Flame-resistant polymer mixtures

Claim 1

Flame-resistant polymer mixtures, characterized in that they contain (a) from 5 to 94% by weight of a polycarbonate, the linear chains of which consist of at least 85 mol % of recurring structural units corresponding to formula (1): ##STR15## and at most 15 mol % of recurring units corresponding to formula (2): ##STR16## wherein --R-- represents an o-, m- or p-phenylene radical or a radical of the formula (2a) ##STR17## wherein R 1 represents hydrogen, halogen such as chlorine or bromine and C 1 -C 3 -alkyl and X represents a C 1 -C 5 alkylene- or alkylidene radical, a C 3 -C 6 cycloalkylene or cycloalkylidene radical, a single bond, --S-- or a radical of the formula (2b), ##STR18## in which the two alkyl-substituents can have o-, m- or -position to each other, or represents a radical of the formula (2c) ##STR19## whereby units of the formula (1) are not comprised, (b) from 94 to 5% by weight of a styrene polymer and/or a graft polymer (c) from 1 to 35% by weight of a branched polyphosphate which consists of at least 1 mol % of recurring structural units corresponding to formula (3): ##STR20## and/or to formula (4): ##STR21## wherein X represents a C 1 -C 5 alkylene or alkylidene radical, a C 5 -C 6 cycloalkylene or cycloalkylidene radical, a single bond, --S-- or ##STR22## and M represents H, alkali metal or 1/2 alkaline earth metal, Y or --R--OH wherein Y represents an alkyl-, aryl-, cycloalkyl- or aralkyl-radical, and R is as defined above, and at most 99 mol % of recurring structural units corresponding to formulae (5) and/or (6): ##STR23## wherein R and M are as defined above, but not including units corresponding to formulae (3) and (4), (d) from 0 to 20% by weight of one or more organic chloride and/or bromine compounds which contain only aromatically bound chloride and/or bromine, have a decomposition temperature of above 250° C. and do not boil under normal pressure up to at least 300° C., (e) from 0 to 1% by weight of polytetrafluoroethylene.