Aluminum-based metal material with chemical conversion coating, chemical conversion treatment liquid for aluminum-based metal material, and surface treatment method for aluminum-based metal material

Abstract

Provided is an aluminum-based metal material with a chemical conversion coating film, which has excellent corrosion resistance not only in a neutral environment, but also in an acidic environment and an environment containing Cu. Provided is an aluminum-based metal material with a chemical conversion coating film, the aluminum-based metal material having, on the surface thereof, a chemical conversion coating film containing 1 mg / m2 to 160 mg / m2 of at least one metal element (A) selected from the group consisting of Zr, Ti and V, 5 mg / m2 to 50 mg / m2 of Cr element (B) of non-hexavalent Cr, and 6 mg / m2 to 100 mg / m2 of C element, the mass ratio (A / B) of the metal element (A) to the Cr element (B) of non-hexavalent Cr being 1.45 to 5.0, and the mass ratio (C / B) of the element C to the element Cr (B) of the non-hexavalent Cr is 0.15-7.2.

Description

Technical Field

[0001] This invention relates to aluminum-based metal materials with chemical conversion coatings, chemical conversion treatment solutions for aluminum-based metal materials, and surface treatment methods for aluminum-based metal materials. Background Technology

[0002] In a wide range of fields such as aircraft materials, building materials, and automotive parts, chemical conversion treatment solutions have been used in the past to develop metal materials containing trivalent chromium.

[0003] For example, Patent Document 1 discloses a chemical conversion treatment liquid for metallic materials, which contains a component (A) comprising a water-soluble trivalent chromium compound, a component (B) comprising at least one selected from water-soluble titanium compound and water-soluble zirconium compound, a component (C) comprising a water-soluble nitrate compound, a component (D) comprising a water-soluble aluminum compound, and a component (E) comprising a fluorine compound.

[0004] Patent document 2 discloses a chemical conversion treatment liquid for metallic materials, which contains a specified amount of a specific trivalent chromium compound, a specific zirconium compound, and a specific dicarboxylic acid compound.

[0005] Patent document 3 discloses a chemical conversion treatment liquid for metallic materials, which contains a specified amount of a specific trivalent chromium compound, a specific zirconium compound, a specific phenolic compound, and a fluorine-containing compound. Existing technical documents

[0006] Patent documents Patent Document 1: Japanese Patent Application Publication No. 2006-328501 Patent Document 2: Japanese Patent Application Publication No. 2006-316334 Patent Document 3: International Publication No. 2019 / 131436 Summary of the Invention The problem that the invention aims to solve

[0007] However, while the chemical conversion treatment solutions for metal materials in Patent Documents 1-3 can form a chemical conversion film with excellent corrosion resistance in a neutral environment on aluminum-based metal materials, it is difficult to form a chemical conversion film with excellent corrosion resistance in acidic environments and Cu-containing environments.

[0008] In view of the above, in one embodiment, the object of the present invention is to provide an aluminum-based metal material with a chemical conversion coating that exhibits excellent corrosion resistance not only in neutral environments but also in acidic environments and environments containing Cu. In another embodiment, the object of the present invention is to provide a chemical conversion treatment solution for aluminum-based metal materials suitable for obtaining the aforementioned aluminum-based metal material with a chemical conversion coating. In yet another embodiment, the object of the present invention is to provide a surface treatment method for aluminum-based metal materials using the aforementioned chemical conversion treatment solution for aluminum-based metal materials. means for solving problems

[0009] Through dedicated research, the inventors discovered that the above-mentioned problems can be solved by forming a chemical conversion film containing a specified amount of a specified component on the surface of an aluminum-based metal material, thus completing the present invention.

[0010] That is, the present invention is illustrated below. [Option 1] An aluminum-based metal material with a chemical conversion coating, wherein the surface of the aluminum-based metal material has a content of 1 mg / m 2 ~160mg / m 2 The element selected is at least one metallic element (A) from the group consisting of Zr, Ti, and V, and 5 mg / m 2 ~50mg / m 2 Non-hexavalent Cr element (B) and 6 mg / m 2 ~100mg / m 2 The chemical conversion coating of element C is used, wherein the mass ratio (A / B) of the metal element (A) to the non-hexavalent Cr element (B) is 1.45 to 5.0, and the mass ratio (C / B) of the C element to the non-hexavalent Cr element (B) is 0.15 to 7.2. [Option 2] The aluminum-based metal material with a chemical conversion coating as described in Scheme 1, wherein the C element of the chemical conversion coating is derived from a polymer having a carbonyl group. [Option 3] An aluminum-based metal material with a chemical conversion coating as described in Scheme 1 or 2, wherein the chemical conversion coating contains the element F. [Option 4] The aluminum-based metal material with a chemical conversion coating as described in any one of Schemes 1 to 3, wherein, in the luminescence intensity analysis performed using a Markus-type high-frequency glow discharge surface analysis apparatus (GD-OES), when the depth range within 20 nm from the outermost surface is defined as the surface side, and the depth range where the Al intensity first reaches less than 5 times the average Al intensity in the depth range from the outermost surface to 5 nm is defined as the substrate side, C and O elements exhibit maximum strength on the surface side, and at least one element selected from the metal element (A) and the non-hexavalent Cr element (B) exhibits maximum strength on the substrate side. [Option 5] A chemical conversion treatment liquid for aluminum-based metal materials, wherein the chemical conversion treatment liquid for aluminum-based metal materials comprises at least one metal compound (a) selected from the group consisting of zirconium compounds, titanium compounds and vanadium compounds, a trivalent chromium compound (b), a polymer having a carbonyl group (C), and a fluorine-containing compound (D). [Option 6] The chemical conversion treatment solution for aluminum-based metal materials as described in Scheme 5, wherein the mass ratio (A / B) of at least one metal element (A) selected from the group consisting of Zr, Ti and V to the non-hexavalent Cr element (B) is 0.6 to 7.0, and the mass ratio (C / B) of C element to the non-hexavalent Cr element (B) is 0.5 to 20. [Option 7] The chemical conversion treatment solution for aluminum-based metal materials as described in Scheme 5 or 6, wherein the mass ratio (X / Y) of the polymer (C) having carbonyl groups to the total mass (Y) of Zr, Ti, V and Cr is 0.50 to 2.80. [Option 8] A surface treatment method for an aluminum-based metal material, wherein the surface treatment method for the aluminum-based metal material includes the following steps: Step (i), wherein the aluminum-based metal material is contacted with the chemical conversion treatment solution of the aluminum-based metal material described in any one of Schemes 5 to 7 for at least 60 seconds; and Step (ii), wherein, after step (i), the aluminum-based metal material is washed with water. [Option 9] The surface treatment method for aluminum-based metal materials as described in Scheme 8, wherein in step (i), the contact time between the aluminum-based metal material and the aluminum-based metal material chemical conversion treatment solution is 60 seconds to 600 seconds. Invention Effects

[0011] According to one embodiment of the present invention, an aluminum-based metal material with a chemical conversion coating exhibiting excellent corrosion resistance not only in neutral environments but also in acidic environments and environments containing Cu can be obtained. According to another embodiment of the present invention, a chemical conversion treatment solution for aluminum-based metal materials suitable for obtaining the aforementioned aluminum-based metal material with the chemical conversion coating can be obtained. According to yet another embodiment of the present invention, a surface treatment method for aluminum-based metal materials using the aforementioned chemical conversion treatment solution for aluminum-based metal materials can be obtained. Attached Figure Description

[0012] Figure 1 This is an example of the luminescence intensity distribution map of each element obtained when performing depth-direction analysis using GD-OES. Detailed Implementation

[0013] The embodiments of the present invention will be described below. It should be noted that in the present invention, the description of "X to Y" representing a numerical range means "X or more and Y or less".

[0014] <<1. Aluminum-based metal materials with chemical conversion coatings>> (Aluminum-based metal materials) As one embodiment of the present invention, the aluminum-based metal material is not particularly limited, and pure aluminum materials, aluminum alloy materials, etc., can be used. Examples of aluminum alloy materials include Al-Cu, Al-Si, Al-Mg, Al-Zn, Al-Si-Cu, Al-Si-Mg, Al-Co-Cu, Al-Mn-Mg, Al-Mn-Fe, and Al-Mn-Zn-Fe-Mg systems. The aluminum-based metal material can be used as a single substance or as a composite material combined with other metals, ceramics, etc.

[0015] (Choose at least one metallic element (A) from the group consisting of Zr, Ti and V) In one embodiment of the present invention, the chemical conversion coating comprises at least one metallic element (A) selected from the group consisting of Zr (zirconium), Ti (titanium) and V (vanadium). The content of metal element (A) in the chemically converted film is 1 mg / m³. 2 ~160mg / m 2 Preferably 5mg / m 2 ~160mg / m 2 More preferably 10 mg / m 2 ~160mg / m 2 More preferably 20 mg / m 2 ~160mg / m 2In cases where the chemically converted film contains two or more metal elements (A), the total content of these metal elements (A) is taken as the content of metal element (A). When the content of metal element (A) is less than 1 mg / m³... 2 In cases where the content of metallic element (A) exceeds 160 mg / m³, sufficient corrosion resistance cannot be obtained. 2 In such cases, costs increase.

[0016] In one embodiment of the present invention, there is no particular limitation on the compound form of the metal element (A) contained in the chemical conversion coating. Regarding the metal element (A) in the chemical conversion coating, it may be a metal compound (a) contained in the chemical conversion treatment solution for aluminum-based metal materials described later, which is directly incorporated into the chemical conversion coating, or the metal compound (a) may be incorporated into the chemical conversion coating after being transformed into other compound forms (oxides, etc.) through a chemical conversion reaction with the aluminum-based metal material.

[0017] (Cr element (B) that is not hexavalent) In one embodiment of the present invention, the chemical conversion coating contains non-hexavalent Cr (chromium) element (B). The content of non-hexavalent Cr (B) in the chemically converted film was 5 mg / m³. 2 ~50mg / m 2 Preferably 10 mg / m 2 ~50mg / m 2 More preferably 15 mg / m 2 ~50mg / m 2 More preferably 20 mg / m 2 ~50mg / m 2 The content of non-hexavalent Cr (B) is less than 5 mg / m³. 2 In such cases, sufficient corrosion resistance cannot be obtained when the content of non-hexavalent Cr (B) exceeds 50 mg / m³. 2 In such cases, costs increase.

