Surfactant treatment of aromatic polyimide gas separation membranes
CA 2027021 A1 · Owner: L'Air Liquide, Societe Anonyme Pour L'Etude Et L'Exploitation Des Proced Es Georges Claude · Inventors: Hayes, Richard A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for improving the permselectivity of an aromatic polyimide gas separation membrane comprising contacting said membrane with a solution of a surfactant in a solvent which swells the membrane but in which the membrane material is soluble to an extent of no more than 3% under the conditions used to contact the membrane.
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 5, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 5, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 5, 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.