METAL PRETREATMENT WITH ACIDIC AQUEOUS COMPOSITIONS COMPRISING SILANES

摘要

The object of the underlying invention consists of 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. 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.