JP7126344B2 - Curable composition and optical element using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an energy ray-curable composition that forms a cured product excellent in curability, heat resistance, and heat resistance to yellowing, a cured product using the same, and an optical element using the same.

Conventionally, onium salts such as iodonium and sulfonium salts are known as cationic polymerization initiators for curing cationic polymerizable compounds such as epoxy compounds by irradiation with active energy rays such as heat, light, and electron beams (Patent Documents 1 to 10). 10).
These onium salts are also called acid generators because they generate acid by heat or irradiation with active energy rays, and are also used in resists and photosensitive materials (Patent Documents 11 to 13).

By the way, the cationic polymerization initiators (acid generators) described in these specifications contain BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , and SbF ₆ ⁻ as anions. Curing performance and cross-linking reaction performance with an acid catalyst differ depending on the type of anion, and are improved in the order of BF ₄ ⁻ <PF ₆ ⁻ <AsF ₆ ⁻ <SbF ₆ ⁻ . However, cationic polymerization initiators (acid generators) containing AsF ₆ ^{- and} SbF ₆ ^- , which have good polymerization and cross _- linking properties, have limited applications due to the toxicity of As and Sb. It is only used for limited purposes such as Therefore ^, _{PF 6} ^{-salts ,} which are inferior in polymerization and cross _- linking performance, are generally used. The amount of unreacted initiator (acid generator), the amount of solvent used as necessary to dissolve the initiator (acid generator), or the residual amount of decomposition products of the initiator Since the amount of HF is increased, the physical properties of the cured product are impaired, and the amount of HF produced as a byproduct due to the decomposition of the initiator increases, which causes problems such as susceptibility to corrosion of substrates, equipment, and the like. Therefore, there has been a strong demand for a cationic polymerization initiator that does not contain toxic metals and has a cationic polymerization initiation ability comparable to that of SbF ₆ ^-salts .

In recent years, the demand for portable electronic devices such as mobile phones and smart phones is increasing. Such electronic devices are equipped with a small and thin imaging unit, and the imaging unit is generally composed of a solid-state imaging device (such as a CCD image sensor or a CMOS image sensor) and an optical element such as a lens. ing.

Optical elements mounted in electronic devices are required to have heat resistance and heat yellowing that enable mounting by reflow soldering for the purpose of improving manufacturing efficiency. In recent years, the use of lead has been restricted due to environmental considerations, and lead-free solder has been used for soldering. Became.

As a material for optical elements such as lenses, cationic curable compositions are preferably used because they are less inhibited by oxygen than radical curable compositions and shrinkage during curing is small.

The present inventors have found a fluorinated alkyl phosphate onium salt-based acid generator as a cationic polymerization initiator (acid generator) that does not contain toxic metals and has cationic polymerization performance and cross-linking reaction performance comparable to SbF ₆ ^-salt . (Patent Document 14), but there is a problem that the transparency of the cured product using this product decreases especially after a heat resistance test, and application to members that require the above optical properties has not progressed. .

JP-A-50-151997 JP-A-50-158680 JP-A-2-178303 JP-A-2-178303 U.S. Pat. No. 4,069,054 U.S. Pat. No. 4,450,360 U.S. Pat. No. 4,576,999 U.S. Pat. No. 4,640,967 Canadian Patent No. 1274646 European Patent Publication No. 203829 JP-A-2002-193925 JP-A-2001-354669 Japanese Patent Application Laid-Open No. 2001-294570 WO2005-116038

Therefore, the object of the present invention is to provide a product that has excellent curability and is excellent in heat resistance and heat-resistant yellowing by applying light irradiation or heat treatment (that is, it maintains its shape even under high-temperature conditions such as reflow soldering). It is an object of the present invention to provide an energy ray-curable composition capable of forming a cured product that can be cured and does not easily yellow.
Another object of the present invention is to provide a cured product obtained by curing the energy ray-curable composition, which has both curability, heat resistance and heat yellowing resistance.
Another object of the present invention is to provide an optical element having the cured product as a constituent element, and an optical device having the optical element.

As a result of intensive studies by the present inventors to solve the above problems, an acid generator containing an onium gallate salt represented by the general formula (1) and an onium phosphate salt represented by the following general formula (2) The energy ray-curable composition containing a cationic polymerizable compound has excellent curability, and when subjected to light irradiation or heat treatment, exhibits excellent curability and transparency, and can be used under high-temperature conditions such as reflow soldering. It has been found that it is possible to form a cured product having properties (=heat resistance and heat yellowing) that are resistant to deformation and yellowing even under low temperatures. The present invention has been completed based on these findings.

That is, the present invention contains an onium gallate salt represented by the following general formula (1), an acid generator containing an onium phosphate salt represented by the following general formula (2), and a cationically polymerizable compound. It is an energy ray-curable composition.

[(R5) _n+1 ^- E] ⁺ [( ^R1 )( ^R2 ) ⁽ R3)( ^R4 )Ga] ^- (1)
[wherein R ¹ to R ⁴ are each independently an alkyl group having 1 to 18 carbon atoms or Ar, provided that at least one is Ar;
Ar is an aryl group having 6 to 14 carbon atoms (excluding the number of carbon atoms of the substituents below), wherein some of the hydrogen atoms in the aryl group are alkyl groups having 1 to 18 carbon atoms, and halogen atoms are substituted alkyl group having 1 to 8 carbon atoms, alkenyl group having 2 to 18 carbon atoms, alkynyl group having 2 to 18 carbon atoms, aryl group having 6 to 14 carbon atoms, nitro group, hydroxyl group, cyano group, —OR ⁶ an alkoxy group or an aryloxy group represented by R ⁷ CO—, an acyloxy group represented by R ⁸ COO—, an alkylthio or arylthio group represented by —SR ⁹ , —NR ¹⁰ R ¹¹ An amino group represented by, or may be substituted with a halogen atom,
R ⁶ to R ⁹ are alkyl groups having 1 to 8 carbon atoms or aryl groups having 6 to 14 carbon atoms;
R ¹⁰ and R ¹¹ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 14 carbon atoms;
E represents an element of group 15 to group 17 (IUPAC notation) with valence n,
n is an integer from 1 to 3,
R ⁵ is an organic group bonded to E, the number of R ⁵ is n+1, (n+1) R ⁵ may be the same or different, and two or more R ⁵ are A ring structure containing the element E directly to each other or via -O-, -S-, -SO-, _-SO2- , -NH-, -CO-, -COO-, -CONH-, an alkylene group or a phenylene group may be formed. ]

[(R5) _n+1 ^- E] ⁺ [(Rf)bPF6 _{-b ]} ^- (2)
[In the formula, Rf represents an alkyl group in which 80% or more of the hydrogen atoms are substituted with fluorine atoms. b indicates the number and is an integer of 1-5. The b Rf's may be the same or different. The definitions of R ⁵ , E, and n are the same as those of general formula (1). ]

The present invention also provides a cured product obtained by curing the energy ray-curable composition described above.

The present invention also provides an optical element containing the cured product described above as a component.

The present invention also provides an optical device comprising an optical element as described above.

Since the energy ray-curable composition of the present invention has the above structure, it is excellent in curability, and by light irradiation or heat treatment, it forms a cured product excellent in curability, transparency, heat resistance, and heat yellowing resistance. can do. Therefore, the energy ray-curable composition of the present invention can be used as optical element materials (lens or prism materials, sealing materials, optical waveguide forming materials, adhesives, optical fiber forming materials, imprint materials, alternative glass forming materials, etc.), resists , a coating agent, and the like. For example, when the energy ray-curable composition of the present invention is used as an optical element material, the resulting optical element has excellent transparency and is prevented from yellowing even when subjected to a reflow soldering process. can be maintained. Therefore, there is no need to mount the optical element in a separate process, and it is possible to collectively mount the optical element on the board by reflow soldering together with other parts, and it is possible to manufacture an optical device equipped with the optical element with excellent work efficiency. . It can also be used for in-vehicle electronic equipment that requires heat resistance.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
The energy ray-curable composition of the present invention contains compounds represented by the following general formulas (1) and (2) as acid generators.

[(R5) _n+1 ^- E] ⁺ [( ^R1 )( ^R2 ) ⁽ R3)( ^R4 )Ga] ^- (1)
[wherein R ¹ to R ⁴ are each independently an alkyl group having 1 to 18 carbon atoms or Ar, provided that at least one is Ar;
Ar is an aryl group having 6 to 14 carbon atoms (excluding the number of carbon atoms of the substituents below), wherein some of the hydrogen atoms in the aryl group are alkyl groups having 1 to 18 carbon atoms, and halogen atoms are substituted alkyl group having 1 to 8 carbon atoms, alkenyl group having 2 to 18 carbon atoms, alkynyl group having 2 to 18 carbon atoms, aryl group having 6 to 14 carbon atoms, nitro group, hydroxyl group, cyano group, —OR ⁶ an alkoxy group or an aryloxy group represented by R ⁷ CO—, an acyloxy group represented by R ⁸ COO—, an alkylthio or arylthio group represented by —SR ⁹ , —NR ¹⁰ R ¹¹ An amino group represented by, or may be substituted with a halogen atom,
R ⁶ to R ⁹ are alkyl groups having 1 to 8 carbon atoms or aryl groups having 6 to 14 carbon atoms;
R ¹⁰ and R ¹¹ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 14 carbon atoms;
E represents an element of group 15 to group 17 (IUPAC notation) with valence n,
n is an integer from 1 to 3,
R ⁵ is an organic group bonded to E, the number of R ⁵ is n+1, (n+1) R ⁵ may be the same or different, and two or more R ⁵ are A ring structure containing the element E directly to each other or via -O-, -S-, -SO-, _-SO2- , -NH-, -CO-, -COO-, -CONH-, an alkylene group or a phenylene group may be formed. ]

[(R5) _n+1 ^- E] ⁺ [(Rf)bPF6 _{-b ]} ^- (2)
[In the formula, Rf represents an alkyl group in which 80% or more of the hydrogen atoms are substituted with fluorine atoms. b indicates the number and is an integer of 1-5. The b Rf's may be the same or different. The definitions of R ⁵ , E, and n are the same as those of general formula (1). ]

In the general formula (1), the alkyl group having 1 to 18 carbon atoms in R ¹ to R ⁴ includes linear alkyl groups (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl and n-octadecyl, etc.), branched alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, 2- ethylhexyl and 1,1,3,3-tetramethylbutyl), cycloalkyl groups (such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl) and bridged cyclic alkyl groups (such as norbornyl, adamantyl and pinanyl).
From the viewpoint of catalytic activity in a cationic polymerization reaction, those substituted with a halogen atom, a nitro group, or a cyano group are preferred, and those substituted with a fluorine atom are more preferred.

In general formula (1), the aryl group having 6 to 14 carbon atoms (not including the number of carbon atoms in the substituents below) in R ¹ to R ⁴ includes a monocyclic aryl group (such as phenyl) and a condensed polycyclic Formula aryl groups (naphthyl, anthracenyl, phenanthrenyl, anthraquinolyl, fluorenyl, naphthoquinolyl, etc.) and aromatic heterocyclic hydrocarbon groups (thienyl, furanyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidyl, pyrazinyl, etc. monocyclic heterocycles; and indolyl, benzofuranyl, isobenzofuranyl, benzothienyl, isobenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenothiazinyl, phenazinyl, xanthenyl, thianthrenyl, phenoxazinyl, phenoxathiinyl, chromanyl, isochromanyl, coumarinyl , dibenzothienyl, xanthonyl, thioxanthonyl, dibenzofuranyl and other condensed polycyclic heterocycles).
As the aryl group, in addition to the above, a part of the hydrogen atoms in the aryl group is an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 8 carbon atoms substituted with a halogen atom, and 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, an alkoxy group or an aryloxy group represented by —OR ⁶ , or R ⁷ CO— It may be substituted with an acyl group, an acyloxy group represented by R ⁸ COO—, an alkylthio group or arylthio group represented by —SR ⁹ , an amino group represented by —NR ¹⁰ R ¹¹ , or a halogen atom.

In the above substituents, the alkenyl group having 2 to 18 carbon atoms includes a linear or branched alkenyl group (vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1- methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl and 2-methyl-2-propenyl, etc.), cycloalkenyl groups (2-cyclohexenyl and 3-cyclohexenyl, etc.) and Arylalkenyl groups (such as styryl and cinnamyl) are included.

In the above substituents, the alkynyl group having 2 to 18 carbon atoms includes a linear or branched alkynyl group (ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methyl- 2-propynyl, 1,1-dimethyl-2-propynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-methyl-2-butynyl, 3-methyl-1-butynyl, 1-decynyl , 2-decynyl, 8-decynyl, 1-dodecynyl, 2-dodecynyl and 10-dodecynyl, etc.) and arylalkynyl groups (phenylethynyl, etc.).

In the above substituents, the alkyl group having 1 to 8 carbon atoms substituted with a halogen atom includes linear alkyl groups (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, perfluoro-n-octyl, etc.), branched alkyl groups (hexafluoroisopropyl, hexachloroisopropyl, hexafluoroisobutyl, nonafluoro- tert-butyl, etc.), cycloalkyl groups (pentafluorocyclopropyl, nonafluorocyclobutyl, perfluorocyclopentyl and perfluorocyclohexyl, etc.) and bridged cyclic alkyl groups (perfluoroadamantyl, etc.).

Among the above substituents, an alkoxy group represented by —OR ⁶ , an acyl group represented by R ⁷ CO—, an acyloxy group represented by R ⁸ COO—, an alkylthio group represented by —SR ⁹ , and —NR ¹⁰ Examples of R ⁶ to R ¹¹ in the amino group represented by R ¹¹ include alkyl groups having 1 to 8 carbon atoms, specifically, among the above alkyl groups, alkyl groups having 1 to 8 carbon atoms. .

In the above substituents, an aryloxy group represented by —OR ⁶ , an acyl group represented by R ⁷ CO—, an acyloxy group represented by R ⁸ COO—, an arylthio group represented by —SR ⁹ , and —NR In the amino group represented by ¹⁰ R ¹¹ , R ⁶ to R ¹¹ include aryl groups having 6 to 14 carbon atoms, specifically the above aryl groups having 6 to 14 carbon atoms.

