US4087288A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solar absorber surfaces
Assignee: Commonwealth Scientific and Industrial Research Organisation
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Filing: 1976-07-14
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Granted: 1978-05-02
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Expires: 1996-07-14
Abstract
Abstract A method for improving the selectivity of a black copper oxide absorber surface which comprises treating the surface with a solution containing chromate ions and ammonium ions. Copper black surfaces when so treated and solar absorbers with such surfaces are included.
Inventors
- 👤 Alan Forrest Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:38
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/24; F; F24; F24S; F24S70/00; F24S70/20; F24S70/225; F24S70/25; Y; Y02; Y02E; Y02E10/00; Y02E10/40; Y10; Y10S; Y10S126/00; Y10S126/907; Y10S126/908
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
50 words
A method for improving the selectivity of a black copper oxide absorber surface which comprises contacting the surface with a solution containing chromate ions and ammonium ions for a period of time sufficient to increase solor absorption characteristics and minimize infrared re-emission characteristics of said black copper oxide absorber surface.
Claim 2
Independent Claim
50 words
A method for improving the selectivity of a black copper oxide absorber surface which comprises contacting the surface with a solution containing chromate ions and ammonium ions for a period of time sufficient to increase solor absorption characteristics and minimize infrared re-emission characteristics of said black copper oxide absorber surface.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1, wherein the solution is an ammonium chromate solution.
Claim 4
Dependent Claim
30 words
A method as claimed in claim 1, wherein the solution contains about 10% by weight of ammonium chromate or the equivalent concentrations of a chromate salt and an ammonium salt.
Claim 5
Dependent Claim
23 words
A method as claimed in claim 1, wherein the treatment is carried out at a temperature of from 20° C to 80° C.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 4, wherein the temperature is from 45° C to 80° C and the treatment time is from 5 to 20 minutes.
Claim 7
Dependent Claim
14 words
A black copper absorber having a surface produced by the method of claim 1.
Claim 8
Dependent Claim
47 words
A method for forming a black copper oxide absorber for solar energy absorption, which comprises forming an absorber having a surface of copper or a copper alloy, forming a copper black film on the surface, and treating the black film by the method claimed in claim 1.
Claim 9
Dependent Claim
22 words
A method as claimed in claim 1, wherein said solution is one which does not dissolve a black copper oxide absorper surface.
Claim 10
Dependent Claim
16 words
A method as claimed in claim 1, wherein the solution is alkaline, neutral or slightly acid.
Claim 11
Dependent Claim
23 words
A method as claimed in claim 9, wherein the treatment is carried out at a temperature of from 20° C to 80° C.
Claim 12
Dependent Claim
33 words
A method as claimed in claim 9, wherein the treatment is carried out at a temperature of from 45° C to 80° C and the treatment time is from 5 to 20 minutes.
Claim 13
Dependent Claim
30 words
A method as claimed in claim 11, wherein the solution contains about 10% by weight of ammonium chromate or the equivalent concentrations of a chromate salt and an ammonium salt.
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) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |