Formulators of waterborne and solvent-based exterior architectural coatings can now develop paints with improved water resistance using only low levels of new silicone-based materials from Dow Corning. Dow Corning 87 Additive and Dow Corning 88 Additive create a hydrophobic silicone network in the paint that repels water but is permeable to water vapor coming from the substrate. Even when used at levels as low as two percent by weight of the formulation, these additives improve the water repellency of coatings without causing cracking and blistering, according to the firm.
Dow Corning 87 Additive is a silicone resin emulsion designed for use in waterborne paints and is ideal for applications where visual water beading is desired. When water reduction is the primary requirement, Dow Corning 88 Additive, a silane/siloxane blend, is effective and can be used both in acrylic emulsion paints containing polar solvents and in solvent-based systems. With access to these two sustainable solutions, formulators can leverage the technology for a wide range of decorative coating products.