Radical polymerizable adhesive

Abstract

The present invention addresses the problem of providing a radical polymerizable adhesive that exhibits an excellent hot tensile shear adhesive strength and also an excellent tensile shear adhesive strength after heat treatment. Provided as the solution is a radical polymerizable adhesive comprising (A) a radical polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having a radical polymerizable group, and (D) a non-radical polymerizable polymer having a molecular weight of at least 1,000. For this radical polymerizable adhesive, the hot tensile shear adhesive strength retention ratio Ra is at least 13% and the retention ratio Rb for the thermal aging resistance by the tensile shear adhesive strength is at least 50%. The hot tensile shear adhesive strength retention ratio Ra is calculated using formula (i) where A in formula (i) is the tensile shear adhesive strength (N / mm2) for bonding at 23°C and B is the 150°C hot tensile shear adhesive strength (N / mm2). The retention ratio Rb for the thermal aging resistance by the tensile shear adhesive strength is calculated using formula (ii) where A in formula (ii) is the tensile shear adhesive strength (N / mm2) for bonding at 23°C and C is the tensile shear adhesive strength (N / mm2) after heating at 200°C for 2 hours and then cooling to 23°C.

Description

Radical Polymerization Adhesive

[0001] The present invention relates to a radically polymerizable adhesive.

[0002] Radical polymerizable adhesives contain a radical polymerizable compound, such as a radical polymerizable compound having a (meth)acryloyl group, as a constituent component and polymerize and cure through a radical curing reaction, a type of chain reaction. Anaerobic adhesives, a type of radical polymerizable adhesive, are one-component adhesives that are stable under oxygen, e.g., air, conditions and do not cure over long periods at room temperature (25°C ± 5°C). When an anaerobic adhesive is applied to an adherend and then shielded from oxygen (air), it immediately begins to cure, enabling the adhesion of the adherend. Anaerobic adhesives, utilizing their unique properties, are used for bonding metal plates, preventing screws and bolts from loosening, securing fittings such as bearings, sealing, and so on.

[0003] Examples of radically polymerizable adhesives are disclosed in Patent Documents 1 to 3. Patent Document 1 describes applying an anaerobic adhesive to a metal bolt / nut that has been coated with a curing accelerator containing a chelate compound, and then fastening the bolt / nut. Patent Document 2 describes applying an anaerobic adhesive to a metal bolt / nut that has been coated with a pretreatment agent for accelerating the curing of the anaerobic adhesive, and then fastening the bolt / nut. Patent Document 3 describes applying an anaerobic adhesive composition containing an acrylic acid ester monomer, an organic peroxide, and a phosphoric acid compound having a (meth)acryloyl group to the inner wall and / or shaft of a ring, and then inserting and fitting the shaft into the ring to secure it.

[0004] JP-A-60-179407, JP-A-49-021093, JP-A-51-132234

[0005] Articles manufactured by bonding with anaerobic adhesives, a type of radical-polymerizable adhesive, are painted or otherwise processed to form final products. Typically, painting involves a heating and drying process or a baking process. The anaerobic adhesives described in Patent Documents 1 to 3 have excellent adhesive strength, but there is a risk of the adhesive strength (hot adhesive strength) decreasing in a heated environment, resulting in peeling of the bonded area. Furthermore, the anaerobic adhesives described in Patent Documents 1 to 3 have insufficient heat aging resistance, resulting in a decrease in adhesive strength and peeling of the bonded area after a heat treatment (baking) process following painting. The problem to be solved by the present invention is to provide a radical-polymerizable adhesive that has excellent hot tensile shear adhesive strength and tensile shear adhesive strength after heat treatment.

[0006] The present inventors have conducted extensive research to solve the above problems, and as a result have found that the above problems can be solved by a radically polymerizable adhesive having a specific composition, thereby completing the present invention. Specifically, the invention is as follows: [Item 1] A radically polymerizable adhesive containing (A) a radically polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having a radically polymerizable group, and (D) a non-radical polymerizable polymer having a molecular weight of 1,000 or more, wherein the hot tensile shear adhesive strength retention rate R ａ is 13% or more and heat aging tensile shear adhesive strength retention rate R ｂ is 50% or more, and the hot tensile shear bond strength retention rate R ａ is represented by formula (i): In formula (i), A is the tensile shear adhesive strength (N / mm ２ ) and B is the 150°C hot tensile shear adhesive strength (N / mm ２ ) wherein the heat aging tensile shear adhesive strength retention rate R ｂ is represented by formula (ii): In the formula (ii), A is the tensile shear adhesive strength (N / mm ２ ) and C is the tensile shear adhesive strength (N / mm ２[Item 2] The radical polymerizable adhesive (A), wherein the radical polymerizable compound (A) has a formula (1) in the molecule: Item 1. The radical polymerizable adhesive according to Item 1, comprising a radical polymerizable compound having a structure represented by the following formula: and / or (a2) a urethane (meth)acrylate. [Item 3] The radical polymerizable adhesive according to Item 1 or 2, wherein the radical polymerizable adhesive is an anaerobic adhesive. [Item 4] The radical polymerizable adhesive according to Item 3, wherein the radical polymerizable adhesive is an anaerobic adhesive for metals.

[0007] The present invention provides a radically polymerizable adhesive that is excellent in hot tensile shear bond strength and tensile shear bond strength after heat treatment.

[0008] The radical polymerizable adhesive of the present invention is a radical polymerizable adhesive containing (A) a radical polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having a radical polymerizable group, and (D) a non-radically polymerizable polymer having a molecular weight of 1,000 or more, and has a hot tensile shear adhesive strength retention rate R ａ is 13% or more and heat aging tensile shear adhesive strength retention rate R ｂ is 50% or more, and the hot tensile shear bond strength retention rate R ａ is represented by formula (i): In formula (i), A is the tensile shear adhesive strength (N / mm ２ ) and B is the 150°C hot tensile shear adhesive strength (N / mm ２ ) wherein the heat aging tensile shear adhesive strength retention rate R ｂ is represented by formula (ii): In the formula (ii), A is the tensile shear adhesive strength (N / mm ２ ) and C is the tensile shear adhesive strength (N / mm ２ The radical polymerizable adhesive of the present invention is characterized in that the radical polymerizable compound (A) has a structure represented by the formula (1): (a1) in the molecule: and / or (a2) a urethane (meth)acrylate. The radical polymerizable adhesive of the present invention may be an anaerobic adhesive, preferably an anaerobic adhesive for metals. The radical polymerizable adhesive of the present invention will be described in detail below. In this specification, "(meth)acrylic" means "acrylic" and "methacrylic", "(meth)acrylate" means "acrylate" and "methacrylate", and "(meth)acryloyl" means "acryloyl" and "methacryloyl", respectively.

[0009] [(A) Radically Polymerizable Compound] The (A) radically polymerizable compound contained in the radically polymerizable adhesive of the present invention is a compound having a radically polymerizable functional group, in particular a radically polymerizable ethylenically unsaturated group, and is a compound other than "(C) a phosphate compound having a radically polymerizable group." Examples of the radically polymerizable functional group include a (meth)acryloyl group, a vinyl group, an allyl group, a (meth)acrylamide group, a styryl group, an alkenyl group, an alkenylene group, and a maleimide group, and of these, a (meth)acryloyl group is preferred.

[0010] The number of radically polymerizable groups contained in the molecule of the radically polymerizable compound (A) is not particularly limited. From the viewpoint of curability, adhesiveness, etc., it is, for example, 1 to 10, preferably 1 to 8, and more preferably 1 to 6. In particular, in the present invention, it is preferable to use one or more radically polymerizable compounds having one or two (meth)acryloyl groups as the radically polymerizable compound (A). Alternatively, a mixture of one or more radically polymerizable compounds having one (meth)acryloyl group and one or more radically polymerizable compounds having two or more (meth)acryloyl groups may be used.

[0011] The radical polymerizable compound (A) may be one or more selected from the group consisting of radical polymerizable oligomers and radical polymerizable monomers. In the present invention, the radical polymerizable oligomer may be, for example, a compound having one or more radical polymerizable groups and a weight average molecular weight of 400 or more. In the present invention, the radical polymerizable monomer may be, for example, a compound other than the radical polymerizable oligomer, having one or more radical polymerizable groups and a molecular weight of less than 400.

