Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/34—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C2222/00—Aspects relating to chemical surface treatment of metallic material by reaction of the surface with a reactive medium
  • C23C2222/10—Use of solutions containing trivalent chromium but free of hexavalent chromium

Definitions

• the present invention relates to a surface treatment agent used for surface treatment of an aluminum or an aluminum alloy material, an aluminum or an aluminum alloy material which has a surface treatment coating formed by the surface treatment agent, and a method of producing the aluminum or the aluminum alloy material.
• metallic material surface treatment agents containing trivalent chromium have been developed as surface treatment agents for aluminum and aluminum alloy materials in a wide range of fields, such as aircraft materials, construction materials, and automobile parts.
• 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 a water-soluble titanium compound and a 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, and which has pH controlled in a range of 2.3 to 5.0.
• Patent Document 2 discloses a chemical conversion treatment liquid which contains a predetermined amount of a specific trivalent chromium compound, a specific zirconium compound, and a specific dicarboxylic acid compound.
• Patent Document 1 Japanese Unexamined Patent Application Publication No. 2006-328501
• Patent Document 2 Japanese Unexamined Patent Application Publication No. 2006-316334
• the corrosion resistance may be reduced due to exposure to a high temperature environment, depending on the use of the aluminum or the aluminum alloy materials.
• An object of the present invention is to provide a surface treatment agent capable of forming, on an aluminum or an aluminum alloy material, a surface treatment coating that has excellent corrosion resistance and has excellent corrosion resistance even when the coating is exposed to a high temperature, an aluminum or an aluminum alloy material which has a surface treatment coating formed by the surface treatment agent, and a method of producing the aluminum or the aluminum alloy material.
• a surface treatment agent containing a trivalent chromium-containing ion (A), at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion, a zinc-containing ion (C), a free fluorine ion (D), and a nitrate ion (E) is capable of forming, on an aluminum or aluminum alloy material, a surface treatment coating that has excellent corrosion resistance and has excellent corrosion resistance even when the coating is exposed to a high temperature, thereby completing the present invention.
• the present invention encompasses the followings:
• a surface treatment agent used for surface treatment of an aluminum or an aluminum alloy material wherein the surface treatment agent contains a trivalent chromium-containing ion (A), at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion, a zinc-containing ion (C), a free fluorine ion (D), and a nitrate ion (E);
• A trivalent chromium-containing ion
• B at least one ion selected from a titanium-containing ion and a zirconium-containing ion, a zinc-containing ion (C), a free fluorine ion (D), and a nitrate ion (E);
• a method of producing an aluminum or an aluminum alloy material having a surface treatment coating including a contact step of contacting the surface treatment agent according to (1) on or over a surface of an aluminum or an aluminum alloy material;
• a surface treatment agent capable of forming, on an aluminum or an aluminum alloy material, a surface treatment coating that has excellent corrosion resistance and has excellent corrosion resistance even when the coating is exposed to a high temperature
• an aluminum or an aluminum alloy material which has a surface treatment coating formed by the surface treatment agent
• a method of producing the aluminum or the aluminum alloy material can be provided: a surface treatment agent capable of forming, on an aluminum or an aluminum alloy material, a surface treatment coating that has excellent corrosion resistance and has excellent corrosion resistance even when the coating is exposed to a high temperature; an aluminum or an aluminum alloy material which has a surface treatment coating formed by the surface treatment agent; and a method of producing the aluminum or the aluminum alloy material.
• the surface treatment agent of the present embodiment is a treatment agent for performing a surface treatment of an aluminum or an aluminum alloy material.
• the surface treatment agent can also be utilized as a chemical conversion treatment agent.
• the surface treatment agent contains a trivalent chromium-containing ion (A), at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion, a zinc-containing ion (C), a free fluorine ion (D), and a nitrate ion (E).
• the surface treatment agent may be obtained by mixing an aqueous medium with sources of these ions exclusively, or by mixing an aqueous medium with sources of these ions and other components.
• the respective components, formulations (contents) thereof, and liquid properties are described below in detail. Examples of the above-described metal-containing ions include metal ions, metal oxide ions, metal hydroxide ions, and metal complex ions.
• a supply source of the trivalent chromium-containing ion (A) is not particularly limited as long as it is capable of providing the ion (A) by mixing with an aqueous medium.
• the supply source include chromium fluoride, chromium nitrate, chromium sulfate, and chromium phosphate. These supply sources may be used singly, or in combination of two or more thereof.
• the content of the ion (A) in the surface treatment agent is not particularly limited, however, it is usually in a range of 5 to 1,000 mg/L, preferably in a range of 20 to 700 mg/L, in terms of chromium-equivalent mass concentration.
