Resin composition, resin composition for metal surface treatment, method for manufacturing metal laminate, and metal laminate

Abstract

Provided is a resin composition which contains a component (A) that contains an epoxy resin that is solid at 25 DEG C and a component (B) that contains one or more substances selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes. Also provided is a method for producing a metal laminate, which comprises: a step in which the resin composition is applied to the surface of a first metal plate to form a coating film; and a step for forming a metal laminate by laminating a second metal plate on the coating film of the first metal plate.

Description

Technical Field

[0001] This invention relates to resin compositions having excellent adhesive properties. Background Technology

[0002] Epoxy resins and polyurethane resins exhibit excellent adhesion to various substrates, resulting in cured products with superior corrosion resistance, heat resistance, chemical resistance, electrical properties, and mechanical properties. Therefore, they are widely used in various fields as adhesives, coatings, and paints. Furthermore, in recent years, from the perspective of reducing environmental impact and safety, there has been a need to formulate aqueous resin compositions using water as a solvent, particularly for adhesives, coatings, and coatings containing epoxy and polyurethane resins. Patent Document 1 describes an environmentally friendly aqueous epoxy resin emulsion with excellent storage stability and rust prevention, and an aqueous coating containing the emulsion. Patent Document 2 describes an aqueous epoxy resin dispersion with low volatile organic compounds (VOCs), particularly suitable for coating metals and concrete.

[0003] In addition, various metal surface treatment agents using water-based epoxy resins and the like, which possess metal adhesion and corrosion resistance, have been developed. For example, Patent Document 3 describes a water-based coating composition that can improve the water resistance and adhesion of steel sheets that have undergone surface treatments such as plating, and form a coating film with excellent corrosion resistance / corrosion resistance. Patent Document 4 describes a surface treatment agent for metal materials that can produce surface-treated metal materials with excellent corrosion resistance and adhesion, eliminating the need for substrate preparation.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-009270

[0007] Patent Document 2: Japanese Patent Application Publication No. 2015-214698

[0008] Patent Document 3: Japanese Patent Application Publication No. 2015-124234

[0009] Patent Document 4: International Publication No. 2015 / 056355 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, these water-based resin compositions and metal surface treatment agents do not have sufficient adhesion to metal surfaces, and there is a market demand for resin compositions with excellent adhesion.

[0012] In view of the above situation, the objective of the present invention is to provide a resin composition having excellent adhesive properties.

[0013] Methods for solving problems

[0014] Therefore, through in-depth research, the inventors discovered that a resin composition containing specific components solves the above-mentioned problems.

[0015] That is, the present invention provides a resin composition comprising: an component (A) comprising an epoxy resin that is solid at 25°C, and a component (B) comprising one or more components selected from polyether polyurethane prepolymer and polyether polyurethane.

[0016] The effects of the invention

[0017] According to the present invention, a resin composition with excellent adhesive properties can be provided. Detailed Implementation

[0018] 1. Resin composition

[0019] The resin composition of the present invention comprises a component (A) containing an epoxy resin that is solid at 25°C, and a component (B) containing one or more components selected from polyether polyurethane prepolymer and polyether polyurethane. The resin composition of the present invention will be described in detail below.

[0020] 1-1. Ingredients (A)

[0021] The component (A) used in this invention comprises an epoxy resin that is solid at 25°C. In this invention, any epoxy resin that is solid at 25°C can be used without particular limitation. Examples of such epoxy resins include, for instance, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AD ​​type epoxy resin, etc. (which are solid at 25°C), resorcinol type epoxy resin, hydroquinone type epoxy resin, catechol type epoxy resin, dihydroxynaphthalene type epoxy resin, biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, oxazolidinone cyclic epoxy resin, phenolic varnish type epoxy resin, and so on. Phenolic resin clear varnish type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin, naphthol phenolic clear varnish type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol cocondensed phenolic clear varnish type epoxy resin, naphthol-cresol cocondensed phenolic clear varnish type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenolic resin type epoxy resin, biphenyl modified phenolic clear varnish type epoxy resin, etc. One or more of these can be used. From the viewpoint of improving the adhesiveness of the obtained resin composition, especially the adhesiveness produced by short-time pressing, it is preferable to use a bisphenol type epoxy resin that is solid at 25°C. More preferably, it is preferable to use one or more of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin that are solid at 25°C. It is even more preferable to use a bisphenol A type epoxy resin that is solid at 25°C. It should be noted that in this invention, "solid at 25°C" means that the melting point is higher than 25°C and the resin is solid at 25°C. There is no particular limitation if the melting point of the epoxy resin is higher than 25°C. From the viewpoint of the adhesiveness of the obtained resin composition, the melting point of the epoxy resin is preferably 40°C to 180°C, more preferably 70°C to 150°C. In addition, the component (A) containing the epoxy resin that is solid at 25°C is clearly distinguished from the phosphoric acid modified epoxy resin described later.

[0022] The epoxy equivalent of the epoxy resin, which is solid at 25°C, is not particularly limited and can be adjusted according to the purpose. From the viewpoint of improving the adhesiveness of the obtained resin composition, especially the adhesiveness produced by short-time pressing, the epoxy equivalent of the epoxy resin, which is solid at 25°C, is preferably 500 g / eq. to 30000 g / eq., more preferably 1000 g / eq. to 10000 g / eq., further preferably 1500 g / eq. to 6000 g / eq., even more preferably 2000 g / eq. to 5000 g / eq., and particularly preferably 2500 g / eq. to 3500 g / eq. In this invention, the epoxy equivalent of the epoxy resin is determined according to JIS K7236 (2009).

[0023] 1-2. Component (B)

[0024] The component (B) used in this invention comprises one or more selected from polyether polyurethane prepolymers and polyether polyurethanes. In this invention, a polyether polyurethane prepolymer refers to a compound obtained by reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound to leave unreacted isocyanate groups in the compound. Furthermore, in this invention, a polyether polyurethane refers to a compound obtained by reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound to prevent the presence of unreacted isocyanate groups in the compound, or by end-capping a polyether polyurethane prepolymer obtained by the above method with an end-capping agent or extending its chain with a chain extender.

[0025] In this invention, the polyether polyol compound that can be used to manufacture polyether polyurethane prepolymers can include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polyethylene glycol-polypropylene glycol random copolymers, polyethylene glycol-polypropylene glycol block copolymers, and polyoxyethylene propylene glycol, ethylene glycol, propylene glycol, butanediol, and other diol compounds such as polyoxyethylene adducts, polyoxypropylene adducts, and polyoxybutylene adducts. From the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use one or more polyalkylene glycols, more preferably one or more selected from polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol, further preferably one or more selected from polypropylene glycol and polytetramethylene ether glycol, and particularly preferably polytetramethylene ether glycol. There is no particular limitation on the molecular weight of the polyether polyol compound used. From the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, it is preferable to use polyether polyol compounds with a number average molecular weight of 200 to 10,000, more preferably with a number average molecular weight of 400 to 5,000, even more preferably with a number average molecular weight of 600 to 2,000, and particularly preferably with a number average molecular weight of 800 to 1,500. It should be noted that in this invention, the number average molecular weight of the polyether polyol compound is determined by gel permeation chromatography (GPC) and calculated using polystyrene.

[0026] In this invention, any polyisocyanate compound that can be used in the manufacture of polyether polyurethane prepolymers can be used without particular limitation, as long as it has two or more isocyanate groups in its molecule. Examples of such polyisocyanate compounds include, for instance, aromatic diisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, terephthalic diisocyanate, xylene diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, bianisidine diisocyanate, and tetramethylxylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, trans-1,4-cyclohexyl diisocyanate, and norbornene diisocyanate; and 1,4-tetramethylene diisocyanate. Aliphatic diisocyanates, including esters, 1,6-hexamethylene diisocyanate, 1,8-octamethylene diisocyanate, 2-methyl-1,5-pentamethylene diisocyanate, 2,2-dimethyl-1,5-pentamethylene diisocyanate, 1,11-undecanethylene diisocyanate, 2,2,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4,4-trimethyl-1,6-hexamethylene diisocyanate, 2,4-dimethyl-1,8-octamethylene diisocyanate, 5-methyl-1,9-nonamethylene diisocyanate, lysine diisocyanate, lysine methyl ester diisocyanate, etc. In addition, in the manufacture of polyether polyurethane prepolymers, polyisocyanate compounds having three or more isocyanate groups in the molecule, such as isocyanurate trimers, biuret trimers, trimethylolpropane adducts, triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, and dimethyltriphenylmethane tetraisocyanate, can also be used as polyisocyanate compounds. In this invention, from the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, it is preferable to use one or more selected from aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates; more preferably, it is preferable to use one or more selected from toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, terephthalic diisocyanate, xylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and 1,6-hexamethylene diisocyanate; and even more preferably, it is preferable to use one or more selected from hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and 1,6-hexamethylene diisocyanate.

[0027] As for the polyether polyurethane prepolymer that can be used in this invention, it can be used without particular limitation as long as it is a substance obtained by reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound to leave unreacted isocyanate groups. For example, a polyether polyurethane prepolymer obtained by reacting a raw material containing the above-mentioned polyether polyol compound and polyisocyanate compound in an amount in which the ratio of the number of hydroxyl groups in the polyether polyol compound to the number of isocyanate groups in the polyisocyanate compound is 0.20 to 0.99:1 can be used.

[0028] In addition, as the polyether polyurethane prepolymer used in this invention, a compound obtained by reacting the following raw materials to leave unreacted isocyanate groups in the compound can also be used: the raw materials include, in addition to at least one polyether polyol compound and at least one polyisocyanate compound, an anionic group introducing agent, melamine-based compound, low molecular weight polyol, etc., and one or more reactive groups such as hydroxyl and amino groups that can react with the polyisocyanate compound.

[0029] As an anionic group introducing agent that can be used in the manufacture of polyether polyurethane prepolymers, any compound having anionic groups such as carboxyl groups and sulfonic acid groups, and reactive groups such as hydroxyl groups and amino groups that can react with polyisocyanate compounds, can be used without limitation. Examples of such anionic group introducing agents include compounds containing carboxyl and hydroxyl groups such as dimethylolpropionic acid, dimethylolbutyric acid, dimethylolbutyric acid, and dimethylolvalerate; and compounds containing sulfonic acid groups and hydroxyl groups such as 1,4-butanediol-2-sulfonic acid. One or more of these can be used. Among these, in this invention, from the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, compounds having carboxyl and hydroxyl groups within the molecule are preferred as anionic group introducing agents, compounds with a molecular weight of 100 to 5000 having carboxyl and hydroxyl groups within the molecule are more preferred, dimethylolpropionic acid or dimethylolbutyric acid is even more preferred, and dimethylolpropionic acid is particularly preferred.

[0030] In this invention, there is no particular limitation on the amount of anionic group introducing agent used when manufacturing polyether polyurethane prepolymers, and it can be appropriately adjusted according to the purpose. For example, when the number of isocyanate groups in the polyisocyanate compound used is set to 1, the amount of anionic group introducing agent with the number of reactive groups such as hydroxyl and amino groups that can react with the polyisocyanate compound can be 0.01 to 0.80, preferably 0.05 to 0.60, and more preferably 0.10 to 0.50.

[0031] Furthermore, when using an anionic group introducing agent in the manufacture of polyether polyurethane prepolymers, the amount of the anionic group introducing agent relative to the polyether polyol compound is not particularly limited and can be appropriately adjusted according to the purpose. For example, when the number of reactive groups such as hydroxyl and amino groups in the polyether polyol compound that can react with the polyisocyanate compound is set to 1, the anionic group introducing agent can be used in an amount where the number of reactive groups such as hydroxyl and amino groups that can react with the polyisocyanate compound is 0.05 to 20, preferably in an amount of 0.1 to 10, and more preferably in an amount of 0.2 to 5.

