Azo dyes, a process for their preparation and their use in the dyeing or printing of hydrophobic fiber materials
View Patent ↗The present invention relates to an azo dye of formula (1), wherein R 1 is the radical of a diazo component of the benzene, naphthalene, diphenyl, azobenzene, thiophene, benzothiazole, thiadiazole, indazole, benzatriazole, pyrazole, anthraquinone, naphtholic acid imide, chromone, phthalimide or diphenylene oxide series, R 2 is an unsubstitued or substitued aryl radical or an unsubstituted or substituted aralkyl radical and R 3 is an unsubstituted or substituted aryl radical or an unsubstituted or substituted aralkyl radical, with the proviso that one of the substituents R 2 and R 3 is an unsubstituted or substituted aryl radical and the other is an unsubstituted or substituted aralkyl radical, 2-hydroxy-2-phenylethyl being expected as a substituted aralkyl radical, to mixtures comprising at least two structually different azo dyes of formula (1) and to the use of those azo dyes and dye mixtures in the dyeing or printing of semi-synthetic or synthetic hydrophobic fibre materials.
1. An azo dye of formula
wherein
R 1 is 2-trifluoromethyl-4-nitrophenyl, 2-cyano-4-nitrophenyl,
2-cyano-4-nitro-6-bromophenyl, 2-trifluoromethyl-4-chlorophenyl,
3,5-dicyano-4-methyl-2-thienyl or 2-cyano-4-nitro-1-naphthyl,
R 2 is phenyl, benzyl or 2-phenylethyl and
R 3 is phenyl, benzyl or 2-phenylethyl,
with the proviso that either R 2 is phenyl and R 3 is benzyl or 2-phenylethyl or R 3 is phenyl and R 2 is benzyl or 2-phenylethyl.
2. A process for the preparation of an azo dye of formula (1) according to claim 1 , wherein a compound of formula
R 1 —NH 2 (50)
is diazotised in accordance with a customary procedure and then coupled to a coupling component of formula
wherein R 1 , R 2 and R 3 are as defined for formula (1).
3. A process for the dyeing or printing of semi-synthetic or synthetic hydrophobic fibre material, wherein an azo dye of formula (1) according to claim 1 is applied to the said material or is incorporated into that material.
4. A method of dyeing or printing of semi-synthetic or synthetic hydrophobic fibre materials comprising treating said materials with an azo dye of formula (1) according to claim 1 .
5. A semi-synthetic or synthetic hydrophobic fibre material dyed or printed with a dye of formula (1) according to claim 1 .