Thermally cationically polymerizable resin composition

Abstract

To provide a heat-cationic polymerizable resin composition with a high Tg, reduced outgassing, excellent heat-resistance transparency, and excellent heat-curing properties.SOLUTION: A heat-cationic polymerizable resin composition includes: (A) a cation curable resin, (B) an iodonium gallate salt represented by the following formula (1): Ar1-I+-Ar2 [(R1)(R2)(R3)(R4) Ga]-(1) [wherein R1-R4 independently represent an alkyl group or Ar3, where at least one of R1-R4 is Ar3; Ar1-Ar3 independently represent an aryl group or a heteroaryl group, where the aryl group or heteroaryl group may be substituted with an alkyl group, a halogen atom-substituted alkyl group, an alkenyl group, an alkynyl group, a nitro group, a hydroxy group, a cyano group, a -OR6 group, a -COR7 group, a -OCOR8 group, a -SR9 group, a -NR10R11 group or a halogen atom, where R6 is an alkyl group, a hydroxy group-substituted alkyl group, an aryl group or a heteroaryl group; R7-R9 independently represent an alkyl group, an aryl group or a heteroaryl group; R10 and R11 independently represent a hydrogen atom, an alkyl group, an aryl group or heteroaryl group], and (C) organic peroxide.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermally cationically polymerizable resin composition. [Background technology]

[0002] Cation-curable resins are widely used in a variety of fields, including paints, electrical and electronics, civil engineering and construction, and adhesives, because the cured products have excellent properties such as mechanical strength, chemical resistance, electrical insulation, and adhesive properties.

[0003] In general, thermosetting resin compositions utilizing a radical redox mechanism (a combination of an iodonium salt-based photocationic polymerization initiator and an organic peroxide (thermal radical polymerization initiator)) can be cured at low temperatures, and even when only thermally cured, they can exhibit physical properties equivalent to those when both ultraviolet curing and thermal curing are performed. Patent Documents 1 to 3 disclose such compositions, which are thermally cationically polymerizable compositions containing the above-mentioned radical redox mechanism and a cationically curable resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-129473 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-129474 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-116977 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the findings of the inventors, it has been found that the thermally cationically polymerizable compositions described in Patent Documents 1 to 3 have room for improvement in terms of Tg (glass transition temperature), outgassing amount, and heat-resistant transparency.

[0006] Therefore, an object of the present invention is to provide a thermally cationically polymerizable resin composition that has a high Tg, a reduced amount of outgassing, excellent heat resistance transparency, and excellent thermosetting properties. [Means for solving the problem]

[0007] The present inventors have conducted extensive research in light of the above-mentioned problems and have found that by using an iodonium salt-based acid generator having a gallium-type anion structure in a formulation utilizing a radical redox mechanism, it is possible to reduce the amount of outgassing while maintaining Tg at a high temperature, and also to achieve excellent heat-resistant transparency.

[0008] The present invention relates to the following [1] to [4]. [1] (A) a cationically curable resin, (B) Formula (1): Ar 1 -I + -Ar 2 ·[(R 1 )(R 2 )(R 3 )(R 4 )Ga] - (1) [During the ceremony, R 1 ~R 4 are each independently an alkyl group or Ar 3 However, R 1 ~R 4 At least one of 3 and Ar 1 ~Ar 3 are each independently an aryl group or a heteroaryl group, and the aryl group or the heteroaryl group is an alkyl group, an alkyl group substituted with a halogen atom, an alkenyl group, an alkynyl group, a nitro group, a hydroxyl group, a cyano group, -OR 6 group, -COR 7 group, -OCOR 8 Group, -SR 9 group, -NR 10 R 11 may be substituted with a group or a halogen atom, where R 6is an alkyl group, a hydroxyl-substituted alkyl group, an aryl group, or a heteroaryl group; R 7 ~R 9 are each independently an alkyl group, an aryl group, or a heteroaryl group, and R 10 and R 11 are each independently a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group; and (C)Organic peroxide A thermally cationically polymerizable resin composition comprising: [2] The thermally cationically polymerizable resin composition according to [1], further comprising (D) a thermally cationically polymerizable initiator. [3] The thermally cationically polymerizable resin composition according to [1] or [2], wherein the component (A) is at least one selected from the group consisting of epoxy resins and oxetane resins. [Effects of the Invention]

[0009] The present invention provides a thermally cationically polymerizable resin composition that has a high Tg, a reduced amount of outgassing, excellent heat resistance and transparency, and excellent thermosetting properties. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail.

[0011] [Thermal cationically polymerizable resin composition] The thermally cationically polymerizable resin composition contains (A) a cationically curable resin, (B) an iodonium gallate salt represented by the above formula (1), and (C) an organic peroxide.

[0012] <(A) Cationic curable resin> The cationically curable resin is not particularly limited as long as it has one or more cationically polymerizable groups in the molecule. Examples of the cationically polymerizable group include an epoxy group, an oxetanyl group, and a vinyl ether group. Specific examples of the cationically curable resin include an epoxy resin, an oxetane resin, a polystyrene compound, and a vinyl ether compound.

[0013] ≪Epoxy resin≫ Epoxy resins include aromatic, aliphatic and cycloaliphatic epoxy resins.

[0014] Examples of aromatic epoxy compounds include bisphenol A epoxy resins (such as EPICLON 850, 850-S, EXA-850CRP, and EXA-8067 manufactured by DIC Corporation), bisphenol F epoxy resins (such as EPICLON 830-S and EXA-830LVP manufactured by DIC Corporation), bisphenol AD ​​epoxy resins, bisphenol S epoxy resins, naphthalene epoxy resins (such as EPICLON HP-4032D and HP-7200H manufactured by DIC Corporation), phenol novolac epoxy resins (such as EPICLON N-740 and N-770 manufactured by DIC Corporation), cresol novolac epoxy resins (such as EPICLON N-660, N-670, and N-655-EXP-S manufactured by DIC Corporation), and multifunctional epoxy resins. Examples of polyfunctional epoxy compounds include glycidyl ethers of tetra(hydroxyphenyl)alkanes, glycidyl ethers of tetrahydroxybenzophenones, and epoxidized polyvinylphenols.

[0015] Examples of aliphatic epoxy resins include polyglycidyl ethers of polyhydric alcohols or their alkylene oxide adducts. Specific examples of aliphatic epoxy compounds include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether (Epolite 100MF manufactured by Kyoeisha Chemical Co., Ltd.), polyethylene glycol diglycidyl ether, and 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (EHPE3150 manufactured by Daicel Corporation).

[0016] Aliphatic epoxy resins are resins with a structure in which an epoxy group is formed by two carbon atoms and an oxygen atom forming an alicyclic structure. Aliphatic epoxy resins in which an epoxy group is bonded to one carbon atom forming the alicyclic structure are not included. Examples of alicyclic epoxy compounds include cyclohexane-based, cyclohexyl methyl ester-based, cyclohexyl methyl ether-based, spiro-based, and tricyclodecane-based epoxy compounds. Specific examples of alicyclic epoxy compounds include (3,3',4,4'-diepoxy)bicyclohexyl (e.g., Celloxide 8010 manufactured by Daicel Corporation), 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (e.g., Celloxide 2021P manufactured by Daicel Corporation), 1,2:8,9-diepoxylimonene, and 1,2-epoxy-4-vinylcyclohexane.

[0017] <Oxetane resin> Specific examples of oxetane resins include 3-ethyl-3-hydroxymethyloxetane (oxetane alcohol) (e.g., OXT-101 manufactured by Toagosei Co., Ltd.), 2-ethylhexyloxetane (e.g., OXT-212 manufactured by Toagosei Co., Ltd.), xylylene bisoxetane (XDO, e.g., OXT-121 manufactured by Toagosei Co., Ltd.), 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (e.g., OXT-221 manufactured by Toagosei Co., Ltd.), oxetanyl silsesquioxetane (e.g., OXT-191 manufactured by Toagosei Co., Ltd.), phenol novolac oxetane (e.g., PHOX manufactured by Toagosei Co., Ltd.), and 3-ethyl-3-phenoxymethyloxetane (POX, e.g., OXT-211 manufactured by Toagosei Co., Ltd.).

[0018] <Vinyl ether compounds> Specific examples of vinyl ether compounds include hydroxybutyl vinyl ether (such as HBVE manufactured by ISP), vinyl ether of 1,4-cyclohexanedimethanol (such as CHVE manufactured by ISP), triethylene glycol divinyl ether (such as DVE-3 manufactured by ISP), dodecyl vinyl ether (such as DDVE manufactured by ISP), and cyclohexyl vinyl ether (such as CVE manufactured by ISP).

[0019] <Preferred cationically curable resin> The component (A) is preferably at least one selected from the group consisting of epoxy resins and oxetane resins. The component (A) may be one type or a combination of two or more types.

