Coated metal strip

• US 5,470,667 A
• Filed: 11/14/1994
• Issued: 11/28/1995
• Est. Priority Date: 04/05/1993
• Status: Expired due to Term

• Current Assignee: Revere Copper Products, Inc.
• Original Assignee: The Louis Berkman Company
• Inventors: Zamanzadeh, Mehrooz, Carey, Jay F. II
• Primary Examiner(s): ZIMMERMAN, JOHN J
• Application Number:
  US08/338,386
• Time in Patent Office: 379 Days
• Field of Search: 428/658, 428/659, 428/935, 428/939, 428/646-648, 428/650, 428/674, 428/685, 427/433, 148/242
• US Class Current: 428/659
• CPC Class Codes: C23C 2/024 by cleaning or etching
• CPC Class Codes: C23C 2/06 Zinc or cadmium or alloys based thereon
• CPC Class Codes: C23C 2/08 Tin or alloys based thereon
• CPC Class Codes: C25D 5/12 at least one layer being of nickel or chromium
• CPC Class Codes: Y02A 30/254 Roof garden systems; Roof coverings with high solar reflectance
• CPC Class Codes: Y02B 80/00 Architectural or constructional elements improving the thermal performance of buildings
• CPC Class Codes: Y10S 428/939 Molten or fused coating
• CPC Class Codes: Y10T 428/12792 Zn-base component
• CPC Class Codes: Y10T 428/12799 Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/12979 Containing more than 10% nonferrous elements [e.g., high alloy, stainless]

Abstract

A corrosion-resistant colored architectural material which is essentially lead free and is not highly reflective. The coating on the material is a two-phase metallic coating comprised of a large weight percentage of zinc and a relatively large weight percentage of tin. The tin-zinc composition provides for both a highly corrosive-resistant coating which protects the surface of the architectural material from oxidation and also produces a gray, earth tone colored which is not highly reflective.

Claims

1. A metal strip unwound from a roll of strip and coated in a continuous hot dip process forming a coating with a highly corrosive-resistant, two phase tin-zinc colored metallic coating, said coating comprising at least 65 weight percent zinc, at least 15 weight percent tin and at least 0.01 weight percent metallic stabilizer wherein said stabilizer is a metal selected from the group consisting of bismuth, antimony and mixtures thereof.

2. A coated metal strip as defined in claim 1, wherein said weight percent of said metal stabilizer is up to 9.2 weight percent.

3. A coated metal strip as defined in claim 2, wherein said metal additive includes 0.01-2.0 weight percent copper.

4. A coated metal strip as defined in claim 1, wherein said alloy contains lead.

5. A coated metal strip as defined in claim 4, wherein said lead content is less than 0.01 weight percent.

6. A coated metal strip as defined in claim 1, wherein said base metal strip is coated with a thin nickel layer prior to applying said alloy coating.

7. A coated metal strip as defined in claim 6, wherein said nickel layer has a thickness up to 3 microns.

8. A coated metal strip as defined in claim 1, wherein said metal strip is stainless steel.

9. A coated metal strip including a base strip of steel or copper with parallel surfaces both of which are coated with a highly corrosive-resistant, homogeneous two-phase tin-zinc alloy with zinc being the primary constituent and tin forming one of said two-phases, said coating being applied by continuously passing the continuous metal strip through a bath of molten tin-zinc alloy at a speed to deposit onto said base strip an impervious two-phase layer of said tin-zinc alloy having a uniform thickness on both surfaces in the range of 0.001-0.05 inch, said two-phase tin-zinc alloy coating comprising discrete sections of zinc in a tin rich matrix, said two-phases being formed by proportioning the zinc and tin to provide a majority by weight zinc and over 15 percent by weight tin with 0.01-11.25 percent by weight of said coating alloy being one or more metals additive, which additive does not change the two-phase characteristic of said coating alloy deposited on the moving strip wherein said metal additives are selected from the group consisting of antimony, bismuth, copper, iron and mixtures thereof.

10. A coated metal strip as defined in claim 9, wherein said weight percent of said metal additive is up to 2.0 weight percent.

