Process for purifying hydrogen fluoride
CA 2028430 A1 · Owner: Gumprecht, William H. · Inventors: Gumprecht, William H.; Gumprecht, William H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing hydrogen fluoride that involves treating anhydrous hydrogen fluoride containing primarily trivalent arsenic impurities with an iodine compound capable of providing iodide ions (e.g. HI) so as to precipitate the arsenic (i.e. as AsI3) following by separation and recovery (e.g. by distillation or filtration) of purified anhydrous hydrogen fluoride.
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 24, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 24, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 24, 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.