Alkoxy groups represented by —OR ⁶ include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, iso-pentoxy, neo-pentoxy and 2- and methylbutoxy.
The aryloxy group represented by —OR ⁶ includes phenoxy, naphthoxy and the like.
Acyl groups represented by R ⁷ CO— include acetyl, propanoyl, butanoyl, pivaloyl and benzoyl.
The acyloxy group represented by R ⁸ COO-- includes acetoxy, butanoyloxy and benzoyloxy.
The alkylthio group represented by ^-SR9 includes methylthio, ethylthio, butylthio, hexylthio, cyclohexylthio and the like.
The arylthio group represented by -SR ⁹ includes phenylthio, naphthylthio and the like.
The amino group represented by -NR ¹⁰ R ¹¹ includes methylamino, ethylamino, propylamino, dimethylamino, diethylamino, methylethylamino, dipropylamino, dipropylamino and piperidino.
Halogen atoms include fluorine, chlorine, bromine and iodine atoms.

Among these substituents, from the viewpoint of catalytic activity in a cationic polymerization reaction, an alkyl group having 1 to 8 carbon atoms substituted with a halogen atom, a halogen atom, a nitro group, or a cyano group is preferred, and a C 1 to 8 group substituted with a fluorine atom is preferable. and fluorine atoms are more preferred.

R ¹ , R ² , R ³ and R ⁴ in the onium gallate salt represented by the general formula (1) are preferably perfluoroalkyl groups or fluorine-substituted phenyl groups, pentafluorophenyl groups or bis A (trifluoromethyl)phenyl group is more preferred.
Particularly preferably, the gallate anion represented by [(R ¹ )(R ² )(R ³ )(R ⁴ )Ga] ^- of the onium gallate salt represented by the general formula (1) is [Ga(C ₆ F ₅ ) ₄ ] ^—or [Ga((CF ₃ ) ₂ C ₆ H ₃ ) ₄ ] ^— .

R5 in formulas (1) and ( ² ) represents an organic group bonded to E and may be the same or different. R ⁵ includes 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. 1 to 18 alkyl group, C2 to C18 alkenyl group, C2 to C18 alkynyl group, C6 to C14 aryl group, nitro group, hydroxyl group, cyano group, alkoxy represented by ^-OR6 or an aryloxy group, an acyl group represented by R ⁷ CO—, an acyloxy group represented by R ⁸ COO—, an alkylthio or arylthio group represented by —SR ⁹ , or —NR ¹⁰ R ¹¹ It may be substituted with an amino group or a halogen atom.

The aryl group having 6 to 14 carbon atoms, the alkyl group having 1 to 18 carbon atoms, the alkenyl group having 2 to 18 carbon atoms and the alkynyl group having 2 to 18 carbon atoms of the organic group are represented by R in general formula (1). ¹ to R ⁴ are the same as those described above.

and two or more R ⁵ are directly connected to each other or -O-, -S-, -SO-, _-SO2- , -NH-, -CO-, -COO-, -CONH-, an alkylene group or a phenylene group. A ring structure containing the element A may be formed through.

E in formulas (1) and (2) represents an element of group 15 to group 17 (IUPAC notation) with a valence of n, and combines with the organic group R ⁵ to form an onium ion [E ⁺ ]. Among the elements of groups 15 to 17, preferred are O (oxygen), N (nitrogen), P (phosphorus), S (sulfur) or I (iodine), and the corresponding onium ions are oxonium, ammonium, phosphonium, sulfonium and iodonium. Among them, ammonium, phosphonium, sulfonium, and iodonium are preferable because they are stable and easy to handle, and sulfonium and iodonium, which are excellent in cationic polymerization performance and cross-linking reaction performance, are more preferable.
n represents the valence of element E and is an integer of 1-3.

Specific examples of oxonium ions include oxonium such as trimethyloxonium, diethylmethyloxonium, triethyloxonium, tetramethylenemethyloxonium; - pyririnium such as di-tert-butylpyrilinium, 2,6-diphenylpyrilinium; chromenium and isochromenium such as 2,4-dimethylchromenium, 1,3-dimethylisochromenium.

Specific examples of ammonium ions include tetraalkylammonium such as tetramethylammonium, ethyltrimethylammonium, diethyldimethylammonium, triethylmethylammonium and tetraethylammonium; N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium; pyrrolidinium such as N,N-diethylpyrrolidinium; N,N'-dimethylimidazolinium, N,N'-diethylimidazolinium, N-ethyl-N'-methylimidazolinium, 1,3, imidazolinium such as 4-trimethylimidazolinium, 1,2,3,4-tetramethylimidazolinium; tetrahydropyrimidinium such as N,N'-dimethyltetrahydropyrimidinium; N,N'-dimethylmol morpholinium such as folinium; piperidinium such as N,N'-diethylpiperidinium; pyridinium such as N-methylpyridinium, N-benzylpyridinium, N-phenacylpyridinium; N,N'-dimethylimidazolium, etc. imidazolium; quinolium such as N-methylquinolium, N-benzylquinolium and N-phenacylquinolium; isoquinolium such as N-methylisoquinolium; thiazonium such as benzylbenzothiazonium and phenacylbenzothiazonium ; acridiums such as benzyl acridium and phenacyl acridium;

Specific examples of phosphonium ions 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, triphenylphenacylphosphonium, triphenylmethylphosphonium, triphenylbutylphosphonium; triethylbenzylphosphonium, tributylbenzylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetrahexylphosphonium, triethylphenacylphosphonium , tetraalkylphosphonium such as tributylphenacylphosphonium, and the like.

Specific examples of sulfonium ions include triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tris(4-methoxyphenyl)sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, tris(4 -fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-tolylthio)phenyldi-p-tolyl Sulfonium, 4-(4-methoxyphenylthio)phenylbis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(phenylthio)phenylbis(4-methoxyphenyl)sulfonium , 4-(phenylthio)phenyldi-p-tolylsulfonium, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium, [4-(2-thioxanthonylthio)phenyl]diphenylsulfonium, bis [4-(diphenylsulfonio)phenyl]sulfide, bis[4-{bis[4-(2-hydroxyethoxy)phenyl]sulfonio}phenyl]sulfide, bis{4-[bis(4-fluorophenyl)sulfonio]phenyl }sulfide, bis{4-[bis(4-methylphenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methoxyphenyl)sulfonio]phenyl}sulfide, 4-(4-benzoyl-2-chlorophenylthio ) phenylbis(4-fluorophenyl)sulfonium, 4-(4-benzoyl-2-chlorophenylthio)phenyldiphenylsulfonium, 4-(4-benzoylphenylthio)phenylbis(4-fluorophenyl)sulfonium, 4-(4 -benzoylphenylthio)phenyldiphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yldi-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9 , 10-dihydroanthracen-2-yldiphenylsulfonium, 2-[(di-p-tolyl)sulfonio]thioxanthone, 2-[(diphenyl)sulfonio]thioxanthone, 4-(9-oxo-9H-thioxanthene-2- yl)thiophenyl- 9-oxo-9H-thioxanthen-2-yl phenylsulfonium, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyldi-p-tolylsulfonium, 4-[4-(4-tert-butylbenzoyl) Phenylthio]phenyldiphenylsulfonium, 4-[4-(benzoylphenylthio)]phenyldi-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyldiphenylsulfonium, 5-(4-methoxyphenyl)thianthrenium , 5-phenylthiathrenium, 5-tolylthiathrenium, 5-(4-ethoxyphenyl)thiathrenium, 5-(2,4,6-trimethylphenyl)thiathrenium; diphenylphena; diarylsulfonium such as silsulfonium, diphenyl-4-nitrophenacylsulfonium, diphenylbenzylsulfonium, diphenylmethylsulfonium; phenylmethylbenzylsulfonium, 4-hydroxyphenylmethylbenzylsulfonium, 4-methoxyphenylmethylbenzylsulfonium, 4-acetocarbonyloxyphenyl methylbenzylsulfonium, 4-hydroxyphenyl(2-naphthylmethyl)methylsulfonium, 2-naphthylmethylbenzylsulfonium, 2-naphthylmethyl(1-ethoxycarbonyl)ethylsulfonium, phenylmethylphenacylsulfonium, 4-hydroxyphenylmethylphenacyl sulfonium, 4-methoxyphenylmethylphenacylsulfonium, 4-acetocarbonyloxyphenylmethylphenacylsulfonium, 2-naphthylmethylphenacylsulfonium, 2-naphthyloctadecylphenacylsulfonium, 9-anthracenylmethylphenacylsulfonium and other mono arylsulfonium; trialkylsulfonium such as dimethylphenacylsulfonium, phenacyltetrahydrothiophenium, dimethylbenzylsulfonium, benzyltetrahydrothiophenium, octadecylmethylphenacylsulfonium;

