Dyes derived from aminothiophenes .6. Application of some nitro-substituted thiophene-based azo disperse dyes to hydrophobic fibres

Monoazo disperse dyes prepared from 2- and 3-aminonitrothiophenes were applied to three hydrophobic fibre types, furnishing reddish-blue to green and yellow to orange dyeings, respectively, Colour yields varied greatly: the dyes exhibited marked differences in build-up on polyester as a result of only small alterations in molecular structure, while the strengths of the nylon and diacetate dyeings were generally unsatisfactory. On the whole, levels of fastness on polyester were good, trends in wet and sublimation fastness were identified. The light-fastness ratings of the thienyl-2-azo dyes on polyester and diacetate were high and superior to those of the thienyl-3-azo analogues; however, on nylon, both dye types had poor photostability. (C) 1997 Elsevier Science Ltd.