Method for producing sulfonium borate salt

Abstract

To provide a production method enabling high-yield and simple production of high-quality sulfonium borate salts.SOLUTION: A method for producing a sulfonium borate salt comprises a step of forming the sulfonium borate salt by reacting an ammonium borate salt with a sulfonium salt. The ammonium borate salt preferably has a structure represented by NH4+[(Y)kB(Phf)4-k]-. See the specification for definitions of Y, Phf, and k in the formula. The sulfonium salt is preferably an aromatic sulfonium salt.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing a sulfonium borate salt.

Background Art

[0002] Sulfonium borate salts are used in various applications, for example, as a polymerization initiator for a polymerizable composition.

[0003] Sulfonium borate salts are produced by reacting a sulfonium salt and a borate salt in a solvent. For example, in Patent Document 1, a sulfonium borate salt is produced by reacting a lithium borate salt and a sulfonium salt in a solvent. In the production method described in the same document, a solution containing a sulfonium borate salt is subjected to oil-water separation to recover an oil phase containing the sulfonium borate salt, and the recovered oil phase is subjected to a purification treatment of washing with water to obtain a sulfonium borate salt.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] From the viewpoint of economy, there is a demand for a production method capable of simply producing a sulfonium borate salt with high yield without reducing purity and quality. When the inventor verified the yield of the sulfonium borate salt in the production method described in Patent Document 1, it was found that there is room for improvement.

[0006] Therefore, an object of the present invention is to provide a method for producing a sulfonium borate salt that can simply produce a sulfonium borate salt with high yield.

[0007] To solve the above problems, the inventors conducted intensive studies. As a result, they found that by enhancing the oil-water separability of a solution containing a sulfonium borate salt, the oil phase containing the sulfonium borate salt can be efficiently recovered, and as a result, the yield of the sulfonium borate salt can be increased. Further studies revealed that, surprisingly, by using an ammonium borate salt as the borate salt used in the production of the sulfonium borate salt, the sulfonium borate salt can be easily produced with a high yield, and the obtained sulfonium borate salt sufficiently has the quality required for its use, for example, as a polymerization initiator.

Means for Solving the Problems

[0008] The present invention is based on the above findings and provides the following [1] to

[10] .

[0009] [1] A method for producing a sulfonium borate salt, comprising a step of reacting an ammonium borate salt with a sulfonium salt to form a sulfonium borate salt.

[0010] [2] The method for producing a sulfonium borate salt according to [1], wherein the ammonium borate salt is an ammonium borate salt represented by the following general formula (1). NH4 + [(Y) k B(Phf) 4-k - (1) (In the formula, Y represents an aryl group having 6 to 30 carbon atoms or a heterocyclic group having 4 to 30 carbon atoms, and the hydrogen atoms of the aryl group and the heterocyclic group may be substituted with substituents excluding groups containing a halogen atom. Phf represents a phenyl group in which at least one of the hydrogen atoms is substituted with any one of a perfluoroalkyl group, a perfluoroalkoxy group, and a halogen atom. k represents an integer of 0 to 4.)

[0011] ​ [3] The method for producing a sulfonium borate salt according to [2], wherein k in the general formula (1) is 0.

[0012] [4] The method for producing a sulfonium borate salt according to [2], wherein Phf in the general formula (1) is a phenyl group in which at least one hydrogen atom is substituted with a halogen atom.

[0013] [5] The method for producing a sulfonium borate salt according to any one of [1] to [4], wherein the sulfonium salt is an aromatic sulfonium salt.

[0014] [6] The production method according to any one of [1] to [5], wherein the amount of ammonium borate salt used is 0.90n to 0.99n moles per mole of the n-valent sulfonium salt.

[0015] [7] The method for producing a sulfonium borate salt according to any one of [1] to [6], wherein an ammonium borate salt and a sulfonium salt are reacted in a solvent.

[0016] [8] The method for producing a sulfonium borate salt according to [7], wherein the solvent is a chlorine-based solvent.

[0017] [9] A polymerization initiator containing a sulfonium borate salt produced by the production method according to any one of [1] to [8].

[0018]

[10] A polymerizable composition containing the polymerization initiator according to [9] and a cationically polymerizable compound.

[11] A cured product obtained from the polymerizable composition according to

[10] .

[12] A method for producing a cured product, comprising a step of irradiating the polymerizable composition according to

[10] with active energy rays. [Advantages of the Invention]

[0019] According to the production method of the present invention, a sulfonium borate salt can be easily produced with a high yield. The obtained sulfonium borate salt has sufficient quality required for its use, for example, the quality required as a polymerization initiator.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, the production method of the sulfonium borate salt of the present invention will be described in detail based on preferred embodiments. The production method of the present invention has a step of reacting an ammonium borate salt with a sulfonium salt to form a sulfonium borate salt. By using an ammonium borate salt as a raw material for producing a sulfonium borate salt, the oil-water separability of a solution containing the sulfonium borate salt becomes good, and as a result, the yield of the sulfonium borate salt increases. Specific examples of a solution containing an ammonium borate salt include those containing an organic solvent and water, such as a reaction solution of an ammonium borate salt and a sulfonium salt, an organic solvent fraction of the reaction solution, and a mixed solution of the fraction and water. In the present specification, when referring to a solution, a state where the ammonium borate salt is dispersed without being completely dissolved in the solvent is also allowed.

[0021] In the production method of the present invention, a known ammonium borate salt can be used without particular limitation. As the ammonium cation in the ammonium borate salt, an inorganic ammonium cation (NH4 + ) and an organic ammonium cation in which 1 to 4 hydrogen atoms in the inorganic ammonium cation are substituted with organic groups are known. Since the oil-water separability becomes good and as a result, the yield of the sulfonium borate salt further increases, as the ammonium cation in the ammonium borate salt, an inorganic ammonium cation (NH4 + ) is preferred. Further, as the borate anion in the ammonium borate salt, an inorganic borate anion (BH4 -It is preferable that one or more of the hydrogen atoms in ( ) are substituted with an organic group, and a quaternary borate anion in which all four hydrogen atoms are substituted with an organic group is preferable. In particular, since the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased, it is particularly preferable to use the one represented by the following formula (1). NH4 + [(Y) k B(Phf) 4-k - (1)

[0022] (In the formula, Y represents an aryl group having 6 to 30 carbon atoms or a heterocyclic group having 4 to 30 carbon atoms, and the hydrogen atoms of the aryl group and the heterocyclic group may be substituted with substituents excluding groups containing a halogen atom. Phf represents a phenyl group in which at least one of the hydrogen atoms is substituted with any one of a perfluoroalkyl group, a perfluoroalkoxy group, and a halogen atom. k represents an integer of 0 to 4.)

