Process for the removal of catalysts from polyether polyols
CA 2023634 A1 · Owner: Bayer Aktiengesellschaft · Inventors: Gupta, Pramod; Sandhagen, Hans-Joachim; Rosenbaum, Heinz J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention thus relates to a process for removing a basic catalyst from a polyether polyol having a hydroxyl number of from about 4 to 800 comprising (a) adding from about 0.7 to 10 percent by weight of water based on said polyether polyol, to an alkaline medium containing said polyether polyol at a temperature of from about 25 to 140°C;, (b) introducing about 1 to 2 times the stoichiometric amount of gaseous carbon dioxide, based on the amount of base in the alkaline reaction medium, at a temperature of from about 75 to 120°C, thereby forming a carbonate salt; (c) removing said carbonate salt by filtration to give a filtrate containing the polyether polyol; and (d) neutralizing …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed August 20, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 20, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 20, 2012.
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Timeline
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Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.