Expired Canadian patentCanada
Hydrolytically and oxidatively stable polyimides
CA 2093353 C · Owner: E. I. Du Pont De Nemours And Company · Inventors: Kaku, Mureo
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyimide prepared from 3,3',4,4'-biphenyltetracarboxylic dianhydride and an aromatic diamine which is at least about 60 % meta-phenylene diamine exhibits excellent hydrolytic and oxidative stability.
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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 October 10, 1991 and granted July 30, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 10, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 10, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 10, 1991
GrantedJuly 30, 2002
Term endedOctober 10, 2011
Patent numberCA 2093353 C
Classification (IPC)C08G73/10 +1 more
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.