The Synthesis and Application of Some Aziridinyl Disperse Dyes

The aziridinyl group has been introduced as a terminal substituent into a series of monoazo disperse dyes; the dyes adsorb hypsochromically in comparison with their counterparts containing larger terminal ring systems. When applied from aqueous dyebaths the dyes exhibit higher wash fastness on nylon 6.6 and diacetate fibres than conventional disperse dyes of similar structure and relative molecular mass. On polyester and triacetate fibres the aziridinyl dyes display similar wash fastness to conventional dyes. Dye polymerisation and/or covalent fixation may account for the observed high fastness of the dyes on diacetate and nylon fibres. With the exception of nylon 6.6, the aziridinyl dyes display lower light fastness than conventional disperse dyes on the fibres studied, this being attributable to the greater susceptibility of the aziridinyl dyes to oxidative rather than reductive photodegradation