Features Of Sulfur Dyes

Sulfur dyes are a class of sulfur-containing dyes that contain sulfur bonds composed of two or more sulfur atoms in the molecule, which are reduced to cryptochromatic bodies when applied, dissolved in water, and stained fibers. The characteristics of sulfur dye staining vary depending on the type of dye. Sulfur dyes have high washing fastness and strong applicability, although the rubbing fastness and brightness are not as good as reactive dyes, but their color fastness and lightfastness are better than reactive dyes, and sulfur dyes are dyed with less salt and less water consumption. Sulfur dyes are organic compounds containing nitro and amino groups, most of which are formed by reacting with sulfur and sodium sulfide at high temperatures. Many sulfur dyes do not have a certain chemical formula. Sulfur dyes and vat dyes dye dyeing principle is similar, they through chemical reduction reaction, form a water-soluble morphological cryptochromosome with affinity with the fiber to dye the fiber, and then tightly bind with the fiber through the oxidation process.
Sulfur dyes are insoluble in water, and sodium sulfide or other reducing agents are used to reduce the dye to soluble cryptochromatic bodies. It has an affinity for fibers and dyes fibers, and then after oxidation and color development, it returns to its insoluble state and is fixed on the fibers. So sulfur dyes are also a vat dye. Sulfur dyes can be used for the dyeing of cotton, linen, viscose and other fibers, its manufacturing process is relatively simple, low cost, can dye single color, can also be color-matching, good fastness to light, poor fastness to wear resistance. The color spectrum lacks red and purple, and the color is dark, suitable for dyeing thick colors.