Photoacid generator

Abstract

The present invention provides a useful photoacid generator which is used for a photocurable composition or a chemically amplified negative photoresist composition, and which is useful for yellowing resistance of these compositions. The present invention provides a photoacid generator which is characterized by containing a sulfonium salt (CA) represented by general formula (1) and a compound (S) represented by general formula (2), and which is also characterized in that if the total content of the sulfonium salt (CA) and the compound (S) is determined by high-speed liquid chromatography (HPLC) and the total area of the sulfonium salt (CA) and the compound (S) is taken as 100, the area ratio of the compound (S) is from 0.02 to 3.0.

Description

[Technical Field]

[0001] The present invention relates to a photoacid generator useful in photocurable compositions and chemically amplified negative photoresist compositions, and to a photoacid generator useful in preventing yellowing of these compositions. [Background technology]

[0002] Onium salts such as sulfonium salts are known as photocationic polymerization initiators that cure cationically polymerizable compounds such as epoxy compounds upon irradiation with active energy rays (hereinafter referred to as light) such as light or electron beams (Patent Documents 1 to 3), or as photoacid generators that generate acid upon irradiation with light, and are widely used in photoresists, photosensitive materials, and the like (Patent Documents 4 to 6).

[0003] The photoacid generators described in these specifications, particularly sulfonium salts, are produced by known methods (Patent Documents 1 and 3). However, the sulfonium salts produced by these methods include not only monosulfonium salts having one sulfonio group per molecule, but also bissulfonium salts having two sulfonio groups per molecule. Generally, bissulfonium salts have higher photopolymerization initiation ability than monosulfonium salts, but also have lower solubility in cationic polymerizable monomers and diluent solvents used as needed. Therefore, after adding and dissolving the sulfonium salt at the required concentration in these solvents, the bissulfonium salt can precipitate and settle from the sulfonium salt solution over time. Furthermore, cationic polymerizable compounds containing bissulfonium salts tend to thicken over time, making them difficult to store for long periods. To address these issues, the present applicant has disclosed a production method for efficiently obtaining high-purity monosulfonium salts (Patent Document 7). However, there has been a demand for further improvement in the balance between photocurable compositions and resist compositions and curability in terms of the change in hue over time of the cured product (this refers to the phenomenon in which the cured product turns yellow to brown, etc. over time; hereinafter referred to as yellowing). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 55-125105 [Patent Document 2] Japanese Unexamined Patent Publication No. 61-190524 [Patent Document 3] Japanese Patent Publication No. 61-212554 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-193925 [Patent Document 5] Japanese Patent Application Laid-Open No. 2001-354669 [Patent Document 6] Japanese Patent Application Laid-Open No. 2001-294570 [Patent Document 7] Patent No. 4602252 Summary of the Invention [Problem to be solved by the invention]

[0005] In light of the above background, an object of the present invention is to provide a useful photoacid generator for use in photocurable compositions and chemically amplified negative photoresist compositions, which is useful for improving the yellowing resistance of these compositions. [Means for solving the problem]

[0006] The present inventors have discovered a photoacid generator suitable for the above purpose. That is, the present invention provides a photoacid generator comprising a sulfonium salt (CA) represented by the following general formula (1) and a compound (S) represented by the following general formula (2), wherein the total content of the sulfonium salt (CA) and the compound (S) is such that the area ratio of the compound (S) to the total area of ​​the sulfonium salt (CA) and the compound (S) is 100, as measured by high performance liquid chromatography (HPLC), is 0.02 or more and 3.0 or less.

[0007] [ka]

[0008] [In formulas (1) to (2), R 1 ~R 3 is an organic group bonded to a benzene ring, and p, q, and r are R 1 ~R 3 p is an integer of 0 to 4, q and r are integers of 0 to 5, and when p is 0, a hydrogen atom is bonded to it. When p, q and r are 2 or more, they may be the same or different from each other. 1 ~R 3 may form a ring structure with each other directly or via -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, an alkylene group or a phenylene group, X is an atom (group) that can become a monovalent anion, Ar 1 ~Ar 3 are each an aryl group having 6 to 18 carbon atoms or a heteroaryl group having 4 to 18 carbon atoms, which may be the same or different, and Ar 1 The aryl group or heteroaryl group may be further substituted with a group represented by formula (3), and in formula (3), R 2 , R 3 , r, q, and X are the same as in formula (1), and in formula (2), n is an integer of 1 or 2.]

[0009] [ka]

[0010] The present invention also relates to a photocurable composition comprising the above-mentioned photoacid generator and a cationically polymerizable compound; a cured product obtained by curing the above-mentioned photocurable composition; a chemically amplified negative photoresist composition comprising the above-mentioned photoacid generator, component (F) which is an alkali-soluble resin having a phenolic hydroxyl group, and crosslinker component (G); and a cured product obtained by curing the above-mentioned chemically amplified negative photoresist composition. [Effects of the Invention]

[0011] The photoacid generator of the present invention has high activity against light, and also has cationic polymerization performance and crosslinking reaction performance. Furthermore, by using the photoacid generator of the present invention, a useful composition that is effective in terms of yellowing resistance can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail.

[0013] R in formulas (1) to (3) 1 ~R 3 R represents an organic group bonded to a benzene ring, and may be the same or different. 1 ~R 3 Examples of the organic group include an aryl group having 6 to 30 carbon atoms, a heteroaryl group having 4 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms or an alkynyl group having 2 to 30 carbon atoms, a hydroxy group, an alkoxy group having 1 to 18 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an alkylcarbonyl group having 2 to 19 carbon atoms, an arylcarbonyl group having 7 to 11 carbon atoms, an alkoxycarbonyl group having 2 to 19 carbon atoms, an aryloxy group having 7 to 1 ... Examples of such groups include an oxycarbonyl group, an arylthiocarbonyl group having 7 to 11 carbon atoms, an acyloxy group having 2 to 19 carbon atoms, an arylthio group having 6 to 20 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, an alkylsulfinyl group having 1 to 18 carbon atoms, an arylsulfinyl group having 6 to 10 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, an arylsulfonyl group having 6 to 10 carbon atoms, an alkyleneoxy group, an amino group, a cyano group, a nitro group, and a halogen group.

[0014] Examples of the aryl group having 6 to 30 carbon atoms include monocyclic aryl groups such as a phenyl group and a biphenylyl group, and condensed polycyclic aryl groups such as naphthyl, anthracenyl, phenanthrenyl, pyrenyl, chrysenyl, naphthacenyl, benzanthracenyl, anthraquinolyl, fluorenyl, naphthoquinone, and anthraquinone.

[0015] Examples of heteroaryl groups having 4 to 30 carbon atoms include cyclic groups containing 1 to 3 heteroatoms such as oxygen, nitrogen, and sulfur, which may be the same or different. Specific examples include monocyclic heteroaryl groups such as thienyl, furanyl, pyranyl, pyrrolyl, oxazolyl, thiazolyl, pyridyl, pyrimidyl, and pyrazinyl, and fused polycyclic heteroaryl groups such as indolyl, benzofuranyl, isobenzofuranyl, benzothienyl, isobenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, carbazolyl, acridinyl, phenothiazinyl, phenazinyl, xanthenyl, thianthrenyl, phenoxazinyl, phenoxathiinyl, chromanyl, isochromanyl, dibenzothienyl, xanthonyl, thioxanthonyl, and dibenzofuranyl.

[0016] Examples of the alkyl group having 1 to 30 carbon atoms include linear alkyl groups such as methyl, ethyl, propyl, butyl, hexadecyl, and octadecyl; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, and isohexyl; and cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0017] Examples of the alkenyl group having 2 to 30 carbon atoms include vinyl, allyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, and 1-methyl-1-propenyl.

[0018] Examples of the alkynyl group having 2 to 30 carbon atoms include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methyl-1-propynyl, and 1-methyl-2-propynyl.

[0019] Examples of the alkoxy group having 1 to 18 carbon atoms include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, and dodecyloxy.

[0020] Examples of the aryloxy group having 6 to 10 carbon atoms include phenoxy and naphthyloxy.

[0021] Examples of the alkylcarbonyl group having 2 to 19 carbon atoms include acetyl, trifluoroacetyl, propionyl, butanoyl, 2-methylpropionyl, heptanoyl, 2-methylbutanoyl, 3-methylbutanoyl, and octanoyl.

[0022] Examples of the arylcarbonyl group having 7 to 11 carbon atoms include benzoyl, 4-tert-butylbenzoyl, and naphthoyl.

[0023] Examples of the alkoxycarbonyl group having 2 to 19 carbon atoms include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl, and tert-butoxycarbonyl.

[0024] Examples of the aryloxycarbonyl group having 7 to 11 carbon atoms include phenoxycarbonyl and naphthoxycarbonyl.

[0025] Examples of the arylthiocarbonyl group having 7 to 11 carbon atoms include phenylthiocarbonyl and naphthoxythiocarbonyl.

[0026] Examples of the acyloxy group having 2 to 19 carbon atoms include acetoxy, ethylcarbonyloxy, propylcarbonyloxy, isobutylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, and octadecylcarbonyloxy.

[0027] Examples of the arylthio group having 6 to 20 carbon atoms include phenylthio, biphenylylthio, methylphenylthio, chlorophenylthio, bromophenylthio, fluorophenylthio, hydroxyphenylthio, methoxyphenylthio, naphthylthio, 4-[4-(phenylthio)benzoyl]phenylthio, 4-[4-(phenylthio)phenoxy]phenylthio, 4-[4-(phenylthio)phenyl]phenylthio, 4-(phenylthio)phenylthio, 4-benzoylphenylthio, 4-benzoyl-chlorophenylthio, 4-benzoyl-methylthiophenylthio, 4-(methylthiobenzoyl)phenylthio, and 4-(p-tert-butylbenzoyl)phenylthio.

[0028] Examples of the alkylthio group having 1 to 18 carbon atoms include methylthio, ethylthio, propylthio, tert-butylthio, neopentylthio, and dodecylthio.

[0029] Examples of the alkylsulfinyl group having 1 to 18 carbon atoms include methylsulfinyl, ethylsulfinyl, propylsulfinyl, tert-pentylsulfinyl, and octylsulfinyl.

[0030] Examples of the arylsulfinyl group having 6 to 10 carbon atoms include phenylsulfinyl, tolylsulfinyl, and naphthylsulfinyl.

[0031] Examples of the alkylsulfonyl group having 1 to 18 carbon atoms include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, and octylsulfonyl.

[0032] Examples of the arylsulfonyl group having 6 to 10 carbon atoms include phenylsulfonyl, tolylsulfonyl, and naphthylsulfonyl.

[0033] Halogen groups include fluoro, chloro, bromo, and iodo.

[0034] Of these organic groups, preferred are alkyl groups having 1 to 6 carbon atoms, aryl groups having 6 to 14 carbon atoms, hydroxy groups, alkoxy groups having 1 to 6 carbon atoms, alkylcarbonyl groups having 2 to 6 carbon atoms, arylcarbonyl groups having 7 to 11 carbon atoms, alkylthio groups having 1 to 6 carbon atoms, arylthio groups having 6 to 14 carbon atoms, aryloxy groups having 6 to 10 carbon atoms, chloro groups, and fluoro groups, and more preferred are alkyl groups having 1 to 6 carbon atoms, aryl groups having 6 to 14 carbon atoms, heteroaryl groups having 4 to 14 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, alkylcarbonyl groups having 2 to 6 carbon atoms, benzoyl groups, aryloxy groups having 6 to 10 carbon atoms, and fluoro groups.

[0035] In formulas (1) to (3), p, q, and r are R 1 ~R 3 p is an integer of 0 to 4, q and r are integers of 0 to 5, and when p is 0, a hydrogen atom is bonded to it. When p, q and r are 2 or more, they may be the same or different from each other. 1 ~R 3 may form a ring structure with each other directly or via -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, an alkylene group, or a phenylene group. For example, when p is 2 or more, two of R 1 form a ring structure either directly or via -O-, -S-, -SO-, -SO2-, -NH-, -CO-, -COO-, -CONH-, an alkylene group or a phenylene group.

