Metal surface treatment composition and metal material

Abstract

To provide a metal surface treatment composition which can impart preferable adhesion to a laminate, to a metal material.SOLUTION: A metal surface treatment composition contains a water-soluble metal compound (A), a water-soluble or water-insoluble acrylic resin (B), and a resin (C) that is at least any one of a polyvinyl alcohol-based resin and a polyacrylic acid, wherein the water-soluble metal compound (A) has concentration in terms of a metal atom of 100-100,000 mass ppm, the resin (B) has a solid content acid value of 150-740 mgKOH / g and a solid content hydroxyl value of 24-350 mgKOH / g, the total of the concentration of the resin (B) and the concentration of the resin (C) is 200-200,000 mass ppm in terms of the solid content, and a ratio (A / (B+C)) of the concentration of the water-soluble metal compound (A) in terms of the metal atom to the total of the concentration of the resin (B) and the concentration of the resin (C) is 3 / 97 to 91 / 9.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a metal surface treatment composition and a metal material. [Background technology]

[0002] Conventionally, lamination technology has been used to protect and design metal materials such as aluminum and aluminum alloys. The laminate film adhered to the surface of the metal material during lamination offers excellent workability, corrosion resistance, and barrier properties for contents. Unlike paints, laminate films do not generate volatile organic compounds during the manufacturing process, making them environmentally friendly. They are therefore widely used as surface protection materials for food cans, capacitor cases, battery components, and the like.

[0003] When applying lamination, it is important to improve the adhesion between the laminate film and the metal material from the viewpoint of maintaining aesthetic appearance and corrosion resistance. For this reason, a technique is known in which an oxazoline group-containing resin and an acrylic resin are used as a base treatment layer for the metal material to improve the adhesion between the metal material and the laminate film (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-187386 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 improves adhesion by having an amide ester moiety in the undercoat treatment layer formed by the reaction of an oxazoline group with a carboxyl group, but there is still room for improvement in terms of obtaining desirable adhesion.In addition, since a resin containing an oxazoline group is required, there is also room for improvement in terms of production costs.

[0006] The present invention has been made in view of the above, and aims to provide a metal surface treatment composition that can impart desirable adhesion to a laminate film to a metal material. [Means for solving the problem]

[0007] (1) The present invention relates to a metal surface treatment composition comprising a water-soluble metal compound (A), a water-soluble or water-dispersible acrylic resin (B), and a resin (C) that is at least one of a polyvinyl alcohol resin and a polyacrylic acid, wherein the concentration of the water-soluble metal compound (A) is 100 to 100,000 ppm by mass in terms of metal atoms, the water-soluble or water-dispersible acrylic resin (B) has an acid value of 150 to 740 mg KOH / g of solids and a hydroxyl value of 24 to 350 mg KOH / g of solids, the sum of the concentrations of the water-soluble or water-dispersible acrylic resin (B) and the resin (C) is 200 to 200,000 ppm by mass in terms of solids, and the ratio (A / (B+C)) of the concentration of the water-soluble metal compound (A) in terms of metal atoms to the sum of the concentrations of the water-soluble or water-dispersible acrylic resin (B) and the resin (C) is 3 / 97 to 91 / 9.

[0008] (2) The metal surface treatment composition according to (1), wherein the resin (C) has a vinyl alcohol skeleton.

[0009] (3) A metal material having at least one surface treated with the metal surface treatment composition according to (1) or (2).

[0010] (4) The water-soluble metal compound (A) is present in an amount of 0.8 to 3200 mg / m in terms of metal atom in the coating mass after drying per at least one of the surfaces. 2 It contains the water-soluble or water-dispersible acrylic resin (B) and the resin (C) in a total solid content of 1.0 to 4000 mg / m². 2 The metallic material described in (3), wherein a film containing the material is formed on it. [Effects of the Invention]

[0011] According to the present invention, a metal surface treatment composition can be provided that can impart desirable adhesion to a laminate film to a metal material. DETAILED DESCRIPTION OF THE INVENTION

[0012] The embodiments of the present invention will be described below. The present invention is not limited to the embodiments described below.

[0013] <Metal surface treatment composition> The metal surface treatment composition according to the present embodiment forms a coating on the surface of a metal material, which improves adhesion to a laminate film. The metal material laminated with the coating and the laminate film (hereinafter, sometimes referred to as a "laminated metal material") can be used for various purposes, including, but not limited to, cans, heat exchangers, and metal components for batteries.

