Solvent dyeing of silk with reactive triazinyl dyes from aqueous alcoholic dyebath.

Abstract

Solvent dyeing of silk with 3-carboxypyridinio-triazinyl (MNT), monochlorotriazinyl (MCT), and vinylsulfonyl (VS) reactive dyes from aqueous alcoholic dyebath was investigated. MNT and MCT stilbene monoazo yellow dyes, MNT and MCT disazo red dyes (C. I. Reactive Red 120), Red 3, Blue 5, and Blue 19 were used. With an increase in the content of alcohol in the neutral salt dyebath, the amounts of adsorption of these dyes decreased to the minimum value, and increased to the maximum value at the saturated concentration of the dyebath, and then decreased again.The minimum was attained at 40-50 (vol.)% and the maximum about 80-90%.The alcohol concentration of maximum dyeing varied with dyes and was inversely proportional to the number of sulfonic acid groups of dyes. From the aqueous dyebath with neutral salt the adsorption of triazinyl dyes was Langmuir-type, while from the 90% alcohol dyebath it was Nernst-type.With an increase in the content of alcohol in the aqueous dyebath, the contribution of Langmuir-type to the adsorption was decreased, while that of Nernst-type was increased.It was confirmed that silk fabrics can be dyed from the aqueous alcoholic dyebath. Although there remains some problems to be solved from the practical point of view, 80-90 (vol.)% ethanol solution brought about the most effective dye fixation.