Method for the surface purification of a graphite containing impurities using a dilute aqueous solution of nh4f and h2so4
CA 2478428 C · Owner: Kinoshita, Kimio · Inventors: Guerfi, Abdelbast; Zaghib, Karim; Armand, Michel
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a method of preparing surface-purified graphite particles from particles of an impure graphite. The inventive method comprises at least one step whereby the graphite particles are treated with a dilute aqueous solution of (H¿2?SO¿4? and NH¿4?F). According to the invention the H¿2?SO¿4? and the NH¿4?F each have a weight content in the dilute aqueous solution of between 5 and 30 % of the total weight of said solution while the quantity of the dilute aqueous solution represents between 70 and 95 % of the weight of the graphite particles to be purified.
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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 February 12, 2003 and granted July 23, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 12, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 12, 2025.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.