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US4070255A
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Process for electrolytically coloring aluminum and aluminum alloys
Assignee: YKK Corp
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Filing: 1976-03-03
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Granted: 1978-01-24
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Expires: 1996-03-03
Abstract
Abstract Aluminum or aluminum alloy is first anodized to form an oxide film thereon. With the pores in this oxide film unsealed, the basis metal is then electrolyzed by use of alternating current at a preselected starting voltage, and this voltage is lowered at least once before completion of the electrolytic coloring of the basis metal. The electrolytic solution in which the electrolysis is effected contains either at least three metallic salts or at least two metallic salts and a strong reducing compound.
Inventors
- 👤 Mutsuo Hasegawa
- 👤 Kazuo Aikawa
- 👤 Katsuyuki Nagata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:58
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/20; C25D11/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
73 words
A process for electrolytically coloring aluminum or aluminum alloy which comprises anodizing a desired basis metal, and electrolyzing the anodized basis metal in an acidic aqueous electrolyte by use of a constantly applied alternating current, the voltage at which the anodized basis metal is electrolyzed being lowered at least once by a value of from about 1 to 10 volts but not to a sustained zero potential in the course of the electrolysis.
Claim 2
Dependent Claim
73 words
A process for electrolytically coloring aluminum or aluminum alloy which comprises anodizing a desired basis metal, and electrolyzing the anodized basis metal in an acidic aqueous electrolyte by use of a constantly applied alternating current, the voltage at which the anodized basis metal is electrolyzed being lowered at least once by a value of from about 1 to 10 volts but not to a sustained zero potential in the course of the electrolysis.
Claim 3
Dependent Claim
28 words
The process as recited in claim 1, wherein the anodized basis metal is electrolyzed at a starting voltage in the range of from about 6 to 50 volts.
Claim 4
Dependent Claim
22 words
The process as recited in claim 1, wherein the voltage is lowered within about 2 minutes following the start of the electrolysis.
Claim 5
Dependent Claim
26 words
The process as recited in claim 1, wherein the electrolyte contains at least three metallic salts in a concentration of 5 to 500 grams per liter.
Claim 6
Dependent Claim
40 words
The process as recited in claim 4, wherein the metallic salts are selected from the group consisting of inorganic and organic acid salts of nickel, cobalt, chromium, copper, magnesium, iron, cadmium, titanium, manganese, molybdenum, calcium, vanadium, tin, lead, and zinc.
Claim 7
Dependent Claim
49 words
The process as recited in claim 1, wherein the electrolyte contains at least two metallic salts and a strong reducing compound selected from the group consisting of dithionites, thiosulfates, bisulfites, sulfurous acid, sulfites, thioglycolic acid, and thioglycolates in a concentration of from about 0.05 to 10 grams per liter.
Claim 8
Dependent Claim
40 words
The process as recited in claim 6, wherein the metallic salts are selected from the group consisting of inorganic and organic acid salts of nickel, cobalt, chromium, copper, magnesium, iron, cadmium, titanium, manganese, molybdenum, calcium, vanadium, tin, lead, and zinc.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |