GB457184A - Process for the manufacture of water-insoluble azodyestuffs on cellulosic fibres - Google Patents

Abstract

Water-insoluble azo-dyes are prepared on cellulosic fibres by applying the coupling component to the fibre in an undissolved finely divided form and developing by treatment with a diazo solution. The dispersion of coupling component is effected in known manner for instance by suspension in water containing a dispersing agent or protective colloid followed or not by evaporating to dryness; suitable agents are sulphite waste liquor and its condensation products with organic bases, condensation products of formaldehyde and naphthalene sulphonic acids, alkali metal salts of isobutyl- or propylnaphthalene sulphonic acids, acid amides, esters and ethers of higher molecular saturated or unsaturated or hydroxy fatty acids, and ethers and esters of higher molecular fatty alcohols and their sulphonation products. The finely divided component is worked into a slop-padding liquor and the material impregnated in this is developed, if desired after passing through an alkaline bath such as dilute caustic soda or ammonia and drying. In examples: (1) 1-(2<1>.3<1>-oxynaphthoylamino)-3.4.5.-trichlorbenzene is pasted with a formaldehyde-b -naphthalenesulphonic acid condensation product and evaporated to dryness; this preparation is stirred with water containing turkey red oil or triethanolamine and cotton impregnated therein is passed through a bath of dilute caustic soda prior to development with diazotized 2.5-dichloraniline; (2) 1-(2<1>.3<1> - oxynaphthoylamino) - 2.4 - dimethoxy-5-chlorbenzene is pasted with oleylmethyltaurine and ground prior to making up with water; a mixed cotton-viscose silk fabric is slop-padded in this and developed in a solution of diazotized 1-methoxy-2-amino-benzene-4-sulphonic acid diethylamide; the fabric may be passed through a dilute caustic soda bath prior to development.