[0023] The aryl group having 6 to 30 carbon atoms represented by Y may have a monocyclic structure or a condensed ring structure. Further, the above aryl group may be a linkage of a monocyclic aryl group and a monocyclic aryl group, a linkage of a monocyclic aryl group and a condensed ring aryl group, or a linkage of a condensed ring aryl group and a condensed ring aryl group. Examples of the aryl group having a monocyclic structure include phenyl and biphenylyl. Examples of the aryl group having a condensed ring structure include naphthyl, anthryl, and phenanthrenyl.

[0024] ​The heterocyclic group having 2 to 30 carbon atoms represented by Y may have a monocyclic structure or a condensed ring structure. Further, the heterocyclic group may be one in which a monocyclic heterocyclic group is linked to a monocyclic heterocyclic group, one in which a monocyclic heterocyclic group is linked to a heterocyclic group having a condensed ring structure, or one in which a heterocyclic group having a condensed ring structure is linked to a heterocyclic group having a condensed ring structure. Examples of the monocyclic heterocyclic group include pyridyl, pyrimidyl, pyridazyl, piperazyl, piperidyl, pyranyl, pyrazolyl, triazolyl, pyrrolidyl, imidazolyl, triazolyl, furyl, furanyl, thienyl, thiophenyl, thiadiazolyl, thiazolyl, oxazolyl, isothiazolyl, isoxazolyl, urolidyl, morpholinyl, thiomorpholinyl, 2-pyrrolidinone-1-yl, 2-piperidone-1-yl, 2,4-dioxoimidazolidin-3-yl, 2,4-dioxooxazolidin-3-yl and the like. Examples of the heterocyclic group having a condensed ring structure include condensed ring heterocyclic groups such as quinolyl, isoquinolyl, benzimidazolyl, benzofuranyl, benzothiophenyl, benzothiazolyl, benzoxazolyl and indolyl.

[0025] Examples of the substituent that substitutes the hydrogen atom of the aryl group having 6 to 30 carbon atoms and the heterocyclic group having 4 to 30 carbon atoms represented by Y include alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group and butyl group, cyano group, nitro group, hydroxyl group, amino group, carboxy group, methacryloyl group, acryloyl group, epoxy group, vinyl ether group, mercapto group, and isocyanate group and the like.

[0026] In the group represented by Phf, when the number of carbon atoms of the perfluoroalkyl group substituting the hydrogen atom of the phenyl group is 1 to 18, a polymerization initiator with high sensitivity can be obtained when the resulting sulfonium borate salt is used as a polymerization initiator, which is preferable, and more preferably 1 to 10. The perfluoroalkyl group may be linear or branched. Specific examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, a perfluorooctyl group, and a perfluorodecyl group.

[0027] In the group represented by Phf, when the number of carbon atoms of the perfluoroalkoxy group substituting the hydrogen atom of the phenyl group is 1 to 18, a polymerization initiator with high sensitivity can be obtained when the resulting sulfonium borate salt is used as a polymerization initiator, which is preferable, and more preferably 1 to 10. The perfluoroalkoxy group may be linear or branched. Specific examples of the perfluoroalkoxy group include a trifluoromethoxy group, a perfluoroethoxy group, a perfluoropropoxy group, a perfluorobutoxy group, a perfluoropentoxy group, a perfluorohexyloxy group, a perfluoroheptyloxy group, a perfluorooctyloxy group, and a perfluorodecyloxy group.

[0028] Examples of the halogen atom substituting the aryl group and the heterocyclic group represented by Y, and the halogen atom substituting the hydrogen atom of the phenyl group in the group represented by Phf include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0029] In this specification, the number of carbon atoms of a group substituted with a substituent shall be within the scope defined in the annotation of the general formula. For example, when a hydrogen atom in an aryl group having 6 to 30 carbon atoms represented by Y or the like is substituted with a group containing a carbon atom as a substituent, the number of carbon atoms of the substituted aryl group shall be 6 to 30, which is the number of carbon atoms of the aryl group represented by Y or the like in the annotation of formula (1) including the number of carbon atoms of the substituent.

[0030] In the production method of the present invention, since the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased, k in formula (1) is preferably 0 to 3, more preferably 0 to 2, still more preferably 0 to 1, and particularly preferably 0.

[0031] In the production method of the present invention, Phf in formula (1) is preferably a halogenated phenyl group in which at least one hydrogen atom is substituted with a halogen atom. This is because the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased. Further, when the obtained sulfonium borate salt is used as a polymerization initiator, a polymerization initiator with high sensitivity can be obtained, which is also preferable. From the same viewpoint, Phf is preferably a halogenated phenyl group in which 2 to 5 hydrogen atoms on the benzene ring are substituted with halogen atoms, more preferably a halogenated phenyl group in which 4 to 5 hydrogen atoms are substituted with halogen atoms, and still more preferably a halogenated phenyl group in which all 5 hydrogen atoms are substituted with halogen atoms. From the same viewpoint, the halogen atom substituting the phenyl group in Phf is more preferably a fluorine atom.

[0032] Specific examples of the halogenated phenyl group represented by Phf include, for example, phenyl fluoride groups such as monofluorophenyl group, difluorophenyl group, trifluorophenyl group, and pentafluorophenyl group; phenyl chloride groups such as monochlorophenyl group and dichlorophenyl group; phenyl bromide group such as bromophenyl group; and chlorofluorophenyl group and the like. The halogenated phenyl group is preferably a phenyl fluoride group, more preferably a p-fluorophenyl group or a pentafluorophenyl group, and even more preferably a pentafluorophenyl group because the sensitivity becomes even better when used as a polymerization initiator. The monofluorophenyl group is preferably a p-fluorophenyl group.

[0033] In the production method of the present invention, known sulfonium salts can be used without particular limitation. Since excellent sensitivity and storage stability are achieved when a sulfonium borate salt is used as a polymerization initiator, it is preferable to use an aromatic sulfonium salt as the sulfonium salt. As the aromatic sulfonium salt, it is preferable to use a salt of a sulfonium cation represented by any of the following formulas (2) to (5) and an anion.

