Continuous process for the preparation of acetic anhydride or mixtures of acetic anhydride and acetic acid
CA 2097494 C · Owner: Outlaw, Charles E. · Inventors: Moncier, Regina M.; Zoeller, Joseph R.; Outlaw, Charles E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a continuous process for the preparation of acetic anhydride which comprises carbonylating a mixture comprising (i) methyl iodide and (ii) methyl acetate and/or dimethyl ether in the presence of a rhodium catalyst and a promoter wherein the concentration of mesityl oxide in the carbonylation mixture is suppressed by the presence therein of at least 100 ppm of dissolved ferrous and/or cobaltous ion.
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 December 3, 1991 and granted December 23, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 3, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 3, 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.
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.