Recovery of 2-pyrrolidone
CA 1061792 A · Owner: Chevron Research And Technology Company · Inventors: Anshus, Byron E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A two-stage evaporative method for recovering polymerizable 2pyrrolidone from alkaline aqueous solutions such as those obtained by washing the catalyst from an incompletely reacted polypyrrolidone polymerizate includes the steps of neutralizing the base with mineral acid removing most, of the water in an initial reduced pressure evaporation and recovering the pyrrolidone from a salt/pyrrolidone slurry by vaporization under reduced pressure.
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
- Granted September 4, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 4, 1996.
- 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.