Novel onium salt, photoacid generator, and photocurable resin composition using the same

Abstract

To provide an acid generator that has excellent curable properties and can be light-irradiated or heated to suitably form a cured product having excellent heat resistance, and a curable resin composition comprising the same.SOLUTION: In an onium salt (A), a cation is selected from the group of iodonium, sulfonium, and ammonium, and an anion is a fluorophosphate anion (B) represented by the general formula (1). Out of two isomers of facial and meridional bodies of the anion, the proportion of the meridional bodies is 50.0-85.0 wt.%. [(R1)3(F)3P]-(1)SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a novel onium salt, a photoacid generator suitable for forming a cured product excellent in curability and heat resistance, and a photocurable resin composition using the same.

Background Art

[0002] Conventionally, onium salts such as iodonium and sulfonium salts are known as cationic polymerization initiators for curing cationic polymerizable compounds such as epoxy compounds by irradiation with active energy rays such as heat, light, and electron beams.

[0003] The curing performance of cationic polymerizable compounds and the cross-linking reaction performance by acid catalysts vary depending on the type of anion. Generally, BF 4 - <PF 6 - <SbF 6 - Improve in this order. However, cationic polymerization initiators (acid generators) containing SbF 6 - Which have good polymerization and cross-linking performance are limited in their use due to the problem of the toxicity of Sb. Therefore, cationic polymerization initiators having a high cationic polymerization initiation ability such as those not containing toxic metals and SbF 6 - Are required. In addition, salts using these anion species are widely known as cationic polymerization initiators (Patent Document 1).

[0004] On the other hand, the demand for portable electronic devices such as mobile phones and smartphones is expanding. Such electronic devices are equipped with a small and thin imaging unit, and the imaging unit is generally composed of a solid-state imaging device (such as a CCD type image sensor or a CMOS type image sensor) and optical elements such as lenses. In order to be used as materials for optical elements such as lenses, insulating materials, and adhesives for electronic components, cationic curable compositions are preferably used compared to radical curable compositions in terms of no curing inhibition by oxygen and small shrinkage during curing.

[0005] free of toxic metals, SbF 6 - As cationic polymerization initiators (acid generators) having high cationic polymerization performance and crosslinking reaction performance like salts, special phosphorus-based ones have been disclosed, but these are not sufficient in terms of curability and heat resistance (Patent Document 2). There are also those that describe the production method of this special phosphorus-based one, but useful photoacid generators could not be found with this (Patent Document 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, an object of the present invention is to provide a novel onium salt, a photoacid generator, and a photocurable resin composition using the same, which are excellent in curability and form a cured product excellent in heat resistance (that is, can maintain its shape even under high temperature conditions such as soldering by the reflow method) by performing light irradiation or heat treatment.

Means for Solving the Problems

[0008] The present inventor has found that a novel onium salt and a photoacid generator having a specific anion structure and further controlling the stereoisomers of the anion structure within a certain range can be used for the above applications, and as a result of intensive studies to solve the above problems, the present invention has been completed.

Effects of the Invention

[0009] The onium salt (A) of the present invention functions as a photoacid generator, and this photoacid generator reacts with a cationically polymerizable organic compound (D) by the action of an acid generated by irradiation with active energy rays such as light or an electron beam, and has excellent heat resistance (that is, it can maintain its shape even under high temperature conditions such as soldering by the reflow method). A photocurable resin composition specialized for applications such as cured products for insulators of electronic material components, mounting adhesives, and resins for stereolithography can be obtained.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail.

[0011] In the present invention, the cation is selected from the group consisting of iodonium, sulfonium, and ammonium, and the anion is a fluorophosphate anion (B) represented by the general formula (1). Among the two isomers of the facial form and the meridional form of the anion, the proportion of the meridional form is 50.0 to 85.0% by weight of the onium salt (A). [(R 1 ) 3 (F) 3 P] - (1) [In formula (1), R 1 is an alkyl group having 1 to 18 carbon atoms substituted with a halogen atom, or an aryl group having 1 to 18 carbon atoms (the carbon number of the following substituents is not included). A part of the hydrogen atoms in the aryl group may be substituted with an alkyl group having 1 to 18 carbon atoms, a halogen atom, an alkyl group having 1 to 8 carbon atoms substituted with a halogen atom, an alkenyl group having 2 to 18 carbon atoms, or an alkynyl group having 2 to 18 carbon atoms.]

[0012] In general formula (1), P represents a phosphorus atom and F represents a fluorine atom.

[0013] The fluorophosphate anion (B) represented by the general formula (1) {hereinafter abbreviated as anion (B)} has P as the central element, F, and R 1They are bonded in a structure where six ligands are coordinated in sets of three. In this case, there are two types of isomers: a facial form in which the same type of ligands are cis to each other, and a meridional form in which the same ligands are in the same plane.

[0014] When the onium salt (A) functions as a photoacid generator, the proton-added form of this anion (B) functions as an acid. Therefore, controlling the quantitative ratio of the two types of isomers is an extremely important factor. Among the two isomers, the facial form and the meridional form, by setting the ratio of the meridional form to 50.0 to 85.0% by weight, the ease of cationic polymerization is dramatically improved. As a result, it has been found that when the cationically polymerizable organic compound (D) using the onium salt (A) is cured, a cured product having both curability and heat resistance is obtained. Among the two isomers, the facial form and the meridional form, a more preferable range for the ratio of the meridional form is 55.0 to 80.0% by weight, and most preferably 55.0 to 70.0% by weight.

[0015] R 1 is an alkyl group having 1 to 18 carbon atoms substituted with a halogen atom, or an aryl group having 6 to 18 carbon atoms (the number of carbon atoms of the following substituents is not included). Some of the hydrogen atoms in the aryl group may be substituted with an alkyl group having 1 to 18 carbon atoms, a halogen atom, an alkyl group having 1 to 8 carbon atoms substituted with a halogen atom, an alkenyl group having 2 to 18 carbon atoms, or an alkynyl group having 2 to 18 carbon atoms. Examples of these substituents are the same as the examples of R 2 described later. Among these, a perfluoroalkyl group and a phenyl group substituted with a fluorine atom are preferable, and specifically, a pentafluoroethyl group, a heptafluoro-n-propyl group, a nonafluoro-n-butyl group, a heptafluoro-i-propyl group, a trifluoromethyl group, etc. are more preferable.

[0016] The following two methods are exemplified for the method of controlling the quantitative ratio of the two isomers, the facial form and the meridional form. The first is the phosphorane ((R1 ) 3 (F) 2 It can be controlled by optimizing the polarity of the solvent, the amount of the solvent and the substrate (i.e., concentration), and the reaction temperature when reacting (P) with a fluorinating agent, and the isomer suitable for the purpose can be synthesized. Examples of the fluorinating agent include hydrogen fluoride, metal fluorides (sodium fluoride, potassium fluoride), etc. Secondly, using hydrogen fluoride as the fluorinating agent, an acid of the anionic component (the one with a proton attached to the general formula (1)) is synthesized once, and under acidic conditions, heat is applied to isomerize from the facial form to the meridional form, and then it can also be made into a metal salt or an onium salt. In the latter case, the isomer can be controlled by the degree of acidity and the temperature history.

[0017] The cation of the onium salt (A) is selected from the group consisting of iodonium, sulfonium, and ammonium.

