Dyeing method using a specific active methylene compound and a compound selected among a specific aldehyde, a specific ketone, a quinone and a di-imino-isoindoline or 3-amino-isoindolone derivative
CA 2320922 A1 · Owner: Lagrange, Alain · Inventors: Lagrange, Alain; Andrean, Herve
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention concerns the use for dyeing keratinous fibres of at least a specific active methylene compound and a compound selected among a specific aldehyde a specific ketone, a quinone and a di-iminoisoindoline or 3-amino-isoindolone derivative for dyeing by reaction without oxidising agent, said keratinous fibres.
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 22, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 22, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 22, 2021.
- 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.