Thermally cationically polymerizable composition, use of same, cationic polymerization method using same, and stabilizer for thermally cationically polymerizable compositions

Abstract

Provided is a thermally cationically polymerizable composition which contains a cationically polymerizable compound (A), a cationic polymerization initiator (B), and a stabilizer (C) that is represented by formula (2), wherein 0.01-20 parts by mass of the cationic polymerization initiator (B) is contained relative to 100 parts by mass of the cationically polymerizable compound (A), and 0.1-50 parts by mass of the stabilizer (C) is contained relative to 100 parts by mass of the cationic polymerization initiator (B). In formula (2), R4, R5 and R6 each independently represent an optionally substituted alkyl group having 1-10 carbon atoms, an optionally substituted aryl group having 6-15 carbon atoms, or an optionally substituted aralkyl group having 7-15 carbon atoms. As a result, the present invention provides a thermally cationically polymerizable composition which has a long pot life, while using a cationic polymerization initiator that has a low polymerization initiation temperature.

Description

Thermally cationically polymerizable composition, its uses, cationic polymerization method using the same, and stabilizer for thermally cationically polymerizable composition

[0001] The present invention relates to a thermally cationically polymerizable composition that undergoes cationic polymerization upon heating, and uses thereof. It also relates to a cationic polymerization method using the thermally cationically polymerizable composition. Furthermore, it relates to a stabilizer for a thermally cationically polymerizable composition.

[0002] A widely used method is to heat a cationically polymerizable composition containing a cationically polymerizable compound and a cationic polymerization initiator to cause cationic polymerization. For example, a cured epoxy resin can be obtained by mixing a liquid epoxy compound with a cationic polymerization initiator and then heating the mixture. Such epoxy resins are widely used in a variety of applications, including bonding and sealing electronic components.

[0003] Onium salts, such as sulfonium salts, are widely used as cationic polymerization initiators. The anion species contained in the onium salt is often an anion species derived from a super strong acid, such as tetrakis(pentafluorophenyl)borate or hexafluoroantimonate, which can lower the initiation temperature of cationic polymerization. Lowering the initiation temperature is preferable from the viewpoints of suppressing shrinkage after curing, protecting electronic components, and reducing energy consumption. On the other hand, cationic polymerizable compositions with low initiation temperatures may undergo cationic polymerization during storage, resulting in a short pot life. Therefore, stabilizers may be used to suppress the progression of cationic polymerization during storage.

[0004] For example, Patent Document 1 describes a method for stabilizing an alicyclic epoxy resin, in which a sulfonium salt containing hexafluoroantimonate, hexafluorophosphate, tetrakis(pentafluorophenyl)borate, or the like as an anion species is blended with a sulfonium salt containing methyl sulfate or ethyl sulfate as an anion species and an aromatic sulfide as a stabilizer to an alicyclic epoxy resin containing a sulfonium salt as an anion species as a polymerization initiator. However, the stabilizing effect is still insufficient, and it has sometimes been difficult to achieve a long pot life.

[0005] On the other hand, Patent Document 2 describes the use of a sulfonium salt containing trifluoromethanesulfonate as an anion species as a polymerization initiator. However, this polymerization initiator has a problem in that it has a high polymerization initiation temperature.

[0006] JP 2019-189698 A JP 2004-217551 A

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a thermally cationically polymerizable composition having a long pot life even when using a cationic polymerization initiator with a low polymerization initiation temperature, and uses thereof. Another object of the present invention is to provide a cationic polymerization method using the thermally cationically polymerizable composition. Another object of the present invention is to provide a stabilizer for a thermally cationically polymerizable composition having a long pot life.

[0008] The above-mentioned problems are solved by providing a thermally cationically polymerizable composition comprising a cationically polymerizable compound (A), a cationic polymerization initiator (B) represented by the following formula (1), and a stabilizer (C) represented by the following formula (2), wherein the composition contains 0.01 to 20 parts by mass of the cationic polymerization initiator (B) per 100 parts by mass of the cationically polymerizable compound (A), and 0.1 to 50 parts by mass of the stabilizer (C) per 100 parts by mass of the cationic polymerization initiator (B):

[0009]

[0010] [In formula (1), R １ , R ２ and R３ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent. X is B(R ｆ １ ) ４ , Sb(R ｆ ２ ) ６ , P(R ｆ ３ ) ６ , N(R ｆ ４ ) ２ , C(R ｆ ５ ) ３ , Al(R ｆ ６ ) ４ or Ga(R ｆ ７ ) ４ and R ｆ １～７ are each independently a fluorine-containing group selected from the group consisting of a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, a perfluoroaryl group having 6 to 10 carbon atoms, a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms, a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and a perfluoroalkoxy group having 1 to 6 carbon atoms. A plurality of perfluoroalkyl groups, perfluoroalkylsulfonyl groups, or perfluoroalkoxy groups may be bonded to form a ring.]

[0011]

[0012] [In formula (2), R ４ , R ５ and R ６ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent.

[0013] In this case, in the formula (1), R ｆ １is a fluorine atom, a perfluoroaryl group having 6 to 10 carbon atoms, a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms, or a perfluoroalkoxy group having 1 to 6 carbon atoms, and R ｆ ２ is a fluorine atom, and R ｆ ３ is a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and R ｆ ４ is a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and R ｆ ５ is a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and R ｆ ６ is a perfluoroalkoxy group having 1 to 6 carbon atoms, and R ｆ ７ is preferably a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, a perfluoroaryl group having 6 to 10 carbon atoms, or a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms.