11. A coated metal strip as defined in claim 9, wherein said zinc content is 65-85 weight percent and said tin content is 15-35 weight percent.

12. A coated metal strip as defined in claim 9, wherein said alloy includes at least 0.01 weight percent metal stabilizer selected from the group consisting of antimony, bismuth and mixtures thereof.

13. A coated metal strip as defined in claim 9, wherein said coating thickness is 0.001 to 0.002.

14. A coated metal strip as defined in claim 9, wherein said alloy contains lead.

15. A coated metal strip as defined in claim 14, wherein said lead content is less than 0.01 weight percent.

16. A coated metal strip as defined in claim 9, wherein said base metal strip is coated with a thin nickel layer prior to applying said alloy coating.

17. A coated metal strip as defined in claim 16, wherein said nickel layer has a thickness up to 3 microns.

18. A coated metal strip as defined in claim 16, wherein said nickel layer is coated by an electroplating process.

19. A coated metal strip including a base strip of steel or copper with parallel surfaces both of which are coated with a highly corrosive-resistant, homogeneous two-phase tin-zinc alloy with zinc being the majority constituent and tin forming at least 15 weight percent of said two-phases, said coating being applied by continuously passing the continuous metal strip through a bath of molten tin-zinc alloy at a speed to deposit onto said base strip an impervious two-phase layer of said tin-zinc alloy having a uniform thickness on both surfaces in the range of 0.001-0.05 inch, said two-phase tin-zinc alloy coating comprising a majority of zinc and formed by discrete sections of zinc in a tin rich matrix, and wherein said base strip is plated with a thin layer of metal prior to applying said two-phase metallic coating, wherein said two-phase coating alloy includes 0.01-2.0 weight percent metal additive selected from the group consisting of antimony, bismuth, copper, iron and mixtures thereof.

20. A coated steel strip as defined in claim 19, wherein said metal layer is nickel.

21. A coated metal strip as defined in claim 19, wherein said metal layer thickness is up to 3 microns.

22. A coated metal strip as defined in claim 19, wherein said metal layer is electroplated onto said metal strip.

23. A coated metal strip as defined in claim 19, wherein said two-phase coating alloy includes lead.

24. A coated metal strip as defined in claim 19, wherein said steel is stainless steel.

25. A coated metal strip as defined in claim 19, wherein said zinc content is 65-85 weight percent and said tin content is 15-35 weight percent.

26. A coated metal strip as defined in claim 19, wherein said metal additive includes 0.01-2.0 weight percent copper.

27. A coated metal strip including a base strip of stainless steel with parallel surfaces both of Which are coated with a highly corrosive-resistant, homogeneous two-phase tin-zinc alloy, said coating being applied by continuously passing the continuous metal strip through a bath of molten tin-zinc alloy at a speed to deposit onto said base strip an impervious two-phase layer of said tin-zinc alloy having a uniform thickness on both surfaces in the range of 0.001-0.05 inch, said two-phase tin-zinc alloy coating comprising a majority of zinc and at least 15 weight percent tin and formed of discrete sections of zinc in a tin matrix, wherein said two-phase coating alloy includes 0.01-2.0 weight percent metal additive selected from the group consisting of antimony, bismuth, cooper iron and mixtures thereof.

28. A coated metal strip as defined in claim 27, wherein said strip includes chromium.

29. A coated metal strip as defined in claim 27, wherein said strip includes nickel.

30. A coated metal strip as defined in claim 28, wherein said strip includes nickel.

31. A coated material strip including a base strip of stainless steel with parallel surfaces both of which are coated with a highly corrosive-resistant, homogeneous two-phase tin-zinc alloy, said coating being applied by continuously passing the continuous metal strip through a bath of molten tin-zinc alloy at a speed to deposit onto said base strip an impervious two-phase layer of said tin-zinc alloy having a uniform thickness on both surfaces in the range of 0.001-0.05 inch, said two-phase tin-zinc alloy coating comprising a majority of zinc and at least 15 weight percent tin and formed of discrete sections of zinc in a tin matrix, wherein said alloy includes 0.01-2.0 weight percent cooper.