• the surface treatment agent does not contain hexavalent chromium ions. It is noted here that “does not contain hexavalent chromium ions” does not mean that the content of the hexavalent chromium ions is 0, but unavoidable incorporation of hexavalent chromium ions is acceptable. Specifically, the content of hexavalent chromium ions may be 10 mg/L or less, 5 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, or 0.1 mg/L or less.
• a supply source of at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion is not particularly limited as long as it is capable of providing the ion (B) by mixing with an aqueous medium.
• Examples of the supply source include titanium sulfate, titanium oxysulfate, titanium ammonium sulfate, titanium nitrate, titanium oxynitrate, titanium ammonium nitrate, hexafluorotitanic acid, hexafluorotitanium complex salts, zirconium sulfate, zirconium oxynitrate, zirconium ammonium sulfate, zirconium nitrate, zirconium oxynitrate, zirconium ammonium nitrate, hexafluorozirconic acid, hexafluorozirconium complex salts, titanium lactate, titanium acetylacetonate, titanium triethanolaminate, titanium octyl glycolate, tetraisopropyl titanate, tetra-n-butyl titanate, zirconyl acetate, zirconyl lactate, zirconium tetraacety
• the content of the ion (B) in the surface treatment agent is not particularly limited, however, it is usually in a range of 5 to 1,000 mg/L, preferably in a range of 20 to 700 mg/L, in terms of metal-equivalent mass concentration (total metal-equivalent mass concentration when two or more supply sources are combined).
• a supply source of the zinc-containing ion (C) is not particularly limited as long as as it is capable of providing the ion (C) by mixing with an aqueous medium.
• the supply source include metallic zinc, zinc oxide, zinc carbonate, zinc nitrate, zinc chloride, zinc sulfate, zinc fluoride, zinc iodide, zinc dihydrogen phosphate, and zinc acetylacetonate. These supply sources may be used singly, or in combination of two or more thereof.
• the content of the ion (C) in the surface treatment agent is not particularly limited, however, it is usually in a range of 20 to 10,000 mg/L and may be in a range of 50 to 10,000 mg/L, preferably in a range of 300 to 8,000 mg/L, more preferably in a range of 700 to 5,000 mg/L, in terms of zinc-equivalent mass concentration.
• a supply source of the free fluorine ion (D) is not particularly limited as long as it is capable of providing the free fluorine ion (D) by mixing with an aqueous medium.
• the supply source include hydrofluoric acid, ammonium fluoride, chromium fluoride, hexafluorotitanic acid, hexafluorotitanium complex salts, hexafluorozirconic acid, hexafluorozirconium complex salts, magnesium fluoride, aluminum fluoride, hexafluorosilicic acid, sodium fluoride, potassium fluoride, and zinc fluoride.
• These supply sources may be used singly, or in combination of two or more thereof.
• the free fluorine ion (D) may be provided by the same compound as the above-described supply source(s) of (A), (B) and/or (C), or may be provided by a different compound.
• the fluorine-equivalent mass concentration of the free fluorine ion (D) is preferably 3 to 100 mg/L, more preferably 5 to 70 mg/L.
• a supply source of the nitrate ion (E) is not particularly limited as long as it is capable of providing the nitrate ion (E) by mixing with an aqueous medium.
• the supply source include nitric acid, sodium nitrate, potassium nitrate, magnesium nitrate, ammonium nitrate, cerium nitrate, manganese nitrate, strontium nitrate, calcium nitrate, cobalt nitrate, aluminum nitrate, and zinc nitrate. These supply sources may be used singly, or in combination of two or more thereof.
• the nitrate ion (E) may be provided by the same compound as the above-described supply source(s) of (A), (B) and/or (C), or may be provided by a different compound.
• the content of the nitrate ion (E) in the surface treatment agent is not particularly limited, however, it is usually in a range of 100 to 30,000 mg/L in terms of nitric acid-equivalent mass concentration.
• metal components and additives may be incorporated as long as they do not impair the effects of the present invention.
• the metal components include vanadium, molybdenum, tungsten, manganese, cerium, magnesium, calcium, cobalt, nickel, strontium, lithium, niobium, yttrium, and bismuth.
• additives examples include hydroxy group-containing compounds, formyl group-containing compounds, benzoyl group-containing compounds, amino group-containing compounds, imino group-containing compounds, cyano group-containing compounds, azo group-containing compounds, thiol group-containing compounds, sulfo group-containing compounds, nitro group-containing compounds, and urethane bond-containing compounds.
• These metal components and additives may be used singly, or in combination of two or more thereof.
• These additives are incorporated within a range that does not impair the effects of the present invention, therefore, the content thereof is at most several percent by mass with respect to a total amount of the surface treatment agent.
