Synthesis and Application of High-Washability 4-Amino-4′-Fluorosulfonylazobenzene Disperse Dyes to Cellulose Diacetate for High Color Fastness

The susceptibility of cellulose acetate fibers to alkaline hydrolysis makes it difficult to ensure high wash fastness, due to restrictions imposed by the application of conventional reduction clearing as an aftertreatment. A series of high-washability azo disperse dyes containing a fluorosulfonyl group was synthesized, and their dyeing and fastness properties on cellulose diacetate fibers were investigated. The dyes exhibited reasonable levels of build-up and excellent color fastness on the cellulose diacetate fibers. Samples subjected to aftertreatments of soaping and hot rinsing, as well as the non-treated dyed samples, exhibited similarly excellent levels of wash fastness owing to their outstanding wash-off properties. Based on the results, 4-amino-4'-fluorosulfonylazobenzene disperse dyes can be promising alternatives to high-value-added dyes, as the former can provide high color fastness on cellulose diacetate without excess wastewater discharge during washing.