Catalyst recovery for halogen exchange reactions
CA 2320283 A1 · Owner: Balhoff, John F. · Inventors: Lin, Ronny W.; Balhoff, John F.; Cheng, Chi Hung
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
It has been found possible to separate catalytically-active aminophosphonium catalysts from mixtures composed predominately of aminophosphonium catalyst residue(s) and heavy ends form a halogen exchange reaction conducted in an aprotic solvent/diluent by extracting such mixtures with a neutral or acidic aqueous extraction solvent medium. Various ways of isolating form the halogen exchange reaction product mixture a mixture composed predominately of aminophosphonium catalyst residue(s) and heavy ends are described. Halogen exchange processes in which the catalytically-active aminophosphonium catalysts are separated for reuse are also described. Since aminophosphonium catalysts are …
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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 December 11, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 11, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 11, 2020.
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Timeline
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.