Patent ID: 8771829

Claim:
A sheet having a thickness of 2-3 mm, comprising a thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises: a branched cyanophenyl endcapped polycarbonate having: repeating structural carbonate units of the formula: wherein at least 60 percent of the total number of R 1 groups contain aromatic organic groups and the balance thereof are aliphatic, alicyclic, or aromatic groups; branching groups derived from reaction with a branching agent; and cyanophenyl endcapping groups derived from reaction with a cyanophenol; 0.01 wt. % to 0.6 wt. % of an aromatic sulphone sulphonate; a brominated polycarbonate, in an amount such that the composition comprises 0.26 wt. % to 5.2 wt. % bromine, wherein, said sheet has smoke density and flammability properties such that a 3 mm thick extruded sheet has a smoke density of less than 200 at an exposure period of 240 seconds in accordance with the smoke density test as set forth in ASTM E662-06, and has no burning drips on the sheet for a duration of 10 minutes in accordance with the flammability test as set forth in NF-P-92-505.