Preparation process of paper for increasing filler contents and enhancing scott internal bond strength
CA 2187757 C · Owner: Sohn, Chang Man · Inventors: Han, Sin Ho; Sohn, Chang Man; Ow, Steven Say-Kyoun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a preparation process of paper for increasing the contents of the inorganic fillers in the paper and enhancing Scott internal bond strength. Additional to a conventional preparation process of paper as a cellulase type enzyme, an enzyme produced by Trichoderma longibrachiatum which has a carboxymethylcellulase activity of 3,600 U/ml or more is added to a pulp in an amount of 0.01 ~ 0.2 % by weight based on the weight of the wood pulp. The contents of fillers in the paper is increased and Scott internal bond strength is enhanced.
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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 November 25, 1994 and granted July 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 25, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 25, 2016.
- 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.