Sulfonium compound and polymerisation initator comprising the sulfonium compound as the main ingredient

Abstract: Sulfonium compounds represented by the formulae (I) or (II) : where R₁ represents ethoxy group, phenyl group, benzyloxy group, chloromethyl group, phenoxy group, 9-fluorenylmethoxy group or trichloromethyl group, R₂ and R₃ represent, independently, hydrogen, halogen or alkyl group, R₄ represents hydrogen or methoxy group, R₅ represents alkyl group, R₆ represents hydrogen, methyl group, acetyl group, methoxy carbonyl group, ethoxy carbonyl group, chloroacetyl group, trichloroacetyl group, benzyloxy carbonyl group, benzoyl group, phenoxy carbonyl group or 9-fluorenyl methoxy carbonyl group, Q represents chlorobenzyl group, methyl benzyl group, nitrobenzyl group, dinitrobenzyl group, α-naphthylmethyl group or β-naphthylmethyl group and X represents SbF₆, PF₆, AsF₆ or BF₄, providing that if R₆ is hydrogen, methyl group, acetyl group or methoxy­ carbonyl group, Q does not include chlorobenzyl group or methylbenzyl group, are used as polymerisation initiators.

Description: The present invention concerns a novel sulfonium compound, a polymerization initiator comprising the sulfonium compound as the main ingredient and a polymerization process using the polymerization initiator More specifically, the present invention relates to a cationically polymerizable composition containing a novel sulfonium compound useful for obtaining a curing product having satisfactory property or an oligomer of a cationically polymerizable vinyl compound having practical usefulness by polymerizing cationically polymerizable material in a short period of time by means of heat or radiation rays such as light or electron beam, a curing agent for such polymerization and a polymerization process. Generally, cationically polymerizable materials, among all, epoxy resins have been employed for various application uses requiring materials of high performance. Particularly, since the method of curing by polymerization under the irradiation of radiation rays at predetermined wavelength such as ultraviolet rays can provide curing within a short period of time by a simple polymerization process, it has been used for various application uses. Epoxy resins have so far been used generally in the form of a two-component system by incorporating an active amine-containing compound or a carboxylic acid anhydride as a curing agent. However, the two-component system using such a curing agent involves a drawback that the ingredients have to be mixed completely and it needs curing time as long as several hours. In addition, there is a boron trifluoride-monoethyl amine system for curing the epoxy resin in a one component system but it takes from 1 to 8 hours even at a high temperature of 160°C or higher. As an improvement, although there can be mentioned U.S. Patent No. 3565861, it also requires high temperature. Accordingly, these compositions can not be used for the coating of heat sensitive electronic parts, etc. Further, in a case of curing an epoxy resin by light, there has been proposed a method of using an aryl diazonium metal halide complex. However, since polymerization is taken place rapidly and premature gelation tends to occur in this method, it may be considered that the composition can not be stored satisfactorily even for a short period of time if it is in a dark place. In view of the above, it has been proposed to suppress the premature gelation of the composition and provide storage-stability in a dark place for epoxy material containing metal halide salt of an aryl diazonium salt. However, since nitrogen is released during curing from such a composition, the resultant curing material involves a problem of incorporating bubbles, as well as the cost is increased and completely satisfactory results have not yet been obtained. By the way, various photodegrading sulfonium salts have been known for the onium salt. For instance, it has been known to use p-hydroxyphenyl dimethylsulfonium hexafluoro arsenates as a photocuring agent in Japanese Patent Laid-Open No. Sho 54-53181 and phenyl sulfonium salt as a photocuring agent for epoxy resins in Japanese Patent Laid-Open No. Sho 50-151997. Further, there has been disclosure in Research Disclosure May 1988, p 298 - 299 of using p-cyanobenzylmethyl-9-anthryl sulfonium trifluoromethanesulfonate, etc. as a photocuring agent. However, although such onium salts can photocure epoxy resins, epoxy resins can not be cured by merely applying heat. Further, a photopolymerization initiator that changes its dissolving behavior by radiation rays has been disclosed in Japanese Patent Laid-Open No. Sho 64-26550. On the other hand, as the thermal latent type initiator capable of activating onium salts by applying heat thereby curing epoxy resins, there have been reported benzyl sulfonium salt, for example, dialkylbenzyl sulfonium hexafluoroantimonate in Japanese Patent Laid-Open Nos. Sho 58-37003, 63-223002 and a trialkyl sulfonium salt in Japanese Patent Laid-Open No. Sho 56-162833, and a dialkyl hydroxyaryl sulfonium salt in Japanese Patent Publication Nos. 56-500218 and 56-500496. However, these sulfonium salts are inert to light and can not cure epoxy resins in a short period of time, as well as require temperature, for example, 150°C or higher, and can not be said practical both in view of the heating time and the temperature. Further, Japanese Patent Laid-Open No. 60-188425 discloses a curing agent for the heat polymerization of special esters such as spiro type esters. On the other hand, as the cationic polymerization catalyst for cationically polymerizable vinyl compounds, there have been known Lewis acid catalyst such as mineral acid, BF₃, ZnCl₂, AlCl₃ and halogen-containing organic aluminum compound such as AlR₂Cl and AlRCl₂. However, since these catalysts cause too violent cationic polymerization reaction at a temperature of 0°C or higher polymerization reaction can not be controlled as desired and polymerization degree can not be increased. It is of course impossible to previously formulate a cationically polymerizable monomer and such a catalyst into one-part system at a room temperature for storage. For polymerizing a vinyl compound, it is necessary for controlling the chain transfer reaction or termination reaction and, accordingly, polymerization reaction has usually been conducted by