[0012] <Radical Polymerizable Oligomer> The radical polymerizable oligomer is not particularly limited as long as it is a compound having one or more radical polymerizable groups in the molecule, has a weight average molecular weight of 400 or more, and is a radical polymerizable compound other than the phosphate ester compound (C) having a radical polymerizable group. In the present invention, from the viewpoints of the adhesive strength to metal of the radical polymerizable adhesive, the curing rate, the heat aging resistance, etc., it is preferable to use a (meth)acrylate oligomer having one or more (meth)acryloyl groups as the radical polymerizable oligomer.

[0013] The number of (meth)acryloyl groups contained in the molecule of the (meth)acrylate oligomer is not particularly limited. For example, it can be 1 to 10, preferably 1 to 8, and more preferably 1 to 6. The upper limit of the weight average molecular weight of the (meth)acrylate oligomer is not particularly limited. For example, it can be 100,000 or less, preferably 30,000 or less, and more preferably 20,000 or less.

[0014] Examples of the (meth)acrylate oligomer include one or more selected from the group consisting of urethane (meth)acrylate, epoxy (meth)acrylate, bisphenol alkylene oxide adduct (meth)acrylate, ether (meth)acrylate, ester (meth)acrylate, isoprene-based (meth)acrylate, hydrogenated isoprene-based (meth)acrylate, (meth)acrylic group-containing acrylic polymer, (meth)acrylic group-containing polyisobutylene, etc. Either a commercially available product or a synthetic product may be used as the (meth)acrylate oligomer.

[0015] Examples of urethane (meth)acrylates include those obtained by reacting at least a polyol component, a polyisocyanate component, and a compound having a functional group reactive with a hydroxyl group or an isocyanate group and a (meth)acrylate group. Examples of the polyol component include those containing one or more polymer polyols selected from the group consisting of (hydrogenated) butadiene polyols, polycarbonate polyols, polyether polyols, polyester polyols, polyacrylate polyols (acrylic polyols), urethane polyols, etc. Examples of the polyisocyanate component include one or more selected from the group consisting of aliphatic polyisocyanates (e.g., hexamethylene diisocyanate), alicyclic polyisocyanates (e.g., dicyclohexylmethane diisocyanate, isobornyl diisocyanate), aromatic polyisocyanates (e.g., toluene diisocyanate, diphenylmethane diisocyanate), and araliphatic polyisocyanates (e.g., xylylene diisocyanate). Examples of the compound having a (meth)acrylate group and a functional group reactive with a hydroxyl group or an isocyanate group include a (meth)acrylate having a group reactive with an isocyanate group (e.g., one or more selected from the group consisting of hydroxyl group-containing (meth)acrylates and / or carboxyl group-containing (meth)acrylates described in <Radical Polymerizable Monomers>) and one or more selected from the group consisting of an isocyanate group and a containing (meth)acrylate.

[0016] Examples of the urethane (meth)acrylate include one or more selected from the group consisting of urethane (meth)acrylates having a (hydrogenated) polybutadiene skeleton, urethane (meth)acrylates having a polycarbonate skeleton, urethane (meth)acrylates having a polyether skeleton, urethane (meth)acrylates having a polyester skeleton, urethane (meth)acrylates having a polyacrylate skeleton, urethane (meth)acrylates having a urethane skeleton, and urethane (meth)acrylates having a castor oil skeleton.

[0017] Epoxy (meth)acrylates can be obtained, for example, by reacting an epoxy resin with a (meth)acrylate compound having a functional group reactive with an epoxy group. Examples of epoxy resins include one or more selected from the group consisting of bisphenol-type epoxy resins (bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, etc.), phenol novolac-type epoxy resins, and epoxy resins such as terminal glycidyl ethers of alkylene oxide adducts of bisphenol-type epoxy resins. Examples of (meth)acrylate compounds having a functional group reactive with an epoxy group include one or more selected from the group consisting of hydroxyl-group-containing (meth)acrylates and / or carboxyl-group-containing (meth)acrylates described in <Radical Polymerizable Monomers>. Commercially available epoxy (meth)acrylates can be used. For example, EPICLON UE-8071-60BH, UE-8740, UE-8410 (manufactured by DIC Corporation); KAYARD R-115F (manufactured by Nippon Kayaku Co., Ltd.); HITAROID 7851 (manufactured by Showa Denko K.K.); Epoxy Ester 3000MK, 3000A, 3002A(N), 3002M(N) (manufactured by Kyoeisha Chemical Co., Ltd.); Light Acrylate BP-4EAL, BP-4PA (manufactured by Kyoeisha Chemical Co., Ltd.); NK Ester Examples of the copolymer include one or more selected from the group consisting of BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BPE-1300N, ABE-300, A-BPE-10, BPE-20, BPE-30, and A-BPE-4 (manufactured by Shin-Nakamura Chemical Co., Ltd.); Viscoat #540 (manufactured by Osaka Organic Chemical Industry Co., Ltd.); EBECRYL 600 and 3700 (manufactured by Daicel Allnex Corporation); and BPE-4, BPE-10, BPE-20, BPEM-10, BPP-4, and HBPE-4 (manufactured by Daiichi Kogyo Co., Ltd.).

[0018] Examples of the bisphenol alkylene oxide adduct (meth)acrylate include those represented by the following formula (A): (In formula (A), R １１ is a hydrogen atom or a methyl group. １２ is a hydrogen atom or a methyl group. １is an alkylene group having 1 to 6 carbon atoms, and when there are a plurality of groups, they may be different from each other. ２ represents an alkylene group having 1 to 6 carbon atoms, and when there are a plurality of groups, they may be different from each other. X represents a direct bond, —CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３ )-, -O-, -S-, -SO ２ -, -CO-, -CF ２ -, -C(CF ３ ) ２ -, -C(Ph) ２ -, -CH(Ph)- (Ph is a phenyl group). m is an integer of 0 or 1 or more. n is an integer of 0 or 1 or more.) Among these, one or more compounds selected from the group consisting of (poly)oxyalkylene-modified bisphenol A di(meth)acrylate, for example, (poly)oxyethylene-modified bisphenol A di(meth)acrylate, (poly)oxypropylene-modified bisphenol A di(meth)acrylate, etc. can be mentioned. Specifically, in the compound represented by the above formula (A), R １１ is a hydrogen atom or a methyl group, and R １２ is a hydrogen atom or a methyl group, and A １ is an alkylene group having 2 to 6 carbon atoms (preferably 2 to 4), and A ２ is an alkylene group having 2 to 6 carbon atoms (preferably 2 to 4), and X is —C(CH ３ ) ２ - and compounds in which m+n (ie, ethoxy equivalents) is 1 to 40 (preferably 2 to 10) are preferred.

[0019] Examples of the ester (meth)acrylate oligomer include those obtained by adding, for example, a hydroxyl group-containing (meth)acrylate and / or a carboxyl group-containing (meth)acrylate described in <Radical Polymerizable Monomer> to a carboxyl group and / or a hydroxyl group possessed by an ester-based oligomer obtained by reacting a polyol with a polycarboxylic acid.

[0020] Examples of the ether (meth)acrylate oligomer include those obtained by adding a hydroxyl group-containing (meth)acrylate and / or a carboxyl group-containing (meth)acrylate described in <Radical Polymerizable Monomers> to the hydroxyl groups of an aliphatic polyether polyol or to the hydroxyl groups of an aromatic polyether polyol made from a raw material such as bisphenol.

[0021] Among these radical polymerizable oligomers, in particular, those having excellent properties in normal adhesiveness (normal tensile shear adhesive strength), hot adhesiveness (hot tensile shear adhesive strength), and hot tensile shear adhesive strength retention rate R ａ , heat aging resistance (heat aging tensile shear adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂ From these viewpoints, it is preferable to use one or more selected from the group consisting of urethane (meth)acrylate, epoxy (meth)acrylate, bisphenol alkylene oxide adduct (meth)acrylate, and ether (meth)acrylate.

