Expired Canadian patentCanada
Polystyrene foams containing 1,1-difluoroethane and process of preparation
CA 2109626 C · Owner: E. I. Du Pont De Nemours And Company · Inventors: York, Robert O.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to the use of polyfluorocarbon blowing agents in the preparation of polymer foams; particularly the use of 1,1-difluoroethane in the preparation of polystyrene foams for food packaging and food serving.
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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 18, 1992 and granted September 10, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 18, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 18, 2014.
- 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 18, 1992
GrantedSeptember 10, 2002
Term endedMay 18, 2012
Patent numberCA 2109626 C
Classification (IPC)C08L25/06 +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.