Definition of sulphur dyes

The sulphur dye has a history of more than a hundred 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, forms non -fixed and easy to dissolve in water, and gets green dyeing products with alkaline baths and sulfide bath two baths. When the air is exposed or chemically oxidized by the diluration of chromate solution, the cotton cloth can be brown 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 melt the 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 processes 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 vulcanized dyes around the world reaches 100,000 tons, and the most important variety is sulfide black dye. In front of it, the output of sulfide accounted for 75%to 85%of the total output of dyes in dyes. Due to its simple synthesis, low cost, good accuracy, and no carcinogenicity, it was 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.

Production

There are two types of industrial production methods for sulfur dyes:

(1) Baking method, the amine, phenol or nitrics or sulfur or polysulfide of raw aromatics are baked at high temperature to make yellow, orange, and brown sulfur dyes.

(2) The boiling method, the amine, phenol or nitrodolians of the raw aromatics, and the nitrite and nitro -polysulfide are heated and boiled in water or organic solvents to make black, blue, and green sulfurized dyes.