Polymer composition containing A) from 40 to 80 parts by weight, based on the entirety of components A and B, of at least one compound selected from the group consisting of polycarbonate, polyester and polyester carbonate, B) from 20 to 60 parts by weight, based on the entirety of components A and B, of a mixture of Ba) a first rubber-modified vinyl (co)polymer, Bb) a second rubber-modified vinyl (co)polymer and Bc) optionally at least one rubber-free vinyl (co)polymer, where the first rubber-modified vinyl (co)polymer Ba) is at least one graft polymer produced by emulsion polymerization and the second rubber-modified vinyl (co)polymer Bb) is at least one graft polymer produced by bulk polymerization, C) at least one compound selected from the group consisting of polyether amides, polyester amides and polyether ester amides, D) at least one Brönstedt-acidic compound selected from the group consisting of organic fruit acids, inorganic acidic phosphorus compounds and compounds of formula IV wherein R 9 and R 10 independently of one another denote C 1 - to C 9 -alkyl, optionally substituted C 5 - to C 6 -cycloalkyl, C 6 - to C 10 -aryl or C 7 - to C 12 -aralkyl, and Y denotes S or CZ 1 Z 2, wherein Z 1 and Z 2 independently of one another represent H, C 1 - to C 6 -alkyl, cyclohexenyl or cyclohexyl, and E) optionally further additives. A) from 40 to 80 parts by weight, based on the entirety of components A and B, of at least one compound selected from the group consisting of polycarbonate, polyester and polyester carbonate, B) from 20 to 60 parts by weight, based on the entirety of components A and B, of a mixture of Ba) a first rubber-modified vinyl (co)polymer, Bb) a second rubber-modified vinyl (co)polymer and Bc) optionally at least one rubber-free vinyl (co)polymer, where the first rubber-modified vinyl (co)polymer Ba) is at least one graft polymer produced by emulsion polymerization and the second rubber-modified vinyl (co)polymer Bb) is at least one graft polymer produced by bulk polymerization, Ba) a first rubber-modified vinyl (co)polymer, Bb) a second rubber-modified vinyl (co)polymer and Bc) optionally at least one rubber-free vinyl (co)polymer, where the first rubber-modified vinyl (co)polymer Ba) is at least one graft polymer produced by emulsion polymerization and the second rubber-modified vinyl (co)polymer Bb) is at least one graft polymer produced by bulk polymerization, C) at least one compound selected from the group consisting of polyether amides, polyester amides and polyether ester amides, D) at least one Brönstedt-acidic compound selected from the group consisting of organic fruit acids, inorganic acidic phosphorus compounds and compounds of formula IV wherein R 9 and R 10 independently of one another denote C 1 - to C 9 -alkyl, optionally substituted C 5 - to C 6 -cycloalkyl, C 6 - to C 10 -aryl or C 7 - to C 12 -aralkyl, and Y denotes S or CZ 1 Z 2, wherein Z 1 and Z 2 independently of one another represent H, C 1 - to C 6 -alkyl, cyclohexenyl or cyclohexyl, and R 9 and R 10 independently of one another denote C 1 - to C 9 -alkyl, optionally substituted C 5 - to C 6 -cycloalkyl, C 6 - to C 10 -aryl or C 7 - to C 12 -aralkyl, and Y denotes S or CZ 1 Z 2, wherein Z 1 and Z 2 independently of one another represent H, C 1 - to C 6 -alkyl, cyclohexenyl or cyclohexyl, and E) optionally further additives.