[0018] Specific examples of iodonium are exemplified below Iodonium ions such as diphenyliodonium, di-p-tolyliodonium, di(4-tert-butylphenyl)iodonium, di(4-dodecylphenyl)iodonium, di(4-methoxyphenyl)iodonium, (4-octyloxyphenyl)phenyl iodonium, di(4-decyloxyphenyl)iodonium, 4-(2-hydroxytetradecyloxy)phenylphenyl iodonium, 4-isopropylphenyl(p-tolyl)iodonium, phenyl(2,4,6-trimethoxyphenyl)iodonium, and 4-isobutylphenyl(p-tolyl)iodonium, etc.

[0019] Specific examples of sulfonium are exemplified below Triphenylsulfonium, tri-p-tolylsulfonium, tri-o-tolylsulfonium, tris(4-methoxyphenyl)sulfonium, 1-naphthyldiphenylsulfonium, 2-naphthyldiphenylsulfonium, tris(4-fluorophenyl)sulfonium, tri-1-naphthylsulfonium, tri-2-naphthylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-(phenylthio)phenyl diphenylsulfonium, 4-(p-tolylthio)phenyl di-p-tolylsulfonium, 4-(4-methoxyphenylthio)phenyl bis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyl bis(4-fluorophenyl)sulfonium, 4-(phenylthio)phenyl bis(4-methoxyphenyl)sulfonium, 4-(phenylthio)phenyl di-p-tolylsulfonium, [4-(4-biphenylylthio)phenyl]-4-biphenylylphenylsulfonium, [4-(2-thioxanthonylthio)phenyl]diphenylsulfonium, bis[4-(diphenylsulfonio)phenyl]sulfide, bis〔4-{bis[4-(2-hydroxyethoxy)phenyl]sulfonio}phenyl〕sulfide, bis{4-[bis(4-fluorophenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methylphenyl)sulfonio]phenyl}sulfide, bis{4-[bis(4-methoxyphenyl)sulfonio]phenyl}sulfide, 4-(4-benzoyl-2-chlorophenylthio)phenyl bis(4-fluorophenyl)sulfonium, 4-(4-benzoyl-2-chlorophenylthio)phenyl diphenylsulfonium, 4-(4-benzoylphenylthio)phenyl bis(4-fluorophenyl)sulfonium, 4-(4-benzoylphenylthio)phenyl diphenylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-dihydroanthracen-2-yl di-p-tolylsulfonium, 7-isopropyl-9-oxo-10-thia-9,10-Dihydroanthracen-2-yl diphenylsulfonium, 2-[(di-p-tolyl)sulfonio]thioxanthone, 2-[(diphenyl)sulfonio]thioxanthone, 4-(9-oxo-9H-thioxanthen-2-yl)phenyl-9-oxo-9H-thioxanthen-2-yl phenylsulfonium, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyl di-p-tolylsulfonium, 4-[4-(4-tert-butylbenzoyl)phenylthio]phenyl diphenylsulfonium, 4-[4-(benzoylphenylthio)]phenyl di-p-tolylsulfonium, 4-[4-(benzoylphenylthio)]phenyl diphenylsulfonium, 5-(4-methoxyphenyl)thianthrenium, 5-phenylthianthrenium, 5-tolylthianthrenium, 5-(4-ethoxyphenyl) thianthrenium, 5-(2,4,Triarylsulfonium such as (6 - trimethylphenyl) thianthrenium; diarylsulfonium such as diphenylphenacylsulfonium, diphenyl 4 - nitrophenacylsulfonium, diphenylbenzylsulfonium, diphenylmethylsulfonium; monoarylsulfonium such as phenylmethylbenzylsulfonium, 4 - hydroxyphenylmethylbenzylsulfonium, 4 - methoxyphenylmethylbenzylsulfonium, 4 - acetoxyphenylmethylbenzylsulfonium, 4 - acetoxyphenyldimethylsulfonium, 4 - hydroxyphenyl(1 - naphthylmethyl)methylsulfonium, 2 - naphthylmethylbenzylsulfonium, 4 - hydroxyphenyl(4 - nitrobenzyl)methylsulfonium, 2 - naphthylmethyl(1 - ethoxycarbonyl)ethylsulfonium, phenylmethylphenacylsulfonium, 4 - hydroxyphenylmethylphenacylsulfonium, 4 - methoxyphenylmethylphenacylsulfonium, 4 - acetoxyphenylmethylphenacylsulfonium, 2 - naphthylmethylphenacylsulfonium, 2 - naphthyloctadecylphenacylsulfonium, 9 - anthracenylmethylphenacylsulfonium; trialkylsulfonium such as dimethylphenacylsulfonium, phenacyltetrahydrothiophenium, dimethylbenzylsulfonium, benzyltetrahydrothiophenium, octadecylmethylphenacylsulfonium, etc. are exemplified.,

[0020] Specific examples as ammonium are exemplified below Tetraalkylammonium such as tetramethylammonium, ethyltrimethylammonium, diethyldimethylammonium, triethylmethylammonium, tetraethylammonium; Pyrrolidinium such as N,N-dimethylpyrrolidinium, N-ethyl-N-methylpyrrolidinium, N,N-diethylpyrrolidinium; Imidazolinium such as N,N'-dimethylimidazolinium, N,N'-diethylimidazolinium, N-ethyl-N'-methylimidazolinium, 1,3,4-trimethylimidazolinium, 1,2,3,4-tetramethylimidazolinium; Tetrahydropyrimidinium such as N,N'-dimethyltetrahydropyrimidinium; Morpholinium such as N,N'-dimethylmorpholinium; Piperidinium such as N,N'-diethylpiperidinium; Pyridinium such as N-methylpyridinium, N-benzylpyridinium, N-phenacylpyridinium; Imidazolium such as N,N'-dimethylimidazolium; Quinolinium such as N-methylquinolinium, N-benzylquinolinium, N-phenacylquinolinium; Isoquinolinium such as N-methylisoquinolinium; Thiazolium such as benzylbenzothiazolium, phenacylbenzothiazolium; Acridinium such as benzylacridinium, phenacylacridinium are mentioned.

[0021] The onium salt (A) represented by the formula (1) of the present invention can be produced by a metathesis method. The metathesis method is described in, for example, New Experimental Chemistry Course, Volume 14-I (1978, Maruzen) p-448; Advance in Polymer Science, 62, 1-48 (1984); New Experimental Chemistry Course, Volume 14-III (1978, Maruzen) pp1838-1846; Organic Sulfur Chemistry (Synthesis Reaction Edition, 1982, Kagaku Doujin), Chapter 8, pp237-280; Journal of the Chemical Society of Japan, 87, (5), 74 (1966); JP-A-64-45357, JP-A-61-212554, JP-A-61-100557, JP-A-5-4996, JP-A-7-82244, JP-A-7-82245, JP-A-58-210904, JP-A-6-184170, etc. First, the F of the onium cation - Cl - Br - I- Halide salts such as; OH - Salt; ClO 4 - Salt; FSO 3 - 、ClSO 3 - 、CH 3 SO 3 - 、C 6 H 5 SO 3 - 、CF 3 SO 3 - Salts with sulfonate ions such as; HSO 4 - 、SO 4 2- Salts with sulfate ions such as; HCO 3 - 、CO 3 2- 、Salts with carbonate ions such as; H 2 PO 4 - 、HPO 4 2- 、PO 4 3- Salts with phosphate ions etc. are produced, and this is added to an alkali metal salt, alkaline earth metal salt or quaternary ammonium salt of the anion constituting the onium salt represented by formula (1) in a solvent and an aqueous solution and subjected to metathesis. As the solvent, water or an organic solvent can be used. Examples of the organic solvent include hydrocarbons (hexane, heptane, toluene, xylene, etc.), cyclic ethers (tetrahydrofuran, dioxane, etc.), chlorine-based solvents (chloroform, dichloromethane, etc.), alcohols (methanol, ethanol, isopropyl alcohol, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), nitriles (acetonitrile, etc.) and polar organic solvents (dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, etc.). These solvents may be used alone or in combination of two or more.

[0022] The resulting desired onium salt (A) separates out as a crystal or an oil. In the case of an oil, it can be obtained by separating the precipitated oil from the organic solvent solution and further distilling off the organic solvent contained in the oil. In the case of a crystal, it can be obtained by separating the precipitated solid from the organic solvent solution and further distilling off the organic solvent contained in the solid. The thus obtained desired onium salt can be purified by recrystallization or by methods such as washing with water or a solvent, if necessary.

[0023] Purification by recrystallization involves dissolving the desired onium salt (A) in a small amount of an organic solvent, and separation from the organic solvent can be carried out by directly adding (or after concentration) a poor solvent to the organic solvent solution containing the desired onium salt to precipitate the desired onium salt. Examples of the poor solvent used here include chain ethers (such as diethyl ether and dipropyl ether), esters (such as ethyl acetate and butyl acetate), aliphatic hydrocarbons (such as hexane and cyclohexane), and aromatic hydrocarbons (such as toluene and xylene). Also, purification can be carried out by utilizing the difference in solubility due to temperature. The purification can be carried out by recrystallization (methods using the difference in solubility by cooling, methods of adding a poor solvent to precipitate, and combinations thereof). Also, when the target product is an oil (when it does not crystallize), it can be purified by a method of washing the oil with water or a poor solvent.

[0024] When the onium salt (A) of the present invention is used as a photoacid generator, it functions as a cationic polymerization initiator. By blending it with a cationically polymerizable organic compound (D) or the like, a photocurable resin composition is obtained. This composition can be cured by irradiating it with an energy ray to obtain a cured product. The energy ray may be any as long as it has the energy to induce the decomposition of the photoacid generator of the present invention, but it includes low-pressure, medium-pressure, high-pressure or ultra-high-pressure mercury lamps, metal halide lamps, LED lamps, xenon lamps, carbon arc lamps, fluorescent lamps, semiconductor solid lasers, argon lasers, He-Cd lasers, KrF excimer lasers, ArF excimer lasers or F 2Energy rays in the ultraviolet to visible light region (wavelength: about 100 to about 800 nm) obtained from a laser or the like are preferable. Note that as the energy rays, radiation having high energy such as electron beams or X-rays can also be used.

[0025] Examples of the cationic polymerizable organic compound (D) include epoxy compounds and oxetane compounds. Further, examples of the epoxy compounds include epoxy compounds such as alicyclic epoxy compounds, aliphatic epoxy compounds, and aromatic epoxy compounds.

[0026] Examples of the alicyclic epoxy compound include polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring, or cyclohexene oxide structure-containing compounds or cyclopentene oxide structure-containing compounds obtained by epoxidizing cyclohexene ring-containing compounds or cyclopentene ring-containing compounds with an appropriate oxidizing agent such as hydrogen peroxide or peracid. More specifically, as the alicyclic epoxy compound, for example, the following general formula (D-1);

[0027]

Chemical formula

[0028] (In the formula, R 12 represents a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol S residue, a hydrogenated bisphenol Z residue, a hydrogenated bisphenol AD residue, a cyclohexanedimethanol residue, or a tricyclodecanedimethanol residue.) Examples of the alicyclic diglycidyl ether compound [hereinafter referred to as "alicyclic diglycidyl ether compound (D-1)"] represented by include hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, hydrogenated bisphenol AD diglycidyl ether, hydrogenated bisphenol Z diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and tricyclodecanedimethanol diglycidyl ether).

[0029] In addition, examples of the compound containing a cyclohexene oxide structure or the compound containing a cyclopentene oxide structure include 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylcyclohexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexane-methadioxane, bis(3,4-epoxycyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexylcarboxylate, dicyclopentadiene diepoxide, ethylenebis(3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, and the like. In addition, examples also include ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, trimethylcaprolactone-modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone-modified 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate, methylenebis(3,4-epoxycyclohexane), and the 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, which are sold by Daicel Corporation. Furthermore, bis(3,4-epoxycyclohexyl)methane, 2,2-bis(3,4-epoxycyclohexyl)propane, 1,1-bis(3,4-epoxycyclohexyl)ethane, alpha-pinene oxide, camphorene aldehyde, limonene monooxide, limonene dioxide, 4-vinylcyclohexene monooxide, 4-vinylcyclohexene dioxide, etc. can also be mentioned.

[0030] The aliphatic epoxy compound is not particularly limited. Examples of the aliphatic epoxy compound include polyglycidyl ethers of aliphatic polyhydric alcohols or their alkylene oxide adducts, polyglycidyl esters of aliphatic long-chain polybasic acids, homopolymers synthesized by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate, copolymers synthesized by vinyl polymerization of glycidyl acrylate and / or glycidyl methacrylate with other vinyl monomers, etc. Typical compounds include, for example, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, glycidyl ethers of higher alcohols, diglycidyl ethers of alkylene diols (e.g., di(3,4-epoxycyclohexylmethyl) ether of ethylene glycol, diglycidyl ether of 1,4-butanediol, diglycidyl ether of 1,6-hexanediol, diglycidyl ether of neopentyl glycol, etc.), triglycidyl ether of glycerin, diglycidyl ether of trimethylolpropane, triglycidyl ether of trimethylolpropane, tetraglycidyl ether of sorbitol, hexaglycidyl ether of dipentaerythritol, diglycidyl ethers of polyethylene glycol, diglycidyl ethers of polypropylene glycol, diglycidyl ethers of polytetramethylene glycol, etc., i.e., glycidyl ethers of polyhydric alcohols. Furthermore, polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as propylene, trimethylolpropane, and glycerin, diglycidyl esters of aliphatic long-chain dibasic acids, etc. can be mentioned. Furthermore, monoglycidyl ethers of higher aliphatic alcohols, phenol, cresol, butylphenol, or monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxides to these, glycidyl esters of higher fatty acids, epoxidized soybean oil, butyl epoxystearate, octyl epoxystearate, epoxidized linseed oil, epoxidized polybutadiene, epoxy novolak resin, cresol novolak resin, glycidylated polybutadiene, etc. can be mentioned. Moreover, examples of the epoxyalkane include 1,2-epoxydecane, 1,2-epoxydodecane, 1,2-epoxytetradecane, 1,2-epoxycetane, 1,2-epoxyoctadecane, 1,2-epoxyeicosane. As an example of the above-mentioned commercial product, Grilonit F713 (manufactured by EMS-CHEMI) can be mentioned.

[0031] The aromatic epoxy compound is not particularly limited, and examples thereof include polyglycidyl ethers and polyglycidyl esters of polyhydric phenols or their alkylene oxide adducts. Specifically, for example, bisphenol A, bisphenol E, bisphenol F, bisphenol S, bisphenol AD, bisphenol Z, brominated bisphenol A, brominated bisphenol F, brominated bisphenol S, or glycidyl ethers of compounds obtained by further adding alkylene oxides such as ethylene oxide and propylene oxide to these, phenyl glycidyl ether, tert-butyl phenyl glycidyl ether, resorcinol diglycidyl ether, tetraglycidyl ether of tetraphenol ethane, triglycidyl ether of triphenol methane, glycidylates of condensates of phenols or naphthols and aldehydes (such as phenol resins and novolak resins), glycidylates of condensates of phenols and isopropenyl acetophenone, glycidylates of reaction products of phenols and dicyclopentadiene, diglycidyl ester of terephthalic acid, diglycidyl ester of isophthalic acid, diglycidyl ester of o-phthalic acid, etc. can be mentioned. Furthermore, diglycidyl ether of biphenol, diglycidyl ether of tetramethylbiphenol, EPOX-MK R710, R1710 sold by Printec Co., Ltd., VG3101L represented by the following chemical formula, and other aromatic epoxy compounds, etc. can be mentioned.

[0032]

Chemical formula

[0033] In the present invention, as the cationically polymerizable organic compound (D), one or more of the above-described epoxy compounds can be used, and based on the total weight of the cationically polymerizable organic compound (D), it is preferable to contain a polyepoxy compound having two or more epoxy groups in one molecule at a ratio of 30% by weight or more.

[0034] When an alicyclic diglycidyl ether compound represented by the above general formula (D-1) is contained as part of the cationically polymerizable organic compound (D) in the photocurable resin composition of the present invention, generally, it has excellent dimensional stability over time, water resistance, moisture resistance, heat resistance, etc. Further, when an aromatic compound having three or more glycidyl etherified phenol groups represented by the following formula (D-2a) [hereinafter referred to as "aromatic compound (D-2)"] is contained as part of the cationically polymerizable organic compound (D) in the photocurable resin composition of the present invention, a curable resin composition having a high heat distortion temperature and excellent heat resistance can be obtained. When the aromatic compound (D-2) is contained as part of the cationically polymerizable organic compound (D) to improve heat resistance, the content of the aromatic compound (D-2) is preferably 5 to 80% by weight, more preferably 10 to 50% by weight, and still more preferably 20 to 40% by weight based on the total weight of the cationically polymerizable organic compound (D).

[0035]

Chemical formula

[0036] As the aromatic compound (D-2), any one can be used as long as it can maintain the viscosity of the photocurable resin composition at an appropriate viscosity. For example, polyglycidyl ethers of phenol resins such as novolak resins and resol resins, tetraglycidyl ether of tetraphenol ethane, triglycidyl ether of triphenol methane, the above-mentioned VG3101L, that is, 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-([2,3-epoxypropoxy]phenyl]ethyl]phenyl]propane, etc. can be mentioned.

[0037] When the above-mentioned VG3101L, that is, 2-[4-(2,3-epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-([2,3-epoxypropoxy]phenyl]ethyl]phenyl]propane is contained in the photocurable resin composition as part of the cationically polymerizable organic compound, the heat distortion temperature increases and the heat resistance is improved. When VG3101L is contained as part of the cationically polymerizable organic compound (D) to improve the heat resistance, the content of VG3101L is preferably 1.5 to 80% by weight, more preferably 5 to 50% by weight, and even more preferably 20 to 40% by weight based on the total weight of the cationically polymerizable organic compound (D).

[0038] From the viewpoints of the photocuring performance of the photocurable resin composition and the improvement in workability due to the reduction in viscosity, the photocurable resin composition of the present invention preferably contains the oxetane compound (D-3) in a proportion of 1 to 35% by weight, more preferably 5 to 20% by weight, based on the total weight of the cationically polymerizable organic compound (D) contained in the photocurable resin composition.

[0039] As the oxetane compound [hereinafter sometimes referred to as "oxetane compound (D-3)"], one or more of a mono-oxetane compound having one oxetane group in one molecule and a poly-oxetane compound having two or more oxetane groups in one molecule can be used. In particular, when the oxetane compound (D-3) is used as part of the cationically polymerizable organic compound (D), and at that time, as the oxetane compound (D-3), a mono-oxetane compound (D-3a) having one oxetane group in one molecule and a poly-oxetane compound (D-3b) having two or more oxetane groups in one molecule are used in a weight ratio of mono-oxetane compound (A-3a):poly-oxetane compound (D-3b) = 95:5 to 5:95, further 10:90 to 90:10, especially 20:80 to 80:20, the absorption rate of moisture and humidity of the photocurable resin composition in a high humidity state decreases, the initial high curing sensitivity can be maintained over a long period, and moreover, the toughness is improved.

[0040] At that time, as the monooxetane compound (D-3a), any compound having one oxetane group in one molecule can be used, but in particular, a monooxetane monoalcohol compound having one oxetane group and one alcoholic hydroxyl group in one molecule is preferably used. Among such monooxetane monoalcohol compounds, compounds represented by the following general formula (D-3a1) and the following general formula (D-3a2) are preferably used from the viewpoints of easy availability, high reactivity, low viscosity, etc.

[0041] [Chemical formula]

[0042] (In the formula, R 13 and R 14 are alkyl groups having 1 to 5 carbon atoms, and R 15 represents an alkylene group having 2 to 10 carbon atoms which may have an ether bond.)

[0043] In the above general formula (D-3a1), examples of R 13 include methyl, ethyl, propyl, butyl, and pentyl. Specific examples of the monooxetane alcohol (D-3a1) include 3-hydroxymethyl-3-methyloxetane, 3-hydroxymethyl-3-ethyloxetane, 3-hydroxymethyl-3-propyloxetane, 3-hydroxymethyl-3-normal butyloxetane, 3-hydroxymethyl-3-propyloxetane, etc., and one or more of these can be used. Among them, 3-hydroxymethyl-3-methyloxetane and 3-hydroxymethyl-3-ethyloxetane are more preferably used from the viewpoints of easy availability, reactivity, etc.

[0044] In the above general formula (D-3a2), examples of R 14 include methyl, ethyl, propyl, butyl, and pentyl. Also, in the above general formula (D-3a2), R15 may be a linear or branched alkylene group having 2 to 10 carbon atoms, or may be a linear or branched alkylene group having 2 to 10 carbon atoms and having an ether bond (ether oxygen atom) in the middle of the alkylene group (alkylene chain). R 15 Specific examples of include an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, a 3-oxypentylene group, and the like. Among them, R 15 is preferably a trimethylene group, a tetramethylene group, a pentamethylene group or a heptamethylene group in terms of ease of synthesis, easy handling because the compound is liquid at room temperature, and the like.

[0045] In addition, as the polyoxetane compound (D-3b), any of a compound having two oxetane groups, a compound having three or more oxetane groups, and a compound having four or more oxetane groups can be used, but a dioxetane compound having two oxetane groups is preferably used. Among them, the dioxetane compound represented by the following general formula (D-3b0) is preferably used in terms of availability, reactivity, low hygroscopicity, mechanical properties of the cured product, and the like.

[0046]

Chemical formula

[0047] (In the formula, two Rs 16 are the same or different alkyl groups having 1 to 5 carbon atoms, R 17 is a divalent organic group having or not having an aromatic ring, and n represents 0 or 1.)

[0048] In the above general formula (D-3b0), examples of R 16 include methyl, ethyl, propyl, butyl, and pentyl. Also, R 17Examples include linear or branched alkylene groups having 1 to 12 carbon atoms (such as ethylene group, propylene group, butylene group, neopentylene group, n-pentamethylene group, n-hexamethylene group, etc.), a divalent group represented by the formula: -CH 2 -Ph-CH 2 - or -CH 2 -Ph-Ph-CH 2 -, a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol S residue, a hydrogenated bisphenol Z residue, a cyclohexanedimethanol residue, a tricyclodecanedimethanol residue, a terephthalic acid residue, an isophthalic acid residue, an o-phthalic acid residue, etc.

