CN114761460A

CN114761460A - Cation-curable composition, cured product, and bonded body

Info

Publication number: CN114761460A
Application number: CN202080084621.6A
Authority: CN
Inventors: 松冈宽人
Original assignee: ThreeBond Co Ltd
Current assignee: ThreeBond Co Ltd
Priority date: 2019-12-11
Filing date: 2020-11-09
Publication date: 2022-07-15
Anticipated expiration: 2040-11-09
Also published as: JPWO2021117396A1; CN114761460B; TW202122444A; WO2021117396A1

Abstract

The purpose of the present invention is to provide a cationically curable composition which has excellent adhesion to aluminum die castings, PPS, and the like while maintaining photocurability and low-temperature curability. The cationic curable composition of the present invention contains the following components (A) to (E), and contains 12 to 100 parts by mass of component (E) per 100 parts by mass of the total amount of components (A) and (B). (A) The components: an aromatic epoxy resin; (B) the components: at least one of a hydrogenated epoxy resin (B1) and an alicyclic epoxy resin (B2); (C) the components: a photo cation polymerization initiator; (D) the components: a thermal cationic polymerization initiator; (E) the components: a polycaprolactone polyol having 3 or more (including 3) functional hydroxyl groups and having a molecular weight of 1700 or less (including 1700).

Description

Cation-curable composition, cured product, and bonded body

Technical Field

The present invention relates to a cationically curable composition, a cured product, and a bonded body.

Background

Conventionally, a cationically curable composition containing an epoxy resin or the like has been used in various applications such as adhesives, sealants, potting agents, coating agents, and conductive adhesives because of its excellent adhesiveness, sealing properties, high strength, heat resistance, electrical characteristics, and chemical resistance. Further, the object is wide, and particularly, in electronic/electric machines, the liquid crystal display, the organic electroluminescence, the flat panel display such as a touch panel, the hard disk device, the mobile terminal device, the semiconductor, the camera module, and the like.

Jp 59-204676 a discloses a cationically photopolymerizable resin composition comprising an epoxy resin and a cationic photopolymerization initiator which generates a lewis acid by irradiation with active energy rays such as ultraviolet rays. Further, international publication No. 2005/059002 (corresponding to U.S. patent application publication No. 2007/0208106) discloses a cationically curable epoxy resin composition containing an epoxy resin component, a photocationic polymerization initiator, a thermal cationic polymerization initiator, and a filler.

Disclosure of Invention

However, the cationically polymerizable resin composition disclosed in JP-A-59-204676 has a problem that it is impossible to cure the resin composition where it is not exposed to light. In order to solve this problem, when heating to about 200 ℃, an acid can be generated from a cationic initiator and cured, but since the curing conditions are high temperature, it is difficult to apply the composition to applications such as liquid crystal display devices and organic EL devices, which are easily deteriorated by heat. On the other hand, the cationically curable epoxy resin composition disclosed in international publication No. 2005/059002 (corresponding to U.S. patent application publication No. 2007/0208106) has poor adhesion to electronic/electric component modules, aluminum die castings, polyphenylene sulfide (PPS), and the like, which are generally used as materials for automobile parts, although a thermal cationic polymerization initiator is improved to allow curing at a relatively low temperature in unexposed areas.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a cationically curable composition having excellent adhesion to an aluminum die casting, PPS, or the like, while maintaining photocurability and low-temperature curability.

The present invention overcomes the above-described conventional problems, and has the following points.

[1] A cationically curable composition comprising the following components (A) to (E) and 12 to 100 parts by mass of component (E) per 100 parts by mass of the total amount of components (A) and (B),

(A) the components: aromatic epoxy resin

(B) The components: at least one member selected from the group consisting of hydrogenated epoxy resins (B1) and alicyclic epoxy resins (B2)

(C) The components: photo cation polymerization initiator

(D) The components: thermal cationic polymerization initiator

(E) The components: a polycaprolactone polyol having 3 or more (including 3) functional hydroxyl groups and having a molecular weight of 1700 or less (including 1700).

[2] The cationically curable composition according to [1], wherein the content of the component (B) is 10 to 80 parts by mass based on 100 parts by mass of the total amount of the component (A) and the component (B).

[3] The cationic curable composition according to [1] or [2], wherein the component (D) is at least 1 selected from the group consisting of an aromatic sulfonium thermal cationic polymerization initiator, an aromatic iodonium thermal cationic polymerization initiator, and a thermal cationic polymerization initiator containing an amine salt.

[4] The cationically curable composition according to any one of the above [1] to [3], wherein the component (D) contains a thermal cationic polymerization initiator having a salt of a quaternary ammonium cation.

[5] The cationic curable composition according to any one of [1] to [4], wherein component (C) comprises at least one of an aromatic iodonium salt and an aromatic sulfonium salt.

[6] The cationically curable composition according to any one of the above [1] to [5], wherein the component (A) contains at least 1 selected from the group consisting of an aromatic bisphenol A type epoxy resin, an aromatic bisphenol F type epoxy resin, and an aromatic bisphenol E type epoxy resin.

[7] The cationically curable composition according to any one of the above [1] to [6], wherein the component (B) contains only one of the hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2).

[8] The cationically curable composition according to any one of the above [1] to [6], wherein the component (B) includes a hydrogenated epoxy resin (B1) and an alicyclic epoxy resin (B2).

[9] The cationically curable composition according to any one of the above [1] to [8], which is used for an adhesive.

[10] The cationically curable composition according to any one of the above [1] to [8], which is used for an adhesive when an adherend is an aluminum die casting or PPS.

[11] A cured product of the cationically curable composition according to any one of [1] to [10 ].

[12] A bonded body obtained by bonding an adherend with the use of the cationic curable composition according to any one of [1] to [10 ].

Detailed Description

The present invention will be described in detail below. In the present specification, "X to Y" are used to indicate numerical values (X and Y) described before and after the description as a lower limit value and an upper limit value, and mean "X is equal to or greater than (including X) and equal to or less than Y (including Y)".

