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US4100041A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming a colored and oxide film on aluminum and aluminum alloys

Assignee: Toyo Chuo Kagaku Kenkyusho
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Filing: 1977-09-29
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Granted: 1978-07-11
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Expires: 1997-09-29
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Abstract

Abstract A method in which aluminum and aluminum alloys are subjected to anodic oxidizing treatment by use of a novel electrolyte to form a good colored and oxide film on the surface thereof. The electrolyte comprises an organic acid solution resulting from the sulfonation of fumaric acid (hereinafter tentatively referred to as the sulfofumaric acid) as a main liquid, into which either oxalic acid as an organic acid, or sulfuric acid or metal sulfate as the inorganic acid are added.

Inventors

  • 👤 Shozo Kimura
  • 👤 Hidetoshi Yoshida

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 04:54
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/14

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 76 words
A method of forming a yellow-black colored and oxide film on aluminum and aluminum alloys comprising subjecting defatted and washed aluminum and aluminum alloys to treatment of electrolytic oxidation by direct current, ac-dc combined current or pulse wave-form in an electrolyte comprising 5 - 500 g/l of sulfofumaric acid and at least one of 0.1 - 30 g/l of sulfuric acid, 0.1 - 50 g/l of oxalic acid and 0.1 - 50 g/l of metal sulfate.
Claim 2
Independent Claim 76 words
A method of forming a yellow-black colored and oxide film on aluminum and aluminum alloys comprising subjecting defatted and washed aluminum and aluminum alloys to treatment of electrolytic oxidation by direct current, ac-dc combined current or pulse wave-form in an electrolyte comprising 5 - 500 g/l of sulfofumaric acid and at least one of 0.1 - 30 g/l of sulfuric acid, 0.1 - 50 g/l of oxalic acid and 0.1 - 50 g/l of metal sulfate.

References Cited (Backward Citations)

DE1913574A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-07-10 1982-01-09 1982-07-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-07-10 1986-01-09 1986-07-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-07-10 1990-01-09 1990-07-11 $7700.00 Window Closed / Lapsed

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