Flame resistant halogenated polycarbonates - prepd. from statistical mixtures of halogenated and unhalogenated bis-phenols

摘要

High m.wt. aromatic thermoplastic polycarbonates are claimed, the polymers contg. Br and/or Cl and having recurrent, but not identical, structural units of formula (III): (where X is 1-9C alkylene, 2-9C alkylidene, 5-15C cycloalkylene or cycloalkylidene, a direct bond, O, S, SO, SO2, CO or -C(CH3)2-Ph-C(CH3)2-; R1-4 are H, Br or Cl; n is 20-800; E is phenyl, alkyl-substd. phenyl, bromo-substd. phenyl or chloro-substd. phenyl; and the total amt. of halogen resulting from R1-4 E is 2-45%, with a Br content of 0.45% and a Cl content of 0.27%), the polymers being derived from statistical mixts. of non-halogenated bis-phenols of formula (II) and mono- di-, tri- and tetrabromo- or -chloro-bisphenols of formula (I): by the methods known for the manufacture of polycarbonates.