[0018] In one embodiment of the present invention, there is no particular limitation on the compound form of the non-hexavalent Cr element (B) contained in the chemical conversion coating. Regarding the non-hexavalent Cr element (B) in the chemical conversion coating, it can be a trivalent chromium compound (b) contained in the chemical conversion treatment solution for aluminum-based metal materials (described later) directly incorporated into the chemical conversion coating, or it can be a trivalent chromium compound (b) that has undergone a chemical conversion reaction with the aluminum-based metal material to transform into other compound forms (oxides, etc.) before being incorporated into the chemical conversion coating.

[0019] It should be noted that, although hexavalent Cr may be included in the chemical conversion coating in one embodiment of the present invention without compromising the target effect of the present invention, it is preferable not to include hexavalent Cr in consideration of the environmental impact.

[0020] (Element C) In one embodiment of the present invention, the chemical conversion coating contains carbon (C) element. The C element content in the chemical conversion coating is 6 mg / m³. 2 ~100mg / m 2 Preferably 10 mg / m 2 ~100mg / m 2 More preferably 15 mg / m 2 ~100mg / m 2 More preferably 20 mg / m 2 ~100mg / m 2 When the C element content is below 6 mg / m³ 2 In cases where the C element content exceeds 100 mg / m³, sufficient corrosion resistance cannot be obtained. 2 In such cases, costs increase.

[0021] The source of element C is not particularly limited, but it is preferably derived from polymers (C) containing a carbonyl group. As for polymers (C) containing a carbonyl group, there are no particular restrictions as long as the polymer has a carbonyl group in its structure. More specifically, examples of functional groups containing a carbonyl group include: amide groups, urethane groups, carboxyl groups, acryloyl groups, ester groups, etc. Examples of polymers (C) containing a carbonyl group include: polyesters, polyacrylamide, polyurethanes, polyacrylic acid, polyacrylates, etc. Regarding polymers (C) containing a carbonyl group, the chemical conversion coating may contain only one type or more types.

[0022] In one embodiment of the present invention, the carbonyl polymer (C) in the chemical conversion coating can be a carbonyl polymer (C) contained in the chemical conversion treatment solution for aluminum-based metal materials described later, which can be directly incorporated into the chemical conversion coating. Alternatively, the carbonyl polymer (C) can form a complex with the metal compounds and chromium compounds in the chemical conversion treatment solution for aluminum-based metal materials, and co-deposit with the metal compounds and chromium compounds through contact with the aluminum-based metal materials.

[0023] Corrosion resistance can be improved by appropriately adjusting the mass ratio (A / B) of metallic element (A) to non-hexavalent Cr element (B). Specifically, the mass ratio (A / B) of metallic element (A) to non-hexavalent Cr element (B) is preferably 1.45 to 5.0, more preferably 1.45 to 4.2, and even more preferably 1.45 to 3.64. When the chemical conversion coating contains two or more metallic elements (A), A / B is calculated based on their total content.

[0024] Corrosion resistance can be improved by appropriately adjusting the mass ratio (C / B) of carbon (C) to non-hexavalent chromium (B). Specifically, the mass ratio (C / B) of carbon (C) to non-hexavalent chromium (B) is preferably 0.15 to 7.2, more preferably 0.5 to 7.2, and even more preferably 1.35 to 7.2.

[0025] In one embodiment of the invention, the chemical conversion coating contains fluorine (F). The presence of F can be confirmed by fluorescence X-ray analysis. From the viewpoint of corrosion resistance, the inclusion of fluorine (F) in the chemical conversion coating is preferred.

[0026] In one embodiment of the present invention, the thickness of the chemical conversion coating is not particularly limited, but is preferably 10 nm to 600 nm, and more preferably 30 nm to 600 nm.

[0027] In one embodiment of the present invention, the chemical conversion coating contains a predetermined amount of each of the aforementioned coating components, and there is no particular limitation on the distribution of each coating component in the depth direction. In the depth direction luminescence intensity analysis performed using a Markus-type high-frequency glow discharge luminescence surface analysis device (GD-OES), when C and O elements are enriched on the surface side, and at least one, preferably two or more, selected from metallic elements (A) and non-hexavalent Cr elements (B) are enriched on the substrate side (hereinafter referred to as "gradient structure of chemical conversion coating"), corrosion resistance can be improved compared to other cases where this is not the case, and is therefore preferred.

[0028] Here, "surface side" refers to the depth range within 20 nm of the outermost surface of the chemically converted coating in the luminescence intensity distribution map of each element obtained during depth-direction analysis using a Markus-type high-frequency glow discharge surface analysis device (GD-OES). "Substrate side" refers to the depth range where the Al intensity first reaches less than 5 times the average Al intensity from the outermost surface to 5 nm of the chemically converted coating as measured by GD-OES. "Enrichment" refers to the location where the intensity of each coating component, measured by GD-OES, shows its maximum value within the measurement range. Figure 1The diagram shows an example of the luminescence intensity distribution of each element obtained using GD-OES for depth orientation analysis. In this specification, the depth obtained using GD-OES is a value calculated based on the sputtering rate of Si. Specifically, sputtering conditions with a sputtering rate of 40 nm / s for Si are predetermined, and depth orientation analysis is performed using GD-OES under these sputtering conditions, converting the sputtering time into depth.

[0029] The gradient structure of the chemical conversion coating is formed, for example, by contacting an aluminum-based metal material comprising at least one metal compound (a) selected from the group consisting of zirconium compounds, titanium compounds and vanadium compounds, a trivalent chromium compound (b), a polymer having a carbonyl group (C) and a fluorine-containing compound (D) with a chemical conversion treatment solution for more than 60 seconds, and then washing the aluminum-based metal material with water.

