Plural stage purification of propylene oxide
CA 2102853 A1 · Owner: Texaco Petrochemical Inc. · Inventors: Mueller, Mark Allan; Demoll, Gregory Brian; Meyer, Robert Allen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Impure propylene oxide is purified by a distillation process wherein it is (a) extractively distilled in a first column using a C2 to C6 alkylene glycol extractive distillation agent to form a first overhead fraction comprising propylene oxide, C5-C7 hydrocarbons, methanol water and, oxygen-containing impurities (b) wherein the first overhead, fraction is separated in a second column into a second overhead fraction comprising most of the pentanes pentenes, and oxygen-containing impurities and a partially purified propylene oxide bottoms fraction comprising propylene oxide hexenes, hexanes, and only residual quantities of pentenes and pentanes, (c) wherein the partially purified bottoms …
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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 November 10, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 10, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 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.