Hamilton Convention Centre, Hamilton, Ontario, Canada, June 2, 2009

A New Metal Finishing Pretreatment: Waterborne Silane-Based Conversion Coating

Speaker: Ian McLeod, B.Eng. M.C.I.C.


















Abstract

Since the mid-twentieth century, iron phosphate or modified zinc phosphate metal pretreatment, combined with hexivalent or trivalent chromate sealers, have been used as a successful adhesion promoter and performance base for solvent-borne paints, waterborne paints, and powdercoat paints. The ubiquitous push for greener alternatives is today of considerable interest to industry and society. The difficulty for industry has been developing a technology that generated equal or better field performance expected by the consumer.

One of the newest and promising forms of pretreatment alternatives for both cold rolled steel and aluminum is an organofunctional silane and nanoparticle hybrid system. These proprietary water soluble silanes have been commercially available since the 1970’s, but in the 1990’s, they were recognized as an environmentally friendly substitute for highly toxic chromate sealers over iron and zinc phosphate coatings, and more recently as replacements for iron and zinc phosphate coatings. In this presentation, the non-phosphate and non-chromate technology is described and details of performance testing are presented.