Trisazofarbstoffe

摘要

The invention concerns trisazo dyes, in the free state or as transition-metal complexes, of general formula (I) in which the variables are defined as follows: R<1> hydrogen, C1-C4 alkyl, halogen, nitro, hydroxysulphonyl, sulphamoyl, mono or di-(C1-C4 alkyl)-sulphamoyl, (C1-C4 alkyl)-sulphonyl or (C1-C4 alkoxy)-sulphonyl, R<2> hydrogen, halogen, nitro or hydroxysulphonyl, at least one of the groups R<1> and R<2> being nitro, R<3>, R<4> independently of each other, hydroxy or amino, R<5> hydrogen, C1-C4 alkyl, hydroxysulphonyl, sulphamoyl, mono- or di-(C1-C4 alkyl)-sulphamoyl, (C1-C4 alkyl)-sulphonyl, (C1-C4 alkoxy)-sulphonyl or carboxyl, R<6> hydrogen or C1-C4 alkyl, R<7> hydrogen, C1-C4 alkyl, hydroxysulphonyl, sulphamoyl, mono- or di-(C1-C4 alkyl)-sulphamoyl, (C1-C4 alkyl)-sulphonyl, (C1-C4 alkoxy)-sulphonyl, SO2N(CH2COOH)2 or carboxyl, R<8> hydrogen, C1-C4 alkyl, hydroxy, C1-C4 alkoxy, halogen or nitro, with the provision that at least one of the two groups R<5> and R<7> is COOH or SO3H and, when R<5> or R<7> is SO3H, the other is COOH or R<3> and/or R<4> is amino or R<1> is hydrogen or R<6> is alkyl. Such dyes are suitable for use in dyeing leather, textile fibres and paper.