[0014] In this case, any of the above-mentioned thermally cationically polymerizable compositions may contain 0.001 to 1,000 parts by mass of organic solvent (D) per 100 parts by mass of cationically polymerizable compound (A). Furthermore, the organic solvent (D) may be an organic solvent (d1) capable of dissolving the same mass of cationic polymerization initiator (B) at 25°C, and the composition may contain 10 to 1,000 parts by mass of organic solvent (d1) per 100 parts by mass of cationic polymerization initiator (B).

[0015] In this case, the content of the organic solvent (D) in any of the above-mentioned thermally cationic polymerizable compositions may be less than 10 parts by mass per 100 parts by mass of the cationic polymerization initiator (B). Furthermore, the thermally cationic polymerizable composition may be substantially free of the organic solvent (D).

[0016] The above-mentioned object can also be achieved by providing a cationic polymerization method in which any of the above-mentioned thermally cationically polymerizable compositions is optionally dried and then heated to cause cationic polymerization. The above-mentioned object can also be achieved by providing a cationic polymerization method in which any of the above-mentioned thermally cationically polymerizable compositions is transported outdoors, optionally dried, and then heated to cause cationic polymerization. Furthermore, a preferred embodiment is an adhesive or coating agent comprising the above-mentioned thermally cationically polymerizable composition.

[0017] Furthermore, the above-mentioned problems can also be solved by providing a stabilizer (C) for a thermally cationically polymerizable composition represented by the following formula (2):

[0018]

[0019] [In formula (2), R ４ , R ５ and R ６ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent.

[0020] The thermally cationic polymerizable composition of the present invention has a long pot life despite the use of a cationic polymerization initiator with a low polymerization initiation temperature. Therefore, the thermally cationic polymerizable composition has a high degree of freedom in the preparation, storage, and transportation methods thereof, and the composition exhibits minimal fluctuations in physical properties during the coating and curing processes. Furthermore, the production method of the present invention makes it possible to produce such a thermally cationic polymerizable composition. Furthermore, the use of the stabilizer of the present invention makes it possible to obtain a thermally cationic polymerizable composition with a long pot life.

[0021] 1 shows DSC curves of the thermally cationically polymerizable compositions of Example 1, Example 5, Comparative Example 1, and Comparative Example 6.

[0022] The present invention relates to a thermally cationic polymerizable composition containing a cationic polymerizable compound (A), a cationic polymerization initiator (B), and a stabilizer (C). Specifically, the composition containing the cationic polymerizable compound (A), the cationic polymerization initiator (B), and the stabilizer (C) is used for thermal cationic polymerization. When the thermally cationic polymerizable composition of the present invention is heated, the cationic polymerization initiator (B) thermally decomposes, and the resulting cationic species react with the cationic polymerizable compound (A), initiating a polymerization reaction of the cationic polymerizable compound (A) to produce a polymer. The stabilizer (C) functions to prevent the polymerization reaction from proceeding during storage. Each component is described in detail below.

[0023] The cationically polymerizable compound (A) is not particularly limited as long as it is a compound capable of undergoing cation polymerization. Examples include compounds having a cyclic ether group such as an epoxy group or an oxetane group; a compound having a cyclic thioether group; a vinyl ether group; and a compound having a styryl group. Among these, compounds having a cyclic ether group such as an epoxy group or an oxetane group are preferred from the viewpoints of adhesiveness and chemical resistance. Of these, epoxy compounds having an epoxy group in the molecule are particularly preferred. Furthermore, from the viewpoint of handleability, the cationically polymerizable compound (A) is preferably a liquid at room temperature (25°C). It is also preferable that the molecular weight of the cationically polymerizable compound (A) be 100 to 700.

[0024] The epoxy compound may be a monoepoxy compound having one epoxy group per molecule, or a polyepoxy compound having two or more epoxy groups per molecule, or a mixture of these may be used. Polyepoxy compounds are preferred to increase the hardness and modulus of elasticity of the cured epoxy resin. Polyepoxy compounds typically contain 2 to 7 epoxy groups per molecule. From the standpoint of fluidity and suppression of unreacted epoxy groups, it is preferable for one epoxy molecule to contain two epoxy groups. Furthermore, from the standpoint of cationic polymerizability, alicyclic epoxy compounds are preferred, and compounds containing epoxycyclohexane groups are particularly preferred. Therefore, compounds containing two epoxycyclohexane groups per molecule are particularly preferred, a representative example of which is 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

[0025] The cationic polymerization initiator (B) is a compound represented by the following formula (1): The cationic polymerization initiator (B) is decomposed by heating to form R １ , R ２ or R ３ One of the two groups becomes a cation, and the remaining group forms a sulfide. １ , R ２ or R ３ The cation reacts with the cationically polymerizable compound (A) such as an epoxy group, and cationic polymerization proceeds from there.

[0026]

[0027] In the above formula (1), R １ , R ２ and R ３ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent. １ , R ２ and R ３may be the same or different. The alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, and an isopropyl group. The aryl group preferably has 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms. Specific examples of the aryl group include a 4-hydroxyphenyl group and a 4-acetoxyphenyl group. The aralkyl group preferably has 7 to 11 carbon atoms, more preferably 7 to 9 carbon atoms. Specific examples of the aralkyl group include a benzyl group, a 2-methylbenzyl group, a 4-methylbenzyl group, and a 1-naphthylmethyl group.

[0028] In formula (1), R １ is an aryl group or an alkyl group, and R ２ is an alkyl group or an aralkyl group, and R ３ is preferably an alkyl group.

[0029] In addition, in formula (1), X is B(R ｆ １ ) ４ , Sb(R ｆ ２ ) ６ , P(R ｆ ３ ) ６ , N(R ｆ ４ ) ２ , C(R ｆ ５ ) ３ , Al(R ｆ ６ ) ４ or Ga(R ｆ ７ ) ４ and R ｆ １～７are each independently a fluorine-containing group selected from the group consisting of a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, a perfluoroaryl group having 6 to 10 carbon atoms, a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms, a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and a perfluoroalkoxy group having 1 to 6 carbon atoms. B, Sb, P, N, C, Al, or Ga is selected as the central metal, and R is a strong electron-withdrawing group containing fluorine. ｆ The anion species (X) can be bonded to form a monovalent anion as a whole. － ) Multiple R atoms bonded to the same central element. ｆ The groups may be the same or different, but all of the groups bonded to R ｆ The group must be a perfluoroalkyl group. Multiple perfluoroalkyl groups, perfluoroalkylsulfonyl groups, and perfluoroalkoxy groups bonded to one central element may be bonded to each other to form a perfluoroalkylene group, thereby forming a ring. The conjugate acids (HX) of these anionic species are all stronger acids than trifluoromethanesulfonic acid. Therefore, the pKa values ​​at 25°C of the conjugate acids (HX) of these anionic species are all smaller than that of trifluoromethanesulfonic acid.

[0030] In the formula (1), R ｆ １ is a fluorine atom, a perfluoroaryl group having 6 to 10 carbon atoms, a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms, or a perfluoroalkoxy group having 1 to 6 carbon atoms, and R ｆ ２ is a fluorine atom, and R ｆ ３ is a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and R ｆ ４ is a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and R ｆ ５ is a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and R ｆ ６ is a perfluoroalkoxy group having 1 to 6 carbon atoms, and Rｆ ７ is preferably a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, a perfluoroaryl group having 6 to 10 carbon atoms, or a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms. In this case, a plurality of perfluoroalkyl groups, perfluoroalkylsulfonyl groups, and perfluoroalkoxy groups bonded to one central element may be bonded to each other to form a perfluoroalkylene group, thereby forming a ring.

[0031] In the formula (1), the number of carbon atoms in the perfluoroalkyl group is preferably 1 to 4, more preferably 1 to 3. Specific examples of perfluoroalkyl groups include trifluoromethyl, pentafluoroethyl, heptafluoro-normal-propyl, heptafluoroisopropyl, and nonafluoro-t-butyl groups. The number of carbon atoms in the perfluoroaryl group is preferably 6 to 8, more preferably 6 to 7. Specific examples of perfluoroaryl groups include pentafluorophenyl groups. A perfluoroalkyl-substituted aryl group is a group in which at least a portion of the hydrogen atoms bonded to the aromatic ring of an aryl group are replaced with perfluoroalkyl groups, and hydrogen atoms bonded to the aromatic ring may remain. The number of carbon atoms in the perfluoroalkyl-substituted aryl group is preferably 7 to 12, more preferably 7 to 10. Specific examples of perfluoroalkyl-substituted aryl groups include 3,5-bistrifluoromethylphenyl groups. The number of carbon atoms in the perfluoroalkylsulfonyl group is preferably 1 to 4, more preferably 1 to 3. Specific examples of perfluoroalkylsulfonyl groups include trifluoromethanesulfonyl groups. Also suitable are groups in which two perfluoroalkylsulfonyl groups are bonded together and the two sulfonyl groups are connected via a hexafluoropropylene group. The number of carbon atoms in the perfluoroalkoxy group is preferably 1 to 4. Specific examples of perfluoroalkoxy groups include nonafluoro-t-butyloxy groups.

[0032] In the formula (1), "X －" include anions represented by the following formulae (1x) to (11x). Among these, it is particularly significant to employ the thermally cationically polymerizable composition of the present invention when the cationic polymerization initiator (B) is likely to generate cations and the polymerization initiation temperature is low. From this viewpoint, anions represented by formulae (1x) to (10x) are preferred, anions represented by formulae (1x) to (7x) are more preferred, and anions represented by formulae (1x) to (2x) are even more preferred.

[0033]

[0034] The cationic polymerization initiator (B), which is the compound represented by the formula (1), can be any of various sulfonium salts commercially available as cationic polymerization initiators. Alternatively, the cationic polymerization initiator (B) can be produced by exchanging anions from a commercially available sulfonium salt.

[0035] The stabilizer (C) is a compound represented by the following formula (2).

[0036]

[0037] The anion species in formula (2) is trifluoromethanesulfonate. When the anion species of the stabilizer (C) is trifluoromethanesulfonate, the viscosity increase of the thermally cationic polymerizable composition at low temperatures can be effectively suppressed, the composition can be maintained in a low-viscosity liquid state, and the pot life can be extended. As described in Patent Document 2, the compound represented by formula (2) itself can also function as a cationic polymerization initiator, but when combined with a more active cationic polymerization initiator (B), the viscosity increase of the thermally cationic polymerizable composition can be suppressed for a long period of time during storage at low temperatures.

[0038] In formula (2), R ４ , R ５ and R ６ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent. ４ , R ５ and R６ may be the same or different. The alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, and an isopropyl group. The aryl group preferably has 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms. Specific examples of the aryl group include a 4-hydroxyphenyl group and a 4-acetoxyphenyl group. The aralkyl group preferably has 7 to 11 carbon atoms, more preferably 7 to 9 carbon atoms. Specific examples of the aralkyl group include a benzyl group, a 2-methylbenzyl group, a 4-methylbenzyl group, and a 1-naphthylmethyl group.

[0039] In formula (2), R ４ is an aryl group or an alkyl group, and R ５ is an alkyl group or an aralkyl group, and R ６ is preferably an alkyl group.

[0040] The method for producing the compound represented by formula (2) used as stabilizer (C) is not particularly limited. As described in Patent Document 2, it can be produced by reacting sulfonium chloride with sodium trifluoromethanesulfonate. It can also be produced by reacting sulfonium methyl sulfate with sodium trifluoromethanesulfonate. It can also be produced by reacting sulfide with alkyl trifluoromethanesulfonate.