[0020] <(B) Iodonium gallate salt represented by formula (1)> The component (B) is represented by the following formula (1): Ar 1 -I + -Ar 2 ·[(R 1 )(R 2 )(R 3 )(R 4 )Ga] - (1) [During the ceremony, R 1 ~R 4 are each independently an alkyl group or Ar 3 However, R 1 ~R 4 At least one of 3 and Ar 1 ~Ar 3 are each independently an aryl group or a heteroaryl group, and the aryl group or heteroaryl group is an alkyl group, an alkyl group substituted with a halogen atom, an alkenyl group, an alkynyl group, a nitro group (-NO group), a hydroxyl group (-OH group), a cyano group (-CN group), an -OR group, 6 group, -COR 7 group, -OCOR 8 Group, -SR 9 group, -NR 10 R 11 may be substituted with a group or a halogen atom, R 6 is an alkyl group, a hydroxyl-substituted alkyl group, an aryl group, or a heteroaryl group; R 7 ~R 9 are each independently an alkyl group, an aryl group, or a heteroaryl group, and R 10 and R 11are each independently a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group (hereinafter, also referred to simply as "iodonium gallate salt").

[0021] As used herein, alone or in combination with other terms, an "alkyl group" is a monovalent group which is linear or branched, cyclic or acyclic. The number of carbon atoms in the acyclic alkyl group is preferably 1 to 20, more preferably 1 to 18, even more preferably 1 to 10, and particularly preferably 1 to 4. Examples of the acyclic alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group. The number of carbon atoms in the cyclic alkyl group is preferably 3 to 20. The cyclic alkyl group may be monocyclic or polycyclic, and examples thereof include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl; and bridged cyclic alkyl groups such as norbornyl and adamantyl.

[0022] In this specification, the term "aryl group", whether used alone or in combination with other terms, refers to a monovalent group having a monocyclic or polycyclic aromatic ring. The aryl group preferably has 6 to 20 carbon atoms. Monocyclic aryl groups include phenyl groups. Examples of the polycyclic aryl group include a biphenylyl group, a naphthyl group, a terphenylyl group, an anthracenyl group, a phenanthrenyl group, an anthraquinolyl group, a fluorenyl group, and a naphthoquinolyl group.

[0023] As used herein, the term "heteroaryl group," whether used alone or in combination with other terms, refers to a monovalent monocyclic or polycyclic heterocyclic group containing, in addition to carbon atoms, at least one heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen atoms. The heteroaryl group preferably contains 5 to 30 atoms in total. Examples of heteroaryl groups include phthalimidyl, imidazolyl, xanthenyl, thioxanthenyl, thienyl, dibenzofuryl, chromenyl, isothiochromenyl, phenoxathiinyl, pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolizinyl, isoindolyl, indolyl, indazolyl, purinyl, and quinolizinyl. group, an isoquinolyl group, a quinolyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a pteridinyl group, a carbazolyl group, a β-carbolinyl group, a phenanthridinyl group, an acridinyl group, a perimidinyl group, a phenanthrolinyl group, a phenazinyl group, an isothiazolyl group, a phenothiazinyl group, an isoxazolyl group, and a furazanyl group.

[0024] In this specification, either alone or in combination with other terms, an "alkenyl group" refers to a linear or branched, cyclic or acyclic monovalent group. The number of unsaturated bonds in the alkenyl group is preferably 1 to 5, and particularly preferably 1 or 2. The number of carbon atoms in the alkenyl group is preferably 2 to 20, more preferably 3 to 20, even more preferably 3 to 15, and particularly preferably 3 to 10. Examples of the acyclic alkenyl group include a vinyl group, a 1-methylvinyl group, a 1-propenyl group, a 2-propenyl group, a 1-methyl-1-propenyl group, a 2-methyl-1-propenyl group, a 2-butenyl group, a 3-butenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 2-hexenyl group, a 3-hexenyl group, a 4-hexenyl group, a 5-hexenyl group, and a 9-decenyl group. The number of carbon atoms in the cyclic alkenyl group is preferably 3 to 20. The cyclic alkenyl group is monocyclic or polycyclic, and examples thereof include a 2-cyclohexenyl group and a 3-cyclohexenyl group.

[0025] As used herein, alone or in combination with other terms, an "alkynyl group" refers to a linear or branched monovalent group. The alkynyl group preferably contains 2 to 20 carbon atoms, and particularly preferably 2 to 15 carbon atoms. Examples of the alkynyl group include an ethynyl group, a propargyl group, a 2-butynyl group, a 3-butynyl group, a 2-pentynyl group, a 3-pentynyl group, a 4-pentynyl group, a 2-hexynyl group, a 3-hexynyl group, a 4-hexynyl group, and a 5-hexynyl group.

[0026] As used herein, the term "halogen atom", alone or in combination with other terms, includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. As used herein, either alone or in combination with other terms, the term "an alkyl group substituted with a halogen atom" refers to a halogenoalkyl group in which at least one hydrogen atom of the alkyl group is substituted with a halogen atom, and is preferably a perfluoroalkyl group such as a trifluoromethyl group.

[0027] R 6 -OR when is an alkyl group 6 Examples of the group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, an i-pentoxy group, a neo-pentoxy group, an n-hexyloxy group, an n-octyloxy group, an n-decyloxy group, an n-dodecyloxy group, an n-octadecyloxy group, and a 2-methylbutoxy group. 6 When R is an alkyl group, the alkyl group may be substituted with a hydroxyl group. 6 -OR when is an aryl group 6 Examples of the group include a phenoxy group and a naphthoxy group.

[0028] -COR 7 Examples of the group include an acetyl group, a propanoyl group, a butanoyl group, a pivaloyl group, and a benzoyl group.

[0029] -OCOR 8 Examples of the group include an acetoxy group, a butanoyloxy group, and a benzoyloxy group.

[0030] R 9 -SR when is an alkyl group 9 Examples of the group include a methylthio group, an ethylthio group, a butylthio group, a hexylthio group, a 2-ethylhexylthio group, and a cyclohexylthio group. 9 -SR when is an aryl group 9 Examples of the group include a phenylthio group and a naphthylthio group.

[0031] -NR 10 R 11 Examples of the group include a methylamino group, an ethylamino group, a propylamino group, a dimethylamino group, a diethylamino group, a methylethylamino group, a dipropylamino group, a dipropylamino group, a phenylmethylamino group, a diphenylamino group, and a piperidino group.

[0032] <Preferred embodiment> Ar 1 and Ar 2 is preferably an unsubstituted aryl group or an aryl group substituted with the above-mentioned groups, and is preferably an unsubstituted aryl group or an alkyl group or -OR 6 It is particularly preferred that the aryl group be substituted with an Ar group. 1 -I + -Ar 2Examples of the iodonium cation represented by the formula (I) include diphenyliodonium, di-p-tolyliodonium, 4-methylphenyl-4-(1-methylethyl)phenyliodonium (4-isopropylphenyl(p-tolyl)iodonium), di-(4-tert-butylphenyl)iodonium, di-(4-tert-pentylphenyl)iodonium, 4-octyloxyphenylphenyliodonium, di-4-isopropylphenyliodonium, 4-isobutylphenyl(p-tolyl)iodonium, bis(2,4-di Preferred are bis(4-isopropylphenyl)iodonium, 4-hexylphenyl(p-tolyl)iodonium, 4-cyclohexylphenyl(p-tolyl)iodonium, bis(4-dodecylphenyl)iodonium, 4-octyloxyphenyl(2,4,6-trimethoxyphenyl)iodonium, bis(4-octadecylphenyl)iodonium, bis(4-methoxyphenyl)iodonium, bis(4-decyloxyphenyl)iodonium, 4-(2-hydroxytetradecyloxyphenyl)phenyliodonium, and the like.

[0033] R 1 ~R 4 are independently 3 From the viewpoint of thermal stability, it is preferable that Ar 3 is preferably an aryl group substituted with the above-mentioned group, more preferably an alkyl group having 1 to 8 carbon atoms substituted with a halogen atom, an aryl group substituted with a halogen atom, a nitro group or a cyano group, and even more preferably an alkyl group having 1 to 8 carbon atoms substituted with a fluorine atom or an aryl group substituted with a fluorine atom. Therefore, the [(R 1 )(R 2 )(R 3 )(R 4 )Ga] - The gallate anion represented by [Ga(C6F5)4] - , [Ga(C6F3H2)4] - , [Ga((CF3)2C6H3)4] - , [Ga(C6F5)3(C4F9)] -, or [Ga(C6F5)3(C6H5)] - It is particularly preferred that: The component (B) may be one type or a combination of two or more types.

[0034] <(C)Organic peroxide> (C) Organic peroxide is a compound containing a peroxy group (-OO-). Organic peroxides are radical sources. The radicals generated from the organic peroxide reductively decompose the iodonium gallate salt of component (B), generating an acid independent of light, thereby accelerating cationic polymerization. Examples of organic peroxides include diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, peroxyesters, and peroxycarbonates.

[0035] Specific examples of component (C) include diacyl peroxides such as dilauroyl peroxide, dibenzoyl peroxide, and bis-3,5,5-trimethylhexanoyl peroxide; hydroperoxides such as 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide (e.g., Kayacumene H manufactured by Kayaku Aguzo Co., Ltd.), and t-butyl hydroperoxide; dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t- Dialkyl peroxides such as butylperoxyisopropyl)benzene, t-butylcumyl peroxide, di-t-butyl peroxide, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3; peroxyketals such as 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, 1,1-di-t-butylperoxycyclohexane, and 2,2-di-t-butylperoxybutane; 1,1,3,3-tetramethylbutylperoxyneodecanoate, α -Cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxyneoheptanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, t-amyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy Examples of organic peroxides include peroxyesters such as diisopropyl peroxybenzoate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, and t-amyl peroxybenzoate; and peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, t-butyl peroxyisopropyl carbonate, t-butylperoxy 2-ethylhexyl carbonate, and 1,6-bis(t-butylperoxycarbonyloxy)hexane. These organic peroxides are commercially available from reagent suppliers and can be easily obtained.

