Azo derivatives of pyridine n-oxide for use in hair dye compositions
AssigneeL'oreal
InventorGerard Lang
Life of this patent
Estimating the term…
Abstract
Compositions for dyeing human hair contain in an aqueous or hydroalcoholic solution an azo derivative of pyridine N-oxide as a hair dye present in amounts of 0.001-1 weight percent of said composition which has a pH ranging from 3-9.5. Certain of said azo derivatives of pyridine N-oxide are new compounds.
Claims16
A dye composition for human hair comprising a solution in a solvent selected from the group consisting of water and aqueous alcohol solution of about 0.001-1 percent by weight of at least one dye selected from the group consisting of ##STR13## wherein Y and Y' each represent hydrogen, halogen, lower alkyl having 1-4 carbon atoms, lower alkoxy having 1-4 carbon atoms, nitro or carboxyl;
- B represents a member selected from the group consisting of ##STR14## said composition having a pH ranging from 3-9.5.
Dependencies are inferred from the claim text.