5,6-DIHYDROXYINDOLINE ALS ADDITIV ZU HAARFAERBEREZEPTUREN

摘要

The invention concerns the use of indoline derivatives of the formula (I), in which R<1>, R<2>, R<3>, R<4> and R<5>, independently of each other, may be hydrogen atoms or alkyl groups with 1 to 4 C-atoms, or R<4> and R<5> together with the oxygen atoms to which they are bound may be an alkylenedioxy group with 1 to 4 C-atoms, or salts of such indoline derivatives, as additives to hair-dyeing agents of the direct-dyeing or developer/coupler type, thus producing hair dyeings with excellent colour-fastness characteristics.