charging a catalyst solution after cooling a cationically polymerizable monomer dissolved in an appropriate solvent to a predetermined extremely low temperature. However, for conducting the polymerizing reaction industrially at an extremely low temperature (for instance, from -130°C to -40°C), since it is necessary to use a cooling medium at low temperature, this makes the operation complicate and increases the cooling cost and, accordingly, it can not be said to be quite satisfactory. Although US. Patent No. 3283010 describes the release of benzyl cations, polymerization for the polymer is not intended in this patent. Further, in view of compounds, p-hydroxyphenyl benzylsulfonium compound is disclosed in Japanese Patent Laid-Open Sho 50-29511 and p-hydroxyphenyl benzylsulfonium halide is disclosed in U.S. Patent No. 4034046. However, substituted or not-substituted oxyphenyl benzyl or naphthylmethyl alkyl sulfonium (sub)metal polyfluoride complex has not yet been known. OBJECT AND SUMMARY OF THE INVENTION The object of the present invention is to provide a cationically polymerizable composition containing a novel sulfonium compound capable of polymerizing cationically polymerizable materials such as epoxy resins in a short period of time under the irradiation of heat or radiation rays such as light or electron rays, and utilizable as sealant, matrix resin for composite material, etc., a polymerization initiator comprising the novel sulfonium compound as the main ingredient, as well as a polymerization process using such a polymerization initiator. Another object of the present invention is to provide a monomer composition capable of polymerizing a cationically polymerizable vinyl compound such as styrene monomer under a certaincondition and excellent in storage stability as a mixture with polymerization initiator, industrially provide an oligomer of a vinyl compound of practical usefulness, as well as provide a polymerization process therefor and a catalyst as a novel compound. The novel compound referred to in the present invention is a sulfonium compound represented by the general formulae (I) or (II) : where R₁ represents ethoxy group, phenyl group, benzyloxy group, chloromethyl group, phenoxy group, 9-fluorenylmethoxy group or trichloromethyl group, R₂ and R₃ represent, independently, hydrogen, halogen or C₁ - C₄ alkyl group, R₄ represents hydrogen or methoxy group, R₅ represents C₁ - C₄ alkyl group, R₆ represents hydrogen, methyl group, acetyl group, methoxy carbonyl group, ethoxy carbonyl group, chloroacetyl group, trichloroacetyl group, benzyloxy carbonyl group, benzoyl group, phenoxy carbonyl group or 9-fluorenyl methoxy carbonyl group, Q represents chlorobenzyl group, methyl benzyl group, nitrobenzyl group, dinitrobenzyl group, α-naphthylmethyl group or β-naphthylmethyl group and X represents SbF₆, PF₆, AsF₆ or BF₄, providing that if R₆ is hydrogen, methyl group, acetyl group or methoxycarbonyl group, Q does not include chlorobenzyl group or methylbenzyl group. As has been described above, the present invention comprises essentially substituted or not-substituted oxyphenyl, substituted or not-substituted benzyl or naphthylmethyl alkyl sulfonium (sub)metal polyfluoride complex in which the novelty of the invention is present. The present compound is synthesized by using a corresponding sulfonium chloride or sulfonium methylsulfate as the starting material and reacting it with an alkali metal salt of a predetermined acid, for example, NaSbF₆, KSbF₆, NaBF₄, LiBF₄, NaPF₆, KPF₆, NaAsF₆, KAsF₆ in a predetermined anhydrous or hydrous organic solvent. The organic solvent used in this case is selected from methanol, acetone, ethyl acetate, ethanol and acetonitrile. Other solvents than described above, for example, benzene or toluene cause no reaction since they do not substantially dissolve the inorganic salt. Further, although DMF or DMSO can proceed the reaction due to their solubility, they are difficult to be removed from the reaction system owing to their high boiling point. As the second synthesis method, it is also proposed a method of obtaining a substituted oxyphenyl benzyl/naphthylmethyl sulfonium compound by reacting the hydroxy group of a hydroxyphenyl benzyl/naphthylmethyl alkyl sulfonium compound with an acid halide such as chloromethyl carbonate, acetyl chloride or acetyl iodine under the presence of tertiary amine. The reaction solvent in this method includes ethyl acetate and acetonitrile. Other solvents can not provide preferred result. For instance, protonic solvents such as water, methanol or ethanol react with acid halide. Aromatic solvents typically represented by benzene do not dissolve the product and, accordingly, reduce the purity thereof. Polar solvents typically represented by the DMF or DMSO can provide reaction, but it is difficult to remove them from the reaction system due to their high boiling point, causing, for example, decomposition of products during removal. The reaction temperature is preferably 20°C or lower, particularly preferably, 5°C or lower for avoiding the decomposition of the product. The tertiary amine added as a dehydrogen halide agent is preferably triethylamine, trimethylamine, N-methylmorpholine, etc., which may be used alone or as a mixture of two or more of them. The polymerization initiator according to the present invention comprises a paired compound of a (substituted or not-substituted)-benzyl/naphthylmethyl-4-(substituted or not-substituted)-oxyphenyl solfonium cation and a predetermined anion represented by the general formula (I) or (II) as the constituent factor. The catinically polymerizable material used in the present invention is an acid polymerizable or acid curable material and epoxy resins are used particularly preferably. Examples of suitable material are epoxide monomers, episulfide monomers, polyepoxides (or epoxy resin), polyepisulfides (or episulfide resins), phenyl/formaldehyde resin, melamine/formaldehyde resin, urea/formaldehyde resin, cyclic ether and thiocyclic ether such as spiro-orthoester, bicycloorthoester and spiro-ortho carbonate (other than epoxide and episulfide) and polymers thereof, lactone, styrene, vinyl ether and vinyl thioether, as well as those resins containing a crosslinker for crosslinking or curing resins when treated with acid, which may be used alone or as a mixture of two or more of them. Preferred benzyl sulfonium salt used as the polymerization catalyst in the present invention can include, for example, o-nitrobenzyl-4-hydroxphenyolmethylsulfonium hexafluoroantimonate, m-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, o-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, m-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 3,5-dinitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 3,5-dinitrobenzyl-4-hydroxyphenylethylsulfonium hexafluoroantimonate, o-nitrobenzyl-4-hydroxyphenylethylsulfonium hexafluoroantimonate, o-nitrobenzyl-3-chlor-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 2,4,6-trinitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 2,4-dinitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, β-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, α-naphthylmethyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate, α-naphthylmethyl-4-(methoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate, 4-(benzoyloxy)phenylbenzylmethylsulfonium hexafluoroantimonate 4-(benzoyloxy)phenylbenzylethylsulfonium hexafluoroantimonate, 4-(benzoyloxy)phenylbenzylmethylsulfonium hexafluorophosphate, 4-(benzoyloxy)phenylbenzylmethylsulfonium tetrafluoroborate, 4-(benzoyloxy)phenylbenzylmethylsulfonium hexafluoroarsenate, benzyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate, benzyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate, benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate, benzyl-4-(phenoxycarbonyoxy)phenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-(benzoyloxy)phenylmethylsulfonium hexafluorophosphate, p-methylbenzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate, p-methylbenzyl-4-chloracetoxyphenylmethylsulfonium hexafluroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, and p-nitrobenzyl-3-methyl-4-hydroxyphenylethylsulfonium hexafluoroantimonate, The sulfonium salts used in the present invention increase the activity to heat, as well as have an activity to radiation rays such as light or electron beam. That is, it is considered that such benzyl sulfonium salts excited by heat or radiation rays release benzyl cations or naphthylmethyl cations thereby proceeding the polymerization of the cationicaly polymerizable material described above. Further, in the present invention, in a case where the cationically polymerizable material is a vinyl compound, solution polymerization is usually conducted by using a solvent inert to the catalyst or the monomer upon polymerization reaction, but bulk polymerization is also employed. As the solution usable herein, there can be mentioned, for example, aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as n-hexane and n-heptane, cycloaliphatic hydrocarbons such as cyclohexane, hydrocarbon mixtures such as petroleum ether and ligroin, and halogenated hydrocarbons such as chlorobenzene and dichloroethane. The polymerizing reaction for the vinyl compounds is conducted under a normal or elevated pressure at a reaction temperature of 20°C or higher, preferably, from 30 to 150°C at which heating can easily be conducted industrially. Further, since the sulfonium salt used as the polymerization initiator in the present invention does not start the cationic polymerization reaction, for instance p-methylbenzyl-4-substituted oxy or 4-hydroxyphenylmethylsulfonium salt in a cold place and α-naphthylmethyl-4-substituted oxy or 4-hydroxyphenylmethylsulfonium salt in a dark and cold place, it is also possible, if required, to form the monomer and the initiator previously into a one component system by using an appropriate solvent and store them. The sulfonium salt used in the present invention is used from 0.01 to 20 parts by weight, preferably, from 0.1 to 10 parts by weight based on 100 parts by weight of a resin. If it is less than 0.01 parts by weight, no sufficient polymer can be obtained. With an addition amount in excess of 20 parts by weight, no preferred products can be obtained in view of the physical property after the polymerization and it is neither preferred in view of the cost. Further, polymerizatin reaction or curing reaction is conducted by treatment with radiation rays or heat and, if required, heating and irradiation of radiation rays may be used in combination. Further, a solvent may be used, if required, upon polymerization. As the radiation rays in the present invention, ultraviolet rays at a wavelength within a range from 200 to 400 nm show best efficiency and, accordingly, there can be mentioned low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, xenone lamp, carbon arc lamp, etc. as the light source and, further, polymerization reaction or curing reaction may be conducted by the irradiation of electron beam or sunlight. The composition according to the present invention may be used, depending on the case, in admixture with auxiliary agents typically represented by extender, flame retardant, antistatic agent, surface active agent and acid anhydride, and it can be used for lustering varnish, ink, paint, adhesive, laminated board,prepreg, molding material, sealing material, etc. Since the curable composition according to the present invention does not start the cationic polymerization, for example, p-methylbenzyl-4-substituted oxy or 4-hydroxyphenylmethylsulfonium salt in a cold place and α-naphthylmethyl-4-substituted oxy or 4-hydroxyphenylmethylsulfonium salt in a dark and cold place, it can be stored for a long period of time and has a function of rapidly starting the polymerization under the irradiation of radiation rays such as light or electron beam, heating at a temperature of 150°C or lower or by the combined use of heating and radiation treatment, and can provide curing products of excellent curability at high temperature, with no hydroscopic property and excellent in water proofness, chemical resistance and electrical property. Further, the cationically polymerizable vinyl compound composition has a feature capable of storing the monomer and the catalyst in one-part system which has been difficult so far, enabling cation polymerization at a temperature of 20°C or higher and obtaining a polymer at high polymerization degree of practical usefulness by simple heating. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is to be described referring to preferred embodiment but it should be noted that the invention is not limited only to the following examples. Synthetic Example 1 Synthesis for o-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate o-Nitrobenzyl-4-hydroxyphenylmethylsulfonium chloride was dissolved in an amount of 7.50 g (0.024 mol) into 500 ml of methanol, to which 6.60 g (0.024 mol) of powder of KSbF₆ was added under stirring and they were stirred further for one hour. The solution was concentrated under a reduced pressure and the residue was extracted. The extract was washed with water, dried and then concentrated to obtain 9.50 g (77.2% yield) of the aimed product as white crystals from the residue. Melting point 121.0∼124.0°C IR (KBr) cm⁻¹ 3480, 1530, 1345, 675 NMR (Acetone-d₆) ppm δ = 3.63 (3H, S, C H₃ S⁺<) δ = 5.35 (2H, dd, -C H₂ C₆H₄-) δ = 7.01∼8.30 (8H, m, -C₆ H₄ - × 2) δ = 9.80 (1H, S, H O-) Elementary analysis C₁₄H₁₄NO₃SSbF₆ Theoretical value C ; 32.84%, H ; 2.76% Measured value C ; 32.60%, H ; 2.88% Synthetic Example 2 Synthetic for 3,5-dinitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate 3,5-dinitrobenzyl-4-hydroxyphenylmethylsulfonium chloride was dissolved in an amount of 10 g (0.028 mol) into 900 ml of methanol, to which a powder of 7.7 g (0.028 mol) of KSbF₆ was added under stirring. Subsequently, the same procedures as those in Synthetic Example 1 were applied to obtain 11.0 g (70.5% yield) of the aimed product as yellow crystals. Melting point 180.0∼183.0°C IR (KBr) cm⁻¹ 3475, 1545, 1350, 665 NMR (Acetone-d₆) ppm δ = 3.57 (3H, S, C H₃ S⁺<) δ = 5.16-5.63 (2H, dd, -C H₂ C₆H₃-) δ = 7.07-8.04 (4H, dd, HOC₆ H₄ -) δ = 8.57-8.62 (2H, d, δ = 8.89-8.96 (1H, t, δ = 9.86 (1H, S, H O-) Elementary analysis C₁₄H₁₃O₅N₂SSbF₆ Theoretical value C ; 30.19%, H ; 2.35% Measured value C ; 29.95%, H ; 2.31% Synthetic Example 3 Synthesis for α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate α-naphthylmethyl-4-hydroxyphenylmethylsulfonium chloride was dissolved in an amount of 5.00 g (0.015 mol) into 200 ml of methanol, to which 4.08 g (0.015 mol) of powder of KSbF₆ was added under stirring. Subsequently, the same procedures as those in Synthesis Example 1 were applied o obtain 6.32 g (82.3% yield) of the aimed product as white crystals. Melting point 125.5°C (decomposition) IR (KBr) cm⁻¹ 3480, 665 NMR (Acetone-d₆) ppm δ = 3.57 (3H, S, C H₃ S⁺<) δ = 5.23-5.91 (2H, dd, -C H₂ C₁₀H₇) δ = 6.93∼8.35 (11H, m, -C₆ H₄ -, -CH₂C₁₀ H₇ ) δ = 9.72 (1H, S, H O-) Elementary analysis C₁₈H₁₇OSSbF₆ Theoretical value C ; 41.81%, H ; 3.31% Measured value C ; 41.63%, H ; 3.25% Synthetic Example 4 Synthesis for p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 3.12 g (0.01 mol) into 300 ml of methanol, to which a powder of 2.75 g (0.01 mol) of KSbF₆ was added under stirring. Subsequently, the same procedures as those in Synthetic Example 1 were applied obtained 4.04 g (78.9% yield) of p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate as white crystals. Melting point 165.0∼167.0°C IR (KBr) cm⁻¹ 3510, 665 NMR (Acetone-d₆) ppm δ = 3.56 (3H, S, C H₃ S⁺<) δ = 4.99∼5.49 (2H, dd, -C₆H₄C H₂ -) δ = 7.01∼8.30 (8H, m, -C₆ H₄ - × 2) δ = 9.79 (1H, S, H O-) Elementary analysis C₁₄H₁₄O₃NSSbF₆ Theoretical value C ; 32.84%, H ; 2.76% Measured value C ; 32.73%, H ; 2.69% Synthetic Example 5 Synthesis for p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate p-nitrobenzyl-4-hydroxyphenylmethylsulfonium chloride was dissolved in an amount of 3.12 g (0.01 mol) into 300 ml of methanol, to which a powder of 1.84 g (0.01 mol) of KPF₆ was added under stirring. Subsequently, the same procedures as those in Synthetic Example 1 were applied to obtain 3.48 g (82.5% yield) of p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate as white crystals. Melting point 161.0∼163.0°C IR (KBr) cm⁻¹ 3500, 850 NMR (Acetone-d₆) ppm δ = 3.50 (3H, S, C H ₃S⁺<) δ = 4.92∼5.40 (2H, dd, -C₆H₄C H₂ -) δ = 6.95∼8.23 (8H, m, -C₆ H₄ - × 2) Elementary analysis C₁₄H₁₄O₃NSPF₆ Theoretical value C ; 39.91%, H ; 3.35% Measured value C ; 40.03%, H ; 3.29% Synthetic Example 6 When reaction was conducted by using p-nitrobenzyl-4-hydroxyphenylmethylsulfonium bromide instead of p-nitrobenzyl-4-hydroxyphenylmethylsulfonium chloride in Synthetic Example 4, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was obtained at 65.2% yield. Synthetic Example 7 Synthesis for benzyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate Benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 20.0 g (0.043 mol) into 230 ml of ethyl acetate, to which 4.6 g (0.045 mol) of triethylamine was added at a temperature lower than 5°C and 4.9 g (0.045 mol) of ethyl chloroformate was dropped at that temperature. After stirring for 3 hours, by produced triethylamine hydrogen chloride was removed by filtration and the acetonitrile layer was concentrated under a reduced pressure. The residue was recrystallzied to obtain 16.0 g (69.3% yield) of the aimed product as white crystals. Melting Point 108.0∼110.0°C IR (KBr) cm⁻¹ 1770, 660 Elementary analysis C₁₇H₁₉O₃SSbF₆ Theoretical value C ; 37.92%, H ; 3.53% Measured value C ; 37.86%, H ; 3.53% NMR (Acetone-d₆) ppm δ = 1.35 (3H, t, J = 7Hz, C H₃ CH₂-) δ = 3.50 (3H, S, C H₃ S⁺<) δ = 4.30 (2H, dd, J = 14Hz, 7Hz, CH₃C H₂ -) δ = 5.12 (2H, dd, J = 16Hz, 12Hz, C₆H₅C H₂ -) δ = 7.50 (2H, d, J = 9Hz) = 7.94 (2H, d, J = 9Hz) overall (4H, -C₆ H₄ -) δ = 7.33 (5H, S, C₆ H₅ -) Synthetic Example 8 Synthesis for benzyl-4-(phenoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate Benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 20.0 g (0.043 mol) into 230 ml of acetonitrile, to which 4.6 g (0.045 mol) of triethylamine was added at a temperature lower than 5°C and 7.1 g (0.045 mol) of phenyl chloroformate was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 17.8 g (70.8% yield) of the aimed product as white crystals. melting point 94.0∼96.0°C IR (KBr) cm⁻¹ 1770, 660 Elementary analysis C₂₁H₁₉O₃SSbF₆ Theoretical value C ; 42.95%, H ; 3.26% Measured value C ; 43.22%, H ; 3.28% NMR (Acetone-d₆) ppm δ = 3.50 (3H, S, C H₃ S⁺<) δ = 5.12 (2H, dd, J = 16Hz, 12Hz, C₆H₅C H₂ -) δ = 7.35 (10H, S, C₆ H₅ - × 2) δ = 7.63 (2H, d, J = 9Hz) = 8.02 (2H, d, J = 9Hz) overall (4H, -C₆ H₄ -) Synthetic Example 9 Synthesis for benzyl-4-(benzoyloxy)phenylmethylsulfonium hexafluoroantimonate Benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 20.0 g (0.043 mol) into 230 ml of acetonitrile, to which 4.6 g (0.045 mol) of triethylamine was added at a temperature lower than 5°C and 6.4 g (0.045 mol) of