WO2024203515A1 - Resin composition, resin composition for metal surface treatment, method for producing metal laminate, and metal laminate - Google Patents

Abstract

Provided is a resin composition containing: a component (A) which is composed of an epoxy resin that is in a solid state at 25°C; and a component (B) which is composed of one or more compounds selected from the group consisting of a polyether polyurethane prepolymer and a polyether polyurethane. Also provided is a method for producing a metal laminate, the method comprising: a step in which the resin composition is applied to the surface of a first metal plate so as to form a coating film; and a step in which a second metal plate is superposed on the coating film of the first metal plate so as to form a metal laminate.

Description

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

The present invention relates to a resin composition that has excellent adhesive properties.

Epoxy resins and urethane resins have excellent adhesion to various substrates, and can produce cured products that are excellent in corrosion resistance, heat resistance, chemical resistance, electrical properties, and mechanical properties, and are therefore widely used in various fields as adhesives, coating agents, paints, and the like. In recent years, there has been a demand for adhesives, paints, coating agents, and the like that contain epoxy resins and urethane resins to be water-based resin compositions that use water as a solvent, from the standpoint of reducing environmental impact and safety. As such water-based resin compositions, Patent Document 1 describes an environmentally friendly aqueous epoxy resin emulsion that has excellent storage stability and rust prevention properties, and an aqueous paint that contains the same. Patent Document 2 describes an aqueous epoxy resin dispersion with low volatile organic compounds (VOCs), particularly for coating metals and concrete.

Also, various metal surface treatment agents that have metal adhesion and corrosion prevention properties using water-based epoxy resins and the like are being developed. For example, Patent Document 3 describes an aqueous paint composition that can form a coating film that improves the water-resistant adhesion to steel sheets that have been surface-treated by plating or other methods, and exhibits excellent corrosion resistance and corrosion prevention. Patent Document 4 describes a surface treatment agent for metal materials that can produce a surface-treated metal material with a coating film that has excellent corrosion resistance and adhesion, even when the paint base treatment is omitted.

JP 2014-009270 A JP 2015-214698 A JP 2015-124234 A International Publication No. 2015/056355

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

In view of the above, the present invention aims to provide a resin composition with excellent adhesive properties.

Therefore, the present inventors conducted extensive research and found that a resin composition containing a specific component solves the above problems.
That is, the present invention provides a resin composition containing component (A) consisting of an epoxy resin that is solid at 25°C, and component (B) consisting of one or more members selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes.

The present invention provides a resin composition with excellent adhesive properties.

1. Resin Composition The resin composition of the present invention is a resin composition containing component (A) consisting of an epoxy resin that is solid at 25° C., and component (B) consisting of one or more members selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes. The resin composition of the present invention will be described in detail below.
1-1. Component (A)
The component (A) used in the present invention is an epoxy resin that is solid at 25° C. In the present invention, there are no particular limitations on the epoxy resin that can be used as long as it is solid at 25° C. Examples of such epoxy resins include bisphenol type epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AD type epoxy resins, which are solid at 25° C., resorcin type epoxy resins, hydroquinone type epoxy resins, catechol type epoxy resins, dihydroxynaphthalene type epoxy resins, biphenyl type epoxy resins, tetramethylbiphenyl type epoxy resins, oxazolidone ring type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, triphenylmethane type epoxy resins, tetraphenylethane type epoxy resins, dicyclopentadiene-phenol addition reaction type epoxy resins, phenol aralkyl type epoxy resins, naphthol novolac type epoxy resins, naphthol aralkyl type epoxy resins, naphthol-phenol co-condensed novolac type epoxy resins, naphthol-cresol co-condensed novolac type epoxy resins, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resins, biphenyl modified novolac type epoxy resins, etc. One or more of these may be used. Among these, from the viewpoint of improving the adhesiveness of the resulting resin composition, particularly the adhesiveness by short-time pressure bonding, it is preferable to use a bisphenol type epoxy resin that is solid at 25 ° C., more preferably to use one or more selected from the group consisting of 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 to use a bisphenol A type epoxy resin that is solid at 25 ° C. In the present invention, being solid at 25 ° C. means that the melting point is higher than 25 ° C. and is solid at 25 ° C. The melting point of the epoxy resin is not particularly limited as long as it is higher than 25 ° C. From the viewpoint of the adhesiveness of the resulting 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) consisting of an epoxy resin that is solid at 25 ° C. does not include the phosphoric acid-modified epoxy resin described later and is clearly distinguished.

The epoxy equivalent of the epoxy resin in a solid state at 25°C is not particularly limited and can be adjusted according to the purpose. From the viewpoint of improving the adhesiveness of the resulting resin composition, particularly the adhesiveness by short-time compression, the epoxy equivalent of the epoxy resin in a solid state at 25°C is preferably 500 g/eq. to 30,000 g/eq., more preferably 1,000 g/eq. to 10,000 g/eq., even more preferably 1,500 g/eq. to 6,000 g/eq., even more preferably 2,000 g/eq. to 5,000 g/eq., and particularly preferably 2,500 g/eq. to 3,500 g/eq. In the present invention, the epoxy equivalent of the epoxy resin is measured in accordance with JIS K 7236 (2009).

1-2. Component (B)
The component (B) used in the present invention is one or more selected from the group consisting of polyether polyurethane prepolymer and polyether polyurethane. In the present invention, the 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 so that unreacted isocyanate groups remain in the compound. In the present invention, the 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 so that unreacted isocyanate groups remain in the compound, or by blocking the polyether polyurethane prepolymer obtained by the above-mentioned method with a blocking agent, or by chain-extending the polyether polyurethane prepolymer with a chain extender.

In the present invention, examples of polyether polyol compounds that can be used in the production of polyether polyurethane prepolymers include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, polyethylene glycol-polypropylene glycol random copolymers, and polyethylene glycol-polypropylene glycol block copolymers, as well as polyoxyethylene adducts, polyoxypropylene adducts, and polyoxybutylene adducts of diol compounds such as ethylene glycol, propanediol, and butanediol. Among these, 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 the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol, even more preferably one or more selected from the group consisting of polypropylene glycol and polytetramethylene ether glycol, and particularly preferably polytetramethylene ether glycol. The molecular weight of the polyether polyol compound used is not particularly limited. From the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use a polyether polyol compound having a number average molecular weight of 200 to 10,000, more preferably a polyether polyol compound having a number average molecular weight of 400 to 5,000, even more preferably a polyether polyol compound having a number average molecular weight of 600 to 2,000, and particularly preferably a polyether polyol compound having a number average molecular weight of 800 to 1,500. In the present invention, the number average molecular weight of the polyether polyol compound is measured by gel permeation chromatography (GPC) and is the number average molecular weight calculated in terms of polystyrene.

In the present invention, the polyisocyanate compound that can be used in the production of the polyether polyurethane prepolymer is not particularly limited as long as it has two or more isocyanate groups in the molecule. Examples of such polyisocyanate compounds include aromatic diisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, dianisidine diisocyanate, and tetramethylxylylene diisocyanate; alicyclic diisocyanates such as isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, trans-1,4-cyclohexyl diisocyanate, and norbornene diisocyanate; and 1,4-tetramethylphenyl diisocyanate. Aliphatic diisocyanates such as lamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,8-octamethylene diisocyanate, 2-methyl-1,5-pentamethylene diisocyanate, 2,2-dimethyl-1,5-pentamethylene diisocyanate, 1,11-undecamethylene 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, and lysine methyl ester diisocyanate are included. In addition, in the production of the polyether polyurethane prepolymer, as the polyisocyanate compound, an isocyanurate trimer, a biuret trimer, or a trimethylolpropane adduct of the above-mentioned diisocyanate compound, or a polyisocyanate compound having three or more isocyanate groups in the molecule, such as triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, or dimethyltriphenylmethane tetraisocyanate, can also be used. In the present invention, from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use one or more selected from the group consisting of aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates, and it is more preferable to use one or more selected from the group consisting of tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and 1,6-hexamethylene diisocyanate, and it is even more preferable to use one or more selected from the group consisting of hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and 1,6-hexamethylene diisocyanate.

The polyether polyurethane prepolymer that can be used in the present invention can be any polyether polyurethane prepolymer obtained by reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound in such a way that unreacted isocyanate groups remain. For example, a polyether polyurethane prepolymer obtained by reacting the above-mentioned polyether polyol compound and a raw material containing a polyisocyanate compound in an amount such that 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.

The polyether polyurethane prepolymer used in the present invention may be a compound obtained by reacting at least one polyether polyol compound, at least one polyisocyanate compound, and one or more raw materials having a reactive group such as a hydroxyl group or an amino group that can react with the polyisocyanate compound, such as an anionic group-introducing agent, a melamine compound, or a low molecular weight polyol, such that unreacted isocyanate groups remain in the compound.

Anionic group introducing agents that can be used in the production of polyether polyurethane prepolymers are not particularly limited, and can be any compound that has an anionic group, such as a carboxyl group or a sulfonic acid group, and a reactive group, such as a hydroxyl group or an amino group, that can react with a polyisocyanate compound in the molecule. Examples of such anionic group introducing agents include compounds that contain a carboxyl group and a hydroxyl group, such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolbutyric acid, and dimethylolvaleric acid; and compounds that contain a sulfonic acid group and a hydroxyl group, such as 1,4-butanediol-2-sulfonic acid. One or more of these can be used. Among these, in the present invention, from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use a compound having a carboxyl group and a hydroxyl group in the molecule as the anionic group introducing agent, it is more preferable to use a compound having a carboxyl group and a hydroxyl group in the molecule and a molecular weight of 100 to 5,000, it is even more preferable to use dimethylolpropionic acid or dimethylolbutanoic acid, and it is particularly preferable to use dimethylolpropionic acid.

In the present invention, when an anionic group introducing agent is used to produce a polyether polyurethane prepolymer, the amount of the anionic group introducing agent used is not particularly limited and can be adjusted appropriately depending on the purpose. For example, when the number of isocyanate groups in the polyisocyanate compound used is taken as 1, the anionic group introducing agent can be used in an amount such that the number of reactive groups such as hydroxyl groups and amino groups that can react with the polyisocyanate compound in the anionic group introducing agent is 0.01 to 0.80, preferably 0.05 to 0.60, and more preferably 0.10 to 0.50.

