Anaerobic curing adhesive composition, adhesive laminate, motor, and anaerobic curing primer composition

Abstract

The anaerobic curing adhesive composition according to the present disclosure comprises a compound having an aromatic ring and an ethylenically unsaturated group, a polymer or oligomer that has at least two (meth)acryloyl groups in each molecule, a radical polymerization initiator, and an anaerobic curing catalyst.

Description

[Technical Field]

[0001] The present invention relates to an anaerobic curing adhesive composition, an adhesive laminate, a motor, and an anaerobic curing primer composition. [Background technology]

[0002] In recent years, a method of laminating steel sheets using adhesives has been attracting attention when manufacturing motor cores for small motors. Compared to the conventional method of fixing steel sheets using physical unevenness, this method of laminating steel sheets using adhesives is expected to reduce distortion in the steel sheets and improve energy efficiency.

[0003] An example of a conventional anaerobic curing adhesive composition is that described in Patent Document 1. Patent Document 1 discloses an anaerobic curing adhesive containing a phosphate ester compound.

[0004] Patent Document 1: International Publication No. 2019 / 123885 Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, Patent Document 1 discloses an anaerobic curing adhesive containing a phosphate ester compound. Patent Document 1 proposes a method in which an organic solvent and an anaerobic curing accelerator are dissolved in punching oil, the resulting solution is applied to a steel plate, the punching oil is substantially evaporated in a drying process at room temperature, and then the anaerobic curing adhesive is cured at room temperature. In other words, the invention described in Patent Document 1 requires the removal of punching oil, which is essential when punching steel sheets, and there is a concern that performance such as sufficient adhesiveness may not be achieved in the presence of oil or other oils.

[0006] The problem to be solved by the present invention is to provide an anaerobic curing adhesive composition that has excellent adhesion to oily surfaces. Another problem to be solved by the present invention is to provide an adhesive laminate and a motor using the above-mentioned anaerobic curing adhesive composition. A further problem to be solved by the present invention is to provide an anaerobically curable primer composition which has excellent adhesion to oily surfaces. [Means for solving the problem]

[0007] The means for solving the above problems include the following aspects. <1> An anaerobic curing adhesive composition comprising a compound having an aromatic ring and an ethylenically unsaturated group, a polymer or oligomer having two or more (meth)acryloyl groups in one molecule, a radical polymerization initiator, and an anaerobic curing catalyst. <2> The compound having an aromatic ring and an ethylenically unsaturated group includes a compound having only one ethylenically unsaturated group. <1> The anaerobic curing adhesive composition according to claim 1. <3> The compound having an aromatic ring and an ethylenically unsaturated group includes a compound having an oxycarbonyl group having an ethylenically unsaturated group on the aromatic ring. <1> or <2> The anaerobic curing adhesive composition according to claim 1. <4> The compound having an aromatic ring and an ethylenically unsaturated group includes a phthalic acid-modified compound having an ethylenically unsaturated group. <1> ~ <3> The anaerobic curing adhesive according to any one of composition. <5> The phthalic acid-modified compound having an ethylenically unsaturated group contains mono(meth)acryloxy(poly)alkyleneoxyalkyl phthalate. <4> The anaerobic curing adhesive composition according to claim 1. <6> The content of the compound having an aromatic ring and an ethylenically unsaturated group is 0.05% by mass to 5% by mass relative to the total mass of the adhesive composition. <1> ~ <5> 1. The anaerobic curing adhesive composition according to any one of the above. <7> The polymer or oligomer is 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 (meth)acrylic group-containing acrylic polymer. <1> ~ <6> 1. The anaerobic curing adhesive composition according to any one of the above. <8> The polymer or oligomer is a urethane (meth)acrylate or an epoxy (meth)acrylate. <1> ~ <7> 1. The anaerobic curing adhesive composition according to any one of the above. <9> The polymer or oligomer is a urethane (meth)acrylate. <1> ~ <8> 1. The anaerobic curing adhesive composition according to any one of the above. <10> The total content of the polymer or oligomer is 15% by mass to 70% by mass based on the total mass of the adhesive composition. <1> ~ <9> 1. The anaerobic curing adhesive composition according to any one of the above. <11> The radical polymerization initiator is an organic peroxide. <1> ~ <10> 1. The anaerobic curing adhesive composition according to any one of the above. <12> Further containing a monofunctional ethylenically unsaturated compound other than the compound having an aromatic ring and an ethylenically unsaturated group. <1> ~ <11> 1. The anaerobic curing adhesive composition according to any one of the above. <13> An anaerobic curing adhesive composition for steel sheets <1> ~ <12> 1. The anaerobic curing adhesive composition according to any one of the above. <14> <1> ~ <13> 1. An adhesive laminate obtained by bonding and laminating two or more steel plates with the anaerobic curing adhesive composition according to any one of the above items. <15> <14> A motor comprising the adhesive laminate according to claim 1. <16> An anaerobically curable primer composition comprising a compound having an aromatic ring and an ethylenically unsaturated group. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an anaerobic curing adhesive composition that has excellent adhesion to oily surfaces. According to the present invention, it is possible to provide an adhesive laminate and a motor using the above-mentioned anaerobic curing adhesive composition. According to the present invention, it is possible to provide an anaerobically curable primer composition that has excellent adhesion to oily surfaces. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an example of an adhesive laminate (motor core) according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following description of the constituent elements may be based on a representative embodiment of the present disclosure, but the present disclosure is not limited to such an embodiment. In this specification, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit. In the present specification, the upper or lower limit of one numerical range may be replaced by the upper or lower limit of another numerical range. In the present specification, the upper or lower limit of a numerical range may be replaced by a value shown in the examples. In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, "(meth)acrylate" refers to at least one of acrylate and methacrylate. "(meth)acrylic acid" refers to at least one of acrylic acid and methacrylic acid. "(meth)acryloyl group" refers to at least one of acryloyl group and methacryloyl group. "(meth)acryloxy group" refers to at least one of acryloxy group and methacryloxy group. "(meth)acrylamide group" refers to at least one of acrylamide group and methacrylamide group. The contents of the present disclosure will be described in detail below.

[0011] (Anaerobic curing adhesive composition) The anaerobic curing adhesive composition of the present disclosure comprises a compound having an aromatic ring and an ethylenically unsaturated group, a polymer or oligomer having two or more (meth)acryloyl groups in one molecule, a radical polymerization initiator, and an anaerobic curing catalyst. The anaerobic curing adhesive composition of the present disclosure can be suitably used as an anaerobic curing adhesive composition for steel plates.

[0012] The anaerobic curing adhesive composition of the present disclosure contains a compound having an aromatic ring and an ethylenically unsaturated group, and a polymer or oligomer having two or more (meth)acryloyl groups per molecule, and is cured anaerobically. Although the detailed mechanism is unknown, the adhesive performance is not affected even in the presence of oil, and the composition cures at room temperature (e.g., 10°C to 35°C) in a short time. Therefore, it is presumed that the anaerobic curing adhesive composition of the present disclosure has excellent adhesion (oil surface adhesion) even on oil-adhered bonding surfaces. The anaerobic curing adhesive composition of the present disclosure has excellent fast curing properties and does not require a drying step to dry off oil adhering to the bonding surface, making it possible to produce bonded articles with high production efficiency using the anaerobic curing adhesive composition of the present disclosure.

[0013] The anaerobic curing adhesive composition of the present disclosure has excellent adhesion to oily surfaces and can therefore be suitably used in the production of adhesive laminates in which steel plates are bonded and laminated, motor cores, motors, and the like.

