Hydrophobic coagulants used as retention and drainage aids in papermaking processes
CA 2122956 A1 · Owner: Chung, Daniel K. · Inventors: Chung, Daniel K.; Shetty, Chandrashekar S.; Ramesh, Manian
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for making paper which comprises forming an aqueous cellulosic suspension, adding a hydrophobic coagulant and a flocculant to the cellulosic suspension draining the cellulosic suspension to form a sheet and drying the sheet, wherein the hydrophobic coagulant comprises a copolymer of diallyl dimethyl ammonium chloride and a hydrophobic monomer selected from the group consisting of: quaternized dialkylaminoalkylacrylates quaternized, dialkylaminoalkylmethacrylates and long chain alkyl (C6 to, C20) esters of (meth)acrylic acids.
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 May 5, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 5, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 5, 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.