METAL PRETREATMENT COMPOSITIONS COMPRISING SILANES AND ORGANOPHOSPORUS ACIDS

摘要

The object of the underlying invention consists of an acidic aqueous metal pretreatment solution that comprises amino-functional organosilanes and organophosphorus acids. These types of metal pretreatment solutions effectively reduce temporary corrosion when applied to metal surfaces and in addition confer good adhesion properties for subsequently coated organic lacquers. The invention consequently also encompasses 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.

主权项

1. An acidic aqueous metal pretreatment solution with a pH in the range from 2.0 to 5.5 comprising:
a) more than 0.2 wt.-% calculated with respect to the element Si of at least one organosilane with at least one hydrolyzable substituent and one to three non hydrolyzable substituents, wherein at least one of the non hydrolyzable substituents carries at least one amino group, and wherein the total number of substituents at each silicium atom of the organosilanes is four, and c) at least one organophosphorus acid.