Cationic azo-dyes

A cationic dye of formula I

• where
• R1 and R2 are independently hydrogen, nitro, halogen, C1-C6-alkyl,
• R3 is hydrogen, C1-C6-alkyl with or without interruption by 1 or 2 nonadjacent oxy, imino, C1-C6-alkylimino groups or by a
• radical,
• A1 and A2 are independently oxy, imino or substituted or unsubstituted C1-C6-alkylimino,
• B1 and B2 are independently C1-C6-alkylene with or without interruption by 1 or 2 nonadjacent oxy, imino, substituted or unsubstituted Cl1-6-alkylimino groups or by a
• radical,
• n is 1, and
• K is the radical of a coupling component or the radical of a monoazo dye of the formula
• where
• R4′ and R5′ are independently hydroxyl, amino, morpholino or mono- or di(C1-C6)alkylamino, whose alkyl radicals are unsubstituted or substituted by hydroxyl, amino, cyano, C1-C6-alkoxycarbonyl, carbamoyl or mono- or di(C1-C6)alkylcarbamoyl and uninterrupted or interrupted by oxy,
• Q1, Q2 and Q3 are independently hydrogen, C1-C10-alkyl with or without interruption by from 1 to 4 nonadjacent oxy, imino and substituted or unsubstituted C1-C4-alkylimino groups and with or without hydroxyl, halogen or phenyl substitution, or Q1 and Q2 combine with the linking nitrogen atom to form a 5- or 6-membered heterocyclic radical which optionally contains nitrogen or oxygen as further hetero atom, and
• An⊖ is the equivalent of an anion,
• and additionally n is from 2 to 8 when K is the radical of a coupling component of the formula IIIa′
• where
• R6′ is hydrogen, C1-C6-alkoxy with or without oxy interruption in its alkyl radical, mono- or di(C1-C6)alkylamino, C1-C6-alkoxycarbonyl, carbamoyl, mono- or di(C1-C6))alkylcarbamoyl, sulfamoyl, mono- or di(C1-C6)alkylsulfamoyl.