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Expired Canadian patentCanada

Process for the production of chlorine dioxide

CA 2041054 C · Owner: Eka Nobel Ab · Inventors: Sundblad, Birgitta; Lovetro, David C.

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A process for a continuous production of chlorine dioxide in a cooled reaction vessel subjected to an overpressure, comprising continuous addition of an aqueous solution of an alkali metal chlorate, sulfuric acid and sulfur dioxide to the reaction vessel in proportions to generate chlorine dioxide at a temperature from about 30 to about 60°C and at an acidity of about 5 to about 11 N. The reaction solution containing dissolved chlorine dioxide is continuously withdrawn. At the start up of the process the reaction vessel is filled with the water solution of alkali metal chlorate, optionally containing alkali metal chloride, and the sulphuric acid with a feed concentration of from, about 20 …

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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 23, 1991 and granted January 14, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 23, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 23, 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.
FiledApril 23, 1991
GrantedJanuary 14, 1997
Term endedApril 23, 2011
Patent numberCA 2041054 C
Classification (IPC)C01B11/02

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedApril 23, 1991Patent grantedJan 14, 1997Term endedApril 23, 2011

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.