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US4021315A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for electrolytic coloring of the anodic oxide film on aluminum or aluminum base alloys

Assignee: Sumitomo Chemical Co Ltd
•
Filing: 1975-08-27
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Granted: 1977-05-03
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Expires: 1995-08-27
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Abstract

Abstract In the process of coloring an anodized aluminum or aluminum alloy article by subjecting the anodized article to an electrolytic treatment with a direct current in an aqueous electrolytic coloring bath containing a water-soluble metallic salt, the oxide film on the article can be easily colored in a stable manner and in a uniform color, by subjecting the anodized article previously to an anodic direct current electrolysis in an aqueous solution containing the same metallic ion as in the coloring bath, and then to a cathodic direct current electrolysis for coloring the anodized oxide film on the article.

Inventors

  • 👤 Kiyomi Yanagida
  • 👤 Tadashi Hirokane
  • 👤 Tadashi Tsukiyasu
  • 👤 Tomoari Sato

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 22:14
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/20; C25D11/22

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 130 words
In a process for electrolytically coloring an anodic oxide film on an aluminum or aluminum alloy article by (1) subjecting said article to anodic oxidation in an aqueous anodic oxidation bath consisting essentially of sulfuric acid or an aromatic sulfonic acid to form an anodic oxide film; and (2) subjecting said anodic oxidized article to cathodic electrolytic coloring using a direct current in an aqueous, electrolytic coloring bath containing a water-soluble metallic salt; the improvement which comprises subjecting said anodic oxidized article to anodic electrolysis using a direct current in an aqueous anodic electrolysis bath containing the same metal ion as in the coloring bath but having no ability to form an oxide film on said article, after step (1) above but prior to said electrolytic coloring step (2) above.
Claim 2
Dependent Claim 130 words
In a process for electrolytically coloring an anodic oxide film on an aluminum or aluminum alloy article by (1) subjecting said article to anodic oxidation in an aqueous anodic oxidation bath consisting essentially of sulfuric acid or an aromatic sulfonic acid to form an anodic oxide film; and (2) subjecting said anodic oxidized article to cathodic electrolytic coloring using a direct current in an aqueous, electrolytic coloring bath containing a water-soluble metallic salt; the improvement which comprises subjecting said anodic oxidized article to anodic electrolysis using a direct current in an aqueous anodic electrolysis bath containing the same metal ion as in the coloring bath but having no ability to form an oxide film on said article, after step (1) above but prior to said electrolytic coloring step (2) above.
Claim 3
Dependent Claim 23 words
The process according to claim 1, wherein the current density in said cathodic electrolytic coloring is about 0.05 to 3.0 A/dm 2 .
Claim 4
Dependent Claim 17 words
The process according to claim 2, wherein the current density is 0.1 to 2.0 A/dm 2 .
Claim 5
Dependent Claim 23 words
The process according to claim 1, wherein said anodic electrolysis is carried out in the same bath as the cathodic electrolytic coloring bath.
Claim 6
Dependent Claim 22 words
The process according to claim 1, wherein the current density in the anodic electrolysis is about 0.01 to 1.0 A/dm 2 .
Claim 7
Dependent Claim 20 words
The process according to claim 1, wherein the electrolysis time in the anodic electrolysis is up to about 3 minutes.
Claim 8
Dependent Claim 19 words
The process according to claim 1, wherein the temperature in the anodic electrolysis is about 10° to 40° C.
Claim 9
Dependent Claim 33 words
The process according to claim 1, wherein the water-soluble metallic salt is a water-soluble nickel salt, a water-soluble copper salt, a water-soluble tin salt, a water-soluble cobalt salt or a water-soluble iron salt.
Claim 10
Dependent Claim 19 words
The process according to claim 1, wherein the temperature in said cathodic electrolytic coloring is 10° to 40° C.
Claim 11
Dependent Claim 44 words
The process according to claim 1, wherein said anodic electrolysis and said cathodic electrolytic coloring are repeated alternately, each at least once, in an aqueous electrolytic coloring bath containing 15 to 100 g/l of nickel sulfate and 10 to 50 g/l of boric acid.
Claim 12
Dependent Claim 26 words
The process according to claim 1, wherein said aqueous electrolytic coloring bath further contains boric acid and said aqueous anodic electrolysis bath further contains boric acid.
Claim 13
Dependent Claim 146 words
The process for electrolytically coloring an anodic oxide film on an aluminum or aluminum alloy article by (1) subjecting said article to anodic oxidation in an aqueous oxidation bath consisting essentially of sulfuric acid or an aromatic sulfonic acid to form an anodic oxide film; and (2) subjecting said anodic oxidized article to cathodic electrolytic coloring used a direct current in an aqueous electrolytic coloring bath containing a water-soluble metallic salt; the improvement which comprises subjecting said anodic oxidized article to anodic electrolysis using a direct current in an aqueous anodic electrolysis bath containing the same metallic ion as in the coloring bath but having no ability to form an oxide film on said article, after step (1) above but prior to said electrolytic coloring step (2) above, and repeating said anodic electrolysis and said cathodic electrolytic coloring alternately at least twice in the order recited.
Claim 14
Dependent Claim 146 words
The process for electrolytically coloring an anodic oxide film on an aluminum or aluminum alloy article by (1) subjecting said article to anodic oxidation in an aqueous oxidation bath consisting essentially of sulfuric acid or an aromatic sulfonic acid to form an anodic oxide film; and (2) subjecting said anodic oxidized article to cathodic electrolytic coloring used a direct current in an aqueous electrolytic coloring bath containing a water-soluble metallic salt; the improvement which comprises subjecting said anodic oxidized article to anodic electrolysis using a direct current in an aqueous anodic electrolysis bath containing the same metallic ion as in the coloring bath but having no ability to form an oxide film on said article, after step (1) above but prior to said electrolytic coloring step (2) above, and repeating said anodic electrolysis and said cathodic electrolytic coloring alternately at least twice in the order recited.
Claim 15
Dependent Claim 26 words
The process according to claim 12, wherein said aqueous electrolytic coloring bath further contains boric acid and said aqueous anodic electrolysis bath further contains boric acid.

References Cited (Backward Citations)

US3892636A Cited
US3878056A Cited
US3929612A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-05-02 1980-11-01 1981-05-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-05-02 1984-11-01 1985-05-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-05-02 1988-11-01 1989-05-03 $7700.00 Window Closed / Lapsed

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