• the surface treatment agent of the present embodiment preferably does not contain carboxyl group-containing compounds, preferably does not contain amidino group-containing compounds, preferably does not contain aromatic ring-containing compounds, and more preferably does not contain organic matters.
• the surface treatment agent which does not contain organic matters a reduction in the corrosion resistance of the resulting coating can be suppressed. It is noted here that “does not contain organic matters” does not necessarily mean that the content of organic matters is 0, and it is acceptable that the surface treatment agent contains organic matters within a range that does not significantly impair the effects of the present invention.
• organic matters may be 10 mg/L or less, 5 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, or 0.1 mg/L or less, or 0 mg/L.
• organic matters used herein refers to compounds containing carbon as a main component, and may encompass derivatives of such compounds.
• the pH of the surface treatment agent of the present embodiment is not particularly limited, however, it is preferably 2.3 to 5.0, more preferably 3.0 to 4.5.
• the pH means a value measured at a temperature at which the surface treatment agent is contacted on or over a surface of an aluminum or an aluminum alloy material.
• the pH can be measured using, for example, a portable electrical conductivity/pH meter (WM-32EP, manufactured by DKK-TOA Corporation).
• another aspect of the present invention is a surface treatment agent which is used for surface treatment of an aluminum or an aluminum alloy material, and which is obtainable by mixing a source of a trivalent chromium-containing ion (A), a supply source of at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion, a supply source of a zinc-containing ion (C), a supply source of a free fluorine ion (D), and a supply source of a nitrate ion (E).
• A trivalent chromium-containing ion
• B a supply source of at least one ion
• C zinc-containing ion
• D free fluorine ion
• E a supply source of a nitrate ion
• the supply source of the free fluorine ion (D) may be the same compound as the supply source(s) of (A), (B) and/or (C), or may be a different compound.
• the supply source of the nitrate ion (E) may be the same compound as the supply source(s) of (A), (B) and/or (C), or may be a different compound.
• the surface treatment agent of the present embodiment can be obtained by mixing an aqueous medium with appropriate amounts of supply sources of the above-described trivalent chromium-containing ion (A), at least one ion (B) selected from a titanium-containing ion and a zirconium-containing ion, zinc-containing ion (C), free fluorine ion (D), and nitrate ion (E), and stirring the resulting mixture.
• solid supply sources may be added to the aqueous medium, or the solid supply sources may be dissolved in the aqueous medium in advance and then added as an aqueous medium solution.
• the pH of the resulting surface treatment agent is preferably adjusted to be in the above-described range using a pH modifier, such as nitric acid, hydrofluoric acid, ammonium hydrogen carbonate, or aqueous ammonia, however, the pH modifier is not limited to these components.
• a pH modifier such as nitric acid, hydrofluoric acid, ammonium hydrogen carbonate, or aqueous ammonia
• Such a pH modifier may be used singly, or two or more thereof may be used in combination.
• the aqueous medium water is typically used.
• the aqueous medium may contain a water-miscible organic solvent within a range that does not impair the effects of the present invention, however, the aqueous medium is preferably water.
• the aqueous medium contains a water-miscible organic solvent, the content thereof may be 10 mg/L or less, 5 mg/L or less, 1 mg/L or less, 0.5 mg/L or less, or 0.1 mg/L or less.
• a method of producing an aluminum or an aluminum alloy material having a coating formed by the surface treatment agent of the present embodiment includes a contact step of contacting the surface treatment agent of the present embodiment on or over a surface of an aluminum or an aluminum alloy material. By this step, a surface treatment coating is formed on or over the surface of the aluminum or an aluminum alloy material. Pretreatment steps, such as the degreasing step, the pickling step, and the like may also be performed prior to the contact step.
• the water-washing step may be performed after each step, and the drying step may be performed after each water-washing step.
• An aluminum or an aluminum alloy material to be treated with the surface treatment agent is not particularly limited, and the surface treatment agent is particularly effective for aluminum die-cast materials which have a thick surface oxide film and in which an alloy component is segregated.
• the use of the aluminum or the aluminum alloy material is not particularly limited, and examples thereof include ship propulsion engines and peripherals thereof, as well as components of motorcycle internal combustion engines.
• the degreasing step of contacting a known degreasing agent on or over the surface of the aluminum or the aluminum alloy material.
• a degreasing method is not particularly limited, and examples thereof include solvent degreasing and alkali degreasing.
• the contact temperature and the contact time are not particularly limited, however, usually, the surface treatment agent is contacted on or over the surface of the aluminum or the aluminum alloy material at 30 to 80° C., preferably at 40 to 70° C., for 10 to 600 seconds.
• the aluminum or the aluminum alloy material may be washed with water and then with deionized water, followed by drying.
