Process for manufacturing bisphenols
CA 2044247 A1 · Owner: Biller, Efim · Inventors: Biller, Efim
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of recovering or purifying bisphenols in particular bisphenol A, from crude product prepared in accordance with any prior art process characterized by the, fact that theses crude products possibly after removal of low boiling compounds and excess phenol, are recovered or worked up from solvents by crystallization from high-boiling aromatic hydrocarbons (HBS) having a boiling point which is above 200°C and below the boiling point of the bisphenols. H:34262.PAT
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 October 15, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 15, 2012.
- 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.