Stabilized sodium hydrosulfite composition and process for bleaching wood pulp therewith
CA 1061509 A · Owner: Ventron Corporation · Inventors: Sullivan, Edward A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aqueous composition for bleaching wood pulp containing sodium hydrosulfite, and at least 2 weight percent hexamethylenetetramine based upon the weight of sodium hydrosulfite wherein the solution has a pH between, about 4 and about 11. The hexamethylenetetramine prevents or substantially reduces hydrogen sulfide formation during bleaching of the wood pulp.
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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 September 4, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 4, 1996.
- 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.