[0036] In formula (1) or (2), Ar 1 ~Ar 3 are each an aryl group having 6 to 18 carbon atoms or a heteroaryl group having 4 to 18 carbon atoms, which may be the same or different, and Ar 1 The aryl group or heteroaryl group may be further substituted with a group represented by formula (3). The aryl group having 6 to 18 carbon atoms includes R 1 ~R 3Among the aryl groups having 6 to 30 carbon atoms in the above formula, aryl groups having 6 to 18 carbon atoms are exemplified, and preferably aryl groups having 6 to 14 carbon atoms. Examples of heteroaryl groups having 4 to 18 carbon atoms include R 1 ~R 3 Among the heteroaryl groups having 4 to 30 carbon atoms in the formula (I), examples include heteroaryl groups having 4 to 18 carbon atoms, and preferably heteroaryl groups having 4 to 14 carbon atoms. These aryl groups and heteroaryl groups may have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 14 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylcarbonyl group having 2 to 6 carbon atoms, an arylcarbonyl group having 7 to 11 carbon atoms, an arylthio group having 6 to 14 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, a chloro group, and a fluoro group.

[0037] In formula (2), n represents an integer of 1 or 2. When n is within this range, the effect of suppressing coloration (yellowing) is exhibited without affecting the photoresponsiveness of the sulfonium salt. When n = 0, there is no effect on yellowing resistance, and obtaining a compound where n is 3 or more is complicated and industrially disadvantageous.

[0038] Among the sulfonium salts represented by formula (1), specific examples of preferred cation moieties (C) are shown below.

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] Among the compounds (S) represented by formula (2), preferred specific examples are shown below.

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] Among the sulfonium salts (CA) represented by formula (1), specific examples of the cation moiety (C) that are more preferred in terms of sensitivity and solubility are shown below.

[0048] [ka]

[0049] [ka]

[0050] Among the compounds (S) represented by formula (2), specific examples that are more preferable from the viewpoint of solubility are shown below.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] In formula (1) and formula (3), X is an atom (group) that can become a monovalent anion, i.e., X - is the anion corresponding to the acid (HX) generated by irradiating a sulfonium salt with light (visible light, ultraviolet light, electron beam, X-ray, etc.). - is not restricted other than being a monovalent polyatomic anion, but MY a - , (Rf) b PF 6-b - , R 8 c BY 4-c - , R 8 c Gay 4-c - , R 9 SO3 - , (R 9 SO2)3C - or (R 9 SO2)2N - Anions represented by the following formula are preferred.

[0055] M represents a phosphorus atom, a boron atom, or an antimony atom. Y represents a halogen atom (preferably a fluorine atom).

[0056] 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 have been substituted with fluorine atoms. Examples of alkyl groups that become Rf through fluorine substitution include linear alkyl groups (methyl, ethyl, propyl, butyl, pentyl, octyl, etc.), branched alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, etc.), and cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.). The proportion of hydrogen atoms in these alkyl groups substituted with fluorine atoms in Rf is preferably 80 mol % or more, more preferably 90 mol % or more, and particularly preferably 100%, based on the number of moles of hydrogen atoms in the original alkyl group. When the substitution ratio with fluorine atoms is within these preferred ranges, the photosensitivity of the sulfonium salt is further improved. Particularly preferred Rf include CF3-, CF3CF2-, (CF3)2CF-, CF3CF2CF2-, CF3CF2CF2CF2-, (CF3)2CFCF2-, CF3CF2(CF3)CF- and (CF3)3C-. The b Rfs are independent of each other and may therefore be the same or different.

[0057] P represents a phosphorus atom, and F represents a fluorine atom.

[0058] R 8 represents a phenyl group in which a portion of the hydrogen atoms has been substituted with at least one element or electron-withdrawing group. Examples of such an element include a halogen atom, such as a fluorine atom, a chlorine atom, and a bromine atom. Examples of electron-withdrawing groups include a trifluoromethyl group, a nitro group, and a cyano group. Of these, a phenyl group in which one hydrogen atom has been substituted with a fluorine atom or a trifluoromethyl group is preferred. c R 8 are mutually independent and therefore may be the same or different from each other.

[0059] B represents a boron atom, and Ga represents a gallium atom.

[0060] R 9represents an alkyl group having 1 to 20 carbon atoms, a perfluoroalkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a fluorine atom, and the alkyl group and perfluoroalkyl group may be linear, branched, or cyclic, and the aryl group may be unsubstituted or may have a substituent.

[0061] S represents a sulfur atom, O represents an oxygen atom, C represents a carbon atom, and N represents a nitrogen atom. a represents an integer of 4 to 6. b is preferably an integer of 1 to 5, more preferably 2 to 4, and particularly preferably 2 or 3. c is preferably an integer of 1 to 4, and more preferably 4.

[0062] MY a - The anion represented by is SbF6 - , PF6 - and BF4 - Examples of the anion include anions represented by the following formula:

[0063] (Rf) b PF 6-b - The anion represented by (CF3CF2)2PF4 - , (CF3CF2)3PF3 - , ((CF3)2CF)2PF4 - , ((CF3)2CF)3PF3 - , (CF3CF2CF2)2PF4 - , (CF3CF2CF2)3PF3 - , ((CF3)2CFCF2)2PF4 - , ((CF3)2CFCF2)3PF3 - , (CF3CF2CF2CF2)2PF4 - and (CF3CF2CF2CF2)3PF3 - Among these, anions represented by (CF3CF2)3PF3 - , (CF3CF2CF2)3PF3 - , ((CF3)2CF)3PF3 - , ((CF3)2CF)2PF4 -, ((CF3)2CFCF2)3PF3 - and ((CF3)2CFCF2)2PF4 - Anions represented by the following formula are preferred.

[0064] R 8 c BY 4-c - As an anion represented by (C6F5)4B - , ((CF3)2C6H3)4B - , (CF3C6H4)4B - , (C6F5)2BF2 - , C6F5BF3 - and (C6H3F2)4B - Among these, anions represented by (C6F5)4B - and ((CF3)2C6H3)4B - Anions represented by the following formula are preferred.

[0065] R 8 c Gay 4-c - The anion represented by the formula is (C6F5)4Ga - , ((CF3)2C6H3)4Ga - , (CF3C6H4)4Ga - , (C6F5)2GaF2 - , C6F5GaF3 - and (C6H3F2)4Ga - Among these, (C6F5)4Ga - and ((CF3)2C6H3)4Ga - Anions represented by the following formula are preferred.

[0066] R 9 SO3 -Examples of the anion represented by the formula (I) include a trifluoromethanesulfonate anion, a pentafluoroethanesulfonate anion, a heptafluoropropanesulfonate anion, a nonafluorobutanesulfonate anion, a pentafluorophenylsulfonate anion, a fluorosulfonate anion, a p-toluenesulfonate anion, a benzenesulfonate anion, a camphorsulfonate anion, a methanesulfonate anion, an ethanesulfonate anion, a propanesulfonate anion, a butanesulfonate anion, and an octanesulfonate anion. Among these, a trifluoromethanesulfonate anion, a nonafluorobutanesulfonate anion, a methanesulfonate anion, a butanesulfonate anion, a camphorsulfonate anion, a benzenesulfonate anion, and a p-toluenesulfonate anion are preferred.

[0067] (R 9 SO2)3C - The anion represented by (FSO2)3C - , (CF3SO2)3C - , (C2F5SO2)3C - , (C3F7SO2)3C - and (C4F9SO2)3C - Examples of the anion include anions represented by the following formula:

[0068] (R 9 SO2)2N - The anion represented by (FSO2)2N - , (CF3SO2)2N - , (C2F5SO2)2N - , (C3F7SO2)2N - and (C4F9SO2)2N - Examples of the anion include anions represented by the following formula:

[0069] Monovalent polyatomic anions include MY a - , (Rf) b PF 6-b - , R 8 c BY 4-c- , R 8 c Gay 4-c - , R 9 SO3 - , (R 9 SO2)3C - or (R 9 SO2)2N - In addition to the anions represented by - , BrO4 - etc.), halogenated sulfonate ions (FSO3 - , ClSO3 - etc.), sulfate ions (CH3SO4 - , CF3SO4 - , HSO4 - etc.), carbonate ions (HCO3 - , CH3CO3 - etc.), aluminate ions (AlCl4 - , AlF4 - , Al(OC4F9)4 - etc.), hexafluorobismuthate ion (BiF6 - ), carboxylate ion (CH3COO - , CF3COO - , C6H5COO - , CH3C6H4COO - , C6F5COO - , CF3C6H4COO - etc.), aryl borate ions (B(C6H5)4 - , CH3CH2CH2CH2B(C6H5)3 - etc.), thiocyanate ion (SCN - ) and nitrate ions (NO3 - ) etc. can be used.

[0070] These X - Among them, MY a - , (Rf) b PF 6-b - , R 8 c BY 4-c - , R 8 c Gay4-c - , R 9 SO3 - , (R 9 SO2)3C - or (R 9 SO2)2N - The anion represented by the formula: SbF6 is preferred. - , PF6 - , (CF3CF2)3PF3 - , ((CF3)2CF)3PF3 - , (CF3CF2CF2)3PF3 - , (C6F5)4B - , ((CF3)2C6H3)4B - , (C6F5)4Ga - , ((CF3)2C6H3)4Ga - , trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, butanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion, p-toluenesulfonate anion, (FSO2)3C - , (CF3SO2)3C - , (FSO2)2N - and (CF3SO2)2N - is more preferable in terms of improving the resist resolution and pattern shape, and (CF3CF2)3PF3 - , ((CF3)2CF)3PF3 - , (CF3CF2CF2)3PF3 - , nonafluorobutanesulfonate anion, (C6F5)4B - and ((CF3)2C6H3)4B - , (CF3SO2)3C - is particularly preferred because it has good compatibility with the resist composition.

[0071] The sulfonium salt represented by formula (1) can be produced by known production methods, such as reacting a diaryl sulfide with chlorine, reacting a diaryl sulfide with chlorine and an aromatic hydrocarbon such as benzene, reacting a diaryl sulfide with a diaryliodonium salt in the presence of a copper catalyst, or reacting a diaryl sulfide with a diaryl sulfoxide in the presence of a dehydrating agent.

[0072] The dehydrating agent is not particularly limited, and any agent that is used as a dehydrating agent in organic chemical reactions may be used, such as concentrated sulfuric acid, phosphoric anhydride, methanesulfonic acid, trifluoromethanesulfonic acid, or anhydrides thereof, and two or more of these may be mixed and used. A solvent may also be used as appropriate.

[0073] When diaryl sulfoxide and diaryl sulfide are reacted in the presence of a dehydrating agent, the molar ratio of sulfoxide to sulfide is 10:1 to 1:1, more preferably 7:1 to 2:1, and most preferably 5:1 to 2.5:1. The reaction temperature is -10°C to 70°C, preferably 0°C to 50°C, and most preferably 10°C to 30°C.

[0074] After the reaction, the sulfonium salt can be efficiently produced by exchanging the anion with an acid (HX) and salt (AXn) having an anion represented by X in formulas (1) and (3). - where n represents the number of anions X relative to the valence of cation A. A represents an alkali metal such as Na, K, or Li, an alkaline earth metal such as Mg or Ca, or an ammonium cation. Alkali metals are more preferred because of the ease of obtaining raw materials and the ease of purifying the sulfonium salt produced.

[0075] High performance liquid chromatography (HPLC) is used to analyze the content of the photoacid generator of the present invention containing the sulfonium salt (CA) represented by general formula (1) and the compound (S) represented by general formula (2). The content can be determined by calculating the ratio of the peak area of ​​compound (S) to the sum of the peak areas of the sulfonium salt (CA) and compound (S) obtained by HPLC, which is set to 100. The HPLC measurement conditions are as follows. Instrument: Model (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.

