Synthesis and Studies of Some Acid Dyes

Abstract

Investigations of the adsorption of acid dyes containing acetoacetanilide and pyrazolone by woollen fabric have been carried out. It has been found that the adsorption levels are unexpectedly different for various dyes.· Both acetoacetanilide and pyrazolone colorants have good fastness of dyes to washing, light and heal The light fastness of the dyes was found to depend on the influence of the substituents on the electron density around the azo group. An electron­ accepting substituents (o-COOH) afforded a good values of light fastness. A correlation between light fastness and dye absorption spectra has been suggested, which showed that n-n- electronic transition is an important parameter in determining the stability of the system. The visible absorption spectra and Munsell renotations of all the dyes showed that the colours of dyes lie in the range of yellow -red -green.