Back to results
US 4,721,818 AGranted
Purification of polyols prepared using double metal cyanide complex catalysts
AssigneeAtlantic Richfield Company
InventorsStephen D. Harper, Stephen H. Harris
Life of this patent
Estimating the term…
Abstract
A method for removing double metal cyanide complex catalyst residue from polyols using alkali metal hydrides is disclosed. In one embodiment, the catalyst residue is converted into an insoluble ionic metal species and separated by filtration using magnesium or aluminum silicate to facilitate separation.
Claims12
A method for removing double metal cyanide complex catalyst residue from polyols which comprises after polyol formation the steps of:
- (a) incorporating into the catalyst residue-containing polyol an effective amount of an alkali metal hydride to convert the double metal cyanide complex catalyst into an insoluble ionic metal species separable from the polyol wherein the polyol hydroxyl groups are also converted to alkoxide groups;
- and
- (b) separating the insoluble ionic metal species from the polyol.
Dependencies are inferred from the claim text.