[0076] The content of the sulfonium salt (CA) represented by general formula (1) and the compound (S) represented by general formula (2) is determined according to the above content measurement method, such that the area ratio of compound (S) is 0.02 or more and 3.0 or less when the total area of ​​the sulfonium salt (CA) and compound (S) is taken as 100. It is believed that the inclusion of a certain amount of compound (S) represented by general formula (2) relative to the sulfonium salt (CA) represented by general formula (1) traps the generated conjugate acid and traps oxygen in the system, thereby suppressing coloration due to protonation, oxidation, etc.

[0077] The photoacid generator of the present invention may contain other conventionally known photoacid generators in addition to the sulfonium salts listed above, if necessary. Note that, in the following, the photoacid generator of the present invention means a sulfonium salt (CA) represented by general formula (1) and a compound (S) represented by general formula (2), but does not include other photoacid generators.

[0078] When another photoacid generator is contained, the content (mol %) of the other photoacid generator is preferably 0.1 to 100, more preferably 0.5 to 50, relative to the number of moles of the sulfonium salt (CA) represented by general formula (1) of the present invention.

[0079] Other photoacid generators include conventionally known ones such as onium salts (sulfonium, iodonium, selenium, ammonium, phosphonium, etc.) and salts of transition metal complex ions and anions.

[0080] In order to facilitate dissolution of the photoacid generator of the present invention in a cationically polymerizable compound or a chemically amplified resist composition, the photoacid generator may be dissolved in advance in a solvent that does not inhibit polymerization, crosslinking, deprotection reactions, etc.

[0081] Examples of the solvent 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; and monomethyl ethers, monoethyl ethers, monopropyl ethers, monobutyl ethers, and monophenyl ethers of ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and dipropylene glycol monoacetate. polyhydric alcohols such as ethanol and derivatives thereof; cyclic ethers such as dioxane; esters such as 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 acetate, and 3-methyl-3-methoxybutyl acetate; and aromatic hydrocarbons such as toluene and xylene.

[0082] When a solvent is used, the proportion of the solvent used is preferably 15 to 1000 parts by weight, more preferably 30 to 500 parts by weight, relative to 100 parts by weight of the photoacid generator of the present invention. The solvents used may be used alone or in combination of two or more kinds.

[0083] The photocurable composition of the present invention comprises the above-mentioned photoacid generator and a cationically polymerizable compound.

[0084] Examples of the cationically polymerizable compound that is a component of the photocurable composition include cyclic ethers (epoxides, oxetanes, etc.), ethylenically unsaturated compounds (vinyl ethers, styrenes, etc.), bicycloorthoesters, spiroorthocarbonates, and spiroorthoesters (see JP-A-11-060996, JP-A-09-302269, JP-A-2003-026993, JP-A-2002-206017, 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-200 8-20838, JP 2008-20839, JP 2008-20841, JP 2008-26660, JP 2008-26644, JP 2007-277327, "Photopolymer Handbook" edited by the Photopolymer Forum (1989, Industrial Research Institute), "UV / EB Curing Technology" edited by the General Technology Center (1982, General Technology Center), "UV / EB Curing Materials" edited by the RadTech Research Group (1992, CMC), "Causes of Curing Defects and Inhibitions in UV Curing and Countermeasures" edited by the Technical Information Association (2003, Technical Information Association), Color Materials, 68, (5), 286-293 (1995), Fine Chemicals, 29, (19), 5-14 (2000), etc.

[0085] As the epoxide, known epoxides can be used, including aromatic epoxides, alicyclic epoxides and aliphatic epoxides.

[0086] Examples of aromatic epoxides include glycidyl ethers of mono- or polyhydric phenols having at least one aromatic ring (phenol, bisphenol A, phenol novolak, and alkylene oxide adducts of these compounds).

[0087] Examples of alicyclic epoxides include compounds obtained by epoxidizing a compound having at least one cyclohexene or cyclopentene ring with an oxidizing agent (e.g., 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate).

[0088] Examples of aliphatic epoxides include polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts (1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, etc.), polyglycidyl esters of aliphatic polybasic acids (diglycidyl tetrahydrophthalate, etc.), and epoxidized products of long-chain unsaturated compounds (epoxidized soybean oil, epoxidized polybutadiene, etc.).

[0089] As the oxetane, known oxetanes can be used, and examples thereof include 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyl(3-ethyl-3-oxetanylmethyl)ether, 2-hydroxyethyl(3-ethyl-3-oxetanylmethyl)ether, 2-hydroxypropyl(3-ethyl-3-oxetanylmethyl)ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, oxetanylsilsesquioxetane, and phenol novolac oxetane.

[0090] As the ethylenically unsaturated compound, known cationically polymerizable monomers can be used, including aliphatic monovinyl ethers, aromatic monovinyl ethers, polyfunctional vinyl ethers, styrene, and cationically polymerizable nitrogen-containing monomers.

[0091] Examples of the aliphatic monovinyl ether include methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and cyclohexyl vinyl ether.

[0092] Examples of aromatic monovinyl ethers include 2-phenoxyethyl vinyl ether, phenyl vinyl ether, and p-methoxyphenyl vinyl ether.

[0093] Examples of polyfunctional vinyl ethers include butanediol-1,4-divinyl ether and triethylene glycol divinyl ether.

[0094] Examples of the styrene include styrene, α-methylstyrene, p-methoxystyrene, and p-tert-butoxystyrene.

[0095] Examples of the cationically polymerizable nitrogen-containing monomer include N-vinylcarbazole and N-vinylpyrrolidone.

[0096] Examples of bicyclo orthoesters 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.

[0097] 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.

[0098] Examples of spiro orthoesters include 1,4,6-trioxaspiro[4.4]nonane, 2-methyl-1,4,6-trioxaspiro[4.4]nonane, and 1,4,6-trioxaspiro[4.5]decane.

[0099] Furthermore, polyorganosiloxanes having at least one cationically polymerizable group per molecule can be used (e.g., those described in JP-A Nos. 2001-348482, 2000-281965, 2007-242828, and 2008-195931, Journal of Polym. Sci., Part A, Polym. Chem., Vol. 28, 497 (1990), etc.). These polyorganosiloxanes may be linear, branched, or cyclic, or may be mixtures of these.

[0100] 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 in combination of two or more.

[0101] The content of the photoacid generator of the present invention in the photocurable composition is preferably 0.05 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the cationically polymerizable compound. Within this range, polymerization of the cationically polymerizable compound is more sufficient, resulting in better physical properties of the cured product. Note that this content is determined by taking into consideration various factors such as the properties of the cationically polymerizable compound, the type of light (light source, wavelength, etc.), the irradiation dose, temperature, curing time, humidity, and coating thickness, and is not limited to the above range.

[0102] The photocurable composition of the present invention may contain known additives (sensitizers, pigments, fillers, antistatic agents, flame retardants, antifoaming agents, flow control agents, light stabilizers, antioxidants, adhesion imparting agents, ion scavengers, coloration inhibitors, solvents, non-reactive resins, radically polymerizable compounds, etc.) as needed.

[0103] As the sensitizer, known sensitizers (such as those disclosed in JP-A-11-279212 and JP-A-09-183960) can be used, and examples thereof include 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; Thioxanthone {thioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 2,4-diethylthioxanthone, etc.}; Phenothiazine {phenothiazine, N-methylphenothiazine, N-ethylphenothiazine, N-phenylphenothiazine, etc.}; Xanthone; Naphthalene {1-naphthol, 2-naphthol, 1-methoxal, ketones {dimethoxyacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 4'-isopropyl-2-hydroxy-2-methylpropiophenone, 4-benzoyl-4'-methyldiphenyl sulfide, etc.}; carbazoles {N-phenylcarbazole, N-ethylcarbazole, poly-N-vinylcarbazole, N-glycidylcarbazole, etc.}; chrysene {1,4-dimethoxychrysene, 1,4-di-α-methylbenzyloxychrysene, etc.}; phenanthrene {9-hydroxyphenanthrene, 9-methoxyphenanthrene, 9-hydroxy-10-methoxyphenanthrene, 9-hydroxy-10-ethoxyphenanthrene, etc.};

[0104] When a sensitizer is contained, the content of the sensitizer is preferably 1 to 300 parts by weight, more preferably 5 to 200 parts by weight, relative to 100 parts of the photoacid generator.

[0105] 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.).

[0106] When a pigment is contained, the content of the pigment is preferably 0.5 to 400,000 parts by weight, and more preferably 10 to 150,000 parts by weight, relative to 100 parts of the photoacid generator.

[0107] As the filler, known fillers can be used, such as fused silica, crystalline silica, calcium carbonate, aluminum oxide, aluminum hydroxide, zirconium oxide, magnesium carbonate, mica, talc, calcium silicate, and lithium aluminum silicate.

[0108] When a filler is contained, the content of the filler is preferably 50 to 600,000 parts by weight, and more preferably 300 to 200,000 parts by weight, per 100 parts of the photoacid generator.

[0109] As the antistatic agent, known antistatic agents can be used, and examples thereof include nonionic antistatic agents, anionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, and polymeric antistatic agents.

[0110] When an antistatic agent is contained, the content of the antistatic agent is preferably 0.1 to 20,000 parts by weight, and more preferably 0.6 to 5,000 parts by weight, relative to 100 parts of the photoacid generator.

[0111] As the flame retardant, known flame retardants can be used, and examples thereof include inorganic flame retardants {antimony trioxide, antimony pentoxide, tin oxide, tin hydroxide, molybdenum oxide, zinc borate, barium metaborate, red phosphorus, aluminum hydroxide, magnesium hydroxide, calcium aluminate, etc.}; bromine flame retardants {tetrabromophthalic anhydride, hexabromobenzene, decabromobiphenyl ether, etc.}; and phosphate ester flame retardants {tris(tribromophenyl)phosphate, etc.}.

[0112] When a flame retardant is contained, the content of the flame retardant is preferably 0.5 to 40,000 parts by weight, and more preferably 5 to 10,000 parts by weight, per 100 parts of the photoacid generator.

[0113] As the defoaming agent, known defoaming agents can be used, and examples thereof include alcohol defoaming agents, metal soap defoaming agents, phosphate ester defoaming agents, fatty acid ester defoaming agents, polyether defoaming agents, silicone defoaming agents, and mineral oil defoaming agents.

[0114] As the flow modifier, known flow modifiers can be used, and examples thereof include hydrogenated castor oil, oxidized polyethylene, organic bentonite, colloidal silica, amide wax, metal soap, and acrylic ester polymer. As the light stabilizer, known light stabilizers can be used, and examples thereof include ultraviolet absorbing stabilizers (benzotriazole, benzophenone, salicylate, cyanoacrylate, and derivatives thereof, etc.); radical scavenging stabilizers (hindered amines, etc.); and quenching stabilizers (nickel complexes, etc.). As the antioxidant, known antioxidants can be used, and examples thereof include phenol-based antioxidants (monophenol-based, bisphenol-based, polymeric phenol-based, etc.), sulfur-based antioxidants, and phosphorus-based antioxidants. As the adhesion promoter, known adhesion promoters can be used, and examples thereof include coupling agents, silane coupling agents, and titanium coupling agents. As the ion scavenger, known ion scavenger can be used, and examples thereof include organic aluminum (alkoxy aluminum, phenoxy aluminum, etc.). As the coloring inhibitor, known coloring inhibitors can be used, and generally, antioxidants are effective, and examples thereof include phenol-based antioxidants (monophenol-based, bisphenol-based, polymeric phenol-based, etc.), sulfur-based antioxidants, and phosphorus-based antioxidants, but they are almost ineffective in preventing coloring during heat resistance tests at high temperatures.

