Method of preparing high activity sulfonated lignin dye dispersants, high activity sulfonated lignin dye dispersants produced thereby and dyes tuff compositions containing the same
CA 2215375 A1 · Owner: Dilling, Peter · Inventors: Huguenin, Sallie B.; Dilling, Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Improved dyestuff compositions comprising a dye cake and a dye dispersant are disclosed wherein the dye dispersant comprises sulfonated or sulfomethylated lignin of increased activity and improved heat stability properties and which dispersants are disclosed to be prepared by substantial removal of the low molecular weight component of the sulfonated and sulfomethylated lignin. Exclusion of the low molecular weight portion of the dispersant may be accomplished by fractionation of the sulfonated or sulfomethylated lignin to remove a substantial portion of the molecules having a molecular weight below 3,000. Alternatively in the case of lignin recovered from sulfate or soda wood pulping …
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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
- Filed September 12, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 12, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 12, 2019.
- 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.