Primer composition, production method for primer composition, production method for laminate, production method for laminated steel sheet, adhesive composition kit, and curing acceleration method for anaerobic adhesive agent

Abstract

The present disclosure provides a means with which it is possible to suppress a reduction in the performance (a reduction in the lubricating properties over time) of a primer composition containing a curing accelerator and a lubricating oil (e.g. a press working oil) and to improve the curing speed and the adhesion strength of an anaerobic adhesive agent. The present disclosure relates to a primer composition which is a curing accelerator for an anaerobic adhesive agent containing components (A)-(C) below, said primer composition containing components (D) and (E) below, not containing ethanol, and not containing acetone.　Component (A): a compound having at least one (meth)acryloyl group Component (B): An organic peroxide Component (C): An anaerobic curing catalyst Component (D): a metal complex Component (E): A solvent having a boiling point of 80°C or higher

Description

Primer composition, method for producing primer composition, method for producing laminate, method for producing laminated steel sheet, adhesive composition kit, and method for accelerating the curing of anaerobic adhesive

[0001] The present invention relates to a primer composition, a method for producing a primer composition, a method for producing a laminate, a method for producing a laminated steel sheet, an adhesive composition kit, and a method for accelerating the curing of an anaerobic adhesive.

[0002] Currently, motors and stators are made by laminating electromagnetic steel sheets. While these laminated steel sheets can be assembled using laser welding and / or crimping, the trend toward thinner electromagnetic steel sheets due to the increasing power output of motors has led to the adoption of adhesive bonding (see Japanese Patent Laid-Open Publication No. 2006-334648). Furthermore, with the aim of improving quality and productivity, simplifying the manufacturing process, and / or reducing the size of manufacturing equipment, a method has been adopted in which electromagnetic steel sheets are coated with press processing oil containing a hardening accelerator, and then the electromagnetic steel sheets are laminated and assembled with steel sheets coated with an adhesive (see Japanese Patent Laid-Open Publication No. 2006-334648).

[0003] However, while conventional curing accelerators added to press processing oils improve the curing rate of adhesives, there are concerns that they may degrade the properties (performance) of the press processing oils. In particular, conventional curing accelerators have the problem of increasing the friction coefficient of the press processing oil over time (reducing its lubrication performance).

[0004] Therefore, an object of the present invention is to provide a method for improving the cure rate and adhesive strength of an anaerobic adhesive while suppressing performance degradation (decrease in lubricating performance over time) of a primer composition containing a cure accelerator and a lubricating oil (e.g., press processing oil, etc.).

[0005] As a result of investigations conducted by the inventors to achieve the above-mentioned object, they discovered a method for improving the cure rate and adhesive strength of an anaerobic adhesive while suppressing performance degradation (decrease in lubricating performance over time) of a primer composition containing a cure accelerator and a lubricating oil (e.g., press processing oil) even when the cure accelerator is added to the lubricating oil (e.g., press processing oil), thereby completing the present invention.

[0006] The gist of the present invention will now be described.

[0007] One aspect of the present invention that can achieve at least one of the above objects relates to the following item [1]: [1] A primer composition that is a curing accelerator for an anaerobic adhesive, comprising the following components (A) to (C): component (D) and component (E), and that does not contain ethanol or acetone; component (A): a compound having one or more (meth)acryloyl groups; component (B): an organic peroxide; component (C): an anaerobic curing catalyst; component (D): a metal complex; and component (E): a solvent having a boiling point of 80°C or higher.

[0008] The present invention also includes the following embodiments [2] to

[15] as non-limiting examples of preferred embodiments.

[0009] [2] The primer composition according to [1], which does not contain a solvent having a boiling point of less than 80°C.

[0010] [3] The primer composition according to [1] or [2], further comprising a lubricating oil as component (F).

[0011] [4] The primer composition according to [3], wherein the component (F) is a press processing oil.

[0012] [5] The primer composition according to any one of [1] to [4], wherein the component (E) is an alcohol-based solvent and / or mineral spirits.

[0013] [6] The primer composition according to any one of [1] to [5], which is used for an anaerobic adhesive, in which the component (A) contains one or more compounds selected from the group consisting of urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring.

[0014] [7] The primer composition according to any one of [1] to [6], comprising 0.1 to 10 parts by mass of the (D) component per 100 parts by mass of the (E) component.

[0015] [8] The primer composition according to any one of [1] to [7], which is used for assembling laminated steel sheets.

[0016] [9] A method for producing a laminate, comprising: applying the primer composition according to any one of [1] to [8] to an adherend; applying an anaerobic adhesive to the adherend, a coating of the primer composition, or both; and, after applying the primer composition and the anaerobic adhesive, bonding the adherend to an adherend to be bonded, and then curing the anaerobic adhesive.

[0017]

[10] The manufacturing method according to [9], wherein the anaerobic adhesive contains the components (A) to (C).

[0018]

[11] A method for producing a laminated steel sheet, comprising: applying the primer composition according to any one of [1] to [8] to an electromagnetic steel sheet; applying an anaerobic adhesive to the electromagnetic steel sheet, a coating of the primer composition, or both; and, after applying the primer composition and the anaerobic adhesive, bonding the electromagnetic steel sheet to an electromagnetic steel sheet to be bonded, and then curing the anaerobic adhesive to obtain a laminate.

[0019]

[12] The manufacturing method according to

[11] , wherein the anaerobic adhesive contains the components (A) to (C).

[0020]

[13] An adhesive composition kit comprising an anaerobic adhesive containing the following components (A) to (C) and the primer composition according to any one of [1] to [8]: component (A): a compound having one or more (meth)acryloyl groups; component (B): an organic peroxide; and component (C): an anaerobic curing catalyst.

[0021]

[14] A method for accelerating the curing of an anaerobic adhesive, comprising curing an anaerobic adhesive in a state in which the anaerobic adhesive is in contact with a coating film of the primer composition according to any one of [1] to [8] and the anaerobic adhesive containing the following components (A) to (C): Component (A): a compound having one or more (meth)acryloyl groups; Component (B): an organic peroxide; and Component (C): an anaerobic curing catalyst.

[0022] Another aspect of the present invention that can achieve at least one of the above objects relates to the following

[15] .

[0023]

[15] A method for producing a primer composition, the method comprising mixing the following component (D) and component (E), but not mixing ethanol or acetone, the primer composition being a curing accelerator for an anaerobic adhesive, the anaerobic adhesive comprising the following components (A) to (C): component (A): a compound having one or more (meth)acryloyl groups, component (B): an organic peroxide, component (C): an anaerobic curing catalyst, component (D): a metal complex, and component (E): a solvent having a boiling point of 80°C or higher.

[0024] The present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0025] In this specification, "X to Y" means a range that includes the numerical values ​​(X and Y) written before and after it as the lower and upper limits, and means "at least X and at most Y."

[0026] In this specification, unless otherwise specified, operations and measurements of physical properties are carried out under conditions of 25° C. and a relative humidity of 55% RH.

[0027] In this specification, the term "(meth)acryloyl" includes both acryloyl and methacryloyl. Similarly, the term "(meth)acrylate" includes both acrylate and methacrylate, the term "(meth)acryl" includes both acryl and methacryl, and the term "(meth)acrylamide" includes both acrylamide and methacrylamide. Thus, for example, the term "(meth)acryloyl group" includes an acryloyl group (H ２ C=CH-C(=O)-*) and methacryloyl groups (H ２ C=C(CH ３ )-C(=O)-*). Here, * represents the linking site to the adjacent atom. The (meth)acryloyl group may exist in the form of a (meth)acryloyloxy group. Therefore, a compound having a (meth)acryloyl group may be, for example, a (meth)acrylate.

[0028] In this specification, anaerobic adhesives are also referred to as anaerobic curing adhesives.

[0029] One aspect of the present invention relates to a primer composition that is a curing accelerator for an anaerobic adhesive containing the following components (A) to (C): the primer composition contains the following component (D) and component (E), and does not contain ethanol or acetone: component (A): a compound having one or more (meth)acryloyl groups, component (B): an organic peroxide, component (C): an anaerobic curing catalyst, component (D): a metal complex, and component (E): a solvent having a boiling point of 80°C or higher.

[0030] The primer composition according to this embodiment can improve the cure rate and adhesive strength of the anaerobic adhesive while suppressing deterioration in performance (decrease in lubricating performance over time) of the primer composition containing a cure accelerator and a lubricating oil (e.g., press processing oil, etc.).

[0031] The primer composition according to this embodiment will be described in detail below, but the primer composition according to this embodiment is not limited to the following embodiments.

[0032] <Anaerobic Adhesive> The primer composition according to this embodiment can be suitably used as a curing accelerator for an anaerobic adhesive containing the above-mentioned component (A), component (B), and component (C).

[0033] [Component (A)] Component (A) is a compound having one or more (meth)acryloyl groups. Component (A) is the main component constituting the adhesive in this embodiment. Component (A) may be used alone, or two or more types may be used in combination.

[0034] Component (A) may be a polymer having one or more (meth)acryloyl groups per molecule, a monomer having one or more (meth)acryloyl groups per molecule, or a combination thereof. The polymer may contain a portion in which a monomer unit is repeated, a portion derived therefrom, or both. Examples of component (A) include, but are not limited to, an oligomer having one or more (meth)acryloyl groups per molecule and a monomer having one or more (meth)acryloyl groups per molecule. Here, an oligomer refers to a polymer in which two to several tens (e.g., 2 to 10, 2 to 20, 2 to 30, 2 to 40, or 2 to 50) of monomer units (including monomer units other than (meth)acrylate monomers) are repeated. The oligomer may be a polymer containing two to several tens (e.g., 2 to 10, 2 to 20, 2 to 30, 2 to 40, or 2 to 50) of repeated monomer units, a portion derived therefrom, or both.

[0035] Component (A): The compound having one or more (meth)acryloyl groups preferably includes an oligomer having one or more (meth)acryloyl groups in one molecule, and more preferably includes an oligomer having one or more (meth)acryloyl groups in one molecule and a monomer having one or more (meth)acryloyl groups in one molecule. The mass ratio of the oligomer having one or more (meth)acryloyl groups in the molecule to the monomer having one or more (meth)acryloyl groups in the molecule in component (A) is not particularly limited, but is preferably from 1:99 to 99:1 (oligomer having one or more (meth)acryloyl groups in the molecule:monomer having one or more (meth)acryloyl groups in the molecule), more preferably from 20:80 to 80:20 (oligomer having one or more (meth)acryloyl groups in the molecule:monomer having one or more (meth)acryloyl groups in the molecule), and even more preferably from 50:50 to 75:25 (oligomer having one or more (meth)acryloyl groups in the molecule).

[0036] Examples of types of oligomers having one or more (meth)acryloyl groups in one molecule are not particularly limited, but include urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring.

[0037] From the viewpoint of curability and adhesive strength to laminated steel sheets, it is preferable that the component (A): compound having one or more (meth)acryloyl groups contains one or more compounds selected from the group consisting of urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring. The primer composition according to one embodiment is preferably used in an anaerobic adhesive in which the component (A): compound having one or more (meth)acryloyl groups contains one or more compounds selected from the group consisting of urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring.