< cationically curable composition >

The components (a) to (E) contained in the cationic curable composition of the invention are as follows.

(A) The components: aromatic epoxy resin

(B) The components: at least one of hydrogenated epoxy resin (B1) and alicyclic epoxy resin (B2)

(C) The components: photo cation polymerization initiator

(D) The components: thermal cationic polymerization initiator

(E) The components: a polycaprolactone polyol having 3 or more (including 3) functional hydroxyl groups and having a molecular weight of 1500 or less (including 1500).

< ingredient (A) >

The aromatic epoxy resin as the component (a) in the present invention is a compound which initiates a crosslinking reaction with a cationic species generated by a cationic polymerization initiator by irradiation with active energy rays or heating. (A) The kind of the component is not particularly limited, and examples thereof include: aromatic bisphenol a-type epoxy resins, aromatic bisphenol F-type epoxy resins, aromatic bisphenol E-type epoxy resins, diglycidyl ethers of aromatic bisphenol a-type alkylene oxide adducts, diglycidyl ethers of aromatic bisphenol F-type alkylene oxide adducts, diglycidyl ethers of aromatic bisphenol E-type alkylene oxide adducts, aromatic novolak-type epoxy resins, urethane-modified aromatic epoxy resins, nitrogen-containing aromatic epoxy resins, rubber-modified aromatic epoxy resins containing polybutadiene or acrylonitrile-butadiene rubber (NBR), and the like. Among these, from the viewpoint of obtaining a cationically curable composition having excellent adhesion to an aluminum die casting, PPS, or the like, an aromatic bisphenol a-type epoxy resin, an aromatic bisphenol F-type epoxy resin, or an aromatic bisphenol E-type epoxy resin is preferable.

Examples of commercially available products of the aromatic epoxy resin include: jER (registered trademark, the same applies hereinafter) 825, jER827, jER828EL, jER828US, jER828XA, jER834, jER806H, jER807ST, jER604, and jER630 (manufactured by Mitsubishi chemical corporation); EPICLON (registered trademark, the same shall apply hereinafter) 830, EPICLONEXA-830LVP, EPICLONEXA-850CRP, EPICLON835LV, EPICLONHP4032D, EPICLON703, EPICLON720, EPICLON726, EPICLONHP820, EPICLONN-660, EPICLONN-680, EPICLON-695, EPICLONN-655-EXP-S, EPICLONN-665-EXP-S, EPICLONN-685-EXP-S, EPICLONN-740, EPICLONN-775, and EPICLONN-865 (manufactured by DIC corporation, supra); ADEKARESIN (registered trademark, the same shall apply hereinafter) EP4100, ADEKARESINEP4000, ADEKARESINEP4080, ADEKARESINEP4085, ADEKARESINEP4088, ADEKARESINEP4100HF, ADEKARESINEP4901HF, ADEKARESINEP4000S, ADEKARESINEP4000L, ADEKARESINEP4003S, ADEKARESINEP4010S, ADEKARESINEP4010L (manufactured by ADEKA corporation); DENACOL (registered trademark, the same applies hereinafter) EX-614B, DENACOLEX-411, DENACOLEX-314, DENACOLEX-201, DENACOLEX-212, DENACOLEX-252 (manufactured by Nagase Chemte X, Inc., above), and the like, but is not limited thereto. These aromatic epoxy resins may be used alone or in combination of 2 or more (including 2).

< ingredient (B) >

The component (B) of the present invention is at least one selected from the group consisting of a hydrogenated epoxy resin (B1) and an alicyclic epoxy resin (B2), and is a compound that initiates a crosslinking reaction by a cationic species generated by a cationic polymerization initiator by irradiation or heating with an active energy ray. The hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2) may be used alone, or the hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2) may be used in combination. The hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2) are preferable because they have more excellent adhesion to an aluminum die casting when used alone. When these are used in combination, the balance between photocurability and low-temperature curability is excellent, and appropriate adhesiveness to each member can be maintained, so that these are preferable. The hydrogenated epoxy resin (B1) is a compound having no unsaturated bond, which is obtained by core-hydrogenating an aromatic ring of an aromatic epoxy resin.

The type of the hydrogenated epoxy resin (B1) is not particularly limited, and examples thereof include: hydrogenated bisphenol a type epoxy resins, hydrogenated bisphenol F type epoxy resins, hydrogenated bisphenol E type epoxy resins, diglycidyl ethers of hydrogenated bisphenol a type alkylene oxide adducts, diglycidyl ethers of hydrogenated bisphenol F type alkylene oxide adducts, hydrogenated phenol novolac epoxy resins, hydrogenated cresol novolac epoxy resins, and the like. Among these, hydrogenated bisphenol a type epoxy resins, hydrogenated bisphenol F type epoxy resins, or hydrogenated bisphenol E type epoxy resins are preferable from the viewpoint of obtaining a cationically curable composition having excellent adhesion to aluminum die castings, PPS, or the like.

Examples of commercially available products of hydrogenated bisphenol a epoxy resins include: jERYX-8000, jERYX-8034 (manufactured by Mitsubishi chemical corporation, supra); EPICLONEXA-7015 (available from DIC corporation); ST-3000 (Nichiku chemical Co., Ltd.); RIKARESINHBE-100 (manufactured by NINGRINII CHEMICAL CO., LTD.); DENACOLEX-252 (NagaseChemteX) and the like. Further, as a commercially available product of the hydrogenated bisphenol F type epoxy resin, for example: YL-6753 (manufactured by Mitsubishi chemical corporation), and the like.

