Acid generator, curable composition containing the acid generator, and cured product thereof

Abstract

To provide a novel acid generator excellent in cation polymerization initiating capacity, and excellent in solubility into a resin.SOLUTION: An acid generator of the present invention contains a salt (1) of an onium cation (a) and an anion represented by the following formula (I-1), and a salt (2) of an onium cation (a) and an anion represented by the following formula (I-2). [(R1CF2)tPFs]- (I-1) (wherein R1 represents a fluorine atom or a perfluoroalkyl group, and s and t are the same or different and represent an integer of 1 or more, provided that s+t=6) [(R1CHR2)t1(R1CF2]t2PFs] - (I-2) (wherein R1 and s are the same as above, R2 represents a fluorine atom or a hydrogen atom, and t1 and t2 are the same or different and are integer of 1 or more, where s+t1+t2=6).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel acid generator, a curable composition containing the acid generator, and a cured product thereof. [Background technology]

[0002] Onium salts have been known as compounds that cure cationically polymerizable compounds by heating or irradiation with active energy rays. These onium salts are called acid generators because they generate acid when exposed to heat or active energy rays.

[0003] The cationic polymerization initiation ability of the onium salt varies depending on the type of anion, and AsF6 - and SbF6 - However, the toxicity of As and Sb has limited its applications.

[0004] Patent Document 1 describes SbF6 - As compounds having cationic polymerization initiation ability comparable to that of onium salts having the anion, salts of onium cations and perfluoroalkylfluorophosphate anions, such as 4-(phenylthio)phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate, have been described. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2005 / 116038 Summary of the Invention [Problem to be solved by the invention]

[0006] The solubility of the salt of onium cation and perfluoroalkyl fluorophosphate anion in resin is -Although this is better than the salt, it is still insufficient, and even if it is once dissolved, it is prone to precipitation when stored at low temperature for a while. In other words, the curable composition containing a salt of an onium cation and a perfluoroalkylfluorophosphate anion has a problem of low storage stability.

[0007] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a novel acid generator which has excellent cationic polymerization initiation ability and excellent solubility in resins. Another object of the present invention is to provide a curable composition which has excellent storage stability and can rapidly form a cured product upon heating or irradiation with active energy rays. [Means for solving the problem]

[0008] As a result of intensive research aimed at solving the above problems, the present inventors have found that adding a partially fluorinated alkylfluorophosphate onium salt, in which the perfluoroalkyl group is partially hydrogenated, to a perfluoroalkylfluorophosphate onium salt significantly improves the solubility in resins. The present invention was completed based on these findings.

[0009] That is, the present invention provides a compound represented by the following formula (I-1): [(R 1 CF2) t PF s ] - (I-1) (In the formula, R 1 represents a fluorine atom or a perfluoroalkyl group, and s and t are the same or different and represent an integer of 1 or more, provided that s+t=6. A salt (1) of an anion represented by Onium cation (a) and the following formula (I-2) [(R 1 CHR 2 ) t1 (R 1 CF2) t2 PF s ] - (I-2) (In the formula, R 1 , s is the same as above. R2 represents a fluorine atom or a hydrogen atom, and t1 and t2 are the same or different and represent an integer of 1 or more, provided that s+t1+t2=6. A salt (2) of an anion represented by The present invention provides an acid generator comprising:

[0010] The present invention also provides the acid generator, wherein the ratio of the contents of the salt (1) and the salt (2) (former / latter; weight ratio) is 85 / 15 to 99.8 / 0.2.

[0011] The present invention also provides the acid generator, wherein the onium cation (a) is an onium cation selected from a sulfonium ion, an iodonium ion, a selenium ion, an ammonium ion, and a phosphonium ion.

[0012] The present invention also provides the acid generator, wherein the onium cation (a) is an arylsulfonium ion or an aryliodonium ion.

[0013] The present invention also provides a curable composition containing the acid generator and a cationically polymerizable compound.

[0014] The present invention also provides a cured product of the curable composition. [Effects of the Invention]

[0015] The acid generator of the present invention has excellent cationic polymerization initiation ability equivalent to that of an acid generator containing only a perfluoroalkylfluorophosphate onium salt (or containing less than 0.2 wt % of a partially fluorinated alkylfluorophosphate onium salt based on the total amount of the acid generator). Furthermore, the acid generator has superior solubility in resins compared to an acid generator containing only a perfluoroalkylfluorophosphate onium salt (or containing less than 0.2 wt % of a partially fluorinated alkylfluorophosphate onium salt based on the total amount of the acid generator). Therefore, a curable composition containing the acid generator of the present invention and a resin is easy to handle and does not precipitate the acid generator under a wide range of storage conditions. Furthermore, the acid generator of the present invention is safe because it does not contain highly toxic components such as As and Sb. DETAILED DESCRIPTION OF THE INVENTION

[0016] [Acid generator] The acid generator of the present invention contains a salt (1) and a salt (2). The salt (1) is a salt of an onium cation (a) and an anion represented by the following formula (I-1): [(R 1 CF2) t PF s ] - (I-1) (In the formula, R 1 represents a fluorine atom or a perfluoroalkyl group, and s and t are the same or different and represent an integer of 1 or more, provided that s+t=6. The salt (2) is a salt of an onium cation (a) and an anion represented by the following formula (I-2): [(R 1 CHR 2 ) t1 (R 1 CF2) t2 PF s ] - (I-2) (In the formula, R 1 , s is the same as above. R 2 represents a fluorine atom or a hydrogen atom, and t1 and t2 are the same or different and represent an integer of 1 or more, provided that s+t1+t2=6.

[0017] The salt (2) includes at least one of salt (2-1), salt (2-2), and salt (2-3). 1 , s, t1, and t2 are the same as above. t3 and t4 are the same or different and represent integers of 1 or more, and t3+t4=t1. The salt (2-1) is a salt of an onium cation (a) and an anion represented by the following formula (I-2-1): [(R 1 CHF) t1 (R 1 CF2) t2 PF s ] - (I-2-1) The salt (2-2) is a salt of an onium cation (a) and an anion represented by the following formula (I-2-2): [(R 1 CH2) t1 (R 1 CF2) t2 PF s ] - (I-2-2) The salt (2-3) is a salt of an onium cation (a) and an anion represented by the following formula (I-2-3): [(R 1 CH2) t3 (R 1 CHF) t4 (R 1 CF2) t2 PF s ] - (I-2-3)

[0018] As the salt (2), a mixture of two or more salts selected from the salts (2-1) to (2-3) is preferred, and a mixture of the salt (2-1) and the salt (2-2) is particularly preferred, in terms of particularly excellent solubility in resins.

[0019] When the salt (2) contains both the salt (2-1) and the salt (2-2), the weight ratio of [salt (2-1) / salt (2-2)] is, for example, 10 / 90 to 90 / 10, preferably 10 / 90 to 50 / 50, preferably 15 / 85 to 40 / 60, and particularly preferably 20 / 80 to 30 / 70.

[0020] The onium cation (a) contained in the salt (1) and the salt (2) is the same and is, for example, an onium cation selected from a sulfonium ion, an iodonium ion, a selenium ion, an ammonium ion, a phosphonium ion, and the like.

[0021] Examples of the sulfonium ion include aryl sulfonium ions. Examples of the aryl sulfonium ion include monoaryl sulfonium ions such as 4-hydroxyphenylmethylbenzyl sulfonium ion and phenylmethylbenzyl sulfonium ion; diarylsulfonium ions such as diphenylphenacylsulfonium ion, diphenylbenzyl sulfonium ion and diphenylmethyl sulfonium ion; and triarylsulfonium ions such as triphenylsulfonium ion, tri-p-tolylsulfonium ion, tri-o-tolylsulfonium ion, tris(4-methoxyphenyl)sulfonium ion, 1-naphthyldiphenylsulfonium ion, 4-(phenylthio)phenyldiphenylsulfonium, 4-(p-acetylphenylthio)phenyldiphenylsulfonium, and 4-(biphenylylthio)phenylbiphenylylphenylsulfonium.

[0022] The sulfonium ion is preferably an arylsulfonium ion, and particularly preferably a triarylsulfonium ion.

[0023] Examples of the iodonium ion include aryliodonium ions such as p-cumenyl(p-tolyl)iodonium ion, diphenyliodonium ion, di-p-tolyliodonium ion, bis(4-dodecylphenyl)iodonium ion, bis(4-methoxyphenyl)iodonium ion, and (4-octyloxyphenyl)phenyliodonium ion.

[0024] Examples of the selenium ion include arylselenium ions such as a triphenylselenium ion, a tri-p-tolylselenium ion, a tri-o-tolylselenium ion, a tris(4-methoxyphenyl)selenium ion, a 1-naphthyldiphenylselenium ion, a tris(4-fluorophenyl)selenium ion, a tri-1-naphthylselenium ion, and a tri-2-naphthylselenium ion.

[0025] Examples of the ammonium ion include quaternary ammonium ions such as tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, tetrapentylammonium ion, tetrahexylammonium ion, tetraheptylammonium ion, tetraoctylammonium ion, trimethylhexylammonium ion, and trimethyloctylammonium ion.

[0026] As the onium cation (a), a sulfonium ion or an iodonium ion is preferred, and an arylsulfonium ion or an aryliodonium ion is particularly preferred, from the viewpoint of excellent cationic polymerization initiation ability.

[0027] R 1 The perfluoroalkyl group in the above formula is, for example, a group represented by the following formula (Rf). [ka] (wherein n represents an integer of 0 or more; the bond marked with a wavy line binds to a carbon atom in formula (I-1) or (I-2))

[0028] n is an integer of 0 or more, for example, an integer of 0 to 4, preferably 0 or 1, and particularly preferably 0.

[0029] Therefore, the perfluoroalkyl group may be, for example, perfluoro C 1-5 Alkyl groups, preferably perfluoro C 1-2An alkyl group is particularly preferred, and a trifluoromethyl group is particularly preferred.

[0030] s and t are the same or different and each represent an integer of 1 or more, and t+s=6. The s is preferably 2 or 3, and when s=2, t=4, and when s=3, t=3. s and t are particularly preferably 3.

[0031] t1 and t2 are the same or different and each represent an integer of 1 or greater, and s+t1+t2=6. The s is preferably 2 or 3, and particularly preferably 3. Therefore, when s=2, (t1+t2)=4, and when s=3, (t1+t2)=3. t1 is preferably 1 or 2, and particularly preferably 1. Therefore, when (t1+t2)=4, it is preferable that t1=1 and t2=3, and when (t1+t2)=3, it is preferable that t1=1 and t2=2.

