| 摘要 |
<p>A method for dyeing keratin fibres, wherein a composition is applied to said fibres which contains, in a suitable dyeing medium, at least one coupler having formula (I), wherein R1 is hydrogen or alkyl; R2 and R3 are hydrogen, alkyl, COOR', where R' is alkyl or hydrogen; R4 is hydrogen, hydroxyalkyl, alkyl, polyhydroxyalkyl or acetyl or aminoalkyl wherein the amine may be mono- or disubstituted by alkyl; Z1 and Z2 are hydrogen, alkyl, hydroxy, halogen, alkoxy or a salt thereof; at least one precursor of an oxidation hair dye; and at least one oxidizing agent, the pH of the composition applied to the fibres being less than 7.</p> |