[0032] Examples of melamine-based compounds that can be used in the manufacture of polyether polyurethane prepolymers include melamine, monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, methylated methylol melamine, butylated methylol melamine, and melamine resins. One or more of these can be used. In this invention, from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use one or more of melamine, monomethylol melamine, and dimethylol melamine as the melamine-based compound, and more preferably melamine.

[0033] In this invention, the amount of melamine-based compounds used in the manufacture of polyether polyurethane prepolymers is not particularly limited and can be appropriately adjusted according to the purpose. For example, when the number of isocyanate groups in the polyisocyanate compound used is set to 1, it can be used in an amount where the number of amino groups in the melamine-based compound is 0.01 to 0.50, preferably in an amount where the number of amino groups is 0.05 to 0.40, and more preferably in an amount where the number of amino groups is 0.10 to 0.30.

[0034] Furthermore, when using melamine-based compounds in the manufacture of polyether polyurethane prepolymers, the amount of melamine-based compound relative to the polyether polyol compound is not particularly limited and can be appropriately adjusted according to the purpose. For example, when the number of reactive groups such as hydroxyl and amino groups in the polyether polyol compound that can react with the polyisocyanate compound is set to 1, it can be used in an amount where the number of amino groups in the melamine-based compound is 0.05 to 20, preferably in an amount of 0.1 to 10, and more preferably in an amount of 0.2 to 5.

[0035] Examples of low-molecular-weight polyols that can be used in the manufacture of polyether polyurethane prepolymers include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, and 2,4-di-propanediol. Aliphatic diols such as ethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, and triethylene glycol; alicyclic diols such as cyclohexanediol and cyclohexanediol; and tri- or higher alcohols such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerol, pentaerythritol, and tetramethylolpropane. One or more of these alcohols can be used.

[0036] In this invention, the amount of low-molecular-weight polyol used in the manufacture of polyether polyurethane prepolymers is not particularly limited and can be appropriately adjusted according to the purpose. For example, when the number of isocyanate groups in the polyisocyanate compound used is set to 1, the amount of low-molecular-weight polyol with reactive groups such as hydroxyl groups that can react with the polyisocyanate compound can be 0.01 to 0.50, preferably 0.05 to 0.40, and more preferably 0.10 to 0.30.

[0037] In this invention, from the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, as a polyether polyurethane prepolymer, it is preferable to use a polyether polyurethane prepolymer obtained from raw materials comprising at least one polyether polyol compound, at least one polyisocyanate compound, and one or more raw materials selected from anionic group introducing agents and melamine-based compounds. More preferably, a polyether polyurethane prepolymer obtained from raw materials comprising at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine-based compound is used. Even more preferably, a polyether polyurethane prepolymer obtained by reacting raw materials composed of at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine-based compound is used.

[0038] In this invention, when manufacturing polyether polyurethane prepolymers using raw materials comprising at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group-introducing agent, and at least one melamine-based compound, the amounts of the polyether polyol compound, polyisocyanate compound, anionic group-introducing agent, and melamine-based compound used are not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, for example, when the number of isocyanate groups in the polyisocyanate compound is set to 1, the sum of the number of reactive groups such as hydroxyl groups in the polyether polyol compound, the number of reactive groups such as hydroxyl groups in the anionic group-introducing agent, and the number of amino groups in the melamine-based compound is preferably used in an amount of 0.20 to 0.99, more preferably in an amount of 0.30 to 0.95, and even more preferably in an amount of 0.40 to 0.90.

[0039] Furthermore, when manufacturing polyether polyurethane prepolymers using raw materials comprising at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group-introducing agent, and at least one melamine-based compound, the amounts of the polyether polyol compound, polyisocyanate compound, anionic group-introducing agent, and melamine-based compound used, from the viewpoint of the adhesion and corrosion resistance of the resulting resin composition, are preferably used in an amount where the ratio of the number of isocyanate groups in the polyisocyanate compound, the number of reactive groups such as hydroxyl groups in the polyether polyol compound, the number of reactive groups such as hydroxyl groups in the anionic group-introducing agent, and the number of amino groups in the melamine-based compound is 1:0.01-0.9:0.01-0.9:0.01-0.5, more preferably in an amount where the ratio is 1:0.05-0.6:0.05-0.6:0.05-0.4, and even more preferably in an amount where the ratio is 1:0.1-0.5:0.1-0.5:0.05-0.3.

[0040] There is no particular limitation on the acid value of the polyether polyurethane prepolymer that can be used in this invention, and it can be appropriately adjusted according to the purpose. From the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, the acid value of the polyether polyurethane prepolymer is preferably 0 to 70 mg KOH / g, more preferably 10 to 60 mg KOH / g, even more preferably 15 to 50 mg KOH / g, and particularly preferably 20 to 40 mg KOH / g. In this invention, the acid value of the polyether polyurethane prepolymer is determined by neutralization titration according to JIS K0070 (1992).

[0041] There are no particular limitations on the polyether polyurethane prepolymer used in this invention. It can be manufactured by adding the aforementioned raw materials together or in multiple separate additions to a reaction vessel in the presence of a solvent, catalyst, etc., as needed. For example, the materials can be mixed at room temperature to 180°C and at a pressure of 0.01 Pa to 100 MPa for 10 minutes to 24 hours to allow the reaction to proceed. In this case, by using the raw materials in such a way that the number of isocyanate groups in the polyisocyanate compound is greater than the number of reactive groups such as hydroxyl and amino groups in the polyether polyol compound or other raw materials that can react with isocyanate groups, a polyether polyurethane prepolymer with unreacted isocyanate groups can be produced.

[0042] There are no particular limitations on the catalysts that can be used in the manufacture of polyether polyurethane prepolymers, and known catalysts can be used. Examples of such catalysts include N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropanediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N",N"-pentamethyl(3-aminopropyl)ethylenediamine, N,N,N',N",N"-pentamethyldipropylenetriamine, N,N,N',N'-tetramethylguanidine, 1,3,5-tris(N,N-dimethylaminopropyl)hexahydro-S-triazine, 1,8-diazabicyclo[5.4.0]undecene-7, triethylenediamine, N,N,N',N'-tetramethylhexamethylenediamine, N-methyl-N'-(2-dimethylaminoethyl)piperazine, and N,N'-dimethylpiperazine. Tertiary amines such as azines, N,N-dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, bis(2-dimethylaminoethyl) ether, N,N-dimethyllauroamine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, and 1-dimethylaminopropylimidazole; quaternary ammonium salts such as tetraalkylammonium halides (e.g., tetramethylammonium hydroxide), tetraalkylammonium hydroxide (e.g., tetramethylammonium 2-ethylhexanoate), and tetraalkylammonium organic acid salts (e.g., tetraalkylammonium diacetate), stannous dioctanoate, stannous dioleate, stannous dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, lead octanoate, lead naphthenate, nickel naphthenate, and cobalt naphthenate. One or more of these can be used. There is no particular limitation on the amount of catalyst used; it can be adjusted appropriately according to the purpose. The catalyst, for example, can be used at a mass ratio of 0.0001 to 1% relative to the total mass of the raw materials used.

[0043] As a solvent that can be used in the manufacture of polyether polyurethane prepolymers, known solvents can be used. Examples of such solvents include acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, and propylene glycol monomethyl ether acetate. One or more of these solvents can be used. There is no particular limitation on the amount of solvent used, which can be adjusted appropriately according to the purpose. For example, the solvent can be used at a rate of 0.1% to 80% by mass relative to the total mass of the raw materials used.

[0044] In this invention, there is no particular limitation on the reaction time for reacting polyether polyol compounds, polyisocyanate compounds, and other raw materials to manufacture polyether polyurethane prepolymers. From the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, the reaction time is preferably 30 minutes to 15 hours, more preferably 1 hour to 10 hours, and even more preferably 3 to 7 hours.

[0045] The polyether polyurethane prepolymer obtained by the above method is produced by reacting a polyether polyol compound, a polyisocyanate compound, an anionic group-introducing agent (if desired), and a melamine-based compound. In this invention, a wide variety of compounds can be used as the polyether polyol compound, polyisocyanate compound, anionic group-introducing agent, and melamine-based compound. Therefore, the structure of the aforementioned polyether polyurethane prepolymer varies greatly depending on the structure of the raw materials used in its manufacture. Consequently, it is not possible to uniformly represent the structure of polyether polyurethane prepolymers using a single general formula; this is common knowledge among those skilled in the art. Furthermore, if the structure is not determined, it is difficult to know the corresponding properties of the substance, and therefore, it is impossible to describe it using properties. On the other hand, the present invention relates to the following invention: when a polyether polyurethane prepolymer obtained by reacting raw materials comprising at least one polyether polyol compound and at least one polyisocyanate compound is used with component (A) comprising an epoxy resin that is solid at 25°C, a resin composition exhibiting excellent adhesiveness, particularly adhesiveness that can be achieved by short-time compression bonding, and corrosion resistance is obtained. Therefore, in the present invention, the polyether polyurethane prepolymer must be defined as "a polyether polyurethane prepolymer obtained by reacting raw materials comprising at least one polyether polyol compound and at least one polyisocyanate compound".

[0046] As polyether polyurethanes that can be used in this invention, polyether polyurethanes obtained by capping the polyether polyurethane prepolymer obtained by the above method with an end-capping agent or extending the chain with a chain extender can be used; polyether polyurethanes obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound so that no unreacted isocyanate groups remain in the compound, etc.

[0047] In this invention, there are no particular limitations on the end-capping agent used when capping the polyether polyurethane prepolymer, and known end-capping agents can be used. Examples of such end-capping agents include alcohols such as methanol and ethanol; dialkylamines such as diethylamine, dimethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, di(dodecyl)amine, and distearate; diarylamines such as diphenylamine; and heterocyclic compounds containing secondary amino groups such as morpholine, piperidine, pyrrole, pyrrolidine, pyrazole, and imidazole. One or more of these can be used. In this case, there are no particular limitations on the amount of end-capping agent used, and it can be appropriately adjusted according to the purpose. For example, the amount of the end-capping agent containing reactive groups that can react with isocyanate groups relative to the number of isocyanate groups in the polyether polyurethane prepolymer can be set to 0.01 to 2.0 in equivalence ratio.

[0048] Furthermore, in this invention, there are no particular limitations on the chain extender used when extending the chain of the polyether polyurethane prepolymer, and known chain extenders can be used. Examples of such chain extenders include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. Aliphatic diols such as 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; alicyclic diols such as cyclohexanediol and cyclohexanediol; low molecular weight diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, toluenediamine, piperazine, and 2-methylpiperazine; polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; and alkyl groups such as monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, and 2-(2-aminoethylamino)ethanol. Alkylamines; polyether diamines such as polyoxypropylene diamine and polyoxyethylene diamine; alicyclic diamines such as menthene diamine, isophorone diamine, norbornene diamine, aminoethylaminoethanol, bis(4-amino-3-methyldicyclohexyl)methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro(5,5)undecane; and m-phenylenediamine, α-(m / p-aminophenyl)ethylamine, m-phenylenediamine, diaminodiphenylmethane, and diaminodiphenylmethane. Polyamines such as phenyl sulfone, diaminodimethyldiphenylmethane, diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, and α,α'-bis(4-aminophenyl)-p-diisopropylbenzene, etc.; hydrazides such as succinic dihydrazide, adipate dihydrazide, sebacic dihydrazide, phthalic acid dihydrazide, hydrazine hydrate, 1,6-hexamethylenebis(N,N-dimethylaminourea), 1,1,1',1'-tetramethyl-4,4'-(methylene-di-p-phenylene)diaminourea, and water, etc. One or more of these can be used. From the viewpoint of various properties of the resulting polyether polyurethane, one or more of a selection from low molecular weight diamines, polyether diamines, and water is preferred; more preferably, one or more of a selection from ethylenediamine, propylenediamine, and water is preferred. In this case, there is no particular limitation on the amount of chain extender used, and it can be appropriately adjusted according to the purpose. For example, the number of reactive groups in the chain extender that can react with isocyanate groups relative to the number of isocyanate groups in the polyether polyurethane prepolymer can be set to 0.01 or more in an equivalent ratio. From the viewpoint of various properties of the obtained polyether polyurethane, it is preferable to set it to 0.5 or more in an equivalent ratio, and more preferably to set it to 1 or more.In this invention, when water is used as a chain extender, water also functions as a solvent for the resulting resin composition; therefore, there is no particular upper limit on the amount of water-containing chain extender used. For example, the water-containing chain extender can be used in quantities ranging from 10% to 1000% by mass relative to the mass of the polyether polyurethane prepolymer.