benzoyl chloride was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 19.9 g (81.3% yield) of the aimed product as white crystals. melting point 113.0∼115.0°C IR (KBr) cm⁻¹ 1750, 660 Elementary analysis C₂₁H₁₉O₂SSbF₆ Theoretical value C ; 44.16%, H ; 3.35% Measured value C ; 44.31%, H ; 3.50% NMR (Acetone-d₆) ppm δ = 3.53 (3H, S, C H₃ S⁺<) δ = 5.17 (2H, dd, J = 16Hz, 12Hz, C₆H₅C H₂ -) δ = 7.36∼8.23 (14H, m, C₆ H₅ - × 2, -C₆ H₄ -) Synthetic Example 10 Synthesis for benzyl-4-(benzoyloxy)phenylmethylsulfonium hexafluorophosphate Benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate was dissolved in an amount of 20.0 g (0.053 mol) into 230 ml of acetonitrile, to which 5.7 g (0.056 mol) of triethylamine was added at a temperature lower than 5°C and 7.9 g (0.056 mol) of benzoyl chloride was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 20.6 g (80.6% yield) of the aimed product as white crystals. Melting point 146.0∼146.5°C IR (KBr) cm⁻¹ 1740 , 830 Elementary analysis C₂₁H₁₉O₂SPF₆ Theoretical value C ; 52.50%, H ; 3.98% Measured value C ; 52.68%, H ; 3.96% NMR (Acetone-d₆) ppm δ = 3.55 (3H, S, C H₃ S⁺<) δ = 5.16 (2H, dd, J = 16Hz, 12Hz, C₆H₅C H₂ -) δ = 7.37∼8.24 (14H, m, C₆ H₅ - × 2, -C₆ H₄ -) Synthetic Example 11 Synthesis for benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate Benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 20.0 g (0.043 mol) into 230 ml of acetonitrile, to which 4.6 g (0.045 mol) of triethylamine was added at a temperature lower than 5°C and 7.7 g (0.045 mol) of benzyl chloroformate was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 23.3 g (90.5% yield) of the aimed product as white crystals. Melting point 119.0∼120.0°C IR (KBr) cm⁻¹ 1770, 660 Elementary analysis C₂₂H₂₁O₃SSbF₆ Theoretical value C ; 43.95%, H ; 3.52% Measured value C ; 44.03%, H ; 3.83% NMR (Acetone-d₆) ppm δ = 3.50 (3H, S, C H₃ S⁺<) δ = 5.10 (2H, dd, J = 16Hz, 12Hz, C₆H₅C H₂ -) δ = 5.32 (2H, S, C₆H₅C H₂O -) δ = 7.34∼8.05 (14H, m, C₆ H₅ - × 2, -C₆ H₄ -) Synthetic Example 12 Synthesis for benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate Benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate was dissolved in an amount of 20.0 g (0.053 mol) into 230 ml of acetonitrile, to which 5.7 g (0.056 mol) of triethylamine was added at a temperature lower than 5°C and 9.6 g (0.056 mol) of benzyl chloroformate was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 23.4 g (86.2% yield) of the aimed product as white crystals. Melting point 114.0∼116.0°C IR (KBr) cm⁻¹ 1750, 830 Elementary analysis C₂₂H₂₁O₃SPF₆ Theoretical value C ; 51.77%, H ; 4.14% Measured value C ; 51.57%, H ; 4.22% NMR (Acetone-d₆) ppm δ = 3.50 (3H, S, C H₃ S⁺<) δ = 5.10 (2H, dd, J = 16Hz, 12Hz, C₆H₅C H₂ -) δ = 5.32 (2H, S, C₆H₅C H₂ O-) δ = 7.34∼8.05 (14H, m, C₆ H₅ - × 2, -C₆ H₄ -) Synthetic Example 13 Synthesis for p-methylbenzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate Benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 24.06 g (0.050 mol) into 250 ml of acetonitrile, to which 5.36 g (0.053 mol) of triethylamine was added at a temperature lower than 5°C and 9.04 g (0.053 mol) of benzyl chloroformate was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 27.2 g (88.3% yield) of the aimed product as white crystals. Melting point 98.5∼101.0°C IR (KBr) cm⁻¹ 1755, 665 Elementary analysis C₂₃H₂₃O₃SSbF₆ Theoretical value C ; 44.90%, H ; 3.77% Measured value C ; 44.96%, H ; 3.61% NMR (Acetone-d₆) ppm δ = 2.32 (3H, S, -C₆H₄C H₃ ) δ = 3.48 (3H, S, C H₃ S⁺<) δ = 5.10 (2H, dd, J = 16Hz, 12Hz, -C H₂ C₆H₄-) δ = 5.31 (2H, S, C₆H₅C H₂ O-) δ = 7.18∼8.05 (13H, m, C₆ H₅ -, -C₆ H₄ - × 2) Synthetic Example 14 Synthesis for benzyl-4-chloroacetoxyphenylmethylsulfonium hexafluoroantimonate Benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 24.0 g (0.051 mol) into 280 ml of acetonitrile, to which 5.46 g (0.054 mol) of triethylamine was added at a temperature lower than 5°C and 6.09 g (0.054 mol) of chloroacetyl chloride was dropped at that temperature. Subsequently, the same procedures as those in Synthetic Example 7 were applied to obtain 24.3 g (87.0% yield) of the aimed product as white crystals. Melting point 138.0∼140.0°C IR (KBr) cm⁻¹ 1780, 660 Elementary analysis C₁₆H₁₆O₂SClSbF₆ Theoretical value C ; 35.49%, H ; 2.77% Measured value C ; 35.51%, H ; 2.96% NMR (Acetone-d₆) ppm δ = 3.48 (3H, S, C H₃ S⁺<) δ = 4.59 (2H, S, ClC H₂ COO-) δ = 5.12 (2H, dd, J = 16Hz, 12Hz, -C H₂ C₆H₅) δ = 7.25∼8.05 (9H, m, -C₆ H₄ -, -C₆ H₅ ) Synthetic Example 15 Synthesis for α-naphthylmethyl-4-(methoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate Using α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate synthesized in Synthetic Example 3 as the starting material in an amount of 5.00 g (0.015 mol) and synthesis was conducted in the same procedures as those in Synthetic Example 7 to obtain 6.99 g (81.0% yield) of the aimed product as white crystals. Melting point 125.5∼126.0°C IR (KBr) cm⁻¹ 1760, 1210, 660 NMR (Acetone-d₆) ppm δ = 3.65 (3H, s, C H₃ S⁺<) δ = 3.90 (3H, s, C H₃ OCOO-) δ = 5.39∼5.92 (2H, dd, -C H₂ C₁₀H₇) δ = 7.33∼8.32 (11H, m, -C₆ H₄ -, -CH₂C₁₀ H₇ ) Elementary analysis C₂₀H₁₉O₃SSbF₆ Theoretical value C ; 41.82%, H ; 3.33% Measured value C ; 42.12%, H ; 3.24% Synthetic Example 16 Synthesis for α-naphthylmethyl-4-acetoxyphenylmethylsulfonium hexafluoroantimonate Using α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate synthesized in Synthetic Example 3 as the starting material in an amount of 5.00 g (0.015 mol) and synthesis was conducted in the same procedures as those in Synthetic Example 7 to obtain 6.65 g (79.3% yield) of the aimed product as white crystals. Melting point 118.0∼120.0°C IR (KBr) cm⁻¹ 1775, 1195, 655 NMR (Acetone-d₆) ppm δ = 2.29 (3H, S, C H₃ COO-) δ = 3.60 (3H, S, C H₃ S⁺<) δ = 5.33∼5.87 (2H, dd, -C H₂ C₁₀H₇) δ = 7.25∼8.31 (11H, m, -C₆ H₄ -, -CH₂C₁₀ H₇ ) Elementary analysis C₂₀H₁₉O₂SSbF₆ Theoretical value C ; 43.02%, H ; 3.43% Measured value C ; 43.19%, H ; 3.47% Comparative Example 1 Synthesis for o-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was tried in the same procedures as those in Synthetic Example 1 except for using benzene instead of methanol, but aimed products could not be obtained. Comparative Example 2 Synthesis for benzoyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate was tried in the same procedures as those in Synthetic Example 7 except for