Claims
- 1. A metal sheet adapted to selectively absorb solar radiation comprising a stainless steel sheet base containing iron and chromium and a selective absorption film formed on said base, wherein said selected absorption film
- is a chemical conversion film which comprises a chromium oxide, an iron oxide, a chromium hydroxide, metallic iron, and metallic chromium;
- has a concentration profile thereacross, so that the total concentration of said metallic iron and said metallic chromium is from 3 to 10 atomic % at an outer surface thereof and is the same as that of said base at an inner surface thereof on said base, said concentration increasing in a direction from said outer surface to said inner surface;
- has a thickness of from 1000 to 2500 .ANG.; and
- has an electric resistance not greater than 1.6 M.OMEGA./cm.sup.2.
- 2. A selective absorption sheet of solar radiation according to claim 1, wherein said metal, which is dispersed at the outer surface of said selective absorption film of solar radiation, is mainly iron.
- 3. A selective absorption sheet of solar radiation according to claim 1, wherein said stainless steel sheet, on which said selective absorption film is formed, has a surface roughness of from Ra 0.08 to 0.5.
- 4. A selective absorption sheet of solar radiation according to claim 1, wherein minute pores present on the surface of said selective absorption film are not more than fifty per .mu.m.sup.2 of said film.
- 5. A selective absorption sheet of solar radiation according to claim 1, wherein said selective absorption film is formed on only one surface of said base.
Priority Claims (1)
Number |
Date |
Country |
Kind |
55-156392 |
Nov 1980 |
JPX |
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of our earlier application Ser. No. 541,491 filed Oct. 17, 1983, now U.S. Pat. No. 4,491,487, which in turn is a continuation of our application Ser. No. 318,564 filed Nov. 5, 1981, now abandoned.
US Referenced Citations (3)
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Date |
Kind |
4026737 |
Tekahari et al. |
May 1977 |
|
4097311 |
Ishibashi et al. |
Jun 1978 |
|
4491487 |
Mizunuma et al. |
Jan 1985 |
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Foreign Referenced Citations (4)
Number |
Date |
Country |
2423877 |
Dec 1974 |
DEX |
2288796 |
Jun 1976 |
FRX |
53-34653 |
Sep 1978 |
JPX |
54-15327 |
Jun 1979 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
541491 |
Oct 1983 |
|
Continuations (1)
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Number |
Date |
Country |
Parent |
318564 |
Nov 1981 |
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