyclic epoxy compounds provide a hardened material with high hardness, and preferably are alicyclic epoxy compounds represented by the following formulas (b01-1) to (b01-5).

(In formula (b01-1), ^Z01 represents a single bond or a linking group (a divalent group having one or more atoms). ^Rb01 to ^Rb018 are each independently a group selected from the group consisting of a hydrogen atom, a halogen atom, and an organic group.)

Examples of the linking group Z ⁰¹ include a divalent hydrocarbon group, -O-, -O-CO-, -S-, -SO-, -SO ₂ -, -CBr ₂ -, -C(CBr ₃ ) ₂ -, -C(CF ₃ ) ₂ -, and a divalent group selected from the group consisting of -R ^b019 -O-CO-, and a group having plural bonds thereof.

Examples of the divalent alkyl group of the linking group ^Z01 include linear or branched alkylene groups having 1 to 18 carbon atoms and divalent alicyclic alkyl groups. Examples of the linear or branched alkylene groups having 1 to 18 carbon atoms include methylene groups, methylmethylene groups, dimethylmethylene groups, dimethylene groups, and propylene groups. Examples of the divalent alicyclic alkyl groups include cycloalkylene groups (including cycloalkylene groups) such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylene.

R ^b019 is an alkylene group having 1 to 8 carbon atoms, preferably a methylene group or an ethylene group.

(In formula (b01-2), R ^b01 to R ^b018 are groups selected from the group consisting of hydrogen atoms, halogen atoms, and organic groups. R ^b02 and R ^b010 may bond to each other. R ^b013 and R ^b016 may bond to each other to form a ring. m ^b1 is 0 or 1.)

The alicyclic epoxy compound represented by the above formula (b01-2) is preferably a compound represented by the following formula (b01-2-1), which is equivalent to the compound in which m ^b1 in the above formula (b01-2) is 0. (In formula (b01-2-1), R ^b01 to R ^b012 are groups selected from the group consisting of hydrogen atoms, halogen atoms, and organic groups. R ^b02 and R ^b010 may bond to each other to form a ring.)

(In formula (b01-3), R ^b01 to R ^b010 are groups selected from the group consisting of hydrogen atoms, halogen atoms, and organic groups. R ^b02 and R ^b08 may be bonded to each other.)

(In formula (b01-4), R ^b01 to R ^b012 are groups selected from the group consisting of hydrogen atoms, halogen atoms, and organic groups. R ^b02 and R ^b010 may be bonded to each other.)

(In formula (b01-5), R ^b01 to R ^b012 are groups selected from the group consisting of hydrogen atoms, halogen atoms, and organic groups.)

In formula (b01-1) to (b01-5), when R ^b01 to R ^b018 are organic groups, the organic groups are not particularly limited within the scope not hindering the purpose of the present invention, and may be alkyl groups, groups composed of carbon atoms and halogen atoms, or groups containing carbon atoms and hydrogen atoms together with impurity atoms such as halogen atoms, oxygen atoms, sulfur atoms, nitrogen atoms, and silicon atoms. Examples of halogen atoms include chlorine atoms, bromine atoms, iodine atoms, and fluorine atoms.

As the organic group, preferably, a alkyl group, a group consisting of carbon atoms, hydrogen atoms, and oxygen atoms, a halogenated alkyl group, a group consisting of carbon atoms, oxygen atoms, and halogen atoms, and a group consisting of carbon atoms, hydrogen atoms, oxygen atoms, and halogen atoms are preferred. When the organic group is a alkyl group, the alkyl group may be an aromatic alkyl group, an aliphatic alkyl 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.

Specific examples of the alkyl 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-eicosyl; vinyl, 1-propenyl, 2-n-propenyl, 1-butylene, 2-propenyl, 2-butylene, 2-propenyl, 2-pentylene ... chain alkenyl such as alkenyl (allyl), 1-n-butenyl, 2-n-butenyl, and 3-n-butenyl; cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl; aryl such as phenyl, o-tolyl, m-tolyl, p-tolyl, α-naphthyl, β-naphthyl, biphenyl-4-yl, biphenyl-3-yl, biphenyl-2-yl, anthracenyl, and phenanthryl; aralkyl such as benzyl, phenethyl, α-naphthylmethyl, β-naphthylmethyl, α-naphthylethyl, and β-naphthylethyl.

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

Specific examples of the group composed of carbon atoms, hydrogen atoms, and oxygen atoms include hydroxy chain alkyl groups such as hydroxymethyl, 2-hydroxyethyl, 3-hydroxy-n-propyl, and 4-hydroxy-n-butyl; halogenated cycloalkyl groups such as 2-hydroxycyclohexyl, 3-hydroxycyclohexyl, and 4-hydroxycyclohexyl; 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2,3-dihydroxyphenyl, 2,4-dihydroxyphenyl, 2,5-dihydroxyphenyl, 2 , 6-dihydroxyphenyl, 3,4-dihydroxyphenyl, and 3,5-dihydroxyphenyl; hydroxyaralkyl such as 2-hydroxyphenylmethyl, 3-hydroxyphenylmethyl, and 4-hydroxyphenylmethyl; methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, 2-ethylhexyloxy, n- chain alkoxy groups such as nonyloxy, n-decyloxy, n-undecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, n-nonadecyloxy, and n-icosyloxy; chain alkenyloxy groups such as vinyloxy, 1-propenyloxy, 2-n-propenyloxy (allyloxy), 1-n-butenyloxy, 2-n-butenyloxy, and 3-n-butenyloxy; aryloxy groups such as phenoxy, o-tolyloxy, m-tolyloxy, p-tolyloxy, α-naphthyloxy, β-naphthyloxy, biphenyl-4-yloxy (yloxy), biphenyl-3-yloxy, biphenyl-2-yloxy, anthracenyloxy, and phenanthrenyloxy; aralkyloxy groups such as benzyloxy, phenethyloxy, α-naphthylmethoxy, β-naphthylmethoxy, α-naphthylethoxy, and β-naphthylethoxy; methoxy alkyloxy, methoxymethoxy, ethoxymethoxy, n-propoxymethoxy, 2-methoxyethyl, 2-ethoxyethyl, 2-n-propoxyethyl, 3-methoxy-n-propyl, 3-ethoxy-n-propyl, 3-n-propoxy-n-propyl, 4-methoxy-n-butyl, 4-ethoxy-n-butyl, and 4-n-propoxy-n-butyl; alkoxyalkyl such as ... alkoxyalkoxy such as 2-methoxyphenyl, 3-methoxyphenyl and 4-methoxyphenyl; 2-methoxyphenoxy, 3-methoxyphenoxy, 3-methoxyphenoxy, 3-methoxyphenoxy, 4-methoxyphenoxy, 4-ethoxyphenoxy, 4-n-propoxyphenoxy, 4-n-propoxyphenoxy, 4-n-propoxyphenoxy, 4-n-propoxyphenoxy, 4-n-propoxyphenoxy, 4-n-butoxy, 4-methoxyphenoxy-n-butoxy, 4-n-propoxyphenoxy-n-butoxy, 4-methoxyphenoxy-n-butoxy, 4-methoxyphenoxy-n-butoxy, 4-n-propoxy-n-butoxy, 4-methoxyphen ... 4-Methoxyphenoxy and other alkoxyaryloxy groups; aliphatic acyl groups such as formyl, acetyl, propionyl, butyryl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; aromatic acyl groups such as benzyl, α-naphthoyl, and β-naphthoyl; methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, n-butoxycarbonyl, n-pentyloxycarbonyl, n-hexylcarbonyl, n-heptyloxycarbonyl, n- Chain alkoxycarbonyl groups such as octyloxycarbonyl, n-nonyloxycarbonyl and n-decyloxycarbonyl; aryloxycarbonyl groups such as phenoxycarbonyl, α-naphthyloxycarbonyl and β-naphthyloxycarbonyl; aliphatic acyloxy groups such as formyloxy, acetyloxy, propionyloxy, butyryloxy, pentanoyloxy, hexanoyloxy, heptanoyloxy, octanoyloxy, nonanoyloxy and decanoyloxy; aromatic acyloxy groups such as benzyloxy, α-naphthyloxy and β-naphthyloxy.

It is preferred that R ^b01 to R ^b018 are each independently 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, so that a cured film having particularly excellent mechanical properties can be formed. It is more preferred that all of R ^b01 to R ^b018 are hydrogen atoms.

In formula (b01-2) to (b01-5), R ^b01 to R ^b018 are the same as R ^b01 to R ^b018 in formula (b01-1). When R ^b02 and R ^b010 in formula (b01-2) and formula (b01-4) are bonded to each other, when R ^b013 and R ^b016 in formula (b01-2) are bonded to each other, and when R ^b02 and R ^b08 in formula (b01-3) are bonded to each other, the divalent groups formed include, for example, -CH ₂ - and -C(CH ₃ ) ₂ -.

Among the alicyclic epoxy compounds represented by formula (b01-1), specific examples of preferred compounds include alicyclic epoxy compounds represented by the following formulas (b01-1a), (b01-1b), and (b01-1c), or 2,2-bis(3,4-epoxycyclohexane-1-yl)propane [=2,2-bis(3,4-epoxycyclohexyl)propane], etc.

Specific examples of preferred compounds among the alicyclic epoxy compounds represented by the formula (b01-2) include alicyclic epoxy compounds represented by the following formula (b01-2a) and the following formula (b01-2b).

Specific examples of preferred alicyclic epoxy compounds represented by formula (b01-3) include S-spiro[3-oxatricyclo[3.2.1.0 ^2,4 ]octane-6,2'-ethylene oxide] and the like.

Specific examples of preferred alicyclic epoxy compounds represented by formula (b01-4) include 4-vinylcyclohexene dioxide, dipentene dioxide, limonene dioxide, 1-methyl-4-(3-methyloxiran-2-yl)-7-oxabicyclo[4.1.0]heptane, and the like.

Specific examples of preferred alicyclic epoxy compounds represented by formula (b01-5) include 1,2,5,6-diepoxycyclooctane and the like.

In addition, a compound represented by the following formula (b1-1) can be used as the cation-curable compound (B). (In formula (b1-I), X ^b1 , X ^b2 , and X ^b3 are each independently a hydrogen atom or an organic group that may contain an epoxide group, and the total number of epoxide groups contained in X ^b1 , X ^b2 , and X ^b3 is 2 or more.)

The compound represented by the above formula (b1-I) is preferably a compound represented by the following formula (b1-II). (In formula (b1-II), ^Rb20 to ^Rb22 are linear, branched or cyclic alkylene groups, arylene groups, -O-, -C(=O)-, -NH- and combinations thereof, and may be the same or different. ^E1 to ^E3 are at least one substituent selected from the group consisting of an epoxide group, an oxobutyl group, an ethylenically unsaturated group, an alkoxysilyl group, an isocyanate group, a blocked isocyanate group, a thiol group, a carboxyl group, a hydroxyl group and a succinic anhydride group, or a hydrogen atom. However, at least two of ^E1 to ^E3 are at least one substituent selected from the group consisting of an epoxide group and an oxobutyl group.)

In formula (b1-II), the groups represented by R ^b20 and E ¹ , R ^b21 and E ² , and R ^b22 and E ³ are preferably at least two groups each represented by the following formula (b1-IIa), and more preferably at least one group each represented by the following formula (b1-IIa). The groups represented by the formula (b1-IIa) bonded to one compound are preferably the same group. (In formula (b1-IIa), L is a linear, branched or cyclic alkylene group, arylene group, -O-, -C(=O)-, -NH- or a combination thereof, and ^Cb is an epoxide group. In formula (b1-IIa), L and ^Cb are bonded to form a ring structure.)

In the formula (b1-IIa), the linear, branched or cyclic alkylene group as L is preferably an alkylene group having 1 to 10 carbon atoms, and the arylene group as L is preferably an arylene group having 5 to 10 carbon atoms. In the formula (b1-IIa), L is preferably a linear alkylene group having 1 to 3 carbon atoms, a phenylene group, -O-, -C(=O)-, -NH-, and a combination thereof, at least one of a linear alkylene group having 1 to 3 carbon atoms such as a methylene group and a phenylene group, or a combination thereof with at least one of -O-, -C(=O)-, and NH-.

In formula (b1-IIa), when L and C ^b are bonded to form a cyclic structure, for example, when a branched alkylene group and an epoxy group are bonded to form a cyclic structure (a structure of an epoxy group having an alicyclic structure), the following organic groups represented by formulas (b1-IIb) to (b1-IId) can be listed. (In formula (b1-IIb), R ^b23 is a hydrogen atom or a methyl group.)

Hereinafter, examples of the compound represented by formula (b1-II) include epoxy compounds having an ethylene oxide group or an alicyclic epoxy group, but are not limited thereto.

Furthermore, a siloxane compound having two or more glycidyl groups in the molecule (hereinafter sometimes simply referred to as a "silicone compound") can be suitably used as the cationic curable compound (B).

Siloxane compounds are compounds that have a siloxane skeleton composed of siloxane bonds (Si-O-Si) and two or more glycidyl groups in the molecule. The siloxane skeleton in the siloxane compound can be, for example, a cyclic siloxane skeleton or a cage-type or ladder-type polysilsesquioxane skeleton.

As the siloxane compound, a compound having a cyclosiloxane skeleton represented by the following formula (b1-III) (hereinafter sometimes referred to as "cyclosiloxane") is preferred.

In formula (b1-III), R ^b24 and R ^b25 represent a monovalent group or an alkyl group containing an epoxy group. However, among x1 R ^b24 and x1 R ^b25 in the compound represented by formula (b1-III), at least 2 are monovalent groups containing an epoxy group. In addition, x1 in formula (b1-III) represents an integer greater than 3. In addition, R ^b24 and R ^b25 in the compound represented by formula (b1-III) may be the same or different. In addition, a plurality of R ^b24 may be the same or different. A plurality of R ^b25 may be the same or different. As the above-mentioned alkyl group, there can be listed a linear or branched chain alkyl group having 1 to 18 carbon atoms (preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), such as methyl, ethyl, propyl, isopropyl, etc.

In formula (b1-III), x1 represents an integer greater than or equal to 3, and is preferably an integer greater than or equal to 3 and less than or equal to 6 from the viewpoint of excellent crosslinking reactivity when a cured film is formed.

