Formulating to Minimize Film Defects in 100 g/L VOC Solventborne 2K Polyurethane Coatings

By Clifford Seipke, Yasmin Akoum, Kristen Bruley, Aaron Cherep, Sarah Dolan, Donald Handlen

Coatings formulators around the globe share the challenge of creating coatings with ever-decreasing volatile organic compound (VOC) levels. In the United States and Canada, this is frequently achieved through judicious use of solvents that are exempt from VOC regulation. Specifically within California’s South Coast Air Quality Management District (SCAQMD), however, formulators need to create coatings as low as 100 g/L VOC, and are limited to a very select few VOC-exempt solvents.

Unfortunately, those few VOC-exempt solvents have the tendency to cause defects in coatings during the drying and curing stage, such as solvent popping and low gloss. This formulation study examines the basic components in a 100 g/L VOC solventborne two-component polyurethane coating system, including polyols and solvents, to minimize film defects.