Radical polymerizable adhesive

Abstract

The objective of this invention is to provide a free radical polymerizable adhesive with excellent high-temperature tensile shear bond strength and excellent tensile shear bond strength after heat treatment. As a solution, a free radical polymerizable adhesive is provided, which is a free radical polymerizable adhesive containing (A) a free radical polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having free radical polymerizable groups, and (D) a non-free radical polymerizable polymer with a molecular weight of 1,000 or more, wherein the high-temperature tensile shear bond strength retention rate R... a The percentage is above 13%, and the retention rate of heat-resistant aging tensile shear bond strength R b The high-temperature tensile shear bond strength retention rate R is above 50%. a Calculated from equation (i): In equation (i), A is the tensile shear bond strength (N / mm) when bonding is performed at 23℃. 2 B represents the tensile shear bond strength at 150℃ (N / mm²). 2 The heat aging tensile shear bond strength retention rate R b Calculated by equation (ii): In equation (ii), A is the tensile shear bond strength (N / mm) when bonding is performed at 23℃. 2 C represents the tensile shear bond strength (N / mm) after heating at 200℃ for 2 hours and cooling to 23℃. 2 ).

Description

Technical Field

[0001] This invention relates to free radical polymerizable adhesives. Background Technology

[0002] Free radical polymerizable adhesives contain free radical polymerizable compounds, such as those with (meth)acryloyl groups, as constituent components. They are adhesives that cure through polymerization via a free radical curing reaction, a type of chain reaction. Anaerobic adhesives, as a type of free radical polymerizable adhesive, are one-component adhesives that remain stable for extended periods at room temperature (25°C ± 5°C) even when exposed to oxygen, such as air. When an anaerobic adhesive is applied to the materials to be bonded and contact with oxygen is blocked (contact with air is blocked), it begins to cure immediately, thus bonding the materials together.

[0003] Anaerobic adhesives, with their unique properties, are used for bonding metal plates, preventing loosening of screws and bolts, and fixing and sealing mating parts such as bearings.

[0004] Examples of free radical polymerizable adhesives are disclosed in Patent Documents 1-3.

[0005] Patent document 1 describes a method of fixing a metal bolt / nut by applying an anaerobic adhesive to a metal bolt / nut that has been coated with a curing accelerator containing a chelate.

[0006] Patent document 2 describes a method for fixing metal bolts / nuts by applying an anaerobic adhesive to a curing accelerator pretreatment agent coated with an anaerobic adhesive.

[0007] Patent document 3 describes an anaerobic adhesive composition containing acrylate monomers, organic peroxides, and phosphoric acid compounds having (meth)acryloyl groups, which is applied to the inner wall of a ring and / or a shaft, and then the shaft is inserted into the ring for fitting and fixing.

[0008] Patent documents: Patent Document 1: Japanese Patent Application Publication No. 60-179407 Patent Document 2: Japanese Patent Publication No. 49-021093 Patent Document 3: Japanese Patent Application Publication No. 51-132234 Summary of the Invention Articles and other items manufactured by bonding with anaerobic adhesives, which are free radical polymerizable adhesives, are then coated to produce final products. Typically, the coating process involves a heat drying process or a baking process.

[0009] While the anaerobic adhesives described in Patent Documents 1-3 exhibit excellent adhesive strength, they are susceptible to delamination at the bonded surfaces due to a decrease in adhesive strength (thermal adhesive strength) under heating conditions. Furthermore, the anaerobic adhesives described in Patent Documents 1-3 also exhibit insufficient heat aging resistance, leading to a decrease in adhesive strength and subsequent delamination at the bonded surfaces after heat treatment (baking) following coating.

[0010] The problem to be solved by the present invention is to provide a free radical polymerizable adhesive with excellent high-temperature tensile shear bond strength and heat-treated tensile shear bond strength.

[0011] The inventors conducted in-depth research to solve the above-mentioned problems and found that the above-mentioned problems can be solved by using a free radical polymerizable adhesive with a specific composition, thus completing the present invention.

[0012] Specifically, it is shown below.

[0013] [Item 1] A free radical polymerizable adhesive comprising (A) a free radical polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having free radical polymerizable groups, and (D) a non-free radical polymerizable polymer with a molecular weight of 1,000 or more. Its high-temperature tensile shear bond strength retention rate R a The percentage is above 13%, and the retention rate of heat-resistant aging tensile shear bond strength R b More than 50%, The high-temperature tensile shear bond strength retention rate R a Calculated by equation (i): [Number 1]

[0014] In equation (i), A is the tensile shear bond strength (N / mm) when bonding is performed at 23°C. 2 B represents the tensile shear bond strength at 150℃ (N / mm²). 2 ), The heat aging tensile shear bond strength retention rate R b Calculated by equation (ii): [Number 2]

[0015] In formula (ii), A is the tensile shear bond strength (N / mm) when bonding is performed at 23℃. 2 C represents the tensile shear bond strength (N / mm) after heating at 200℃ for 2 hours and cooling to 23℃. 2 ).

[0016] [Item 2] According to the free radical polymerizable adhesive of claim 1, it is characterized in that, The free radical polymerizable compound (A) contains: (a1) A free radical polymerizable compound having the structure represented by formula (1) within its molecule. [Chemistry 1]

[0017] And / or (a2) urethane (meth)acrylate.

[0018] [Item 3] The free radical polymerizable adhesive according to item 1 or 2 is characterized in that the free radical polymerizable adhesive is an anaerobic adhesive.

[0019] [Item 4] According to item 3, the free radical polymerizable adhesive is characterized in that the free radical polymerizable adhesive is an anaerobic adhesive for metals.

[0020] According to the present invention, a free radical polymerizable adhesive with excellent high-temperature tensile shear bond strength and heat-treated tensile shear bond strength can be provided. Detailed Implementation

[0021] The free radical polymerizable adhesive of the present invention is a free radical polymerizable adhesive containing (A) a free radical polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having free radical polymerizable groups, and (D) a non-free radical polymerizable polymer with a molecular weight of 1,000 or more, and its high-temperature tensile shear bond strength retention rate R a The percentage is above 13%, and the retention rate of heat-resistant aging tensile shear bond strength R b More than 50%, The high-temperature tensile shear bond strength retention rate R a Calculated by equation (i): [Number 3]

[0022] In formula (i), A is the tensile shear bond strength (N / mm) when bonded at 23°C. 2 B represents the tensile shear bond strength at 150℃ (N / mm²). 2 ), The heat aging tensile shear bond strength retention rate R b Calculated by equation (ii): [Number 4]

[0023] In formula (ii), A is the tensile shear bond strength (N / mm) when bonded at 23℃. 2 C represents the tensile shear bond strength (N / mm) after heating at 200℃ for 2 hours and cooling to 23℃. 2 ).

[0024] In the free radical polymerizable adhesive of the present invention, the free radical polymerizable compound (A) may contain: (a1) A free radical polymerizable compound having the structure represented by formula (1) within its molecule. [Chemistry 2]

[0025] And / or (a2) urethane (meth)acrylate.

[0026] The free radical polymerizable adhesive of the present invention can be an anaerobic adhesive, preferably an anaerobic adhesive for metals.

[0027] The following provides a detailed description of the free radical polymerizable adhesive of the present invention.

[0028] In addition, in this specification, "(meth)acrylic acid" refers to "acrylic acid" and "methacrylic acid", "(meth)acrylate" refers to "acrylate" and "methacrylate", and "(meth)acryloyl" refers to "acryloyl" and "methacryloyl".

[0029] [(A) Free radical polymerizable compounds] The free radical polymerizable adhesive of the present invention contains (A) a free radical polymerizable compound, which is a compound having a free radical polymerizable functional group, especially an olefinic unsaturated group having free radical polymerizability, and is a compound other than "(C) a phosphate ester compound having a free radical polymerizable group".

