GB915711A - Disazo-dyestuffs insoluble in water and a process for their manufacture - Google Patents

Abstract

The invention comprises water-insoluble dyestuffs of the formula <FORM:0915711/IV (b)/1> where X is halogen, R1 is hydrogen or bromine and R is a substituted or unsubstituted aryl or heterocyclic group free from groups imparting solubility in water. The dyestuffs may be prepared by coupling a diazonium compound of an amine of the p formula <FORM:0915711/IV (b)/2> in substance or on the fibre or other substratum with an appropriate naphthalene ortho-hydroxy carboxylic acid amide substituted at the nitrogen atom by an aryl or heterocyclic radical free from groups imparting solubility in water. The diazo components may be used in the form of stabilized diazo compounds, particularly as zinc chloride double salts, diazo amino compounds, or antidiazotates in one of the usual printing processes. Many examples are given in which values specified for X are chlorine and bromine, for R, radicals of benzene, naphthalene, 2.5-dimethoxy-4-chlorobenzene, 2-methyl-4 and 5-chlorobenzene, 2-methoxy-4-chloro5-methyl benzene, 2- and 4-methyl benzene, 2- and 4-methoxy and ethoxy benzene, 2.3-and 2.4-dimethyl benzene, 4-chlorobenzene, 2.5-dimethoxy benzene, 3-methoxy-diphenylene oxide, and 2.5-dimethoxy-4-chlorobenzene. Alkyl substituents specified are methyl and ethyl. The dyestuffs dye regenerated cellulose, and may be used for colouring plastic masses of high molecular weight and for preparing colour lakes. They may be applied to textiles by pigment printing processes. Examples are given of the dyeing of cotton yarns and fabrics. Dyebaths containing aluminium sulphate, and a printing paste containing a chromate, are described. In the preparation of the dyes coupling may take place in presence of a substratum suitable for the preparation of colour lakes.