[0038] From the viewpoint of curability and adhesive strength to laminated steel sheets, the component (A): a compound having one or more (meth)acryloyl groups preferably includes a compound having two or more (meth)acryloyl groups, and more preferably includes an oligomer having two or more (meth)acryloyl groups in one molecule. Examples of the oligomer having two or more (meth)acryloyl groups are not particularly limited, but include urethane-modified (meth)acrylates having two or more (meth)acryloyl groups, epoxy-modified (meth)acrylates having two or more (meth)acryloyl groups, and (meth)acrylates having two or more (meth)acryloyl groups and an aromatic ring.

[0039] From the viewpoint of curability and adhesive strength to laminated steel sheets, the component (A): compound having one or more (meth)acryloyl groups preferably includes one or more compounds selected from the group consisting of a urethane-modified (meth)acrylate having two or more (meth)acryloyl groups, an epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups, and a (meth)acrylate having two or more (meth)acryloyl groups and having an aromatic ring. The component (A): compound having one or more (meth)acryloyl groups more preferably includes a urethane-modified (meth)acrylate having two or more (meth)acryloyl groups and / or an epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups, and even more preferably includes a urethane-modified (meth)acrylate having two or more (meth)acryloyl groups and an epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups.

[0040] In one embodiment, the oligomer having one or more (meth)acryloyl groups in one molecule preferably comprises one or more compounds selected from the group consisting of urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring, more preferably comprises a urethane-modified (meth)acrylate and / or an epoxy-modified (meth)acrylate, and even more preferably comprises a urethane-modified (meth)acrylate and an epoxy-modified (meth)acrylate. In one embodiment, the oligomer having one or more (meth)acryloyl groups in one molecule is preferably one or more compounds selected from the group consisting of urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring, more preferably a urethane-modified (meth)acrylate and / or an epoxy-modified (meth)acrylate, and even more preferably a urethane-modified (meth)acrylate and an epoxy-modified (meth)acrylate.

[0041] When two or more compounds having one or more (meth)acryloyl groups are used in combination as component (A), the content of the urethane-modified (meth)acrylate is not particularly limited, but is preferably 1 to 90 mass%, more preferably 5 to 90 mass%, even more preferably 10 to 80 mass%, and particularly preferably 15 to 70 mass%, relative to the total mass of component (A). By including 1 to 90 mass% of the urethane-modified (meth)acrylate relative to the total mass of component (A), the adhesive strength to laminated steel sheets is superior.

[0042] When two or more types of compounds having one or more (meth)acryloyl groups are used in combination as component (A), the content of the epoxy-modified (meth)acrylate is not particularly limited, but is preferably 1 to 90 mass%, more preferably 5 to 70 mass%, even more preferably 10 to 50 mass%, and particularly preferably 10 to 30 mass%, relative to the total mass of component (A). By including 1 to 90 mass% of the epoxy-modified (meth)acrylate relative to the total mass of component (A), better curability is achieved.

[0043] When the component (A): compound having one or more (meth)acryloyl groups includes a urethane-modified (meth)acrylate and an epoxy-modified (meth)acrylate, the mass ratio of the urethane-modified (meth)acrylate to the epoxy-modified (meth)acrylate in the component (A) is not particularly limited. The mass ratio of the urethane-modified (meth)acrylate to the epoxy-modified (meth)acrylate in the component (A) is preferably urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate=10:90 to 90:10, more preferably urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate=30:70 to 85:15, and even more preferably urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate=50:50 to 80:20.

[0044] A urethane-modified (meth)acrylate is a compound having a urethane bond in the main chain and a (meth)acryloyl group, formed by reacting an isocyanate group with a hydroxyl group. From the viewpoint of curability, the (meth)acryloyl group is preferably at the molecular chain terminal. Examples of a method for producing a urethane-modified (meth)acrylate include, but are not limited to, a method of reacting a polyol compound having a hydroxyl group with a (meth)acrylate having an isocyanate group, and a method of reacting a polyol compound having a hydroxyl group, a polyisocyanate compound, and a (meth)acrylate having a hydroxyl group. In one embodiment, the urethane-modified (meth)acrylate preferably has a polyether skeleton. The urethane-modified (meth)acrylate may be used alone or in combination of two or more types.

[0045] Examples of the polyol compound having a hydroxyl group that can be used in the method for producing a urethane-modified (meth)acrylate include, but are not limited to, polyester polyols, polycarbonate polyols, polyether polyols, etc. These may be used alone or in combination of two or more.

[0046] Examples of the (meth)acrylate having an isocyanate group used in the method for producing a urethane-modified (meth)acrylate include, but are not limited to, 2-methacryloyloxyethyl isocyanate (also known as 2-isocyanatoethyl methacrylate), 2-isocyanatoethyl acrylate, etc. These may be used alone or in combination of two or more.

[0047] Examples of polyisocyanate compounds used in the method for producing a urethane-modified (meth)acrylate include, but are not limited to, aromatic polyisocyanates, alicyclic polyisocyanates, linear or branched aliphatic polyisocyanates, etc. Examples of aromatic polyisocyanates include, but are not limited to, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, tetramethylxylylene diisocyanate, diphenylmethane diisocyanate, naphthalene-1,5-disocyanate, triphenylmethane triisocyanate, etc. Examples of alicyclic polyisocyanates include, but are not limited to, isophorone diisocyanate, bis(4-isocyanatocyclohexyl)methane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, norbornane diisocyanate, bicycloheptane triisocyanate, etc. Examples of linear or branched aliphatic polyisocyanates include, but are not limited to, hexamethylene diisocyanate, 1,3,6-hexamethylene triisocyanate, 1,6,11-undeca triisocyanate, etc. These may be used alone or in combination of two or more.

[0048] Examples of (meth)acrylates having a hydroxyl group that can be used in the method for producing a urethane-modified (meth)acrylate include, but are not limited to, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, 1,6-hexanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, (poly)ethylene glycol mono(meth)acrylate, (poly)propylene glycol mono(meth)acrylate, pentaerythritol tri(meth)acrylate, etc. These may be used alone or in combination of two or more.

[0049] The epoxy-modified (meth)acrylate may be a compound that can be synthesized by ring-opening polymerization of acrylic acid or the like with the glycidyl group of a glycidyl ether compound. However, the synthesis method of the epoxy-modified (meth)acrylate is not limited to this method. The main chain of the glycidyl ether can be one having a variety of skeletons, such as bisphenol A, bisphenol F, phenol novolac, hydrogenated bisphenol A, and / or hydrogenated bisphenol F. These may be used alone or in combination of two or more. In one embodiment, the epoxy-modified (meth)acrylate preferably has a bisphenol A skeleton. Specific examples of the epoxy-modified (meth)acrylate include, but are not limited to, bisphenol A diglycidyl ether epoxy diacrylate (e.g., Viscoat #540 manufactured by Osaka Organic Chemical Industry Co., Ltd.), ethoxylated bisphenol A diglycidyl ether epoxy dimethacrylate, fatty acid-modified epoxy acrylate, amine-modified bisphenol epoxy acrylate, novolac epoxy acrylate, and epoxidized soybean oil acrylate. These may be used alone or in combination of two or more.

[0050] The (meth)acrylate having an aromatic ring is not particularly limited as long as it has one or more (meth)acryloyl groups and an aromatic ring in the molecule. However, a compound corresponding to a urethane-modified (meth)acrylate is not treated as a (meth)acrylate having an aromatic ring, but as a urethane-modified (meth)acrylate. In other words, if a compound corresponding to a urethane-modified (meth)acrylate has an aromatic ring, the compound is not treated as a (meth)acrylate having an aromatic ring, but as a urethane (meth)acrylate. A compound corresponding to an epoxy-modified (meth)acrylate is not treated as a (meth)acrylate having an aromatic ring, but as an epoxy-modified (meth)acrylate. In other words, if a compound corresponding to an epoxy-modified (meth)acrylate has an aromatic ring, the compound is not treated as a (meth)acrylate having an aromatic ring, but as an epoxy-modified (meth)acrylate. Specific examples of the (meth)acrylate having an aromatic ring include, but are not limited to, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, ethoxylated nonylphenyl (meth)acrylate (also known as nonylphenol EO-modified acrylate), etc. These may be used alone or in combination of two or more.

[0051] In one embodiment, the component (A): a compound having one or more (meth)acryloyl groups preferably includes one or more compounds selected from the group consisting of a urethane-modified (meth)acrylate having two (meth)acryloyl groups at both ends, an epoxy-modified (meth)acrylate having two (meth)acryloyl groups at both ends, and a (meth)acrylate having two (meth)acryloyl groups at both ends and having an aromatic ring, and the component (A): a compound having one or more (meth)acryloyl groups at both ends, and an epoxy-modified (meth)acrylate having two (meth)acryloyl groups at both ends and having an aromatic ring It is more preferable that the composition contains an epoxy-modified (meth)acrylate having two (meth)acryloyl groups at both ends, even more preferable that the composition contains a urethane-modified acrylate having two acryloyl groups at both ends and an epoxy-modified acrylate having two acryloyl groups at both ends, and particularly preferable that the composition contains a urethane-modified acrylate having two acryloyl groups at both ends and a polyether skeleton, and an epoxy-modified acrylate having two acryloyl groups at both ends and a bisphenol A skeleton.

[0052] The (A) component: compound having one or more (meth)acryloyl groups preferably includes at least one compound selected from the group consisting of monofunctional (meth)acrylate compounds, which are compounds having one (meth)acryloyl group per molecule, and polyfunctional (meth)acrylate compounds, which are compounds having two or more (meth)acryloyl groups per molecule. The (A) component: compound having one or more (meth)acryloyl groups preferably includes a monomer having a (meth)acryloyl group. Examples of monomers having a (meth)acryloyl group include monofunctional (meth)acrylate monomers, which are monomers having one (meth)acryloyl group per molecule, and polyfunctional (meth)acrylate monomers, which are monomers having two or more (meth)acryloyl groups per molecule. These may be used alone or in combination. The monofunctional (meth)acrylate compound may be a monofunctional (meth)acrylate monomer. The polyfunctional (meth)acrylate compound may be a polyfunctional (meth)acrylate monomer.

[0053] Component (A): The compound having one or more (meth)acryloyl groups preferably includes one or more compounds selected from the group consisting of monofunctional (meth)acrylate monomers and polyfunctional (meth)acrylate monomers, more preferably includes a monofunctional (meth)acrylate monomer, and even more preferably includes a monofunctional methacrylate monomer.

[0054] The monofunctional (meth)acrylate compound is not particularly limited, but may be a monofunctional (meth)acrylate compound (I) that is not a urethane-modified (meth)acrylate, not an epoxy-modified (meth)acrylate, or not a (meth)acrylate having an aromatic ring. The monofunctional (meth)acrylate compound (I) preferably does not contain a portion in which a monomer unit is repeated, and does not contain a portion derived therefrom. That is, the monofunctional (meth)acrylate compound (I) is preferably a monofunctional (meth)acrylate monomer.