[0032] The acid generator preferably contains a salt (1a) and a salt (2a), where the onium cation (a) is the same as above. The salt (1a) is a salt of an onium cation (a) and an anion represented by the following formula (I-1a): [(CF3CF2)3PF3] - (I-1a) The salt (2a) is a salt (2a-1) of an onium cation (a) and an anion represented by the following formula (I-2-1a), a salt (2a-2) of an onium cation (a) and an anion represented by the following formula (I-2-2a), a salt (2a-3) of an onium cation (a) and an anion represented by the following formula (I-2-3a), or a mixture of two or more salts selected from the salts (2a-1) to (2a-3). [(CF3CHF)1(CF3CF2)2PF3] - (I-2-1a) [(CF3CH2)1(CF3CF2)2PF3] - (I-2-2a) [(CF3CH2)1(CF3CHF)1(CF3CF2)1PF3] - (I-2-3a)

[0033] As the salt (2a), a mixture of two or more salts selected from the salts (2a-1) to (2a-3) is preferred, and a mixture of the salt (2a-1) and the salt (2a-2) is particularly preferred, as they have particularly excellent solubility in resins.

[0034] When the salt (2a) contains the salt (2a-1) and the salt (2a-2), the weight ratio of [salt (2a-1) / salt (2a-2)] is, for example, 10 / 90 to 90 / 10, preferably 10 / 90 to 50 / 50, preferably 15 / 85 to 40 / 60, and particularly preferably 20 / 80 to 30 / 70.

[0035] The acid generator may contain the following salt (1b) and salt (2b): The onium cation (a) is the same as above. The salt (1b) is a salt of the onium cation (a) and an anion represented by the following formula (I-1b). [(CF3CF2)4PF2] - (I-1b) The salt (2b) is a salt (2b-1) of an onium cation (a) and an anion represented by the following formula (I-2-1b), a salt (2b-2) of an onium cation (a) and an anion represented by the following formula (I-2-2b), a salt (2b-3) of an onium cation (a) and an anion represented by the following formula (I-2-3b), or a mixture of two or more salts selected from the salts (2b-1) to (2b-3). [(CF3CHF)1(CF3CF2)3PF2] - (I-2-1b) [(CF3CH2)1(CF3CF2)3PF2] - (I-2-2b) [(CF3CH2)1(CF3CHF)1(CF3CF2)2PF2] - (I-2-3b)

[0036] As the salt (2b), a mixture of two or more salts selected from the salts (2b-1) to (2b-3) is preferred, and a mixture of the salt (2b-1) and the salt (2b-2) is particularly preferred, as they have particularly excellent solubility in resins.

[0037] When the salt (2b) contains the salt (2b-1) and the salt (2b-2), the weight ratio of [salt (2b-1) / salt (2b-2)] is, for example, 10 / 90 to 90 / 10, preferably 10 / 90 to 50 / 50, preferably 15 / 85 to 40 / 60, and particularly preferably 20 / 80 to 30 / 70.

[0038] The ratio of the contents of the salt (1) and the salt (2) [preferably the salt (1a) and the salt (2a), or the salt (1b) and the salt (2b)] in the acid generator (former / latter; weight ratio) is, for example, 85 / 15 to 99.8 / 0.2. From the viewpoint of having excellent cationic polymerization initiation ability, the lower limit of the ratio is preferably 91 / 9, more preferably 95 / 5, particularly preferably 98 / 2, and most preferably 99.5 / 0.5. From the viewpoint of excellent solubility in resins and suppression of precipitation even at low temperatures, the upper limit of the ratio is preferably 99.7 / 0.3, more preferably 99.6 / 0.4. From the viewpoint of excellent solubility in resins and suppression of precipitation even at low temperatures, the lower limit of the ratio is preferably 91 / 9, more preferably 95 / 5, particularly preferably 98 / 2, and most preferably 99.5 / 0.5, and the upper limit of the ratio is preferably 99.7 / 0.3, and more preferably 99.6 / 0.4.

[0039] The ratio of the content of the salt (1) to the content of the salt (2) [or the content of the salt (1), the salt (2-1), and the salt (2-2)] in the acid generator is: 19 It can be determined from the peak area ratio by measuring F-NMR.

[0040] The acid generator may contain onium salts other than the salts (1) and (2), but the proportion of the total content of the salts (1) and (2) in the total amount of onium salts contained in the acid generator (100% by weight) is, for example, 80% by weight or more, preferably 90% by weight or more, particularly preferably 95% by weight or more, most preferably 99% by weight or more, and particularly preferably 99.9% by weight or more. The upper limit of the total content is 100% by weight.

[0041] The acid generator may contain components other than the salt (1) and the salt (2), but the proportion of the total content of the salt (1) and the salt (2) in the total amount of the acid generator (100% by weight) is, for example, 80% by weight or more, preferably 90% by weight or more, particularly preferably 95% by weight or more, most preferably 99% by weight or more, and particularly preferably 99.9% by weight or more. The upper limit of the total content is 100% by weight.

[0042] The acid generator of the present invention has the above-described structure, and therefore has excellent cationic polymerization initiation ability and excellent solubility in resins.

[0043] [Method of manufacturing the acid generator] The acid generator can be produced, for example, through the following steps. Step 1: An alkylphosphine is subjected to electrochemical fluorination (ECF) to obtain a mixture of fully and partially fluorinated phosphoranes 1. Step 2: The mixture 1 is reacted with a fluorinating agent to obtain a mixture 2 of a salt containing a fully fluorinated phosphate anion and a salt containing a partially fluorinated phosphate anion. Step 3: The cation of the salt contained in mixture 2 is converted to an onium cation (a).

[0044] (Process 1) Step 1 is a step in which alkylphosphine is subjected to electrolytic fluorination treatment to obtain a mixture of fully fluorinated phosphorane and partially fluorinated phosphorane 1. The reaction in step 1 is represented by the following formula: [ka]

[0045] The alkylphosphine is a compound represented by the above formula (III). 11 represents a hydrogen atom or an alkyl group, and u represents an integer of 0 or greater. t, like t in formula (I-1), represents an integer of 1 or greater. In addition, t+u=3.

