Patent ID: 8841366

Claim:
A thermoplastic composition comprising a polycarbonate copolymer comprising first repeating units and second repeating units, wherein the first repeating units are first carbonate units and the second repeating units are second carbonate units that are different from the first carbonate units; and an organophosphorus compound in an amount effective to provide 0.1-1 wt % phosphorus, based on the total weight of the polycarbonates in the composition; wherein an article molded from the composition has a smoke density after 4 minutes (Ds-4) of equal to or less than 600 as determined according to ISO 5659-2 on a 3 mm thick plaque, a maximum average rate of heat emission (MAHRE) of less than or equal to 160 kW/m 2 as determined according to ISO 5660-1 on a 3 mm thick plaque, and a multiaxial impact energy equal to or higher than 100 J as determined according to ISO 6603 on a 3.2 mm thick disc, wherein the first carbonate units are of the formula wherein R a and R b are each independently a C 1-12 alkyl group, p and q are each independently integers of 0 to 4, and X a is a single bond, —O—, —S—, —S(O)—, —S(O) 2 —, —C(O)—, a C 1-12 alkylidene of formula —C(R c )(R d )— wherein R c and R d are each independently hydrogen or C 1-11 alkyl, or a group of the formula —C(═R e )— wherein R e is a divalent C 1-11 hydrocarbon group, and wherein the second carbonate units are of the formula wherein R a and R b are each independently a C 1-3 alkyl group, p and q are each independently integers of 0 to 4, R 3 is each independently a C 1-6 alkyl group, j is 0 to 4, and R 4 is hydrogen, C 1-6 alkyl, or phenyl optionally substituted with 1 to 5 C 1-6 alkyl groups.