US3787295A
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Method of electrolytic coloring of oxide layers on aluminum and aluminum base alloys
Assignee: Rio Tinto Switzerland AG
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Filing: 1971-04-01
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Granted: 1974-01-22
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Expires: 1991-04-01
Abstract
Abstract Method for electrolytic coloring of oxide layers produced by anodisation on aluminum and aluminum alloys, in at least two color sequences, consisting in using one coloring electrolyte which contains at least two metal salts of which each one renders different colors to the others, for example copper and tin salts, the different color sequences being obtained by adjusting the electrolysis AC-current voltage adequately. The counter electrode may be of the same metal that is dissolved in form of a salt in the electrolyte.
Inventors
- 👤 F Endinger
- 👤 W Zweifel
- 👤 F Schneeberger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:31
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/20; C25D11/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
67 words
Method according to claim 1, in which said colouring electrolyte contains at least two kinds of differently colouring ions of the metals in the Cu, Ag, Cd, Mn, Sn, Ni, Co and Mo group and as anion-producing acids at least one acid or one salt of the citric, tartaric, maleic, succinic, fumaric, adipic, acetic, lactic, malonic, phthalic, sulfuric, selenic, phosphoric, fluoboric, formic, sulfamic, sulfosalicylic, phenolsulfonic acids group.
Claim 2
Dependent Claim
29 words
Method according to claim 2 in which in the said colouring electrolyte at least two different acids or their salts are used as anion-producing acids or as acid radicals.
Claim 3
Dependent Claim
71 words
Method according to claim 3 in which the said colouring electrolyte contains at least Cu ions and tin ions, and as anion-producing acids at least one acid or one salt of the acids of the citric, tartaric, maleic, succinic, fumaric, adipic, acetic, lactic, malonic, phthalic acids group and at least one further acid or salt of an acid of the sulfuric, selenic, phosphoric, fLuoboric, formic, sulfamic, sulfo-salicylic, sulfanic, phenosulfonic acids group.
Claim 4
Dependent Claim
130 words
Method for colouring previously anodised protective layers on aluminium and aluminium base alloys in various colour sequences by means of electrolytic treatment of the protective layers with alternating current under the application of counter electrodes in acidiferous electrolytes containing colouring-metal salts, in which a single colouring electrolyte is used containing salts of at least two colouring metals of which each one renders a different colour from the other or others and wherein in this same electrolyte these different colours are obtained by varying the value of the electrical voltage for the electrolytic treatment, wherein a colouring electrolyte is used containing: 0.5 up to 100 g/l tin-II-sulfate 0.5 up to 70 g/l CuSO4 . 5 H2O 0.5 up to 100 g/l citric acid 0.5 up to 100 g/l sulfuric acid conc.
Claim 5
Dependent Claim
43 words
Method according to claim 5 in which a colouring electrolyte is used containing: 5 up to 20 g/l tin-II-sulfate 5 up to 10 g/l CuSO4 . 5 H2O 5 up to 20 g/l citric acid 5 up to 20 g/l sulfuric acid conc.
Claim 6
Dependent Claim
42 words
Method according to claim 6 in which a colouring electrolyte is used containing 13 up to 17 g/l tin-II-sulfate 5 up to 10 g/l CuSO4 . 5 H2O 8 up to 12 g/l citric acid 8 up to 12 g/l sulfuric acid.
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |