Anaerobically curable composition

Abstract

Provided is an anaerobically curable composition that suppresses chelating agent precipitates and residues and has excellent storage stability. This anaerobically curable composition contains the following components (A)-(D), and the content of component (D) is 0.00001-0.01 mass% relative to the total mass of the anaerobically curable composition.　Component (A): a (meth)acrylate compound (excluding phosphate ester compounds containing a (meth)acryloyl group in one molecule); component (B): an organic peroxide; component (C): an anaerobic curing catalyst; and component (D): a chelating agent.

Description

Anaerobic curable composition

[0001] The present invention relates to an anaerobic curable composition.

[0002] As disclosed in JP-A-61-211386, methods for maintaining the storage stability of anaerobic curable compositions have been studied. Among them, by adding a chelating agent, impurities present in the anaerobic curable composition, particularly metal ions, are captured. However, the chelating agent has low compatibility with the resin and may precipitate over time even if it is once dissolved in the resin. Also, even when a small amount of the chelating agent is added, it is difficult to confirm whether it has dissolved in the resin, and there is a risk of remaining undissolved when the charged amount of the chelating agent is large.

[0003] Conventionally, it has been known to add a chelating agent to maintain the storage stability of an anaerobic curable composition. However, it has been difficult to confirm whether a small amount of the chelating agent has been dissolved, especially when the charged amount during preparation is large.

[0004] The present invention has been made in view of the above situation, and an object thereof is to provide an anaerobic curable composition that suppresses precipitates and residues of a chelating agent and has excellent storage stability.

[0005] As a result of intensive studies to achieve the above object, the present inventors have discovered a method for obtaining an anaerobic curable composition that suppresses precipitates and residues of a chelating agent and has excellent storage stability, and have completed the present invention.

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

[0007] A first embodiment of the present invention is an anaerobic curable composition containing the following components (A) to (D), wherein the content of the component (D) is 0.00001 to 0.01% by mass based on the total mass of the anaerobic curable composition: Component (A): (meth)acrylate compound (excluding a phosphate ester compound containing a (meth)acryloyl group in one molecule); Component (B): organic peroxide; Component (C): anaerobic curing catalyst; and Component (D): chelating agent.

[0008] A second embodiment of the present invention is the anaerobic curing composition according to the first embodiment, wherein component (D) is an organic sodium salt and / or an organic potassium salt.

[0009] A third embodiment of the present invention is an anaerobic curing composition according to the first or second embodiment, further comprising a phosphoric acid compound as component (E).

[0010] A fourth embodiment of the present invention is the anaerobic curing composition according to the third embodiment, wherein component (E) is a phosphate ester compound.

[0011] A fifth embodiment of the present invention is an anaerobic curable composition according to the third or fourth embodiment, wherein component (E) is a phosphate ester compound containing a (meth)acryloyl group in one molecule.

[0012] A sixth embodiment of the present invention is a method for producing an anaerobic curable composition according to any of the third to fifth embodiments, comprising mixing a composition obtained by completely dissolving component (D) in component (E) with components (A) to (C) or components (A) to (C) and component (E).

[0013] A seventh embodiment of the present invention is the manufacturing method described in the sixth embodiment, wherein the composition obtained by completely dissolving component (D) in component (E) is such that the concentration of component (D) is 0.1 to 1.0% by mass.

[0014] The present invention will now be described in detail. The present invention is not limited to the embodiments described below, and can be modified in various ways within the scope of the claims. The embodiments described herein can be combined in any way to form other embodiments.

[0015] Throughout this specification, singular expressions should be understood to include the concept of their plural form unless otherwise specified. Therefore, singular articles (e.g., "a," "an," "the" in English) should be understood to include the concept of their plural form unless otherwise specified. Furthermore, terms used herein should be understood to have the meaning commonly used in the art unless otherwise specified. Accordingly, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. In case of any conflict, this specification (including definitions) shall prevail.

[0016] In this specification, "X to Y" is used to mean "X or more and Y or less," including the numerical values ​​(X and Y) before and after it as the lower and upper limits, respectively. In this specification, the term (meth)acrylic means both acrylic and methacrylic, the term (meth)acryloyl means both acryloyl and methacryloyl, and the term (meth)acrylate means both acrylate and methacrylate. For example, the term (meth)acryloyl group means an acryloyl group (H ２ C=CH-C(=O)-) and methacryloyl group (H ２ C = C(CH) ３ This includes both A and B. "A and / or B" means that it includes A, B, and any combination thereof.

[0017] In this specification, concentration and % represent mass concentration and mass % respectively unless otherwise specified, and ratios represent mass ratios unless otherwise specified. Unless otherwise specified, operations and measurements of physical properties are carried out under conditions of room temperature (25°C) / relative humidity of 40-55% RH.

[0018] One aspect of the present invention is an anaerobic curable composition comprising the following components (A) to (D), wherein the content of component (D) is 0.00001 to 0.01% by mass relative to the total mass of the anaerobic curable composition: (A) component: (meth)acrylate compound (excluding phosphate ester compounds containing a (meth)acryloyl group in one molecule); (B) component: organic peroxide; (C) component: anaerobic curable catalyst; and (D) component: chelating agent.