[0055] Examples of the monofunctional (meth)acrylate compound (I) are not particularly limited, but include methoxydiethylene glycol mono(meth)acrylate, methoxytriethylene glycol mono(meth)acrylate, methoxytetraethylene glycol mono(meth)acrylate, methoxypentaethylene glycol mono(meth)acrylate, methoxyhexaethylene glycol mono(meth)acrylate, methoxyheptaethylene glycol mono(meth)acrylate, methoxyhexaethylene glycol mono(meth)acrylate, methoxyoctaethylene glycol mono(meth)acrylate, methoxynonaethylene glycol mono(meth)acrylate, methoxydecaethylene glycol mono(meth)acrylate, methoxytripropylene glycol mono(meth)acrylate, methoxytetrapropylene glycol mono(meth)acrylate, methoxypentapropylene glycol mono(meth)acrylate, methoxyhexapropylene glycol mono(meth)acrylate, methoxyheptapropylene glycol mono(meth)acrylate, methoxyhectapropylene glycol mono(meth)acrylate, Acrylate, methoxyoctapropylene glycol mono(meth)acrylate, methoxynonapropylene glycol mono(meth)acrylate, methoxydecapropylene glycol mono(meth)acrylate, methoxytributylene glycol mono(meth)acrylate, methoxytetrabutylene glycol mono(meth)acrylate, methoxypentabtylene glycol mono(meth)acrylate, methoxyhexabtylene glycol mono(meth)acrylate, methoxyheptabtylene glycol mono(meth)acrylate, methoxyhectabtylene glycol ethylene glycol mono(meth)acrylate, methoxyoctabutylene glycol mono(meth)acrylate, methoxynonabtylene glycol mono(meth)acrylate, methoxydecabutylene glycol mono(meth)acrylate, ethoxydiethylene glycol mono(meth)acrylate, ethoxytriethylene glycol mono(meth)acrylate, ethoxytetraethylene glycol mono(meth)acrylate, ethoxypentaethylene glycol mono(meth)acrylate, ethoxyhexaethylene glycol mono(meth)acrylate,Ethoxyheptaethylene glycol mono(meth)acrylate, ethoxyhexaethylene glycol mono(meth)acrylate, ethoxyoctaethylene glycol mono(meth)acrylate, ethoxynonaethylene glycol mono(meth)acrylate, ethoxydecaethylene glycol mono(meth)acrylate, ethoxytripropylene glycol mono(meth)acrylate, ethoxytetrapropylene glycol mono(meth)acrylate, ethoxypentapropylene glycol mono(meth)acrylate, ethoxyhexapropylene glycol mono(meth)acrylate, ethoxyheptapropylene glycol mono(meth)acrylate, ethoxyhexapropylene glycol mono(meth)acrylate, ethoxyoctapropylene glycol mono(meth)acrylate, ethoxynonapropylene glycol mono(meth)acrylate, ethoxydecapropylene glycol mono(meth)acrylate, ethoxytributylene glycol mono(meth)acrylate acrylate, ethoxytetrabutylene glycol mono(meth)acrylate, ethoxypentabtylene glycol mono(meth)acrylate, ethoxyhexabtylene glycol mono(meth)acrylate, ethoxyheptabtylene glycol mono(meth)acrylate, ethoxyhexabtylene glycol mono(meth)acrylate, ethoxyoctabtylene glycol mono(meth)acrylate, ethoxynonabtylene glycol mono(meth)acrylate, ethoxydecabtylene glycol mono(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, 1,6-hexanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, (poly)ethylene glycol mono(meth)acrylate, (poly)propylene glycol mono(meth)acrylate, and the like. These may be used alone or in combination of two or more. Among these, preferred examples of the monofunctional (meth)acrylate monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate,Examples of such acrylates include 4-hydroxycyclohexyl (meth)acrylate, 1,6-hexanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, ethylene glycol mono(meth)acrylate, and propylene glycol mono(meth)acrylate. These may be used alone or in combination of two or more.

[0056] The monofunctional (meth)acrylate compound may be a monofunctional (meth)acrylate monomer having an aromatic ring. Examples of the monofunctional (meth)acrylate monomer having an aromatic ring include, but are not limited to, 2-hydroxy-3-phenoxypropyl acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, and phenoxyethyl (meth)acrylate. Monomers having a monofunctional (meth)acryloyl group can be used alone or in combination of two or more.

[0057] The monofunctional (meth)acrylate compounds can be used alone or in combination of two or more.

[0058] In one embodiment, the component (A): a compound having one or more (meth)acryloyl groups preferably includes a monofunctional (meth)acrylate compound, more preferably includes a monofunctional (meth)acrylate compound (I), and even more preferably includes at least one compound selected from the group consisting of the monofunctional (meth)acrylate compounds (I) exemplified above.

[0059] In one embodiment, the component (A): the compound having one or more (meth)acryloyl groups preferably includes a monofunctional (meth)acrylate monomer, and more preferably includes a monofunctional (meth)acrylate monomer that is the monofunctional (meth)acrylate compound (I).

[0060] In one embodiment, the component (A): the compound having one or more (meth)acryloyl groups preferably includes a monofunctional (meth)acrylate monomer having a hydroxyl group, and more preferably includes a monofunctional (meth)acrylate monomer having a hydroxyl group, which is the monofunctional (meth)acrylate compound (I).

[0061] In one embodiment, the component (A): a compound having one or more (meth)acryloyl groups preferably includes 2-hydroxyethyl (meth)acrylate, and particularly preferably includes 2-hydroxyethyl methacrylate.

[0062] In one embodiment, the monofunctional (meth)acrylate compound may be a monomer having a monofunctional (meth)acryloyl group, may be a monofunctional (meth)acrylate monomer having a hydroxyl group, may be a monofunctional (meth)acrylate monomer having a hydroxyl group, which is the monofunctional (meth)acrylate compound (I), may be 2-hydroxyethyl (meth)acrylate, or may be 2-hydroxyethyl methacrylate.

[0063] The polyfunctional (meth)acrylate compound is not particularly limited, but may be a polyfunctional (meth)acrylate compound (II) that is not a urethane-modified (meth)acrylate, not an epoxy-modified (meth)acrylate, or not a (meth)acrylate having an aromatic ring. The polyfunctional (meth)acrylate compound may be a combination of at least one compound selected from the group consisting of a urethane-modified (meth)acrylate, an epoxy-modified (meth)acrylate, and a (meth)acrylate having an aromatic ring with the polyfunctional (meth)acrylate compound (II). The polyfunctional (meth)acrylate compound (II) preferably does not contain a portion in which a monomer unit is repeated, and preferably does not contain a portion derived therefrom. That is, the polyfunctional (meth)acrylate compound (II) is preferably a polyfunctional (meth)acrylate monomer. Examples of polyfunctional (meth)acrylate compounds include, but are not limited to, bifunctional (meth)acrylate compounds, trifunctional (meth)acrylate compounds, tetrafunctional (meth)acrylate compounds, pentafunctional (meth)acrylate compounds, and hexafunctional (meth)acrylate compounds. Examples of polyfunctional (meth)acrylate monomers include, but are not limited to, bifunctional (meth)acrylate monomers, trifunctional (meth)acrylate monomers, tetrafunctional (meth)acrylate monomers, pentafunctional (meth)acrylate monomers, and hexafunctional (meth)acrylate monomers. Preferred examples of polyfunctional (meth)acrylate compounds include, as described above, urethane-modified (meth)acrylates having two or more (meth)acryloyl groups, epoxy-modified (meth)acrylates having two or more (meth)acryloyl groups, and (meth)acrylates having two or more (meth)acryloyl groups and an aromatic ring.

[0064] The polyfunctional (meth)acrylate compound (II) is not particularly limited. Examples of the bifunctional (meth)acrylate compound that is the polyfunctional (meth)acrylate compound (II) are not particularly limited, but include ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, tricyclodecanol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and 2-hydroxy-3-methacrylpropyl acrylate. Preferred examples of the bifunctional (meth)acrylate monomer that is the polyfunctional (meth)acrylate compound (II) include, but are not limited to, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tricyclodecanol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 2-hydroxy-3-methacrylpropyl acrylate, etc. Examples of the trifunctional (meth)acrylate monomer that is the polyfunctional (meth)acrylate compound (II) include, but are not limited to, trimethylolpropane trimethacrylate, etc. Examples of the tetrafunctional (meth)acrylate compound that is the polyfunctional (meth)acrylate compound (II) include, but are not limited to, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, etc. Preferred examples of the tetrafunctional (meth)acrylate monomer that is the polyfunctional (meth)acrylate compound (II) include, but are not limited to, pentaerythritol tetra(meth)acrylate, etc.Examples of the pentafunctional (meth)acrylate compound that is the polyfunctional (meth)acrylate compound (II) include, but are not limited to, dipentaerythritol monohydroxypenta(meth)acrylate, alkyl-modified dipentaerythritol penta(meth)acrylate, etc. Examples of the hexafunctional (meth)acrylate compound that is the polyfunctional (meth)acrylate compound (II) include, but are not limited to, dipentaerythritol hexa(meth)acrylate, etc. The polyfunctional (meth)acrylate compounds may be used alone or in combination of two or more.

[0065] The polyfunctional (meth)acrylate compound preferably contains at least one compound selected from the group consisting of the compounds exemplified above. The polyfunctional (meth)acrylate compound may be at least one compound selected from the group consisting of the compounds exemplified above.

[0066] The mass ratio of the polyfunctional (meth)acrylate compound to the monofunctional (meth)acrylate compound in the component (A) is not particularly limited, but is preferably polyfunctional (meth)acrylate compound:monofunctional (meth)acrylate compound=1:99 to 99:1, more preferably polyfunctional (meth)acrylate compound:monofunctional (meth)acrylate compound=20:80 to 80:20, and even more preferably polyfunctional (meth)acrylate compound:monofunctional (meth)acrylate compound=50:50 to 75:25.

[0067] The compound having one or more (meth)acryloyl groups may be used alone or in combination of two or more. Component (A): The compound having one or more (meth)acryloyl groups preferably includes at least one compound selected from the group consisting of the above-mentioned compounds. Component (A): The compound having one or more (meth)acryloyl groups more preferably includes, for example, a urethane-modified (meth)acrylate having two or more (meth)acryloyl groups, an epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups, and a monofunctional (meth)acrylate compound (I). In this case, preferred examples of the urethane-modified (meth)acrylate having two or more (meth)acryloyl groups, the epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups, and the monofunctional (meth)acrylate compound (I) are as described above.

