Expired Canadian patentCanada
Pulping process using oxygen and sodium tetraborate
CA 1082859 A · Owner: Domtar Inc. · Inventors: Markham, Larry D.
Overview
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Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process of oxygen pulping is disclosed wherein cellulosic material is digested with oxygen in the presence of borax in an amount between 12% and 22% as Na2O on wood, at a temperature between on 120° and 155°C.
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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 August 5, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 5, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 5, 1976
GrantedAugust 5, 1980
Term endedAugust 5, 1997
Patent numberCA 1082859 A
Classification (IPC)D21C3/02
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.