[0022] <Radical Polymerizable Monomer> The radical polymerizable monomer is not particularly limited as long as it is a compound having one or more radical polymerizable groups in the molecule, is not a radical polymerizable oligomer or a radical polymerizable polymer, has a molecular weight of less than 400, and is a radical polymerizable compound other than the phosphate ester compound (C) having a radical polymerizable group. In the present invention, from the viewpoints of the adhesive strength to metal of the radical polymerizable adhesive, the curing rate, the heat aging resistance, etc., it is preferable to use a (meth)acrylate monomer having one or more (meth)acryloyl groups as the radical polymerizable monomer.

[0023] Among (meth)acrylate monomers having one or more (meth)acryloyl groups, examples of (meth)acrylate monomers having one (meth)acryloyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, neopentyl (meth)acrylate, and lauryl (meth)acrylate. Aliphatic (meth)acrylates such as methyl (meth)acrylate and stearyl (meth)acrylate; alicyclic (meth)acrylates such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate and adamantyl (meth)acrylate; benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate aromatic ring-containing (meth)acrylates such as acrylate, nonylphenoxyethyl (meth)acrylate, nonylphenoxytetraethylene glycol (meth)acrylate, and nonylphenyl polypropylene glycol (meth)acrylate; hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerol (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, ethylene oxide-modified phthalic acid (meth)acrylate, ethylene oxide-modified succinic acid (meth)acrylate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, and caprolactone-modified tetrahydrofurfuryl (meth)acrylate;Carboxyl group-containing (meth)acrylates such as (meth)acrylic acid, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl phthalate, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid; alkoxy group-containing (meth)acrylates such as methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, butoxytriethylene glycol (meth)acrylate, 2-ethylhexyl polyethylene glycol (meth)acrylate, and methoxydipropylene glycol (meth)acrylate; acrylamide, hydroxyethyl acrylamide, dimethylacrylamide, diethylacrylamide, methacrylamide, N-methyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methyl ...methylol(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol p) acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N,N-diisobutyl(meth)acrylamide, N,N-di-tert-butyl(meth)acrylamide, N,N-diheptyl(meth)acrylamide, N,N-dioctyl(meth)acrylamide, N,N-di-tert-octyl (meth)acryloyl group-containing amides such as (meth)acrylamide, N,N-didodecyl(meth)acrylamide, N,N-dioctadecyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, and N,N-dimethylaminoethyl(meth)acrylamide; amino group-containing (meth)acrylates such as N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl(meth)acrylate, and N-t-butylaminoethyl(meth)acrylate;One or more selected from the group consisting of heterocycle-containing (meth)acrylates such as glycidyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4yl)methyl (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, pentamethylpiperidyl (meth)acrylate, isocyanuric acid di(meth)acrylate, isocyanuric acid tri(meth)acrylate, triazine tri(meth)acrylate, N-(meth)acryloxysuccinimide, and N-(meth)acryloxyphthalimide are examples thereof;

[0024] Among (meth)acrylates having one or more (meth)acryloyl groups, (meth)acrylates having two (meth)acryloyl groups include, for example, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, ethoxylated propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-Nonanediol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, glycidol di(meth)acrylate, pentaerythritol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, ethylene oxide-modified neopentyl glycol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A ethylene oxide-modified di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, bisphenol A propylene oxide-modified di(meth)acrylate Examples of the di(meth)acrylate include one or more selected from the group consisting of ethylene oxide-modified dicyclopentenyl di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, hydroxypivalic acid ester neopentyl glycol diacrylate, caprolactone-modified hydroxypivalic acid ester neopentyl glycol diacrylate, neopentyl glycol-modified trimethylolpropane di(meth)acrylate, stearic acid-modified pentaerythritol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, ethylene oxide-modified dicyclopentenyl di(meth)acrylate, di(meth)acryloyl isocyanurate, dimethyloltricyclodecane di(meth)acrylate, and the like.

[0025] Among (meth)acrylates having one or more (meth)acryloyl groups, (meth)acrylates having three or more (meth)acryloyl groups include, for example, glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, tetramethylolmethane triacrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(acryloyloxyethyl)isocyanurate, and ε-caprolactone-modified tris(acryloxyethyl)isocyanurate. and tri(meth)acrylates having three (meth)acryloyl groups, such as ethoxylated isocyanuric acid triacrylate; and poly(meth)acrylates having four or more (meth)acryloyl groups, such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, and tetrapentaerythritol hexa(meth)acrylate.

[0026] Among these radical polymerizable monomers, aliphatic (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, neopentyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; alicyclic (meth)acrylates such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate; and 2-hydroxypropyl (meth)acrylate. Hydroxyl group-containing (meth)acrylates such as propyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, and polypropylene glycol (meth)acrylate; carboxyl group-containing (meth)acrylates such as (meth)acrylic acid and 2-(meth)acryloyloxyethyl succinic acid; ethylene glycol di(meth)acrylate, polyethylene glycol Di(meth)acryloyl groups having 2 groups each having 1 to 2 carbon atoms, such as 1,4-butanediol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A di(meth)acrylate, bisphenol A ethylene oxide-modified di(meth)acrylate, bisphenol A propylene oxide-modified di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, and dicyclopentenyl di(meth)acrylate. di(meth)acrylates having one or more (meth)acryloyl groups; tri(meth)acrylates having three (meth)acryloyl groups, such as glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate; poly(meth)acrylates having four or more (meth)acryloyl groups, such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate;Preferably, one or more selected from the group consisting of:

[0027] <Preferred embodiment of (A) radical polymerizable compound> In the present invention, the (A) radical polymerizable compound is a compound having a high hot adhesion (hot tensile shear bond strength), a hot tensile shear bond strength retention rate R ａ , heat aging resistance (heat aging tensile shear adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂ From the viewpoint of the above, (a1) the molecule contains the formula (1): It is preferable that the composition contains a radical polymerizable compound having a structure represented by formula (1) in the molecule, and / or (a2) a urethane (meth)acrylate. One or more types of radical polymerizable compounds having a structure represented by formula (1) in the molecule can be used, and one or more types of urethane (meth)acrylates can be used.

[0028] (a1) Examples of the radical polymerizable compound having a structure represented by the formula (1) in the molecule include: (i) one or more epoxy (meth)acrylates which are reaction products of epoxy resins having a structure represented by the formula (A) in the molecule, such as bisphenol A type epoxy resins and terminal glycidyl ethers of alkylene oxide adducts of bisphenol A type epoxy resins, with hydroxyl group-containing (meth)acrylates and / or carboxyl group-containing (meth)acrylates (commercially available products include, for example, EPICLON UE-8071-60BH, UE-8740, UE-8410 (manufactured by DIC Corporation), Kayard R-115F (manufactured by Nippon Kayaku Co., Ltd.), HITALOID 7851 (manufactured by Showa Denko KK), Epoxy Ester 3000MK, 3000A, 3002A(N), 3002M(N) (manufactured by Kyoeisha Chemical Co., Ltd.), and Light Acrylate BP-4EAL, BP-4PA (manufactured by Kyoeisha Chemical Co., Ltd.), NK ester BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BPE-1300N, ABE-300, A-BPE-10, BPE-20, BPE-30, A-BPE-4 (manufactured by Shin-Nakamura Chemical Co., Ltd.), Viscoat #540 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), EBECRYL 600, 3700 (manufactured by Daicel Allnex Co., Ltd.), BPE-4, BPE-10, BPE-20, BPEM-10, BPP-4, HBPE-4 (manufactured by Daiichi Kogyo Co., Ltd.), Viscoat VR-77 (manufactured by Showa Polymer Co., Ltd.), etc.); (ii) bisphenol A di(meth)acrylate; (iii) (poly)oxyalkylene-modified bisphenol A di(meth)acrylate (e.g., bisphenol A ethylene oxide-modified di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, bisphenol A propylene oxide-modified di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, etc.); and the like.

