Abstract: This invention provides a coating for zinc coated steel surfaces and other zinc containing alloys, including zinc/iron, zinc/nickel, zinc/cobalt, zinc/aluminum, and any other suitable metal surface. The coating product of this inventions contains the following ingredients: copolymers made from acrylic, vinylacrylic, and acrylstyrene monomers, has carboxylic radicals from acrylic and/or methacrylic acids, and has an Ia of 30 to 60 mg. of KOH. The water soluble copolymers and lubricatory additives, which include natural or synthetic waxes, graphite, and molybdenum sulfide, are in solid form dispersed in aqueous solution at a ratio of from 1 to 10%.
Type:
Grant
Filed:
January 26, 1993
Date of Patent:
August 15, 1995
Assignee:
Procoat S.A.
Inventors:
Juan F. Brugarolas, Federico S. Rodellas
Abstract: A method for coating a metal surface includes heating an untreated metal surface to a temperature of about 40.degree. C. to 250.degree. C. and spraying a coating composition onto the hot untreated metal surface, while continuously moving the metal surface, so that a corrosion resistant coating is formed on the surface, the coating composition having a pH of 0.5 to 1.5 and containing; (a) 20 to 40% by weight acrylic organic polymer in aqueous dispersion; (b) 1 to 5% by weight chromium in a soluble form and selected from the group of hexavalent chromium and mixtures of hexavalent and trivalent chromium wherein the trivalent is about 0.1 to 20% by weight of the total chromium in the mixture; (c) 1.5 to 4% by weight phosphoric acid; and (d) 0.1 to 1.5% by weight organic reducing agent.
Type:
Grant
Filed:
September 12, 1988
Date of Patent:
August 13, 1991
Assignee:
Procoat S.A.
Inventors:
Juan F. Brugarolas, Federico S. Rodellas