[0014] The metal surface treatment composition according to this embodiment contains a water-soluble metal compound (A), a water-soluble or water-dispersible acrylic resin (B), and a resin (C) which is at least one of a polyvinyl alcohol-based resin and a polyacrylic acid.

[0015] (Water-soluble metal compound (A)) The water-soluble metal compound (A) is not particularly limited, but may be at least one of a water-soluble zirconium compound, a water-soluble titanium compound, and a water-soluble vanadium compound. When the water-soluble metal compound is contained in the metal surface treatment composition, a coating containing the water-soluble metal compound (A) is formed on the surface of the metal material. Examples of water-soluble zirconium compounds include, but are not limited to, hydrofluorozirconic acid (HZrF), ammonium hexafluorozirconate ((NH)ZrF), ammonium zirconium carbonate ((NH)ZrO(CO)), tetraalkylammonium-modified zirconium, zirconium monoacetylacetate, and zirconium tetraacetylacetate. Examples of water-soluble titanium compounds include, but are not limited to, ammonium titanium fluoride, alkoxy titanium, and ammonium titanium lactate. The water-soluble vanadium compound is not particularly limited, but examples thereof include vanadyl sulfate, vanadium pentoxide, metavanadic acid, ammonium metavanadate, sodium metavanadate, vanadium oxytrichloride, vanadium trioxide, vanadium dioxide, vanadium oxyacetylacetonate, vanadium acetylacetonate, vanadium trichloride, and phosphovanadomolybdic acid.

[0016] In this specification, the water-soluble metal compound (A) also includes an aqueous dispersion of a metal compound. Examples of aqueous dispersions of metal compounds include zirconia sol, titania sol, and vanadium oxide sol, which contain zirconia (ZrO2) as a zirconium compound, titania (TiO2) as a titanium compound, or divanadium pentoxide (VO5) as a vanadium compound as a dispersoid, and water as a dispersion medium. The water-soluble metal compound (A) can be used alone or in combination of two or more.

[0017] The concentration of the water-soluble metal compound (A) in the metal surface treatment composition is 100 to 100,000 ppm by mass in terms of metal atoms. If the above concentration is less than 100 ppm, the adhesion and corrosion resistance of the laminated metal material will decrease. If the above concentration exceeds 100,000 ppm, the adhesion will decrease and the cost of the metal surface treatment composition will increase. From the above viewpoint, it is preferable that the concentration of the water-soluble metal compound (A) is 100 to 32,000 ppm by mass in terms of metal atoms.

[0018] (Water-soluble or water-dispersible acrylic resin (B)) The water-soluble or water-dispersible acrylic resin (B) is a polymer or copolymer of monomer (b) containing a radical polymerizable monomer, and can be obtained, for example, by a known method utilizing a radical polymerization reaction using monomer (b) containing a radical polymerizable monomer as a raw material component. The radical polymerizable monomer is not particularly limited, but examples include hydroxyl group-containing radical polymerizable monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, allyl alcohol, methacrylic alcohol, adducts of 2-hydroxyethyl (meth)acrylate and ε-caprolactone, methyl (meth)acrylate, ethyl (meth)acrylate, methoxypolyethylene methacrylate, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, acrylic acid dimer, and ε-caprolactone of acrylic acid. Examples include (meth)acrylic acid and its derivatives such as lactone adducts, unsaturated dibasic acids such as maleic acid, fumaric acid, and itaconic acid, and radical polymerizable monomers having a carboxyl group such as their half-esters, half-amides, and half-thioesters, as well as amide group-containing radical polymerizable monomers such as (meth)acrylamide, N-methylol(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-dibutyl(meth)acrylamide, N,N-dioctyl(meth)acrylamide, N-monobutyl(meth)acrylamide, and N-monooctyl(meth)acrylamide.

[0019] In addition to the above, examples of the monomer (b) that can be used to obtain a water-soluble or water-dispersible acrylic resin include (meth)acrylates such as n-butyl (meth)acrylate, isobutyl acrylate, t-butyl acrylate, 2-ethylhexyl (meth)acrylate, lauryl methacrylate, phenyl acrylate, isobornyl (meth)acrylate, cyclohexyl methacrylate, t-butylcyclohexyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, and dihydrodicyclopentadienyl (meth)acrylate; polymerizable aromatic compounds such as styrene, α-methylstyrene, vinyl ketone, t-butylstyrene, parachlorostyrene, and vinylnaphthalene; polymerizable nitriles such as acrylonitrile and methacrylonitrile; α-olefins such as ethylene and propylene; vinyl esters such as vinyl acetate and vinyl propionate; and dienes such as butadiene and isoprene.