In addition, when an anionic group introducing agent is used in the production of a polyether polyurethane prepolymer, the amount of the anionic group introducing agent relative to the polyether polyol compound is not particularly limited and can be adjusted appropriately depending on the purpose. For example, when the number of reactive groups such as hydroxyl groups and amino groups that can react with a polyisocyanate compound in the polyether polyol compound used is taken as 1, the anionic group introducing agent can be used in an amount such that the number of reactive groups such as hydroxyl groups and amino groups that can react with a polyisocyanate compound in the anionic group introducing agent is 0.05 to 20, preferably 0.1 to 10, and more preferably 0.2 to 5.

Examples of melamine-based compounds that can be used in the production 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. Among these, in the present invention, from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use one or more of the melamine-based compounds selected from the group consisting of melamine, monomethylol melamine, and dimethylol melamine, and it is more preferable to use melamine.

In the present invention, when a melamine-based compound is used to produce a polyether polyurethane prepolymer, the amount of the melamine-based compound used is not particularly limited and can be adjusted appropriately depending on the purpose. For example, when the number of isocyanate groups in the polyisocyanate compound used is taken as 1, the melamine-based compound can be used in an amount such that the number of amino groups in the melamine-based compound is 0.01 to 0.50, preferably 0.05 to 0.40, and more preferably 0.10 to 0.30.

In addition, when a melamine-based compound is used to produce a polyether polyurethane prepolymer, the amount of the melamine-based compound relative to the polyether polyol compound is not particularly limited and can be adjusted appropriately depending on the purpose. For example, when the number of reactive groups such as hydroxyl groups and amino groups that can react with a polyisocyanate compound in the polyether polyol compound used is taken as 1, the melamine-based compound can be used in an amount that results in the number of amino groups of 0.05 to 20, preferably 0.1 to 10, and more preferably 0.2 to 5.

Low molecular weight polyols that can be used in the production of polyether polyurethane prepolymers include, for example, 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, 2,4-diethyl-1,5-pentanediol, aliphatic diols such as 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 cyclohexanedimethanol and cyclohexanediol; and trihydric or higher alcohols such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, pentaerythritol, and tetramethylolpropane. One or more of these can be used.

In the present invention, when a low molecular weight polyol is used to produce a polyether polyurethane prepolymer, the amount of low molecular weight polyol used is not particularly limited and can be adjusted appropriately depending on the purpose. For example, when the number of isocyanate groups in the polyisocyanate compound used is taken as 1, the low molecular weight polyol can be used in an amount such that the number of reactive groups such as hydroxyl groups that can react with the polyisocyanate compound in the low molecular weight polyol is 0.01 to 0.50, preferably 0.05 to 0.40, and more preferably 0.10 to 0.30.

In the present invention, from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, it is preferable to use, as the polyether polyurethane prepolymer, a polyether polyurethane prepolymer obtained using a raw material containing at least one polyether polyol compound, at least one polyisocyanate compound, and one or more selected from the group consisting of an anionic group-introducing agent and a melamine-based compound, it is more preferable to use a polyether polyurethane prepolymer obtained using a raw material containing 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, and it is even more preferable to use a polyether polyurethane prepolymer obtained by reacting raw materials consisting 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.

In the present invention, when a polyether polyurethane prepolymer is produced using raw materials containing 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, the polyisocyanate compound, the anionic group-introducing agent, and the melamine-based compound used are not particularly limited and can be appropriately adjusted depending on the purpose. From the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, for example, when the number of isocyanate groups in the polyisocyanate compound is taken as 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 0.30 to 0.95, and even more preferably 0.40 to 0.90.

In addition, when producing a polyether polyurethane prepolymer using raw materials containing 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, the polyisocyanate compound, the anionic group introducing agent, and the melamine-based compound used are determined based on the amount of isocyanate in the polyisocyanate compound from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition. It is preferable to use an amount such that the ratio of the number of anate groups, 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 compound is 1:0.01-0.9:0.01-0.9:0.01-0.5, more preferably 1:0.05-0.6:0.05-0.6:0.05-0.4, and even more preferably 1:0.1-0.5:0.1-0.5:0.05-0.3.

The acid value of the polyether polyurethane prepolymer that can be used in the present invention is not particularly limited, and can be adjusted appropriately depending on the purpose. From the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, the acid value of the polyether polyurethane prepolymer is preferably 0 to 70 mgKOH/g, more preferably 10 to 60 mgKOH/g, even more preferably 15 to 50 mgKOH/g, and particularly preferably 20 to 40 mgKOH/g. In the present invention, the acid value of the polyether polyurethane prepolymer is a value measured by the neutralization titration method of JIS K 0070 (1992).

The polyether polyurethane prepolymer used in the present invention is not particularly limited, and can be produced by adding the above-mentioned raw materials, either at once or in multiple batches, to a reaction vessel in the presence of a solvent, catalyst, etc. as necessary, and mixing and reacting for 10 minutes to 24 hours, for example, in an environment of room temperature to 180°C and 0.01 Pa to 100 MPa. At this time, by reacting the raw materials so that the number of isocyanate groups in the polyisocyanate compound contained in the raw materials is greater than the number of reactive groups such as hydroxyl groups and amino groups that can react with the isocyanate groups contained in raw materials such as polyether polyol compounds, a polyether polyurethane prepolymer having unreacted isocyanate groups can be produced.

The catalyst that can be used in producing the polyether polyurethane prepolymer is not particularly limited, and any known catalyst can be used. Examples of such catalysts include N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, 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, N,N'-dimethylpiperazine, N,N-dimethylcyclohexylamine, N-methylmorpholine, N-ethylmorpholine, bis(2-dimethyl Tertiary amines such as tertiary amines (aminoethyl) ether, N,N-dimethyllaurylamine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, and 1-dimethylaminopropylimidazole; quaternary ammonium salts such as tetraalkylammonium halides (tetramethylammonium chloride), tetraalkylammonium hydroxides (tetramethylammonium hydroxide salts), and tetraalkylammonium organic acid salts (tetramethylammonium 2-ethylhexanoate); and organometallic catalysts such as stannous diacetate, stannous dioctoate, 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. The amount of the catalyst used when using the catalyst is not particularly limited, and can be appropriately adjusted depending on the purpose. The catalyst can be used, for example, in an amount of 0.0001 to 1% by mass based on the total mass of the raw materials used.

　Any known solvent can be used as the solvent for producing the polyether polyurethane prepolymer. 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 can be used. When using a solvent, the amount of the solvent used is not particularly limited and can be adjusted appropriately depending on the purpose. For example, the solvent can be used in an amount of 0.1 to 80% by mass based on the total mass of the raw materials used.

In the present invention, the reaction time when the polyether polyol compound, the polyisocyanate compound, and other raw materials are reacted to produce the polyether polyurethane prepolymer is not particularly limited. 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 hours to 7 hours.

The polyether polyurethane prepolymer obtained by the above-mentioned method is obtained by reacting a polyether polyol compound, a polyisocyanate compound, and, if necessary, an anionic group introducing agent and a melamine-based compound. In the present invention, a wide variety of compounds can be used as the polyether polyol compound, the polyisocyanate compound, the anionic group introducing agent, and the melamine-based compound. For this reason, since the structure of the above-mentioned polyether polyurethane prepolymer varies greatly depending on the structure of the raw material used in the production of the polyether polyurethane prepolymer, it is impossible to uniformly express the structure of the polyether polyurethane prepolymer by a certain general formula, and this is technical common knowledge for those skilled in the art. Furthermore, unless the structure is specified, the properties of the substance determined accordingly cannot be easily understood, and therefore it is impossible to express them in terms of properties. On the other hand, the present invention relates to an invention that has discovered that a polyether polyurethane prepolymer obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound can be used in combination with component (A) consisting of an epoxy resin that is solid at 25°C to obtain a resin composition having excellent adhesion, particularly adhesion that allows adhesion with short pressure bonding, and corrosion resistance. Therefore, in the present invention, the polyether polyurethane prepolymer must be defined as "a polyether polyurethane prepolymer obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound."

Polyether polyurethanes that can be used in the present invention include polyether polyurethanes obtained by blocking the polyether polyurethane prepolymer obtained by the above-mentioned method with a blocking agent or by extending the chain with a chain extender, and polyether polyurethanes obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound in such a way that no unreacted isocyanate groups remain in the compound.

In the present invention, the blocking agent used when blocking the polyether polyurethane prepolymer is not particularly limited, and any known blocking agent can be used. Examples of such blocking agents include alcohols such as methanol and ethanol; dialkylamines such as diethylamine, dimethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, didodecylamine, and distearylamine; diarylamines such as diphenylamine; and secondary amino group-containing heterocyclic compounds such as morpholine, piperidine, pyrrole, pyrrolidine, pyrazole, and imidazole. One or more of these can be used. In this case, the amount of the blocking agent used is not particularly limited, and can be appropriately adjusted depending on the purpose. For example, the amount can be set to an amount such that the number of reactive groups in the blocking agent that can react with the isocyanate groups relative to the number of isocyanate groups in the polyether polyurethane prepolymer is 0.01 to 2.0 in terms of equivalent ratio.

In the present invention, the chain extender used when extending the chain of the polyether polyurethane prepolymer is not particularly limited, and any known chain extender 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, 1,7-heptanediol, 3,5-heptanediol, and the like. aliphatic diols such as diol, 1,8-octanediol, 2-methyl-1,8-octanediol, and 1,9-nonanediol; alicyclic diols such as cyclohexanedimethanol and cyclohexanediol; low molecular weight diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, tolylenediamine, piperazine, and 2-methylpiperazine; polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, 2- alkanolamines such as (2-aminoethylamino)ethanol; polyether diamines such as polyoxypropylene diamine and polyoxyethylene diamine; alicyclic diamines such as menthene diamine, isophorone diamine, norbornene diamine, aminoethyl aminoethanol, bis(4-amino-3-methyldicyclohexyl)methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro(5,5)undecane; m-xylene diamine, α-(m/p-aminophenyl)ethylamine, m-phenylenediamine, diamino Examples of the polyamines include aromatic diamines such as diphenylmethane, diaminodiphenylsulfone, diaminodimethyldiphenylmethane, diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, and α,α'-bis(4-aminophenyl)-p-diisopropylbenzene; hydrazines such as succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, hydrazine hydrate, 1,6-hexamethylenebis(N,N-dimethylsemicarbazide), and 1,1,1',1'-tetramethyl-4,4'-(methylene-di-para-phenylene) disemicarbazide; and water. These may be used alone or in combination. Among these, from the viewpoint of various properties of the resulting polyether polyurethane, it is preferable to use one or more selected from the group consisting of low molecular weight diamines, polyether diamines, and water, and it is more preferable to use one or more selected from the group consisting of ethylene diamine, propylene diamine, and water. In this case, the amount of the chain extender used is not particularly limited and can be appropriately adjusted depending on the purpose. For example, the number of reactive groups in the chain extender that can react with the isocyanate groups relative to the number of isocyanate groups in the polyether polyurethane prepolymer can be 0.01 or more in equivalent ratio, and from the viewpoint of various properties of the resulting polyether polyurethane, it is preferable to set the equivalent ratio to 0.5 or more, and more preferably to set it to 1 or more. In the present invention, when water is used as the chain extender, water also functions as a solvent for the resulting resin composition, so the upper limit of the amount of the chain extender containing water to be used is not particularly limited. The chain extender containing water can be used, for example, in an amount of 10% by mass to 1000% by mass relative to the mass of the polyether polyurethane prepolymer.