[0019] The anaerobic curable composition according to the present invention suppresses chelating agent precipitates and residues, and provides an anaerobic curable composition with excellent storage stability.

[0020] Details of the present invention will be described below.

[0021] The component (A) that can be used in the present invention is a (meth)acrylate compound (excluding phosphate ester compounds containing a (meth)acryloyl group in one molecule). A (meth)acrylate compound refers to a compound containing a (meth)acryloyl group. Specifically, examples of component (A) include (meth)acrylate oligomers and (meth)acrylate monomers, which may be used individually or in combination of multiple types (two or more).

[0022] Examples of (meth)acrylate oligomers include, but are not limited to, epoxy-modified (meth)acrylate oligomers, urethane-modified (meth)acrylate oligomers, and oligomers having a main skeleton polymerized from (meth)acrylate monomers and having (meth)acryloyl groups at the ends of the main skeleton. In this specification, "oligomer" refers to a polymer in which monomer units are repeated approximately 2 to several dozen times.

[0023] Examples of urethane-modified (meth)acrylate oligomers include compounds synthesized by combining a polyhydric polyol with a polyfunctional isocyanate, a (meth)acryloyl group, and a hydroxyl group. The polyhydric polyol may have various skeletons, and polyhydric polyols having ethylene oxide skeletons, polyester skeletons, polyether skeletons, polybutadiene skeletons, or hydrogenated polybutadiene skeletons can be used.

[0024] Examples of epoxy-modified (meth)acrylate oligomers include, but are not limited to, epoxy-modified (meth)acrylate oligomers obtained by adding (meth)acrylic acid to bisphenol A type epoxy resin, bisphenol F type epoxy resin, or phenol novolac resin, as well as epoxy-modified (meth)acrylate oligomers obtained by reacting epoxy resin with an acid anhydride to increase the molecular weight of the main skeleton and then adding (meth)acrylic acid to the ends.

[0025] In an oligomer having a main skeleton formed by polymerizing (meth)acrylate monomers and having (meth)acryloyl groups at the ends of the main skeleton, the monofunctional (meth)acrylate monomers described later can be used as the (meth)acrylate monomers used to form the main skeleton. It is preferable to use (meth)acrylate monomers having hydrocarbon groups for polymerization. Methods for introducing (meth)acryloyl groups into the polymer of the (meth)acrylate monomer that is the main skeleton include (1) a method by reacting a vinyl polymer having hydroxyl groups at its ends with chlorine, bromine, or a (meth)acrylate compound containing hydroxyl groups, and (2) a method by reacting a vinyl polymer having halogen groups at its ends with an alkali metal ion or a (meth)acrylate compound containing a quaternary ammonium ion. These methods are already publicly known and are described in Japanese Patent Publication No. 61-133201, Japanese Patent Publication No. 11-80250, Japanese Patent Publication No. 2000-38404, Japanese Patent Publication No. 2001-271055, Japanese Patent Publication No. 2002-69121, and others.

[0026] The weight-average molecular weight of the (meth)acrylate oligomer in component (A) is 1,000 to 100,000, and the weight-average molecular weight (or molecular weight) of the (meth)acrylate monomer described later is less than 1,000. In this specification, weight-average molecular weight refers to the weight-average molecular weight on a polystyrene basis measured by gel permeation chromatography.

[0027] (A) A (meth)acrylate monomer can also be used as component. To lower the viscosity of the anaerobic curable composition and improve workability, a mixture of (meth)acrylate oligomer and (meth)acrylate monomer can be used, or the (meth)acrylate oligomer or (meth)acrylate monomer can be used alone. Examples of (meth)acrylate monomers include monofunctional (meth)acrylate monomers, difunctional (meth)acrylate monomers, trifunctional (meth)acrylate monomers, and tetrafunctional or more functional (meth)acrylate monomers. Preferably, the (meth)acrylate monomer is a low molecular weight (for example, a molecular weight of less than 1000), and more preferably a (meth)acrylate monomer having a molecular weight of 500 or less, as this provides the effect of lowering viscosity when added.

[0028] Specific examples of monofunctional (meth)acrylate monomers include lauryl (meth)acrylate, stearyl (meth)acrylate, ethyl carbitol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, nonylphenoxyethyl (meth)acrylate, nonylphenoxytetraethylene glycol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, and butoxyethyl (meth)acrylate. Examples of suitable methacrylates include, but are not limited to, but butoxytriethylene glycol (meth)acrylate, 2-ethylhexyl polyethylene glycol (meth)acrylate, 4-hydroxybutyl (meth)acrylate, nonylphenyl polypropylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerol (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, epichlorohydrin (ECH) modified butyl (meth)acrylate, epichlorohydrin (ECH) modified phenoxy (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and N,N-diethylaminoethyl (meth)acrylate.

[0029] Specific examples of difunctional (meth)acrylate monomers include ethoxylated bisphenol A di(meth)acrylate (e.g., total number of alkylene oxide repeats: 2-5), 1,3-butylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexane glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and EO variants. Examples include, but are not limited to, neopentyl glycol di(meth)acrylate, propylene oxide (PO)-modified neopentyl glycol di(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, caprolactone-modified hydroxypivalate neopentyl glycol di(meth)acrylate, neopentyl glycol-modified trimethylolpropane di(meth)acrylate, stearic acid-modified pentaerythritol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, EO-modified dicyclopentenyl di(meth)acrylate, and diacryloyl isocyanurate.

[0030] Specific examples of trifunctional (meth)acrylate monomers include, but are not limited to, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, ECH-modified trimethylolpropane tri(meth)acrylate, ECH-modified glycerol tri(meth)acrylate, tris(acryloyloxyethyl) isocyanurate, and ethylene oxide isocyanurate-modified tri(meth)acrylate.

[0031] Specific examples of (meth)acrylate monomers with four or more functionalities include, but are not limited to, ditrimethylolpropanetetra(meth)acrylate, pentaerythritoltetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, alkyl-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0032] The (meth)acrylate monomer in component (A) can also be used to adjust the viscosity of the anaerobic curable composition and improve its workability. A (meth)acrylate monomer is a low molecular weight compound, specifically a compound having a molecular weight of less than 1000. The (meth)acrylic monomer is preferably a (meth)acrylate monomer having a hydroxyl group in one molecule and / or a (meth)acrylate monomer having a saturated alicyclic structure. Specific examples of (meth)acrylate monomers having a hydroxyl group include, but are not limited to, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate. The (meth)acrylate monomers having a hydroxyl group are most preferably 2-hydroxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, and / or 2-hydroxyethyl methacrylate, but are not limited to these. Specific examples of (meth)acrylate monomers having a saturated alicyclic structure include, but are not limited to, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, cyclohexyl (meth)acrylate, and adamantanyl (meth)acrylate. The (meth)acrylate monomers having a saturated alicyclic structure are most preferably (meth)acrylate monomers having an isobornyl skeleton (e.g., isobornyl (meth)acrylate) and / or (meth)acrylate monomers having a dicyclopentanyl skeleton (e.g., dicyclopentanyl (meth)acrylate).

[0033] (A) Examples of commercially available components include DICLITE® UE-8071-60BH, UE-8740, UE-8410 (all manufactured by DIC Corporation), NK ester BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BPE-1300N (all manufactured by Shin Nakamura Chemical Industry Co., Ltd.), Shiko series UV-3000B, UV-3700B (all manufactured by Mitsubishi Chemical Corporation), Light ester IB-X (all manufactured by Kyoeisha Chemical Co., Ltd.), and epoxy ester M-600A (all manufactured by Kyoeisha Chemical Co., Ltd.).

[0034] The component (B) that can be used in the present invention is an organic peroxide. The organic peroxide is particularly preferably a hydroperoxide. A hydroperoxide is an organic peroxide having the structure shown in the following general formula 1, where R １ This refers to linear aliphatic hydrocarbons, cyclic aliphatic hydrocarbons, aromatic hydrocarbons, or derivatives thereof. Specific examples of organic peroxides include, but are not limited to, p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide.

[0035]

[0036] The content (amount added) of component (B) is preferably 0.1 to 5.0 parts by mass per 100 parts by mass of component (A). When the content (amount added) of component (B) is 0.1 parts by mass or more, curability can be achieved, and when the content (amount added) of component (B) is 5.0 parts by mass or less, storage stability can be maintained. The content (amount added) of component (B) may be 0.5 to 1.5 parts by mass or 0.7 to 1.2 parts by mass per 100 parts by mass of component (A).

[0037] Component (C) that can be used in the present invention is an anaerobic curing catalyst. In an anaerobic state where it has not come into contact with oxygen, component (C) reacts with the metal ions of the adherend, decomposes the above-mentioned component (B), and generates free radicals. In particular, as component (C), it is preferable to use saccharin such as that in Formula 2, the sodium salt of saccharin, the potassium salt of saccharin, etc.

[0038]

[0039] The content (addition amount) of component (C) with respect to 100 parts by mass of component (A) is preferably 0.1 to 5.0 parts by mass, and more preferably 0.1 to 2.0 parts by mass. When the content (addition amount) of component (C) is 0.1 part by mass or more, anaerobic curability can be exhibited, and when the content (addition amount) of component (C) is 5.0 parts by mass or less, storage stability can be maintained. The content (addition amount) of component (C) may be 1.0 to 1.8 parts by mass or 1.2 to 1.6 parts by mass with respect to 100 parts by mass of component (A).

[0040] Component (D) that can be used in the present invention is a chelating agent. In particular, a chelating agent that is solid at 25°C can be used. Component (D) is preferably an organic sodium salt and / or an organic potassium salt. Also, when adding to component (A), component (D) is preferably used as a composition dissolved by the following-mentioned component (E). Hereinafter, this composition is also referred to as a chelating agent master. When dissolving component (D) in component (E), it may be heated to 30 to 60°C. Component (D) is a compound that can coordinate with metal ions, which are impurities in the anaerobic curable composition, chelate the metal to make it inactive, and suppress the reactivity in the anaerobic curable composition. Therefore, the anaerobic curable composition can maintain storage stability by component (D).