[0115] When an antifoaming agent, a flow control agent, a light stabilizer, an antioxidant, an adhesion imparting agent, an ion scavenger, or a coloring inhibitor is contained, the content of each is preferably 0.1 to 20,000 parts by weight, and more preferably 0.5 to 5,000 parts by weight, relative to 100 parts of the photoacid generator.

[0116] There are no limitations on the solvent as long as it can be used to dissolve the cationically polymerizable compound and adjust the viscosity of the photocurable composition, and the solvents listed above as solvents for the photoacid generator can be used.

[0117] When a solvent is contained, the content of the solvent is preferably 50 to 2,000,000 parts by weight, and more preferably 200 to 500,000 parts by weight, relative to 100 parts of the photoacid generator.

[0118] Examples of non-reactive resins include polyester, polyvinyl acetate, polyvinyl chloride, polybutadiene, polycarbonate, polystyrene, polyvinyl ether, polyvinyl butyral, polybutene, hydrogenated styrene-butadiene block copolymer, (meth)acrylic acid ester copolymer, polyurethane, etc. 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).

[0119] When a non-reactive resin is contained, the content of the non-reactive resin is preferably 5 to 400,000 parts by weight, and more preferably 50 to 150,000 parts by weight, relative to 100 parts of the photoacid generator.

[0120] When a non-reactive resin is contained, it is desirable to dissolve the non-reactive resin in a solvent in advance so that the non-reactive resin can be easily dissolved in the cationically polymerizable compound or the like.

[0121] Examples of radical polymerizable compounds that can be used include known radical polymerizable compounds such as those described in "Photopolymer Handbook" edited by the Photopolymer Forum (1989, Industrial Research Institute), "UV / EB Curing Technology" edited by the General Technology Center (1982, General Technology Center), "UV / EB Curing Materials" edited by the RadTech Research Group (1992, CMC), and "Causes of Curing Failure and Inhibition in UV Curing and Countermeasures Therefor" edited by the Technical Information Association (2003, Technical Information Association), and include monofunctional monomers, bifunctional monomers, polyfunctional monomers, epoxy (meth)acrylates, polyester (meth)acrylates, and urethane (meth)acrylates.

[0122] When a radical polymerizable compound is contained, the content of the radical polymerizable compound is preferably 5 to 400,000 parts by weight, and more preferably 50 to 150,000 parts by weight, relative to 100 parts of the photoacid generator.

[0123] When a radically polymerizable compound is 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 the compound by radical polymerization.

[0124] As the radical polymerization initiator, known radical polymerization initiators can be used, including thermal radical polymerization initiators (organic peroxides, azo compounds, etc.) and photoradical polymerization initiators (acetophenone-based initiators, benzophenone-based initiators, Michler's ketone-based initiators, benzoin-based initiators, thioxanthone-based initiators, acylphosphine-based initiators, etc.).

[0125] 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, based on 100 parts of the radical polymerizable compound.

[0126] The photocurable composition of the present invention can be prepared by uniformly mixing and dissolving the cationically polymerizable compound, the photoacid generator, and, if necessary, the additives at room temperature (about 20 to 30°C) or, if necessary, under heating (about 40 to 90°C), or by further kneading them using a three-roll mill or the like.

[0127] The photocurable composition of the present invention can be cured by irradiation with light to obtain a cured product. The light used here may be any light as long as it has enough energy to induce decomposition of the photoacid generator of the present invention. However, light in the ultraviolet to visible light range (wavelength: about 100 to about 800 nm) obtained from a low-pressure, medium-pressure, high-pressure, or ultra-high-pressure mercury lamp, metal halide lamp, LED lamp, xenon lamp, carbon arc lamp, fluorescent lamp, semiconductor solid-state laser, argon laser, He-Cd laser, KrF excimer laser, ArF excimer laser, or F2 laser is preferred. High-energy radiation such as electron beams or X-rays can also be used as the light.

[0128] The light irradiation time is affected by the intensity of the light source and the light transmittance of the photocurable composition, but 0.1 to 10 seconds at room temperature (approximately 20 to 30°C) is sufficient. However, if the light transmittance is low or the film thickness of the photocurable composition is thick, it may be preferable to use a longer irradiation time. Most photocurable compositions cure by cationic polymerization within 0.1 seconds to several minutes after light irradiation, but if necessary, they can be post-cured by heating at room temperature (approximately 20 to 30°C) to 200°C for several seconds to several hours after light irradiation.

[0129] Specific applications of the photocurable composition of the present invention include paints, coating agents, various coating materials (hard coats, stain-resistant coatings, anti-fogging coatings, contact-resistant coatings, optical fibers, etc.), backside treatment agents for adhesive tapes, release coating materials for release sheets for adhesive labels (release paper, release plastic films, release metal foils, etc.), printing plates, dental materials (dental compounds, dental composites), inkjet inks, resist films, liquid resists, negative resists (surface protective films for semiconductor elements, etc., interlayer insulating films, permanent film materials such as planarizing films, etc.), resists for MEMS, negative photosensitive materials, various adhesives (temporary fixing agents for various electronic components, Examples of applications include adhesives for HDDs, adhesives for pickup lenses, adhesives for functional films for FPDs (deflectors, anti-reflection films, etc.), resins for holographs, FPD materials (color filters, black matrices, partition materials, photospacers, ribs, alignment films for liquid crystal displays, sealants for FPDs, etc.), optical components, molding materials (for construction materials, optical parts, lenses), casting materials, putty, glass fiber impregnation agents, fillers, sealants, encapsulants, optical semiconductor (LED) encapsulants, optical waveguide materials, nanoimprint materials, materials for stereolithography and micro stereolithography, and the resulting cured products have little coloring and excellent transparency, making them ideal for optical applications.

[0130] Since the photoacid generator of the present invention generates a strong acid upon irradiation with light, it can also be used as a photoacid generator for known chemically amplified resist materials (e.g., JP-A Nos. 2003-267968, 2003-261529, and 2002-193925).

[0131] Chemically amplified resist materials include (1) two-component chemically amplified positive resists containing, as essential components, a resin that becomes soluble in an alkaline developer under the action of acid and a photoacid generator, (2) three-component chemically amplified positive resists containing, as essential components, a resin that is soluble in an alkaline developer, a dissolution inhibitor that becomes soluble in an alkaline developer under the action of acid, and a photoacid generator, and (3) chemically amplified negative resists containing, as essential components, a resin that is soluble in an alkaline developer, a crosslinker that crosslinks the resin by heat treatment in the presence of acid to make it insoluble in an alkaline developer, and a photoacid generator. From the viewpoint of yellowing resistance, the photoacid generator of the present invention is preferably used in chemically amplified negative resists that are used as protective films, etc. even after pattern formation.

[0132] The chemically amplified negative photoresist composition of the present invention is characterized by containing a component (E) containing the photoacid generator of the present invention, which is a compound that generates an acid upon exposure to light or radiation, an alkali-soluble resin (F) having a phenolic hydroxyl group, and a crosslinking agent (G).

[0133] In the chemically amplified negative photoresist composition of the present invention, component (E) may be used in combination with other conventionally known photoacid generators, such as onium salt compounds, sulfone compounds, sulfonate ester compounds, sulfonimide compounds, disulfonyldiazomethane compounds, disulfonylmethane compounds, oxime sulfonate compounds, hydrazine sulfonate compounds, triazine compounds, and nitrobenzyl compounds, as well as organic halides and disulfones.

[0134] As other conventionally known photoacid generators, one or more compounds selected from the group consisting of onium compounds, sulfonimide compounds, diazomethane compounds and oxime sulfonate compounds are preferred.

[0135] When such other conventionally known photoacid generators are used in combination, the proportions thereof may be arbitrary, but typically the proportion of the other photoacid generators is 10 to 900 parts by weight, preferably 25 to 400 parts by weight, per 100 parts by weight of the total weight of the photoacid generators of the present invention.

[0136] The content of the component (E) is preferably 0.01 to 10% by weight of the solid content of the chemically amplified negative photoresist composition.

[0137] Alkali-soluble resin containing phenolic hydroxyl groups (F) Examples of the "alkali-soluble resin having a phenolic hydroxyl group" (hereinafter referred to as "phenolic resin (F)") used in the present invention include novolak resins, polyhydroxystyrenes, copolymers of polyhydroxystyrenes, copolymers of hydroxystyrene and styrene, copolymers of hydroxystyrene, styrene and a (meth)acrylic acid derivative, phenol-xylylene glycol condensation resins, cresol-xylylene glycol condensation resins, and phenol-dicyclopentadiene condensation resins. Among these, novolak resins, polyhydroxystyrenes, copolymers of polyhydroxystyrenes, copolymers of hydroxystyrene and styrene, copolymers of hydroxystyrene, styrene and a (meth)acrylic acid derivative, and phenol-xylylene glycol condensation resins are preferred. These phenolic resins (F) may be used alone or in combination of two or more.

[0138] The phenolic resin (F) may contain a low molecular weight phenolic compound as part of its components. Examples of the phenolic low molecular weight compound include 4,4'-dihydroxydiphenylmethane and 4,4'-dihydroxydiphenyl ether.

[0139] Crosslinker (G) The "crosslinking agent" (hereinafter also referred to as "crosslinking agent (G)") in the present invention is not particularly limited as long as it acts as a crosslinking component (curing component) that reacts with the phenolic resin (F). Examples of the crosslinking agent (G) include compounds having at least two or more alkyl-etherified amino groups in the molecule, compounds having at least two or more alkyl-etherified benzene groups in the molecule as a skeleton, oxirane ring-containing compounds, thiirane ring-containing compounds, oxetanyl group-containing compounds, and isocyanate group-containing compounds (including blocked compounds).

[0140] Among these crosslinking agents (G), compounds having at least two alkyl-etherified amino groups in the molecule and oxirane ring-containing compounds are preferred, and it is more preferred to use a compound having at least two alkyl-etherified amino groups in the molecule and an oxirane ring-containing compound in combination.

[0141] The amount of the crosslinking agent (G) in the present invention is preferably 1 to 100 parts by weight, more preferably 5 to 50 parts by weight, relative to 100 parts by weight of the phenolic resin (F). When the amount of the crosslinking agent (G) is 1 to 100 parts by weight, the curing reaction proceeds sufficiently, and the resulting cured product has a high resolution and a good pattern shape, and is excellent in heat resistance and electrical insulation, which is preferable. Furthermore, when a compound having an alkyl-etherified amino group and an oxirane ring-containing compound are used in combination, the content of the oxirane ring-containing compound is preferably 50% by weight or less, more preferably 5 to 40% by weight, and particularly preferably 5 to 30% by weight, when the total of the compound having an alkyl-etherified amino group and the oxirane ring-containing compound is taken as 100% by weight. In this case, the resulting cured film is preferable because it has excellent chemical resistance without impairing high resolution.

[0142] Crosslinked fine particles (H) The chemically amplified negative photoresist composition of the present invention may further contain crosslinked fine particles (hereinafter also referred to as "crosslinked fine particles (H)") in order to improve the durability and thermal shock resistance of the resulting cured product.

[0143] The average particle size of the crosslinked fine particles (H) is usually 30 to 500 nm, preferably 40 to 200 nm, and more preferably 50 to 120 nm. The method for controlling the particle size of the crosslinked microparticles (H) is not particularly limited. For example, when synthesizing crosslinked microparticles by emulsion polymerization, the particle size can be controlled by controlling the number of micelles during emulsion polymerization through the amount of emulsifier used. The average particle size of the crosslinked fine particles (H) is a value measured by diluting a dispersion of the crosslinked fine particles in a conventional manner using a light scattering flow distribution measuring device or the like.

[0144] The amount of crosslinked fine particles (H) blended is preferably 0.5 to 50 parts by weight, more preferably 1 to 30 parts by weight, per 100 parts by weight of the phenolic resin (F). When the amount of crosslinked fine particles (H) blended is 0.5 to 50 parts by weight, excellent compatibility or dispersibility with other components can be achieved, and the thermal shock resistance and heat resistance of the resulting cured film can be improved.