[0049] Specific examples of the dioxetane compound (D-3b0) include dioxetane compounds represented by the following formula (D-3b1) or formula (D-3b2).

[0050]

Chemical formula

[0051] (In the formula, two R 18 are the same or different alkyl groups having 1 to 5 carbon atoms, and R 19 represents a divalent organic group with or without an aromatic ring.)

[0052] Specific examples of the dioxetane compound represented by the above formula (D-3b1) include bis(3-methyl-3-oxetanylmethyl) ether, bis(3-ethyl-3-oxetanylmethyl) ether, bis(3-propyl-3-oxetanylmethyl) ether, bis(3-butyl-3-oxetanylmethyl) ether, etc. Also, specific examples of the dioxetane compound represented by the above formula (D-3b2) include those in which two R 18 in the above formula (D-3b2) are both methyl, ethyl, propyl, butyl or pentyl groups, and R 19is an ethylene group, a propylene group, a butylene group, a neopentylene group, an n-pentamethylene group, an n-hexamethylene group, etc.), the formula: -CH 2 -Ph-CH 2 - or -CH 2 -Ph-Ph-CH 2 - a divalent group represented by, a hydrogenated bisphenol A residue, a hydrogenated bisphenol F residue, a hydrogenated bisphenol S residue, a hydrogenated bisphenol Z residue, a cyclohexanedimethanol residue, a tricyclodecanedimethanol residue, and examples of the dioxetane compound can be given.

[0053] Among them, as the dioxetane compound (D-3b0), in the above formula (D-3b1), two Rs 18 are both methyl groups or ethyl groups, bis(3-methyl-3-oxetanylmethyl) ether and / or bis(3-ethyl-3-oxetanylmethyl) ether are preferably used from the viewpoints of easy availability, low hygroscopicity, mechanical properties of the cured product, etc., and bis(3-ethyl-3-oxetanylmethyl) ether is more preferably used.

[0054] In addition, when the photocurable resin composition of the present invention contains a diglycidyl ether (D-4) of an alkylene diol, the toughness is improved. As the diglycidyl ether of an alkylene diol, diglycidyl ethers of alkylene diols having 2 to 10 carbon atoms such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether, hexanediol diglycidyl ether, heptanediol diglycidyl ether, octanediol diglycidyl ether, nonanediol diglycidyl ether, decanediol diglycidyl ether are preferable, and one or more of these can be used. Among them, 1,6-hexanediol diglycidyl ether is more preferably used from the viewpoint of curing performance. When a diglycidyl ether of an alkylene diol is contained in the photocurable resin composition of the present invention to improve toughness, the content of the diglycidyl ether of the alkylene diol is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, and still more preferably 1 to 5% by weight based on the total weight of the cationically polymerizable organic compound (D) contained in the photocurable resin composition.

[0055] Further, the photocurable resin composition of the present invention preferably contains a radically polymerizable organic compound (E) and a radical polymerization initiator (F).

[0056] Typical examples of the radically polymerizable organic compound (E) include compounds having a (meth)acrylate group, unsaturated polyester compounds, allyl urethane compounds, polythiol compounds, etc., and one or more of the radically polymerizable organic compounds can be used. Among them, a compound having at least one (meth)acryloyloxy group in one molecule is preferably used, and specific examples include reaction products of epoxy compounds and (meth)acrylic acid, (meth)acrylic acid esters of alcohols, urethane (meth)acrylates, polyester (meth)acrylates, polyether (meth)acrylates, etc.

[0057] Examples of the reaction product of an epoxy compound and (meth)acrylic acid include (meth)acrylate-based reaction products obtained by reacting an aromatic epoxy compound, an alicyclic epoxy compound and / or an aliphatic epoxy compound with (meth)acrylic acid. Specific examples include (meth)acrylates obtained by reacting glycidyl ethers obtained by reacting bisphenol compounds such as bisphenol A and bisphenol S or bisphenol compounds such as bisphenol A and bisphenol S in which a benzene ring is substituted with an alkoxy group or the like or alkylene oxide adducts of the above-described bisphenol compounds or substituted bisphenol compounds with an epoxidizing agent such as epichlorohydrin with (meth)acrylic acid, and (meth)acrylate-based reaction products obtained by reacting an epoxy novolak resin with (meth)acrylic acid.

[0058] Examples of the (meth)acrylic acid ester of alcohols include (meth)acrylates obtained by reacting an aromatic alcohol, an aliphatic alcohol, an alicyclic alcohol and / or an alkylene oxide adduct thereof having at least one hydroxyl group in the molecule with (meth)acrylic acid. More specifically, for example, bisphenol compounds such as bisphenol A and bisphenol S, or di(meth)acrylates of bisphenol compounds such as bisphenol A and bisphenol S in which the benzene ring is substituted by an alkoxy group or the like, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isooctyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyalkylene glycol di(meth)acrylate [for example, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, etc.], trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other poly(meth)acrylates of polyhydric alcohols having three or more hydroxyl groups, (meth)acrylates of alkylene oxide adducts of polyhydric alcohols such as the above-mentioned diols, triols, tetraols, hexaols, etc. can be mentioned.

[0059] In addition, examples of the urethane (meth)acrylate include (meth)acrylates obtained by reacting a hydroxyl group-containing (meth)acrylate ester with an isocyanate compound. As the hydroxyl group-containing (meth)acrylate ester, a hydroxyl group-containing (meth)acrylate ester obtained by an esterification reaction of an aliphatic dihydric alcohol and (meth)acrylic acid is preferable, and specific examples include 2-hydroxyethyl (meth)acrylate. Further, as the isocyanate compound, a polyisocyanate compound having two or more isocyanate groups in one molecule, such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, etc., is preferable.

[0060] Furthermore, examples of the polyester (meth)acrylate include polyester (meth)acrylates obtained by reacting a hydroxyl group-containing polyester with (meth)acrylic acid. Also, examples of the above-mentioned polyether (meth)acrylate include polyether acrylates obtained by reacting a hydroxyl group-containing polyether with acrylic acid.

[0061] When a photo-curable resin composition contains, as part of the radically polymerizable organic compound (E), 1 to 40% by weight, particularly 5 to 20% by weight, of a polyalkylene glycol di(meth)acrylate such as polytetramethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, etc., based on the weight of the radically polymerizable organic compound (E), the toughness of the cured product obtained from the photo-curable resin composition is improved. However, if the content of the polyalkylene glycol di(meth)acrylate is too high, the heat distortion temperature of the obtained cured product becomes low and the heat resistance decreases.

[0062] The photocurable resin composition of the present invention can use any polymerization initiator that can initiate the radical polymerization of the radically polymerizable organic compound (E) when irradiated with active energy rays such as light. For example, benzyl or its dialkyl acetal compounds, phenyl ketone compounds, acetophenone compounds, benzoin or its alkyl ether compounds, benzophenone compounds, thioxanthone compounds, etc. can be mentioned.

[0063] Specifically, examples of the benzyl or its dialkyl acetal compounds include benzyl dimethyl ketal, benzyl-β-methoxyethyl acetal, etc. Examples of the phenyl ketone compounds include 1-hydroxy-cyclohexyl phenyl ketone, etc. In addition, examples of the acetophenone compounds include diethoxyacetophenone, 2-hydroxymethyl-1-phenylpropan-1-one, 4'-isopropyl-2-hydroxy-2-methyl-propiophenone, 2-hydroxy-2-methyl-propiophenone, p-dimethylaminoacetophenone, p-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, p-azidobenzalacetophenone, etc.

