Processes for purifying polyether polyols using ion exchange resins
AssigneeCovestro LLC
InventorsDaniel R. Wagner, Brian L Neal
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Abstract
Processes for purifying polyether polyols via treatment with ion exchange resins. A mixture that includes the polyether polyol and alkali metal ions is passed through a first bed that includes a cation exchange resin comprising carboxylic acid and/or phosphonic acid groups to remove alkali metal ions from the mixture. Thereafter, the product is passed through a second bed comprising an anion exchange resin comprising quaternary ammonium groups and a cation exchange resin comprising carboxylic acid and/or phosphonic acid groups to thereby produce a purified polyether polyol.
Claims20
A process for removing alkali metal ions from a polyether polyol, comprising:
- (a) passing a mixture comprising the polyether polyol and the alkali metal ions through a first bed comprising a cation exchange resin comprising carboxylic acid and/or phosphonic acid groups to remove alkali metal ions from the mixture;
- and (b) passing the product of step (a) through a second bed comprising an anion exchange resin comprising quaternary ammonium groups and a cation exchange resin comprising carboxylic acid and/or phosphonic acid groups to thereby produce a purified polyether polyol, wherein the first bed and the second bed are each free of a cation exchange resin that comprises sulfonic acid groups.
A process for producing a polyether polyol, comprising:
- (a) adding an alkylene oxide onto an H-functional starter in the presence of an alkali metal catalyst to produce an alkali metal-containing crude polyol comprising a mixture comprising the polyether polyol and alkali metal ions;
- (b) passing the mixture through a first bed comprising a cation exchange resin comprising carboxylic acid and/or phosphonic acid groups to remove alkali metal ions from the mixture;
- and (c) passing the product of step (b) through a second bed comprising an anion exchange resin comprising quaternary ammonium groups and a cation exchange resin comprising carboxylic acid and/or phosphonic acid groups to thereby produce a purified polyether polyol, wherein the first bed and the second bed are each free of a cation exchange resin that comprises sulfonic acid groups.
Dependencies are inferred from the claim text.