Anaerobic curable adhesive composition, adhesive laminate, and motor

Abstract

An anaerobic curable adhesive composition containing a bifunctional ethylenically unsaturated compound, a trifunctional or higher polyfunctional ethylenically unsaturated compound, a radical polymerization initiator, and an anaerobic curing catalyst, the content of the bifunctional ethylenically unsaturated compound being 2-30 mass%, the content of the trifunctional or higher polyfunctional ethylenically unsaturated compound being 1-30 mass%, and the content of the radical polymerization initiator being 1-30 mass%. The content of the trifunctional or higher polyfunctional ethylenically unsaturated compound is 2% by mass or more, the content of the radical polymerization initiator is 2.0% by mass or less, and two or more steel sheets are bonded and laminated by the anaerobic curable adhesive composition; and a motor provided with the adhesive laminate.

Description

Technical Field

[0001] The present invention relates to an anaerobic curable adhesive composition, an adhesive laminate, and a motor. Background Art

[0002] In recent years, when manufacturing a motor core of a small motor, a method of laminating steel plates using an adhesive has attracted attention. Compared with the method of fixing steel plates using physical unevenness as a conventional method, the method of laminating steel plates using an adhesive can be expected to reduce the strain of the steel plates and improve the energy efficiency.

[0003] As an example of a conventional adhesive composition, the adhesive composition described in Patent Document 1 can be cited.

[0004] Patent Document 1 discloses an anaerobic curable adhesive containing a phosphate compound.

[0005] [Prior Art Documents]

[0006] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2019 / 123885 Summary of the Invention

[0008] [Problems to be Solved by the Invention]

[0009] As described above, Patent Document 1 relates to an anaerobic curable adhesive containing a phosphate compound, and proposes the following method: an organic solvent and an anaerobic curing promoter are dissolved in stamping oil and applied to a steel plate, and then substantially the stamping oil is evaporated in a drying process at room temperature, and then the anaerobic curable adhesive is cured at normal temperature.

[0010] In addition, conventionally, high temperatures are applied during the manufacturing and operation of a motor core, and therefore, adhesive strength at high temperatures is also required for the adhesive, that is, adhesive strength at high temperatures is important.

[0011] The problem to be solved by the present invention is to provide an anaerobic curable adhesive composition having excellent adhesive strength at high temperatures (150°C).

[0012] Another problem to be solved by the present invention is to provide an adhesive laminate and a motor using the anaerobic curable adhesive composition.

[0013] [Means for Solving the Problems]

[0014] The solution for solving the above problems includes the following aspects.

[0015] <1>An anaerobic curable adhesive composition comprising a bifunctional ethylenically unsaturated compound, a polyfunctional ethylenically unsaturated compound having three or more functional groups, a free radical polymerization initiator, and an anaerobic curing catalyst, wherein the content of the bifunctional ethylenically unsaturated compound is 2% by mass to 30% by mass, the content of the polyfunctional ethylenically unsaturated compound having three or more functional groups is 2% by mass or more, and the content of the free radical polymerization initiator is 2.0% by mass or less.

[0016] <2>The anaerobic curable adhesive composition according to <1>, wherein the total content M M (unit: mole) of the bifunctional ethylenically unsaturated compound and the polyfunctional ethylenically unsaturated compound having three or more functional groups and the content M R (unit: mole) of the free radical polymerization initiator, the ratio (M M / M R ) is 0.8 to 30.

[0017] <3>The anaerobic curable adhesive composition according to <1> or <2>, wherein the content M M3 (unit: mole) of the polyfunctional ethylenically unsaturated compound having three or more functional groups and the content M R (unit: mole) of the free radical polymerization initiator, the ratio (M M3 / M R ) is 0.6 to 27.

[0018] <4>The anaerobic curable adhesive composition according to any one of <1> to <3>, wherein the bifunctional ethylenically unsaturated compound is a polymer or oligomer having two or more (meth)acryloyl groups in one molecule.

[0019] <5>The anaerobic curable adhesive composition according to any one of <1> to <4>, wherein the polymer or oligomer having two or more (meth)acryloyl groups in one molecule contains urethane (meth)acrylate.

[0020] <6>The anaerobic curable adhesive composition according to any one of <1> to <5>, wherein the polyfunctional ethylenically unsaturated compound contains a pentafunctional ethylenically unsaturated compound or a hexafunctional ethylenically unsaturated compound.

[0021] <7>The anaerobic curable adhesive composition according to any one of <1> to <6>, wherein the content of the free radical polymerization initiator is 0.1% by mass to 2.0% by mass.

[0022] <8>The anaerobic curable adhesive composition according to any one of <1> to <7>, and this composition is an anaerobic curable adhesive composition for steel plates.

[0023] <9> The anaerobic curable adhesive composition according to any one of <1> to <8> is an anaerobic curable adhesive composition for preventing screw loosening.

[0024] <10> The anaerobic curable adhesive composition according to any one of <1> to <9> is an anaerobic curable adhesive composition for fitting and fixing.

[0025] <11> An adhesive laminate is formed by bonding and laminating two or more steel plates with the anaerobic curable adhesive composition according to any one of <1> to <8>.

[0026] <12> A motor includes the adhesive laminate described in <12>.

[0027] [Advantages of the Invention]

[0028] According to the present invention, an anaerobic curable adhesive composition having excellent adhesive strength at high temperature (150 °C) can be provided.

[0029] In addition, according to the present invention, an adhesive laminate and a motor using the anaerobic curable adhesive composition can be provided. Detailed Description of the Invention

[0030] The description of the constituent elements described below is sometimes made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. It should be noted that in the present specification, "~" is used to mean including the numerical values described before and after it as the lower limit value and the upper limit value.

[0031] In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in one numerical range can also be replaced with the upper limit value or the lower limit value of other numerically described ranges. In addition, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range can also be replaced with the values shown in the examples.

[0032] In the present invention, "mass %" has the same meaning as "weight %", and "parts by mass" has the same meaning as "parts by weight".

[0033] In addition, in the present invention, a combination of two or more preferred modes is a more preferred mode.

[0034] Hereinafter, the content of the present invention will be described in detail.

[0035] (Anaerobic Curable Adhesive Composition)

[0036] The anaerobic curable adhesive composition of the present invention contains a bifunctional ethylenically unsaturated compound, a polyfunctional ethylenically unsaturated compound having three or more functional groups, a radical polymerization initiator, and an anaerobic curing catalyst. The content of the bifunctional ethylenically unsaturated compound is 2% by mass to 30% by mass, the content of the polyfunctional ethylenically unsaturated compound having three or more functional groups is 2% by mass or more, and the content of the radical polymerization initiator is 2.0% by mass or less.

[0037] In addition, the anaerobic curable adhesive composition of the present invention can be suitably used as an anaerobic curable adhesive composition for steel plates.

[0038] The use of the anaerobic curable adhesive composition of the present invention is not particularly limited. Since the adhesive strength at high temperatures is excellent, it can be suitably used for manufacturing an adhesive laminate formed by bonding and laminating steel plates, a motor core, a motor, and the like.

[0039] In addition, the anaerobic curable adhesive composition of the present invention can be suitably used for anti-loosening of screws or as an anaerobic curable adhesive composition for fitting and fixing.

[0040] <Bifunctional ethylenically unsaturated compound>

[0041] The anaerobic curable adhesive composition of the present invention contains a bifunctional ethylenically unsaturated compound.

[0042] The bifunctional ethylenically unsaturated compound may be a monomer, preferably a polymer and / or an oligomer. As a preferred bifunctional ethylenically unsaturated compound, a polymer and / or an oligomer having two or more (meth)acryloyl groups in one molecule can be cited.

[0043] In this specification, an oligomer is a polymer having a weight average molecular weight of 500 or more and less than 5000, and a polymer is a polymer having a weight average molecular weight of 5000 or more. It should be noted that the molecular weight in the present invention refers to a value obtained by converting the weight average molecular weight measured by GPC (gel permeation chromatography) using polystyrene as a standard substance. The number average molecular weight can be obtained, for example, by the following steps.

[0044] Separation is carried out using a gel permeation chromatograph (manufactured by Tosoh Corporation, HLC-8320 GPC) in a tetrahydrofuran solvent at 40 °C using a GPC column "TSK gel Super Multipore HZ-M" (manufactured by Tosoh Corporation), and the weight average molecular weight in terms of standard polystyrene is calculated from the retention time.

[0045] In the polymer or oligomer having two or more (meth)acryloyl groups in one molecule, the position of the (meth)acryloyl group is preferably at the terminal, but it may also be contained in the monomer units constituting the main chain of the polymer or oligomer.

[0046] The polymer and / or oligomer having two or more (meth)acryloyl groups in one molecule is not particularly limited. From the viewpoint of the adhesive strength at high temperatures, it is preferably at least one compound selected from the group consisting of urethane (meth)acrylate, epoxy (meth)acrylate, ester (meth)acrylate, isoprene-based (meth)acrylate, hydrogenated isoprene-based (meth)acrylate, and acrylate polymers containing (meth)acryloyl groups. More preferably, it is urethane (meth)acrylate or epoxy (meth)acrylate. Further preferably, it is urethane (meth)acrylate. Particularly preferably, it is urethane methacrylate.

[0047] In addition, from the viewpoint of the adhesive strength at high temperatures, the polymer and / or oligomer having two or more (meth)acryloyl groups in one molecule is preferably a polymer or oligomer having a methacryloyl group at the terminal.

[0048] Examples of the urethane (meth)acrylate include the reaction product of a polyol, a polyisocyanate, and a hydroxy (meth)acrylate compound, or the reaction product of a polyisocyanate and a hydroxy (meth)acrylate compound without using a polyol.

[0049] Specific examples of the polyol include polyether polyols such as polypropylene glycol and polytetramethylene glycol, polyester polyols obtained by the reaction of a polyol and a polycarboxylic acid, caprolactone polyols obtained by the reaction of a polyol, a polycarboxylic acid, and ε-caprolactone, and polycarbonate polyols (for example, polycarbonate polyols obtained by the reaction of 1,6-hexanediol and diphenyl carbonate, etc.).

[0050] Specific examples of the organic polyisocyanate include alicyclic polyisocyanates (isophorone diisocyanate, dicyclopentyl diisocyanate, etc.), aliphatic polyisocyanates (hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, etc.), and aromatic polyisocyanates (toluene diisocyanate, xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, etc.).

[0051] As the urethane (meth)acrylate, from the aspect of excellent adhesive force, it is preferably manufactured from a polyether polyol, a polyester polyol, or a polycarbonate polyol as the raw material polyol. In addition, from the aspect of excellent adhesive force, it is preferably manufactured from isophorone diisocyanate, hexamethylene diisocyanate, or xylylene diisocyanate as the raw material organic polyisocyanate.

[0052] In addition, examples of the urethane (meth)acrylate include urethane (meth)acrylates having a polybutadiene skeleton, urethane (meth)acrylates having a hydrogenated polybutadiene skeleton, urethane (meth)acrylates having a polycarbonate skeleton, urethane (meth)acrylates having a hydrogenated bisphenol A skeleton, urethane (meth)acrylates having a polyether skeleton, urethane (meth)acrylates having a polyester skeleton, urethane (meth)acrylates having a castor oil skeleton, and the like.

[0053] Examples of the epoxy (meth)acrylate include epoxy (meth)acrylates obtained by reacting epoxy resins such as conventionally known aromatic epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins with (meth)acrylic acid.

[0054] From the viewpoint of oil surface adhesiveness, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains a compound in which the maximum value of tanδ observed by dynamic viscoelasticity measurement (1 Hz, 2 °C / min.) is observed at 25 °C or lower.

[0055] The maximum value of tanδ can be measured, for example, using the following dynamic viscoelasticity measurement device according to the following steps. Tanδ is calculated from the ratio of the storage modulus and the loss modulus detected during the measurement. For example, a cured adhesive sample cut into 50 mm × 20 mm and having a thickness of 1 mm is mounted on the measurement device, cooled to -60 °C, isothermally held for 5 minutes, and then while periodically stretching at a frequency of 1 Hz, the maximum value of tanδ is confirmed under the condition of heating to 250 °C at 2 °C / min.

[0056] Measurement device: DMS6100 manufactured by SEIKO Instruments Inc.

[0057] Measurement atmosphere: Nitrogen

[0058] Furthermore, from the viewpoint of oil surface adhesiveness, the polymer or oligomer having a (meth)acryloyl group at the terminal preferably contains a compound having a viscosity of 500 mPa·s or more at 25 °C measured with an E-type viscometer.

[0059] In addition, when the anaerobic curable adhesive composition of the present invention contains two or more of the polymers or oligomers having two or more (meth)acryloyl groups in one molecule, the following mode is preferred.

[0060] From the viewpoint of oil surface adhesiveness, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains a compound in which a maximum value of tanδ observed by dynamic viscoelasticity measurement (1 Hz, 2 °C / min.) is observed at 25 °C or lower and a compound in which a maximum value of tanδ observed by dynamic viscoelasticity measurement (1 Hz, 2 °C / min.) is observed at higher than 25 °C.

[0061] From the viewpoint of oil surface adhesiveness, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains a compound in which a maximum value of tanδ observed by dynamic viscoelasticity measurement (1 Hz, 2 °C / min.) is observed at 25 °C or lower and a compound in which a maximum value of tanδ higher than the maximum value of tanδ of the said compound by 30 °C or more is observed.