[0034]

Chemical formula

[0035] (In the formula, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 , R 20 , R 21 , R22 , R 23 , R 24 , R 25 , R 26 , R 27 , R 28 , R 29 , R 30 , R 31 , R 32 , R 33 , R 34 , R 35 and R 36 (Hereinafter, referred to as "R 1 ~R 36 ") are each independently a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, or an arylthio group having 6 to 30 carbon atoms, One or more hydrogen atoms in the alkyl group, the acyl group, the alkoxy group, the alkylthio group and the arylthio group may be substituted with a halogen atom, a hydroxyl group, or a group represented by the following formula (12), One or more methylene groups in the alkyl group, the acyl group, the alkoxy group and the alkylthio group may be replaced by a carbon-carbon double bond, -O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O-, -O-CO-O-, -S-CO-, -CO-S-, -S-CO-O-, -O-CO-S-, -S-S-, -SO2- or a combination thereof X represents an oxygen atom, a sulfur atom, a carbonyl group or a direct bond, Ar represents a group represented by any of the following general formulas (6) to (9).)

[0036] [Chemical formula]

[0037] (In the formula, Z represents -O-, -S- or -CO-, R 76 , R 77 , R 78 , R 79 and R80 (Hereinafter, "R 76 ~R 80 " is described.) Each independently represents a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, or an arylthio group having 6 to 30 carbon atoms, one or more hydrogen atoms in the alkyl group, the acyl group, the alkoxy group, the alkylthio group, and the arylthio group may be substituted with a halogen atom or a hydroxyl group, one or more methylene groups in the alkyl group, the acyl group, the alkoxy group, and the alkylthio group may be replaced with a carbon-carbon double bond, -O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O-, -O-CO-O-, -S-CO-, -CO-S-, -S-CO-O-, -O-CO-S-, -S-S-, -SO2-, or a combination thereof, * represents a bond.)

[0038]

Chemical formula

[0039] (In the formula, R 37 , R 38 , R 39 , R 40 , R 41 , R 42 , R 43 , R 44 , R 45 , R 46 , R 47 , R 48 , R 49 , R 50 , R 51 , R 52 , R 53 , R 54 , R 55 , R 56 , R 57 , R 58 , R 59 , R 60 , R 61 , R 62, R 63 , R 64 , R 65 , R 66 , R 67 , R 68 , R 69 , R 70 , R 71 and 72 (hereinafter referred to as "R 37 ~R 72 "). Each independently represents a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 18 carbon atoms, an acyl group having 2 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, or an arylthio group having 6 to 30 carbon atoms, one or more hydrogen atoms in the alkyl group, the acyl group, the alkoxy group, the alkylthio group and the arylthio group may be substituted with a halogen atom or a hydroxyl group, one or more methylene groups in the alkyl group, the acyl group, the alkoxy group and the alkylthio group may be replaced with a carbon-carbon double bond, -O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O-, -O-CO-O-, -S-CO-, -CO-S-, -S-CO-O-, -O-CO-S-, -S-S-, -SO2- or a combination thereof, * represents a bond.)

[0040] R 1 ~R 36 , R 37 ~R 72 and R 76 ~R 80 Examples of the alkyl group having 1 to 18 carbon atoms represented by include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, hexyl, 2-hexyl, 3-hexyl, cyclohexyl, 1-methylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, isoheptyl, tert-heptyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl, nonyl, isononyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl.

[0041] R 1 ~R 36 , R 37 ~R 72 and R 76 ~R 80 The acyl group having 2 to 18 carbon atoms represented by the formula: 81 R is a group represented by the formula -CO-. 81 R represents a hydrocarbon group having 1 to 17 carbon atoms. 81Examples of the hydrocarbon group represented by the formula (I) include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, hexyl, 2-hexyl, 3-hexyl, cyclohexyl, 1-methylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, isoheptyl, tert-heptyl, n-octyl, isooctyl, tert-octyl, 2-ethylhexyl, nonyl, isononyl, decyl, dodecyl, tridecyl, Alkyl groups such as tetradecyl, pentadecyl, hexadecyl and heptadecyl; alkenyl groups such as vinyl, 1-methylethenyl, 2-methylethenyl, propenyl, butenyl, isobutenyl, pentenyl, hexenyl, cyclohexenyl, heptenyl, octenyl, decenyl and pentadecenyl; alkynyl groups in which the carbon-carbon double bond of these alkenyls is replaced by a triple bond; phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, aryl groups such as ethylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4-butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4-(2-ethylhexyl)phenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl, 2,5-di-tert-butylphenyl, 2,6-di-tert-butylphenyl, 2,4-di-tert-pentylphenyl, 2,5-di-tert-amylphenyl, cyclohexylphenyl, biphenyl, and 2,4,5-trimethylphenyl; and arylalkyl groups such as benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl, and cinnamyl.

[0042] R 1 ~R 36 , R 37 ~R 72 and R 76 ~R 80Examples of the alkoxy group having 1 to 18 carbon atoms represented by the formula (I) include methyloxy, ethyloxy, propyloxy, isopropyloxy, butyloxy, sec-butyloxy, tert-butyloxy, isobutyloxy, amyloxy, isoamyloxy, tert-amyloxy, hexyloxy, cyclohexyloxy, heptyloxy, isoheptyloxy, tert-heptyloxy, n-octyloxy, isooctyloxy, tert-octyloxy, 2-ethylhexyloxy, nonyloxy, isononyloxy, decyloxy, dodecyloxy, tridecyloxy, tetradecyloxy, pentadecyloxy, hexadecyloxy, heptadecyloxy, and octadecyloxy.

[0043] R 1 ~R 36 , R 37 ~R 72 and R 76 ~R 80 Examples of the alkylthio group having 1 to 18 carbon atoms represented by the following formula include groups in which the oxygen atom directly bonded to the alkyl group of the above alkoxy group is replaced with a sulfur atom.

