Production of filled paper and compositions for use in this
CA 2180372 C · Owner: Satterfield, Brian Frederic · Inventors: Cauley, Thomas Adrian; Satterfield, Brian Frederic; Evans, Bruce
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Filled paper is made by adding a cationising amount of cationic polymer to precipitated calcium carbonate or other filler either as a slurry or in a thick stock component producing a thin stock containing the cationised filler and then treating the thin stock with a formaldehyde resin and polyethylene oxide as a retention system prior to drainage and drying.
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 July 2, 1996 and granted October 2, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 2, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 2, 2018.
- 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.