[0030] <<2. Chemical Conversion Treatment Solution for Aluminum-Based Metal Materials>> (Select at least one metallic compound (a) from the group consisting of zirconium compounds, titanium compounds and vanadium compounds) In one embodiment of the present invention, the chemical conversion treatment solution for aluminum-based metal materials contains at least one metal compound (a) selected from the group consisting of zirconium compounds, titanium compounds, and vanadium compounds. One metal compound (a) may be used, or two or more may be used in combination.

[0031] Examples of zirconium compounds include zirconium tetrapropoxide, hexafluorozirconic acid, zirconium nitrate, zirconium oxynitrate, zirconium carbonate, zirconium hydroxide, and zirconium oxide. Zirconium compounds can exist as zirconium ions in chemical conversion treatment solutions for aluminum-based metal materials. Examples of zirconium ions include zirconium metal ions, zirconium-containing complex ions, and zirconium oxide ions. Examples of zirconium-containing complex ions include ammonium hexafluorozirconate, zirconium tetrafluoride, ammonium trifluorozirconate, and hexafluorozirconate salts.

[0032] Examples of titanium compounds include titanium tetrapropoxide, hexafluorotitanic acid, titanium nitrate, titanium carbonate, titanium hydroxide, and titanium oxide. Titanium compounds can exist as titanium ions in chemical conversion treatment solutions for aluminum-based metal materials. Examples of titanium ions include metallic titanium ions, titanium-containing complex ions, and titanium oxide ions. Examples of titanium-containing complex ions include ammonium hexafluorotitanate, hexafluorotitanate, titanium tetrafluoride, and ammonium trifluorotitanate.

[0033] Examples of vanadium compounds include vanadium tripropanol oxide, vanadium nitrate, vanadium carbonate, vanadium hydroxide, and vanadium oxide. Vanadium compounds can exist as vanadium ions in chemical conversion treatment solutions for aluminum-based metal materials. Examples of vanadium ions include vanadium metal ions, vanadium-containing complex ions, and vanadium oxide ions. Examples of vanadium-containing complex ions include vanadium fluoride and hexafluorovanadate.

[0034] In one embodiment of the present invention, the content of metal compound (a) in the chemical conversion treatment solution for aluminum-based metal materials is not particularly limited. As a value converted to zirconium, titanium, or vanadium, it is typically 1.5 mg / L to 500 mg / L, more preferably 25 mg / L to 300 mg / L. When using two or more metal compounds (a), the total content of zirconium, titanium, or vanadium contained in each metal compound (a) is taken as the content of metal compound (a).

[0035] (Trivalent chromium compound (b)) In one embodiment of the present invention, the chemical conversion treatment solution for aluminum-based metal materials contains a trivalent chromium compound (b). Examples of trivalent chromium compounds include chromium (III) fluoride, chromium (III) nitrate, chromium (III) sulfate, chromium oxysulfate (III), and chromium (III) phosphate. The trivalent chromium compound may exist in the chemical conversion treatment solution for aluminum-based metal materials in the form of chromium ions. Only one trivalent chromium compound may be used, or two or more may be used in combination. There is no particular limitation on the content of the trivalent chromium compound in the chemical conversion treatment solution for aluminum-based metal materials; as a value converted to chromium, it is generally 1 mg / L to 200 mg / L, more preferably 25 mg / L to 150 mg / L. When two or more trivalent chromium compounds are used, the total content of these chromium compounds is taken as the content of the trivalent chromium compound.

[0036] (Polymers with carbonyl groups (C)) In one embodiment of the present invention, the chemical conversion treatment liquid for aluminum-based metal materials contains a polymer (C) having a carbonyl group. As described above, the polymer (C) having a carbonyl group is not particularly limited as long as it is a polymer having a carbonyl group in its structure. More specifically, examples of functional groups having a carbonyl group include: amide group, urethane group, carboxyl group, acryloyl group, ester group, etc. The polymer (C) having a carbonyl group may have only one carbonyl group in its structure, or it may have two or more carbonyl groups. Examples of polymers (C) having a carbonyl group include, for example, polyester, polyacrylamide, polyurethane, polyacrylic acid, polyacrylate, etc. The polymer (C) having a carbonyl group may be used only one, or two or more may be used in combination. The content of the polymer (C) having a carbonyl group in the chemical conversion treatment liquid for aluminum-based metal materials is not particularly limited, and as a value converted to carbon, it is generally 1 mg / L to 1000 mg / L, more preferably 100 mg / L to 600 mg / L. When using two or more polymers (C) containing carbonyl groups, their total content is taken as the content of the polymer (C) containing carbonyl groups.

[0037] (Fluorine-containing compound (D)) In one embodiment of the present invention, the chemical conversion treatment solution for aluminum-based metal materials contains a fluorinated compound (D). Examples of fluorinated compounds (D) include hydrofluoric acid, ammonium fluoride, ammonium hydrogen fluoride, germanium fluoride, potassium fluoride, potassium hydrogen fluoride, iron fluoride, fluorosilicic acid, sodium fluoride, sodium hydrogen fluoride, hexafluorozirconic acid, hexafluorotitanic acid, and chromium (III) fluoride. It should be noted that compounds equivalent to both the metal compound (a) or the trivalent chromium compound (b) and the fluorinated compound (D) (e.g., hexafluorozirconic acid, hexafluorotitanic acid, chromium (III) fluoride, etc.) function as individual compounds. Only one fluorinated compound may be used, or two or more may be used in combination. The content of the fluorinated compound in the chemical conversion treatment solution for aluminum-based metal materials is not particularly limited, but the overall free fluoride ion concentration of the chemical conversion treatment solution for aluminum-based metal materials is typically 3 mg / L to 100 mg / L, more preferably 5 mg / L to 70 mg / L. The concentration of free fluoride ions can be measured using commercially available fluoride ion meters {ion electrode: fluoride ion composite electrode F-2021 (manufactured by Toa DKK Corporation)}.

