Method for the reactive coloration of leather

A process comprising treating leather with at least one anionic polyazo dye F, or a metal complex thereof, which has at least 3 diazo groups and at least one alkaline-activatable group of the formula A;

• wherein
• - - - - denotes the bond to the dye or metal complex thereof;
• X is C1-C4-alkyl or C1-C4-alkoxy,
• k is 0, 1, 2 or 3,
• n is 0 or 1 and
• B is a CH═CH2 group or a CH2—CH2-Q group, wherein Q is halogen, —O—SO3H, —S—SO3H, a quaternary ammonium radical, RaS(O)2—, RbS(O)2—O—, or RcC(O)—O—, wherein Ra and Rb are independently alkyl, haloalkyl or optionally substituted phenyl and Rc is hydrogen, alkyl, haloalkyl or optionally substituted phenyl, at a pH of not less than 8 and at most 11,
• wherein the dye F, or metal complex thereof, is selected from the dyes of the general formulae I to VII:
• Dk1-N═N-[Napth1-N═N-]pKk1[-N═N-Dk2]m (I)
• Dk1-N═N-Napht1-N═N-Tk1-N═N-Kk1[-N═N-Dk2]n (II)
• Dk1-N═N-Napht1-N═N-Tk1-N═N-Kk1-N═N-Tk2-N═N-Napht2-N═N-Dk2 (III)
• Dk1-N═N-Kk1-N═N-Tk1-N═N-Kk2-N═N-Dk2 (IV)
• Dk1-N═N-Napth1-N═N-Napth2-N═N-Kk1[-N═N-Dk2]n (V)
• Kk3-N═N-Tk1-N═N-Kk1-N═N-A (VI)
• Dk1-N═N—P—N═N-Kk1-N═N—R′—N═N-Dk2 (VII)
• wherein
• n and p are independently 0 or 1;
• m is 0, 1 or 2 subject to the condition that m+p=2 or 3 in the formula I;
• Dk1, Dk2 independently represent an aromatic amine radical or denote a group of the formula A subject to the condition that in each of the formulae I - V and VII at least one of Dk1 and Dk2 represents a radical of the formula A
• Kk1, Kk2 independently represent a mono-, di- or trivalent aromatic radical of benzene, naphthalene, pyrazole, quinoline, diphenylamine, diphenylmethane, pyridine, pyrimidine or diphenyl ether and which may optionally comprise one or more of the following radicals as substituents:
• SO3H, COOH, OH, NH2, NO2, CN, halogen, C1-C4-alkyl, C1-C4-hydroxyalkyl, carboxy-C1-C4-alkyl, C1-C4-alkoxy, C1-C4-alkylamino, C1-C4-dialkylamino, C1-C4-alkylaminocarbonyl, C1-C4-dialkylaminocarbonyl, C1-C4-alkylcarbonylamino, N-(C1-C4- alkylcarbonyl)-N-(C1-C4-alkylcarbonyl) amino, C1-C4-hydroxy-C1-C4-alkylamino, carboxy-C1-C4-alkylamino, phenylcarbonylamino, C1-C4 -alkylsulfonyl, C1-C4-alkylaminosulfonyl, C1-C4-alkylsulfonylamino, phenylsulfonyl, phenylsulfonylamino, formamide or 5- or 6-membered heterocyclyl, which is optionally substituted by 1 to 3 of the following radicals:
• OH, halogen, C1-C4-alkyl or phenyl, 5-membered aromatic heterocyclyl optionally bearing on the nitrogen a phenyl or naphthyl group which can optionally comprise one or two of the following radicals:
• OH, SO3H, C1-C4-alkyl, and/or C1-C4-alkoxy;
