Color variations of cotton dyed with reactive Cu-complex azo dyes by histidine, and testing methods for color fastness to perspiration

Abstract

The adsorption of histidine (His) on cellophane films dyed with five reactive Cu-complex azo dyes, CI Reactive Red 23, CI Reactive Violet 5, and 1:1 and 1:2 Cu-complex azo dyes, from aqueous His was estimated as a function of immersing time. During the incomplete abstraction of copper on immersion, the dyed films adsorbed His to a larger extent than the amount of adsorption on the undyed film. On immersing the dyed fabrics in aqueous His, the rates of color variations of Cu-complex azo dyes on cotton fabrics were faster than those on cellophane, although the order of the rates of the dyes on both the samples was similar to each other except for monochlorotriazinyl dyes examined. Although the Cu-complex azo dyes examined are not suitable for the dying of cotton materials subject to perspiration, the ISO and JIS methods for color fastness to perspiration are too mild to assess the reactive dyeings investigated.