[0020] The monomer (b) used to obtain the water-soluble or water-dispersible acrylic resin (B) preferably contains a monomer containing at least one of a glycidyl group, an amide group, a silanol group, a phosphate group, and an imide group as a modifier. This improves the adhesion between the coating formed by the metal surface treatment composition and the metal material. The monomer (b) containing the glycidyl group, an amide group, a silanol group, a phosphate group, and an imide group may be used in combination.

[0021] Examples of monomers that can be used as the modifier include glycidyl group-containing monomers such as glycidyl (meth)acrylate and (meth)allyl glycidyl ether, amide group-containing monomers such as (meth)acrylamide, phosphate group-containing monomers such as acid phosphooxyethyl methacrylate and acid phosphooxypolyoxyethylene glycol monomethacrylate, silanol group-containing monomers such as vinyl methoxysilane, vinyl trimethoxysilane, vinyl ethoxysilane, vinyl triethoxysilane, 3-aminopropyl trimethoxysilane and 3-methacryloxypropyl triethoxysilane, imide group-containing monomers such as amide imide, and hydroxyl group-containing monomers. The monomer (b) containing the radical polymerizable monomer can be used alone or in combination of two or more.

[0022] The polymerization method for obtaining the water-soluble or water-dispersible acrylic resin (B) is not particularly limited, and the resin can be synthesized by a known method such as solution radical polymerization, emulsion polymerization, suspension polymerization, etc. For example, the water-soluble or water-dispersible acrylic resin (B) can be obtained by adding a mixed solution of a known radical polymerization initiator and the above-mentioned monomers dropwise to an appropriate solvent while stirring the mixture at a polymerization temperature of 60 to 160°C for 2 to 10 hours.

[0023] The solid content acid value of water-soluble or water-dispersible acrylic resin (B) is 150 to 740 mgKOH / g. If it is less than 150 mgKOH / g, the water solubility decreases, leading to a deterioration in the appearance of the film and a decrease in the adhesion to the laminated metal material. If it exceeds 740 mgKOH / g, the required hydroxyl value described later cannot be obtained.

[0024] The solids hydroxyl value of water-soluble or water-dispersible acrylic resin (B) is 24 to 350 mgKOH / g. If it is less than 24 mgKOH / g, the adhesion and corrosion resistance of the laminated metal material will decrease. If it exceeds 350 mgKOH / g, the storage stability of the resulting acrylic resin will decrease.

[0025] The solid content acid value and solid content hydroxyl value of the water-soluble or water-dispersible acrylic resin (B) can be measured in accordance with JIS K0070.

[0026] The molecular weight of the water-soluble or water-dispersible acrylic resin (B) is not particularly limited, but it is preferable that the number average molecular weight be between 15,000 and 500,000. If the number average molecular weight is less than 15,000, the preferred adhesion of the formed film to the metal material and laminate film cannot be obtained. If the number average molecular weight exceeds 500,000, the viscosity of the resulting metal surface treatment composition increases, and the paintability and storage stability deteriorate. The number average molecular weight of the water-soluble or water-dispersible acrylic resin (B) is preferably between 20,000 and 200,000, and more preferably between 50,000 and 200,000. The number average molecular weight of the water-soluble or water-dispersible acrylic resin (B) can also be between 10,000 and 800,000 depending on the required performance and other conditions. The above number average molecular weight is determined by the GPC method using polyethylene oxide as the standard.

[0027] (Resin (C)) Resin (C) is at least one of a polyvinyl alcohol-based resin and polyacrylic acid. The inclusion of resin (C) in the metal surface treatment composition improves the adhesion between the film formed by the metal surface treatment composition and the laminate film. Resin (C) preferably has a vinyl alcohol skeleton.

[0028] Examples of polyvinyl alcohol-based resins include polyvinyl alcohol obtained by saponifying vinyl acetate polymer (hereinafter sometimes referred to as "PVA"), ethylene-vinyl alcohol copolymer resin obtained by saponifying copolymer of ethylene and vinyl ester (hereinafter sometimes referred to as "EVOH"), copolymer resin of butenediol and vinyl alcohol (hereinafter sometimes referred to as "BVOH"), and derivatives of PVA. Examples of PVA derivatives include those in which some of the hydroxyl groups of PVA are replaced with alkyl groups such as propyl groups and butyl groups, or acetoacetyl groups, ethylene glycol groups, silanol groups, etc., and those obtained by graft polymerization of hydrophilic compounds such as polyvinylpyrrolidone onto PVA.

