Novel Metal-Free Catalysts for Epoxy Carboxy Coatings

By Ravi Ravichandran, Michael Emmet, Matthew Gadman, John Florio, Steven Woltornist

A new class of metal-free catalysts has been developed that promotes the crosslinking reaction of epoxy functional polymers with carboxyl functional compounds and polymers. Particularly effective at much lower cure temperatures, these catalysts provide stable single package formula-tions and improved resistance properties. In addition, unlike amine-based compounds, these catalysts do not yellow during cure or on over-bake.

Epoxy resins are commercially and technologically relevant and play a critical role in several key applications such as coatings, adhesives, laminates, castings, encapsulations, and moldings. Epoxy-based polymer resins are an important part of the automotive clearcoat and powder coating market segments.

Their versatility of cross-linking with various agents [e.g. acids, anhydrides, dicyandiamide (DICY), and phenolics], in addition to their ability to provide superior chemical resistance, extraordinary acid etch resistance, and good adhesion, make epoxy functional resins attractive in several end-use markets.