Paper quality improver
CA 2492931 A1 · Owner: Kao Corporation · Inventors: Satoh, Haruyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A paper improver for use in papermaking which even when a pulp feedstock is , formed into a sheet under high-speed conditions enables the sheet to be , improved in bulkiness whiteness, opacity, and paper strength. The paper improver comprises, in a specific proportion by weight (A) a copolymer , comprising structural units derived from one or more nonionic monomers having a solubility parameter of 20.5 (MPa)1/2 or smaller and structural units derived from one or more anionic or cationic monomers and (B) a surfactant. It produces at least one of the following paper quality-improving effects: (i) the degree of improvement in standard bulkiness is 0.02 g/cm3 or higher (ii) , the degree of …
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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 July 17, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 17, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 17, 2025.
- 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.