[0041] The thermally cationically polymerizable composition of the present invention contains 0.01 to 20 parts by mass of a cationic polymerization initiator (B) relative to 100 parts by mass of a cationic polymerizable compound (A), and also contains 0.1 to 50 parts by mass of a stabilizer (C) relative to 100 parts by mass of the cationic polymerization initiator (B).

[0042] If the content of the cationic polymerization initiator (B) per 100 parts by mass of the cationic polymerizable compound (A) is less than 0.01 parts by mass, the polymerization reaction may not proceed sufficiently, resulting in a low hardness of the cured product and an increased amount of unreacted monomer. The content of the cationic polymerization initiator (B) is preferably 0.02 parts by mass or more, more preferably 0.04 parts by mass or more. On the other hand, if the content of the cationic polymerization initiator (B) per 100 parts by mass of the cationic polymerizable compound (A) exceeds 20 parts by mass, the amount of volatile decomposition products increases and the production cost also increases. The content of the cationic polymerization initiator (B) is preferably 5 parts by mass or less, more preferably 2 parts by mass or less.

[0043] Furthermore, if the content of stabilizer (C) per 100 parts by mass of cationic polymerization initiator (B) is less than 0.1 parts by mass, the storage stability of the thermally cationic polymerizable composition will be reduced, resulting in a shortened pot life. The content of stabilizer (C) is preferably 0.2 parts by mass or more, more preferably 0.4 parts by mass or more. On the other hand, if the content of stabilizer (C) per 100 parts by mass of cationic polymerization initiator (B) is more than 50 parts by mass, the polymerization reaction will not proceed sufficiently at relatively low temperatures, which may result in a reduced hardness of the cured product or an increased amount of unreacted monomer. The content of stabilizer (C) is preferably 20 parts by mass or less, more preferably 10 parts by mass or less.

[0044] The thermally cationic polymerizable composition of the present invention may contain an organic solvent (D) in addition to the cationic polymerizable compound (A), the cationic polymerization initiator (B), and the stabilizer (C). The organic solvent (D) may be present in an amount of 0.001 to 1,000 parts by mass per 100 parts by mass of the cationic polymerizable compound (A). The inclusion of an organic solvent may reduce viscosity and improve coatability. Furthermore, the cationic polymerization initiator (B) and the stabilizer (C) may be easily dissolved in the thermally cationic polymerizable composition. When used to adjust viscosity, the organic solvent (D) may be present in an amount of 5 to 500 parts by mass or 10 to 200 parts by mass per 100 parts by mass of the cationic polymerizable compound (A).

[0045] In a preferred embodiment, the organic solvent (D) is an organic solvent (d1) capable of dissolving the same mass of cationic polymerization initiator (B) at 25°C, and the organic solvent (d1) is contained in an amount of 10 to 1,000 parts by mass per 100 parts by mass of cationic polymerization initiator (B). This means that the composition contains a small amount of good solvent necessary to dissolve the cationic polymerization initiator (B). Since the content of organic solvent (d1) in the thermally cationic polymerizable composition is low, energy consumption in the drying step is low and the surrounding environment is less likely to be polluted. If the content is low, the drying step may be omitted to allow cationic polymerization to proceed. The content of organic solvent (d1) per 100 parts by mass of cationic polymerization initiator (B) may be 20 to 500 parts by mass or 50 to 200 parts by mass.

[0046] When preparing a thermally cationic polymerizable composition containing an organic solvent (d1), it is preferable to dissolve the cationic polymerization initiator (B) and stabilizer (C) in the organic solvent (d1) beforehand and then mix them with the cationic polymerizable compound (A). This allows the cationic polymerization initiator (B) and stabilizer (C) to be uniformly mixed in the thermally cationic polymerizable composition. Alternatively, the cationic polymerization initiator (B) can be dissolved in the organic solvent (d1) beforehand and then mixed with the cationic polymerizable compound (A) containing the stabilizer (C). The stabilizer (C) of the present invention has superior solubility in the cationic polymerizable compound (A) compared to the compound described in Patent Document 1 (sulfonium methyl sulfate: Comparative Example 1).

[0047] On the other hand, the content of the organic solvent (D) in the thermally cationic polymerizable composition may be less than 10 parts by mass per 100 parts by mass of the cationic polymerization initiator (B). This can suppress the generation of organic volatile components, and in some cases, the drying step can be omitted. Furthermore, it is preferable that the thermally cationic polymerizable composition is substantially free of the organic solvent (D), which can suppress the generation of organic volatile components and also eliminate the need for the drying step. This is particularly important in the manufacturing process of electronic components and semiconductors, where contamination of the working environment is undesirable.

[0048] In this way, when the thermally cationic polymerizable composition does not substantially contain an organic solvent (D), it is preferable to produce the thermally cationic polymerizable composition by dissolving the stabilizer (C) in the cationic polymerizable compound (A) in advance and then mixing the resulting solution with the cationic polymerization initiator (B). Alternatively, the thermally cationic polymerizable composition can also be produced by adding both the cationic polymerization initiator (B) and the stabilizer (C) to the cationic polymerizable compound (A) and mixing them together. In these cases, it is preferable to use a cationic polymerization initiator (B) that has excellent solubility in organic compounds, and in the formula (1), X is B(R ｆ １ ) ４ It is preferable that the

