Use of blends of dispersion polymers and coagulants for coated broke treatment
CA 2210776 A1 · Owner: Nalco Chemical Company · Inventors: Weinstein, David I.; Gerli, Alessandra
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved papermaking process comprising forming an aqueous cellulosic papermaking slurry and adding a blend of a water-soluble dispersion polymer and a coagulant to the slurry to increase retention and/or drainage is disclosed. After addition of the polymers, the slurry is drained to form a sheet and the sheet is dried.
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 July 18, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 18, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 18, 2019.
- 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.