In the present invention, the polyether polyol compound and polyisocyanate compound that can be used when reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound so that no unreacted isocyanate groups remain in the compound to produce a polyether polyurethane can be used without any particular limitation as long as they are known polyether polyol compounds and polyisocyanate compounds, respectively. As such polyether polyol compounds and polyisocyanate compounds, for example, the polyether polyol compounds and polyisocyanate compounds that can be used in the production of the above-mentioned polyether polyurethane prepolymer can be used, respectively. In addition, the ratio of the amount of the polyether polyol compound and the polyisocyanate compound used when reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound so that no unreacted isocyanate groups remain in the compound is not particularly limited and can be appropriately adjusted according to the purpose. For example, the polyether polyol compound and the polyisocyanate compound can be used in amounts such that 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.

Among these, from the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, the polyether polyurethane is preferably a polyether polyurethane obtained by reacting a raw material containing at least one polyether polyol compound and at least one polyisocyanate compound, and then blocking the polyether polyurethane prepolymer with a blocking agent or extending the chain with a chain extender, and more preferably a polyether polyurethane obtained by blocking a polyether polyurethane prepolymer obtained using a raw material containing at least one polyether polyol compound, at least one polyisocyanate compound, and one or more selected from the group consisting of an anionic group-introducing agent and a melamine-based compound, and then blocking the polyether polyurethane prepolymer with a blocking agent or extending the chain with a chain extender. More preferably, the polyether polyurethane is obtained by blocking with a blocking agent or by extending the chain of a polyether polyurethane prepolymer obtained by using a raw material containing at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine compound, and even more preferably, the polyether polyurethane is obtained by blocking with a blocking agent or by extending the chain of a polyether polyurethane prepolymer obtained by reacting raw materials consisting of at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine compound, and particularly preferably, the polyether polyurethane is obtained by blocking with a blocking agent or by extending the chain of a polyether polyurethane prepolymer obtained by reacting raw materials consisting of at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine compound, and by extending the chain of the polyether polyurethane prepolymer obtained by reacting raw materials consisting of at least one polyether polyol compound, at least one polyisocyanate compound, at least one anionic group introducing agent, and at least one melamine compound, and

The acid value of the polyether polyurethane that can be used in the present invention is not particularly limited, and can be adjusted appropriately depending on the purpose. From the viewpoint of the adhesiveness and corrosion resistance of the resulting resin composition, the acid value of the polyether polyurethane is preferably 0 to 70 mgKOH/g, more preferably 10 to 60 mgKOH/g, even more preferably 15 to 50 mgKOH/g, and particularly preferably 20 to 40 mgKOH/g. In the present invention, the acid value of the polyether polyurethane is a value measured by the neutralization titration method of JIS K 0070 (1992).

The polyether polyurethane obtained by the above-mentioned method is obtained by reacting a polyether polyol compound, a polyisocyanate compound, and, if necessary, an anionic group introduction agent, a melamine-based compound, and a blocking agent or a chain extender. In the present invention, a wide variety of compounds can be used as the polyether polyol compound, the polyisocyanate compound, the anionic group introduction agent, the melamine-based compound, the blocking agent, and the chain extender. For this reason, since the structure of the above-mentioned polyether polyurethane varies greatly depending on the structure of the raw materials used in the production of the polyether polyurethane, it is currently impossible to uniformly express the structure of polyether polyurethane by a certain general formula, and this is technical common knowledge for those skilled in the art. Furthermore, unless the structure is specified, the properties of the substance determined accordingly cannot be easily understood, and therefore it is impossible to express it in terms of properties. On the other hand, the present invention relates to an invention that has discovered that a polyether polyurethane obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound can obtain a resin composition having excellent adhesion, particularly adhesion that allows adhesion with short pressure bonding, and corrosion resistance, when used in combination with component (A) consisting of an epoxy resin that is solid at 25°C. Therefore, in the present invention, polyether polyurethane must be defined as "a polyether polyurethane obtained by reacting raw materials containing at least one polyether polyol compound and at least one polyisocyanate compound."

The present invention relates to an invention that has discovered that when component (B) consisting of one or more selected from the group consisting of the above-mentioned polyether polyurethane prepolymer and polyether polyurethane is used in combination with component (A) consisting of an epoxy resin that is solid at 25°C, a resin composition having excellent adhesive properties, particularly adhesive properties that allow bonding by short-time pressure bonding and corrosion resistance, can be obtained. In this case, from the viewpoint of improving adhesive properties and corrosion resistance by using component (A) in combination, particularly adhesive properties that allow bonding by short-time pressure bonding and corrosion resistance, the content ratio of polyether structures in the polyether polyurethane prepolymer or polyether polyurethane is preferably 10 to 70 mass%, more preferably 15 to 60 mass%, and even more preferably 20 to 50 mass%, based on the total mass of the polyether polyurethane prepolymer or polyether polyurethane. In the present invention, the content ratio of polyether structures in the polyether polyurethane prepolymer or polyether polyurethane is calculated from the mass content of polyether structures in the raw materials used.

Component (B) used in the present invention may consist of only the above-mentioned polyether polyurethane prepolymer, may consist of only polyether polyurethane, or may consist of polyether polyurethane prepolymer and polyether polyurethane. From the viewpoint of the various properties of the resulting resin composition, it is preferable that component (B) contains polyether polyurethane.

The content of component (A) in the resin composition of the present invention is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of improving the adhesiveness of the resulting resin composition, particularly the adhesiveness by short-term compression bonding, the content of component (A) in the resin composition is preferably 3 to 60 mass % relative to the total amount of the resin composition, more preferably 5 to 50 mass %, even more preferably 8 to 45 mass %, and even more preferably 20 to 40 mass %.

The content of component (B) in the resin composition of the present invention is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of improving the adhesiveness of the resulting resin composition, particularly the adhesiveness by short-term compression bonding, the content of component (B) in the resin composition is preferably 1 to 50 mass % relative to the total amount of the resin composition, more preferably 2 to 40 mass %, even more preferably 3 to 30 mass %, and particularly preferably 4 to 10 mass %.

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 resulting resin composition, particularly the adhesiveness by short-time compression bonding, the content ratio of component (A) to component (B) in the resin composition is preferably 5:95 to 98:2 by mass, more preferably 20:80 to 95:5, even more preferably 50:50 to 92:8, and particularly preferably 70:30 to 90:10.

1-3. Water The resin composition of the present invention may further contain water. The content of water in the resin composition of the present invention is not particularly limited and can be appropriately adjusted. From the viewpoints of adhesion and corrosion resistance of the resin composition to metals, reduction of the burden on the environment, and ease of handling of the resin composition, the resin composition preferably contains 10 to 90% by mass of water, 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, pure water, etc. can be used as the water depending on the purpose.

When the resin composition of the present invention contains water, the content ratio of component (A), component (B), and water is not particularly limited and can be adjusted according to the purpose. From the viewpoints of adhesion and corrosion resistance of the resin composition to metals, reduction in environmental load, and ease of handling of the resin composition, the content ratio of component (A), component (B), and water in the resin composition is preferably 3-80:1-60:10-90, 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, when the sum of the contents of component (A), component (B), and water is taken as 100. By containing the above-mentioned specific component (A), component (B), and water in such a content ratio, the resin composition of the present invention can obtain a water-dispersed emulsion having excellent dispersion stability as a resin composition, and therefore can be a resin composition having reduced environmental load and excellent ease of handling.

When the resin composition of the present invention contains water, as component (A), from the viewpoint of 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 among the epoxy resins that are solid at 25°C described above, and it is more preferable to use one or more selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AD type epoxy resins that are solid at 25°C, and it is even more preferable to use a bisphenol A type epoxy resin that is solid at 25°C. Also, from the viewpoint of dispersion stability and various properties of the obtained resin composition, it is preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 500 g/eq. to 30,000 g/eq. as component (A) among the epoxy resins that are solid at 25°C described above, and it is more preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 1,000 g/eq. to 10,000 g/eq., and it is even more preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 1,500 g/eq. It is even more preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 2,000 g/eq. to 5,000 g/eq., and it is particularly preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 2,500 g/eq. to 3,500 g/eq.

When the resin composition of the present invention contains water, from the viewpoint of the dispersion stability and various properties of the resulting resin composition, it is preferable to use, as component (B), one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more polyalkylene glycols, among the above-mentioned polyether polyurethane prepolymers and polyether polyurethanes, more preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol, even more preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from the group consisting of polypropylene glycol and polytetramethylene ether glycol, and particularly preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing polytetramethylene ether glycol. In addition, from the viewpoint of the dispersion stability and various properties of the resulting resin composition, the acid value of the polyether polyurethane prepolymer and polyether polyurethane used is preferably 0 to 70 mgKOH/g, more preferably 10 to 60 mgKOH/g, even more preferably 15 to 50 mgKOH/g, and particularly preferably 20 to 40 mgKOH/g.

1-4. Other components In addition to the above-mentioned components (A), (B) and water, the resin composition of the present invention may contain, depending on the purpose, a solvent, a neutralizing agent, a surfactant, an aminosilane-based compound, an amide-based compound, a carbodiimide compound, an isocyanate-based compound (excluding polyether polyurethane prepolymer), a polyetheramine-based compound, a phosphoric acid-modified epoxy resin, a melamine resin, a phenolic resin, and the like. The solvent that may be contained in the resin composition of the present invention is not particularly limited, and a known solvent 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 can be used. When the resin composition of the present invention contains a solvent, the content of the solvent is not particularly limited, and can be appropriately adjusted depending on the purpose. For example, the solvent can be contained in an amount of 0.1 to 50 mass% based on the total amount of the resin composition. From the viewpoints of adhesion and corrosion resistance of the resin composition to metals, reduction of the burden on the environment, and ease of handling of the resin composition, the upper limit of the solvent content is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, based on the total amount of the resin composition. In the present invention, by containing the above-mentioned component (A) and component (B), a resin composition having excellent stability and ease of handling can be produced even when the solvent content is small or not contained.

