US3770600A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for coloring the surface of aluminum workpieces by anodization
Assignee: Vereinigte Aluminium Werke AG
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Filing: 1970-10-08
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Granted: 1973-11-06
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Expires: 1990-10-08
Abstract
Abstract This invention relates to the coloring of the surface of aluminum workpieces by anodization process wherein the anolyte consists principally of maleic acid with a small proportion of sulfuric acid for conductivity, and the catholyte consists of an organic acid of good conductivity or a mixture of organic acid to which a small quantity of sulfuric acid is added to conductivity. The anolyte and the catholyte are separated by a porous, ionpermeable diaphragm.
Inventors
- 👤 W Sautter
- 👤 A Gilak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:41
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/14; C25D11/005; C25D17/00; C25D17/002
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
37 words
A process as defined in claim 1 in which the anolyte comprises approximately 20 percent by weight of maleic acid, approximately 1 percent by weight of oxalic acid, and approximately 0.4 percent by weight of oxalic acid.
Claim 2
Dependent Claim
33 words
A process as defined in claim 1 in which the catholyte comprises between 3 and 8 percent by weight of oxalic acid and between 0.2 and 1 percent by weight of sulfuric acid.
Claim 3
Dependent Claim
34 words
A process as defined in claim 1 in which the organic acid in the catholyte is oxalic, citric, sulfosalicylic, or sulfophthalic acid, in an amount equivalent to between 5 and 30 percent by weight.
References Cited (Backward Citations)
US3634213A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |