JP5089316B2 - Metal surface treatment composition, aluminum metal surface treatment method using this composition, and aluminum metal surface treatment substrate produced using this method - Google Patents

Description

  The present invention relates to a metal surface treatment composition used for surface treatment of an aluminum-based metal substrate, a method for surface treatment of an aluminum-based metal material substrate using the composition, and an aluminum-based metal produced using this method The present invention relates to a surface treatment substrate.

  Conventionally, in order to protect the surface of a metal material and apply a design, the surface of the metal substrate has been laminated or painted. Laminate films are often used as surface protective agents for metal substrates for packaging used in food cans and the like because of excellent molding processability, corrosion resistance, and barrier properties of contents.

  Here, the laminate film has the excellent characteristics as described above. On the other hand, in the metal material subjected to the lamination process, the adhesion between the metal substrate and the laminate film is not sufficient. In some cases, the laminate film may be peeled off from the metal base material when performing advanced processing as described above, or adding the contents to the processed packaging material and subjecting it to heat treatment. Such peeling of the laminate film from the metal substrate has been a major cause of reducing the aesthetics and corrosion resistance of the metal material.

  Therefore, in order to solve such a problem in a metal material subjected to lamination, a surface treatment layer is formed by a metal surface treatment composition on the surface of the metal substrate prior to lamination, and the laminate film and metal Improvement of adhesiveness with a base material is performed.

  On the other hand, when coating a metal substrate, surface treatment with a phosphate chromate surface treatment agent has been conventionally performed in order to improve the adhesion between the coating film formed of various paints and the metal substrate. It was. The phosphate chromate surface treatment layer formed with a phosphate chromate surface treatment agent is excellent in corrosion resistance and adhesion after coating various paints, so its uses are for building materials, home appliances, fin materials, car evaporators, beverage cans Etc. (for example, refer to Patent Document 1). However, the phosphoric acid chromate surface treatment agent has a difficulty in waste liquid treatment because it uses harmful chromium metal. For this reason, environment-friendly non-chromium metal surface treatment compositions are being developed in recent years.

  Here, Patent Document 2 discloses a water-soluble vanadium compound (A) and a titanium-based or zirconium-based water-soluble complex fluoride as a metal material base treatment agent, which is performed prior to laminating or coating with various paints. A surface treatment agent containing a chemical compound (B) and a resin (C) is disclosed. According to the invention described in Patent Document 2, it is said that a plate material excellent in corrosion resistance, a laminate film, or an adhesive film formed with a top coating can be provided with high productivity.

Patent Document 3 discloses a battery exterior aluminum laminate composition having a total thickness of 250 μm used for the exterior of the battery, and in the battery exterior aluminum laminate composition, from the inside, from an unstretched thermoplastic resin film. An innermost layer, a first adhesive layer made of a urethane-based adhesive, one or more inorganic elements selected from zirconium, titanium, zinc, chromium, and silicon, and a water-soluble acrylic resin film. A first surface treatment layer comprising: an aluminum foil layer comprising an aluminum alloy; a second surface treatment layer comprising the inorganic element resin film; a second adhesive layer comprising a urethane-based adhesive; and a stretched thermoplastic resin film. And the aluminum alloy has a predetermined composition, and the inorganic element is coated with the inorganic element in the inorganic element resin film. The amount is a predetermined amount of deposited aluminum laminate arrangement is disclosed for a battery exterior. The aluminum laminate composition for battery exterior described in Patent Document 3 is said to exhibit excellent moldability, gas barrier properties, heat seal properties, and electrolytic solution resistance.
JP-A-5-125555 JP 2002-060699 A Japanese Patent Laid-Open No. 2007-073402

  However, even if the surface treatment is performed on the aluminum-based metal material using the surface treatment agent described in Patent Document 2, the adhesion with the coating film formed by the laminate film or the top coating is still not sufficient. Further improvement of the surface treatment agent has been desired. In addition, the invention described in Patent Document 2 uses a titanium-based or zirconium-based water-soluble complex fluoride, and fluorine ions contained in the waste liquid and the like may give an environmental load. In order to remove ions, there was also a problem that the waste liquid treatment cost was increased.

  Moreover, in the aluminum laminate composition for battery exterior described in Patent Document 3, a surface treatment layer is formed on the upper layer of the aluminum foil, and an adhesive layer is formed on the upper layer of the surface treatment layer. There is a problem that the manufacturing process is complicated.

  The present invention has been made in view of the above problems, and is a metal surface treatment composition used for surface treatment of an aluminum-based metal substrate, which is formed on the aluminum-based metal substrate by a laminate film or various paints. In the case of forming a coating film, it is possible to ensure sufficient adhesion between the laminate film or the coating film and the aluminum-based metal substrate, and further does not contain fluorine ions, chromium ions, and organic solvents, An object of the present invention is to provide a metal surface treatment composition that can be applied to aluminum-based substrates for battery exteriors and food cans and has a low environmental impact.

  The present inventors are a metal surface treatment composition used for the surface treatment of an aluminum-based metal substrate, which is a basic zirconium compound and / or cerium compound, a carboxyl group-containing resin, an oxazoline group-containing acrylic resin, The present inventors have found that the adhesion and corrosion resistance between an aluminum-based metal substrate and a coating film formed from a laminate film or various paints can be improved when using a metal surface treatment composition containing the present invention. It was.

  Specifically, the present invention provides the following.

  (1) A metal surface treatment composition used for surface treatment of an aluminum-based metal substrate, comprising a basic zirconium compound and / or cerium compound, a carboxyl group-containing resin, and an oxazoline group-containing acrylic resin, Metal surface treatment composition containing no fluorine.

  (2) The metal surface treatment composition according to (1), wherein a mass ratio of the content of the carboxyl group-containing resin to the content of the oxazoline group-containing acrylic resin is 0.10 or more and 9 or less.

  (3) The metal surface treatment composition according to (1) or (2), wherein an acid value of the carboxyl group-containing resin is 300 mgKOH / g or more in terms of resin solid content.

  (4) Any of (1) to (3), wherein the basic zirconium compound is at least one selected from the group consisting of zirconium zirconium carbonate, basic zirconium sulfate, ammonium zirconium acetate, and tetraalkylammonium modified zirconium sol. A metal surface treatment composition according to claim 1.

  (5) The mass ratio of the total content of the carboxyl group-containing resin and the oxazoline group-containing acrylic resin to the total content of metal components in the basic zirconium compound and / or the cerium compound is 0.6 or more and 20 or less. The metal surface treatment composition according to any one of (1) to (4).

  (6) The metal surface treatment composition according to any one of (1) to (5), further comprising a thermally crosslinkable resin.

  (7) The metal surface treatment composition according to (6), wherein the thermally crosslinkable resin is a phenol resin and / or a melamine resin.

  (8) A surface treatment method for an aluminum-based metal substrate for forming a laminate film and / or a coating film, wherein (1) to (7) prior to the step of forming the laminate film and / or coating film The surface treatment method of the aluminum-type metal base material which performs the process which makes the metal surface treatment composition in any one of contact.

(9) The total content of zirconium and / or cerium derived from the basic zirconium compound and / or cerium compound is 5 mg / m ² or more and 200 mg / m ² or less in terms of metal element, and the carboxyl group-containing resin and An aluminum-based metal produced by the surface treatment method for an aluminum-based metal substrate according to (8), wherein a film having a total content of the oxazoline group-containing acrylic resin of 6 mg / m ² or more and 200 mg / m ² or less is formed. Surface treatment substrate.

  Since the metal surface treatment composition of the present invention contains a carboxyl group-containing resin and an oxazoline group-containing acrylic resin in addition to the basic zirconium compound and / or cerium compound, Adhesion and corrosion resistance with the coating film to be formed can be improved. Furthermore, since the metal surface treatment composition of the present invention does not contain fluorine ions, chromium ions, and organic solvents, the load on the environment is small, and the cost for waste liquid treatment can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail.

<Metal surface treatment composition>
The metal surface treatment composition of the present invention is a metal surface treatment composition used for the base treatment of an aluminum-based metal substrate, and includes a basic zirconium compound and / or cerium compound, a carboxyl group-containing resin, and an oxazoline group-containing acrylic. Resin. Furthermore, the metal surface treatment composition of this invention may contain the heat-crosslinkable resin, for example, a phenol resin and / or a melamine resin as needed.

[Basic zirconium compounds]
The basic zirconium compound contained in the metal surface treatment composition of the present invention is incorporated into the surface treatment layer together with the resin component described later, and acts as a film-forming component, and includes a carboxyl group, a hydroxyl group, And a functional group such as a methylol group binds to a zirconium ion to act as a crosslinking agent.

  Examples of the basic zirconium compound used in the present invention include basic zirconium compounds that are not fluorine-based zirconium compounds, such as ammonium zirconium carbonate, basic zirconium sulfate, potassium zirconium carbonate, and ammonium zirconium acetate; Organic modified zirconium sol such as ammonium modified zirconium sol can be used. Among these, it is preferable to use zirconium carbonate ammonium and tetraalkylammonium modified zirconium sol. Examples of the basic zirconium compound described above include “Zircozol AC-7” (zirconium carbonate, manufactured by Daiichi Rare Chemicals Co., Ltd.), “Zircozol AC-20” (zirconium ammonium carbonate, manufactured by Daiichi Rare Chemicals Co., Ltd.). "AZC" (ammonium zirconium carbonate, manufactured by Nippon Light Metal Co., Ltd.), "Bakote 20" (ammonium zirconium carbonate, manufactured by Nippon Light Metal Co., Ltd.), "Zirgel K" (potassium zirconium carbonate, manufactured by Nippon Light Metal Co., Ltd.), "Natrizirconium phosphate" ( Nippon Light Metal Co., Ltd.), “Nanouse ZR-40BL” (tetraalkylammonium modified zirconium sol, manufactured by Nissan Chemical Industries, Ltd.), “Nanouse ZR-30BS” (tetraalkylammonium modified zirconium sol, manufactured by Nissan Chemical Industries, Ltd.), “Nanouse Commercially available products such as “ZR-30BH” (tetraalkylammonium-modified zirconium sol, manufactured by Nissan Chemical Industries, Ltd.) may be used.

  The content of the basic zirconium compound in the metal surface treatment composition is preferably 100 ppm or more and 200,000 ppm or less, more preferably 1000 ppm or more and 20000 ppm or less in terms of zirconium element. When the content of the basic zirconium compound in terms of zirconium element is less than 100 ppm, the surface treatment layer containing a sufficient amount of zirconium cannot be formed, so that adhesion and corrosion resistance may be reduced. Even if it exceeds 200,000 ppm, the amount taken into the surface treatment layer does not increase any more, and further improvement in performance as a crosslinking agent cannot be expected.

[Cerium compound]
The cerium compound contained in the metal surface treatment composition of the present invention is incorporated into the surface treatment layer together with the resin component described later, and exhibits a corrosion prevention effect as a film-forming component, and the carboxyl group contained in the resin component is a cerium ion. By bonding, the carboxyl group-containing resin functions as a crosslinking agent.

  Examples of the cerium compound used in the present invention generally include cerium salts such as cerium organic acid salts and ammonium salts of acidic cerium. Further, a cerium oxide sol obtained by acid-denaturing or base-modifying cerium oxide to impart water dispersibility can also be used. Here, as the cerium salt, “cerium acetate” (manufactured by Daiichi Elemental Chemical Co., Ltd.), “first cerium ammonium nitrate” (manufactured by Chikamochi Pure Chemicals Co., Ltd.), “diammonium cerium nitrate” (manufactured by Chikamochi Pure Chemicals Co., Ltd.) Commercially available products such as “4 ammonium cerium nitrate” (manufactured by Chikamochi Pure Chemicals Co., Ltd.) and “ammonium cerium sulfate” (manufactured by Mitsuwa Chemicals) may also be used. Further, as the cerium oxide sol, “CESL-15N” (manufactured by Daiichi Kagaku Kagaku Kogyo Co., Ltd.), “Nidoral P-10” (manufactured by Taki Chemical Co., Ltd.), and “Nidoral U-15” (manufactured by Taki Chemical Co., Ltd.) Etc. may be used.

  The content of the cerium compound in the metal surface treatment composition is preferably 100 ppm or more and 200,000 ppm or less, more preferably 1000 ppm or more and 20000 ppm or less, and further preferably 1000 ppm or more and 10,000 ppm or less in terms of cerium element. It is particularly preferable that the amount be 1000 ppm or more and 5000 ppm or less. When the content of the cerium compound in terms of cerium element is less than 100 ppm, a surface treatment layer containing a sufficient amount of cerium cannot be formed, so that adhesion and corrosion resistance may be reduced. On the other hand, even if it exceeds 200,000 ppm, the amount taken into the surface treatment layer does not increase any more, and further improvement in performance as a crosslinking agent cannot be expected.

[Oxazoline group-containing acrylic resin]
The oxazoline group-containing acrylic resin contained in the metal surface treatment composition of the present invention forms a three-dimensional network structure by reacting and crosslinking the oxazoline group that this oxazoline group has with the carboxyl group of the carboxyl group-containing resin described later. The adhesion between the laminate film or various coating films and the metal substrate is improved.

  The oxazoline group-containing acrylic resin is not particularly limited as long as the main chain is an acrylic skeleton and has a plurality of oxazoline groups. As the oxazoline group-containing acrylic resin, commercially available ones can be used. For example, “Epocross WS300” (trade name, manufactured by Nippon Shokubai Co., Ltd.) “Epocross WS500” (trade name, manufactured by Nippon Shokubai Co., Ltd.), “Epocross WS700” (Trade name, manufactured by Nippon Shokubai Co., Ltd.) and “NK Linker FX” (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) can be used. The oxazoline value of the oxazoline group-containing acrylic resin is preferably 120 to 240. Outside these ranges, it becomes difficult to form the three-dimensional network structure formed by the oxazoline group together with the carboxyl group of the carboxyl group-containing resin described later.

  The content of the oxazoline group-containing acrylic resin in the metal surface treatment composition of the present invention is preferably 10% by mass to 90% by mass and more preferably 20% by mass to 80% by mass per resin solid content. Further preferred. If the content of the oxazoline group-containing acrylic resin is less than 10% by mass, the content of the oxazoline group is not sufficient, so that the adhesion between the laminate film or coating film and the metal material may be reduced. Since the content of the carboxyl group-containing resin described later decreases, a sufficient crosslinking effect cannot be obtained, and adhesion between the laminate film or various coating films and the metal substrate cannot be obtained.

[Carboxyl group-containing resin]
The carboxyl group-containing resin is a polymer obtained by polymerizing a monomer having an ethylenically unsaturated double bond, and a resin having a plurality of carboxyl groups can be used. Such resins include, as monomers, polymers obtained by radical polymerization of acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, etc., and these monomers and other ethylenic polymers. A copolymer obtained by radical polymerization of a saturated monomer can be used. Although it does not specifically limit as an ethylenically unsaturated monomer which can be used as a monomer, For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl ( Ethylenically unsaturated monomers containing hydroxyl groups such as meth) acrylate, allyl alcohol, methacryl alcohol, and adducts of 2-hydroxyethyl (meth) acrylate and ε-caprolactone; having carboxyl groups such as half amide and half thioester Ethylenically unsaturated monomers; (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dibutyl (meth) acrylamide, N, N-dioctyl (meth) acrylamide, N - Ethylenically unsaturated monomers containing amide groups such as butyl (meth) acrylamide and N-monooctyl (meth) acrylamide; methyl (meth) acrylate, ethyl (meth) acrylate, 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 dihydro (Meth) acrylate ester monomers such as dicyclopentadienyl (meth) acrylate; styrene, α-methylstyrene, vinyl ketone, t-butylstyrene, parachloro Polymerizable aromatic compounds such as tylene 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 butadiene and isoprene Mention may be made of other monomers such as dienes. In the present invention, a commercially available carboxyl group-containing resin may be used, such as “Aron A30” (polyammonium acrylate, manufactured by Toa Gosei Co., Ltd.), “Jurimer AC-10L” (polyacrylic acid, Nippon Pure Chemical Industries, Ltd.). , "PIA728" (polyitaconic acid, manufactured by Iwata Chemical Co., Ltd.) and "Aquaric HL580" (polyacrylic acid, manufactured by Nippon Shokubai Co., Ltd.) can be used.

  In the present invention, as the carboxyl group-containing resin, it is preferable to use a resin in which (meth) acrylic acid and (meth) acrylic acid derivatives are used in an amount of 50% by mass or more based on the entire monomer, It is more preferable to use a carboxyl group-containing acrylic resin that is an acrylic skeleton.

  The acid value of the carboxyl group-containing resin in the metal surface treatment composition of the present invention is 300 mgKOH in terms of resin solids from the viewpoint of maintaining reactivity with the oxazoline group-containing acrylic resin and the basic zirconium compound and / or cerium compound. / G or more is preferable. When the said acid value is less than 300 mgKOH / g, there exists a possibility that the reactivity of carboxyl group-containing resin may fall and adhesiveness and corrosion resistance may fall.

  In addition, the carboxyl group-containing resin in the metal surface treatment composition of the present invention is preferably neutralized with a basic neutralizing agent from the viewpoint of maintaining temporal stability when mixed with a basic zirconium compound. . In addition, when metal components such as sodium and potassium are used as the basic neutralizing agent, the salt formed from the carboxyl group and the basic neutralizing agent does not dissociate during the formation of the surface treatment layer by drying. The crosslinking reaction between the group-containing resin and the oxazoline group-containing acrylic resin and the crosslinking reaction between the carboxyl group-containing resin and the basic zirconium compound / cerium compound are inhibited. In order to avoid this, it is preferable to use volatile amine or ammonia as the basic neutralizing agent. As the volatile amine, monoethanolamine, methylethanolamine, dimethylethanolamine, trimethylamine, triethylamine, morpholine and the like can be used.

  The content of the carboxyl group-containing resin in the metal surface treatment composition of the present invention is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 80% by mass or less per resin solid content. preferable. If the content of the carboxyl group-containing resin is less than 10% by mass, a surface treatment layer that sufficiently contains the carboxyl group-containing resin cannot be formed, and the adhesion between the laminate film or coating film and the metal material may be reduced. When the content exceeds 90% by mass, the content of the oxazoline group-containing acrylic resin is decreased, so that a sufficient crosslinking effect cannot be obtained, and as a result, sufficient adhesion to a coating film or the like may not be obtained. .

  In the metal surface treatment composition of the present invention, the carboxyl group-containing resin preferably has a hydroxyl group from the viewpoint that the degree of crosslinking is improved particularly when a thermally crosslinkable resin is blended. The hydroxyl value in terms of solid content of the carboxyl group-containing resin is preferably 50 mgKOH / g or more, and more preferably 100 mgKOH / g or more.

[Mass ratio of content of carboxyl group-containing resin to content of oxazoline group-containing acrylic resin]
The mass ratio of the content of the carboxyl group-containing resin to the content of the oxazoline group-containing acrylic resin is preferably 0.1 or more and 9 or less, and more preferably 0.25 or more and 4 or less. By setting the mass ratio of the content of the oxazoline group-containing acrylic resin and the carboxyl group-containing resin within the above range, the content ratio of the oxazoline group and the carboxyl group in the surface treatment film can be maintained within a suitable range. The formation rate of the crosslinked structure by the group and the carboxyl group can be kept high. For this reason, the adhesiveness of an aluminum-type metal base material and a laminate film or various coating films can be kept favorable.

[Heat-crosslinkable resin]
The metal surface treatment composition of the present invention may contain a thermally crosslinkable resin as necessary. The heat-crosslinkable resin refers to a resin that is cured by being crosslinked by heating. Examples of the thermally crosslinkable resin include a phenol resin and a melamine resin.

(Phenolic resin)
Although it does not specifically limit as a phenol resin, For example, a resol type phenol resin can be used. When a resol type phenol resin is used, the phenolic hydroxyl group contained in the resole type phenol resin and the oxazoline group contained in the oxazoline group-containing acrylic resin form a cross-linked structure by heating, thereby forming a strong three-dimensional network. Since the structure is formed, the adhesion between the laminate film or various coating films and the metal substrate can be improved. As the resol type phenolic resin, commercially available products can be used. For example, “Shonol BRL141B” (trade name, manufactured by Showa Polymer Co., Ltd.), “Shonol BRL2854” (trade name, manufactured by Showa Polymer Co., Ltd.), "Shonol BRL120Z" (trade name, manufactured by Showa Polymer Co., Ltd.), "Resi Top PL-4012" (trade name, manufactured by Gunei Chemical Industry Co., Ltd.), and "Resi Top PL-6745" (trade name, Gunei Chemical Industry Co., Ltd.) Etc.) can be used.

  The phenol resin is preferably contained in an amount of 5% by mass or more and 40% by mass or less, more preferably 10% by mass or more and 30% by mass or less, based on the resin solid content. If the content of the phenolic resin is less than 5% by mass, a surface treatment layer containing a sufficient amount of the phenolic resin cannot be formed, so that the effect as a crosslinking agent cannot be sufficiently obtained. There is a possibility that the effect of improving adhesion and water resistance cannot be obtained. On the other hand, when the content of the phenol resin exceeds 40% by mass, the content of other resin components decreases, and the adhesion between the laminate film and the aluminum-based metal substrate decreases.

(Melamine resin)
The metal surface treatment composition of this invention may contain the melamine resin as needed. In the melamine resin, a methylol group or imino group reacts with a functional group such as a carboxyl group or a hydroxyl group contained in a carboxyl group-containing resin or an oxazoline group contained in an oxazoline group-containing acrylic resin to form a crosslinked structure. This contributes to the improvement of the adhesion between various coating films and laminate films and the metal substrate and the adhesion after the hot water treatment. Although it does not specifically limit as a melamine resin, For example, the water-soluble melamine resin which condensed melamine, formaldehyde, and a C1-C4 alkyl monoalcohol is preferable. Examples of the melamine resin include “Cymel 385” (non-volatile content 80%, manufactured by Mitsui Chemicals), “Nicarak MX-035” (non-volatile content 70%, manufactured by Sanwa Chemical Co., Ltd.), and “Nicarak MX-042”. (Non-volatile content 70%, manufactured by Sanwa Chemical Co., Ltd.) can be used.

  The melamine resin is preferably contained in an amount of 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 20% by mass or less, per resin solid content. When the content of the melamine resin is less than 5% by mass, a surface treatment layer containing a sufficient amount of melamine resin cannot be formed, so that a sufficient effect as a crosslinking agent cannot be obtained. There is a possibility that the effect of improving adhesion and water resistance cannot be obtained. On the other hand, when the content of the melamine resin exceeds 30% by mass, the self-crosslinking of the melamine resin proceeds, and the adhesion between the laminate film and the metal material may be reduced.

[Mass ratio of content of organic component to content of inorganic component]
In the metal surface treatment composition of the present invention, the mass ratio of the total content of the carboxyl group-containing resin and the oxazoline group-containing acrylic resin to the total content of the metal components of the basic zirconium compound and / or cerium compound is 0.00. It is preferably 6 or more and 20 or less. High adhesion after hydrothermal treatment by the mass ratio of the total content of carboxyl group-containing resin and oxazoline group-containing acrylic resin to the total content of basic zirconium compound and / or cerium compound And corrosion resistance can be provided. The mass ratio is more preferably 1 or more and 10 or less.

  Further, when the metal surface treatment composition of the present invention contains a phenol resin and / or a melamine resin, the carboxyl group-containing resin and the oxazoline group-containing acrylic resin with respect to the total content of the basic zirconium compound and / or the cerium compound, In addition, the mass ratio of the total content of the phenol resin and / or melamine resin is preferably 0.8 or more and 20 or less, and more preferably 1 or more and 10 or less.

  The metal surface treatment composition of the present invention does not contain fluorine ions. That is, the metal surface treatment composition of the present invention etches the surface of an aluminum-based metal substrate by combining a basic zirconium compound and / or cerium compound, an oxazoline group-containing acrylic resin, and a carboxyl group-containing resin. It is possible to maintain sufficient adhesion and corrosion resistance between the aluminum-based metal substrate and the laminate film or various coating films. The metal surface treatment composition of the present invention does not contain an organic solvent. Thus, by not containing fluorine ions, chromium ions or organic solvents, the surface treatment of the aluminum-based metal substrate can be performed while minimizing the influence on the environment.

<Aluminum metal base>
The metal surface treatment composition of the present invention is used for surface treatment of an aluminum-based metal substrate. The aluminum-based metal substrate to which the metal surface treatment composition of the present invention can be applied is not particularly limited as long as it is a metal substrate having at least a surface made of aluminum or an aluminum alloy. A-1050 material, A- Examples of conventionally known aluminum and aluminum alloys such as 1100, A-1N30, A-3004, A-3105, A-5021, A-5052, A-5182, and A-8079 Can do.

<Surface treatment method for aluminum-based metal substrate>
In the surface treatment method for an aluminum-based metal substrate of the present invention, the surface of the aluminum-based metal substrate is cleaned as necessary for the aluminum-based metal substrate, and the metal surface-treatment composition of the present invention is used. Surface treatment.

[Preprocessing]
When the metal surface treatment composition of the present invention is applied to an aluminum-based metal substrate, it is preferable to first clean the surface. As a washing method, washing with pure water, alkali washing, acid washing, or washing with a solvent can be appropriately combined. Moreover, it is good also as an alternative to chemical cleaning by heating the aluminum metal substrate to around 500 ° C. and volatilizing the organic contamination components.

  From the standpoint of hardness and the like, an aluminum base containing an aluminum alloy containing magnesium may be used. In this case, when performing alkali cleaning, the aluminum-based metal base after alkali cleaning is further acidified. It is preferable to wash. Thereby, the magnesium component localized on the surface of the aluminum-based metal substrate can be removed by alkali cleaning, and the adhesion and corrosion resistance between the aluminum-based metal substrate and the laminate film can be improved. From the viewpoint of hardness and the like, an aluminum-based metal base material using an aluminum alloy containing 0.5% by mass to 10% by mass, preferably 0.5% by mass to 6% by mass may be used. However, the amount of magnesium localized on the surface of the aluminum substrate is preferably 1.0% by mass or less.

  The method for pretreating the aluminum-based metal substrate is not particularly limited, and a conventionally known treatment method such as an immersion method or a spray method can be selected.

[surface treatment]
In the surface treatment method for an aluminum-based metal substrate of the present invention, the metal surface treatment composition of the present invention is brought into contact with the surface of the aluminum-based metal substrate that has been pretreated as necessary. The method for bringing the aluminum-based metal substrate into contact with the metal surface treatment composition is not particularly limited, and an immersion method, a spray method, a roll coating method, a bar coating method, a pouring treatment method, and the like are applied. be able to. Among these, the roll coat method and the bar coat method are particularly preferable because the wet coating amount can be strictly controlled.

<Aluminum-based metal surface treatment substrate>
The aluminum-based metal surface-treated substrate of the present invention is a treated substrate obtained by performing the above-described surface treatment method for an aluminum-based metal substrate.

Here, in the surface treatment layer in the aluminum-based metal surface treatment substrate, the total content of zirconium and / or cerium derived from the basic zirconium compound and / or cerium compound is 5 mg / m ² or more and 200 mg in terms of metal element. / M ² or less, preferably 10 mg / m ² or more and 100 mg / m ² or less. When the coating amount of the surface treatment layer is less than 5 mg / m ² , the content of zirconium and / or cerium contained in the surface treatment layer is not sufficient, and the adhesion and corrosion resistance may be reduced. When the coating amount of the surface treatment layer is more than 200 mg / m ² , the adhesion may be reduced due to the cohesive failure of the coating.

Moreover, in the surface treatment layer in the aluminum-based metal-treated substrate, the total content of the carboxyl group-containing resin and the oxazoline group-containing acrylic resin is preferably 6 mg / m ² or more and 200 mg / m ² or less, and 12 mg / m ^2. More preferably, it is 100 mg / m ² or less. When the coating amount of the surface treatment layer is less than 6 mg / m ² , the content of carboxyl group and oxazoline group contained in the surface treatment layer is not sufficient, so that the adhesion and corrosion resistance may be lowered. When the coating amount of the surface treatment layer is more than 200 mg / m ² , the adhesion may be reduced due to the cohesive failure of the coating.

In the present invention, the metal surface treatment composition described above is preferably applied to the aluminum metal substrate in 0.5 g / ^{m 2} or more 20 g / ^{m 2} or less of coating weight, 1 g / ^{m 2} or more 5g More preferably, it is applied to the aluminum-based metal substrate with an application amount of / m ² or less. Here, in the present invention, the concentration of each component in the metal surface treatment composition and the metal surface treatment composition are within the preferable concentration range described above in order to realize the value of the film amount in the aluminum-based metal treatment substrate. It is preferable to adjust the coating amount.

<Laminated film>
The laminate film that can be formed on the aluminum-based metal substrate subjected to the surface treatment method of the aluminum-based metal substrate of the present invention is not particularly limited, and is formed by processing such as a dry laminating method or an extrusion laminating method. Can be used. Film materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), polycarbonate (PC), triacetyl cellulose (TAC), polyvinyl chloride (PVC), polyester, polyolefin, and acrylic. And other thermoplastic resins.

<Coating film>
The coating film that can be formed on the aluminum-based metal substrate subjected to the surface treatment method for the aluminum-based metal substrate of the present invention is not particularly limited. For example, epoxy-based, polyester-based, acrylic-based, polyurethane-based In addition, a thermally crosslinkable or thermoplastic coating mainly composed of a resin component such as vinyl chloride can be used. In addition, as the form of paint, use a liquid paint diluted in a solvent such as an organic solvent, water, or a mixture of an organic solvent and water, a UV or EV curable paint that does not use a solvent, and a powder paint. Can do.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example at all. Unless otherwise specified, “parts” and “%” in Examples and Comparative Examples represent “parts by mass” and “% by mass”, respectively.

<Synthesis of carboxyl group-containing resin>
[Synthesis of Resin “A”]
775 parts by mass of ion-exchanged water was charged into a four-necked vessel equipped with a heating / stirring device, and the content liquid was heated to 80 ° C. while stirring and refluxing with nitrogen. Next, while performing heating, stirring and nitrogen reflux, a mixed monomer solution of 120 parts by mass of acrylic acid, 20 parts by mass of ethyl acrylate, and 60 parts by mass of 2-hydroxyethyl methacrylate; 1.6 parts by mass of ammonium persulfate; and ion exchange A mixture of 23.4 parts by mass of water was added dropwise over 3 hours using a dropping funnel. After completion of dropping, heating / stirring / nitrogen reflux was continued for 2 hours, then heating / nitrogen reflux was stopped, and the solution was cooled to 30 ° C. while stirring. Furthermore, after adding 113 mass parts of 25 mass% ammonia water and 887 mass parts of ion-exchange water, and stirring for 20 minutes, it filtered using a 200 mesh sieve, and obtained the aqueous solution of colorless and transparent carboxyl group containing resin "A". It was. The aqueous solution of the obtained resin “A” had a nonvolatile content of 10 mass%, an acid value in terms of solid content of the resin of 467 mgKOH / g, and a hydroxyl value in terms of resin solid content of 129 mgKOH / g.

[Synthesis of Resin “B”]
The monomer composition is 80 parts by mass of acrylic acid, 80 parts by mass of ethyl acrylate, and 40 parts by mass of methyl methacrylate, the addition amount of 25% by mass ammonia water added after cooling is 76 parts by mass, and the addition amount of ion exchange water is A colorless and transparent aqueous solution of a carboxyl group-containing resin “B” was obtained in the same procedure as the synthesis of the resin “A” except that the amount was 924 parts by mass. The aqueous solution of the obtained resin “B” had a nonvolatile content of 10% by mass and an acid value in terms of resin solid content of 311 mgKOH / g.

[Synthesis of Resin “C”]
The monomer composition is 60 parts by mass of acrylic acid, 100 parts by mass of ethyl acrylate, and 40 parts by mass of methyl methacrylate, the addition amount of 25% by mass ammonia water added after cooling is 56 parts by mass, and the addition amount of ion exchange water is A colorless and transparent aqueous solution of a carboxyl group-containing resin “C” was obtained in the same procedure as the synthesis of the resin “A” except that the amount was 944 parts by mass. The non-volatile content of the aqueous solution of the resin “C” was 10% by mass, and the acid value in terms of resin solid content was 233 mg KOH / g.

[Synthesis of Resin “D”]
775 parts by mass of ion-exchanged water was charged into a four-necked vessel equipped with a heating / stirring device, and the content liquid was heated to 80 ° C. while stirring and refluxing with nitrogen. Next, a mixed monomer solution of 40 parts by mass of acrylic acid, 120 parts by mass of ethyl acrylate, and 40 parts by mass of methyl methacrylate while heating, stirring, and refluxing with nitrogen; 1.6 parts by mass of ammonium persulfate; and ion-exchanged water 23 .4 parts by mass of the mixed solution was added dropwise using a separatory funnel over 3 hours. After completion of dropping, heating / stirring / nitrogen reflux was continued for 2 hours, then heating / nitrogen reflux was stopped, and the solution was cooled to 30 ° C. while stirring. Here, while the synthetic resin was being cooled in the vessel, the liquid became cloudy in the vicinity of about 50 ° C. Therefore, before cooling to 30 ° C., 38 parts by mass of 25% by mass ammonia water and 962 parts by mass of ion-exchanged water were added, and 30 ° C. The solution was cooled to 50 ° C. and filtered using a 200-mesh sieve to obtain an aqueous solution of a colorless and transparent carboxyl group-containing resin “D”. The nonvolatile content of the aqueous solution of the resin “D” was 10% by mass, and the acid value in terms of the resin solid content was 156 mgKOH / g.

<Example 1>
97.21 parts by mass of ion-exchanged water is placed in a stainless steel container equipped with a stirrer, and “Zircozol AC-7” (zirconium carbonate, containing 9.6% by mass in terms of zirconium metal) as a basic zirconium compound. 1.04 parts by mass, as a carboxyl group-containing resin, 1.5 parts by mass of an aqueous solution of a carboxyl group-containing resin “A” in terms of resin solids, and “Epocross WS-700” (effective) as an oxazoline group-containing acrylic resin A component containing 20% by mass, manufactured by Nippon Shokubai Co., Ltd.) was added in an amount of 0.25 parts by mass in terms of resin solid content while stirring to prepare a metal surface treatment composition having pH of 9.5. At this time, the content of the components in the obtained aqueous solution was 1000 ppm for the basic zirconium compound in terms of zirconium element, 1500 ppm for the carboxyl group-containing resin, and 500 ppm for the oxazoline group-containing acrylic resin.

An aluminum alloy material (A-3004: plate thickness 0.28 mm) cut into 30 cm × 20 cm was used at 60 ° C. with a 2% aqueous solution of “Surf Cleaner EC370” (alkaline detergent, manufactured by Nippon Paint Co., Ltd.). After spray cleaning for 2 seconds, the alkaline cleaning liquid remaining on the plate surface was washed away using industrial water. Subsequently, the 2 mass% sulfuric acid aqueous solution was used for spray cleaning at 45 ° C. for 2 seconds, and then the pickling solution remaining on the plate surface was washed away using industrial water. After spray cleaning with ion exchange water for 2 seconds, water was squeezed out with a rubber roll and dried at 80 ° C. for 10 seconds. Next, the metal surface treatment composition is applied by a bar coater so that the wet coating amount is 10 g / m ^2, and is dried for 30 seconds using an oven at a furnace temperature of 100 ° C. The surface treatment base material was obtained by performing the surface treatment.

  Here, with respect to the aluminum base material, (i) the base plate of the aluminum base material of A-3004 not performing the cleaning step, (ii) the aluminum base material subjected to only alkali cleaning and dried after water washing, iii) X-ray photoelectron analyzer “ESCA-3200” before the surface treatment with the metal surface treatment composition is performed on the aluminum substrate that has been dried by performing both the alkali washing and the acid washing described above. (Apparatus name, manufactured by Shimadzu Corporation) was used to measure the magnesium content localized on the surface of the aluminum substrate. The surface magnesium content of the aluminum base material is (i) 2.1% by mass for the aluminum base plate not subjected to the degreasing step, (ii) 10.6% by mass for the aluminum base material subjected to only alkaline degreasing, (iii) It was 0.9 mass% in the aluminum base material which performed both alkali degreasing and acid washing, and was dried.

