Patent ID: 8017814
Filing Date: 2011-09-13
Classification: C08G

Abstract:
1. A process for the preparation of a polyether polyol containing at most about 15 ppm of sodium and potassium, comprising: a) reacting an initiator having at least two active hydrogen atoms with at least one alkylene oxide in the presence of a catalyst having an alkali metal hydroxide to form a polyether polyol reaction product; b) neutralizing the polyether polyol reaction product obtained in step (a) by contacting this reaction product with phosphoric acid and water, wherein the acid and water are added in such amounts that after addition: the water content is less than about 0.5% by weight on the basis of total weight of polyether polyol present and the molar ratio of acid to alkali metal hydroxide is in the range of from about 0.3 to about 1.0 thereby producing salt crystals; and c) removing the salt crystals produced in (b) from the polyether polyol by filtration or centrifugation and recovering the neutralized polyether polyol containing at most about 15 ppm of sodium and potassium, wherein no adsorption agent and no hydrate of a metal salt of the acid are used before, during or after the neutralization.