abstract |
A coating system comprising a thermosetting asphalt-extended and chemically cross-linked urethane/epoxy hybrid basecoat in contact with a substrate; and a thermoplastic powder coating topcoat overlying at least the basecoat. Preferably the substrate is a porous substrate, such as concrete or wood, that is normally difficult to coat due to substrate off-gassing or thermal decomposition. The thermosetting basecoat composition consists essentially of, based on wt% of the total composition, between 10 and 90 % of a petroleum asphalt, between 10 and 90 % of a hydroxy-terminated homopolymer, and between 0.1 and 30 % of an epoxy-functional reactive diluent for reducing the viscosity of the composition; and further up to 5% of a surfactant for improving surface imperfections, up to 5 % of an anti-oxidant, and up to 25 % of a thickening agent. |