The dyes are of formula (in which A is the gp. of a 8-hydroxynaphthyl, 4,6-or 3,6-di-sulphonic acid a 8-hydroxynaphthyl-4,5 or 6 sulphonic acid, a 5-hydroxynaphthyl 7-sulphonic acid or a 6-hydroxynaphthyl 8-sulphonic acid, or an acid amide derived from these. The azo gp. is in o-position to the -OH. D and D' are heterocyclic, phenyl or naphthyl groups and R is a group from an aldehyde D, D' and R may contain an opt. -SO3H subst. acylamine or azinylamino gp. which is opt. fibre-reactive or an NO2 or NH2 gp. The sulphonamide gp. may be mono or di-substd.) They are made by coupling diazotised amines of formula D'-NH2 with a 1H or 3-H naphtho (1,2,-d) imidazole cpd. Depending on the presence of SO3H or fibre-reactive gps. the dyes are suitable as water-sol. or reactive dyes or as insol. pigments for natural or synthetic fibres esp. cellulose, wool and polyamides, giving very pure shades.
展开▼
