Separation of bisphenol-a from the alkaline phase generated in the production of polycarbonates
CA 1049565 A · Owner: Mobay Chemical Corporation · Inventors: Cleveland, Thomas H.; Bailey, John V.; Wirfel, Emanuel W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to polycarbonates and more particularly to separating unreacted bisphenol-A from the alkaline phase generated in the production of polycarbonates comprising contacting the alkaline phase with phosgene in a secondary reaction stream in the presence of an organic solvent to convert the unreacted bisphenol-A to a low molecular weight polymer having chlorocarbonate end groups separating the solvent solution of the low molecular weight polymer from the aqueous alkaline phase and preferably, returning said solvent solution to the main reaction stream.
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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
- Granted February 27, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 27, 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.