The neutralizing agent that may be contained in the resin composition of the present invention is not particularly limited, and known neutralizing agents may be used. Examples of such neutralizing agents include 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-dialkanolamines and trialkanolamines such as triethanolamine; ammonia, trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide. One or more of these may be used. In the present invention, when one or more types selected from the group consisting of polyether polyurethane prepolymers having an acid value of 10 to 60 mgKOH/g and polyether polyurethanes having an acid value of 10 to 60 mgKOH/g are used as component (B), from the viewpoint of the stability and handleability of the resin composition, it is preferable to contain 0.01 to 5 mass% of a neutralizing agent, and more preferably 0.05 to 3 mass%, based on the total amount of the resin composition.

The surfactant that may be contained in the resin composition of the present invention is not particularly limited, and any known surfactant may be used. Examples of such surfactants include known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. One or more of these may be used.

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 polyglycol ether sulfate and ammonium polyoxyethylene alkyl ether sulfate; ammonium salts of alkyl sulfonates such as ammonium salts of sulfonated paraffin; fatty acid salts such as sodium laurate, triethanolamine oleate, and triethanolamine abietate; alkylaryl sulfonates such as sodium benzenesulfonate and alkali metal sulfates of alkali phenol hydroxyethylene; alkylnaphthalenesulfonates, naphthalenesulfonic acid-formaldehyde condensates, dialkylsulfosuccinates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkylaryl sulfate salts, polyoxyethylene ether phosphates, polyoxyethylene alkyl ether acetates, N-acyl amino acid salts, and N-acyl methyl taurine salts. One or more of these can be used.

Nonionic surfactants include fatty acid partial esters of polyhydric alcohols such as sorbitan monolaurate and sorbitan monooleate; polyoxyethylene glycol fatty acid esters; polyglycerin fatty acid esters; ethylene oxide and/or propylene oxide adducts of alcohols having 1 to 18 carbon atoms; ethylene oxide and/or propylene oxide adducts of alkylphenols; ethylene oxide and/or propylene oxide adducts of alkylene glycols and/or alkylenediamines, etc. Examples of alcohols having 1 to 18 carbon atoms that constitute nonionic surfactants include methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tertiary butanol, amyl alcohol, isoamyl alcohol, tertiary amyl alcohol, hexanol, octanol, decane alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, and stearyl alcohol. Examples of alkylphenols constituting the nonionic surfactant 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. Examples of alkylene glycols constituting the nonionic surfactant 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. Examples of alkylene diamines include those in which the alcoholic hydroxyl groups of these alkylene glycols are replaced with amino groups. Furthermore, the ethylene oxide and propylene oxide adducts may be random adducts or block adducts.

Cationic surfactants include quaternary ammonium salts such as lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, lauryl benzyl dimethyl ammonium chloride, and didecyl dimethyl ammonium chloride; alkyl pyridinium bromide, imidazolinium laurate, etc. One or more of these can be used.

Examples of amphoteric surfactants include betaine-type amphoteric surfactants such as coconut oil fatty acid amidopropyl dimethyl acetate betaine, lauryl dimethyl amino acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxymethyl imidazolinium betaine, lauryl hydroxysulfobetaine, lauroyl amidoethyl hydroxyethyl carboxymethyl betaine, and metal salts of hydroxypropyl phosphate; amino acid-type, sulfate ester-type, and sulfonic acid-type amphoteric surfactants such as metal salts of β-lauryl aminopropionic acid. One or more of these may be used.

In the present invention, from the viewpoints of the adhesiveness and corrosion resistance of the resin composition to metals, the ease of handling of the resin composition, etc., it is preferable to contain one or more surfactants selected from the group consisting of anionic surfactants and nonionic surfactants, it is more preferable to contain at least one nonionic surfactant, and it is even more preferable to contain at least one nonionic surfactant having an alkylene oxide skeleton. In this case, among the nonionic surfactants, it is preferable to contain a nonionic surfactant having a weight average molecular weight of 1,000 to 50,000, it is more preferable to contain a nonionic surfactant having a weight average molecular weight of 5,000 to 30,000, it is even more preferable to contain a nonionic surfactant having a weight average molecular weight of 10,000 to 20,000, and it is particularly preferable to contain a nonionic surfactant having a weight average molecular weight of 14,000 to 18,000.

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 adjusted appropriately depending on the purpose. From the viewpoint of the handleability of the resulting resin composition and the adhesion to metals and corrosion resistance, the content of the surfactant in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 15 mass%, even more preferably 0.2 to 10 mass%, even more preferably 0.5 to 6 mass%, and particularly preferably 3.0 to 5.0 mass%, based on the total amount of the resin composition.

The aminosilane compounds that can be used in the present invention are not particularly limited as long as they contain an amino group and a silicon-containing 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-t-butylaminopropyltrimethoxysilane, and 3-cyclohexylaminopropyltrimethoxysilane. , N-methyl-3-amino-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-trimethylbutyl N-(3-trimethoxysilylpropyl)amine, N-(3-trimethoxysilylpropyl)-3-amino-2-methylpropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-trimethoxysilylpropyl-3-[N-(3-trimethoxysilyl)-propylamino]-2-methylpropionate, 3-triethoxysilylpropyl-3-[N-(3-triethoxysilyl)-propylamino]-2-methylpropionate, 3-trimethoxysilylpropyl-3-[N-(3-triethoxysilyl)-propylamino]-2-methylpropionate, N-ethyl-4-amino-3,3-dimethylbutyldimethoxymethylsilane, N-ethyl-4-amino-3,3-di Examples include methylbutyltrimethoxysilane, 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, and N,N-bis[(3-trimethoxysilyl)-2-methylpropyl]amine. These can be used alone or in combination.

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 adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition, the content of the aminosilane compound in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, relative to the total mass of the resin composition.

Amide compounds that can be used in the present invention are not particularly limited as long as they have one or more amide groups in the molecule. Examples of such amide compounds include succinic acid dihydrazide, adipic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, p-oxybenzoic acid hydrazide, salicylic acid hydrazide, maleic acid dihydrazide, dicyandiamide, methylguanidine, ethylguanidine, propylguanidine, butylguanidine, dimethylguanidine, trimethylguanidine, phenylguanidine, diphenylguanidine, and the like. One or more of these can be used.

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 adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metal and corrosion resistance of the resulting resin composition, the content of the amide compound in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, relative to the total mass of the resin composition.

The carbodiimide compound that can be used in the present invention is not particularly limited as long as it has one or more carbodiimide groups (-N=C=N-) in the molecule. 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), and N,N'-dicyclohexylcarbodiimide. Poly(4,4'-methylenebiscyclohexylcarbodiimide), poly(1,3-cyclohexylenecarbodiimide), poly(1,4-cyclohexylenecarbodiimide), poly(4,4'-dicyclohexylmethanecarbodiimide), etc. can be used, and also commercially available products such as Carbodilite V-02, V-02-L2, SV-02, V-04, V-10, E-02, E-03A, and E-05 (all manufactured by Nisshinbo Chemical Co., Ltd.) can be used. In the present invention, among these, from the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition, it is preferable to use a carbodiimide compound having a carbodiimide equivalent of 100 to 800 g/eq. as the carbodiimide compound, and a carbodiimide equivalent of 200 to 700 g/eq. It is more preferable to use a carbodiimide compound having a carbodiimide equivalent of 300 to 600 g/eq., even more preferable to use a carbodiimide compound having a carbodiimide equivalent of 300 to 600 g/eq., and particularly preferable to use a carbodiimide compound having a carbodiimide equivalent of 400 to 500 g/eq.

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 adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition, the content of the carbodiimide compound in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, based on the total amount of the resin composition.

The isocyanate-based compound that can be used in the present invention is not particularly limited as long as it has one or two or more isocyanate groups in the molecule. From the viewpoint of the adhesion to metals and corrosion resistance of the resulting resin composition, an isocyanate-based compound having two isocyanate groups in the molecule is preferred. Examples of such isocyanate compounds include aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, alicyclic diisocyanates such as isophorone diisocyanate, 4,4-dicyclohexylmethane diisocyanate and 1,3-bis(isocyanatemethyl)cyclohexane, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 1,4-naphthylene diisocyanate, and the like. Examples of the aromatic diisocyanates include aromatic diisocyanates such as anate, phenylene diisocyanate, tetramethylxylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, and xylylene diisocyanate. Polymers, adducts, biuret forms, nurate forms, and blocked forms blocked with a blocking agent may also be used. In this case, examples of the blocking agent include phenol-based blocking agents such as phenol, cresol, xylenol, chlorophenol, and ethylphenol; lactam-based blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, and β-propiolactam; active methylene-based blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, 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, methyl lactate, and lactic acid. Examples of blocking agents that can be used include alcohol-based blocking agents such as ethyl; oxime-based blocking agents such as formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, and cyclohexane oxime; mercaptan-based blocking agents such as butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, methylthiophenol, and ethylthiophenol; acid amide-based blocking agents such as acetate amide and benzamide; imide-based blocking agents such as succinimide and maleimide; amine-based blocking agents such as xylidine, aniline, butylamine, and dibutylamine; imidazole-based blocking agents such as imidazole and 2-ethylimidazole; and imine-based blocking agents such as methyleneimine and propyleneimine.

When the resin composition of the present invention contains an isocyanate compound, the content of the isocyanate compound in the resin composition is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition, the content of the isocyanate compound in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, based on the total amount of the resin composition.

The polyetheramine compound that can be used in the present invention can be any compound that has a polyether group consisting of a polyoxyalkylene structure such as a polyoxyethylene group, a polyoxypropylene group, or a polyoxybutylene group in the molecule, and at least one amino group. In this case, the polyetheramine compound may have only polyoxyethylene groups, only polyoxypropylene groups, only polyoxybutylene groups, or two or more types selected from the group consisting of polyoxyethylene groups, polyoxypropylene groups, and polyoxybutylene groups, as the polyether group in the molecule. In addition, the number of repetitions of the oxyalkylene structure in the polyether group is not particularly limited, and can be adjusted according to the purpose. For example, the number of repetitions of the oxyalkylene structure in the polyetheramine compound can be 2 to 500, as the total number of repetitions of one or more types of oxyalkylene groups. Examples of such polyetheramine compounds include polyethylene glycol amine, polyethylene glycol diamine, methoxypolyethylene glycol amine, polypropylene glycol amine, polypropylene glycol diamine, methoxypolypropylene glycol amine, polybutylene glycol amine, polybutylene glycol diamine, methoxypolybutylene glycol amine, polyoxyethylene polyoxypropylene amine, polyoxyethylene polyoxypropylene diamine, and methoxypolyoxyethylene polyoxypropylene amine. Commercially available polyetheramine compounds can also be used, and 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).