[0062] From the viewpoint of oil surface adhesiveness, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains two or more compounds having a viscosity of 1000 mPa·s or more at 25 °C measured with an E-type viscometer.

[0063] The monomer as the bifunctional ethylenically unsaturated compound is not particularly limited, and examples thereof include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, ethylene oxide-modified neopentyl glycol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, hydroxypivalate neopentyl glycol diacrylate, caprolactone-modified hydroxypivalate 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, dimethylol tricyclodecane di(meth)acrylate, etc.

[0064] The anaerobic curable adhesive composition of the present invention may contain one kind of the bifunctional ethylenically unsaturated compound alone, or may contain two or more kinds.

[0065] The content of the bifunctional ethylenically unsaturated compound is 2% by mass to 30% by mass, and from the viewpoint of the adhesive strength at high temperature, it is preferably 4% by mass to 27% by mass, more preferably 10% by mass to 25% by mass, and particularly preferably 15% by mass to 25% by mass with respect to the total mass of the adhesive composition.

[0066] <Polyfunctional ethylenically unsaturated compounds having three or more functional groups>

[0067] The anaerobic curable adhesive composition of the present invention contains a polyfunctional ethylenically unsaturated compound having three or more functional groups.

[0068] It should be noted that, unless otherwise specified, the "polyfunctional ethylenically unsaturated compound" in the present invention refers to a polyfunctional ethylenically unsaturated compound having three or more functional groups.

[0069] As the polyfunctional ethylenically unsaturated compound, any compound having three or more ethylenically unsaturated groups may be used. From the viewpoints of curability and adhesive strength at high temperatures, and also from the viewpoint of curability, a polyfunctional (meth)acrylate compound having three or more functional groups is preferably included.

[0070] In addition, the number of functional groups in the polyfunctional ethylenically unsaturated compound is not particularly limited. From the viewpoint of adhesive strength at high temperatures, an ethylenically unsaturated compound having 3 to 10 functional groups is preferably included, more preferably an ethylenically unsaturated compound having 3 to 9 functional groups, still more preferably an ethylenically unsaturated compound having 4 to 8 functional groups, and particularly preferably an ethylenically unsaturated compound having 5 or 6 functional groups.

[0071] As the polyfunctional ethylenically unsaturated compound, there is no particular limitation, and examples thereof include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, epichlorohydrin-modified trimethylolpropane tri(meth)acrylate, epichlorohydrin-modified glycerol tri(meth)acrylate, tris(acryloyloxyethyl) isocyanurate, bis-trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, alkyl-modified dipentaerythritol pentaacrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0072] Among them, from the viewpoints of heat resistance and adhesive strength at high temperatures, at least one compound selected from dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate is preferably included.

[0073] The anaerobic curable adhesive composition of the present invention may contain one kind of the above polyfunctional ethylenically unsaturated compound alone, or may contain two or more kinds.

[0074] The content of the polyfunctional ethylenically unsaturated compound is 2% by mass or more, and from the viewpoint of the adhesive strength at high temperatures, it is preferably 2% to 80% by mass, more preferably 3% to 60% by mass, still more preferably 3% to 20% by mass, and particularly preferably 5% to 10% by mass, based on the total mass of the adhesive composition.

[0075] <monofunctional ethylenically unsaturated compound>

[0076] From the viewpoint of anaerobic curability, the anaerobic curable adhesive composition of the present invention preferably contains a monofunctional ethylenically unsaturated compound.

[0077] In addition, as the monofunctional ethylenically unsaturated compound, any compound having only one ethylenically unsaturated group may be used.

[0078] Examples of the monofunctional ethylenically unsaturated compound include lauryl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy diethylene glycol (meth)acrylate, phenoxy tetraethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, nonylphenoxy tetraethylene glycol (meth)acrylate, methoxy diethylene glycol (meth)acrylate, ethoxy diethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, butoxy triethylene glycol (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylhexyl polyethylene glycol (meth)acrylate, nonylphenyl polypropylene glycol (meth)acrylate, methoxy dipropylene glycol (meth)acrylate, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, modified butyl (meth)acrylate, epichlorohydrin-modified phenoxy (meth)acrylate, ethylene oxide-modified phthalic (meth)acrylate, ethylene oxide-modified succinic (meth)acrylate, 2-acryloyloxyethyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, morpholino (meth)acrylate, N-phenylmaleimide, N-(4-hydroxyphenyl)maleimide, N-(4-acetylphenyl)maleimide, N-(4-methoxyphenyl)maleimide, N-(4-ethoxyphenyl)maleimide, N-(4-chlorophenyl)maleimide, N-(4-bromophenyl)maleimide, N-benzylmaleimide, and the like.

[0079] Among them, from the viewpoint of adhesion to metal materials, it is preferable to contain at least one compound selected from 2-hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, morpholino (meth)acrylate, N-phenylmaleimide, and tetrahydrofurfuryl (meth)acrylate, and more preferably to contain at least two compounds selected from 2-hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, morpholino (meth)acrylate, N-phenylmaleimide, and tetrahydrofurfuryl (meth)acrylate.

[0080] In addition, as the monofunctional ethylenically unsaturated compound, from the viewpoints of the adhesive strength at high temperatures and the adhesive force to metal materials, a monofunctional ethylenically unsaturated compound having a hydroxyl group is preferably included, and a monofunctional (meth)acrylate compound having a hydroxyl group is more preferably included.

[0081] As the monofunctional ethylenically unsaturated compound having a hydroxyl group, the compound having a hydroxyl group among the monofunctional ethylenically unsaturated compounds can be preferably cited.

[0082] The anaerobic curable adhesive composition of the present invention may contain one kind of the monofunctional ethylenically unsaturated compound having a hydroxyl group alone, or may contain two or more kinds.

[0083] From the viewpoints of anaerobic curability and the adhesive strength at high temperatures, the content of the monofunctional ethylenically unsaturated compound having a hydroxyl group is preferably 5% by mass to 90% by mass, more preferably 10% by mass to 85% by mass, still more preferably 20% by mass to 80% by mass, and particularly preferably 30% by mass to 75% by mass with respect to the total mass of the adhesive composition.

[0084] In addition, from the viewpoints of the viscosity of the composition, the adhesiveness of the cured product, and the adhesive strength at high temperatures, the content of the monofunctional ethylenically unsaturated compound having a hydroxyl group is preferably 40% by mass or more with respect to the total mass of the adhesive composition.

[0085] In addition, as the monofunctional ethylenically unsaturated compound, a monofunctional ethylenically unsaturated compound having a carboxyl group or an acid anhydride structure is preferably included.