Examples of the alicyclic epoxy resin (B2) include compounds having a functional group represented by the following formula (1). More specific examples are not particularly limited, and examples thereof include: 3, 4-epoxycyclohexylmethyl (3',4' -epoxy group) cyclohexanecarboxylate, epsilon-caprolactone-modified 3',4' -epoxycyclohexylmethyl, 3, 4-epoxycyclohexanecarboxylate, bis (3, 4-epoxycyclohexyl) adipate, 1, 2-epoxy-4-vinylcyclohexane, 1, 4-cyclohexanedimethanol diglycidyl ether, epoxyethyldivinylcyclohexane, diepoxyvinylcyclohexane, 1,2, 4-triepoxyethylcyclohexane, limonene dioxide, alicyclic epoxy group-containing siloxane oligomer, and the like. Among these, from the viewpoint of obtaining a cationically curable composition having excellent adhesion to aluminum die castings, PPS, and the like, 3, 4-epoxycyclohexylmethyl (3',4' -epoxy) cyclohexanecarboxylate, epsilon-caprolactone-modified 3',4' -epoxycyclohexylmethyl, 3, 4-epoxycyclohexanecarboxylate, bis (3, 4-epoxycyclohexyl) adipate, 1, 2-epoxy-4-vinylcyclohexane, or 1, 4-cyclohexanedimethanol diglycidyl ether is preferable.

The commercially available product of the alicyclic epoxy resin (B2) is not particularly limited, and examples thereof include: CELLOXIDE (registered trademark) 2081(3',4' -epoxycyclohexylmethyl 3, 4-epoxycyclohexanecarboxylate), CELLOXIDE (registered trademark) 2021P (3',4' -epoxycyclohexylmethyl 3, 4-epoxycyclohexanecarboxylate), CELLOXIDE (registered trademark) 2000(1, 2-epoxy-4-vinylcyclohexane), CELLOXIDE (registered trademark) 3000 (1-methyl-4- (2-methylepoxyethyl) -7-oxabicyclo [4.1.0] heptane), and EHPE3150 (1, 2-epoxy-4- (2-epoxyethyl) cyclohexane adduct of 2, 2-bis (hydroxymethyl) -1-butanol) (manufactured by Daicel corporation, supra); TTA21 (manufactured by shoyuetake chemical corporation); x-40-2670, X-22-169AS, X-22-169B (manufactured by shin-Etsu chemical Co., Ltd.) and the like, but are not limited thereto.

(B) The amount of the component (B) to be added is not particularly limited, but is preferably 10 to 95 parts by mass, more preferably 20 to 90 parts by mass, and still more preferably 30 to 85 parts by mass, based on 100 parts by mass of the total amount of the component (A) and the component (B). The amount of the hydrogenated epoxy resin of component (B) to be added is not particularly limited, but is preferably 50 to 700 parts by mass, more preferably 100 to 600 parts by mass, and still more preferably 150 to 550 parts by mass, based on 100 parts by mass of component (A). The amount of the alicyclic epoxy resin of component (B) added is not particularly limited, but is preferably in the range of 20 to 300 parts by mass, more preferably in the range of 50 to 250 parts by mass, and still more preferably in the range of 70 to 200 parts by mass, based on 100 parts by mass of component (a). When the amount of the component (B) is within the above range, a cationically curable composition having more excellent adhesion to an aluminum die casting, PPS, or the like can be provided.

When the hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2) are used together as the component (B), the amount of the alicyclic epoxy resin (B2) used is preferably 10 to 300 parts by mass, more preferably 30 to 150 parts by mass, and still more preferably 40 to 100 parts by mass, based on 100 parts by mass of the hydrogenated epoxy resin (B1). When the hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2) are used together as the component (B), the ratio of the component (a) to the component (B) is as described above. (B1) When the amount of the component (B2) and the component (B2) is within the above range, the balance between the photocurability and low-temperature curability is good, and the proper adhesiveness to various members can be maintained.

< ingredient (C) >

The component (C) of the present invention is a compound which is a photo cation polymerization initiator and generates a cation species by irradiation of an active energy ray. The type of component (C) is not particularly limited, and examples thereof include: an onium salt such as an aromatic sulfonium salt or an aromatic iodonium salt. (C) The components can be used alone, or in combination of 2 or more (including 2). Further, a cationic polymerization initiator having activity to both active energy rays and heat is considered as the component (C) in the present invention.

Examples of the aromatic iodonium salt include: the 2 groups bound to the iodine atom are iodonium ion-containing salts of aryl groups. More specifically, examples thereof include: iodonium tetrakis (pentafluorophenyl) borate, a diphenyliodonium hexafluorophosphate, a diphenyliodonium hexafluoroantimonate, a bis (4-nonylphenyl) iodonium hexafluorophosphate, a 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate, and the like.

Examples of commercially available products of the above aromatic iodonium salt include: omnicat (registered trademark) 250 (manufactured by igmesensbv corporation); BluesilPI2074 (4-methylphenyl-4- (1-methylethyl) phenyliodonium-tetrakis (pentafluorophenyl) borate, manufactured by Rhodia corporation); b2380 (bis (4-tertiary butylphenyl) iodonium hexafluorophosphate), B2381, D2238, D2248, D2253, and I0591 (manufactured by Tokyo chemical Co., Ltd.); WPI-113 (bis [ 4-n-alkyl (C10-13) phenyl ] iodonium hexafluorophosphate), WPI-116 (bis [ n-alkyl (C10-13) phenyl ] iodonium hexafluoroantimonate), WPI-169, WPI-170 (bis (4-t-butylphenyl) iodonium hexafluorophosphate), WPI-124 (bis [ 4-n-alkyl (C10-13) phenyl ] iodonium tetrafluorophenylborate) (manufactured by Fuji film and Wako Junyaku Co., Ltd., above), and the like.