Specific examples of iodonium ions include diphenyliodonium, di-p-tolyliodonium, bis(4-dodecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyliodonium, bis(4- iodonium ions such as decyloxy)phenyliodonium, 4-(2-hydroxytetradecyloxy)phenylphenyliodonium, 4-isopropylphenyl(p-tolyl)iodonium and 4-isobutylphenyl(p-tolyl)iodonium.

As the anion structure of the acid generator represented by general formula (1), for example, those represented by the following chemical formulas (A-1) to (A-5) can be preferably exemplified.

In the anion represented by formula (2), Rf represents an alkyl group substituted with a fluorine atom and preferably has 1 to 4 carbon atoms. Specific examples of alkyl groups include straight chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl and octyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl and tert-butyl; Examples thereof include cycloalkyl groups such as cyclohexyl, and the ratio of hydrogen atoms in alkyl groups substituted with fluorine atoms is usually 80% or more, preferably 90% or more, and more preferably 100%. If the substitution rate of fluorine atoms is less than 80%, the polymerization and crosslinking performance of the fluorinated alkylfluorophosphate onium salt-based acid generator of the present invention are lowered.

Particularly preferred Rf is a linear or branched alkyl group having 1 to 4 carbon atoms and a fluorine atom substitution rate of 100%, and specific examples thereof include CF ₃ , CF ₃ CF ₂ and (CF ₃ ) ₂ CF. , _CF3CF2CF2 , _{CF3CF2CF2CF2 , ( CF3} ) _{2CFCF2 , CF3CF2 ( CF3} ) _{CF , ( CF3} ) _3C .

In formula (1), the number b of Rf is an integer of 1 to 5, preferably 2 to 4, and particularly preferably 2 to 3. The b Rf's may be the same or different.

Specific examples of preferred fluorinated alkylfluorophosphate anions include [(CF ₃ CF ₂ ) ₃ PF ₃ ]-, [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ]-, [((CF ₃ ) ₂ CF) ₃ PF ₃ ]-, [((CF ₃ ) ₂ CF) ₂ PF ₄ ]-, [((CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ]- and [((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ]-.

From the viewpoint of heat-resistant transparency, the content of the onium gallate salt represented by the general formula (1) contained in the energy ray-curable composition is less than the content of the onium phosphate salt represented by the general formula (2). It is preferably 0.05 times or more, more preferably 0.1 to 3 times.

¹ H-NMR, ¹³ C-NMR, ¹⁹ F-NMR and high performance liquid chromatograph (HPLC) are used as methods for analyzing the amount of impurities in the onium gallate salt defined in the present invention. The measurement conditions for ¹ H-NMR, ¹³ C-NMR and ¹⁹ F-NMR are as follows. Equipment: AL-300 (manufactured by JEOL Ltd.), solvent: dimethylsulfoxide. The HPLC measurement conditions are as follows. Equipment: model name (L-2130), manufacturer (Hitachi), column: (Ph-3) manufacturer (GL Sciences Inc), mobile phase: methanol: water: sodium perchlorate monohydrate = 600: 68: 20 : solution, detector: UV (210 nm), injection volume 10 μl, column temperature 40°C.

The onium salts (acid generators) represented by formulas (1) and (2) may be dissolved in advance in a solvent that does not inhibit the polymerization or crosslinking reaction in order to facilitate dissolution in the cationically polymerizable compound. .

Examples of solvents include carbonates such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate and diethyl carbonate; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone and 2-heptanone; ethylene glycol and ethylene glycol. Polyhydric alcohols such as monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol and monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether of dipropylene glycol monoacetate and derivatives thereof; cyclic ethers such as dioxane; ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate , methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl esters such as acetate and 3-methyl-3-methoxybutyl acetate; and aromatic hydrocarbons such as toluene and xylene.

When a solvent is used, the ratio of the solvent used is preferably 15 to 1000 parts by weight with respect to 100 parts by weight of the onium salt (acid generator) represented by the formulas (1) and (2) of the present invention. It is preferably 30 to 500 parts by weight. The solvent to be used may be used alone or in combination of two or more.

The energy ray-curable composition (hereinafter referred to as the curable composition) of the present invention comprises the acid generator and the cationic polymerizable compound.

Examples of cationic polymerizable compounds that are constituents of the curable composition include cyclic ethers (epoxides, oxetanes, etc.), ethylenically unsaturated compounds (vinyl ethers, styrene, etc.), bicycloorthoesters, spiroorthocarbonates, spiroorthoesters, and the like. {(For example, as the cationic polymerizable compound component in the active energy ray-curable composition, JP-A-11-349895, JP-A-10-212343, JP-A-2000-119306, JP-A-10-67812, JP-A-2000-186071, JP-A-08-85775, JP-A-08-134405, JP-A-2008-20838, JP-A-2008-20839, JP-A-2008-20841, JP-A-2008-26660, JP-A-2008-26644, JP-A-2007-277327, "Photopolymer Handbook" (1989, Industrial Survey Committee), Comprehensive Technology Center "UV/EB Curing Technology" (1982, Comprehensive Technology Center), Rad Tech Study Group "UV/EB Curing Materials" (1992, CMC), Technical Information Association "UV Curing" Insufficient curing / obstruction causes and countermeasures in "(2003, Technical Information Association), Shikizai, 68, (5), 286-293 (1995), Fine Chemicals, 29, (19), 5-14 (2000), etc. These may be used as cationic polymerizable compound components in thermosetting compositions.}.

Known epoxides can be used, including aromatic epoxides, alicyclic epoxides, heterocyclic epoxides and aliphatic epoxides.

Examples of aromatic epoxides include glycidyl ethers of monohydric or polyhydric phenols (phenol, bisphenol A, phenol novolak and their alkylene oxide adducts) having at least one aromatic ring.

Alicyclic epoxides include compounds obtained by epoxidizing a compound having at least one cyclohexene or cyclopentene ring with an oxidizing agent (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, (3 ,4,3′,4′-diepoxy)bicyclohexyl, bis(3,4-epoxycyclohexylmethyl)ether, 1,2-epoxy-1,2-bis(3,4-epoxycyclohexan-1-yl)ethane , 2,2-bis(3,4-epoxycyclohexan-1-yl)propane, 1,2-bis(3,4-epoxycyclohexan-1-yl)ethane, etc.).

