Sulfur dye has a history of more than 100 years since its birth. The first sulfur dye was made by Croissant and Bretonniere in 1873. They will contain organic fibers, such as wood chips, bran, scrap cotton and waste. Paper and other sulfide and polysulfonal alkali are obtained. This dark hygroscopic dye that has a faint odor, which forms non -fixed and easy to dissolve in water, and get green dyeing products when dyeing cotton with alkaline bath and sulfide bath. When it is exposed to the air or chemically oxidized by the drooling of chromate, the cotton cloth can be turned into brown. Because these dyes have excellent dyeing properties, coupled with the low price, they can be used in the cotton chroma industry.
In 1893, R.vikal made black sulfide dyes to melted amino phenols and sodium sulfide and sulfur sulfur. dye. Since then, people have developed blue, red, and green sulfur dyes on this basis. At the same time, the preparation methods and dyeing techniques have also improved. Water -soluble vulcanized dyes, liquid sulfur dyes and environmentally friendly sulfur dyes have appeared, making vulcanized dyes Get flourishing.
Sulfur dyes are one of the most widely used dyes at present. According to reports, the output of sulfide dyes around the world reaches 100,000 tons, and the most important variety is sulfide black dye. At present, the yield of sulfide accounts for 75%to 85%of the total dye yield of vulcanized dyes. Due to its simple synthesis, low cost, good accuracy, and no carcinogenicity, it is deeply favored by various printing and dyeing manufacturers. The dyeing of cotton and other cellulose fibers is widely used, and the black and blue series are most widely used.
There are two types of industrial production methods for sulfur dyes:
(1) Baking method, the amine, phenol or nitrate or sulfur or polysulfide of the raw aromatics are baked at high temperature to make yellow, orange, and brown sulfur dyes.
(2) The boiling method, the amine, phenol or nitrodolians and polysulfide of the raw aromatics are heated and boiled in water or organic solvents to make black, blue, and green sulfurized dyes.
The dye structure is D-S-S-D. Generally, it is necessary to boil sodium sulfide and apply it after dissolving. This type of dye is insoluble in water. The alkaline reduction can restore dyes into hidden colors and dissolved in water.
Water -soluble sulfurization
The dye structure is D-SSO3NA. This type of dye is characterized by water-soluble groups in the molecular structure of the dye, with good solubility and good dyeability. The normal sulfur dye reacts with sodium sulfate or sodium sodium sulfate to generate sulfate sulfate of dyes. It is 150g/L at 20 ° C. It is used for continuous dyeing. The solubility of water -soluble vulcanized dyes at room temperature is fast. There is no insoluble substance. The amount of saturated solubility is sufficient to meet the all -solubility requirements of dye chromators. Water -soluble sulfur dyes have excellent high temperature resistance. However, the dye does not contain a reducing agent, which is not affinity for fiber. When dyeing, sulfide needs to be added, and it is transformed into a state of affinity for cellulose fiber through a nuclear reaction and reduction reaction. Generally, suspended rolling dyeing method is applied to textiles.
The dye structure is D-SNA, which contains a certain amount of sodium sulfide reducing agent, and the dyes are pre-reduced into water-soluble hidden colors. Use a reducing agent to restore ordinary sulfur dyes into water -soluble colors, and add excessive reduction agent as antioxidants, and add liquid dyes made of penetrating agents, inorganic salts and soft water, also known as pre -reduction dyes. Dilute with water during use, you can directly apply it. Such dyes have sulfur -containing, such as Cassulfon dyes contain sodium sulfide, and also contain or contain a very small amount of sulfur, such as immedial dye, and there is no sulfur -containing wastewater during dyeing.