[0029] Examples of (a2) urethane (meth)acrylates include at least one selected from the group consisting of urethane (meth)acrylates having a polyether skeleton, urethane (meth)acrylates having a polyester skeleton, urethane (meth)acrylates having a polyacrylate skeleton, urethane (meth)acrylates having a urethane skeleton, urethane (meth)acrylates having a (hydrogenated) polybutadiene skeleton, urethane (meth)acrylates having a polycarbonate skeleton, and urethane (meth)acrylates having a castor oil skeleton. Preferably, it is at least one selected from the group consisting of urethane (meth)acrylates having a polyether skeleton, urethane (meth)acrylates having a polyester skeleton, urethane (meth)acrylates having a polycarbonate skeleton, urethane (meth)acrylates having a polyacrylate skeleton, and urethane (meth)acrylates having a urethane skeleton, more preferably at least one selected from the group consisting of urethane (meth)acrylates having a polyether skeleton, urethane (meth)acrylates having a polyester skeleton, and urethane (meth)acrylates having a polycarbonate skeleton, and even more preferably at least one urethane (meth)acrylate having a polyether skeleton. Examples of the polyether skeleton in the urethane (meth)acrylate having a polyether skeleton include -(-CH ２ CH ２ O-)-skeleton, -(-CH ２ CH (CH ３ )O-)-skeleton, -(-CH(CH ３ ) CH ２ O-)-skeleton, -(-CH ２ CH ２ CH ２ O-)-skeleton, -(-CH ２ CH ２ CH ２ CH ２ O-)-skeleton and the like.

[0030] (a2) Commercially available urethane (meth)acrylates include, for example, Shiko UV-2750B, UV-7000B, UV-6640B, UV-7510B, UV-6630B, UV-7550B, UV-7610B, UV-7650B, UV-6300, UV-7620B, UV-7600B, UV-7630B, UV-7605B, UV-7640B, UV-1700B, and UV-3310B (manufactured by Mitsubishi Chemical Corporation); Art Resin UN-6200, UN-6207, UN-6303, UN-6304, UN-6305, UN-6306, UN-6307, UN-6060S, UN-6303PR, PMH101B, PMH-401B, MB-1 91, STQI-037PR, UN-333, UN-350, UN-352, UN-353, UN-7600, UN-7700, MBU-71, UN-5500, UN-5590, UN-9000PEP, UN-92 00A, UN-2310, UN-2601, UN-2701, SMT-001, CWD-8E26, UN-3320HA, UN-3320HC, UN-3320HS, UN-904, UN-901T, UN-952, UN-954, UN-905, H-575, UN-906S, JHP-001, UN-1000PEP, UN-2500, UN-5200, UN-380G, UN-500, UN-9832, etc. (manufactured by Negami Kogyo); NK Oligo UA-4200, UA-160TM, UA-290TM, UA-7100, UA-W2A, UA-4400, UA-122P, U-200PA, UA-1100H, U-6LPA, UA-33H, U-10HA, U-10PA, U-15HA, and the like (manufactured by Shin-Nakamura Chemical Co., Ltd.); Aronix Examples of the acrylic acid ester include, but are not limited to, one or more selected from the group consisting of M-1100, M-1200, etc. (manufactured by Toagosei Co., Ltd.); CN8899NS, etc. (manufactured by Arkema); AH-600, AT-600, UA-306H, UF-8001G, etc. (manufactured by Kyoeisha Chemical Co., Ltd.); RUA-071, RUA-003VE, RUA-075, RUA-048, etc. (manufactured by Asia Chemical Industry Co., Ltd.); AU-2040, etc. (manufactured by Tokushiki Chemical Co., Ltd.); KUA-PC2I, etc. (manufactured by KSM Corporation).

[0031] In the present invention, from the viewpoint of adhesive strength to adherends, particularly metals, it is preferable that the radical polymerizable compound (A) contains one or more radical polymerizable compounds having one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, and an amino group. The content of the radical polymerizable compound having a functional group in the radical polymerizable compound (A) is not particularly limited. It can be, for example, 30% by mass or more, preferably 35% by mass or more, and can be, for example, 60% by mass or less, preferably 55% by mass or less.

[0032] <Content of (A) radical polymerizable compound> The content of the (A) radical polymerizable compound in the radical polymerizable adhesive is not particularly limited. It can be, for example, 50% by mass or more, preferably 75% by mass or more, and for example, 99% by mass or less, preferably 98% by mass or less, based on the total amount of the radical polymerizable adhesive being 100% by mass. When the content of the (A) radical polymerizable compound is less than 50% by mass based on the total amount of the radical polymerizable adhesive being 100% by mass, the normal adhesion (normal tensile shear bond strength), hot adhesion (hot tensile bond strength), and hot tensile shear bond strength retention rate R ａ , heat aging resistance (heat aging tensile adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂ If the content exceeds 99 mass %, the normal adhesion, hot adhesion, heat aging resistance, curing speed, etc. of the radical polymerizable adhesive may become insufficient.

[0033] [(B) Organic Peroxide] The (B) organic peroxide, a component of the radical-polymerizable adhesive of the present invention, is used to impart curability, such as anaerobic curability and / or heat curability, to the radical-polymerizable adhesive. Examples of the (B) organic peroxide include hydroperoxide compounds such as cumene hydroperoxide, t-butyl hydroperoxide, p-menthane hydroperoxide, methyl ethyl ketone peroxide, cyclohexane peroxide, dicumyl peroxide, and diisopropylbenzene hydroperoxide, as well as one or more compounds selected from the group consisting of ketone peroxide compounds, diallyl peroxide compounds, and peroxyester compounds. Of these, hydroperoxide compounds are preferred from the viewpoints of the reactivity and storage stability of the radical-polymerizable adhesive.

[0034] From the viewpoint of excellent curability, particularly excellent anaerobic curability, (B) organic peroxides having a one-hour half-life temperature of 80°C or higher, preferably 100°C or higher, and 300°C or lower, preferably 200°C or lower, are preferred. The one-hour half-life temperature is a value measured by thermal decomposition under conditions of an organic peroxide concentration of 0.1 mol / L in benzene. Examples of organic peroxides having a one-hour half-life temperature of 80°C or higher and 300°C or lower include hydroperoxides. Specific examples of hydroperoxides include one or more selected from the group consisting of p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide.

[0035] The content of the (B) organic peroxide in the radical polymerizable adhesive is not particularly limited. It can be, for example, 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less, relative to 100 parts by mass of the (A) radical polymerizable compound. By setting the blending amount of the (B) organic peroxide in the radical polymerizable adhesive to be in the range of 0.05 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the (A) radical polymerizable compound, the normal adhesion (normal tensile shear bond strength), hot adhesion (hot tensile bond strength), and hot tensile shear bond strength retention R of the radical polymerizable adhesive can be improved. ａ , heat aging resistance (heat aging tensile adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂ etc. can be made even better.

[0036] [(C) Phosphate Ester Compound Having a Radically Polymerizable Group] The phosphate ester compound having a radically polymerizable group (C), which is a component of the radically polymerizable adhesive of the present invention, is a compound having a radically polymerizable functional group and a group represented by the following formula (2) or (3): -O-P(O)(OH)-O- (2) -O-P(O)(OH) ２ ...(3) The radically polymerizable functional group is one or more phosphate ester compounds having a group represented by the formula: (3) The radically polymerizable functional group may be, for example, an ethylenically unsaturated bond. Examples of the ethylenically unsaturated bond include a (meth)acryloyl group, a vinyl group, an allyl group, a (meth)acrylamide group, a styryl group, an alkenyl group, an alkenylene group, and a maleimide group. Of these, a (meth)acryloyl group is preferred. The number of radically polymerizable groups possessed by the phosphate ester compound having a radically polymerizable group (C) is not particularly limited. It is 1 or more, and can be 3 or less, preferably 2 or less, in consideration of reactivity and availability. The use of the phosphate ester compound having a radically polymerizable group (C) in combination with the radically polymerizable compound (A) and the organic peroxide (B) has the remarkable effect of producing a radically polymerizable adhesive that exhibits excellent adhesive strength (normal tensile shear adhesive strength) to various adherends, such as metal plates and plastics, particularly steel plates.