[0044] R 1 ~R 36 , R 37 ~R 72 and R 76 ~R 80 The arylthio group having 6 to 30 carbon atoms represented by the formula: 1 Examples include Ar 1 represents an aryl group having 6 to 30 carbon atoms. 1Examples include phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4-butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4-(2-ethylhexyl)phenyl, 4-stearylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl, 2,5-di-tert-butylphenyl, 2,6-di-tert-butylphenyl, 2,4-di-tert-pentylphenyl, 2,5-di-tert-amylphenyl, 2,5-di-tert-octylphenyl, 2,4-dicumylphenyl, cyclohexylphenyl, biphenyl, 2,4,5-trimethylphenyl, 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 4-fluorophenyl, 2-chloro-4-(phenylcarbonyl)phenyl, and 2-fluoro-4-(phenylcarbonyl)phenyl, etc.

[0045] In this specification, when two or more methylene groups in a hydrocarbon group such as an alkyl group or a group containing a heterocyclic ring are substituted with a divalent group selected from a carbon-carbon double bond, -O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O-, -O-CO-O-, -S-CO-, -CO-S-, -S-CO-O-, -O-CO-S-, -S-S-, -SO2- or a combination thereof, oxygen atoms or sulfur atoms shall not be adjacent to each other, and preferably these divalent groups shall not be adjacent to each other.

[0046] Specific examples of the sulfonium cation represented by any of formulas (2) to (5) include those represented by the following Group I or Group II.

[0047]

Chemical formula

[0048]

Chem.

[0049] In the present invention, since the oil-water separability is improved and as a result, the yield of the sulfonium borate salt is further increased, it is preferable to use a sulfonium cation represented by the formula (2) or the formula (5).

[0050] R in the formula (2) 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 (hereinafter referred to as "R 1 ~R 10 ").) are each independently preferably a hydrogen atom, a halogen atom or an optionally substituted arylthio group having 6 to 30 carbon atoms. This is because the oil-water separability is improved and as a result, the yield of the sulfonium borate salt is further increased. Further, at least one of the groups of R 1 ~R 10 in the formula (2) is preferably an optionally substituted arylthio group having 6 to 30 carbon atoms, more preferably 1 to 2 of the groups of R 1 ~R 10 in the formula (2) are optionally substituted arylthio groups having 6 to 30 carbon atoms, and particularly preferably 1 to 2 of the groups of R 1 ~R 10 are arylthio groups having 6 to 30 carbon atoms substituted with the formula (12). This is because the oil-water separability is improved and as a result, the yield of the sulfonium borate salt is further increased. Further, Ar is preferably a monocyclic aryl group. This is because the oil-water separability is improved and as a result, the yield of the sulfonium borate salt is further increased.

[0051] R in the formula (5) 19~R 36 is preferably a hydrogen atom, a halogen atom, or a group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a halogen atom, and even more preferably a hydrogen atom. This is because the oil-water separability becomes good, and as a result, the yield of the sulfonium borate salt increases further. Also, Ar is preferably a group represented by the formula (6). This is because the oil-water separability becomes good, and as a result, the yield of the sulfonium borate salt increases further.

[0052] The anion that forms a salt with one of the sulfonium cations represented by the formulas (2) to (5) is not particularly limited, and examples thereof include oxo acid ions, halide ions, and metal chloride anions. In the present invention, since the oil-water separability becomes good and as a result, the yield of the sulfonium borate salt increases further, the anion is preferably an oxo acid ion.

[0053] Examples of the oxo acid ion include carboxylic acid ions, nitrate ions, sulfate ions, sulfate ester ions, sulfonic acid ions, phosphate ester ions, phosphate ions, phosphonate ester ions, and phosphonate ions. Examples of the carboxylic acid ion include formate ion, acetate ion, citrate ion, malate ion, succinate ion, benzoate ion, salicylate ion, and the like. Examples of the sulfate ester ion include methyl sulfate ion, ethyl sulfate ion, and the like. Examples of the sulfonic acid ion include tolylsulfonic acid ion, trifluoromethanesulfonic acid ion, and the like. Examples of the phosphate ion include phosphate ion, trifluorophosphate ion, and the like. Examples of the phosphate ester ion include dibutyl phosphate ion, dimethyl phosphate ion, and the like. Examples of the phosphonate ester ion include dimethyl phosphonate ion, methylmethylphosphonic acid ion, methylphosphonic acid ion, and the like. Among oxo acid ions, it is preferable that at least one selected from sulfate ions, sulfate ester ions, and sulfonate ions is used because it results in good oil-water separability, and as a result, the yield of the sulfonium borate salt is further increased.

[0054] Examples of the halide ion include Cl - , Br - and I - and the like.

[0055] Examples of the metal chloride anion include aluminum chloride anions such as AlCl4 - and Al2Cl7 - and the like.

[0056] There are no particular restrictions on the amounts of the ammonium borate salt and the sulfonium salt used in the production method of the present invention, and they can be appropriately determined based on the ammonium borate salt and the sulfonium salt used in the production. Since good oil-water separability is achieved and, as a result, the yield of the sulfonium borate salt is further increased, it is preferable to use the ammonium borate salt in an amount less than equivalent on a molar ratio basis with respect to the sulfonium cation. Specifically, the amount of the ammonium borate salt used is preferably 0.90n mol to 0.99n mol, more preferably 0.92n mol to 0.97n mol, and even more preferably 0.94n mol to 0.96n mol with respect to 1 mol of the n-valent sulfonium salt used.

[0057] In the production method of the present invention, it is preferable to react the ammonium borate salt and the sulfonium salt in a solvent. When using a solvent, the sulfonium salt may be added after adding the ammonium borate salt to the solvent, the ammonium borate salt may be added after adding the sulfonium salt to the solvent, or the ammonium borate salt and the sulfonium salt may be added to the solvent simultaneously.

[0058] Specific examples of the solvent used in the production method of the present invention include water, chlorinated solvents, acidic solvents, basic solvents, ethers, polar solvents, esters, aromatic solvents, and alcohol solvents. In the production method of the present invention, since the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased, it is preferable to use a chlorinated solvent.

[0059] Examples of the chlorinated solvent include chlorinated hydrocarbons. Since the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased, the number of carbon atoms of the chlorinated hydrocarbon is preferably 1 to 6, more preferably 1 to 4, still more preferably 1 to 2, and particularly preferably 2.