Heterocyclic epoxides include, for example, heterocyclic rings other than epoxy groups in the molecule [e.g., tetrahydrofuran ring, tetrahydropyran ring, morpholine ring, chroman ring, isochroman ring, tetrahydrothiophene ring, tetrahydrothiopyran ring, aziridine ring, pyrrolidine ring, ring, piperidine ring, piperazine ring, indoline ring, 2,6-dioxabicyclo[3.3.0]octane ring, 1,3,5-triazacyclohexane ring, 1,3,5-triazacyclohexa- Non-aromatic heterocycles such as 2,4,6-trione ring (isocyanuric ring), dihydroimidazo[4,5-d]imidazole-2,5-dione ring (glycoluril ring); thiophene ring, pyrrole ring, aromatic heterocycles such as furan ring and pyridine ring] and an epoxy group, such as monoallyl diglycidyl isocyanurate, 1-allyl-3,5-bis(2-methylepoxypropyl) isocyanurate, 1-(2-methylpropenyl)-3,5-diglycidyl isocyanurate, 1-(2-methylpropenyl)-3,5-bis(2-methylepoxypropyl) isocyanurate, diallyl monoglycidyl isocyanurate , 1,3-diallyl-5-(2-methylepoxypropyl)isocyanurate, 1,3-bis(2-methylpropenyl)-5-glycidyl isocyanurate, 1,3-bis(2-methylpropenyl)-5 - (2-methylepoxypropyl) isocyanurate, triglycidyl isocyanurate, tris (2-methylepoxypropyl) isocyanurate, 1,3,4,6-tetraglycidyl glycoluril, 1,3,4,6-tetrakis ( 2-methylepoxypropyl)glycoluril, 1-allyl-3,4,6-triglycidylglycoluril, 1-allyl-3,4,6-tris(2-methylepoxypropyl)glycoluril, 1-(2- methylpropenyl)-3,4,6-triglycidylglycoluril, 1-(2-methylpropenyl)-3,4,6-tris(2-methylepoxypropyl)glycoluril, 1,4-diallyl-3,6 -diglycidyl glycoluril, 1,4-diallyl-3,6-bis(2-methylepoxypropyl) glycoluril, 1,4-bis(2-methylpropenyl)-3,6-diglycidyl glycoluril, 1, 4-bis(2-methylpropenyl)-3,6-bis(2-methylepoxy propyl) glycoluril, 1,3-diallyl-4,6-diglycidyl glycoluril, 1,3-diallyl-4,6-bis(2-methylepoxypropyl) glycoluril, 1,3-bis(2-methyl propenyl)-4,6-diglycidyl glycoluril, 1,3-bis(2-methylpropenyl)-4,6-bis(2-methylepoxypropyl) glycoluril, 1,6-diallyl-3,4-di Glycidyl glycoluril, 1,6-diallyl-3,4-bis(2-methylepoxypropyl) glycoluril, 1,6-bis(2-methylpropenyl)-3,4-diglycidyl glycoluril, 1,6- Bis(2-methylpropenyl)-3,4-bis(2-methylepoxypropyl)glycoluril, 1,3,4-triallyl-6-glycidylglycoluril, 1,3,4-triallyl-6-(2- methylepoxypropyl)glycoluril, 1,3,4-tris(2-methylpropenyl)-6-glycidylglycoluril, 1,3,4-tris(2-methylpropenyl)-6-(2-methylepoxypropyl) glycoluril and the like.

Aliphatic epoxides include polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof (1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, etc.), and aliphatic polybasic acids. Examples include polyglycidyl esters (diglycidyl tetrahydrophthalate, etc.), epoxidized long-chain unsaturated compounds (epoxidized soybean oil, epoxidized polybutadiene, etc.).

As the oxetane, known ones can be used. oxetanylmethyl)ether, 2-hydroxypropyl(3-ethyl-3-oxetanylmethyl)ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, oxetanylsilsesquioxetane and phenol novolak oxetane, etc. is mentioned.

As the ethylenically unsaturated compound, known cationic polymerizable monomers and the like can be used, including aliphatic monovinyl ethers, aromatic monovinyl ethers, polyfunctional vinyl ethers, styrene and cationic polymerizable nitrogen-containing monomers.

Examples of aliphatic monovinyl ethers include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether.

Aromatic monovinyl ethers include 2-phenoxyethyl vinyl ether, phenyl vinyl ether and p-methoxyphenyl vinyl ether.

Polyfunctional vinyl ethers include butanediol-1,4-divinyl ether and triethylene glycol divinyl ether.

Styrene includes styrene, α-methylstyrene, p-methoxystyrene and p-tert-butoxystyrene.

Cationic polymerizable nitrogen-containing monomers include N-vinylcarbazole and N-vinylpyrrolidone.

Bicycloorthoesters include 1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane and 1-ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo - [2.2.2] octane and the like.

Examples of spiro orthocarbonates include 1,5,7,11-tetraoxaspiro[5.5]undecane and 3,9-dibenzyl-1,5,7,11-tetraoxaspiro[5.5]undecane. be done.

Spiro orthoesters include 1,4,6-trioxaspiro[4.4]nonane, 2-methyl-1,4,6-trioxaspiro[4.4]nonane and 1,4,6-trioxas pyro[4.5]decane and the like.

Furthermore, it is possible to use polyorganosiloxane having at least one cationically polymerizable group in one molecule (JP-A-2001-348482, JP-A-2000-281965, JP-A-7-242828, Sci., Part A, Polym. Chem., Vol. 28, 497 (1990), etc.).
These polyorganosiloxanes may be linear, branched, cyclic, or mixtures thereof.

Among these cationically polymerizable compounds, epoxides, oxetanes and vinyl ethers are preferred, epoxides and oxetanes are more preferred, and alicyclic epoxides and oxetanes are particularly preferred. These cationically polymerizable compounds may be used alone, or two or more of them may be used in combination.

The content of the onium salt (acid generator) represented by the formulas (1) and (2) of the present invention in the curable composition is 0.05 to 20 parts by weight with respect to 100 parts by weight of the cationic polymerizable compound. is preferred, and more preferably 0.1 to 10 parts by weight. Within this range, the cationic polymerizable compound is sufficiently polymerized, and the physical properties of the cured product are further improved. In addition, this content depends on various factors such as the properties of the cationic polymerizable compound, the type and irradiation amount of the active energy ray (when using the active energy ray), heating temperature, curing time, humidity, and thickness of the coating film. determined by consideration and not limited to the above ranges.

The curable composition of the present invention may optionally contain known additives (sensitizers, pigments, fillers, conductive particles, antistatic agents, flame retardants, antifoaming agents, flow control agents, light stabilizers, agents, antioxidants, adhesion imparting agents, ion scavengers, anti-coloring agents, solvents, non-reactive resins, radically polymerizable compounds, etc.).

