Cryogenic rectification process for producing ultra high purity nitrogen
CA 2012217 C · Owner: Union Carbide Corporation · Inventors: Cheung, Harry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing ultra high purity nitrogen from nitrogen produced by the cryogenic rectification of air wherein superatomospheric nitrogen is progressively condensed and revaporized to effect rejection of lower boiling impurities without need for additional energy beyond that contained in the nitrogen input.
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 15, 1990 and granted December 14, 1993. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 15, 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.