[0060] Specific examples of the chlorinated hydrocarbons include chlorinated methanes such as dichloromethane, chloroform, and carbon tetrachloride; chlorinated ethanes such as dichloroethane, trichloroethane, tetrachloroethane, pentachloroethane, and hexachloroethane; chlorinated ethylenes such as dichloroethylene, trichloroethylene, and tetrachloroethylene; chlorinated propanes such as dichloropropane and trichloropropane; and chlorinated propenes such as dichloropropene. In the present invention, since the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased, it is preferable to use chlorinated ethanes as the solvent.

[0061] Specific examples of the acidic solvent include sulfuric acid, fuming sulfuric acid, formic acid, acetic acid, propionic acid, and acetic anhydride. Specific examples of the basic solvent include pyridine, triethylamine, and trimethylamine. Specific examples of the ethers include tetrahydrofuran, dioxane, and diethyl ether. Specific examples of the polar solvent include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, sulfolane, nitromethane, acetone, acetonitrile, and benzonitrile. Specific examples of the esters include ethyl acetate and butyl acetate. Specific examples of the aromatic solvents include benzene, toluene, xylene, nitrobenzene, and the like. Specific examples of the alcohol solvents include methanol, ethanol, isopropanol, and the like.

[0062] There is no particular limitation on the amount of the solvent used in the production method of the present invention, and it may be appropriately determined according to the types of the ammonium borate salt and the sulfonium salt used. When using an ammonium borate salt represented by the formula (I) and using a sulfonium salt containing at least one of the sulfonium cations represented by the formulas (2) to (5), it is preferable to use 100 to 500 parts by mass of the solvent with respect to 100 parts by mass of the total amount of the ammonium borate salt and the sulfonium salt, and more preferably 200 to 300 parts by mass.

[0063] In the production method of the present invention, there is no particular limitation on the temperature of the reaction system in which the ammonium borate salt and the sulfonium salt are reacted. In the production method of the present invention, since the oil-water separability is good and, as a result, the yield of the sulfonium borate salt is further increased, it is preferable to control the temperature of the reaction system to -10 to 60°C, more preferably 10 to 50°C, and still more preferably 20 to 40°C.

[0064] In the production method of the present invention, the reaction between the ammonium borate salt and the sulfonium salt may be carried out under pressurized conditions or under normal pressure. The normal pressure includes, for example, atmospheric pressure, but also includes cases of slightly positive or negative pressure compared to atmospheric pressure. For example, as an example, a case of about 990 to 1050 hPa can be mentioned. From the viewpoint of simplicity, it is preferable to carry out the reaction between the ammonium borate salt and the sulfonium salt under normal pressure.

[0065] In the production method of the present invention, the reaction between the ammonium borate salt and the sulfonium salt may be carried out in the air or in an inert atmosphere. From the viewpoint of simplicity, in the production method of the present invention, it is preferable to carry out the reaction between the ammonium borate salt and the sulfonium salt in the air.

[0066] In the production method of the present invention, there is no particular limitation on the reaction time between the ammonium borate salt and the sulfonium salt. In the production method of the present invention, since the oil-water separability is good and as a result, the yield of the sulfonium borate salt is further increased, it is preferable to set the reaction time to 30 to 120 minutes, more preferably 40 to 100 minutes, and even more preferably 50 to 80 minutes.

[0067] By reacting the ammonium borate salt and the sulfonium salt in a solvent, a sulfonium borate salt-containing solution containing the sulfonium borate salt is obtained. In the production method of the present invention, the solvent may be distilled off from the sulfonium borate salt-containing solution to recover the sulfonium borate salt. Since the solution containing the sulfonium borate salt produced by the production method of the present invention has high oil-water separability, the sulfonium borate salt can be recovered in a high yield. However, in order to recover the sulfonium borate salt in an even higher yield, it is preferable to have a purification step of performing a purification treatment on the sulfonium borate salt-containing solution produced by the production method of the present invention.

[0068] The solution containing the sulfonium borate salt produced by the production method of the present invention has high oil-water separability. In order to make the most of its characteristics, the purification process preferably includes a water washing treatment. Specifically, it is preferable to perform oil-water separation on the solution containing the sulfonium borate salt to recover the oil phase, and then perform a water washing treatment on the recovered oil phase. Examples of the water washing treatment include those commonly performed in the technical field to which the present invention pertains. For example, the water washing treatment includes a step of adding water such as ion-exchanged water to the collected oil phase to prepare a mixed solution, a step of stirring the mixed solution for 1 to 30 minutes while controlling the temperature of the prepared mixed solution at 20 to 35°C, a step of allowing the mixed solution to stand for 20 to 90 minutes, and a step of separating the oil phase from the standing mixed solution. There is no particular limitation on the number of times of performing the water washing treatment. In the production method of the present invention, since the oil phase containing the sulfonium borate salt solution has high separability from the aqueous phase, the sulfonium borate salt solution can be purified by performing the water washing treatment 1 to 4 times.

[0069] According to the production method of the present invention described above, for example, k B(Phf) 4-k - a sulfonium borate salt composed of an anion represented by and at least one kind of sulfonium cation represented by the formulas (2) to (5) is produced.

[0070] The use of the sulfonium borate salt produced by the production method of the present invention is not particularly limited. When the sulfonium borate salt is composed of an anion represented by k B(Phf) 4-k - and at least one kind of sulfonium cation represented by the formulas (2) to (5), since it has good sensitivity and storage stability, it is preferably used as a polymerization initiator, particularly a photo cationic polymerization initiator, used in a polymerizable composition.

[0071] ​​Incidentally, as described above, the sulfonium borate salt of the present invention is obtained by reacting a wide variety of ammonium borate salts with a wide variety of sulfonium salts. Therefore, the structure of the sulfonium borate salt varies greatly depending on the structure of the raw materials used in the production of the sulfonium borate salt. Therefore, at present, it is impossible to uniformly represent the structure of the sulfonium borate salt by a certain general formula, which is common general knowledge in the art. And since the properties of the substance, which are determined accordingly, cannot be easily understood without specifying the structure, it is also impossible to express it in terms of properties. Therefore, it is necessary to define the sulfonium borate salt as being produced by the production method of the present invention. As is clear from the above, regarding the sulfonium borate salt, there is a situation where "directly specifying it by its structure or properties" is impossible or approximately impractical.

