Separation process
CA 2103745 A1 · Owner: Chawla, Surendra K. · Inventors: Chawla, Surendra K.; Maier, Thomas R.; Hahn, Bruce R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention discloses a process for separating acetone, dichloromethane and trifluoroacetic acid from a mixture of acetone, dichloromethane, and a trifluoroacetic acid/acetone azeotrope comprising the steps of:, (1) fractionally distilling the mixture of acetone, dichloromethane, and the trifluoroacetic acid/acetone azeotrope to separate the dichloromethane from a mixture of the trifluoroacetic acid/acetone azeotrope and free acetone;, (2) fractionally distilling the mixture of the trifluoroacetic acid/acetone azeotrope and free acetone to separate the free acetone from the trifluoroacetic acid/acetone azeotrope; (3) adding at least about 16 parts of water to the trifluoroacetic …
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 August 10, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 10, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 10, 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.
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.