| abstract |
The present invention relates to a process for the preparation of a double metal cyanide (DMC) catalyst, which process involves: n (a) combining an aqueous solution of a metal salt with an aqueous solution of a metal cyanide salt and reacting these solutions; and n (b) recovering the DMC catalyst from the reaction mixture, n in which process the DMC catalyst is prepared in the presence of from 0.03 to 0.4 mole of alkaline metal compound, based on amount of metal salt. n Further, the present invention relates to DMC catalyst obtainable by such process, to DMC catalyst prepared from a metal salt and a metal cyanide salt in which the molar ratio of metal derived from the metal salt to metal derived from the metal cyanide salt is at least 2.25 and to a process for polymerization of alkylene oxides which process involves reacting initiator with alkylene oxide in the presence of at most 15 ppm of DMC catalyst. |