Studies on the New Testing Methods for the Colorfastness to Light and Perspiration for Reactive Cellulosic Dyeings

研究了10种单氯三嗪基（MCT）活性偶氮染料在纤维素上的光褪色。光谱分析表明，在没有底物的情况下，纤维素上的这些染料在脱氧水中暴露后会通过光还原而褪色。氧抑制或抑制某些染料的还原性褪色，导致氧化性褪色。在pH为2.5 ~ 9的好氧和厌氧水溶液中，研究了pH对三种乙烯基磺酰偶氮染料对纤维素的褪色影响。研究了乳酸浓度、pH值、浸泡时间、挤压方式、染料浓度等因素对几种VS染料褪色的影响，改进了耐光色牢度和耐汗色牢度的测试方法。采用7种试验方法测定了4种VS染料在棉织物上的耐光色牢度和耐汗色牢度。通过试验研究了pH值对光、汗复合作用下的退色效果的影响。JIS L 0888测定酸性和碱性汗液牢度的方法不能测定其牢度差异。将组氨酸加入到cu -络合物反应偶氮染料的水溶液中，形成1:1的络合物，其稳定常数估计为63-115 mol^<-1> dm^<-3>，取决于25℃时的pH值。将染色玻璃纸浸泡在组氨酸水溶液中，观察到吸收光谱的复杂变化取决于组氨酸溶液的pH。

The photofading of ten monochlorotriazinyl(MCT) reactive azo dyes on cellulose was investigated under wet conditions. It was shown by spectral analysis that these dyes on cellulose were faded via photoreduction on exposure in deaerated water in spite of the absence of substrate. Oxygen suppressed the reductive fading for some of the dyes or inhibited it, resulting in oxidative fading.The effects of pH on the fading of three vinylsulfonyl(VS) azo dyes on cellulose immersed in aerobic and anaerobic aqueous solutions were also investigated in the pH range between 2.5 and 9.The effects of the concentration and pH of lactic acid, the time of immersion, the methods of squeezing, and the concentration of dye on cotton fabrics on the fading for some VS dyes were studied to improve the testing methods for colorfastness to light and perspiration.The colorfastness to light and perspiration for four VS dyes on cotton fabrics was examined by seven testing methods. The pH effects on the fading by the compound action of light and sweat were also studied by the testing methods. JIS L 0888 method using with acid and alkaline perspiration could not estimate the difference in their fastness.The addition of histidine to an aqueous solution of a Cu-complex reactive azo dye gave a 1 : 1 complex formation, the stability constants of which were estimated to be 63-115 mol^<-1> dm^<-3>, depending on pH at 25。C.On immersing the dyed cellophane in aqueous histidine, complex variations in the absorption spectra were observed depending upon the pH of the histidine solution.