Synthesis and Screening of New Water Soluble Organometallic Catalysts for CASE Applications

Abstract

New water soluble catalysts have been synthesized utilizing various strategies to impart water solubility. Bismuth, zinc, and tin containing catalysts were prepared with several different ligands to impart water solubility or dispersibility to the final compound. Water soluble or dispersible catalysts are of commercial interest, because the use of currently available urethane catalysts in waterborne applications presents many challenges. Almost all of the commercially available catalysts are not soluble in aqueous systems, and most are susceptible to hydrolysis. These new water soluble catalysts were tested in a two component, waterborne polyurethane system. The catalytic activities of the catalysts were compared by monitoring the curing of the coatings by FT-IR spectroscopy and by typical tests for monitoring cure. Initial evaluations of shelf lives and pot lives were also conducted.