Process for the production of chlorine dioxide
CA 2014691 C · Owner: Eka Nobel Ab · Inventors: Svedin, Bjorn Henrik; Engstrom, Jorgen; Sundblad, Birgitta
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing chlorine dioxide by reacting in a reaction vessel an alkali metal chlorate mineral, acid and a reducing agent in such proportions that chlorine dioxide is produced in a reaction medium maintained at a temperature of from about 50 °C to about 100 °C and at an acidity within a range of from about 2 to about 11 N. The reaction medium is subjected to subatmospheric pressure sufficient for evaporating water a mixture of, chlorine dioxide and water vapour being withdrawn from an evaporation zone in the reaction vessel and alkali metal sulfate being precipitated in a crystallization zone in the reaction vessel. A mixture of formaldehyde and methanol is used as reducing …
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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 April 17, 1990 and granted September 30, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 17, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 17, 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
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.