• the drying temperature is not particularly limited, however, it is preferably 50 to 140° C.
• a method of contacting the surface treatment agent on or over the surface of the aluminum or the aluminum alloy material is not particularly limited, and examples thereof include an immersion method, a spray method, and a flow-coating method.
• An aluminum or an aluminum alloy material having a surface treatment coating which is produced by the above-described production method, is another embodiment of the present invention.
• the amount of the adhered surface treatment coating on the aluminum or the aluminum alloy material is not particularly limited, however, a total mass of Cr, Ti, and/or Zr, Zn that are contained in the surface treatment coating per unit area is preferably 1 to 200 mg/m 2 .
• the aluminum or the aluminum alloy material having the surface treatment coating according to the present embodiment has excellent corrosion resistance even without performing a painting step of applying paintings onto the surface treatment coating, and has excellent corrosion resistance even when the coating is exposed to a high temperature, however, a painting step may be performed as well.
• the painting step is not particularly limited and can be performed by, for example, a painting method such as aqueous painting, solvent painting, powder painting, anionic electrodeposition painting, cationic electrodeposition painting, or the like using a known painting composition.
• a painting method such as aqueous painting, solvent painting, powder painting, anionic electrodeposition painting, cationic electrodeposition painting, or the like using a known painting composition.
• Example 1 A1 150 B1 100 C1 1700 D1 15 E1, C1 4224 4 50
• Example 2 A2 150 B1 100 C1 1700 D1 15 E1, A2, C1 4760 4 50
• Example 3 A3 150 B2 100 C1 1700 D1 15 E1, C1 4224 4 50
• Example 5 A2 150 B1 100 C3 1700 D1
• the above-described aluminum die-cast material was immersed in an alkali degreasing agent [20-g/L aqueous solution of FINE CLEANER 315E (manufactured by Nihon Parkerizing Co., Ltd.)] at 60° C. for 2 minutes, and the surface thereof was cleaned by rinsing with tap water. Subsequently, each surface treatment agent was sprayed onto or over the surface of the aluminum die-cast material at the contact temperature shown in Table 6 to perform the contact step. Thereafter, the aluminum die-cast material was washed with running tap water (at normal temperature for 30 seconds) and then washed with deionized water (at normal temperature for 30 seconds), followed by drying in an electric oven (at 80° C. for 5 minutes), whereby aluminum die-cast materials having surface treatment coatings (test pieces 1 to 23) were each produced.
• an alkali degreasing agent [20-g/L aqueous solution of FINE CLEANER 315E (manufactured by Nihon
• Test Piece 1 Example 1 35 Test Piece 2 Example 2 35 Test Piece 3 Example 3 35 Test Piece 4 Example 4 35 Test Piece 5 Example 5 35 Test Piece 6 Example 6 35 Test Piece 7 Example 7 37 Test Piece 8 Example 8 35 Test Piece 9 Example 9 13 Test Piece 10 Example 10 20 Test Piece 11 Example 11 35 Test Piece 12 Example 12 35 Test Piece 13 Example 13 35 Test Piece 14 Example 14 35 Test Piece 15 Example 15 35 Test Piece 16 Example 16 35 Test Piece 17 Example 17 35 Test Piece 18 Example 18 35 Test Piece 19 Example 19 35 Test Piece 20 Example 20 35 Test Piece 21 Comparative Example 1 20 Test Piece 22 Comparative Example 2 2 Test Piece 23 Comparative Example 3 35
• test pieces 1 to 23 Further, for the test pieces 1 to 23, the following tests were conducted to determine the corrosion resistance and the post-heating corrosion resistance of each surface treatment coating were evaluated. The results thereof are shown in Table 8.
• a 240-hour neutral salt spray test (JIS Z2371:2015) was performed on the test pieces 1 to 23. After the test pieces 1 to 23 were dried, the ratio of white rust generated on the surface of each test piece was visually measured. The ratio of white rust is the ratio of the area of generated white rust with respect to the area of the observed part.
• the evaluation criteria were as follows. The evaluation results are shown in Table 8.
• test pieces were each heated in an electric oven (at 180° C. for 20 minutes) and then subjected to a 240-hour neutral salt spray test (JIS Z2371:2015). After the test pieces were dried, the ratio of white rust generated on the surface of each test piece was visually measured. The ratio of white rust is the ratio of the area of generated white rust with respect to the area of the observed part.
• the evaluation criteria were as follows. The evaluation results are shown in Table 8.

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• 2019
  • 2019-03-20 CN CN202211478035.7A patent/CN115786897B/zh active Active
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  • 2019-03-20 KR KR1020207027289A patent/KR102500400B1/ko active Active
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