Patent ID: 7825205

Claim:
A process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, which comprises: reaction of one or more polyetherdiol with a stoichiometric excess of one or more α,ω-dihydropolydimethylsiloxane, in the presence of one or more compounds of elements of main group III and/or of transition group 3 as catalyst, wherein, after the stoichiometric reaction of the polyetherdiol with the α,ω-dihydropolydimethylsiloxane, continuing the reaction in the presence of one or more compounds of elements of main group III and/or of transition group 3 as catalyst until no remaining ≡Si(H) groups are detectable by a gas-volumetric method.