Methanol-based chlorine dioxide process
CA 2085375 C · Owner: Superior Plus Inc. · Inventors: Bechberger, Edward J.; Bigauskas, Tomas Daniel; Fredette, Maurice C.J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Chlorine dioxide is produced at high efficiency by reduction of sodium chlorate with methanol in an aqueous acid reaction medium at a total acid normality below 7 with the reaction medium being at its boiling point while a subatmospheric pressure is applied thereto and having a chlorate concentration of at least about 2.0 molar. By employing such conditions the, tendency is eliminated for the reaction to be subject to white-outs in the absence of added chloride ion. In this way, the chlorine content of product aqueous chlorine dioxide solution arising from this source is eliminated.
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 June 20, 1991 and granted February 1, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2013.
- 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.