The number of epoxy groups in the siloxane compound in the molecule is 2 or more, preferably 2 or more and 6 or less, and particularly preferably 2 or more and 4 or less, from the viewpoint of excellent cross-linking reactivity when forming a cured film.

The monovalent group containing the above-mentioned epoxide group is preferably an alicyclic epoxide group and a glycidyl ether group represented by ^-DB - ^ORb26 [ ^DB represents an alkylene group, and ^Rb26 represents a glycidyl group], more preferably an alicyclic epoxide group, and still more preferably an alicyclic epoxide group represented by the following formula (b1-IIIa) or the following formula (b1-IIIb). Examples of the above-mentioned ^DB (alkylene group) include linear or branched alkylene groups having 1 to 18 carbon atoms, such as methylene, methylmethylene, dimethylmethylene, dimethylene, and propylene. (In the above formula (b1-IIIa) and formula (b1-IIIb), ^D1 and ^D2 each independently represent an alkylene group, and ms represents an integer of 0 or more and 2 or less.)

The curable composition may contain, as the cationic curable compound (B), in addition to the siloxane compound represented by the formula (b1-III), a compound having a siloxane skeleton such as an alicyclic epoxy group-containing cyclosiloxane, an alicyclic epoxy group-containing polysiloxane resin described in Japanese Patent Application Publication No. 2008-248169, and an organic polysilsesquioxane resin having at least two epoxy functional groups in one molecule described in Japanese Patent Application Publication No. 2008-19422.

More specifically, the siloxane compound includes cyclosiloxanes having two or more glycidyl groups in the molecule represented by the following formula. As the siloxane compound, for example, commercial 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.) can be used.

<Other ingredients> The curable composition may contain additives such as crosslinking agents (for example, including P1 or P2 described below), sensitizers, surfactants, thermal polymerization inhibitors, defoaming agents, silane coupling agents, coloring agents (pigments, dyes), inorganic fillers, organic fillers, etc., if necessary. All additives can use conventionally known additives. In addition, the curable composition is substantially composed of non-polymer components, and may contain polymers (known thermosetting resins such as epoxy resins, thermoplastic resins, alkali-soluble resins, etc.) within the scope that does not impair the effect of the present invention. The content of the polymer is relative to the total solid components of the curable composition, for example, 0 mass% or more and 5 mass% or less.

As the sensitizer, there is no particular limitation on the use of known sensitizers that have been used in combination with various cationic polymerization initiators. Specific examples of sensitizers include anthracene compounds such as anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, and 9,10-dipropoxyanthracene; pyrene; 1,2-benzanthracene; perylene; tetraphenylene; coronene; thiothione compounds such as thiothione, 2-methylthiothione, 2-ethylthiothione, 2-chlorothiothione, 2-isopropylthiothione and 2,4-diethylthiothione; phenothiazine compounds such as phenothiazine, N-methylphenothiazine, N-ethylphenothiazine and N-phenylphenothiazine; xanthenes; naphthalene compounds such as 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dihydroxynaphthalene and 4-methoxy-1-naphthol; dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy -2-methyl-1-phenylpropane-1-one, 4'-isopropyl-2-hydroxy-2-methylpropiophenone, and 4-benzoyl-4'-methyldiphenyl sulfide; carbazole compounds such as N-phenylcarbazole, N-ethylcarbazole, poly-N-vinylcarbazole, and N-glycidylcarbazole; fused dinaphthalene compounds such as 1,4-dimethoxyfused dinaphthalene and 1,4-di-α-methylbenzyloxyfused dinaphthalene; phenanthrene compounds such as 9-hydroxyphenanthrene, 9-methoxyphenanthrene, 9-hydroxy-10-methoxyphenanthrene, and 9-hydroxy-10-ethoxyphenanthrene. These sensitizers can be used in combination of two or more. The amount of the sensitizer used is not particularly limited, but is preferably 1 to 300 parts by mass, more preferably 5 to 200 parts by mass, relative to 100 parts by mass of the energy-sensitive hardener (A). By using a sensitizer within this range, the desired sensitization effect can be easily obtained.

As surfactants, anionic, cationic, and nonionic compounds can be cited, as thermal polymerization inhibitors, hydroquinone, hydroquinone monoethyl ether, etc. can be cited, and as defoamers, silicone and fluorine compounds can be cited. In addition, the curable composition may contain a polymerizable compound other than an aromatic vinyl ether compound (B) such as a vinyl ether compound or an epoxy compound that does not have a vinyloxy group on the aromatic group, within the scope that does not hinder the purpose of the present invention.

In this embodiment, from the viewpoint of increasing the refractive index of the cured product, one of the preferred aspects is that the curable composition contains a fluorene compound containing an epoxy group. Typically, a compound represented by the following formula (P1) containing 9,9-bis(glycidyloxynaphthyl)fluorene is more preferred.

