Primer composition, production method for laminate, production method for laminated steel sheet, and adhesive composition kit

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 curable adhesive agent. The present disclosure relates to a primer composition containing an (A) component and a (B) component, wherein the (A) component contains an (A-1) metal complex, and the (A) component content is 35 parts by mass per 100 parts by mass of the (B) component.　(A) component: a curing accelerator for an anaerobic curing adhesive agent (B) component: a lubricating oil

Description

Primer composition, method for manufacturing laminate, method for manufacturing laminated steel sheet, and adhesive composition kit

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

[0002] Currently, motors and stators are manufactured by stacking steel sheets to obtain a laminated steel sheet. While this laminated steel sheet can be assembled using laser welding and / or crimping, the trend toward thinner laminated steel sheets due to the increasing power output of motors has led to the adoption of an assembly method using 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 a press processing oil containing a hardening accelerator is applied to a steel sheet, and the applied steel sheet and another steel sheet coated with an adhesive are then stacked and assembled (see Japanese Patent Laid-Open Publication No. 2006-334648).

[0003] However, while conventional curing accelerators added to press processing oils improve the curing speed of adhesives, there are concerns that they may degrade the properties (performance) of the press processing oil. In particular, conventional curing accelerators have the problem of increasing the friction coefficient of the press processing oil (deteriorating its lubrication performance) over time, which can lead to the problem of seizure during processing of metals, etc.

[0004] Therefore, an object of the present invention is to provide a method for improving the cure rate and adhesive strength of an anaerobic curing 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 curing 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-mentioned objects relates to: [1] a primer composition comprising the following component (A) and component (B), wherein component (A) comprises an (A-1) metal complex, and the amount of component (A) is 35 parts by mass or less per 100 parts by mass of component (B); component (A): a curing accelerator for an anaerobic curing adhesive; and component (B): a lubricating oil.

[0008] The present invention also includes the following embodiments [2] to [8] as non-limiting examples of preferred embodiments.

[0009] [2] The primer composition according to [1], wherein the amount of the component (A) is 0.1 to 35 parts by mass per 100 parts by mass of the component (B).

[0010] [3] The primer composition according to [1] or [2], wherein the component (A) further contains a solvent (A-2).

[0011] [4] The primer composition according to [3], wherein the component (A) consists solely of the components (A-1) and (A-2).

[0012] [5] The primer composition according to [3] or [4], wherein (A-2) is a ketone-based solvent and / or an alcohol-based solvent.

[0013] [6] The primer composition according to any one of [1] to [5], wherein the anaerobic curing adhesive 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], which is used for assembling laminated steel sheets.

[0015] [8] The primer composition according to any one of [1] to [7], wherein the component (B) is a press processing oil.

[0016] Another aspect of the present invention that can achieve at least one of the above objects relates to [9] a primer composition comprising the following components (A-1), (A-2), and (B), wherein the total of (A-1) and (A-2) is 35 parts by mass or less per 100 parts by mass of component (B): (A-1): metal complex (A-2): solvent Component (B): lubricating oil.

[0017] The present invention also includes the following embodiments

[10] to

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

[0018]

[10] The primer composition according to [9], wherein the total amount of the components (A-1) and (A-2) is 0.1 to 35 parts by mass per 100 parts by mass of the component (B).

[0019]

[11] The primer composition according to [9] or

[10] , wherein (A-2) is a ketone-based solvent and / or an alcohol-based solvent.

[0020]

[12] The primer composition according to any one of [9] to

[11] , which is used for assembling laminated steel sheets.

[0021]

[13] The primer composition according to any one of [9] to

[12] , wherein the component (B) is a press processing oil.

[0022] The present invention also includes the following embodiments

[14] to

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

[0023]

[14] A method for producing a laminate, comprising: applying the primer composition according to any one of [1] to

[13] to an adherend; applying an anaerobically curable adhesive to the adherend, a coating of the primer composition, or both; and, after applying the primer composition and the anaerobically curable adhesive, bonding the adherend to an adherend to be bonded, and then curing the anaerobically curable adhesive.

[0024]

[15] The manufacturing method according to

[14] , wherein the anaerobic curing adhesive 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.

[0025]

[16] A method for producing a laminated steel sheet, using (including) the following steps 1 to 4: Step 1: applying the primer composition according to any one of [1] to

[13] to a strip-shaped steel sheet; Step 2: punching the strip-shaped steel sheet coated with the primer composition into a predetermined shape to obtain a thin steel sheet (a thin steel sheet coated with the primer composition); Step 3: applying an anaerobically curable adhesive in a planar or dotted manner to the thin steel sheet coated with the primer composition, and laminating the thin steel sheet with another thin steel sheet (a thin steel sheet to be laminated); Step 4: curing the anaerobically curable adhesive under predetermined conditions to obtain a laminated steel sheet.

[0026]

[17] The manufacturing method according to

[16] , wherein the anaerobic curing adhesive 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.

[0027]

[18] A bonding composition kit comprising an anaerobic curing adhesive and the primer composition according to any one of [1] to

[13] .

[0028]

[19] The adhesive composition kit according to

[18] , wherein the anaerobic curing adhesive 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.

[0029]

[20] A method for accelerating the curing of an anaerobically curable adhesive, comprising curing the anaerobically curable adhesive while a coating film of the primer composition according to any one of [1] to

[13] and the anaerobically curable adhesive are in contact with each other.

[0030]

[21] The curing acceleration method according to

[20] , wherein the anaerobic curing adhesive 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.

[0031] Another aspect of the present invention that can achieve at least one of the above objects relates to the following

[22] .

[0032]

[22] A method for producing a primer composition, comprising mixing the following component (A) and component (B) in an amount of 35 parts by mass or less of component (A) per 100 parts by mass of component (B): component (A): a curing accelerator for an anaerobic curing adhesive, and component (B): a lubricating oil.

[0033] The present invention also includes the following embodiments

[23] to

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

[0034]

[23] The method according to

[22] , comprising mixing 0.1 to 35 parts by mass of the component (A) with 100 parts by mass of the component (B).

[0035]

[24] The manufacturing method according to

[22] or

[23] , wherein the anaerobic curing adhesive 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.

[0036] The present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0037] 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 but not more than Y."

[0038] 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.

[0039] 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.

[0040] <Primer Composition> One aspect (first aspect) of the present invention relates to a primer composition comprising the following component (A) and component (B), wherein the component (A) contains an (A-1) metal complex, and the amount of the component (A) is 35 parts by mass or less per 100 parts by mass of the component (B): component (A): a curing accelerator for an anaerobic curable adhesive, and component (B): a lubricating oil.

[0041] The primer composition according to this embodiment can improve the cure rate and adhesive strength of the anaerobic curing adhesive while suppressing performance degradation (decrease in lubricating performance over time) in a primer composition containing a cure accelerator and a lubricating oil (e.g., press processing oil, etc.).

[0042] 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.

[0043] [Component (A)] Component (A) is a curing accelerator for an anaerobic curing adhesive. Component (A) is a component that accelerates the curing of an anaerobic curing adhesive (particularly preferably an anaerobic curing adhesive containing components (C) to (E) described below). Furthermore, the primer composition referred to in this specification may also refer to a composition containing a curing accelerator.

[0044] The curing accelerator contains (A-1) a metal complex, and (A-1) is a main component that promotes the effects of the anaerobic curing adhesive described below. The curing accelerator may contain (A-2) a solvent in addition to (A-1). (A-2) dissolves (A-1), thereby dispersing (A-1) uniformly in the primer composition and improving the curing acceleration effect. Component (A) may consist solely of (A-1), or may consist solely of (A-1) and (A-2).

