thermally conductive polyester molding compositions.

Thermoplastic molding compositions comprising A) from 10 to 69% by weight of a thermoplastic polyester B) from 30 to 79% by weight of an aluminum oxide C) from 0.01 to 10% by weight of an organic or inorganic acid or mixture of these D) from 0 to 10% by weight of D1) at least one highly branched or hyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, part 2), or D2) at least one highly branched or hyperbranched polyester of AxBy type, where x is at least 1.1 and y is at least 2.1, or a mixture of these E) from 0 to 50% by weight of other additives, where the entirety of the percentages by weight of components A) to E) gives 100%.