[0086] As the monofunctional ethylenically unsaturated compound having a carboxyl group, unsaturated carboxylic acids can be preferably cited.

[0087] As the unsaturated carboxylic acids, (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, monoalkyl esters of unsaturated dicarboxylic acids (monoalkyl esters such as maleic acid, fumaric acid, itaconic acid, citraconic acid), etc. can be cited.

[0088] As the monofunctional ethylenically unsaturated compound having an acid anhydride group, unsaturated carboxylic anhydrides can be preferably cited.

[0089] As the unsaturated carboxylic anhydrides, maleic anhydride, itaconic anhydride, citraconic anhydride, 4-methylphthalic anhydride, etc. can be cited.

[0090] Among them, from the viewpoints of heat resistance and adhesiveness to metal materials, (meth)acrylic acid is preferred.

[0091] The anaerobic curable adhesive composition of the present invention may contain one kind of the monofunctional ethylenically unsaturated compound having a carboxyl group or an acid anhydride structure alone, or may contain two or more kinds.

[0092] From the viewpoints of anaerobic curability and adhesive strength at high temperatures, the content of the monofunctional ethylenically unsaturated compound having a carboxyl group or an acid anhydride structure is preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass to 5% by mass, and particularly preferably 0.1% by mass to 3% by mass with respect to the total mass of the adhesive composition.

[0093] The anaerobic curable adhesive composition of the present invention may contain one kind of the monofunctional ethylenically unsaturated compound alone, or may contain two or more kinds. From the viewpoint of adhesive strength at high temperatures, it is preferably to contain two or more kinds, and more preferably to contain three or more kinds.

[0094] From the viewpoint of adhesive strength at high temperatures, the content of the monofunctional ethylenically unsaturated compound is preferably 10% by mass to 90% by mass, more preferably 50% by mass to 80% by mass, and particularly preferably 60% by mass to 80% by mass with respect to the total mass of the adhesive composition.

[0095] <Free radical polymerization initiator>

[0096] The anaerobic curable adhesive composition of the present invention contains a free radical polymerization initiator.

[0097] Examples of the free radical polymerization initiator include thermal free radical polymerization initiators, photo free radical polymerization initiators, etc. From the viewpoint of anaerobic curability, thermal free radical polymerization initiators are preferred.

[0098] The thermal free radical polymerization initiator is not particularly limited, and examples thereof include organic peroxides, azo compounds, etc. Among them, organic peroxides are particularly preferred.

[0099] Examples of the organic peroxide include hydroperoxides such as cumene hydroperoxide, tert-butyl hydroperoxide, p-methane hydroperoxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, dicumyl peroxide, diisopropylbenzene hydroperoxide, etc., and organic peroxides such as ketone peroxides, diallyl peroxides, and peroxy esters.

[0100] Examples of the azo compound include azobisisobutyronitrile, azobisisovaleronitrile, and azobisisohexanenitrile.

[0101] Among them, from the viewpoint of storage stability, it is preferable to use hydroperoxides.

[0102] In addition, as the organic peroxide, from the viewpoint of excellent anaerobic curability, an organic peroxide having a 1-hour half-life temperature in the range of 80°C to 300°C is preferred, and an organic peroxide in the range of 100°C to 200°C is more preferred. The 1-hour half-life temperature is a value measured by thermal decomposition under the condition that the concentration of the peroxide in benzene is 0.1 mol / L.

[0103] Examples of the organic peroxide having a 1-hour half-life temperature in the range of 80°C to 300°C include hydroperoxides. Specific examples of the hydroperoxide include p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide, and the like.

[0104] The photo radical generator is not particularly limited, and examples thereof include acetophenone-based photo radical polymerization initiators, benzoin-based photo radical polymerization initiators, benzophenone-based photo radical polymerization initiators, thioxanthone-based photo radical polymerization initiators, acylphosphine oxide-based photo radical polymerization initiators, titanocene-based photo radical polymerization initiators, and the like.

[0105] Examples of the acetophenone-based photo radical polymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzil dimethyl ketal, 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone, 2-hydroxy-2-methyl-1-[4-(1-methylethenyl)phenyl]acetone oligomer, and the like.

[0106] Examples of commercially available products of the acetophenone-based photo radical polymerization initiator include IRGACURE184, IRGACUR1173, IRGACURE2959, IRGACURE127 (manufactured by BASF), and ESUREKIP-150 (manufactured by Lamberti.p.a.).

[0107] In addition, examples of the acylphosphine oxide-based photo radical polymerization initiator include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, and the like.

[0108] Examples of commercially available products of the acylphosphine oxide-based photo radical polymerization initiator include OmniradTPO, Omnirad819 (manufactured by IGM Resins B.V.), and IRGACURE819 DW (manufactured by BASF).

[0109] The anaerobic curable adhesive composition of the present invention may contain one kind of the radical polymerization initiator alone, or may contain two or more kinds.

[0110] The content of the radical polymerization initiator is 2.0% by mass or less, and from the viewpoints of anaerobic curability and adhesive strength at high temperatures, it is preferably 0.01% by mass to 2.0% by mass, more preferably 0.05% by mass to 1.5% by mass, and particularly preferably 0.1% by mass to 1.0% by mass, based on the total mass of the adhesive composition.

[0111] <Relationship between the content of the polyfunctional ethylenically unsaturated compound and the content of the radical polymerization initiator>

[0112] In the anaerobic curable adhesive composition of the present invention, from the viewpoint of adhesive strength at high temperatures, the total content M M (unit: mole) of the difunctional ethylenically unsaturated compound and the polyfunctional ethylenically unsaturated compound having three or more functional groups and the content M R (unit: mole) of the radical polymerization initiator The ratio (M M / M R ) is preferably 0.8 to 30, more preferably 1 to 10, and particularly preferably 1.5 to 4.

[0113] From the viewpoint of adhesive strength at high temperatures, the content M M3 (unit: mole) of the polyfunctional ethylenically unsaturated compound having three or more functional groups and the content M R (unit: mole) of the radical polymerization initiator The ratio (M M3 / M R ) is preferably 0.6 to 27, more preferably 0.7 to 6.

[0114] From the viewpoint of adhesive strength at high temperatures, the content M M3 (unit: mole) of the polyfunctional ethylenically unsaturated compound having three or more functional groups and the content M M2 (unit: mole) of the difunctional ethylenically unsaturated compound The ratio (M M3 / M M2 ) is preferably 1 to 40, more preferably 2 to 15, and particularly preferably 3 to 12.

[0115] <Anaerobic curing catalyst>

[0116] The anaerobic curable adhesive composition of the present invention contains an anaerobic curing catalyst.

[0117] Examples of the anaerobic curing catalyst include saccharin, amine compounds, azole compounds, thiol compounds, hydrazine compounds, and salts thereof.