[0068] In one embodiment, the component (A): compound having one or more (meth)acryloyl groups may be, for example, a urethane-modified (meth)acrylate having two or more (meth)acryloyl groups, an epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups, or a monofunctional (meth)acrylate compound (I), or may be a monofunctional (meth)acrylate monomer such as a urethane-modified (meth)acrylate having two or more (meth)acryloyl groups, an epoxy-modified (meth)acrylate having two or more (meth)acryloyl groups, or a monofunctional (meth)acrylate compound (I), The monomer may be a monofunctional (meth)acrylate monomer, such as a urethane-modified (meth)acrylate having two (meth)acryloyl groups at both ends, an epoxy-modified (meth)acrylate having two (meth)acryloyl groups at both ends, or a monofunctional (meth)acrylate compound (I), or a monofunctional (meth)acrylate monomer having a hydroxyl group, such as a urethane-modified (meth)acrylate having two (meth)acryloyl groups at both ends, an epoxy-modified (meth)acrylate having two (meth)acryloyl groups at both ends, or a monofunctional (meth)acrylate compound (I).

[0069] In one embodiment, component (A): the compound having one or more (meth)acryloyl groups may be, for example, a urethane-modified (meth)acrylate having two (meth)acryloyl groups at both ends, an epoxy-modified (meth)acrylate having two (meth)acryloyl groups at both ends, and 2-hydroxyethyl (meth)acrylate, or a urethane-modified acrylate having two acryloyl groups at both ends, an epoxy-modified acrylate having two acryloyl groups at both ends, and 2-hydroxyethyl methacrylate.

[0070] In one embodiment, component (A): the compound having one or more (meth)acryloyl groups may be, for example, a urethane-modified (meth)acrylate having two (meth)acryloyl groups at both ends and a polyether skeleton, an epoxy-modified (meth)acrylate and 2-hydroxyethyl (meth)acrylate having two (meth)acryloyl groups at both ends and a bisphenol A skeleton, or a urethane-modified acrylate having two acryloyl groups at both ends and a polyether skeleton, or an epoxy-modified acrylate and 2-hydroxyethyl methacrylate having two acryloyl groups at both ends and a bisphenol A skeleton.

[0071] The content of component (A) in the anaerobic adhesive is not particularly limited. The content of component (A) is preferably 50% by mass or more but less than 100% by mass, more preferably 60 to 99% by mass, and even more preferably 70 to 99% by mass, relative to the total mass of the anaerobic adhesive. The content of component (A) may be 60% by mass or more but less than 100% by mass, 70% by mass or more but less than 100% by mass, 90% by mass or more but less than 100% by mass, or 95% by mass or more but less than 100% by mass, relative to the total mass of the anaerobic adhesive. When two or more types of component (A) are used in combination, the amount of component (A) represents the total amount of these.

[0072] [Component (B)] Component (B) is an organic peroxide. Component (B) is a major component for curing the anaerobic adhesive. Examples of component (B) include, but are not limited to, hydroperoxides, ketone peroxides, diallyl peroxides, and peroxyesters. These may be used alone or in combination of two or more. Specific examples of component (D) include, but are not limited to, cumene hydroperoxide, t-butyl hydroperoxide, p-menthane hydroperoxide, methyl ethyl ketone peroxide, cyclohexane peroxide, dicumyl peroxide, and diisopropylbenzene hydroperoxide. These may be used alone or in combination of two or more. Among these, hydroperoxides are preferred, with cumene hydroperoxide being more preferred, due to their excellent anaerobic curing properties and the storage stability of the adhesive. Organic peroxides may be used alone or in combination of two or more. The component (B): organic peroxide preferably contains at least one compound selected from the group consisting of the compounds exemplified above. In one embodiment, the component (B): organic peroxide is preferably at least one compound selected from the group consisting of hydroperoxides, ketone peroxides, diallyl peroxides, and peroxy esters, more preferably at least one compound selected from the group consisting of cumene hydroperoxide, t-butyl hydroperoxide, p-menthane hydroperoxide, methyl ethyl ketone peroxide, cyclohexane peroxide, dicumyl peroxide, and diisopropylbenzene hydroperoxide, and even more preferably cumene hydroperoxide. In one embodiment, the component (B): organic peroxide may be, for example, a hydroperoxide.

[0073] The content of component (B) in the anaerobic adhesive is not particularly limited. From the viewpoint of anaerobic curability, the content of component (B) is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of component (A). The content of component (B) may be 0.1 to 30 parts by mass, 0.3 to 15 parts by mass, or even 0.5 to 10 parts by mass, per 100 parts by mass of component (A). When two or more types of component (A) are used in combination, the amount of component (A) represents the total amount thereof. When two or more types of component (B) are used in combination, the amount of component (B) represents the total amount thereof.

[0074] The content of component (B) in the anaerobic adhesive is not particularly limited. The content of component (B) is preferably 1 to 300 parts by mass, more preferably 3 to 150 parts by mass, and even more preferably 5 to 100 parts by mass, per 100 parts by mass of component (C). When the content of component (B) is 1 to 300 parts by mass per 100 parts by mass of component (C), both anaerobic curability and storage stability can be achieved. When two or more types of component (B) are used in combination, the amount of component (B) represents the total amount thereof. When two or more types of component (C) are used in combination, the amount of component (C) represents the total amount thereof.

[0075] [Component (C)] Component (C) is an anaerobic curing catalyst. Component (C) is the main component for achieving anaerobic curing of the adhesive. Component (C) decomposes component (B) under anaerobic conditions without contact with oxygen, generating free radicals and accelerating curing. Examples of component (C) include, but are not limited to, saccharin, amine compounds, azole compounds, mercaptan compounds, hydrazine compounds, and derivatives thereof. These compounds may be used alone or in combination. In this specification, azole compounds are not considered to include saccharin. Component (C): the anaerobic curing catalyst preferably contains at least one compound selected from the group consisting of the compounds exemplified above. In particular, from the viewpoint of excellent anaerobic curing properties at room temperature, the component (C): anaerobic curing catalyst preferably contains at least one compound selected from the group consisting of saccharin, an azole compound, a mercaptan compound, and a hydrazine compound, more preferably contains at least one compound selected from the group consisting of saccharin and a hydrazine compound, even more preferably contains saccharin, and particularly preferably contains a combination of saccharin and a hydrazine compound.

[0076] Examples of amine compounds include, but are not limited to, heterocyclic secondary amines, heterocyclic tertiary amines, and aromatic tertiary amines. Examples of heterocyclic secondary amines include, but are not limited to, 1,2,3,4-tetrahydroquinoline and 1,2,3,4-tetrahydroquinaldine. Examples of heterocyclic tertiary amines include, but are not limited to, quinoline, methylquinoline, quinaldine, and quinoxalinephenazine. Examples of aromatic tertiary amines include, but are not limited to, N,N-dimethyl-anisidine and N,N-dimethylaniline. These may be used alone or in combination of two or more.

[0077] Examples of azole compounds include, but are not limited to, thiazole, isothiazole, thiadiazole, oxazole, isoxazole, oxadiazole, diazole, triazole, etc. More specific examples of azole compounds include, but are not limited to, benzothiazole, 1,2,4-triazole, benzotriazole, hydroxybenzotriazole, benzoxazole, 1,2,3-benzothiadiazole, 3-mercaptobenzotriazole, etc. These may be used alone or in combination of two or more.

[0078] Examples of the mercaptan compound include, but are not limited to, linear mercaptans. Examples of linear mercaptans include, but are not limited to, n-dodecyl mercaptan, ethyl mercaptan, and butyl mercaptan. These may be used alone or in combination of two or more.

[0079] Examples of hydrazine compounds include, but are not limited to, 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), ethyl carbazate, p-nitrophenylhydrazine, and p-toluenesulfonylhydrazide. These compounds may be used alone or in combination of two or more. The hydrazine compound preferably contains at least one compound selected from the group consisting of the compounds exemplified above.

[0080] In one embodiment, the anaerobic curing catalyst (Component C) preferably contains a hydrazine compound, more preferably contains at least one compound selected from the group consisting of the hydrazine compounds exemplified above, and even more preferably contains 1-acetyl-2-phenylhydrazine. In one embodiment, the anaerobic curing catalyst (Component C) preferably contains a hydrazine compound having an acetyl group. In one embodiment, the hydrazine compound may be, for example, a hydrazine compound having an acetyl group, or may be 1-acetyl-2-phenylhydrazine.

[0081] The anaerobic curing catalyst may be used alone or in combination of two or more types. The component (C): anaerobic curing catalyst preferably contains at least one compound selected from the group consisting of the above-mentioned compounds. In one embodiment, the component (C): anaerobic curing catalyst is preferably saccharin and a hydrazine compound, more preferably at least one compound selected from the group consisting of saccharin and the hydrazine compounds exemplified above, and even more preferably saccharin and 1-acetyl-2-phenylhydrazine. In one embodiment, the component (C): anaerobic curing catalyst is preferably saccharin and a hydrazine compound having an acetyl group.

[0082] The content of component (C) in the anaerobic adhesive is not particularly limited. From the viewpoint of anaerobic curing property, the content of component (C) is preferably 0.01 to 40 parts by mass per 100 parts by mass of component (A). The content of component (C) may be 0.5 to 30 parts by mass or 1 to 25 parts by mass per 100 parts by mass of component (A). The content of component (C) may be, for example, 0.01 to 10 parts by mass or 0.01 to 5 parts by mass per 100 parts by mass of component (A). The content of component (C) may be, for example, 0.1 to 10 parts by mass or 0.1 to 5 parts by mass per 100 parts by mass of component (A). The content of component (C) may be, for example, 0.5 to 10 parts by mass or 0.5 to 5 parts by mass per 100 parts by mass of component (A). The content of the (C) component may be, for example, 1 to 10 parts by mass or 1 to 5 parts by mass per 100 parts by mass of the (A) component. When two or more types of the (A) component are used in combination, the amount of the (A) component represents the total amount thereof. When two or more types of the (C) component are used in combination, the amount of the (C) component represents the total amount thereof.

[0083] When saccharin and a hydrazine compound are combined, i.e., when the component (C) anaerobic curing catalyst contains saccharin and a hydrazine compound, the mass ratio of the saccharin to the hydrazine compound in the component (C) is not particularly limited. The mass ratio of the saccharin to the hydrazine compound in the component (C) is preferably saccharin:hydrazine compound = 10:90 to 90:10, more preferably saccharin:hydrazine compound = 20:80 to 80:20, even more preferably saccharin:hydrazine compound = 50:50 to 80:20, and particularly preferably saccharin:hydrazine compound = 60:40 to 75:25. When two or more hydrazine compounds are used in combination, the amount of the hydrazine compound refers to the total amount of these.

[0084] [Other Components in Anaerobic Adhesive] The anaerobic adhesive may or may not further contain one or more other components. The other components in the anaerobic adhesive are not particularly limited as long as they are components other than components (A) to (C). The anaerobic adhesive (anaerobic curing adhesive) may further contain an appropriate amount of one or more additives (one or more other components) such as stabilizers, inorganic fillers, organic fillers, silane coupling agents, light stabilizers, photosensitizers, polymerization inhibitors, and chelating agents, as long as the properties are not impaired. The anaerobic adhesive preferably further contains at least one additive selected from the group consisting of the additives exemplified above, and more preferably further contains a stabilizer.