[0041] Specific examples of chelating agents that are solid at 25°C include compounds such as 2NA (EDTA-2Na) (ethylenediamine-N,N,N',N'-tetraacetic acid disodium salt dihydrate) and 4NA (EDTA-4Na) (ethylenediamine-N,N,N',N'-tetraacetic acid tetrahydrate) manufactured by Dojin Chemical Laboratory Co., Ltd., and EDTA-based (ethylenediaminetetraacetic acid), NTA-based (nitrilotetraacetic acid), DTPA-based (diethylenetriaminepentaacetic acid), HEDTA-based (hydroxyethylethylenediaminetriacetic acid), and TTHA-based (triethylenetetraacetic acid) manufactured by Kirest Co., Ltd. Examples of compounds include, but are not limited to, lamin hexaacetic acid, PDTA-based (1,3-propanediaminetetraacetic acid), DPTA-OH-based (1,3-diamino-2-hydroxypropanetetraacetic acid), HIDA-based (hydroxyethyliminodiacetic acid), DHEG-based (dihydroxyethylglycine), GEDTA-based (glycol etherdiaminetetraacetic acid), CMGA-based (dialboxymethylglutamic acid), EDDS-based ((S,S)-ethylenediaminedisuccinic acid) and EDTMP-based (ethylenediaminetetra(methylenephosphonic acid)) compounds. Component (D) may contain a chelating agent that is liquid at 25°C. Specific examples of chelating agents that are liquid at 25°C include, but are not limited to, MZ-8 manufactured by Kirest Co., Ltd., HEDP-based (1-hydroxyethane-1,1-diphosphonic acid), NTMP-based (nitrilotris (methylenephosphonic acid)), and PBTC-based (2-phosphono-1,2,4-butanetricarboxylic acid) compounds. Component (D) dissolves in polar oligomers and monomers, but does not dissolve in low-polarity oligomers and monomers, or precipitates later even if dissolved initially. From the viewpoint of improving storage stability with the addition of a small amount, component (D) is preferably an EDTA-based chelating agent, and preferably 2NA (EDTA-2Na) and / or 4NA (EDTA-4Na).

[0042] The content (addition amount) of component (D) is 0.00001 to 0.01% by mass based on the whole (total mass) of the anaerobic curable composition. The content (addition amount) of component (D) may be 0.00005 to 0.005% by mass or 0.0001 to 0.002% by mass based on the whole (total mass) of the anaerobic curable composition. The content (addition amount) of component (D) is preferably 0.00001 to 0.01 parts by mass based on 100 parts by mass of component (A). The content (addition amount) of component (D) may be 0.00005 to 0.005 parts by mass or 0.0001 to 0.003 parts by mass based on 100 parts by mass of component (A).

[0043] The anaerobic curable composition according to the present invention may further contain a phosphoric acid compound as component (E). Component (E) that can be used in the present invention is a phosphoric acid compound. The phosphoric acid compound is preferably liquid under a 25°C atmosphere. Component (E) is preferably a phosphoric acid ester compound, and more preferably a phosphoric acid ester compound containing a (meth)acryloyl group in one molecule. Examples of the phosphoric acid ester compound containing a (meth)acryloyl group in one molecule include, but are not limited to, 2-hydroxyethyl (meth)acrylate acid phosphate, 2-hydroxyethyl di(meth)acrylate acid phosphate, etc. However, when component (E) is a phosphoric acid ester compound containing a (meth)acryloyl group in one molecule, component (E) is not included in component (A). Any phosphoric acid compound other than the phosphoric acid ester compound is treated as component (E) even if it has a (meth)acryloyl group. Component (E) does not contain a phosphoric acid compound that is a photoinitiator and an antioxidant.

[0044] In the above chelating agent master, component (E) is not limited as long as it is a phosphoric acid compound capable of dissolving component (D). Component (E) in the chelating agent master is preferably a (meth)acrylate monomer having a phosphoric acid ester skeleton such as 2-hydroxyethyl (meth)acrylate acid phosphate. Particularly preferably, it is a compound represented by General Formula 3. Here, n represents an integer of 1 or 2. R ２ represents hydrogen or an alkyl group, and the alkyl group is preferably a methyl group. R３ This represents a divalent organic group, preferably an alkylene group having 1 to 5 carbon atoms.

[0045]

[0046] The content (amount added) of component (E) per 100 parts by mass of component (A) is preferably 0.01 to 1.0 parts by mass, and more preferably 0.1 to 0.5 parts by mass. The content (amount added) of component (E) may be 0.15 to 0.45 parts by mass per 100 parts by mass of component (A).