[0049] In this invention, the polyether polyol compound and polyisocyanate compound used to manufacture polyether polyurethane by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound to ensure that no unreacted isocyanate groups remain in the compound are not present in the compound. As long as they are both known polyether polyol compounds and polyisocyanate compounds, they can be used without particular limitation. For example, polyether polyol compounds and polyisocyanate compounds that are used in the manufacture of the aforementioned polyether polyurethane prepolymer can be used. Furthermore, the ratio of the amount of polyether polyol compound to polyisocyanate compound used when reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound to ensure that no unreacted isocyanate groups remain in the compound is not particularly limited and can be appropriately adjusted according to the purpose. For example, polyether polyol compounds and polyisocyanate compounds can be used in amounts where the ratio of the number of hydroxyl groups in the polyether polyol compound to the number of isocyanate groups in the polyisocyanate compound is 1:0.5 to 0.99.

[0050] Of these, from the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, it is preferable to obtain a polyether polyurethane prepolymer obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound with an end-capping agent or by chain extension with a chain extender. More preferably, it is preferable to obtain a polyether polyurethane prepolymer obtained by using raw materials containing at least one polyether polyol compound, at least one polyisocyanate compound, and one or more raw materials selected from anionic group introducing agents and melamine compounds with an end-capping agent or by chain extension with a chain extender. The polyurethane is further preferably obtained by capping a polyether polyurethane prepolymer made from raw materials comprising at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine-based compound with an end-capping agent or by extending the chain with a chain extender. It is particularly preferred to obtain a polyether polyurethane prepolymer made by reacting raw materials comprising at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine-based compound with an end-capping agent or by extending the chain with a chain extender.

[0051] There is no particular limitation on the acid value of the polyether polyurethane that can be used in this invention, and it can be appropriately adjusted according to the purpose. From the viewpoint of the adhesiveness and corrosion resistance of the obtained resin composition, it is preferred that the acid value of the polyether polyurethane is 0 to 70 mg KOH / g, more preferably 10 to 60 mg KOH / g, even more preferably 15 to 50 mg KOH / g, and particularly preferably 20 to 40 mg KOH / g. In this invention, the acid value of the polyether polyurethane is determined by neutralization titration method according to JIS K 0070 (1992).

[0052] The polyether polyurethane obtained by the above method is produced by reacting a polyether polyol compound, a polyisocyanate compound, an anionic group-introducing agent (if desired), a melamine-based compound, and a capping agent or chain extender. In this invention, a wide variety of compounds can be used as the polyether polyol compound, polyisocyanate compound, anionic group-introducing agent, melamine-based compound, capping agent, and chain extender. Therefore, the structure of the polyether polyurethane varies greatly depending on the structure of the raw materials used in its manufacture. Consequently, it is not possible to uniformly represent the structure of polyether polyurethane using a single general formula; this is common knowledge among those skilled in the art. Furthermore, if the structure is not determined, it is difficult to know the properties of the correspondingly determined substance, and therefore, it is impossible to describe it using properties. On the other hand, the present invention relates to the following invention: when a polyether polyurethane obtained by reacting a raw material comprising at least one polyether polyol compound and at least one polyisocyanate compound is used with a component (A) comprising an epoxy resin that is solid at 25°C, a resin composition exhibiting excellent adhesion, particularly adhesion that can be achieved through short-time compression bonding, and corrosion resistance is obtained. Therefore, in the present invention, the polyether polyurethane must be defined as "a polyether polyurethane obtained by reacting a raw material comprising at least one polyether polyol compound and at least one polyisocyanate compound".

[0053] This invention relates to the following: when a component (B) comprising one or more of the above-mentioned polyether polyurethane prepolymers and polyether polyurethanes is used together with a component (A) comprising an epoxy resin that is solid at 25°C, it is found that a resin composition with excellent adhesion, particularly adhesion that can be achieved by short-time pressing, and corrosion resistance is obtained. From the viewpoint of improved adhesion and corrosion resistance resulting from the combined use with component (A), particularly improved adhesion that can be achieved by short-time pressing, the content ratio of the polyether structure in the polyether polyurethane prepolymer or polyether polyurethane relative to the total mass of the polyether polyurethane prepolymer or polyether polyurethane is preferably 10-70% by mass, more preferably 15-60% by mass, and even more preferably 20-50% by mass. In this invention, the content ratio of the polyether structure in the polyether polyurethane prepolymer or polyether polyurethane is calculated using the mass percentage of the polyether structure in the raw materials used.

[0054] As component (B) used in this invention, it may contain only the aforementioned polyether polyurethane prepolymer, only polyether polyurethane, or a mixture of both polyether polyurethane prepolymer and polyether polyurethane. From the viewpoint of various properties of the resulting resin composition, component (B) preferably contains polyether polyurethane.

[0055] The content of component (A) in the resin composition of the present invention is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of improving the adhesiveness of the obtained resin composition, especially the adhesiveness produced by short-time pressing, the content of component (A) in the resin composition relative to the total amount of the resin composition is preferably 3 to 60% by mass, more preferably 5 to 50% by mass, further preferably 8 to 45% by mass, and even more preferably 20 to 40% by mass.

[0056] The content of component (B) in the resin composition of the present invention is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of improving the adhesiveness of the obtained resin composition, especially the adhesiveness produced by short-time pressing, the content of component (B) in the resin composition relative to the total amount of the resin composition is preferably 1 to 50% by mass, more preferably 2 to 40% by mass, further preferably 3 to 30% by mass, and particularly preferably 4 to 10% by mass.

[0057] The content ratio of component (A) to component (B) in the resin composition of the present invention is not particularly limited and can be adjusted according to the purpose. From the viewpoint of improving the adhesiveness of the obtained resin composition, especially the adhesiveness produced by short-time pressing, the content ratio of component (A) to component (B) in the resin composition, expressed as a mass ratio, is preferably 5:95 to 98:2, more preferably 20:80 to 95:5, further preferably 50:50 to 92:8, and particularly preferably 70:30 to 90:10.

[0058] 1-3. Water

[0059] The resin composition of the present invention may further contain water. There is no particular limitation on the water content in the resin composition of the present invention, and it can be appropriately adjusted. From the viewpoints of the resin composition's adhesion to metals and corrosion resistance, reduction of environmental impact, and processability, it is preferable to contain 10 to 90% by mass of water relative to the total amount of the resin composition, more preferably 20 to 80% by mass, even more preferably 30 to 70% by mass, and particularly preferably 40 to 60% by mass. In this case, tap water, ion-exchanged water, distilled water, natural water, purified water, etc., can be appropriately used depending on the purpose.

[0060] The ratio of component (A) and component (B) to water in the resin composition of the present invention is not particularly limited and can be adjusted according to the purpose. From the viewpoints of the resin composition's adhesion to metals and corrosion resistance, reduced environmental impact, and processability, the ratio of component (A) and component (B) to water in the resin composition is preferably 3-80:1-60:10-90 when the sum of the contents of component (A) and component (B) to water is set to 100, more preferably 5-60:2-50:20-80, even more preferably 8-50:3-40:30-70, and particularly preferably 20-40:4-10:40-60. By containing the specific components (A) and component (B) and water described above in such a ratio, the resin composition of the present invention can be used to obtain an aqueous dispersion emulsion with excellent dispersion stability, and thus can be used to produce a resin composition with reduced environmental impact and excellent processability.

[0061] When the resin composition of the present invention contains water, as component (A), among the epoxy resins that are solid at 25°C, from the viewpoint of the dispersion stability and various properties of the obtained resin composition, it is preferable to use a bisphenol type epoxy resin that is solid at 25°C, more preferably one or more selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin that are solid at 25°C, and even more preferably bisphenol A type epoxy resin that is solid at 25°C. Furthermore, from the viewpoint of the dispersion stability and various properties of the obtained resin composition, as component (A), among the epoxy resins that are solid at 25°C as described above, it is preferable to use epoxy resins that are solid at 25°C with an epoxy equivalent of 500 g / eq. to 30000 g / eq., more preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 1000 g / eq. to 10000 g / eq., even more preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 1500 g / eq. to 6000 g / eq., even more preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 2000 g / eq. to 5000 g / eq., and particularly preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 2500 g / eq. to 3500 g / eq.

[0062] When the resin composition of the present invention contains water, as component (B), from the viewpoint of the dispersion stability and various properties of the obtained resin composition, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more polyalkylene glycols; more preferably, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol; even more preferably, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from polypropylene glycol and polytetramethylene ether glycol; and particularly preferably, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing polytetramethylene ether glycol. Furthermore, from the viewpoint of the dispersion stability and various properties of the obtained resin composition, the acid values ​​of the polyether polyurethane prepolymer and the polyether polyurethane used are preferably 0 to 70 mg KOH / g, more preferably 10 to 60 mg KOH / g, even more preferably 15 to 50 mg KOH / g, and particularly preferably 20 to 40 mg KOH / g.

[0063] 1-4. Other ingredients

[0064] In addition to components (A), (B), and water described above, the resin composition of the present invention may contain, depending on the purpose, solvents, neutralizing agents, surfactants, aminosilane compounds, amide compounds, carbodiimide compounds, isocyanate compounds (however, excluding polyether polyurethane prepolymers), polyether amine compounds, phosphate-modified epoxy resins, melamine resins, phenolic resins, etc. There are no particular limitations on the solvents that may be contained in the resin composition of the present invention, and known solvents can be used. Examples of such solvents include acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-2-pyrrolidone, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, etc. One or more of these can be used. There are no particular limitations on the solvent content when the resin composition of the present invention contains solvents, and it can be appropriately adjusted according to the purpose. For example, relative to the total amount of the resin composition, it may contain 0.1% to 50% by mass of solvent. From the viewpoints of the adhesion and corrosion resistance of the resin composition to metals, the reduction of environmental impact, and the processability of the resin composition, the upper limit of the solvent content relative to the total amount of the resin composition is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less. It should be noted that, in this invention, by including the above-described components (A) and (B), a resin composition with excellent stability and processability can be manufactured even when the solvent content is low or absent.

[0065] There are no particular limitations on the neutralizing agents that can be contained in the resin composition of the present invention, and known neutralizing agents can be used. Examples of such neutralizing agents include, for instance, trialkylamines such as trimethylamine, triethylamine, and tributylamine; N,N-dialkylalkanolamines such as N,N-dimethylethanolamine, N,N-dimethylpropanolamine, N,N-dipropylethanolamine, and 1-dimethylamino-2-methyl-2-propanol; tertiary amine compounds such as N-alkyl-N,N-dialkylolamines and triethanolamine; and ammonia, trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide. One or more of these can be used. In this invention, as component (B), when using one or more of a polyether polyurethane prepolymer with an acid value of 10 to 60 mg KOH / g and a polyether polyurethane with an acid value of 10 to 60 mg KOH / g, from the viewpoint of the stability and processability of the resin composition, it is preferable to contain 0.01 to 5% by mass of a neutralizing agent relative to the total amount of the resin composition, more preferably 0.05 to 3% by mass.

