Removal of organic cations from polar fluids
CA 2031600 A1 · Owner: Schmidt, Donald L. · Inventors: Skelly, Norman E.; Schmidt, Donald L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cationic organic impurities such as ternary sulfonium ions and quaternary ammonium and phosphonium compounds are effectively removed from polar liquids such as water or water/alcohol mixtures by contacting the polar liquid with an absorbent comprising a trinitroarenol such as a picric acid. This method is particularly effective for removing such cationic impurities from polar liquids containing organic zwitterions. 37,417-F
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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
- Filed December 5, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 5, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 5, 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
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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.