[0145] Adhesion aid The chemically amplified negative photoresist composition of the present invention may also contain an adhesion aid in order to improve adhesion to a substrate. Examples of the adhesion aid include functional silane coupling agents having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, or an epoxy group.

[0146] The amount of the adhesion aid is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, relative to 100 parts by weight of the phenolic resin (F). When the amount of the adhesion aid is 0.2 to 10 parts by weight, excellent storage stability and good adhesion can be obtained, which is preferable.

[0147] solvent The chemically amplified negative photoresist composition of the present invention may contain a solvent in order to improve the handleability of the resin composition and to adjust the viscosity and storage stability. The solvent is not particularly limited, but specific examples include those described above.

[0148] Other additives The chemically amplified negative photoresist composition of the present invention may contain other additives, if necessary, to the extent that the properties of the present invention are not impaired. Examples of such additives include inorganic fillers, sensitizers, quenchers, leveling agents, surfactants, etc.

[0149] The method for preparing the chemically amplified negative photoresist composition of the present invention is not particularly limited, and it can be prepared by any known method. It can also be prepared by stirring a sample bottle containing each component and a completely stoppered sample bottle on a wave rotor.

[0150] The cured product of the present invention is characterized by being obtained by curing the chemically amplified negative photoresist composition. The chemically amplified negative photoresist composition according to the present invention has a high film retention rate and excellent resolution, and the cured product thereof has excellent electrical insulation properties, thermal shock resistance, etc., and therefore the cured product thereof can be suitably used as a surface protection film, a planarizing film, an interlayer insulating film material, etc. for electronic components such as semiconductor elements and semiconductor packages.

[0151] To form the cured product of the present invention, the aforementioned chemically amplified negative photoresist composition of the present invention is first applied to a support (such as a resin-coated copper foil, a copper-clad laminate, or a silicon wafer or alumina substrate with a metal sputtered film), and then dried to volatilize the solvent, forming a coating film. The resulting coating is then exposed to light through a desired mask pattern and heat-treated (hereinafter, this heat treatment is referred to as "PEB") to promote the reaction between the phenolic resin (F) and the crosslinking agent (G). The resulting coating is then developed with an alkaline developer to dissolve and remove the unexposed areas, yielding the desired pattern. A heat treatment is then performed to develop insulating film properties, yielding a cured film.

[0152] The resin composition can be applied to a support by a coating method such as dipping, spraying, bar coating, roll coating, spin coating, etc. The thickness of the coating film can be appropriately controlled by adjusting the coating means and the solids concentration and viscosity of the composition solution. Here, "light" is synonymous with active energy rays and may be any light that activates a photoacid generator to generate an acid, including ultraviolet rays, visible light, and far ultraviolet rays, and "radiation" refers to X-rays, electron beams, ion beams, etc. Examples of sources of light or radiation include ultraviolet rays from low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, g-line steppers, h-line steppers, i-line steppers, gh-line steppers, ghi-line steppers, and the like, electron beams, and laser beams. The exposure dose is appropriately selected depending on the light source used, the resin film thickness, and the like. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, the exposure dose is 100 to 50,000 J / m for a resin film thickness of 1 to 50 μm. 2 That's about it.

[0153] After exposure, the PEB treatment is carried out to promote the curing reaction between the phenolic resin (F) and the crosslinking agent (G) due to the generated acid. The PEB conditions vary depending on the amount of resin composition used, the film thickness used, and other factors, but are typically performed at 70 to 150°C, preferably 80 to 120°C, for approximately 1 to 60 minutes. The film is then developed with an alkaline developer to dissolve and remove the unexposed areas, forming the desired pattern. Examples of development methods include shower development, spray development, immersion development, and puddle development. Development conditions typically involve a temperature of 20 to 40°C for approximately 1 to 10 minutes.

[0154] Furthermore, after development, the composition can be sufficiently cured by a heat treatment to fully develop its insulating film properties. The curing conditions are not particularly limited, but depending on the intended use of the cured product, the composition can be cured by heating at a temperature of 50 to 250°C for approximately 30 minutes to 10 hours. Alternatively, to fully promote curing or prevent deformation of the resulting pattern, the composition can be heated in two stages. For example, in the first stage, the composition can be heated at a temperature of 50 to 120°C for approximately 5 minutes to 2 hours, and then further heated at a temperature of 80 to 250°C for approximately 10 minutes to 10 hours to achieve curing. Under these curing conditions, a typical oven, infrared furnace, or the like can be used as heating equipment. [Example]

[0155] The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited thereto. In each example, parts are by weight.

[0156] [Production Example 1] Synthesis of Photoacid Generator (PAG-1) 43 g of potassium hexafluorophosphate, 100 mL of acetonitrile, 36 g of diphenyl sulfide, 60 g of acetic anhydride, and 23 g of concentrated sulfuric acid were mixed uniformly. A solution of 40 g of diphenyl sulfoxide in 50 mL of acetonitrile was added dropwise below 40°C. After stirring at 40°C for 3 hours, the mixture was cooled to room temperature, 200 mL of water was added, and the mixture was stirred for 10 minutes, resulting in the separation of an oily substance. 200 mL of ethyl acetate was added to dissolve the oily substance, and the organic layer was separated. This organic layer was washed with 100 mL of 20% caustic soda and then with 100 mL of water three times. The acetonitrile and ethyl acetate were then distilled off under reduced pressure to obtain a pale yellow solid. Crystallization from dichloromethane / hexane yielded 85 g of a white solid (88% yield). Analyses by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of hexafluorophosphate (CA-1) having the cationic structure of (C-1) and compound (S1-1), with a ratio of 99.25:0.75.

[0157] [Production Example 2] Synthesis of Photoacid Generator (PAG-2) 98 g of a white solid was obtained (yield 87%) in the same manner as in Production Example 1, except that 43 g of potassium hexafluorophosphate was replaced with 55 g of potassium hexafluoroantimonate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of hexafluoroantimonate (CA-2) having the cation structure of (C-1) and compound (S1-1), with the ratio being 99.81:0.19.

[0158] [Production Example 3] Synthesis of Photoacid Generator (PAG-3) A white solid (115 g, 59% yield) was obtained in the same manner as in Production Example 1, except that 43 g of potassium hexafluorophosphate was replaced with 160 g of lithium tetrakispentafluorophenylborate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of tetrakispentafluorophenylborate salt (CA-3) having the cation structure of (C-1) and compound (S1-1), with the ratio being 99.45:0.55.

[0159] [Production Example 4] Synthesis of Photoacid Generator (PAG-4) Except for changing 43 g of potassium hexafluorophosphate to 101 g of potassium trispentafluoroethyl trifluorophosphate in Production Example 1, 106 g of a white solid was obtained (70% yield) in the same manner as in Production Example 1. Analysis by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-4) having the cation structure of (C-1) and compound (S1-1), with the ratio being 99.64:0.36.

[0160] [Production Example 5] Synthesis of Photoacid Generator (PAG-5) A white solid (130 g, yield 63%) was obtained in the same manner as in Production Example 1, except that 43 g of potassium hexafluorophosphate was replaced with 177 g of sodium tetrakispentafluorophenyl gallate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of tetrakispentafluorophenyl gallate salt (CA-5) having the cation structure of (C-1) and compound (S1-1), with the ratio being 99.01:0.99.

[0161] [Production Example 6] Synthesis of Photoacid Generator (PAG-6) A pale yellow solid (86 g, 84% yield) was obtained in the same manner as in Production Example 1, except that 40 g of diphenyl sulfoxide was replaced with 47 g of 4,4'-difluorodiphenyl sulfoxide. Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate salt (CA-6) having the cation structure of (C-2) and compound (S2-1), with the ratio being 99.14:0.86.

[0162] [Production Example 7] Synthesis of photoacid generator (PAG-7) A pale yellow solid (109 g, yield 69%) was obtained in the same manner as in Production Example 1, except that 40 g of diphenyl sulfoxide was replaced with 47 g of 4,4'-difluorodiphenyl sulfoxide and 43 g of potassium hexafluorophosphate was replaced with 101 g of potassium trispentafluoroethyl trifluorophosphate. Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-7) having the cation structure of (C-2) and compound (S2-1), with the ratio being 99.04:0.96.

[0163] [Production Example 8] Synthesis of photoacid generator (PAG-8) A pale yellow solid (151 g, yield 71%) was obtained in the same manner as in Production Example 1, except that 40 g of diphenyl sulfoxide was replaced with 47 g of 4,4'-difluorodiphenyl sulfoxide and 43 g of potassium hexafluorophosphate was replaced with 177 g of sodium tetrakispentafluorophenyl gallate. Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of tetrakispentafluorophenyl gallate salt (CA-8) having the cation structure of (C-2) and compound (S2-1), with the ratio being 99.11:0.89.

[0164] [Production Example 9] Synthesis of photoacid generator (PAG-9) Except for changing 40 g of diphenyl sulfoxide to 67 g of 2-phenylsulfenylthioxanthone and 36 g of diphenyl sulfide to 62 g of 2-phenylthiothioxanthone in Production Example 1, 117 g of a yellow solid was obtained (yield 80%) in the same manner as in Production Example 1. Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of hexafluorophosphate salt (CA-9) having the cation structure of (C-8), compound (S8-1), and compound (S8-2), with the ratio being 99.22:0.75:0.03.

[0165] [Production Example 10] Synthesis of Photoacid Generator (PAG-10) The same procedure as in Production Example 1 was repeated, except that 40 g of diphenyl sulfoxide was replaced with 67 g of 2-phenylsulfenylthioxanthone, 36 g of diphenyl sulfide was replaced with 62 g of 2-phenylthiothioxanthone, and 43 g of potassium hexafluorophosphate was replaced with 160 g of lithium tetrakispentafluorophenylborate, to obtain 182 g of a yellow solid (74% yield). Analyses by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-10) having the cation structure of (C-8), compound (S8-1), and compound (S8-2), with the ratio being 99.22:0.75:0.03.

[0166] [Production Example 11] Synthesis of Photoacid Generator (PAG-11) Except for changing the amounts of diphenyl sulfoxide (40 g) to 67 g of 2-phenylsulfenylthioxanthone, diphenyl sulfide (36 g) to 62 g of 2-phenylthiothioxanthone, and potassium hexafluorophosphate (43 g) to 101 g of potassium trispentafluoroethyl trifluorophosphate in Production Example 1, 149 g of a yellow solid was obtained (74% yield) in the same manner as in Production Example 1. Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-11) having the cation structure (C-8), compound (S8-1), and compound (S8-2), with the ratio being 99.32:0.65:0.03.

[0167] [Production Example 12] Synthesis of Photoacid Generator (PAG-12) Except for changing 40 g of diphenyl sulfoxide to 66 g of 2-phenylsulfenyl anthraquinone and 36 g of diphenyl sulfide to 61 g of 2-phenylthioanthraquinone in Production Example 1, 101 g of a yellow solid was obtained (70% yield) in the same manner as in Production Example 1. Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of hexafluorophosphate salt (CA-12) having the cation structure of (C-9), compound (S9-1), and compound (S9-2), with the ratio being 99.71:0.27:0.02.

[0168] [Production Example 13] Synthesis of photoacid generator (PAG-13) The same procedure as in Production Example 1 was repeated, except that 40 g of diphenyl sulfoxide was replaced with 61 g of 2-phenylthioanthraquinone, 36 g of diphenyl sulfide with 66 g of 2-phenylsulfenyl anthraquinone, and 43 g of potassium hexafluorophosphate with 160 g of lithium tetrakispentafluorophenylborate. 168 g of a yellow solid was obtained (yield 66%). Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-13) having the cation structure of (C-9), compound (S9-1), and compound (S9-2), with the ratio being 99.44:0.54:0.02.