[0118] Among them, from the viewpoint of anaerobic curability, it is preferable to use saccharin and a hydrazine compound or a salt thereof in combination.

[0119] Examples of the amine compound include 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 quinoxaline phenazine; and aromatic tertiary amines such as N,N-dimethyl-methoxyaniline, N,N-dimethylaniline, and N,N'-dimethyl-p-toluidine.

[0120] Examples of the azole compound include 1,2,4-triazole, oxazole, oxadiazole, thiadiazole, benzotriazole, hydroxybenzotriazole, benzoxazole, 1,2,3-benzothiadiazole, and 3-mercaptobenzotriazole.

[0121] Examples of the thiol compound include linear thiols such as n-dodecyl mercaptan, ethyl mercaptan, and butyl mercaptan.

[0122] 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-diphenylcarbohydrazide, 1-acetyl-2-phenylhydrazine, 1-acetyl-2-(p-bromophenyl)hydrazine, 1-acetyl-2-(p-nitrophenyl)hydrazine, 1-acetyl-2-(2'-phenylethylhydrazine), p-nitrophenylhydrazine, and p-toluenesulfonylhydrazide.

[0123] In addition, examples of the salt of the hydrazine compound include 4-methylsulfonylphenylhydrazine hydrochloride, hydrazine monohydrochloride, and p-tolylhydrazine hydrochloride.

[0124] The anaerobic curable adhesive composition of the present invention may contain one kind of the anaerobic curing catalyst alone or two or more kinds thereof.

[0125] From the viewpoints of anaerobic curability and adhesive strength at high temperatures, the content of the anaerobic curing catalyst is preferably 0.05% by mass to 30% by mass, more preferably 0.1% by mass to 20% by mass, and particularly preferably 0.2% by mass to 10% by mass based on the total mass of the adhesive composition.

[0126] <Acid and / or acid anhydride>

[0127] The anaerobic curable adhesive composition of the present invention may contain an acid and / or an acid anhydride that does not have an ethylenically unsaturated group.

[0128] There is no particular limitation on the acid or acid anhydride, and known acids or acid anhydrides can be used. Organic acids or organic acid anhydrides are preferred, and carboxylic acids or carboxylic anhydrides are more preferred.

[0129] In addition, as the acid or acid anhydride, pyromellitic acid, trimellitic anhydride, etc. can be suitably cited.

[0130] The anaerobic curable adhesive composition of the present invention may contain one kind of acid or acid anhydride alone, may contain two or more kinds, or may use an acid and an acid anhydride in combination.

[0131] From the viewpoints of anaerobic curability and adhesiveness, the content of the acid and acid anhydride is preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass to 5% by mass, based on the total mass of the adhesive composition.

[0132] <Other components>

[0133] In the anaerobic curable adhesive composition of the present invention, as other components other than the above, additives such as fillers, various elastomers, storage stabilizers, antioxidants, light stabilizers, heavy metal passivators, silane coupling agents, tackifiers, plasticizers, defoamers, pigments, rust inhibitors, leveling agents, dispersants, rheology modifiers, flame retardants, etc. can be used within the range that does not impair the object of the present invention.

[0134] In order to improve the elastic modulus, fluidity, etc. of the cured product, the anaerobic curable adhesive composition of the present invention can add fillers in an amount that does not hinder storage stability. Specifically, organic powders, inorganic powders, etc. can be cited.

[0135] As the filler of the inorganic powder, there is no particular limitation, and examples thereof include glass, fumed silica, alumina, mica, ceramics, silicone rubber powder, calcium carbonate, aluminum nitride, carbon powder, kaolin, dried clay minerals, dried diatomaceous earth, etc.

[0136] Relative to 100 mass parts of the polymerizable components (the total content of the polymer and / or oligomer having a (meth)acryloyl group at the terminal, the polyfunctional ethylenically unsaturated compound, the compound having an aromatic ring and an ethylenically unsaturated group, and other ethylenically unsaturated compounds, the same applies hereinafter), the content of the inorganic powder is preferably 0.1 mass part to 100 mass parts.

[0137] Fumed silica is incorporated to adjust the viscosity of the anaerobic curable adhesive composition or improve the mechanical strength of the cured product. Fumed silica surface-treated with dimethylsilane, trimethylsilane, alkylsilane, methacryloxy silane, organochlorosilane, polydimethylsiloxane, hexamethyldisilazane, etc. is preferably used.

[0138] Examples of commercially available products of fumed silica include, for example, AEROSIL (registered trademark) R972, R972V, R972CF, R974, R976, R976S, R9200, RX50, NAX50, NX90, RX200, RX300, R812, R812S, R8200, RY50, NY50, RY200S, RY200, RY300, R104, R106, R202, R805, R816, T805, R711, RM50, R7200, etc. (all of the above are manufactured by Nippon Aerosil Co., Ltd.).

[0139] There is no particular limitation on the filler material for the organic matter powder, and examples thereof include polyethylene, polypropylene, nylon (registered trademark), crosslinked acrylic acid, crosslinked polystyrene, polyester, polyvinyl alcohol, polyvinyl butyral, polycarbonate, etc.

[0140] The content of the organic matter powder is preferably 0.1 part by mass to 100 parts by mass with respect to 100 parts by mass of the polymer component.

[0141] The anaerobic curable adhesive composition of the present invention may contain a storage stabilizer.

[0142] As the storage stabilizer, radical inhibitors such as benzoquinone, hydroquinone, and monomethyl ether of hydroquinone, and metal chelating agents such as ethylenediaminetetraacetic acid or its disodium salt, oxalic acid, acetylacetone, and o-aminophenol may also be added.

[0143] Among them, from the viewpoint of storage stability, the anaerobic curable adhesive composition of the present invention preferably contains a radical inhibitor and a metal chelating agent, and more preferably contains at least one selected from the group consisting of hydroquinone and monomethyl ether of hydroquinone, and at least one selected from the group consisting of ethylenediaminetetraacetic acid and disodium salt of ethylenediaminetetraacetic acid.

[0144] The content of the storage stabilizer is preferably 0.0001 part by mass to 1 part by mass with respect to 100 parts by mass of the polymer component.

[0145] The anaerobic curable adhesive composition of the present invention may contain an antioxidant.

[0146] Examples of antioxidants include quinone compounds such as β-naphthoquinone, 2-methoxy-1,4-naphthoquinone, methylhydroquinone, hydroquinone, hydroquinone monomethyl ether, monoterbutylhydroquinone, 2,5-di-tert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-di-tert-butyl-p-benzoquinone; phenothiazine, 2,2-methylenebis(4-methyl-6-tert-butylphenol), catechol, tert-butylcatechol, 2-butyl-4-hydroxyanisole, 2,6-di-tert-butyl-p-cresol, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate; 2-[1-(2-hydroxy-3,5-di-tert-amylphenyl)ethyl]-4,6-di-tert-amylphenyl acrylate, 4,4'-butylidenebis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propanoyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanamide], phenylpropionic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, C7-C9 branched alkyl ester, 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl] phosphate, 3,3',3",5,5',5"-hexatert-butyl-α,α',α"-(mesitylene-2,4,6-triyl)tris-p-cresol, calcium diethyl bis[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl] phosphonate, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-dimethylphenyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, reaction product of N-phenylaniline and 2,4,6-trimethylpentene, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, picric acid, citric acid and other phenols;Phosphorus compounds such as tris(2,4-di-tert-butylphenyl) phosphite, tris[2-[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphocin-6-yloxy]ethyl]amine, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl] ethyl phosphite, tetra(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4'-diylbisphosphonate, 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphine, etc.; sulfur compounds such as dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, pentaerythritol tetrakis(3-laurylthiopropionate), 2-mercaptobenzimidazole, etc.; amine compounds such as phenothiazine; lactone compounds; vitamin E compounds, etc. Among them, phenolic compounds are preferred.

[0147] The anaerobic curable adhesive composition of the present invention may contain a silane coupling agent.

[0148] As the silane coupling agent, there is no particular limitation, and examples thereof include γ-chloropropyltrimethoxysilane, octenyltrimethoxysilane, glycidyloxyoctyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, p-styryltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, etc.

[0149] From the viewpoint of adhesiveness to metal materials, the content of the silane coupling agent (adhesion-imparting agent) is preferably 0.05 parts by mass to 30 parts by mass, more preferably 0.2 parts by mass to 10 parts by mass, relative to 100 parts by mass of the polymer component.

[0150] The method for producing the anaerobic curable adhesive composition of the present invention is not particularly limited and can be produced by a known method. For example, it can be produced by blending a predetermined amount of each component and using a mixing means such as a mixer, preferably at a temperature of 10°C to 100°C, and preferably mixing for 0.1 hour to 5 hours.

[0151] The viscosity of the anaerobic curable adhesive composition of the present invention at 25°C is preferably 10,000 mPa·s or less, more preferably 10 mPa·s to 8000 mPa·s, further preferably 25 mPa·s to 5000 mPa·s, and particularly preferably 50 mPa·s to 3000 mPa·s, from the viewpoints of the easy diffusibility of the adhesive composition coated on the metal material and the fact that the adhesive composition does not extremely overflow from the bonding surface during bonding.

[0152] The method for measuring the viscosity of the anaerobic curable adhesive composition of the present invention is as described below.

[0153] Take a specified amount of the adhesive composition and spray it into the measuring cup. Use an EHD viscometer (manufactured by Toki Sangyo Co., Ltd.) to measure the viscosity at 25°C under the condition of a shear rate of 76.6 (1 / s).

[0154] (Adhesive laminate)

[0155] The adhesive laminate of the present invention may be an adhesive laminate bonded with the anaerobic curable adhesive composition of the present invention, and preferably an adhesive laminate bonded and laminated with two or more kinds of metal materials using the anaerobic curable adhesive composition of the present invention.

[0156] In addition, adhesive laminates formed by bonding two or more threaded members (for example, threads and threaded holes, etc.) and two or more fitting members (for example, convex members and concave members, rod members and hole members, etc.) using the anaerobic curable adhesive composition of the present invention can also be suitably cited.

[0157] Among metal materials, the anaerobic hardening type adhesive of the present invention is suitable for bonding steel plates. As the steel plate, there is no particular limitation, and electromagnetic steel plates, cold-rolled steel plates, etc. are preferably cited.

[0158] In addition, the electromagnetic steel plate may be a directional electromagnetic steel plate or a non-directional electromagnetic steel plate, but in the case of being used for a motor core, rotor, stator, etc. described later, a non-directional electromagnetic steel plate is preferred.

[0159] As the use of the adhesive laminate of the present invention, there is no particular limitation, and it can be used for various uses.

[0160] Among them, since the adhesive laminate of the present invention is insulated by the cured product of the anaerobic curable adhesive composition of the present invention, it has less current loss, high performance and high reliability, disperses stress on the surface, and does not generate stress concentration and strain concentration, so it is suitable for use in a motor core of a motor, etc.

[0161] As the manufacturing method of the adhesive laminate of the present invention, there is no particular limitation, and it preferably includes: a step of applying a primer composition containing a solvent and an organometallic complex to at least one of the metal materials to be bonded, a step of applying an anaerobic curable adhesive composition to at least one of the metal materials to be bonded, and a step of laminating other metal materials on the metal material to which the adhesive composition has been applied.

[0162] The primer composition used in the present invention is not particularly limited, and examples thereof include compositions obtained by diluting organometallic complexes such as copper ethylhexanoate, iron acetylacetonate, cobalt acetylacetonate, copper acetylacetonate, copper propylenediamine, copper ethylenediamine, copper naphthenate, nickel naphthenate, cobalt naphthenate, copper naphthenate, copper octanoate, iron hexanoate, iron propionate, and vanadium acetylacetonate with solvents such as ethanol, toluene, acetone, and heptanone.

[0163] Examples of the oil include stamping oil.

[0164] The stamping oil is an oil used for the purpose of preventing scratches or galling. The composition of the stamping oil is not particularly limited, and components mainly composed of mineral oil or synthetic oil can be listed. Furthermore, rust inhibitors, preservatives, etc. can also be added as optional components.

[0165] After the process of bonding other steel plates, heating can be performed in order to cure the adhesive composition in a shorter time.

[0166] The heating method is not particularly limited, and examples thereof include a constant temperature bath, a far-infrared heater, etc.

[0167] The temperature and time during heating only need to be conditions that can sufficiently cure, and it is preferably carried out under the conditions of 40°C to 300°C, more preferably 60°C to 150°C, preferably 10 seconds to 3 hours, and more preferably 20 seconds to 60 minutes. When placing the adhesive laminate in a constant temperature layer, it is preferable to fix it in advance with a fixing jig or the like to prevent position deviation.

[0168] In addition, as the coating method of the primer composition and the adhesive composition, there is no particular limitation, and known methods can be used. As the coating means, examples include rollers, dispersion, spraying, inkjet, dipping, etc.

[0169] Examples of the manufacturing method of the adhesive laminate using the primer composition and the anaerobic curable adhesive composition are shown below.

[0170] In the case where there is no special description, the manufacturing method shown below can be appropriately changed in the order and conditions of the processes according to the adhesive laminate to be manufactured, and further processes can also be added. For example, the primer composition can be coated by dipping and the anaerobic curable adhesive composition can be coated by roller, and they can be coated by different methods respectively.

[0171] The number of layers of the adhesive laminate obtained by the manufacturing method described below is not particularly limited. When manufacturing an adhesive laminate having three or more layers by the manufacturing method described below, the adherend metals can be laminated and adhered in sequence to manufacture the adhesive laminate. In the case of an unfinished adhesive laminate that has not reached the target number of layers and has a layer containing the adherend metal that has already been laminated and adhered, the adherend metal that has not been laminated can be laminated and adhered to the topmost layer or the bottommost layer to manufacture the adhesive laminate. In the case of laminating and adhering such adherend metals in sequence, the topmost layer or the bottommost layer of the unfinished adhesive laminate can be regarded as the adherend metal.

[0172] In one embodiment, a method for manufacturing an adhesive laminate includes: step (1), preparing a first adherend metal coated with a primer composition on at least one surface; step (2), preparing a second adherend metal coated with an anaerobic curable adhesive composition on at least one surface; and step (3), overlapping the surface of the first adherend metal coated with the primer composition with the surface of the second adherend metal coated with the anaerobic curable adhesive composition.

[0173] In one embodiment, a method for manufacturing an adhesive laminate includes: step (1), preparing a plurality of adherend metals coated with a primer composition on one surface and an anaerobic curable adhesive composition on the other surface; and step (2), overlapping the plurality of adherend metals prepared in step (1) such that the surface coated with the primer composition is in contact with the surface coated with the anaerobic curable adhesive composition.

[0174] In one embodiment, a method for manufacturing an adhesive laminate includes: step (1), preparing a plurality of first adherend metals coated with a primer composition on both surfaces; step (2), preparing a plurality of second adherend metals coated with an anaerobic curable adhesive composition on both surfaces; and step (3), alternately overlapping the first adherend metals and the second adherend metals such that the surface of the first adherend metal coated with the primer composition is in contact with the surface of the second adherend metal coated with the anaerobic curable adhesive composition.

[0175] Alternatively, a laminate of adherend metals can be formed before applying at least one of the primer composition and the anaerobic curable adhesive composition to the adherend metals, and then the primer composition and the anaerobic curable adhesive composition that have not been applied between the adherend metals can be supplied to bond the adherend metals forming the laminate.

[0176] When only laminating between adherend metals, there can be a gap to the extent that the primer composition and the anaerobic curable adhesive composition can penetrate. Therefore, by blowing the primer composition or the anaerobic curable adhesive composition from the side of the laminate using a sprayer, or by immersing the laminate in the primer composition or the anaerobic curable adhesive composition, the primer composition or the anaerobic curable adhesive composition can penetrate into the interior of the laminate. Additionally, an injection nozzle can be inserted between the adherend metals to directly inject the primer composition or the anaerobic curable adhesive composition between the adherend metals. When supplying the primer composition or the anaerobic curable adhesive composition between the adherend metals, it is preferable to physically fix the laminate from the outside.

[0177] In one embodiment, a method for manufacturing a bonded laminate includes: step (1), preparing a laminate formed by laminating at least two or more adherend metal layers; step (2), supplying a primer composition between the adherend metals of the laminate; and step (3), supplying an anaerobic curable adhesive composition between the adherend metals of the laminate.

[0178] In one embodiment, a method for manufacturing a bonded laminate includes: step (1), laminating adherend metals coated with a primer composition on at least one surface to prepare a laminate; and step (2), supplying an anaerobic curable adhesive composition between the adherend metals of the laminate.

[0179] In the case of using electromagnetic steel sheets as adherend metals to produce a bonded laminate, the following method is generally implemented: while continuously or intermittently feeding a strip steel, the adherend metals obtained by punching are sequentially laminated. Any of the above-described methods for manufacturing a bonded laminate can be used to continuously laminate and bond electromagnetic steel sheets from hoop materials.

[0180] For example, a bonded laminate of electromagnetic steel sheets can be manufactured by a method for manufacturing a bonded laminate including the following steps: step (1), coating a primer composition on one surface of a hoop material; step (2), coating an anaerobic curable adhesive composition on the surface of the hoop material where the primer composition is not coated; step (3), punching the hoop material to manufacture adherend metals of a specified shape; and step (4), sequentially laminating the obtained adherend metals. In this method, step (5) can be implemented before the punching process to coat a stamping oil on at least one surface of the hoop material.

[0181] When the diluent contained in the primer composition is a stamping oil, the primer composition can also be used as the stamping oil. Thereby, the step of coating the stamping oil on the hoop material can be omitted. That is, the step of coating the stamping oil and the step of coating the primer composition can be implemented in one step, and a bonded laminate of electromagnetic steel sheets can be efficiently manufactured.

[0182] When the primer composition is used as a stamping oil, the mass ratio of the stamping oil in the diluent is preferably 70% by mass or more, more preferably 90% by mass or more, and may be 100% by mass.

[0183] [Examples]

[0184] Hereinafter, the present invention will be specifically described based on examples. In addition, the present invention is not limited to these examples. In addition, hereinafter, unless otherwise specified, "parts" and "%" represent "parts by mass" and "% by mass", respectively.

[0185] Each of the components described in Table 1 was mixed at room temperature (25°C) for 60 minutes using a mixer so as to have the contents described in Table 1, and anaerobic curable adhesive compositions of Examples 1 to 16 and Comparative Examples 1 to 4 were obtained, respectively.

[0186] The unit of each value shown in Table 1 is parts by mass.

[0187] The details of the abbreviations described in Table 1 are as follows.

[0188] UMA-1: Alicyclic difunctional urethane methacrylate having a structural unit based on isophorone diisocyanate, maximum value of tanδ: -10°C (1 Hz, 2°C / min)

[0189] M-401B: A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, manufactured by Toagosei Co., Ltd., ARONIX (registered trademark) M-401B

[0190] CHP: Cumene hydroperoxide, manufactured by NOF Corporation, PERCUMYL H

[0191] Saccharin: Manufactured by Fujifilm Wako Pure Chemical Corporation

[0192] HEMA: 2-Hydroxyethyl methacrylate, manufactured by Mitsubishi Gas Chemical Company, Inc.

[0193] IBXMA: Isobornyl methacrylate, manufactured by Kyoeisha Chemical Co., Ltd.

[0194] AA: Acrylic acid, manufactured by Toagosei Co., Ltd.

[0195] EDTA-2 Na: Disodium ethylenediaminetetraacetate, manufactured by Fujifilm Wako Pure Chemical Corporation

[0196] [Production of Adhesive Laminate]

[0197] Prepare 2 electromagnetic steel sheets (35H300L manufactured by Nippon Steel & Sumitomo Metal Corporation). Apply a primer and processing oil on one side of one electromagnetic steel sheet. Apply only the processing oil on one side of the other electromagnetic steel sheet, and drop an anaerobic curable adhesive composition so that the film thickness after curing is 10 μm or less. Bond the 2 electromagnetic steel sheets together, clamp them tightly with double clamps, and let them stand overnight at 25°C to produce a test piece. Conduct a tensile shear test on the test piece according to the method described below, and measure the shear strength.

