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

Three new bis azo reactive dyes of different metallic salts (Na, K, Li) were synthesized. The synthesis was obtained by diazotization of 4-amino-2:5 di methoxy phenylene-beta hydroxyl ethyl sulphone sulphate ester and coupling with 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid (H-acid) (moles ratio 2:1). The dyes were purified-concentrated by ultrafiltration technology, characterized and applied on cotton, wool and nylon 6,6 fabric by exhaustion (dyeing) and by ink-jet printing. Fastness properties of the dyeings were measured. Wash fastness was investigated according to international standard methods and was found to be very good to excellent in all cases, while light fastness values were medium to low. Ink-jet ink formulations were prepared using the ultra filtrated reactive blue dyes UF RB(a-c) and their properties pH, conductivity, surface tension and viscosity were monitored over a period of 90 days. The inks were used to print digitally cotton and nylon 6,6 samples and wash- and light fastness properties of the prints were measured. Wash fastness properties were excellent while light fastness values are low Colour measurements of the dyeings and prints were conducted.