Liquid suspension of polyethylene oxide for use in treating paper and pulp wastewater
CA 2058745 A1 · Owner: Nalco Chemical Company · Inventors: Chung, Daniel K.; Warrick, Stephen B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A flocculating agent which comprises: a particulate ethylene oxide polymer present in an amount of between about 20 to about 35% by weight; an inert liquid vehicle comprising a mixture of a glycol which is present in an amount between about 25 to about 30% by weight and, glycerine which is present in an amount between about 45 to about 50% by weight, wherein the specific gravity of the ethylene oxide polymer is approximately the same as the specific gravity of the inert liquid vehicle; and a suspension agent which is present in an amount between about 0.4 to about 0.6% by weight, wherein the flocculating agent has a viscosity in the range between about 1800 to about 5900 cps.
Read the whole patent
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 January 3, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 3, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 3, 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
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.