[0198] <Tensile Shear Test>

[0199] Using Strograph 20-C of Toyo Seiki Seisaku-sho, Ltd., stretch the test piece at 150°C at 10 mm / min. to measure the shear strength, and record the measurement result as "Shear Strength @150°C" in Table 1. The higher the value of the shear strength at 150°C, the more excellent the bonding strength at high temperatures.

[0200] [Table 1]

[0201]

[0202] [Table 2]

[0203]

[0204] The units of the numerical values of each raw material in Table 1 and Table 2 are mass%.

[0205] In Table 1 and Table 2, "> trifunctional (mol) / bifunctional (mol)" represents the molar ratio of the content of polyfunctional ethylenically unsaturated compounds with 3 or more functional groups to the content of bifunctional ethylenically unsaturated compounds.

[0206] In Table 1 and Table 2, "bifunctional (mol) / CHP (mol)" represents the molar ratio of the content of bifunctional ethylenically unsaturated compounds to the content of the radical polymerization initiator (cumene hydroperoxide).

[0207] In Table 1 and Table 2, "> bifunctional (mol) / CHP (mol)" represents the molar ratio of the total content of bifunctional ethylenically unsaturated compounds and polyfunctional ethylenically unsaturated compounds with 3 or more functional groups to the content of the radical polymerization initiator (cumene hydroperoxide).

[0208] In Table 1 and Table 2, "> trifunctional (mol) / CHP (mol)" represents the molar ratio of the total content of polyfunctional ethylenically unsaturated compounds with 3 or more functional groups to the content of the radical polymerization initiator (cumene hydroperoxide).

[0209] In the anaerobic curable adhesive composition of Comparative Example 1, the content of the bifunctional ethylenically unsaturated compound is less than 2% by mass, and further, the content of the polyfunctional ethylenically unsaturated compound having 3 or more functional groups is also less than 2% by mass. Compared with Examples 1 to 16, the shear strength at 150°C of Comparative Example 1 is low. The anaerobic curable adhesive composition of Comparative Example 2 does not use a polyfunctional ethylenically unsaturated compound. Compared with Examples 1 to 16, the shear strength at 150°C of Comparative Example 2 is low. In the anaerobic curable adhesive composition of Comparative Example 3, the content of the bifunctional ethylenically unsaturated compound exceeds 30% by mass. Compared with Examples 1 to 16, the shear strength at 150°C of Comparative Example 3 is low. In Comparative Example 4, the content of the radical polymerization initiator exceeds 2% by mass. Compared with Examples 1 to 16, the shear strength at 150°C of Comparative Example 4 is low.

[0210] For the anaerobic curable adhesive compositions of Examples 1 to 8, “> trifunctional (mol) / CHP (mol)” is 4 or less, and compared with the anaerobic curable adhesive compositions of Examples 9, 11 to 16, the shear strength at 150°C is high. Further, in the anaerobic curable adhesive compositions of Examples 1 to 8, the content of the polyfunctional ethylenically unsaturated compound having 3 or more functional groups is 3% by mass or more, and compared with the anaerobic curable adhesive composition of Example 10, the shear strength at 150°C is high.

[0211] [Industrial Applicability]

[0212] The present invention can provide, for example, an anaerobic curable adhesive composition for use in a high-temperature atmosphere, an anaerobic curable adhesive composition for preventing screw loosening, an anaerobic curable adhesive composition for fitting and fixing, etc. Further, an anaerobic curable adhesive composition capable of obtaining an adhesive laminate that contributes to high performance and high reliability of a rotor and a stator of a motor is provided. Therefore, it is extremely effective and can be used in a wide range of products and technical fields, and is industrially useful.

[0213] The disclosure of Japanese Patent Application No. 2022-204851 filed on December 21, 2022 is incorporated herein by reference in its entirety.

[0214] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each document, patent application, and technical standard were specifically and individually described as being incorporated by reference.

Claims

1. An anaerobic curable adhesive composition comprising a bifunctional ethylenically unsaturated compound, a polyfunctional ethylenically unsaturated compound having three or more functional groups, a radical polymerization initiator, and an anaerobic curing catalyst, wherein the content of the bifunctional ethylenically unsaturated compound is 2% by mass to 30% by mass, the content of the polyfunctional ethylenically unsaturated compound having three or more functional groups is 2% by mass or more, and the content of the radical polymerization initiator is 2.0% by mass or less.

2. The anaerobic curable adhesive composition according to claim 1, the total content M of the bifunctional ethylenically unsaturated compound and the polyfunctional ethylenically unsaturated compound having three or more functional groups M and the content M of the radical polymerization initiator R The ratio M M / M R is 0.8 to 30, where M M and M R are in units of moles.

3. The anaerobic curable adhesive composition according to claim 1, the content M of the polyfunctional ethylenically unsaturated compound having 3 or more functional groups M3 and the content M of the radical polymerization initiator R The ratio M M3 / M R is 0.6 to 27, and the units of M M3 and M R are moles.

4. The anaerobic curable adhesive composition according to claim 1, wherein the bifunctional ethylenically unsaturated compound is a polymer or oligomer having two or more (meth)acryloyl groups in one molecule.

5. The anaerobic curable adhesive composition according to claim 4, wherein the polymer or oligomer having two or more (meth)acryloyl groups in one molecule comprises urethane (meth)acrylate.

6. The anaerobic curable adhesive composition according to claim 1, wherein the polyfunctional ethylenically unsaturated compound comprises a pentafunctional ethylenically unsaturated compound or a hexafunctional ethylenically unsaturated compound.

7. The anaerobic curable adhesive composition according to claim 1, wherein the content of the radical polymerization initiator is 0.1% by mass to 2.0% by mass.

8. The anaerobic curable adhesive composition according to claim 1, wherein the anaerobic curable adhesive composition is an anaerobic curable adhesive composition for steel plates.

9. The anaerobic curable adhesive composition according to claim 1, wherein the anaerobic curable adhesive composition is an anaerobic curable adhesive composition for preventing screw loosening.

10. The anaerobic curable adhesive composition according to claim 1, wherein the anaerobic curable adhesive composition is an anaerobic curable adhesive composition for fitting and fixing.

11. An adhesive laminate formed by bonding and laminating two or more steel plates with the anaerobic curable adhesive composition according to any one of claims 1 to 8.

12. A motor comprising the adhesive laminate according to claim 11.

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