Study On Improving Color Fastness To Chlorinated Water Of Cotton Fabrics Dyed With Reactive Dyes

Recently, with tap water and washing machines are widely used, the color fastness to chlorinated water of cotton fabrics dyed with reactive dyes which are frequently washed faces a new requirement. Especially after China's accession to the WTO, the requirements of export orders are more and more rigorous, at present, at the market of the United States, Canada and European countries and so on, the color fastness to chlorinated water of cotton fabrics dyed with reactive dyes must be four or above, it has become an important research direction that how to improve the color fastness to chlorinated water of cotton fabrics dyed with reactive dyes. So no matter from meeting the domestic people's demands for textiles consumption or adapting to the requirements of foreign markets, improving reactive dyes' color fastness to chlorinated water is imperative.This paper has analyzed the reasons of reactive dyes' anti-chlorine hydrolysis, the main factor that affects reactive dyes' color fastness to chlorinated water is the structure of dyes, such as the dyes with azo structure, their resistance to chlorinated water are relatively poor, while anthraquinone and phthalocyanine structures are better, and there are some difficulties to synthesize new tricolors again with high color fastness to chlorinated water by using existing reactive radicals and parent dyes. Therefore, besides selecting the dyes with good color fastness to chlorinated water, it is necessary to research appropriate auxiliaries to improve the color fastness to chlorinated water of ordinary dyes, such auxiliaries are highly reactive, they can react with active chlorine, faster than dyes, so as to protect reactive dyes from being or less attacked by the active chlorine.This paper selected representative dyes by testing the color fastness to chlorinated water of samples which dyed with four series of dyes (Argazol, Colvazol, Remazol and Reactex HQ-L) respectively, and their optimum conditions were discussed. Optimum conditions were also discussed concerning four kinds of chlorinated water upgrade agent which are NF, CF, Sandofix CLC and Levogen WRD-T, and through comparing their processing effect, two of which with better effect were selected and used to treat with the dyes which have worse color fastness to chlorinated water. What's more, the complex experiments of upgrade agent NF and CF were studied, as well as the best proportion between NF and CF. Using such auxiliary to improve the wettability of upgrade agent NF, and ensure that the color fastness to chlorinated water of treated samples is up to demands of domestic and international markets. At last, the compatibility of reactive dyes which have excellent color fastness to chlorinated water was also discussed, through testing their S, E, F, R values.The study showed that upgrade agent NF, Sandofix CLC and composite auxiliary could impart Colvazol dyes which have worse color fastness to chlorinated water better color fastness to chlorinated water(usually can improve by 1-2 grade), while exerted little effects on other color fastnesses; Argazol Red BF-RR, Colvazol Yellow 3RS and Colvazol Navy Blue BF had excellent color fastness to chlorinated water, their S, E, F, R values were close, and it proved that they could be used as tricolors, by testing these three dyes' dye-uptake and dye-fixing curves and carrying on color matching experiment.Tricolor, chlorinated water fastness upgrade agent and composite auxiliary which are selected, can deal with the problem that color fastness to chlorinated water of cotton fabrics dyed with reactive dyes is weak, and can be further applied according to actual need.