[0037] The phosphate ester compound (C) having a radical polymerizable group is not particularly limited, and examples thereof include one or more compounds selected from the group consisting of 2-hydroxymethyl(meth)acrylate acid phosphate, 2-hydroxyethyl(meth)acrylate acid phosphate, 2-hydroxypropyl(meth)acrylate acid phosphate, bis(meth)acryloyloxy acid phosphate, bis(2-(meth)acryloyloxyethyl acid)phosphate, di-(2-(meth)acryloyloxy)hydrogen phosphate, ethylene oxide-modified di(meth)acrylate phosphate, ethylene oxide-modified tri(meth)acrylate phosphate, caprolactone-modified ethylene oxide-modified di(meth)acrylate phosphate, and dipentaerythryl penta(meth)acryloyloxydihydrogen phosphate.

[0038] The (C) phosphate ester compound having a radical polymerizable group may be synthesized or may be a commercially available product, such as one or more selected from the group consisting of Light Ester P-A, P-1M, and P-2M (all manufactured by Kyoeisha Chemical Co., Ltd.), Kayamar PM-1 (manufactured by Nippon Kayaku Co., Ltd.), and JPA-514 (manufactured by Johoku Chemical Industry Co., Ltd.).

[0039] The content of the (C) phosphate ester compound having a radical polymerizable group in the radical polymerizable adhesive is not particularly limited. ａ , heat aging resistance (heat aging tensile adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂFrom the viewpoint of the curing speed, the content of the (C) phosphate ester compound having a radical polymerizable group is, for example, 0.05 part by mass or more, preferably 0.06 part by mass or more, more preferably 0.07 part by mass or more, relative to 100 parts by mass of the (A) radical polymerizable compound, and can be, for example, less than 1.0 part by mass, preferably 0.8 part by mass or less, more preferably 0.5 part by mass or less. If the content of the (C) phosphate ester compound having a radical polymerizable group is 1.0 part by mass or more relative to 100 parts by mass of the (A) radical polymerizable compound, the curing speed may be insufficient. If the content is less than 0.05 part by mass, the normal adhesion (normal tensile shear bond strength), hot adhesion (hot tensile bond strength), and hot tensile shear bond strength retention R of the radical polymerizable adhesive may be insufficient. ａ , heat aging resistance (heat aging tensile adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂ There is a risk that the above may be insufficient.

[0040] [(D) Non-Radical Polymerizable Polymer with Molecular Weight of 1,000 or More] The (D) non-radical polymerizable polymer with a molecular weight of 1,000 or more, which is a component of the radically polymerizable adhesive of the present invention, is a polymer having a weight-average molecular weight of 1,000 or more and having no radically polymerizable groups in the molecule. Here, examples of the radically polymerizable functional group include ethylenically unsaturated bonds. Examples of the ethylenically unsaturated bond include (meth)acryloyl groups, vinyl groups, allyl groups, (meth)acrylamide groups, styryl groups, alkenyl groups, alkenylene groups, and maleimide groups.

[0041] The weight-average molecular weight of the (D) non-radical polymerizable polymer having a molecular weight of 1,000 or more is not particularly limited as long as it is 1,000 or more. For example, it is 3,000 or more, preferably 5,000 or more, more preferably 10,000 or more, and for example, 500,000 or less, preferably 300,000 or less, more preferably 200,000 or less. As the weight-average molecular weight, for example, the weight-average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography) can be used.

[0042] The glass transition temperature (Tg) of the (D) non-radical polymerizable polymer having a molecular weight of 1,000 or more is not particularly limited. For example, it is −50° C. or higher, preferably −20° C. or higher, more preferably 10° C. or higher, and for example, 200° C. or lower, preferably 150° C. or lower, more preferably 120° C. or lower. The glass transition temperature (Tg) can be determined from the weight loss in the TG curve obtained by simultaneous differential thermal analysis (TG / DTA) at 600° C. under conditions of a nitrogen atmosphere, a heating rate of 5° C. / min, and a tensile mode (100 mN) using a thermal analyzer.

[0043] Examples of (D) non-radically polymerizable polymers having a molecular weight of 1,000 or more include one or more selected from the group consisting of (meth)acrylic resins, polyolefin resins, polystyrene resins, epoxy resins, rubber elastomers, polyvinyl alcohol resins, polyvinyl ester resins, diene resins, ABS resins, AS resins, styrene-butadiene resins, halogenated vinyl resins, cyclic polyolefin resins, polyester resins, polyether resins, phenoxy resins, urethane resins, polyamide resins, polycarbonate resins, polyimide resins, polysiloxane resins, phenolic resins, cellulose resins, rosin resins, and modified resins of these resins. In the present invention, the resin is preferably a thermoplastic resin, more preferably at least one selected from the group consisting of (meth)acrylic resin, polyolefin resin, polystyrene resin, epoxy resin, rubber / elastomer, polyvinyl alcohol resin, polyvinyl ester resin, ABS resin, AS resin, styrene / butadiene resin, vinyl halide resin, polyester resin, polyether resin, phenoxy resin, urethane resin, and polyamide resin, and even more preferably at least one selected from the group consisting of (meth)acrylic resin, polyolefin resin, polystyrene resin, epoxy resin, rubber / elastomer, polyester resin, polyether resin, phenoxy resin, urethane resin, and polyamide resin.

[0044] The content of (D) the non-radical polymerizable polymer having a molecular weight of 1,000 or more in the radical polymerizable adhesive is not particularly limited as long as it does not impair the properties of the radical polymerizable adhesive, such as the applicability and adhesive strength. Taking the total amount of the radical polymerizable adhesive as 100% by mass, the content can be, for example, 0.1% by mass or more, preferably 1% by mass or more, more preferably 10% by mass or more, and can be, for example, 60% by mass or less, preferably 50% by mass or less. By setting the content of (D) the non-radical polymerizable polymer having a molecular weight of 1,000 or more to 60% by mass or less, relative to 100% by mass of the total amount of the radical polymerizable adhesive, the applicability, normal adhesion (normal tensile shear adhesive strength), hot adhesion (hot tensile adhesive strength), and hot tensile shear adhesive strength retention R of the radical polymerizable adhesive can be improved. ａ , heat aging resistance (heat aging tensile adhesive strength), heat aging tensile shear adhesive strength retention rate R ｂ One or more of the above can be made more excellent.

[0045] [(E) Curing Catalyst] The radically polymerizable adhesive of the present invention preferably further contains (E) a curing catalyst. The (E) curing catalyst is not particularly limited. For example, one or more compounds selected from the group consisting of imide-based compounds, amine-based compounds, azole-based compounds, mercaptan-based compounds, and hydrazine-based compounds can be used. These curing catalysts are also useful as anaerobic curing catalysts. Of these, imide-based compounds are preferred from the viewpoint of improving curability, particularly anaerobic curability.

[0046] The imide-based compound is represented by the following formula (4) or (5): -CONHCO- (4) -CONHSO ２ - (5) or a salt thereof. Examples of the imide-based compound include one or more compounds selected from the group consisting of o-benzoic acid sulfimide (saccharin), succinic acid imide, phthalic acid imide, and salts thereof (particularly alkali metal salts such as sodium and potassium).

[0047] Examples of the amine compound include one or more compounds selected from the group consisting of heterocyclic secondary amines such as 1,2,3,4-tetrahydroquinoline and 1,2,3,4-tetrahydroquinaldine, heterocyclic tertiary amines such as quinoline, methylquinoline, quinaldine and quinoxalinephenazine, and aromatic tertiary amines such as N,N-dimethyl-anisidine and N,N-dimethylaniline.

[0048] Examples of the azole compound include one or more compounds selected from the group consisting of 1,2,4-triazole, oxazole, oxadiazole, thiadiazole, benzotriazole, hydroxybenzotriazole, benzoxazole, 1,2,3-benzothiadiazole, and 3-mercaptobenzotriazole.

[0049] The mercaptan compound may be, for example, one or more selected from the group consisting of straight-chain mercaptans such as n-dodecyl mercaptan, ethyl mercaptan, and butyl mercaptan.

