Patent US3898981A successfully refreshed from Google Patents.
Patent US4195124A successfully refreshed from Google Patents.
US4195124A
Expired / Lapsed
US
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Solar radiation energy absorber
Assignee: Sekisui Chemical Co Ltd
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Filing: 1977-04-21
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Granted: 1980-03-25
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Expires: 1997-04-21
Abstract
Abstract A solar energy absorber consisting of a metallic copper or copper alloy substrate and a black to dark brown copper oxide coating on its surface. The copper oxide coating is formed by treating the surface of the substrate with an aqueous alkaline solution containing peroxodisulfuric acid or an inorganic peroxodisulfate. The solution may be activated by adding an oxidizing agent or applying ultraviolet or ultrasonic irradiation.
Inventors
- 👤 Hiroshi Doi
- 👤 Shiyuichiro Ochiai
- 👤 Shigeyuki Kawai
- 👤 Kazuaki Miyamoto
- 👤 Tadashi Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:58
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/60; C23C22/63; 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; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
127 words
A selective solar energy absorber consisting of a metallic copper or copper alloy substrate and a permanent black to dark brown copper oxide coating having a thickness of 0.2 to 0.6 microns on its surface, said coating having been produced by dipping the substrate in an aqueous alkaline solution consisting essentially of 3 to 10% by weight, based on the weight of water, of an alkali metal hydroxide or an alkali metal carbonate and 0.5 to 10% by weight, based on the weight of the aqueous alkaline solution of at least one member selected from the group consisting of peroxodisulfuric acid, alkali metal peroxodisulfate and ammonium peroxodisulfate, at a temperature of from 40° C. to 80° C. for a period of from 1 minute to 20 minutes.
Claim 2
Dependent Claim
127 words
A selective solar energy absorber consisting of a metallic copper or copper alloy substrate and a permanent black to dark brown copper oxide coating having a thickness of 0.2 to 0.6 microns on its surface, said coating having been produced by dipping the substrate in an aqueous alkaline solution consisting essentially of 3 to 10% by weight, based on the weight of water, of an alkali metal hydroxide or an alkali metal carbonate and 0.5 to 10% by weight, based on the weight of the aqueous alkaline solution of at least one member selected from the group consisting of peroxodisulfuric acid, alkali metal peroxodisulfate and ammonium peroxodisulfate, at a temperature of from 40° C. to 80° C. for a period of from 1 minute to 20 minutes.
Claim 3
Dependent Claim
31 words
The selective absorber of claim 1 wherein the aqueous alkaline solution is activated to decrease the temperature or reduce the treatment time in a blackening reaction of copper or copper alloy.
Claim 4
Dependent Claim
36 words
The selective absorber of claim 2 wherein the activation is carried out by applying ultraviolet irradiation to the solution to decrease the temperature or reduce the treatment time in a blackening reaction of copperor copper alloy.
Claim 5
Dependent Claim
37 words
The selective absorber of claim 2 wherein the activation is carried out by applying ultrasonic irradiation to the solution to decrease the temperature or reduce the treatment time in a blackening reaction of copper or copper alloy.
Claim 6
Dependent Claim
20 words
The selective absorber of claim 2 wherein the activation is carried out by adding an oxidizing agent to the solution.
Claim 7
Dependent Claim
13 words
The selective absorber of claim 5 wherein the oxidizing agent is potassium chromate.
References Cited (Backward Citations)
US1844420A
Cited
US2475981A
Cited
US2457493A
Cited
US2917817A
Cited
US3279957A
Cited
US3332882A
Cited
US3630866A
Cited
US3809588A
Cited
US3726800A
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US3839098A
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US3927189A
Cited
US4029853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-25 | 1983-09-24 | 1984-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-25 | 1987-09-24 | 1988-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-25 | 1991-09-24 | 1992-03-25 | $7700.00 | Window Closed / Lapsed |