Synthesis and application of some new disperse azo dyes derived from 2‐cyanomethyl benzothiazole

Abstract

Purpose

To synthesize some new heterocyclic disperse azo dyes and their utilization in textile printing.

Design/methodology/approach

To prepare 1‐cayno‐1‐substituted aryl azo‐2‐methyl benzothiazole by the reaction of 2‐aminothiophenol with malononitrile and the end product coupled with different diazonium salts. The prepared dyestuffs are established using element analysis, IR measurements, ¹H‐NMR and Mass spectra. Printing pastes containing the prepared dyestuffs and a thickener were used for printing polyester and/or nylon 6 using either transfer printing or traditional printing.

Findings

New selected arylazo cyanomethyl benzothiazole dyes were obtained from the reaction of diazotized aniline derivatives with 2‐cyanomethyl benzothiazole as a coupling component. The suitability of the prepared dyestuffs for either heat transfer printing or traditional printing on polyester and nylon 6 fabrics has been investigated. The prints obtained from dyes containing non polar groups which have sublimation properties possess high colour strength as well as good overall fastness properties if compared to those obtained using dyes containing polar groups.

Research limitations/implications

The new heterocyclic disperse azo dyes were prepared from 2‐cyanomethylbenzothiazole and were utilized in preparing pastes for textile printing to print polyester and nylon 6 fabrics. In addition, the variation in substituents on the synthesized dyes could also be studied.

Practical implications

The method of synthesis of the new dyestuffs provides a simple and practical solution to prepare some new heterocyclic disperse azo dyes with low molecular weight, suitable for sublimation in heat transfer printing methods.

Originality/value

The methods for synthesis of the new heterocyclic disperse azo dyes are simple. These dyestuffs could be used in textile printing of polyester and nylon 6 on an industrial scale.

Citation

El‐Kashouti, M.A., Elgemeie, G.H., El‐Molla, M.M., El‐Sayad, H.S. and Ahmed, K.A.E. (2007), "Synthesis and application of some new disperse azo dyes derived from 2‐cyanomethyl benzothiazole", Pigment & Resin Technology, Vol. 36 No. 6, pp. 382-391. https://doi.org/10.1108/03699420710831809