[0038] In one embodiment of the present invention, the pH of the chemical conversion treatment solution for aluminum-based metal materials is not particularly limited, but is preferably 2.3 to 5.0, more preferably 3.0 to 4.5. pH adjustment can be achieved by adding an acid or alkali (e.g., sodium hydroxide, ammonia, ammonium bicarbonate, nitric acid, sulfuric acid, hydrochloric acid, hydrofluoric acid, etc.). Here, pH in this specification refers to the value at 25°C. pH measurement can be performed using, for example, a portable conductivity / pH meter {WM-32EP (manufactured by Toa DKK Corporation)}.

[0039] In a chemical conversion treatment solution for aluminum-based metal materials according to one embodiment of the present invention, corrosion resistance can be improved by appropriately adjusting the mass ratio (A / B) of metal element (A) to non-hexavalent Cr element (B). Specifically, A / B is preferably 0.6 to 7.0, more preferably 0.6 to 4.2, and even more preferably 0.6 to 1.67. When the chemical conversion treatment solution contains two or more metal elements (A), A / B is calculated based on their total content.

[0040] In one embodiment of the present invention, the corrosion resistance of the chemical conversion treatment solution for aluminum-based metal materials can be further improved by appropriately adjusting the mass ratio (C / B) of C element to non-hexavalent Cr element (B). Specifically, the C / B ratio is preferably 0.5 to 20, more preferably 0.5 to 7.2, and even more preferably 0.5 to 3.33.

[0041] In one embodiment of the present invention, the corrosion resistance of the chemical conversion treatment solution for aluminum-based metal materials can be further improved by appropriately adjusting the mass ratio (X / Y) of the polymer (C) having carbonyl groups to the total mass (Y) of Zr, Ti, V, and Cr. Specifically, X / Y is preferably 0.50 to 2.80, more preferably 0.50 to 1.76, and even more preferably 0.50 to 1.25.

[0042] <<3. Surface Treatment Methods for Aluminum-Based Metal Materials>> In one embodiment of the present invention, the aluminum-based metal material with a chemical conversion coating can be obtained by a surface treatment method comprising the following steps: step (i) (hereinafter referred to as the "chemical conversion treatment step"), wherein the aluminum-based metal material is contacted with an aluminum-based metal material in a chemical conversion treatment solution for at least 60 seconds; and step (ii) (hereinafter referred to as the "water washing treatment step"), wherein, after step (i), the aluminum-based metal material is washed with water. The contact method is not particularly limited, and methods such as immersion treatment, spraying treatment, flow coating treatment, or combinations thereof can be used.

[0043] In the chemical conversion treatment step, the temperature of the chemical conversion treatment solution used for contacting the aluminum-based metal material is preferably in the range of 30°C to 70°C. Furthermore, the contact time is preferably in the range of 60 seconds to 600 seconds, more preferably in the range of 60 seconds to 300 seconds, and even more preferably in the range of 120 seconds to 180 seconds. A water washing step is performed after the chemical conversion treatment step. Additionally, a drying step may be performed after the chemical conversion treatment step or the water washing step following the chemical conversion treatment step. For example, drying can be performed in an atmosphere of 30°C to 250°C for 10 seconds to 6000 seconds.

[0044] Prior to the chemical conversion treatment step, degreasing, hot water washing, acid washing, and solvent cleaning (hereinafter referred to as "cleaning steps") are typically performed in combination to remove oil and dirt adhering to the aluminum-based metal material, but this is not mandatory. There are no particular limitations on the degreasing method; any method conventionally used in the degreasing treatment of aluminum-based metal materials can be appropriately selected. Examples of degreasing methods include solvent degreasing (solvent cleaning, solvent vapor cleaning), alkaline degreasing, electrolytic alkaline degreasing, and emulsion degreasing. The aluminum-based metal material after the cleaning step can be subjected to a water washing step before the chemical conversion treatment step.

[0045] Furthermore, when manufacturing an aluminum-based metal material that also has a surface treatment film on the chemical conversion film produced by the manufacturing method of an aluminum-based metal material with a chemical conversion film according to one embodiment of the present invention, a step for forming a surface treatment film can be performed after the chemical conversion film is manufactured. This step can be performed multiple times to form one or more layers of surface treatment film. Additionally, one or more water washing steps can be performed after the aforementioned chemical conversion treatment step and before the step for forming the surface treatment film. After the water washing step, a drying step to dry the surface of the metal material can then be performed.

[0046] The process for forming the above-mentioned surface-treated film can be carried out on the surface of the metal material having the above-mentioned chemical conversion film using a surface-treated agent or coating. There are no particular limitations on the treatment method, and conventionally known methods can be used, such as dipping, curtain coating, airless spraying, thermal spraying, roller coating, electrophoretic coating (e.g., cationic electrophoretic coating, anionic electrophoretic coating, etc.), electrostatic (powder) coating, roller coating, brush coating, bar coating, fluidized bed dipping, etc. After treatment, a baking process or a drying process can be performed as needed.