[0049] The thermally cationic polymerizable composition of the present invention may contain other components in addition to the cationic polymerizable compound (A), cationic polymerization initiator (B), stabilizer (C), and organic solvent (D), as long as the effects of the present invention are not impaired. Various other components, such as fillers, reinforcing fibers, conductive particles, colorants, photopolymerization initiators, UV absorbers, photosensitizers, antioxidants, flame retardants, leveling agents, silane coupling agents, radically polymerizable compounds, (meth)acrylic resins, polyurethane resins, polyamide resins, and polyester resins, can be added depending on the application. Among these, the amount of components that are incorporated as solids and do not dissolve or melt and are not directly involved in the cationic polymerization reaction, such as fillers, fibers, and particles, is not particularly limited and can be adjusted appropriately depending on the application. The amount of such components can be, for example, 0.1 to 1,000 parts by mass per 100 parts by mass of the cationic polymerizable compound (A). Meanwhile, the content of other components that are uniformly mixed with (A), (B), (C), and (D) is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0050] A preferred cationic polymerization method of the present invention is a method in which the thermally cationically polymerizable composition is optionally dried and then heated to cause cationic polymerization. In many cases, the thermally cationically polymerizable composition, which is liquid at room temperature, is heated to cause cationic polymerization (curing reaction) and obtain a product (cured composition). In this case, the thermally cationically polymerizable composition is preferably dried at a temperature of 50°C or less and then heated at 60 to 260°C for 1 to 300 minutes to cause cationic polymerization. A heating temperature of 60°C or higher allows the cationic polymerization initiator (B) to release reactive cations, facilitating the progress of cationic polymerization. The heating temperature is more preferably 80°C or higher, and even more preferably 100°C or higher. The higher the reaction temperature, the faster the reaction rate, allowing cationic polymerization to proceed in a shorter time. On the other hand, curing at high temperatures can cause problems with adhesion due to shrinkage upon cooling after curing, and in applications such as bonding or sealing electronic components or semiconductors, high temperatures may also affect electrical performance. Therefore, the heating temperature is preferably 260°C or less, more preferably 230°C or less, and even more preferably 200°C or less.

[0051] The thermally cationically polymerizable composition of the present invention, which contains the stabilizer (C), has a long pot life because it remains liquid for a long period of time without increasing in viscosity. This allows for a longer shelf life. This point is also demonstrated in the examples of the present application, where it was found that the number of days (pot life) until the viscosity doubled compared to before storage when refrigerated at 5°C was extended by approximately three days, from 4-5 days to 7-8 days, compared to conventional stabilizers. The approximately three-day extension of the refrigerated shelf life is extremely significant in terms of process management. Until now, due to the short pot life, thermally cationically polymerizable compositions were mostly prepared at user factories, where the composition was cured by heating, by blending the cationically polymerizable compound (A), the cationic polymerization initiator (B), and the stabilizer (C). However, with the present invention, pharmaceutical manufacturers can now blend the cationically polymerizable compound (A), the cationic polymerization initiator (B), and the stabilizer (C) to produce a thermally cationically polymerizable composition, transport it outdoors, optionally dry it, and then heat it to allow the cationic polymerization to proceed. This allows pharmaceutical manufacturers to manufacture products in bulk, eliminating the burden of operating and managing mixing equipment for users. While there are no particular limitations on the means of outdoor transportation, refrigerated transportation under temperature control is preferred. The refrigeration temperature is preferably 15°C or lower, and more preferably 10°C or lower. On the other hand, to avoid freezing, it is preferably 0°C or higher.

[0052] Furthermore, it has been revealed that the thermally cationic polymerizable composition of the present invention has a longer pot life, while at the same time, as shown in the DSC curve of the Examples ( FIG. 1 ), the polymerization initiation temperature is lower than that of conventional stabilizers. This has revealed that it is possible to suppress an increase in the polymerization initiation temperature while suppressing unnecessary polymerization reactions at storage temperatures, thereby achieving both long-term storage and low-temperature curing. The thermally cationic polymerizable composition of the present invention preferably has an exothermic onset temperature of 80°C or lower in temperature-rising measurement by DSC (10°C / min). The exothermic onset temperature is more preferably 78°C or lower, and even more preferably 76°C or lower. On the other hand, the exothermic onset temperature is usually 60°C or higher.

[0053] As shown in the DSC curves of the examples (FIG. 1), when no organic solvent (d1) was used (Example 5), the exothermic onset temperature was higher than when organic solvent (d1) was used (Example 1), but the calorific value of the first exothermic peak (first peak) was significantly larger, which is considered to be useful for rapid curing. Moreover, since no organic solvent is used, a drying step is not required and evaporation of the organic solvent (d1) into the working environment can be suppressed, which is useful.

[0054] Generally, the addition of a stabilizer reduces the electrical resistivity of a cured product of a thermally cationic polymerizable composition. However, the electrical resistivity of the cured product of the thermally cationic polymerizable composition of the present invention is less likely to decrease than when a conventional stabilizer is used. Therefore, the composition is suitable for applications requiring high insulating properties. The electrical resistivity of the cured product of the thermally cationic polymerizable composition of the present invention is 3×10 ７ It is preferable that the resistance is Ω·m or more, and 4×10 ７ It is more preferable that the resistivity is Ω·m or more. However, when the organic solvent (d1) is not used (Example 5), the electrical resistivity is lower than when an organic solvent is used and a conventional stabilizer is used. Although this is at a level that does not cause any problems in terms of general insulation, it is preferable to use them depending on the application.

[0055] The applications of such a thermally cationically polymerizable composition are not particularly limited, but it is preferably used as a thermosetting liquid resin composition. The thermally cationically polymerizable composition of the present invention can be cured at a relatively low temperature and has good adhesion to resins, metals, and the like, making it suitable as an adhesive or coating agent. Adhesives can be used to bond multiple components, and include various types of adhesives. For example, compositions containing conductive particles can be used as conductive pastes or anisotropically conductive films (ACFs). Coating agents can be used to cover the surfaces of components, and include various types of coating agents. For example, they can be used as sealing materials, insulating materials, resist materials, and the like. In addition, the thermally cationically polymerizable composition of the present invention is also useful as fiber-reinforced plastics (FRPs) and nanoimprint materials. Because the thermally cationically polymerizable composition of the present invention can be cured at a relatively low temperature, it can suppress thermal damage to electronic components, semiconductors, and the like. Furthermore, it can reduce the amount of volatile organic solvents, making it suitable for applications such as electronic components and semiconductors.