[0050] Examples of the hydrazine compound include 1-acetyl-2-phenylhydrazine, 1-acetyl-2-(p-tolyl)hydrazine, 1-benzoyl-2-phenylhydrazine, 1-(1',1',1'-trifluoro)acetyl-2-phenylhydrazine, 1,5-diphenyl-carbohydrazine, 1-formyl-2-phenylhydrazine, 1-acetyl-2-(p-bromophenyl)hydrazine, 1-acetyl-2-(p-nitrophenyl)hydrazine, 1-acetyl-2-(p-methoxyphenyl)hydrazine, 1-acetyl-2-(2'-phenylethylhydrazine), p-nitrophenylhydrazine, p-trisulfonylhydrazide, 1-acetyl-2-methylhydrazine, 1-phenylsemicarbazide, 2-phenyl-t-butylcarbazate, succinic acid di(phenylhydrazide), and the like.

[0051] The content of the (E) curing catalyst in the radical-polymerizable adhesive is not particularly limited, as long as it does not impair the properties of the radical-polymerizable adhesive, such as handleability, adhesive strength, curing rate, and storage stability. It can be 0 parts by mass or more, for example 0.1 parts by mass or more, preferably 0.5 parts by mass or more, per 100 parts by mass of the (A) radical-polymerizable compound, and can be, for example, 5 parts by mass or less, preferably 3 parts by mass or less. By setting the content of the (E) curing catalyst in the radical-polymerizable adhesive to 5 parts by mass or less per 100 parts by mass of the (A) radical-polymerizable compound, it is possible to improve the curability and storage stability of the radical-polymerizable adhesive, particularly the anaerobic curability and storage stability.

[0052] [(F) Storage Stabilizer] The radically polymerizable adhesive of the present invention may further contain (F) a storage stabilizer. Examples of the storage stabilizer include one or more selected from the group consisting of polymerization inhibitors (radical scavengers, metal chelating agents), antioxidants, etc.

[0053] Examples of the polymerization inhibitor include one or more metal chelating agents selected from the group consisting of ethylenediaminetetraacetic acid, its di-sodium salt, its 4-sodium salt, oxalic acid, acetylacetone, o-aminophenol, and the like; one or more quinone compounds selected from the group consisting of hydroquinone, benzoquinone, hydroquinone monomethyl ether, β-naphthoquinone, 2-methoxy-1,4-naphthoquinone, methylhydroquinone, hydroquinone monomethyl ether, mono-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-di-tert-butyl-p-benzoquinone, and the like; pentaerythritol tetrakis(3-(3,5-ditert-butyl)-p-benzoquinone; and one or more hindered phenol compounds selected from the group consisting of N-methyl-N-nitrosoaniline, N-nitrosodiphenylamine, N-nitrosophenylhydroxyamine aluminum salt, and the like; phosphorus compounds such as triphenyl phosphite; phenothiazine, N-isopropyl-N'-phenyl-p-phenylenediamine, diethylhydroxylamine, sulfur, t-butylcatechol, potassium triiodide, and the like.

[0054] The content of the storage stabilizer (F) in the radically polymerizable adhesive is not particularly limited and may be 0 parts by mass or more, for example 0.001 parts by mass or more, and preferably 0.002 parts by mass or more, relative to 100 parts by mass of the radically polymerizable compound (A), and may be 7 parts by mass or less, and preferably 5 parts by mass or less.

[0055] [(G) Other Components] The radically polymerizable adhesive of the present invention may contain (G) other components in addition to (A) the radically polymerizable compound, (B) the organic peroxide, (C) the phosphate ester compound having a radically polymerizable group, (D) the non-radical polymerizable polymer having a molecular weight of 1,000 or more, (E) the curing catalyst, and (F) the storage stabilizer, to the extent that the functions of the adhesive, such as curability and adhesiveness of the cured product, are not impaired. Examples of (G) other components include one or more selected from the group consisting of inorganic fillers, silane coupling agents, curing rate modifiers, plasticizers, antifoaming agents, heavy metal deactivators, adhesives and / or tackifiers, antioxidants, light stabilizers, reinforcing agents, colorants, flame retardants, rust inhibitors, dispersants, thixotropic agents, precipitation inhibitors, antioxidants, light stabilizers, UV absorbers, fragrances, etc.

[0056] (G) Among the other components, examples of inorganic fillers include one or more selected from the group consisting of glass, silica, alumina, mica, ceramics, calcium carbonate, aluminum nitride, carbon powder, kaolin clay, dried clay minerals, dried diatomaceous earth, etc.

[0057] Among the (G) other components, the silane coupling agent is used as an adhesion promoter. Examples of the silane coupling agent include γ-chloropropyltrimethoxysilane, octenyltrimethoxysilane, glycidoxyoctyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-isocyanatepropyltriethoxysilane, γ-ureidopropyltriethoxysilane, and p-styryltrimethoxysilane.

[0058] [Hot tensile shear adhesive strength retention rate R ａ and heat aging tensile shear adhesive strength retention rate R ｂ The radical polymerizable adhesive of the present invention has a hot tensile shear adhesive strength retention rate R ａ is 13% or more and heat aging tensile shear adhesive strength retention rate R ｂ That is, the radical polymerizable adhesive of the present invention has a hot tensile shear adhesive strength retention rate R ａ The requirement that the tensile shear bond strength retention rate R ｂ The requirement that the ratio of the total to the total weight of the product is 50% or more is satisfied.

[0059] <Hot tensile shear adhesive strength retention rate R ａ > Hot tensile shear adhesive strength retention rate R of the radically polymerizable adhesive of the present invention ａ is 13% or more, preferably 14% or more, and more preferably 15% or more. ａ (%) is calculated using formula (i): In formula (i), A is the tensile shear adhesive strength (N / mm ２ ) and B is the 150°C hot tensile shear adhesive strength (N / mm ２ )

[0060] Hot tensile shear adhesive strength retention rate R of radical polymerizable adhesive ａ When the bond strength is 13% or more, preferably 14% or more, and more preferably 15% or more, peeling of the bonded portion during heating (hot) during heating and drying can be suppressed even when coating is performed after bonding and then the resulting material is dried by heating, which is advantageous in terms of reducing the product defect rate and improving productivity.

[0061] Hot tensile shear bond strength retention rate R ａ The tensile shear strength (normal tensile shear adhesive strength) when bonded at 23°C used in calculating the retention rate R can be confirmed by the method described in <Normal tensile shear adhesive strength> in the Examples. ａThe 150°C hot tensile shear adhesive strength (hot tensile shear adhesive strength) used in the calculation of can be confirmed by the method described in <Hot tensile shear adhesive strength> in the Examples.

[0062] <Heat aging tensile shear adhesive strength retention rate R ｂ > Heat aging tensile shear adhesive strength retention rate R of the radical polymerizable adhesive of the present invention ｂ is 50% or more, preferably 70% or more, and more preferably 80% or more. ａ is represented by formula (ii): In the formula (ii), A is the tensile shear adhesive strength (N / mm ２ ) and C is the tensile shear adhesive strength (N / mm ２ )

[0063] Heat-aging tensile shear bond strength retention rate R of radically polymerizable adhesives ｂ If the bond strength is 50% or more, even when the adhesive is coated and then heated and dried, peeling of the adhesive portion can be suppressed when the adhesive is cooled after heating, which is advantageous in terms of reducing the product defect rate and improving productivity.

[0064] Heat aging tensile shear adhesive strength retention rate R ｂ The tensile shear strength (normal tensile shear adhesive strength) when bonded at 23°C used in calculating the heat aging tensile shear adhesive strength retention rate R ｂ The tensile shear adhesive strength (heat aging tensile shear adhesive strength) after heating at 200°C for 2 hours and cooling to 23°C used in the calculation of (a) can be confirmed by the method described in <Heat aging tensile shear adhesive strength> in the Examples.

[0065] [Other Properties of the Radical Polymerizable Adhesive] <Lap-shear Adhesive Strength When Bonded at 23°C> The radical polymerizable adhesive of the present invention has a tensile shear adhesive strength (normal tensile shear adhesive strength) of 2.50 N / mm when bonded at 23°C. ２ It is preferable that the strength is 2.75 N / mm or more.２ More preferably, 3.00 N / mm ２ More preferably, 3.25 N / mm ２ The upper limit of the tensile shear adhesive strength (normal tensile shear adhesive strength) when bonded at 23°C is not particularly limited, but is, for example, 9.00 N / mm ２ The tensile shear adhesive strength when bonded at 23°C (normal tensile shear adhesive strength) can be confirmed by the method described in <Normal tensile shear adhesive strength> in the Examples.