[0169] [Production Example 14] Synthesis of photoacid generator (PAG-14) The procedure was the same as in Production Example 1, except that 40 g of diphenyl sulfoxide was replaced with 61 g of 2-phenylthioanthraquinone, 36 g of diphenyl sulfide with 66 g of 2-phenylsulfenyl anthraquinone, and 43 g of potassium hexafluorophosphate with 177 g of sodium tetrakispentafluorophenyl gallate. 191 g of a yellow solid was obtained (75% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of tetrakispentafluorophenyl gallate salt (CA-14) having the cation structure (C-9), compound (S9-1), and compound (S9-2), with the ratio being 99.32:0.65:0.03.

[0170] [Production Example 15] Synthesis of Photoacid Generator (PAG-15) Except for changing 40 g of diphenyl sulfoxide to 67 g of 2-phenylsulfenylthianthrene and 36 g of diphenyl sulfide to 62 g of 2-phenylthiothianthrene in Production Example 1, 47 g of a yellow solid was obtained (yield 32%) in the same manner as in Production Example 1. Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of hexafluorophosphate salt (CA-15) having a (C-10) cation structure, compound (S10-1), and compound (S10-2), with the ratio being 99.23:0.75:0.02.

[0171] [Production Example 16] Synthesis of Photoacid Generator (PAG-16) The same procedure as in Production Example 1 was repeated, except that 40 g of diphenyl sulfoxide was replaced with 67 g of 2-phenylsulfenylthianthrene, 36 g of diphenyl sulfide with 62 g of 2-phenylthiothianthrene, and 43 g of potassium hexafluorophosphate with 160 g of lithium tetrakispentafluorophenylborate. 99 g of a yellow solid was obtained (40% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-16) having a (C-10) cation structure, compound (S10-1), and compound (S10-2), with the ratio being 99.12:0.85:0.03.

[0172] [Production Example 17] Synthesis of photoacid generator (PAG-17) The same procedure as in Production Example 1 was repeated, except that 40 g of diphenyl sulfoxide was replaced with 67 g of 2-phenylsulfenylthianthrene, 36 g of diphenyl sulfide with 62 g of 2-phenylthiothianthrene, and 43 g of potassium hexafluorophosphate with 177 g of sodium tetrakispentafluorophenyl gallate. 93 g of a yellow solid was obtained (yield 36%). Analysis by H-NMR, C-NMR, and HPLC confirmed that this yellow solid was a mixture of tetrakispentafluorophenyl gallate salt (CA-17) having a (C-10) cation structure, compound (S10-1), and compound (S10-2), with the ratio being 99.27:0.71:0.02.

[0173] [Production Example 18] Synthesis of photoacid generator (PAG-18) The product was dissolved in 7.9 g of diphenyl sulfoxide, 16 g of methanesulfonic acid, and 22 g of acetic anhydride. A solution of 8.9 g of 4-(phenylthio)acetophenone in 30 mL of acetonitrile was added dropwise thereto, keeping the temperature at 40°C, and the reaction was continued at 65°C for 3 hours. The reaction solution was cooled to room temperature, poured into 100 mL of ion-exchanged water, extracted with 100 g 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 removed, yielding a brown solid. This was washed with ethyl acetate and hexane, and the organic solvent was concentrated to obtain the methanesulfonate salt (intermediate-1) with the cation structure of (C-3). The structure was confirmed by H-NMR. 5.1 g of (Intermediate-1) was dissolved in 60 mL of dichloromethane and mixed with 50 g of an equimolar aqueous solution of sodium hexafluorophosphate at room temperature. The mixture was stirred for 3 hours. The dichloromethane layer was separated and washed five times with water. The mixture was then transferred to a rotary evaporator to remove the solvent, yielding a yellow solid. Further crystallization from dichloromethane / hexane yielded 4.3 g of a pale yellow solid (75% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-18) with the cationic structure of (C-3) and compound (S3-1), with a ratio of 99.17:0.83.

[0174] [Production Example 19] Synthesis of photoacid generator (PAG-19) A pale yellow solid (8.2 g, 74% yield) was obtained in the same manner as in Production Example 18, except that 50 g of the aqueous sodium hexafluorophosphate solution was replaced with 100 g of an aqueous lithium tetrakispentafluorophenylborate solution. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-19) having the cation structure of (C-3) and compound (S3-1), with the ratio being 99.07:0.93.

[0175] [Production Example 20] Synthesis of Photoacid Generator (PAG-20) A pale yellow solid (4.7 g, 81% yield) was obtained in the same manner as in Production Example 18, except that 50 g of the aqueous sodium hexafluorophosphate solution was replaced with 50 g of an aqueous potassium trifluoromethanesulfonate solution. Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-20) having the cation structure of (C-3) and compound (S3-1), with the ratio being 99.23:0.77.

[0176] [Production Example 21] Synthesis of Photoacid Generator (PAG-21) A pale yellow solid (7.4 g, 84% yield) was obtained in the same manner as in Production Example 18, except that 50 g of the sodium hexafluorophosphate aqueous solution was replaced with 50 g of potassium trispentafluoroethyl trifluorophosphate aqueous solution. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-21) having the cation structure (C-3) and compound (S3-1), with the ratio being 99.23:0.77.

[0177] [Production Example 22] Synthesis of Photoacid Generator (PAG-22) A pale yellow solid (6.2 g, 85% yield) was obtained in the same manner as in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of (3-benzoylphenyl)phenyl sulfoxide and 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of (3-benzoylphenyl)phenyl sulfide. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-22) having the cation structure of (C-4) and compound (S4-1), with the ratio being 98.85:1.15.

[0178] [Production Example 23] Synthesis of photoacid generator (PAG-23) The procedure was repeated in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of (3-benzoylphenyl)phenyl sulfoxide, 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of (3-benzoylphenyl)phenyl sulfide, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trispentafluoroethyl trifluorophosphate solution. 7.4 g of a pale yellow solid was obtained (72% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-23) having the cation structure (C-4) and compound (S4-1), with the ratio being 98.86:1.14.

[0179] [Production Example 24] Synthesis of photoacid generator (PAG-24) The procedure was repeated in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of (3-benzoylphenyl)phenyl sulfoxide, 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of (3-benzoylphenyl)phenyl sulfide, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trifluoromethanesulfonate solution, yielding 5.1 g of a pale yellow solid (70% yield). Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-24) having the cation structure of (C-4) and compound (S4-1), with the ratio being 98.92:1.08.

[0180] [Production Example 25] Synthesis of Photoacid Generator (PAG-25) The procedure was repeated in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 11 g of 4-[(phenyl)sulfinyl]biphenyl and 8.9 g of 4-(phenylthio)acetophenone was replaced with 10 g of 4-(phenylthio)biphenyl, yielding 5.3 g of a pale yellow solid (79% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-25) having the cation structure of (C-5) and compounds (S5-1) and (S5-2), with the ratio of these compounds being 99.44:0.55:0.01.

[0181] [Production Example 26] Synthesis of Photoacid Generator (PAG-26) The procedure of Production Example 18 was repeated, except that 7.9 g of diphenyl sulfoxide was replaced with 11 g of 4-[(phenyl)sulfinyl]biphenyl, 8.9 g of 4-(phenylthio)acetophenone was replaced with 10 g of 4-(phenylthio)biphenyl, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trispentafluoroethyl trifluorophosphate solution. 7.5 g of a pale yellow solid was obtained (77% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-26) having the cation structure (C-5) and compounds (S5-1) and (S5-2), with the ratio being 99.51:0.47:0.02.

[0182] [Production Example 27] Synthesis of photoacid generator (PAG-27) The procedure of Production Example 18 was repeated, except that 7.9 g of diphenyl sulfoxide was replaced with 11 g of 4-[(phenyl)sulfinyl]biphenyl, 8.9 g of 4-(phenylthio)acetophenone was replaced with 10 g of 4-(phenylthio)biphenyl, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trifluoromethanesulfonate. 5.5 g of a pale yellow solid was obtained (yield 82%). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-27) having the cation structure of (C-5) and compounds (S5-1) and (S5-2), with the ratio of these compounds being 99.24:0.75:0.01.

[0183] [Production Example 28] Synthesis of photoacid generator (PAG-28) The procedure was repeated as in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 11 g of 3-[(phenyl)sulfinyl]biphenyl and 8.9 g of 4-(phenylthio)acetophenone was replaced with 10 g of 3-(phenylthio)biphenyl. 5.4 g of a pale yellow solid was obtained (yield 80%). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-28) having the cation structure of (C-6) and compounds (S6-1) and (S6-2), with the ratio being 98.89:1.07:0.04.

[0184] [Production Example 29] Synthesis of photoacid generator (PAG-29) The procedure of Production Example 18 was repeated, except that 7.9 g of diphenyl sulfoxide was replaced with 11 g of 3-[(phenyl)sulfinyl]biphenyl, 8.9 g of 4-(phenylthio)acetophenone was replaced with 12 g of 3-(phenylthio)biphenyl, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trispentafluoroethyl trifluorophosphate solution, yielding 7.1 g of a pale yellow solid (73% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-29) having the cation structure (C-6) and compounds (S6-1) and (S6-2), with the ratio being 98.88:1.07:0.05.

[0185] [Production Example 30] Synthesis of Photoacid Generator (PAG-30) The procedure was repeated in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 11 g of 3-[(phenyl)sulfinyl]biphenyl, 8.9 g of 4-(phenylthio)acetophenone was replaced with 12 g of 3-(phenylthio)biphenyl, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trifluoromethanesulfonate. 5.3 g of a pale yellow solid was obtained (79% yield). Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-30) having the cation structure of (C-6) and compounds (S6-1) and (S6-2), with the ratio being 98.97:0.99:0.04.

[0186] [Production Example 31] Synthesis of photoacid generator (PAG-31) The procedure was repeated as in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of 4-[(2-methoxyphenyl)sulfinyl]biphenyl and 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of 4-(2-methoxyphenylthio)biphenyl, yielding 6.0 g of a pale yellow solid (82% yield). Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-31) having the cation structure of (C-7) and compounds (S7-1) and (S7-2), with the ratio of these compounds being 99.25:0.52:0.23.

[0187] [Production Example 32] Synthesis of photoacid generator (PAG-32) The procedure of Production Example 18 was repeated, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of 4-[(2-methoxyphenyl)sulfinyl]biphenyl, 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of 4-(2-methoxyphenylthio)biphenyl, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trifluoromethanesulfonate. 6.0 g of a pale yellow solid was obtained (yield 82%). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-32) having the cation structure of (C-7) and compounds (S7-1) and (S7-2), with the ratio of these compounds being 99.21:0.56:0.23.

[0188] [Production Example 33] Synthesis of photoacid generator (PAG-33) The procedure was repeated in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of 4-[(2-methoxyphenyl)sulfinyl]biphenyl, 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of 4-(2-methoxyphenylthio)biphenyl, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 100 g of aqueous lithium tetrakispentafluorophenylborate solution. 8.3 g of a pale yellow solid was obtained (66% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-33) having the cation structure (C-7) and compounds (S7-1) and (S7-2), with the ratio of these compounds being 99.33:0.34:0.33.

[0189] [Production Example 34] Synthesis of photoacid generator (PAG-34) A pale yellow solid (5.9 g, 84% yield) was obtained in the same manner as in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of (4-phenoxyphenyl)phenyl sulfoxide and 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of (4-phenoxyphenyl)phenyl sulfide. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-34) having the cation structure of (C-11) and compounds (S11-1) and (S11-2), with the ratio of these compounds being 99.62:0.34:0.04.

[0190] [Production Example 35] Synthesis of photoacid generator (PAG-35) The procedure was repeated as in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of (4-phenoxyphenyl)phenyl sulfoxide, 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of (4-phenoxyphenyl)phenyl sulfide, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 50 g of aqueous potassium trifluoromethanesulfonate solution, yielding 6.0 g of a pale yellow solid (85% yield). Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-35) having a cation structure of (C-11) and compounds (S11-1) and (S11-2), with the ratio being 99.67:0.27:0.06.