<Example 2>
Except that 0.67 parts by mass of “Nanouse ZR-40BL” (tetraalkylammonium-modified zirconium sol, containing 14.8% by mass in terms of zirconium metal, manufactured by Nissan Chemical Industries, Ltd.) was used as the basic zirconium compound. In the same manner as in Example 1, a metal surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Example 3>
Example 1 except that 0.39 parts by mass of “diammonium cerium nitrate” (containing 25.5% by mass in terms of cerium metal, manufactured by Chikamochi Pure Chemicals) was used as a cerium compound without using a basic zirconium compound. In the same manner as in No. 1, a metal surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Example 4>
A point using 1.23 parts by mass of “Nidoral P-10” (cerium oxide sol dispersion, containing 8.1% by mass in terms of cerium metal, manufactured by Taki Chemical Co., Ltd.) as a cerium compound without using a basic zirconium compound. Except for this, a metal surface treatment composition was prepared in the same manner as in Example 1, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Example 5>
In the same manner as in Example 1, except that 0.34 parts by mass of “Nanouse ZR-40BL” was used as the basic zirconium compound and 0.62 parts by mass of “Nidoral P-10” was used as the cerium compound, the metal surface A treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Example 6>
A metal surface treatment composition was prepared in the same manner as in Example 2 except that the carboxyl group-containing resin “B” was used as the carboxyl group-containing resin, and the metal surface treatment composition was used to make an aluminum substrate. Surface treatment was performed to obtain an aluminum surface-treated substrate.

<Example 7>
A metal surface treatment composition was prepared in the same manner as in Example 2 except that the carboxyl group-containing resin “C” was used as the carboxyl group-containing resin, and an aluminum substrate was prepared using this metal surface treatment composition. Surface treatment was performed to obtain an aluminum surface-treated substrate.

<Example 8>
A metal surface treatment composition was prepared in the same manner as in Example 2 except that the carboxyl group-containing resin “D” was used as the carboxyl group-containing resin, and the metal surface treatment composition was used to make an aluminum substrate. Surface treatment was performed to obtain an aluminum surface-treated substrate.

<Example 9>
Except that 0.50 parts by mass of “Aron A-30” (polyammonium acrylate, nonvolatile content 30% by mass, manufactured by Toa Gosei Co., Ltd.) was used as the carboxyl group-containing resin, A metal surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Example 10>
Implementation was performed except that 0.62 parts by mass of “Nidoral P-10” was used as a cerium compound and 0.50 parts by mass of “Aron A-30” was used as a carboxyl group-containing resin without using a basic zirconium compound. In the same manner as in Example 1, a metal surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Examples 11 to 23>
A metal surface treatment composition was prepared in the same manner as in Example 1 except that the content concentration of each material used in Example 1 was changed to the concentration described in Table 1, and this metal surface treatment composition was used. Then, the surface treatment of the aluminum substrate was performed to obtain an aluminum surface treatment substrate.

<Examples 24-29>
A metal surface treatment composition was prepared in the same manner as in Example 3 except that the content concentration of each material used in Example 3 was changed to the concentration shown in Table 1, and this metal surface treatment composition was used. Then, the surface treatment of the aluminum substrate was performed to obtain an aluminum surface treatment substrate.

<Example 30>
In the step of cleaning the aluminum substrate used in Example 2, the surface of the aluminum substrate was subjected to surface treatment by the same method as in Example 2 except that acid cleaning with sulfuric acid was not performed after alkali cleaning. An aluminum surface-treated substrate was used.

<Example 31>
As a basic zirconium compound, 0.34 parts by mass of “Nanouse ZR-40BL”, as a carboxyl group-containing resin, 1.425 parts by mass of a carboxyl group-containing resin “A”, and as an oxazoline group-containing acrylic resin, “Epocross WS-700” As in Example 30, except that 0.2375 parts by mass and 0.0222 parts by mass of “Shonol BRL141B” (active ingredient 45% by mass, manufactured by Showa Polymer Co., Ltd.) were used as the phenol resin. A metal surface treatment composition was prepared, and using this metal surface treatment composition, an aluminum substrate was subjected to a surface treatment to obtain an aluminum surface treatment substrate.

<Examples 32 and 33>
A metal surface treatment composition was prepared in the same manner as in Example 31 except that the concentration of each material used in Example 31 was changed to the concentration shown in Table 1, and aluminum was prepared using this metal surface treatment composition. The substrate was surface treated to obtain an aluminum surface-treated substrate.

<Example 34>
As a basic zirconium compound, 0.34 parts by mass of “Nanouse ZR-40BL”, as a carboxyl group-containing resin, 1.425 parts by mass of a carboxyl group-containing resin “A”, and as an oxazoline group-containing acrylic resin, “Epocross WS-700” Metal surface treatment was carried out in the same manner as in Example 30, except that 0.2375 parts by mass and 0.0125 parts by mass of “Cymel 385” (nonvolatile content: 80% by mass, manufactured by Mitsui Chemicals) were used as the melamine resin. A composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface-treated substrate.

<Examples 35 and 36>
A metal surface treatment composition was prepared in the same manner as in Example 34 except that the content concentration of each material used in Example 34 was changed to the concentration shown in Table 1, and this metal surface treatment composition was used. Then, the surface treatment of the aluminum substrate was performed to obtain an aluminum surface treatment substrate.

<Example 37>
As a basic zirconium compound, 0.34 parts by mass of “Nanouse ZR-40BL”, as a carboxyl group-containing resin, 1.425 parts by mass of a carboxyl group-containing resin “A”, and as an oxazoline group-containing acrylic resin, “Epocross WS-700” In the same manner as in Example 30, except that 0.2375 parts by mass, 0.0111 parts by mass of “Shonol BRL141B” as the phenol resin, and 0.0063 parts by mass of “Cymel 385” as the melamine resin were used. A surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Example 38>
The metal surface treatment composition was the same as in Example 30, except that the aluminum substrate used in Example 30 was changed to an aluminum A-1100 substrate (plate thickness of 0.11 mm) substantially free of magnesium. An aluminum substrate was surface-treated using this metal surface treatment composition to obtain an aluminum surface-treated substrate.

