Conversion of manganate to permanganate
CA 2003997 C · Owner: Macdermid, Incorporated · Inventors: D'Ambrisi, Joseph J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electrolytic oxidation process for producing alkali metal permanganate from alkali metal manganate and particularly for effecting such production to regenerate a permanganate working bath such as used in, desmearing, etch-back or cleaning processes in the manufacture of printed circuits, which has reached a level of decreased working efficiency, wherein an aqueous alkaline solution of manganate in alkali metal hydroxide is electrolytically oxidized using a non-sacrificial anode and a cathode comprised of an alkali-resistant cathode electrode immersed in a concentrated aqueous solution of sodium hydroxide in a container porous to ions which is formed from ion-porous polymeric membrane …
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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 November 27, 1989 and granted January 5, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 27, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 27, 2011.
- 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.