[0030] Examples of functional groups that can be polymerized on a free radical basis include (meth)acryloyl, vinyl, allyl, (meth)acrylamido, styryl, alkenyl, alkenyl, maleimide, etc., among which (meth)acryloyl is preferred.

[0031] (A) The number of free radical polymerizable groups contained within the molecule of the free radical polymerizable compound is not particularly limited. From the perspective of curability, adhesion, etc., for example, it is 1 to 10, preferably 1 to 8, and more preferably 1 to 6. In particular, in the present invention, as the (A) free radical polymerizable compound, it is preferable to use one or more free radical polymerizable compounds having one or two (meth)acryloyl groups. In addition, a mixture of one or more free radical polymerizable compounds having one (meth)acryloyl group and one or more free radical polymerizable compounds having two or more (meth)acryloyl groups may also be used.

[0032] As (A) the free radical polymerizable compound, one or more selected from free radical polymerizable oligomers and free radical polymerizable monomers may be used. In this invention, free radical polymerizable oligomers may include, for example, compounds having one or more free radical polymerizable groups with a weight-average molecular weight of 400 or more. In this invention, free radical polymerizable monomers may be compounds other than free radical polymerizable oligomers; for example, compounds having one or more free radical polymerizable groups with a molecular weight of less than 400 may be included.

[0033] <Free radical polymerizable oligomers> As for free radical polymerizable oligomers, there are no particular limitations as long as they are compounds with one or more free radical polymerizable groups in the molecule and a weight average molecular weight of 400 or more, and further, (C) free radical polymerizable compounds other than phosphate ester compounds with free radical polymerizable groups.

[0034] In this invention, from the perspective of the adhesion strength, curing speed and heat aging resistance of the free radical polymerizable adhesive relative to the metal, a (meth)acrylate oligomer having one or more (meth)acryloyl groups is preferred as the free radical polymerizable oligomer.

[0035] The number of (meth)acryloyl groups contained in the molecule of (meth)acrylate oligomers is not particularly limited. For example, it can be 1 to 10, preferably 1 to 8, and more preferably 1 to 6.

[0036] There is no particular upper limit to the weight-average molecular weight of (meth)acrylate oligomers. For example, it can be set to 100,000 or less, preferably 30,000 or less, and more preferably 20,000 or less.

[0037] As (meth)acrylate oligomers, examples include one or more selected from the following: urethane (meth)acrylates, epoxy (meth)acrylates, bisphenol epoxy alkyl adduct (meth)acrylates, ether (meth)acrylates, ester (meth)acrylates, isoprene (meth)acrylates, hydrogenated isoprene (meth)acrylates, acrylic polymers containing (meth)acryloyl groups, polyisobutylene containing (meth)acryloyl groups, etc. (Meth)acrylate oligomers can be either commercially available or synthetic products.

[0038] As urethane (meth)acrylates, at least the following substances can be listed: substances obtained by reacting a polyol component, a polyisocyanate component, and a compound having a functional group and a (meth)acrylate group that can react with a hydroxyl or isocyanate group.

[0039] As a polyol component, for example, one or more polymeric polyols selected from (hydrogenated) butadiene polyols, polycarbonate polyols, polyether polyols, polyester polyols, polyacrylate polyols (acrylic polyols), urethane polyols, etc., may be used.

[0040] As a polyisocyanate component, for example, one or more selected from the following can be used: aliphatic polyisocyanates (such as hexamethylene diisocyanate), alicyclic polyisocyanates (such as dicyclohexylmethane diisocyanate and isobornyl diisocyanate), aromatic polyisocyanates (such as toluene diisocyanate and diphenylmethane diisocyanate), and aromatic aliphatic polyisocyanates (such as phenyldimethyl diisocyanate).

[0041] As a compound having a functional group that reacts with a hydroxyl or isocyanate group and a (meth)acrylate group, for example, one or more of the following can be used: (meth)acrylates having a group that reacts with an isocyanate group (for example, one or more of the hydroxyl-containing (meth)acrylates and / or carboxyl-containing (meth)acrylates described in <Free Radical Polymerizable Monomers>), or (meth)acrylates containing an isocyanate group, etc.

[0042] As a urethane (meth)acrylate, examples include one or more selected from the following: urethane (meth)acrylate having a (hydrogenated) polybutadiene backbone, urethane (meth)acrylate having a polycarbonate backbone, urethane (meth)acrylate having a polyether backbone, urethane (meth)acrylate having a polyester backbone, urethane (meth)acrylate having a polyacrylate backbone, urethane (meth)acrylate having a urethane backbone, urethane (meth)acrylate having a castor oil backbone, etc.

[0043] As an epoxy (meth)acrylate, for example, it can be obtained by reacting an epoxy resin with a (meth)acrylate compound having a functional group that can react with an epoxy group.

[0044] Examples of epoxy resins include one or more selected from bisphenol type epoxy resins (bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc.), phenolic varnish type epoxy resins, and epoxy resins with terminal glycidyl ethers of alkyl oxy groups of bisphenol type epoxy resins.

[0045] As a (meth)acrylate compound having a functional group that can react with an epoxy group, one or more of the following can be listed, for example, as hydroxyl-containing (meth)acrylates and / or carboxyl-containing (meth)acrylates described in <Free Radical Polymerizable Monomers>.

[0046] As epoxy (meth)acrylates, commercially available products can be used. Examples include 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 Corporation); 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 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 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.); and one or more of the following.

[0047] As bisphenol alkyl oxide adducts (meth)acrylates, at least one compound represented by formula (A) can be listed as an example: [Chemistry 3]

[0048] (In formula (A), R 11 It can be a hydrogen atom or a methyl group.

[0049] R 12 It can be a hydrogen atom or a methyl group.

[0050] A 1 It is an alkylene group having 1 to 6 carbon atoms, and when multiple alkylene groups exist, they can be different from each other.

[0051] A 2 It is an alkylene group having 1 to 6 carbon atoms, and when multiple alkylene groups exist, they can be different from each other.

[0052] X is any one of the following: directly bonded, -CH2-, -C(CH3)2-, -CH(CH3)-, -O-, -S-, -SO2-, -CO-, -CF2-, -C(CF3)2-, -C(Ph)2-, -CH(Ph)- (Ph is phenyl).

[0053] m is an integer greater than or equal to 0 or 1.

[0054] n is an integer greater than or equal to 0 or 1.

[0055] Among these, (poly)oxyalkylene-modified bisphenol A di(meth)acrylates can be listed, for example, selected from one or more of (poly)oxyethylene-modified bisphenol A di(meth)acrylates, (poly)oxypropylene-modified bisphenol A di(meth)acrylates, etc. Specifically, in the compounds shown in formula (A) above, R is preferred. 11 R is a hydrogen atom or a methyl group. 12 A is a hydrogen atom or a methyl group. 1 A is an alkylene group having 2 to 6 carbon atoms (preferably 2 to 4). 2 It is a compound having 2 to 6 carbon atoms (preferably 2 to 4) of alkylene, X being -C(CH3)2-, and m+n (i.e., ethoxy equivalent) being 1 to 40 (preferably 2 to 10).

[0056] Examples of ester (meth)acrylate oligomers include substances obtained by adding carboxyl and / or hydroxyl groups to ester oligomers obtained by the reaction of polyols with polycarboxylic acids, such as those described in <Free Radical Polymers>, to hydroxyl-containing (meth)acrylates and / or carboxyl-containing (meth)acrylates.

[0057] Examples of ether (meth)acrylate oligomers include substances obtained by adding hydroxyl-containing (meth)acrylates and / or carboxyl-containing (meth)acrylates, as described in <Free Radical Polymerizable Monomers>, to the hydroxyl groups of aliphatic polyether polyols or aromatic polyether polyols made from bisphenols.