[0014] <Compound Having an Aromatic Ring and an Ethylenically Unsaturated Group> The anaerobic curing adhesive composition of the present disclosure contains a compound having an aromatic ring and an ethylenically unsaturated group. The compound having an aromatic ring and an ethylenically unsaturated group is preferably a compound having a molecular weight of less than 1,000, and more preferably a compound having a molecular weight of less than 500. The aromatic ring in the compound having an aromatic ring and an ethylenically unsaturated group is not particularly limited, but from the viewpoint of adhesion to oily surfaces, it is preferably an aromatic hydrocarbon ring, more preferably a benzene ring or a naphthalene ring, and particularly preferably a benzene ring. The ethylenically unsaturated group in the compound having an aromatic ring and an ethylenically unsaturated group is not particularly limited, but from the viewpoints of curability and adhesion to oily surfaces, it is preferably at least one group selected from the group consisting of a (meth)acryloxy group, a (meth)acrylamide group, a styryl group, an allyl group, a vinyl ether group, and a vinyl ester group, and more preferably a (meth)acryloxy group. Preferred examples of the compound having an aromatic ring and an ethylenically unsaturated group include styrene and its derivatives, benzyl (meth)acrylate, (meth)acrylate compounds of aromatic carboxylic acids, and (meth)acrylate compounds of (poly)alkylene glycol-modified aromatic carboxylic acids.

[0015] The number of ethylenically unsaturated groups in the compound having an aromatic ring and an ethylenically unsaturated group is not particularly limited, but from the viewpoint of adhesion to an oily surface, it is preferably 1 to 6, and more preferably 1 to 3. It is more preferable that the number is 1 or 2, and even more preferable that the number is 1 or 2. From the viewpoint of adhesion to oily surfaces, the compound having an aromatic ring and an ethylenically unsaturated group more preferably includes a compound having only one ethylenically unsaturated group. From the viewpoint of adhesion to oily surfaces, the compound having an aromatic ring and an ethylenically unsaturated group preferably includes a compound having an ester bond, and more preferably includes a compound having an oxycarbonyl group having an ethylenically unsaturated group on the aromatic ring.

[0016] From the viewpoint of adhesion to oily surfaces, the compound having an aromatic ring and an ethylenically unsaturated group preferably includes a phthalic acid-modified compound having an ethylenically unsaturated group. The phthalic acid-modified compound having an ethylenically unsaturated group may be a compound having one or more ethylenically unsaturated groups and a phthalic acid structure (1,2-bis(carbonyloxy)benzene structure). The group having an ethylenically unsaturated group in the phthalic acid-modified compound having an ethylenically unsaturated group may be bonded to one or two of the two carbonyloxy groups in the phthalic acid structure, or may be bonded to the benzene ring of the phthalic acid structure.

[0017] From the viewpoint of adhesion to oily surfaces, the phthalic acid-modified compound having an ethylenically unsaturated group preferably contains a phthalic acid-modified compound having only one ethylenically unsaturated group, and more preferably contains a mono(meth)acryloxy(poly)alkyleneoxyalkyl phthalate. Furthermore, from the viewpoint of adhesion to oily surfaces, the phthalic acid-modified compound having an ethylenically unsaturated group preferably contains a compound represented by the following formula (1):

[0018] [ka]

[0019] In formula (1) and formula (2), L 1 R each independently represents a hydrocarbon group having 1 to 10 carbon atoms (for example, an aliphatic hydrocarbon group such as an ethylene group or a 1,2-propylene group). 1 R each independently represents a hydrogen atom or a methyl group. 2 R each independently represents an alkyl group, an aryl group, a halogen atom, a hydroxy group, an alkoxy group, an aryloxy group, an amino group, an alkylamino group, an arylamino group, a dialkylamino group, a diarylamino group, an alkylarylamino group, an acyl group, or an acyloxy group. 3 represents a group represented by formula (2). 4 represents a hydrogen atom, an alkyl group, an aryl group, or a group represented by formula (2). L represents 0 or 1. m represents an integer of 0 to 4. n represents an integer of 1 or more and 100 or less.

[0020] L in Equation (2) 1 The 1,2-propylene group may be either —CH(CH3)CH2— or —CH2CH(CH3)—. L in Equation (2) 1 is preferably an ethylene group from the viewpoint of adhesion to oily surfaces. R in Equation (2) 1 is preferably a hydrogen atom from the viewpoints of curability and adhesion to oily surfaces. R in Equation (1) 2 is preferably an alkyl group, an aryl group, a halogen atom, a hydroxy group, an alkoxy group, or an aryloxy group, and more preferably an alkyl group, an aryl group, an alkoxy group, or an aryloxy group. The number of carbon atoms in the alkyl group and alkoxy group is preferably 1 to 10, and more preferably 1 to 5. R in Equation (1) 2 and -COOR 4 The bonding position of -COOR can be any position on the benzene ring. 4 From the viewpoint of adhesion to oily surfaces, the bonding position of -COOR 3 Preferably, the bond is at the ortho position relative to the bonding position of R in Equation (1) 4 is preferably a hydrogen atom, an alkyl group or a group represented by formula (2), more preferably a hydrogen atom or a group represented by formula (2). The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms. In formula (1), L is preferably 1 from the viewpoint of adhesion to oily surfaces. In formula (1), m is preferably an integer of 0 to 3, more preferably 0 or 1, and particularly preferably 0. In formula (2), n is preferably an integer of 1 to 50, more preferably an integer of 1 to 20, even more preferably an integer of 1 to 10, and particularly preferably 1, from the viewpoint of adhesion to oily surfaces.

[0021] Specific examples of the compound having an aromatic ring and an ethylenically unsaturated group include, but are not limited to, the following compounds:

[0022] [ka]

[0023] The anaerobically curable adhesive composition of the present disclosure may contain one type of compound having an aromatic ring and an ethylenically unsaturated group, or may contain two or more types of compounds having an aromatic ring and an ethylenically unsaturated group. From the viewpoint of adhesion to oily surfaces, the content of the compound having an aromatic ring and an ethylenically unsaturated group 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 2% by mass, relative to the total mass of the adhesive composition.

[0024] <Polymer or oligomer having two or more (meth)acryloyl groups in one molecule> The anaerobic curing adhesive composition of the present disclosure contains a polymer or oligomer having two or more (meth)acryloyl groups in one molecule. In this specification, an "oligomer" refers to a polymer having a weight-average molecular weight of 500 or more but less than 5,000. A "polymer" refers to a polymer having a weight-average molecular weight of 5,000 or more. In this disclosure, "molecular weight" 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 weight-average molecular weight can be determined, for example, by the following procedure. Separation is performed using a gel permeation chromatograph (HLC-8320GPC manufactured by Tosoh Corporation) in tetrahydrofuran solvent at 40°C using a GPC column "TSK gel SuperMultiporeHZ-M" (manufactured by Tosoh Corporation), and the weight-average molecular weight converted into standard polystyrene is calculated from the retention time.

[0025] The (meth)acryloyl group contained in the polymer or oligomer having two or more (meth)acryloyl groups in one molecule is preferably at a terminal position, but may be contained in a monomer unit constituting the main chain of the polymer or oligomer.

[0026] The polymer or oligomer having two or more (meth)acryloyl groups in one molecule is not particularly limited, but from the viewpoint of adhesion to oily surfaces, 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 (meth)acrylic group-containing acrylic polymer, more preferably urethane (meth)acrylate or epoxy (meth)acrylate, and particularly preferably urethane (meth)acrylate.

[0027] Examples of the urethane (meth)acrylate include a reaction product of a polyhydric alcohol, a polyhydric isocyanate, and a hydroxy (meth)acrylate compound, and a reaction product of a polyhydric isocyanate and a hydroxy (meth)acrylate compound without using a polyhydric alcohol. Specific examples of polyhydric alcohols include polyether polyols (e.g., polypropylene glycol, polytetramethylene glycol, etc.), polyester polyols obtained by reacting a polyhydric alcohol with a polybasic acid, caprolactone polyols obtained by reacting a polyhydric alcohol, a polybasic acid, and ε-caprolactone, and polycarbonate polyols (e.g., polycarbonate polyols obtained by reacting 1,6-hexanediol with diphenyl carbonate). Specific examples of organic polyisocyanates include alicyclic polyisocyanates (such as isophorone diisocyanate and dicyclopentanyl diisocyanate), aliphatic polyisocyanates (such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate), and aromatic polyisocyanates (such as tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane-4,4'-diisocyanate). The urethane (meth)acrylate is preferably produced from a polyether polyol, a polyester polyol, or a polycarbonate polyol as a raw material polyol, because of its excellent resistance to deterioration over time and adhesive strength.The urethane (meth)acrylate is preferably produced from an isophorone diisocyanate, a hexamethylene diisocyanate, or a xylene diisocyanate as a raw material organic polyisocyanate, because of its excellent resistance to deterioration over time.

[0028] 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, and urethane (meth)acrylates having a castor oil skeleton.

[0029] Examples of epoxy (meth)acrylates include (meth)acrylates obtained by reacting an epoxy resin (e.g., a conventionally known aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc.) with (meth)acrylic acid.

[0030] From the viewpoint of adhesion to oily surfaces, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains a compound whose maximum value of tan δ observed in dynamic viscoelasticity measurement (1 Hz, 2°C / min.) is observed at 25°C or lower. From the viewpoint of adhesion to oily surfaces, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains a compound having a viscosity of 500 mPa·s or more at 25°C as measured with an E-type viscometer.

[0031] When the anaerobically curable adhesive composition of the present disclosure contains two or more types of polymers or oligomers having two or more (meth)acryloyl groups in one molecule, the polymers or oligomers having two or more (meth)acryloyl groups in one molecule preferably have the following features. From the viewpoint of adhesion to oily surfaces, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably includes a compound whose maximum value of tan δ observed in dynamic viscoelasticity measurement (1 Hz, 2°C / min.) is observed at 25°C or less, and a compound whose maximum value of tan δ observed in dynamic viscoelasticity measurement (1 Hz, 2°C / min.) is observed above 25°C. From the viewpoint of adhesion to oily surfaces, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains a compound whose maximum value of tan δ observed in dynamic viscoelasticity measurement (1 Hz, 2°C / min.) is observed at 25°C or less, and a compound whose maximum value of tan δ is 30°C or more higher than the maximum value of tan δ of the compound. From the viewpoint of adhesion to oily surfaces, the polymer or oligomer having two or more (meth)acryloyl groups in one molecule preferably contains two or more compounds having a viscosity of 1,000 mPa·s or more at 25°C as measured with an E-type viscometer.

[0032] The maximum value of tan δ can be measured, for example, using the following dynamic viscoelasticity measuring device according to the following procedure. Tan δ is calculated from the ratio of the storage modulus and loss modulus detected during measurement. For example, a cured adhesive sample cut to a size of 50 mm x 20 mm and 1 mm thick is attached to the measuring device, cooled to -60°C, and held isothermal for 5 minutes. After that, the maximum value of tan δ is confirmed under the following conditions: the sample is periodically stretched at a frequency of 1 Hz while the temperature is raised to 250°C at a rate of 2°C / min. Measuring equipment: SEIKO Instruments DMS6100 Measurement atmosphere: Nitrogen

[0033] The anaerobically curable adhesive composition of the present disclosure may contain one type of polymer or oligomer having two or more (meth)acryloyl groups in one molecule, or may contain two or more types of polymers or oligomers. From the viewpoint of adhesion to oily surfaces, the total content of the polymer or oligomer having two or more (meth)acryloyl groups in one molecule is preferably 5% by mass to 90% by mass, more preferably 10% by mass to 70% by mass, and particularly preferably 15% by mass to 60% by mass, relative to the total mass of the adhesive composition.

[0034] <Radical polymerization initiator> The anaerobic curing adhesive composition of the present disclosure includes a radical polymerization initiator. Examples of the radical polymerization initiator include organic peroxides and photoradical generators, and from the viewpoint of anaerobic curability, organic peroxides are preferred. Examples of the organic peroxide include hydroperoxides, ketone peroxides, diallyl peroxides, and peroxy esters. Among these, hydroperoxides are preferred from the viewpoint of storage stability. Examples of the hydroperoxides include cumene hydroperoxide, t-butyl hydroperoxide, p-methane hydroperoxide, methyl ethyl ketone peroxide, cyclohexane peroxide, dicumyl peroxide, and diisopropylbenzene hydroperoxide.

[0035] From the viewpoint of excellent anaerobic curing properties, the organic peroxide is preferably an organic peroxide having a one-hour half-life temperature in the range of 80° C. to 300° C., more preferably an organic peroxide having a one-hour half-life temperature in the range of 100° C. to 200° C. The one-hour half-life temperature is a value measured by thermal decomposition in benzene at a peroxide concentration of 0.1 mol / L.

[0036] Examples of the organic peroxides having a one-hour half-life temperature in the range of 80° C. to 300° C. include hydroperoxides. Specific examples of the hydroperoxides include p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide.

[0037] The photoradical generator is not particularly limited, but examples thereof include an acetophenone-based photoradical polymerization initiator, a benzoin-based photoradical polymerization initiator, a benzophenone-based photoradical polymerization initiator, a thioxanthone-based photoradical polymerization initiator, an acylphosphine oxide-based photoradical polymerization initiator, and a titanocene-based photoradical polymerization initiator.

[0038] Examples of the acetophenone-based photoradical polymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzyl 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, and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer. Commercially available products of the acetophenone-based photoradical polymerization initiator include Omnirad184, Omnirad1173, Omnirad2959, and Omnirad127 (manufactured by IGM Resins), and ESACUREKIP-150 (manufactured by Lamberti Spa). Examples of the acylphosphine oxide-based photoradical polymerization initiator include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Commercially available products of the acylphosphine oxide-based photoradical polymerization initiator include OmniradTPO and Omnirad819 (manufactured by IGM Resins BV).

[0039] The anaerobic curing adhesive composition of the present disclosure may contain one type of radical polymerization initiator alone, or may contain two or more types of radical polymerization initiators. From the viewpoints of anaerobic curability and adhesion to oily surfaces, the content of the radical polymerization initiator is preferably 0.05% by mass to 20% by mass, more preferably 0.1% by mass to 10% by mass, and particularly preferably 0.5% by mass to 5% by mass, relative to the total mass of the adhesive composition.

[0040] <Anaerobic curing catalyst> The anaerobic curing adhesive composition of the present disclosure includes an anaerobic curing catalyst. Examples of the anaerobic curing catalyst include saccharin, amine compounds, azole compounds, mercaptan compounds, hydrazine compounds, and salts thereof. Among these, a combination of saccharin and a hydrazine compound or a salt thereof is preferred from the viewpoint of anaerobic curability.

[0041] Examples of the amine compound include heterocyclic secondary amines (e.g., 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroquinaldine, etc.), heterocyclic tertiary amines (e.g., quinoline, methylquinoline, quinaldine, quinoxaline phenazine, etc.), and aromatic tertiary amines (e.g., N,N-dimethyl-anisidine, N,N-dimethylaniline, N,N'-dimethyl-p-toluidine, etc.).

[0042] Examples of the azole compounds include 1,2,4-triazole, oxazole, oxadiazole, thiadiazole, benzotriazole, hydroxybenzotriazole, benzoxazole, 1,2,3-benzothiadiazole, and 3-mercaptobenzotriazole.

[0043] Examples of the mercaptan compound include linear mercaptans such as n-dodecyl mercaptan, ethyl mercaptan, and butyl mercaptan.

[0044] Examples of the hydrazine compound include 1-acetyl-2-phenylhydrazine, 1-acetyl-2(p-tolyl)hydrazine, 1-benzoyl-2-phenylhydrazine, 1-(1',1',1'-trifluoro)acetyl-2-phenylhydrazine, 1,5-diphenyl-carbohydrazine, 1-formyl-2-phenylhydrazine, 1-acetyl-2-(p-bromophenyl)hydrazine, 1-acetyl-2-(p-nitrophenyl)hydrazine, 1-acetyl-2-(2'-phenylethylhydrazine), p-nitrophenylhydrazine, and p-trisulfonylhydrazide. Examples of the salts of the hydrazine compounds include 4-methylsulfonylphenylhydrazine hydrochloride, hydrazine monohydrochloride, and p-tolylhydrazine hydrochloride.

[0045] The anaerobic curing adhesive composition of the present disclosure may contain one type of anaerobic curing catalyst alone, or may contain two or more types of anaerobic curing catalysts. From the viewpoints of anaerobic curing property and adhesion to oily surfaces, the content of the anaerobic curing catalyst is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more, relative to the total mass of the adhesive composition, and the upper limit is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less.

[0046] <Other ethylenically unsaturated compounds> From the viewpoints of anaerobic curability and adhesion to oily surfaces, the anaerobically curable adhesive composition of the present disclosure preferably contains an ethylenically unsaturated compound other than those described above (hereinafter also referred to as "other ethylenically unsaturated compounds"). The other ethylenically unsaturated compound may be a monofunctional ethylenically unsaturated compound, a polyfunctional ethylenically unsaturated compound, or both. However, from the viewpoints of anaerobic curability and adhesion to oily surfaces, it is preferable to include a monofunctional ethylenically unsaturated compound. The other ethylenically unsaturated compound may be any compound having an ethylenically unsaturated group other than those mentioned above, but is preferably a (meth)acrylate compound.

[0047] 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, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and phenoxytetraethylene glycol (meth)acrylate. Ethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, nonylphenoxytetraethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, butoxyethyl (meth)acrylate, butoxytriethylene glycol (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-ethylhexyl polyethylene glycol (meth)acrylate, nonylphenyl polypropylene glycol (meth)acrylate acrylate, methoxydipropylene 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 succinic acid (meth)acrylate, caprolactam Examples of the methacrylate-modified 2-hydroxyethyl (meth)acrylate include 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, and N-benzylmaleimide.

[0048] Of these, from the viewpoint of adhesive strength to steel sheets, the monofunctional ethylenically unsaturated compound preferably contains at least one compound selected from the group consisting of 2-hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, morpholino (meth)acrylate, N-phenylmaleimide, and tetrahydrofurfuryl (meth)acrylate, and more preferably contains at least two compounds selected from the group consisting of 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, morpholino (meth)acrylate, N-phenylmaleimide, and tetrahydrofurfuryl (meth)acrylate.

[0049] Examples of the polyfunctional ethylenically unsaturated compound include a difunctional ethylenically unsaturated compound and a trifunctional ethylenically unsaturated compound.

[0050] The polyfunctional ethylenically unsaturated compound is not particularly limited, and examples thereof include 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexane glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and ethylene oxide-modified neopentyl glycol di(meth)acrylate. Licorice di(meth)acrylate, propylene oxide modified neopentyl glycol di(meth)acrylate, hydroxypivalic acid ester neopentyl glycol diacrylate, caprolactone modified hydroxypivalic acid ester neopentyl glycol diacrylate, neopentyl glycol modified trimethylolpropane di(meth)acrylate, stearic acid modified pentaerythritol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, ethylene oxide modified dicyclopentenyl di(meth)acrylate acrylate, di(meth)acryloyl isocyanurate, dimethyloltricyclodecane di(meth)acrylate, 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(acryloyl Oxyethyl) isocyanurate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, alkyl-modified dipentaerythritol pentaacrylate, dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, phenylene bismaleimide, 4,4'-diphenylmethane bismaleimide, 3,3'-diphenylmethane bismaleimide, 3,Examples of such bismaleimide include 4'-diphenylmethane bismaleimide, phenylmethane maleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,5-bismaleimidopentane, 1,6-bismaleimidohexane, 1,6-bismaleimido-(2,2,4-trimethyl)hexane, and 1,5-bis(maleimido)-2-methylpentane.

[0051] Of these, from the viewpoints of heat resistance and adhesion to steel sheets, the polyfunctional ethylenically unsaturated compound preferably contains at least one compound selected from the group consisting of dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and more preferably contains at least two compounds selected from the group consisting of dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate.

[0052] From the viewpoints of adhesion to oily surfaces and adhesion to steel sheets, the other ethylenically unsaturated compounds preferably include an ethylenically unsaturated compound having a hydroxy group, more preferably a monofunctional ethylenically unsaturated compound having a hydroxy group, and particularly preferably a monofunctional (meth)acrylate compound having a hydroxy group. Preferred examples of the ethylenically unsaturated compound having a hydroxy group include those ethylenically unsaturated compounds described above that have a hydroxy group. The anaerobically curable adhesive composition of the present disclosure may contain one type of ethylenically unsaturated compound having a hydroxy group, or may contain two or more types of such ethylenically unsaturated compounds. From the viewpoints of anaerobic curability and adhesion to oily surfaces, the content of the ethylenically unsaturated compound having a hydroxy group is preferably 5% by mass to 75% by mass, more preferably 10% by mass to 70% by mass, even more preferably 20% by mass to 65% by mass, and particularly preferably 30% by mass to 60% by mass, relative to the total mass of the adhesive composition.

[0053] Furthermore, the other ethylenically unsaturated compounds may include ethylenically unsaturated compounds having a carboxy group or an acid anhydride structure. Suitable examples of the ethylenically unsaturated compound having a carboxy group include unsaturated carboxylic acids. Examples of unsaturated carboxylic acids include (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, citraconic acid, cinnamic acid, monoalkyl esters of unsaturated dicarboxylic acids, etc. Examples of unsaturated dicarboxylic acids include maleic acid, fumaric acid, itaconic acid, and citraconic acid. Suitable examples of the ethylenically unsaturated compound having an acid anhydride group include unsaturated carboxylic acid anhydrides. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, and citraconic anhydride. Of these, (meth)acrylic acid is preferred from the viewpoint of adhesion to steel sheets. The anaerobically curable adhesive composition of the present disclosure may contain one type of ethylenically unsaturated compound having a carboxy group or an acid anhydride structure, or may contain two or more types of such ethylenically unsaturated compounds. From the viewpoints of anaerobic curability and adhesion to oily surfaces, the content of the ethylenically unsaturated compound having a carboxy group or an acid anhydride structure is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less, relative to the total mass of the adhesive composition.

