Process for bleaching a chemical pulp
CA 2175817 A1 · Owner: Troughton, Nicholas A. · Inventors: Troughton, Nicholas A.; Desprez, Francois; Devenyns, Johan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for bleaching a chemical pulp through a sequence of processing steps comprising in this order, a step for decontaminating the pulp by removing its transition metals an alcaline hydrogen peroxide processing step and a processing step using a non peroxygenated acid.
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 October 28, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 28, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 28, 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.