US3658665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic method for producing a colored anodized layer on aluminum and alloys of aluminum
Assignee: Pechiney SA
•
Filing: 1969-04-15
•
Granted: 1972-04-25
•
Expires: 1989-04-15
Abstract
Abstract The invention is addressed to the coloring of aluminum and alloys of aluminum by anodization wherein the aluminum article is immersed as the anode in an electrolytic bath formulated of an aqueous solution of a naphthalene sulphonic acid or alkali metal salt thereof and sulphuric acid, with or without an aliphatic acid of carbon atoms.
Inventors
- 👤 Roland Chretien
- 👤 Henri Richaud
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:27
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/14
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
23 words
A process as claimed in claim 1 in which the sulphuric acid is present in an amount up to 50 grams per liter.
Claim 2
Dependent Claim
22 words
A process as claimed in claim 1 in which the sulphuric acid is present in an amount from 3-10 grams per liter.
Claim 3
Dependent Claim
23 words
A process as claimed in claim 1 in which the disulphonic acid component is present within a range of 1-20 grams per liter.
Claim 4
Dependent Claim
28 words
The process as claimed in claim 1 which includes a step in maintaining the bath at a temperature within the range of 0* to 70* C during electrolysis.
Claim 5
Dependent Claim
26 words
The process as claimed in claim 1 which includes a step in maintaining the bath at a temperature within the range of 15*-30* C during electrolysis.
Claim 6
Dependent Claim
23 words
A process as claimed in claim 1 in which the current that is passed between the electrodes through the bath is direct current.
Claim 7
Dependent Claim
23 words
A process as claimed in claim 1 in which the current that is passed between the electrodes through the bath is alternating current.
Claim 8
Dependent Claim
23 words
A process as claimed in claim 1 in which the current that is passed between the electrodes through the bath is pulsating current.
Claim 9
Dependent Claim
20 words
A process as claimed in claim 1 in which the current is passed at a current density of 1-10 A/dm2.
Claim 10
Dependent Claim
22 words
A process as claimed in claim 1 in which the current is passed at a current density of 1.4 to 4.5 A/dm2.
Claim 11
Dependent Claim
55 words
An electrolytic bath for coloring aluminum and alloys of aluminum by anodization comprising an aqueous solution containing the combination of a naphthalene sulphonic acid selected from the group consisting of 2-naphthol-6, 8-disulphonic acid, 2-naphthol-3, 6-disulphonic acid, 1,8-dihydroxynaphthalene-3, 6-disulphonic acid and 1-naphthol-8-amino-3, 6-disulphonic acid, an aliphatic acid of less than five carbon atoms and sulphuric acid.
Claim 12
Dependent Claim
33 words
An electrolytic bath as claimed in claim 12 in which the naphthalene sulphonic acid or alkali metal salt is present in an amount within the range of 10 to 200 grams per liter.
Claim 13
Dependent Claim
33 words
An electrolytic bath as claimed in claim 12 in which the naphthalene sulphonic acid or alkali metal salt is present in an amount within the range of 50 to 100 grams per liter.
Claim 14
Dependent Claim
33 words
An electrolytic bath as claimed in claim 12 in which the naphthalene sulphonic acid or salt contains an amine group, and is present in the bath in an amount to saturate the solution.
Claim 15
Dependent Claim
28 words
An electrolytic bath as claimed in claim 12 in which the aliphatic acid is present in an amount within the range of 10 to 100 grams per liter.
Claim 16
Dependent Claim
28 words
An electrolytic bath as claimed in claim 12 in which the sulphuric acid is present in an amount within the range of 3 to 10 grams per liter.
Claim 17
Dependent Claim
71 words
An electrolytic bath as claimed in claim 12 in which the naphthalene sulphonic acid or its alkali metal salt is present in an amount within thE range of 10 to 200 grams per liter, the aliphatic acid is present in an amount within the range of 10 to 100 grams per liter and the sulphuric acid is present in an amount within the range of 3 to 10 grams per liter.
Claim 18
Dependent Claim
31 words
An electrolytic bath as claimed in claim 12 in which the aliphatic acid is selected from the group consisting of saturated monocarboxylic acids, saturated dicarboxylic acids and ethylenically unsaturated dicarboxylic acids.
Claim 19
Dependent Claim
35 words
An electrolytic bath as claimed in claim 12 in which the aliphatic acid is selected from the group consisting of acetic acid, propionic acid, oxalic acid, succinic acid, maleic acid, itaconic acid and citraconic acid.
Claim 20
Dependent Claim
51 words
In the method of coloring aluminum and alloys of aluminum by anodizing, the step of immersing the aluminum or alloy of aluminum in an electrolytic bath as claimed in claim 12, as one electrode, providing another electrode in the bath and passing an electric current through the bath between said electrodes.
Claim 21
Dependent Claim
19 words
The method as claimed in claim 21 which includes the step of degreasing the aluminum base alloy before anodization.
Claim 22
Dependent Claim
26 words
The method as claimed in claim 21 which includes the step of sealing the anodized surface with an boiling aqueous solution of an organo metallic salt.
Claim 23
Dependent Claim
36 words
The method as claimed in claim 23 in which the salt dissolved in the sealing solution is nickel acetate present in the solution in an amount within the range of 0.5 to 1 gram per liter.
Claim 24
Dependent Claim
36 words
The method as claimed in claim 21 in which a color ranging from light to deep bronze is produced on aluminum and on aluminum-magnesium-silicon alloys and a black color is produced on aluminum-silicon-magnesium-manganese and aluminum-magnesium-manganese alloys.
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |