Non-migrating PIN FR for polycarbonate
A US patent assigned to PolyOne, Ohio, is published for a phosphorus-mineral flame retardant for polycarbonate, formed by reacting in situ (within the polymer) a phosphorus compound (alkyl-functional phenoxyphosphazene) and a silicon compound (hydride-functional siloxane).
The patent states as its achieved objectives of non-halogenated, UL94-V0 fire performance (3.2mm) in polycarbonates, non-dripping and using no solvent in production. The in-situ reaction results in an interpenetrating network (IPN) PIN FR molecular structure within the final polycarbonate polymer, so ensuring that the FR will not migrate out of the polymer into the environment.
US patent 2016/0272812, published 22 Septe mber 2016, C. Zhou, R. Avakian, Polyone Corporation “Phosphazene flame retardant polycarbonate compounds” http://www.freepatentsonline.net/20160272812.pdf