Akzo Nobel Coatings International has been granted a patent for a chip-resistant powder topcoat on a steel substrate having a corrosion resistant powder coating basecoat thereon.
The topcoat is comprised of the cured or fused product of a coating powder of one or more resin component of one or more toughened epoxy resin, from 0.1 to 5 parts per hundred parts resin (phr) of one or more wax and from 75 phr to 200 phr of one or more extenders wherein the one or more extenders is selected from the group consisting of barium sulfate, titanium dioxide, iron oxides, crystalline silica (quartz), calcium metasilicate, soda lime glass spheres, magnesium silicate, nepheline syenite, muscovite mica, diatomaceous earth, kaolin clay and calcium carbonate.