[0056] As explained above, it has been revealed that the thermally cationic polymerizable composition of the present invention, by containing the novel stabilizer (C), has a longer pot life and can suppress an increase in the heat generation initiation temperature compared to conventional stabilizers. The use of the compound represented by formula (2) as a stabilizer for a thermally cationic polymerizable composition is itself novel. Therefore, the object of the present invention can also be achieved by providing the stabilizer (C) for a thermally cationic polymerizable composition represented by formula (2). In other words, the present invention provides a novel and useful stabilizer.

[0057] Example 1 [Synthesis of stabilizer] 6.66 g (25 mmol) of 4-hydroxyphenyldimethylsulfonium methyl sulfate ("San-Aid SI-S" manufactured by Sanshin Chemical Industry Co., Ltd.: formula (2e) in Comparative Example 1), 4.3 g (25 mmol) of sodium trifluoromethanesulfonate, and 85 mL of ethanol were placed in a 200 mL four-neck flask and stirred at 25°C for 24 hours. The reaction solution was filtered and the obtained filtrate was concentrated, and then 100 mL of hexane was added to the concentrate and stirred. The resulting precipitate was filtered to obtain white crystalline 4-hydroxyphenyldimethylsulfonium trifluoromethanesulfonate (formula (2a) below) in a yield of 95%. [ 1 H-NMR (400MHz, CD ３ CN): δ 8.50 (s, 1H), 7.82 (d, 2H), 7.11 (d, 2H), 3.17 (s, 6H)]. The stabilizer (2a) is summarized in Table 1.

[0058]

[0059] [Solubility of Stabilizer] At 25°C, 1 g of stabilizer (2a) was placed in a 30 mL screw tube, and 1 g of solvent was added thereto and mixed using a planetary centrifugal mixer "ARE-310" manufactured by Thinky Corporation. The mass Ws (g) of solvent required to completely dissolve the stabilizer (2a) was measured. The solubility (S), which is the mass of solute that can be dissolved in 100 g of solvent, was calculated according to the following formula. The solubility when dissolved in 1 g of solvent is indicated as "≧100", and the solubility when not completely dissolved even after adding 100 g of solvent is indicated as "<1". Water, propylene carbonate (PC), methyl isobutyl ketone (MIBK), and propylene glycol monomethyl ether acetate (PGMAc) were used as solvents. The cationically polymerizable compound 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate "Celloxide 2021P" was also subjected to the same test to evaluate the solubility of the stabilizer. As a result, the solubility of stabilizer (2a) was 100 [g / 100g-solv.] or more in water, PC, MIBK, and PGMAc, and 25 [g / 100g-solv.] in "Celloxide 2021P." S [g / 100g-solv.] = 1 / (Ws / 100)

[0060] [Preparation of Thermally Cationic Polymerizable Composition] A thermally cationic polymerizable composition was prepared using the stabilizer (2a) obtained in this manner. First, 20.0 mg of 4-acetoxyphenylbenzylmethylsulfonium tetrakis(pentafluorophenyl)borate (Sanshin Chemical Industry Co., Ltd.'s "Sanade SI-B3A": Formula (1a) below) as a polymerization initiator and 0.2 mg of stabilizer (2a) were placed in a 10 mL screw tube, and 20.0 mg of propylene carbonate as a solvent was added and completely dissolved to prepare an initiator solution. 20.1 mg of the prepared initiator solution was placed in a 30 mL screw tube, and 10 g of 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (Daicel Corporation's "Celloxide 2021P": Formula (3a) below) as a cationically polymerizable compound was added. The mixture was immediately mixed using a planetary centrifugal mixer "ARE-310" to prepare a thermally cationic polymerizable composition. The thermally cationically polymerizable compositions obtained are summarized in Table 2.

[0061]

[0062]

[0063] [Storage stability] The prepared thermally cationically polymerizable composition was placed in a 30 mL screw tube and allowed to stand in a constant temperature bath at 5°C, and the viscosity of the sample was measured at 25°C every few days. For the viscosity measurement, an E-type viscometer "TV-100EH" manufactured by Toki Sangyo Co., Ltd. was used. The pot life was defined as 7 days, which is the number of days until the viscosity doubled compared to before the start of storage.

[0064] [Thermosetting] 5.0 mg of the prepared thermally cationically polymerizable composition (thermosetting composition) was weighed out and heated from 30°C to 310°C at a rate of 10°C / min in a nitrogen gas flow of 40 mL / min using a Hitachi High-Technologies Corporation differential scanning calorimeter "X-DSC7000." A DSC curve was obtained. The obtained DSC curve is shown in Figure 1. In the DSC curve, exotherm was observed in the range of about 70 to about 250°C, and three exothermic peaks were observed. The first (lowest temperature) exothermic peak was designated as the first exothermic peak. The first exothermic peak temperature was 81°C, and the heat generation amount (peak height) of the first exothermic peak was 8 mW. The exothermic onset temperature was 72°C, which is the temperature at the intersection of the tangent to the low-temperature inflection point of the first exothermic peak and the baseline.

[0065] [Electrical Resistivity] A sample was prepared by applying a thermally cationically polymerizable composition to the electrode surface of a polyimide resin film having a tin-plated copper comb electrode formed thereon, and the sample was set in a dielectric analyzer "LT-451" manufactured by Syscom Co., Ltd. The sample was maintained at a temperature of 70°C while an AC voltage of 1 kHz and 1 V was applied, and the electrical resistivity was monitored. After 2 hours, the thermally cationically polymerizable composition had cured, and the electrical resistivity of the cured product was 5.1 x 10 ７ The thermally cationically polymerizable composition after curing was firmly adhered to both the metal surface of the interdigital electrode and the resin surface of the substrate.