[0054] The anaerobically curable adhesive composition of the present disclosure may contain one type of other ethylenically unsaturated compound alone, or may contain two or more types of such other ethylenically unsaturated compounds. From the viewpoint of adhesion to oily surfaces, however, it is preferable that the composition contain two or more types. From the viewpoint of adhesion to oily surfaces, the content of the other ethylenically unsaturated compounds is preferably 3% by mass to 90% by mass, more preferably 5% by mass to 85% by mass, and particularly preferably 7% by mass to 80% by mass, relative to the total mass of the adhesive composition.

[0055] <Acid and / or Acid Anhydride> The anaerobic curing adhesive composition of the present disclosure may contain an acid and / or an acid anhydride that does not have an ethylenically unsaturated group. The acid or acid anhydride is not particularly limited, and any known acid or acid anhydride can be used. The acid or acid anhydride is preferably an organic acid or organic acid anhydride, and more preferably a carboxylic acid or carboxylic acid anhydride. Suitable examples of the acid or acid anhydride include pyromellitic acid and trimellitic anhydride.

[0056] The anaerobically curable adhesive composition of the present disclosure may contain one kind of acid or acid anhydride alone, or may contain two or more kinds of acid or acid anhydride, or may use an acid and an acid anhydride in combination. From the viewpoints of anaerobic curability and adhesion to oily surfaces, the content of the acid and acid anhydride is preferably 0.01% by mass to 10% by mass, and more preferably 0.05% by mass to 5% by mass, relative to the total mass of the adhesive composition.

[0057] <Other ingredients> The anaerobic curing adhesive composition of the present disclosure may contain additives as components other than those described above, provided that the purpose of the present disclosure is not impaired. Examples of additives include fillers, various elastomers, storage stabilizers, antioxidants, light stabilizers, heavy metal deactivators, silane coupling agents, tackifiers, plasticizers, defoamers, pigments, rust inhibitors, leveling agents, dispersants, rheology modifiers, and flame retardants.

[0058] The anaerobically curable adhesive composition of the present disclosure may contain a filler to the extent that it does not impair storage stability, for the purpose of improving the elastic modulus, flowability, etc. of the cured product. Specific examples of such a filler include organic powders and inorganic powders.

[0059] Examples of inorganic powder fillers include, but are not limited to, glass, fumed silica, alumina, mica, ceramics, silicone rubber powder, calcium carbonate, aluminum nitride, carbon powder, kaolin clay, dried clay minerals, and dried diatomaceous earth. The content of the inorganic powder is preferably 0.1 to 100 parts by mass per 100 parts by mass of the total content of the phthalic acid-modified compound having an ethylenically unsaturated group, the urethane (meth)acrylate, and other ethylenically unsaturated compounds (hereinafter also referred to as "polymerization components").

[0060] Fumed silica is blended to adjust the viscosity of the radically polymerizable adhesive composition for adhesively bonding laminated steel sheets or to improve the mechanical strength of the cured product. Surface-treated fumed silica is preferably used. Examples of surface-treated materials include dimethylsilane, trimethylsilane, alkylsilane, methacryloxysilane, organochlorosilane, polydimethylsiloxane, and hexamethyldisilazane. Commercially available fumed silica products 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, and R7200 (all manufactured by Nippon Aerosil Co., Ltd.).

[0061] The organic powder filler is not particularly limited, but examples thereof include polyethylene, polypropylene, nylon (registered trademark), cross-linked acrylic, cross-linked polystyrene, polyester, polyvinyl alcohol, polyvinyl butyral, and polycarbonate. The content of the organic powder is preferably 100 parts by mass or less based on 100 parts by mass of the polymerizable components.

[0062] The anaerobic curing adhesive composition of the present disclosure may also contain a storage stabilizer. Examples of storage stabilizers include radical absorbers and metal chelating agents. Examples of radical absorbers include benzoquinone, hydroquinone, hydroquinone monomethyl ether, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), and 2,4-dinitroresorcinol. Examples of metal chelating agents include ethylenediaminetetraacetic acid or its disodium salt, oxalic acid, acetylacetone, and o-aminophenol. In particular, from the viewpoint of storage stability, the anaerobic curing adhesive composition of the present disclosure preferably contains a radical absorber and a metal chelating agent, and more preferably contains at least one selected from the group consisting of hydroquinone and hydroquinone monomethyl ether, and at least one selected from the group consisting of ethylenediaminetetraacetic acid and ethylenediaminetetraacetic acid disodium salt. The content of the storage stabilizer is preferably 0.0001 to 1 part by mass with respect to 100 parts by mass of the polymerizable component.

[0063] The anaerobic curing adhesive composition of the present disclosure may also contain an antioxidant. Examples of antioxidants include quinone compounds such as β-naphthoquinone, 2-methoxy-1,4-naphthoquinone, methylhydroquinone, hydroquinone, hydroquinone monomethyl ether, mono-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, and 2,5-di-tert-butyl-p-benzoquinone; phenothiazine, 2,2-methylene-bis(4-methyl-6-tert-butylphenol), catechol, tert-butylcatechol, and 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-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl 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)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, pentaerythritol tetrakis[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)propionamide], benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, C7-C9 side chain alkyl ester, 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 3,3',3”,5,5',5”-hexa-tert-butyl-a,a',a”-(mesitylene-2,4,6-tolyl)tri-p-cresol, calcium diethylbis[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl]phosphonate, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl- 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, reaction products of N-phenylbenzenamine with 2,4,6-trimethylpentene, 2,6- Phenols such as di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, picric acid, and citric acid; tris(2,4-di-tert-butylphenyl)phosphite, tris[2-[[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphen-6-yl]oxy]ethyl]amine, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, tetrakis(2,4-di-tert-butylphenyl)[1,1-bisphenyl]-4,4'-diylbisphosphonite, 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, Examples of suitable compounds include phosphorus compounds such as [3-(2-hydroxypropyl)-2,4,8,10-tetra-tert-butyldibenz[d,f][1,3,2]dioxaphosphene]; sulfur compounds such as dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, pentaerythrityl tetrakis(3-laurylthiopropionate) and 2-mercaptobenzimidazole; amine compounds such as phenothiazine; lactone compounds; and vitamin E compounds. Among these, phenolic compounds are preferred.

[0064] The anaerobic curing adhesive composition of the present disclosure may also contain adhesion promoters such as silane coupling agents and metal chelate complexes. Examples of the silane coupling agent include, but are not limited to, γ-chloropropyltrimethoxysilane, octenyltrimethoxysilane, glycidoxyoctyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and 8-methacryloxyoctyltrimethoxysilane. Metals contained in the metal chelate complexes include aluminum, nickel, chromium, and palladium, and ligands include acetylacetone, ethylenediamine, ethylenediaminetetraacetic acid, and porphyrin. As the metal chelate complex, for example, ethylacetoacetatoaluminum diisopropoxide and aluminum tris(ethylacetoacetate) can be suitably used. The adhesion promoter may be used alone or in combination of two or more. From the viewpoint of adhesion to the steel sheet, the content of the adhesion promoter is preferably 0.05 to 30 parts by mass, and more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the polymerizable components.

[0065] The method for producing the anaerobic curing adhesive composition of the present disclosure is not particularly limited, and the composition can be produced by a known method, for example, by blending predetermined amounts of each component and mixing them using a mixing means such as a mixer at a temperature of preferably 10°C to 100°C for preferably 0.1 to 5 hours.

