Coating solution for metal surfaces
View Patent ↗An aqueous metal treatment composition designed to improve adhesion and corrosion resistance of the metal surface includes an organofunctional silane in combination with a fluorozirconic or fluorotitanic acid, methanesulfonic acid and nitric acid. The methanesulfonic acid acts to reduce sludge formation. Preferably, the composition also includes a fluorosilicic acid which likewise reduces sludge and improves corrosion resistance.
1. An aqueous metal treatment composition comprising an organofunctional silane in combination with a source of at least one of fluorozirconic acid and fluorotitanic acid, or combinations thereof, methane sulfonic acid in an amount of 0.005% to 0.1%, and an acidic nitrogen compound in an amount of 0.0006% to 0.05%.
2. The composition claimed in claim 1 further comprising fluorosilicic acid.
3. The composition claimed in claim 1 wherein said acidic nitrogen compound is selected from the group consisting of nitric acid, urea, and combinations thereof.
4. The composition claimed in claim 1 wherein said organofunctional silane is an aminoalkoxy silane.
5. The composition claimed in claim 1 wherein said organofunctional silane is an alkoxy silane.
6. The composition claimed in claim 1 further comprising a cleaning agent.
7. The composition claimed in claim 1 further comprising an anti-rust agent.
8. An aqueous metal treatment composition comprising an organofunctional silane in combination with a source of zirconium, methanesulfonic acid, and nitric acid, wherein the said composition comprises:
Water,
Organofunctional silane
0.005-0.3%
Fluorozirconic acid
0.005-0.2%
Methanesulfonic acid
0.005-0.1%, and
Nitric acid
0.0006-0.05%
9. The composition claimed in claim 8 further comprising a cleaning agent.
10. The composition claimed in claim 8 further comprising an anti-rust agent.
11. The composition claimed in claim 8 , further comprising a fluorosilicic acid in the range of 0.005-0.07%.
12. A method of treating a metal surface comprising contacting said metal surface with an aqueous based metal treatment composition comprising an organofunctional silane in combination with a source of at least one of fluorozirconic acid and fluorotitanic acid, or combinations there, methane sulfonic acid in an amount of 0.005% to 0.1%, and an acidic nitrogen compound in an amount of 0.0006% to 0.05%.
13. The method claimed in claim 12 wherein said composition further comprises fluorosilicic acid.
14. The method claimed in claim 12 wherein said composition further comprises a cleaning agent.
15. The method claimed in claim 12 wherein said composition further comprises an anti-rust agent.
16. A method of treating a metal surface comprising contacting said metal surface with an aqueous based metal treatment composition comprising an organofunctional silane in combination with a source of zirconium, methane sulfonic acid, and nitric acid, wherein said composition comprises
Water,
Organofunctional silane
0.005-0.3%
Fluorozirconic acid
0.005-0.2%
Methanesulfonic acid
0.005-0.1%, and
Nitric acid
0.0006-0.05%
17. The method claimed in claim 16 , wherein the composition of the method further comprises a fluorosilicic acid in the range of 0.005-0.07%.
18. A metal surface treated with an aqueous based metal treatment composition comprising an organofunctional silane in combination with a source of at least one of fluorotitanic acid and fluorozirconic acid, or combinations thereof, methane sulfonic acid in an amount of 0.005% to 0.1%, and an acidic nitrogen compound in an amount of 0.0006% to 0.05%.