<Example 39>
Instead of the aluminum base material used in Example 3, an aluminum A-8079 base material (thickness 0.08 mm) annealed at 500 ° C. to volatilize organic components was used to perform alkaline degreasing and sulfuric acid pickling. Except for the points not described above, a metal surface treatment composition was prepared in the same manner as in Example 3, and the surface treatment of the aluminum substrate was performed using the metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Comparative Example 1>
As the carboxyl group-containing resin used in Example 1, an aqueous solution of the carboxyl group-containing resin “A” was used in an amount of 2.0 parts by mass in terms of resin solid content, except that the oxazoline group-containing acrylic resin was not used. In the same manner as in Example 1, a metal surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Comparative example 2>
A metal surface treatment composition was prepared in the same manner as in Example 1 except that the carboxyl group-containing resin used in Example 1 was not used and the content of the oxazoline group-containing acrylic resin was 1 part by mass. The surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Comparative Example 3>
As the carboxyl group-containing resin used in Example 3, the aqueous solution of the carboxyl group-containing resin “A” is 2.0 parts by mass in terms of resin solid content, and the example is the same as the example except that the oxazoline group-containing acrylic resin is not used. In the same manner as in No. 1, a metal surface treatment composition was prepared, and the surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Comparative example 4>
A metal surface treatment composition was prepared in the same manner as in Example 3 except that the carboxyl group-containing resin used in Example 3 was not used and the content of the oxazoline group-containing acrylic resin was 1 part by mass. The surface treatment of the aluminum substrate was performed using this metal surface treatment composition to obtain an aluminum surface treatment substrate.

<Comparative Example 5>
A metal surface treatment composition was prepared in the same manner as in Example 1 except that neither a basic zirconium compound nor a cerium compound was used, and the surface treatment of an aluminum substrate was performed using this metal surface treatment composition. To obtain an aluminum surface-treated substrate.

<Evaluation>
[T-peel adhesion test of laminate film]
Two aluminum surface-treated substrates manufactured in each Example and each Comparative Example were cut into a size of 150 mm × 5 mm, and a PET film having a thickness of 15 μm cut into a size of 100 mm × 5 mm was sandwiched therebetween, and 245 ° C. Was thermocompression bonded at 7 kgf / m ² for 15 seconds. This test piece was heat treated with steam at 125 ° C. for 30 minutes and then peeled off at a peeling speed of 40 mm / min using a desktop tensile tester “TENSILON UTM-II-20” (trade name, manufactured by Toyo Baldwin). Intensity measurements were taken. ○ Based on the above, the results were accepted. The results of peel strength are shown in Tables 3 and 4.
◎: Tensile strength exceeding 1.5 kgf / 5 mm ○: Tensile strength 1.0 kgf / 5 mm to less than 1.5 kgf / 5 mm Δ: Tensile strength 0.5 kgf / 5 mm to less than 1.0 kgf / 5 mm ×: Tensile strength 0.5 kgf / Less than 5mm

[Water resistance of water-based paints]
Using a reverse coater, “Can liner 100” (epoxy-based water-based paint, non-volatile content 30% by mass, manufactured by Nippon Paint Co., Ltd.) was wetted on one side of the aluminum surface-treated substrate produced in each Example and each Comparative Example. Apply the coating amount to 15 g / m ^2, and bake for 30 seconds at a raw material temperature of 250 ° C. using a conveyor oven, to form an aqueous paint-coated aluminum base material with a dry coating weight of 4.5 g / m ² Obtained. This water-based paint-coated aluminum base material was cut out to 150 mm × 70 mm and a cross cut was formed at the center of the painted surface, and then a salt spray resistance test (JIS K.5600.7.1) was performed. After conducting the salt water exposure test for 500 hours, the corrosion length (mm) from the cut portion was measured. ○ Based on the above, the results were accepted. The results of the corrosion length are shown in Tables 3 and 4.
◎: Corrosion length less than 0.5 mm ○: Corrosion length 0.5 mm or more and less than 1 mm △: Corrosion length 1 mm or more and less than 2 mm ×: Corrosion length 2 mm or more

Claims (9)

A metal surface treatment composition used for surface treatment of an aluminum-based metal substrate,
A basic zirconium compound and / or a cerium compound;
A carboxyl group-containing resin;
An oxazoline group-containing acrylic resin, and a metal surface treatment composition containing no fluorine.   The metal surface treatment composition of Claim 1 whose mass ratio of content of the said carboxyl group-containing resin with respect to content of the said oxazoline group-containing acrylic resin is 0.10-9.   The metal surface treatment composition of Claim 1 or 2 whose acid value of the said carboxyl group-containing resin is 300 mgKOH / g or more in conversion of resin solid content.   The metal according to any one of claims 1 to 3, wherein the basic zirconium compound is at least one selected from the group consisting of ammonium zirconium carbonate, basic zirconium sulfate, zirconium ammonium acetate, and tetraalkylammonium-modified zirconium sol. Surface treatment composition.   The mass ratio of the total content of the carboxyl group-containing resin and the oxazoline group-containing acrylic resin to the total content of metal components in the basic zirconium compound and / or the cerium compound is 0.6 or more and 20 or less. The metal surface treatment composition according to any one of claims 1 to 4.   Furthermore, the metal surface treatment composition in any one of Claim 1 to 5 containing a heat crosslinkable resin.   The metal surface treatment composition according to claim 6, wherein the thermally crosslinkable resin is a phenol resin and / or a melamine resin.   It is a surface treatment method of the aluminum-type metal base material for formation of a laminate film and / or a coating film, Comprising: Prior to the process of forming the said laminate film and / or coating film, it is in any one of Claim 1 to 7 The surface treatment method of the aluminum-type metal base material which performs the process which makes the metal surface treatment composition contact. The total content of zirconium and / or cerium derived from the basic zirconium compound and / or cerium compound is 5 mg / m ² or more and 200 mg / m ² or less in terms of metal element, and the carboxyl group-containing resin and the oxazoline group The aluminum-based metal surface treatment group produced by the surface treatment method for an aluminum-based metal substrate according to claim 8, wherein a film having a total content of the containing acrylic resin of 6 mg / m ² or more and 200 mg / m ² or less is formed. Wood.