[0046] The alkyl group may be, for example, C 1-5 Alkyl groups, preferably C 1-2 An alkyl group, particularly preferably a methyl group.

[0047] The alkylphosphine is preferably a trialkylphosphine such as triethylphosphine.

[0048] The alkylphosphine represented by the above formula (III) (hereinafter sometimes referred to as "alkylphosphine (III)") is subjected to electrolytic fluorination treatment to obtain a reaction product containing a fully fluorinated phosphorane represented by the above formula (II-1) (hereinafter sometimes referred to as "fully fluorinated phosphorane (II-1)") and a partially fluorinated phosphorane represented by the above formula (II-2) (hereinafter sometimes referred to as "partially fluorinated phosphorane (II-2)"). In the above formulas (II-1) and (II-2), t1 and t2, like t1 and t2 in the above formula (I-2), are the same or different and represent an integer of 1 or greater. Like u in formula (III), u represents an integer of 0 or greater. Note that t1 + t2 + u = 3.

[0049] The electrolytic fluorination treatment is, for example, a treatment in which alkylphosphine (III) and anhydrous hydrofluoric acid as raw materials are charged together in an electrolytic cell and electrolyzed in a nitrogen gas atmosphere under normal pressure, whereby hydrogen atoms in the alkylphosphine are substituted with fluorine atoms to obtain a reaction product containing fully fluorinated phosphorane and partially fluorinated phosphorane.

[0050] The electrolysis conditions are, for example, within the ranges described below. Electrode voltage: 4.5~5.5V Current: 1.0~25A Electrolyzer temperature: 5~-5℃

[0051] As the electrolytic fluorination treatment proceeds, the reaction solution separates into two layers, with the target products, fully fluorinated phosphorane (II-1) and partially fluorinated phosphorane (II-2), being produced in the lower layer.

[0052] The reaction product obtained by the electrolytic fluorination treatment may contain impurities, such as unreacted raw materials and compounds with a lower fluorination rate than the partially fluorinated phosphorane (II-2), in addition to the target product. However, these impurities are mainly contained in the upper layer of the reaction solution, which is divided into two layers. Therefore, removing the upper layer can increase the purity of the target product. Furthermore, by subjecting the lower layer to a distillation treatment, impurities mixed in the lower layer can be removed, and at the same time, the content ratio of the fully fluorinated phosphorane (II-1) and the partially fluorinated phosphorane (II-2) can be controlled within a desired range.

[0053] This gives a mixture 1 of fully fluorinated phosphorane (II-1) and partially fluorinated phosphorane (II-2).

[0054] The ratio of the contents of the perfluorinated phosphorane (II-1) and the partially fluorinated phosphorane (II-2) in the mixture 1 (former / latter; weight ratio) is, for example, 85 / 15 to 99.8 / 0.2. From the viewpoint of obtaining an acid generator having excellent cationic polymerization initiation ability, the lower limit of the ratio is preferably 91 / 9, more preferably 95 / 5, particularly preferably 98 / 2, and most preferably 99.5 / 0.5. From the viewpoint of obtaining an acid generator that has excellent solubility in resins and can suppress precipitation even at low temperatures, the upper limit of the ratio is preferably 99.7 / 0.3, and more preferably 99.6 / 0.4. From the viewpoint of obtaining an acid generator that has excellent solubility in resins and that can suppress precipitation even at low temperatures, the lower limit of the ratio is preferably 91 / 9, more preferably 95 / 5, particularly preferably 98 / 2, and most preferably 99.5 / 0.5, and the upper limit of the ratio is preferably 99.7 / 0.3, and more preferably 99.6 / 0.4.

[0055] (Process 2) Step 2 is a step in which a fluorinating agent is reacted with the mixture 1 obtained through step 1 to obtain a mixture 2 of a salt containing a fully fluorinated phosphate anion and a salt containing a partially fluorinated phosphate anion. The reaction in step 2 is represented by the following formula. 1 , s, t, t1, t2, and u are the same as above. b F represents a fluorinating agent. [ka]

[0056] When a mixture 1 of perfluorinated phosphorane (II-1) and partially fluorinated phosphorane (II-2) is reacted with a fluorinating agent, a mixture 2 of a salt containing a perfluorinated phosphate anion represented by the above formula (I-1) and a salt containing a partially fluorinated phosphate anion represented by the above formula (I-2) is obtained.

[0057] The fluorinating agent (R b F) is not particularly limited, and examples thereof include hydrogen fluoride; metal fluorides such as LiF, NaF, KF, RbF, CsF, and AgF; quaternary ammonium fluorides such as tetramethylammonium fluoride, tetraethylammonium fluoride, and tetrabutylammonium fluoride; and quaternary phosphonium fluorides such as tetramethylphosphonium fluoride, tetraethylphosphonium fluoride, and tetrabutylphosphonium fluoride. These may be used alone or in combination of two or more.

[0058] The amount of the fluorinating agent used is, for example, 0.9 to 2.0 moles per mole of the total of the fully fluorinated phosphorane (II-1) and the partially fluorinated phosphorane (II-2).

[0059] (Step 3) Step 3 is a step of converting the cation of the salt contained in the mixture 2 obtained through step 2 into the desired onium cation (a). An example of the reaction in step 3 is shown in the following formula. The example below is a reaction of converting the cation of the salt contained in the mixture 2 into 4-(phenylthio)phenyldiphenylsulfonium, which is one type of onium cation (a). R in the following formula 1 , s, t, t1, t2, and u are the same as above. [ka]

[0060] The cation conversion can be carried out, for example, by reacting a salt of the desired onium cation (a) with another anion (an anion other than a perfluoroalkylfluorophosphate anion), or a raw material thereof, with the mixture 2. For example, when the onium cation (a) is 4-(phenylthio)phenyldiphenylsulfonium, examples of the reaction include a method of reacting a salt of 4-(phenylthio)phenyldiphenylsulfonium (e.g., 4-(phenylthio)phenyldiphenylsulfonium=trifluoromethanesulfonic acid) with the mixture 2, and a method of reacting diphenyl sulfoxide, diphenyl sulfide, and methanesulfonic acid, which are raw materials for the salt.

