Purification of aromatic diacids
CA 2383346 A1 · Owner: Brownscombe, Thomas F. · Inventors: Brownscombe, Thomas F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method is provided to produce dicarboxylic or tricarboxylic aromatic acid from salts of such acids, the method including the steps of providing an aqueous solution of a salt of a dicarboxylic or tricarboxylic aromatic acid the aqueous solution having a pH of about 7 or greater; contacting the aqueous solution with sufficient carbon dioxide to lower the pH of the aqueous solution resulting in precipitation of at least a portion of the dicarboxylic or tricarboxylic aromatic acid; separating precipitated dicarboxylic or tricarboxylic aromatic acid from the solution; and recovering carbon dioxide from the solution.
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 8, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 8, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 8, 2022.
- 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.