using methanol instead of acetonitrile but aimed products could not be obtained. Comparative Example 3 Benzyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate was synthesized in the same procedures as those in Synthetic Example 7 except for using DMF instead of acetonitrile, but the aimed products were decomposed upon removing DMF and the yield was 3.4 g (14.8% yield). Working Example 1 α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.034 g to 1.0 g of phenyl glycidyl ether. The mixture was deaerated and subjected to bulk polymerization in a sealed tube at a predetermined temperature for one hour and, after the reaction, the conversion ratio was determined based on ¹H-NMR spectrum. The result is shown below. Temperature (°C) 30 40 60 80 Conversion ratio (%) 0 8 75 86 Working Example 2 The sulfonium salt used in Working Example 1 was mixed by 0.034 g to 1.0 g of phenyl glycidyl ether, deaerated and sealed in a tube. When photo-induced bulk polymerization was conducted at 10°C by using a 400 W high pressure mercury lamp having main wavelength at 312 nm as a light source and using a rotary photochemical reactor (RH400-10W type) manufactured by Riko Kagaku Sangyo Co., the conversion ratio in two hours was 65%. Working Example 3 o-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was dissolved in an amount of 1 g into 100 g of Epikote 828 (bisphenol-A epoxy resin, manufactured by Yuka Shell Epoxy Co.), which was coated to a thickness of 0.5 mm on a glass plate. Then, when it was irradiated by sunlight for 5 hrs, the resin was completely gelled. Working Examples 4 - 12 Blends comprising 100 parts by weight of Epikote 828 (bisphenol-A epoxy resin, manufactured by Yuka Shell Epoxy Co.) and each 3 parts by weight of various sulfonium salts were prepared and each of them was taken in an amount of about 100 mg and gelling time was measured on a hot plate heated to 150°C. The results are shown in Table 1. Further, when the composition prepared in this way was left at 10°C for one month under light shielding, no remarkable increase of viscosity was observed. Working Examples 13 - 20 Blends comprising 100 parts by weight of Epikote 828 (bisphenol-A epoxy resin, manufactured by Yuka Shell Epoxy Co.) and each 3 parts by weight of various sulfonium salts were prepared and each of them was taken in an amount of about 100 mg and gelling time was measured on a hot plate heated to 100°C. The results are shown in Table 2. Working Example 21 Benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate and 4-(benzoyloxy)phenylmethylsulfonium hexafluoroantimonate were mixed by 0.040 g and 0.038 g respectively to 1.0 g of phenyl glycidyl ether. The mixture was deaerated and subjected to bulk polymerization in a sealed tube at 50°C for one hour to determine the conversion ratio from ¹H-NMR spectrum. The results were 75% and 68% respectively. Working Examples 22 - 29 Various sulfonium salts were mixed each by 0.030 g to 1.0 g of phenyl glycidyl ether. The mixture was deaerated, sealed in a tube and subjected to polymerization at 30°C and 60°C for one hour respectively, to determine a conversion ratio from ¹H-NMR spectrum. The results are shown in Table 3. When the compositions thus prepared were left at 5°C for one month, no remarkable viscosity increase was observed. Working Example 30 - 36 Various sulfonium salts were mixed each by 0.030 g to 1.0 g of phenyl glycidyl ether. The mixture was deaerated, sealed in a tube and subjected to photo-induced bulk polymerization for 90 min to determine a conversion ratio from ¹H-NMR spectrum. A 400 W high pressure mercury lamp was used as a light source and a rotary photochemical reactor manufactured by Riko Kagaku Sangyo was used. The temperature for the polymerization was 10°C (under water cooling). The results are shown in Table 4. Working Examples 37 - 38 Procedures were according to the methods of Working Examples 30 - 36 except for setting the polymerization temperature to 20°C. The results are shown in Table 5. Working Example 39 P-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed in an amount of 1 g into 100 g of Epikote 828 (bisphenol-A epoxy resin, manufactured by Yuka Shell Epoxy Co.), which was coated to a thickness of 0.5 mm on a glass plate. Then, it was irradiated by an ultra-violet lamp (80 W/cm, high pressure mercury lamp) at a distance of 10 cm for 1 min. After irradiation, the resin was completely gelled. When the mixture was irradiated by a ultra-violet ray lamp for 30 sec., the viscosity was increased. When it was further treated at 120°C for 5 min, a glass-like curing product was obtained. When the mixture prepared was left at 15°C for one month under light shielding, no viscosity increase was observed. Working Example 40 p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.030 g to 1.0 g of phenyl glycidyl ether. The mixture was deaerated, sealed in a tube and subjected to polymerization at 60°C and 120°C for one hour respectively, to determine a phenyl glycidyl conversion ratio by using ¹H-NMR spectrum. The result was 0% at 60°C and 70% at 120°C. When the thus prepared composition prepared was left at 15°C for one month under light shielding, no further remarkable viscosity increase was observed. Working Example 41 α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.015 g to 0.5 g of 1-phenyl-4-ethyl-2,6,7-trioxabicyclo(2,2,2)octane, deaerated and sealed in a tube. The mixture was subjected to bulk polymerization at 120°C for 20 hrs. After the polymerization, the conversion ratio was confirmed to be 100% from ¹H-NMR spectrum. Then, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then, a hexane insoluble portion was dried to obtain 0.35 g of polymer. Working Example 42 4-(benzoyloxy)phenylmethylsulfonium hexafluoroantimonate was mixed by 0.039 g to 0.5 g of the monomer used in Working Example 41, deaerated and sealed in a tube. The mixture was subjected to bulk polymerization at 80°C for 24 hrs. After the polymerization, the conversion ratio was confirmed to be 100% from ¹H-NMR spectrum. Then, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then a hexane insoluble portion was dried to obtain 0.40 g of a polymer. Working Example 43 The sulfonium salt used in Working Example 42 was mixed by 0.025 g to 0.5 g of 3,9-dibenzyl-1,5,7,11-tetraoxaspiro(5,5)undecane, deaerated and sealed in a tube. The mixture was subjected to bulk polymerization