[0058] Among these free radical polymerizable oligomers, especially in the case of metal-to-metal bonding, the normal adhesion (normal tensile shear bond strength), high-temperature adhesion (high-temperature tensile shear bond strength), and high-temperature tensile shear bond strength retention rate R... aHeat aging resistance (heat aging tensile shear bond strength), heat aging tensile shear bond strength retention rate R b From the perspective of the same angle, it is preferred to use one or more of the following: urethane (meth) acrylate, epoxy (meth) acrylate, bisphenol epoxy alkyl adduct (meth) acrylate, and ether (meth) acrylate.

[0059] <Free radical polymerizable monomers> As for free radical polymerizable monomers, there are no particular limitations as long as they are compounds having one or more free radical polymerizable groups within the molecule, and are not free radical polymerizable oligomers or free radical polymers, with a molecular weight of less than 400, and further, (C) free radical polymerizable compounds other than phosphate ester compounds having free radical polymerizable groups.

[0060] In this invention, from the perspective of the adhesion strength, curing speed and heat aging resistance of the free radical polymerizable adhesive relative to the metal, a (meth)acrylate monomer having one or more (meth)acryloyl groups is preferably used as the free radical polymerizable monomer.

[0061] Among (meth)acrylate monomers having one or more (meth)acryloyl groups, (meth)acrylate monomers having one (meth)acryloyl group may include, for example, one or more selected from the following: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, neopentyl methacrylate, lauryl methacrylate, stearyl methacrylate, and other aliphatic (meth)acrylates. Alicyclic (meth)acrylates such as cyclohexyl methacrylate, isobornyl methacrylate, dicyclopentyl methacrylate, and adamantyl methacrylate; aromatic (meth)acrylates such as benzyl methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, nonylphenoxyethyl methacrylate, nonylphenoxytetraethylene glycol (meth)acrylate, and nonylphenyl polypropylene glycol (meth)acrylate; 2-hydroxyethyl methacrylate. Ester, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, glycerol methacrylate, polyethylene glycol methacrylate, polypropylene glycol methacrylate, ethylene oxide modified phthalic acid methacrylate, ethylene oxide modified succinic acid methacrylate, caprolactone modified 2-hydroxyethyl methacrylate, caprolactone modified tetrahydrofurfural methacrylate Hydroxyl-containing (meth)acrylates such as methyl esters; carboxyl-containing (meth)acrylates such as (meth)acrylic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl phthalic acid, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid; alkoxy-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, hydroxyethylacrylamide, dimethylacrylamide, diethylacrylamide, methacrylamide, N-methylacrylamide, N-hydroxyethylacrylamide, N-ethylacrylamide, N-hydroxymethylacrylamide, N-methoxymethylacrylamide, N-butoxymethylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-dipropylacrylamide, N,N-diethylacrylamide Isopropyl (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)acrylamide, N,N-bis(dodecyl)acrylamide, N,N-bis(octadecyl)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-dimethylamino Acrylamide and other amides containing (meth)acryloyl groups; amino-containing (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and N-tert-butylaminoethyl (meth)acrylate; glycidyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxacyclopentan-4-yl)methyl (meth)acrylate, alkoxylated tetrahydrofurfuryl (meth)acrylate, and (meth)acrylate... (3-Ethyloxetane-3-yl)methyl ester, 4-hydroxybutyl (meth)acrylate glycidyl ether, (meth)acryloylmorpholine, N-(meth)acryloyloxyethyl hexahydrophthalimide, (meth)acrylate pentamethylpiperidinyl ester, di(meth)acrylate isocyanurate, tri(meth)acrylate isocyanurate, triazine tri(meth)acrylate, N-(meth)acryloyloxysuccinimide, N-(meth)acryloyloxyphthalimide, and other heterocyclic (meth)acrylates; etc.

[0062] Among (meth)acrylates having one or more (meth)acryloyl groups, (meth)acrylates having two (meth)acryloyl groups may include, for example, one or more selected from the following: ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene dimethacrylate, ethoxylated polypropylene glycol dimethacrylate, ethoxylated propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, glycerol dimethacrylate, trimethylolpropane dimethacrylate, glycidol dimethacrylate, Pentaerythritol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-modified neopentyl glycol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, bisphenol A di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated Bisphenol A di(meth)acrylate, hydroxypentacolate neopentyl glycol diacrylate, caprolactone-modified hydroxypentacolate 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, etc.

[0063] Among (meth)acrylates having one or more (meth)acryloyl groups, (meth)acrylates having three or more (meth)acryloyl groups may include, for example, one or more selected from the following: glycerol trimethacrylate, trimethylolpropane trimethacrylate, di-trimethylolpropane trimethacrylate, tetramethylolmethane trimethacrylate, propylene oxide-modified trimethylolpropane trimethacrylate, ethylene oxide-modified trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, tris(acryloyloxyethyl)isocyanurate, ε-hexylene Tri(meth)acrylates with three (meth)acryloyl groups, such as lactone-modified tri(acryloyloxyethyl)isocyanurate and ethoxylated isocyanurate triacrylate; poly(meth)acrylates with four or more (meth)acryloyl groups, such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, and tetrapentaerythritol hexa(meth)acrylate; etc.

[0064] These free radical polymerizable monomers are preferably selected from one or more of the following: aliphatic (meth)acrylates such as methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, neopentyl methacrylate, lauryl methacrylate, and stearyl methacrylate; alicyclic (meth)acrylates such as cyclohexyl methacrylate, isobornyl methacrylate, and dicyclopentyl methacrylate; hydroxyl-containing (meth)acrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, polyethylene glycol (meth)acrylate, and polypropylene glycol (meth)acrylate; carboxyl-containing (meth)acrylates such as methacrylic acid and 2-(meth)acryloyloxyethyl succinic acid; and ethylene glycol di(meth)acrylate. Polyethylene glycol dimethacrylate, propylene glycol dimethacrylate, polypropylene dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, bisphenol A dimethacrylate, bisphenol A ethylene oxide modified dimethacrylate, bisphenol A propylene oxide modified dimethacrylate, propoxylated bisphenol A dimethacrylate, dicyclopentenyl dimethacrylate, etc., all containing two methacryloyl groups. Di(meth)acrylates with 3 (meth)acryloyl groups; glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, di-trimethylolpropane tri(meth)acrylate, etc.; poly(meth)acrylates with 4 or more (meth)acryloyl groups, such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc.; etc.

[0065] <(A) Preferred forms of free radical polymerizable compounds> In this invention, regarding (A) free radical polymerizable compounds, the high-temperature adhesiveness (high-temperature tensile shear bond strength) and the high-temperature tensile shear bond strength retention rate R are considered. a Heat aging resistance (heat aging tensile shear bond strength), heat aging tensile shear bond strength retention rate R b From the perspective of equal proportions, the preferred option is to have (a1) molecules containing formula (1): [Chemistry 4]

[0066] The free radical polymerizable compounds with the represented structure, and / or, (a2) Carbamate (meth)acrylate.

[0067] As a free radical polymerizable compound having the structure represented by formula (1) within the molecule (a1), one or more types may be used; as a urethane (meth)acrylate (a2), one or more types may be used.

[0068] As a free radical polymerizable compound having the structure represented by formula (1) within the molecule (a1), for example, one or more of the following can be listed: (i) One or more epoxy (meth)acrylates, wherein the epoxy (meth)acrylate is an epoxy resin having the structure represented by formula (A) within its molecule, such as a bisphenol A type epoxy resin or a terminal glycidyl ether of an epoxy alkyl adduct of a bisphenol A type epoxy resin, and a product of the reaction with a hydroxyl-containing (meth)acrylate and / or a carboxyl-containing (meth)acrylate (as commercially available products, such as EPICLON UE-8071-60BH, UE-8740, UE-8410 (manufactured by DIC Corporation), KAYARDR-115F (manufactured by Nippon Kayaku Co., Ltd.), HITALOID 7851 (manufactured by Showa Denko Corporation), 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 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 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.); etc.