[0036] The component (C) may be one type or a combination of two or more types.

[0037] <Other ingredients> The thermally cationically polymerizable resin composition may contain other components in addition to components (A) to (C) depending on the purpose, as long as the effects of the present invention are not impaired. Examples of other components include (D) a thermally cationically polymerizable initiator, (E) an iodonium salt other than component (B), and (F) an additive.

[0038] <(D) Thermal cationic polymerization initiator> (D) The thermal cationic polymerization initiator is a component that serves as a cation generating source when cationic polymerization is carried out by heating. The thermal cationic polymerization initiator is a compound in which the cationic moiety is an aromatic sulfonium, aromatic diazonium, aromatic ammonium, thianthrhenium, thioxanthonium, or (2,4-cyclopentadien-1-yl)[(1-methylethylbenzene]-Fe cation and the anionic moiety is [(R 1 )(R 2 )(R 3 )(R 4 )Ga] - (In the formula, R 1 ~R 4 is as above), [P(R F ) n F 6-n ] - (In the formula, R F are independently a partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and n is an integer from 0 to 5), SbF6 - , BF4 - , PF6 - , B(C6F5)4 - , or [BX4] - (wherein X is a phenyl group substituted with at least two fluorine atoms or trifluoromethyl groups). The thermal cationic polymerization initiator is preferably a sulfonium salt. In addition, when the anion portion of the thermal cationic polymerization initiator is [(R 1 )(R 2 )(R 3 )(R 4 )Ga] - (In the formula, R1 ~R 4 is as above), [P(R F ) n F 6-n ] - (In the formula, R F are preferably independently a partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and n is an integer of 0 to 5).

[0039] Commercially available products of component (D) include TA-60, TA-60B, TA-100, TA-100FG, and TA-120 manufactured by San-Apro Co., Ltd.; Adeka Opton CP-77 and Adeka Opton CP-66 manufactured by ADEKA Corporation; CI-2639 and CI-2624 manufactured by Nippon Soda Co., Ltd.; CXC-1612 and CXC-1738 manufactured by King Industries Co., Ltd.; and San-Aid SI-45, San-Aid SI-60, San-Aid SI-80, San-Aid SI-100, San-Aid SI-110, San-Aid SI-B3, San-Aid SI-B3A, and San-Aid SI-B4 manufactured by Sanshin Chemical Industry Co., Ltd.

[0040] The component (D) may be one type or a combination of two or more types.

[0041] <(E): Iodonium salt other than component (B)> Component (E) is an iodonium salt other than component (B) (hereinafter also referred to as "other iodonium salt"). Component (E) is not particularly limited as long as it is an iodonium salt having a non-gallium anion. Such component (E) is an iodonium salt represented by the formula (2): Ar 4 -I + -Ar 5 X - (In formula (2), Ar 4 and Ar 5 are independently 1 and Ar 2 is synonymous with X - is an anion that does not contain gallium). Ar 4 and Ar 5 Ar 1 and Ar 2In the above, the groups mentioned above can be mentioned. X - X does not contain gallium and is a monovalent counter anion. - is preferably a non-antimony based anion, such as BF4 - , AsF6 - , B(C6F5)4 - , [P(R F ) n F 6-n ] - , [C(R F SO2)3] - , or [N(R F SO2)2] - (In the formula, R F are particularly preferably independently a partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and n is an integer of 0 to 5).

[0042] Specific examples of component (E) include diphenyliodonium hexafluoroarsenate, di(4-chlorophenyl)iodonium hexafluoroarsenate, di(4-bromophenyl)iodonium hexafluoroarsenate, phenyl(4-methoxyphenyl)iodonium hexafluoroarsenate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluorophosphate, 4-methylphenyl-4-(1-methylethyl)phenyliodonium tri(pentafluoroethyl)trifluorophosphate (e.g., IK-1 manufactured by San-Apro Co., Ltd.), 4-methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate (e.g., PI-2074 manufactured by Rhodia Co., Ltd.), 4-methylphenyl-4-(2-methylpropyl)phenyliodonium hexafluorophosphate (e.g., IRGACURE® 250 manufactured by BASF), bis(C 10~14Examples of suitable iodonium salts include 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluorophosphate (e.g., WPI-113 manufactured by Wako Pure Chemical Industries, Ltd.), and 4-methylphenyl-4-(1-methylethyl)phenyliodonium hexafluoroantimonate (e.g., WPI-116 manufactured by Wako Pure Chemical Industries, Ltd.). These iodonium salts are commercially available as cationic initiators from reagent suppliers and are readily available.

