Process for Dyeing Cellulosic Fibre Materials With at Least Two Vat Dyes
A process for dyeing cellulosic fibre materials, wherein the fibre material is brought into contact with at least two dyes from the group of formulae (1), (2), (3) and (4) wherein A is hydrogen or a radical of formula (5), R 1 , R 2 , R 3 and R 4 are each independently of the other halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro, benzoylamino which is unsubstituted or substituted in the phenyl ring, or unsubstituted or substituted amino, n, m, r and s are each independently of the others the number 0, 1, or 2, and p is the number 0, 1, 2, 3 or 4, produces level, tinctorially strong dyeings.
1 . A process for dyeing cellulosic fibre materials, wherein the fibre material is brought into contact with at least two dyes from the group of formulae
wherein
A is hydrogen or a radical of formula
R 1 , R 2 , R 3 and R 4 are each independently of the others halogen, C 1 -C 4 alkyl or C 1 -C 4 alkoxy,
R 5 is halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro, benzoylamino which is unsubstituted or substituted in the phenyl ring, or unsubstituted or substituted amino,
n, m, r and s are each independently of the others the number 0, 1 or 2, and
p is the number 0, 1, 2, 3 or 4.
2 . A process according to claim 1 , wherein
R 1 , R 2 , R 3 , R 4 and R 5 are each independently of the others halogen or C 1 -C 4 alkyl.
3 . A process according to claim 1 , wherein
n, m, r and s are each independently of the others 0 or 1.
4 . A process according to claim 1 , wherein
p is the number 0°, 1 or 2.
5 . A process according to claim 1 , wherein dyeing is carried out at a pH of from 10.2 to 11.8.
6 . A process according to claim 1 , wherein dyeing is carried out at a pH of from 10.8 to 11.6.
7 . A process according to claim 1 , wherein the dyes are applied by the pad-dyeing method.
8 . A process according to claim 1 , wherein the dyeing process is carried out continuously in a plurality of passes.
9 . A process according to claim 1 , wherein the dyeing process is carried out on a hank dyeing machine or an open-width dyeing machine.
10 . A dye mixture comprising at least two dyes from the group of formulae
wherein
A is hydrogen or a radical of formula
R 1 , R 2 , R 3 and R 4 are each independently of the others halogen, C 1 -C 4 alkyl or C 1 -C 4 alkoxy,
R 5 is halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro, benzoylamino which is unsubstituted or substituted in the phenyl ring, or unsubstituted or substituted amino,
n, m, r and s are each independently of the others the number 0, 1 or 2, and
p is the number 0, 1, 2, 3 or 4.
11 . A process according to claim 1 , wherein
R 1 , R 2 , R 3 , R 4 and R 5 are each independently of the others chlorine or methyl.