[0069] As (a2) urethane (meth)acrylate, examples include one or more selected from the following: urethane (meth)acrylate having a polyether backbone, urethane (meth)acrylate having a polyester backbone, urethane (meth)acrylate having a polyacrylate backbone, urethane (meth)acrylate having a urethane backbone, urethane (meth)acrylate having a (hydrogenated) polybutadiene backbone, urethane (meth)acrylate having a polycarbonate backbone, urethane (meth)acrylate having a castor oil backbone, etc. Preferably, it is selected from one or more of the following: urethane (meth)acrylates having a polyether backbone, urethane (meth)acrylates having a polyester backbone, urethane (meth)acrylates having a polycarbonate backbone, urethane (meth)acrylates having a polyacrylate backbone, and urethane (meth)acrylates having a urethane backbone; more preferably, it is selected from one or more of the following: urethane (meth)acrylates having a polyether backbone, urethane (meth)acrylates having a polyester backbone, and urethane (meth)acrylates having a polycarbonate backbone; and even more preferably, it is selected from one or more of urethane (meth)acrylates having a polyether backbone.

[0070] The polyether backbone of the urethane (meth)acrylate having a polyether backbone may be selected from one or more of the following: -(-CH2CH2O-)- backbone, -(-CH2CH(CH3)O-)- backbone, -(-CH(CH3)CH2O-)- backbone, -(-CH2CH2CH2O-)- backbone, -(-CH2CH2CH2CH2O-)- backbone, and -(-CH2CH2CH2CH2O-)- backbone.

[0071] Commercially available (a2) urethane (meth)acrylates include, for example, one or more of the following: 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, UV-3310B, etc. (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-19 1. STQI-037PR, UN-333, UN-350, UN-352, UN-353, UN-7600, UN-7700, MBU-71, UN-5500, UN-5590, UN-9000PEP, UN-920 0A, 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 Nejou Kogyo Co., Ltd.); 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, etc. (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.); ARONIX M-1100, M-1200, etc. (manufactured by Toa Synthetic Co., Ltd.); CN8899NS, etc. (manufactured by ARKEMA Co., Ltd.); 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 Co., Ltd.); KUA-PC2I, etc. (manufactured by KSM Co., Ltd.); etc., but not limited to these.

[0072] In this invention, from the perspective of adhesive strength to the bonded materials, especially to metals, the (A) free radical polymerizable compound preferably comprises one or more free radical polymerizable compounds having one or more functional groups selected from hydroxyl, carboxyl, and amino groups. The content of the free radical polymerizable compound having functional groups in the (A) free radical polymerizable compound is not particularly limited. For example, it may be 30% by mass or more, preferably 35% by mass or more, for example, it may be 60% by mass or less, preferably 55% by mass or less.

[0073] <(A) Content of free radical polymerizable compounds> The content of (A) free radical polymerizable compound in the free radical polymerizable adhesive is not particularly limited. The total amount of the free radical polymerizable adhesive is set to 100% by mass, for example, it can be 50% by mass or more, preferably 75% by mass or more, for example, it can be 99% by mass or less, preferably 98% by mass or less. If the content of (A) free radical polymerizable compound is less than 50% by mass, then the following properties of the free radical polymerizable adhesive are obtained: normal adhesion (normal tensile shear bond strength), high-temperature adhesion (high-temperature tensile bond strength), and high-temperature tensile shear bond strength retention rate R. a Heat aging resistance (heat aging tensile bond strength), heat aging tensile shear bond strength retention rate R b If the percentage exceeds 99% by mass, there is a risk of insufficient adhesion, high-temperature adhesion, heat aging resistance, and curing speed of the free radical polymerizable adhesive.

[0074] [(B) Organic peroxides] The (B) organic peroxide, which is a component of the free radical polymerizable adhesive of the present invention, is a substance used to impart curability, such as anaerobic curability and / or heat curability, to the free radical polymerizable adhesive.

[0075] As for (B) organic peroxides, examples include hydroperoxides selected from one or more of the following: cumene hydroperoxide, tert-butyl hydroperoxide, p-menthol hydroperoxide, methyl ethyl ketone peroxide, cyclohexane peroxide, dicumene peroxide, dicumene hydroperoxide, etc., as well as ketone peroxides, diallyl peroxides, ester peroxides, etc. Among these, hydroperoxides are preferred from the perspective of the reactivity and storage stability of free radical polymerizable adhesives.

[0076] As for (B) organic peroxides, from the perspective of excellent curability, especially excellent anaerobic curability, organic peroxides with a 1-hour half-life temperature of 80°C or higher are preferred, more preferably 100°C or higher, less preferably 300°C or lower, and more preferably less than 200°C. The 1-hour half-life temperature refers to the value measured under the condition of thermal decomposition in benzene at a concentration of 0.1 mol / L.

[0077] Organic peroxides with a half-life of 1 hour and a temperature in the range of 80°C to 300°C can be exemplified by hydroperoxides. Specific examples of hydroperoxides include one or more selected from p-menthol hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, isopropylbenzene hydroperoxide, tert-butyl hydroperoxide, etc.

[0078] The content of (B) organic peroxide in the free radical polymerizable adhesive is not particularly limited. Relative to 100 parts by mass of (A) free radical polymerizable compound, it can be set to, for example, 0.05 parts by mass or more, preferably 0.1 parts by mass or more, for example, 10 parts by mass or less, preferably 5 parts by mass or less. By setting the amount of (B) organic peroxide in the free radical polymerizable adhesive to a range of 0.05 parts by mass or more and 10 parts by mass relative to 100 parts by mass of (A) free radical polymerizable compound, the normal adhesion (normal tensile shear strength), high-temperature adhesion (high-temperature tensile strength), and high-temperature tensile shear strength retention rate R of the free radical polymerizable adhesive can be improved. a Heat aging resistance (heat aging tensile bond strength), heat aging tensile shear bond strength retention rate R b Even better.

[0079] [(C) Phosphate ester compounds with free radical polymerizable groups] (C), a phosphate ester compound having a free radical polymerizable group, which is a component of the free radical polymerizable adhesive of the present invention, is a compound having a free radical polymerizable functional group and the following formula (2) or (3): -OP(O)(OH)-O- (2) -OP(O)(OH)2 (3) One or more phosphate ester compounds of the indicated group.

[0080] Examples of free radical polymerizable functional groups include, for example, olefinic unsaturated bonds. Examples of olefinic unsaturated bonds include: (meth)acryloyl, vinyl, allyl, (meth)acrylamido, styryl, alkenyl, alkenyl, maleimide, etc., among which (meth)acryloyl is preferred. (C) The number of free radical polymerizable groups in the phosphate ester compound having free radical polymerizable groups is not particularly limited. It can be set to 1 or more, and from the perspective of reactivity or ease of acquisition, it can be set to 3 or less, preferably 2 or less. By using the phosphate ester compound having free radical polymerizable groups in combination with (A) free radical polymerizable compound and (B) organic peroxide, the following significant effect can be achieved: a free radical polymerizable adhesive that exhibits excellent adhesive strength (normal tensile shear adhesive strength) for various bonded materials, such as metal sheets or plastics, especially for steel sheets.

[0081] As (C) a phosphate ester compound having a free radical polymerizable group, there is no particular limitation, for example, one or more of the following can be listed: 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)acryloyloxyethyl) phosphate, ethylene oxide modified di(meth)acrylate, ethylene oxide modified tri(meth)acrylate, caprolactone modified ethylene oxide modified di(meth)acrylate, dipentaerythritol penta(meth)acryloyloxydihydrogen phosphate, etc.

[0082] (C) Phosphate ester compounds having free radical polymerizable groups, which can be synthesized or commercially available products can be used. Commercially available products include, for example, one or more selected from Light ester PA, P-1M, P-2M (all manufactured by Kyoeisha Chemical Co., Ltd.), KAYAMERPM-1 (manufactured by Nippon Kayaku Co., Ltd.), JPA-514 (manufactured by Johoku Chemical Co., Ltd.).

