A compound obtained by reacting a compound having a carbohydrazide structure with an acid or a base
CA 2758182 C · Owner: Toray Industries, Inc. · Inventors: Moriyama, Hideki; Tsukuda, Akimitsu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for producing a film which comprises an aromatic amide oxadiazole polymer containing an oxadiazole structure, the method comprising: immersing a film containing a carbohydrazide structure in a dehydration-cyclization agent solution bath at room temperature to produce a compound having an oxadiazole structure by dehydration-cyclization of the carbohydrazide structure, wherein the dehydration-cyclization agent solution consists of a base and solvent; and heat treating the film at a temperature 200°C to 500°C for several seconds to several minutes.
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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 March 2, 2004 and granted March 25, 2014. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 2, 2024.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 2, 2026.
- 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.