Use of n-substituted-5,6-dihydroxyindoles as a hair coloring agent
CA 1324320 C · Owner: Mayer, Alice A. · Inventors: Schultz, Thomas M.; Brown, Keith C.; Lim, Mu-Ill
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The use of N-substituted-5,6-dihydroxyindoles in solution as a hair dyeing agent in combination with the pre-treatment of the hair to be dyed with a solution comprising the water soluble salt of various metals is also provided. This yields hair colors from light golden to light reddish brown to dark auburn to black.
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
- Granted November 16, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 16, 2010.
- 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.