The aromatic sulfonium salt is a sulfonium ion in which 3 groups bonded to a sulfur atom are all aryl groups. More specifically, examples thereof include: triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, 4' -bis [ diphenyldihydrothio ] diphenylsulfide-bis hexafluorophosphate, 4' -bis [ bis (. beta. -hydroxyethoxy) phenyldihydrothio ] diphenylsulfide-bis hexafluoroantimonate, 4' -bis [ bis (. beta. -hydroxyethoxy) phenyldihydrothio ] diphenylsulfide-bis hexafluorophosphate, 7- [ bis (p-tolyl) dihydrothio ] -2-isopropylthioxanthone hexafluoroantimonate, 7- [ bis (p-tolyl) thio ] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate, 4-phenylcarbonyl-4 ' -diphenylthio-diphenylsulfide-hexafluorophosphate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluoroantimonate, 4' -diphenylthiocyanato-diphenylsulfide-hexafluorophosphate, and mixtures thereof, 4- (p-t-butylphenylcarbonyl) -4 '-diphenylthiocyano) -diphenylsulfide-hexafluoroantimonate, 4- (p-t-butylphenylcarbonyl) -4' -di (p-tolyl) dihydrothio-diphenylsulfide-tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) phenylsulfonium-tetrakis (pentafluorophenyl) borate, etc. However, it is not limited to these. These aromatic sulfonium salts may be used singly or in combination of 2 or more (including 2).

Examples of commercially available products of aromatic sulfonium salts include: AdecaAkles (registered trademark, the same applies hereinafter) SP-150, AdecaAklesSP-170, AdecaAklesSP-172 (manufactured by ADEKA Co., Ltd.); CPI-100P, CPI-101A, CPI-110B, CPI-200K, CPI-210S (manufactured by SunAppro, Inc., supra); t1608, T1609, T2041 (tris (4-methylphenyl) sulfonium hexafluorophosphate), T2042 (tris-p-tolylsulfonium trifluoromethanesulfonate) (manufactured by tokyo chemical industries, ltd.); CyracureUVI-6990, CyracureUVI-6974 (Union carbide), DTS-200 (greening chemical Co., Ltd.).

The amount of component (C) in the cationically curable composition of the present invention is not particularly limited, but is preferably in the range of 0.1 to 30 parts by mass, more preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the total amount of component (a) and component (B). When the content of the component (C) is 0.1 parts by mass or more (including 0.1 parts by mass) based on 100 parts by mass of the total amount of the component (a) and the component (B), sufficient photocurability can be obtained, and when the content is 30 parts by mass or less (including 30 parts by mass), the composition is preferable from the viewpoint of excellent adhesion to an aluminum die casting, PPS, or the like.

< ingredient (D) >

The component (D) of the present invention is a compound which is a thermal cationic polymerization initiator and generates cationic species by heating. The kind thereof is not particularly limited, and examples thereof include: an aromatic sulfonium thermal cationic polymerization initiator, an aromatic iodonium thermal cationic polymerization initiator, a thermal cationic polymerization initiator containing an amine salt, and the like, and among these, a thermal cationic polymerization initiator containing an amine salt is preferable from the viewpoint of obtaining a cation-curable composition having excellent adhesion to an aluminum die casting, PPS, or the like while maintaining photocurability and low-temperature curability. These can be used alone, can also be combined with 2 or more (including 2 kinds).

Examples of the thermal cationic polymerization initiator containing an amine salt include: a thermal cationic polymerization initiator containing a salt having a quaternary ammonium cation, and the like. More specific examples of the salt having a quaternary ammonium cation include: salts of quaternary ammonium cations with borate anions, salts of quaternary ammonium cations with antimony anions, salts of quaternary ammonium cations with phosphate anions, and the like. Among these, a salt of a quaternary ammonium cation and a borate anion or a salt of a quaternary ammonium cation and an antimony anion is preferable in terms of excellent adhesion to an aluminum die casting, PPS, or the like.

Examples of the borate anion include: tetrafluoroborate anion, tetrakis (perfluorophenyl) borate anion, and the like. Examples of the antimony anion include: tetrafluroantimony anion, tetrakis (perfluorophenyl) antimony anion, and the like. Examples of the phosphate anion include: hexafluorophosphate anion, trifluoro [ tris (perfluoroethyl) ] and the like.

Examples of commercially available products of the thermal cationic polymerization initiator containing an amine salt include: K-PURE (registered trademark, the same shall apply hereinafter) CXC-1612 (thermal cationic polymerization initiator containing a salt of a quaternary ammonium cation and a borate anion, manufactured by King industries), K-PURECXC-1821 (thermal cationic polymerization initiator containing a salt of a quaternary ammonium cation and an antimonate anion, manufactured by King industries), and the like.

Examples of the commercial products of the aromatic sulfonium thermal cationic polymerization initiator include: SanAid (registered trademark, the same shall apply hereinafter) SI-60, SanAidSI-60L, SanAidSI-80, SanAidSI-80L, SanAidSI-100, SanAidSI-100L, SanAidSI-180L, SanAidSI-B2A, SanAidSI-B3A (manufactured by Sanxin chemical industries, Ltd.); CI-2624 (manufactured by Nippon Caoda corporation) and the like. Further, examples of the aromatic iodonium-based thermal cationic polymerization initiator include: iodonium trifluoromethanesulfonate (reagent), and the like.

The amount of component (D) in the cationically curable composition of the present invention is not particularly limited, but is preferably in the range of 0.1 to 30 parts by mass, more preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the total amount of the above-mentioned components (a) and (B). When the amount of the component (D) is 0.1 parts by mass or more (including 0.1 parts by mass) relative to 100 parts by mass of the total amount of the components (a) and (B), sufficient low-temperature curability is obtained, and when the amount is 30 parts by mass or less (including 30 parts by mass), it is preferable from the viewpoint of excellent adhesion to aluminum die castings, PPS, and the like.

< ingredient (E) >

The component (E) in the present invention is not particularly limited as long as it is a polycaprolactone polyol having 3-or more (including 3-functional) hydroxyl groups and having a molecular weight of 1700 or less (including 1700). The component (E) of the present invention can be combined with other components of the present invention, and by setting the compounding range to be described later, it has a remarkable effect of excellent adhesion to aluminum die cast, PPS, or the like, while maintaining photocurability and low-temperature curability. (E) The molecular weight of the component (A) is more preferably in the range of 200 to 1500, and particularly preferably in the range of 250 to 1000. The molecular weight was determined according to JIS K1557-1: 2007 measured hydroxyl value of polycaprolactone polyol.