[0061] Through the cation exchange reaction, an acid generator containing a salt (1) of a fully fluorinated phosphate anion represented by the above formula (I-1) and a desired onium cation (a), and a salt (2) of a partially fluorinated phosphate anion represented by the above formula (I-2) and a desired onium cation (a) are obtained.

[0062] After completion of the reaction, the resulting reaction product may be subjected to a general separation and purification treatment (for example, precipitation, washing, filtration, etc.).

[0063] [Curable composition] The curable composition of the present invention contains the acid generator and a cationically polymerizable compound as a resin component. The acid generator and the cationically polymerizable compound may each be contained alone or in combination of two or more.

[0064] The content of the acid generator is, for example, 0.05 to 20 parts by weight, and preferably 0.1 to 10 parts by weight, relative to 100 parts by weight of the cationically polymerizable compound.

[0065] The cationically polymerizable compound is a compound having one or more cationically polymerizable groups selected from an epoxy group, an oxetanyl group, a vinyl ether group, etc. The epoxy group is a group containing a three-membered cyclic ether skeleton, and the oxetanyl group is a group containing a four-membered cyclic ether skeleton.

[0066] Examples of the cationically polymerizable compound include a compound having an epoxy group as a cationically polymerizable group (=epoxy compound), a compound having an oxetanyl group as a cationically polymerizable group (=oxetane compound), a compound having a vinyl ether group as a cationically polymerizable group (=vinyl ether compound), a compound having an epoxy group and an oxetanyl group as cationically polymerizable groups, a compound having an epoxy group and a vinyl ether group as cationically polymerizable groups, and a compound having an oxetanyl group and a vinyl ether group as cationically polymerizable groups.

[0067] (epoxy compounds) Examples of epoxy compounds include epoxy-modified siloxane compounds, alicyclic epoxy compounds (alicyclic epoxy resins), aromatic epoxy compounds (aromatic epoxy resins), and aliphatic epoxy compounds (aliphatic epoxy resins).

[0068] <Epoxy-modified siloxane compound> Examples of the epoxy-modified siloxane compound include epoxy-modified silicone and epoxy-modified polyorganosilsesquioxane.

[0069] <Alicyclic epoxy compounds> Examples of the alicyclic epoxy compound include known or commonly used compounds having one or more alicyclic rings and one or more epoxy groups in the molecule, and are not particularly limited, but include, for example, the following compounds: (1) Compounds with alicyclic epoxy groups (= epoxy groups consisting of two adjacent carbon atoms and an oxygen atom that form an alicyclic ring within the molecule) (2) Compounds containing an alicyclic ring and a glycidyl ether group

[0070] Examples of the compound (1) having an alicyclic epoxy group include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate, 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-3-methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexanecarboxylate, 3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylhexanecarboxylate, 1-methyl-3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylhexanecarboxylate, 1-methyl-3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylcyclo ... Examples include bis-5-methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexanecarboxylate, 2-(3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy)cyclohexanemetadioxane, bis(3,4-epoxycyclohexylmethyl)adipate, 3,4-epoxy-6-methylcyclohexylcarboxylate, methylenebis(3,4-epoxycyclohexane), dicyclopentadiene diepoxide, and ethylenebis(3,4-epoxycyclohexanecarboxylate).

[0071] Examples of the compound (2) having an alicyclic ring and a glycidyl ether group include glycidyl ethers of alicyclic alcohols (particularly alicyclic polyhydric alcohols). More specifically, examples include hydrogenated compounds of bisphenol A epoxy compounds such as 2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane and 2,2-bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]propane (hydrogenated bisphenol A epoxy compounds); bis[o,o-(2,3-epoxypropoxy)cyclohexyl]methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]propane ... Examples of such epoxy compounds include hydrogenated compounds of bisphenol F epoxy compounds such as bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane and bis[3,5-dimethyl-4-(2,3-epoxypropoxy)cyclohexyl]methane (hydrogenated bisphenol F epoxy compounds); hydrogenated biphenol epoxy compounds; hydrogenated phenol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds; hydrogenated cresol novolac epoxy compounds of bisphenol A; hydrogenated naphthalene epoxy compounds; and hydrogenated trisphenolmethane epoxy compounds.

[0072] <Aromatic epoxy compounds> Examples of the aromatic epoxy compounds include epibis-type glycidyl ether epoxy resins obtained by a condensation reaction between bisphenols [e.g., bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc.] and epihalohydrin; high molecular weight epibis-type glycidyl ether epoxy resins obtained by further addition reaction of these epibis-type glycidyl ether epoxy resins with the above-mentioned bisphenols; phenols [e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol B, etc.]; Examples include novolak alkyl type glycidyl ether epoxy resins obtained by condensing polyhydric alcohols obtained by the condensation reaction of polyphenols (e.g., phenol F, bisphenol S) with aldehydes (e.g., formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, salicylaldehyde) with epihalohydrin; and epoxy compounds in which two phenol skeletons are bonded to the 9-position of the fluorene ring and a glycidyl group is bonded to each of the oxygen atoms obtained by removing the hydrogen atom from the hydroxyl group of these phenol skeletons, either directly or via an alkyleneoxy group.

