Method for precipitation of sulphonated lignin from sulfite liquors
CA 1187487 A · Owner: Gesellschaft Fur Biotechnologische Forschung M.B.H. · Inventors: Haars, Annegret; Huttermann, Aloys
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is provided a method for the precipitation of lignin sulphonates from sulfite liquors by the use of polyimines with a low polarity as polycations whereby there is separated an alkali-soluble precipitation complex and the polyimine can be recovered by extraction with organic solvents. The novel method provides the advantage that the sulfite liquor can be used as it is discharged from the boiler without further treatment such as thickening.
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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 May 21, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 21, 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
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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.