Patent No. U.S. 7,951,869 B2
Excalibur Paint and Coatings, Ltd. has been granted a patent for a 2K waterborne isocyanate free coating system and methods thereof designed for use as a DTM topcoat in heavy duty industrial applications where gloss retention, chemical and corrosion resistance are a primary requirement. The waterborne acrylic epoxy composition has < 50 g/l VOC and contains no isocyanates, and thus provides a high performing alternative for applications where handling of and exposure to isocyanates is prohibited and/or must be highly avoided. Part A of the two component emulsion system is comprised of a blend of hydroxy functional acrylic polymer co-reactant, suitable additives, pigments and epoxy resin, while Part B is preferably a waterborne amine hardener for curing or crosslinking the first component. The new coating can be applied in thicknesses ranging from 2 mils to approximately 16 mils and cures without foaming even at high film builds. The two component emulsion system also calls for a water-based zinc primer and zinc conversion coating primer that have remarkable adhesion on a variety of substrates including, but not limited to, aluminum, galvanized metal (both electroplated and hot-dipped), various stainless steels, PVC, carbon/fiberglass composites, and the like.