NOVEL CROSS-LINKING MECHANISM FOR THIN ORGANIC COATINGS BASED ON THE HANTZSCH DIHYDROPYRIDINE SYNTHESIS REACTION

摘要

Disclosed is cross-linking process for cross-linking polymeric chains in a coating composition. In one embodiment the process utilizes a Hantzsch dihydropyridine reaction to form reaction products including cross-linking polymeric resin chains having beta-keto ester functions using a source of aldehyde and a source of ammonia or a primary amine to form a permanent dihydropyridine bond between the beta- keto ester functions. The novel cross-linking reaction can occur at lower temperatures compared to typical cross-linking reactions and can occur in aqueous solutions that have a neutral to mildly alkaline pH of from 6 to 11. The novel cross-linking reaction provides many advantages to performing cross-linking of polymeric chains in coating resins.