[0047] The concentration of component (D) in the chelating agent master is preferably 0.01 to 5.0% by mass, and more preferably 0.1 to 3.0% by mass, relative to the total mass of the chelating agent master, from the viewpoint of being able to suppress the precipitation of component (D). The concentration of component (D) in the chelating agent master may also be 0.1 to 2.0% by mass or 0.1 to 1.0% by mass.

[0048] In the anaerobic curable composition according to the present invention, the concentration of component (D) when converted to a chelating agent master is preferably 0.001 to 5.0% by mass, and more preferably 0.01 to 1.0% by mass, from the viewpoint of being able to suppress the precipitation of component (D). The concentration of component (D) when converted to a chelating agent master may also be 0.01 to 0.5% by mass.

[0049] Component (A) may contain residual metal catalysts from the synthesis process, and it is necessary to dissolve component (D) beforehand to capture these metal catalysts. However, component (D) is affected by the solubility of the entire anaerobic curing composition, and once dissolved, component (D) may precipitate over time. Therefore, adding it as a chelating agent master can suppress the precipitation of component (D).

[0050] The anaerobic curable composition according to the present invention may contain appropriate amounts of additives such as (meth)acrylamide monomer, curing accelerator, inorganic filler, polymerization inhibitor, photoinitiator, antioxidant, surfactant, leveling agent, plasticizer, light stabilizer, and water, to the extent that the properties of the anaerobic curable composition according to the present invention are not impaired. The appearance, flowability, strength of the cured product, etc., can be adjusted by adding these components.

[0051] Examples of (meth)acrylamide monomers include, but are not limited to, dimethylacrylamide, acryloylmorpholine, and diethylacrylamide. Considering price and availability, diethylacrylamide or dimethylacrylamide are preferred as (meth)acrylamide monomers. Specific examples of (meth)acrylamide monomers include, but are not limited to, DMAA®, ACMO®, and DEAA® manufactured by KJ Chemicals Co., Ltd.

[0052] As the curing accelerator mentioned above, compounds that promote the reaction between component (A) and component (B) can be used. Specifically, examples of curing accelerators include, but are not limited to, tertiary amines such as N,N-dimethylaniline, N,N-dimethyl-P-toluidine, diisopropanol-P-toluidine, and triethylamine; polyamines such as diethylenetriamine, triethylenetetramine, and pentaethylenehexamine; thioureas such as thiourea, ethylenethiourea, benzoylthiourea, acetylthiourea, and tetramethylthiourea; hydrazines such as 1-acetyl-2-phenylhydrazine; azole compounds such as benzothiazole, 1,2,4-triazole, benzotriazole, hydroxybenzotriazole, benzoxazole, 1,2,3-benzothiadiazole, and 3-mercaptobenzotrizole; and mercaptan compounds such as n-dodecyl mercaptan, ethyl mercaptan, butyl mercaptan, and dodecanethiol. The curing accelerator is preferably selected from the group consisting of hydrazines, azole compounds, and mercaptan compounds, and more preferably from the group consisting of 1-acetyl-2-phenylhydrazine, benzothiazole, and dodecanethiol. The curing accelerator may be used alone or in combination of two or more.

[0053] In one embodiment, the anaerobic curable composition according to the present invention comprises the above-described components (A) to (E) and a curing accelerator.

[0054] The amount of curing accelerator added is not particularly limited. The amount of curing accelerator added is, for example, 0.1 to 2.0 parts by mass, preferably 0.4 to 1.5 parts by mass, per 100 parts by mass of component (A).

[0055] As the inorganic filler mentioned above, fumed silica powder can be used to adjust viscosity. Examples of fumed silica powder include hydrophilic types in which silanol remains on the untreated surface, and hydrophobic types in which the silanol on the surface is treated with dimethyldichlorosilane or the like to make the silica surface hydrophobic, but are not limited to these. Specific examples of hydrophilic fumed silica powder products include Aerosil 90, 130, 150, 200, 255, 300, and 380 manufactured by Nippon Aerosil Co., Ltd. Specific examples of hydrophobic fumed silica powders include Aerosil R972 (dimethyldichlorosilane treated), R974 (dimethyldichlorosilane treated), R104 (octamethylcyclotetrasiloxane treated), R106 (octamethylcyclotetrasiloxane treated), R202 (polydimethylsiloxane treated), R805 (octylsilane treated), R812 (hexamethyldisilazane treated), R816 (hexadecylsilane treated), and R711 (methacrylicsilane treated), all manufactured by Nippon Aerosil Co., Ltd. Other specific examples of fumed silica powders include the Cabotsil series of fumed silica products manufactured by Cabot Co., Ltd.

[0056] The polymerization inhibitors mentioned above can be used to further suppress viscosity changes over time. Specific examples of polymerization inhibitors include, but are not limited to, 2,6-di-t-butyl-4-methylphenol (2,6-di-t-butyl-p-cresol), hydroquinone (1,2,3,4-tetrahydroquinoline), hydroquinone monomethyl ether, and 4-t-butylcatechol.

[0057] In one embodiment, the anaerobic curable composition according to the present invention comprises the above-described components (A) to (E) and a polymerization inhibitor.

