Metal free acid dyes, methods for the production thereof and their use

1. A dye of the formula (1)

in which

each of R 1 , R 2 , R 3 and R 4 , independently from one another is hydrogen or (C 1 -C 6 ) alkyl;

each of R 5 and R 6 , independently from one another is hydrogen, (C 1 -C 6 ) alkyl or (C 1 -C 6 ) alkyl substituted by hydroxy;

each of R 7 and R 8 , independently from one another is hydrogen, (C 1 -C 6 ) alkyl or phenyl;

each of R 9 and R 10 , independently from one another is hydrogen, (C 1 -C 6 ) alkyl, (C 1 -C 6 ) alkoxy, trifluoromethyl, hydroxy, cyano, nitro, halogen, —NHCHO, —NHCO(C 1 -C 6 )-alkyl, —NHCOaryl, —NHSO 2 (C 1 -C 6 )-alkyl or —NHSO 2 aryl; and

each of D 1 and D 2 , independently from one another is the residue of a diazo component, which comprises at least one group —SO 3 M, wherein M is hydrogen, an alkali metal, ammonium or one equivalent of an alkali earth metal.

2. The dye of the formula (1) according to claim 1 , wherein

R 1 to R 4 are identical and are hydrogen or (C 1 -C 4 ) alkyl;

R 5 and R 6 are identical and are hydrogen, (C 1 -C 4 ) alkyl or (C 1 -C 4 ) alkyl substituted by hydroxy;

R 7 and R 8 are identical and are hydrogen, methyl or ethyl; and

R 9 and R 10 are identical and are hydrogen, methyl, or ethyl.

3. The dye of the formula (1) according to claim 1 , which has the formula (1a)

in which

R 9a and R 10a are identical and are hydrogen or methoxy; and

D 1 and D 2 are defined as given in claim 1 .

4. The dye of the formula (1) according to claim 1 , in which

each of D 1 and D 2 , independently of one another denotes a group of the formula (I)

where

R 11 is hydrogen, (C 1 -C 4 )-alkyl, (C 1 -C 4 )-alkoxy, trifluoromethyl or halogen; and

M is hydrogen, an alkali metal, ammonium or one equivalent of an alkali earth metal; or

each of D 1 and D 2 , independently of one another denotes a group of the formula (II)

where R 12 is hydrogen or (C 1 -C 4 )-alkyl;

n is 0 or 1; and

M is defined as given above;

or

each of D 1 and D 2 , independently of one another denotes a group of the formula (III)

where

R 13 is hydrogen, (C 1 -C 4 )-alkyl, (C 1 -C 4 )-alkoxy or halogen; and

M is defined as given above;

or

each of D 1 and D 2 , independently of one another denotes a group of the formula (IV)

where

R 14 is hydrogen, cyano

R 15 is hydrogen, —CHO or a group of the formula (a)

wherein R 16 is hydrogen, halogen or —CONH 2 ;

m is 0 or 1; and

M is defined as given above;

or

each of D 1 and D 2 denotes a group of the formula (V)

M is defined as given above; or

each of D 1 and D 2 denotes a group of the formula (VI)

where R 17 is —SO 3 M, —CHO, —CH═C(CN) 2 , a group of the formula (a) as defined above or a group of the formula (b)

R 18 is —SO 3 M, (C 1 -C 4 )-alkyl, sulfophenyl-(C 1 -C 4 )-alkylamino, morpholino or piperidino;

and M is defined as given above;

or

each of D 1 and D 2 , independently of one another denotes a group of the formula (VII)

where

R 19 is hydrogen, (C 1 -C 4 )-alkyl, (C 1 -C 4 )-alkoxy or halogen, and

M is defined as given above.

5. The dye of the formula (1) according to claim 4 , in which D 1 and D 2 are identical and denote one of the groups (I) to (VI) as defined in claim 4 .

6. A process for the preparation of the dye of the formula (1) according to claim 1 which comprises diazotization of the compounds of the formulae (2) and (3)

D 1 -NH 2   (2)

D 2 -NH 2   (3)

wherein D 1 and D 2 are defined as given in claim 1 , and reacting it with a compound of the formula (4)

wherein R 1 to R 10 are defined as given in claim 1 .

7. A process for dyeing or printing carboxamido- and/or hydroxyl-containing material, which comprises using as colorant a dye of the formula (I) as claimed in claim 1 .

8. An ink for digital textile printing by the inkjet process, which comprises a dye of the formula (I) as claimed in claim 1 .