Cell wall loading of never-dried pulp fibers
CA 2063567 C · Owner: Allan, G. Graham · Inventors: Allan, G. Graham
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There is disclosed a filled paper composition comprising intact cellulose fibers and fillers wherein the cellulose fibers are originally never-dried, and wherein the filler material is in an insoluble precipitate formed in situ within the cell wall of the never-dried cellulose pulp fibers. The filled paper composition is characterized by having increased strength characteristics relative to a corresponding conventionally loaded paper composition containing the same amount of the same filler material. There is also disclosed a process for the production of filled paper using never-dried pulp fibers and filler comprising an insoluble precipitate that is precipitated in situ within the …
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 24, 1990 and granted December 26, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 24, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 24, 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.