Paper sizing composition and sizing method
CA 2033265 C · Owner: Ikeda, Tsuyoshi · Inventors: Iwai, Kiyoshi; Ikeda, Tsuyoshi; Hyuga, Satoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a paper sizing composition comprising a rosin material and cationic acrylamide and/or methacrylamide polymers having hydrophobic groups wherein said rosin material is directly emulsified in water with said polymers. The sizing composition has an improved storage stability and exhibits an excellent sizing performance in the acidic through neutral pH range.
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 December 27, 1990 and granted June 12, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 2012.
- 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.