Synthesis, characterization and ultrafiltration of reactive dyes. Application by exhaustion and/or ink-jet printing—II

Three novel vinyl sulfone reactive dyes of various metallic salts (Na, K, Li) have been synthesized by coupling 1-amino-phenyl-4-beta hydroxyethyl sulfone sulfate ester with 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid (H-acid). The reactive dyes were then purified using ultrafiltration (UF). The ultrafiltrated dyes of the various metallic salts were characterized by their spectrophotometrical data using Ultra Violet-visible (UV-vis), Fourier transform infra-red and optical emission spectroscopy, X-ray diffraction, and elemental analysis. The purity of the dyes was checked by Thin Layer Chromatography (TLC). The solubility characteristics of the various salts of the ultrafiltrated reactive dyes were assessed and compared with the non-ultrafiltrated reactive dyes of the same salts. The dyes were characterized and applied to cotton, wool, and nylon 66 by exhaustion (dyeing). Novel water-based reactive ink-jet inks were prepared with the ultrafiltrated reactive dyes of the various metallic salts. Their suitability for digital printing applications was examined by using a digital printer on suitably pretreated cotton samples. Color and fastness properties measurements were performed for both the dyed and digitally printed samples. K/S values of the dyed samples were higher than those of the digitally printed ones, whereas K/S values of the samples dyed with the ultrafiltrated dyes were much higher than those of the non-ultrafiltrated dyes. The other coloristic co-ordinates L*, a*, b*, C*, and h ^o were in line with strength changes of the dyes before and after UF. The dyed and digitally printed samples had excellent wash and good light fastness properties. UF slightly improved the fastness properties of the dyed samples.