The component (E) is not particularly limited, and examples thereof include: and a compound represented by the following general formula (2).

R-[O[CO(CH₂)₅O]_nH]_m (2)

(wherein R is a 3-or 4-valent aliphatic hydrocarbon group, n is in the range of 2 to 500, and m is 3 or 4.)

(E) Specific examples of the component (A) include: polycaprolactone triol, polycaprolactone tetraol, and the like. Further, as commercially available products of the component (E), there can be mentioned: praxel (registered trademark, the same applies hereinafter) 303, Praxel305, Praxel308, Praxel309, Praxel312, Praxel400 (manufactured by Daicel co., ltd.), and the like.

The cation-curable composition of the present invention is characterized in that: the content of the component (E) is 12 to 100 parts by mass, preferably 15 to 70 parts by mass, and more preferably 17 to 50 parts by mass, based on 100 parts by mass of the total amount of the component (A) and the component (B). When the amount is within the above range, a cationically curable composition having excellent adhesion to an aluminum die casting, PPS, or the like can be obtained while maintaining photocurability and low-temperature curability.

< optional component >

Further, additives such as a silane coupling agent, a colorant, an oxetane compound, a vinyl ether compound, a sensitizer, a peroxide, a thiol compound, and a storage stabilizer may be appropriately blended in the cationically curable composition of the present invention within a range not to impair the characteristics of the present invention. The cationic curable composition of the present invention may further contain, in an amount not detrimental to the characteristics of the present invention: inorganic fillers having an average particle diameter of 0.001 to 100 μm, such as calcium carbonate, magnesium carbonate, titanium oxide, magnesium hydroxide, talc, silica, alumina, glass, aluminum hydroxide, boron nitride, aluminum nitride, and magnesium oxide; conductive particles such as silver: a flame retardant; rubbers such as acrylic rubber and silicone rubber; plasticizers, organic solvents; antioxidants such as phenol-based antioxidants and phosphorus-based antioxidants; a light stabilizer; an ultraviolet absorber; defoaming agents; a foaming agent; a release agent; leveling agent; a rheology modifier; a tackifier; a cure retarder; and various additives such as polymers or thermoplastic elastomers, for example, polyimide resins, polyamide resins, phenoxy resins, cyanates, poly (meth) acrylate resins, polyurethane resins, polyurea resins, polyester resins, polyvinyl butyral resins, styrene-butadiene-styrene copolymers (SBS) and styrene-ethylene-butylene-styrene copolymers (SEBS). By adding these, a cationically curable composition excellent in resin strength, adhesive strength, flame retardancy, thermal conductivity, workability and the like, and a cured product thereof can be obtained.

The silane coupling agent improves the compatibility of the components (a) to (E), and can further improve low-temperature curability, and can also provide a compound of a cationically curable composition having excellent adhesion to an aluminum die casting, PPS, or the like. The silane coupling agent is not particularly limited, and specific examples thereof include: glycidyl group-containing silane coupling agents such as 3-glycidylpropyltriethoxysilane, 3-glycidylpropylmethyldimethoxysilane, 3-glycidylpropyltrimethoxysilane and 3-glycidylpropylmethyldiethoxysilane; vinyl group-containing silane coupling agents such as vinyltris (β -methoxyethoxy) silane, vinyltriethoxysilane, and vinyltrimethoxysilane; a (meth) acrylic group-containing silane coupling agent such as γ -methacryloxypropyltrimethoxysilane; amino group-containing silane coupling agents such as N- β - (aminoethyl) - γ -aminopropyltrimethoxysilane, γ -aminopropyltriethoxysilane, and N-phenyl- γ -aminopropyltrimethoxysilane; and other gamma-mercaptopropyltrimethoxysilane, gamma-chloropropyltrimethoxysilane and the like. Among these, a glycidyl group-containing silane coupling agent is preferable, and among the glycidyl group-containing silane coupling agents, 3-glycidylpropyltrimethoxysilane and 3-glycidylpropyltriethoxysilane are preferable. These silane coupling agents may be used alone, or 2 or more (including 2) silane coupling agents may be used in combination. The amount of the silane coupling agent to be blended is not particularly limited, but is preferably in the range of 0.1 to 30 parts by mass, more preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the total of the components (A) and (B).

As the colorant, there may be mentioned: pigments, dyes, and the like, among which pigments are preferred from the viewpoint of durability. Among the pigments, a black pigment is preferable from the viewpoint of excellent covering property. Examples of black pigments include: carbon black, black titanium oxide, copper chromium black, cyanine black, aniline black, and the like. Among these, carbon black is preferable from the viewpoint of covering property and dispersibility in the component (a) of the present invention. The amount of the colorant to be blended in the cationically curable composition of the present invention is not particularly limited, but is preferably in the range of 0.01 to 30 parts by mass, more preferably in the range of 0.05 to 10 parts by mass, and still more preferably in the range of 0.1 to 5 parts by mass, based on 100 parts by mass of the total amount of the component (a) and the component (B).

Examples of oxetane compounds include: 3-ethyl-3-hydroxymethyloxetane, 3- (methyl) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) methylbenzene, 4-fluoro- [1- (3-ethyl-3-oxetanylmethoxy) methyl ] benzene, [1- (3-ethyl-3-oxetanylmethoxy) ethyl ] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, ethylmethylene glycol (3-ethyl-3-oxetanylmeth) ether, ethylmethylene glycol (3-ethylmethylene glycol) ether, ethylmethylene glycol (ethylmethylene glycol) ether, and mixtures thereof, Tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, Pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether, and the like. Examples of commercially available oxetane compounds include: aronoxetane (registered trademark, the same applies hereinafter) OXT-212, AronoxetaneOXT-221, AronoxetaneOXT-213, AronoxetaneOXT-101 (manufactured by Toyo Seisakusho Co., Ltd.), and the like.

