of k is preferably between 0 5 and 2 5 more preferably between 1 4 and 2 0 the average value of l is preferably between 0 01 and 1 0 more preferably between 0 01 and 0 6 and the average value of m is preferably between 0 and 2 0 more preferably between 0 and 0 2 with the proviso that the sum of k l and m is not more than 3 organopolysiloxanes comprising units of formula x and usable according to the present invention preferably have a viscosity at 25 u00b0 c of from 5 to 10 5 mpas more preferably from 10 to 10 4 mpas examples of organopolysiloxanes comprising units of formula x and usable according to the present invention are h 2 n ch 2 3 u2014 si och 3 2 u2014 o u2014 si ch 3 och 3 2 h 2 n ch 2 3 u2014 si oc 2 h 5 2 u2014 o u2014 si ch 3 och 3 2 h 2 n ch 2 3 u2014 si oc 2 h 5 2 u2014 o u2014 si ch 3 oc 2 h 5 2 h 2 n ch 2 3 u2014 si och 3 ch 3 u2014 o u2014 si ch 3 och 3 2 h 2 n ch 2 3 u2014 si och 3 ch 3 u2014 o u2014 si och 3 3 h 2 n ch 2 3 u2014 si oc 2 h 5 ch 3 u2014 o u2014 si och 3 3 h 2 n ch 2.