Abstract: The invention relates to the polyoxyalkylene-polysiloxane block polymers of general formula (I) C-B-(AB)a-C1 (I), wherein A=a polyoxyalkylene block of the general formula —(CnH2nO)b—, B=a polysiloxane block of the general formula —(SiR2—O)c—, C, C1=the same or different alkoxypolyoxyalkylene groups of the general formula Z-O—[CH2—CH(R1)O]d—, R=the same or different C1-4 alkyl groups or phenyl groups, with the proviso that at least 90% of the groups R are methyl groups, R1=the same or different hydrogen, C1-12alkyl groups or phenyl groups, Z=an alkyl, alkylene, aryl or alkylaryl group, a=1 to 20, preferably 2 to 10, b=an average value of 10 to 130, preferably 20 to 100, c=3 to 100, preferably 10 to 80, d=independently is in the range of C/C1 values of 2 to 20, preferably 2 to 12, with the proviso that the average value is in the range of 2 to <15, preferably 2 to 12, especially 5 to 10, and d is preferably unequal b, n=2 to 12 having an average value of 2.7 to 4.0.