[0064] And examples of the benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin normal butyl ether, benzoin isobutyl ether, etc. In addition, examples of the benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, Michler's ketone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, etc. Examples of the thioxanthone-based compounds include thioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, and the like.

[0065] In the present invention, one or more radical polymerization initiators (F) can be blended and used according to desired performance. Among them, in the present invention, 1-hydroxycyclohexyl phenyl ketone is preferably used as the radical polymerization initiator (F) because the cured product has excellent strength and heat resistance and good reactivity.

[0066] From the viewpoints of photocuring performance, dimensional stability of the obtained cured product, mechanical properties, etc., the cationically polymerizable organic compound (D) and the radically polymerizable organic compound (E) of the photocurable resin composition of the present invention are in a weight ratio of cationically polymerizable organic compound (D): radically polymerizable organic compound (E) = 30:70 to 90:10, more preferably 50:50 to 90:10, particularly preferably 60:40 to 90:10. Further, the photocurable resin composition of the present invention contains the onium salt (A) used as a cationic polymerization initiator in a proportion of 0.1 to 10% by weight, particularly 1 to 5% by weight, based on the weight of the cationically polymerizable organic compound (D), and contains the radical polymerization initiator (F) in a proportion of 0.1 to 10% by weight, particularly 1 to 5% by weight, based on the weight of the radically polymerizable organic compound (E).

[0067] Specific applications of the photocurable resin composition of the present invention include paints, coating agents, various coating materials (hard coats, stain-resistant coatings, anti-fog coatings, corrosion-resistant coatings, optical fibers, etc.), back surface treatment agents for adhesive tapes, release coating materials for release sheets for adhesive labels (release papers, release plastic films, release metal foils, etc.), printed boards, dental materials (dental formulations, dental composites), inks, inkjet inks, various adhesives (temporary fixing agents for various electronic components, adhesives for HDDs, adhesives for pickup lenses, adhesives for functional films for FPDs (deflection plates, anti-reflection films, etc.), insulating films for circuit formation and semiconductor encapsulation, anisotropic conductive adhesives (ACA), films (ACF), pastes (ACP), etc.), hologram resins, FPD materials (color filters, black matrices, partition materials, photo spacers, ribs, alignment films for liquid crystals, sealants for FPDs, etc.), optical members, molding materials (for building materials, optical components, lenses), casting materials, putties, glass fiber impregnants, caulking materials, sealing materials, chip encapsulation materials for flip chips, COFs, etc., encapsulation materials for packages such as CSPs or BGAs, optical semiconductor (LED) encapsulation materials, optical waveguide materials, nanoimprint materials, materials for stereolithography, and materials for microstereolithography, etc.

[0068] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, parts in each example indicate parts by weight.

Examples

[0069] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, parts in each example indicate parts by weight.

[0070] Production Examples of Anions (B1) to (B5)

[0071] Production Example of Anion (B1) 3.14 g (0.0628 mol) of a 40% aqueous hydrofluoric acid solution was diluted with 25.0 g of triethylene glycol dimethyl ether, cooled to 20 °C or lower in advance, and then 26.55 g (0.0623 mol) of tris(pentafluoroethyl)difluorophosphorane was slowly added with stirring. The addition was made slowly with cooling so that the temperature would be 10 °C or lower to cause a reaction. Thereafter, 0.83 g (0.0166 mol) of a 40% aqueous hydrofluoric acid solution was further added thereto, the temperature was raised to 60 °C, heated for 15 minutes, and then cooled to room temperature. 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added to obtain a solution of potassium tris(pentafluoroethyl)trifluorophosphonate (K + [(C 2 F 5 ) 3 (F) 3 P] - ). As a result of 19F-NMR, the proportion of the meridional form among the two isomers was 84.5% by weight.

[0072] Production Example of Anion (B2) 3.14 g (0.0628 mol) of a 40% aqueous hydrofluoric acid solution was diluted with 25.0 g of triethylene glycol dimethyl ether, cooled to 20 °C or lower in advance, and then 26.55 g (0.0623 mol) of tris(pentafluoroethyl)difluorophosphorane was slowly added with stirring. The addition was made slowly with cooling so that the temperature would be 10 °C or lower to cause a reaction. Thereafter, 0.93 g (0.0186 mol) of a 40% aqueous hydrofluoric acid solution was further added thereto, the temperature was raised to 65 °C, heated for 15 minutes, and then cooled to room temperature. 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added to obtain a solution of potassium tris(pentafluoroethyl)trifluorophosphonate (K + [(C 2 F 5 ) 3 (F) 3 P] - ). As a result of 19F-NMR, the proportion of the meridional form among the two isomers was 79.2% by weight.

[0073] Production Example of Anion (B3) 3.14 g (0.0628 mol) of a 40% hydrofluoric acid aqueous solution was diluted with 25.0 g of triethylene glycol dimethyl ether, cooled to 20 °C or lower in advance, and then 26.55 g (0.0623 mol) of tris(pentafluoroethyl)difluorophosphorane was slowly added while stirring. The addition was made slowly with cooling so that the temperature would be 10 °C or lower, and the reaction was carried out. Then, 2.11 g (0.0422 mol) of a 40% hydrofluoric acid aqueous solution was further added thereto, the temperature was raised to 70 °C, heated for 15 minutes, and then cooled to room temperature. 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added, and a solution of potassium tris(pentafluoroethyl)trifluorophosphonate (K + [(C 2 F 5 ) 3 (F) 3 P] - ) was obtained. As a result of 19F-NMR, among the two isomers, the proportion of the meridional form was 55.6% by weight.

[0074] Production Example of Anion (B4) 3.14 g (0.0628 mol) of a 40% hydrofluoric acid aqueous solution was diluted with 25.0 g of triethylene glycol dimethyl ether, cooled to 20 °C or lower in advance, and then 26.55 g (0.0623 mol) of tris(pentafluoroethyl)difluorophosphorane was slowly added while stirring. The addition was made slowly with cooling so that the temperature would be 10 °C or lower, and the reaction was carried out. Then, 3.14 g (0.0628 mol) of a 40% hydrofluoric acid aqueous solution was further added thereto, the temperature was raised to 80 °C, heated for 15 minutes, and then cooled to room temperature. 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added, and a solution of potassium tris(pentafluoroethyl)trifluorophosphonate (K + [(C 2 F 5 ) 3 (F) 3 P]- ) A solution was obtained. As a result of 19F-NMR, the proportion of the meridional form among the two isomers was 50.8% by weight.

[0075] Production Example of Anion (B5) 3.14 g (0.0628 mol) of a 40% aqueous hydrofluoric acid solution was diluted with 25.0 g of triethylene glycol dimethyl ether, cooled to 20 °C or lower in advance, and then 35.90 g (0.0623 mol) of tris(heptafluoropropyl)difluorophosphorane was slowly added with stirring. The addition was carried out slowly with cooling so that the temperature would be 10 °C or lower to cause a reaction. Then, 2.14 g (0.0428 mol) of a 40% aqueous hydrofluoric acid solution was further added thereto, the temperature was raised to 70 °C, heated for 15 minutes, and then cooled to room temperature. 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added, and the potassium salt of tris(heptafluoropropyl)trifluorophosphonate (K + [(C 3 F 7 ) 3 (F) 3 P] - ) A solution was obtained. As a result of 19F-NMR, the proportion of the meridional form among the two isomers was 55.9% by weight.

[0076] Production Example of Anion (B'1) While cooling, 1.26 g (0.0628 mol) of hydrogen fluoride (HF) was slowly added to 20.0 g of diethyl ether, and then 33.6 g of tris(pentafluoroethyl)difluorophosphorane was slowly added with stirring. The addition was carried out slowly with cooling so that the temperature would be 5 °C or lower to cause a reaction. Then, 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added, and the potassium salt of tris(heptafluoropropyl)trifluorophosphonate (K + [(C 2 F 5 ) 3 (F) 3 P] -) A solution was obtained. As a result of 19F-NMR, the proportion of the meridional form among the two isomers was 88.3% by weight.

[0077] Production Example of Anion (B’2) 3.14 g (0.0628 mol) of a 40% aqueous hydrofluoric acid solution was diluted with 25.0 g of triethylene glycol dimethyl ether, cooled to 20 °C or lower in advance, and then 26.55 g (0.0623 mol) of tris(pentafluoroethyl)difluorophosphorane was slowly added while stirring. The addition was carried out slowly with cooling so that the temperature would be 10 °C or lower, and the reaction was allowed to proceed. Then, 5.22 g (0.104 mol) of a 40% aqueous hydrofluoric acid solution was further added thereto, the temperature was raised to 90 °C, heated for 15 minutes, and then cooled to room temperature. 3.50 g (0.0623 mol) of potassium hydroxide was dissolved in 30 g of ion-exchanged water in advance and then added, and the potassium salt of tris(pentafluoroethyl)trifluorophosphonate (K + [(C 2 F 5 ) 3 (F) 3 P] - ) A solution was obtained. As a result of 19F-NMR, the proportion of the meridional form among the two isomers was 48.2% by weight.

[0078] Example of Onium Salt (A-1) Production of 4-(phenylthio)phenyl diphenylsulfonium·tris(pentafluoroethyl)trifluorophosphonate (meridional form of anion: 84.5% by weight) 12.12 g of diphenyl sulfoxide, 9.3 g of diphenyl sulfide, and 43.0 g of methanesulfonic acid were uniformly mixed, and then 7.9 g of acetic anhydride was added dropwise. After reacting at 50 °C for 5 hours, it was cooled to room temperature. To this reaction solution, 124.5 g of an anion (B1) adjusted to a 20% aqueous solution or a solvent-substituted one was added dropwise, and the mixture was stirred for 2 hours. The precipitated oily matter was extracted with 120 g of ethyl acetate. After separating the aqueous layer, the organic layer was further washed three times. The solvent was removed from this organic layer, 50 g of toluene was added and dissolved, and then 270 g of hexane was added and mixed. Then, it was left standing for 1 hour to separate into two layers. The upper layer was removed, 150 g of hexane was added to the remaining lower layer, and when it was stirred well, crystals precipitated. These crystals were filtered and dried under reduced pressure to obtain 4-(phenylthio)phenyl diphenylsulfonium tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 84.5% by weight) (A-1). The chemical formula is as shown in the following (a1).

[0079] [Chemical formula]

[0080] Examples of onium salts (A-2) to (A-5) and comparative examples (A'-1) to (A'-2)

[0081] Using anions (B2) to (B5) and anions (B'1) to (B'2) respectively instead of the anion (B1) in the production example of (A-1), onium salts (A-2) to (A-5) and (A'-1) to (A'-2) were obtained. Note that only the amount of the 20% aqueous solution of anion (B5) was 167 g. The names of the synthesized compounds are as follows respectively. (A-2): 4-(phenylthio)phenyl diphenylsulfonium · tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 79.2% by weight) (A-3): 4-(phenylthio)phenyl diphenylsulfonium · tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 55.6% by weight) (A-4): 4-(Phenylthio)phenyl diphenylsulfonium tris(pentafluoroethyl) trifluorophosphate (Meridional form of anion: 50.8 wt%) (A-5): 4-(Phenylthio)phenyl diphenylsulfonium tris(heptafluoropropyl) trifluorophosphate (Meridional form of anion: 55.9 wt%) (A’-1): 4-(Phenylthio)phenyl diphenylsulfonium tris(pentafluoroethyl) trifluorophosphate (Meridional form of anion: 88.3 wt%) (A’-2): 4-(Phenylthio)phenyl diphenylsulfonium tris(pentafluoroethyl) trifluorophosphate (Meridional form of anion: 48.2 wt%)

[0082] The chemical formulas of (A-2) to (A-4) and (A’-1) to (A’-2) are (a1), and that of (A-5) is (a2).

[0083] [Chemical formula]

[0084] Examples of the onium salt (A-6) Production of (4-isopropylphenyl)tolyl iodonium tris(pentafluoroethyl) trifluorophosphate (Meridional form of anion: 55.6 wt%) 20 g of 4-methyl iodobenzene was added, and further 50 g of acetic acid and 10 g of sulfuric acid were added and dissolved. While cooling in an ice-water bath, 10 g of potassium persulfate was added little by little at 15°C or lower. The reaction was carried out at 20°C for 4 hours, and 24.4 g of cumene was added dropwise thereto so that the temperature did not exceed 20°C. Then the reaction was carried out at room temperature for 20 hours. The reaction solution was poured into 500 parts of an aqueous solution containing an equimolar amount of anion (B3), and further stirred for 3 hours. 500 parts of dichloromethane was added thereto. After standing, the aqueous layer was removed by liquid separation, and the organic layer was washed 5 times with 100 parts of water. Dichloromethane was concentrated and recrystallized from cyclohexane to obtain (4-isopropylphenyl)tolyl iodonium tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 55.6% by weight) (A-6). The chemical formula is as follows, according to formula (a3).

[0085] [Chemical formula]

[0086] Examples of the onium salt (A-7) Production of [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 55.6% by weight) 11 g of 4-[(phenyl)sulfinyl]biphenyl, 12 g of 4-(phenylthio)biphenyl, 22 g of acetic anhydride and 16 parts of methanesulfonic acid were uniformly mixed and reacted 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 to distill off the solvent, and a brown solid was obtained. This was washed with ethyl acetate / hexane, and the organic solvent was concentrated to obtain an intermediate. Dissolve 6.2 g of this intermediate in 60 mL of dichloromethane, mix with 70 g of an aqueous solution containing anion (B3) at room temperature, stir for 3 hours as it is, wash the dichloromethane layer 5 times with water by liquid separation operation, then transfer it to a rotary evaporator to distill off the solvent, thereby obtaining [4-(4-biphenylthio)phenyl]-4-biphenylphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate (meridional form of anion: 55.6% by weight) (A-7). The chemical formula is as follows, in formula (a4).

[0087] [Chemical formula]

[0088] Examples of onium salt (A-8) Production of [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate (meridional form of anion: 55.6% by weight) 89 parts of a dichloromethane solution containing 32 parts of (4-phenylthio)phenyl diphenylsulfonium trifluoromethanesulfonate was added dropwise with stirring and cooling to a suspension obtained by mixing 36 parts of aluminum chloride, 12 parts of acetyl chloride, and 200 parts of dichloromethane under the condition that the temperature inside the system was 10 °C or lower. After the addition, the mixture was stirred at room temperature for 2 hours, and then 300 parts of cold water was added. After removing the upper layer, the dichloromethane layer was washed with ion-exchanged water until the pH became neutral. Then, 70 g of an aqueous solution containing anion (B3) was mixed at room temperature, stirred for 3 hours as it was, the dichloromethane layer was washed 5 times with water by liquid separation operation, and then transferred to a rotary evaporator to distill off the solvent, thereby obtaining [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphonate (meridional form of anion: 55.6% by weight). The chemical formula is as follows, in formula (a5).

[0089] [Chemical formula]

[0090] Examples of onium salts (A-9) Production of fluorene skeleton sulfonium tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 55.6% by weight) 1.0 part of 2-[(phenyl)sulfinyl]-9,9-dimethylfluorene, 1.1 parts of 2-(phenylthio)-9,9-dimethylfluorene, 2.0 parts of acetic anhydride and 1.6 parts of methanesulfonic acid were charged and stirred at 65 °C for 3 hours. The reaction solution was cooled to room temperature, poured into 5.0 parts of ion-exchanged water, extracted with 5.0 parts of dichloromethane, and washed with ion-exchanged water until the pH of the aqueous layer became neutral. Next, 70 g of an aqueous solution containing anion (B3) was mixed with the dichloromethane layer at room temperature with stirring, and the mixture was stirred for 3 hours as it was. The dichloromethane layer was washed 5 times with water by liquid separation operation, and then transferred to a rotary evaporator to distill off the solvent, thereby obtaining [4-(4-acetylphenylthio)]phenyldiphenylsulfonium tris(pentafluoroethyl) trifluorophosphonate (meridional form of anion: 55.6% by weight). The chemical formula is as follows, according to formula (a6).

[0091] [Chemical formula]

[0092] [Adjustment of photocurable resin composition] (Examples 1 to 12 and Comparative Examples 1 and 2) They were uniformly mixed in the compounding amounts shown in Table 1 to obtain a photocurable resin composition. Subsequently, the above photocurable resin composition was applied to a glass substrate, and then ultraviolet light with a wavelength limited by a filter was irradiated to the glass substrate using an ultraviolet irradiation device (500 mJ / cm 2) Note that a 365 filter (manufactured by Eye Graphics Co., Ltd., a filter that cuts light with a wavelength of less than 365 nm) was used. After irradiation, it was heated at 100 °C for 2 hours for post-curing, and test pieces for physical property measurement (dumbbell-shaped test pieces conforming to JIS K-7113, bar-shaped test pieces conforming to JIS K-7171, and test pieces for Izod impact test conforming to JIS K-7110) were produced. The mechanical properties and heat distortion temperature of the test pieces after post-curing were measured by the following methods. The results are shown in Table 1.

[0093] The measurement of the mechanical properties [tensile properties (tensile strength at break, tensile modulus), flexural properties (flexural strength), impact strength] and heat distortion temperature of the cured product was carried out as follows.

[0094] (1) Tensile properties (tensile strength at break, tensile modulus) of the cured product: Using the cured products prepared in the following examples or comparative examples (dumbbell-shaped test pieces conforming to JIS K-7113), the tensile strength at break (tensile strength) and tensile modulus of the test pieces were measured in accordance with JIS K-7113 using an autograph "AGS-10kNX" manufactured by Shimadzu Corporation.

[0095] (2) Flexural properties (flexural strength) of the cured product: Using the cured products prepared in the following examples or comparative examples (bar-shaped test pieces conforming to JIS K-7171), the flexural strength of the test pieces was measured in accordance with JIS K-7171.

[0096] (3) Impact strength of the cured product: Using an impact tester "No.258-D" manufactured by Yasuda Seiki Seisakusho Co., Ltd., the notched Izod impact strength was measured in accordance with JIS K-7110.

[0097] (4) Heat distortion temperature of the cured product: Using the cured products (bar-shaped test pieces conforming to JIS K-7171) prepared in the following Examples or Comparative Examples, the heat distortion temperature of the test pieces was measured in accordance with JIS K-7207 (Method A) by applying a load of 1.81 MPa to the test pieces using a heat distortion tester "No. 148-HDPC3" manufactured by Yasuda Seiki Seisakusho Co., Ltd., and further, the heat distortion temperature of the test pieces was measured in accordance with JIS K-7207 (Method B) by applying a load of 0.45 MPa to the test pieces.

[0098]

Table 1

[0099] D-1a: 3,4-Epoxycyclohexylmethyl-3’,4’-epoxycyclohexanecarboxylate ("Cel-2021P" manufactured by Daicel Corporation) D-2b: [2-[4-(2,3-Epoxypropoxy)phenyl]-2-[4-[1,1-bis[4-([2,3-epoxypropoxy]phenyl]ethyl]phenyl]propane] ("VG3101L" manufactured by Printteq Co., Ltd.) D-1b: Hydrogenated bisphenol A diglycidyl ether ("HBE-100" manufactured by Shin Nippon Rika Co., Ltd.) D-3a1-1: 3-Ethyl-3-hydroxymethylxetane ("OXT101" manufactured by Toagosei Co., Ltd.) D-3b1-1: Bis(3-ethyl-3-oxetanylmethyl)ether ("OXT221" manufactured by Toagosei Co., Ltd.) D-4: 1,6-Hexanediol diglycidyl ether ("EX-212" manufactured by Nagase ChemteX Corporation) E-1: Dipentaerythritol pentaacrylate ("A-9550W" manufactured by Shin-Nakamura Chemical Co., Ltd.) E-2: Lauryl acrylate ("NK Ester-LA" manufactured by Shin-Nakamura Chemical Co., Ltd.) F-1: 1-Hydroxy-cyclohexyl phenyl ketone ("Irgacure-184" manufactured by BASF)

[0100] From the results in Table 1, the photocurable resin composition containing the onium salt (A) obtained by the present invention is excellent in toughness, strong and difficult to break, and further has a high heat distortion temperature and can produce a cured product excellent in heat resistance. Moreover, since it is also excellent in dimensional accuracy, other mechanical properties, and heat resistance, it is extremely useful as a photocurable resin composition.

Industrial Applicability

[0101] The onium salt (A) of the present invention functions as a photoacid generator, and further, this photoacid generator reacts with the cationically polymerizable organic compound (D) by the action of an acid generated by irradiation with active energy rays such as light or electron beams, and can obtain a cured product excellent in heat resistance (that is, capable of maintaining its shape even under high-temperature conditions such as soldering by the reflow method). It becomes a cationically polymerizable composition specialized for applications such as cured products for insulators of electronic material parts, mounting adhesives, and resins for stereolithography.

Claims

1. The cation is selected from the group consisting of iodonium and sulfonium, and the anion is a fluoro phosphate anion (B) represented by the general formula (1). Among the two isomers of the facial form and the meridional form of the anion, the proportion of the meridional form is 55.0 to 80.0% by weight of the onium salt (A). [(R 1 ) ３ (F) ３ P] － (1) [In formula (1), R １ is a perfluoroalkyl group. ]

2. A photoacid generator containing the onium salt (A) according to Claim 1.

3. A photocurable resin composition comprising the photoacid generator according to Claim 2 and a cationically polymerizable organic compound (D), wherein the onium salt (A) is contained in a proportion of 0.1 to 10% by weight based on the weight of the cationically polymerizable organic compound (D).

4. The photocurable resin composition according to Claim 3, which contains an oxetane compound (D-3) as the cationically polymerizable organic compound (D), and the oxetane compound (D3) is contained in a proportion of 1 to 35% by weight based on the weight of the cationically polymerizable organic compound (D).

5. Further comprising a radically polymerizable organic compound (E) and a radical polymerization initiator (F), wherein the content ratio of the cationically polymerizable organic compound (D):radically polymerizable organic compound (E) is 30:70 to 90:10 (weight ratio), and the radical polymerization initiator (F) is contained in a proportion of 0.1 to 10% by weight based on the weight of the radically polymerizable organic compound (E). The photocurable resin composition according to Claim 3 or 4.

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