• Kk3 is a monovalent radical of benzene, pyridine, pyrimidine or naphthalene and which optionally comprises 1 or 2 hydroxysulfonyl groups and optionally 1 to 3 further substituents selected from SO3H, COOH, OH, NH2, NO2, CN, halogen, C1-C4-alkyl, C1-C4-hydroxyalkyl, carboxy-C1-C4-alkyl, C1-C4-alkoxy, C1-C4-alkylamino, C1-C4-dialkylamino, C1-C4-alkylaminocarbonyl, C1-C4 dialkylaminocarbonyl, C1-C4-alkylcarbonylamino, N-(C1-C4- alkylcarbonyl)-N-(C1-C4-alkylcarbonyl) amino, C1-C4-hydroxy-C 1 -C4- alkylamino, carboxy-C1-C4-alkylamino, phenylcarbonylamino, C1-C4- alkylsulfonyl, C1-C4-alkylaminosulfonyl, C1-C4-alkylsulfonylamino, phenylsulfonyl, phenylsulfonylamino, formamide or 5- or 6-membered heterocyclyl, which is optionally substituted by 1 to 3 of the following radicals:
• OH, halogen, C1-C4-alkyl or phenyl, 5-membered aromatic heterocyclyl optionally bearing on the nitrogen a phenyl or naphthyl group which can optionally comprise one or two of the following radicals:
• OH, SO3H, C1-C4-alkyl, and/or C1-C4-alkoxy;
• Tkl, Tk2 independently represent a divalent aromatic radical of benzene, phenyl benzenesulfonate, phenylaminosulfinylbenzene, pyridine, pyrimidine, diphenylamine, biphenyl, diphenylmethane, 2-phenylbenzimidazole, phenylsulfonylbenzene, phenylaminosulfonylbenzene, stilbene or phenylaminocarbonylbenzene which may each optionally comprise one or more of the following radicals as substituents:
• SO3H, COOH, OH, NH2, NO2, halogen, C1-C4-alkyl;
• P and R′ independently represent a divalent aromatic radical of benzene or naphthalene which may each optionally comprise one or more of the following radicals as substituents:
• SO3H, COOH, OH, NH2, NO2, halogen, C1-C4-alkyl, C1-C4-hydroxyalkyl, carboxy-C1-C4-alkyl, C1-C4-alkoxy, C1-C4-alkylamino, C1-C4-dialkylamino, C1-C4-alkylaminocarbonyl, C1-C4-dialkylaminocarbonyl, C1-C4alkylcarbonylamino, N-(C1-C4-alkylcarbonyl)-N-(C1-C4-alkylcarbonyl) amino, C1-C4-hydroxy-C1-C4-alkylamino, carboxy-C1-C4-alkylamino, phenylcarbonylamino, C1-C4alkylsulfonyl, C1-C4-alkylaminosulfonyl, C1-C4-alkylsulfonylamino, phenylsulfonyl, phenylsulfonylamino, formamide or 5- or 6-membered heterocyclyl, which is optionally substituted by 1 to 3 of the following radicals:
• OH, halogen, C1-C4-alkyl or phenyl, 5-membered aromatic heterocyclyl optionally bearing on the nitrogen a phenyl or naphthyl group which can optionally comprise one or two of the following radicals:
• OH, SO3H, C1-C4-alkyl, and/or C1-C4-alkoxy;
• Napht1, Napht2 independently represent a divalent radical of naphthalene and which comprises 1 or 2 hydroxysulfonyl groups and may optionally comprise 1 to 3 further substituents selected from OH, NH2, C1-C4-alkylamino, C1-C4-dialkylamino, C1-C4-alkylsulfonylamino, phenylsulfonylamino, 4-methylphenylsulfonylamino, C1-C4-alkylaminosulfonyl, di-C1-C4-alkylaminosulfonyl, phenylaminosulfonyl, 4-methylphenylaminosulfonyl and NHC(O )Rx radicals, where Rx hydrogen, C1-C4-alkyl, maleinyl or phenyl;
• and metal complexes of these dyes,
• wherein the process obtains a fixation rate of 85% or more.