at 80°C for 2 hrs. After the polymerization, the conversion ratio was confirmed to be 99% from ¹H-NMR spectrum. Then, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then, a hexane insoluble portion was dried to obtain 0.45 g of a polymer. Working Example 44 o-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.015 g to 0.5 g of the monomer in Working Example 43, deaerated and sealed in a tube. The mixture was subjected to bulk polymerization at 150°C for 2 hours. After the polymerization, the conversion ratio was confirmed to be 95% from ¹H-NMR spectrum. Then, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then, a hexane insoluble portion was dried to obtain 0.40 g of a polymer. Working Example 45 o-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.010 g to 0.5 g of purified styrene, deaerated and sealed in a tube. Then, polymerization was taken place under stirring at 100°C. After 60 min, the solidified reaction solution was dissolved by 2 ml of carbon tetrachloride and the conversion ratio was confirmed to be 89% from ¹H-NMR spectrum. The product was then poured into methanol to stop the polymerization and deposit the polymer. The purified and dried polymer was white crystals and the yield was 75%. Further, based on GPC (converted as polystyrene), Mn = 3800, Mw / Mn = 1.89. Working Examples 46 - 53 Styrene was polymerized by using various sulfonium salts according to Working Examples 45. The results are shown in Table 6. Working Example 54 Styrene was polymerized at 60°C for 60 min with the same formulation as Working Example 45, but the conversion ratio was 0%. Further, 10 g of purified styrene and 0.30 g of the sulfonium salt used in Working Example 45 were dissolved in 20 ml of chlorobenzene, deaerated and sealed in a tube. When they were left at 10°C for one month under light shielding, polymerization of styrene did not occur. Working Example 55 Benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate was mixed by 0.030 g to 0.5 g of purified styrene, deaerated and sealed in a tube. Then, polymerifzation was taken place under stirring at 60°C. Subsequently, they were treated in the same procedures as thoes in Working Example 45. The conversion ratio was confirmed to be 97%. The polymer was white crystals and the yield was 85%. Further, based on GPC (converted as polystyrene), Mn = 4200, Mw / Mn = 2.01. Working Examples 56 - 61 Styrene was polymerized by using various sulfonium salts according to Working Example 55. The results are shown in Table 7. Working Example 62 Solution polymerization was conducted by using 2 ml of chlorobenzene as a solvent under the conditions as in Working Example 55 to obtain polystyrene. Conversion rate: 99%, yield: 85%, Mn = 3900, Mw / Mn = 1.86. Styrene was polymerized at 10°C for 60 min according to Working Example 55, but the conversion ratio was 0%. Working Example 63 Polymerization was conducted quite in the same manner as in Working Example 43 except for using 0.5 g of n-butyl vinyl ether instead of 0.5 g of styrene, to obtain a polymer of n-butyl vinyl ether. Conversion ratio : 90%, yield: 71%, Mn = 4700, Mw / Mn = 1.91. Working Example 64 10 g of purified styrene and 1.73 g of benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate were dissolved in 20 ml of chlorobenzene, deaerated and sealed in a tube. Then, when they were left at 5°C for one month, polymerization of styrene did not occur. Working Example 65 p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.015 g to 0.5 g of 1-phenyl-4-ethyl-2,6,7-trioxabicyclo(2,2,2)octane, deaerated and sealed in a tube. The mixture was subjected to bulk polymerization at 120°C for 24 hrs. After the polymerization, the conversion ratio was confirmed to be 100% from ¹H-NMR spectrum. Then, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then, a hexane insoluble portion was dried to obtain 0.33 g of a polymer. Working Example 66 p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed by 0.015 g to 0.5 g of 3,9-dibenzyl-1,5,7,11-tetraoxaspiro(5,5)undecane, deaerated and sealed in a tube. The mixture was subjected to bulk polymerization at 130°C for 2 hrs. After the polymerization, the conversion ratio was confirmed to be 96% from ¹H-NMR spectrum. Then, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then a hexane insoluble portion was dried to obtain 0.43 g of a polymer. Working Examples 67 - 68 Compositions comprising each 100 parts by weight of Epikote 828 (bisphenol-A epoxy resin, manufactured by Yuka Shell Epoxy) and 3 parts by weight of various sulfonium salts were prepared. Then, each of the compositions was charged in a glass bottle and heated in an oil bath to conduct a curing test at 150°C and measure the time required for the curing. The results are shown in Table 8. Further, when each of the compositions was left at 15°C for one month, no remarkable viscosity increase was observed. Further, when each of the compositions of was left at 15°C for one month under light sheilding, no remarkable viscosity increase was observed. (Effect of the Invention) As apparent from the synthetic examples and working examples described above, the novel sulfonium compound according to the present invention is effective as an epoxy curing agent requiring high purity and, further, as industrial intermediate material. Further, the specified sulfonium salt according to the present invention is useful as the polymerization initiator for cationically polymerizable material, and the polymer composition containing the same can be polymerized and cured by the polymerization process based on the irradiation of radiation rays such as light and electron beam and/or by heat treatment. In particular, the sulfonium salt of the general formula (II) as defined in claim 5, wherein R₂=R₃=H, R₅ = CH₃, R₆ = ethoxycarbonyl group or benzyloxycarbonyl group and Q = methylbenzyl group shows high activity to heat and a one-component type composition prepared therefrom is polymerizable or curable rapidly at a room temperature or under slight heating, although it should be stored at low temperature. Further, the sulfonium salt of the general formula (II) as defined in claim 5, wherein R₂=R₃=H, R₅ = CH₃, R₆ = H and Q = nitrobenzyl group shows high activity to light and polymerizable or curable only by irradiating radiation rays for a short time and it has excellent storability under light shielding and at a room temperature.