[0058] In one embodiment, the anaerobic curable composition according to the present invention comprises the above-mentioned components (A) to (E), a curing accelerator, and a polymerization inhibitor.

[0059] The amount of polymerization inhibitor (amount added) is not particularly limited. The amount of polymerization inhibitor (amount added) is, for example, 0.1 to 1.5 parts by mass, preferably 0.3 to 1.0 parts by mass, per 100 parts by mass of component (A).

[0060] The above photoinitiators can be used to impart photocurability. Specific examples of photoinitiators include acetophenone, propiophenone, benzophenone, xanthol, fluorein, benzaldehyde, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone, 3-pentylacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 2,2-diethoxyacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 2,4,6-trimethylbenzophenone, oligo(2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone), 4-allylacetophenone, camphorquinone, 2 Examples include, but are not limited to, 4,6-trimethylbenzoyldiphenylphosphine oxide, 4-methylbenzophenone, 4-chloro-4'-benzylbenzophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 3-chloroxantone, 3,9-dichloroxantone, 3-chloro-8-nonylxantone, benzoyl, benzoyl methyl ether, benzoin butyl ether, bis(4-dimethylaminophenyl) ketone, benzyl methoxyketal, 2-chlorothioxantone, o-methylbenzoate, benzyldimethyl ketal, and methylbenzoyl methyl phosphate.

[0061] The above-mentioned antioxidants can be used to prevent deterioration of the cured product. Specific examples of antioxidants include, but are not limited to, phenolic antioxidants, thioether-based antioxidants, phosphorus-based antioxidants, and nitroxide-based antioxidants.

[0062] The water used may include, but is not limited to, tap water, purified water from a purification system, ion-exchanged water, or distilled water.

[0063] The anaerobic curable composition according to the present invention can be produced by mixing and stirring each component. The stirring conditions are not particularly limited, and the stirring temperature is, for example, 23 to 60°C, and the stirring time is, for example, 10 minutes to 12 hours. Component (D) is preferably added in the form of a chelating agent master dissolved in component (E). Furthermore, even when using a chelating agent master, there is no restriction on adding additional component (E). In the production of the chelating agent master, the stirring conditions are not particularly limited, and the stirring temperature is, for example, 23 to 60°C, and the stirring time is, for example, 1 to 12 hours. In this specification, a state in which component (D) is completely dissolved in component (E) means a state in which, when the chelating agent master is filtered through 80 to 200 mesh, no residue of component (D) can be seen when the mesh is visually inspected or examined under a microscope, and it may also mean a state in which no precipitates of component (D) can be seen when the composition is spread and observed under a microscope or the like.

[0064] One embodiment of the method for producing an anaerobic curable composition according to the present invention includes adding and mixing a composition (chelating agent master) obtained by completely dissolving component (D) in component (E) with components (A) to (C) or components (A) to (C) and component (E). The mixing order of each component is just an example, and the mixing order of each component is not particularly limited. Each component may be added to the mixing means all at once and mixed, or added sequentially and mixed.

[0065] In a preferred embodiment of the method for producing an anaerobic curable composition according to the present invention, in a composition (chelating agent master) obtained by completely dissolving component (D) in component (E), the concentration of component (D) is 0.1 to 1.0% by mass.

[0066] The adherend for the anaerobic curing composition according to the present invention is preferably a metal. In particular, the metal is preferably one from which metal ions are generated from the surface of the adherend, such as a steel plate.

[0067] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Hereinafter, the anaerobic curable composition will also be simply referred to as the composition. Unless otherwise specified, the tests were conducted under conditions of 25°C and 50% RH.

[0068] [Examples 1-10 and Comparative Examples 1-2] The following components were prepared to prepare anaerobic curable compositions. (A) Component: A mixture of (meth)acrylate compound, epoxy-modified acrylate / 2-hydroxyethyl acrylate in a ratio of 6:4 (mass ratio) (DICLITE® UE-8071-60BH, manufactured by DIC Corporation) - Ethoxylated bisphenol A dimethacrylate with a total number of alkylene oxide repeats of 4.0 (BPE-200, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) - Ethoxylated bisphenol A dimethacrylate with a total number of alkylene oxide repeats of 2.6 (BPE-100, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) - Urethane-modified acrylate oligomer with 2 functional groups (acryloyl groups) and a weight-average molecular weight (Mw) of 38000 (Shiko ＴＭ (B) Component: Organic peroxide / cumene hydroperoxide (perkmyl H-80, manufactured by Nippon Oil & Fats Co., Ltd.) (C) Component: Anaerobic curing catalyst / saccharin (reagent) (D) Component: Chelating agent / ethylenediamine-N,N,N',N'-tetraacetate disodium dihydrate (solid at 25°C) (2NA (EDTA-2Na), manufactured by Dojin Chemical Laboratory Co., Ltd.) • Ethylenediamine-N,N,N',N'-tetraacetate tetrasodium salt tetrahydrate (solid at 25°C) (4NA (EDTA-4Na) manufactured by Dojin Chemical Laboratory Co., Ltd.) (E) Component: Phosphate compound - 2-hydroxyethyl methacrylate acid phosphate (JPA-514 manufactured by Johoku Chemical Industry Co., Ltd.) Curing accelerator - Benzothiazole (reagent) - Dodecanethiol (reagent) - 1-Acetyl-2-phenylhydrazine (reagent) Polymerization inhibitor - 1,2,3,4-tetrahydroquinoline (reagent) - 2,6-di-t-butyl-p-cresol (reagent).

[0069] [Preparation of Chelating Agent Masters] According to the amounts (parts by mass) listed in Table 1, component (D) was added to component (E), and the mixture was stirred at 50°C for 2 hours to prepare chelating agent masters. Hereinafter, the prepared chelating agent masters will be referred to as Masters 1 to 5. The concentrations (by mass) of component (D) (chelating agent) in Masters 1 to 5 are also shown together in Table 1.

[0070]

[0071] Compositions for Examples 1-5 and Comparative Example 1 were prepared. Compositions for Examples 1-5 were prepared as follows: Components (A), chelating agent master, component (E) (Example 1 only), and polymerization inhibitor were weighed into a beaker and added to a stirring kettle, where they were stirred for 60 minutes at 25°C. Then, components (B), (C), and curing accelerator were weighed into a beaker and added to the stirring kettle, where they were stirred for another 60 minutes at 25°C to prepare the compositions for Examples 1-5. Composition for Comparative Example 1 was prepared as follows: Components (A), (D), and polymerization inhibitor were weighed into a beaker and added to a stirring kettle, where they were stirred for 2 hours at 50°C. Then, components (B), (C), and curing accelerator were weighed into a beaker and added to the stirring kettle, where they were stirred for another 60 minutes at 25°C to prepare the composition for Comparative Example 1. Detailed preparation amounts are shown in Table 2, and all values ​​are expressed in parts by mass. Table 2 also shows the "amount of component (D) added" in the composition (including component (D) derived from the chelating agent master), the "amount of component (E) added" in the composition (including component (E) derived from the chelating agent master), the "concentration of component (D) relative to the entire composition (mass%)", and the "concentration of component (D) converted to the chelating agent master (mass%)".

[0072] [Mesh Verification (Evaluation of Precipitates and Residues)] The composition immediately after manufacturing (initial) and the composition after being stored at 25°C for 4 months were filtered through an 80-mesh filter, and the mesh surface was observed under a microscope and evaluated according to the following evaluation criteria. The results are shown in Table 2 under "Mesh Verification". Evaluation Criteria Good: No precipitates or residues. Poor: Precipitates or residues are present.

[0073]

[0074] As shown in the mesh confirmation in Table 2, all of Examples 1-4 and Comparative Example 1 performed well initially. However, in the case of Comparative Example 1, it was confirmed that precipitates and residues were filtered through the mesh after 4 months in a 25°C atmosphere.

[0075] Torque measurements, set time measurements, and gel time measurements were performed on the compositions of Example 3, Example 5, and Comparative Example 1. The results are summarized in Table 3.

[0076] [Torque Measurement] M10, P=1.5 x 20 mm hexagonal bolts (JIS B1180) and M10, P=1.5 hexagonal nuts were used. 20 mg of the composition was applied to the threaded portion of the bolt, inserted into the nut, and left at 25°C for 2 hours or 24 hours to allow the composition to harden anaerobically. With the bolt and nut attached, the bolt head was fixed with a fixing jig, and the nut was rotated using a torque wrench. The strength at which the nut first began to move was measured as the "breaking torque (N・m)". Furthermore, the torque after a quarter turn was measured as the "residual torque (N・m)". A torque of 30 N・m or higher is considered sufficient to indicate that hardening is complete.

[0077] [Set Time Measurement] A hexagonal bolt (JIS B1180) of size M10, P=1.5 x 20 mm, and a hexagonal nut of size M10, P=1.5 were used. 20 mg of the composition was applied to the threaded portion of the bolt, and after assembling the nut, the nut was moved with a finger, and the time was measured every minute using a stopwatch until the nut could no longer be moved. The time at which the nut could no longer be moved was defined as the "set time (minutes)". This measurement is a method to confirm the initial curability of the composition; a shorter set time indicates higher curability. To improve workability, a set time of 5 minutes or less is preferable.

[0078] [Gel Time Measurement] 4 g of the composition was placed in a test tube with an inner diameter of 15 mm and left in an 80°C atmosphere. The composition was visually checked every hour to see if it was flowing. The time at which the composition stopped flowing was defined as the "gel time (hours)". If the composition was still flowing after 24 hours, the gel time was indicated as "longer than 24 hours". This measurement is equivalent to an accelerated test of storage stability, and a longer gel time indicates higher storage stability. To prevent gelation during transport, a gel time of 5 hours or more is preferable.

