Direct Blue

H-acid, l-hydroxy-3,6,8-ttisulfonic acid, which is one of the most important letter acids, is prepared as naphthalene is sulfonated with sulfuric acid to ttisulfonic acid. The product is then nitrated and neutralized with lime to produce the calcium salt of l-nitronaphthalene-3,6,8-ttisulfonic acid, which is then reduced to T-acid (Koch acid) with Fe and HCl modem processes use continuous catalytical hydrogenation with Ni catalyst. Hydrogenation has been performed in aqueous medium in the presence of Raney nickel or Raney Ni—Fe catalyst with a low catalyst consumption and better yield (51). Fusion of the T-acid with sodium hydroxide and neutralization with sulfuric acid yields H-acid. Azo dyes such as Direct Blue 15 [2429-74-5] (17) and Acid... 

Phthalocyanine Dyes. In addition to their use as pigments, the phthalocyanines have found widespread appHcation as dyestuffs, eg, direct and reactive dyes, water-soluble dyes with physical or chemical binding, solvent-soluble dyes with physical or chemical binding, a2o reactive dyes, a2o nonreactive dyes, sulfur dyes, and wet dyes. The first phthalocyanine dyes were used in the early 1930s to dye textiles like cotton (qv). The water-soluble forms Hke sodium salts of copper phthalocyanine disulfonic acid. Direct Blue 86 [1330-38-7] (Cl 74180), Direct Blue 87 [1330-39-8] (Cl 74200), Acid Blue 249 [36485-85-5] (Cl 74220), and their derivatives are used to dye natural and synthetic textiles (qv), paper, and leather (qv). The sodium salt of cobalt phthalocyanine, ie. Vat Blue 29 [1328-50-3] (Cl 74140) is mostly appHed to ceUulose fibers (qv). 

Direct Blues. Direct Blue 86, a phthalocyanine direct dye, represents a small but important segment of the direct dye stmcture groups. The dyes are brilliant greenish blue or turquoise shades. Sales of nearly 2 million were reported in the United States in 1988. Among the disazo blues. Direct Blue 80 (74) and Direct Blue 98 (75) were sold in 152 t and 107 t quantities at an average cost of 2.22 and 1.81/kg, respectively, in 1988. Table 7 and Figure 6 show some direct blues. 

Direct Blue 218 had reported sales of 623 t valued at 4.4 million ia 1987. It is produced from Direct Blue 15 (76) by metallizing and elimination of methyl groups from the methoxide to form the copper complex. Direct Blue 15 (76) is prepared by coupling o-dianisidine [119-90-4] to two moles of H-acid (4-amiQO-5-hydroxy-2,7-naphthalenedisulfonic acid) under alkaline pH conditions. Other important direct blues iaclude Direct Blue 80 (74), (9-dianisidine coupled to two moles of R-acid (3-hydroxy-2,7-naphthalenedisulfonic acid [148-75-4]) followed by metallizing to form a bis copper complex, and Direct Blue 22 (77), an asymmetrical disazo dye, prepared by coupling o-dianisidine to Chicago acid [82-47-3] and 2-naphthol. Direct Blue 75 (78) is an example of a trisazo dye represented as metanilic acid — 1,6-Q.eve s acid — 1,6-Q.eve s acid — (alb) Ai-phenyl J-acid. 

Of all the metal complexes evaluated, copper phthalocyanines give the best combination of color and properties and consequentiy the majority of phthalocyanine dyes are based on copper phthalocyanine Cl Direct Blue 86 [1330-38-7] (Cl 74180) (68) is a typical dye. 

Copper and chromium are used for complexing a number of dyes such as the coppered direct and reactive dyes for cotton and metaUi2ed and neutral metal complex acid dyes for nylon, wool, etc. Examples are Direct Blue 218 [28407-37-6] (Cl 24401) (317), Reactive Violet 2 [8063-57-8] (Cl 18157) (318), and Acid Black 52 [5610-64-0] (Cl 15711) (319). 

DHEW/NIOSH/NCI, Joiat Intelligence Bulletin No. 24, Direct Black 38, Direct Blue 6, and Direct Brown 95," Ben dine DerivedDjes, NIOSH Pubhcation No. 78—148, Dept, of Health, Education, and Welfare, Washington, D.C., 1978. 

Figure 18.6 Diffraction of x-rays by a crystal, (a) When a beam of x-rays (red) shines on a crystal all atoms (green) in the crystal scatter x-rays in all directions. Most of these scattered x-rays cancel out, but in certain directions (blue arrow) they reinforce each other and add up to a diffracted beam, (b) Different sets of parallel planes can be arranged through the crystal so that each corner of all unit cells is on one of the planes of the set. The diagram shows in two dimensions three simple sets of parallel lines red, blue, and green. A similar effect is seen when driving past a plantation of regularly spaced trees. One sees the trees arranged in different sets of parallel rows.

Chryene Cl Basic Red 9 Cl Direct Black 38 Cl Direct Blue 6 Cl Direct Red 28 Cl Disperse Blue 1 Clarified oils (petroleum),... 

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