Universal dyeing compositions for dyeing textile materials

Application of salts of monovalent copper for dyeing polyacrylonitrile (PAN) fibers with anionic dyes has been known for a long time. Thus, Feld and Fremont [1] were the first to discover that some acidic and direct dyes under certain conditions can bind to PAN fibers. They believed that the dyeing process of these fibers in the presence of copper is similar to the dyeing process of wool with acid-etching dyes, i.e. as a result of dyeing, copper ions form complex compounds with dye molecules and amino groups of polyacrylonitrile macromolecules. The amino groups, as well as carboxyl groups, can be formed due to hydrolysis of nitrile groups. As shown by our studies, oxidation of partially hydrolyzed in aqueous sulfuric acid solution of PAN fiber with sodium hypochlorite increases the content of amino groups in it.