In the present invention, from the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition, it is preferable to use, among these, a polyetheramine compound having a polyether group, an amino group, and a methoxy group in the molecule as the polyetheramine compound, and it is also preferable to use a polyetheramine compound having only a polyoxyethylene group, only a polyoxypropylene group, or a polyoxyethylene group and a polyoxypropylene group as the polyether group. More specifically, in the present invention, it is particularly preferable to use, as the polyetheramine compound, a methoxypolyoxyethylenepolyoxypropyleneamine compound in which the number of repeats of oxyethylene groups in the molecule is 1 to 100 and the number of repeats of oxypropylene groups is 2 to 50.

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 adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metal and corrosion resistance of the resulting resin composition, the content of the polyetheramine compound in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, based on the total amount of the resin composition.

The phosphoric acid-modified epoxy resin that can be used in the present invention is not particularly limited as long as it is a modified product obtained by reacting phosphoric acids with an epoxy compound. As such phosphoric acids, orthophosphoric acid, phosphorous acid, hypophosphorous acid, phosphonic acid, pyrophosphoric acid, triphosphoric acid and other polyphosphoric acids can be used. In this case, the epoxy compound can be used without particular limitation as long as it is a compound having at least one epoxy group in the molecule, and examples thereof include n-butyl glycidyl ether, C ₁₂ -C Compounds having one epoxy group in the molecule, such as alkyl glycidyl ether of ₁₄ , allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether, p-sec-butylphenyl glycidyl ether, t-butylphenyl glycidyl ether, glycidyl methacrylate, and tertiary carboxylic acid glycidyl ester; compounds having two epoxy groups in the molecule, such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether; compounds having three epoxy groups in the molecule, such as trimethylolpropane triglycidyl ether and glycerin triglycidyl ether; bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol Examples of the epoxy resins include phenol S type epoxy resins, bisphenol AD type epoxy resins, resorcin type epoxy resins, hydroquinone type epoxy resins, catechol type epoxy resins, dihydroxynaphthalene type epoxy resins, biphenyl type epoxy resins, tetramethylbiphenyl type epoxy resins, oxazolidone ring type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, triphenylmethane type epoxy resins, tetraphenylethane type epoxy resins, dicyclopentadiene-phenol addition reaction type epoxy resins, phenol aralkyl type epoxy resins, naphthol novolac type epoxy resins, naphthol aralkyl type epoxy resins, naphthol-phenol co-condensed novolac type epoxy resins, naphthol-cresol co-condensed novolac type epoxy resins, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resins, biphenyl modified novolac type epoxy resins, etc. One or more of these may be used.

The phosphoric acid-modified epoxy resin that can be used in the present invention can be obtained by reacting the above-mentioned epoxy compound with phosphoric acids, for example, at an equivalent ratio of 1:0.1 to 1:5 at room temperature to 100°C. In this case, from the viewpoint of 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 the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and bisphenol AD type epoxy resin with a phosphoric acid compound such as orthophosphoric acid, metaphosphoric acid, phosphonic acid, pyrophosphoric acid, or polyphosphoric acid at an equivalent ratio of 1:0.5 to 1:3, and it is more preferable to use a phosphoric acid-modified epoxy resin obtained by reacting at an equivalent ratio of 1:1 to 1:2.

When the resin composition of the present invention contains a phosphoric acid-modified epoxy resin, the content of the phosphoric acid-modified epoxy resin in the resin composition is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metal and corrosion resistance of the resulting resin composition, the content of the phosphoric acid-modified epoxy resin in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, based on the total amount of the resin composition.

As the melamine resin that can be used in the present invention, any known melamine resin can be used without any particular limitation. Examples of such melamine resins include partially or completely methylolated melamine obtained by the reaction of melamine with formaldehyde, alkyl ether type melamine resins obtained by partially or completely etherifying the methylol groups of methylolated melamine resins with alcohol, imino group-containing melamine resins, and mixtures thereof. One or more of these can be used. In the present invention, among these, it is preferable to use an imino group-containing melamine resin as the melamine resin from the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition. In addition, as the melamine resin that can be used in the present invention, a commercially available product can be used, for example, a series of melamine resins bearing the name CYMEL (registered trademark) (manufactured by Allnex Co., Ltd.) can be used.

When the resin composition of the present invention contains a melamine resin, the content of the melamine resin in the resin composition is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of the adhesion to metal and corrosion resistance of the resulting resin composition, the content of the melamine resin in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, based on the total amount of the resin composition.

The phenolic resin that can be used in the present invention can be any known phenolic resin without any particular restrictions. Examples of such phenolic resins include bisphenol A type phenolic resins, bisphenol E type phenolic resins, bisphenol F type phenolic resins, bisphenol S type phenolic resins, phenol novolac resins, bisphenol A novolac type phenolic resins, glycidyl ester type phenolic resins, aralkyl novolac type phenolic resins, biphenyl aralkyl type phenolic resins, resol type phenolic resins, cresol novolac type phenolic resins, multifunctional phenolic resins, naphthol resins, naphthol novolac resins, multifunctional naphthol resins, anthracene type phenolic resins, naphthalene skeleton modified novolac type phenolic resins, phenol aralkyl type phenolic resins, naphthol aralkyl type phenolic resins, dicyclopentadiene type phenolic resins, biphenyl type phenolic resins, alicyclic phenolic resins, polyol type phenolic resins, phosphorus-containing phenolic resins, polymerizable unsaturated hydrocarbon group-containing phenolic resins, and hydroxyl group-containing silicone resins. One or more of these can be used. In the present invention, among these, it is preferable to use a resol type phenolic resin as the phenolic resin from the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition. In addition, commercially available products can be used as the phenolic resin that can be used in the present invention, for example, a series of phenolic resins bearing the name SUMILITE RESIN (registered trademark) (manufactured by Sumitomo Bakelite Co., Ltd.) can be used.

When the resin composition of the present invention contains a phenolic resin, the content of the phenolic resin in the resin composition is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of adhesion to metals and corrosion resistance of the resulting resin composition, the content of the phenolic resin in the resin composition is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, and even more preferably 0.2 to 5 mass%, based on the total amount of the resin composition.

The resin composition of the present invention contains components such as polyether polyurethane prepolymer and polyether polyurethane, which have excellent polymer chain freedom due to their main structure of polyether urethane, and is therefore believed to have excellent adhesion, particularly in a short time. In addition, the resin composition of the present invention contains an epoxy resin that is solid at 25°C, which improves the stability and coatability of the resin composition, and is therefore believed to have excellent adhesion, particularly in a short time, and corrosion resistance.

1-5. Manufacturing method of resin composition The method for manufacturing the resin composition of the present invention is not particularly limited, and it can be manufactured by a method of mixing component (A) consisting of an epoxy resin solid at 25 ° C. with component (B) consisting of one or more selected from the group consisting of polyether polyurethane prepolymer and polyether polyurethane by a known method. At this time, component (A) consisting of an epoxy resin solid at 25 ° C. may be used in a solid state, in a state dispersed in water, or in a state dissolved in a solvent. From the viewpoint of easily manufacturing a resin composition having excellent stability and handling properties, it is preferable to manufacture the resin composition using an aqueous dispersion emulsion in which component (A) consisting of an epoxy resin solid at 25 ° C. is dispersed in a solvent containing water. At this time, the method for dispersing component (A) consisting of an epoxy resin solid at 25 ° C. in water is not particularly limited, and for example, a method of forcibly emulsifying an epoxy resin in water using a surfactant, a method of dispersing an epoxy resin having self-emulsifying properties in water, etc. can be used.

In the present invention, the surfactant that can be used when producing a resin composition using an aqueous dispersion emulsion in which component (A) consisting of an epoxy resin that is solid at 25°C is dispersed in a solvent containing water is not particularly limited, and the above-mentioned known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. can be used. From the viewpoint of adhesion to metals, corrosion resistance, handleability, etc. of the resulting resin composition, it is preferable to contain one or more surfactants selected from the group consisting of anionic surfactants and nonionic surfactants, it is more preferable to contain at least one nonionic surfactant, and it is even more preferable to contain at least one nonionic surfactant having an alkylene oxide skeleton. At this time, among the nonionic surfactants, from the viewpoint of adhesion to metals, corrosion resistance, handling properties, etc. of the resin composition obtained, it is preferable to contain a nonionic surfactant having a weight average molecular weight of 1,000 to 50,000, more preferably a nonionic surfactant having a weight average molecular weight of 5,000 to 30,000, even more preferably a nonionic surfactant having a weight average molecular weight of 10,000 to 20,000, and particularly preferably a nonionic surfactant having a weight average molecular weight of 14,000 to 18,000. In addition, the content of the surfactant in the water-dispersed emulsion in which component (A) consisting of a solid epoxy resin at 25 ° C. is dispersed in a solvent containing water is not particularly limited, but can be, for example, 0.01 to 20 mass%. From the viewpoints of adhesion to metals, corrosion resistance, handling properties, etc. of the resulting resin composition, the content of the surfactant is preferably 0.1 to 20 mass% relative to the total amount of the water-dispersed emulsion in which component (A), which is a solid epoxy resin at 25°C, is dispersed in a solvent containing water, more preferably 0.5 to 10 mass%, even more preferably 0.5 to 8.0 mass%, and particularly preferably 3.0 to 6.0 mass%.

In addition, when producing the resin composition of the present invention, the polyether polyurethane prepolymer may be used as a solid or liquid polyether polyurethane prepolymer alone, or may be used in a state dispersed in water, or may be used in a state dissolved in a solvent. From the viewpoint of easily producing a resin composition having excellent stability and ease of handling, it is preferable to produce the resin composition using an aqueous dispersion emulsion in which the polyether polyurethane prepolymer is dispersed in a solvent containing water. At this time, the method of dispersing the polyether polyurethane prepolymer in water is not particularly limited, and for example, a method of forcibly emulsifying the polyether polyurethane prepolymer in water using a surfactant, a method of dispersing a polyether polyurethane prepolymer having self-emulsifying properties in water, etc. can be used. The surfactant that can be used at this time is not particularly limited, and the above-mentioned known anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. can be used, and the content thereof is also not particularly limited. The content of the surfactant is, for example, 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, relative to the total amount of the water-dispersed emulsion in which the polyether polyurethane prepolymer is dispersed in a solvent containing water.

