Application of silane technology to prevent corrosion of metals and improve paint adhesion

Environmental, safety and cost issues surrounding the continued use of chromates have led to increased R&D activities to find alternative materials. Recent developments in the application of silane coupling agents to metals involves their use as corrosion-inhibiting pretreatments. It was initially observed and reported that silane treatments of metals can increase their corrosion performance after painting. However, very recently it has been demonstrated that, especially if non-organofunctional silanes are used, protection can be obtained even without paint coatings. In this presentation an overview is given of the results obtained in our laboratories in recent years. The chemistry is described and representative results are given of applications where silane treatments have the potential to replace currently used pretreatments by chromate and or phosphate systems. The metals to be discussed are cold-rolled steel, galvanized steel, aluminum and ifs alloys, and Galvalume (R).