(In formula (P1), ring Z ^P1 represents a condensed polycyclic aromatic hydrocarbon ring, R ^P1 and R ^P2 represent substituents, R ^P3 represents a hydrogen atom or a methyl group, k1 is an integer of 0 to 4, k2 is an integer of 0 to 0, and k3 is an integer of 1 to 1.)

In the above formula (P1), the condensed polycyclic aromatic hydrocarbon ring represented by ring Z ^P1 includes condensed bicyclic hydrocarbon rings (for example, C8-C20 condensed bicyclic hydrocarbon rings such as indene ring and naphthyl ring, preferably C10-C16 condensed bicyclic hydrocarbon rings), condensed tricyclic hydrocarbon rings (for example, anthracene ring and phenanthrene ring), and condensed bi- to tetracyclic hydrocarbon rings. Preferred condensed polycyclic aromatic hydrocarbon rings include naphthyl ring and anthracene ring, and naphthyl ring is particularly preferred. Furthermore, the two rings Z ^P1 substituted at the 9-position of fluorene may be the same or different rings, and may usually be the same ring.

The substitution position of the ring Z ^P1 substituted at the 9-position of fluorene is not particularly limited. For example, the naphthyl substituted at the 9-position of fluorene may be 1-naphthyl, 2-naphthyl, etc., and is particularly preferably 2-naphthyl.

In the above formula (P1), the substituent represented by R ^P1 includes, for example, a non-reactive substituent such as a cyano group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a alkyl group [e.g., an alkyl group, an aryl group (C6-C10 aryl group such as phenyl), etc.], and in particular, a halogen atom, a cyano group or an alkyl group (especially an alkyl group) is more common. As the alkyl group, a C1-C6 alkyl group (e.g., a C1-C4 alkyl group, especially a methyl group) such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, etc. can be listed. In addition, when k1 is a plural number (2 or more), R ^P1 may be different or the same. In addition, R ^P1 substituted on two benzene rings constituting fluorene (or a fluorene skeleton) may be the same or different. The bonding position (substitution position) of R ^P1 with respect to the benzene ring constituting fluorene is not particularly limited. Preferred k1 is 0 or 1, particularly 0. In the two benzene rings constituting fluorene, k1 may be the same or different.

R ^P2 substituted by ring Z ^P1 may be, for example, an alkyl group (e.g., a C1-C12 alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, etc., preferably a C1-C8 alkyl group, and more preferably a C1-C6 alkyl group), a cycloalkyl group (e.g., a C5-C8 cycloalkyl group such as cyclohexyl, preferably a C5-C6 cycloalkyl group), an aryl group (e.g., a C6-C14 aryl group such as phenyl, tolyl, xylyl, etc., preferably a C6-C10 aryl group), or a cycloalkyl group (e.g., a C5-C8 cycloalkyl group such as cyclohexyl, preferably a C5-C6 cycloalkyl group). -OR -SR ^P4 (wherein R ^P4 is the same as above); an alkylthio group (e.g., a C1-C8 alkylthio group such as a methylthio ^group , preferably a C1-C6 alkylthio group, etc.); an acyl group (e.g., a C1-C6 acyl group such as an acetyl ^group ); an alkoxycarbonyl group (e.g., an alkoxycarbonyl group formed by bonding a C1-C4 alkoxy group such as a methoxycarbonyl group to a carbonyl group); a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.); a hydroxyl group; a nitro group; a cyano group; a substituted amino group (e.g., a dialkylamino group such as a dimethylamino group, etc.); and the like.

Among these, R ^P2 is preferably a alkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aralkyloxy group, an acyl group, a halogen atom, a nitro group, a cyano group, a substituted amino group, etc., and particularly preferably R ^P2 is a alkyl group [e.g., an alkyl group (e.g., a C1~C6 alkyl group)], an alkoxy group (C1~C4 alkoxy group, etc.), a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), etc.

Furthermore, in the same ring Z ^P1 , when k2 is plural (2 or more), R ^P2 may be different or the same. Furthermore, in two rings Z ^P1 , R ^P2 may be the same or different. Furthermore, k2 is preferably 0 to 8, preferably 0 to 6 (for example, 1 to 5), more preferably 0 to 4, particularly 0 to 2 (for example, 0 or 1). Furthermore, in two rings Z ^P1 , k2 may be the same or different.

In the above formula (P1), ^RP3 is a hydrogen atom or a methyl group, preferably ^RP3 is a hydrogen atom.