[0083] There is no particular limitation on the content of phosphate ester compounds with free radical polymerizable groups (C) in free radical polymerizable adhesives. The adhesive properties, particularly for metals, include normal adhesion (normal tensile shear strength), high-temperature adhesion (high-temperature tensile strength), and high-temperature tensile shear strength retention rate R. a Heat aging resistance (heat aging tensile bond strength), heat aging tensile shear bond strength retention rate R bFrom the perspective of curing speed, relative to 100 parts by mass of the free radical polymerizable compound (A), it can be set to 0.05 parts by mass or more, preferably 0.06 parts by mass or more, more preferably 0.07 parts by mass or more, for example, it can be set to less than 1.0 parts by mass, preferably less than 0.8 parts by mass, more preferably less than 0.5 parts by mass. If the content of the phosphate ester compound with free radical polymerizable groups (C) is 1.0 parts by mass or more relative to 100 parts by mass of the free radical polymerizable compound (A), the curing speed may become insufficient; if it is less than 0.05 parts by mass, the normal adhesion (normal tensile shear bond strength), high-temperature adhesion (high-temperature tensile bond strength), and high-temperature tensile shear bond strength retention rate R of the free radical polymerizable adhesive will be affected. a Heat aging resistance (heat aging tensile bond strength), heat aging tensile shear bond strength retention rate R b There is a risk that it will become insufficient.

[0084] [(D) Non-radical polymers with a molecular weight of 1,000 or higher] The non-radical polymeric polymer (D) with a molecular weight of 1,000 or more, which is a component of the free radical polymeric adhesive of the present invention, is a polymer with a weight-average molecular weight of 1,000 or more and which does not have free radical polymeric groups within its molecule. Here, examples of free radical polymeric functional groups include olefinic unsaturated bonds. Examples of olefinic unsaturated bonds include (meth)acryloyl, vinyl, allyl, (meth)acrylamido, styryl, alkenyl, alkenyl, maleimide, etc.

[0085] (D) The weight-average molecular weight of non-radical polymers with 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, 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 converted from polystyrene obtained by GPC (gel permeation chromatography) can be used.

[0086] (D) The glass transition temperature (Tg) of non-radical polymers with a molecular weight of 1,000 or higher is not particularly limited. For example, it is -50°C or higher, preferably -20°C or higher, more preferably 10°C or higher, for example, 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower. Regarding the glass transition temperature (Tg), it can be determined by simultaneous differential thermal and thermogravimetric analysis (TG / DTA) at 600°C under nitrogen atmosphere, heating rate of 5°C / min, and tensile mode (100mN), and by the weight reduction of the resulting TG curve.

[0087] As a non-radical polymerizable polymer with a molecular weight of 1,000 or more (D), examples include one or more selected from the following: (meth)acrylic resin, polyolefin resin, polystyrene resin, epoxy resin, rubber / elastomer, polyvinyl alcohol resin, polyvinyl ester resin, diene resin, ABS resin, AS resin, styrene-butadiene resin, halogenated vinyl resin, cyclic polyolefin resin, polyester resin, polyether resin, phenoxy resin, urethane resin, polyamide resin, polycarbonate resin, polyimide resin, polysiloxane resin, phenolic resin, cellulose resin, rosin resin, and modified resins of the above resins. In this invention, a thermoplastic resin is preferred, more preferably selected from one or more 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, halogenated vinyl resin, polyester resin, polyether resin, phenoxy resin, urethane resin, and polyamide resin. Further preferably selected from one or more of (meth)acrylic resin, polyolefin resin, polystyrene resin, epoxy resin, rubber / elastomer, polyester resin, polyether resin, phenoxy resin, urethane resin, and polyamide resin.

[0088] The content of non-radical polymers with a molecular weight of 1,000 or higher in the free radical polymerizable adhesive is not particularly limited, as long as it does not impair the coatability, adhesive strength, and other properties of the free radical polymerizable adhesive. The total amount of the free radical polymerizable adhesive can be set to 100% by mass, for example, it can be set to 0.1% by mass or more, preferably 1% by mass or more, more preferably 10% by mass or more, for example, it can be set to 60% by mass or less, preferably 50% by mass or less. By setting the content of non-radical polymers with a molecular weight of 1,000 or higher in the (D) molecular weight of 1,000 or more to 60% by mass relative to 100% by mass of the total amount of the free radical polymerizable adhesive, the coatability, normal adhesion (normal tensile shear bond strength), high-temperature adhesion (high-temperature tensile bond strength), and high-temperature tensile shear bond strength retention rate R of the free radical polymerizable adhesive can be improved. a Heat aging resistance (heat aging tensile bond strength), heat aging tensile shear bond strength retention rate R b One or more of them become superior.

[0089] [(E) Curing Catalyst] The free radical polymerizable adhesive of the present invention preferably further contains (E) curing catalyst.

[0090] There are no particular limitations on the (E) curing catalyst. For example, one or more selected from imide compounds, amine compounds, azole compounds, thiols, hydrazine compounds, etc. can be listed. These curing catalysts are also very useful as anaerobic curing catalysts. Among these, imide compounds are preferred from the perspective of improving curability, especially improving anaerobic curing ability.

[0091] Imide compounds are those having the following formula (4) or (5): -CONHCO- (4) -CONHSO2- (5) One or more of the compounds or salts thereof representing the group.

[0092] As an imide compound, examples include one or more selected from o-benzoylsulfonylimide (saccharin), succinimide, phthalimide or its salts (especially alkali metal salts such as sodium or potassium).

[0093] As amine compounds, examples include one or more heterocyclic secondary amines selected from 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroquinalidine, etc.; heterocyclic tertiary amines selected from quinoline, methylquinoline, quinalidine, quinoxaline, phenazine, etc.; and aromatic tertiary amines selected from N,N-dimethyl-methoxyaniline, N,N-dimethylaniline, etc.

[0094] As azole compounds, examples include one or more selected from 1,2,4-triazole, oxazole, oxadiazole, thiadiazole, benzotriazole, hydroxybenzotriazole, benzoxazole, 1,2,3-benzothiadiazole, 3-mercaptobenzotriazole, etc.

[0095] As a thiol compound, one or more straight-chain thiols such as n-dodecyl thiol, ethanethiol, and butanethiol can be listed as examples.

[0096] Examples of hydrazine compounds include, for example, one or more of the following: 1-acetyl-2-phenylhydrazine, 1-acetyl-2-(p-tolyl)hydrazine, 1-benzoyl-2-phenylhydrazine, 1-(1',1',1'-trifluoro)acetyl-2-phenylhydrazine, 1,5-diphenylcarbazine, 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-trisulfonylhydrazine, 1-acetyl-2-methylhydrazine, 1-phenylhexacarbazine, tert-butyl 2-phenylhydrazine formate, di(phenylhydrazine) succinate, etc.

[0097] The content of the (E) curing catalyst in the free radical polymerizable adhesive is not particularly limited, as long as it does not impair the processability, bond strength, curing speed, storage stability, and other properties of the free radical polymerizable adhesive. It can be 0 parts by mass or more relative to 100 parts by mass of the (A) free radical polymerizable compound, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, 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 free radical polymerizable adhesive to 5 parts by mass or less relative to 100 parts by mass of the (A) free radical polymerizable compound, the curability and storage stability of the free radical polymerizable adhesive, especially its anaerobic curing and storage stability, can be improved.

[0098] [(F) Preservative Stabilizer] The free radical polymerizable adhesive of the present invention may further contain a (F) preservation stabilizer. Examples of preservation stabilizers include one or more selected from polymerization inhibitors (free radical scavengers, metal chelators), antioxidants, etc.

