Ketimine systems cure by a two stage process. The first reaction involves a reaction of the ketimine with atmospheric moisture to produce a ketone and a highly reactive amine. The amine can then react with either an acetoacetate functional acrylic, or an unsaturated acrylic polymer. The cure reaction is extremely quick and would result in rapid gelation if the amine crosslinker was not blocked with a ketone. The chemical linkage produced may display poor acid resistance, due to its basic nature. The evolution of an organic blocking agent would also be expected to hinder the use of the chemistry in low VOC coatings.
Ketimine/Activated Hydrogen
12 сентября, 2015 Malyar