Record material utilising a vinyl carbinol or derivative thereof as a chromogenic compound
CA 2029966 A1 · Owner: The Wiggins Teape Group Limited · Inventors: Shanton, Kenneth J.; Azizian, Farid
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Pressure- or heat-sensitive record material utilises a chromogenic material of the formula (I) (Ia or Ib): (I), (Ia) (Ib), in which:, one of A1 and A3 is an optionally-substituted carbocyclic aryl group and the other of A1 and A3 is either an optionally-substituted aryl group which is the same as or different from A1, or an optionally-substituted nitrogencontaining aromatic heterocyclic group with the proviso, that if both A1 and A3 are aryl groups then at least one of, A1 and A3 has a substituted amino or -N-heterocyclic substituent in the 4- position (relative to the bond joining A1 or A3 respectively to the remainder of the molecule);, A2 is hydrogen or an optionally-substituted aryl …
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 14, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 14, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 14, 2012.
- 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.