[0043] <(F) Additives> The (F) additive is a component other than the (A) to (E) components, and examples thereof include a pot life stabilizer, a polymerization inhibitor, a solvent, a photosensitizer, a filler, a coupling agent (particularly a silane coupling agent), a reinforcing agent, a colorant, a stabilizer, an extender, a viscosity modifier, a tackifier, a flame retardant, an ultraviolet absorber, an antioxidant, a discoloration inhibitor, an antibacterial agent, an antifungal agent, an antiaging agent, an antistatic agent, a plasticizer, a lubricant, a leveling agent, a foaming agent, and a mold release agent.

[0044] Examples of the polymerization inhibitor include hydroquinone, paramethoxyphenol, and dibutylhydroxytoluene. Examples of pot life stabilizers include SI aids (4-hydroxyphenyldimethylsulfonium methylsulfite) and hindered phenol-based antioxidants. Components other than those mentioned above can be appropriately selected from known components.

[0045] The component (F) may be one or a combination of two or more. For example, the component (E) may be a combination of one or more pot life stabilizers and one or more solvents.

[0046] <Method for preparing the composition> The thermally cationically polymerizable resin composition can be produced by mixing the components. When components (B) to (F) are solids, they may be dissolved in a solvent to improve compatibility with the components (particularly component (A)) before use in producing the cationically polymerizable resin composition.

[0047] [Curing method] The thermally cationic polymerizable resin composition can be cured by applying heat. Alternatively, the thermally cationic polymerizable resin composition may be temporarily cured (temporarily fixed) by irradiating it with energy rays such as ultraviolet rays, and then permanently cured (fixed) by applying heat. Therefore, the thermally cationic polymerizable resin composition may be a thermosetting composition or a photo- and thermosetting composition. When the thermally cationic polymerizable resin composition is temporarily cured by irradiating it with energy rays, the thermally cationic polymerizable resin composition may contain a photosensitizer.

[0048] <Content of ingredients> The content of each component in the thermally cationically polymerizable resin composition is preferably as follows. The total content of the oxetane resins in the component (A) is preferably 5 to 50 parts by weight, and particularly preferably 10 to 40 parts by weight, per 125 parts by weight of the component (A). The total amount of epoxy resin and oxetane resin in component (A) is preferably 60 to 100 parts by weight, and particularly preferably 80 to 100 parts by weight, per 100 parts by weight of component (A). The total amount of alicyclic epoxy resin and aromatic epoxy resin in component (A) is preferably 60 to 100 parts by weight, and particularly preferably 80 to 100 parts by weight, per 100 parts by weight of the epoxy resin in component (A). The content of the (B) component is preferably 0.1 to 10.0 parts by weight, and particularly preferably 0.5 to 5.0 parts by weight, per 125 parts by weight of the (A) component, from the viewpoint of further increasing the thermosetting property and Tg. From the viewpoint of outgassing, the content of component (C) is preferably 0.1 to 10.0 parts by weight, more preferably 0.5 to 5.0 parts by weight, and particularly preferably 1.0 to 3.0 parts by weight, per 125 parts by weight of component (A). From the viewpoint of heat-resistant transparency, the content of component (C) is preferably 0.1 to 10.0 parts by weight, more preferably 0.5 to 5.0 parts by weight, per 125 parts by weight of component (A). From the viewpoint of further increasing Tg, the content of the component (D) is preferably 0.01 to 1.5 parts by weight or less, and particularly preferably 0.03 to 1.0 part by weight, per 125 parts by weight of the component (A). From the viewpoint of efficiently achieving both a high Tg and heat-resistant transparency, the content of the (E) component is preferably 5.0 parts by weight or less, more preferably 3.0 parts by weight or less, and particularly preferably 0.1 to 3.0 parts by weight, per 125 parts by weight of the (A) component. The total amount of components (A) to (E) is preferably 20 to 100 parts by weight, more preferably 30 to 100 parts by weight, and particularly preferably 40 to 100 parts by weight, based on the total amount of the thermally cationically polymerizable resin composition, with the remainder being component (F).

[0049] [Application] The thermally cationically polymerizable resin composition can be used for fixing optical components (e.g., backlight unit assembly of a display device, optical pickup assembly), camera module assembly, lens module assembly, optical communication module assembly, hard disk assembly, and protection of electronic components (e.g., molds). [Example]

[0050] Examples are given below to clarify specific embodiments of the present invention, but the present invention is not limited to the examples shown here.

