4-4-(substituted-amino)phenyl- or heteroaryl-2, 6-bis(heteroaryl) pyridines as color formers in pressure-sensitive and thermal imaging systems
CA 1180331 A · Owner: Sterling Drug Inc. · Inventors: Hung, William M.; Schmidt, Paul J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel 4-4-(substituted-amino)phenyl- or heteroaryl- 2,6-bis(heteroaryl)pyridines which are useful as color formers in pressure-sensitive carbonless duplicating systems and thermal marking systems are prepared by reacting a heteroaryl methyl ketone with a 2-R4-4-NR5R6-benzaldehyde or a heteroaryl aldehyde in the presence of ammonia or an ammonia-releasing agent.
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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
- Granted January 2, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 2, 2002.
- 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.