Semipermeable membrane made from a homogeneously miscible polymer blend
CA 2008328 C · Owner: Krieg, Claus-Peter · Inventors: Kreuder, Willi; Wildhardt, Juergen; Krieg, Claus-Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A semipermeable membrane is described which comprises a homogeneously miscible polymer blend of an aromatic polyamide and polyvinylpyrrolidone. The aromatic polyamide is in particular formed of recurrent units of the formula I:, (see formula I) wherein E1 and E2 are identical or different and are selected from the groupings, (see formula II) -Ar1-, and, -Ar1-X-Ar2, where Ar1 and Ar2 are the same or different 1,2-phenylene, 1,3-phenylene or 1,4-phenylene groups which may be substituted by (C1-C6) -alkyl (C1-C6)-alkoxy, -CF3 or halogen and X denotes a) a direct bond or one of the following divalent groups, -O-, -C (CF3)2-, -SO2- -CO-, -C(R1)2-, with R2, being hydrogen (C1-C6)-alkyl or …
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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 January 23, 1990 and granted April 10, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 23, 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
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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.