[0066] There are no particular limitations on the surfactants that can be contained in the resin composition of the present invention, and known surfactants can be used. Examples of such surfactants include known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. One or more of these can be used.

[0067] Examples of anionic surfactants include alkyl sulfates such as sodium dodecyl sulfate, potassium dodecyl sulfate, and ammonium dodecyl sulfate; polyoxyethylene ether sulfates such as sodium dodecyl polyethylene glycol ether sulfate and ammonium polyoxyethylene alkyl ether sulfate; ammonium salts of alkyl sulfonic acids such as ammonium salts of sulfonated paraffin; fatty acid salts such as sodium laurate, triethanolamine oleate, and triethanolamine rosinate; alkyl aryl sulfonates such as sodium benzenesulfonate and alkaliphenolhydroxyethylene alkali metal sulfates; alkyl naphthalene sulfonates, formalin condensates of naphthalene sulfonate, dialkyl sulfosuccinates, polyoxyethylene alkyl sulfates, polyoxyethylene alkyl aryl sulfates, polyoxyethylene ether phosphates, polyoxyethylene alkyl ether acetates, N-acyl amino acid salts, and N-acylmethyl taurate. One or more of these can be used.

[0068] Examples of nonionic surfactants include fatty acid fractions of polyols such as sorbitan monolaurate and sorbitan monooleate; polyoxyethylene glycol fatty acid esters; polyglycerol fatty acid esters; ethylene oxide and / or propylene oxide adducts of alcohols with 1 to 18 carbon atoms; ethylene oxide and / or propylene oxide adducts of alkylphenols; and ethylene oxide and / or propylene oxide adducts of alkylene glycols and / or alkylene diamines. Examples of alcohols with 1 to 18 carbon atoms constituting nonionic surfactants include methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tert-butanol, pentanol, isoamyl alcohol, tert-amyl alcohol, hexanol, octanol, decanol, lauryl alcohol, myristol, palmitol, and stearyl alcohol. In addition, examples of alkylphenols that constitute nonionic surfactants include phenol, methylphenol, 2,4-di-tert-butylphenol, 2,5-di-tert-butylphenol, 3,5-di-tert-butylphenol, 4-(1,3-tetramethylbutyl)phenol, 4-isooctylphenol, 4-nonylphenol, 4-tert-octylphenol, 4-dodecylphenol, 2-(3,5-dimethylheptyl)phenol, 4-(3,5-dimethylheptyl)phenol, naphthol, bisphenol A, and bisphenol F. Furthermore, examples of alkylene glycols constituting nonionic surfactants include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, and 1,6-hexanediol. Additionally, examples of alkylene diamines include substances in which the hydroxyl groups of these alkylene glycols are replaced with amino groups. Furthermore, ethylene oxide and propylene oxide adducts can be either random adducts or block adducts.

[0069] Examples of cationic surfactants include quaternary ammonium salts such as lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, distearate dimethylammonium chloride, dialcyldimethylammonium chloride, laurylbenzyldimethylammonium chloride, and dialcyldimethylammonium chloride; alkylpyridinium bromide, imidazoline laurate, etc. One or more of these can be used.

[0070] Examples of amphoteric surfactants include betaine-type surfactants such as coconut oil fatty acid amamidopropyl dimethyl acetate betaine, lauryl dimethyl amino acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxymethyl imidazoline betaine, lauryl hydroxysulfonyl betaine, lauramide ethyl hydroxyethyl carboxymethyl betaine, and metal salts of hydroxypropyl phosphate; and amino acid-type, sulfate-type, and sulfonic acid-type amphoteric surfactants such as metal salts of β-laurylaminopropionic acid. One or more of these can be used.

[0071] In this invention, from the viewpoint of the adhesiveness and corrosion resistance of the resin composition to metals, and the processability of the resin composition, it is preferable to contain one or more surfactants selected from anionic surfactants and nonionic surfactants, more preferably to contain at least one nonionic surfactant, and even more preferably to contain at least one nonionic surfactant having an oxidized olefin skeleton. Furthermore, in this case, the nonionic surfactant preferably contains a nonionic surfactant with a weight-average molecular weight of 1000 to 50000, more preferably a nonionic surfactant with a weight-average molecular weight of 5000 to 30000, even more preferably a nonionic surfactant with a weight-average molecular weight of 10000 to 20000, and particularly preferably a nonionic surfactant with a weight-average molecular weight of 14000 to 18000.

[0072] When the resin composition of the present invention contains a surfactant, the content of the surfactant in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the processability of the obtained resin composition and its adhesion to metals and corrosion resistance, the content of surfactant in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, even more preferably 0.2 to 10% by mass, even more preferably 0.5 to 6% by mass, and particularly preferably 3.0 to 5.0% by mass.

[0073] As for the aminosilane compounds that can be used in this invention, there are no particular limitations as long as the compound contains an amino group and a silicon group in the molecule, and known silane coupling agents can be used.Examples of such aminosilane compounds include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-methyl-3-(trimethoxysilyl)propylamine, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, N-(6-aminohexyl)-3-aminopropyltrimethoxysilane, 3-aminopropyldiethoxymethylsilane, 3-tert-butylaminopropyltrimethoxysilane, 3-cyclohexylaminopropyltrimethoxysilane, and N-methyl-3-aminopropyltrimethoxysilane. 2-Methylpropyltrimethoxysilane, N-ethyl-3-amino-2-methylpropylmethyldimethoxysilane, N-ethyl-3-amino-2-methylpropyltrimethoxysilane, N-ethyl-3-amino-2-methylpropyldiethoxymethylsilane, N-ethyl-3-amino-2-methylpropyltriethoxysilane, N-butyl-3-amino-2-methylpropyltrimethoxysilane, 3-(N-methyl-2-amino-1-methyl-1-ethoxy)propyltrimethoxysilane, N-ethyl-4-amino-3,3-dimethylbutyldimethoxymethylsilane, N-ethyl-4-amino-3,3-dimethylbutyltrimethoxysilane, bis-(3-trimethoxysilyl-2- Methylpropylamine, N-(3-trimethoxysilylpropyl)-3-amino-2-methylpropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-trimethoxysilylpropyl-3-[N-(3-trimethoxysilyl)-propylamino]-2-propanoic acid methyl, 3-triethoxysilylpropyl-3-[N-(3-triethoxysilyl)-propylamino]-2-propanoic acid methyl, 3-trimethoxysilylpropyl-3-[N-(3-triethoxysilyl)-propylamino]-2-propanoic acid methyl, N-ethyl-4-amino-3,3-dimethylbutyldimethoxymethylsilane, N-ethyl-4-amino-3,3-dimethyl... Butyltrimethoxysilane, N-(3-trimethoxysilyl)propyl-3-[N-(3-trimethoxysilyl)propylamino]propionamide, N-(3-triethoxysilyl)propyl-3-[N-(3-triethoxysilyl)propylamino]propionamide, N-(3-trimethoxysilyl)propyl-3-[N-(3-triethoxysilyl)propylamino]propionamide, N,N-bis[(3-trimethoxysilyl)propyl]amine, N,N-bis[(3-triethoxysilyl)propyl]amine, N,N-bis[(3-tripropoxysilyl)propyl]amine, N,N-bis[(3-trimethoxysilyl)2-methylpropyl]amine, etc. One or more of these can be used.

[0074] When the resin composition of the present invention contains an aminosilane compound, the content of the aminosilane compound in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion to metals and corrosion resistance of the obtained resin composition, the content of the aminosilane compound in the resin composition relative to the total mass of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0075] As for the amide compounds that can be used in this invention, any compound having one or more amide groups within its molecule can be used without particular limitation. Examples of such amide compounds include, for instance, succinic acid dihydrazide, adipate dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, p-hydroxybenzoic acid dihydrazide, salicylic acid dihydrazide, maleic acid dihydrazide, dicyandiamide, methylguanidine, ethylguanidine, propylguanidine, butylguanidine, dimethylguanidine, trimethylguanidine, phenylguanidine, diphenylguanidine, etc. One or more of these compounds can be used.

[0076] When the resin composition of the present invention contains an amide compound, the content of the amide compound in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion and corrosion resistance of the obtained resin composition to metals, the content of the amide compound in the resin composition relative to the total mass of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0077] As for the carbodiimide compounds that can be used in this invention, any compound having one or more carbodiimide groups (-N=C=N-) in its molecule can be used without particular limitation. Examples of such carbodiimide compounds include N,N'-dicyclohexylcarbodiimide, N,N'-dimethylcarbodiimide, N,N'-diisopropylcarbodiimide, N,N'-diisobutylcarbodiimide, N,N'-dioctylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, poly(1,6-hexamethylenecarbodiimide), poly(4,4'-methylenebicyclohexylcarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1,4-cyclohexylenecarbodiimide), poly(4,4'-dicyclohexylmethanecarbodiimide), etc. Additionally, Carbodilite can also be used. Commercially available products such as V-02, V-02-L2, SV-02, V-04, V-10, E-02, E-03A, and E-05 (manufactured by Nisshinbo Chemical Co., Ltd.) are used. In this invention, from the viewpoint of the adhesion to metals and corrosion resistance of the obtained resin composition, the carbodiimide compound preferably has a carbodiimide equivalent of 100 to 800 g / eq., more preferably has a carbodiimide equivalent of 200 to 700 g / eq., even more preferably has a carbodiimide equivalent of 300 to 600 g / eq., and particularly preferably has a carbodiimide equivalent of 400 to 500 g / eq.

[0078] When the resin composition of the present invention contains a carbodiimide compound, the content of the carbodiimide compound in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion and corrosion resistance of the obtained resin composition to metals, the content of the carbodiimide compound in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0079] As isocyanate compounds that can be used in this invention, compounds having one or more isocyanate groups within the molecule can be used without particular limitation. From the viewpoint of the adhesion to metals and corrosion resistance of the resulting resin composition, isocyanate compounds having two isocyanate groups within the molecule are preferred. Examples of such isocyanate compounds include, for example, aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, and 1,4-naphthalene diisocyanate. Aromatic diisocyanates such as isocyanates, phenyl diisocyanates, tetramethylxylene diisocyanates, 4,4'-diphenyl ether diisocyanates, 2-nitrodiphenyl-4,4'-diisocyanates, 2,2'-diphenylpropane-4,4'-diisocyanates, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanates, 4,4'-diphenylpropane diisocyanates, 3,3'-dimethoxydiphenyl-4,4'-diisocyanates, and xylene diisocyanates can also be used as polymers, adducts, biuret bodies, ureate bodies, and blocked bodies sealed with blocking agents. At this point, as blocking agents, phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol can be used; lactam blocking agents such as ε-caprolactam, δ-valerol, γ-butyrolactam, and β-propiolactam; active methylene blocking agents such as ethyl acetoacetate and acetylacetone; and methanol, ethanol, propanol, butanol, pentanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl ether, methyl glycolate, butyl glycolate, diacetone alcohol, and methyl lactate can be used. Alcohol-based blocking agents such as ethyl lactate; oxime-based blocking agents such as formaldehyde oxime, acetaldehyde oxime, acetone oxime, methyl ethyl ketone oxime, diacetyl monooxime, and cyclohexane oxime; thiol-based blocking agents such as butyl mercaptan, hexyl mercaptan, tert-butyl mercaptan, thiophene, methyl thiophene, and ethyl thiophene; amide-based blocking agents such as acetamide and benzamide; imide-based blocking agents such as succinimide and maleimide; amine-based blocking agents such as dimethylaniline, aniline, butylamine, and dibutylamine; imidazole-based blocking agents such as imidazole and 2-ethylimidazole; and imine-based blocking agents such as methyleneimide and propyleneimide.

