Polymer mixtures ofA) 5 to 98 parts by weight and preferably 20 to 95 parts by weight of an aromatic polycarbonate,B) 2 to 70 parts by weight and preferably 5 to 60 parts by weight of a graft polymer of resin-forming monomers on a particulate diene and/or acrylate rubber having an average particle diameter (d.sub.50) of from 80 to 800 nm and preferably from 100 to 600 nm,C) 0 to 80 parts by weight and preferably 0.5 to 40 parts by weight of an uncrosslinked thermoplastic vinyl copolymer having a softening temperature above 30.degree. C.,in which either the resin-forming monomers in B) or a monomer of the thermoplastic vinyl copolymer C) or both have contained a monomer corresponding to formula (I) ##STR1## in which R.sup.1 =H, CH.sub.3 ; R.sup.2 =C.sub.1-8 alkylene; R.sup.3 =C.sub.1-4 alkylene, in such a quantity that the structural elements containing oxetanyl groups emanating therefrom make up from 0.05 to 5% by weight and the use of the thermoplastic molding compounds.