Semipermeable membranes bases on specified 4,4'-(1h-alkylidene) bis¬2,3,6,6-trialkylphenol type polyesters
CA 2006591 A1 · Owner: Muruganadam, Natarajan · Inventors: Brode, George L.; Muruganadam, Natarajan; Kawakami, James H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
36 -, SEMIPERMEABLE MEMBRANES BASED ON SPECIFIED 4,4'-(1H-ALKYLIDENE)BIS2,3,6-TRIALKYLPHENOL TYPE POLYESTERS, Abstract of the Invention Permeable membranes comprised predominantly of specifically defined polyester of, 4,9'-(1H-alkylidene) bis2,3,6-trialkylphenol and aromatic dicarboxylic acids. The invention also pertains to the novel permeation processes for recovery of an oxygen/nitrogen or carbon dioxide/methane or helium/methane component from a mixture of said component with other components in the mixture. D-16101-3
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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 December 22, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 22, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 22, 2011.
- 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
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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.