As the sensitizer, known sensitizers (JP-A-11-279212, JP-A-09-183960, etc.) can be used, and benzoquinone {1,4-benzoquinone, 1,2-benzoquinone, etc.}; naphthoquinone { 1,4-naphthoquinone, 1,2-naphthoquinone, etc.}; anthraquinone {2-methylanthraquinone, 2-ethylanthraquinone, etc.}, anthracene {anthracene, 9,10-dibutoxyanthracene, 9,10-dimethoxyanthracene, 9, 10-diethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-dipropoxyanthracene, etc.}; pyrene; 1,2-benzanthracene; perylene; tetracene; coronene; thioxanthone {thioxanthone, 2-methylthioxanthone , 2-ethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone and 2,4-diethylthioxanthone, etc.}; phenothiazine {phenothiazine, N-methylphenothiazine, N-ethylphenothiazine, N-phenylphenothiazine, etc.}; xanthone; naphthalene { 1-naphthol, 2-naphthol, 1-methoxynaphthalene, 2-methoxynaphthalene, 1,4-dihydroxynaphthalene, and 4-methoxy-1-naphthol, etc.}; ketones {dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy-2 -methyl-1-phenylpropan-1-one, 4'-isopropyl-2-hydroxy-2-methylpropiophenone and 4-benzoyl-4'-methyldiphenylsulfide, etc.}; carbazole {N-phenylcarbazole, N- ethylcarbazole, poly-N-vinylcarbazole and N-glycidylcarbazole, etc.}; chrysene {1,4-dimethoxychrysene and 1,4-di-α-methylbenzyloxychrysene, etc.}; phenanthrene {9-hydroxyphenanthrene, 9- methoxyphenanthrene, 9-hydroxy-10-methoxyphenanthrene, 9-hydroxy-10-ethoxyphenanthrene, etc.} and the like.

When a sensitizer is contained, the content of the sensitizer is preferably 1-300 parts by weight, more preferably 5-200 parts by weight, per 100 parts by weight of the acid generator.

As the pigment, known pigments can be used, including inorganic pigments (titanium oxide, iron oxide, carbon black, etc.) and organic pigments (azo pigments, cyanine pigments, phthalocyanine pigments, quinacridone pigments, etc.).

When a pigment is contained, the content of the pigment is preferably 0.5 to 400,000 parts by weight, more preferably 10 to 150,000 parts by weight, per 100 parts of the acid generator.

As the filler, known fillers can be used, and examples thereof include fused silica, crystalline silica, calcium carbonate, aluminum oxide, aluminum hydroxide, zirconium oxide, magnesium carbonate, mica, talc, calcium silicate and lithium aluminum silicate. mentioned.

When a filler is contained, the content of the filler is preferably 50 to 600,000 parts by weight, more preferably 300 to 200,000 parts by weight, per 100 parts of the acid generator.

As the conductive particles, known conductive particles can be used, and metal particles such as Ni, Ag, Au, Cu, Pd, Pb, Sn, Fe, Ni, Al, etc., and plated metal obtained by further metal plating these metal particles. Particles, plated resin particles obtained by plating resin particles with a metal, and particles of conductive substances such as carbon can be used.

When conductive particles are contained, the content of the conductive particles is preferably 50 to 30,000 parts by weight, more preferably 100 to 20,000 parts by weight, per 100 parts of the acid generator.

As the antistatic agent, known antistatic agents can be used, and examples include nonionic antistatic agents, anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents and polymeric antistatic agents. .

When an antistatic agent is contained, the content of the antistatic agent is preferably 0.1 to 20,000 parts by weight, more preferably 0.6 to 5,000 parts by weight, per 100 parts of the acid generator.

As flame retardants, known flame retardants can be used, and inorganic flame retardants {antimony trioxide, antimony pentoxide, tin oxide, tin hydroxide, molybdenum oxide, zinc borate, barium metaborate, red phosphorus, aluminum hydroxide, , magnesium hydroxide and calcium aluminate}; bromine flame retardants {tetrabromophthalic anhydride, hexabromobenzene and decabromobiphenyl ether, etc.}; and phosphate ester flame retardants {tris(tribromophenyl) phosphate, etc.}. be done.

When a flame retardant is contained, the content of the flame retardant is preferably 0.5 to 40,000 parts by weight, more preferably 5 to 10,000 parts by weight, per 100 parts of the acid generator.

As the antifoaming agent, known antifoaming agents can be used, such as alcohol antifoaming agents, metal soap antifoaming agents, phosphate ester antifoaming agents, fatty acid ester antifoaming agents, polyether antifoaming agents, and silicone antifoaming agents. and mineral oil antifoaming agents.

As the fluidity modifier, known fluidity modifiers and the like can be used, including hydrogenated castor oil, polyethylene oxide, organic bentonite, colloidal silica, amide wax, metal soap, acrylic acid ester polymer, and the like.
As the light stabilizer, known light stabilizers and the like can be used, and UV-absorbing stabilizers {benzotriazole, benzophenone, salicylate, cyanoacrylate, and derivatives thereof}; radical-scavenging stabilizers {hindered amines, etc.}; type stabilizer {nickel complex, etc.}, and the like.
As the antioxidant, known antioxidants can be used, and examples include phenolic antioxidants (monophenolic, bisphenolic, polymer phenolic, etc.), sulfuric antioxidants and phosphorus antioxidants. be done.
As the adhesion-imparting agent, a known adhesion-imparting agent or the like can be used, and examples thereof include coupling agents, silane coupling agents and titanium coupling agents.
As the ion scavenger, known ion scavengers and the like can be used, and organic aluminum (alkoxyaluminum, phenoxyaluminum, etc.) and the like can be mentioned.
As the anti-coloring agent, known anti-coloring agents can be used, and antioxidants are generally effective. Examples include antioxidants and phosphorus-based antioxidants.

When containing antifoaming agents, flow regulators, light stabilizers, antioxidants, adhesion imparting agents, ion scavengers, or anti-coloring agents, the content of each is 0 per 100 parts of the acid generator. .1 to 20000 parts by weight, more preferably 0.5 to 5000 parts by weight.

The solvent is not particularly limited as long as it can be used for dissolving the cationic polymerizable compound and adjusting the viscosity of the energy ray-curable composition.

When a solvent is contained, the content of the solvent is preferably 50 to 2,000,000 parts by weight, more preferably 200 to 500,000 parts by weight, per 100 parts of the acid generator.

Non-reactive resins include copolymers of polyester, polyvinyl acetate, polyvinyl chloride, polybutadiene, polycarbonate, polystyrene, polyvinyl ether, polyvinyl butyral, polybutene, hydrogenated styrene-butadiene block copolymer, and (meth)acrylic acid ester. Coalescing and polyurethane, and the like. The number average molecular weight of these resins is preferably 1,000 to 500,000, more preferably 5,000 to 100,000 (the number average molecular weight is a value measured by a general method such as GPC).

When a non-reactive resin is contained, the content of the non-reactive resin is preferably 5 to 400,000 parts by weight, more preferably 50 to 150,000 parts by weight, per 100 parts of the acid generator.

When a non-reactive resin is included, it is desirable to dissolve the non-reactive resin in a solvent in advance in order to facilitate dissolution of the non-reactive resin with the cationic polymerizable compound and the like.

As a radically polymerizable compound, known {Photopolymer Konwakai ed. "Photopolymer Handbook" (1989, Industrial Research Institute), General Technology Center ed. "UV/EB Curing Technology" (1982, General Technology Center), Radtech Research "UV/EB Curing Materials" (1992, CMC), edited by the Association, and "Poor Curing/Inhibition Causes and Countermeasures in UV Curing" (2003, Technical Information Association) edited by the Technical Information Association. Radically polymerizable compounds, etc. Monofunctional monomers, difunctional monomers, multifunctional monomers, epoxy (meth)acrylates, polyester (meth)acrylates and urethane (meth)acrylates can be used.