[0066] <Lap-shear adhesive strength after heating at 200°C for 2 hours and cooling to 23°C> The radical polymerizable adhesive of the present invention has a tensile shear adhesive strength (heat aging tensile shear adhesive strength) of 2.50 N / mm after heating at 200°C for 2 hours and cooling to 23°C. ２ It is preferable that the strength is 2.75 N / mm or more. ２ More preferably, 3.00 N / mm ２ More preferably, 3.25 N / mm ２ The upper limit of the tensile shear adhesive strength (heat aging tensile shear adhesive strength) after heating at 200°C for 2 hours and cooling to 23°C is not particularly limited, but is, for example, 9.00 N / mm ２ The tensile shear adhesive strength (heat aging tensile shear adhesive strength) of the radical polymerizable adhesive after heating at 200°C for 2 hours and cooling to 23°C is 2.50 N / mm ２ If the adhesive strength is above this level, even when the adhesive is coated and then heated and dried, peeling of the adhesive site upon cooling after heating can be suppressed, which is advantageous in terms of reducing the product defect rate and improving productivity, etc. The tensile shear bond strength (heat aging tensile shear bond strength) after heating at 200°C for 2 hours and cooling to 23°C can be confirmed by the method described in <Heat aging tensile shear bond strength> in the Examples.

[0067] <Viscosity> The viscosity of the radically polymerizable adhesive of the present invention is not particularly limited. From the viewpoints of ease of handling and prevention of extrusion during adhesion, the viscosity is, for example, 0.01 Pa·s or more, preferably 0.05 Pa·s or more, more preferably 0.5 Pa·s or more, and can be, for example, 50 Pa·s or less, preferably 30 Pa·s or less, more preferably 15 Pa·s or less. The viscosity can be adjusted using a viscosity adjustment method known in the adhesive field, such as blending a viscosity modifier (thixotropic agent). The viscosity can be obtained, for example, by putting 100 g of the radically polymerizable adhesive into a bottle and discharging it into a measuring cup, and measuring the viscosity using a Brookfield viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25°C and 60 rpm.

[0068] [Method for Producing Radically Polymerizable Adhesive] The method for producing the radically polymerizable adhesive of the present invention is not particularly limited. For example, the adhesive can be produced by adding predetermined amounts of at least (A) the radically polymerizable compound, (B) the organic peroxide, and (C) the phosphate ester compound having a radically polymerizable group to a mixing vessel in any order and mixing them.

[0069] For mixing, a mixing device such as a mixer (rotating / revolving mixer, planetary mixer, etc.), a tumbler, a stirrer, an agitator, a mechanical homogenizer, an ultrasonic homogenizer, a high-pressure homogenizer, a shaker, a V-type blender, or a Nauta mixer can be used, and it is preferable to use a mixer. The mixing conditions are not particularly limited. The temperature conditions can be, for example, 0°C or higher, preferably 10°C or higher, and for example, 100°C or lower, preferably 70°C or lower. The mixing time can be, for example, 1 minute or longer, preferably 5 minutes or longer, and for example, 10 hours or shorter, preferably 5 hours or shorter.

[0070] [Uses of the radical polymerizable adhesive] The radical polymerizable adhesive of the present invention can be used as an anaerobic adhesive. In the present invention, the radical polymerizable adhesive is preferably an anaerobic adhesive, particularly an anaerobic adhesive for metals. The radical polymerizable adhesive of the present invention can be used in various fields such as for various electric and electronic parts, automobiles, machinery, buildings, and civil engineering.

[0071] The radical polymerizable adhesive of the present invention can be used to bond various adherends and can rapidly cure and bond at 25°C (room temperature). Examples of adherends include one or more of various metals such as iron, aluminum, magnesium, stainless steel, titanium, and copper, as well as resins, glass, ceramics, paper, cloth, and fibers. The radical polymerizable adhesive of the present invention has excellent adhesion to metals and is preferably used for metals. In particular, due to its curing properties, it may be applied to molded products in which two or more metal plates are bonded together. Examples of metal plates include one or more selected from steel plates (various iron-made steel plates such as cold-rolled steel plates (SPCC, SPCC-SD), and coated steel plates), aluminum plates, stainless steel plates, magnesium plates, and copper plates. The thickness of the metal plate is not particularly limited and can be determined appropriately depending on the application. It is, for example, 0.01 mm or more, preferably 0.1 mm or more, and for example, 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less.

[0072] When the radically polymerizable adhesive of the present invention is used for bonding metals, for example, anaerobic bonding of metals, it is preferable to apply a primer to the metal. When the radically polymerizable adhesive of the present invention is used for bonding metals, the primer applied to the metal preferably contains a transition metal compound, particularly a copper compound, as a radically polymerizable adhesion promoter. In addition to the transition metal compound, the primer may also contain a liquid medium, a rust inhibitor, an antiseptic, etc.

[0073] Examples of the copper compound include one or more compounds selected from the group consisting of copper salts of carboxylic acids such as copper neodecanoate, copper 2-ethylhexanoate, copper naphthenate, copper octenate, copper hexanoate, copper propionate, and copper 2,4-pentadionate (copper acetylacetonate); copper complexes such as ethylenediamine copper and propylenediamine copper; and the like.

[0074] The liquid medium may include one or more organic solvents and / or water. The organic solvent is not particularly limited. Examples of the solvent include one or more solvents selected from the group consisting of aliphatic hydrocarbon solvents having 5 to 40 carbon atoms (hexane, heptone, paraffin, etc.); alicyclic hydrocarbon solvents having 5 to 20 carbon atoms; aromatic hydrocarbon solvents having 6 to 20 carbon atoms (benzene, toluene, xylene, ethylbenzene, indene, etc.); alcohol solvents having 1 to 10 carbon atoms (methanol, ethanol, propanol, isopropanol, hexanol, etc.); ketone solvents having 3 to 20 carbon atoms (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.); ether solvents having 2 to 20 carbon atoms (tetrahydrofuran, diethyl ether, dioxane, ethyl cellosolve, propylene glycol monomethyl ether, etc.); ester solvents having 2 to 20 carbon atoms (methyl acetate, ethyl acetate, butyl acetate, etc.); and oils (punching oil, mineral oil, synthetic oil, animal and vegetable oil, etc.). In particular, the use of oils provides rust prevention for metals and also makes machining such as punching easier after bonding.

[0075] The composition of the primer is not particularly limited. The copper compound is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and for example, 15.0% by mass or less, preferably 10.0% by mass or less, more preferably 8.0% by mass or less, when the total amount of the primer is taken as 100% by mass. Furthermore, the oil in the liquid medium is, for example, 20.0% by mass or more, preferably 25.0% by mass or more, more preferably 30.0% by mass or more, and for example, 80.0% by mass or less, preferably 70.0% by mass or less, more preferably 60.0% by mass or less, when the total amount of the primer is taken as 100% by mass.

[0076] The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples. In each example, unless otherwise specified, "parts" represents "parts by mass" and "%" represents "% by mass." In addition, all descriptions relating to blending ratios in the tables are in "parts by mass."

[0077] [Constituent Components of Radically Polymerizable Adhesive] In the Examples and Comparative Examples shown in Tables 1 and 2, the constituent components of the radically polymerizable adhesive are as follows: HEMA: hydroxyethyl methacrylate BPEPMA: a compound represented by the following formula (B): Bifunctional bisphenol A type epoxy methacrylate BPEDM represented by the following formula (C): PUA: Polytetramethylene glycol urethane acrylate (weight average molecular weight 28,000, both terminal acrylates) AcPolym: Acrylic polymer (Tg: 47°C, weight average molecular weight 55,000) PHNXR: Phenoxy resin (weight average molecular weight 52,000) BPU: Block polyether urethane resin (block NCO equivalent 1,400; viscosity 25,000 mPa·s (50°C); solids content 100%) MAEP: 2-methacryloyloxyethyl acid phosphate EDTANa: Tetrasodium ethylenediaminetetraacetate SACC: Saccharin CHP: Cumene hydroperoxide

[0078] [Evaluation of adhesive properties] <Preparation of test steel plate> A cold-rolled steel plate (SPCC-SD) having a thickness of 0.5 mm conforming to JIS G 3141 was cut to a size of 25 mm width × 100 mm length (W25mm × L100mm) to prepare a test cold-rolled steel plate.

