Polycarbonate molding compostions

A thermoplastic molding composition comprising:

• A) 10 to 90 parts by weight of at least one member selected from a first group consisting of aromatic polycarbonate and polyester carbonate,
• B) 10 to 90 parts by weight of a member selected from a second group consisting of:
• B.1 rubber-modified graft polymer, wherein B.1 contains substances acting as bases resulting from its production, and wherein B.1 consists of one or more graft polymers of
• B.1.1 5 to 95 weight % based on the weight of B.1 of at least one vinyl monomer selected from the group consisting of vinyl aromatics and/or ring-substituted vinyl aromatics, styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, (C1-C8) alkyl methacrylates, methyl methacrylate, ethyl methacrylate, vinyl cyanides, unsaturated nitriles, acrylonitrile, methacrylonitrile, n-butyl acrylate, t-butyl acrylate, anhydrides and imides of unsaturated carboxylic acids, maleic anhydride, N-phenylmaleimide and mixtures thereof,
• on
• B.1.2 95 to 5 weight % based on the weight of B.1 of one or more backbones with glass transition temperatures of <10° C., wherein the backbones are selected from the group consisting of diene rubbers, EP(D)M rubbers, EP(D)M rubbers based on ethylene/propylene, diene rubbers, acrylate rubbers, polyurethane rubbers, silicone rubbers, chloroprene rubbers, ethylene/vinyl acetate rubbers, silicone/acrylate composite rubbers, diene rubbers based on butadiene and isoprene, mixtures of diene rubbers or copolymers of diene rubbers,
• and a mixture of
• B.1 with B.2 rubber-free (co)polymer of at least one monomer selected from a third group consisting of vinyl aromatic, styrene, alpha-methylstyrene, vinyl cyanide, C1-C8alkyl(meth)acrylate, unsaturated carboxylic acid, and anhydrides and imides of unsaturated carboxylic acid, and
• C) 0.01 to 0.15 parts by weight, based on 100 parts by weight of the sum of components A and B, of citric acid,
• whereby component C) is in a first step premixed with component B) and in a second step the resulting mixture of C) and B) is mixed with a melt comprising component A), and wherein the molding composition has ΔMVR, after storage at 300° C. for 15 minutes measured according to ISO 1133 at 260° C. with a 5 kg load, of less than 7 ml/10 min.