Colouration of textile materials

摘要

The fastness of dyeings on textile materials made of or containing cellulose acetate is improved by impregnating the dyed materials with an aqueous solution of cyanamide and drying and heating the impregnated materials. Advantageously, the heating is effected at 110-150 DEG C. The process is especially applicable for the improvement of the fastness to combustion products of coal gas of dyeings with violet or blue aminoanthraquinone dyes such as 1 : 4-diamino-, 1 : 4-di-(methylamino)-, 1 - methylamino - 4 - (b - hydroxyethyl)amino-, 1 - amino - 4 - methylamino- and 1 - amino - 4 - phenylamino-anthraquinones. In an example, a cellulose, dyed with 1-methylamino-4-(b -hydroxyethyl)amino-anthraquinone is padded with an aqueous solution of cyanamide containing acetic acid, dried and heated for 20 minutes at 130 DEG C. Specification 569,557 is referred to in the Provisional Specification. Cyanamide in aqueous solution is obtained by treating commercial calcium cyanamide with water at 40 DEG C. or lower, filtering, passing carbon dioxide through the filtrate, removing the precipitated calcium carbonate by filtration and concentrating the filtrate at a low temperature, e.g. at 40 DEG C. under reduced pressure.