When producing the resin composition of the present invention, the polyether polyurethane may be used as a solid or liquid polyether polyurethane alone, or may be used in a state dispersed in water, or may be used in a state dissolved in a solvent. From the viewpoint of easily producing a resin composition having excellent stability and ease of handling, it is preferable to produce the resin composition using an aqueous dispersion emulsion in which the polyether polyurethane is dispersed in a solvent containing water. At this time, the method for dispersing the polyether polyurethane in water is not particularly limited, and for example, a method of forcibly emulsifying the polyether polyurethane in water using a surfactant, or a method of dispersing a polyether polyurethane having self-emulsifying properties in water, etc. can be used. At this time, the surfactant that can be used is not particularly limited, and the above-mentioned known anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant, etc. can be used, and the content thereof is also not particularly limited. For example, the content of the surfactant is preferably 0.1 to 20 mass % relative to the total amount of the aqueous dispersion emulsion in which the polyether polyurethane is dispersed in a solvent containing water, more preferably 0.5 to 10 mass %, even more preferably 0.5 to 8.0 mass %, and particularly preferably 3.0 to 6.0 mass %.

In the present invention, from the viewpoint of more easily obtaining an aqueous resin composition having excellent adhesive properties, particularly adhesive properties that can be bonded by pressure bonding in a short time, and corrosion resistance, it is particularly preferred to produce the resin composition by mixing an aqueous dispersion emulsion of component (A) consisting of an epoxy resin that is solid at 25°C with an aqueous dispersion emulsion of component (B) consisting of one or more members selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes.

1-6. Uses of the resin composition The resin composition of the present invention can be used without any particular limitation as long as the application uses an epoxy resin or a urethane resin. The resin composition of the present invention can be used, for example, as an adhesive, coating agent, sealant agent, etc. for substrates such as metal, wood, glass, concrete, plastic, ceramic, etc., and more specifically, it can be used as an adhesive or coating agent for bonding various substrates in the fields of automobiles, vehicles (bullet trains, trains, etc.), civil engineering, architecture, ships, airplanes, and the space industry, adhesives for general office materials, medical materials, and electronic material materials, sealants, etc. Among these, the resin composition of the present invention contains the above-mentioned specific component (A) and component (B), and therefore has excellent adhesion to metals in particular, 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 another substrate, or a coating agent for a metal substrate.

2. Metal surface treatment resin composition The metal surface treatment resin composition of the present invention is a metal surface treatment resin composition containing component (A) consisting of an epoxy resin solid at 25 ° C. and component (B) consisting of one or more selected from the group consisting of polyether polyurethane prepolymer and polyether polyurethane. In this case, the above-mentioned components can be used as component (A) consisting of an epoxy resin solid at 25 ° C. and component (B) consisting of one or more selected from the group consisting of polyether polyurethane prepolymer and polyether polyurethane. The content of component (A) consisting of an epoxy resin solid at 25 ° C. in the metal surface treatment resin composition of the present invention is not particularly limited and can be appropriately adjusted depending on the purpose. From the viewpoint of improving the adhesion and corrosion resistance of the metal surface treatment resin composition, particularly the adhesion by short-time pressure bonding, the content of component (A) in the metal surface treatment resin composition is preferably 3 to 60 mass % relative to the total amount of the metal surface treatment resin composition, more preferably 5 to 50 mass %, even more preferably 8 to 45 mass %, and even more preferably 20 to 40 mass %.

The content of component (B) consisting of one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes in the resin composition for metal surface treatment of the present invention is not particularly limited and can be adjusted appropriately depending on the purpose. From the viewpoint of improving the adhesiveness and corrosion resistance of the resin composition for metal surface treatment, particularly the adhesiveness by short-time pressing, the content of component (B) is preferably 1 to 50 mass % relative to the total amount of the resin composition for metal surface treatment, more preferably 2 to 40 mass %, even more preferably 3 to 30 mass %, and particularly preferably 4 to 10 mass %.

The content ratio of component (A) consisting of an epoxy resin that is solid at 25°C and component (B) consisting of one or more selected from the group consisting of 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, particularly the adhesion by short-time pressing, the content ratio of component (A) to component (B) in the resin composition for metal surface treatment is preferably 5:95 to 98:2 by mass, more preferably 20:80 to 95:5, even more preferably 50:50 to 92:8, and particularly preferably 70:30 to 90:10.

The water content in the resin composition for metal surface treatment of the present invention is not particularly limited and can be adjusted as appropriate. From the viewpoints of adhesion and corrosion resistance of the resin composition for metal surface treatment to metal, reduction of the burden on the environment, and ease of handling of the resin composition for metal surface treatment, the resin composition for metal surface treatment preferably contains 10 to 90% by mass of water relative to the total amount of the resin composition for metal surface treatment, 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, pure water, etc. can be used as the water depending on the purpose.

When the resin composition for metal surface treatment of the present invention contains water, the ratio of the contents of component (A), component (B), and water is not particularly limited and can be adjusted according to the purpose. From the viewpoints of adhesion and corrosion resistance of the resin composition for metal surface treatment to metal, reduction of the burden on the environment, and ease of handling of the resin composition for metal surface treatment, the ratio of the contents of component (A), component (B), and water in the resin composition for metal surface treatment is preferably 3-80:1-60:10-90, 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, when the sum of the contents of component (A), component (B), and water is taken as 100. The resin composition for metal surface treatment of the present invention contains the above-mentioned specific component (A), component (B), and water in such a content ratio, so that a water-dispersed emulsion with excellent dispersion stability can be obtained as a resin composition for metal surface treatment, and therefore it can be a resin composition for metal surface treatment that reduces the burden on the environment and is easy to handle.

When the resin composition for metal surface treatment of the present invention contains water, it is preferable to use, as component (A), from the viewpoint of the dispersion stability and various properties of the resin composition for metal surface treatment obtained, a bisphenol type epoxy resin that is solid at 25°C among the epoxy resins that are solid at 25°C described above, and it is more preferable to use one or more selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and bisphenol AD type epoxy resins that are solid at 25°C, and it is even more preferable to use a bisphenol A type epoxy resin that is solid at 25°C. Also, from the viewpoint of the dispersion stability and various properties of the resin composition for metal surface treatment obtained, it is preferable to use, as component (A), an epoxy resin that is solid at 25°C and has an epoxy equivalent of 500 g/eq. to 30,000 g/eq. among the epoxy resins that are solid at 25°C described above, and an epoxy equivalent of 1,000 g/eq. to 10,000 g/eq. It is more preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 1,500 g/eq. to 6,000 g/eq., even more preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 2,000 g/eq. to 5,000 g/eq., and particularly preferable to use an epoxy resin that is solid at 25°C and has an epoxy equivalent of 2,500 g/eq. to 3,500 g/eq.

When the resin composition for metal surface treatment of the present invention contains water, as component (B), from the viewpoint of the dispersion stability and various properties of the resulting resin composition for metal surface treatment, it is preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more polyalkylene glycols, among the above-mentioned polyether polyurethane prepolymers and polyether polyurethanes, it is more preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol, it is even more preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing one or more selected from the group consisting of polypropylene glycol and polytetramethylene ether glycol, and it is particularly preferable to use one or more selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes obtained by reacting raw materials containing polytetramethylene ether glycol. In addition, from the viewpoint of the dispersion stability and various properties of the resulting resin composition for metal surface treatment, the acid value of the polyether polyurethane prepolymer and polyether polyurethane used is preferably 0 to 70 mgKOH/g, more preferably 10 to 60 mgKOH/g, even more preferably 15 to 50 mgKOH/g, and particularly preferably 20 to 40 mgKOH/g.

In addition to the above-mentioned components (A), (B) and water, 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, anticorrosive agents, flow control agents, thixotropic agents, dispersants, antioxidants, adhesion promoters, light stabilizers, etc., depending on the purpose. In this case, examples of surfactants that may be contained in the resin composition for metal surface treatment of the present invention include the above-mentioned anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. One or more of these can be used. When the resin composition for metal surface treatment of the present invention contains a surfactant, the content of the surfactant in the resin composition for metal surface treatment is not particularly limited and can be appropriately adjusted depending on the purpose. From the viewpoint of the handleability of the resulting resin composition for metal surface treatment and the adhesion to metal and corrosion resistance, the content of the surfactant in the resin composition for metal surface treatment is preferably 0.01 to 20 mass%, more preferably 0.1 to 15 mass%, even more preferably 0.2 to 10 mass%, even more preferably 0.5 to 6 mass%, and particularly preferably 3.0 to 5.0 mass%, based on the total amount of the resin composition for metal surface treatment.

The metal material to be treated with the resin composition for metal surface treatment of the present invention is not particularly limited, and examples include copper, aluminum, gold, silver, iron, platinum, chromium, nickel, tin, titanium, zinc, manganese, magnesium, molybdenum, cobalt, tungsten, zirconium, lead, gallium, indium, and composite materials thereof. Metal oxides include single oxides and/or composite oxides of these metals. The resin composition for metal surface treatment of the present invention can be applied to metal surfaces that have been processed into a plate or foil shape, etc., and have been subjected to plating treatment, etc., as necessary. The resin composition for metal surface treatment of the present invention can also be used as an adhesive between metal substrates made of such metal materials, or between metal substrates and other substrates, or as a coating agent for metal substrates, etc.

The method of 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, the resin composition for metal surface treatment of the present invention can be applied to a metal surface using spray coating, dip coating, roll coating, curtain coating, spin coating, and combinations of these methods. At this time, the temperature of the metal surface and the resin composition for metal surface treatment during application 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 application can be, for example, 10°C to 90°C. In addition, the method of drying after application of the resin composition for metal surface treatment to the metal surface is not particularly limited, and known methods can be used. As such a drying method, for example, a method using a drying oven, an electromagnetic induction heating oven, etc., with a maximum temperature of 40°C to 250°C can be used. In addition, when the resin composition for metal surface treatment of the present invention is used as an adhesive between metal substrates or between a metal substrate and another substrate, for example, the resin composition for metal surface treatment can be applied to a metal substrate by the method described above, and then dried as necessary. After that, another substrate can be laminated on the coating of the resin composition for metal surface treatment on the surface of the metal substrate, and the laminate can be pressed and bonded by applying a pressure of 0.1 MPa to 100 MPa to the laminate while heating to a maximum temperature of 40°C to 250°C, batchwise or continuously, using a press, drying furnace, electromagnetic induction heating furnace, or the like as necessary.

