Cationic polysaccharides and reagents for their preparation
CA 2019675 C · Owner: Tsai, John J. · Inventors: Rutenberg, Morton W.; Philbin, Michael T.; Tessler, Martin M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cationic polysaccharide derivatives are prepared by reacting a polysaccharide with a polycationic reagent having one polysaccharide reactive group and at least two cationic groups. Suitable reagents include polycationic alkyl, aryl, alkaryl, cycloaliphatic or heterocyclic amines, some of, which are novel compositions. The polycationic polysaccharide derivatives prepared from these reagents are useful in the manufacture of paper.
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 June 22, 1990 and granted December 30, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 22, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 22, 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.