[0073] <Aliphatic epoxy compounds> Examples of the aliphatic epoxy compound include glycidyl ethers of q-valent alcohols (q is a natural number) that do not have a cyclic structure; glycidyl esters of monovalent or polyvalent carboxylic acids (e.g., acetic acid, propionic acid, butyric acid, stearic acid, adipic acid, sebacic acid, maleic acid, itaconic acid, etc.); epoxidized products of fats and oils having double bonds, such as epoxidized linseed oil, epoxidized soybean oil, and epoxidized castor oil; and epoxidized products of polyolefins (including polyalkadiene), such as epoxidized polybutadiene. Examples of the q-valent alcohol not having a cyclic structure include monohydric alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, and 1-butanol; dihydric alcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; and trihydric or higher polyhydric alcohols such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and sorbitol. The q-valent alcohol may also be polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, or the like.

[0074] (Oxetane compounds) Examples of the oxetane compound include 3,3-bis(vinyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-(hydroxymethyl)oxetane, 3-ethyl-3-[(phenoxy)methyl]oxetane, 3-ethyl-3-(hexyloxymethyl)oxetane, 3-ethyl-3-(chloromethyl)oxetane, 3,3-bis(chloromethyl)oxetane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, and bis(vinyloxymethyl)oxetane. Examples of the bisoxetane include bis([1-ethyl(3-oxetanyl)]methyl)ether, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexyl, 4,4'-bis[3-ethyl-(3-oxetanyl)methoxymethyl]biphenyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 1,4-bis([(3-ethyl-3-oxetanyl)methoxy]methyl)benzene, 3-ethyl-3([(3-ethyloxetan-3-yl)methoxy]methyl)oxetane, and xylylene bisoxetane.

[0075] (Vinyl ether compounds) Examples of the vinyl ether compound include aryl vinyl ethers such as phenyl vinyl ether; alkyl vinyl ethers such as n-butyl vinyl ether and n-octyl vinyl ether; cycloalkyl vinyl ethers such as cyclohexyl vinyl ether; vinyl ethers having a hydroxyl group such as 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether and 2-hydroxybutyl vinyl ether; and polyfunctional vinyl ethers such as hydroquinone divinyl ether, 1,4-butanediol divinyl ether, cyclohexane divinyl ether, cyclohexane dimethanol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether and triethylene glycol divinyl ether.

[0076] In addition to the above components, the curable composition may contain one or more other components as needed. Examples of such other components include sensitizers, sensitization aids, antioxidants, stabilizers, surfactants, solvents, rheology control agents, leveling agents, silane coupling agents, fillers, conductive particles, polymerization inhibitors, light stabilizers, plasticizers, antifoaming agents, foaming agents, UV absorbers, tackifiers, cure retarders, ion adsorbents, pigments, dyes, fluorescent materials, mold release agents, antistatic agents, flame retardants, radically polymerizable compounds, polyimide resins, polyamide resins, phenoxy resins, poly(meth)acrylate resins, polyurethane resins, polyurea resins, polyester resins, polyvinyl butyral resins, SBS, and SEBS. The content of these components (the total amount when two or more components are contained) is, for example, about 0.05 to 50 wt %, preferably 0.05 to 10 wt %, and particularly preferably 0.1 to 5 wt % of the total amount of the curable composition (100 wt %).

[0077] The curable composition can be produced by uniformly mixing the acid generator, the cationically polymerizable compound, and other components added as needed using commonly known mixing equipment such as a planetary mixer, a homogenizer, a planetary mixer, a three-roll mill, a bead mill, etc. The components may be mixed simultaneously or sequentially.

[0078] The use of the curable composition is not particularly limited, and examples thereof include paints, coating agents, inks, positive resists, resist films, liquid resists, photosensitive materials, adhesives, molding materials, casting materials, putties, glass fiber impregnating agents, fillers, sealing materials, encapsulants, and materials for optical shaping.

[0079] The curable composition contains an acid generator with excellent cationic polymerization initiation ability, and thus can rapidly form a cured product by irradiation with active energy rays or heat treatment. Furthermore, the curable composition contains an acid generator with excellent solubility in resins, and can prevent precipitation of the acid generator even when the composition is stored in a low-temperature environment (for example, a temperature environment of 0°C or below, preferably a temperature environment of -25°C or below) after preparation. Therefore, there is ample time between preparation and use, and the composition is easy to handle.

[0080] [Cured product] The cured product of the present invention is a cured product of the curable composition.

[0081] The cured product can be obtained by curing the curable composition.

[0082] The curable composition can be cured by irradiating it with active energy rays. The active energy rays can be any type that has enough energy to induce decomposition of the salt contained in the acid generator. However, active energy rays with wavelengths in the ultraviolet to visible light range, such as those obtained from low-, medium-, high-, or ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, fluorescent lamps, semiconductor solid-state lasers, argon lasers, He-Cd lasers, KrF excimer lasers, ArF excimer lasers, or F2 lasers, are preferred. High-energy radiation such as electron beams and X-rays can also be used. The irradiation time for the active energy rays depends on the intensity of the energy rays and the transmittance of the curable composition to the active energy rays, but is typically about 0.1 to 10 seconds at room temperature. If necessary, the composition may be subjected to a heat treatment at room temperature to 150°C for several seconds to several hours after irradiation with the active energy rays.

[0083] The curable composition can also be cured by heat treatment. The heat treatment temperature is, for example, 50 to 250° C., and preferably 80 to 200° C. The heat treatment time is, for example, several minutes to several hours.