[0072] In addition to the sulfonium borate salt produced by the production method of the present invention, the polymerizable composition contains a polymerizable compound. As the polymerizable compound, known ones can be used without particular limitation. Specific examples of the polymerizable compound include, for example, cyclic ethers such as epoxy compounds, vinyl ether compounds, and oxetane compounds, and ethylenically unsaturated compounds such as styrene, (meth)acrylic acid, and (meth)acrylic acid esters. Known ones can be appropriately used. The content of the sulfonium borate salt in the polymerizable composition is not particularly limited and can be appropriately determined depending on the type of the polymerizable compound. For example, it can be usually 0.1 to 10 parts by mass, preferably 0.5 to 7 parts by mass, based on 100 parts by mass of the polymerizable compound. Further, in addition to the sulfonium borate salt and the polymerizable compound, the polymerizable composition may contain other components. As the other components, known components used for the polymerizable composition can be used without particular limitation.

[0073] A cured product is obtained by curing the polymerizable composition. There is no particular limitation on the curing method of the polymerizable composition, but it is preferably cured by irradiating active energy rays such as visible light, ultraviolet rays, electron beams, X-rays, radiation, and high frequency. There are no particular limitations on the irradiation conditions such as the irradiation time of the active energy rays, and they may be appropriately determined according to the type of the polymerizable compound and the like.

Examples

[0074] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

[0075] Example 1: Synthesis of Sulfonium Borate Salt No. 1 80.9 g (0.40 mol) of diphenyl sulfoxide was dissolved in 519 g of concentrated sulfuric acid to prepare a solution. 74.5 g (0.40 mol) of diphenyl sulfide was added dropwise to the prepared solution over 90 minutes, and then reacted for 6 hours to obtain a reaction solution. During the reaction, it was cooled with an ice bath to maintain the temperature of the reaction system at 2°C ± 1°C. Then, the reaction solution was slowly poured into a mixed solution prepared by mixing 639 g of cooled water, 162 g of methanol, and 243 g of toluene, and the temperature of the mixed solution was not allowed to exceed 50°C. After stirring for 5 minutes, it was allowed to stand to obtain a mixed reaction solution. The toluene layer was removed from the mixed reaction solution to obtain an aqueous solution containing a mixture of bis-[4-(diphenylsulfonio)phenyl]sulfide sulfate and diphenyl,4-(phenylsulfide)phenylsulfonium sulfate in a molar ratio of the former:the latter of 33:67. After adding 100 g of dichloroethane to the aqueous solution three times, the solvent was removed to extract diphenyl,4-(phenylsulfide)phenylsulfonium sulfate.

[0076] 54.0 g of dichloroethane and 132.4 g (0.044 mol) of a 23% by mass aqueous solution of ammonium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 21.6 g (0.046 mol) of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate prepared previously was charged into the flask, and the reaction was carried out for 1 hour while controlling the temperature of the reaction system at 20 - 35°C to obtain a reaction solution. The amount of ammonium tetrakis(pentafluorophenyl)borate used per 1 mol of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was 0.96 mol. After completion of the reaction, the obtained reaction solution was subjected to oil-water separation to obtain an oil phase. 80 g of ion-exchanged water was added to the obtained oil phase to prepare a mixed solution, and then the mixed solution was stirred for 5 minutes while controlling the temperature at 20 - 35°C. After allowing the mixed solution to stand for 30 minutes, a water washing treatment for separating the oil phase from the mixed solution was carried out 3 times to obtain a solution containing sulfonium borate salt No.1 below. The solvent was distilled off from the obtained solution, and propylene carbonate was added and dissolved so that the solid content concentration of sulfonium borate salt No.1 became 50% by mass to obtain a 50% by mass propylene carbonate solution of sulfonium borate salt No.1. The yield of sulfonium borate salt No.1 in the production method of Example 1 was 92.6%.

[0077]

Chemical formula

[0078] Example 2: Synthesis of Sulfonium Borate Salt No.1 and Sulfonium Borate Salt No.2 64.7 g (0.32 mol) of diphenyl sulfoxide was dissolved in 259 g of concentrated sulfuric acid to prepare a solution. 37.3 g (0.20 mol) of diphenyl sulfide was added dropwise to the prepared solution over 90 minutes, and then the mixture was reacted for 6 hours to obtain a reaction solution. During the reaction, it was cooled in an ice bath to maintain the temperature of the reaction system at 2 °C ± 1 °C. Then, the reaction solution was slowly poured into a mixed solution of 797 g of cooled water, 130 g of methanol, and 194 g of toluene so that the temperature of the mixed solution did not exceed 50 °C. After stirring for 5 minutes, it was allowed to stand to obtain a mixed reaction solution. The toluene layer was removed from the mixed reaction solution, washed with 194 g of toluene, and an aqueous solution 1 of a mixture containing bis-[4-(diphenylsulfonio)phenyl] sulfide sulfate and diphenyl,4-(phenylsulfide)phenylsulfonium sulfate in a molar ratio of the former:the latter = 75:25 was obtained. The content of the mixture in the aqueous solution was 15% by mass.

[0079] 73 g of dichloroethane and 215.6 g (0.071 mol) of a 23% by mass aqueous solution of ammonium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 194.1 g (0.043 mol) of the aqueous solution of the previously prepared mixture was charged, and the mixture was stirred for 1 hour while controlling the temperature of the reaction system at 20 to 35 °C to obtain a reaction solution. The amount of ammonium tetrakis(pentafluorophenyl)borate used when the total of bis-[4-(diphenylsulfonio)phenyl]sulfide sulfate and diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was 1 mol was 1.7 mol. After completion of the reaction, the obtained reaction solution was subjected to oil-water separation to obtain an oil phase. After adding 80 g of ion-exchanged water to the obtained oil phase to prepare a mixed solution, the mixed solution was stirred for 5 minutes while controlling the temperature at 20 to 35 °C, allowed to stand for 30 minutes, and then subjected to a water washing treatment of separating the oil phase from the mixed solution three times to obtain a solution containing a mixture of the above-mentioned sulfonium borate salt No. 1 and the following sulfonium borate salt No. 2 at a molar ratio of the former:the latter of 25:75. The solvent was distilled off, propylene carbonate was added so that the solid content concentration became 50% by mass and dissolved to obtain a 50% by mass propylene carbonate solution of a mixture of sulfonium borate salt No. 1 and sulfonium borate salt No. 2. The yields of sulfonium borate salt No. 1 and sulfonium borate salt No. 2 in the production method of Example 2 were 93.4%.