[0080] When the resin composition of the present invention contains isocyanate compounds, the content of the isocyanate compounds in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion to metals and corrosion resistance of the obtained resin composition, the content of the isocyanate compounds in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0081] As a polyetheramine compound that can be used in this invention, any compound having a polyether group containing a polyoxyethylene structure such as polyoxyethylene, polyoxypropylene, or polyoxybutylene, and at least one amino group can be used without particular limitation. In this case, the polyether group within the molecule may contain only polyoxyethylene, only polyoxypropylene, or only polyoxybutylene groups, or may contain two or more selected from polyoxyethylene, polyoxypropylene, and polyoxybutylene groups. Furthermore, the number of repetitions of the olefin structure in the polyether group is not particularly limited and can be adjusted according to the purpose. For example, regarding the number of repetitions of the olefin structure in the polyetheramine compound, the total number of repetitions of one or more olefin groups can be set from 2 to 500. Examples of such polyetheramine compounds include polyethylene glycolamine, polyethylene glycol diamine, methoxy polyethylene glycolamine, polypropylene glycolamine, polypropylene glycol diamine, methoxy polypropylene glycolamine, polybutylene glycolamine, polybutylene glycol diamine, methoxy polybutylene glycolamine, polyoxyethylene polyoxypropylene amine, polyoxyethylene polyoxypropylene diamine, and methoxy polyethylene polyoxypropylene amine. In addition, commercially available products can also be used as polyetheramine compounds. Examples of commercially available products include JEFFAMINE (registered trademark) M series (M-600, M-1000, M-2005, M-2070), JEFFAMINE D series (D-230, D-400, D-2000, D-4000), JEFFAMINE ED series (ED-600, ED-900, ED-2003), and JEFFAMINE T series (T-403, T-3000, T-5000) (all manufactured by HUNTSMAN).

[0082] In this invention, from the viewpoint of the adhesion to metals and corrosion resistance of the obtained resin composition, polyetheramine compounds having polyether groups, amino groups, and methoxy groups within the molecule are preferred as polyetheramine compounds. Furthermore, polyetheramine compounds having only polyoxyethylene groups, only polyoxypropylene groups, or both polyoxyethylene and polyoxypropylene groups are preferred. More specifically, in this invention, methoxylated polyoxyethylene polyoxypropylene amine compounds having an intramolecular repeat number of oxyethylene groups of 1 to 100 and an intramolecular repeat number of oxypropylene groups of 2 to 50 are particularly preferred as polyetheramine compounds.

[0083] When the resin composition of the present invention contains a polyetheramine compound, the content of the polyetheramine compound in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion to metals and corrosion resistance of the obtained resin composition, the content of the polyetheramine compound in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0084] As the phosphoric acid-modified epoxy resin that can be used in this invention, any modified product obtained by reacting a phosphoric acid with an epoxy compound can be used without particular limitation. As such a phosphoric acid, polyphosphoric acids such as orthophosphoric acid, phosphorous acid, hypophosphoric acid, phosphonic acid, pyrophosphoric acid, and triphosphoric acid can be used. As for the epoxy compound, any compound having at least one epoxy group in its molecule can be used without particular limitation; examples include n-butyl glycidyl ether, C... 12 ~C 14Compounds containing one epoxy group in the molecule include alkyl glycidyl ethers, allyl glycidyl ethers, 2-ethylhexyl glycidyl ethers, styrene oxide, phenyl glycidyl ethers, tolyl glycidyl ethers, p-sec-butylphenyl glycidyl ethers, tert-butylphenyl glycidyl ethers, glycidyl methacrylate, and tert-carboxylic acid glycidyl ethers; compounds containing two epoxy groups in the molecule include ethylene glycol diglycidyl ethers, propylene glycol diglycidyl ethers, butanediol diglycidyl ethers, 1,6-hexanediol diglycidyl ethers, and neopentyl glycol diglycidyl ethers; compounds containing three epoxy groups in the molecule include trimethylolpropane triglycidyl ethers and glycerol triglycidyl ethers; and bisphenol A type epoxy resins and bisphenol F type epoxy resins. The epoxy resins include esters, bisphenol S-type epoxy resins, bisphenol AD-type epoxy resins, resorcinol-type epoxy resins, hydroquinone-type epoxy resins, catechol-type epoxy resins, dihydroxynaphthalene-type epoxy resins, biphenyl-type epoxy resins, tetramethylbiphenyl-type epoxy resins, oxazolidinone cyclic epoxy resins, phenolic varnish-type epoxy resins, cresolic varnish-type epoxy resins, triphenylmethane-type epoxy resins, tetraphenylethane-type epoxy resins, dicyclopentadiene-phenol addition reaction epoxy resins, phenol aralkyl-type epoxy resins, naphthol varnish-type epoxy resins, naphthol aralkyl-type epoxy resins, naphthol-phenol cocondensed phenolic varnish-type epoxy resins, naphthol-cresol cocondensed phenolic varnish-type epoxy resins, aromatic hydrocarbon formaldehyde resin modified phenolic resin type epoxy resins, and biphenyl modified phenolic varnish-type epoxy resins, etc. One or more of these can be used.

[0085] The phosphoric acid modified epoxy resin that can be used in this invention can be obtained by reacting the above-mentioned epoxy compound and phosphoric acid, for example, at an equivalent ratio of 1:0.1 to 1:5, at room temperature to 100°C. From the viewpoint of the adhesion to metals and corrosion resistance of the resulting resin composition, it is preferable to use a phosphoric acid modified epoxy resin obtained by reacting one or more epoxy compounds selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin with phosphoric acid compounds such as orthophosphoric acid, metaphosphoric acid, phosphonic acid, pyrophosphoric acid, and polyphosphoric acid at an equivalent ratio of 1:0.5 to 1:3. More preferably, a phosphoric acid modified epoxy resin obtained by reacting at an equivalent ratio of 1:1 to 1:2 is used.

[0086] When the resin composition of the present invention contains phosphate-modified epoxy resin, the content of phosphate-modified epoxy resin in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion and corrosion resistance of the obtained resin composition to metals, the content of phosphate-modified epoxy resin in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0087] As for the melamine resin that can be used in this invention, any known melamine resin can be used without particular limitation. Examples of such melamine resins include, for instance, partially or fully hydroxymethylated melamine obtained by reacting melamine with formaldehyde, alkyl ether type melamine resins obtained by partially or fully etherifying the hydroxymethyl groups of hydroxymethylated melamine resin with alcohol, melamine resins containing imine groups, and mixtures thereof. One or more of these can be used. In this invention, from the viewpoint of the adhesion to metals and corrosion resistance of the resulting resin composition, melamine resins containing imine groups are preferred. Furthermore, commercially available products can also be used as the melamine resin that can be used in this invention, such as a series of melamine resins with the name CYMEL (registered trademark) (manufactured by Allnex).

[0088] When the resin composition of the present invention contains melamine resin, the content of melamine resin in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion to metals and corrosion resistance of the obtained resin composition, the content of melamine resin in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0089] As for the phenolic resin that can be used in this invention, any known phenolic resin can be used without particular limitation. Examples of such phenolic resins include bisphenol A type phenolic resin, bisphenol E type phenolic resin, bisphenol F type phenolic resin, bisphenol S type phenolic resin, phenolic varnish resin, bisphenol A phenolic varnish type phenolic resin, glycidyl ester type phenolic resin, aralkyl phenolic varnish type phenolic resin, biphenyl aralkyl type phenolic resin, methyl phenolic resin, cresol phenolic varnish type phenolic resin, polyfunctional phenolic resin, naphthol resin, naphthol phenolic varnish resin, polyfunctional naphthol resin, anthracene type phenolic resin, naphthalene skeleton modified phenolic varnish type phenolic resin, phenol aralkyl type phenolic resin, naphthol aralkyl type phenolic resin, dicyclopentadiene type phenolic resin, biphenyl type phenolic resin, alicyclic phenolic resin, polyol type phenolic resin, phosphorus-containing phenolic resin, phenolic resin containing polymerizable unsaturated hydrocarbon groups, and organosilicon resins containing hydroxyl groups. One or more of these can be used. In this invention, from the viewpoint of the adhesion to metals and corrosion resistance of the resulting resin composition, a methyl phenolic resin is preferred as the phenolic resin. Furthermore, as the phenolic resin suitable for use in this invention, commercially available products can be used, such as a series of phenolic resins bearing the name Sumilite Resin (registered trademark) (manufactured by Sumitomo Bakelite Co., Ltd.).

[0090] When the resin composition of the present invention contains phenolic resin, the content of phenolic resin in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the adhesion and corrosion resistance of the obtained resin composition to metals, the content of phenolic resin in the resin composition relative to the total amount of the resin composition is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and even more preferably 0.2 to 5% by mass.

[0091] The resin composition of the present invention is considered to possess excellent adhesive properties, particularly excellent short-term adhesive properties, due to the presence of polyether polyurethane prepolymer and polyether polyurethane, which exhibit excellent polymer chain freedom through the use of polyether urethane as the main backbone. Furthermore, the resin composition of the present invention is considered to have improved stability and coatability by containing epoxy resin, which is solid at 25°C, thus exhibiting excellent adhesive properties, particularly short-term adhesive properties, and corrosion resistance.

[0092] 1-5. Methods for manufacturing resin compositions

[0093] The method for manufacturing the resin composition of the present invention is not particularly limited, and can be manufactured by mixing a component (A) containing an epoxy resin that is solid at 25°C and a component (B) containing one or more components selected from polyether polyurethane prepolymer and polyether polyurethane using a known method. In this case, the component (A) containing the epoxy resin that is solid at 25°C can be used directly in solid form, in a dispersed state in water, or in a dissolved state in a solvent. From the viewpoint of easily manufacturing a resin composition with excellent stability and processability, it is preferable to manufacture the resin composition using an aqueous dispersion emulsion obtained by dispersing the component (A) containing the epoxy resin that is solid at 25°C in a solvent containing water. In this case, the method for dispersing the component (A) containing the epoxy resin that is solid at 25°C in water is not particularly limited; for example, methods such as using a surfactant to forcibly emulsify the epoxy resin in water or dispersing a self-emulsifying epoxy resin in water can be used.

[0094] In this invention, the surfactant used in manufacturing the resin composition is not particularly limited, and can be any of the aforementioned known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., can be used, as well as the component (A) containing an epoxy resin that is solid at 25°C, dispersed in a solvent containing water. From the viewpoint of the resulting resin composition's adhesion to metals, corrosion resistance, and processability, it is preferable to contain one or more surfactants selected from anionic and nonionic surfactants, more preferably to contain at least one nonionic surfactant, and even more preferably to contain at least one nonionic surfactant having an olefinic skeleton. At this point, from the viewpoint of the adhesion to metals, corrosion resistance, and processability of the obtained resin composition, it is preferable to contain a nonionic surfactant with a weight-average molecular weight of 1,000 to 50,000, more preferably a nonionic surfactant with a weight-average molecular weight of 5,000 to 30,000, even more preferably a nonionic surfactant with a weight-average molecular weight of 10,000 to 20,000, and particularly preferably a nonionic surfactant with a weight-average molecular weight of 14,000 to 18,000. Furthermore, the content of the surfactant in the aqueous dispersion emulsion obtained by dispersing component (A), which contains an epoxy resin that is solid at 25°C, in a solvent containing water, is not particularly limited; for example, it can be 0.01 to 20% by mass. From the viewpoint of the adhesion to metals, corrosion resistance, and processability of the obtained resin composition, the content of surfactant is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, further preferably 0.5 to 8.0% by mass, and particularly preferably 3.0 to 6.0% by mass, relative to the total amount of the aqueous dispersion emulsion obtained by dispersing component (A) containing epoxy resin, which is solid at 25°C, in a solvent containing water.

