Dying with sulphur dyes

Definition:       The sulphur dye contains “-s-S-” linkage in its chemical structure and here it is so called.

Chemistry of dyeing with sulphur dyes:

          Sulphur dyes are water insoluble and need reduction for solubilization. After solubilization it is applied in the fibers and oxidation is necessary for making the dyes insoluble again in the fibers. The dye is similar to vat dye during application.

                  

Properties of sulphur dyes:

(1)       Sulphur dyes are complex hetero cyclic molecules containing sulphur linkage.

(2)       Dyes are excessively amorphous a few show crystalline.

(3)       Water insoluble and chemical composition varies among the producers.

(4)       Applied specially for black shades in the cellulosic fibers.

(5)       Fastness properties average to good.

(6)       Cheap and easy to apply.

(7)       Oxidation is necessary for final shade development