[0045] The primer composition according to this embodiment contains the curing accelerator and the component (B) described below. Therefore, the primer composition according to this embodiment can be used as a lubricant for metal processing, and when combined with an anaerobic curing adhesive described below, the primer composition according to this embodiment can accelerate the curing of the adhesive.

[0046] 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 curing-accelerating effect of component (A) is usually not achieved by the primer composition alone, and curing does not occur by the primer composition alone.

[0047] (A-1) is a metal complex. (A-1) is a main component as a curing accelerator that accelerates the curing of the anaerobic curing adhesive described below. The metal complex may be used alone or in combination of two or more types.

[0048] Examples of the metal species in the (A-1): metal complex include, but are not limited to, Mg, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, and Ag. The metal species in the metal complex may be used alone, or two or more may be used in combination. 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 anaerobic curing adhesive. In one embodiment, the metal species in the (A-1): metal complex is preferably at least one selected from the group consisting of the metal species exemplified above, and more preferably Cu.

[0049] Specific examples of (A-1) 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 curing adhesive. The (A-1): metal complex preferably contains at least one compound selected from the group consisting of the compounds exemplified above. In one embodiment, the (A-1): 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.

[0050] The curing accelerator according to one embodiment may contain a solvent as (A-2). Various solvents can be used as (A-2).

[0051] The boiling point of the solvent is not particularly limited, but is preferably less than 80° C. In one embodiment, (A-2) preferably contains a solvent having a boiling point of less than 80° C., and more preferably a solvent having a boiling point of less than 80° C. In this specification, the boiling point is expressed as a value at 1 atmosphere (760 mmHg, 1013.25 hPa).

[0052] Examples of the (A-2): solvent include, but are not limited to, ketone-based solvents, alcohol-based solvents, hydrocarbon-based solvents, ester-based solvents, glycol-based solvents, glycol ether-based solvents, and the like. These solvents may be used alone or in combination of two or more. From the viewpoint of the solubility and dispersibility of (A-1), the (A-2): solvent is preferably at least one selected from the group consisting of ketone-based solvents, alcohol-based solvents, hydrocarbon-based solvents, ester-based solvents, glycol-based solvents, and glycol ether-based solvents, more preferably ketone-based solvents and / or alcohol-based solvents, and even more preferably ketone-based solvents. Examples of ketone-based solvents include, but are not limited to, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, diacetone alcohol, and the like. These may be used alone or in combination of two or more. Examples of alcohol-based solvents include, but are not limited to, methanol, ethanol, denatured ethanol, isopropyl alcohol, normal propyl alcohol, isobutyl alcohol, higher alcohols (alcohols having 6 or more carbon atoms), benzyl alcohol, and the like. These solvents can be used alone or in combination of two or more. Examples of hydrocarbon solvents include, but are not limited to, benzene, toluene, xylene, styrene, normal hexane, isohexane, cyclohexane, methylcyclohexane, normal heptane, and mineral spirits. These solvents can be used alone or in combination of two or more. In this specification, mineral spirits refers to a mixture containing hydrocarbons having 9 to 16 carbon atoms, including aliphatic and aromatic hydrocarbons. Mineral spirits are preferably a mixture of hydrocarbon compounds with a boiling point in the range of 100 to 300°C. In one embodiment, (A-2): solvent may contain at least one solvent selected from the group consisting of the solvents exemplified above, or may contain at least one ketone solvent selected from the group consisting of the ketone solvents exemplified above.In one embodiment, (A-2): the solvent may be at least one ketone solvent selected from the group consisting of the ketone solvents exemplified above, or may be acetone.

[0053] When the component (A) contains (A-1) and (A-2), the content ratio of (A-1) and (A-2) is not particularly limited. When the component (A) contains (A-1) and (A-2), the component (A) preferably contains 0.1 to 200 parts by mass of (A-1) per 100 parts by mass of (A-2), more preferably contains 1 to 100 parts by mass of (A-1) per 100 parts by mass of (A-2), even more preferably contains 2 to 50 parts by mass of (A-1) per 100 parts by mass of (A-2), and even more preferably contains 2 to 20 parts by mass of (A-1) per 100 parts by mass of (A-2). It may contain 5 to 20 parts by mass of (A-1) per 100 parts by mass of (A-2), it may contain 5 to 17 parts by mass of (A-1) per 100 parts by mass of (A-2), it may contain 5 to 15 parts by mass of (A-1) per 100 parts by mass of (A-2), it may contain 5 to 12 parts by mass of (A-1) per 100 parts by mass of (A-2), or it may contain 5 to 10 parts by mass of (A-1) per 100 parts by mass of (A-2). It may contain 9 to 20 parts by mass of (A-1) per 100 parts by mass of (A-2), it may contain 10 to 20 parts by mass of (A-1) per 100 parts by mass of (A-2), it may contain 12 to 20 parts by mass of (A-1) per 100 parts by mass of (A-2), or it may contain 15 to 20 parts by mass of (A-1) per 100 parts by mass of (A-2). It may contain 2 to 12 parts by mass of (A-1) per 100 parts by mass of (A-2), or 5 to 12 parts by mass of (A-1) per 100 parts by mass of (A-2), or 7 to 12 parts by mass of (A-1) per 100 parts by mass of (A-2). It may contain 2 to 10 parts by mass of (A-1) per 100 parts by mass of (A-2), or 5 to 10 parts by mass of (A-1) per 100 parts by mass of (A-2), or 7 to 10 parts by mass of (A-1) per 100 parts by mass of (A-2). By containing 0.1 to 200 parts by mass of (A-1) per 100 parts by mass of (A-2), it is possible to improve dispersibility in component (B) without reducing the properties as a curing accelerator. When two or more types of (A-1) are used in combination, the amount of (A-1) represents the total amount thereof. When two or more types of (A-2) are used in combination, the amount of (A-2) represents the total amount thereof.

[0054] The content of (A-1) is not particularly limited, but is preferably 0.1 to 25 mass% relative to 100 mass% of the primer composition (relative to the total mass of the primer composition), more preferably 0.3 to 20 mass%, even more preferably 0.4 to 10 mass%, even more preferably 0.4 to 2.5 mass%, and even more preferably 0.4 to 1.5 mass%. The content of (A-1) may be 0.4 to 2.1 mass%, 0.4 to 1 mass%, or 0.4 to 1 mass%, or 0.4 parts by mass or more but less than 0.9 mass%, or even 0.4 to 0.8 mass%, relative to 100 mass% of the primer composition. The content of (A-1) may be 0.6 to 2.5 mass%, 0.6 to 2.2 mass%, or 0.6 to 2.1 mass%, relative to 100 mass% of the primer composition. The content of (A-1) may be 0.8 to 2.5 mass%, 0.8 to 2.2 mass%, or 0.8 to 2.1 mass%, based on 100 mass% of the primer composition. The content of (A-1) may be 0.6 to 1.5 mass%, 0.7 to 1.5 mass%, 0.8 to 1.5 mass%, or 0.9 to 1.5 mass%, based on 100 mass% of the primer composition. The content of (A-1) may be 1 to 2.5 mass%, or 1.5 to 2.5 mass%, based on 100 mass% of the primer composition. The content of (A-1) may be 1 to 2.2 mass%, or 1.5 to 2.1 mass%, based on 100 mass% of the primer composition. When the content of (A-1) is 0.1 to 25 mass% relative to 100 mass% of the primer composition, the effect of accelerating the curing of the anaerobic curing adhesive without increasing the coefficient of friction is further enhanced. When two or more types of (A-1) are used in combination, the amount of (A-1) represents the total amount thereof.

[0055] The content of (A-2) is not particularly limited, but is preferably 1 to 25 mass%, more preferably 3 to 25 mass%, even more preferably 5 to 20 mass%, and even more preferably 5 to 15 mass%, relative to 100 mass% of the primer composition (based on the total mass of the primer composition). The content of (A-2) may be 7 to 25 mass%, 7 to 20 mass%, or 7 to 15 mass%, or may be 7 mass% or more but less than 14 mass%, relative to 100 mass% of the primer composition. The content of (A-2) may be 10 to 25 mass%, 10 to 20 mass%, 10 to 15 mass%, or may be 10 mass% or more but less than 14 mass%, relative to 100 mass% of the primer composition. The content of (A-2) may be 5 to 25 mass%, 10 to 25 mass%, 15 to 25 mass%, or 20 to 25 mass%, relative to 100 mass% of the primer composition. When the content of (A-2) is 1 to 25 mass% relative to 100 mass% of the primer composition, the effect of accelerating the curing of the anaerobic curing adhesive without increasing the coefficient of friction is further enhanced. When two or more types of (A-2) are used in combination, the amount of (A-2) represents the total amount thereof.

[0056] The content of the (A) component (the total content of the (A) component) is 35 parts by mass or less per 100 parts by mass of the (B) component described below. That is, the total content of the (A) component is more than 0 parts by mass and 35 parts by mass or less per 100 parts by mass of the (B) component. The content of the (A) component (the total content of the (A) component) is more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less (lower limit: more than 0 parts by mass) per 100 parts by mass of the (B) component. By having the content of the (A) component be 35 parts by mass or less per 100 parts by mass of the (B) component, there is no risk of an increase in the coefficient of friction of the primer composition. The lower limit of the content of the (A) component is not particularly limited. The content of the (A) component (the total content of the (A) component) is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 5 parts by mass or more per 100 parts by mass of the (B) component. When the content of component (A) is 0.1 parts by mass or more per 100 parts by mass of component (B), the curing of the anaerobic curing adhesive can be further accelerated. The adhesive may contain 0.1 to 35 parts by mass of component (A) per 100 parts by mass of component (B), 1 to 25 parts by mass of component (A) per 100 parts by mass of component (B), or 5 to 20 parts by mass of component (A) per 100 parts by mass of component (B). The adhesive may contain 1 to 35 parts by mass of component (A) per 100 parts by mass of component (B), 5 to 35 parts by mass of component (A) per 100 parts by mass of component (B), or 15 to 35 parts by mass of component (A) per 100 parts by mass of component (B). The composition may contain 10 to 25 parts by mass of component (A) per 100 parts by mass of component (B), 10 to 20 parts by mass of component (A) per 100 parts by mass of component (B), 10 parts by mass or more but less than 20 parts by mass of component (A) per 100 parts by mass of component (B), or 10 to 18 parts by mass of component (A) per 100 parts by mass of component (B). The composition may contain 15 to 25 parts by mass of component (A) per 100 parts by mass of component (B), 15 to 20 parts by mass of component (A) per 100 parts by mass of component (B), 15 parts by mass or more but less than 20 parts by mass of component (A) per 100 parts by mass of component (B), or 15 to 18 parts by mass of component (A) per 100 parts by mass of component (B).When two or more types of (A) components are used in combination, the amount of the (A) component represents the total amount thereof. When two or more types of (B) components are used in combination, the amount of the (B) component represents the total amount thereof.

[0057] The content of component (A) (the total content of component (A)) is not particularly limited. The primer composition preferably contains 0.1 to 26% by mass of component (A) relative to 100% by mass (relative to the total mass of the primer composition), more preferably 1 to 25% by mass of component (A) relative to 100% by mass of the primer composition, even more preferably 3 to 20% by mass of component (A) relative to 100% by mass of the primer composition, and even more preferably 5 to 17% by mass of component (A) relative to 100% by mass of the primer composition. The content of component (A) may be 7 to 26% by mass, 7 to 25% by mass, 7 to 20% by mass, or 7 to 17% by mass relative to 100% by mass of the primer composition. The content of component (A) may be 9 to 26% by mass, 10 to 26% by mass, 10 to 25% by mass, 10 to 20% by mass, or 10 to 17% by mass relative to 100% by mass of the primer composition. The content of component (A) may be 12 to 26% by mass, 12 to 25% by mass, 12 to 20% by mass, or 12 to 17% by mass, based on 100% by mass of the primer composition. When two or more types of component (A) are used in combination, the amount of component (A) represents the total amount of these.

[0058] [Component (B)] Component (B) is a lubricating oil. The primer composition according to one embodiment preferably contains a lubricating oil as component (B). Component (B) is preferably used to prevent seizure during processing of metals, etc. Since the aforementioned component (A) does not significantly increase the coefficient of friction of component (B), the primer composition according to this embodiment can be used to stably process metals, etc. When the primer composition according to one embodiment contains component (A-2), component (A-2) is preferably a component other than component (B). Component (B) may be free of a ketone-based solvent. Component (B) may be free of acetone. Component (B) may be free of a ketone-based solvent and may be free of an alcohol-based solvent. Component (B) may be free of a solvent with a boiling point of less than 80°C.

[0059] Component (B): Lubricating oils include, but are not limited to, mineral oil-based lubricating oils, synthetic oils, etc. Examples of mineral oil-based lubricating oils include, but are not limited to, hydrogenated petroleum fractions, etc. Component (B): Lubricating oils may be used alone or in combination of two or more.

[0060] The type of component (B) is not particularly limited, but is preferably a press processing oil. A press processing oil is a base oil mixed with one or more 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, hydrogenated petroleum fractions that can be used as lubricants (oils that can function as general lubricants on their own). Press processing oils preferably contain 50% by mass or more of the hydrogenated petroleum fractions (50% by mass or more relative to 100% by mass of the press processing oil (relative to the total mass of the press processing oil)). The upper limit of the content of the hydrogenated petroleum fraction in the press processing oil is less than 100% by mass relative to the total mass of the press processing oil. The press processing oils may be used alone, or two or more types may be used in combination. In one embodiment, the component (B): lubricating oil preferably contains a press processing oil, and more preferably is a press processing oil.

[0061] The lubricating oil (B) may be a commercially available product, a synthetic product, or a combination of these. Examples of commercially available products include, but are not limited to, G-6338F manufactured by Nippon Kogyo Yu Co., Ltd.

[0062] The content of component (B) is not particularly limited. The content of component (B) is preferably 72 to 95 mass%, more preferably 75 to 95 mass%, even more preferably 80 to 95 mass%, and even more preferably 82 to 93 mass%, relative to the total mass of the primer composition (100 mass% of the primer composition). The content of component (B) may be 72 mass% or more but less than 90 mass%, or may be 72 to 88 mass%, relative to 100 mass% of the primer composition. The content of component (B) may be 82 mass% or more but less than 90 mass%, or may be 82 to 88 mass%, relative to 100 mass% of the primer composition. A content of component (B) of 72 to 95 mass%, relative to 100 mass% of the primer composition, reduces the possibility of increasing the coefficient of friction of the primer composition. When two or more (B) components are used in combination, the amount of component (B) represents the total amount of these components.

