Hair dye compositions and method
CA 2021297 A1 · Owner: Bristol-Myers Squibb Company · Inventors: Wenke, Gottfried
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An aromatic amine or cosmetically acceptable salt thereof, is reacted with an aromatic aldehyde in a reaction medium containing water. 2,6-dihydroxypyridine or a, cosmetically acceptable salt thereof is reacted with, hydrogen peroxide in a reaction medium containing water. The two reaction mediums are combined so that both reactions are carried out together on hair. Preferably the, two reactions are carried out together in the same reaction medium. pH is adjusted so that the pH of the common reaction medium is about 5 to 7. Surprisingly substantially no cross reaction occurs between the two reactions on hair.
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 July 16, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 16, 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.