[0047] When manufacturing an aluminum-based metal material having a surface-treated coating on a chemical conversion coating produced by the manufacturing method of an aluminum-based material with a chemical conversion coating according to one embodiment of the present invention, a surface-treated agent may be applied for the purpose of imparting hydrophilicity, etc. The surface-treated agent may be a resin. There are no particular limitations on the resin, and examples include polyurethane resin, polyvinyl alcohol resin, polyamide resin, epoxy resin, acrylic resin, amine resin, phenolic resin, polyvinylpyrrolidone resin, polycarbodiimide resin, etc. It should be noted that the resin may be a homopolymer of these resins (including modified products obtained by modifying the side chains of the homopolymer with other compounds), or a copolymer obtained by combining and polymerizing two or more monomers used to obtain these resins or modified products. Preferably, a resin having at least one functional group selected from amino, amide, carboxyl, and hydroxyl groups is used. The resin may have only one of these functional groups, or it may have two or more. Furthermore, the surface-treated agent may contain only one type of resin, or it may contain two or more types of resin. In addition to resin, surface treatment agents may contain appropriate amounts of deionized water, water-miscible solvents, etc.

[0048] The use of the aluminum-based metal material with a chemical conversion coating in one embodiment of the present invention is not particularly limited, for example, for use in heat exchangers, building materials, automotive components, battery materials, etc.

[0049] The above-described treatment yields an aluminum-based metal material with a chemical conversion coating or an aluminum-based metal material further having a surface-treated coating. The preferred coating thickness is as described above. The surface-treated coating on the chemical conversion coating can be a single layer or, by performing multiple treatments as described above, can be multiple layers. Example

[0050] The present invention will now be described in more detail based on embodiments, but the present invention is not limited to these embodiments.

[0051] (1. Raw materials used to prepare surface treatment agents for aluminum-based metal materials) As shown in Table 1, raw materials A1 to A5 are used as metal compounds (a), raw materials B1 to B3 are used as trivalent chromium compounds (b), raw materials C1 to C4 are used as carbonyl polymers (C), and raw material D1 is used as fluorine-containing compounds (D).

[0052] Table 1

[0053] (2. Surface treatment agents for aluminum-based metal materials) Using the raw materials shown in Table 1, and in a manner that achieves the concentrations shown in Table 2, the raw materials were combined and mixed in water to obtain surface treatment agents 1 to 23 for aluminum-based metal materials.

[0054] It should be noted that the content (Y1) of the metal compound (a) shown in Table 2 is the mass concentration converted to metal, the content (Y3) of the trivalent chromium compound (b) is the mass concentration converted to chromium, and the content (X) of the polymer with carbonyl group (C) is the mass concentration of the polymer itself.

[0055] <Determination of Free Fluoride Ion Concentration> The concentration of free fluoride ions in various surface treatment agents for aluminum-based metal materials was determined using a commercially available fluoride ion meter {ion electrode: fluoride ion composite electrode F-2021 (manufactured by Toa DKK Corporation)}. The results are shown in Table 2.

[0056] Table 2

[0057] (3. Surface treatment of aluminum-based metal materials) <Example 1 (Chemical Conversion Treatment)> A flat sheet of pure aluminum (A1050P as specified in JIS H 4000:2014) measuring 70mm × 75mm × 0.8mm was immersed in an alkaline degreasing agent (a 20g / L aqueous solution of FINE CLEANER 315E manufactured by Parkerizing, Japan) heated to 60°C for 3 minutes. The surface was then rinsed with deionized water for cleaning. Next, the cleaned pure aluminum was immersed in a surface treatment agent 1 at 53°C with ammonia water adjusted to pH 3.7 for 60 seconds. The pure aluminum was then removed from the surface treatment agent 1, rinsed with deionized water, and dried in an electric oven (at 80°C for 5 minutes) to obtain an aluminum-based metal material with a chemical conversion coating.

[0058] <Examples 2-17 and Comparative Examples 1-6 (Chemical Conversion Treatment)> The conditions were changed to those described in Table 3. Otherwise, chemical conversion treatment was performed under the same conditions as in Example 1 to obtain aluminum-based metal materials with chemical conversion coatings as in Examples 2-17 and Comparative Examples 1-6.

[0059] <Comparative Examples 7-9 (Painting)> The pure aluminum materials listed in Table 3, cleaned under the same conditions as in Example 1, were immersed in surface treatment agents 12, 16, or 23 at room temperature (approximately 25°C) for 20 seconds. Then, without rinsing, the pure aluminum materials were removed from surface treatment agents 12, 16, or 23 and dried in an electric oven (at 150°C for 6 minutes). This yielded the aluminum-based metal materials with coatings of Comparative Examples 7-9.

[0060] Table 3

[0061] (4. Analysis of surface-treated aluminum materials) The mass of metal and carbon per unit area contained in the coating of surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9 were determined using the following methods. The results are shown in Table 4.

[0062] In addition, the enrichment locations (surface side or substrate side) of each element contained in the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9 in the film thickness direction were determined using the following methods. The measurement results are shown in Table 4. It should be noted that sometimes enrichment also occurs at locations between the surface side and the substrate side, and not all elements are enriched on either the surface side or the substrate side.

