Dye‐fibre bond stabilities of dyeings of bifunctional reactive dyes containing a monochlorotriazine and a ß‐hydroxyethylsulphone sulphuric acid ester group

The dye‐fibre bond stabilities of various bifunctional dyes (commercially known as Sumifix Supra dyes) have been investigated by measuring the kinetics of dye‐cotton bond hydrolysis in aqueous buffer solution at 98d̀C. The stabilities are generally found to be somewhat higher than those of comparable monofunctional reactive dyes. Significantly better, however, is the fixation yield of the bifunctional dyes. Reasons for a very low uptake of a non‐commercial bromamine acid‐based bifunctional dye are discussed.