Disperse Dyeing of Nylon 6 Fibers with 1,4-Diaminoanthraquinone in the Presence of Didodecyldimethylammonium Bromide

The dyeing behavior of 1,4-diaminoanthraquinone (1,4-DAA) on nylon 6 fiber in the presence of didodecyldimethylammonium bromide (DDDMAB) is investigated. Both dyeing rate and dye saturation value of 1,4-DAA improve considerably with DDDMAB, compared with a dyehouse grade of 1,4-DAA, Miketon Fast Red Violet R. There is no evidence for a reduction in T g of the fiber pretreated with aqueous DDDMAB solution. The apparent solubility of 1,4-DAA in aqueous DDDMAB solution as well as the amount of DDDMAB adsorbed onto nylon 6 fiber is large. The enhanced dyeing properties of the fiber in the presence of DDDMAB are attributed to the formation of the concentrated layer of monomeric dye molecules on the fiber surface.