[0063] In addition, the presence or absence of carbonyl groups in the polymers of the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9 was determined by the following method. The results are shown in Table 4.

[0064] In addition, the presence or absence of fluorine (F) was determined in the surface-treated aluminum films of Examples 1-17 and Comparative Examples 1-9 using the following method. The measurement results are shown in Table 4.

[0065] In addition, the presence or absence of hexavalent chromium was determined for the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9 using the following method. The measurement results are shown in Table 4.

[0066] In addition, the film thickness of the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9 was measured using the following method. The measurement results are shown in Table 4.

[0067] <Mass of metal per unit area> Based on a standard curve pre-prepared to vary the content of each metal in the coating, measurements were performed using a scanning X-ray fluorescence analyzer {ZSX primus II (manufactured by Rigaku Corporation)}, and the measured metal mass was divided by the X-ray irradiation area (π×15×15mm). 2 This allows for the calculation of the mass of metal (Zr, V, Ti, Cr) per unit area. The X-ray irradiation diameter is set to 30 mm. The surface-treated aluminum material was cut into 3.2cm square pieces and used as analytical samples. The average value of the samples from three points was taken as the measured value.

[0068] <Carbon mass per unit area> Using a Total Organic Carbon (TOC-L) analyzer (manufactured by Shimadzu Corporation) equipped with a solid sample combustion device, the organic matter contained in the surface-treated aluminum material was completely burned at a furnace temperature of 700°C. The carbon mass was measured according to a standard curve prepared in advance using standard samples. The measured carbon mass was divided by the surface area (projected area) of the surface-treated aluminum material used for testing to calculate the carbon equivalent mass per unit area. The surface-treated aluminum material was cut into 7.5mm pieces. The samples were then used as analytical samples, and the average value of the five samples was taken as the measured value.

[0069] <Presence or absence of carbonyl group> Measurements were performed using the reflection method on a Fourier transform infrared spectrometer (FT-IR) {Spectrum Two (PerkinElmer)} with a variable-angle reflector. Measurements were taken at an infrared light incident angle of 45° and a resolution of 4 cm⁻¹. -1 32 cumulative counts, wavenumber range 400cm -1 ~4000cm -1 The experiment was conducted at 25°C. The presence or absence of an absorption peak originating from the carbonyl group (2000 cm⁻¹) was confirmed based on the obtained infrared absorption spectrum. -1 ~1500cm -1 Considering the variability due to different measurement locations, the presence or absence of carbonyl groups is evaluated based on results obtained from three randomly selected points on the surface-treated aluminum material. In this case, if a carbonyl peak is confirmed at two or more of the three measurement locations, it is recorded as "present" carbonyl.

[0070] <Analysis of the Gradient Structure of the Membrane> The luminescence intensity analysis of each element using a Markus-type high-frequency glow discharge luminescent surface analyzer (GD-OES) was performed using a JY-5000RF device manufactured by Horiba Corporation. The GD-OES analysis was conducted within a measurement range of 10 mm. Measurements were performed using argon sputtering in pulsed sputtering mode. The outermost surface of the surface-treated aluminum was used as the starting point for measurement. Measurements were taken every 0.8 nm from the outermost surface towards the base aluminum until a depth of 2.5 mm was reached. The depth range from the outermost surface of the chemically converted film to 20 nm was defined as the "surface side." The depth range where the Al intensity first reaches five times the average Al intensity from the outermost surface to 5 nm was defined as the "substrate side." The locations where the intensity of each film component showed its maximum value (enrichment) within the measurement range were examined. Considering variations due to different measurement locations, the gradient structure was evaluated based on the analysis results at three randomly selected points on the surface-treated aluminum. At this point, the same gradient structure was confirmed at two or more of the three points.

[0071] Analysis of Fluorine in the Coating A scanning fluorescence X-ray analyzer {ZSX primus II (Rigaku Corporation)} was used to scan the wavelength range of fluorescence X-rays that can detect elements from Be to U, thereby examining whether F element was detected in the coating of surface-treated aluminum. It should be noted that an Rh X-ray tube was used, and the X-ray irradiation area of ​​the analyzed sample was set to 30 mm². The surface-treated aluminum material was cut into 3.2cm square pieces and used as the analytical sample. Three points were analyzed on the sample. If a fluorine peak was confirmed at two or more of the three measurement points, it was recorded as "fluorine detected". If no fluorine peak was confirmed, it was recorded as "fluorine not detected".

[0072] Analysis of Hexavalent Chromium The presence of hexavalent chromium in surface-treated aluminum was confirmed by conducting a hexavalent chromium leaching test according to the diphenylcarbazide colorimetric method of JIS H8625-1993. Results were categorized as "detected" hexavalent chromium levels above 0.05 mg / L, and "not detected" hexavalent chromium levels below 0.05 mg / L.

[0073] <Film thickness of coating> The film thickness was determined based on the analysis results of GD-OES. The film thickness was calculated by multiplying the sputtering time (seconds) at this point by the sputtering rate of Si (40 nm / second) by the average Al intensity in the depth range from the outermost surface to 5 nm.

