| 摘要 |
The invention is directed to an acidic aqueous metal pretreatment solution that comprises amino-functional organosilanes, complex anions of the elements Zr, Ti, Hf and/or Si as well as oxyacids of phosphorus; a process for the treatment of metal substrates, especially selected from zinc and zinc-coated steel substrates, wherein metal pretreatment solutions of this invention are applied to reduce corrosion when applied to metal surfaces and in addition confer good adhesion properties for subsequently coated organic lacquers. |
| 主权项 |
1. An acidic aqueous metal pretreatment solution comprising:
a) at least one organosilane with at least one hydrolyzable substituent and one to three non-hydrolyzable substituents, present in an amount of more than 0.2 wt.-% calculated with respect to the element Si, wherein at least one of the non-hydrolyzable substituents carries at least one amino group, and wherein each silicon atom of the at least one organosilane has a total number of substituents that is four; b) at least one complex anion of an element selected from B, Zr, Ti, Hf and/or Si; and c) at least one oxyacid of phosphorus;wherein the metal pretreatment solution has a pH in a range from 2.0 to 5.5 and a molar ratio of a total amount of organosilanes, calculated with respect to the element Si, to a total amount of complex anions of the elements B, Zr, Ti, Hf and/or Si, calculated with respect to the elements B, Zr, Ti, Hf and/or Si, in a range from 80 to 500. |