[0066] The viscosity of the anaerobic curing adhesive composition of the present disclosure at 25°C is preferably 10,000 mPa·s or less, more preferably 10 mPa·s to 8,000 mPa·s, even more preferably 15 mPa·s to 7,000 mPa·s, and particularly preferably 30 mPa·s to 6,000 mPa·s, from the viewpoints of ease of spreading of the adhesive composition applied to steel sheets and preventing the adhesive composition from excessively overflowing from the bonding surfaces when the steel sheets are bonded together. The viscosity of the anaerobic curing adhesive composition of the present disclosure is measured as follows. A specified amount of adhesive composition is sampled and dispensed into a measuring cup. Viscosity is measured using an EHD viscometer (manufactured by Toki Sangyo Co., Ltd.) at 25°C and a shear rate of 76.6 (1 / s).

[0067] (Adhesive laminate) The adhesive laminate of the present disclosure is an adhesive laminate formed by bonding and laminating two or more steel plates with the anaerobic curing adhesive composition of the present disclosure. The steel sheet is not particularly limited, and suitable examples include an electrical steel sheet and a cold-rolled steel sheet. The electrical steel sheet may be a directional electrical steel sheet or a non-directional electrical steel sheet. When the adhesive laminate of the present disclosure is used for a motor core, rotor, stator, etc., as described below, the electrical steel sheet is preferably a non-directional electrical steel sheet. The shape of the steel sheet, particularly the shape in the plane direction, is not particularly limited, and any appropriate shape can be selected as desired. There is no particular limitation on the thickness of the steel plate, and it can be appropriately selected depending on the application. For example, when the adhesive laminate of the present disclosure is used in a motor, the thickness of the steel sheet is preferably 0.10 mm to 0.35 mm, more preferably 0.15 mm to 0.30 mm, in response to the increasing need for even thinner adhesive laminates as motors become smaller. The thickness of the adhesive layer when the adhesive laminate of the present disclosure is used in a motor is also preferably 0.1 μm to 1,000 μm, more preferably 0.5 μm to 500 μm, in response to the same need. The number of steel plates used in the adhesive laminate of the present disclosure is not particularly limited and can be selected appropriately depending on the usage of the motor or the like.

[0068] In the non-oriented electrical steel sheet used in the present disclosure, the average magnetic flux density B in the entire circumferential direction when excited with a magnetizing force of 5000 A / m 50 is preferably 1.50(T) or more, and more preferably 1.60(T) or more.

[0069] Here, the "average magnetic flux density B of the non-oriented electrical steel sheet in the entire circumferential direction" 50 " is the magnetic flux density B in five directions: the rolling direction (0°), and 22.5°, 45°, 67.5°, and 90° with respect to the rolling direction. 50 is the average value of

[0070] The chemical composition of the base steel plate (base material of the steel plate) contains basic elements, optional elements as needed, and the balance being Fe and impurities. The chemical composition of the base steel plate contains, for example, the following elements. Hereinafter, unless otherwise specified, "%" means mass %.

[0071] [Basic elements] The base steel sheet has a chemical composition containing Si, Al, and Mn as basic elements, which will be described below.

[0072] Si: 2.5 to 4.5% Silicon (Si) increases the electrical resistance of steel and reduces eddy current loss. As a result, iron loss of the steel sheet is reduced. Si increases the strength of steel. When the Si content is 2.5% or more, the iron loss of the steel sheet can be further reduced. On the other hand, when the Si content is 4.5% or less, the workability of the steel is improved. Therefore, the Si content is preferably 2.5 to 4.5%. A more preferable lower limit of the Si content is 2.6%, and even more preferably 2.7%. A more preferable upper limit of the Si content is 4.3%, and even more preferably 4.2%.

[0073] Al: 0.1 to 1.5% Aluminum (Al) increases the electrical resistance of steel and reduces eddy current loss. As a result, iron loss of the steel sheet is reduced. When the Al content is 0.1% or more, the iron loss of the steel sheet can be further reduced. On the other hand, when the Al content is 1.5% or less, the occurrence of a decrease in saturation magnetic flux density is suppressed. Therefore, the Al content is preferably 0.1 to 1.5%. A more preferable lower limit of the Al content is 0.15%, and even more preferably 0.2%. A more preferable upper limit of the Al content is 1.4%, and even more preferably 1.3%.

[0074] Mn: 0.2 to 4.0% Manganese (Mn) increases the electrical resistance of steel and reduces eddy current loss. As a result, the iron loss of steel sheet decreases. Mn has unfavorable {111} <112> When the Mn content is 0.2% or more, the iron loss of the steel sheet can be further reduced, and the {111} <112> The formation of texture can be further suppressed. On the other hand, if the Mn content is 4.0% or less, the change in texture is suppressed, and the deterioration of hysteresis loss is suppressed. Therefore, the Mn content is preferably 0.2 to 4.0%. The lower limit of the Mn content is more preferably 0.3%, and even more preferably 0.4%. Mn content A more preferred upper limit of the amount is 3.8%, and even more preferred is 3.6%.

[0075] In the present disclosure, the chemical composition of the base steel sheet may contain impurities. Here, "impurities" include elements that are mixed in from raw materials such as ore and scrap when the base steel sheet is industrially produced, and elements that are mixed in from the manufacturing environment, etc. Examples of impurities include elements such as C, P, S, and N.

[0076] The chemical composition of the base steel sheet can be measured by a known chemical analysis method, for example, by using inductively coupled plasma-atomic emission spectrometry (ICP-AES).

[0077] The adhesive laminate of the present disclosure may be used for a variety of purposes without any particular limitation. In particular, the adhesive laminate of the present disclosure is preferably used for motor cores, etc. The cured product of the anaerobic curing adhesive composition of the present disclosure electrically insulates each of the multiple electrical steel sheets that make up the motor core. Therefore, a motor core using the adhesive laminate of the present disclosure has low current loss, high performance, and high reliability, and distributes stress across the surface, preventing stress concentration and strain concentration. As a result, the adhesive laminate of the present disclosure is preferably used for motor cores, etc.

[0078] There are no particular limitations on the method for producing the adhesive laminate of the present disclosure, but it is preferable that the method include the steps of applying a primer composition containing a solvent and an organometallic complex to a steel plate, applying oil to the steel plate to which the primer composition has been applied, applying the anaerobic curing adhesive composition of the present disclosure to the steel plate to which the oil has been applied, and laminating another steel plate to the steel plate to which the adhesive composition has been applied.

[0079] The primer composition used in the present disclosure is not particularly limited, and examples thereof include compositions prepared by diluting an organometallic complex with a solvent. Examples of organometallic complexes include copper ethylhexanoate, iron pentadione, cobalt pentadione, copper pentadione, propylenediamine copper, ethylenediamine copper, iron naphthate, nickel naphthate, cobalt naphthate, copper naphthate, copper octate, iron hexoate, iron propionate, and vanadium acetylacetonate. Examples of solvents include ethanol, toluene, acetone, and heptone. The oil may be, for example, punching oil. The "punching oil" is an oil used for the purpose of preventing galling and seizure. The components of the punching oil are not particularly limited, but examples thereof include those containing mineral oil or synthetic oil as the main component, and may further contain an anti-rust agent, an antiseptic agent, etc. as an optional component.

