US3646946A
Expired / Lapsed
US
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Copper alloy cleaning process
Assignee: Olin Corp
•
Filing: 1969-01-06
•
Granted: 1972-03-07
•
Expires: 1989-01-06
Abstract
Abstract A process for removing surface oxides from copper alloys. For example, these alloys which form, on annealing, A12O3 and related oxides are uniquely cleaned by a process which consists of a duplex treatment requiring a first immersion in a hot alkaline solution followed by a second immersion in a hot mineral acid solution.
Inventors
- 👤 James A Ford
- 👤 Stuart R Saunders
- 👤 Elmer J Caule
- 👤 Charles D Mclain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:15
CPC Classifications
C; C23; C23G; C23G1/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
18 words
A process according to claim 1 in which the copper base alloy surface has a complex oxide thereon.
Claim 2
Dependent Claim
20 words
A process according to claim 1 in which the temperature of the acid bath is from 125* to 175* F.
Claim 3
Dependent Claim
14 words
A process according to claim 1 in which said alkaline solution contains lithium hydroxide.
Claim 4
Dependent Claim
14 words
A process according to claim 1 in which said alkaline solution contains sodium hydroxide.
Claim 5
Dependent Claim
18 words
A process according to claim 1 in which the acid solution consists of an aqueous solution of H2SO4.
Claim 6
Dependent Claim
27 words
A process according to claim 1 in which sodium dichromate is present in the acid solution in an amount of from 1 to 8 ounces per gallon.
Claim 7
Dependent Claim
21 words
A process according to claim 1 in which the thickness of the oxide after cleaning is less than 10 Angstrom units.
Claim 8
Dependent Claim
17 words
A process according to claim 1 in which the oxide is at least in part a spinel.
Claim 9
Dependent Claim
18 words
A process according to claim 1 wherein the temperature of said alkaline solution is at the boiling point.
Claim 10
Dependent Claim
107 words
A process for cleaning a copper base alloy surface having a thermally formed oxide thereon, comprising: immersing the surface to be cleaned in an aqueous alkaline solution having a pH of from 11 to 14 at a temperature from 160* F. to the boiling point of said aqueous alkaline solution for from 5 seconds to 1 minute; and then immersing the surface to be cleaned in an aqueous mineral acid solution at a temperature from 125* to 175* F. for a period of from 5 seconds to 1 minute, said acid solution having an acid equivalent to an H2SO4 solution of 5 to 20 percent by volume.
Claim 11
Dependent Claim
18 words
A process according to claim 11 wherein the temperature of said alkaline solution is at the boiling point.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-07 | 1975-09-06 | 1976-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-07 | 1979-09-06 | 1980-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-07 | 1983-09-06 | 1984-03-07 | $7700.00 | Window Closed / Lapsed |