Polycarbonate containing a metal salt of a perhalometalate as an ignition depressant

Claim 1

A composition consisting essentially of an aromatic carbonate polymer having dispersed therein a metal salt of a perhalometalate in an amount of about 0.1 weight percent based on the polymer or less which amount is sufficient to retard combustion when the composition is exposed to a low temperature ignition source, said metal salt being represented by the formula: M.sub.y M'X.sub.z wherein M is alkali metal; M' is a transition metal; X is fluoro, chloro or bromo; z is a whole number which corresponds to the coordination number of M'; and y is a whole number equal to the valence of M'X z , provided that when the metal salt is K 2 TiF 6 it is present in an amount from about 0.02 to about 0.05 weight percent based on the polymer, said composition having Underwriter's Laboratories' (UL-94) flame retardance rating of V-1 or V-0 as determined using a test bar having the following dimensions: 12.7 cm×1.27 cm×0.32 cm.