| abstract |
Keratin fibres, esp. human hair, are dyed by applying in either order- … … (A) a composition comprising- … … (i) a monohydroxy indole of formula I below, and … (ii) either iodide ions or hydrogen peroxide; and … … (B) a composition comprising either iodide ions or hydrogen peroxide (whichever was absent from composition (A)).… …<IMAGE>… in which:… R1 is H or C1-C4 alkyl;… R2 and R3 are each H, C1-C4 alkyl, COOH, or C1-C4 alkoxycarbonyl; and… the OH radical is in position 4, 5, 6 or 7;… or a salt or precursor thereof (e.g. O-acyl derivative);… provided that when the OH radical is in position 5, at least one of R1, R2 and R3 is not H. … …<??>The compositions may additionally comprise 5,6-dihydroxyindoles, oxidation dyes, "rapid" oxidation dyes, couplers, or direct dyes. …<??>The following compounds, and their salts, are claimed per se -… 5-hydroxy-3-methylindole… 6-hydroxy-1-methylindole… 7-hydroxy-3-methylindole |