When a radically polymerizable compound is contained, the content of the radically polymerizable compound is preferably 5 to 400,000 parts by weight, more preferably 50 to 150,000 parts by weight, per 100 parts of the acid generator.

When radically polymerizable compounds are contained, it is preferable to use a radical polymerization initiator that initiates polymerization by heat or light in order to increase the molecular weight of these compounds by radical polymerization.

As the radical polymerization initiator, known radical polymerization initiators can be used, and thermal radical polymerization initiators (organic peroxides, azo compounds, etc.) and photoradical polymerization initiators (acetophenone initiators, benzophenone initiators, Michler ketone initiators, benzoin initiators, thioxanthone initiators, acylphosphine initiators, etc.).

When a radical polymerization initiator is contained, the content of the radical polymerization initiator is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, relative to 100 parts of the radically polymerizable compound. .

The energy ray-curable composition of the present invention is prepared by uniformly adding a cationic polymerizable compound, an acid generator, and optionally an additive at room temperature (about 20 to 30° C.) or under heating (about 40 to 90° C.). It can be prepared by mixing and dissolving, or by kneading with a triple roll or the like.

The energy ray-curable composition of the present invention can be cured by irradiation with an energy ray to obtain a cured product.
Any energy beam may be used as long as it has energy that induces decomposition of the acid generator of the present invention, and low-pressure, medium-pressure, high-pressure or ultra-high pressure mercury lamps, metal halide lamps, LED lamps, xenon lamps and carbon arc lamps may be used. , fluorescent lamps, semiconductor solid-state lasers, argon lasers, He _— Cd lasers, KrF excimer lasers, ArF excimer lasers, F2 lasers, and the like, and energy rays in the ultraviolet to visible light region (wavelength: about 100 to about 800 nm) are preferred. . Note that high-energy radiation such as an electron beam or an X-ray can also be used as the energy beam.

The energy ray irradiation time is affected by the intensity of the energy ray and the permeability of the energy ray to the energy ray-curable composition. is. However, in the case where the energy ray-curable composition has a low transmittance or the film thickness of the energy ray-curable composition is large, it may be preferable to spend a longer time. 0.1 seconds to several minutes after energy ray irradiation, most energy ray-curable compositions are cured by cationic polymerization. After-curing by heating at ℃ for several seconds to several hours is also possible.

The cured product obtained by curing the energy ray-curable composition of the present invention has excellent heat resistance, and the 5% weight loss temperature is, for example, 260° C. or higher, preferably 280° C. or higher, and particularly preferably 300° C. or higher. be. The 5% weight loss temperature is determined by differential thermal-thermogravimetric simultaneous measurement (TG-DTA). Therefore, the shape can be maintained even under high temperature conditions such as reflow soldering.

Furthermore, the cured product obtained by curing the energy ray-curable composition of the present invention has excellent transparency, and the yellowness index (YI) of the cured product before being subjected to a heat resistance test is, for example, 1.5 or less. In addition, the cured product obtained by curing the curable composition of the present invention can suppress yellowing and maintain transparency even under high temperature conditions such as reflow soldering, and was subjected to a heat resistance test. The yellowness index (YI) of the post-cured product is, for example, 1.5 or less. The method for measuring the yellowness index is as described in Examples.

Since the energy ray-curable composition of the present invention has the above properties, it can be used as an optical element material (lens or prism material, sealing material, optical waveguide forming material, adhesive, optical fiber forming material, imprint material, alternative glass forming material, etc.). ), resists, coating agents and the like.

(optical element)
The optical element of the present invention is an optical element containing, as a component, a cured product obtained by curing the curable composition. Therefore, the optical element of the present invention has excellent curability, heat resistance, and heat yellowing resistance.

Examples of optical elements of the present invention include lenses, prisms, LEDs, organic EL elements, semiconductor lasers, transistors, solar cells, CCD image sensors, optical waveguides, optical fibers, alternative glass (e.g. display substrates, hard disk substrates, polarizing film), etc.

The optical element of the present invention has excellent heat resistance. Therefore, it can be collectively mounted together with other components by reflow processing when mounting on a substrate. It can also be used for in-vehicle electronic equipment that requires heat resistance.

(optical device)
An optical device of the present invention is an optical device including the above optical element, and can be manufactured, for example, by mounting the above optical element on a substrate by reflow soldering. Examples of the optical device of the present invention include portable electronic devices such as mobile phones, smartphones, and tablet PCs (personal computers); near-infrared sensors, millimeter wave radars, LED spot lighting devices, near-infrared LED lighting devices, mirrors In-vehicle electronic equipment such as a monitor, a meter panel, a combiner for a head-mounted display (projection type), a combiner for a head-up display, and the like can be mentioned. The optical device of the present invention does not need to mount the optical element in a separate process, and can be collectively mounted together with other parts by reflow treatment, so that it can be manufactured efficiently and at low cost.

EXAMPLES The present invention will be further described with reference to examples below, but the present invention is not intended to be limited to these examples. Unless otherwise specified, parts means parts by weight and % means % by weight.

<Synthesis of acid generator>
(Synthesis Example 1) Synthesis of lithium tetrakis(pentafluorophenyl)gallate A 125 mL four-necked flask sufficiently dried under a nitrogen atmosphere was charged with 360 parts of super-dehydrated diethyl ether and 30 parts of pentafluorobromobenzene, and then mixed with dry ice/acetone. Cooled to −78° C. using a bath. 70 parts of a 2.5 mol/L n-butyllithium hexane solution was added dropwise over 10 minutes, followed by stirring at -78°C for 30 minutes. To this, 68 parts of a diethyl ether solution in which 5 parts of gallium (III) chloride was dissolved was added dropwise over 10 minutes, and the mixture was stirred at -78°C for 3 hours. The reaction solution was stirred while gradually returning to room temperature, and after returning to room temperature, was further stirred for 5 hours. The precipitated solid was filtered, the reaction solution was transferred to an evaporator, and the solvent was distilled off to obtain an off-white product. After the product was washed four times with 50 parts of ultra-dehydrated hexane, it was vacuum-dried overnight to obtain lithium tetrakis(pentafluorophenyl)gallate. The product was identified by ¹⁹ F-NMR.

(Synthesis Example 2) Synthesis of [4-(phenylthio)phenyl] diphenylsulfonium tetrakis(pentafluorophenyl)gallate (a-1) Diphenyl sulfoxide (1.6 parts, 8 mmol), diphenyl sulfide (1.5 parts, 8 mmol) , acetic anhydride (2.5 parts, 24 mmol), trifluoromethanesulfonic acid (1.5 parts, 10 mmol) and 13 parts of acetonitrile were uniformly mixed and reacted at 40° C. for 6 hours. The reaction solution was cooled to room temperature, poured into 60 parts of ion-exchanged water, extracted with 60 parts of dichloromethane, and washed with ion-exchanged water until the pH of the aqueous layer became neutral. The dichloromethane layer was transferred to a rotary evaporator and the solvent was distilled off to obtain a brown liquid product. Add 20 parts of ethyl acetate to this, dissolve in a water bath at 60°C, add 60 parts of hexane, stir, cool to 5°C, allow to stand for 30 minutes, remove the supernatant, and remove the supernatant twice. The product was washed. [4-(phenylthio)phenyl] diphenylsulfonium triflate was obtained by transferring this to a rotary evaporator and distilling off the solvent.
(double decomposition method)
This triflate was dissolved in 50 parts of dichloromethane, mixed with 66 parts of an equimolar lithium tetrakis(pentafluorophenyl)gallate aqueous solution at room temperature, stirred for 3 hours, and the dichloromethane layer was washed twice with water by liquid separation. After that, it was transferred to a rotary evaporator and the solvent was distilled off to obtain (a-1).

