Process for the delignifying bleaching of cellulose pulp
CA 1180511 A · Owner: Mo Och Domsjo Aktiegolag · Inventors: Samuelson, Hans O.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for delignifying bleaching cellulose pulp in three stages, an activating stage, and first and second alkaline stages NO and/or NO2 and O2, and optionally HNO3 being supplied to the, water-containing pulp in the activating stage; in the first alkaline stage alkali being supplied as carbonate, primarily HCO3with oxygen gas, having a partial pressure on average, of from 0 to 0.2 MPa, the, lignin content of the pulp being lowered in this stage so that the Kappa number of the pulp after the stage is from 10 to 60% of the Kappa number of the pulp entering the activating stage; in the second alkaline stage, alkali being supplied as carbonate primarily CO3=, with oxygen, gas at a partial …
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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
- Granted January 8, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 8, 2002.
- 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.