Reactive dyes history

Reactive dyes, 9 173-178, 242, 463-500 26 397. See also Modern reactive dyes anthraquinone, 9 319-320 antisetting agents and, 9 493-498 development history, 9 463-470 Reactive extrusion (REX), 10 364 ... 

In a study of allergic contact dermatitis in consumers, 1813 consecutive patients were tested with an additional textile series of 12 reactive dyes, and 18 patients (0.99%) were found to be sensitized to reactive dyes. However, only five patients had a history of intolerance to garments, and two of the four patch tests performed with pieces of garment were positive. In practice, reactive dyes in clothing should not be sensitizers. If they can be extracted from fibers, they are in a hydrolyzed, nonsensitizing form. 

Insolubilization. Insolubilization of compounds within textiles parallels the history of humanity the direct dyeing techniques for cotton were highly advanced in the Bronze Age. With the exception of fiber-reactive dyes discussed earlier, other cotton dyes, ie, vat and sulfur, are insolubilized within the fiber after an oxidization step. Insoluble metal oxides have been used to flameproof cotton, and zirconium compounds have been insolubilized on cotton to render the fabric microbial resistant (135) or mildew resistant (136) via a mineral dyeing process (see Textile Finishing). 

The fact that the aftertreatment of direct dyes has a long history is not surprising since wet fastness within this class is not particularly good. Their prime advantages are ease of application and economy compared with dyes of higher fastness (reactive, sulphur or vat) -hence the continued search for highly effective aftertreatments that improve wet fastness... 

The most important azo compounds employed in the manufacture of dyes of this type are those containing the < ,o -dihydroxyazo-, the o-hydroxy-o -carboxyazo- and the o-hydroxy-o -amino-diarylazo systems. It is well established3 33-0 that these form four-coordinate copper and nickel complexes (35) in which the coordination sphere of the metal can be completed by a variety of neutral ligands. In both cases the light-fastness of the parent azo compound is improved as a result of complex formation but the nickel complexes are insufficiently stable towards acid to be of commercial interest as dyestuffs. The history of copper complexes has already been discussed (Section 58.1) and will not be considered further here, although it is worthy of mention that currently the most important copper complex dyestuffs are those containing fibre-reactive systems, e.g. (36), for application on cellulosic fibres. 

Guar gum can cause occupational rhinitis (5) and asthma (6). Of 162 employees at a carpet-manufacturing plant where guar gum was used to adhere dye to the fiber, 37 (23%) had a history suggestive of occupational asthma and 59 (36%) occupational rhinitis (7). Eight (5%) had immediate skin reactivity to guar gum and 11 (8.3%) had serum IgE antibodies to guar gum. 

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