Process for manufacture of cationic starch derivatives using concentrated alkali
CA 2082702 A1 · Owner: National Starch And Chemical Investment Holding Corporation · Inventors: Johnson, Scott; Buffa, Vito
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention is directed to an improvement in the manufacture of dry non-gelatinized cationic quaternary amine starch derivatives. An alkaline solution having a concentration up to 50% is reacted in-line with a quaternary amine/epihalohydrin condensate to form the epoxide reaction product immediately before addition to a starch slurry. After formation the epoxide is introduced into a starch slurry for the formation of the starch derivative. The reaction of the quaternary amine/epihalohydrin condensate with alkali out of presence of the starch slurry permits the use of the higher concentration of alkaline solution over known methods allowing, more kettle volume for starch and greater …
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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 November 12, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 12, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 12, 2014.
- 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.