[0099] As polymerization inhibitors, examples include one or more metal chelating agents selected from the following: ethylenediaminetetraacetic acid, its 2-sodium salt, its 4-sodium salt, oxalic acid, acetylacetone, o-aminophenol, etc.; quinone compounds selected from 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, etc.; pentaerythritol tetra(3-(3,5-di-tert-butyl) One or more hindered phenolic compounds selected from N-methyl-N-nitrosoaniline, N-nitrosodiphenylamine, and N-nitrosophenylhydroxylamine aluminum salt; hindered amine compounds; one or more nitrosamine compounds selected from N-methyl-N-nitrosoaniline, N-nitrosodiphenylamine, and N-nitrosophenylhydroxylamine aluminum salt; phosphorus compounds such as triphenyl phosphite; and compounds selected from phenothiazine, N-isopropyl-N'-phenyl-p-phenylenediamine, diethylhydroxylamine, sulfur, 4-tert-butylcatechol, and potassium triiodide.

[0100] The content of the (F) preservative stabilizer in the free radical polymerizable adhesive is not particularly limited. It is 0 parts by mass or more relative to 100 parts by mass of the (A) free radical polymerizable compound, for example, it can be set to 0.001 parts by mass or more, preferably 0.002 parts by mass or more, for example, it can be set to 7 parts by mass or less, preferably 5 parts by mass or less.

[0101] [(G) Other ingredients] The free radical polymerizable adhesive of the present invention may contain (G) other components, in addition to (A) free radical polymerizable compounds, (B) organic peroxides, (C) phosphate ester compounds having free radical polymerizable groups, (D) non-free radical polymerizable polymers with a molecular weight of 1,000 or more, (E) curing catalysts and (F) preservation stabilizers, to the extent that the functions of the adhesive, such as curability or the adhesion of the cured product, are not impaired.

[0102] (G) Other ingredients may include, for example, one or more of the following: inorganic fillers, silane coupling agents, curing speed modifiers, plasticizers, defoamers, heavy metal deactivators, adhesives and / or tackifiers, antioxidants, light stabilizers, reinforcing agents, colorants, flame retardants, rust inhibitors, dispersants, thixotropic agents, antisettling agents, anti-aging agents, light stabilizers, ultraviolet absorbers, fragrances, etc.

[0103] (G) Among the other components, as inorganic fillers, one or more may be selected from glass, silicon dioxide, alumina, mica, ceramics, calcium carbonate, aluminum nitride, carbon powder, kaolin, dried clay minerals, dried diatomaceous earth, etc.

[0104] (G) Among the other components, a silane coupling agent is used as a binding agent. Examples of silane coupling agents include, for instance, one or more selected from the following: γ-chloropropyltrimethoxysilane, octenyltrimethoxysilane, epoxypropoxyoctyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-epoxypropoxypropyltrimethoxysilane, γ-epoxypropoxypropyltriethoxysilane, γ-epoxypropoxypropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, N-2 -(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-γ-aminopropyltrimethoxysilane, γ-(meth)acryloyloxypropyltrimethoxysilane, γ-(meth)acryloyloxypropyltriethoxysilane, γ-isocyanate-propyltriethoxysilane, γ-ureopropyltriethoxysilane, p-styryltrimethoxysilane, etc.

[0105] High-temperature tensile shear bond strength retention rate R a and the retention rate of heat aging tensile shear bond strength R b ] Regarding the free radical polymerizable adhesive of the present invention, its high-temperature tensile shear bond strength retention rate R a The retention rate of tensile and shear bond strength R for heat aging is above 13%. b It is over 50%.

[0106] That is, the free radical polymerizable adhesive of the present invention satisfies the requirement of "high temperature tensile shear bond strength retention rate R". a The conditions are "above 13%" and "heat aging tensile shear bond strength retention rate R". b Both conditions are "more than 50%".

[0107] High-temperature tensile shear bond strength retention rate R a > The high-temperature tensile shear bond strength retention rate R of the free radical polymerizable adhesive of the present invention a It is 13% or more, preferably 14% or more, and more preferably 15% or more.

[0108] High-temperature tensile shear bond strength retention rate R a (%) is calculated using equation (i): [Number 5]

[0109] In equation (i), A is the tensile shear bond strength (N / mm) when bonding is performed at 23°C. 2 B represents the tensile shear bond strength at 150℃ (N / mm²). 2 ).

[0110] High-temperature tensile shear bond strength retention rate R of free radical polymerizable adhesives a If the content is 13% or more, preferably 14% or more, and more preferably 15% or more, then when coating and heating drying are performed after bonding, the peeling of the bonded parts during heating (high temperature) can be suppressed, which is beneficial in terms of reducing product defect rate and improving productivity.

[0111] High-temperature tensile shear bond strength retention rate R a The tensile shear strength (normal tensile shear bond strength) used in the calculation when bonding at 23°C can be determined by the method described in the <Normal Tensile Shear Bond Strength> section of the embodiments.

[0112] High-temperature tensile shear bond strength retention rate R a The high-temperature tensile shear bond strength (high-temperature tensile shear bond strength) used in the calculation can be determined by the method described in the <High-Temperature Tensile Shear Bond Strength> section of the embodiments.

[0113] < Heat aging tensile shear bond strength retention rate R b > The heat aging tensile shear bond strength retention rate R of the free radical polymerizable adhesive of the present invention b It is 50% or more, preferably 70% or more. More preferably 80% or more.

[0114] Heat aging tensile shear bond strength retention rate R b Calculated using equation (ii): [Number 6]

[0115] In formula (ii), A is the tensile shear bond strength (N / mm) when bonding is performed at 23℃. 2 C represents the tensile shear bond strength (N / mm) after heating at 200℃ for 2 hours and cooling to 23℃. 2 ).

[0116] If the heat aging tensile shear bond strength retention rate R of the free radical polymerizable adhesive b If the bonding rate is above 50%, then when coating and heating drying are performed after bonding, peeling of the bonded parts during cooling after heating can be suppressed, which is beneficial in reducing product defect rate and improving productivity.

[0117] Heat aging tensile shear bond strength retention rate R b The tensile shear strength (normal tensile shear bond strength) used in the calculation when bonding at 23°C can be determined by the method described in the <Normal Tensile Shear Bond Strength> section of the embodiments.

[0118] Heat aging tensile shear bond strength retention rate R b The tensile shear bond strength (heat-resistant aging tensile shear bond strength) used in the calculation after heating at 200°C for 2 hours and cooling to 23°C can be determined by the method described in the <Heat-resistant aging tensile shear bond strength> example.

[0119] Other properties of free radical polymerizable adhesives <Tensile shear bond strength when bonded at 23°C> The free radical polymerizable adhesive of the present invention preferably has a tensile shear bond strength (normal tensile shear bond strength) of 2.50 N / mm when bonded at 23°C. 2 The above is preferred. 2.75 N / mm 2 The above, more preferably 3.00 N / mm 2 The above is further preferred to be 3.25 N / mm. 2 The above. There is no specific upper limit to the tensile shear bond strength (normal tensile shear bond strength) when bonding at 23°C, for example, it can be 9.00 N / mm. 2 the following.

[0120] The tensile shear bond strength (normal tensile shear bond strength) when bonding is performed at 23°C can be determined by the method described in the <Normal Tensile Shear Bond Strength> section of the examples.

[0121] <Tensile shear bond strength after heating at 200°C for 2 hours and cooling to 23°C> The free radical polymerizable adhesive of the present invention, after being heated at 200°C for 2 hours and cooled to 23°C, preferably has a tensile shear bond strength (heat-resistant aging tensile shear bond strength) of 2.50 N / mm. 2 The above is preferred. 2.75 N / mm 2 The above, more preferably 3.00 N / mm 2 The above is further preferred to be 3.25 N / mm. 2 The above. There is no particular upper limit to the tensile shear bond strength (heat-resistant aging tensile shear bond strength) after heating at 200°C for 2 hours and cooling to 23°C, for example, 9.00 N / mm. 2 the following.

