STRENGTHENED ANTIICORROSIVE COMPOSITE COATING FILM AND METHOD OF MAKING SAME

摘要

Composite coatings, established on metal substrates, now exhibit enhanced film integrity, such as when exposed to chemicals, solvents and salt. Additional desirable coating characteristics are also maintained. The undercoating of the composite contains a hexavalent- chromium- providing substance. Included in the topcoating applied over the uncured undercoating is a hydroxyl-containing resin and isocyanate adduct. Subsequent heating fully develops the undercoat curing while concomitantly curing the topcoating.