[0029] Commercially available products can be used as PVA, EVOH, BVOH, and derivatives of PVA. Examples of commercially available products include the "Kuraray Poval" (trade name, polyvinyl alcohol, manufactured by Kuraray Co., Ltd.) series, the "Eval" (trade name, ethylene-vinyl alcohol copolymer, manufactured by Kuraray Co., Ltd.) series, the "Nichigo G Polymer" (trade name, butenediol vinyl alcohol copolymer, manufactured by Mitsubishi Chemical Corporation) series, the "Gosenex" (trade name) WO series (hydrophilic group modified polyvinyl alcohol, manufactured by Mitsubishi Chemical Corporation), and the Z series (acetoacetyl group-containing modified PVA, manufactured by Mitsubishi Chemical Corporation), and Pitzcol V7154 (trade name, polyvinylpyrrolidone modified polyvinyl alcohol, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

[0030] The average degree of saponification of the polyvinyl alcohol-based resin is preferably 60% to 100%. The degree of polymerization of polyvinyl alcohol in the polyvinyl alcohol-based resin is preferably 300 to 9500.

[0031] Examples of polyacrylic acid include homopolymers of acrylic acid, and copolymers of acrylic acid with at least one monomer selected from the group consisting of methacrylic acid, acrylic acid esters, and methacrylic acid esters. Polyacrylic acid may also be a salt of sodium polyacrylate, etc. Commercially available polyacrylic acid can be used; for example, Julimar AC-10L (trade name, manufactured by Toagosei Co., Ltd.), Julimar AC-103P (trade name, manufactured by Toagosei Co., Ltd.), etc. Polyacrylic acid may have functional groups such as sulfonic acid groups. Specific examples of polyacrylic acid having sulfonic acid groups include Aron (trade name) A-6012, A-6016, A-6017, and A-6020 (all sodium salts of copolymers of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid, manufactured by Toagosei Co., Ltd.).

[0032] The solid content acid value of polyacrylic acid is preferably 750 to 778 mg KOH / g. Having the solid content acid value of polyacrylic acid within this range improves the adhesion between the film formed by the metal surface treatment composition and the metal material.

[0033] The total concentration of water-soluble or water-dispersible acrylic resin (B) and resin (C) in the metal surface treatment composition is 200 to 200,000 ppm by mass in terms of solid content. If it is less than 200 ppm by mass, the adhesion and corrosion resistance of the laminated metal material will decrease. If it exceeds 200,000 ppm by mass, the viscosity of the resulting metal surface treatment composition will increase, making it difficult to handle. In addition, the performance improvement will not be commensurate with the increase in the amount added, and the cost will increase. From the above viewpoint, it is preferable that the total concentration of water-soluble or water-dispersible acrylic resin (B) and resin (C) in the metal surface treatment composition is 1,000 to 25,000 ppm by mass in terms of solid content.

[0034] The ratio (A / (B+C)) of the mass concentration of the water-soluble metal compound (A) converted to metal atoms to the sum of the concentrations of the water-soluble or water-dispersible acrylic resin (B) and the resin (C) is 3 / 97 to 91 / 9. If the proportion of the water-soluble metal compound (A) in this concentration ratio is lower than 3 / 97, the adhesion of the film formed from the metal surface treatment composition to metal materials such as aluminum and laminate films will decrease. If the proportion of the water-soluble metal compound (A) in this concentration ratio is higher than 91 / 9, the adhesion of the film to metal materials such as aluminum will decrease.

[0035] (Other ingredients) The metal surface treatment composition according to this embodiment may contain other resins in addition to the water-soluble metal compound (A), the water-soluble or water-dispersible acrylic resin (B), and the resin (C). For example, it may contain polyester resin, alkyd resin, epoxy resin, urethane resin, etc. These resins may be used alone or in combination of two or more.

[0036] The metal surface treatment composition according to this embodiment may not contain a crosslinking agent. Even if the metal surface treatment composition according to this embodiment does not contain a crosslinking agent, favorable adhesion and corrosion resistance of the laminated metal material can be obtained. However, the metal surface treatment composition according to this embodiment may contain a crosslinking agent. Examples of the crosslinking agent include, but are not limited to, water-dispersible thermosetting crosslinking agents such as water-soluble melamine resins and water-soluble phenolic resins.

[0037] In addition to the above, the metal surface treatment composition according to this embodiment may contain known additives such as stabilizers, antioxidants, surface conditioners, and antifoaming agents, as needed.

[0038] <Method for manufacturing metal surface treatment compositions> The method for producing the metal surface treatment composition according to the present embodiment is not particularly limited, and the composition can be produced by a known method, such as mixing and stirring the water-soluble metal compound (A), the water-soluble or water-dispersible acrylic resin (B), and the resin (C), as well as other components as necessary, in water as a solvent.

[0039] The metal surface treatment composition according to this embodiment is prepared as an aqueous solution or dispersion of a water-soluble metal compound (A), a water-soluble or water-dispersible acrylic resin (B), and a resin (C). This eliminates the need to include an organic solvent in the metal surface treatment composition, and is therefore excellent in terms of the environment and workability.

[0040] <Laminated metal material> The metal surface treatment composition according to this embodiment is used in the manufacture of laminated metal materials, which are produced by forming a film on at least one surface of a metal material and then adhering a laminate film to it. The method for manufacturing the laminated metal material is not particularly limited. For example, a method may be used in which a metal material such as a thin sheet is degreased, and if necessary, washed with water, pickled, and surface-treated, the metal surface treatment composition according to this embodiment is applied, heated and dried to form a film on the surface of the metal material, and then a laminate film made of a thermoplastic resin or the like is adhered to it.

[0041] Examples of metal materials to be treated with the metal surface treatment composition according to this embodiment include aluminum or aluminum alloys, iron, iron alloys, copper, copper alloys, and stainless steel. Among these, aluminum or aluminum alloys are preferred from the viewpoints of workability and adhesion. For example, aluminum alloys 3004, 3104, and 3005 are preferred for beverage and food can bodies; aluminum alloys 5052 and 5182 are preferred for beverage and food can lids; aluminum alloys 1050, 1100, and 1200 are preferred for dry battery containers; aluminum alloys 8079 are preferred for battery packaging; and aluminum alloys 8021 are preferred for electrode materials. Aluminum die-cast (ADC) materials may also be used as aluminum alloys. In addition to the above, oxygen-free copper such as C1020P and commercially available copper foils are preferred as copper metal materials, and austenitic stainless steels such as SUS304 and SUS301 are preferred as SUS. In addition to the above, plated metal materials such as Ni-plated steel sheets, Zn-plated steel sheets, Zn-Ni-plated steel sheets, etc. may also be used as the metal material. Examples of the above include Ni-plated steel sheets, Zn-plated steel sheets, Zn-Ni-plated steel sheets, etc., using SPCC, SPCD, SPCE, etc. as the base steel sheet.

[0042] The degreasing treatment is not particularly limited, and for example, a known method such as alkaline degreasing cleaning can be used. The degreasing treatment is usually performed by a spray method. After the degreasing treatment, a water washing treatment is performed to remove the degreasing agent remaining on the substrate surface, and then moisture on the substrate surface is removed by a method such as draining with a roll, air blowing, or hot air drying.

[0043] The coating formed on at least one surface of the metal material has a coating mass per surface after drying of the water-soluble metal compound (A) of 0.8 to 3200 mg / m in terms of metal atom. 2 Similarly, the total amount of the water-soluble or water-dispersible acrylic resin (B) and the resin (C) in terms of solid content per surface after drying is preferably 1.0 to 4000 mg / m 2The coating may be formed on any one surface of the metal material, and for example, the coating may be formed on both surfaces of a thin plate material.

[0044] The application method for the metal surface treatment composition according to this embodiment is not particularly limited, as long as the mass of each component of the formed film falls within the above range. For example, roll coating, bar coating, spray treatment, immersion treatment, etc., can be used. Among these, the roll coating method is preferred.

[0045] The method for heat-drying the metal surface treatment composition according to this embodiment is not particularly limited, but examples thereof include oven drying, forced circulation of hot air, etc. The heat-drying conditions can be, for example, 40 to 160°C for 2 to 60 seconds.

[0046] The method for adhering a laminate film to a metal material on which a film has been formed on its surface using the above-mentioned metal surface treatment composition is not particularly limited, and known methods such as dry lamination and extrusion lamination can be used. The laminate film is not particularly limited, and known laminate films can be used. Examples of the laminate film include films made of thermoplastic resins such as polypropylene, polyethylene terephthalate, nylon, polyethylene naphthalate, and polyester.

[0047] The laminated metal material according to this embodiment may have a film formed by the metal surface treatment composition and layers other than the laminate film. For example, it may have an adhesive layer disposed between the film formed by the metal surface treatment composition and the laminate film. The adhesive layer is not particularly limited and may be formed by a one-component adhesive or a two-component adhesive. As the adhesive, known resin adhesives such as urethane-based, polyester-based, ether-based, epoxy-based, and olefin-based adhesives can be used.

[0048] The metal surface treatment composition according to this embodiment contains specific amounts of a water-soluble metal compound (A), a water-soluble or water-dispersible acrylic resin (B), and a resin (C), and therefore exhibits excellent coating workability and stability, and the resulting laminated metal material exhibits sufficient adhesion. While metal surface treatment compositions that simply contain an acrylic resin and a zirconium compound exhibit corrosion resistance, the metal surface treatment composition according to this embodiment has the advantage of being able to form a coating that not only exhibits improved adhesion to the laminate film but also exhibits corrosion resistance. Therefore, the metal surface treatment composition according to this embodiment is particularly suitable for use in the production of laminated metal materials that require high levels of adhesion and corrosion resistance after processing. [Example]

[0049] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0050] (Example of acrylic resin A synthesis) Acrylic resin A, which served as water-soluble or water-dispersible acrylic resin (B), was prepared by the following method. 95.14 parts by mass of ion-exchanged water was placed in a Kolben equipped with a heating and stirring device and heated to 80°C while stirring and refluxing with nitrogen. Next, while heating, stirring, and refluxing with nitrogen, a mixture of the monomers shown in Table 1, ACVA (4,4'-azobis(4-cyanovaleric acid)) as a polymerization initiator, and a 25% aqueous ammonia solution was added dropwise using a dropping funnel over a period of 3 hours. After the addition was completed, heating, stirring, and refluxing with nitrogen were continued for 2 hours. Then, heating and refluxing with nitrogen were stopped, and the solution was cooled to 30°C while stirring. The solution was neutralized to pH 9 with 25% aqueous ammonia, and filtered through a 200-mesh filter to obtain a colorless, transparent water-soluble acrylic resin A. The obtained acrylic resin A had a number average molecular weight of 100,000, an acid value of the solid content of 626 mgKOH / g, and a hydroxyl value of the solid content of 84 mgKOH / g, as shown in Table 1. In Table 1, values ​​without a unit are in parts by mass. The amount of 25% aqueous ammonia used in the neutralization is not included in the amount of aqueous ammonia solution in Table 1, but is the amount used separately as a neutralizing agent.

[0051] (Synthesis example of acrylic resins B, C, D, and E) Acrylic resins B, C, D, and E were obtained as water-soluble or water-dispersible acrylic resins (B) in the same manner as acrylic resin A, except that the blending amounts of raw materials were as shown in Table 1. The number average molecular weight, solid content acid value, and solid content hydroxyl value are each shown in Table 1.

[0052] [Table 1]

[0053] <<Preparation of Metal Surface Treatment Composition>> Example 1 Deionized water was placed in a Kolben equipped with a heater and stirrer, and while stirring at room temperature, the aqueous solution of acrylic resin A obtained in Synthesis Example was gradually added to the mixture to a concentration of 9,000 ppm by mass in terms of solids. While stirring, PVA-1 (Kuraray Poval 5-98 (trade name, manufactured by Kuraray Co., Ltd.)) as resin (C) was gradually added to a concentration of 1,000 ppm by mass in terms of solids, and the mixture was stirred for approximately 5 minutes to achieve uniformity. Furthermore, while stirring, a water-soluble zirconium compound (ammonium zirconium carbonate, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., trade name Zircosol AC-7, containing 13% zirconium atoms) as water-soluble metal compound (A) was gradually added to a concentration of 1,000 ppm by mass in terms of zirconium atoms, and stirring was continued for 20 minutes to prepare the metal surface treatment composition of Example 1.

[0054] (Examples 2 to 37, Comparative Examples 1 to 12) Metal surface treatment compositions of Examples 2 to 37 and Comparative Examples 1 to 12 were prepared in the same manner as in Example 1, except that the types and concentrations of the acrylic resin, water-soluble metal compound, and resin (C) were as shown in Table 2.