[0063] [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 component (A) and component (B). As described above, it is preferable that the primer composition according to one embodiment does not contain a curing component. Examples of the curing component include, but are not particularly limited to, reactive resins.

[0064] [Anaerobic curing adhesive] The primer composition according to one embodiment is preferably used for the purpose of promoting the curing of an anaerobic curing adhesive. The anaerobic curing adhesive is not particularly limited, but preferably contains a compound having one or more (meth)acryloyl groups as component (C), an organic peroxide as component (D), and an anaerobic curing catalyst as component (E).

[0065] <Component (C)> The component (C) is a compound having one or more (meth)acryloyl groups. The component (C) may be used alone, or two or more types may be used in combination.

[0066] Component (C) 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 (C) 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 of repeated monomer units, a portion derived therefrom, or both.

[0067] Component (C): 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 (C) is not particularly limited, but is preferably such that the ratio of oligomer having one or more (meth)acryloyl groups in the molecule:monomer having one or more (meth)acryloyl groups in the molecule is 1:99 to 99:1, more preferably such that the ratio of oligomer having one or more (meth)acryloyl groups in the molecule:monomer having one or more (meth)acryloyl groups in the molecule is 20:80 to 80:20, and even more preferably such that the ratio of oligomer having one or more (meth)acryloyl groups in the molecule:monomer having one or more (meth)acryloyl groups in the molecule is 50:50 to 75:25.

[0068] 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.

[0069] From the viewpoint of adhesive strength to laminated steel sheets, component (C): a compound having one or more (meth)acryloyl groups preferably includes 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 includes a urethane-modified (meth)acrylate and / or an epoxy-modified (meth)acrylate, and even more preferably includes a urethane-modified (meth)acrylate and an epoxy-modified (meth)acrylate. In one embodiment, the anaerobic curing adhesive preferably includes 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.

[0070] From the viewpoint of curability and adhesive strength to laminated steel sheets, the component (C): 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.

[0071] From the viewpoint of curability and adhesive strength to laminated steel sheets, the (C) component: 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 an aromatic ring. The (C) component: 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.

[0072] 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.

[0073] When two or more compounds having one or more (meth)acryloyl groups are used in combination as component (C), the content of the urethane-modified (meth)acrylate is not particularly limited, but is preferably 1 to 90 mass% relative to the entire component (C) (total mass of component (C)), more preferably 5 to 90 mass%, even more preferably 10 to 80 mass%, and particularly preferably 15 to 70 mass%. By including 1 to 90 mass% of the urethane-modified (meth)acrylate relative to the entire component (C) (total mass of component (C)), the adhesive strength to laminated steel sheets is superior.

[0074] When two or more types of compounds having one or more (meth)acryloyl groups are used in combination as component (C), 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 entire component (C) (total mass of component (C)). By including 1 to 90 mass% of the epoxy-modified (meth)acrylate relative to the entire component (C) (total mass of component (C)), curability is more excellent.

[0075] When a urethane-modified (meth)acrylate and an epoxy-modified (meth)acrylate are used in combination (when the component (C): 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 is not particularly limited. The mass ratio of the urethane-modified (meth)acrylate to the epoxy-modified (meth)acrylate is preferably urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate=90:10 to 10:90, more preferably urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate=85:15 to 30:70, and even more preferably urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate=80:20 to 50:50. When the mass ratio of urethane-modified (meth)acrylate:epoxy-modified (meth)acrylate is 90:10 to 10:90, the curability and adhesive strength to laminated steel sheets are superior.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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 type, bisphenol F type, phenol novolac type, hydrogenated bisphenol A type, and / or hydrogenated bisphenol F type. 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 type skeleton. Specific examples of epoxy-modified (meth)acrylates include, but are not limited to, bisphenol A diglycidyl ether type epoxy diacrylate (e.g., Viscoat #540 manufactured by Osaka Organic Chemical Industry Co., Ltd.), ethoxylated bisphenol A diglycidyl ether type epoxy dimethacrylate, fatty acid-modified epoxy (meth)acrylate, amine-modified bisphenol epoxy (meth)acrylate, novolac epoxy (meth)acrylate, epoxidized soybean oil (meth)acrylate, etc. These may be used alone or in combination of two or more.

[0082] 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.

[0083] In one embodiment, the component (C): 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 (C): 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.

[0084] The (C) 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 (C) 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.

[0085] Component (C): 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.

[0086] Examples of the monofunctional (meth)acrylate compound are 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.

[0087] Examples of the monofunctional (meth)acrylate compound (I) are not particularly limited, but include ethyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl methacrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentaerythritol, methyl methyl methacrylate ... Tanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxy (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 acrylate, isobornyl (meth)acrylate, 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, methoxyhectaethylene 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,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, methoxyheptabtylene glycol glycol mono(meth)acrylate, methoxyoctabtylene 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, ethoxy Heptaethylene 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, ethoxytetrabutylene glycol mono(meth)acrylate, ethoxypentabtylene glycol mono(meth)acrylate,Examples of such monomers include 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, and ethoxydecabutylene glycol mono(meth)acrylate. These may be used alone or in combination of two or more. Of these, preferred examples of monofunctional (meth)acrylate monomers include 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, ethylene glycol mono(meth)acrylate, and propylene glycol mono(meth)acrylate. These may be used alone or in combination of two or more.

[0088] 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.

[0089] The monofunctional (meth)acrylate compounds can be used alone or in combination of two or more.

[0090] In one embodiment, the component (C): 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.

[0091] In one embodiment, the component (C): a 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).

[0092] In one embodiment, the component (C): 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).

[0093] In one embodiment, the component (C): a compound having one or more (meth)acryloyl groups, more preferably includes 2-hydroxyethyl (meth)acrylate, and particularly preferably includes 2-hydroxyethyl methacrylate.

[0094] In one embodiment, the monofunctional (meth)acrylate compound may be a monomer having a monofunctional (meth)acryloyl group, or may be a monomer having a monofunctional (meth)acryloyl group having a hydroxyl group, or may be a monomer having a monofunctional (meth)acryloyl group having a hydroxyl group, which is the monofunctional (meth)acrylate compound (I), or may be 2-hydroxyethyl (meth)acrylate, or may be 2-hydroxyethyl methacrylate.

[0095] 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.

[0096] 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, dimethylol-tricyclodecane 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, which is the polyfunctional (meth)acrylate compound (II), are not particularly limited, but include ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, etc. Preferred examples of the tetrafunctional (meth)acrylate monomer are not particularly limited, but include 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 can be used alone or in combination of two or more.

[0097] 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.

[0098] The mass ratio of the polyfunctional (meth)acrylate compound to the monofunctional (meth)acrylate compound in the component (C) 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.

[0099] The compound having one or more (meth)acryloyl groups may be used alone or in combination of two or more. Component (C): 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 (C): 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.

[0100] In one embodiment, the component (C): 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).

[0101] In one embodiment, the component (C): 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.

[0102] In one embodiment, the component (C): 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.

[0103] The content of component (C) in the anaerobic curing adhesive is not particularly limited. The content of component (C) is preferably 50% by mass or more but less than 100% by mass, more preferably 60% by mass or more but less than 100% by mass, even more preferably 70% by mass or more but less than 100% by mass, even more preferably 90% by mass or more but less than 100% by mass, and particularly preferably 95% by mass or more but less than 100% by mass, based on 100% by mass of the anaerobic curing adhesive (based on the total mass of the anaerobic curing adhesive). The content of component (C) may be 60 to 99% by mass, or may be 70 to 99% by mass, based on 100% by mass of the anaerobic curing adhesive (based on the total mass of the anaerobic curing adhesive). When two or more types of component (C) are used in combination, the amount of component (C) represents the total amount of these.