[0085] The anaerobic adhesive may or may not further contain a stabilizer. The stabilizer may be used alone or in combination of two or more types. Examples of stabilizers include, but are not limited to, 2,6-di-t-butyl-p-cresol (also known as 2,6-di-tert-butyl-p-cresol), hydroquinone, hydroquinone monomethyl ether, and 4-t-butylcatechol (also known as 4-tert-butylcatechol). These may be used alone or in combination of two or more types. From the viewpoint of the storage stability of the adhesive, 2,6-di-t-butyl-p-cresol is preferably used as the stabilizer. The stabilizer preferably contains at least one compound selected from the group consisting of the compounds exemplified above. In one embodiment, the stabilizer is preferably at least one compound selected from the group consisting of the compounds exemplified above, and more preferably 2,6-di-t-butyl-p-cresol. In one embodiment, the content of the stabilizer is not particularly limited, but is preferably 0.1 to 5.0 mass% relative to the entire composition (total mass of the anaerobic adhesive), more preferably 0.2 to 3.0 mass%, and even more preferably 0.05 to 0.15 mass%. When two or more stabilizers are used in combination, the amount of stabilizer represents the total amount thereof.

[0086] The anaerobic adhesive may or may not further contain an inorganic filler. Examples of inorganic fillers include, but are not limited to, glass, silica, talc, alumina, mica, ceramics, silicone particles, calcium carbonate, aluminum nitride, carbon powder, kaolin clay, dried clay minerals, dried diatomaceous earth, etc. These may be used alone or in combination of two or more.

[0087] The anaerobic adhesive may or may not further contain an organic filler. Examples of organic fillers are not particularly limited, but may be organic powders composed of rubber, elastomer, plastic, and / or polymers (homopolymers and / or copolymers). These may be used alone, or two or more types may be used in combination. The organic filler may be an organic filler having a multilayer structure, such as a core-shell type. The average particle size of the organic filler is not particularly limited, but is preferably in the range of 0.05 to 50 μm.

[0088] The anaerobic adhesive may or may not further contain a silane coupling agent. Examples of the silane coupling agent are not particularly limited, but include glycidyl group-containing silane coupling agents, vinyl group-containing silane coupling agents, (meth)acrylic group-containing silane coupling agents, amino group-containing silane coupling agents, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, etc. Examples of glycidyl group-containing silane coupling agents include, but are not limited to, 3-acryloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldipropyloxysilane, 3-glycidoxypropyldimethylmonomethoxysilane, 3-glycidoxypropyldimethylmonoethoxysilane, 3-glycidoxypropyldimethylmonopropyloxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, etc. Examples of vinyl group-containing silane coupling agents include, but are not limited to, vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, vinyltrimethoxysilane, etc. Examples of the (meth)acrylic group-containing silane coupling agent are not particularly limited, but include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyldimethylmonomethoxysilane, 3-methacryloxypropyldimethylmonoethoxysilane, 3-acryloxypropylmethyldipropyloxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3-acryloxypropylmethyldipropyloxysilane, 3-acryloxypropyldimethylmonopropyloxysilane, 3-acryloxypropyldimethylmonomethoxysilane, 3-acryloxypropyldimethylmonoethoxysilane, 3-acryloxypropyldimethylmonopropyloxysilane, and γ-methacryloxypropyltrimethoxysilane.Examples of amino group-containing silane coupling agents include, but are not limited to, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. It is preferable that component (A) does not contain a (meth)acrylic-containing silane coupling agent. In this specification, component (A) does not contain a (meth)acrylic-containing silane coupling agent. In one embodiment, component (A) preferably does not contain a compound containing a silicon (Si) atom to which a hydroxyl group and / or a hydrolyzable group is bonded, and more preferably does not contain a compound containing a Si atom. In this specification, component (C) does not contain an amino group-containing silane coupling agent, and component (C) does not contain a mercapto group-containing silane coupling agent. In one embodiment, component (C) preferably does not contain a compound containing a silicon (Si) atom to which a hydroxyl group and / or a hydrolyzable group is bonded, and more preferably does not contain a compound containing a Si atom.

[0089] The anaerobic adhesive may or may not further contain at least one additive selected from the group consisting of a light stabilizer, a photosensitizer, a polymerization inhibitor, and a chelating agent. The anaerobic adhesive may not contain any of a light stabilizer, a photosensitizer, a polymerization inhibitor, and a chelating agent.

[0090] From the viewpoint of storage stability, it is preferable that the anaerobic adhesive (anaerobic curing adhesive) does not contain metal as a component. In this specification, "the anaerobic adhesive does not contain metal as a component" means that none of the components constituting the anaerobic adhesive contain metal elements. In one embodiment, it is preferable that the anaerobic adhesive does not contain metal elements. In this specification, "the anaerobic adhesive does not contain metal elements" means that the anaerobic adhesive contains metal elements only as unavoidable impurities, or does not contain any metal elements at all.

[0091] <Primer Composition> The primer composition according to this embodiment contains the component (D) and the component (E), but does not contain ethanol or acetone. The primer composition according to one embodiment is preferably used as a curing accelerator for an anaerobic adhesive containing the components (A) to (C). The primer composition according to one embodiment is preferably used in a bonding method for laminated steel sheets.

[0092] The primer composition has the function of accelerating the curing of the adhesive (anaerobic adhesive) by being applied to an adherend in advance before the application of the adhesive (anaerobic adhesive). As a result, the primer composition can shorten the curing time of the adhesive (anaerobic adhesive) and / or improve the adhesive strength.

[0093] The primer composition according to one embodiment can be suitably used by mixing it with a lubricating oil (for example, press working oil) used when punching laminated steel sheets.

[0094] As described above, the primer composition according to this embodiment contains a metal complex as component (D) and a solvent having a boiling point of 80°C or higher as component (E). Component (E) dissolves component (D). The primer composition according to one embodiment preferably does not contain a curing component such as a reactive resin. When the primer composition does not contain a curing component such as a reactive resin, the primer composition does not usually cure on its own.

[0095] [Component (D)] Component (D) is a metal complex. Component (D) is a major component constituting the primer composition that accelerates the curing of the adhesive. The metal complex may be used alone or in combination of two or more types.

[0096] Examples of the metal species in the (D) component:metal complex include, but are not limited to, Mg, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Ag, etc. The metal species in the metal complex may be used alone or in combination of two or more. The metal species in the metal complex preferably includes at least one selected from the group consisting of the metal species exemplified above. Among these, Cu is preferred from the viewpoint of further accelerating the curing rate of the adhesive. In one embodiment, the metal species in the (D) component:metal complex is preferably at least one selected from the group consisting of the metal species exemplified above, and more preferably Cu.

[0097] Specific examples of component (D) include, but are not limited to, cobalt naphthenate, cobalt octoate, copper naphthenate, copper neodecanoate, copper 2-ethylhexanoate, vanadyl acetylacetonate, and the like. These may be used alone or in combination of two or more. Among these, copper naphthenate, copper neodecanoate, and copper 2-ethylhexanoate are preferred examples from the viewpoint of further accelerating the curing rate of the anaerobic adhesive. The component (D) metal complex preferably contains at least one compound selected from the group consisting of the compounds exemplified above. In one embodiment, the component (D) metal complex is preferably at least one compound selected from the group consisting of the compounds exemplified above, more preferably at least one compound selected from the group consisting of copper naphthenate, copper neodecanoate, and copper 2-ethylhexanoate, and even more preferably copper neodecanoate.

[0098] The content of the component (D) in the primer composition according to one embodiment is not particularly limited. The content of the component (D) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, even more preferably 50 to 150 parts by mass, and particularly preferably 80 to 120 parts by mass, per 100 parts by mass of the component (E). The content of the component (D) may be 1 to 100 parts by mass or may be 0.1 to 10 parts by mass, per 100 parts by mass of the component (E). The primer composition according to one embodiment may contain 1 to 100 parts by mass of the component (D) per 100 parts by mass of the component (E), or may contain 0.1 to 10 parts by mass of the component (D) per 100 parts by mass of the component (E). When two or more types of the component (D) are used in combination, the amount of the component (D) refers to the total amount thereof. When two or more types of the component (E) are used in combination, the amount of the component (E) refers to the total amount thereof.

[0099] [Component (E)] Component (E) is a solvent with a boiling point of 80°C or higher. Various solvents can be used as component (E). When the primer composition contains two or more solvents, it is sufficient that at least one of the solvents has a boiling point of 80°C or higher, but it is preferable that all of the solvents have boiling points of 80°C or higher. In other words, it is preferable that the primer composition contains only solvents corresponding to component (E) as solvents. In this specification, boiling points are expressed as values ​​at 1 atmosphere (760 mmHg, 1013.25 hPa).

[0100] If the primer composition according to this embodiment contains at least one solvent selected from the group consisting of ethanol and acetone, the friction coefficient of the primer composition containing the curing accelerator and lubricating oil (e.g., press processing oil) tends to increase over time, which is undesirable. For this reason, the primer composition according to this embodiment does not contain ethanol or acetone. From the same perspective, the primer composition according to one embodiment preferably does not contain methanol, ethanol, or acetone, more preferably does not contain methanol, ethanol, acetone, or methyl ethyl ketone, even more preferably does not contain methanol, ethanol, acetone, methyl ethyl ketone, or hexane, even more preferably does not contain methanol, ethanol, acetone, methyl ethyl ketone, hexane, chloroform, carbon tetrachloride, ethyl acetate, or tetrahydrofuran (THF), and particularly preferably does not contain a solvent with a boiling point below 80 ° C.

[0101] From the viewpoint of dissolving and dispersing the metal complex, the lower limit of the boiling point of the component (E): solvent having a boiling point of 80°C or higher is preferably 80°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and particularly preferably 130°C or higher. The upper limit of the boiling point of the component (E): solvent having a boiling point of 80°C or higher is not particularly limited, but is preferably 250°C or lower. The boiling point of the component (E): solvent is preferably 80 to 250°C, more preferably 90 to 250°C, even more preferably 100 to 250°C, and particularly preferably 130 to 250°C.

[0102] The type of component (E) is not particularly limited, but from the viewpoint of the solubility and dispersibility of component (D), the type of component (E) is preferably an alcohol-based solvent and / or mineral spirits. In one embodiment, the component (E): solvent having a boiling point of 80°C or higher more preferably includes an alcohol-based solvent and / or mineral spirits, even more preferably includes an alcohol-based solvent and / or mineral spirits having a boiling point of 80°C or higher, and particularly preferably includes mineral spirits having a boiling point of 80°C or higher. In one embodiment, the component (E): solvent may be an alcohol-based solvent having a boiling point of 80°C or higher and / or mineral spirits having a boiling point of 80°C or higher, or may be mineral spirits having a boiling point of 80°C or higher.