In the above formula (P1), k3 may be 1 or more, for example, 1 or more and 4 or less, preferably 1 or more and 3 or less, further preferably 1 or 2, and particularly 1. Moreover, k3 may be the same or different in each ring Z ^P1 , and is usually the same in many cases. Moreover, the substitution position of the epoxy-containing group is not particularly limited, and the group may be substituted at an appropriate substitution position of the ring Z ^P1 . In particular, the epoxy-containing group is often substituted with at least another hydrocarbon ring different from the hydrocarbon ring bonded to the 9-position of fluorene (for example, the 5-position, 6-position of the naphthyl ring, etc.) in the condensed polycyclic hydrocarbon ring.

Specific compounds represented by the above formula (P1) include, for example, 9,9-bis(glycidyloxynaphthyl)fluorene [e.g., 9,9-bis(6-glycidyloxy-2-naphthyl)fluorene, 9,9-bis(5-glycidyloxy-1-naphthyl)fluorene, etc.], and compounds wherein k3 is 1 in the above formula (P1).

In this embodiment, from the viewpoint of increasing the refractive index of the cured product, one of the preferred aspects is that the curable composition contains a hydroxyl-containing fluorene compound. Typically, it is preferred to contain a compound represented by the following formula (P2). In formula (P2), R ^P1 , R ^P2 , Z ^P1 , k1, k2, and k3 are the same as those in formula (P1).

<Solvent (S)> For the purpose of coating or viscosity adjustment, the curable composition preferably contains a solvent (S). Typically, an organic solvent can be 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 energy-sensitive composition. When the curable composition contains a solvent (S), the solid component concentration of the curable composition is, for example, 0.1 mass % to 50 mass %, preferably 0.5 mass % to 30 mass %. By setting it within the above range, coating or handling becomes good.

Preferred 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- (Poly) alkylene glycol monoalkyl ethers such as n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, etc.; (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, propylene glycol monoethyl ether acetate, etc.; other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, tetrahydrofuran, etc.; methyl ethyl ketone, cyclopentane Ketones such as hexanone, 2-heptanone, 3-heptanone; alkyl lactates such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate; ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-acetic acid Propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl formate, isoamyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetylacetate, ethyl acetylacetate, ethyl 2-oxobutyrate and other esters; aromatic hydrocarbons such as toluene and xylene; amides such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, etc. These organic solvents may be used alone or in combination of two or more.

The curable composition may contain a high boiling point solvent within the range that does not impair the effect of the present invention. A high boiling point solvent refers to a solvent having a boiling point of 180°C or higher under atmospheric pressure.

The high boiling point solvent may be appropriately selected from hydrocarbons, alcohols, ketones, esters, ethers, chlorine-based solvents, and the like, and examples thereof include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, 1,2-diol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, 1,2-diol, 1,3-butanediol, 1,2-diol, 1,3-hexane ... Alcohol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, n-nonyl acetate, monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether , diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate Ester, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butanediol diacetate, 1,6-hexanediol diacetate, γ-butyrolactone, etc., which can be used alone or in combination. The content of the high boiling point solvent is relative to the total solvent component, for example, it can be prepared in the range of 0 mass% to 25 mass%, preferably 0 mass% to 10 mass%.

≪Method for producing a hardening composition≫ The hardening composition can be produced by uniformly mixing the above-described components at a specific ratio. If necessary, the hardening composition can be filtered using a filter having an opening of a desired size to remove insoluble foreign matter.

≪Method for forming a hardened product≫ The method for forming a hardened product is not particularly limited as long as it is a method for hardening the hardening composition described above to form a desired shape. The hardening composition includes a photoacid generator (A1) and a thermal acid generator (A2). Therefore, usually, when forming a hardened product, exposure and heating are applied to the hardening composition.

The shape of the molded body of the cured composition is not particularly limited, but a film (thin film) is preferred because it is easy to uniformly apply heat to the molded body or to uniformly irradiate the molded body with an exposure light source.

The following description uses a typical example of a method for producing a cured film using a cured product. First, a curable composition is applied to a substrate such as a glass substrate to form a coating film. As coating methods, there are methods using contact transfer coating devices such as a roll coater, a reverse roll coater, and a coating rod, or methods using non-contact coating devices such as a rotator (rotary coating device), a slit coater, and a curtain-type flat coater. The viscosity of the curable composition is adjusted to an appropriate range, and the curable composition is 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.

Next, if necessary, the volatile components of the solvent (S) and the like are removed, and the coating film is dried. The drying method is not particularly limited, and examples thereof include a method of using a vacuum drying device (VCD) to reduce pressure and dry at room temperature, and then drying on a heating plate at a temperature of 80°C to 120°C, preferably 90°C to 100°C, for a time in the range of 60 seconds to 120 seconds. After the coating film is formed in this way, the coating film is exposed and heated. Exposure is performed by irradiating active energy rays such as excimer laser light. The energy dose of the irradiation varies depending on the composition of the curable composition, and is preferably 10 mJ/cm ² to 2000 mJ/cm ² , more preferably 30 mJ/cm ² to 1500 mJ/cm ² , and even more preferably 50 mJ/cm ² to 1200 mJ/cm ^2. The temperature during heating is not particularly limited, and is preferably 120°C to 280°C, more preferably 150°C to 260°C, and particularly preferably 200°C to 250°C. The heating time is typically preferably 1 minute to 60 minutes, more preferably 10 minutes to 50 minutes, and particularly preferably 20 minutes to 40 minutes.

