Asymmetric porous polyamide membranes
CA 2021579 A1 · Owner: Russell, Patrise M. · Inventors: Kolcinski, Bruce E.; Krishnan, Subramanian; Dennison, Kathleen A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Asymmetric porous polyamide membranes permeable, to fluid flow comprising: (A) a porous skin layer, and, (B) adjacent to the skin layer an integral, porous support layer having at least one region comprising a network of substantially parallel, hollow tube-like structures, each of the tube-like structures being oriented such that the longitudinal dimension of each tube-like structure is essentially perpendicular to the skin layer; wherein:, the skin layer is relatively thin and dense compared to the support layer, the pore diameters in the skin layer are relatively small compared to the diameters of the tube-like structures in the support layer, in membranes having support layers with more …
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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 July 19, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 19, 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.