[0080] After the step of laminating another steel sheet, heating can be carried out to cure the adhesive composition in a shorter time. The heating method is not particularly limited, but examples include a thermostatic bath and a far-infrared heater. The heating temperature and heating time during heating may be any conditions that allow for sufficient curing. The heating temperature is preferably 40°C to 300°C, more preferably 60°C to 150°C. The heating time is preferably 10 seconds to 3 hours, more preferably 20 seconds to 60 minutes. From the viewpoint of preventing displacement of the adhesive laminate, it is preferable that the adhesive laminate be fixed in advance with a fixing jig or the like when placed in the thermostatic chamber.

[0081] The method for applying the primer composition, oil, and adhesive composition is not particularly limited, and known methods can be used, such as by roller, dispensing, spraying, inkjet, and dipping.

[0082] The other steel sheet to be bonded may have a primer composition and oil applied to the surface to be bonded, or the other steel sheet to be bonded may have the adhesive composition applied to the surface to be bonded. In the method for producing an adhesive laminate according to the present disclosure, the laminate obtained in the step of laminating another steel plate is used as the steel plate in the step of applying the primer composition to the steel plate, thereby obtaining an adhesive laminate in which three or more steel plates are laminated with an adhesive layer formed by curing the anaerobic curing adhesive composition according to the present disclosure.

[0083] In order to form the adhesive laminate of the present disclosure into a desired shape, after obtaining the adhesive laminate, punching press processing may be performed using a press molding device, etc. Punching press processing may be performed on the steel plates before bonding, or punching press processing may be performed during the bonding step. Furthermore, the steel plate used in the step of applying the primer composition to the steel plate may be subjected to a punching press process.

[0084] When the adhesive laminate of the present disclosure is used as a motor core, the adhesive laminate of the present disclosure may be in a form in which an electromagnetic steel sheet is laminated. Specifically, the adhesive laminate of the present disclosure may be a motor core in which a punched member (steel sheet blank) is produced by punching an electromagnetic steel sheet and this punched member is laminated together. For example, an example of the adhesive laminate of the present disclosure is the motor core shown in FIG. 1.

[0085] Fig. 1 is a schematic diagram showing an example of an adhesive laminate (motor core) according to this embodiment. As shown in Fig. 1, adhesive laminate (motor core) 300 is formed as a laminated portion 33 in which a plurality of punched members 31 made of electromagnetic steel sheets are laminated together with the anaerobic curing adhesive composition (not shown) of the present disclosure interposed therebetween. Punched member 31 is formed with a yoke portion 37 on the outer periphery and teeth portions 35 protruding radially inward from the inner circumferential surface of yoke portion 37.

[0086] Although the motor core shown in FIG. 1 has been described above, the adhesive laminate according to this embodiment is not limited to this.

[0087] Next, a method for manufacturing the motor core will be described. The method for manufacturing the motor core is not particularly limited, and it may be manufactured by a manufacturing method that is normally employed industrially. An example of a preferred method for manufacturing a motor core will now be described. An example of a preferred method for manufacturing a motor core includes a punching step of punching electromagnetic steel sheets to obtain punched members, and a lamination step of laminating the punched members.

[0088] -Punching process- First, the electromagnetic steel sheets are punched into a predetermined shape depending on the purpose, and a predetermined number of punched members are produced depending on the number of laminated sheets. The method for punching the electromagnetic steel sheets to produce the punched members is not particularly limited, and any conventionally known method may be used. The punched members may be formed with crimped portions for stacking and fixing the punched members when punched into a predetermined shape.

[0089] -Lamination process- The punched members produced in the punching process are stacked and fixed together to obtain a motor core. The method for fixing stacked punched members may at least use the anaerobic curing adhesive composition of the present disclosure, for example, by applying the anaerobic curing adhesive composition of the present disclosure to the punched members to form an adhesive layer, and then fixing the punched members via the adhesive layer. A method for fixing stacked punched members by applying a crimping process to mechanically fit crimped portions formed on each punched member into each other may also be combined with the method for fixing stacked punched members.

[0090] Since the metal surfaces of the punched parts come into contact with the crimped parts, there is a risk of a reduction in insulation between the parts. However, by combining this with bonding using the anaerobic curing adhesive composition of the present disclosure, it is possible to reduce the number of crimped parts or to move the joining points away from important locations on the magnetic circuit. As a result, motor core losses can be reduced.

[0091] A motor core is obtained through the above steps. The motor core is manufactured using the anaerobic curing adhesive composition of the present disclosure, which has excellent adhesion to oily surfaces. Therefore, the cured product of the adhesive composition has high insulating properties, resulting in low current loss in the motor core. Because stress is dispersed across the surface and stress and strain concentration do not occur, the motor core has high performance and excellent reliability.

[0092] (motor) The motor of the present disclosure comprises the adhesive laminate of the present disclosure. Motors using the adhesive laminate of the present disclosure as a motor core are suitable for use in mobile phone vibration, camera focus adjustment, hard disk drive, automobile drive, etc. Motors of the present disclosure have low current loss and excellent efficiency.

[0093] (Anaerobic curing primer composition) The anaerobic curing primer composition of the present disclosure contains a compound having an aromatic ring and an ethylenically unsaturated group. Preferred aspects of the compound having an aromatic ring and an ethylenically unsaturated group contained in the anaerobic curing primer composition of the present disclosure are the same as the preferred aspects of the compound having an aromatic ring and an ethylenically unsaturated group in the anaerobic curing adhesive composition of the present disclosure described above.

[0094] The anaerobically curable primer composition of the present disclosure may contain one type of compound having an aromatic ring and an ethylenically unsaturated group, or may contain two or more types of compounds. From the viewpoint of adhesion to oily surfaces, the content of the compound having an aromatic ring and an ethylenically unsaturated group is preferably 0.1 mass % to 99.9 mass %, more preferably 0.3 mass % to 99.9 mass %, and particularly preferably 0.5 mass % to 99.5 mass %, relative to the total mass of the primer composition.

[0095] The anaerobically curable primer composition of the present disclosure preferably contains an organometallic complex. Suitable examples of the organometallic complex include those described above. The anaerobically curable primer composition of the present disclosure may contain one type of organometallic complex alone, or may contain two or more types of organometallic complexes. From the viewpoint of adhesion to oily surfaces, the content of the organometallic complex is preferably 0.001% by mass to 70% by mass, more preferably 0.01% by mass to 60% by mass, and particularly preferably 0.1% by mass to 50% by mass, relative to the total mass of the primer composition.

[0096] The anaerobically curable primer composition of the present disclosure may contain an oil. Suitable examples of the oil include those described above. The anaerobic curing primer composition of the present disclosure preferably contains a solvent such as ethanol, toluene, acetone, or heptone. The anaerobic curing primer composition of the present disclosure can be used in combination with an anaerobic curing adhesive composition, and is preferably used in combination with the anaerobic curing adhesive composition of the present disclosure. The anaerobic curing adhesive composition does not need to contain a compound having an aromatic ring and an ethylenically unsaturated group. [Example]

[0097] The present disclosure will be specifically described below based on examples. The present disclosure is not limited to these examples. In the following, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0098] <Preparation of Base Compositions 1 to 5> The components shown in Table 1 were mixed in a mixer at room temperature (25°C) for 60 minutes so as to have the contents shown in Table 1, to obtain base compositions 1 to 5, respectively.

