Patent ID: 8110649

Claim:
A polycarbonate comprising one or more structural units of formulae (II) through (V) wherein the phenyl rings of said one or more structural units of formulae (II) through (V), independently of one another, are optionally mono- or disubstituted with substituents selected from C 1 to C 8 alkyl and halogen, and X is a single bond, C 1 to C 6 alkylene, C 2 to C 5 alkylidene, or C 5 to C 6 cycloalkylidene, wherein said C 1 to C 6 alkylene, C 2 to C 5 alkylidene, and C 5 to C 6 cycloalkylidene are optionally substituted with C 1 to C 6 alkyl, wherein the quantity of said one or more structural units of formulae (II) through (V) amounts to a total of from 50 to 1210 ppm relative to the base polycarbonate, comprising from 0.1 to 1.2 weight %, based on the overall composition, of cyclic oligomers of formula (I) wherein n is an integer from 2 to 6, and Z is a group of formula (1a) wherein R 1 and R 2 are, independently of one another, H or C 1 to C 8 alkyl, and X is a single bond, C 1 to C 6 alkylene, C 2 to C 5 alkylidene, or C 5 to C 6 cycloalkylidene, wherein said C 1 to C 6 alkylene, C 2 to C 5 alkylidene, and C 5 to C 6 cycloalkylidene are optionally substituted with C 1 to C 6 alkyl.