Sulfur Dye

(redirected from Sulphur dye)

sulfur dye

[′səl·fər ‚dī]
(organic chemistry)

Sulfur Dye

 

any of the organic dyes that are high-molecular-weight compounds containing the heterocycles

and the groups SH and Sn, where n ≥ 2 (the precise chemical structure has not been established). Sulfur dyes are amorphous substances, insoluble in water and most organic solvents; when acted upon by Na2 S, they form water-soluble leuco compounds according to the scheme

After imparting color, these compounds are oxidized by oxygen in the air and are reconverted on the fiber to insoluble sulfur dyes.

Sulfur dyes are obtained by a prolonged heating of such organic compounds as aromatic amino, nitro, amino-hydroxy, and nitro-hydroxy compounds and heterocyclic azines with sulfur or a polysulfide of sodium (Na2 Sn’n = 2–9).

Sulfur dyes are usually pale. The black, blue, brown, and green dyes have the greatest importance; the yellow and orange dyes have only limited use. Red sulfur dyes are unknown. While the black dyes are fast, the other sulfur dyes impart colors of lesser permanence. Sulfur dyes are inexpensive and convenient. They are widely used for dyeing cotton fabric; in the textile industry, however, they have been partially replaced by vat dyes and reaction dyes, which offer brighter and more permanent colors.

REFERENCCE

Chekalin, M. A., B. V. Passet, and B. A. Ioffe. Tekhnologiia organiches-kikh krasiteleii promezhulochnykh produktov. Leningrad, 1972.

M. A. Chekalin

References in periodicals archive ?
Further, the availability of dye in various commercial forms such as solubilized, conventional water insoluble and leuco form is providing the consumers with a wide choice of selection, thereby increasing demand for Sulphur dye.
And these include bleaching agents vat dyes, azo dyes, sulphur dye, color pigment, which are manufactured by using formaldehydes, hydrochloric acid, chromium salts, ammonia, caustic soda, and many other toxic chemicals.
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In spite of this, dyestuff sales increased 8% mostly as the result of the acquisition in May of the sulphur dye business of Southern Dye & Chemical Company.
Profits from dyestuffs were up modestly with the contribution from the new sulphur dyes offsetting lower profits from other dyes.
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Among their topics are the structure and properties of textile materials, pre-treating and preparing textile materials prior to dyeing, the thermodynamics and kinetics of dyeing and dyebath monitoring systems, molecular modeling and predicting dye properties, the chemistry of reactive dyes and their application processes, disperse dyes, metal-complex dyes, sulphur dyes, environmentally friendly dyes, fluorescent dyes, and near-infrared dyes.
Diresul[R] P: liquid sulphur dyes with improved toxicological profiles
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Sales of the new line of sulphur dyes that the Company began marketing in May 1994 more than offset a modest decline in other dyestuff sales.
In combination with the company's full range of Diresul(r) RDT sulphur dyes, including non-indigo based Diresul(r) RDT Indicolors, Advanced Denim offers unique effects, improved fastness, better reproducibility of shades and easy application for more precise results.