[0066] Example 2: A 200 mL four-neck flask was charged with 3.51 g (25 mmol) of 4-(methylthio)phenol, 3.85 g (25 mmol) of diethyl sulfate, and 25 mL of acetonitrile, and the mixture was stirred at 40°C for 24 hours. The resulting reaction solution was concentrated to obtain the intermediate, 4-hydroxyphenylmethylethylsulfonium ethyl sulfate. 4.3 g (25 mmol) of sodium trifluoromethanesulfonate and 85 mL of ethanol were added to this intermediate, and the mixture was stirred at 25°C for 24 hours. The reaction solution was filtered, and the obtained filtrate was concentrated. 100 mL of hexane was then added to the concentrate, and the mixture was stirred. The resulting precipitate was filtered, yielding a transparent liquid, 4-hydroxyphenylmethylethylsulfonium trifluoromethanesulfonate (formula (2b) below), in an 84% yield. Using the resulting stabilizer (2b), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. [ 1 H-NMR (400MHz, CD ３ CN): δ 9.62 (s, 1H), 7.73 (d, 2H), 7.10 (d, 2H), 3.96 (q, 2H), 3.13 (s, 3H), 1.16 (t, 3H)]. The stabilizer (2b) and the thermally cationically polymerizable composition obtained were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0067]

[0068] Example 3: 3.51 g (25 mmol) of 4-(methylthio)phenol, 3.16 g (25 mmol) of benzyl chloride, and 25 mL of acetonitrile were placed in a 200 mL four-neck flask and stirred at 40°C for 24 hours. The resulting reaction solution was concentrated to obtain the intermediate, 4-hydroxyphenylmethylbenzylsulfonium chloride. Except for using this intermediate, the same procedure as in Example 2 was followed to obtain white crystalline 4-hydroxyphenylmethylbenzylsulfonium trifluoromethanesulfonate (formula (2c) below) in a yield of 96%. 1 H-NMR (400MHz, CD ３CN): δ 6.72-7.40 (m, 10H), 4.43 (q, 2H), 2.79 (s, 3H)]. Using the obtained stabilizer (2c), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. The obtained stabilizer (2c) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0069]

[0070] Example 4: 3.46 g (25 mmol) of benzyl methyl sulfide, 3.15 g (25 mmol) of dimethyl sulfate, and 25 mL of acetonitrile were placed in a 200 mL four-neck flask and stirred at 40°C for 24 hours. The resulting reaction solution was concentrated to obtain the intermediate, benzyl dimethyl sulfonium methyl sulfate. A transparent liquid, benzyl dimethyl sulfonium trifluoromethanesulfonate (formula (2d) below), was obtained in a yield of 93% in the same manner as in Example 2, except that this intermediate was used. 1 H-NMR (400MHz, CD ３ CN): δ 7.15-7.50 (m, 5H), 4.00 (s, 2H), 2.80 (s, 6H)]. Using the obtained stabilizer (2d), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. The obtained stabilizer (2d) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0071]

[0072] Example 5: 0.2 mg of the stabilizer (2a) obtained in Example 1 was placed in a 30 mL screw tube, and 20 g of the cationically polymerizable compound "Celloxide 2021P" was added thereto. The mixture was mixed using a planetary centrifugal mixer "ARE-310" to achieve complete dissolution. Subsequently, 20.0 mg of "Sanaid SI-B3A" (1a) was added as a polymerization initiator, and the mixture was further mixed using the planetary centrifugal mixer to prepare a thermally cationically polymerizable composition that did not contain the solvent propylene carbonate. The obtained thermally cationically polymerizable composition was evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2 and FIG. 1.

[0073] Comparative Example 1 A thermally cationically polymerizable composition was prepared in the same manner as in Example 1, except that 0.2 mg of 4-hydroxyphenyldimethylsulfonium methyl sulfate ("San-Aid SI-S" manufactured by Sanshin Chemical Industry Co., Ltd.: formula (2e) below) was used as the stabilizer. The stabilizer (2e) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2 and FIG. 1. Note that when a thermally cationically polymerizable composition was prepared without using the solvent (PC) in the same manner as in Example 5, the compound (2e) did not completely dissolve.

[0074]

[0075] Comparative Example 2 6.66 g (25 mmol) of 4-hydroxyphenyldimethylsulfonium methylsulfate ("San-Aid SI-S" manufactured by Sanshin Chemical Industry Co., Ltd.: formula (2e) in Comparative Example 1), 2.95 g (25 mmol) of sodium methyl sulfite, and 85 mL of ethanol were placed in a 200 mL four-neck flask and stirred at 25°C for 24 hours. The reaction solution was filtered and the obtained filtrate was concentrated, after which 100 mL of hexane was added to the concentrate and stirred. The resulting precipitate was filtered to obtain 4-hydroxyphenyldimethylsulfonium methylsulfite (formula (2f) below) in a yield of 91%. [ 1 H-NMR (400MHz, CD ３ OD): δ 7.87 (d, 2H), 7.12 (d, 2H), 5.18 (s, 1H), 3.26 (s, 6H), 2.71 (s, 3H). Using the obtained stabilizer (2f), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. The obtained stabilizer (2f) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0076]

[0077] Comparative Example 3 4-hydroxyphenyldimethylsulfonium dimethylphosphate (formula (2g) below) was obtained in a yield of 85% in the same manner as in Comparative Example 2, except that 2.95 g of sodium methyl sulfite was changed to 3.7 g of sodium dimethyl phosphate. 1 H-NMR (400MHz, CD ３OD): δ 7.89 (d, 2H), 7.15 (d, 2H), 5.90 (s, 1H), 3.59 (d, 6H), 3.29 (s, 6H). Using the resulting stabilizer (2 g), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. The resulting stabilizer (2 g) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0078]