[0084] The cured product thus obtained has properties according to the type of cationically polymerizable compound contained in the curable composition as a raw material. For example, when an epoxy compound is contained as the cationically polymerizable compound, a cured product excellent in mechanical properties, water resistance, moisture resistance, chemical resistance, heat resistance, adhesiveness, and electrical properties can be obtained.

[0085] The above-described configurations and combinations thereof of the present invention are merely examples, and additions, omissions, substitutions, and modifications of the configurations are possible as appropriate within the scope of the present invention. [Example]

[0086] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0087] Example 1-1 (Process 1) Triethylphosphine was subjected to electrolytic fluorination in anhydrous hydrofluoric acid. Then, a purification process was carried out. The upper layer of the resulting reaction solution was removed, and the lower layer was subjected to distillation using a distillation column with a theoretical plate count of 5. This resulted in a mixture 1 of tris(pentafluoroethyl)difluorophosphorane, bis(pentafluoroethyl)(tetrafluoroethyl)difluorophosphorane, and bis(pentafluoroethyl)(trifluoroethyl)difluorophosphorane.

[0088] (Process 2) Next, 5.8 g of potassium fluoride and 100 mL of dimethoxyethane were added to a 1 L reaction vessel and stirred, and 27.4 g of the obtained mixture 1 was added dropwise while maintaining the liquid temperature at 20 to 30° C. Thereafter, the mixture was stirred at room temperature for 24 hours, and the reaction liquid was filtered, and dimethoxyethane was distilled off from the filtrate under reduced pressure to obtain 136.0 g of a white powder. 19 F and 31P-NMR confirmed that the powder was a mixture 2 of potassium tris(pentafluoroethyl)trifluorophosphate, potassium bis(pentafluoroethyl)(tetrafluoroethyl)trifluorophosphate, and potassium bis(pentafluoroethyl)(trifluoroethyl)trifluorophosphate.

[0089] (Step 3) A reaction vessel was charged with 22.2 g of diphenyl sulfoxide, 18.6 g of diphenyl sulfide, and 10.5 g of methanesulfonic acid, and the mixture was mixed uniformly. Then, 30.6 g of acetic anhydride was added dropwise. After reacting for 5 hours at 40–50°C, the mixture was cooled to room temperature. This reaction solution was added dropwise to a vessel containing 166 g of a 20% by weight aqueous solution of Mixture 2 and stirred thoroughly at room temperature for 1 hour. The precipitated yellow, slightly viscous oil was extracted with 200 g of ethyl acetate, the aqueous layer was separated, and the organic layer was washed three times with 200 g of water. The solvent was distilled off from the organic layer, and the resulting yellow residue was dissolved in 200 g of toluene. To remove impurities such as unreacted raw materials and by-products, 150 g of hexane was added to the toluene solution, and the mixture was stirred thoroughly at 10°C for 1 hour and then allowed to stand. The solution separated into two layers, and the upper layer was removed by liquid separation. 300 g of hexane was added to the remaining lower layer and mixed thoroughly at room temperature, resulting in the precipitation of pale yellow crystals, which were filtered and dried under reduced pressure to obtain an acid generator containing 4-(phenylthio)phenyldiphenylsulfonium tris(pentafluoroethyl)trifluorophosphate (99.6 wt%), 4-(phenylthio)phenyldiphenylsulfonium bis(pentafluoroethyl)(tetrafluoroethyl)trifluorophosphate (0.1 wt%), and 4-(phenylthio)phenyldiphenylsulfonium bis(pentafluoroethyl)(trifluoroethyl)trifluorophosphate (0.3 wt%).

[0090] The content ratio of each component in the resulting acid generator was: 19 The anion was determined by measuring F-NMR. 19 The F-NMR peak assignments are shown below. The peak assignments are the same for Examples 1-2 to 1-5, Examples 2-1 to 2-5, Examples 3-1 to 3-4, Examples 4-1 to 4-5, and Comparative Examples 1 to 4.

[0091] Tris(pentafluoroethyl)trifluorophosphate: 19 F-NMR (376 MHz, DMSO-d6) δ -44.1 (1F, dm, J = 890.8 Hz), δ -79.6 (3F, m), δ -81.2 (6F, m), δ -87.4 (2F, dm, J = 902.7 Hz), δ -115.5 (2F, br d, J = 82.4 Hz), δ -116.0 (4F, dm, J = 96.8 Hz).

[0092] Bis(pentafluoroethyl)(tetrafluoroethyl)trifluorophosphate: 19 F-NMR (376 MHz, DMSO-d6) δ -60.7 (1F, dm, J = 872.0 Hz), δ -70.1 (1F, dm, J = 849.6 Hz), δ -79.0 (3F, dt, J = 24.6, 4.3 Hz), δ -80.9 (6F, m), δ -111.5 (2F, dd, J = 294.4, 77.3 Hz), δ -114.0 (2F, m), δ -117.2 (1F, m).

[0093] Bis(pentafluoroethyl)(trifluoroethyl)trifluorophosphate: 19 F-NMR (376 MHz, DMSO-d6) δ -37.2 (1F, dm, J = 836.6 Hz), δ -55.8 (3F, m), δ -78.1 (2F, dm, J = 837.4 Hz), δ -80.9 (6F, dt, J = 15.9, 7.2 Hz), δ -117.3 (4F, dm, J = 92.5 Hz).

[0094] Examples 1-2 to 1-5, Comparative Example 1 An acid generator was obtained in the same manner as in Example 1-1, except that in step 1, the purification treatment conditions were changed (the distillation treatment of the lower layer was not performed, or the number of theoretical plates of the distillation column used for the distillation treatment was changed within the range of 2 to 20).

[0095] Example 2-1 An acid generator was obtained in the same manner as in Example 1-1, except that in step 3, 22.9 g of phenyl p-acetylphenyl sulfide was used instead of diphenyl sulfide.

