Catalysts' Role in Low-Gloss Hybrid Powder Coatings
Spring 2002 Vol. 4, No. 1
In this study, the crucial role played by catalysts in the preparation of low-gloss hybrid powder coatings using a reactive additive (styrene maleic anhydride copolymer) is described. First, the reactions that occur during the cure of epoxy/polyester hybrid thermoset powder coatings are reviewed. DSC measurements on model mixtures and fully formulated powder paints reveal relative reactivities and the role of catalysis on the various reaction steps. The gloss properties of the coatings are found to be closely tied to the presence of a catalyst. Several approaches to preparing powder coating formulations that exhibit fast cure kinetics, low-gloss appearance and excellent properties are described.
This paper is adapted from work originally presented at the 2001 International Waterborne, High-Solids, and Powder Coatings Symposium.