[0103] Specific examples of alcohol-based solvents having a boiling point of 80°C or higher include, but are not limited to, propanol, butanol, hexanol, octanol, cyclohexanol, and methylcyclohexanol. Examples of propanol include 1-propanol and isopropanol (also known as 2-propanol). Examples of butanol include 1-butanol, 2-butanol, isobutanol, and tert-butanol. These alcohol-based solvents having a boiling point of 80°C or higher can be used alone or in combination of two or more. Component (E): The solvent having a boiling point of 80°C or higher preferably contains at least one compound selected from the group consisting of the compounds exemplified above, more preferably contains at least one compound selected from the group consisting of propanol, butanol, hexanol, and octanol, even more preferably contains at least one compound selected from the group consisting of 1-propanol, 1-butanol, 1-hexanol, and 1-octanol, even more preferably contains at least one compound selected from the group consisting of 1-butanol, 1-hexanol, and 1-octanol, still more preferably contains at least one compound selected from the group consisting of 1-hexanol and 1-octanol, and particularly preferably contains 1-hexanol or 1-octanol.

[0104] In this specification, mineral spirits refers to a mixture containing hydrocarbons having 9 to 16 carbon atoms, and is a mixture of aliphatic hydrocarbons and aromatic hydrocarbons. There are no particular limitations on the mineral spirits, but a mixture of hydrocarbon compounds having a boiling point of 80°C or higher is preferred, a mixture of hydrocarbon compounds having a boiling point of 100 to 300°C is more preferred, and a mixture of hydrocarbon compounds having a boiling point of 130 to 230°C is even more preferred.

[0105] The solvent having a boiling point of 80°C or higher may be used alone or in combination of two or more. The component (E): solvent having a boiling point of 80°C or higher preferably contains at least one compound selected from the group consisting of the above-mentioned compounds. In one embodiment, the component (E): solvent having a boiling point of 80°C or higher is more preferably a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C, or a combination of a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C with at least one compound selected from the group consisting of propanol, butanol, hexanol, and octanol. In one embodiment, the component (E): solvent having a boiling point of 80°C or higher is more preferably a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C, or a combination of a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C with at least one compound selected from the group consisting of 1-propanol, 1-butanol, 1-hexanol, and 1-octanol. In one embodiment, it is more preferred that the component (E): solvent having a boiling point of 80°C or higher is a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C, or a combination of a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C with at least one compound selected from the group consisting of 1-butanol, 1-hexanol, and 1-octanol. In one embodiment, it is more preferred that the component (E): solvent having a boiling point of 80°C or higher is a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C, or a combination of a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C with at least one compound selected from the group consisting of 1-hexanol and 1-octanol. In one embodiment, it is more preferred that the component (E): solvent having a boiling point of 80°C or higher is a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C, or a combination of a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C with 1-hexanol or 1-octanol. In one embodiment, component (E): a solvent having a boiling point of 80°C or higher is particularly preferably a mixture of hydrocarbon compounds having a boiling point in the range of 130 to 230°C.

[0106] The content of component (E) in the primer composition according to one embodiment is not particularly limited. The content of component (E) is preferably 0.1% by mass or more but less than 100% by mass, more preferably 1% by mass or more but less than 100% by mass, even more preferably 1 to 10% by mass, and particularly preferably 1 to 5% by mass, relative to the total mass of the primer composition. When two or more types of component (E) are used in combination, the amount of component (E) refers to the total amount of these.

[0107] [Component (F)] The primer composition according to one embodiment may further include a lubricating oil as component (F). The primer composition according to one embodiment does not necessarily include component (F): a lubricating oil. Even when the primer composition according to one embodiment includes component (F), the friction coefficient, which is a characteristic value related to the properties of component (F), is not significantly reduced. Therefore, even when using a primer composition containing component (F), metal processing can be performed more stably. Component (F): a lubricating oil may be used alone or in combination with two or more types. In the primer composition according to one embodiment, component (F) is preferably a component other than component (E). Component (F) may be free of alcohol-based solvents with a temperature of 80°C or higher, mineral spirits with a temperature of 80°C or higher, or mineral spirits with a boiling point of 80°C or higher. Component (F) may be free of alcohol-based solvents, mineral spirits, or alcohol-based solvents and mineral spirits.

[0108] The type of component (F) is not particularly limited, but is preferably a press processing oil. In this specification, press processing oil refers to a base oil mixed with additives such as an ashless dispersant, an antioxidant, a metal tarnish inhibitor, an extreme pressure agent, a friction modifier, a viscosity index improver, and / or an antifoaming agent. Examples of base oils include, but are not limited to, mineral oil, synthetic oil, and lubricating oil (an oil that can function as a general lubricating oil on its own). Press processing oils may be used alone or in combination of two or more types. In one embodiment, the lubricating oil for component (F) preferably contains a press processing oil, and is more preferably a press processing oil. Component (F) may be a commercially available product, a synthetic product, or a combination of these. Commercially available press processing oils include, but are not limited to, G6339F manufactured by Nippon Kogyo Oil Co., Ltd.

[0109] When the primer composition according to one embodiment includes component (F), the content of component (F) in the primer composition is not particularly limited. The content of component (F) is preferably 1% by mass or more but less than 100% by mass, more preferably 10% by mass or more but less than 100% by mass, even more preferably 20% by mass or more but less than 100% by mass, even more preferably 30% by mass or more but less than 100% by mass, and particularly preferably 40% by mass or more but less than 100% by mass, relative to the total mass of the primer composition. The content of component (F) may be 1 to 90% by mass, 10 to 80% by mass, 20 to 70% by mass, 30 to 60% by mass, or 40 to 50% by mass, relative to the total mass of the primer composition. When two or more types of component (F) are used in combination, the amount of component (F) refers to the combined amount of these components.

[0110] [Other Components in Primer Composition] The primer composition according to one embodiment may or may not further contain one or more other components. The other components in the primer composition according to one embodiment are not particularly limited as long as they are components other than the above-mentioned components (D) to (F). As mentioned above, the primer composition according to one embodiment preferably does not contain a solvent having a boiling point of less than 80°C. As mentioned above, the primer composition according to one embodiment preferably does not contain a curing component. Examples of the curing component include, but are not particularly limited to, a reactive resin.

[0111] <Adhesive Composition Kit> The primer composition according to the above embodiment is preferably used in a bonding composition kit including the anaerobic adhesive and the primer composition. That is, the primer composition according to the above embodiment is preferably used in a bonding composition kit including the anaerobic adhesive containing the above components (A) to (C) and the primer composition. Therefore, another embodiment of the present invention relates to a bonding composition kit including the anaerobic adhesive containing the above components (A) to (C) and a primer composition containing the above components (D) and (E) and not containing ethanol or acetone. The bonding composition kit according to this embodiment can improve the curing rate and adhesive strength of the anaerobic adhesive while suppressing performance degradation (decrease in lubrication performance over time) of a primer composition containing a curing accelerator and a lubricating oil (e.g., press processing oil, etc.). In the bonding composition kit according to this embodiment, the primer composition and the anaerobic adhesive are present separately. The anaerobic adhesive and primer composition in the bonding composition kit according to this embodiment are the same as those described for the primer composition according to the above embodiment. In the bonding composition kit according to this aspect, preferred embodiments of the anaerobic adhesive and preferred embodiments of the primer composition are also the same as those described in the primer composition according to the above aspect.

[0112] <Uses> The primer composition according to the above embodiment and the adhesive composition kit according to the above embodiment can each be used, for example, for fitting and / or laminating when the adherend is metal. Examples of the adherend include, but are not limited to, steel plate (e.g., electromagnetic steel plate), welch plugs, etc. Examples of metal include, but are not limited to, SPCC (Steel Plate Cold Commercial) (cold-rolled steel plate), copper, etc.

[0113] Depending on the type of metal, there may be cases where anaerobic adhesives (anaerobic curing adhesives) are not normally suitable. However, even for such types of metal, by applying the primer composition according to the above embodiment or the primer composition in the adhesive composition kit according to the above embodiment and using the primer composition in combination with an anaerobic adhesive (anaerobic curing adhesive), it may be possible to promote the curing of the anaerobic adhesive and improve the adhesive strength of the anaerobic adhesive.

[0114] Specific examples of applications in which the primer composition according to the above embodiment and the adhesive composition kit according to the above embodiment are used include, but are not limited to, threading of spark plugs, assembly of laminated steel sheets and / or laminated molds for rotors for rotating electrical machines, assembly of laminated steel sheets and / or laminated molds for solenoids, etc. Among these, the primer composition according to the above embodiment and the adhesive composition kit according to the above embodiment can each be suitably used for assembling laminated steel sheets.

[0115] <Laminate Manufacturing Method Using Primer Composition, and Laminate> The primer composition according to the above aspect is preferably used in a laminate manufacturing method. The adhesive composition kit according to the above aspect is preferably used in a laminate manufacturing method. In this case, the laminate manufacturing method preferably includes applying the primer composition according to the above aspect to an adherend, applying an anaerobic adhesive to the adherend, the primer composition coating, or both, and, after applying the primer composition and the anaerobic adhesive, bonding the adherend to an adherend to be bonded, and then curing the anaerobic adhesive. Therefore, another aspect of the present invention can also be said to relate to a laminate manufacturing method including applying the primer composition according to the above aspect to an adherend, applying an anaerobic adhesive to the adherend, the primer composition coating, or both, and, after applying the primer composition and the anaerobic adhesive, bonding the adherend to an adherend to be bonded, and then curing the anaerobic adhesive. According to the method for manufacturing a laminate according to the above aspect, it is possible to improve the curing rate and adhesive strength of an anaerobic adhesive while suppressing deterioration in performance (decrease in lubricating performance over time) of a primer composition containing a curing accelerator and a lubricating oil (e.g., press processing oil, etc.).

[0116] Examples of the laminate are not particularly limited, but are preferably laminates containing a plurality of steel sheets, and more preferably laminates containing a plurality of electromagnetic steel sheets. The method for producing a laminate according to one embodiment is preferably a method for producing a laminated steel sheet. In this case, the method for producing a laminated steel sheet preferably includes: applying the primer composition according to the above-described embodiment to a steel sheet (preferably an electromagnetic steel sheet); applying an anaerobic adhesive to the steel sheet, the coating of the primer composition, or both; and, after applying the primer composition and the anaerobic adhesive, laminating the steel sheet and a steel sheet (preferably an electromagnetic steel sheet) to be laminated; and then curing the anaerobic adhesive to obtain a laminate. Thus, an example of a method for producing a laminate according to one embodiment includes, but is not limited to, a method for producing a laminated steel sheet, which includes applying the primer composition according to the above aspect to a steel sheet (preferably an electromagnetic steel sheet), applying an anaerobic adhesive to the steel sheet, the coating of the primer composition, or both, and, after applying the primer composition and the anaerobic adhesive, laminating the steel sheet with a steel sheet (preferably an electromagnetic steel sheet) to be laminated, and then curing the anaerobic adhesive to obtain a laminate. In the method for producing a laminate according to one embodiment (preferably a method for producing a laminated steel sheet), the anaerobic adhesive preferably contains components (A) to (C).