[0122] The tensile shear bond strength (heat-resistant aging tensile shear bond strength) of a free radical polymerizable adhesive after heating at 200°C for 2 hours and cooling to 23°C is 2.50 N / mm. 2 Therefore, when coating and heating to dry after bonding, the bonding parts can be prevented from peeling off during cooling after heating, which is beneficial in reducing product defect rate and improving productivity.

[0123] The tensile shear bond strength (heat-resistant 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 the <Heat-resistant aging tensile shear bond strength> section of the examples.

[0124] <Viscosity> The viscosity of the free radical polymerizable adhesive of the present invention is not particularly limited. From the perspective of processability or preventing seepage during bonding, it can be set to, for example, 0.01 Pa. For values ​​above s, a preferred setting is 0.05 Pa. s or more, preferably 0.5 Pa Above s, for example, it can be set to 50Pa. For values ​​below s, a Pa value of 30 Pa is preferred. Below s, it is more preferable to set it to 15 Pa. Below s.

[0125] Viscosity can be adjusted using methods known in the adhesive field, such as the formulation of viscosity modifiers (thixotropic agents).

[0126] Viscosity can be measured as follows: 100g of free radical polymerizable adhesive is placed in a bottle, poured into a measuring cup, and measured using a Brookfield viscometer (manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C and a rotation speed of 60 rpm.

[0127] [Manufacturing method of free radical polymerizable adhesive] The method for manufacturing the free radical polymerizable adhesive of the present invention is not particularly limited. For example, it can be manufactured by mixing at least a specified amount of (A) a free radical polymerizable compound, (B) an organic peroxide and (C) a phosphate ester compound having free radical polymerizable groups in any order in a mixing container.

[0128] When mixing, various mixing devices can be used, such as mixers (rotation / revolution mixers, planetary mixers, etc.), drum mixers, agitators, stirrers, mechanical homogenizers, ultrasonic homogenizers, high-pressure homogenizers, shakers, V-type mixers, and Nota mixers. Mixers are preferred.

[0129] There are no particular limitations on the mixing conditions. For example, the temperature can be set to 0°C or higher, preferably 10°C or higher, or for example, 100°C or lower, preferably 70°C or lower. For the mixing time, for example, it can be set to 1 minute or more, preferably 5 minutes or more, or for example, 10 hours or less, preferably 5 hours or less.

[0130] Applications of free radical polymerizable adhesives The free radical polymerizable adhesive of the present invention can be used as an anaerobic adhesive. In the present invention, the free radical polymerizable adhesive is preferably an anaerobic adhesive, and more preferably an anaerobic adhesive for metals.

[0131] The free radical polymerizable adhesive of the present invention can be used in various fields such as electrical and electronic components, automobiles, machinery, buildings, and civil engineering.

[0132] The free radical polymerizable adhesive of the present invention can be used for bonding various materials, and it can be rapidly cured and bonded at 25°C (room temperature). Examples of materials to be bonded include one or more metals such as iron, aluminum, magnesium, stainless steel, titanium, and copper, resins, glass, ceramics, paper, cloth, and fibers. The free radical polymerizable adhesive of the present invention exhibits excellent adhesion to metals, and is preferably used for metal applications. Especially from the perspective of its curing properties, it can also be applied to molded articles formed by bonding two or more metal plates. Examples of metal plates include one or more selected from steel plates (cold-rolled steel plates (SPCC, SPCC-SD), coated steel plates, etc.), aluminum plates, stainless steel plates, magnesium plates, and copper plates. The thickness of the metal plate is not particularly limited and can be appropriately set according to the application. For example, it can be 0.01 mm or more, preferably 0.1 mm or more, for example, 5 mm or less, preferably 3 mm or less, and more preferably 1 mm or less.

[0133] When using the free radical polymerizable adhesive of the present invention for metal bonding, such as anaerobic metal bonding, it is preferable to pre-apply a primer to the metal. When applying the free radical polymerizable adhesive of the present invention to metal bonding, the primer, which can be applied to the metal, preferably contains a transition metal compound, especially a copper compound, as a free radical polymerizable adhesive promoter. In addition to transition metal compounds, the primer may also contain a liquid medium, rust inhibitor, corrosion inhibitor, etc.

[0134] As copper compounds, examples include copper salts of carboxylic acids such as copper neodecanoate, copper 2-ethylhexanoate, copper naphthenate, copper octenate, copper hexanoate, copper propionate, and copper 2,4-pentanedione (copper acetylacetone); copper complexes such as copper ethylenediamine and copper propylenediamine; and more than one of the following.

[0135] As a liquid medium, one or more organic solvents and / or water may be listed. There are no particular limitations on the organic solvent. For example, one or more selected from the following may be listed: aliphatic hydrocarbon organic solvents with 5 to 40 carbon atoms (hexane, heptane, paraffin, etc.); alicyclic hydrocarbon solvents with 5 to 20 carbon atoms; aromatic hydrocarbon solvents with 6 to 20 carbon atoms (benzene, toluene, xylene, ethylbenzene, indene, etc.); alcohol solvents with 1 to 10 carbon atoms (methanol, ethanol, propanol, isopropanol, hexanol, etc.); ketone solvents with 3 to 20 carbon atoms (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.); ether solvents with 2 to 20 carbon atoms (tetrahydrofuran, diethyl ether, dioxane, ethyl cellosolve, propylene glycol monomethyl ether, etc.); ester solvents with 2 to 20 carbon atoms (methyl acetate, ethyl acetate, butyl acetate, etc.); oils (punching oil, mineral oil, synthetic oil, animal and vegetable oils, etc.); etc. In particular, the use of oils can achieve rust prevention for metals and facilitates mechanical processing operations such as stamping after bonding.

[0136] The composition of the primer is not particularly limited. When the total amount of the primer is set to 100% by mass, 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, for example, 15.0% by mass or less, preferably 10.0% by mass or less, more preferably 8.0% by mass or less. Furthermore, when the total amount of the primer is set to 100% by mass, 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, for example, 80.0% by mass or less, preferably 70.0% by mass or less, more preferably 60.0% by mass or less.

[0137] Example The present invention will be specifically described below through embodiments, but the present invention is not limited to the following embodiments. In addition, unless otherwise specified, in each embodiment, "parts" means "parts by mass" and "%" means "% by mass". Furthermore, all entries in the table relating to proportions are in "parts" (parts by mass).

[0138] [Components of Free Radical Polymerizing Adhesives] In the examples and comparative examples shown in Tables 1 and 2, the constituent components of the free radical polymerizable adhesives are as follows.

[0139] HEMA: Hydroxyethyl methacrylate BPEPMA: The following formula (B): [Chemistry 5]

[0140] The indicated difunctional bisphenol A type epoxy methacrylate BPEDM: The following formula (C): [Chemistry 6]

[0141] The indicated bisphenol A ethylene oxide 10-molar adduct dimethacrylate PUA: Polytetramethylene glycol urethane acrylate (weight average molecular weight 28,000, two-terminal acrylate) AcPolym: Acrylic polymer (Tg: 47℃, 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℃); solid content 100%) MAEP: 2-Methacryloxyethyl phosphate EDTANa: Tetrasodium ethylenediaminetetraacetate SACC: Saccharin CHP: Cumene hydroperoxide [Evaluation of Adhesive Properties] <Preparation of Experimental Steel Plates> Cold-rolled steel sheets with a thickness of 0.5 mm (SPCC-SD) according to Japanese Industrial Standard JIS G 3141 were cut into dimensions of 25 mm wide × 100 mm long (W25 mm × L100 mm) to prepare experimental cold-rolled steel sheets.

[0142] <Preparation of Primer> Take 0.6 parts of a 60% toluene solution of copper neodecanoate, 49.4 parts of ethanol, and 50 parts of drying stamping oil, mix them in a glass container to obtain a primer.

[0143] <Tensile shear bond strength under normal conditions> Normal tensile shear bond strength is the tensile shear bond strength when bonding is performed at 23°C, and it can be obtained in the following way.