[0095] Furthermore, when manufacturing the resin composition of the present invention, the polyether polyurethane prepolymer can be a solid or liquid polyether polyurethane prepolymer monomer, which can be used in a dispersed state in water or in a dissolved state in a solvent. From the viewpoint of being able to easily manufacture a resin composition with excellent stability and processability, it is preferable to use an aqueous dispersion emulsion obtained by dispersing the polyether polyurethane prepolymer in a solvent containing water to manufacture the resin composition. At this time, there is no particular limitation on the method of dispersing the polyether polyurethane prepolymer in water; for example, a method of forcibly emulsifying the polyether polyurethane prepolymer in water using a surfactant, or a method of dispersing a self-emulsifying polyether polyurethane prepolymer in water, etc., can be used. As for the surfactant that can be used at this time, there is no particular limitation; the above-mentioned known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., can be used, and there is no particular limitation on their content. The surfactant content, for example, relative to the total amount of the aqueous dispersion emulsion obtained by dispersing the polyether polyurethane prepolymer in a solvent containing water, is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, even more preferably 0.5 to 8.0% by mass, and particularly preferably 3.0 to 6.0% by mass.

[0096] Furthermore, when manufacturing the resin composition of the present invention, the polyether polyurethane can be a solid or liquid polyether polyurethane monomer, which can be used in a dispersed state in water or in a dissolved state in a solvent. From the viewpoint of being able to easily manufacture a resin composition with excellent stability and processability, it is preferable to use an aqueous dispersion emulsion obtained by dispersing the polyether polyurethane in a solvent containing water to manufacture the resin composition. At this time, there is no particular limitation on the method of dispersing the polyether polyurethane in water; for example, a method of forcibly emulsifying the polyether polyurethane in water using a surfactant, or a method of dispersing a self-emulsifying polyether polyurethane in water, etc., can be used. At this time, there is no particular limitation on the surfactant that can be used; the above-mentioned known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., can be used, and there is no particular limitation on their content. The content of the surfactant is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, further preferably 0.5 to 8.0% by mass, and particularly preferably 3.0 to 6.0% by mass, relative to the total amount of the aqueous dispersion emulsion obtained by dispersing the polyether polyurethane in a solvent containing water.

[0097] In this invention, from the viewpoint of more easily obtaining an aqueous resin composition with excellent adhesiveness, especially adhesiveness and corrosion resistance that can be bonded by short-time pressing, it is particularly preferred to mix an aqueous dispersion emulsion containing an epoxy resin component (A) that is solid at 25°C and an aqueous dispersion emulsion containing one or more components (B) selected from polyether polyurethane prepolymer and polyether polyurethane, thereby manufacturing a resin composition.

[0098] 1-6. Uses of the resin composition

[0099] Regarding the resin composition of the present invention, it can be used without particular limitation as long as it is used for applications involving epoxy resin or polyurethane resin. The resin composition of the present invention can be used, for example, as an adhesive, coating agent, sealant, etc., for substrates such as metal, wood, glass, concrete, plastic, and ceramics. More specifically, it can be used as an adhesive, coating agent, adhesive, sealant, etc., for bonding various substrates in the automotive, vehicle (Shinkansen, tram, etc.), civil engineering, construction, shipbuilding, aircraft, and aerospace industries, as well as for general office components, medical components, and electronic material components. Among these, the resin composition of the present invention, by containing the specific components (A) and (B) described above, exhibits particularly excellent adhesion to metals, and is therefore preferably used as a resin composition for metal surface treatment, such as an adhesive between metal substrates or between a metal substrate and other substrates, or as a coating agent for metal substrates.

[0100] 2. Resin composition for metal surface treatment

[0101] The metal surface treatment resin composition of the present invention comprises a component (A) containing epoxy resin that is solid at 25°C, and a component (B) containing one or more components selected from polyether polyurethane prepolymer and polyether polyurethane. In this case, the aforementioned components can be used separately as the component (A) containing epoxy resin that is solid at 25°C and the component (B) containing one or more components selected from polyether polyurethane prepolymer and polyether polyurethane. The content of the component (A) containing epoxy resin that is solid at 25°C in the metal surface treatment resin composition of the present invention is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of improving the adhesion and corrosion resistance of the metal surface treatment resin composition, especially the adhesion produced by short-time pressing, the content of component (A) in the metal surface treatment resin composition relative to the total amount of the metal surface treatment resin composition is preferably 3 to 60% by mass, more preferably 5 to 50% by mass, further preferably 8 to 45% by mass, and even more preferably 20 to 40% by mass.

[0102] The content of component (B) in the metal surface treatment resin composition of the present invention, which comprises one or more components selected from polyether polyurethane prepolymer and polyether polyurethane, is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of improving the adhesion and corrosion resistance of the metal surface treatment resin composition, especially the adhesion produced by short-time pressing, the content of component (B) relative to the total amount of the metal surface treatment resin composition is preferably 1 to 50% by mass, more preferably 2 to 40% by mass, further preferably 3 to 30% by mass, and particularly preferably 4 to 10% by mass.

[0103] The ratio of component (A) comprising epoxy resin that is solid at 25°C to component (B) comprising one or more selected from polyether polyurethane prepolymer and polyether polyurethane in the resin composition for metal surface treatment of the present invention is not particularly limited and can be adjusted according to the purpose. From the viewpoint of improving the adhesion and corrosion resistance of the resin composition for metal surface treatment, especially the adhesion produced by short-time pressing, the ratio of component (A) to component (B) in the resin composition for metal surface treatment, by mass ratio, is preferably 5:95 to 98:2, more preferably 20:80 to 95:5, further preferably 50:50 to 92:8, and particularly preferably 70:30 to 90:10.

[0104] The water content in the resin composition for metal surface treatment of the present invention is not particularly limited and can be appropriately adjusted. From the viewpoints of the metal surface treatment resin composition's adhesion to metals and corrosion resistance, environmental impact reduction, and treatability, it is preferable to contain 10 to 90% by mass of water relative to the total amount of the metal surface treatment resin composition, more preferably 20 to 80% by mass, even more preferably 30 to 70% by mass, and particularly preferably 40 to 60% by mass. In this case, tap water, ion-exchanged water, distilled water, natural water, purified water, etc., can be appropriately used depending on the purpose.

[0105] The ratio of the content of component (A) and component (B) to water in the metal surface treatment resin composition of the present invention is not particularly limited and can be adjusted according to the purpose. From the viewpoints of the adhesion and corrosion resistance of the metal surface treatment resin composition to metals, the reduction of environmental impact, and the processability of the metal surface treatment resin composition, the ratio of the content of component (A) and component (B) to water in the metal surface treatment resin composition is preferably 3-80:1-60:10-90 when the sum of the contents of component (A) and component (B) to water is set to 100, more preferably 5-60:2-50:20-80, further preferably 8-50:3-40:30-70, and particularly preferably 20-40:4-10:40-60. The metal surface treatment resin composition of the present invention contains the above-mentioned specific components (A) and (B) and water in such a content ratio, thereby obtaining an aqueous dispersion emulsion with excellent dispersion stability as a metal surface treatment resin composition. Therefore, it is possible to produce a metal surface treatment resin composition with reduced environmental impact and excellent processability.

[0106] When the metal surface treatment resin composition of the present invention contains water, as component (A), among the epoxy resins that are solid at 25°C, from the viewpoint of the dispersion stability and various properties of the obtained metal surface treatment resin composition, it is preferable to use a bisphenol type epoxy resin that is solid at 25°C, more preferably one or more selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD ​​type epoxy resin that are solid at 25°C, and even more preferably bisphenol A type epoxy resin that is solid at 25°C. Furthermore, from the viewpoint of the dispersion stability and various properties of the obtained resin composition for metal surface treatment, as component (A), among the epoxy resins that are solid at 25°C as described above, it is preferable to use epoxy resins that are solid at 25°C with an epoxy equivalent of 500 g / eq. to 30000 g / eq., more preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 1000 g / eq. to 10000 g / eq., even more preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 1500 g / eq. to 6000 g / eq., even more preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 2000 g / eq. to 5000 g / eq., and particularly preferably epoxy resins that are solid at 25°C with an epoxy equivalent of 2500 g / eq. to 3500 g / eq.

[0107] When the metal surface treatment resin composition of the present invention contains water, as component (B), from the viewpoint of the dispersion stability and various properties of the obtained metal surface treatment resin composition, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more polyalkylene glycols; more preferably, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol; even more preferably, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from polypropylene glycol and polytetramethylene ether glycol; and particularly preferably, it is preferable to use one or more selected from polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing polytetramethylene ether glycol. Furthermore, from the viewpoint of the dispersion stability and various properties of the obtained resin composition for metal surface treatment, the acid values ​​of the polyether polyurethane prepolymer and the polyether polyurethane used are preferably 0 to 70 mg KOH / g, more preferably 10 to 60 mg KOH / g, even more preferably 15 to 50 mg KOH / g, and particularly preferably 20 to 40 mg KOH / g.

[0108] In addition to components (A), (B), and water described above, the resin composition for metal surface treatment of the present invention may contain other components such as surfactants, fillers, catalysts, lubricants, pigments, dyes, colorants, extenders, corrosion inhibitors, flow modifiers, thixotropic agents, dispersants, antioxidants, adhesion promoters, and light stabilizers, depending on the purpose. Examples of surfactants that may be included in the resin composition for metal surface treatment of the present invention include, for example, the anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants described above. One or more of these can be used. When the resin composition for metal surface treatment of the present invention contains surfactants, the content of the surfactant in the resin composition is not particularly limited and can be appropriately adjusted according to the purpose. From the viewpoint of the treatability, adhesion to metals, and corrosion resistance of the obtained resin composition for metal surface treatment, the content of surfactant in the resin composition for metal surface treatment relative to the total amount of the resin composition for metal surface treatment is preferably 0.01 to 20% by mass, more preferably 0.1 to 15% by mass, even more preferably 0.2 to 10% by mass, even more preferably 0.5 to 6% by mass, and particularly preferably 3.0 to 5.0% by mass.

[0109] The metal materials that can be treated by the resin composition for metal surface treatment of the present invention are not particularly limited. Examples include copper, aluminum, gold, silver, iron, platinum, chromium, nickel, tin, titanium, zinc, manganese, magnesium, molybdenum, cobalt, tungsten, zirconium, lead, gallium, indium, and materials composed of these metals. As metal oxides, individual oxides and / or composite oxides of these metals can be included. The resin composition for metal surface treatment of the present invention can be applied to metal surfaces where such metal materials have been processed into plates, foils, etc., and have undergone plating treatments as needed. Furthermore, the resin composition for metal surface treatment of the present invention can be used as an adhesive between metal substrates containing such metal materials, or between a metal substrate and other substrates, as well as a coating agent for metal substrates.

[0110] The method for applying the resin composition for metal surface treatment of the present invention to a metal surface is not particularly limited, and known methods can be used. For example, spraying, dipping, roller coating, curtain coating, spin coating, and combinations thereof can be used to apply the resin composition for metal surface treatment of the present invention to the metal surface. At this time, the temperature of the metal surface and the resin composition for metal surface treatment during coating is also not particularly limited, and can be adjusted according to the purpose. The temperature of the metal surface and the resin composition for metal surface treatment during coating can be set, for example, from 10°C to 90°C. Furthermore, the drying method after applying the resin composition for metal surface treatment to the metal surface is not particularly limited, and known methods can be used. For example, a drying oven, an electromagnetic induction heating oven, or a method that sets the maximum temperature to 40°C to 250°C can be used. Furthermore, as a method for using the metal surface treatment resin composition of the present invention as an adhesive between metal substrates or between a metal substrate and other substrates, for example, the following method can be used: after coating the metal surface treatment resin composition onto the metal substrate using the above method, and drying it as needed, another substrate is laminated on the coating of the metal surface treatment resin composition on the surface of the metal substrate. As needed, a press, drying oven, electromagnetic induction heating oven, etc., is used to intermittently or continuously heat the laminate to a maximum temperature of 40°C to 250°C while applying a pressure of 0.1 MPa to 100 MPa to press and bond the laminate.

