Fastness property

A series of water-soluble fiber-reactive xanthene dyes has been prepared from the reaction of ben2oxanthenedicatboxylic acid anhydride disulfonic acid with, for example, 3-aminophenyl-P-hydtoxyethyl sulfone to yield dyes, with high brilliance and good fastness properties for dyeing of or printing on leather, wool, sHk, or ceUulosic fibers (53). 

Dyes, application and evaluation). Foi dyeing fibei blends such as viscose—polyamide, polyamide—Spandex, oi polyestei—cotton, only compatible FWAs may be used that do not inteifeie with one another oi have any detrimental effect on fastness properties. 

Sulfurized V tDyes. These dyes occupy an intermediate position between the tme vat colors and sulfur dyes because, like vat dyes, they are dyed preferentially from a sodium dithionite—caustic soda bath. However, some dyes of this class can also be dyed from an alkaU sulfide bath or a combination of the two, depending on the dyeing method used and the nature of the substrate to be dyed. This has led to some confusion because Cl Vat Blue 42 and 43 are Hsted in the constitution section of the Colourindex under sulfur dyes. Although inferior to tme vat dyes in fastness properties, they offer the advantage of better fastness, especially to chlorine, than conventional sulfur dyes. 

Aftertreatments include resin finishes, which improve fastness properties, and dye-fixing agents of the epichlorhydrin—organic amine type. These agents react with the dye to give condensation products that are not water soluble and hence more difficult to remove. 

The low cost of sulfur dyes, coupled with good fastness properties and the ease of appHcation, continues to ensure a high consumption. The number of manufacturers has fallen since the 1960s and production is mainly confined to the United States, U.K., Germany, and Spain. There is one principal producer in each of these countries. There are other, less well-known manufacturers in Russia, the People s RepubHc of China, South Korea, Japan, and Bra2il (Table 7). 

Triphenylmethane dyes comprise one of the oldest classes of synthetic dyes. They are of bdUiant hue, exhibit high tinctorial strength, are relatively inexpensive, and may be appHed to a wide range of substrates. However, they are seriously deficient in fastness properties, especially fastness to light and... 

The dyes used on wool can be divided into the following groups acid dyes, chrome dyes, premetallized dyes and reactive dyes (88,89,92—94,97—99). Strictly speaking, all types of wool dyestuffs can be described as acid dyes, but in practice this term is confined to leveling acid dyes, half-milling dyes, milling dyes, and supermilling dyes (94,97). This subclassification of acid dyes arises out of the methods used for their appHcation and their fastness properties on wool. 

With Orange I [574-69-6] (34) (Cl Acid Orange 20 Cl 14600) the naphthalene moiety was iatroduced to azo chemistry. Basacid Red 340 [1658-56-6] (35) (Cl Acid Red 88 Cl 15620) the first red azo dye of technical value was discovered by BASF ia 1876. Its previous name was Fast Red AV and it is stiU produced ia large amounts ia the United States because of its low cost and good dyeiag and fastness properties. This dye became the prototype of a large number of red azo dyes that were developed simultaneously with the iatroduction of new derivatives of naphthalene. 

Other disazo dyes with good substantivity and high wet-fastness properties on polyamides are Acid Red 114 (40), made by coupling o-toHdine to phenol which is then coupled to G-acid, followed by reaction of the phenoHc hydroxyl group with -toluenesulfonyl chloride, and Acid Blue 113 (41) (metanilic acid — 1-naphthylamine — 8-anilino-1-naphthalenesulfonic acid). 

Mordant Dyes. MetaUizable azo dyes are appHed to wool by the method used for acid dyes and then treated with metal salts such as sodium chromate [7775-11-5] sodium dichromate [10588-01-9] and chromium fluoride [1488-42-5] to form the metal complex in situ. This treatment usually produces a bathochromic shift ia shade, decreases the solubUity of the coloring matter, and yields dyeiags with improved fastness properties. The chromium salts can be appHed to the substrate before dyeiag (chrome-mordant or chrome-bottom method), together with the dye ia a single bath procedure (metachrome process), or as a treatment after dyeiag (afterchrome process). 

Premetallized Dyes. Although discovered in 1912, the 1 1 chromium complexes known as Palatine Fast (BASF) and Neolan (Ciba) dyes had httie practical use as wool dyes until 1920 when it was found that a strongly acidic dyebath (pH ca 2.0) (51) was requited to obtain satisfactory dyeing and acceptable fastness properties. Dyes of this type exemplified by Neolan Blue 2G [6370-12-3] (57) (Cl Acid Blue 158A Cl 15050) are stiU in use despite the damage to the wool caused by the strong acid in the dyebath. 

Application Techniques, Structural Variations, and Fastness Properties. When appHed to polyester fiber, many of the disperse dyes originally developed for ceUulose acetate were found to be deficient in Hghtfastness, build-up properties, and especially fastness to the high temperatures employed in the newer dyeing and finishing, printing, and Thermosol (dry heat) processes. 

Toners derived from 6-chlorometanilic acid [88-43-7] 6-amiao-4-chloro-y -toluene-sulfonic acid [88-51-7] and 6-arriino-y -toluenesulfonic acid [88-44-8] have improved fastness properties and find use in paints, inks, and plastics. 

Thioindigo Pigments. The thioindigos are red and violet pigments developed for textiles. Two red—violets. Pigment Red 88 [14295 3-3] and Pigment Red 198 [6371-39-9] are recommended for plastics because of their excellent fastness properties. 

Deep shades and full fastness properties on polyester can be achieved using disperse dyes and carriers, or temperatures over 100°C with or without carriers. 

The carbocychc azo dye class provides dyes having high cost-effectiveness combined with good all-around fastness properties. However, they lack brightness, and consequendy, they cannot compete with anthraquinone dyes for brightness. This shortcoming of carbocychc azo dyes is overcome by heterocychc azo dyes. 

Heterocyclic Azo Dyes. One long-term aim of dyestuffs research has been to combine the brightness and high fastness properties of anthraquinone dyes with the strength and economy of azo dyes. This aim is now being realized with heterocychc azo dyes, which fall into two main groups those derived from heterocychc coupling components, and those derived from heterocychc diazo components. 

Meta.1 Complexes. The main attributes of anthraquiaone dyes are brightness and good fastness properties, including Hghtfastness. MetaHi2ation would detract from the former, and there is no need to improve the latter. Consequentiy, metalli2ed anthraquiaone dyes are of no importance. 

Properties. The principal advantages of anthraquiaone dyes are brightness and good fastness properties, but they are both expensive and tinctorially weak. However, they are stiU used extensively, particularly ia the red and blue shade areas, because other dyes caimot provide the combination of properties offered by anthraquiaone dyes, albeit at a price. 

If diffusion through the fiber is not carried out efficiendy then not only will the rate of dyeing be slow, with a chance that equihbrium between dye and fiber is not reached, but also the fibers will be dyed unevenly and possibly be ring dyed leading to poor fastness properties. Diffusion through the fiber is dependent on the actual dye and fiber chain molecular stmcture and configuration, and also, especially with hydrophobic fibers, the mobiUty of the chemical chain (7). 

Premetallized Dyes. This dye group is appHed to the same textile fibers and with the same procedures as those with acid dyes. The premetallized dyes offer better fastness properties, but lack brilliancy of shade. Except ia printing of carpeting, the neutral dyeiag types of premetallized dyes are appHed generally without acid or acid donor. 

Vat Dyes. AppUed to ceUulosic fibers, vat dyes yield prints with exceUent fastness properties. They are used to print furnishings, drapes, and camouflage where their iafrared reflectance resembles natural terrain and foUage. Their appUcation can foUow two different procedures. 

The anthraquinone stmcture occurs in both the plant and animal kingdom. Those natural dyes having this stmcture surpass all other natural dyes in fastness properties (see Dyes, anthraquinone). 

Color formers such as 16 and 17 and their mixtures are commonly known as Pyridyl Blues and are excellent products in combination with organic developers, yielding intense blue images with very high fastness properties. However, it has been observed71 that, for some applications, the 7-azaisomer is too reactive and hence it was desirable to modify the... 

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