having a weight average molecular weight of up to 5 000 preferably up to 3 000 particularly preferably up to 2 000 as component iii polyethers are obtainable from the above mentioned bis and or polyhydroxy compounds as starter molecules by reaction with ethylene oxide propylene oxide and or butylene oxide according to known processes of the prior art polyesters are likewise obtainable from the above mentioned bis and or polyhydroxy compounds namely by esterification with industrially available di or tricarboxylic acids according to known processes of the prior art q is an aliphatic hydrocarbon radical having 2 to 18 especially 6 to 10 carbon atoms a cycloaliphatic hydrocarbon radical having 4 to 15 especially 5 to 10 carbon atoms an aromatic hydrocarbon radical having 6 to 15 preferably 6 to 13 carbon atoms or an araliphatic hydrocarbon radical having 8 to 15 preferably 8 to 13 carbon atoms and n and m are independently from 1 to 6 and are especially identical and from 1 to 3 r 1 is in each case independently hydrogen or a straight chain or branched c 1 c 4 alkyl radical wherein along the chr 1 n and chr 1 m alkylene chains r 1 can alternately from carbon atom to carbon atom be not only hydrogen but also a straight chain or branched c 1 c 4 alkyl radical and r 2 is straight chain or branched c 1 c 10 alkyl especially c 1 c 6 alkyl c 1 c 10 cycloalkyl especially c 5 c 6 cycloalkyl c 6 c 12 aryl especially phenyl or a u2014 ch 2 r u2014 oh radical in which r is from 1 to 6 especially from 1 to 3 and the cationic character of the polyurethanes is generated by.