The market, especially the European market, has developed a tin sensitivity. In this article we report on the development of a tin-free aqueous silicone gum dispersion from early tin-based compositions. This class of additive has historically been very difficult to manufacture, especially without the tin condensation catalysts. These new compositions will be compared in several formulations against each other and the industry standard for their ability to reduce coefficient of friction (COF), and provide slip and mar resistance while maintaining coating properties.
These high-molecular-weight (MW) silicone dispersions are used in many coatings and leather treatment formulations to provide slip, and mar and stain resistance. The standard process, which includes catalysis with tin, is under strong regulatory pressure, especially in the EU, due to toxicity concerns of the residual tin compounds.