Process for preparing polyoxyalkylene polyether polyols having low levels of transition metals through double metal cyanide complex polyoxyalkylation

摘要

Substantially transition metal-free polyoxyalkylene polyethers may be prepared by double metal cyanide complex-catalyzed oxyalkylation of a suitable hydric oxyalkylation initiator molecule by employing 15 ppm or less of a double metal cyanide complex oxyalkylation catalyst having a propylene oxide polymerization rate greater than 5 g propylene oxide/minute. The induction periods associated with oxyalkylation employing double metal cyanide complex catalysts may be reduced by preparing preactivated master batches and by increasing the oxyalkylation reactor temperature during at least the induction period.