[0051] Each composition of the examples and comparative examples was produced using the following raw materials. 1. (A) Component: Cationic curable resin (1) Epoxy resin Bisphenol A epoxy resin (DIC, EPICLON EXA-850CRP) Cresol novolac epoxy resin (DIC, EPICLON N-655-EXP-S) Naphthalene-type epoxy resin (DIC, EPICLON HP-4032D) Alicyclic epoxy resin; (3,3',4,4'-diepoxy)bicyclohexyl (Daicel Corporation, Celloxide 8010) (2) Oxetane resin 3-Ethyl-3-phenoxymethyloxetane (Toagosei Co., Ltd., OXT-211(POX)) Xylylene bisoxetane (Toagosei Co., Ltd., OXT-121 (XDO))

[0052] 2. (B) Component: Iodonium gallate salt 4-Methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)gallate (San-Apro Co., Ltd., IK-1FG)

[0053] 4. (C) Component: Organic peroxide 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate (Perocta O, manufactured by NOF Corporation) t-Butyl peroxy-2-ethylhexanoate (Perbutyl O, manufactured by NOF Corporation)

[0054] 5. Component (D): Thermal cationic polymerization initiator 4-Hydroxyphenyl-methyl-benzylsulfonium tetrakis(pentafluorophenyl)gallate (San-Apro Co., Ltd., TA-100FG) 4-Hydroxyphenyl-methyl-benzylsulfonium tris(pentafluoroethyl)trifluorophosphate (San-Apro Co., Ltd., TA-100)

[0055] 3. (E) Component: Other iodonium salts Bis[4-n-alkyl(C10-13)phenyl]iodonium hexafluorophosphate (WPI-113, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 4-Methylphenyl-4-(1-methylethyl)phenyliodonium tetrakis(pentafluorophenyl)borate (Solvay (Rhodia), PI-2074) 4-Methylphenyl-4-(1-methylethyl)phenyliodonium tri(pentafluoroethyl)trifluorophosphate (San-Apro Co., Ltd., IK-1) Substituted diphenyliodonium tri(pentafluoroethyl)trifluorophosphate (San-Apro, IK-2)

[0056] 5. (F) Ingredients: Other ingredients Pot life stabilizer: 4-hydroxyphenyldimethylsulfonium methylsulfite (Sanshin Chemical Co., Ltd., SI auxiliary) Polymerization inhibitor: dibutylhydroxytoluene (Kanto Chemical Co., Ltd., BHT) Solvent: 4-butyrolactone (Kanto Chemical Co., Ltd.) Solvent: Propylene carbonate (Kanto Chemical Co., Ltd.)

[0057] Some solid thermal cationic initiators, iodonium gallate salts, and other iodonium salts are difficult to dissolve in cationic curable resins, so they were dissolved in 4-butyrolactone and propylene carbonate before being mixed with the resin.

[0058] Examples 1 to 11, Comparative Examples 1 to 8 [Preparation conditions] The thermally cationically polymerizable resin compositions were prepared by mixing the components based on the formulations shown in Tables 1 and 2 and stirring with a stirrer at room temperature (25±3°C; the same applies hereinafter) until the mixture became transparent.

[0059] [Evaluation conditions] ·Thermosetting (DSC) 4±2 mg of resin was weighed out and placed in an aluminum pan, and measurement was performed using a DSC (PerkinElmer DSC4000) at a heating rate of 10°C / min. The reaction initiation temperature (peak rise temperature) and peak temperature were read from the obtained peak. The thermosetting property was judged according to the following criteria. ◎ (Excellent thermosetting properties): Reaction initiation temperature is 100°C or less. ○ (Excellent thermosetting properties): The reaction initiation temperature is over 100°C and 110°C or less. × (poor thermosetting properties): The reaction initiation temperature is above 110°C.

[0060] Glass transition temperature (Tg) and storage modulus The mixture was poured into a mold measuring 50 mm in length, 10 mm in width, and 0.5 mm in thickness, and then thermally cured for 60 minutes in a hot air oven (Espec Corp., LC113) at 100°C to prepare cured test specimens. The resulting cured test specimens were measured using a dynamic viscoelasticity measuring device (DMA, Seiko Instruments Inc., DMS6100) while increasing the temperature at a frequency of 1.0 Hz. The peak top temperature of the loss tangent tanδ obtained was taken as Tg. Test pieces of the cured product were prepared under the same conditions as for Tg and measured using a dynamic viscoelasticity measuring device (DMA, Seiko Instruments Inc., DMS6100). From the results obtained, the value of the storage modulus at 25°C was extracted. The high and low Tg values ​​were determined according to the following criteria. ◎ (Higher Tg): Tg is 110°C or higher. ○ (High Tg): Tg is 90°C or higher and lower than 110°C. × (Low Tg): Tg is less than 90°C.

