US Patent 7645848 Process for preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers

The invention therefore relates to a process for preparation of SiOC-linked, linear (AB)d polydimethylsiloxane-polyoxyalkylene block copolymers of the general formula [(R2SiO)x(CnH2nO)y]d, in whichR are monovalent C1-C18, preferably C1-C4, hydrocarbon radicals,n is a number from 2 to 4, preferably 2 or 3,x ≧5,y ≧10,d ≧3,via reaction of aminosiloxanes having primary amino groups with polyoxyalkylenediols, which comprises concomitant use of one or more tertiary amines as catalyst.