Patent US3622471A successfully refreshed from Google Patents.
US3622471A
Expired / Lapsed
US
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Production of inorganically colored coatings on aluminum
Assignee: Alcan Research and Development Ltd
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Filing: 1968-07-02
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Granted: 1971-11-23
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Expires: 1988-07-02
Abstract
Abstract In procedure and apparatus where inorganically colored coatings on aluminum are produced by first anodizing the aluminum articles and then treating such anodically coated aluminum with alternating current in an acidic bath containing metal ions for producing a colored deposit in the coating, the alternating current treatment is effected between an anodized aluminum workload and a plurality of electrode elements constituting a counterelectrode, which are distributed along a region that faces the workload, e.g. elements of the same metal as the ions in the bath, the distribution and spacing of the elements being of a described nature such as to improve the desired results and to facilitate control. With substantially uniform alternating current density over the anodized aluminum in the above manner, control of operation is further facilitated by maintaining a selected current value condition or conditions for corresponding current density control, preferably such that the color obtained is determinable in accordance with duration of the treatment.
Inventors
- 👤 William Ernest Cooke
- 👤 Paul John Sajben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:10
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/20; C25D11/22; C25D11/005; Y; Y10; Y10S; Y10S204/00; Y10S204/07
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
116 words
A method as defined in claim 1, which includes controlling said alternating current passing between said anodized surface and said electrode elements to provide a predetermined condition or successive predetermined conditions of current value during the time said current is passed, for causing the current density at said anodized surface to have a preselected maintained value or program of successive preselected maintained values, suitable for producing a range of color shades of said colored deposit depending substantially only on the time of so passing said alternating current between said workload and electrode elements, and effecting said passage of alternating current for a time selected to produce a colored deposit of selected color shade in said coating.
Claim 2
Dependent Claim
50 words
A method as defined in claim 1 in which said electrode elements are metal electrode elements having a total effective surface area for passage of current to said anodized surface equal to not more than about 25 percent of the area of said region in which said elements are distributed.
Claim 3
Dependent Claim
24 words
A method as defined in claim 3, in which the metal ions in the bath comprise nickel ions and the electrode elements are nickel.
Claim 4
Dependent Claim
96 words
A method as defined in claim 4, which includes controlling said alternating current passing between said anodized surface and said electrOde elements to provide a predetermined substantially constant current value during the time said current is passed, for maintaining a substantially constant current density at said anodized surface of about 3 amperes per square foot, to produce a colored deposit in said coating, of a shade dependent upon the duration of said time, and effecting said passage of alternating current for a time selected to produce a colored deposit of selected color shade in said coating.
Claim 5
Dependent Claim
18 words
A method as defined in claim 1, in which the metal ions in the bath comprise copper ions.
Claim 6
Dependent Claim
96 words
A method as defined in claim 6, which includes controlling said alternating current passing between said anodized surface and said electrode elements to provide a predetermined substantially constant current value during the time said current is passed, for maintaining a substantially constant current density at said anodized surface of about 5 amperes per square foot, to produce a colored deposit in said coating, of a shade dependent upon the duration of said time, and effecting said passage of alternating current for a time selected to produce a colored deposit of selected color shade in said coating.
Claim 7
Dependent Claim
50 words
A method as defined in claim 1, in which said elements are distributed with center-to-center distances not substantially greater than about 12 inches and have a total effective current-passing area equal to not more than about 25 percent of the area of said region in which said elements are distributed.
Claim 8
Dependent Claim
38 words
A method as defined in claim 1, in which the metal of said ions is nickel and said alternating current is controlled to maintain a current density of about 3 amperes per square foot at said anodized surface.
Claim 9
Dependent Claim
38 words
A method as defined in claim 1, in which the metal of said ions is copper and said alternating current is controlled to maintain a current density of about 5 amperes per square foot at said anodized surface.
Claim 10
Dependent Claim
277 words
In a method of producing an inorganically colored anodic coating on an aluminum surface of a workload wherein said surface has first been anodized to produce an anodic coating thereon and wherein alternating current is passed between said workload and a metal electrode while both are immersed in an aqueous acidic bath containing metal ions for producing a colored deposit in the coating, said electrode being of the same metal as said ions, the procedure comprising passing said alternating current between said anodized surface and only a plurality of metal electrode elements, of said electrode, that are mutually spaced and distributed along a region which faces said workload, said elements having a total effective surface area for passage of current to said anodized surface equal to at least about 3 percent of the area of said region in which said elements are distributed, said electrode consisting of a multiplicity of said elements distributed with center-to-center distances not greater than about 18 inches and not substantially greater than the distance between said region and said workload, and said method including controlling the electrical operation of said alternating current treatment by detecting the value of said alternating current and in accordance with said detected value, controlling said current to provide a predetermined substantially constant value thereof during the time said current is passed, for maintaining at said anodized surface a selected current density suitable for producing a range of color shades of said colored deposit depending substantially only on the time of so passing said current, and effecting said passage of alternating current for a time selected to produce a colored deposit of selected color shade in said coating.
Claim 11
Dependent Claim
56 words
A method as defined in claim 11, in which said electrode elements are spaced apart by distances which are at least several times the transverse dimension of the effective current-passing surface of each element, said elements having a total effective current-passiNg area equal to not more than about 25 percent of the area of said region.
Claim 12
Dependent Claim
19 words
A method as defined in claim 12, in which the metal of said ions and electrode elements is nickel.
Claim 13
Dependent Claim
19 words
A method as defined in claim 12, in which the metal of said ions and electrode elements is copper.
Claim 14
Dependent Claim
284 words
In a method of producing an inorganically colored anodic coating on an aluminum surface of a workload wherein said surface has first been anodized to produce an anodic coating thereon and wherein alternating current is passed between said workload and an electrode while both are immersed in an aqueous acidic bath containing metal ions for producing a colored deposit in the coating, the procedure comprising passing said alternating current between said anodized surface and only a plurality of electrode elements, of said electrode, that are mutually spaced and distributed along a region which faces said workload, said electrode consisting of a multiplicity of said elements distributed with center-to-center distances not greater than about 18 inches and not larger than about 50 percent more than the distance between said region and said workload and said elements having a total effective surface area for passage of current to said anodized surface equal to at least about 3 percent of the area of said region in which said elements are distributed, and controlling the electrical operation of said alternating current treatment by detecting the value of said alternating current and in accordance with said detected value, controlling said alternating current to provide a predetermined condition or successive predetermined conditions of current value, for causing the current density at said anodized surface to have a preselected maintained value or program of successive preselected maintained values, suitable for producing a range of color shades of said colored deposit depending substantially only on the time of so passing said alternating current between said workload and electrode elements, and effecting said passage of alternating current for a time selected to produce a colored deposit of selected color shade in said coating.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |