Disazo dyes, and copper complexes thereof, for dyeing paper

A mono- or bis-copper complex of a dye of formula

• wherein
• R1 and/or R3 are hydroxy or alkoxy,
• Z1 is NHR6,
• R6 being a radical of formula CO—R8, CO—NH—R8, SO2-alkyl, SO2-aryl,
• COOR8,
• R8 being hydrogen, alkyl or aryl and
• R7 being COOH or SO3H in the o-position to the NH2 group,
• Z2 is as defined for Z1 or is hydrogen, hydroxy, alkoxy or a radical NHR5,
• R5 being hydrogen, alkyl, aryl, COR8, CO—NHR8 or SO2R8,
• R2 and R4 are each independently of the other hydrogen, hydroxy, alkyl or alkoxy, halogen, sulfo, carboxy, NHCONHR8 or NHCOR8,
• X is a direct bond in which case symmetrical compounds wherein Z1 and Z2 are NHCOCH3, NHCOOCH3 or NHCO-phenyl are excluded, or is —C═C— in which case both Z1 and Z2 cannot simultaneously be acetylamino, benzoylamino or 4-amino-3-sulfo-anilino, or is azo, azoxy, —NR8, —NR8CONR9— or a group of formula
• Y being hydroxy, alkoxy or NR9R10,
• R9 and R10 being each independently of the other hydrogen, unsubstituted or substituted alkyl or unsubstituted or substituted aryl,
• n and m are each independently of the other 1 or 2,
• and wherein the rings A and B may each independently of the other carry a fused-on benzene ring.

A mono-copper complex of a dye of formula

• wherein
• R1 and/or R3 are hydroxy or alkoxy,
• Z1 is NHR6,
• R6 being a radical of formula CO—R8, CO—NH—R8, SO2-alkyl, SO2-aryl,
• COOR8,
• R8 being hydrogen, alkyl or aryl and
• R7 being COOH or SO3H in the o-position to the NH2 group,
• Z2 is as defined for Z1 or is hydrogen, hydroxy, alkoxy or a radical NHR5, R5 being hydrogen, alkyl, aryl, COR8, CO—NHR8 or SO2R8,
• R1 and R3 are each independently of the other hydrogen, hydroxy, alkyl or alkoxy,
• R2 and R4 are each independently of the other hydrogen, hydroxy, alkyl or alkoxy, halogen, sulfo, carboxy, NHCONHR8 or NHCOR8,
• X is a direct bond in which case symmetrical compounds wherein Z1 and Z2 are NHCOCH3, NHCOOCH3 or NHCO-phenyl are excluded, or is —C═C— in which case both Z1 and Z2 cannot simultaneously be acetylamino, benzoylamino or 4-amino-3-sulfo-anilino, or is azo, azoxy, —NR8, —NR8CONR9— or a group of formula
• Y being hydroxy, alkoxy or NR9R10,
• R9 and R10 being each independently of the other hydrogen, unsubstituted or substituted alkyl or unsubstituted or substituted aryl,
• n and m are each independently of the other 1 or 2,
• and wherein the rings A and B may each independently of the other carry a fused-on benzene ring,
• and
• a mixture thereof with a bis-copper complex of a dye of formula (I)
• wherein the substituents are defined as above and optionally, further additives.

A concentrated aqueous solution for dyeing paper, comprising a copper complex of a dye of formula (1)

• wherein
• Z1 is NHR6,
• R6 being a radical of formula CO—R8, CO—NH—R8, SO2-alkyl, SO2-aryl,
• COOR8,
• R8 being hydrogen, alkyl or aryl and
• R7 being COOH or SO3H in the o-position to the NH2 group,
• Z2 is as defined for Z1 or is hydrogen, hydroxy, alkoxy or a radical NHR5,
• R5 being hydrogen, alkyl, aryl, COR8, CO—NHR8 or SO2R8,
• R1 and R3 are each independently of the other hydrogen, hydroxy, alkyl or alkoxy,
• R2 and R4 are each independently of the other hydrogen, hydroxy, alkyl or alkoxy, halogen, sulfo, carboxy, NHCONHR8 or NHCOR8,
• X is a direct bond in which case symmetrical compounds wherein Z1 and Z2 are NHCOCH3, NHCOOCH3 or NHCO-phenyl are excluded, or is —C═C— in which case both Z1 and Z2 cannot simultaneously be acetylamino, benzoylamino or 4-amino-3-sulfo-anilino, or is azo, azoxy, —NR8, —NR8CONR9— or a group of formula
• Y being hydroxy, alkoxy or NR9R10,
• R9 and R10 being each independently of the other hydrogen, unsubstituted or substituted alkyl or unsubstituted or substituted aryl,
• n and m are each independently of the other 1 or 2,
• and wherein the rings A and B may each independently of the other carry a fused-on benzene ring,
• with the proviso that the compounds of formulae
• are excluded and optionally, further additives.