[0191] [Production Example 36] Synthesis of photoacid generator (PAG-36) The procedure was repeated as in Production Example 18, except that 7.9 g of diphenyl sulfoxide was replaced with 12 g of (4-phenoxyphenyl)phenyl sulfoxide, 8.9 g of 4-(phenylthio)acetophenone was replaced with 11 g of (4-phenoxyphenyl)phenyl sulfide, and 50 g of aqueous sodium hexafluorophosphate solution was replaced with 100 g of aqueous lithium tetrakispentafluorophenylborate solution, yielding 8.2 g of a pale yellow solid (66% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-36) having the cation structure (C-11) and compounds (S11-1) and (S11-2), with the ratio being 99.68:0.25:0.07.

[0192] [Production Example 37] Synthesis of photoacid generator (PAG-37) 60.6 g of diphenyl sulfoxide was dissolved in 200 g of sulfuric acid and cooled to 0°C in an ice bath. 18.6 g of diphenyl sulfide dissolved in 30 mL of acetonitrile was added dropwise below 10°C. The reaction solution was poured into 300 g of ice water, and 41 g of potassium hexafluorophosphate was then added. After stirring for 3 hours, the mixture was extracted with 600 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 removed, yielding a pale yellow solid product. This was crystallized twice with 100 parts of methanol, yielding 57.6 g of a white solid (68% yield). H-NMR, C-NMR, and HPLC analyses confirmed that the white solid was a mixture of hexafluorophosphate (CA-37) having the cation structure (C-12) and compound (S12-1) in a ratio of 99.54:0.46.

[0193] [Production Example 38] Synthesis of photoacid generator (PAG-38) A white solid (105 g, 55% yield) was obtained in the same manner as in Production Example 37, except that 41 g of potassium hexafluorophosphate was replaced with 151 g of lithium tetrakispentafluorophenylborate. Analyses by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of tetrakispentafluorophenylborate salt (CA-38) having a (C-12) cation structure and compound (S12-1), with the ratio being 99.65:0.35.

[0194] [Production Example 39] Synthesis of photoacid generator (PAG-39) A white solid (83 g, 57% yield) was obtained in the same manner as in Production Example 37, except that 41 g of potassium hexafluorophosphate was replaced with 167 g of sodium tetrakispentafluorophenyl gallate. Analyses by H-NMR, C-NMR, and HPLC confirmed that this white solid was a mixture of tetrakistetrakispentafluorophenyl gallate salt (CA-39) having a (C-12) cation structure and compound (S12-1), with the ratio being 99.22:0.78.

[0195] [Production Example 40] Synthesis of Photoacid Generator (PAG-40) A pale yellow solid (56 g, 55% yield) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 78.7 g of di(4-methoxyphenyl) sulfoxide. Analyses by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-40) having a cation structure of (C-13) and compounds (S13-1) and (S13-2) in a ratio of 98.99:0.95:0.06.

[0196] [Production Example 41] Synthesis of Photoacid Generator (PAG-41) A pale yellow solid (122 g, 60%) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 78.7 g of di(4-methoxyphenyl) sulfoxide and 41 g of potassium hexafluorophosphate was replaced with 151 g of lithium tetrakispentafluorophenylborate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-41) having the cation structure of (C-13) and compounds (S13-1) and (S13-2), with the ratio being 98.98:0.95:0.07.

[0197] [Production Example 42] Synthesis of photoacid generator (PAG-42) The procedure of Production Example 37 was repeated, except that 60.6 g of diphenyl sulfoxide was replaced with 78.7 g of di(4-methoxyphenyl) sulfoxide and 41 g of potassium hexafluorophosphate was replaced with 107 g of potassium trispentafluoroethyl trifluorophosphate, yielding 92 g of a pale yellow solid (yield 59%). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-42) having the cation structure (C-13) and compounds (S13-1) and (S13-2), with the ratio being 98.95:0.99:0.06.

[0198] [Production Example 43] Synthesis of photoacid generator (PAG-43) A pale yellow solid (67 g, 62%) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 83.5 g of 4-[(phenyl)sulfinyl]biphenyl and 18.6 g of diphenyl sulfide was replaced with 26.2 g of 4-(phenylthio)biphenyl. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-43) having the cation structure (C-14) and compounds (S14-1) to (S14-3), with a ratio of 99.01:0.95:0.03:0.01.

[0199] [Production Example 44] Synthesis of photoacid generator (PAG-44) A pale yellow solid (64 g, 59% yield) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 83.5 g of 4-[(phenyl)sulfinyl]biphenyl, 18.6 g of diphenyl sulfide was replaced with 26.2 g of 4-(phenylthio)biphenyl, and 41 g of potassium hexafluorophosphate was replaced with 38 g of sodium trifluoromethanesulfonate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trifluoromethanesulfonate (CA-44) having a cation structure of (C-14) and compounds (S14-1) to (S14-3), with the ratio of these compounds being 99.03:0.95:0.01:0.01.

[0200] [Production Example 45] Synthesis of photoacid generator (PAG-45) The procedure was repeated in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 83.5 g of 4-[(phenyl)sulfinyl]biphenyl, 18.6 g of diphenyl sulfide was replaced with 26.2 g of 4-(phenylthio)biphenyl, and 41 g of potassium hexafluorophosphate was replaced with 107 g of potassium trispentafluoroethyl trifluorophosphate. 102 g of a pale yellow solid was obtained (61% yield). Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-45) having a (C-14) cation structure and compounds (S14-1) to (S14-3), with the ratio of these compounds being 99.11:0.86:0.02:0.01.

[0201] [Production Example 46] Synthesis of photoacid generator (PAG-46) A pale yellow solid (61 g, 54% yield) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 88.3 g of (4-phenoxyphenyl)phenyl sulfoxide and 18.6 g of diphenyl sulfide was replaced with 27.8 g of (4-phenoxyphenyl)phenyl sulfide. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of hexafluorophosphate (CA-46) having the cation structure (C-15) and compounds (S15-1) to (S15-3), with the ratio of these compounds being 99.29:0.67:0.02:0.02.

[0202] [Production Example 47] Synthesis of photoacid generator (PAG-47) A pale yellow solid (130 g, 59% yield) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 88.3 g of (4-phenoxyphenyl)phenyl sulfoxide, 18.6 g of diphenyl sulfide was replaced with 27.8 g of (4-phenoxyphenyl)phenyl sulfide, and 41 g of potassium hexafluorophosphate was replaced with 151 g of lithium tetrakispentafluorophenylborate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of tetrakispentafluorophenylborate salt (CA-47) having the cation structure (C-15) and compounds (S15-1) to (S15-3), with the ratio of these compounds being 99.18:0.76:0.04:0.02.

[0203] [Production Example 48] Synthesis of photoacid generator (PAG-48) A pale yellow solid (119 g, 69%) was obtained in the same manner as in Production Example 37, except that 60.6 g of diphenyl sulfoxide was replaced with 88.3 g of (4-phenoxyphenyl)phenyl sulfoxide, 18.6 g of diphenyl sulfide was replaced with 27.8 g of (4-phenoxyphenyl)phenyl sulfide, and 41 g of potassium hexafluorophosphate was replaced with 107 g of potassium trispentafluoroethyl trifluorophosphate. Analysis by H-NMR, C-NMR, and HPLC confirmed that this pale yellow solid was a mixture of trispentafluoroethyl trifluorophosphate (CA-48) having a cation structure of (C-15) and compounds (S15-1) to (S15-3), with the ratio of these compounds being 99.16:0.80:0.03:0.01.

[0204] [Reference production example 1] (PAG H-1~H-15) The white solid obtained in Production Example 1 was repeatedly recrystallized from dichloromethane / methanol to obtain a hexafluorophosphate salt (PAG H-1) consisting essentially of cation C-1 (compound (S-1) was below the detection limit (0.005% or less) by HPLC). Similarly, the solids obtained in Production Examples 6, 9, 12, 15, 18, 22, 25, 28, 31, 34, 40, 43, and 46 for PAGs H-2 to H-15 were purified by recrystallization. The compositions of PAGs H-1 to H-8 are shown in Table 1, and those of PAGs H-9 to H15 are shown in Table 3.

[0205] [Reference production example 2] (PAG-49, PAG H-16) In Production Example 1, the crystallization filtrate from dichloromethane / hexane was collected and concentrated using an evaporator. The resulting oil was washed with methanol and hexane to obtain a pale yellow solid. This solid was identified as compound (S1-1) represented by formula (2) by H-NMR and HPLC. By adding an appropriate amount of this to PAG H-1 obtained in Reference Production Example 1, PAG-49 and PAG H-16 were obtained. The composition of each was analyzed by HPLC. The compositions are shown in Table 1.

[0206] [Reference production example 3] (PAG-50~56, PAG H-17~H23) In the same manner as in Reference Production Example 2, PAG-50 to PAG-56 and PAG H-17 to PAG H-23 were purified from the solid or oily material recovered from the crystallization filtrate in Production Examples 6, 9, 12, 15, 37, 40, and 46, respectively. The compounds (S2, S8, S9, S10, S12, S13, and S15) represented by formula (2) were obtained by adding appropriate amounts to the corresponding PAG H-2 to H-8 obtained in Reference Production Example 1, thereby obtaining PAG-42 to PAG-47 and PAG H-14 to PAG H-18. The composition of each compound was analyzed by HPLC. The compositions are shown in Table 1.

[0207] [Reference production example 4] (PAG-57~63, PAG H-24~H30) In the same manner as in Reference Production Example 2, PAG-57 to PAG-63 and PAG H-24 to PAG H-30 were obtained by purifying the solid or oily material recovered from the crystallization filtrate in Production Examples 18, 22, 25, 28, 31, 34, and 43, respectively. The compounds (S3, S4, S5, S6, S7, S11, and S14) represented by formula (2) were obtained by adding appropriate amounts to the corresponding PAG H-9 to H-15 obtained in Reference Production Example 1, thereby obtaining PAG-57 to PAG-63 and PAG H-24 to PAG H-30. The composition of each compound was analyzed by HPLC. The compositions are shown in Table 3.

[0208] [Reference production example 5] (PAG H-31~H36) For comparison, diphenyl sulfide was used as compound (S'-1) instead of compound (S) represented by formula (2) in an appropriate amount to PAG H-1 obtained in Reference Production Example 1, yielding PAGs H-31 to H-33. Each was analyzed for composition by HPLC, and the compositions are shown in Table 1. Similarly, an appropriate amount of 3-phenylthiobiphenyl was added as compound (S'-2) to PAG H-6 obtained in Reference Production Example 1, yielding PAGs H-34 to H-36. Each was analyzed for composition by HPLC, and the compositions are shown in Table 3.

[0209] <Preparation and Evaluation of Photocurable Compositions> The above photoacid generator was dissolved in propylene carbonate (solvent-1) in advance to a concentration of 50% by weight, and then uniformly mixed with an epoxy resin (described below), a cationically polymerizable compound, in the amounts shown in Table 1 to prepare photocurable compositions (Examples 1 to 50 and Comparative Examples 1 to 19). The obtained curable compositions were evaluated according to the following evaluation methods. The results are shown in Table 2. <Epoxy resin> EP-1: 2,2-bis(4-glycidyloxyphenyl)propane EP-2: 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate EP-3: 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane

[0210] [Table 1]

[0211] <Photocuring (cationic polymerization performance) evaluation> The composition was applied to a polyethylene terephthalate (PET) film with an applicator to a thickness of 25 μm. The coated PET film was irradiated with light of a wavelength limited by a filter using an ultraviolet irradiation device. The filter used was an IRCF02 filter (manufactured by iGraphics Co., Ltd., a filter that cuts off light of less than 340 nm). The hardness of the coating film 40 minutes after irradiation was measured using pencil hardness (JIS K5600-5-4:1999), and the results were evaluated according to the following criteria. Table 2 shows the results. A higher pencil hardness indicates better sensitivity (cationic polymerization curability) of the photocurable composition.

