Method for manufacturing polyether polyols

Producing polyether carbonate polyol from at least one hydrogen-functional starter compound, at least one alkylene oxide, and carbon dioxide in presence of a double metal cyanide (DMC) catalyst, comprises (a) providing the hydrogen-functional starter compound or a mixture of at least two hydrogen-functional starter compounds, (b) adding a partial amount of at least one alkylene oxide to the product mixture resulting from step (a), for activating, and (c) continuously adding at least one alkylene oxide and carbon dioxide to the product mixture resulting from step (b). Producing polyether carbonate polyol from at least one hydrogen-functional starter compound, at least one alkylene oxide, and carbon dioxide in presence of a double metal cyanide (DMC) catalyst, comprises (a) providing the hydrogen-functional starter compound or a mixture of at least two hydrogen-functional starter compounds, (b) adding a partial amount of at least one alkylene oxide (based on the total amount of alkylene oxide used in the steps (b) and (c)) to the product mixture resulting from step (a), for activating, where the step (b) is carried out repeatedly for activating, and (c) continuously adding at least one alkylene oxide and carbon dioxide to the product mixture resulting from step (b), where the alkylene oxide used for copolymerizing is same or different from the alkylene oxide used in step (b). In step (c) the carbon dioxide is introduced into the mixture by (i) aerating the reaction mixture in the reactor from the bottom, (ii) using a hollow-shaft stirrer, (iii) combining (i) and (ii), and/or (iv) gassing the liquid surface using multistage stirring elements. Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Polyethercarbonatpolyolen aus einer oder mehreren H-funktionellen Starterverbindungen, eines oder mehrerer Alkylenoxiden und Kohlendioxid in Gegenwart eines Doppelmetallcyanid-Katalysators, wobei (±) die H-funktionelle Startersubstanz oder ein Gemisch aus mindestens zwei H-funktionellen Startersubstanzen vorgelegt werden, (²) zur Aktivierung eine Teilmenge (bezogen auf die Gesamtmenge der in den Schritten (²) und (³) eingesetzten Menge an Alkylenoxiden) von einem oder mehreren Alkylenoxiden zu der aus Schritt (±) resultierenden Mischung zugesetzt wird, wobei der Schritt (²) zur Aktivierung auch mehrfach erfolgen kann, (³) ein oder mehrere Alkylenoxide und Kohlendioxid zu der aus Schritt (²) resultierenden Mischung fortwährend dosiert werden ("Copolymeri