[0144] Prepare two prepared cold-rolled steel sheets for testing. Apply a primer to one sheet and allow it to dry at 25°C for 3 hours. On the other sheet, apply 0.03 mL of a free-radical polymerizable adhesive using a scraper. Immediately after applying the adhesive, press the primer-coated surface against the adhesive-coated surface, ensuring a bonding area of ​​25 mm wide × 12.5 mm long. Then, press the two sheets together for 200 seconds before removing them to obtain the test specimen.

[0145] The prepared test pieces were cured at 23°C for 24 hours, and then subjected to tensile testing at 23°C using a universal tensile testing machine at a tensile speed of 0.5 mm / min. The normal tensile shear bond strength (N / mm²) was obtained according to Japanese Industrial Standard JIS K 6850 (1999). 2 ).

[0146] <High-Temperature Tensile Shear Bond Strength> The high-temperature tensile shear bond strength is the high-temperature tensile shear bond strength at 150℃, which can be obtained through the following methods.

[0147] Prepare two prepared cold-rolled steel sheets for the experiment. Apply a primer to one sheet and allow it to dry at 25°C for 3 hours. On the other sheet, apply 0.03 mL of a free-radical polymerizable adhesive using a scraper. Immediately after applying the adhesive, press the primer-coated surface against the adhesive-coated surface, ensuring a bonding area of ​​25 mm wide × 12.5 mm long. Then, press the two sheets together for 200 seconds for anaerobic bonding before removing them to obtain the experimental specimen.

[0148] After curing the prepared test pieces at 23℃ for 24 hours, they were subjected to tensile testing at 150℃ using a universal tensile testing machine at a tensile speed of 0.5 mm / min. The high-temperature tensile shear bond strength (N / mm²) was obtained according to Japanese Industrial Standard JIS K 6850 (1999). 2 ).

[0149] <Heat aging tensile shear bond strength> The heat-resistant aging tensile shear bond strength is the tensile shear bond strength after heating at 200℃ for 2 hours and cooling to 23℃, and can be obtained in the following way.

[0150] Prepare two prepared cold-rolled steel sheets for the experiment. Apply a primer to one sheet and allow it to dry at 25°C for 3 hours. On the other sheet, apply 0.03 mL of a free-radical polymerizable adhesive using a scraper. Immediately after applying the adhesive, press the primer-coated surface against the adhesive-coated surface, ensuring a bonding area of ​​25 mm wide × 12.5 mm long. Then, press the two sheets together for 200 seconds for anaerobic bonding before removing them to obtain the experimental specimen.

[0151] The prepared test pieces were cured at 23°C for 24 hours, then heated at 200°C for 2 hours. After cooling to 23°C, they were subjected to tensile testing using a universal tensile testing machine at a tensile speed of 0.5 mm / min. The heat-resistant aging tensile shear bond strength (tensile shear bond strength after heating at 200°C for 2 hours and cooling to 23°C) was obtained according to Japanese Industrial Standard JIS K 6850 (1999) (N / mm). 2 ).

[0152] High-temperature tensile shear strength retention rate R a > High-temperature tensile shear strength retention rate R a Calculated by equation (i): [Number 7] .

[0153] In formula (i), A is the tensile shear bond strength (normal tensile shear bond strength) when bonding is performed at 23°C (N / mm²). 2 B represents the high-temperature tensile shear bond strength at 150℃ (high-temperature tensile shear bond strength) (N / mm). 2 ).

[0154] < Heat aging tensile shear strength retention rate R b > Heat aging tensile shear strength retention rate R b Calculated by equation (ii): [Number 8] .

[0155] In formula (ii), A is the tensile shear bond strength (normal tensile shear bond strength) when bonding is performed at 23℃ (N / mm²). 2 C represents the tensile shear bond strength (heat-resistant aging tensile shear bond strength) after heating at 200℃ for 2 hours and cooling to 23℃ (N / mm). 2 ).

[0156] [Examples A1-A6, Comparative Example A1] <Preparation of Free Radical Polymerizing Adhesives> Each component listed in Table 1 was sampled in the amounts (parts by mass) recorded in Table 1 and mixed in a glass container to prepare a free radical polymerizable adhesive.

[0157] Using the obtained free radical polymerizable adhesive, the normal tensile shear bond strength (tensile shear bond strength when bonding at 23°C) and the high-temperature tensile shear bond strength (high-temperature tensile shear bond strength at 150°C) were measured. The high-temperature tensile shear strength retention rate R was calculated using these data. a .

[0158] The retention rates of normal tensile shear bond strength (tensile shear bond strength when bonding at 23°C) and high-temperature tensile shear strength R were respectively compared. a The results are shown in Table 1.

[0159] [Table 1]

[0160] As shown in Table 1, when using the free radical polymerizable adhesives of Examples A1 to A6 of this invention to bond metal plates (steel plates), they exhibit excellent normal tensile shear bond strength at room temperature (23°C), and their high-temperature tensile shear bond strength retention rate R a With a content of 13% or more, especially 15% or more, it exhibits excellent high-temperature tensile shear bond strength even when heated after bonding (e.g., to 150°C) during heating (high temperature).

[0161] [Examples B1-B6, Comparative Example B1] <Preparation of Free Radical Polymerizing Adhesives> Each component listed in Table 2 was sampled in the amounts (parts by mass) recorded in Table 2 and mixed in a glass container to prepare a free radical polymerizable adhesive.

[0162] Using the obtained free radical polymerizable adhesive, the normal tensile shear bond strength (tensile shear bond strength when bonding at 23°C) and the heat-resistant aging tensile shear bond strength (tensile shear bond strength after heating at 200°C for 2 hours and cooling to 23°C) were measured. Using these data, the heat-resistant aging tensile shear bond strength retention rate R was calculated. b .

[0163] The tensile shear bond strength under normal conditions (tensile shear bond strength when bonded at 23°C) and the retention rate R of the tensile shear bond strength under heat aging were respectively compared. b The results are shown in Table 2.

[0164] [Table 2]

[0165] As shown in Table 2, when using the free radical polymerizable adhesives of Examples B1 to B6 of this invention to bond metal plates (steel plates), they exhibit excellent normal tensile shear bond strength at room temperature (23°C), and their heat aging tensile shear bond strength retention rate R b With a strength of over 50%, especially over 80%, it exhibits excellent heat-resistant tensile shear bond strength even after heat treatment following bonding (e.g., heating at 200°C for 2 hours).

Claims

1. A free radical polymerizable adhesive, comprising (A) a free radical polymerizable compound, (B) an organic peroxide, (C) a phosphate ester compound having free radical polymerizable groups, and (D) a non-free radical polymerizable polymer with a molecular weight of 1,000 or more. Its high-temperature tensile shear bond strength retention rate R a The percentage is above 13%, and the retention rate of heat-resistant aging tensile shear bond strength R b More than 50%, The high-temperature tensile shear bond strength retention rate R a Calculated by equation (i): [Number 1] In equation (i), A is the tensile shear bond strength (N / mm) when bonding is performed at 23°C. 2 B represents the tensile shear bond strength at 150℃ (N / mm²). 2 ), The heat aging tensile shear bond strength retention rate R b Calculated by equation (ii): [Number 2] In formula (ii), A is the tensile shear bond strength (N / mm) when bonding is performed at 23℃. 2 C represents the tensile shear bond strength (N / mm) after heating at 200℃ for 2 hours and cooling to 23℃. 2 ).

2. The free radical polymerizable adhesive according to claim 1, characterized in that, The free radical polymerizable compound (A) contains: (a1) A free radical polymerizable compound having the structure represented by formula (1) within its molecule. [Chemistry 1] And / or (a2) urethane (meth)acrylate.

3. The free radical polymerizable adhesive according to claim 1 or 2, characterized in that, The free radical polymerizable adhesive is an anaerobic adhesive.

4. The free radical polymerizable adhesive according to claim 3, characterized in that, The free radical polymerizable adhesive is an anaerobic adhesive for metals.

Images