[0212] (Evaluation criteria) ◎: Pencil hardness is 2H or more ○: Pencil hardness is H to B △: Pencil hardness is 2B to 4B ×: Liquid to tacky, pencil hardness cannot be measured

[0213] (Light irradiation conditions) Ultraviolet irradiation device: Belt conveyor type UV irradiation device (manufactured by iGraphics) Lamp: 1.5kW high-pressure mercury lamp Filter: IRCF02 filter (made by Eye Graphics) Illuminance (measured with a 365nm head illuminometer): 150mW / cm 2 Accumulated light output (measured with a 365nm head illuminometer): 300mJ / cm 2

[0214] <Yellowing resistance evaluation-1> A Teflon (registered trademark) spacer measuring 20 mm in length, 20 mm in width, and 0.1 mm in thickness was prepared and sandwiched between glass slides (trade name "S2111", manufactured by Matsunami Glass Co., Ltd.). The curable composition was poured into the gap and irradiated with light in the same manner as above. After irradiation, the material was left at room temperature for 60 minutes to obtain a cured product. The yellowness index (YI) of the resulting cured product was measured using a spectrophotometer ("U-3900", manufactured by Hitachi High-Tech Corporation). This was designated YI0. The resulting cured product was then heated at 180°C for 30 minutes, and the YI1 of the cured product after heating was measured. The degree of discoloration, ΔYI, was calculated and compared using the following formula. The results are shown in Table 2. The yellowness index (YI) was measured using a 2-degree field of view under a D65 light source; a higher value indicates a greater degree of yellowness. ΔYI=(YI1)-(YI0)

[0215] <Yellowing resistance evaluation-2> The thermoset product obtained in Yellowing Resistance Evaluation-1 before heating was irradiated with light under the conditions described below to perform a light resistance test. The yellowness index YI2 was measured in the same manner as above to evaluate light yellowing resistance. The degree of discoloration ΔYI was calculated based on the following formula and compared. The results are shown in Table 2. ΔYI=(YI2)-(YI0) (Light irradiation conditions) Irradiation device: "LC-8" (Hamamatsu Photonics) Illuminance (measured with a 365nm head illuminometer): 100mW / cm 2 Accumulative irradiation amount (measured with a 365nm head illuminometer): 10J / cm 2

[0216] [Table 2]

[0217] As shown in Table 2, Examples 1 to 50 and Comparative Examples 1 to 19 demonstrate that photocurable compositions containing the photoacid generator composition of the present invention have excellent UV curability and yellowing resistance. Comparative Examples 1 to 8 demonstrate that the structure of formula (1) alone provides excellent UV curability but reduces yellowing resistance. Examples 27 to 34 and Comparative Examples 9 to 16 demonstrate that the inclusion of a certain proportion of compound (S) represented by formula (2) results in reduced UV curability, and therefore the content of compound (S) must be 3.0 or less. On the other hand, as shown in Comparative Examples 17 to 19, the inclusion of a compound similar to compound (S) but not represented by formula (2) (S'-1) does not contribute to yellowing resistance but affects UV curability. Examples 1 to 26 and Examples 35 to 50 demonstrate that photocurable compositions containing the photoacid generator composition of the present invention have excellent UV curability and yellowing resistance, regardless of the anionic structure or type of epoxy resin.

[0218] <Preparation and Evaluation of Negative Photoresist Composition> (Preparation of evaluation samples) As shown in Table 3, the composition contained 1 part of a photoacid generator, 100 parts of a copolymer (Mw=10,000) consisting of p-hydroxystyrene / styrene=80 / 20 (molar ratio) as component (F) which is a phenolic resin, 20 parts of hexamethoxymethylmelamine (manufactured by Sanwa Chemical Co., Ltd., trade name "Nicalac MW-390") as component (G) which is a crosslinking agent, and 1 part of butadiene / acrylonitrile / hydroxybutylmethacrylate as component (H) which is a crosslinked fine particle. Negative photoresist compositions (Examples 51-79, Comparative Examples 20-36) of the present invention were prepared by uniformly dissolving 10 parts of a copolymer (average particle size 65 nm, Tg = -38°C) consisting of acrylate / methacrylic acid / divinylbenzene = 64 / 20 / 8 / 6 / 2 (wt%) and 5 parts of γ-glycidoxypropyltrimethoxysilane (Chisso Corporation, trade name "S510") as an adhesion aid component (J) in 145 parts of ethyl lactate (solvent-2). The negative photoresist compositions were also evaluated using the following methods. The results are shown in Table 4.

[0219] [Table 3]

[0220] <Sensitivity evaluation> Each composition was spin-coated onto a silicon wafer substrate and then heated and dried at 110°C for 3 minutes using a hot plate to obtain a resin coating film with a thickness of approximately 20 μm. Subsequently, pattern exposure (i-line) was performed using a TME-150RSC (manufactured by Topcon Corporation), followed by post-exposure baking (PEB) at 110°C for 3 minutes using a hot plate. Subsequently, development was performed for 2 minutes using an immersion method using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide, followed by rinsing with running water and blowing with nitrogen to obtain a 10 μm line-and-space pattern. Furthermore, the minimum required exposure dose (corresponding to sensitivity) required to form a pattern with a residual film ratio of 95% or more, which indicates the ratio of the residual film before and after development, was measured.

[0221] <Pattern shape evaluation> The dimension of the lower side La and the dimension of the upper side Lb of the cross section of the 20 μm L&S pattern formed on the silicon wafer substrate by the above operation were measured using a scanning electron microscope, and the pattern shape was judged according to the following criteria. ◎: 0.90≦La / Lb≦1 ○: 0.85≦La / Lb<0.90 ×: La / Lb<0.85

[0222] <Yellowing resistance evaluation-3> Each composition was spin-coated onto a glass substrate and then heated and dried at 110°C for 3 minutes using a hot plate to obtain a resin coating film with a thickness of approximately 20 μm. Subsequently, the entire surface was exposed to i-line light using a TME-150RSC (manufactured by Topcon Corporation), followed by post-exposure baking (PEB) at 110°C for 3 minutes using a hot plate. The film was then developed for 2 minutes using an immersion method using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide, rinsed with running water, and blown with nitrogen to obtain a cured film. The yellowness index (YI) of the resulting cured product was measured using a spectrophotometer ("U-3900," manufactured by Hitachi High-Technologies Corporation). This was designated YI0. The resulting cured product was then heated at 180°C for 30 minutes, and the YI3 of the cured product after heating was measured. The degree of discoloration, ΔYI, was calculated from the difference between these values ​​and compared.

[0223] [Table 4]

[0224] As shown in Table 4, Examples 51 to 79 and Comparative Examples 20 to 36 demonstrate that chemically amplified negative photoresist compositions containing a photoacid generator of the present invention exhibit excellent yellowing resistance. Comparative Examples 20 to 26 demonstrate that the structure of formula (1) alone provides excellent resist performance, but reduces yellowing resistance. Furthermore, Examples 73 to 79 and Comparative Examples 27 to 33 demonstrate that the inclusion of a compound (S) represented by formula (2) in a proportion greater than a certain level results in a reduction in resist performance, and therefore the content of compound (S) must be 3.0 or less. On the other hand, as shown in Comparative Examples 34 to 36, the inclusion of a compound similar to compound (S) but not represented by formula (2) (S'-2) does not contribute to yellowing resistance but instead affects resist performance. Furthermore, Examples 51 to 72 demonstrate that compositions containing a photoacid generator of the present invention exhibit excellent yellowing resistance regardless of the anionic structure. [Industrial Applicability]

[0225] The actinic energy ray-curable composition using the photoacid generator of the present invention can be used in paints, coating agents, various coating materials (hard coats, stain-resistant coatings, anti-fogging coatings, contact-resistant coatings, optical fibers, etc.), backside treatment agents for adhesive tapes, release coating materials for release sheets for adhesive labels (release paper, release plastic films, release metal foils, etc.), printing plates, dental materials (dental compounds, dental composites), inks, inkjet inks, resist films, liquid resists, negative resists (surface protective films for semiconductor elements, etc., interlayer insulating films, permanent film materials such as planarizing films, etc.), resists for MEMS, negative photosensitive resists, etc. They are ideally used in materials, various adhesives (temporary fixing agents for various electronic components, adhesives for HDDs, adhesives for pickup lenses, adhesives for functional films for FPDs (deflectors, anti-reflection films, etc.)), holographic resins, FPD materials (color filters, black matrices, partition materials, photospacers, ribs, alignment films for liquid crystals, sealants for FPDs, etc.), optical components, molding materials (for construction materials, optical components, lenses), casting materials, putty, glass fiber impregnation agents, fillers, sealants, encapsulants, optical semiconductor (LED) encapsulants, optical waveguide materials, nanoimprint materials, materials for stereolithography, and materials for micro stereolithography.

Claims

1. A photoacid generator comprising a sulfonium salt (CA) represented by the following general formula (1) and a compound (S) represented by the following general formula (2), wherein the total content of the sulfonium salt (CA) and the compound (S) is such that the area ratio of the compound (S) to the total area of ​​the sulfonium salt (CA) and the compound (S) is 100, as measured by high performance liquid chromatography (HPLC), is 0.19 or more and 2.2 or less. 【Chemistry 1】 [In formulas (1) to (2), R １ ~R ３ is an organic group bonded to the benzene ring, and p, q, and r are R １ ~R ３ p is an integer of 0 to 4, q and r are integers of 0 to 5, and when p is 0, a hydrogen atom is bonded to it. When p, q and r are 2 or more, they may be the same or different from each other. １ ~R ３ are directly connected to each other or -O-, -S-, -SO-, -SO ２ A ring structure may be formed via -, -NH-, -CO-, -COO-, -CONH-, an alkylene group, or a phenylene group, X is an atom (group) that can become a monovalent anion, and Ar １ ~Ar ３ are each an aryl group having 6 to 18 carbon atoms or a heteroaryl group having 4 to 18 carbon atoms, which may be the same or different, and Ar １ The aryl group or heteroaryl group may be further substituted with a group represented by formula (3), and in formula (3), R ２ , R ３ , r, q, and X are the same as in formula (1), and in formula (2), n is an integer of 1 or 2. 【Chemistry 2】

2. X － is SbF ６ － , P.F. ６ － , B.F. ４ － , (CF ３ CF ２ ) ３ PF ３ － , ((CF ３ ) ２ CF) ３ PF ３ － , (CF ３ CF ２ CF ２ ) ３ PF ３ － , (C ６ F ５ ) ４ B － , ((CF ３ ) ２ C ６ H ３ ) ４ B － , (C ６ F ５ ) ４ Ga － , ((CF ３ ) ２ C ６ H ３ ) ４ Ga － , trifluoromethanesulfonate anion, nonafluorobutanesulfonate anion, methanesulfonate anion, butanesulfonate anion, camphorsulfonate anion, benzenesulfonate anion, p-toluenesulfonate anion, (CF ３ SO ２ ) ３ C － , and (CF ３ SO ２ ) ２ N － 2. The photoacid generator according to claim 1, wherein the anion is selected from the group consisting of anions represented by the formula:

3. A photocurable composition comprising the photoacid generator according to claim 1 or 2 and a cationically polymerizable compound.

4. A cured product obtained by curing the photocurable composition according to claim 3.

5. 3. A chemically amplified negative photoresist composition comprising: a component (E) containing the photoacid generator according to claim 1; a component (F) which is an alkali-soluble resin having a phenolic hydroxyl group; and a crosslinker component (G).

6. 6. The chemically amplified negative photoresist composition according to claim 5, further comprising a crosslinked fine particle component (H).

7. A cured product obtained by curing the chemically amplified negative photoresist composition according to claim 5 or 6.

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