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Expired Canadian patentCanada

Acetone removal process

CA 2092901 C · Owner: Schisla, Robert Melvin Jr. · Inventors: Zoeller, Joseph Robert; Outlaw, Charles Emory; Schisla, Robert Melvin Jr.

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Disclosed is an improved process for the removal of acetone from a production system wherein acetic anhydride is produced by contacting a mixture comprising methyl iodide and methyl acetate and/or dimethyl ether with carbon monoxide in the presence of a carbonylation catalyst or catalyst system. The process comprises a water-methyl iodide extraction step wherein acetone is separated from a mixture of methyl acetate methyl iodide and acetone.

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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 September 25, 1991 and granted March 18, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 25, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 25, 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.
FiledSeptember 25, 1991
GrantedMarch 18, 1997
Term endedSeptember 25, 2011
Patent numberCA 2092901 C
Classification (IPC)C07C53/12 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedSep 25, 1991Patent grantedMarch 18, 1997Term endedSep 25, 2011

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.