(Synthesis Example 3) Synthesis of [4-(4-biphenylylthio)phenyl](4-biphenylyl)phenylsulfonium tetrakis(pentafluorophenyl)gallate (a-2) Diphenyl sulfoxide of Synthesis Example 2 (1.6 parts, 8 mmol), diphenyl sulfide (1.5 parts, 8 mmol) was changed to 4-[(phenyl)sulfinyl]biphenyl (2.2 parts, 8 mmol), 4-(phenylthio)biphenyl (2.1 parts, 8 mmol). (a-2) was obtained in the same manner as in Synthesis Example 2.

[Synthesis Example 4] Synthesis of [4-(phenylthio)phenyl] diphenylsulfonium tris(pentafluoroethyl)trifluorophosphate (b-1) 1.6 parts of diphenyl sulfoxide, 1.5 parts of diphenyl sulfide, 2.4 parts of acetic anhydride parts, 1.44 parts of trifluoromethanesulfonic acid and 13.0 parts of acetonitrile were uniformly mixed and reacted at 40° C. for 6 hours. The reaction solution was cooled to room temperature (about 25° C.), poured into 60 parts of distilled water, extracted with 60 parts of dichloromethane, and washed with water until the pH of the aqueous layer became neutral. The dichloromethane layer was transferred to a rotary evaporator and the solvent was distilled off to obtain a brown liquid product. Add 20 parts of ethyl acetate to this, dissolve in a water bath at 60°C, add 60 parts of hexane, stir, cool to 5°C, allow to stand for 30 minutes, and remove the supernatant twice. The product was washed. By transferring this to a rotary evaporator and distilling off the solvent , [ 4-(phenylthio)phenyl] diphenylsulfonium triflate (triflate=trifluoromethanesulfonate anion) was obtained.
(double decomposition method)
Dissolve this triflate in 45 parts of dichloromethane, put it in 42 parts of 10% tris(pentafluoroethyl)trifluoropotassium phosphate aqueous solution, stir at room temperature (about 25 ° C.) for 3 hours, and separate the dichloromethane layer. (b-1) was obtained by washing with water three times at , transferring to a rotary evaporator and distilling off the solvent.

Examples 1-8, Comparative Examples 1-5
Each component shown in Table 1 below was blended according to the composition (unit: parts by weight), and stirred and mixed at room temperature using a rotation/revolution mixer to obtain a uniform and transparent curable composition. The obtained curable compositions were evaluated according to the following evaluation methods.

[Curability]
A 0.03 mm spacer was placed at both ends of a slide glass (trade name “S9112”, manufactured by Matsunami Glass Industry Co., Ltd.), and the curable composition was dropped in the center. A squeegee was used to spread the curable composition to a thickness of 0.03 mm, and light irradiation was performed using a high-pressure mercury lamp under the following conditions. A cured product was obtained by standing at room temperature for 60 minutes after light irradiation.
Light irradiation conditions <High pressure mercury lamp>
Irradiation device: trade name “LC-8” (manufactured by Hamamatsu Photonics Co., Ltd.)
Irradiation intensity: 100mW/cm
Accumulated irradiation dose: 3000mJ/cm2

The curability of the obtained cured product was confirmed from the presence or absence of tackiness on the surface. The presence or absence of tackiness was determined by palpation.
Evaluation criteria ○: no tackiness on the surface, no change in the surface shape of the cured product △: no tackiness on the surface, but the surface shape of the cured product changed ×: the surface had tackiness

[Heat-resistant]
A Teflon (registered trademark) spacer with a length of 30 mm, a width of 20 mm, and a thickness of 0.1 mm was prepared, immersed in a release treatment [trade name “Optool HD1000” (manufactured by Daikin Co., Ltd.), and left in a draft for 24 hours. ] (trade name “S2111”, manufactured by Matsunami Glass Co., Ltd.). A curable composition was cast into the gap and irradiated with light in the same manner as described above to obtain a cured product. 10 mg of the obtained cured product was cut off, and heat resistance was evaluated by measuring the 5% weight loss temperature using TG-DTA (trade name “EXSTAR6300”, manufactured by Hitachi High-Tech Science Co., Ltd.) under the following conditions.
TG-DTA conditions Heating rate: 20 ° C./min
Atmosphere: Nitrogen Temperature conditions: 30°C to 400°C

[transparency]
A Teflon (registered trademark) spacer of 20 mm length×20 mm width×0.1 mm thickness was prepared and sandwiched between slide glasses (trade name “S2111” manufactured by Matsunami Glass Co., Ltd.). A curable composition was poured into the gap, irradiated with light in the same manner as described above, and left at room temperature for 60 minutes after the irradiation to obtain a cured product. The transparency (YI) of the resulting cured product was measured using a spectrophotometer (trade name “U-3900”, manufactured by Hitachi High-Technologies Corporation) to evaluate the transparency. Incidentally, the yellowness index (YI) was read at a 2-degree field of view under a D65 light source.

[Heat resistant transparency]
A heat resistance test based on the reflow temperature profile (maximum temperature: 270 ° C) described in the JEDEC standard is performed on the cured product obtained by the same method as the above [transparency] evaluation using a desktop reflow oven (manufactured by Shinapec). After performing three times in succession, the heat-resistant transparency was evaluated by measuring the transparency (YI) by the same method as above.

The compound name of each component in Table 1 is as follows.
Celoxide 2021P: 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexane carboxylate, trade name "CELLOXIDE2021P", Daicel JER828: Bisphenol A type epoxy resin, trade name "JER828", Japan Epoxy Resin ( Co., Ltd.

Table 1 shows that the energy ray-curable composition obtained by the present invention has excellent cationic polymerization initiation ability and excellent heat-resistant transparency.

The energy ray-curable composition of the present invention has excellent film curability, and can form a cured product having excellent curability, transparency, heat resistance, and heat resistance to yellowing by light irradiation or heat treatment. . Therefore, it can be suitably used as an optical element material, a resist, a coating agent, and the like.

Claims (5)

an onium gallate salt that is [4-(phenylthio)phenyl]diphenylsulfonium tetrakis(pentafluorophenyl)gallate or [4-(4-biphenylylthio)phenyl](4-biphenylyl)phenylsulfonium tetrakis(pentafluorophenyl)gallate; An energy ray-curable composition comprising an acid generator containing an onium phosphate salt of [4-(phenylthio)phenyl]diphenylsulfonium tris(pentafluoroethyl)trifluorophosphate and a cationically polymerizable compound. 2. The energy ray-curable composition according to claim 1 , wherein the content of the onium gallate salt contained in the energy ray-curable composition is 0.1 to 3 times the content of the onium phosphate salt . A cured product obtained by curing the energy ray-curable composition according to claim 1 or 2 . An optical element containing the cured product according to claim 3 as a component. An optical device comprising the optical element according to claim 4 .