Azo dyes based on naphtholic oligomers

Abstract

A series of oligomeric azo dyes has been prepared by coupling various diazonium salts of benzothiazoles to 1‐naphthol/formaldehyde (1‐NF) and 2‐naphthol/formaldehyde (2‐NF) oligomers. They were characterised in terms of their softening point, yield, colour, solubility and UV‐VIS spectra. Structure‐property relationships are discussed. Dyeing on polyester, nylon‐6,6, and wool resulted in orange to red coloration having excellent light and washing fastness properties.