Process for manufacturing paper
CA 2473638 A1 · Owner: Andersson, Kjell · Inventors: Andersson, Kjell; Johansson-Vestin, Hans E.; Froelich, Sten
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to a process for manufacturing paper and board comprising providing a suspension comprising cellulosic fibres and at least a sizing agent, dewatering said suspension thereby forming a paper-web whereby , an aromatic-containing cationic vinyl addition polymer and an anionic polymer , having a weight average molecular weight in the range of from 6,000 up to about 100,000 selected from the group consisting of vinyl addition polymers and condensation polymers is added to the suspension.
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 January 22, 2003. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 22, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 22, 2025.
- 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.