Stable tannin based polymer compound
CA 1267745 C · Owner: Dearborn Chemical Company · Inventors: Quamme, Jane Elizabeth; Kemp, Anne Harrungton
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aqueous flocculant solution containing a tannin based polymer compound is produced which is stable and has a shelf life of at least 3-6 months before gelling. The solution is made by reacting at a temperature of from about 150°-200°F a tannin, an amino compound and an, aldehyde under slightly acidic conditions where the pH is less than 7 and where the molar ratio of the primary amine from the amino compound to the tannin repeating unit is from about 1.5:1 to 3.0:1. The intermediate viscosity of the reaction mixture is monitored until the reaction mixture has an intermediate viscosity within the range of the system key intermediate viscosity range. This system key intermediate viscosity …
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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 April 10, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 10, 2007.
- 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.