| 摘要 |
This disclosure relates to thermoplastic compositions comprising a polycarbonate copolymer, the polycarbonate copolymer comprising first repeating carbonate units and second repeating units selected from carbonate units that are different from the first carbonate units, polysiloxane units, and a combination comprising at least one of the foregoing unit; and an organophosphorus flame retardant in an amount effective to provide 0.1 to 1.0 wt % phosphorus based on the total weight of the composition, wherein an article molded from the composition has a smoke density after 4 minutes (Ds-4) of less than or equal to 600 determined according to ISO 5659-2 on a 3 mm thick plaque, and a material heat release of less than or equal to 160 kW/m2 determined according to ISO 5660-1 on a 3 mm thick plaque. |
| 主权项 |
1. A thermoplastic composition comprising
60 to 99.5 wt % based on the weight of the composition of a polycarbonate copolymer comprising first repeating units repeating units and second repeating units, wherein the second repeating units are polysiloxane 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 the first carbonate units are of the formulawherein
Ra and Rb are each independently a C1-12 alkyl group, p and q are each independently integers of 0 to 4, and Xa is a single bond, —O—, —S—, —S(O)—, —S(O)2—, —C(O)—, a C1-12 alkylidene of formula —C(Rc)(Rd)— wherein Rc and Rd are each independently hydrogen or C1-11 alkyl, or a group of the formula —C(═Re)— wherein Re is a divalent C1-11 hydrocarbon group; and the second repeating units are siloxane units of the formulas or a combination comprising at least one of the foregoing, wherein R is each independently a C1-13 monovalent hydrocarbon group Ar is each independently a C6-C30 aromatic group, R2 is each independently a C2-8 alkylene group, E has an average value of 2 to 200; and 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/m2 as determined according to ISO 5660-1 on a 3 mm thick plaque, anda multiaxial impact energy equal to or higher than 100 J as determined according to ISO 6603 on a 3.2 mm thick disc. |