[0104] <Component (D)> Component (D) is an organic peroxide. Component (D) is used to cure component (C). Examples of component (D) 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 (D): organic peroxide preferably contains at least one compound selected from the group consisting of the compounds exemplified above. In one embodiment, the component (D): 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 (D): organic peroxide may be, for example, a hydroperoxide.

[0105] The content of component (D) in the anaerobic curing adhesive is not particularly limited. The content of component (D) is preferably 0.1 to 30 parts by mass, more preferably 0.3 to 15 parts by mass, and even more preferably 0.5 to 10 parts by mass, per 100 parts by mass of component (C). By having the content of component (D) be 0.1 to 30 parts by mass per 100 parts by mass of component (C), both curability and storage stability can be achieved. The content of component (D) may be 0.1 to 20 parts by mass, 0.3 to 10 parts by mass, or 0.5 to 5 parts by mass per 100 parts by mass of component (C). When two or more types of component (C) are used in combination, the amount of component (C) refers to the total amount thereof. When two or more types of component (D) are used in combination, the amount of component (D) refers to the total amount thereof.

[0106] The content of component (D) in the anaerobic curing adhesive is not particularly limited. The content of component (D) 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 (E). When two or more types of component (D) are used in combination, the amount of component (D) represents the total amount thereof. When two or more types of component (E) are used in combination, the amount of component (E) represents the total amount thereof.

[0107] <Component (E)> Component (E) is an anaerobic curing catalyst. Under anaerobic conditions without contact with oxygen, component (E) decomposes component (D) to generate free radicals, accelerating curing. Examples of component (E) include, but are not limited to, saccharin, amine compounds, azole compounds, mercaptan compounds, hydrazine compounds, and derivatives thereof. These can be used alone or in combination. In this specification, azole compounds are considered to exclude saccharin. Component (C): the anaerobic curing catalyst preferably contains at least one compound selected from the group consisting of the compounds exemplified above. From the perspective of excellent curability, component (C): the anaerobic curing catalyst preferably contains one or more compounds selected from the group consisting of saccharin, azole compounds, mercaptan compounds, and hydrazine compounds, more preferably at least one compound selected from the group consisting of saccharin and hydrazine compounds, even more preferably saccharin, and particularly preferably a combination of saccharin and hydrazine compounds. In one embodiment, it is preferable that a compound corresponding to component (A): a curing accelerator for an anaerobic curing adhesive is not treated as component (E). That is, in one embodiment, it is preferable that component (E) is a compound other than the compounds included in component (A): a curing accelerator for an anaerobic curing adhesive.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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 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. From the viewpoint of excellent curability, hydrazine compounds having an acetyl group are preferred, and 1-acetyl-2-phenylhydrazine is more preferred.

[0112] In one embodiment, the component (E): anaerobic curing catalyst 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 component (E): anaerobic curing catalyst 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.

[0113] The anaerobic curing catalyst may be used alone or in combination of two or more types. The component (E): anaerobic curing catalyst preferably contains at least one compound selected from the group consisting of the above-mentioned compounds. In one embodiment, the component (E): 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 (E): anaerobic curing catalyst is preferably saccharin and a hydrazine compound having an acetyl group.

[0114] The content of component (E) in the anaerobic curing adhesive is not particularly limited. From the viewpoint of curability, the content of component (E) is preferably 0.01 to 40 parts by mass per 100 parts by mass of component (C). The content of component (E) may be 0.5 to 30 parts by mass or 1 to 25 parts by mass per 100 parts by mass of component (C). The content of component (E) 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 (C). The content of component (E) 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 (C). The content of component (E) 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 (C). The content of the (E) 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 (C) component. When two or more (E) components are used in combination, the amount of the (E) component represents the total amount thereof. When two or more (C) components are used in combination, the amount of the (C) component represents the total amount thereof.

[0115] When saccharin and a hydrazine compound are combined, i.e., when the component (E) anaerobic curing catalyst contains saccharin and a hydrazine compound, the mass ratio of the saccharin to the hydrazine compound in the component (E) is not particularly limited. The mass ratio of the saccharin to the hydrazine compound in the component (E) 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, 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 hydrazine compound refers to the total amount of these.

[0116] <<Other Components in Anaerobic Curing Adhesives>> The anaerobic curing adhesive may or may not further contain one or more other components. The other components in the anaerobic curing adhesive are not particularly limited as long as they are components other than components (C) to (E). The anaerobic curing adhesive may further contain an appropriate amount of one or more additives (one or more other components), such as a stabilizer, inorganic filler, organic filler, silane coupling agent, light stabilizer, photosensitizer, polymerization inhibitor, or chelating agent, to the extent that the properties are not impaired. The anaerobic curing 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.

[0117] The anaerobic curing 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 0.01 to 0.5 mass% relative to the entire anaerobic curing adhesive (relative to the total mass of the anaerobic curing adhesive; relative to 100 mass% of the anaerobic curing adhesive), more preferably 0.02 to 0.3 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 of these stabilizers.

[0118] The anaerobic curing 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.

[0119] The anaerobic curing 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.

[0120] The anaerobic curing 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 ((meth)acryloyl 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)acryloyl 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, γ-methacryloxypropyltrimethoxysilane, and the like. 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. Herein, (meth)acryloyl group-containing silane coupling agents are not included in component (C). 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. Herein, amino group-containing silane coupling agents are not included in component (E), and mercapto group-containing silane coupling agents are not included in component (E). In one embodiment, component (E) 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.

[0121] The anaerobic curing 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 curing adhesive may not contain any of a light stabilizer, a photosensitizer, a polymerization inhibitor, and a chelating agent.

[0122] From the viewpoint of storage stability, it is preferable that the anaerobic curing adhesive does not contain metal as a component. In this specification, "the anaerobic curing adhesive does not contain metal as a component" means that none of the components constituting the anaerobic curing adhesive contain metal elements. In one embodiment, it is preferable that the anaerobic curing adhesive does not contain metal elements. In this specification, "the anaerobic curing adhesive does not contain metal elements" means that the anaerobic curing adhesive contains metal elements only as unavoidable impurities, or does not contain any metal elements at all.

[0123] Another aspect (second aspect) of the present invention can also be said to relate to a primer composition comprising the above-mentioned components (A-1), (A-2), and (B), wherein the total of the components (A-1) and (A-2) is 35 parts by mass or less per 100 parts by mass of the component (B) (preferably, the total of the components (A-1) and (A-2) is 0.1 to 35 parts by mass per 100 parts by mass of the component (B)). The primer composition according to this aspect (second aspect) can improve the cure rate and adhesive strength of an anaerobic curing 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.).

[0124] In the primer composition according to this embodiment (second embodiment), the total content of (A-1) and (A-2) is more than 0 parts by mass and not more than 35 parts by mass per 100 parts by mass of the component (B). Preferred examples of the total content of (A-1) and (A-2) in the primer composition according to this embodiment (second embodiment) are not particularly limited, and include, relative to 100 parts by mass of component (B), more than 0 parts by mass and 25 parts by mass or less, more than 0 parts by mass and 20 parts by mass or less, 0.1 parts by mass or more, 1 part by mass or more, 5 parts by mass or more, 0.1 to 35 parts by mass, 1 to 25 parts by mass, 5 to 20 parts by mass, 1 to 35 parts by mass, 5 to 35 parts by mass, 15 to 35 parts by mass, 10 to 25 parts by mass, 10 to 20 parts by mass, 10 to 18 parts by mass, 15 to 25 parts by mass, 15 to 20 parts by mass, 15 parts by mass or more and 15 to 18 parts by mass, etc. When two or more types of (A-1) are used in combination, the amount of (A-1) represents the total amount thereof. When two or more types of (A-2) are used in combination, the amount of (A-2) represents the total amount thereof. When two or more types of (B) components are used in combination, the amount of (B) component represents the total amount thereof.