The aforementioned curable composition, for example, cures well under the aforementioned conditions. Specifically, in the cured product of the aforementioned curable composition, the epoxy group content measured by the following method is preferably 1.8 or less, and more preferably 0.8 or more and 1.3 or less. The smaller the epoxy group content, the better the curing proceeds. The aforementioned epoxy group content is a value obtained by dividing the area of the peak representing the epoxy group measured by the Fourier transform infrared spectrometer (FT-IR) device of the cured product by the area of the peak representing benzene measured by the same FT-IR device.

The cured product formed as described above, especially the cured film, is suitable for use in a display panel or OLED lighting for an image display device.

[Example]

The present invention is described in more detail below with reference to the following embodiments, but the scope of the present invention is not limited to these embodiments.

[Examples 1 to 6 and Comparative Examples 1 to 11] In the Examples and Comparative Examples, A1-1, A1-2, A1-3, and A1-4 were used as the photoacid generator (A1). The structures of A1-1 and A1-2 are as follows. A1-3 is a cobalt salt composed of a cationic portion composed of a triaryl cobalt cation different from the cationic portion possessed by A1-1 and A1-2 and an anionic portion composed of an anionic portion of the same type as the anionic portion possessed by A1-1 and A1-2. A1-4 is a cobalt salt composed of a cation part of the same type as the cation part possessed by A1-3 and an anion part represented by (C ₆ F ₅ ) ₄ Ga ^- . In (C ₆ F ₅ ) ₄ Ga ^- , C ₆ F ₅ is a pentafluorophenyl group. In the Examples and Comparative Examples, A2-1, A2-2, and A2-3 are used as the thermal acid generator (A2). The structures of A2-2 and A2-3 are as follows. A2-1 is a cobalt salt composed of a cation part possessed by A2-2 and A2-3 and an anion part possessed by A1-4.

In the Examples and Comparative Examples, the following compounds were used as the cation-curable compound (B).

The cationic curing agent (A) and the cationic curing compound (B) of the type and amount listed in Table 1 were uniformly dissolved in propylene glycol monomethyl ether acetate at a solid content of 20% by mass to obtain the curable composition of each example and comparative example. The obtained curable composition was used to evaluate the appearance, coloring, solvent resistance, and epoxy content of the cured product of the curable composition according to the following method. The evaluation results are listed in Table 1. However, there are some examples where coloring and epoxy content were not measured.

<Appearance of Cured Product> The curable composition of each embodiment and comparative example was coated on a glass substrate by a rotary coater, and then heated at 100°C for 120 seconds to form a coating film. The entire coating film was exposed at an exposure amount of 1000mJ/ ^cm2 . Then, the exposed coating film was heated at 230°C for 20 minutes to form a cured product (film thickness of about 1μm). The formed cured film was visually observed to confirm that it was transparent or had a yellow tint due to color banding.

<Coloring of Cured Product> For the cured film used for the appearance evaluation of the cured product, the b ^* value in the L ^* a ^* b ^* color system was measured using a "Haze Meter NDH-5000" manufactured by Nippon Denshoku Industries, Ltd.

<Solvent resistance> The cured film formed by the same method as the appearance evaluation of the cured product was immersed in acetone for 2 minutes to evaluate the resistance to acetone. When the change in film thickness before and after immersion was within 3%, it was judged as ○, and when it was more than 10%, it was judged as ×. In addition, the development of solvent resistance means that the curing of the cationic curing compound (B) is well carried out.

<Epoxy group content> The cured film formed by the same method as the appearance evaluation of the cured product was measured by a Fourier transform infrared spectrometer (FT-IR). Based on the measurement results, the value obtained by dividing the area of the peak representing epoxy groups by the area of the peak representing benzene measured by the same FT-IR device was calculated as the epoxy group content. The smaller the value of the epoxy group content, the more the curing of the cationic curing compound (B) is progressing.

According to Table 1, it is known that the curable composition of the embodiment containing: a cationic curing agent (A) containing a photoacid generator (A1) and a thermal acid generator (A2) each satisfying the above-mentioned specific requirements, and an epoxy compound as a cationic curing compound (B) provides a cured film with little coloration, transparency, and excellent solvent resistance, and is cured well by exposure and heating. In addition, according to Table 1, it is known that the curable composition of the comparative example in which at least one of the photoacid generator and the thermal acid generator does not satisfy the specific requirements, or only the photoacid generator as the cationic curing agent (A) cannot suppress coloration during curing and perform good curing.