[0061] Coloring evaluation (transmittance) The resin was applied to a glass slide, then bonded to another glass slide so that the resin thickness was 50 μm. The resin was then thermally cured for 60 minutes in a hot air oven (Espec Corp., LC113) at 100°C to prepare a cured product test specimen. The resulting cured product test specimen was subjected to transmittance measurement using a UV-visible spectrophotometer (JASCO Corp., V-570 spectrophotometer), and the value at 400 nm was extracted. The cured product test specimen was then left at 120°C for 140 hours, after which the transmittance was similarly measured, and the value at 400 nm was extracted. The change in transmittance was calculated using the following formula:

[0062]

number

[0063] The heat resistant transparency was evaluated according to the following criteria. ◎ (better heat-resistant transparency): The change in transmittance is between -3% and +3%. ○ (Excellent heat-resistant transparency): The change in transmittance is −10% or more and less than −3%, or more than +3% and less than +10%. × (poor heat-resistant transparency): The absolute value of the change in transmittance is more than 10% (that is, the change in transmittance is less than −10% (such as −20%) or more than +10%).

[0064] Outgassing amount 10±3 mg of resin was weighed into an aluminum pan and weighed using a TGA (METTLER TOLED TGA / DSC1) (initial weight). It was then held at 100°C for 60 minutes and weighed again (weight after heating). The rate of weight loss on heating (weight change rate (%)) was calculated using the following formula and used as the amount of outgassing.

[0065]

number

[0066] The amount of outgassing was determined according to the following criteria. × (outgassing amount not reduced): The outgassing amount exceeds 1.0%. ∘ (reduced outgassing amount): The outgassing amount is more than 0.5% and 1.0% or less. ◎ (outgassing amount is further reduced): outgassing amount is 0.5% or less.

[0067] The results are summarized in the table below.

[0068] [Table 1]

[0069] [Table 2]

[0070] The thermally cationically polymerizable resin compositions of Examples 1 to 11 had high Tg, reduced outgassing, excellent heat-resistant transparency, and excellent thermosetting properties. A comparison of Examples 1 to 3 showed that when the content of component (B) relative to 125 parts by weight of component (A) was within a particularly preferred range, Tg was higher. A comparison of Examples 1, 4 and 5 revealed that the amount of outgassing was further reduced when the content of component (C) was reduced relative to 125 parts by weight of component (A). Comparison of Example 1 with Examples 9 and 10 shows that even when the thermally cationically polymerizable resin composition further contained component (D), the Tg was higher and the amount of outgassing was reduced. Comparative Examples 1 to 6 did not contain component (B), and therefore either had a low Tg, the amount of outgassing was not reduced, or the heat-resistant transparency was poor. Comparative Example 7 did not contain component (C) and therefore had poor thermosetting properties. Comparative Example 8 did not contain the component (B) but contained the thermal cationic polymerization initiator (D), and therefore had a low Tg.

Claims

1. (A) a cationically curable resin, (B) The following formula (1): Ar １ -I ＋ -Ar ２ ・[(R １ )(R ２ )(R ３ )(R ４ )Ga] － (1) [During the ceremony, R １ ~R ４ are each independently an alkyl group or Ar ３ However, R １ ~R ４ At least one of ３ and Ar １ ~Ar ３ are each independently an aryl group or a heteroaryl group, and the aryl group or the heteroaryl group is an alkyl group, an alkyl group substituted with a halogen atom, an alkenyl group, an alkynyl group, a nitro group, a hydroxyl group, a cyano group, -OR ６ group, -COR ７ Group, -OCOR ８ group, -SR ９ group, -NR １０ R １１ may be substituted with a group or a halogen atom, R ６ is an alkyl group, an alkyl group substituted with a hydroxyl group, an aryl group, or a heteroaryl group, and R ７ ~R ９ are each independently an alkyl group, an aryl group, or a heteroaryl group, and R １０ and R １１ are each independently a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group; and (C) Organic peroxide Including, The component (A) is a combination of an epoxy resin and an oxetane resin, the content of the oxetane resin in the component (A) is 5 to 50 parts by weight per 125 parts by weight of the component (A); The content of the (B) component is 0.1 to 10.0 parts by weight per 125 parts by weight of the (A) component, The content of the component (C) is 0.1 to 10.0 parts by weight per 125 parts by weight of the component (A).

2. The thermally cationically polymerizable resin composition according to claim 1, further comprising (D) a thermally cationically polymerizable resin composition.

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