Epoxy-polysiloxane polymer composition for use as protective coatings that exhibit good weatherability and corrosion resistance after curing

摘要

poxy-polysiloxane polymer compositions of this invention are prepared by combining a resin component with a hardener component. The resin component comprises a non-aromatic epoxy rein ingredient and a polysiloxyne ingredient of formula R2O-[Si-(R1)2]n-R2O. The hardener component comprises an amine and optionally an organotin catalyst. The composition can also include aggregates, pigments, and other additives depending on the particular end use. The composition is prepared using a sufficient amount of water to promote hydrolysis of the polysiloxane and the polycondensation of the silanols produced by such hydrolysis. In its cured form, the epoxy-polysiloxane composition exists as a uniformly dispersed arrangement of linear epoxy chain fragments that are cross-linked with a continuous polysiloxane polymer chain, thereby forming a non-interpenetrating polymer network chemical structure that has substantial advantages over conventional epoxy systems. Protective coatings formed from such compositions exhibit excellent weatherability in sunlight, and superior chemical and corrosion resistance after curing.