Abstract: 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; and (c) removing the salt crystals from the polyether polyol 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.

Abstract: 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; and (c) removing the salt crystals from the polyether polyol 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.

Abstract: Process for the preparation of a polyether polyol containing at most 20 ppm of sodium and/or potassium, which process comprises the steps of: (a) reacting an initiator having at least two active hydrogen atoms with at least one alkylene oxide in the presence of a catalyst comprising an alkali metal hydroxide; (b) neutralising the polyether polyol reaction product obtained in step (a) by contacting this reaction product with an acid having a pKa of less than 5 and water, wherein the acid and water are added in such amount that after addition: the water content is 2% by weight or less on the basis of the total weight of polyether polyol present and the molar ratio of acid to alkali metal hydroxide is in the range of from 0.3 to 1.