[0125] In the primer composition according to this aspect (second aspect), the embodiment of (A-1), the embodiment of (A-2), the embodiment of the component (B), and the embodiments of other components (other components in the primer composition) are the same as those described in the primer composition according to the first aspect.

[0126] <Method of Using the Primer Composition> In this specification, the primer composition refers to a composition that is applied to an adherend before application of the adhesive to promote the curing of the anaerobic curing adhesive and improve the curing time and adhesive strength. The primer composition according to each of the above embodiments may be composed of component (A), component (B), and, if necessary, one or more other components, and is preferably composed of component (A) and component (B). Component (A) and component (B) may be mixed immediately before application of the anaerobic curing adhesive, or may be mixed in advance.

[0127] <Adhesive Composition Kit> The primer composition according to the first aspect is preferably used in an adhesive composition kit comprising an anaerobic curing adhesive and the primer composition. The primer composition according to the second aspect is preferably used in an adhesive composition kit comprising an anaerobic curing adhesive and the primer composition. Therefore, another aspect (third aspect) of the present invention can be said to relate to an adhesive composition kit comprising an anaerobic curing adhesive and the primer composition according to the first aspect or the second aspect. The adhesive composition kit according to this aspect can improve the curing rate and adhesive strength of the anaerobic curing adhesive while suppressing performance degradation (decrease in lubrication performance over time) of the primer composition containing a curing accelerator and a lubricating oil (e.g., press processing oil, etc.). In the adhesive composition kit according to this aspect, the primer composition and the anaerobic curing adhesive are present separately. The anaerobic curing adhesive in the adhesive composition kit according to this aspect is the same as described for the primer composition according to the first aspect. Preferred embodiments of the anaerobic curing adhesive in the adhesive composition kit according to this aspect are also the same as described for the primer composition according to the first aspect. The primer composition in the bonding composition kit according to this aspect is the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. Preferred embodiments of the primer composition in the bonding composition kit according to this aspect are also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. In one embodiment, it is preferable that the anaerobic curing adhesive 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.

[0128] <Uses> The primer composition according to the first aspect, the primer composition according to the second aspect, and the adhesive composition kit according to the third aspect can each be used 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 the metal include, but are not limited to, SPCC (Steel Plate Cold Commercial) (cold-rolled steel plate), copper, etc.

[0129] Some types of metals are not normally suitable for anaerobic curing. However, even for such types of metals, by applying the primer composition according to the first aspect, the primer composition according to the second aspect, or the primer composition in the adhesive composition kit according to the third aspect and using the primer composition in combination with an anaerobic curing adhesive, it may be possible to promote curing and improve the adhesive strength of the anaerobic curing adhesive.

[0130] More specific examples of applications in which the primer composition according to the first aspect, the primer composition according to the second aspect, and the adhesive composition kit according to the third aspect are used, respectively, are not particularly limited, but include threading of spark plugs, assembling laminated steel sheets and / or laminated molds etc. for rotors for rotating electrical machines, assembling laminated steel sheets and / or laminated molds etc. for solenoids, etc. Among these, the primer composition according to the first aspect, the primer composition according to the second aspect, and the adhesive composition kit according to the third aspect can each be suitably used for assembling laminated steel sheets.

[0131] <Laminate Manufacturing Method Using Primer Composition, and Laminate> The primer composition according to the first aspect, the primer composition according to the second aspect, and the adhesive composition kit according to the third aspect are each preferably used in a laminate manufacturing method. In this case, the laminate manufacturing method preferably includes applying the primer composition according to the first aspect or the primer composition according to the second aspect to an adherend, applying an anaerobic curing adhesive to the adherend, the primer composition coating, or both, and, after applying the primer composition and the anaerobic curing adhesive, bonding the adherend to an adherend to be bonded, and then curing the anaerobic curing adhesive. Therefore, another aspect (fourth aspect) of the present invention can be said to relate to a method for manufacturing a laminate, which includes applying the primer composition according to the first aspect or the primer composition according to the second aspect to an adherend, applying an anaerobically curable adhesive to the adherend, the primer composition coating, or both, and, after applying the primer composition and the anaerobically curable adhesive, laminating the adherend to an adherend to be bonded, and then curing the anaerobically curable adhesive. This laminate manufacturing method according to the above aspect can improve the cure rate and adhesive strength of the anaerobically curable adhesive while suppressing performance degradation (decrease in lubrication performance over time) of the primer composition containing a cure accelerator and a lubricating oil (e.g., press processing oil).

[0132] 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 first aspect or the primer composition according to the second aspect to a steel sheet (preferably an electromagnetic steel sheet); applying an anaerobic curing adhesive to the adherend, the coating of the primer composition, or both; and, after applying the primer composition and the anaerobic curing adhesive, bonding the steel sheet to a steel sheet to be bonded (preferably an electromagnetic steel sheet to be bonded), and then curing the anaerobic curing adhesive to obtain a laminate.

[0133] 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 curing adhesive. The anaerobic curing 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 curing 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 curing adhesive, the primer composition coating and the anaerobic curing adhesive coating may be present on different sides of the adherend, or may be laminated on the same side of the adherend.

[0134] The primer composition according to the first aspect, the primer composition according to the second aspect, and the adhesive composition kit according to the third aspect are each particularly suitable for use in a method for producing a laminated steel sheet by stacking a predetermined number of thin steel sheets (preferably, thin electromagnetic steel sheets) that have been punched into a predetermined shape from a steel strip. The method for producing a laminate using the primer composition according to the first aspect, the primer composition according to the second aspect, or the adhesive composition kit according to the third aspect is not particularly limited. Examples of methods for producing a laminated steel sheet using the primer composition according to the first aspect, the primer composition according to the second aspect, or the adhesive composition kit according to the third aspect include, but are not limited to, a method comprising the following steps 1 to 4:

[0135] Step 1: Applying the primer composition according to the first embodiment or the primer composition according to the second embodiment to a strip-shaped steel plate; Step 2: Punching the strip-shaped steel plate to which the primer composition has been applied into a predetermined shape to obtain the thin steel plate to which the primer composition has been applied; Step 3: Applying an anaerobic curing adhesive in a planar or dotted manner to the thin steel plate to which the primer composition has been applied, and laminating the thin steel plate with another thin steel plate (a thin steel plate to be laminated); Step 4: Curing the anaerobic curing adhesive under predetermined conditions to obtain a laminated steel plate.

