Process for removing residual lignin in chemical cellulose pulp
CA 1180510 A · Owner: Mo Och Domsjo Aktiebolag · 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 method at delignification of cellulose pulp A B S T R A C T, When using oxygen gas and alkali to delignify and bleach chemical cellulose pulp, it is not possible to remove more than approximately half the amount of lignin remaining in the cellulose pulp after the cook due to the risk of intensive and uncontrollable degradation of the carbohydrates in the cellulose pulp. By means of the invention it is now possible to remove three quarters of the amount of residual lignin while maintaining good pulp qualities, and the invention relates to a method for delignifying chemical cellulose pulp, in which the pulp is brought into contact in an activating stage with a gas phase containing NO2 and, …
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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.