Examples of the vinyl ether compound include: 1, 4-butanediol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 4-hydroxybutyl vinyl ether, 2- (2-vinyloxyethoxy) ethyl acrylate, 2- (2-vinyloxyethoxy) ethyl methacrylate, and the like. Examples of commercially available vinyl ether compounds include: NPVE, IPVE, NBVE, IBVE, 2-EHVE, CHVE (manufactured by Nippon carbide industries, Ltd.) were used; HEVE, DEGV, HBVE (above, manufactured by PELLE PETROL CO., LTD.); VEEA, VEEM (manufactured by Nippon catalyst Co., Ltd., the above) and the like.

Examples of sensitizers include: 9-fluorenone, anthrone, dibenzosuberone, fluorene, 2-bromofluorene, 9-dimethylfluorene, 2-fluorofluorene, 2-iodofluorene, 2-fluorenamine, 9-fluorenol, 2, 7-dibromofluorene, 9-aminofluorene hydrochloride, 2, 7-diaminofluorene, 9' -spirobis [ 9H-fluorene ], 2-fluorenecarboxylic acid, 9-fluorenylmethanol, 2-acetylfluorene, diphenylketone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzildimethylketal, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxy-cyclohexyl-phenyl-one, 2-methyl-2-N-morpholinyl (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propanone oligomer, nitro compound, coloring matter and the like. The amount of the sensitizer added is not particularly limited, and may be appropriately determined with reference to the absorption wavelength and the molar absorption coefficient.

< method of curing >

The cationically curable composition of the present invention can be cured by irradiation with active energy rays (photocuring). Further, the cationically curable composition of the present invention can be cured under low temperature conditions (low temperature curability). The cationically curable composition of the present invention can be cured under low temperature conditions by irradiation with active energy rays. Here, examples of the active energy ray include: ultraviolet rays, electron beams, visible rays, and the like. The wavelength of the active energy ray is preferably 150 to 830nm, more preferably 200 to 600nm, and further preferably 250 to 380 nm.

Further, the above-mentioned "low temperature" means that the curing temperature of the cationic curable composition of the present invention is relatively low, and actually corresponds to the heating conditions of the curing method of the cationic curable composition of the present invention. The heating conditions (curable temperature) are not particularly limited, and are, for example, 45 ℃ to 150 ℃, preferably 45 ℃ or higher (including 45 ℃) to less than 150 ℃, more preferably 50 ℃ or higher (including 50 ℃) to less than 140 ℃, and still more preferably 55 ℃ or higher (including 55 ℃) to less than 130 ℃. The heating time is preferably in the range of 3 minutes or more (including 3 minutes) and less than 5 hours, and more preferably in the range of 10 minutes or more (including 10 minutes) and 3 hours or less (including 3 hours), at a heat curing temperature of 45 ℃ or more (including 45 ℃) and less than 150 ℃. The cationically curable group of the present invention can be cured by irradiation with active energy raysThe compound is cured. Examples of the active energy ray in this case include: ultraviolet rays, electron beams, visible rays, and the like, but are not particularly limited. The cumulative light amount of the active energy rays is, for example, 300 to 100000mJ/cm²Preferably 500 to 50000mJ/cm²More preferably 1000 to 10000mJ/cm²More preferably 2000 to 5000mJ/cm²Particularly preferably 3000mJ/cm². The wavelength of the active energy ray is preferably 150 to 830nm, more preferably 200 to 600nm, and further preferably 250 to 380 nm.

< bonding method >

The cationic curable composition of the present invention can be used for bonding adherends. Specific examples of the bonding method include: the method for bonding adherends comprises the following step 1 of placing the cationically curable composition of the present invention between a pair of adherends, step 2 of irradiating the cationically curable composition with an active energy ray, and step 3 of heating the composition at a temperature of 45 ℃ or higher (including 45 ℃) and less than 150 ℃ after the irradiation. Hereinafter, each step will be described.

[ step 1] the cationic curable composition of the present invention is disposed between a pair of adherends. Specifically, for example: the cationic curable composition is dropped or applied to one adherend to be disposed, the other adherend is disposed on the disposed cationic curable composition, and the pair of adherends are placed in an arbitrary alignment. For example, a coating method used for a known sealant or adhesive can be used for coating. Specific coating methods include, for example: dispensing, spraying, ink-jetting, screen printing, gravure printing, dip coating, spin coating, and the like are performed using an automatic coater. The adherend can be used, for example: metals, glass, plastics and the like, but from the viewpoint of excellent compatibility with the cationically curable composition of the present invention, preferable examples thereof include: aluminum die casting, PPS.

Step 2 the cationically curable composition disposed in step 1 is irradiated with an active energy ray to cure the cationically curable composition, and a pair of adherends are temporarily bonded. The curing of the cationically curable composition by irradiation with active energy rays is particularly carried out on the surface of the composition and in the vicinity thereof. The irradiation may be performed directly on the disposed cationic curable composition, and particularly, in the case where the adherend is transparent or translucent, the irradiation may be performed indirectly through the adherend.

Step 3 after the irradiation with the active energy ray in step 2, the prepared cation curable composition is further heated at a predetermined temperature to completely cure the cation curable composition and completely bond a pair of adherends (main bonding). The cationic curable composition is cured by heating, and particularly, the curing is performed outside the surface of the composition and in the vicinity thereof and inside the composition. When the curing reaction by irradiation in the above-mentioned step 2 is carried out before the curing reaction by heating in the step 3, the curing (crosslinking) reaction of the resin composition rapidly starts, and the reaction in the interior of the cation curable composition which is not exposed to the active energy ray rapidly proceeds in the curing reaction by heating in the subsequent step 3, whereby complete curing of the cation curable composition can be achieved. The heating temperature in step 3 is preferably 45 to 150 ℃, more preferably 45 ℃ or higher (including 45 ℃) and less than 140 ℃, further preferably 50 ℃ or higher (including 50 ℃) and less than 130 ℃, and particularly preferably 55 ℃ or higher (including 55 ℃) and less than 125 ℃.

