Process for detecting marked mineral oils and new azo dyes
CA 2172959 A1 · Owner: Scholz, Gerhard · Inventors: Beck, Karin Heidrun; Dyllick-Brenzinger, Rainer; Scholz, Gerhard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for detecting marked mineral oils by treating the marked mineral oil with an extracting agent containing water a solvent and a base, in which use , is made as the marking agent of an azo dye of formula (I) in which ring A may , be benzo-anellated and l is 1 or 2 m is 1 to 4, X1 is hydrogen, C1-C4-alkyl cyano, nitro or possibly substituted phenylazo; X2 is hydrogen C1-C4-alkyl, cyano, nitro, C1-C4-alkoxy or C1-C16-alkoxy carbonyl; X3 is hydrogen C1-C4-, alkyl, cyano or C1-C16-alkoxy carbonyl and X4 is hydrogen hydroxy, possibly , substituted C1-C8-alkyl C1-C4-alkoxy, amino, C1-C4-dialkyl amino or possibly substituted C1-C16-monoalkylamino. A partially or completely water-miscible …
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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
- Filed September 30, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 30, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 30, 2016.
- 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
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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.