Tannin extraction
CA 2037041 C · Owner: Connolly, David L. · Inventors: Connolly, David L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Method for extracting tannins from bark and mufti-stage apparatus suitable therefor. The method includes the steps of contacting bark containing tannins with a first tannin enriched aqueous wash medium at elevated temperatures; separating the tannin-rich liquid extract by filtration including dewatering the resulting filter cake under pressure; washing the filter cake with a plurality of aqueous wash media at elevated temperatures; and separating the tannin enriched media after each washing stage by filtration including dewatering the filter cake under pressure; wherein each successive wash medium has a lower degree of tannin enrichment than the preceding wash medium.
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 7, 1990 and granted April 3, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 7, 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.