< use of cationically curable composition >

The use of the cationically curable composition of the present invention is not particularly limited, and examples thereof include: adhesives, sealants, coating agents, potting agents, conductive adhesives, and the like. The field to which the cationically curable composition of the present invention can be applied is not particularly limited, and examples thereof include: the automobile comprises automobile fields such as switch parts, headlamps, internal parts of an engine, electric parts, a driving engine, a brake oil tank and the like; flat panel display fields such as liquid crystal displays, organic electroluminescence, touch panels, plasma displays, light emitting diode display devices, and the like; video disks, CDs, DVDs, MDs, cameras, peripheral components of hard disks, Blu-ray disks, etc.; electronic material fields such as sealing materials for electronic components, circuits, relays, electrical contacts, semiconductor components, and the like, die bonding agents, conductive adhesives, anisotropic conductive adhesives, and interlayer adhesives for multilayer substrates including laminated substrates; a camera module such as a CMOS image sensor; the battery field such as lithium battery, manganese battery, alkaline battery, nickel battery, fuel cell, silicon solar cell, dye-sensitized solar cell, organic solar cell, etc.; optical component fields such as optical fiber materials around optical switches and optical connectors, optical passive components, optical circuit components, and optoelectronic integrated circuit components in optical communication systems; a mobile terminal device; the building field, the aviation field, and the like.

The cationically curable composition of the present invention has excellent adhesion to aluminum die castings, PPS, and the like while maintaining photocurability and low-temperature curability, and is particularly suitable as an adhesive for assembly of electronic/electric component modules, automobile parts, and the like. Examples of the electronic/electric component module include: display housings, computer housings, optical pick-up modules, mobile machine housings, HDD housings, camera modules, projector housings, CD, DVD player housings, heat sinks, relays, connectors, module boxes, and the like. The vehicle parts include: ECU shell, vehicle camera module, vehicle sensor module (vehicle radar module, car owner module etc.), condenser shell, power module, connector, ignition coil etc..

[ examples ]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples.

< preparation of cationically curable composition >

EXAMPLE 1

20 parts by mass of an aromatic bisphenol F-type epoxy resin (a1) (manufactured by Mitsubishi chemical corporation; jER807ST) as component (A) were cured in the absence of light at room temperature (25 ℃ C.),

50 parts by mass of a hydrogenated bisphenol A-type epoxy resin (B1) (manufactured by Mitsubishi chemical corporation; jERYX-8000) and 30 parts by mass of 3',4' -epoxycyclohexylmethyl 3, 4-epoxycyclohexanecarboxylate (B2) (manufactured by Daicel, Inc.; Celloxide2021P) as component (B),

3 parts by mass of 4-methylphenyl-4- (1-methylethyl) phenyliodonium-tetrakis (pentafluorophenyl) borate (C1) (manufactured by Rodia, BluesilPI-2074),

A thermal cationic polymerization initiator (D1) (manufactured by King Industries, K-PURECXC-1821) containing a salt containing a quaternary ammonium cation and a borate anion as the component (D) 2 parts by mass,

Polycaprolactone triol (E1) (produced by Daicel corporation; Placcel305) having 3-functional hydroxyl group and molecular weight of 550 as component (E) 25 parts by mass,

2 parts by mass of 3-glycidylpropyltrimethoxysilane as a silane coupling agent,

the mixture was added to a planetary mixer and mixed for 60 minutes to obtain a cationically curable composition of example 1.

EXAMPLE 2

The same operation as in example 1 was carried out except that in example 1, 20 parts by mass of the component (a1) was changed to 50 parts by mass, the component (b1) was not used, and 30 parts by mass of the component (b2) was changed to 50 parts by mass, thereby preparing a cationically curable composition of example 2.

EXAMPLE 3

The same operation as in example 1 was carried out except that 50 parts by mass of the component (b1) was changed to 80 parts by mass and the component (b2) was not used in example 1, thereby obtaining a cationically curable composition of example 3.

Comparative example 1

A cationic curable composition of comparative example 1 was prepared in the same manner as in example 1, except that (a1) was removed and 50 parts by mass of the component (b1) was changed to 70 parts by mass in example 1.

Comparative example 2

The same operation as in example 1 was carried out except that (e1) was removed in example 1 to prepare a cationically curable composition according to comparative example 2.

Comparative example 3

A cationically curable composition of comparative example 3 was prepared in the same manner as in example 1, except that 25 parts by mass of the component (e1) was changed to 10 parts by mass in example 1.

Comparative example 4

The same operation as in example 1 was carried out except that the component (e1) in example 1 was changed to polycaprolactone polyol (e'1) having a 2-functional hydroxyl group and a molecular weight of 500 (manufactured by Daicel Corp.; Placcel205), to obtain a cationic curable composition of comparative example 4.

Comparative example 5

The same operation as in example 1 was carried out except that the component (e1) in example 1 was changed to polycaprolactone polyol (e'2) having a 3-functional hydroxyl group and a molecular weight of 2000 (manufactured by Daicel corporation; Placcel320), to obtain a cationic curable composition of comparative example 5.

Comparative example 6

The same operation as in example 1 was carried out except that the component (d1) was removed in example 1 to prepare a cationically curable composition of comparative example 6.

< photocurability test >

0.01g of the cationically curable composition was dropped on a glass test piece having a width of 25mm, a length of 100mm and a thickness of 5 mm. Then, the resultant was irradiated with a cumulative light amount of 3000mJ/cm via AN ultraviolet irradiation apparatus (model: JUL-M-433AN-05, manufactured by Jatec corporation; ultraviolet wavelength: 365nm)²The test piece was obtained by irradiating the sample with the active energy ray of (1). Next, a glass rod having a sharp tip was brought into contact with a test piece, and the curability of the cationic curable composition was evaluated according to the following criteria. In the following criteria, the curability was considered to be good when the value is "O".

[ evaluation criteria ]

O: no attachment on the stick

X: the stick has attachments thereon.

