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

研究了10种一氯三嗪基（MCT）活性偶氮染料在纤维素上的湿光褪色。光谱分析表明，尽管没有底物，纤维素上的这些染料在脱气水中暴露时通过光还原而褪色。研究了pH值在2.5 ~ 9范围内对乙烯基磺酰基偶氮染料在纤维素上的氧化褪色的影响，考察了乳酸浓度、pH值、浸泡时间、挤压方式、为改进棉织物耐光、汗渍色牢度的测试方法，研究了棉织物上染料浓度对部分VS染料褪色的影响，采用7种测试方法对4种VS染料在棉织物上的耐光、汗渍色牢度进行了测试。通过测试方法研究了pH值对光汗复合褪色的影响。JISL 0888方法不能测定酸性和碱性汗渍色牢度的差异，在铜络合活性偶氮染料水溶液中加入组氨酸，形成1：1络合物，其稳定常数为63-115 mol·<-1>dm ~（-1<-3>），随pH值的变化而变化。C.将染色的玻璃纸浸入组氨酸水溶液中，根据组氨酸溶液的pH值，观察到吸收光谱的复杂变化。

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.