Ppg Industries Ohio, Inc.

Karen B Allen

Kurt A Humbert

Kurt Gordon Olson

Charles M Kania

Roxalana Lee Martin

Edward R Coleridge

Stephen G McQuown

John M Furar

Karen S Rechenberg

Anton Jurgetz

Curable powder clear coating composition and coated substrate with multilayered coatings have as the predominant film-forming polymer in the coating at least one epoxy acrylic copolymer in an amount from 60 to 99.99 percent by weight and 10 to 40 percent by weight of a polycarboxylic acid crosslinking agent. The percentages by weight are based on solids of the curable coating composition. A single predominant film-forming epoxy acrylic copolymer has a number average molecular weight in the range of about 1000 to 5500; a calculated Tg in the range of 50 to 85&deg; C.; epoxy content in the range of 35 to 85, and a styrene content resulting from an amount of styrene monomer in the range of up to about 25 weight percent based on the weight percent of the monomers to form the copolymer. The blend of epoxy acrylic copolymer has one polymer which is the single epoxy acrylic copolymer or one having a number average molecular weight in the range of about 1000 to about 10,000, a calculated Tg in the range of about 40&deg; C. to 85&deg; C., and an epoxy content from 40 to 60 weight percent of the total weight of the monomers to prepare the epoxy acrylic copolymer. The other polymer of the blend has a number average molecular weight in the range of about 500 to about 3000, a calculated Tg in the range of about 35&deg; C. to about 125&deg; C., and an epoxy content from glycidyl functional ethylenically unsaturated monomer that is higher than that of the first epoxy functional acrylic copolymer of the blend and in the range of about 50 to about 100.

Powder coating compositions and coated substrates with multilayered coatings

A composite coating of a water-borne basecoat and an epoxy-acid clearcoat has improved performance characteristics of reduced yellowing or reduced tendency to chip through the formulation of the composite coating and the process for its application. The process comprises applying to the substrate a film-forming composition to form a basecoat and applying to the basecoat an epoxy-acid clear film-forming composition to form a transparent topcoat over the basecoat. The basecoat is a coating composition comprising a polymeric film-forming resin, aminoplast crosslinking agent and a pigment wherein the crosslinking agent is a partially or fully alkylated aminoplast and has a lower or higher imino content. The lower imino content promotes reduced yellowing of the clearcoat and the higher imino content promotes improved chip resistance when the pigment of the water-borne basecoat reduces yellowing effects. The transparent topcoat, or clearcoat, has an epoxy film forming resin and a polycarboxylic acid crosslinking agent.

Color-plus-clear composite coating and process and coated article for

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Irwin, PA, United States of America

Karen B Allen