Carbon dioxide in neutral and alkaline sizing processes
CA 2069713 C · Owner: Canadian Liquid Air Ltd./ Air Liquide Canada Ltee. · Inventors: Hornsey, Derek
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In the nan-acidic sizing of paper reaction between alkylketene dimer sizing agent and cellulose of cellulosic paper-making fibers is catalyzed by dissolving carbon dioxide in an aqueous vehicle of an aqueous pulp of the paper-making fibers; the carbon dioxide provides bicarbonate ions which catalyse the reaction; the bicarbonate ions may be generated by dissociation of the carbon dioxide in water ar by, reaction of the carbon dioxide with calcium carbonate incorporated in the pulp as a filler for the paper or, with some other alkali present.
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 May 27, 1992 and granted May 13, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 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.