| 摘要 |
The invention relates to oxidation dyeing compositions comprising oxidation dyestuff precursors and N-substituted ortho-nitroanilines of the formula: <IMAGE> in which R1 denotes an alkyl, monohydroxyalkyl or polyhydroxyalkyl group, R2 denotes hydrogen or an amino, monoalkylamino, dialkylamino, mono- or di-(monohydroxyalkyl or polyhydroxyalkyl)-amino, (N-alkyl-N-monohydroxyalkyl or N-alkyl-N-polyhydroxyalkyl)-amino, alkoxy, monohydroxyalkoxy, polyhydroxyalkoxy or aminoalkoxy group and R3 denotes hydrogen or an alkyl group, at least one of R2 and R3 being different from H, with the proviso that if R1 denotes -CH2CH2OH, R2 cannot be di-(monohydroxyalkyl)-amino in an alkaline medium which is non-ammoniacal and comprises an alkali metal or ammonium bisulphite and at least one alkanolamine which is N-(C1 to C4-alkyl-ethanolamine, N,N-di(C1 to C4-alkyl)-ethanolamine, di-(hydroxy-C2 to C3-alkyl)-amine, 2-amino-2-methylpropan-1-ol, 2-dimethylamino-2-methylpropan-1-ol, 2-amino-2-ethylpropane-1,3-diol, 2-amino-2-methylpropane-1,3-diol or 2-amino-2-hydroxymethylpropane-1,3-diol. |