[0079]

[0080] As shown in Table 3, the compositions of Examples 3 and 5 and the composition of Comparative Example 1 have equivalent performance in terms of fracture torque, residual torque, and set time, but there is a difference in gel time. Gel time corresponds to an accelerated test of storage stability, and the compositions of Examples have more than twice the gel time of the comparative example composition under an 80°C atmosphere, indicating that the compositions of Examples have high storage stability. On the other hand, there is no difference between the compositions of Examples and the comparative example composition in terms of curability related to fracture torque, residual torque, and set time. From this, it can be seen that the compositions of Examples have good curability and good storage stability despite having a lower "concentration of component (D) relative to the whole composition (mass%)" than the compositions of the comparative example composition.

[0081] Next, the compositions for Examples 6 to 10 and Comparative Example 2 were prepared. The compositions for Examples 6 to 10 were prepared as follows: Components (A), the chelating agent master, component (E), and the polymerization inhibitor were weighed into beakers and added to a stirring kettle, where they were stirred for 60 minutes at a 25°C atmosphere. Then, components (B), (C), and the curing accelerator were weighed into beakers and added to the stirring kettle, where they were stirred for another 60 minutes at a 25°C atmosphere to prepare the compositions for Examples 6 to 10. The composition for Comparative Example 2 was prepared as follows: Components (A), (D), and the polymerization inhibitor were weighed into beakers and added to a stirring kettle, where they were stirred for 2 hours at a 50°C atmosphere. Then, components (B), (C), and the curing accelerator were weighed into beakers and added to the stirring kettle, where they were stirred for another 60 minutes at a 25°C atmosphere to prepare the composition for Comparative Example 2. Detailed preparation amounts are shown in Table 4, and all values ​​are expressed in parts by mass. Table 4 also shows the "amount of component (D) added" (including component (D) derived from the chelating agent master), the "amount of component (E) added" (including component (E) derived from the chelating agent master), the "concentration of component (D) relative to the entire composition (mass%)", and the "concentration of component (D) converted to the chelating agent master (mass%)".

[0082]

[0083] When the compositions of Examples 6-10 and Comparative Example 2 were evaluated according to the mesh verification described above, all of Examples 6-10 and Comparative Example 2 performed well initially. However, in the case of Comparative Example 2, it was confirmed that precipitates and residues were filtered through the mesh after 4 months in a 25°C atmosphere.

[0084] The torque, set time, and gel time measurements described above were performed on the compositions of Examples 6-10 and Comparative Example 2. The results are summarized in Table 5.

[0085]

[0086] As shown in Table 5, the compositions of Examples 6 to 10 and the composition of Comparative Example 2 have equivalent performance in terms of fracture torque, residual torque, and set time, but there is a difference in gel time. Gel time corresponds to an accelerated test of storage stability, and the compositions of Examples 6 and 7 are equivalent to the composition of Comparative Example 2, while the compositions of Examples 8 to 10 have a gel time more than twice that of the composition of Comparative Example 2, indicating that the compositions of the examples have high storage stability. On the other hand, there is no difference between the compositions of the examples and the comparative examples in terms of curability related to fracture torque, residual torque, and set time. From this, it can be seen that the compositions of the examples have good curability and good storage stability despite having a lower "concentration of component (D) relative to the whole composition (mass%)" than the compositions of the comparative examples.

[0087] In anaerobic curable compositions, chelating agents are dissolved to achieve both storage stability and curability. However, the anaerobic curable composition according to the present invention allows for the effective addition of a smaller amount of chelating agent. This prevents the generation of precipitates and residues from excessively added chelating agents, and suppresses the decrease in storage stability while maintaining the curability of the anaerobic curable composition. In particular, it enables reproducible manufacturing with no lot-to-lot variation when mixing anaerobic curable compositions in large quantities industrially.

[0088] This application is based on Japanese Patent Application No. 2024-165760, filed on 25 September 2024, the disclosures of which are cited in their entirety by reference.

Claims

1. An anaerobic curable composition comprising the following components (A) to (D), wherein the content of component (D) is 0.00001 to 0.01% by mass relative to the total mass of the anaerobic curable composition: (A) component: (meth)acrylate compound (excluding phosphate ester compounds containing a (meth)acryloyl group in one molecule); (B) component: organic peroxide; (C) component: anaerobic curing catalyst; and (D) component: chelating agent.

2. The anaerobic curing composition according to claim 1, wherein component (D) is an organic sodium salt and / or an organic potassium salt.

3. The anaerobic curing composition according to claim 1, further comprising a phosphoric acid compound as component (E).

4. The anaerobic curable composition according to claim 3, wherein component (E) is a phosphate ester compound.

5. The anaerobic curable composition according to claim 4, wherein component (E) is a phosphate ester compound containing a (meth)acryloyl group in one molecule.

6. A method for producing an anaerobic curable composition according to claim 3, comprising mixing a composition obtained by completely dissolving component (D) in component (E) with components (A) to (C) or components (A) to (C) and component (E).

7. The manufacturing method according to claim 6, wherein in a composition obtained by completely dissolving component (D) in component (E), the concentration of component (D) is 0.1 to 1.0% by mass.

Images