Claims (8)

A curable composition comprises a cationic curing agent (A) and a cationic curing compound (B), wherein the cationic curing agent (A) comprises a photoacid generator (A1) and a thermal acid generator (A2), wherein the photoacid generator (A1) is an onium salt having a cationic part represented by the following formula (ai), and wherein the thermal acid generator (A2) is an onium salt having a cationic part represented by the following formula (Ai). (In formula (ai), each ^Ra1 is independently a monovalent organic group, ^Ra2 is an element of Group 15 to Group 17 of the Periodic Table of the Elements according to the IUPAC notation with an atomic valence of t, and at least one of ^Ra1 is an aromatic group which may have a substituent) (In formula (Ai), each of ^RA1 is independently 1 or more phenyl groups which may have a substituent, or a perfluoroalkyl group). The curable composition of claim 1, wherein the thermal acid generator (A2) is an onium salt having a cationic portion represented by the following formula (Aiii): (In formula (Aiii), ^RA01 is a monovalent organic group, D is an element with an atomic valence of u in Groups 15 to 17 of the periodic table of the elements according to the IUPAC notation, ^RA03 is a monovalent organic group, u is an integer from 1 to 3, and v is an integer from 0 to 5). The hardenable composition of claim 2, wherein D is sulfur and u is 2. The hardenable composition of claim 1 or 2, wherein the aforementioned ^Ra2 is sulfur and t is 2. The curable composition of claim 4, wherein the onium salt represented by the aforementioned formula (ai) has a cationic portion represented by the following formula (a1), (In formula (a1), ^R1 and ^R2 independently represent an alkyl group which may be substituted by a halogen atom or a group represented by the following formula (a2), ^R1 and ^R2 are bonded to each other and may form a ring together with the sulfur atom in the formula, ^R3 represents a group represented by the following formula (a3) or a group represented by the following formula (a4), ^A1 represents S, O, or Se, but ^R1 and ^R2 are not both alkyl groups which may be substituted by a halogen atom) (In formula (a2), ring ^Z1 represents an aromatic hydrocarbon ring, ^R4 represents an alkyl group which may be substituted with a halogen atom, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, a thienyl group, a thienylcarbonyl group, a furyl group, a furylcarbonyl group, a phenylselenyl group, a phenylselenylcarbonyl group, a heterocyclic aliphatic hydrocarbon group, an alkylsulfinyl group, an alkylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or a halogen atom, and m1 represents an integer greater than or equal to 0) (In the formula (a3), R ⁵ represents a hydroxyl group, an alkoxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxylene group, an amino group which may be substituted, a cyano group, a nitro group, or an alkylene group which may be substituted with a halogen atom, or a group represented by the following formula (a5), R ^(a6) represents a hydroxyl group, an alkoxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or an alkyl group which may be substituted with a halogen atom, or a group represented by the following formula (a6), ^A2 represents a single bond, S, O, a sulfinyl group, or a carbonyl group, and n1 represents 0 or 1) (In formula (a4), ^R7 and ^R8 independently represent a hydroxyl group, an alkoxyl group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic alkyl group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxylene group, an amino group which may be substituted, a cyano group, a nitro group, or an alkylene group which may be substituted with a halogen atom, or a group represented by the following formula (a5); ^R9 and ^R10 independently represent an alkyl group which may be substituted with a halogen atom, or a group represented by the above formula (a2); ^R9 and ^R10 may be bonded to each other to form a ring together with the sulfur atom in the formula; ^A3 represents a single bond, S, O, a sulfinyl group, or a carbonyl group; X ^- represents a monovalent anion, n2 represents 0 or 1, but ^R9 and ^R10 are not both alkyl groups which may be substituted by a halogen atom) (In formula (a5), ring ^Z2 represents an aromatic hydrocarbon ring, ^R11 represents an alkyl group which may be substituted with a halogen atom, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or a halogen atom, and m2 represents an integer greater than 0) (In formula (a6), ring Z ³ represents an aromatic hydrocarbon ring, R ¹² represents an alkyl group which may be substituted with a halogen atom, a hydroxyl group, an alkoxy group, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an arylthiocarbonyl group, an acyloxy group, an arylthio group, an alkylthio group, a thienylcarbonyl group, a furylcarbonyl group, a phenylselenylcarbonyl group, an aryl group, a heterocyclic hydrocarbon group, an aryloxy group, an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a hydroxyl (poly) alkoxyl group, an amino group which may be substituted, a cyano group, a nitro group, or a halogen atom, and m3 represents an integer greater than 0). The curable composition of claim 1 or 2, wherein the ratio of the mass of the photoacid generator (A1) to the total mass of the photoacid generator (A1) and the thermal acid generator (A2) is 50 mass % or less. A cured product of the curable composition according to any one of claims 1 to 6. A method for forming a cured product comprises exposing and heating the curable composition of any one of claims 1 to 6.