[0099] [Table 1]

[0100] Details of the abbreviations listed in Table 1 are shown below. Soft UMA-1: Aromatic trifunctional urethane methacrylate with a structural unit based on tolylene diisocyanate (weight average molecular weight: 42,000, maximum tan δ value: -34°C) Hard UMA-1: Aliphatic bifunctional urethane methacrylate with structural units based on trimethylhexamethylene diisocyanate (weight average molecular weight: 1,100, maximum tan δ value: 125°C) Soft UMA-2: Alicyclic bifunctional urethane methacrylate with structural units based on isophorone diisocyanate (weight average molecular weight: 10,600, maximum tan δ value: -10°C) Hard UMA-2: Alicyclic bifunctional urethane methacrylate with structural units based on isophorone diisocyanate (weight average molecular weight: 3,300, maximum tan δ value: 50°C) THFMA: Tetrahydrofurfuryl methacrylate, light ester THF (1000), manufactured by Kyoeisha Chemical Co., Ltd. HEMA: 2-hydroxyethyl methacrylate, manufactured by Mitsubishi Gas Chemical Company, Inc. HOA-MPL: The following compound, manufactured by Kyoeisha Chemical Co., Ltd. HOA-MPE: The following compound, manufactured by Kyoeisha Chemical Co., Ltd. P-1M: 2-Methacryloyloxyethyl acid phosphate, Light Ester P-1M manufactured by Kyoeisha Chemical Co., Ltd. P-2M: 2-Methacryloyloxyethyl acid phosphate, Light Ester P-2M manufactured by Kyoeisha Chemical Co., Ltd.

[0101] [ka]

[0102] (Examples 1 to 5 and Comparative Examples 1 to 4) The components listed in Table 2 or Table 3 were mixed in a mixer at room temperature (25°C) for 60 minutes so as to obtain the contents listed in Table 2 or Table 3, thereby obtaining the anaerobic curing adhesive compositions of Examples 1 to 5 or Comparative Examples 1 to 4, respectively. Table 4 shows the viscosity of each anaerobic curing adhesive composition at 25° C. The viscosity was measured by the method described above.

[0103] [Table 2]

[0104] [Table 3]

[0105] Details of the abbreviations in Tables 2 and 3 other than those mentioned above are as follows: IBXMA: Isobornyl methacrylate, manufactured by Tokyo Chemical Industry Co., Ltd. AA: Acrylic acid, manufactured by Toagosei Co., Ltd. Acetylphenylhydrazine: Fujifilm Wako Pure Chemical Industries, Ltd. EDTA-2Na: Ethylenediaminetetraacetic acid disodium salt, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Percumyl H: Cumene hydroperoxide, manufactured by NOF Corporation DCP-A: Dimethylol tricyclodecane diacrylate, Light Acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd. Epoxy acrylate: acrylic acid adduct of bisphenol A epoxy resin (weight average molecular weight of 500 or more)

[0106] <Evaluation of adhesion to oily surfaces> For each type of steel plate listed in Table 4, two of the same type were used as a pair, and 1 μL / cm was applied to the tip of one of the plates. 2 AT Quicka CM (primer, manufactured by Toagosei Co., Ltd.) was applied to the surface. Then, the oils listed in Table 4 were applied to the surface at a concentration of 2 μL / cm. 2 The oils listed in Table 4 were then applied at a rate of 2 μL / cm on a steel plate that had not been primed. 2 Furthermore, 0.1 g of the adhesive composition was dropped onto a steel plate that had not been coated with a primer but had only been coated with machining oil, and the two steel plates were immediately bonded together and clamped with two double clips. The above steps were carried out within 20 seconds, with a bonding area of ​​5 cm. 2 ~6cm 2 The obtained test pieces were left to stand at 25°C (rt) for 12 to 24 hours. After leaving the specimens to stand, the clips were removed and the tensile shear strength (MPa) was measured by pulling the specimens at 23°C, 50%RH to 60%RH, and 10mm / min using a Strograph 20-C manufactured by Toyo Seiki Seisaku-sho, Ltd.

[0107] [Table 4]

[0108] Details of the abbreviations in Table 4 are as follows: <Steel plate> Nippon Steel P: Thickness 0.30mm, density 7.65kg / dm 2 , Nippon Steel Corporation 30HX1600·G Nippon Steel Cr: Thickness 0.30mm, density 7.65kg / dm 2 , Nippon Steel Corporation 30HX1600·L JFE 35JN300A: Non-oriented electrical steel strip, thickness 0.35 mm, density 7.65 kg / dm 2 , JFE Steel Corporation JN Core 35JN300A Nippon Steel 35H300L: Thickness 0.35mm, density 7.65kg / dm 2 , Nippon Steel Corporation 35H300·L

[0109] <Oil> Daphne: Daphne New Punch Oil manufactured by Idemitsu Kosan Co., Ltd. G-6339F: Punching oil (mineral oil), manufactured by Nippon Kogyoyu Co., Ltd.

[0110] As shown in Table 4, the anaerobic curing adhesive composition of the present disclosure has excellent adhesion to oily surfaces. [Industrial Applicability]

[0111] The present disclosure provides an anaerobic curing adhesive composition that can provide an adhesive laminate that contributes to, for example, simplifying the adhesive lamination process and improving the performance and reliability of motor rotors and stators. Therefore, the present disclosure is extremely effective and can be used in a wide range of products and technical fields, making it industrially useful.

[0112] The disclosure of Japanese Patent Application No. 2021-194893, filed on November 30, 2021, is incorporated herein by reference in its entirety. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. a compound having an aromatic ring and an ethylenically unsaturated group, a polymer or oligomer having two or more (meth)acryloyl groups in one molecule; a radical polymerization initiator, and Contains an anaerobic curing catalyst, the compound having an aromatic ring and an ethylenically unsaturated group includes a compound having an oxycarbonyl group having an ethylenically unsaturated group on an aromatic ring, The content of the compound having an aromatic ring and an ethylenically unsaturated group is 0.05% by mass to 5% by mass relative to the total mass of the adhesive composition.

2. The anaerobically curable adhesive composition according to claim 1 , wherein the compound having an aromatic ring and an ethylenically unsaturated group includes a compound having only one ethylenically unsaturated group.

3. The anaerobically curable adhesive composition according to claim 1 , wherein the compound having an aromatic ring and an ethylenically unsaturated group comprises a phthalic acid-modified compound having an ethylenically unsaturated group.

4. The anaerobically curable adhesive composition according to claim 3 , wherein the phthalic acid-modified compound having an ethylenically unsaturated group comprises a mono(meth)acryloxy(poly)alkyleneoxyalkyl phthalate.

5. 2. The anaerobic curing adhesive composition according to claim 1, wherein the polymer or oligomer is 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 (meth)acrylic group-containing acrylic polymer.

6. 2. The anaerobically curable adhesive composition according to claim 1, wherein the polymer or oligomer is a urethane (meth)acrylate or an epoxy (meth)acrylate.

7. 2. The anaerobically curable adhesive composition according to claim 1, wherein the polymer or oligomer is a urethane (meth)acrylate.

8. 2. The anaerobically curable adhesive composition according to claim 1, wherein the total content of the polymer or oligomer is 15% by mass to 70% by mass, based on the total mass of the adhesive composition.

9. The anaerobically curable adhesive composition according to claim 1 , wherein the radical polymerization initiator is an organic peroxide.

10. The anaerobically curable adhesive composition according to claim 1 , further comprising a monofunctional ethylenically unsaturated compound other than the compound having an aromatic ring and an ethylenically unsaturated group.

11. The anaerobic curing adhesive composition according to claim 1, which is an anaerobic curing adhesive composition for steel plates.

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

13. A motor comprising the adhesive laminate of claim 12.

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