US3773631A
Expired / Lapsed
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Aqueous electrolytic bath for coloring anodic oxide layers on aluminum and aluminum alloy substrates and process for coloring said substrates
Assignee: GP-CHEMIE A CORP OF GERMANY GmbH
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Filing: 1971-10-14
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Granted: 1973-11-20
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Expires: 1991-10-14
Abstract
Abstract Coloring aqueous electrolytic baths containing aliphatic aminocarboxylic acids and/or salts thereof in addition to coloring metal salt compounds are used to color anodic oxide layers on aluminum and aluminum alloy substrates by alternating current treatment in said aqueous electrolytic baths.
Inventors
- 👤 W Immel
- 👤 L Laser
- 👤 W Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:05
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/20; C25D11/22
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
24 words
An improvement according to claim 1 wherein the amino acid is present in an amount up to the saturation limit of the electrolyte bath.
Claim 2
Dependent Claim
29 words
An improvement according to claim 2 wherein at least one amino acid is present in an amount of between 2 and 200 g per liter in the electrolyte bath.
Claim 3
Dependent Claim
24 words
An improvement according to claim 3 wherein the amino acid is present in an amount between 5 and 100 g/liter in the electrolyte bath.
Claim 4
Dependent Claim
20 words
An improvement according to claim 1 wherein said aminocarboxylic acid has an isoelectric point not in excess of pH 7.
Claim 5
Dependent Claim
21 words
An improvement according to claim 1 wherein the isoelectric point of the amino acid is not higher than about pH 6.5.
Claim 6
Dependent Claim
24 words
An improvement according to claim 1 wherein the coloring metal salts are water soluble coloring heavy metal salts of an organic or inorganic acid.
Claim 7
Dependent Claim
23 words
An improvement according to claim 1 wherein in the electrolyte bath containing coloring metal salts there is present at least one inorganic acid.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |