关键词: 分散染料, α?苯基重氮酯, 配伍性, 氨纶, 染色性能, 色牢度

Abstract: Spandex is a widely used elastic fiber, but its dyeing problem has not been well solved. For example, when dyeing spandex with conventional disperse dyes, the color fastness to washing is always insufficient. The reason is that the binding forces between conventional disperse dye molecules and spandex fibers are limited to weak interactions such as hydrogen bond and Van der Waals force. Therefore, the purpose of this study was to develop new dyes through structural modification of the dyes from the perspective of enhancing dye-fiber affinity. Additionally, corresponding dyeing and fixation processes were established to obtain black spandex with high color fastness. In this paper, three diazo-type hydrophobic reactive dyes D1–D3 were synthesized by coupling reaction using aniline derivative I containing α-phenyl diazo ester group as coupling component, and corresponding arylamine diazonium salts as diazo components. Then, a black reactive disperse dye H1 was obtained by compounding dyes D1–D3. The dyeing property of dye H1 on spandex was tested and the dyeing and fixing processes were optimized. The dyeing properties of dyed spandex, such as color parameters, fixation rate, color fastness and migration rate, were tested and analyzed by comparing with a commercial black disperse dye HXF.
Coupling reactions produced dyes D1–D3 with yields of 75%–90%. Under heating temperatures at the 110–150 °C range, these dyes could transfer to carbene intermediates, which would further react with N-H bonds on spandex. The dyes D1–D3 showed good compatibility with an optimal compounding ratio of 20:1:20 . When dyed at 95 °C for 45 minutes and then fixing at 140 °C for 30 minutes using dye H1 of 3%(o·w·f) , a dark black dyed spandex with a color depth value of 662.8, L* value of 16.5, a* value of 2.1, b* value of -1.4 and C* value of 2.6 was obtained. The dyed spandex exhibited excellent color resistance to organic solvent extraction with a fixation rate reaching 80%. Furthermore, it boasted excellent resistance to soaping, rubbing and sublimation color fastnesses, all reaching level 4 or above. In addition, the color migration rate was only 8%. As comparison, the color depth value of spandex dyed with commercial black disperse dye HXF was only 299.5 with L* value of 28.6, a* value of 12.5, b* value of 10.5 and C* value of 16.3 under the same dyeing condition. Besides, the color of spandex dyed with HXF could be completely extracted by organic solvents. Tests showed that the color fastnesses to soaping, rubbing and sublimation were grade 3 or less. Additionally, the color migration rate could reach as high as 70%. The breaking strength of spandex yarn dyed with dye H1 was 42 cN, which was similar with that of samples dyed by HXF (43 cN) or blank (46 cN). On a whole, the change of mechanical property of dyed spandex was still in an acceptable range. 
The introduction of α-phenyl diazo ester group into dye molecules made dyes reactive to spandex, and simply heating to the transition temperature was necessary for initiating the reaction. After preparation of black reactive disperse dye using the three diazo-type hydrophobic reactive dyes D1–D3 and dyeing under the optimized condition, a deep black dyed spandex with high color fastness property could be obtained. Thus, the above results were expected to provide a new idea for the molecular design of high performance dyes for spandex dyeing.

Key words: disperse dye, α-phenyl diazo ester, compatibility, spandex, dyeing property, color fastness