Quaternized tertiary aminomethyl acrylamide polymer microemulsions with improved performance
CA 2115412 A1 · Owner: Schmitt, Joseph M. · Inventors: Leone-Bay, Andrea; Schmitt, Joseph M.; Huang, Sun Y.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Quaternized tertiary aminomethyl acrylamide polymer emulsions are treated by 1) adjusting the pH to about 3.6 to about 4.8, 2) adding a formaldehyde scavenger 3), adjusting the water content of the aqueous phase to result in about 10-45 weight percent of quaternized aminomethylated acrylamide polymer and 4) heating the resultant emulsion at-from about 40°C to about 80°C for about 3 to about 20 hours so as to render them more stable, capable of inversion in water independent of water temperature or pH of the medium flocculant and superior dewatering ability.
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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 February 10, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 10, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 10, 2016.
- 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.