[0136] The thin steel sheet obtained in step 2 is a thin steel sheet coated with a primer composition. In step 3, the anaerobic curing 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 (primer composition coating) may be partially or completely dried and / or cured. The applied primer composition (primer composition coating) may be dried and / or cured to an extent that allows, for example, the anaerobic curing adhesive to be laminated. In step 3, the thin steel sheet to be laminated may be coated with a primer composition, an anaerobic curing adhesive, or both. When the thin steel sheet to be laminated is coated with both a primer composition and an anaerobic curing adhesive, the primer composition coating and the anaerobic curing adhesive coating may be present on different sides of the thin steel sheet, or may be laminated on the same side of the thin steel sheet. Step 4 is a step of obtaining a laminated steel sheet by curing the anaerobic curing adhesive under predetermined conditions, which is performed after step 3. The curing of the anaerobic curing adhesive in step 4 is carried out in a laminate including the thin steel sheets coated with the primer composition, the anaerobic curing adhesive, and the thin steel sheets to be laminated.

[0137] In the above-described production method, when the primer composition according to the first aspect or the primer composition according to the second aspect contains (A-2), 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.

[0138] In one embodiment of the method for producing a laminate (preferably a method for producing a laminated steel plate), the anaerobic curing adhesive preferably 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.

[0139] 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.

[0140] 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 curing adhesive layer of an adherend having an anaerobic curing adhesive layer (e.g., an anaerobic curing 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 curing adhesive layer of an adherend having an anaerobic curing 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.). In an adherend having an anaerobic curing adhesive layer on its outermost surface, the adherend and the layer obtained from the primer composition are in contact, and it is preferable that the layer obtained from the primer composition and the layer obtained from the anaerobic curing adhesive are in contact.

[0141] After bonding the two or more adherends together, the anaerobic curing 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 other steps.

[0142] The anaerobic curing adhesive used in the method for producing a laminate according to the fourth aspect is the same as that described for the primer composition according to the first aspect. Preferred embodiments of the anaerobic curing adhesive used in the method for producing a laminate according to the fourth aspect are also the same as that described for the primer composition according to the first aspect. The primer composition used in the method for producing a laminate according to the fourth aspect is also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. Preferred embodiments of the primer composition used in the method for producing a laminate according to the fourth aspect are also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect.

[0143] Another aspect (fifth aspect) of the present invention relates to a laminate produced using the primer composition according to the first aspect, the primer composition according to the second aspect, or the adhesive composition kit according to the third aspect, or by the laminate production method according to the fourth aspect. Examples of the laminate are not particularly limited, but are preferably a laminate including multiple steel sheets, and more preferably a laminate including multiple electrical steel sheets. In one embodiment, the laminate is particularly preferably a steel sheet laminate.

[0144] The anaerobic curing adhesive used in the laminate according to the fifth aspect is the same as that described for the primer composition according to the first aspect. Preferred embodiments of the anaerobic curing adhesive used in the laminate according to the fifth aspect are also the same as that described for the primer composition according to the first aspect. The primer composition used in the laminate according to the fifth aspect is also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. Preferred embodiments of the primer composition used in the laminate according to the fifth aspect are also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. The manufacturing method for obtaining the laminate according to the fifth aspect and preferred embodiments thereof are each the same as those described for the manufacturing method for the laminate according to the fourth aspect.

[0145] <Method for accelerating the cure of an anaerobic curable adhesive using a primer composition> The primer composition according to the first aspect, the primer composition according to the second aspect, and the adhesive composition kit according to the third aspect are each preferably used in a method for accelerating the cure of an anaerobic curable adhesive. In this case, the method for accelerating the cure of an anaerobic curable adhesive preferably includes curing the anaerobic curable adhesive while a coating film of the primer composition according to the first aspect or a coating film of the primer composition according to the second aspect and the anaerobic curable adhesive are in contact with each other. Therefore, another aspect (sixth aspect) of the present invention can also be said to be a method for accelerating the cure of an anaerobic curable adhesive, which includes curing the anaerobic curable adhesive while a coating film of the primer composition according to the first aspect or a coating film of the primer composition according to the second aspect and the anaerobic curable adhesive are in contact with each other. A method for accelerating the cure of an anaerobic curing adhesive according to one embodiment preferably includes applying a primer composition according to the first aspect or a primer composition according to the second aspect; applying the primer composition, and then applying an anaerobic curing adhesive so that the adhesive is in contact with the primer composition coating; and curing the anaerobic curing adhesive after applying the anaerobic curing adhesive. The method for accelerating the cure of an anaerobic curing adhesive according to this aspect can improve the cure rate and adhesive strength of the anaerobic curing 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.). The primer composition coating may be partially or completely dried and / or cured. The primer composition coating may be dried and / or cured, for example, to the extent that the anaerobic curing adhesive can be laminated. The curing method will be described later. The method for accelerating the cure of an anaerobic curing adhesive according to one embodiment may further include other operations and / or other steps.

[0146] The anaerobic curing adhesive in the cure acceleration method according to this aspect is the same as that described for the primer composition according to the first aspect. Preferred embodiments of the anaerobic curing adhesive in the cure acceleration method according to this aspect are also the same as that described for the primer composition according to the first aspect. The primer composition in the cure acceleration method according to this aspect is also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. Preferred embodiments of the primer composition in the cure acceleration method according to this aspect are also the same as that described for the primer composition according to the first aspect or the primer composition according to the second aspect. In one embodiment, the anaerobic curing adhesive preferably contains the above-mentioned components (C) to (E). In one embodiment, the anaerobic curing adhesive preferably 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.

[0147] <Curing Method> Examples of the curing method for the anaerobic curing adhesive include, but are not limited to, room temperature anaerobic curing, heated anaerobic curing, and the like. The curing rate of the anaerobic curing adhesive can be significantly improved by using the primer composition according to the first aspect, the primer composition according to the second aspect, or the primer composition in the adhesive composition kit according to the third aspect in combination. Therefore, in a preferred embodiment, the anaerobic curing 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 curing adhesive may be cured in 1 minute to 24 hours. The curing time may be, for example, 30 minutes to 2 hours.

[0148] <Methods for Producing a Primer Composition and a Bonding Composition Kit> Another aspect (seventh aspect) of the present invention relates to a method for producing a primer composition, comprising mixing the above-mentioned component (A) and the above-mentioned component (B) in an amount of 35 parts by mass or less of the component (A) per 100 parts by mass of the component (B). The primer composition produced by this method can improve the cure rate and adhesive strength of an anaerobic curing 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). A method for producing a primer composition according to one embodiment preferably comprises mixing 0.1 to 35 parts by mass of the component (A) per 100 parts by mass of the component (B). In the method for producing a primer composition according to one embodiment, the anaerobic curing adhesive preferably 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 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.

[0149] Another aspect (eighth aspect) of the present invention is a method for producing a bonding composition kit, the method including producing a primer composition by the method for producing a primer composition according to the above aspect, and producing an anaerobic curing adhesive. The bonding composition kit produced by the method according to this aspect can improve the cure rate and adhesive strength of the anaerobic curing 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 an anaerobic curing adhesive according to one embodiment may further include mixing the above-described components (C) to (E) as needed. The method for producing an anaerobic curing adhesive according to one embodiment may further include mixing one or more other components (one or more other components of the above-described anaerobic curing adhesive) as needed. The bonding composition kit according to the above aspect is preferably produced by the method for producing a bonding composition kit according to this aspect.

[0150] In the production methods according to these aspects, the type and amount of each raw material used for the anaerobic curing adhesive may be the same as the type and content of each component of the anaerobic curing adhesive described in the primer composition according to the first 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 content of each raw material used for the primer composition according to the first aspect or the primer composition according to the second aspect. In the production methods according to these aspects, the type and amount of each raw material used for the anaerobic curing adhesive may also be the same as the type and content of each component of the anaerobic curing adhesive described in the primer composition according to the first aspect. In the production methods according to these aspects, the type and amount of each raw material used for the primer composition may also be the same as the type and content of each raw material used for the primer composition according to the first aspect.

