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US4042468A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for electrolytically coloring aluminum and aluminum alloys

Assignee: YKK Corp
•
Filing: 1976-03-03
•
Granted: 1977-08-16
•
Expires: 1996-03-03
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Abstract

Abstract Aluminum or aluminum alloy is first anodized to form an oxide film thereon. Before being colored electrolytically in an electrolytic solution, the anodized basis metal is made anodic in this solution, and direct current is passed therethrough. The basis metal is then electrolyzed in the same solution by use of alternating current for actual coloring operation. The electrolytic solution in use contains at least two metallic salts, together with or without a strongly reducing compound.

Inventors

  • 👤 Mutsuo Hasegawa
  • 👤 Kazuo Aikawa
  • 👤 Shinji Hayashi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 23:19
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/20; C25D11/22; C25D11/14

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 71 words
A process for electrolytically coloring aluminum or aluminum alloy which comprises anodizing a desired basis metal, electrolyzing the anodized basis metal by use of substantially direct current with the basis metal made anodic in an acidic aqueous electrolyte containing at least two coloring metallic salts in an amount of about 5 to 500 grams per liter, and further electrolyzing the basis metal in the same electrolyte by use of alternating current.
Claim 2
Dependent Claim 71 words
A process for electrolytically coloring aluminum or aluminum alloy which comprises anodizing a desired basis metal, electrolyzing the anodized basis metal by use of substantially direct current with the basis metal made anodic in an acidic aqueous electrolyte containing at least two coloring metallic salts in an amount of about 5 to 500 grams per liter, and further electrolyzing the basis metal in the same electrolyte by use of alternating current.
Claim 3
Dependent Claim 33 words
The process as recited in claim 1, wherein the basis metal is electrolyzed by use of the substantially direct current at a voltage in the range of from about 10 to 50 volts.
Claim 4
Dependent Claim 27 words
The process as recited in claim 1, wherein the basis metal is electrolyzed by use of the substantially direct current for not more than about 5 minutes.
Claim 5
Dependent Claim 32 words
The process as recited in claim 1, wherein the basis metal is electrolyzed by use of the alternating current at a voltage in the range of from about 5 to 50 volts.
Claim 6
Dependent Claim 56 words
The process as recited in claim 1, wherein the metallic salts are selected from the group consisting of the inorganic acid salts sulfates, phosphates, hydrochlorides, chromates, and nitrates of the metals nickel, cobalt, chromium, copper, magnesium, iron, cadmium, titanium, manganese, molybdenum, calcium, vanadium, tin, lead, and zinc; and the organic acid salt oxalates, acetates and tartrates.
Claim 7
Dependent Claim 44 words
The process as recited in claim 1, wherein the electrolyte further contains a strong reducing compound selected from the group consisting of dithionites, thiosulfates, bisulfites, sulfurous acid, sulfites, thioglycolic acid and thioglycolates in the amount of from about 0.05 to 10 grams per liter.

References Cited (Backward Citations)

US3962049A Cited
US3878056A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-08-15 1981-02-14 1981-08-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-08-15 1985-02-14 1985-08-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-08-15 1989-02-14 1989-08-16 $7700.00 Window Closed / Lapsed

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