Pressure sensitive copying paper
CA 2057589 A1 · Owner: The Wiggins Teape Group Limited · Inventors: Tilbury, Susan C.; Hobson, Michael E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Pressure-Sensitive Copying Paper An extracted and isolated soy protein polymer is used for prevention of premature colouration in CFB pressuresensitive copying paper which is neutral- or alkalinesized with an alkyl ketene dimer and which utilizes an acid clay colour developer composition. The soy protein polymer may be carried by the base paper e.g. as a, result of size press or size bath application or may be, present in the microcapsule coating.
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 December 13, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 13, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 13, 2013.
- 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.