A plasticizer composition comprising a) one or two or more compound (s) of the general formula (I), in which X is an unbranched C 2 -C 8 alkylene group or a branched C 6 -C 8 alkylene group or an unbranched or branched C 2 -C 8 alkenylene group, comprising at least one double bond, and R 1 and R 2 independently of one another are selected from C 5 -C 7 cycloalkyl, wherein the cycloalkyl radicals independently of one another either are unsubstituted or are substituted by at least one C 1 -C 10 alkyl radical, and b) one or two or more compound (s) of the general formula (II), in which R 3 and R 4 independently of one another are selected from branched and unbranched C 4 -C 12 alkyl radicals, Y is selected from the groups of the formulae (Y.a) and (Y.b) where # represents the respective points of attachment to the ester groups, with the proviso that the plasticizer composition contains no compound of the formula (I.a) in which A is methyl or ethyl, A 1 and A 2 independently of one another are selected from branched and unbranched C 5 -C 7 cycloalkyl radicals which are unsubstituted or are substituted by at least one C 1 -C 10 alkyl radical, and a is 1 or 2. a) one or two or more compound (s) of the general formula (I), in which X is an unbranched C 2 -C 8 alkylene group or a branched C 6 -C 8 alkylene group or an unbranched or branched C 2 -C 8 alkenylene group, comprising at least one double bond, and R 1 and R 2 independently of one another are selected from C 5 -C 7 cycloalkyl, wherein the cycloalkyl radicals independently of one another either are unsubstituted or are substituted by at least one C 1 -C 10 alkyl radical, and X is an unbranched C 2 -C 8 alkylene group or a branched C 6 -C 8 alkylene group or an unbranched or branched C 2 -C 8 alkenylene group, comprising at least one double bond, and R 1 and R 2 independently of one another are selected from C 5 -C 7 cycloalkyl, wherein the cycloalkyl radicals independently of one another either are unsubstituted or are substituted by at least one C 1 -C 10 alkyl radical, b) one or two or more compound (s) of the general formula (II), in which R 3 and R 4 independently of one another are selected from branched and unbranched C 4 -C 12 alkyl radicals, Y is selected from the groups of the formulae (Y.a) and (Y.b) where # represents the respective points of attachment to the ester groups, with the proviso that the plasticizer composition contains no compound of the formula (I.a) in which A is methyl or ethyl, A 1 and A 2 independently of one another are selected from branched and unbranched C 5 -C 7 cycloalkyl radicals which are unsubstituted or are substituted by at least one C 1 -C 10 alkyl radical, and a is 1 or 2. R 3 and R 4 independently of one another are selected from branched and unbranched C 4 -C 12 alkyl radicals, Y is selected from the groups of the formulae (Y.a) and (Y.b) where # represents the respective points of attachment to the ester groups, A is methyl or ethyl, A 1 and A 2 independently of one another are selected from branched and unbranched C 5 -C 7 cycloalkyl radicals which are unsubstituted or are substituted by at least one C 1 -C 10 alkyl radical, and a is 1 or 2. <EOS>