[0080]

Chemical formula

[0081] Example 3: Preparation of sulfonium borate salt No. 3 70 g of dichloroethane and 132.4 g (0.044 mol) of a 23% by mass aqueous solution of ammonium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 28.0 g (0.046 mol) of 4-[4’-(benzoyl)phenylthio]phenyl-di-(4-fluorophenyl)sulfonium sulfate was charged into the flask, and the reaction was carried out for 1 hour while controlling the temperature of the reaction system at 20 - 35°C to obtain a reaction solution. The amount of ammonium tetrakis(pentafluorophenyl)borate used per mole of 4-[4’-(benzoyl)phenylthio]phenyl-di-(4-fluorophenyl)sulfonium sulfate was 0.96 mol. After completion of the reaction, the reaction solution was subjected to oil-water separation to obtain an oil phase. 80 g of ion-exchanged water was added to the obtained oil phase to prepare a mixed solution, and then the mixed solution was stirred for 5 minutes while controlling the temperature at 20 - 35°C. After allowing the mixed solution to stand for 30 minutes, a water washing treatment for separating the oil phase from the mixed solution was carried out 3 times. Propylene carbonate was added and dissolved so that the solid content concentration became 50% by mass, and a 50% by mass propylene carbonate solution of the following sulfonium borate salt No.3 was obtained. The yield of sulfonium borate salt No.3 in the production method of Example 3 was 93.1%.

[0082] [Chemical formula]

[0083] Comparative Example 1: Synthesis of Sulfonium Borate Salt No.1 Using Sodium Borate Salt 24 g of dichloroethane and 133.4 g (0.019 mol) of a 10% by mass aqueous solution of sodium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 9.4 g (0.020 mol) of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was charged into the flask, and the reaction was carried out for 1 hour while controlling the temperature of the reaction system at 20 to 35°C to obtain a reaction solution. The amount of sodium tetrakis(pentafluorophenyl)borate used per 1 mol of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was 0.95 mol. After completion of the reaction, the obtained reaction solution was subjected to oil-water separation to obtain an oil phase. 80 g of ion-exchanged water was added to the obtained oil phase to prepare a mixed solution, and then the mixed solution was stirred for 5 minutes while controlling the temperature at 20 to 35°C. After allowing the mixed solution to stand for 30 minutes, a water washing treatment for separating the oil phase from the mixed solution was carried out 3 times. Then, the solvent was distilled off, and propylene carbonate was added and dissolved so that the solid content concentration became 50% by mass to obtain a 50% by mass propylene carbonate solution of sulfonium borate salt No.1. The yield of sulfonium borate salt No.1 in the production method of Comparative Example 1 was 75.2%.

[0084] Comparative Example 2: Synthesis of Sulfonium Borate Salt No.1 Using Sodium Borate Salt 24 g of dichloroethane and 168.5 g (0.024 mol) of a 10% by mass aqueous solution of sodium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 9.4 g (0.020 mol) of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was charged into the flask, and the reaction was carried out for 1 hour while controlling the temperature of the reaction system at 20 to 35°C to obtain a reaction solution. The amount of sodium tetrakis(pentafluorophenyl)borate used per 1 mol of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was 1.2 mol. After completion of the reaction, the obtained reaction solution was subjected to oil-water separation to obtain an oil phase. 80 g of ion-exchanged water was added to the obtained oil phase to prepare a mixed solution, and then the mixed solution was stirred for 5 minutes while controlling the temperature at 20 to 35°C. After allowing the mixed solution to stand for 30 minutes, a water washing treatment for separating the oil phase from the mixed solution was carried out 3 times. Then, the solvent was distilled off, and propylene carbonate was added and dissolved so that the solid content concentration became 50% by mass to obtain a 50% by mass propylene carbonate solution of sulfonium borate salt No.1. The yield of sulfonium borate salt No.1 in the production method of Comparative Example 2 was 61.9%.

[0085] Comparative Example 3: Synthesis of Sulfonium Borate Salt No.1 Using Lithium Borate Salt 24 g of dichloroethane and 130.3 g (0.019 mol) of a 10% by mass aqueous solution of lithium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 9.4 g (0.020 mol) of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was charged into the flask, and the reaction was carried out for 1 hour while controlling the temperature of the reaction system at 20 to 35 °C to obtain a reaction solution. The amount of lithium tetrakis(pentafluorophenyl)borate used per 1 mol of diphenyl,4-(phenylsulfide)phenylsulfonium sulfate was 0.95 mol. After completion of the reaction, the obtained reaction solution was subjected to oil-water separation to obtain an oil phase. 80 g of ion-exchanged water was added to the obtained oil phase to prepare a mixed solution, and then the mixed solution was stirred for 5 minutes while controlling the temperature at 20 to 35 °C. After allowing the mixed solution to stand for 30 minutes, a water washing treatment for separating the oil phase from the mixed solution was carried out 3 times. Then, the solvent was distilled off, and propylene carbonate was added and dissolved so that the solid content concentration became 50% by mass to obtain a 50% by mass propylene carbonate solution of sulfonium borate salt No. 1. The yield of sulfonium borate salt No. 1 in the production method of Comparative Example 3 was 77.0%.

[0086] Comparative Example 4: Synthesis of Sulfonium Borate Salt No. 3 Using Sodium Borate Salt 30 g of dichloroethane and 133.4 g (0.019 mol) of a 10% by mass aqueous solution of sodium tetrakis(pentafluorophenyl)borate were charged into a flask. Then, 12.2 g (0.020 mol) of 4-[4'-(benzoyl)phenylthio]phenyl-di-(4-fluorophenyl)sulfonium sulfate was charged into the flask, and the temperature of the reaction system was controlled at 20 to 35 °C and reacted for 1 hour to obtain a reaction solution. The amount of sodium tetrakis(pentafluorophenyl)borate used per 1 mol of 4-[4'-(benzoyl)phenylthio]phenyl-di-(4-fluorophenyl)sulfonium sulfate was 0.95 mol. After completion of the reaction, the obtained reaction solution was subjected to oil-water separation to obtain an oil phase. 80 g of ion-exchanged water was added to the obtained oil phase to prepare a mixed solution, and then the mixed solution was stirred for 5 minutes while controlling the temperature at 20 to 35 °C. After allowing the mixed solution to stand for 30 minutes, a water washing treatment for separating the oil phase from the mixed solution was performed 3 times. Then, the solvent was distilled off, and propylene carbonate was added and dissolved so that the solid content concentration became 50% by mass to obtain a 50% by mass propylene carbonate solution of sulfonium borate salt No. 3. The yield of sulfonium borate salt No. 3 in the production method of Comparative Example 4 was 77.0%.

