Purification of 1,1,1,2-tetrafluoroethane
CA 2062450 A1 · Owner: Imperial Chemical Industries Plc · Inventors: Edwards, Derek W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
QM 36253, ABSTRACT, PURIFICATION OF 1,1,1,2-TETRAFLUOROETHANE A process for the removal of, 1-chloro-2,2-difluoroethylene from 1,1,1,2-tetrafluoroethane which process comprises contacting 1,1,1,2-tetrafluoroethane containing 1-chloro-2,2-difluoroethylene with a zeolite containing strontium cations. The zeolite containing strontium cations may be produced by ion-exchange with a commercially available zeolite for example an A-type zeolite or a chabazite.
Read the whole patent
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 March 6, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 6, 2014.
- 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.