Cellulose pulps of selected morphology for improved paper strength potential
CA 2067641 C · Owner: Erspamer, John Paul · Inventors: Vinson, Kenneth Douglas; Erspamer, John Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cellulose pulp compositions of selected fiber morphology are disclosed. Of particular interest, are morphological forms of wood fibers with the potential to achieve improved paper strength without suffering the penalty of slow drainage rate. These cellulose pulps are especially useful for efficiently producing paper structures such as tissue paper of requisite strength.
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 April 30, 1992 and granted July 15, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 30, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 30, 2014.
- 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.