[0117] The primer composition coating may be partially or completely dried and / or cured. The primer composition coating may be dried and / or cured to an extent that allows, for example, lamination of an anaerobic adhesive. The anaerobic adhesive may be applied to (i.e., directly on) the surface of the adherend (preferably a steel sheet, particularly preferably an electromagnetic steel sheet), to (i.e., directly on) the surface of the primer composition coating, or to both. The adherend to be bonded (preferably a steel sheet, particularly preferably an electromagnetic steel sheet) may be coated with a primer composition, an anaerobic adhesive, or both. When the adherend to be bonded (preferably a steel sheet, particularly preferably an electromagnetic steel sheet) is coated with both a primer composition and an anaerobic adhesive, the primer composition coating and the anaerobic adhesive coating may be present on different sides of the adherend, or may be laminated on the same side of the adherend.

[0118] The primer composition according to the above embodiment and the adhesive composition kit according to the above embodiment are particularly suitable for use in a method for manufacturing a laminated steel sheet, which is formed by laminating a predetermined number of thin steel sheets punched into a predetermined shape from a steel strip. The method for manufacturing a laminate using the primer composition according to the above embodiment or the adhesive composition kit according to the above embodiment is not particularly limited. Examples of methods for manufacturing a laminated steel sheet using the primer composition according to the above embodiment or the adhesive composition kit according to the above embodiment include, but are not limited to, methods including the following steps 1 to 4. Step 1: The primer composition is applied to a steel strip. Step 2: The steel strip coated with the primer composition is punched into a predetermined shape to obtain a thin steel sheet. Step 3: An anaerobic adhesive (anaerobic curing adhesive) is applied in a planar or dotted pattern to the thin steel sheet coated with the primer composition, and the thin steel sheet is laminated with another thin steel sheet (a thin steel sheet to be laminated). Step 4: The anaerobic adhesive (anaerobic curing adhesive) is cured under predetermined conditions to obtain a laminated steel sheet. In step 3, the anaerobic adhesive may be applied to the surface of the adherend (i.e., directly on top of it), to the surface of the applied primer composition (i.e., directly on top of it), or to both. The applied primer composition may be partially or completely dried and / or cured. The applied primer composition (i.e., primer composition coating) may be dried and / or cured to an extent that allows, for example, the anaerobic adhesive to be laminated. In step 3, the steel sheet to be laminated may be coated with a primer composition, an anaerobic adhesive, or both. When the steel sheet to be laminated is a steel sheet coated with both a primer composition and an anaerobic adhesive, the primer composition coating and the anaerobic adhesive coating may be present on different sides of the steel sheet, or may be laminated on the same side of the steel sheet. Step 4, which is performed after step 3, is a step in which the anaerobic adhesive is cured under predetermined conditions to obtain a laminated steel sheet. The curing of the anaerobic adhesive in step 4 is carried out in a laminate including the thin steel sheets coated with the primer composition, the anaerobic adhesive, and the thin steel sheets to be laminated.

[0119] It is preferable to insert a drying step between step 1 and step 2, and / or between step 2 and step 3. The drying temperature in the drying step is not particularly limited, but is preferably 10 to 50° C., more preferably 15 to 40° C., and even more preferably 20 to 30° C. The total drying time in the drying step is not particularly limited, but is preferably 5 seconds to 5 hours, more preferably 5 seconds to 2 hours, and even more preferably 10 seconds to 1.5 hours.

[0120] The materials constituting the two or more adherends to be bonded together are not particularly limited, but it is preferable that at least a part of the materials be common, and it is particularly preferable that the materials be the same.

[0121] The bonding of adherends (preferably steel sheets, particularly preferably electromagnetic steel sheets) is not particularly limited, but is preferably performed, for example, so that the surface of the anaerobic adhesive layer of an adherend having an anaerobic adhesive layer (e.g., an anaerobic adhesive coating film, etc.) on its outermost surface faces one side of the adherend to be bonded. The bonding of adherends may also be performed so that the surface of the anaerobic adhesive layer of an adherend having an anaerobic adhesive layer on its outermost surface faces the surface of the layer obtained from the primer composition of an adherend having a layer obtained from the primer composition (e.g., a primer composition coating film, etc.) on its outermost surface. In an adherend having an anaerobic adhesive layer on its outermost surface, it is preferable that the adherend and the layer obtained from the primer composition are in contact, and that the layer obtained from the primer composition and the anaerobic adhesive layer are in contact.

[0122] After bonding the two or more adherends together, the anaerobic adhesive is cured. The curing method will be described later. The method for producing a laminate according to one embodiment may further include other operations and / or steps.

[0123] The anaerobic adhesive used in the method for producing a laminate according to the above aspect may be the same as that described for the primer composition according to the above aspect. A preferred embodiment of the anaerobic composition used in the method for producing a laminate according to the above aspect may also be the same as that described for the primer composition according to the above aspect. The primer composition used in the method for producing a laminate according to the above aspect is the same as that described for the primer composition according to the above aspect. A preferred embodiment of the primer composition used in the method for producing a laminate according to the above aspect is also the same as that described for the primer composition according to the above aspect.

[0124] Another aspect of the present invention relates to a laminate produced using the primer composition or adhesive composition kit according to the above aspect, or by the laminate production method according to the above aspect. Examples of the laminate are not particularly limited. The laminate is preferably a laminate including a plurality of steel sheets, more preferably a laminate including a plurality of electrical steel sheets. The laminate is particularly preferably a laminated steel sheet.

[0125] The anaerobic adhesive used in the laminate according to the above aspect may be the same as that described for the primer composition according to the above aspect. A preferred embodiment of the anaerobic composition used in the laminate according to the above aspect may also be the same as that described for the primer composition according to the above aspect. The primer composition used in the laminate according to the above aspect is the same as that described for the primer composition according to the above aspect. A preferred embodiment of the primer composition used in the laminate according to the above aspect is also the same as that described for the primer composition according to the above aspect. A manufacturing method for obtaining the laminate according to the above aspect and a preferred embodiment thereof are the same as those described for the manufacturing method of the laminate according to the above aspect.

[0126] <Method for Accelerating the Cure of an Anaerobic Adhesive Using a Primer Composition> The primer composition according to the above aspect and the adhesive composition kit according to the above aspect are preferably used in a method for accelerating the curing of an anaerobic adhesive. In this case, the method for accelerating the curing of an anaerobic adhesive preferably includes curing the anaerobic adhesive while a coating film of the primer composition according to the above aspect and an anaerobic adhesive containing the above components (A) to (C) are in contact with each other. Therefore, another aspect of the present invention can also be said to be a method for accelerating the curing of an anaerobic adhesive, including curing the anaerobic adhesive while a coating film of the primer composition according to the above aspect and an anaerobic adhesive containing the above components (A) to (C) are in contact with each other. The method for accelerating the curing of an anaerobic adhesive according to one embodiment preferably includes applying the primer composition according to the above aspect; applying an anaerobic adhesive containing the above components (A) to (C) in contact with the coating film of the primer composition; and curing the anaerobic adhesive after applying the anaerobic adhesive. According to the method for accelerating the cure of an anaerobic adhesive according to this embodiment, it is possible to improve the cure rate and adhesive strength of the anaerobic adhesive while suppressing performance degradation (decrease in lubrication performance over time) of a primer composition containing a cure accelerator and a lubricating oil (e.g., press processing oil, etc.). The coating of the primer composition may be partially or completely dried and / or cured. The coating of the primer composition may be dried and / or cured, for example, to the extent that the anaerobic adhesive can be laminated. The curing method will be described later. The method for accelerating the cure of an anaerobic adhesive according to one embodiment may further include other operations and / or other steps.

[0127] The anaerobic adhesive and primer composition in the cure acceleration method according to this aspect are the same as those described for the primer composition according to the above aspect. Preferred embodiments of the anaerobic adhesive and primer composition in the cure acceleration method according to this aspect are also the same as those described for the primer composition according to the above aspect.

[0128] <Curing Method> Examples of curing methods for anaerobic adhesives (anaerobic curing adhesives) include, but are not limited to, room temperature anaerobic curing, heated anaerobic curing, and the like. The curing rate of the anaerobic adhesive (anaerobic curing adhesive) can be significantly improved by using the primer composition according to the above-described embodiment, the primer composition in the adhesive composition kit according to the above-described embodiment, or the primer composition in the curing acceleration method according to the above-described embodiment in combination. Therefore, in a preferred embodiment, the anaerobic adhesive may be cured at room temperature. The curing temperature is not particularly limited, but may be, for example, a temperature within a range of 20 to 25°C, or even 25°C. The curing time is not particularly limited. In a preferred embodiment, the anaerobic adhesive may be cured in 30 minutes to 24 hours. The curing time may be, for example, 30 minutes to 2 hours.

[0129] <Methods for Producing Primer Composition and Adhesive Composition Kit> Another aspect of the present invention relates to a method for producing a primer composition, the method comprising mixing the above-mentioned component (D) and the above-mentioned component (E), but not including ethanol or acetone, the primer composition being a curing accelerator for an anaerobic adhesive, and the anaerobic adhesive comprising the above-mentioned components (A) to (C). The primer composition produced by the method according to this aspect can improve the curing rate and adhesive strength of the anaerobic adhesive while suppressing performance degradation (decrease in lubrication performance over time) of a primer composition containing a curing accelerator and a lubricating oil (e.g., press processing oil). The method for producing a primer composition according to one embodiment preferably does not include the mixing of a specific solvent having a boiling point below 80°C, as described in the description of the primer composition according to the above-mentioned aspect, and preferably does not include the mixing of a solvent having a boiling point below 80°C. The method for producing a primer composition according to one embodiment preferably further comprises mixing the above-mentioned component (F). The method for producing a primer composition according to one embodiment may further include mixing one or more other components (one or more other components in the primer composition described above) as necessary. The primer composition according to the above embodiment is preferably produced by the method for producing a primer composition according to this aspect.

[0130] Another aspect of the present invention relates to a method for producing a bonding composition kit, the method comprising producing a primer composition by the method for producing a primer composition according to the above-described aspect, and producing an anaerobic adhesive by a method comprising mixing the above-described components (A) to (C). The bonding composition kit produced by the method according to this aspect can improve the cure rate and adhesive strength of the anaerobic adhesive while suppressing performance degradation (decrease in lubrication performance over time) of a primer composition containing a curing accelerator and a lubricating oil (e.g., press processing oil). The method for producing a primer composition according to one embodiment preferably does not include mixing the specific solvent with a boiling point below 80°C, as described in the description of the primer composition according to the above-described aspect, and preferably does not include mixing a solvent with a boiling point below 80°C. The method for producing an anaerobic adhesive according to one embodiment may further include mixing one or more other components (one or more other components of the anaerobic adhesive) as necessary. The method for producing a bonding composition kit according to the above-described aspect is preferably produced by the method for producing a bonding composition kit according to this aspect.

