Flame-retardant thermoplastic materials and molded parts therefrom

Claim 1

Improved flame-retardant thermoplastic materials comprising (a) polymers of styrene, and (b) organic halogen compounds in amounts effective as flame retardants, wherein the improvement comprises halogen-free compounds, having labile --C--C-- linkages, synergistic with the flame retardants wherein said synergistic compounds contain amide or imide grouping or mixtures of these groupings bonded to the --C--C-- bridge member according to the formula: ##STR5## and wherein R 1 , R 2 , R 3 and R 4 are selected from the group consisting of linear or branched saturated alkyl radicals containing 1 to 10 carbon atoms, saturated cyclic radicals containing 5 to 10 carbon atoms, and alkyl-substituted cycloaliphatic radicals containing 5 to 10 carbon atoms, and wherein Z is a heterocyclic amide or imide, saturated or unsaturated, which may or may not be substituted on the carbon atoms with alkyl or alkenyl radicals containing 1 to 4 carbon atoms, and which cyclic amide or imide may have an aromatic ring as part of the heterocyclic ring, and said aromatic ring may be substituted with alkyl radicals containing 1 to 4 carbon atoms.