Basic investigations for development of new curing mechanisms for powder coatings

Powder coatings have attained great importance as coating materials because of their economic and environmental benefits. However, there are also some limitations which have prevented the penetration of solid paints into some promising markets up to now. A new concept of combined reactions is introd uced in order to find a control mechanism for flow procedure that is depend ent on the curing reaction for powder coatings. Useful combinations were fo und by characterization of reactivity in one-stage curing reactions in bulk using low molecular models. A two-stage reaction mechanism was proved in c ombined low molecular model systems as well as in polymeric powder coating basic systems consisting of binder and hardener for various combined reacti on systems. Results are shown for the combined reaction system epoxide/carb oxylic acid/phenolic compound. (C) 1998 Elsevier Science S.A. All rights re served.