[0055] [Table 2]

[0056] The following types of water-soluble metal compounds (A) shown in Table 2 were used: In Example 21, the following a and c were used in combination. a: Ammonium zirconium carbonate (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd., product name: Zircosol AC-7, contains 13% Zr atom) b: Ammonium zirconate fluoride (Zr(NH4)2F6) c: Titanium triethanol aminate (manufactured by Matsumoto Fine Chemical Co., Ltd., product name: TC-400) d: Vanadyl sulfate (VOSO4)

[0057] The types of resin (C) shown in Table 2 were as follows: PVA-1: Kuraray Poval 5-98 (product name, manufactured by Kuraray Co., Ltd.) PVA-2: Kuraray Poval 3-98 (product name, manufactured by Kuraray Co., Ltd.) PVA-3: Kuraray Poval 5-80 (product name, manufactured by Kuraray Co., Ltd.) PVA-4: Kuraray Poval 25-100 (product name, manufactured by Kuraray Co., Ltd.) Modified PVA-1: Hydrophilic group-modified PVA WO-320N (trade name, manufactured by Mitsubishi Chemical Corporation) Modified PVA-2: Silanol group modified PVA 25-98R (product name, manufactured by Kuraray Co., Ltd.) Modified PVA-3: Acetoacetyl group-modified PVA Z-300 (product name, manufactured by Mitsubishi Chemical Corporation) Modified PVA-4: Polyvinylpyrrolidone-modified PVA, Pitzcol V7154 (product name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) Ethylene-vinyl alcohol copolymer: F-101A (product name, manufactured by Kuraray Co., Ltd.) Polyacrylic acid: Jurimer AC-10L (product name, manufactured by Toagosei Co., Ltd.) Acrylate sulfonic acid copolymer: Aron A-6012 (product name, manufactured by Toagosei Co., Ltd.)

[0058] Coating of metal surface treatment compositions Aluminum alloy 3004 sheet material (Al) was degreased using a 2% diluted solution of "Surf Cleaner 330" manufactured by Nippon Paint Surf Chemicals Co., Ltd. (treated at 65°C for 3 seconds). The metal surface treatment compositions of the above examples and comparative examples were applied to the obtained aluminum material using a nylon bar or stainless steel bar, and dried in a hot air oven at a material temperature of 190°C or higher for 2 minutes to obtain a metal material on which a film was formed on the surface by the metal surface treatment composition. Film mass after drying (mg / m²) 2 Tables 3 and 4 show the mass of metal atoms in the water-soluble metal compound (A) and the total mass of solids in the water-soluble or water-dispersible acrylic resin (B) and resin (C), respectively. In addition, copper (NC-WS manufactured by Furukawa Electric Co., Ltd.) was used as the metal material in Example 34, SUS (SUS304) in Example 35, Ni-plated steel sheet with SPCC as the base material in Example 36, and aluminum die-cast (ADC-12) in Example 37.

[0059] <<Manufacturing of laminated metal materials>> The metal surface treatment compositions described in the above examples and comparative examples were applied to metal materials to which a film had formed on the surface. Laminated metal materials were then prepared using the following four methods for producing laminated metal materials. In Lamination Method 1, a polyester-based two-component adhesive was used as the adhesive, with a drying rate of 3 g / m². 2 The coating was applied to the film formed on the surface of the metal material so that the coating was applied to the surface of the metal material. Next, a PP film was pressed onto the coated surface at 0.38 MPa, and then the film was stored at 60°C for 6 days to obtain a laminated metal material. In lamination method 2, acid-modified polypropylene was used as the adhesive, and the adhesive was 3 g / m2 when dry. 2The coating formed on the surface of the metal material was painted so that the coating was uniform, and then dried at 200°C for 30 seconds. Next, a PP film was attached to the painted surface and pressed at 180°C and 0.38 MPa to obtain a laminated metal material. In lamination method 3, a PET film was pressed onto the coating formed on the surface of the metal material at 180°C and 0.38 MPa, and then dried at 240°C for 60 seconds to obtain a laminated metal material. In lamination method 4, a maleic acid-modified polypropylene film was used, and the film was pressed at 105°C and 0.38 MPa, and then dried at 190°C for 15 seconds to obtain a laminated metal material.

