SILANES IN HIGH-SOLIDS AND WATERBORNE COATINGS

Silanes have been used effectively in solvent-based or waterborne coat ings to crosslink binder resins, increase pigment dispersion and impro ve end use properties, such as mar and solvent resistance and durabili ty. A series of silylated styrene acrylic clearcoats have been prepare d and studied in order to understand the chemical and physical paramet ers that influence the mar resistance and weathering properties of the cured coatings. It was found that the silane content affects the inde ntation hardness, coefficient of friction, modulus, and toughness of t he cured coatings. A relationship between these coating characteristic s and mar resistance is demonstrated. In water dispersed and emulsion polymer systems, silanes maximize properties, such as adhesion and sol vent resistance. Silanes are incorporated into these systems via copol ymerization or post addition. Recent advances in waterborne silane tec hnologies are discussed, including methods of improving formulation st ability.