Preparation of polymer based powder coatings by ionizing radiation

Abstract

Abstract A novel method of preparing polymer based powder coating compositions involves as a first step the preparation of a mixture containing one or more ethylenically unsaturated monomers which are polymerizable by ionizing radiation, and optionally other coating composition additives. Optional additives which may be incorporated in the mixture include pigments, internal or external crosslinkers, chain transfer agents, flow promoters, plasticizers, viscosity control agents, minor proportions of resins, and the like. Pigments are especially desirable additives. The next step in the process is to apply a coating of the mixture to a substrate. Then, the coated substrate is subjected to ionizing radiation to polymerize the ethylenically unsaturated monomers and thereby form a solid film. Finally, the film is broken into particles by any of several mechanical means to form a polymer based powder coating composition which when applied to a substrate and baked, fuses to produce a film. This novel and convenient method is particularly suited to the preparation of pigmented and unpigmented thermoplastic or thermosetting acrylic polymer-based powder coating compositions which form films having excellent properties.

Inventors

• 👤 Roger M. Christenson
• 👤 Rostyslaw Dowbenko
• 👤 Joseph M. Makhlouf

Bibliographic Details