Sulphur black

The manufacture of sulfur dyes involves sulfurisation processes, the chemistry of which remains rather mysterious and may arguably be considered still to be in the realms of alchemy The processes involve heating elemental sulfur or sodium polysulfide, or both, with aromatic amines, phenols or aminophenols. These reactions may be carried out either as a dry bake process at temperatures between 180 and 350 °C or in solvents such as water or aliphatic alcohols at reflux or at even higher temperatures under pressure. C. I. Sulphur Black 1, for example, is prepared by heating 2,4-dinitrophenol with sodium polysulfide. 

The first commercial sulphur dye was discovered accidentally in 1873 by Croissant and BretonniSre who heated lignin-containing organic waste, such as sawdust, with sodium polysulphide at about 300 °C the product was sold under the name Cachou de Laval [52]. Even today an equivalent dye (Cl Sulphur Brown 1) is derived from lignin sulphonate, which is readily available from waste liquors from wood pulp manufacture. The real pioneer of sulphur dyes was Vidal, the first chemist to obtain dyes of this type from specific organic compounds. In particular, Sulphur Black T (Cl Sulphur Black 1) was made from 2,4-dinitrophenol in 1899. At the turn of the century many of the intermediates available were subjected to sulphurisation (thionation), that is, treatment with sulphur, sodium sulphide or sodium polysulphide to introduce sulphur linkages. 

In the Colour Index both conventional sulphur dyes and their leuco counterparts are allocated the same Cl constitution number a different number is given to the related solubilised version. Thus, for example, Cl Sulphur Black 1 and Cl Leuco Sulphur Black 1 have the reference Cl 53185 whereas Cl Solubilised Sulphur Black 1 appears under Cl 53186. Because of the complexity of the final products, sulphur dyes are classified according to the chemical structure of the organic starting material that predominates in the manufacturing process. Typical intermediates include aromatic amines, with or without nitro and phenolic groups, and diphenylamine derivatives. 

Cl Sulphur Black 1, which is produced from the relatively simple intermediate 2,4-dinitrophenol and aqueous sodium polysulphide. A similar product (Cl Sulphur Black 2) is obtained from a mixture of 2,4-dinitrophenol and either picric acid (6.148 X = N02) or picramic acid (6.148 X = NH2). A black dye possessing superior fastness to chlorine when on the fibre (Cl Sulphur Black 11) can be made from the naphthalene intermediate 6.149 by heating it in a solution of sodium polysulphide in butanol. An equivalent reaction using the carbazole intermediate 6.150 gives rise to the reddish blue Cl Vat Blue 43 (Hydron blue). This important compound, which also possesses superior fastness properties, is classified as a sulphurised vat dye because it is normally applied from an alkaline sodium dithionite bath. Interestingly, inclusion of copper(II) sulphate in the sulphurisation of intermediate 6.150 leads to the formation of the bluish black Cl Sulphur Black 4. 

In this way it was established that both thiazone and thianthrene structures are present in all the quinoneimine sulfur dyes studied (C.L. Vat Blue 43, 53630 [1327-79-3] C.L Sulphur Black 6, 53295 [1327-16-8], C.l. Sulphur Black 7, 53300 [1327-17-9]-, C.L Sulphur Black 11, 53290 1327-14-6] and C.L. Sulphur Red 5, 53820). The thianthrene structure was also found to contribute greatly to the sub-stantivity of the dyes. 

Polysulfide melt dyes, which are applied chiefly with dithionite and commonly show a higher degree of fastness, are called sulfur vat dyes. They include such dyes as C.I. Vat Blue 43 and C.I. Sulphur Black 11. 

With a few exceptions, sulfur dyes are used for dyeing cellulosic fibres. They are insoluble in water and are reduced to the water-soluble leuco form for application to the substrate by using sodium sulfide solution. The sulfur dye proper is then formed within the fiber pores by atmospheric or chemical oxidation. Sulfur dyes constitute an important class of dye for producing cost-effective tertiary shades, especially black, on cellulosic fibers. One of the most important dyes is C.I. Sulphur Black 1, prepared by heating 2,4-dinitrophenol with sodium polysulfide. 

The world production of sulfur dyes may still be more than about 100 000 t/a. The most important sulfur dyes, today as in the past, are C.I. Sulphur Black 1, 53185 1326-H2-5 and dyes of the Hydron Blue type such as C.I. Vat Blue 43, 53630 [1327-79-3]. 

Many sulfur dyes contain benzothiazole, thiazone or thianthrene groups, and almost the whole range of shades can be obtained. The number of commercially available sulfur dyes is small but their production volume is large. Sulfur Black T with all conceivable variations may be the biggest synthetic dye which is used as a penetrating dye on leather Sulphur Black 1, 53185 [1326-82-5] (18 most probable structure). 

Sulfur dyes are water-insoluble, macromolecular, colored compounds which are produced by bridging aromatic amines, phenols, and amino phenols with sulfur and/or sodium polysulfide [16], These dyes are of little interest for dyeing paper. Only C.I. Sulphur Black 1 (36), the most important dye of all in terms of volume, is used for special paper dyeings. 

The dinitrochlorobenzene used in the preparation of sulphur black T should be free from the 2,6 isomer. 

Potassium nitrate Charcoal Sulphur Black powder... 

CIC Ethyl butyrate contribute to the fruity, estery note linalool, alpha-terpineol, citronellol and damascenone support the floral, fruity ripe character and 1,8-cineol imparts the freshness. 4-methoxy-2-methyl-2-mercapto butane is responsible for typical catty sulphurous black currant note. Extracts of the black currant buds are more green, herbaceous but they also contain the sulphurous CIC. A similar note, 8-mercapto-p-menthan-3-one has been identified in buchu oil and is often used to imitate the catty black currant aspect. 

Sulphur-dyed cotton fabrics are commonly used for lining boots and other goods made of rubber and, when intended for the purpose, should not be after-treated with copper salts. It is also undesirable to use copper on materials which have been dyed with sulphur blacks because it can cause catalytic oxidation of the sulphur, converting it to sulphuric acid which degrades the cellulose. 

Vidal and other sulphur blacks have been used for dyeing fast shades on pure silk by the method patented by Lodge and Evans. The process is based on the fact that Vidal Black can be converted into its leuco compound, which is soluble in ammonium sulphide, by the action of sulphites or bisulphites. In practice the leuco compound is prepared and dissolved in sodium sulphide, which is then converted into ammonium sulphide by the addition of ammonium sulphate. 

Potassium chlorate is unpredictable with fuses. It will go off spontaneously when mixed dry with certain chemieds such as red phosphorous, sulphur, black antimony sulphide, etc. But for controlled situations, most prefer to set it off with blasting caps, since it also detonates by concussion. 

Another fairly toxic group of phenolic compounds present in wastewaters is that of the nitrophenols. They are toxic when applied perorally, as well as when inhaled or absorbed through the skin. The most toxic is 2,4-dinitrophenol employed in the dyestuff industry (sulphur black). In biochemical reactions, its inhibiting effect on the vital functions of the cell is known. The solubility of some nitrophenols is presented in Table 3.17. 

Sulphur Black is prepared by fusing dinitrophenol, C6H30H(1),(N02)2(2,4), with sulphur or by heating it with a strong solution of sodium polysulphide. The intermediate necessary is prepared from chlorodinitrobenzene which is formed by nitrating chlorobenzene. The chlorine atom is readily replaced by the hydroxyl group when the compound is warmed with a solution of caustic soda. 

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