[0060] [Initial adhesion test] The laminated metal materials according to the examples and comparative examples produced above were cut into a size of 150 mm x 15 mm. The peel strength (N / 15 mm width) required to peel off the film surface of this test piece was measured using a "Tensilon Tensile Tester" (LST-200N-S, manufactured by Minerva). The measurement results were taken as initial adhesion, and a value of 6.0 N or more was considered pass. Regarding lamination method 3, evaluation was performed according to the following evaluation criteria, with a rating of 4 or more considered pass. The results are shown in Tables 3 and 4. 5: 8.0 kgf / 15 mm width or more 4: 6.0 kgf / 15 mm width or more, 8.0 kgf / 15 mm width or less 3: 4.0 kgf / 15 mm width or more, 6.0 kgf / 15 mm width or less 2: 2.0 kgf / 15 mm width or more, 4.0 kgf / 15 mm width or less 1:2.0kgf / less than 15mm width

[0061] [Adhesion test after retort processing] For the laminated metal materials prepared by lamination methods 1, 2, and 3, test specimens were cut into 150 mm x 15 mm pieces from the pressure-bonded metal plates and placed in an autoclave. They were then heat-treated in pressurized steam at 125°C for 30 minutes (retort treatment). The retort-treated test specimens were measured for peel strength (N / 15 mm width) when peeling off the film surface using a Tensilon tensile tester (LST-200N-S, manufactured by Minerva). The measurement results were evaluated as post-retort adhesion using the same criteria as for initial adhesion, with a score of 6.0 N or higher considered acceptable. Regarding lamination method 3, the same criteria were used for initial adhesion, with a score of 4 or higher considered acceptable. The results are shown in Tables 3 and 4.

[0062] [Detergent solution resistance test] Test pieces cut to 150 mm x 15 mm from the metal plates pressure-bonded using lamination method 1 were placed in a solution of commercial Charmy V (Lion Corporation) and stored at 60°C for 7 days. The test pieces were measured for peel strength (N / 15 mm width) when peeling off the film surface using a Tensilon tensile tester (LST-200N-S, manufactured by Minerva). The measurement results were used to evaluate detergent solution resistance using the same evaluation criteria as for initial adhesion, with a score of fair or better considered a pass. The results are shown in Tables 3 and 4. ○: 6.0N / 15mm width or more △: 4.0N / 15mm width or more, 6.0N / less than 15mm width ×: 4.0N / less than 15mm width

[0063] [Adhesion test after water immersion] Test pieces of 150 mm x 15 mm were cut from the metal plates pressure-bonded using lamination methods 2 and 4 and stored in pure water for 7 days. The test pieces were measured for peel strength (N / 15 mm width) when peeling off the film surface using a Tensilon tensile tester (LST-200N-S, manufactured by Minerva). The measurement results were used as adhesion after water immersion and evaluated using the same criteria as for initial adhesion, with a strength of 8.0 N or more considered acceptable. The results are shown in Tables 3 and 4. 〇: 8.0N / 15mm width or more △: 4.0N / 15mm width or more, 8.0N / less than 15mm width ×: 4.0N / less than 15mm width

[0064] [Table 3]

[0065] [Table 4]

[0066] The results in Tables 3 and 4 show that the laminated metal materials in each example exhibited better adhesion compared to the laminated metal materials in the comparative examples.

Claims

1. a water-soluble metal compound (A); a water-soluble or water-dispersible acrylic resin (B); and a resin (C) which is a polyvinyl alcohol-based resin having a vinyl alcohol skeleton, the concentration of the water-soluble metal compound (A) is 100 to 100,000 ppm by mass in terms of metal atoms; the water-soluble or water-dispersible acrylic resin (B) has an acid value of solid content of 150 to 740 mgKOH / g and a hydroxyl value of solid content of 24 to 350 mgKOH / g; the sum of the concentration of the water-soluble or water-dispersible acrylic resin (B) and the concentration of the resin (C) is 200 to 200,000 ppm by mass in terms of solid content, a ratio (A / (B+C)) of the concentration of the water-soluble metal compound (A) in terms of metal atoms to the sum of the concentration of the water-soluble or water-dispersible acrylic resin (B) and the concentration of the resin (C) is 3 / 97 to 91 / 9.

2. A metal material, at least one surface of which has been treated with the metal surface treatment composition according to claim 1.

3. The water-soluble metal compound (A) is present in an amount of 0.8 to 3200 mg / m in terms of metal atom in terms of the film mass after drying per at least one of the surfaces. ２ Contains The water-soluble or water-dispersible acrylic resin (B) and the resin (C) are mixed in an amount of 1.0 to 4,000 mg / m in total in terms of solid content. ２ The metallic material according to claim 2 , which is formed with a coating containing the metal.

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