GB872481A - Water-insoluble benzene-monoazo-benzene dyestuffs and process for their manufacture - Google Patents

Abstract

The invention comprises dyes, free from carboxylic or sulphonic acid groups, of formula A-N=N-B where A is:- <FORM:0872481/IV(c)/1> where X is H or a halogen, alkyl, nitro, cyano, alkyl-sulphone, sulphonamide or carbalkoxy group, Y is H or a halogen, trifluoromethyl, alkoxy, nitro, cyano, alkyl-sulphone, sulphonamide or carbalkoxy group and Z is an alkyl, alkoxy, nitro, cyano, alkyl-sulphone, sulphonamide or carbalkoxy group when X is a nitro group, and B is the residue of an N, N-dicyanoethyl aniline bound to the azo link in p-position to the amino group. They are made by conventional diazotization and coupling methods. Preferred diazo components contain at least one nuclear cyano group. Preferred coupling components are of formula:- <FORM:0872481/IV(c)/2> where R1 is H or a halogen, alkyl, alkoxy or aliphatic acylamino group and R2 is H or an alkyl or alkoxy group. The dyes colour polyamides but are especially used on fibres of cellulose acetate, cellulose triacetate and polyethylene terephthalate. Examples and a Table are provided illustrating the preparation of the dyes and their use in colouring various materials in red and yellow shades.