Expired Canadian patentCanada
Process for producing diaryl carbonate
CA 2013689 C · Owner: Asahi Kasei Kabushiki Kaisha · Inventors: Tojo, Masahiro; Deguchi, Ryoji; Fukuoka, Shinsuke
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for producing a diaryl carbonate which comprises diproportionating an alkylaryl carbonate to a diaryl carbonate and a dialkyl carbonate in the presence of a lead catalyst.
Read the whole patent
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 April 3, 1990 and granted October 28, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 3, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 3, 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.
FiledApril 3, 1990
GrantedOctober 28, 1997
Term endedApril 3, 2010
Patent numberCA 2013689 C
Classification (IPC)C07C68/06 +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.