The present Invention relates to a mixture comprising catenary, branched and for cyclic siloxanes of the general formula (I) where x is 1, 2 or 3, the substituents R are (i) organofunctional groups selected from —CH2—SH, —CH2—S—(CO)—R′, —CH2—(O—C2H4)a—OH with a=1 to 10, —CH2(O—C2H4)b—OR′ with b=1 to 40, —(CH2)—NH2, —(CH2)—NHR′, —(CH2)—NR′2, —(CH2)—NH(CH2)2—NH2, —(CH2)—N[(CH2)2—NH2]2 and —(CH2)—NH(CH2)2—NH(CH2)2—NH2, In which R′ is a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 12 carbon atoms, (ii) hydroxyl, methoxy, ethoxy, 2-methoxyethoxy, isopropoxy, n-propoxy, isobutoxy and for n-butoxy groupe, and (iii) where appropriate, alkyl, alkenyl, isoalkyl, cycloalkyl or fluorcalkyl groups having 1 to 18 carbon atoms or aryl groups having 6 to 12 carbon atoms, whit the proviso that not more than one organofunctional group (i) is attached per silicon atom, the quotient of the molar ratio of the moiety (ii) to silicon le from I to 2, and the degree of oligornerization for compounds of the general formula I is in the range from 2 to 50. The present invention also relates to a specific process for preparing said siloxane mixtures and also to their use.