[0111] 3. Manufacturing method of metal laminates

[0112] The manufacturing method of the metal laminate of the present invention includes the following steps: applying the above-mentioned resin composition to the surface of a first metal plate to form a coating film, and laminating a second metal plate on the coating film of the first metal plate to form a metal laminate. By using the manufacturing method of the metal laminate of the present invention, a metal laminate that strongly bonds the metal plates together can be obtained. In the present invention, there are no particular limitations on the raw materials of the metal plates used as the first and second metal plates. Examples of such raw materials include metal plates and steel plates containing copper, aluminum, gold, silver, iron, platinum, chromium, nickel, tin, titanium, zinc, manganese, magnesium, molybdenum, cobalt, tungsten, zirconium, lead, gallium, indium and their alloys as main components, and optionally containing carbon, silicon, nitrogen, phosphorus, sulfur, boron, niobium, tantalum, vanadium, antimony, germanium, etc. In addition, there are no particular limitations on the thickness of the metal plates used in the present invention, and it can be appropriately adjusted according to the purpose. For example, metal plates with a thickness of 1 μm to 100 cm can be used. Furthermore, in this invention, metal laminates can be manufactured using two metal plates, or three or more metal plates. The multiple metal plates can be made from the same raw materials and thickness, or they can be made from different raw materials and thicknesses.

[0113] The method for applying the resin composition to the surface of the metal plate in the manufacturing method of the metal laminate of the present invention is not particularly limited, and known methods can be used. For example, spraying, dipping, roller coating, curtain coating, spin coating, and combinations thereof can be used to apply the resin composition to the surface of the metal plate. The amount of resin composition applied to the surface of the metal plate is not particularly limited and can be appropriately adjusted according to the purpose. For example, the resin composition can be applied to the surface of the metal plate in an amount such that the film thickness of the coating obtained by applying and drying the resin composition is 0.1 μm to 10 mm.

[0114] The method for manufacturing the metal laminate of the present invention comprises a step of coating the above-mentioned resin composition onto the surface of a first metal plate to form a coating film, and a step of laminating a second metal plate onto the coating film on the surface of the first metal plate to form a metal laminate. Depending on the purpose, it may further include a step of heating the metal laminate and a step of pressing the metal laminate. In the present invention, from the viewpoint of obtaining a metal laminate with stronger adhesion, especially a metal laminate with strong adhesion in a short time, it is preferable to use a method for manufacturing a metal laminate comprising the following steps: a step of coating the resin composition onto the surface of a first metal plate to form a coating film, a step of laminating a second metal plate onto the coating film on the first metal plate to form a metal laminate, and a step of pressing the metal laminate.

[0115] The heating method in the step of heating the metal laminate, which can be included in the manufacturing method of the metal laminate of the present invention, is not particularly limited, and known methods and conditions can be used. For example, a heating method using a drying oven, an electromagnetic induction heating furnace, or similar methods to achieve a temperature of 40°C to 250°C can be employed. Furthermore, the pressing method in the step of pressing the metal laminate, which can be included in the manufacturing method of the metal laminate of the present invention, is not particularly limited, and known methods can be used. For example, a pressing method using a press or similar device to press the metal laminate under a pressure of 0.1 MPa to 100 MPa can be employed. Furthermore, in this invention, the process of heating the metal laminate and the process of pressing the metal laminate can be performed simultaneously. For example, such methods can be used to press the metal laminate at a pressure of 0.1 MPa to 100 MPa using a press or the like in an environment set at 40°C to 250°C, such as a drying oven or an electromagnetic induction heating oven; or to press the metal laminate at a pressure of 0.1 MPa to 100 MPa using a hot press or the like heated to 40°C to 250°C.

[0116] As a method for manufacturing the metal laminate of the present invention, when using a method including a step of coating a resin composition onto the surface of a first metal plate to form a coating film, a step of laminating a second metal plate onto the coating film of the first metal plate to form a metal laminate, and a step of pressing the metal laminate, the raw materials and thickness of the metal plates used are not particularly limited. For example, metal plates made from the aforementioned raw materials and thicknesses can be used. The first metal plate and the second metal plate can be metal plates made from the same raw materials and thicknesses, or they can be metal plates made from different raw materials and thicknesses. Furthermore, as a method for manufacturing the metal laminate of the present invention, when using a method including a step of coating a resin composition onto the surface of a first metal plate to form a coating film, a step of laminating a second metal plate onto the coating film of the first metal plate to form a metal laminate, and a step of pressing the metal laminate, the method of coating the resin composition onto the surface of the metal plate and the amount of resin composition coated onto the surface of the metal plate are not particularly limited. For example, the methods and coating amounts described above can be used respectively.

[0117] Furthermore, as a method for manufacturing the metal laminate of the present invention, when using a method comprising a step of coating a resin composition onto the surface of a first metal plate to form a coating film, a step of laminating a second metal plate onto the coating film of the first metal plate to form a metal laminate, and a step of pressing the metal laminate together, a metal laminate can be manufactured using two metal plates, or a metal laminate can be manufactured using three or more metal plates. The multiple metal plates can be metal plates made from the same raw materials and with the same thickness, or metal plates made from different raw materials and with different thicknesses. In the case of manufacturing a metal laminate using three or more metal plates, the metal laminate can be manufactured by repeatedly performing the following steps: applying a resin composition to the surface of a first metal plate to form a coating film; laminating a second metal plate on the coating film of the first metal plate to form a metal laminate; pressing the metal laminate together; applying a resin composition to the surface of the pressed metal laminate to form a coating film; further laminating a third metal plate on the coating film of the metal laminate to form a metal laminate; and pressing the metal laminate together. Alternatively, the metal laminate can be manufactured by repeatedly applying a resin composition to the surface of three or more metal plates to form a coating film, laminating the metal plates to form a metal laminate, and then pressing the metal laminate together.

[0118] The method for manufacturing the metal laminate of the present invention uses the above-described resin composition and employs the above-described method to obtain a metal laminate with strong adhesion. Regarding the metal laminate obtained according to the present invention, it can be used without particular limitation in any application where metal laminates are used, for example, as a metal laminate for automobiles, vehicles (Shinkansen, trains, etc.), civil engineering, construction, shipbuilding, aircraft, and the aerospace industry.

[0119] 4. Metal laminate

[0120] The metal laminate of the present invention comprises a first metal plate, a coating of the aforementioned resin composition, and a second metal plate sequentially stacked. The first and second metal plates can be made from the same raw materials and thickness, or they can be made from different raw materials and thicknesses. The metal laminate of the present invention can be manufactured, for example, using the aforementioned method for manufacturing metal laminates. Because the metal laminate of the present invention strongly bonds the metal plates together, it can be used without particular limitation in any application where metal laminates are used. For example, the metal laminate of the present invention can be used in the automotive, vehicle (Shinkansen, tram, etc.), civil engineering, construction, shipbuilding, aircraft, and space industries.

[0121] The following schemes can be listed in this disclosure.

[0122] [1] A resin composition comprising: an epoxy resin which is solid at 25°C (A), and an epoxy resin which is selected from polyether polyurethane prepolymer and polyether polyurethane (B).

[0123] [2] According to the resin composition of [1], wherein component (A) contains bisphenol A type epoxy resin which is solid at 25°C.

[0124] [3] The resin composition according to [1] or [2], wherein component (B) contains a polyether polyurethane prepolymer obtained by reacting a polyether polyol compound, a polyisocyanate compound, an anionic group introducer, and a melamine compound.

[0125] [4] The resin composition according to any one of [1] to [3], wherein component (B) contains a polyether polyurethane obtained by reacting a polyether polyol compound, a polyisocyanate compound, an anionic group introducing agent, and a melamine compound with an end-capping agent or a chain extender.

[0126] [5] The resin composition according to any one of [1] to [4], wherein the ratio of the content of component (A) to component (B) in the resin composition is 5:95 to 98:2 by mass.

[0127] [6] The resin composition according to any one of [1] to [5] further contains water, the water content being 10 to 90% by mass.

[0128] [7] A resin composition for metal surface treatment, comprising: an epoxy resin which is solid at 25°C (A), and an epoxy resin which is selected from polyether polyurethane prepolymer and polyether polyurethane (B).

[0129] [8] A method for manufacturing a metal laminate, comprising: a step of coating a resin composition according to any one of [1] to [6] onto the surface of a first metal plate to form a coating film; and a step of laminating a second metal plate on the coating film of the first metal plate to form a metal laminate.

[0130] [9] The method for manufacturing a metal laminate according to [8] further includes a step of pressing the metal laminate together.

[0131]

[10] A metal laminate, wherein a first metal plate, a coating of a resin composition according to any one of [1] to [6], and a second metal plate are sequentially laminated.

[0132] Example

[0133] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited thereto. It should be noted that in the following examples, etc., % is a quality standard unless otherwise specified.

[0134] <Preparation of Aqueous Dispersion Emulsion 1 of Epoxy Resin>

[0135] In a four-necked separable round-bottom flask equipped with a DIMROTH nozzle, stirring blades, and nitrogen tubing, 290.0 g of bisphenol A type epoxy resin (melting point below 0°C, epoxy equivalent 190 g / eq.), 159.5 g of bisphenol A, and 0.1 g of triphenylphosphine as a catalyst were added. The mixture was reacted at 180°C for 5 hours to obtain epoxy resin A-1. Then, 50.5 g of propylene glycol monomethyl ether was added as a solvent, followed by 50.5 g of a nonionic surfactant 1 with an ethylene oxide backbone and a weight average molecular weight of 16,000. The mixture was mixed, cooled to 70°C, and then 449.5 g of water was added. The mixture underwent phase inversion emulsification to produce an aqueous dispersion emulsion 1 of the epoxy resin. The resulting aqueous dispersion emulsion 1 of epoxy resin contains 45.0% by mass of epoxy resin A-1 (bisphenol A type epoxy resin, melting point 140℃, epoxy equivalent 3000g / eq.), 5.0% by mass of nonionic surfactant 1, 5.0% by mass of propylene glycol monomethyl ether, and 45.0% by mass of water.

[0136] <Preparation of Aqueous Dispersion Emulsion 2 of Epoxy Resin>

[0137] In a four-necked separable round-bottom flask equipped with a DIMROTH nozzle, stirring blades, and nitrogen tubing, 450.5 g of bisphenol A type epoxy resin (melting point below 0°C, epoxy equivalent 190 g / eq.), 49.5 g of propylene glycol monomethyl ether as a solvent, and 49.5 g of nonionic surfactant 1 with an ethylene oxide backbone and a weight average molecular weight of 16,000 were added. The mixture was stirred at 70°C, and then 450.5 g of water was added, followed by phase inversion emulsification to produce an aqueous dispersion emulsion 2 of epoxy resin. The resulting aqueous dispersion emulsion 2 of epoxy resin contained 45.0% by weight of epoxy resin A'-2 (bisphenol A type epoxy resin, melting point below 0°C, epoxy equivalent 190 g / eq.), 5.0% by weight of nonionic surfactant 1, 5.0% by weight of propylene glycol monomethyl ether, and 45.0% by weight of water.

[0138] <Preparation of Aqueous Dispersion Emulsion 1 of Polyurethane Resin>

[0139] In a four-necked separable round-bottom flask equipped with a DIMROTH, stirring blades, and nitrogen tubing, 202.7 g of polytetramethylene ether diol (number average molecular weight 1000) as a polyether polyol compound, 436.9 g of hydrogenated diphenylmethane diisocyanate as a polyisocyanate compound, 67.6 g of dimethylolpropionic acid as an anionic group introducer, 33.8 g of melamine, 56.3 g of triethylamine as a neutralizing agent, and 202.7 g of N-methyl-2-pyrrolidone were added. The mixture was reacted at 80°C for 5 hours to prepare a urethane prepolymer solution.

