Process for purifying 1,1,1,2-tetrafluoroethane
CA 2133613 C · Owner: Lantz, Andre · Inventors: Lacroix, Eric; Lantz, Andre; Cheminal, Bernard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
To eliminate olefin impurities (in particular 1-chloro-2,2-difluoroethylene and polyfluoropropenes) present in crude 1,1,1,2-tetrafluoroethane (F-134a) a gas mixture of crude F-134a, hydrofluoric acid and oxygen or air at a temperature between 200 and 350 C and at a pressure between atmospheric pressure and 2.5 MPa is treated in the gas phase in the presence of a fluorination catalyst the HF/F-134a mole ratio being between 0.05 and 0.5 and the O2/F-134a mole ratio between 0.001 and 0.1. The process enables effective and economical purification of the F-134a.
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 October 4, 1994 and granted February 3, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 4, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 4, 2016.
- 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.