Fast dyes

Picric Acid and Ammonium Picrate. Picric acid (PA) (2,4,6,-trinitrophenol) was the first modem high explosive to be used extensively as a burster ia gun projectiles. It was first obtained by nitration of iadigo, and used primarily as a fast dye for silk and wool. It offered many advantages when compressed, it was used as a booster for other explosives, and when cast (melting poiat 122.5°C) served as a burster ia shell it was stable, iasensitive, nonhygroscopic, relatively nontoxic, and of high density when cast, and could be made economically by simple nitration. 

The condensation on the fabric of 1-amino-3-iminoisoindo1enines or 2-amino-5-iminopyrro1enines with phloroglucinol, preferably in the presence of metal salts and solvents, yields fast dyeings in brown shades (158). Metallized azo dyes derived from phloroglucinol yield fast dyeings on leather (qv) or silk (qv) (159). 

Historically the phenazine dyes have played an important part in the dyestuffs industry, although their use has largely been superseded by the more modern, color-fast dyes, in particular those dyes which become chemically bonded to the fibers of the materials being dyed. Amongst the earliest examples of phenazine dyes are those compounds known as the safranines. The discovery of the safranines has been attributed to Greville Williams in 1859 and they were apparently in commercial use shortly after that date, but it was not until 1886 that it was recognized that phenosafranine (138) was indeed a phenazine containing system. 

Bcht-base,/. (Dyeing) fast color base, -baum-wollblau, n. fast cotton blue, -blau, n. fast blue, -braun, n. fast brown, -farben, n. fast dyeing. 

Fix-bleiche,/. bleaching with bleaching powder, -farberei, /. tipping (of plush), dyeing by staining fast dyeing. 

According to Urbanski (Ref 35. p 473) In the second half of the nineteenth century, Picric Acid was very widely used as a fast dye for silk and wool. The first definite suggestions as to the application of Picric Acid for the manufacture of explosives go back to the early second half of the nineteenth century. They referred... 

Because the fluorescence intensity changes observed in response to a change in transmembrane potential are much smaller when using fast dyes in comparison to... 

Slow dyes that respond via a redistribution across the entire membrane (sometimes called Nemstain dyes) do so because of a change in the transmembrane electrical potential. As such, they can only be used as probes of the transmembrane potential and not as probes of the surface potential or the dipole potential. Dyes whose electric field sensing mechanism involves a movement between the aqueous medium and its adjacent membrane interface on one side of the membrane can, in principle, respond to changes in both the transmembrane electrical potential and the surface potential. Fast dyes that remain totally in the membrane phase (e.g., styrylpyridinium, annellated hemicyanine, and 3-hydroxyflavone dyes) respond to their local electric field strength, whatever its origin. Therefore, these dyes can, in principle, be used as probes of the transmembrane electrical potential, the surface potential, or the dipole potential. 

Indanthrone has low fastness to bleaching because the corresponding yellowish green azine (6.66) is formed. Its importance at the time of its discovery lay in the dearth of fast dyes for cotton. Indanthrone is also used as a pigment (Cl Pigment Blue 60). 

Aniline black is also an important fast dye for cotton and is produced on the fibre at a high temperature (by steaming ) from an aniline salt (hydrochloride) and an oxidising agent. It is not probable that the two kinds of this dye which are known have the same constitution, for they have different degrees of stability towards acid technical aniline black probably contains phenazine ring systems (Bucherer, Green). 

Nitro-3,4-dimethoxyaniline (called 4-Amino-5-nitroveratrole by Nakamura et al and 5-Nitro-4-amino-brenzeatechin-dimethyl-ather in Ger), nm-colored prisms or terracotta ndls (from ale), mp 169-75° (Refs 3 6) 4-Niiro-2,3-dimethoxyaniline. Its use as an excellent fast dye on acetate artificial silk is described. No other info given in patent abstract (4)... 

Picric acid [(trinitrophenol) (C6H3N307)] was found to be a suitable replacement for blackpowder in 1885 by Turpin, and in 1888 black-powder was replaced by picric acid in British munitions under the name Liddite. Picric acid is probably the earliest known nitrophenol it is mentioned in the alchemical writings of Glauber as early as 1742. In the second half of the 19th century, picric acid was widely used as a fast dye for silk and wool. It was not until 1830 that the possibility of using picric acid as an explosive was explored by Welter. 

GE Martin, M Tenenbaum, F Alfonso, RH Dyer. High pressure liquid and thin layer chromatography of synthetic acid fast dyes in alcoholic products. J Assoc Off Anal Chem 61(4) 908-910, 1978. 

KM Weaver, ME Neale. High performance liquid chromatographic detection and quantitation of synthetic acid fast dyes with a diode array detector. J Chromatogr 3 486-489, 1985. 

Paper and textile production retention, coagulation, flocculation, wet strength, dry strength improvement, dewatering, color fastness, dye fixation, antistatic agents, antimicrobial treatment... 

With butylcyanoethylaniline a blue dye is obtained that produces very steam-fast dyeings on polyacrylonitrile [76], The dyes with jV-methyldiphcnylaminc as coupling component dye polyacrylonitrile in greenish-blue shades. C.I. Basic Blue 41, 11105 [12270-13-2], for instance,... 

Acid Monoazo Dyes. Among the acid monoazo dyes are a number of much used wool dyes that possess no outstanding coloristic properties but that are distinguished by brilliance of shade, very good leveling power, and particularly low cost, while their wash- and lightfastness meet only low to medium requirements. Partly influenced by the introduction of the International Wool Label to label high-quality wool articles, the fastness requirements have risen considerably, and this has necessitated the development and manufacture of particularly fast dyes. 

A long-known, inexpensive, but only moderately fast dye is C.I. Acid Orange 7, 15510 [633-96-5] (Orange II 3). As a wool dye it is now of secondary importance, but is used in special areas such as leather dyeing and paper coloration. 

Only one class of dyes is also needed when small molecular vat dyes are used. Fast dyeings are obtained in lighter shades. Padding and the thermo sol process are, if necessary, followed by vatting and normal aftertreatment to improve fastness on the cellulose component. 

Dyes. In dyeing PES-wool mixtures, disperse dyes are used for the PES component, and acid or metal-complex dyes for the wool. Disperse dyes can soil wool to a great extent. Since they produce poorly fast dyeings on wool, the dyes selected must stain wool as slightly as possible or must be easily removable by a washing step, which may be reductive if necessary. Frequently used dyes are C.I. Disperse Yellow 23, 54, 64 C.I. Disperse Orange 30, 33 C.I. Disperse Red 50, 60, 73, 91, 167, 179 and C.I. DisperseBlue 56, 73, 87. Premixed dyes consisting of disperse and wool dyes are occasionally available. 

Since anthraquinone is a relatively rare and expensive component of coal tar and petroleum, this type of reaction has been the basis for making relatively inexpensive anthraquinone derivatives for use in making many fast dyes for cotton. 

The development of the synthetic dye industry led to the emergence of classical organic chemistry. Its application in industry was rapid. From the end of the nineteenth century the intermediates employed in the manufacture of synthetic dyes were used to make pharmaceutical products such as aspirin. Some synthetic dyes exhibited bactericidal properties they were called medicinal dyes. Sulfonamides, drugs introduced in the 1930s, are based on research into dyestuffs and their intermediates. Less fast dyes have... 

C. When the diazonium compound is heated to 55° in water solution, the naphthsultone (I) is formed in quantitative yield. The amount of the sultone formed is a direct measure of the purity of the starting material. The naphthsultone is almost always converted to the naphthsultonesulfonic acid, which yields very pure and light-fast dyes with diazo compounds. These dyes have decreased greatly in importonce in recent years. 

It should be mentioned in passing that the first oxazine to attain technical importance was Meldola blue (naphthol blue, Bengal blue), prepared from nitrosodimethylaniline hydrochloride and naphthol. It is a very fast dye but does not give pure shades. Furthermore, its dust irritates the mucuous membranes so severely that many persons cannot work with it. Despite these disadvantages, however, Meldola blue is still rather widely used. 

PENTEX FR is a nonlonic/anlonic blended surfactant that is a biodegradable product for textile wet processing operations. Typical uses are in preparation of fabrics (bleaching), boil-off, and scouring of yarns and fabrics, soaping of fast dye yarns and fabrics particularly when dyed with fiber reactive dyes. 

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