[0140] Next, 724.0 g of water at 40°C was added to a 2L disposable cup and stirred. Then, 500 g of the above-mentioned urethane prepolymer solution was added and stirred for 30 minutes. Then, 52.0 g of an aqueous solution of ethylenediamine / water = 1 / 3 (mass ratio) was added, and the mixture was stirred for 1 hour to obtain an aqueous dispersion emulsion 1 of polyurethane resin. The obtained aqueous dispersion emulsion 1 of polyurethane resin contains 30% by mass of polyether polyurethane B-1 (acid value: 38.0 mg KOH / g, polyether structure content: 27% by mass), 8% by mass of N-methyl-2-pyrrolidone, and 62% by mass of water.

[0141] <Preparation of Aqueous Dispersion Emulsion 2 of Polyurethane Resin>

[0142] In a four-necked separable round-bottom flask equipped with a DIMROTH, stirring blades, and nitrogen tubing, 374.3 g of polytetramethylene ether diol with a number average molecular weight of 1000 (as a polyether polyol compound), 334.2 g of hydrogenated diphenylmethane diisocyanate (as a polyisocyanate compound), 42.8 g of dimethylolpropionic acid (as an anionic group introducer), 13.4 g of melamine, 32.1 g of triethylamine (as a neutralizing agent), and 203.2 g of N-methyl-2-pyrrolidone were added. The mixture was reacted at 80°C for 5 hours to prepare a urethane prepolymer solution.

[0143] Next, 765.8g of water at 40°C was added to a 2L disposable cup and stirred. Then, 500g of the above-mentioned urethane prepolymer solution was added and stirred for 30 minutes. Then, 26.7g of an aqueous solution of ethylenediamine / water = 1 / 3 (mass ratio) was added, and the mixture was stirred for 1 hour to obtain an aqueous dispersion emulsion 2 of polyurethane resin. The obtained aqueous dispersion emulsion 2 of polyurethane resin contains 30% by mass of polyether polyurethane B-2 (acid value: 23.0mgKOH / g, polyether structure content: 49% by mass), 8% by mass of N-methyl-2-pyrrolidone, and 62% by mass of water.

[0144] <Preparation of Aqueous Dispersion Emulsion 3 of Polyurethane Resin>

[0145] In a four-necked separable round-bottom flask equipped with a DIMROTH nozzle, stirring blades, and nitrogen tubing, 253.2 g of polyester polyol with a number average molecular weight of 500, 436.7 g of hydrogenated diphenylmethane diisocyanate as a polyisocyanate compound, 50.6 g of dimethylolpropionic acid as an anionic group introducer, 19.0 g of melamine, 38.0 g of triethylamine as a neutralizing agent, and 202.5 g of N-methyl-2-pyrrolidone were added. The mixture was reacted at 80°C for 5 hours to prepare a urethane prepolymer solution.

[0146] Next, 771.1 g of water at 40°C was added to a 2L disposable cup and stirred. Then, 500 g of the above-mentioned urethane prepolymer solution was added and stirred for 30 minutes. Then, 35.5 g of an aqueous solution of ethylenediamine / water = 1 / 3 (mass ratio) was added, and the mixture was stirred for 1 hour to obtain an aqueous dispersion emulsion 3 of polyurethane resin. The obtained aqueous dispersion emulsion 3 of polyurethane resin contains 30% by mass of polyester polyurethane B'-3 (acid value: 28.0 mg KOH / g), 8% by mass of N-methyl-2-pyrrolidone, and 62% by mass of water.

[0147] <Preparation of Aqueous Dispersion Emulsion 4 of Polyurethane Resin>

[0148] In a four-necked separable round-bottom flask equipped with a DIMROTH nozzle, stirring blades, and nitrogen tubing, 526.8 g of polycarbonate diol with a number average molecular weight of 2000 (as a polycarbonate polyol compound), 229.9 g of hydrogenated diphenylmethane diisocyanate (as a polyisocyanate compound), 43.1 g of dimethylolpropionic acid (as an anionic group introducer), 42.2 g of triethylamine (as a neutralizing agent), and 202.2 g of N-methyl-2-pyrrolidone were added. The mixture was reacted at 80°C for 5 hours to prepare a urethane prepolymer solution.

[0149] Next, 807.8g of water at 40°C was added to a 2L disposable cup and stirred. Then, 500g of the above-mentioned urethane prepolymer solution was added and stirred for 30 minutes. Then, 22.3g of an aqueous solution of ethylenediamine / water = 1 / 3 (mass ratio) was added, and the mixture was stirred for 1 hour to obtain an aqueous dispersion emulsion 4 of polyurethane resin. The obtained aqueous dispersion emulsion 4 of polyurethane resin contains 30% by mass of polycarbonate polyurethane B'-4 (acid value: 23.0mgKOH / g), 8% by mass of N-methyl-2-pyrrolidone, and 62% by mass of water.

[0150] [Examples 1-4, Comparative Examples 1-5]

[0151] The resin compositions of Examples 1-4 and Comparative Examples 1-5 shown in Table 1 were prepared by mixing the aqueous dispersion emulsions 1-2 of the epoxy resin and the aqueous dispersion emulsions 1-4 of the polyurethane resin.

[0152] [Room temperature adhesion evaluation]

[0153] Two steel plates (25 mm wide, 100 mm long, and 1.6 mm thick) were coated on one side respectively with the resin compositions prepared in Examples 1-4 and Comparative Examples 1-5, so that the dried coating thickness was about 4 μm. They were then dried with hot air (reaching a plate temperature of 200°C) to produce surface-treated steel plates with a resin composition coating formed on the entire surface of each steel plate. The two surface-treated steel plates were stacked such that the treated surfaces (coated surfaces) overlapped each other by 10 mm in the length direction (aligned in the width direction). A press was used to press the plates together at room temperature for 10 or 20 minutes while applying a pressure of 3 MPa, thereby producing a metal laminate formed by bonding the two steel plates. The resulting metal laminate was tested using a tensile testing machine with the overlap shear strength (MPa) determined according to the method described in JIS K 6850 (1999). The adhesion was evaluated based on the overlap shear strength value according to the following room temperature adhesion evaluation criteria. The evaluation results of the room temperature adhesion of each resin composition are shown in Table 1. It should be noted that in this evaluation, if the room temperature adhesion evaluation is △ or above, it indicates that it is practical for short-time room temperature bonding methods.

[0154] Evaluation criteria for room temperature adhesion

[0155] ◎: Overlapping shear strength of 15 MPa or higher

[0156] ○: Overlapping shear strength is above 10 MPa but less than 15 MPa

[0157] △: Overlapping shear strength is above 5 MPa but less than 10 MPa

[0158] ×: The overlap shear strength is less than 5 MPa

[0159] [High-Temperature Adhesion Evaluation]

[0160] Two steel plates (25 mm wide, 100 mm long, and 1.6 mm thick) were coated on one side respectively with the resin compositions prepared in Examples 1-4 and Comparative Examples 1-5, so that the dried coating thickness was about 4 μm. They were then dried with hot air (reaching a plate temperature of 200°C) to produce surface-treated steel plates with a resin composition coating formed on the entire surface of each steel plate. The two surface-treated steel plates were stacked such that the treated surfaces (coated surfaces) overlapped each other by 10 mm in the length direction (aligned in the width direction). A hot press was used to press them together at 180°C for 10 minutes while applying a pressure of 3 MPa, thereby producing a metal laminate formed by bonding the two steel plates. The resulting metal laminate was tested using a tensile testing machine with the overlap shear strength (MPa) determined according to the method described in JIS K 6850 (1999). The adhesion was evaluated based on the overlap shear strength value according to the following high-temperature adhesion evaluation criteria. The evaluation results of the high-temperature adhesion of each resin composition are shown in Table 1. It should be noted that in this evaluation, if the high-temperature adhesion evaluation is △ or above, it indicates that it is practical for short-time high-temperature bonding methods.

[0161] Evaluation criteria for high-temperature adhesion

[0162] ◎: Overlapping shear strength is above 2.5 MPa

[0163] ○: Overlapping shear strength is above 1.0 MPa but less than 2.5 Pa

[0164] △: Overlapping shear strength is above 0.1 MPa but less than 1.0 MPa

[0165] ×: The overlap shear strength is less than 0.1 MPa.

[0166] [Corrosion Resistance Evaluation]

[0167] Resin compositions prepared in Examples 1-4 and Comparative Examples 1-5 were coated on one side of a steel plate (25 mm wide, 100 mm long, and 1.6 mm thick) to achieve a coating thickness of approximately 4 μm after drying. The coated plates were then dried with hot air (reaching a plate temperature of 200°C) to produce surface-treated steel plates with a resin composition coating covering the entire surface of each plate. For the prepared surface-treated steel plates, a 24-hour salt spray test at 35°C was conducted on the treated surface (the surface with the coating) using 5% by mass neutral brine, according to JIS Z 2371 (2015). The corrosion resistance of each resin composition was evaluated by visual observation of the coating on the surface-treated steel plate after the test and by the following corrosion resistance evaluation criteria. The evaluation results of the corrosion resistance of each resin composition are shown in Table 1. It should be noted that in this evaluation, a corrosion resistance evaluation of △ or higher indicates practical applicability.

[0168] Evaluation criteria for corrosion resistance

[0169] ◎: The rusted area is less than 10%.

[0170] ○: Rusted area is 10% or more but less than 20% △: Rusted area is 20% or more but less than 40% ×: Rusted area is 40% or more

[0171] Table 1

[0172]

[0173] As shown in Table 1, the resin composition of the present invention containing component (A) which is solid at 25°C and component (B) which contains one or more components selected from polyether polyurethane prepolymer and polyether polyurethane exhibits excellent adhesive properties, particularly adhesive properties that can be achieved by short-time pressing at both room temperature and high temperature, and corrosion resistance. On the other hand, when component (A) is replaced by epoxy resin which is liquid at 25°C, or when component (B) is replaced by polyester polyurethane or polycarbonate polyurethane, adhesive properties that can be achieved by short-time pressing are not present. From these results, it can be seen that, according to the present invention, a resin composition with superior adhesive properties compared to conventional resin compositions can be provided.

Claims

1. A resin composition comprising: an component (A) comprising an epoxy resin that is solid at 25°C, and a component (B) comprising one or more components selected from polyether polyurethane prepolymers and polyether polyurethanes.

2. The resin composition according to claim 1, wherein, The component (A) contains bisphenol A type epoxy resin, which is solid at 25°C.

3. The resin composition according to claim 1, wherein, The component (B) contains a polyether polyurethane prepolymer obtained by reacting a polyether polyol compound, a polyisocyanate compound, an anionic group introducing agent, and a melamine-based compound.

4. The resin composition according to claim 1, wherein, The component (B) contains a polyether polyurethane obtained by reacting a polyether polyol compound, a polyisocyanate compound, an anionic group introducing agent, and a melamine-based compound, followed by end-capping with an end-capping agent or chain extension with a chain extender.

5. The resin composition according to claim 1, wherein, The ratio of the content of component (A) to component (B) in the resin composition is 5:95 to 98:2 by mass.

6. The resin composition according to claim 1, further comprising water, wherein the water content is 10-90% by mass.

7. A resin composition for metal surface treatment, comprising: an component (A) comprising an epoxy resin that is solid at 25°C, and a component (B) comprising one or more components selected from polyether polyurethane prepolymer and polyether polyurethane.

8. A method for manufacturing a metal laminate, comprising: The process of applying the resin composition according to any one of claims 1 to 6 to the surface of a first metal plate to form a coating film; The process of laminating a second metal plate on the coating of the first metal plate to form a metal laminate.

9. The method for manufacturing a metal laminate according to claim 8, further comprising the step of pressing the metal laminate together.

10. A metal laminate, wherein a first metal plate, a coating of the resin composition according to any one of claims 1 to 6, and a second metal plate are sequentially laminated.

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