[0079] Comparative Example 4 4-Hydroxyphenyldimethylsulfonium paratoluenesulfonate (formula (2h) below) was obtained in a yield of 89% in the same manner as in Comparative Example 2, except that 2.95 g of sodium methyl sulfite was changed to 4.86 g of sodium p-toluenesulfonate. 1 H-NMR (400MHz, CD ３ CN): δ 9.02 (s, 1H), 7.69 (d, 4H), 7.15 (d, 2H), 7.05 (d, 2H), 3.09 (s, 6H), 2.26 (s, 3H). Using the obtained stabilizer (2h), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. The obtained stabilizer (2h) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0080]

[0081] Comparative Example 5 4-hydroxyphenyldimethylsulfonium methanesulfonate (formula (2i) below) was obtained in a yield of 94% in the same manner as in Comparative Example 2, except that 2.95 g of sodium methyl sulfite was changed to 2.95 g of sodium methanesulfonate. 1 H-NMR (400MHz, CD ３ CN): δ 7.75 (d, 2H), 7.15 (d, 2H), 3.28 (s, 1H), 3.09 (s, 6H), 2.76 (s, 3H). Using the obtained stabilizer (2i), a thermally cationically polymerizable composition was prepared in the same manner as in Example 1. The obtained stabilizer (2i) and the thermally cationically polymerizable composition were evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

[0082]

[0083] Comparative Example 6 A thermally cationically polymerizable composition was prepared without using a stabilizer. First, 20.0 mg of "Sanaid SI-B3A" (formula (1a) in Example 1) as a polymerization initiator and 20.0 mg of propylene carbonate as a solvent were added to a 10 mL screw tube and completely dissolved to prepare an initiator solution. A thermally cationically polymerizable composition was prepared in the same manner as in Example 1, except that the initiator solution thus obtained was used. The obtained thermally cationically polymerizable composition was evaluated in the same manner as in Example 1, and the results are shown in Tables 1 and 2 and FIG. 1.

[0084]

[0085]

Claims

1. A thermally cationic polymerizable composition comprising a cationic polymerizable compound (A), a cationic polymerization initiator (B) represented by the following formula (1), and a stabilizer (C) represented by the following formula (2), wherein the thermally cationic polymerizable composition comprises 0.01 to 20 parts by mass of the cationic polymerization initiator (B) per 100 parts by mass of the cationic polymerizable compound (A), and comprises 0.1 to 50 parts by mass of the stabilizer (C) per 100 parts by mass of the cationic polymerization initiator (B). [In formula (1), R １ , R ２ and R ３ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent. ｆ １ ) ４ , Sb(R ｆ ２ ) ６ , P(R ｆ ３ ) ６ , N(R ｆ ４ ) ２ , C(R ｆ ５ ) ３ , Al(R ｆ ６ ) ４ Or Ga(R ｆ ７ ) ４ and R ｆ １～７ are each independently a fluorine-containing group selected from the group consisting of a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, a perfluoroaryl group having 6 to 10 carbon atoms, a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms, a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms, and a perfluoroalkoxy group having 1 to 6 carbon atoms. A plurality of perfluoroalkyl groups, perfluoroalkylsulfonyl groups, or perfluoroalkoxy groups may be bonded to form a ring.] [In formula (2), R ４ , R ５ and R ６ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent.

2. In the formula (1), R ｆ １ is a fluorine atom, a perfluoroaryl group having 6 to 10 carbon atoms, a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms, or a perfluoroalkoxy group having 1 to 6 carbon atoms; R ｆ ２ is a fluorine atom, R ｆ ３ is a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms; R ｆ ４ is a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms; R ｆ ５ is a perfluoroalkylsulfonyl group having 1 to 6 carbon atoms; R ｆ ６ is a perfluoroalkoxy group having 1 to 6 carbon atoms, and R ｆ ７ is a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, a perfluoroaryl group having 6 to 10 carbon atoms, or a perfluoroalkyl-substituted aryl group having 7 to 14 carbon atoms.

3. The thermally cationically polymerizable composition according to claim 1 or 2, which contains 0.001 to 1,000 parts by mass of the organic solvent (D) per 100 parts by mass of the cationically polymerizable compound (A).

4. The thermally cationic polymerizable composition according to claim 3, wherein the organic solvent (D) is an organic solvent (d1) capable of dissolving the same mass of the cationic polymerization initiator (B) at 25°C, and the organic solvent (d1) is contained in an amount of 10 to 1,000 parts by mass per 100 parts by mass of the cationic polymerization initiator (B).

5. A thermally cationically polymerizable composition according to claim 1 or 2, wherein the content of the organic solvent (D) is less than 10 parts by mass per 100 parts by mass of the cationic polymerization initiator (B).

6. The thermally cationically polymerizable composition according to claim 5, which is substantially free of an organic solvent (D).

7. A method for cationic polymerization, comprising heating the thermally cationic polymerizable composition according to any one of claims 1 to 6, optionally after drying, to cause cationic polymerization.

8. A method for cationic polymerization, comprising transporting the thermally cationic polymerizable composition according to any one of claims 1 to 6 outdoors, optionally drying the composition, and then heating the composition to cause cationic polymerization to proceed.

9. An adhesive or coating agent comprising the thermally cationic polymerizable composition according to any one of claims 1 to 6.

10. A stabilizer (C) for a thermally polymerizable cationic composition, represented by the following formula (2): [In formula (2), R ４ , R ５ and R ６ are each independently an alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, or an aralkyl group having 7 to 15 carbon atoms which may have a substituent.

Images