N-aminopyridone dyes
CA 2106779 A1 · Owner: Sens, Ruediger · Inventors: Schefczik, Ernst; Sens, Ruediger; Etzbach, Karl-Heinz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Pyridone dyes useful for thermal transfer have the formula, (I) where, R1 is hydrogen or C1-C4-alkyl, R2 and R3 are identical or different and each is independently of the other, hydrogen, substituted or unsubstituted C1-C12-alkyl, C5-C7-cycloalkyl sub-, stituted or unsubstituted phenyl substituted or, unsubstituted pyridyl, substituted or unsubstituted C1-C12-alkanoyl, C1-C12-alkoxycarbonyl substituted or, unsubstituted C1-C12-alkylsulfonyl C5-C7-cycloalkyl-, sulfonyl, substituted or unsubstituted phenylsulfonyl, substituted or unsubstituted pyridylsulfonyl, substituted or unsubstituted benzoyl pyridylcarbonyl or thienylcarbonyl or are together with the nitrogen atom to which they are …
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 March 6, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 6, 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.