[0151] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0152] [Examples 1 to 6, Comparative Examples 1 to 4] <Preparation of Primer Composition> Primer compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were each prepared. Specifically, (A-2) was weighed into a glass container, (A-1) was added to (A-2), and the mixture was stirred for 30 minutes using a Three-One Motor manufactured by Shinto Scientific Co., Ltd. to obtain component (A). Furthermore, component (A) was added to component (B), and the mixture was stirred for 30 minutes. Note that when (A-2) was not included, (A-1) was added directly to component (B), and the mixture was stirred for 30 minutes. Detailed preparation amounts were as shown in Table 1. Note that in Table 1, all numerical values ​​for the amount of each material in the primer composition are expressed in parts by mass.

[0153] <Preparation of Anaerobic Curing Adhesive> Components (C) to (E) and other components were weighed into a glass container, and these components were stirred for 60 minutes using a Three-One Motor manufactured by Shinto Scientific Co., Ltd. to obtain an anaerobic curing adhesive. Specifically, components (C-1), (C-2), (C-3), (D), (E-1), (E-2), and other component (2,6-di-t-butyl-p-cresol) were weighed, and these components were mixed by stirring for 60 minutes using a Three-One Motor manufactured by Shinto Scientific Co., Ltd. to obtain an anaerobic curing adhesive.

[0154] The details of the materials used are as follows:

[0155] [Materials of Primer Composition] <Component (A): Curing Accelerator> (A-1): Copper neodecanoate (reagent) (A-2): Acetone (reagent) <Component (B): Lubricating Oil> Press processing oil (G-6338F, manufactured by Nippon Kogyo Co., Ltd., hydrogenated petroleum fraction: 50% by mass or more) [Materials of Anaerobic Curing Adhesive] <Component (C): Compound Having One or More (Meth)acryloyl Groups> (Oligomer having one or more (meth)acryloyl groups in the molecule) (C-1): 45 parts by mass of urethane-modified acrylate having two acryloyl groups at both ends (C-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) (C-3): 35 parts by mass of 2-hydroxyethyl methacrylate.

[0156] Here, (C-1) was a urethane-modified acrylate having two acryloyl groups at both ends and a polyether skeleton, and (C-2) was an epoxy-modified acrylate having two acryloyl groups at both ends and a bisphenol A skeleton.

[0157] <Component (D): Organic peroxide> Cumene hydroperoxide 1 part by mass <Component (E): Anaerobic curing catalyst> (E-1): Saccharin 1.5 parts by mass (E-2): 1-acetyl-2-phenylhydrazine 0.5 parts by mass <Other components> 2,6-di-t-butyl-p-cresol 0.1 parts by mass.

[0158]

[0159] <Evaluation of Primer Composition> Each evaluation in Table 1 was carried out by the following method.

[0160] [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 with a load of 200 N, while 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 over the five minutes from 0 to 5 minutes after the start of measurement was defined as the initial maximum friction coefficient, and the maximum value of the friction coefficient over the five minutes from 25 to 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 was preferably 0.45 or less initially and after 30 minutes, more preferably 0.30 or less.

[0161] [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 curing 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 edge of the adhesive test piece was pulled at a pulling rate of 50 mm / min using a universal tensile tester, and the 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 15 MPa or more was considered acceptable. In Table 1, "Not measured" indicates that the maximum friction coefficient after 30 minutes exceeded 0.5, indicating that the performance of the press processing oil had deteriorated, and therefore the shear adhesive strength was not measured.

[0162] For Comparative Example 4, the shear adhesive strength was measured in the same manner as above, except that the press processing oil was applied instead of the primer composition.

[0163] Furthermore, when the shear adhesive 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, it was confirmed that the adhesive test piece fixed at 25°C for 1 hour had a shear adhesive strength of 2 MPa, and the adhesive test piece obtained by fixing at 25°C for 24 hours had a shear adhesive strength of 17 MPa.

[0164] As shown in Table 1, the primer compositions of Examples 1 to 6, in which the amount of component (A) was 35 parts by mass or less per 100 parts by mass of component (B), maintained good maximum friction coefficients, a characteristic value related to the characteristics of the press processing oil, even after 30 minutes, and also showed good shear bond strengths. In particular, the primer compositions of Examples 1 to 4, in which the amount of component (A) was 20 parts by mass or less per 100 parts by mass of component (B), showed good results. On the other hand, the primer compositions of Comparative Examples 1 to 3, which contained a large amount of component (A), showed a significant increase in maximum friction coefficients after 30 minutes, indicating that the performance (lubrication performance) of primer compositions containing a cure accelerator and a lubricating oil (e.g., press processing oil) deteriorates over time.

[0165] In the case of Comparative Example 4, in which no curing accelerator was used and only press processing oil was used, no shear adhesive strength was exhibited within one hour of lamination using the anaerobic curing adhesive.

[0166] From the above, it has been confirmed that use of the primer composition of the first aspect or the primer composition of the second aspect contributes to the acceleration of cure and the shear bond strength of the anaerobic curing adhesive without causing a decrease over time in the performance (lubrication performance) of the primer composition containing the cure accelerator and lubricating oil (e.g., press processing oil, etc.).

[0167] 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.

[0168] This application is based on Japanese Patent Application No. 2023-213834, filed on December 19, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A primer composition comprising the following component (A) and component (B), wherein component (A) contains an (A-1) metal complex, and the amount of component (A) is 35 parts by mass or less per 100 parts by mass of component (B); component (A): a curing accelerator for an anaerobic curing adhesive, and component (B): a lubricating oil.

2. The primer composition according to claim 1, wherein the amount of the component (A) is 0.1 to 35 parts by mass per 100 parts by mass of the component (B).

3. The primer composition according to claim 1, wherein the component (A) further comprises a solvent (A-2).

4. The primer composition according to claim 3, wherein (A-2) is a ketone-based solvent and / or an alcohol-based solvent.

5. The primer composition according to any one of claims 1 to 4, wherein the anaerobic curing adhesive 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.

6. The primer composition according to any one of claims 1 to 4, which is used for assembling laminated steel plates.

7. The primer composition according to any one of claims 1 to 4, wherein the component (B) is a press processing oil.

8. A method for producing a laminate comprising: applying the primer composition according to any one of claims 1 to 4 to an adherend; applying an anaerobically curable adhesive to the adherend, a coating of the primer composition, or both; and laminating the adherend and an adherend to be laminated after applying the primer composition and the anaerobically curable adhesive, and then curing the anaerobically curable adhesive.

9. The method according to claim 8, wherein the anaerobic curing adhesive 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.

10. A method for manufacturing a laminated steel sheet, comprising the following steps 1 to 4: step 1: applying the primer composition according to any one of claims 1 to 4 to a strip-shaped steel sheet; step 2: punching out the strip-shaped steel sheet to which the primer composition has been applied into a predetermined shape to obtain a thin steel sheet to which the primer composition has been applied; step 3: applying an anaerobically curable adhesive in a planar or dotted manner to the thin steel sheet to which the primer composition has been applied, and laminating the thin steel sheet with a thin steel sheet to be laminated; step 4: curing the anaerobic curable adhesive under predetermined conditions to obtain a laminated steel sheet.

11. The method according to claim 10, wherein the anaerobic curing adhesive 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.

12. A bonding composition kit comprising an anaerobic curing adhesive and the primer composition according to any one of claims 1 to 4.

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