Expired Canadian patentCanada
Decoloration of polyisocyanates containing isocyanurate and uretdione groups
CA 2095997 C · Owner: Hardt, Richard · Inventors: Wack, Serge; Graf, Hermann; Deuker, Ernst
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for decoloring, polyisocyanates containing isocyanurate and uretdione groups comprises treating the demonomerized polyisocyanates containing isocyanurate and uretdione groups with oxygen.
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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 May 11, 1993 and granted July 11, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 11, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 11, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMay 11, 1993
GrantedJuly 11, 2000
Term endedMay 11, 2013
Patent numberCA 2095997 C
Classification (IPC)C07D251/34 +2 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.