Claims
- 1. A process for phosphating and after-rinsing a metallic surface of which at least 50% by weight consists of one or more of iron, zinc and aluminum, said process comprising operations of:(a) phosphating the surface by contacting it with a nitrite- and nickel-free water-based phosphating solution which has a pH value of 2.7 to 3.6 and comprises: 0.3 to 3 g/l of Zn(II); 5 to 40 g/l of phosphate ions; and at least one of the following accelerators: 0.2 to 2 g/l of m-nitrobenzene sulfonate ions; 0.1 to 10 g/l of hydroxylamine in free or bound form; 0.05 to 2 g/l of m-nitrobenzoate ions; 0.05 to 2 g/l of p-nitrophenol; and 1 to 70 mg/l of hydrogen peroxide in free or bound form; and, after phosphating, with or without intermediate rinsing with water,(b) rinsing the surface phosphated in step (a) with an aqueous solution with a pH value of 3 to 7 which contains 0.01 to 0.1 g/l of copper cations.
- 2. A process as claimed in claim 1, wherein the phosphating solution used in step (a) additionally contains one or more of the following cations: 0.2 to 4 g/l of manganese(II), 0.2 to 2.5 g/l of magnesium(II), 0.2 to 2.5 g/l of calcium(II), 0.01 to 0.5 g/l of iron(II), 0.2 to 1.5 g/l of lithium(I), 0.02 to 0.8 g/l of tungsten(VI), and 0.001 to 0.03 g/l of copper(II).
- 3. A process as claimed in claim 2, wherein the phosphating solution used in step (a) additionally contains up to 2.5 g/l of total fluoride, including up to 0.8 g/l of free fluoride.
- 4. A process as claimed in claim 3, wherein the after-rinse solution used in step (b) has a pH value of 3.4 to 6.
- 5. A process as claimed in claim 4, wherein the after-rinse solution used in step (b) has a temperature of 20 to 50° C.
- 6. A process as claimed in claim 5; wherein the after-rinse solution used in step (b) is sprayed onto the metal surface phosphated in step (a).
- 7. A process as claimed in claim 6, wherein the after-rinse solution used in step (b) is allowed to act on the phosphated metal surface for 0.5 to 10 minutes.
- 8. A process as claimed in claim 7, wherein no intermediate rinsing is carried out between steps (a) and (b).
- 9. A process as claimed in claim 1, wherein the phosphating solution used in step (a) additionally contains up to 2.5 g/l of total fluoride, including up to 0.8 g/l of free fluoride.
- 10. A process as claimed in claim 9, wherein the after-rinse solution used in step (b) has a pH value of 3.4 to 6.
- 11. A process as claimed in claim 10, wherein the after-rinse solution used in step (b) has a temperature of 20 to 50° C.
- 12. A process as claimed in claim 11, wherein no intermediate rinsing is carried out between steps (a) and (b).
- 13. A process as claimed in claim 12, wherein the after-rinse solution used in step (b) is allowed to act on the phosphated metal surface for 0.5 to 10 minutes.
- 14. A process as claimed in claim 1, wherein the after-rinse solution used in step (b) has a pH value of 3.4 to 6.
- 15. A process as claimed in claim 14, wherein the after-rinse solution used in step (b) has a temperature of 20 to 50° C.
- 16. A process as claimed in claim 15, wherein no intermediate rinsing is carried out between steps (a) and (b).
- 17. A process as claimed in claim 16, wherein the after-rinse solution used in step (b) is allowed to act on the phosphated metal surface for 0.5 to 10 minutes.
- 18. A process as claimed in claim 1, wherein the after-rinse solution used in step (b) has a temperature of 20 to 50° C.
- 19. A process as claimed in claim 18, wherein no intermediate rinsing is carried out between steps (a) and (b).
- 20. A process as claimed in claim 1, wherein no intermediate rinsing is carried out between steps (a) and (b).
Priority Claims (1)
Number |
Date |
Country |
Kind |
195 11 573 |
Mar 1995 |
DE |
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 08/930,565 filed Sep. 29, 1997 now U.S. Pat. No. 6,040,224 as the U.S. National Stage of International Application PCT EP96/01196 filed Mar. 20, 1996.
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Number |
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Date |
Kind |
4600447 |
Opitz et al. |
Jul 1986 |
A |
5268041 |
Gehmecker et al. |
Dec 1993 |
A |
6090224 |
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Jul 2000 |
A |
Continuations (1)
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Number |
Date |
Country |
Parent |
08/930565 |
|
US |
Child |
09/617886 |
|
US |