[0096] Examples 2-2 to 2-5, Comparative Example 2 An acid generator was obtained in the same manner as in Example 2-1, except that in step 1, the purification treatment conditions were changed (the distillation treatment of the lower layer was not performed, or the number of theoretical plates of the distillation column used for the distillation treatment was changed within the range of 2 to 20).

[0097] Example 3-1 An acid generator was obtained in the same manner as in Example 1-1, except that in step 3, 30.7 g of 4-biphenylylphenyl sulfoxide was used instead of diphenyl sulfoxide and 26.3 g of 4-biphenylylphenyl sulfide was used instead of diphenyl sulfide.

[0098] Examples 3-2 to 3-4, Comparative Example 3 An acid generator was obtained in the same manner as in Example 3-1, except that in step 1, the purification treatment conditions were changed (the distillation treatment of the lower layer was not performed, or the number of theoretical plates of the distillation column used for the distillation treatment was changed within the range of 2 to 20).

[0099] Example 4-1 An acid generator was obtained in the same manner as in Example 1-1, except that step 3 was changed as follows. Specifically, 39.7 g of p-cumenyl(p-tolyl)iodonium chloride was dissolved in 500 g of methanol and added dropwise to a container containing 664 g of a 5% by weight aqueous solution of Mixture 2. The mixture was stirred at room temperature for 3 hours, resulting in the separation of a slightly viscous oil. The supernatant was removed, and the oil was dissolved in 500 g of diethyl ether. After washing with water, 300 g of hexane was added to the organic layer, resulting in the precipitation of a white solid. The white solid was filtered, washed with hexane, and dried under reduced pressure to obtain an acid generator containing p-cumenyl(p-tolyl)iodonium tris(pentafluoroethyl)trifluorophosphate, p-cumenyl(p-tolyl)iodonium bis(pentafluoroethyl)(tetrafluoroethyl)trifluorophosphate (0.1 wt%), and p-cumenyl(p-tolyl)iodonium bis(pentafluoroethyl)(trifluoroethyl)trifluorophosphate (0.3 wt%).

[0100] Examples 4-2 to 4-5, Comparative Example 4 An acid generator was obtained in the same manner as in Example 4-1, except that in step 1, the purification treatment conditions were changed (the distillation treatment of the lower layer was not performed, or the number of theoretical plates of the distillation column used for the distillation treatment was changed within the range of 2 to 20).

[0101] (Evaluation of solubility in resin) The acid generators obtained in the examples and comparative examples were evaluated for solubility in resin by the following method. That is, the acid generator and the hydrogenated bisphenol A epoxy compound were mixed in a weight ratio of 1:1, and the mixture was stirred at 50° C. to be homogenized. Thereafter, the mixture was left to stand at 50° C., 0° C., or −25° C. for 24 hours, and the presence or absence of precipitation of the acid generator was visually confirmed and evaluated according to the following criteria. The results are summarized in the table below. <Evaluation criteria> ○: No precipitation ×: Precipitation observed

[0102] (Evaluation of cationic polymerization initiation ability) The acid generators obtained in the examples and comparative examples were evaluated for cationic polymerization initiation ability by the following method. That is, 0.5 parts by weight of a 50% by mass propylene carbonate solution of the acid generator was added to 100 parts by weight of a hydrogenated bisphenol A type epoxy compound (manufactured by Mitsubishi Chemical Corporation, trade name, "YX8000") and uniformly mixed to prepare a curable composition. The obtained curable composition was applied onto a PET film using an applicator and irradiated with UV under the following conditions to obtain a coating film (thickness: about 0.2 mm). For the obtained coating film, the pencil hardness was measured 30 minutes after the UV irradiation, and the cationic polymerization initiation ability was evaluated according to the following criteria. The results are summarized in the following table. <UV Irradiation Conditions> · UV irradiation device: Belt conveyor type UV irradiation device (manufactured by Eye Graphics Co., Ltd.) · Lamp: 2KW (100W / cm) parallel light type metal halide lamp · Irradiation distance: 18 cm · Conveyor speed: 4 m / min · Number of irradiation times: 1 time <Evaluation Criteria> ◎: Pencil hardness H or higher ○: Pencil hardness B or higher and less than H △: Pencil hardness 4B or higher and less than B ×: Pencil hardness less than 4B

[0103]

Table 1

[0104]

Table 2

[0105]

Table 3

[0106]

Table 4

Claims

1. Onium cation (a) and the following formula (I-1) [(R １ CF ２ ) ｔ PF ｓ ] － (I-1) (In the formula, R １ represents a fluorine atom or a perfluoroalkyl group, and s and t are the same or different and represent an integer of 1 or more, provided that s+t=6. A salt (1) of an anion represented by Onium cation (a) and the following formula (I-2-1a) [(CF 3 CHF) 1 (CF 3 CF 2 ) 2 PF 3 ] - (I-2-1a) A salt (2a-1) with an anion represented by the formula: Onium cation (a) and the following formula (I-2-2a) [(CF 3 CH 2 ) 1 (CF 3 CF 2 ) 2 PF 3 ] - (I-2-2a) and a salt (2a-2) which is a mixture of a salt (2a-2) with an anion represented by the formula: Including, the onium cation (a) is a triarylsulfonium ion or a diaryliodonium ion, the ratio of the contents of the salt (1) and the salt (2) (former / latter; weight ratio) is 85 / 15 to 99.8 / 0.2; Acid generator.

2. A curable composition comprising the acid generator according to claim 1 and a cationically polymerizable compound.

3. A cured product of the curable composition according to claim 2.

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