Patent ID: 7528288
Filing Date: 2009-05-05
Classification: C08G

Abstract:
1. A process for preparing polyether alcohols by adding alkylene oxides onto H-functional starter substances using DMC catalysts, which comprises, in a first step, adding propylene oxide or a mixture of propylene oxide and ethylene oxide onto H-functional starter substances and, in a second step, transferring the product thus formed into a tubular reactor in which mixtures of ethylene oxide and propylene oxide are metered in at at least two metering points, the proportions of ethylene oxide and propylene oxide in the mixtures metered in in the first and in the second step being different, the proportions of ethylene oxide and propylene oxide in the mixtures metered in at at least two metering points in the second step being different, and the mixture metered in in the second step, at least at the last metering point, comprising at least 40% by weight of ethylene oxide.