[0074] (5. Corrosion resistance test for surface-treated aluminum materials) Corrosion resistance in neutral environments (salt spray test) Neutral salt spray tests (JIS-Z2371:2015) were conducted on the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9. The evaluation time was set to 720 hours. After drying, the proportion of white rust formed on the surface of the surface-treated aluminum materials was visually determined. The proportion of white rust is the ratio of the area with white rust to the area of ​​the observation area. The evaluation criteria are shown below. The evaluation results are shown in Table 4. <Evaluation Criteria> 5. The proportion of white rust is less than 10%. 4. The proportion of white rust is greater than 10% but less than 30%. 3. The proportion of white rust is greater than 30% but less than 50%. 2. The proportion of white rust is greater than 50% and less than 70%. 1. The proportion of white rust is greater than 70%.

[0075] <Corrosion resistance in acidic environments [SWAAT test (Sea Water Acidified Test)]> SWAAT tests (ASTM G85 Annex 2) were performed on the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9. The evaluation cycle number was set to 240 cycles. After drying, the proportion of white rust formed on the surface of the surface-treated aluminum materials was visually determined. The proportion of white rust is the ratio of the area with white rust to the area of ​​the observation area. The evaluation criteria are as follows. The evaluation results are shown in Table 4. <Evaluation Criteria> 5. The proportion of white rust is less than 10%. 4. The proportion of white rust is greater than 10% but less than 30%. 3. The proportion of white rust is greater than 30% but less than 50%. 2. The proportion of white rust is greater than 50% and less than 70%. 1. The proportion of white rust is greater than 70%.

[0076] Corrosion resistance in acidic environments containing Cu (CASS test) CASS tests (JIS-Z2371:2015) were performed on the surface-treated aluminum materials of Examples 1-17 and Comparative Examples 1-9. The evaluation time was set to 24 hours. After drying, the proportion of white rust formed on the surface of the surface-treated aluminum materials was visually measured. The proportion of white rust is the ratio of the area with white rust to the area of ​​the observation area. The evaluation criteria are as follows. The evaluation results are shown in Table 4. <Evaluation Criteria> 5. The proportion of white rust is less than 10%. 4. The proportion of white rust is greater than 10% but less than 30%. 3. The proportion of white rust is greater than 30% but less than 50%. 2. The proportion of white rust is greater than 50% and less than 70%. 1. The proportion of white rust is greater than 70%.

[0077] Table 4

[0078] The present invention has been described in detail above with reference to specific embodiments, but it is obvious that those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention.

Claims

1. An aluminum-based metal material with a chemical conversion coating, wherein, The surface of the aluminum-based metal material contains 1 mg / m 2 ~160mg / m 2 The element selected is at least one metallic element (A) from the group consisting of Zr, Ti, and V, and 5 mg / m 2 ~50mg / m 2 Non-hexavalent Cr element (B) and 6 mg / m 2 ~100mg / m 2 The chemical conversion coating of element C is used, wherein the mass ratio (A / B) of the metal element (A) to the non-hexavalent Cr element (B) is 1.45 to 5.0, and the mass ratio (C / B) of the C element to the non-hexavalent Cr element (B) is 0.15 to 7.

2.

2. The aluminum-based metal material with a chemical conversion coating as described in claim 1, wherein, The C element in the chemical conversion membrane comes from a polymer with a carbonyl group.

3. The aluminum-based metal material with a chemical conversion coating as described in claim 1 or 2, wherein, The chemical conversion membrane contains the element F.

4. The aluminum-based metal material with a chemical conversion coating as described in claim 1 or 2, wherein, In luminescence intensity analysis using a Markus-type high-frequency glow discharge luminescent surface analysis apparatus (GD-OES), when the depth range within 20 nm from the outermost surface is defined as the surface side, and the depth range below which the Al intensity first reaches 5 times the average Al intensity in the depth range from the outermost surface to 5 nm is defined as the substrate side, C and O elements exhibit maximum strength on the surface side, and at least one element selected from the metal element (A) and the non-hexavalent Cr element (B) exhibits maximum strength on the substrate side.

5. A chemical conversion treatment solution for aluminum-based metal materials, wherein, The chemical conversion treatment liquid for aluminum-based metal materials comprises at least one metal compound (a) selected from the group consisting of zirconium compounds, titanium compounds and vanadium compounds, a trivalent chromium compound (b), a polymer having a carbonyl group (C), and a fluorine-containing compound (D).

6. The chemical conversion treatment solution for aluminum-based metal materials as described in claim 5, wherein, The mass ratio (A / B) of at least one metallic element (A) selected from the group consisting of Zr, Ti and V to non-hexavalent Cr element (B) is 0.6 to 7.0, and the mass ratio (C / B) of C element to said non-hexavalent Cr element (B) is 0.5 to 20.

7. The chemical conversion treatment solution for aluminum-based metal materials as described in claim 5 or 6, wherein, The mass ratio (X / Y) of the polymer (C) with carbonyl groups to the total mass (Y) of Zr, Ti, V and Cr is 0.50 to 2.

80.

8. A surface treatment method for aluminum-based metal materials, wherein, The surface treatment method for the aluminum-based metal material includes the following steps: Step (i), wherein the aluminum-based metal material is contacted with the chemical conversion treatment solution of the aluminum-based metal material according to claim 5 or 6 for more than 60 seconds; and Step (ii), wherein, after step (i), the aluminum-based metal material is washed with water.

9. The surface treatment method for aluminum-based metal materials as described in claim 8, wherein, In process (i), the contact time between the aluminum-based metal material and the aluminum-based metal material chemical conversion treatment solution is 60 seconds to 600 seconds.

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