A method for reducing the permeability of paper and board and a substance for the method
CA 2124194 A1 · Owner: Nurmi, Kari · Inventors: Hamunen, Antti; Nurmi, Kari
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns the permeability of paper and board substrate. The permeability of the substrate is reduced by coating it with a modified coating mixture, which is based on a polymer dispersion containing at least one modified starch component. The polymer is prepared preferably by grafting monomers onto the modified starch structure.
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 November 11, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 11, 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.