[0079] <Preparation of Primer> 0.6 parts of a 60% toluene solution of copper neodecanoate, 49.4 parts of ethanol, and 50 parts of drying punching oil were mixed in a glass container to obtain a primer.

[0080] <Normal-state tensile shear adhesive strength> The normal-state tensile shear adhesive strength is the tensile shear adhesive strength when bonded at 23°C, and can be obtained as follows. Two cold-rolled steel sheets for testing were prepared. A primer was spray-coated on one sheet and left to dry at 25°C for 3 hours. 0.03 ml of a radical-polymerizable adhesive was applied to the other sheet with a spatula, and immediately after application of the radical-polymerizable adhesive, the primer-coated surface and the radical-polymerizable adhesive-coated surface were bonded together so that the adhesive area was 25 mm wide x 12.5 mm long. The two test pieces were then clamped together for 200 seconds and removed to prepare test pieces. The prepared test pieces were aged in an environment of 23°C for 24 hours, and then pulled at 23°C using a universal tensile testing machine at a pulling rate of 0.5 mm / min to measure the normal-state tensile shear adhesive strength (N / mm ２ ) was obtained based on JIS K 6850 (1999).

[0081] <Hot tensile shear bond strength> The hot tensile shear bond strength is the 150°C hot tensile shear bond strength, and can be obtained as follows. Two cold-rolled steel sheets for testing were prepared. One sheet was spray-coated with a primer and left to dry at 25°C for 3 hours. The other sheet was coated with 0.03 ml of a radical polymerizable adhesive with a spatula, and immediately after coating the radical polymerizable adhesive, the primer-coated surface and the radical polymerizable adhesive-coated surface were bonded together so that the bond area was 25 mm wide x 12.5 mm long. The two test pieces were then clamped for 200 seconds to allow anaerobically bonding, and then removed to prepare test pieces. The prepared test pieces were aged for 24 hours in a 23°C environment, and then tensile strength (N / mm) was measured at 150°C hot using a universal tensile testing machine at a tensile speed of 0.5 mm / min. ２ ) was obtained based on JIS K 6850 (1999).

[0082] <Heat-Aging Tensile Shear Adhesive Strength> The heat-aging tensile shear adhesive strength is the tensile shear adhesive strength after heating at 200°C for 2 hours and cooling to 23°C, and can be obtained as follows. Two cold-rolled steel sheets for testing were prepared. One sheet was spray-coated with a primer and left to dry at 25°C for 3 hours. 0.03 ml of a radical-polymerizable adhesive was applied to the other sheet with a spatula. Immediately after application of the radical-polymerizable adhesive, the primer-coated surface and the radical-polymerizable adhesive-coated surface were bonded together so that the adhesive area was 25 mm wide x 12.5 mm long. The two test pieces were then clamped for 200 seconds for anaerobically bonding, and then removed to prepare test pieces. The prepared test piece was aged in an environment of 23°C for 24 hours, then heated at 200°C for 2 hours, left to cool to 23°C after heating, and then pulled at a pulling rate of 0.5 mm / min using a universal tensile tester to measure the heat aging tensile shear adhesive strength (tensile shear adhesive strength after heating at 200°C for 2 hours and cooling to 23°C) (N / mm ２ ) was obtained based on JIS K 6850 (1999).

[0083] <Hot tensile shear strength retention rate R ａ > Hot tensile shear strength retention rate R ａ is represented by formula (i): In formula (i), A is the tensile shear adhesive strength (normal tensile shear adhesive strength) (N / mm ２ ) and B is the 150°C hot tensile shear adhesive strength (hot tensile shear adhesive strength) (N / mm ２ )

[0084] <Heat aging tensile shear strength retention rate R ｂ > Heat aging resistance tensile shear strength retention rate R ｂ is represented by formula (ii): In formula (ii), A is the tensile shear adhesive strength (normal tensile shear adhesive strength) (N / mm ２ ), and C is the tensile shear adhesive strength (heat aging tensile shear adhesive strength) (N / mm ２ )

[0085] [Examples A1 to A6, Comparative Example A1] <Preparation of radically polymerizable adhesive> Each component shown in Table 1 was taken in the amount (parts by mass) shown in Table 1 and mixed in a glass container to prepare a radically polymerizable adhesive. Using the obtained radically polymerizable adhesive, the normal tensile shear bond strength (tensile shear bond strength when bonded at 23°C) and hot tensile shear bond strength (hot tensile shear bond strength at 150°C) were measured, and these data were used to calculate the hot tensile shear strength retention rate R ａ The normal tensile shear adhesive strength (tensile shear adhesive strength when bonded at 23°C) and the hot tensile shear strength retention rate R ａ are also shown in Table 1.

[0086]

[0087] As can be seen from Table 1, when metal plates (steel plates) were bonded using the radical polymerizable adhesives of Examples A1 to A6 according to the present invention, excellent normal tensile shear bond strength was exhibited at room temperature (23°C), and the hot tensile shear bond strength retention rate R ａ is 13% or more, particularly 15% or more, it can be seen that when heated after adhesion (for example, heated to 150°C), excellent hot tensile shear adhesive strength is exhibited even during heating (hot).

[0088] [Examples B1 to B6, Comparative Example B1] <Preparation of radically polymerizable adhesive> Each component shown in Table 2 was taken in the amount (parts by mass) shown in Table 2 and mixed in a glass container to prepare a radically polymerizable adhesive. Using the obtained radically polymerizable adhesive, the normal tensile shear bond strength (tensile shear bond strength when bonded at 23°C) and the heat aging tensile shear bond strength (tensile shear bond strength after heating at 200°C for 2 hours and cooling to 23°C) were measured, and these data were used to calculate the heat aging tensile shear bond strength retention rate R ｂ The normal tensile shear adhesive strength (tensile shear adhesive strength when bonded at 23°C) and the heat aging tensile shear adhesive strength retention rate R ｂ are also shown in Table 2.

[0089]

[0090] As can be seen from Table 2, when metal plates (steel plates) were bonded using the radical polymerizable adhesives of Examples B1 to B6 according to the present invention, excellent normal tensile shear bond strength was exhibited at room temperature (23°C), and the heat aging tensile shear bond strength retention rate R ｂ is 50% or more, particularly 80% or more, it can be seen that even after heat treatment (for example, heating at 200°C for 2 hours) after adhesion, excellent heat aging tensile shear adhesive strength is exhibited.

Claims

1. A radical-polymerizable adhesive containing (A) a radically polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having a radically polymerizable group, and (D) a non-radically polymerizable polymer having a molecular weight of 1,000 or more, wherein the heat tensile shear adhesion strength retention rate R ａ is 13% or more and the heat-resistant aging tensile shear adhesion strength retention rate R ｂ is 50% or more, and the heat tensile shear adhesion strength retention rate R ａ is calculated by formula (i): In formula (i), A is the tensile shear adhesion strength (N / mm ２ ) when adhered at 23°C, and B is the heat tensile shear adhesion strength at 150°C (N / mm ２ ). The heat-resistant aging tensile shear adhesion strength retention rate R ｂ is calculated by formula (ii): In formula (ii), A is the tensile shear adhesion strength (N / mm ２ ) when adhered at 23°C, and C is the tensile shear adhesion strength (N / mm ２ ) after heating at 200°C for 2 hours and cooling to 23°C. The radical-polymerizable adhesive.

2. The radical polymerizable compound (A) contains (a1) a radical polymerizable compound having a structure represented by the formula (1) in the molecule: and / or (a2) urethane (meth)acrylate, and the radical polymerizable adhesive according to claim 1.

3. The radical polymerizable adhesive according to claim 1 or 2, wherein the radical polymerizable adhesive is an anaerobic adhesive.

4. The radical polymerizable adhesive according to claim 3, wherein the radical polymerizable adhesive is an anaerobic adhesive for metals.

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