[0087] The oil-water separability and yield of the production methods of the examples and comparative examples were evaluated based on the following criteria. Also, the yield, purity, and stability of the sulfonium borate salts obtained by the production methods of the examples and comparative examples were evaluated based on the following criteria. The results are shown in Table 1 below.

[0088] <Oil-water separability> In the first water washing treatment, the separation state of the oil phase and the water phase of the mixed solution after allowing the mixed solution to stand for 30 minutes was visually observed by a professional panelist and evaluated according to the following criteria. A: The oil phase and the water phase are separated. B: The oil phase and the water phase are separated, but there is an intermediate layer between the oil phase and the water phase. C: The oil phase and the water phase are not separated.

[0089] <Yield evaluation> The yields of the sulfonium borate salts in the production methods of the examples and comparative examples were evaluated according to the following criteria. A: The yield is 100% or less and 90% or more. B: The yield is less than 90% and 80% or more. C: The yield is less than 80%.

[0090] <Purity> The residual amount of the raw material borate salt in the sulfonium borate salt used in the production methods of the examples and comparative examples was quantified by the following method, and the purity of the sulfonium borate salt was evaluated according to the following evaluation criteria. A: The amount of cations derived from the raw material borate salt in the sulfonium borate salt is less than 10 ppm. B: The amount of cations derived from the raw material borate salt in the sulfonium borate salt is 10 ppm or more.

[0091] The amount of cations derived from the raw material borate salt remaining in the sulfonium borate salt was confirmed by capillary electrophoresis. Specifically, the sulfonium borate salt was diluted with a mixed solution of tetrahydrofuran:water (80:20 volume ratio), and capillary electrophoresis (Agilent 7100) was measured. Quantification was performed by the calibration curve method from the peak area of the cation ions.

[0092] <Storage stability> 50 g of neopentyl glycol diglycidyl ether, 50 g of (3’,4’-epoxycyclohexane)methyl 3,4-epoxycyclohexyl carboxylate, and 5 g of a 50 mass% propylene carbonate solution of the sulfonium borate salt obtained in the examples and comparative examples were mixed to prepare a mixed solution. The viscosity of the mixed solution at 25°C immediately after preparation and the viscosity of the mixed solution at 25°C after storage at 40°C for 7 days were measured using an E-type viscometer (TVE-25L manufactured by Toki Sangyo Co., Ltd.). Based on the measured viscosities, the stability of the mixed solution was evaluated according to the following criteria. A: The viscosity after storage for 7 days is less than 101% of the viscosity immediately after preparation. B: The viscosity after storage for 7 days is 101% or more and less than 120% of the viscosity immediately after preparation. C: The viscosity after storage for 7 days is 120% or more of the viscosity immediately after preparation.

[0093]

Table 1

[0094] As is clear from Table 1, the production method of the examples had better oil-water separability than the production method of the comparative examples. Therefore, the production method of the examples was able to efficiently recover the sulfonium borate salt compared to the production method of the comparative examples. As a result, the production method of the examples had a better yield of the sulfonium borate salt than the production method of the comparative examples. In addition, the sulfonium borate salt produced by the production method of the examples had the same purity as the sulfonium borate salt produced by the production method of the comparative examples. This result indicates that the sulfonium borate salt produced by the production method of the present invention has the same quality as the sulfonium borate salt produced by a known production method. This is obvious from the fact that the sulfonium borate salt produced by the production method of the examples has the same storage stability as the sulfonium borate salt produced by the production method of the comparative examples. Furthermore, the production method of the examples was able to produce a high-quality sulfonium borate salt in good yield despite being carried out under atmospheric pressure. This result indicates that according to the production method of the present invention, the sulfonium borate salt can be easily produced. From the above results, it became clear that the production method of the present invention is useful as a production method of the sulfonium borate salt.

Claims

1. A method for producing a sulfonium borate salt, comprising a step of reacting an ammonium borate salt with a sulfonium salt to form a sulfonium borate salt.

2. The method for producing a sulfonium borate salt according to Claim 1, wherein the ammonium borate salt used is an ammonium borate salt represented by the following general formula (1). NH ４ ＋ [(Y) ｋ B(Phf) ４－ｋ － (1)​ (In the formula, Y represents an aryl group having 6 to 30 carbon atoms or a heterocyclic group having 4 to 30 carbon atoms, and the hydrogen atoms of the aryl group and the heterocyclic group may be substituted with substituents excluding groups containing a halogen atom. Phf represents a phenyl group in which at least one hydrogen atom is substituted with any one of a perfluoroalkyl group, a perfluoroalkoxy group, and a halogen atom. k represents an integer of 0 to 4.)

3. The method for producing a sulfonium borate salt according to Claim 2, wherein k in the general formula (1) is 0.

4. The method for producing a sulfonium borate salt according to Claim 2, wherein Phf in the general formula (1) is a phenyl group in which at least one hydrogen atom is substituted with a halogen atom.

5. The method for producing a sulfonium borate salt according to Claim 1, wherein the sulfonium salt is an aromatic sulfonium salt.

6. The production method according to Claim 1, wherein the usage amount of the ammonium borate salt is 0.90n mol to 0.99n mol with respect to 1 mol of the n-valent sulfonium salt.

7. The method for producing a sulfonium borate salt according to Claim 1, wherein the ammonium borate salt and the sulfonium salt are reacted in a solvent.

8. The method for producing a sulfonium borate salt according to Claim 7, wherein the solvent is a chlorine-based solvent.

9. A polymerization initiator containing a sulfonium borate salt produced by the production method according to any one of Claims 1 to 8.

10. A polymerizable composition containing the polymerization initiator according to Claim 9 and a cationically polymerizable compound.

11. A cured product obtained from the polymerizable composition according to Claim 10.

12. A method for producing a cured product, comprising a step of irradiating the polymerizable composition according to Claim 10 with active energy rays.

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