GB844333A - Improvements relating to chromium-containing benzene-monoazo-naphthalene dyestuffs and their use - Google Patents

Abstract

The invention comprises compounds of formula D-Cr-D1 where D and D1, which may be the same or different, represent co-ordinated dyes of formula HO-A-N=N-B where A is a benzene residue bound to N2 #s to OH, and contains at least one non-ionogenic, sulphur-free substituent, and B represents a 1-acylamino-7-naphthol with no ionogenic groups and bound in the 8-position to N2, the acyl residue being from a benzene carboxylic or sulphonic acid, and there must be an acylated primary amino group bound directly to the benzene ring in the acyl radical of the azo component in at least one of D and D1. They are made by chroming appropriate dyes or mixtures of dyes. The chroming processes and methods of production of the metal-free dyes are of conventional character. Examples of acylated primary amino groups are acetyl-, methylsulphonyl-, ethanesulphonyl-, chloromethylsulphonyl-, carbomethoxy-, chloracetyl- and propionyl-amino, the acylamino groups being preferably in the m- or p-position of the benzene ring with regard to the sulphonyl or carbonyl group. The benzoyl and benzenesulphonyl groups may contain non-ionogenic substituents e.g. halogen, alkyl, alkoxy and nitro groups. Dyes containing low molecular weight acylated primary-amino groups are used as water-soluble dyes whereas those with high molecular weight acylated primary amino groups are not water-soluble and may be used in lacquers. Examples of specified 1-a3ylamino-7-naphthols are 21-acetylamino-, 31-carbomethoxyamino-, 31- chloromethanesulphonylamino-, 41-methyl- and -hydroxy -31-acetylamino-benzoyl -1- amino -7- naphthols, 21-methylsulphonyl-, 31-acetyl- and 41-methoxy -31- methylsulphonylaminobenzenesulphonyl -1-amino-7-naphthols. Halogen atoms and nitro groups are preferred substituents for the diazo components, especially when in the p-position to the OH group, amongst those specified being 6-nitro-, 4, 6-dichloro-, 4-methyl-6-nitro- and 4-cyano -2- aminophenols and 2-aminophenol -4-methyl and phenyl ketones and carboxylic acid dimethyl amide, 4-nitro-2-aminophenol being preferred. In a preferred method of obtaining mixed dyes a diazo component is coupled with two coupling components and the product chromed. The dyes, as alkali metal or ammonium salts, colour animal fibres from aqueous baths. Olive and grey shades are obtained. They may also be used to dye superpoly-amide and -urethane fibres. Examples are provided of the preparation of the dyes and their use in dyeing processes. p Reference has been directed by the Comptroller to Specifications 637,404 and 758,016.