Bleaching and delignifying cellulose using caroate/caro's acid and production of same
CA 2284520 A1 · Owner: Peroxid-Chemie Gmbh & Co. Kg · Inventors: Dorn, Maximilian; Gutewort, Sven; Gnann, Michael
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 for bleaching and/or delignifying cellulose in which a) a sodium hydroxide solution and a peroxydisulfate solution are first of all produced by electrolysis of a sulphate b) the peroxydisulphate , solution is converted by hydrolysis into a Caro's acid/caroate solution c) , said Caro's acid/caroate solution is left to cool and d) used immediately as a bleaching solution for bleaching and/or delignifying cellulose the Caro's , acid/caroate solution becoming neutralized upon introduction into the bleaching solution.
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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 March 19, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 19, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 19, 2020.
- 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.