< Low temperature curability test >

0.1g of each of the cationic curable compositions was dropped on a hot plate set at 100 ℃, and after 30 minutes, a glass rod having a sharp tip was brought into contact with the cured product, and the curability of the composition was evaluated according to the following criteria. In the following criteria, low-temperature curability was considered to be good if it was O.

[ evaluation criteria ]

O: no attachment on the stick

X: the stick has attachments thereon.

< tensile shear adhesion Strength test on aluminum die casting >

The cationic curable compositions of examples and comparative examples were applied to test pieces made of aluminum die casting ADC12 having a width of 25mm, a length of 100mm and a thickness of 1 mm. Then, another test piece made of aluminum die-cast ADC12 was attached and fixed by a clip so that the outer package surface became 25mmx10 mm. Then, the resultant was cured in a hot air drying oven set at 120 ℃ for 60 minutes to obtain a test piece. Then, using a test piece, the test piece was measured according to JISK 6850: 1999, tensile shear bond strength (unit: MPa) was measured at 25 ℃ using a universal tensile tester (tensile speed 50 mm/min.). The tensile shear bond strength is a value at the time of maximum strength. In order to use the cationically curable composition of the present invention as an adhesive for assembling electronic/electrical component modules, vehicle components, and the like, the tensile shear adhesive strength is preferably 5.0MPa or more (including 5.0 MPa).

< tensile shear adhesion Strength test to polyphenylene sulfide (PPS) >

The cationic curable compositions of examples and comparative examples were applied to PPS test pieces 25mm in width, 100mm in length and 1mm in thickness. Then, another PPS test piece was attached and fixed by a clip so that the outer package surface became 25mmx10 mm. Then, the resultant was cured in a hot air drying oven set at 120 ℃ for 60 minutes to obtain a test piece. Then, using a test piece, the test piece was measured according to JISK 6850: 1999, tensile shear bond strength (unit: MPa) was measured at 25 ℃ using a universal tensile tester (tensile speed 50 mm/min.). The tensile shear bond strength is a value at the time of maximum strength. Further, in order to use the cationically curable composition of the present invention as an adhesive for assembling electronic/electrical component modules, vehicle parts, and the like, the tensile shear adhesive strength is preferably 5.0MPa or more (including 5.0 MPa).

The test results are summarized in table 1 below. In addition, "-" in table 1 below indicates no measurement.

[ Table 1]

As is apparent from Table 1 above, the cationically curable compositions of examples 1 to 3 have excellent adhesion to aluminum die castings, PPS and the like while maintaining photocurability and low-temperature curability.

Comparative example 1 is a cationically curable composition containing no component (a) of the present invention, and it is found that the adhesion to PPS is poor. Further, comparative example 2 is a cationically curable composition not containing the component (E) of the present invention, and it is found that the adhesiveness to aluminum die castings and PPS is poor. Further, comparative example 3 is a cationically curable composition added in an amount not within the predetermined range of component (E) of the present invention, and it is found that the adhesiveness to aluminum die castings and PPS is poor. Further, comparative examples 4 and 5 are cationic curable compositions when a polyol other than the component (E) of the present invention is used, and it is found that the adhesion to aluminum die castings is poor. Comparative example 6 is a cationic curable composition containing no component (D) of the present invention, and the result of the low temperature curability test is poor.

Industrial applicability

The cationically curable composition of the present invention has excellent adhesion to aluminum die castings, PPS, and the like while maintaining photocurability and low-temperature curability, and therefore, is suitable for use in a wide range of fields such as adhesion of module members of electric and electronic components, and is industrially applicable.

The present application is based on japanese patent application No. 2019-223752, filed on 12/11/2019, the entire disclosure of which is incorporated herein by reference.

Claims

1. A cationically curable composition comprising the following components (A) to (E) and 12 to 100 parts by mass of component (E) per 100 parts by mass of the total amount of components (A) and (B),

(A) the components: aromatic epoxy resin

(C) The components: photo cation polymerization initiator

(D) The components: thermal cationic polymerization initiator

(E) The components: a polycaprolactone polyol having 3 or more hydroxyl groups and a molecular weight of 1700 or less, where 3 or more contains 3 functions and 1700 or less contains 1700.

2. The cationically curable composition according to claim 1, wherein the component (B) is contained in an amount of 10 to 80 parts by mass based on 100 parts by mass of the total amount of the component (A) and the component (B).

3. The cationic curable composition according to claim 1 or 2, wherein component (D) is at least 1 selected from the group consisting of an aromatic sulfonium thermal cationic polymerization initiator, an aromatic iodonium thermal cationic polymerization initiator, and a thermal cationic polymerization initiator containing an amine salt.

4. The cationically curable composition according to any one of claims 1 to 3, wherein the component (D) comprises a thermal cationic polymerization initiator having a salt of a quaternary ammonium cation.

5. The cationic curable composition according to any one of claims 1 to 4, wherein component (C) comprises at least one of an aromatic iodonium salt and an aromatic sulfonium salt.

6. The cationic curable composition according to any one of claims 1 to 5, wherein the component (A) contains at least 1 selected from the group consisting of aromatic bisphenol A epoxy resins, aromatic bisphenol F epoxy resins, and aromatic bisphenol E epoxy resins.

7. The cationically curable composition according to any one of claims 1 to 6, wherein the component (B) comprises only one selected from the group consisting of the hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2).

8. The cationically curable composition according to any one of claims 1 to 6, wherein the component (B) comprises the hydrogenated epoxy resin (B1) and the alicyclic epoxy resin (B2).

9. The cationically curable composition according to any one of claims 1 to 8 for use in adhesives.

10. The cationically curable composition according to any one of claims 1 to 9, which is used as an adhesive when an adherend is an aluminum die casting or PPS.

11. A cured product of the cationically curable composition according to any one of claims 1 to 10.

12. A bonded body obtained by bonding an adherend with the use of the cationic curable composition according to any one of claims 1 to 10.