3. Manufacturing method of metal laminate plate The manufacturing method of the metal laminate plate of the present invention is a manufacturing method of a metal laminate plate including a step of applying the above-mentioned resin composition to 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. By using the manufacturing method of the metal laminate plate of the present invention, a metal laminate plate in which the metal plates are strongly bonded to each other can be obtained. In the present invention, the material of the metal plate used as the first metal plate and the second metal plate is not particularly limited. Examples of such 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 alloys thereof as main components, and may further contain optional components such as carbon, silicon, nitrogen, phosphorus, sulfur, boron, niobium, tantalum, vanadium, antimony, and germanium. In addition, the thickness of the metal plate used in the present invention is not particularly limited, and can be appropriately adjusted according to the purpose. For example, a metal plate having a thickness of 1 μm to 100 cm can be used. In the present invention, the metal laminate plate may be manufactured using two metal plates, or three or more metal plates. The multiple metal plates may be metal plates made of the same material and thickness, or may be metal plates made of different materials and thicknesses.

In the method for producing a metal laminate of the present invention, the method for applying the resin composition to the metal sheet surface is not particularly limited, and known methods can be used. For example, the resin composition can be applied to the metal sheet surface by spray coating, dip coating, roll coating, curtain coating, spin coating, or a combination of these methods. The amount of the resin composition applied to the metal sheet surface is not particularly limited, and can be adjusted appropriately depending on the purpose. For example, the resin composition can be applied to the metal sheet surface in an amount such that the thickness of the coating film obtained by applying and drying the resin composition is 0.1 μm to 10 mm.

The method for producing a metal laminate of the present invention may comprise a step of applying the above-mentioned resin composition to the surface of a first metal sheet to form a coating film, and a step of laminating a second metal sheet onto the coating film on the surface of the first metal sheet to form a metal laminate, and may further comprise a step of heating the metal laminate and a step of pressing the metal laminate, depending on the purpose. In the present invention, from the viewpoint of obtaining a more strongly bonded metal laminate, particularly a metal laminate that is strongly bonded in a short time, it is preferable to use a method for producing a metal laminate that includes a step of applying the resin composition to the surface of a first metal sheet to form a coating film, a step of laminating a second metal sheet onto the coating film of the first metal sheet to form a metal laminate, and a step of pressing the metal laminate.

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. Such a heating method can be, for example, a method of heating to 40°C to 250°C using a drying oven, an electromagnetic induction heating oven, etc. 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. Such a pressing method can be, for example, a method of pressing the metal laminate by applying pressure to it at a pressure of 0.1 MPa to 100 MPa using a press machine, etc. In the present invention, the step of heating the metal laminate and the step of pressing the metal laminate may be performed simultaneously. Examples of such a method include a method of pressing the metal laminate at a pressure of 0.1 MPa to 100 MPa using a press machine or the like in an environment of 40°C to 250°C using a drying furnace, electromagnetic induction heating furnace, or the like, or a method of pressing the metal laminate at a pressure of 0.1 MPa to 100 MPa using a heater press machine or the like heated to 40°C to 250°C.

When using a method for producing a metal laminate plate of the present invention that includes a step of applying a resin composition to the surface of a first metal plate to form a coating film, a step of laminating a second metal plate on the coating film of the first metal plate to form a metal laminate, and a step of pressing the metal laminate, the material and thickness of the metal plate used are not particularly limited, and for example, a metal plate made of the material and thickness described above can be used. The first metal plate and the second metal plate may be metal plates made of the same material and thickness, or may be metal plates made of different materials and thicknesses. In addition, when using a method for producing a metal laminate plate of the present invention that includes a step of applying a resin composition to the surface of a first metal plate to form a coating film, a step of laminating a second metal plate on the coating film of the first metal plate to form a metal laminate, and a step of pressing the metal laminate, the method of applying the resin composition to the metal plate surface and the amount of the resin composition applied to the metal plate surface are not particularly limited, and can be, for example, the method and amount of application described above.

Furthermore, when the method for manufacturing the metal laminate of the present invention includes a step of applying a resin composition to the surface of a first metal plate to form a coating film, a step of laminating a second metal plate on the coating film of the first metal plate to form a metal laminate, and a step of pressing the metal laminate, the metal laminate may be manufactured using two metal plates, or may be manufactured using three or more metal plates. The multiple metal plates may be metal plates made of the same material and thickness, or may be metal plates made of different materials and thicknesses. In this case, when a metal laminate plate is manufactured using three or more metal plates, the metal laminate plate may be manufactured by repeating a process including a step of applying a resin composition to the surface of a first metal plate to form a coating film, a step of laminating a second metal plate on the coating film of the first metal plate to form a metal laminate, a step of pressing the metal laminate, a step of applying a resin composition to the surface of the pressed metal laminate to form a coating film, a step of further laminating a third metal plate on the coating film of the metal laminate to form a metal laminate, and a step of pressing the metal laminate. Alternatively, the metal laminate plate may be manufactured by repeating a process of applying a resin composition to the surfaces of three or more metal plates to form coating films, laminating the metal plates to form a metal laminate, and then pressing the metal laminate.

The method for producing a metal laminate plate of the present invention uses the resin composition described above to produce a strongly bonded metal laminate plate. The metal laminate plate obtained by the present invention can be used without any particular restrictions as long as it is used in applications where a metal laminate plate is used, and can be used, for example, as a metal laminate plate for automobiles, vehicles (bullet trains, trains, etc.), civil engineering, architecture, ships, airplanes, and the space industry.

4. Metal laminate plate The metal laminate plate of the present invention is a metal laminate plate in which a first metal plate, a coating film of the above-mentioned resin composition, and a second metal plate are laminated in this order. The first metal plate and the second metal plate may be metal plates made of the same material and thickness, or may be metal plates made of different materials and thicknesses. The metal laminate plate of the present invention can be manufactured, for example, by the above-mentioned manufacturing method of a metal laminate plate. Since the metal plates of the metal laminate plate of the present invention are strongly bonded to each other, it can be used without any particular limitation as long as it is used for the purpose of a metal laminate plate. The metal laminate plate of the present invention can be used, for example, as a metal laminate plate for automobiles, vehicles (bullet trains, trains, etc.), civil engineering, architecture, ships, airplanes, and the space industry.

The present disclosure includes the following aspects:

[1] A resin composition containing component (A) consisting of an epoxy resin that is solid at 25°C, and component (B) consisting of one or more members selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes.

[2] The resin composition described in [1], in which component (A) contains a bisphenol A type epoxy resin that is solid at 25°C.

[3] The resin composition according to [1] or [2], in which 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 any one of [1] to [3], in which 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, and then blocking the reaction with a blocking agent or extending the chains with a chain extender.

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

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

[7] A resin composition for metal surface treatment, comprising component (A) made of an epoxy resin that is solid at 25°C, and component (B) made of one or more members selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes.

[8] A method for producing a metal laminate plate, comprising the steps of applying the resin composition described in any one of [1] to [6] to the surface of a first metal plate to form a coating film, and laminating a second metal plate onto the coating film of the first metal plate to form a metal laminate.

[9] The method for producing the metal laminate described in [8] further includes a step of crimping the metal laminate.

[10] A metal laminate plate having a first metal plate, a coating film of the resin composition described in any one of [1] to [6], and a second metal plate laminated in this order.

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these. In the following examples, percentages are by weight unless otherwise specified.

<Production of Water-Dispersed Epoxy Resin Emulsion 1>
In a four-necked separable round-bottom flask equipped with a Dimroth stirrer and a nitrogen line, 290.0 g of bisphenol A type epoxy resin (melting point 0°C or less, epoxy equivalent 190 g/eq.), 159.5 g of bisphenol A, and 0.1 g of triphenylphosphine as a catalyst were placed and reacted at 180°C for 5 hours to obtain epoxy resin A-1. After that, 50.5 g of propylene glycol monomethyl ether was added as a solvent, and then 50.5 g of nonionic surfactant 1 having an ethylene oxide skeleton and a weight average molecular weight of 16,000 was added and mixed, and after cooling to 70°C, 449.5 g of water was added to perform phase inversion emulsification, thereby producing water-dispersed emulsion 1 of epoxy resin. The obtained water-dispersed epoxy resin emulsion 1 contained 45.0 mass% of epoxy resin A-1 (bisphenol A type epoxy resin, melting point 140°C, epoxy equivalent 3,000 g/eq.), 5.0 mass% of nonionic surfactant 1, 5.0 mass% of propylene glycol monomethyl ether, and 45.0 mass% of water.

<Preparation of Water-Dispersed Epoxy Resin Emulsion 2>
In a four-neck separable round-bottom flask equipped with a Dimroth stirrer and a nitrogen line, 450.5 g of bisphenol A type epoxy resin (melting point 0°C or less, epoxy equivalent 190 g/eq.), 49.5 g of propylene glycol monomethyl ether as a solvent, and 49.5 g of nonionic surfactant 1 having an ethylene oxide skeleton and a weight average molecular weight of 16,000 were added and mixed at 70°C, and 450.5 g of water was added to perform phase inversion emulsification, thereby producing a water-dispersed emulsion 2 of epoxy resin. The obtained water-dispersed emulsion 2 of epoxy resin contained 45.0 mass% of epoxy resin A'-2 (bisphenol A type epoxy resin, melting point 0°C or less, epoxy equivalent 190 g/eq.), 5.0 mass% of nonionic surfactant 1, 5.0 mass% of propylene glycol monomethyl ether, and 45.0 mass% of water.

<Production of Water-Dispersed Urethane Resin Emulsion 1>
A four-neck separable round-bottom flask equipped with a Dimroth stirrer, a stirring blade, and a nitrogen line was charged with 202.7 g of polytetramethylene ether glycol having a number average molecular weight of 1,000 as a polyether polyol compound, 436.9 g of hydrogenated diphenylmethane diisocyanate as a polyisocyanate compound, 67.6 g of dimethylolpropionic acid and 33.8 g of melamine as anionic group introducing agents, 56.3 g of triethylamine and 202.7 g of N-methyl-2-pyrrolidone as neutralizing agents, and the mixture was allowed to react at 80° C. for 5 hours to produce a urethane prepolymer solution.
Next, 724.0 g of water at 40°C was added to a 2L disposable cup, and after stirring, 500 g of the above 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 stirring was continued for another hour to obtain a water-dispersed emulsion 1 of urethane resin. The obtained water-dispersed emulsion 1 of urethane resin contained 30 mass% of polyether polyurethane B-1 (acid value: 38.0 mg KOH/g, content ratio of polyether structure: 27 mass%), 8 mass% of N-methyl-2-pyrrolidone, and 62 mass% of water.

<Production of Water-Dispersed Urethane Resin Emulsion 2>
A four-neck separable round-bottom flask equipped with a Dimroth stirrer, a stirring blade, and a nitrogen line was charged with 374.3 g of polytetramethylene ether glycol having a number average molecular weight of 1,000 as a polyether polyol compound, 334.2 g of hydrogenated diphenylmethane diisocyanate as a polyisocyanate compound, 42.8 g of dimethylolpropionic acid and 13.4 g of melamine as anionic group introducing agents, 32.1 g of triethylamine and 203.2 g of N-methyl-2-pyrrolidone as neutralizing agents, and the mixture was allowed to react at 80° C. for 5 hours to produce a urethane prepolymer solution.
Next, 765.8 g of water at 40°C was added to a 2L disposable cup, and after stirring, 500 g of the above urethane prepolymer solution was added and stirred for 30 minutes. Then, 26.7 g of an aqueous solution of ethylenediamine/water = 1/3 (mass ratio) was added, and stirring was continued for another hour to obtain a water-dispersed emulsion 2 of a urethane resin. The obtained water-dispersed emulsion 2 of a urethane resin contained 30 mass% of polyether polyurethane B-2 (acid value: 23.0 mg KOH/g, content ratio of polyether structure: 49 mass%), 8 mass% of N-methyl-2-pyrrolidone, and 62 mass% of water.

<Production of Water-Dispersed Urethane Resin Emulsion 3>
A four-neck separable round-bottom flask equipped with a Dimroth stirrer, a stirring blade, and a nitrogen line was charged with 253.2 g of polyester polyol having a number average molecular weight of 500, 436.7 g of hydrogenated diphenylmethane diisocyanate as a polyisocyanate compound, 50.6 g of dimethylolpropionic acid and 19.0 g of melamine as anionic group introducing agents, 38.0 g of triethylamine and 202.5 g of N-methyl-2-pyrrolidone as neutralizing agents, and the mixture was reacted at 80° C. for 5 hours to produce a urethane prepolymer solution.
Next, 771.1 g of water at 40°C was added to a 2L disposable cup, and after stirring, 500 g of the above 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 stirring was continued for another hour to obtain a water-dispersed emulsion of urethane resin 3. The obtained water-dispersed emulsion of urethane resin 3 contained 30 mass% of polyester polyurethane B'-3 (acid value: 28.0 mgKOH/g), 8 mass% of N-methyl-2-pyrrolidone, and 62 mass% of water.

<Production of Water-Dispersed Urethane Resin Emulsion 4>
Into a four-neck separable round-bottom flask equipped with a Dimroth stirrer, stirring blades, and a nitrogen line, 526.8 g of polycarbonate diol having a number average molecular weight of 2,000 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 introducing agent, 42.2 g of triethylamine as a neutralizing agent, and 202.2 g of N-methyl-2-pyrrolidone were added and reacted at 80° C. for 5 hours to produce a urethane prepolymer solution.
Next, 807.8 g of water at 40°C was added to a 2L disposable cup, and after stirring, 500 g of the above urethane prepolymer solution was added and stirred for 30 minutes. Then, 22.3 g of an aqueous solution of ethylenediamine/water = 1/3 (mass ratio) was added, and stirring was continued for another hour to obtain a water-dispersed emulsion of urethane resin 4. The obtained water-dispersed emulsion of urethane resin 4 contained 30 mass% of polycarbonate polyurethane B'-4 (acid value: 23.0 mgKOH/g), 8 mass% of N-methyl-2-pyrrolidone, and 62 mass% of water.

[Examples 1 to 4, Comparative Examples 1 to 5]
The produced water-dispersed epoxy resin emulsions 1 to 2 and the water-dispersed urethane resin emulsions 1 to 4 were mixed to produce the resin compositions of Examples 1 to 4 and Comparative Examples 1 to 5 shown in Table 1, respectively.

[Room temperature adhesion evaluation]
The resin compositions produced in Examples 1 to 4 and Comparative Examples 1 to 5 were applied to one side of two steel plates (width 25 mm, length 100 mm, thickness 1.6 mm) so that the coating thickness after drying was about 4 μm, and then dried with hot air (attained plate temperature 200 ° C.) to produce surface-treated steel plates in which a coating film of the resin composition was formed on the entire surface of each steel plate. The two surface-treated steel plates produced were laminated so that the treated surfaces (surfaces on which the coating film was formed) of the surface-treated steel plates overlapped each other by 10 mm in the length direction (the positions in the width direction were the same), and the two steel plates were pressed at room temperature for 10 minutes or 20 minutes while being pressed with a pressure of 3 MPa using a press machine to produce a metal laminate plate in which the two steel plates were bonded. The overlap shear strength (MPa) of the obtained metal laminate plate was measured using a tensile tester according to the method described in JIS K 6850 (1999), and the adhesion was evaluated from the overlap shear strength value according to the following evaluation criteria for room temperature adhesion. The evaluation results of the room temperature adhesion of each resin composition are shown in Table 1. In this evaluation, if the room temperature adhesion evaluation is Δ or higher, it indicates that the composition has practical applicability in a short-time room temperature adhesion method.

Evaluation criteria for room temperature adhesion: ⊚: Lap shear strength is 15 MPa or more; ◯: Lap shear strength is 10 MPa or more and less than 15 MPa; △: Lap shear strength is 5 MPa or more and less than 10 MPa; ×: Lap shear strength is less than 5 MPa

[High temperature adhesion evaluation]
The resin compositions produced in Examples 1 to 4 and Comparative Examples 1 to 5 were applied to one side of each of two steel plates (width 25 mm, length 100 mm, thickness 1.6 mm) so that the coating thickness after drying was about 4 μm, and then dried with hot air (attained plate temperature 200 ° C.) to produce a surface-treated steel plate in which a coating film of the resin composition was formed on the entire surface of each steel plate. The two surface-treated steel plates produced were laminated so that the treated surfaces (surfaces on which the coating film was formed) of the surface-treated steel plates overlapped each other by 10 mm in the length direction (the positions in the width direction were the same), and the two steel plates were pressed at 180 ° C. for 10 minutes while being pressed at a pressure of 3 MPa using a heater press machine, thereby producing a metal laminate plate in which the two steel plates were bonded. The overlap shear strength (MPa) of the obtained metal laminate plate was measured using a tensile tester according to the method described in JIS K 6850 (1999), and the adhesion was evaluated from the overlap shear strength value according to the following evaluation criteria for high-temperature adhesion. The evaluation results of the high temperature adhesion of each resin composition are shown in Table 1. In this evaluation, if the high temperature adhesion evaluation is Δ or higher, it indicates that the composition has practical applicability in a high temperature adhesion method for a short period of time.

Evaluation criteria for high temperature adhesion: ⊚: Lap shear strength is 2.5 MPa or more; ◯: Lap shear strength is 1.0 MPa or more and less than 2.5 Pa; Δ: Lap shear strength is 0.1 MPa or more and less than 1.0 MPa; ×: Lap shear strength is less than 0.1 MPa

[Corrosion resistance evaluation]
The resin compositions produced in Examples 1 to 4 and Comparative Examples 1 to 5 were applied to one side of a steel plate (width 25 mm, length 100 mm, thickness 1.6 mm) so that the coating thickness after drying was about 4 μm, and then dried with hot air (plate temperature reached 200 ° C.) to produce surface-treated steel plates on which a coating film of the resin composition was formed on the entire surface of each steel plate. For the surface-treated steel plates produced, a salt spray test was performed at 35 ° C. for 24 hours using 5 mass % neutral salt water on the treated surface (surface on which the coating film was formed) of the surface-treated steel plate in accordance with JIS Z 2371 (2015), and the corrosion resistance of each resin composition was evaluated by visual observation of the coating film on the surface-treated steel plate after the test and the following corrosion resistance evaluation criteria. The evaluation results of the corrosion resistance of each resin composition are shown in Table 1. In addition, if the corrosion resistance evaluation in this evaluation is △ or higher, it indicates that it has practical use.

Evaluation criteria for corrosion resistance: ◎: Rust occurred on less than 10% of the surface area. ○: Rust occurred on 10% or more but less than 20% of the surface area. △: Rust occurred on 20% or more but less than 40% of the surface area. ×: Rust occurred on 40% or more of the surface area.

As shown in Table 1, the resin composition of the present invention, which contains component (A) consisting of an epoxy resin that is solid at 25°C and component (B) consisting of one or more selected from the group consisting of polyether polyurethane prepolymer and polyether polyurethane, has excellent adhesive properties, and in particular, has adhesive properties that allow bonding by short-time compression at room temperature and high temperatures, and corrosion resistance. On the other hand, when an epoxy resin that is liquid at 25°C was used instead of component (A), or when polyester polyurethane or polycarbonate polyurethane was used instead of component (B), adhesive properties by short-time compression were not obtained. From these results, it can be seen that the present invention can provide a resin composition that has excellent adhesive properties compared to conventional resin compositions.

Claims (10)

A resin composition containing component (A) consisting of an epoxy resin that is solid at 25°C, and component (B) consisting of one or more components selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes. The resin composition according to claim 1, wherein the component (A) contains a bisphenol A type epoxy resin that is solid at 25°C. 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. The resin composition according to claim 1, 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-based compound, followed by blocking with a blocking agent or chain extension with a chain extender. The resin composition according to claim 1, wherein the ratio of the content of the component (A) to the content of the component (B) in the resin composition is 5:95 to 98:2 by mass ratio. The resin composition according to claim 1, further comprising water, the water content being 10 to 90 mass %. A resin composition for metal surface treatment that contains component (A) consisting of an epoxy resin that is solid at 25°C, and component (B) consisting of one or more components selected from the group consisting of polyether polyurethane prepolymers and polyether polyurethanes. A method for manufacturing a metal laminate plate, comprising the steps 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; and laminating a second metal plate onto the coating film of the first metal plate to form a metal laminate. The method for manufacturing a metal laminate according to claim 8, further comprising a step of crimping the metal laminate. A metal laminate plate in which a first metal plate, a coating film of the resin composition described in any one of claims 1 to 6, and a second metal plate are laminated in this order.