Claims: A sulfonium compound represented by the following general formula (I): where R₁ represents ethoxy group, phenyl group, benzyloxy group, phenoxy group or 9-fluroenylmethoxy group, R₂ and R₃ represent, independently, hydrogen, halogen or C₁ - C₄ alkyl group, R₄ represents hydrogen or methoxy group, R₅ represents C₁ - C₄ alkyl group and X⁻ represents SbF₆, PF₆, AsF₆ or BF₄. A sulfonium compound of claim 1, wherein the sulfonium compound is benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroamtinonate. A sulfonium compound of claim 1, wherein the sulfonium compound is benzyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluoroamtinonate. A sulfonium compound of claim 1, wherein the sulfonium compound is benzyl-4-(phenoxycarbonyloxy)phenylmethylsulfonium. A sulfonium compound represented by the following general formula (II) : where R₂ and R₃ represent, independently, hydrogen, halogen or C₁ - C₄ alkyl group, R₅ represents C₁ - C₄ alkyl group, R₆ represents hydrogen, methyl group, acetyl group, methoxycarbonyl group, ethoxycarbonyl group, chloroacetyl group, trichloroacetyl group, benzyloxy carbonyl group, benzoyl group, phenoxycarbonyl group or 9-fluorenylmethoxycarbonyl group, Q represents chlorobenzyl group, methylbenzyl group, nitrobenzyl group, dinitrobenzyl group, α-naphthylmethyl group or β-naphthylmethyl group and X represents SBF₆, PF₆, AsF₆ or BF₄, providing that when R₆ is hydrogen, methyl group, acetyl group or methoxycarbonyl group, Q does not include chlorobenzyl group or methylbenzyl group. A sulfonium compound of claim 5 wherein the sulfonium compound is p-methylbenzyl-4-(benzyloxycarbonyloxy) phenylmethylsulfonium hexafluoroantimonate. A sulfonium compound of claim 5 wherein the sulfonium compound is p-methylbenzyl-4-(benzyloxycarbonyloxy) phenylmethylsulfonium hexafluorophosphate. A sulfonium compound of claim 5 wherein the sulfonium compound is p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate. A sulfonium compound of claim 5 wherein the sulfonium compound is p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate. A sulfonium compound of claim 5 wherein the sulfonium compound is α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate. A sulfonium compound of claim 5 wherein the sulfonium compound is α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate. A sulfonium compound of claim 5 wherein the sulfonium compound is α-naphthylmethyl-4-(metoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A sulfonium compound of claim 5 wherein the sulfonium compound is α-naphthylmethyl-4-(metoxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate. A sulfonium compound of claim 5 wherein the sulfonium compound is α-naphthylmethyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A sulfonium compound of claim 5 wherein the sulfonium compound is α-naphthylmethyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate. A sulfonium compound of claim 1 wherein the sulfonium compound is benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A polymerization initiator for cationically polymerizable material comprising a sulfonium salt represented by the general formula (I) as defined in claim 1 and/or by the general formula (II) as defined in claim 5. A polymerization initiator as defined in claim 17, wherein sulfonium compound is benzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is benzyl-4-(ethoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is benzyl-4-(phenoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is p-methylbenzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is p-methylbenzyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is α-naphthylmethyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate. A polymerization initiator as defined in claim 18, wherein sulfonium compound is α-naphthylmethyl-4-(methoxycarbonyloxy)phenylmethylsulfonium hexafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is α-naphthylmethyl-4-(methoxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is α-naphthylmethyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium tetrafluoroantimonate. A polymerization initiator as defined in claim 17, wherein sulfonium compound is α-naphthylmethyl-4-(benzyloxycarbonyloxy)phenylmethylsulfonium hexafluorophosphate. A process for polymerizing cationically polymerizable material, which comprises adding one or more of sulfonium salt represented by the general formula (I) as defined in claim 1 and/or by the general formula (II) as defined in claim 5 as a initiator to one or more of cationically polymerizable material and polymerizing them by means of radiation beam and/or heat. A process as defined in claim 31, wherein the cationically polymerizable material is a compound having an epoxy group. A process as defined in claim 31, wherein the cationically polymerizable material is a cationically polymerizable vinyl compound. A process as defined in claim 31, wherein the cationically polymerizable material is a compound having one or more of spiro-ortho ester group, bicyclo-ortho ester group or spiro-ortho carbonate group. A process as defined in claim 31, wherein the radiation rays are ultraviolet rays. A process as defined in claim 31, wherein the polymerization is conducted at a temperature higher than 20°C. A process as defined in claim 31, wherein the radiation rays are sunlight. A process as defined in claim 31, wherein from 0.01 to 20 parts by weight of a sulfonium salt represented by the general formula (I) as defined in claim 1 and/or by the general Formula (II) as defined in claim 5 is added to 100 parts by weight of the cationically polymerizable material.

Inventors: ENDO TAKESHI, HAMAZU FUMIO, KOIZUMI TATSUYA, YAMAMOTO YOSHINARI, ENDO, TAKESHI, HAMAZU, FUMIO, KOIZUMI, TATSUYA, YAMAMOTO, YOSHINARI
Applicants: SANSHIN KAGAKU KOGYO KK, SANSHIN KAGAKU KOGYO CO., LTD.
Application year: 1990
Main classification: C07C381
IPC codes: C08F2, C08G59, C08G85, C07C381