[0131] In the production methods according to these aspects, the type and amount of each raw material used for the anaerobic adhesive may be the same as the type and amount of each component of the anaerobic adhesive described in the description of the primer composition according to the above aspect. In the production methods according to these aspects, the type and amount of each raw material used for the primer composition may be the same as the type and amount of each raw material used for the primer composition according to the above aspect. In the production methods according to these aspects, the preferred embodiments of the type and amount of each raw material used for the anaerobic adhesive may also be the same as the preferred embodiments of the type and amount of each component of the anaerobic adhesive described in the description of the primer composition according to the above aspect. In the production methods according to these aspects, the preferred embodiments of the type and amount of each raw material used for the primer composition may also be the same as the preferred embodiments of the type and amount of each raw material used for the primer composition according to the above aspect.

[0132] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0133] [Examples 1 to 5, Comparative Examples 1 to 3] <Preparation of anaerobic adhesive (anaerobic curing adhesive)> Components (A) to (C) and other components were weighed, and these components were stirred in a mixer for 60 minutes to obtain an anaerobic curing adhesive. Specifically, (A-1), (A-2), (A-3), component (B), (C-1), (C-2), and other component (2,6-di-t-butyl-p-cresol) were weighed, and these were mixed by stirring in a mixer for 60 minutes to obtain an anaerobic curing adhesive.

[0134] <Preparation of Primer Composition> Primer compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were each prepared. Specifically, component (D) was added to component (E) or (E'), and the mixture was stirred in a mixer for 30 minutes. Component (F) was then added to the resulting mixture, and the mixture was stirred in a mixer for 30 minutes. The detailed amounts prepared were as shown in Table 1. In Table 1, all numerical values ​​for the amount of each ingredient in the primer composition are expressed in parts by mass. A blank space for the amount of each ingredient in Table 1 indicates that the primer composition does not contain that ingredient.

[0135] The details of the materials used are as follows:

[0136] [Materials for Anaerobic Curing Adhesive] <Component (A)> Oligomer having one or more (meth)acryloyl groups in the molecule (A-1): 45 parts by mass of urethane-modified acrylate having two acryloyl groups at both ends (A-2): 20 parts by mass of epoxy-modified acrylate having two acryloyl groups at both ends Monomer having one or more (meth)acryloyl groups in the molecule (A-3): 35 parts by mass of 2-hydroxyethyl methacrylate.

[0137] Here, (A-1) was a urethane-modified acrylate having two acryloyl groups at both ends and a polyether skeleton, and (A-2) was an epoxy-modified acrylate having two acryloyl groups at both ends and a bisphenol A skeleton.

[0138] <Component (B)> (B): cumene hydroperoxide 1 part by mass <Component (C)> (C-1): saccharin 1.5 parts by mass (C-2): 1-acetyl-2-phenylhydrazine 0.5 parts by mass <Other Components> 2,6-di-t-butyl-p-cresol 0.1 parts by mass.

[0139] [Materials of Primer Composition] <Component (D)> (D): Copper neodecanoate <Component (E)> (E-1): Mineral spirits (a mixture of hydrocarbon solvents (hydrocarbon compounds) having a boiling point in the range of 130 to 230°C) (E-2): Octanol (specifically, 1-octanol), boiling point 194°C (E-3): Hexanol (specifically, 1-hexanol), boiling point 157°C (E-4): Butanol (specifically, 1-butanol), boiling point 117°C (E-5): Propanol (specifically, 1-propanol), boiling point 97°C <Component (E')> (E'-1): Ethanol, boiling point 78.5°C (E'-2): Acetone, boiling point 56°C <Component (F)> (F): Press processing oil (G6339F, manufactured by Nippon Kogyo Oil Co., Ltd.).

[0140]

[0141] <Evaluation of Primer Composition> Each evaluation in Table 1 was carried out by the following method.

[0142] [Maximum Friction Coefficient (Initial and After 30 Minutes)] 1 g of each primer composition was dropped onto an SPCC-SD test piece measuring 25 mm wide, 100 mm long, and 1.6 mm thick, and spread with a rag to prepare a test specimen. A metal cylinder was pressed vertically against the prepared test specimen (load 200 N), and the test specimen was subjected to 400 horizontal reciprocating movements over 30 minutes to measure the friction coefficient. The maximum value of the friction coefficient from 0 to 5 minutes was defined as the initial maximum friction coefficient, and the maximum value of the friction coefficient from 30 to 35 minutes after 30 minutes was defined as the maximum friction coefficient after 30 minutes. The test was performed using a vibration friction and wear tester manufactured by Shinto Scientific Co., Ltd., and the test method was in accordance with ASTM D6425. The maximum friction coefficient after 30 minutes is preferably less than 0.2, more preferably less than 0.15.

[0143] [Shear Adhesion Strength] 0.1 g of each primer composition was applied to an SPCC-SD test piece measuring 25 mm wide x 100 mm long x 1.6 mm thick, and the primer composition was allowed to dry at 25°C for 1 hour. Next, 0.1 g of the anaerobic adhesive prepared above was applied to the primer-treated test piece, and the other primer-treated test piece was overlapped so that the long edge end was 10 mm long and fixed at 25°C for 1 hour to obtain an adhesive test piece. Next, the end of the adhesive test piece was pulled at a pulling rate of 50 mm / min using a universal tensile tester, and the tensile shear adhesive strength (shear adhesive strength) (unit: MPa) was measured in accordance with JIS K6850 (1999). When using an anaerobic curing adhesive and primer composition, a shear adhesive strength of 20 MPa or more was considered acceptable.

[0144] For Comparative Example 3, the shear bond strength was measured in the same manner as above, except that the press processing oil was applied instead of the primer composition. For Reference Example 1, the shear bond strength was measured in the same manner as above, except that the primer composition was not applied and dried, and an unprimed test piece was used to obtain an adhesive test piece. For Reference Example 1, the shear bond strength of the adhesive test piece obtained by fixing at 25°C for 24 hours was confirmed to be 17 MPa.

[0145] As shown in Table 1, the primer compositions of Examples 1 to 5, which did not contain ethanol or acetone, maintained good maximum friction coefficients, a characteristic value related to the properties of the press processing oil, even after 30 minutes had elapsed. On the other hand, the primer compositions of Comparative Example 1, which contained ethanol, and Comparative Example 2, which contained acetone, showed a significant increase in maximum friction coefficient after 30 minutes, indicating that the performance of the press processing oil (lubrication performance in the state of a mixture containing a cure accelerator and press processing oil) deteriorated over time.

[0146] In the case of Comparative Example 3, in which no primer composition was used and only press processing oil was used instead of the primer composition, no shear bond strength was exhibited one hour after lamination using the anaerobic adhesive. Furthermore, in the case of Reference Example 1, in which bonding was performed using only the anaerobic adhesive without using the primer composition, the shear bond strength one hour after lamination using the anaerobic adhesive was significantly low.

[0147] In addition, in the case of Reference Example 1, the shear adhesive strength was 17 MPa in the measurement using the adhesive test piece obtained by fixing at 25° C. for 24 hours. On the other hand, in Examples 1 to 5, higher shear adhesive strength values ​​were obtained in the measurement using the adhesive test piece that had been fixed for a shorter time.

[0148] From the above, it was confirmed that the use of a primer composition that does not contain a solvent with a boiling point of less than 80°C contributes to accelerating the cure of anaerobic adhesives and improving the shear adhesive strength without causing a decrease in the performance of the press processing oil (the lubrication performance of the mixture containing the cure accelerator and press processing oil) over time.

[0149] In the present invention, the primer composition suppresses an increase in the coefficient of friction of a primer composition containing a curing accelerator and a lubricating oil (e.g., press processing oil) during the assembly of laminated steel sheets, and also improves the curing speed and adhesive strength of the anaerobic curing adhesive, thereby enabling more efficient production of laminated steel sheets and being extremely useful industrially.

[0150] This application is based on Japanese Patent Application No. 2023-213833, filed on December 19, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A primer composition which is an anaerobic adhesive curing accelerator containing the following components (A) to (C), comprising the following component (D) and component (E), and which does not contain ethanol or acetone; Component (A): a compound having one or more (meth)acryloyl groups; Component (B): an organic peroxide; Component (C): an anaerobic curing catalyst; Component (D): a metal complex; and Component (E): a solvent having a boiling point of 80°C or higher.

2. The primer composition according to claim 1, which does not contain any solvent having a boiling point of less than 80°C.

3. The primer composition according to claim 1 or 2, further comprising a lubricating oil as component (F).

4. The primer composition according to claim 3, wherein the component (F) is a press processing oil.

5. The primer composition according to claim 1 or 2, wherein component (E) is an alcohol-based solvent and / or mineral spirits.

6. The primer composition according to claim 1 or 2, which is used in an anaerobic adhesive, wherein the component (A) contains one or more compounds selected from the group consisting of urethane-modified (meth)acrylates, epoxy-modified (meth)acrylates, and (meth)acrylates having an aromatic ring.

7. The primer composition according to claim 1 or 2, comprising 0.1 to 10 parts by mass of the (D) component per 100 parts by mass of the (E) component.

8. The primer composition according to claim 1 or 2, which is used for assembling laminated steel plates.

9. A method for manufacturing a laminate, comprising: applying the primer composition according to claim 1 or 2 to an adherend; applying an anaerobic adhesive to the adherend, a coating of the primer composition, or both; and, after applying the primer composition and the anaerobic adhesive, laminating the adherend with an adherend to be laminated, and then curing the anaerobic adhesive.

10. The manufacturing method according to claim 9, wherein the anaerobic adhesive comprises the components (A) to (C).

11. A method for manufacturing a laminated steel sheet, comprising: applying the primer composition according to claim 1 or 2 to an electromagnetic steel sheet; applying an anaerobic adhesive to the electromagnetic steel sheet, a coating of the primer composition, or both; and, after applying the primer composition and the anaerobic adhesive, laminating the electromagnetic steel sheet and an electromagnetic steel sheet to be laminated, and then curing the anaerobic adhesive to obtain a laminate.

12. The manufacturing method according to claim 11, wherein the anaerobic adhesive comprises the components (A) to (C).

13. An adhesive composition kit comprising an anaerobic adhesive containing the following components (A) to (C) and the primer composition according to claim 1 or 2; component (A): a compound having one or more (meth)acryloyl groups; component (B): an organic peroxide; and component (C): an anaerobic curing catalyst.

14. A method for accelerating the curing of an anaerobic adhesive, comprising curing an anaerobic adhesive in a state in which the anaerobic adhesive is in contact with a coating film of the primer composition according to claim 1 or 2 and the anaerobic adhesive contains the following components (A) to (C); Component (A): a compound having one or more (meth)acryloyl groups, Component (B): an organic peroxide, and Component (C): an anaerobic curing catalyst.

15. A method for producing a primer composition, the method comprising mixing the following component (D) and component (E), but not mixing ethanol or mixing acetone, the primer composition being a curing accelerator for an anaerobic adhesive, the anaerobic adhesive comprising the following components (A) to (C): component (A): a compound having one or more (meth)acryloyl groups, component (B): an organic peroxide, component (C): an anaerobic curing catalyst, component (D): a metal complex, and component (E): a solvent having a boiling point of 80°C or higher.

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