US Patent 11261298 Tailored SiOC-based polyethersiloxanes

SiOC-based polyethersiloxanes are prepared based on linear α,ω-hydroxy group-bearing siloxanes. In a first step, α,ω-acetoxy group-bearing linear polysiloxanes are prepared. In a second step, the α,ω-acetoxy group-bearing linear polysiloxanes are converted into the desired organosiloxane units, preferably shorter organosiloxane units, wherein the thus converted organosiloxane units have α,ω-acetoxy groups. In a third step, the α,ω-acetoxy group-bearing linear polysiloxanes from step 2 react with polyetherols to give SiOC-based polyethersiloxanes.