Process for the removal of catalysts from polyether polyols
CA 2010433 C · Owner: Sandhagen, Hans-Joachim · Inventors: Gupta, Pramod; Rosenbaum, Heinz-Jorg; Sandhagen, Hans-Joachim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for removing a basic catalyst from a polyether polyol having a hydroxyl number of from 4 to 250 comprising adding from 0.7 to 7 percent by weight of water, based on the polyether polyol to, an alkaline reaction medium containing the polyether polyol at a temperature of from 20 to 120°C; introducing 1 to 2 times the stoichiometric amount of gaseous carbon dioxide at a temperature of from 75 to 120°C, thereby forming a carbonate salt; and removing the carbonate salt by filtration.
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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 February 20, 1990 and granted August 17, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 20, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 20, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
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.