Solvent Red

The free base of compound (17) is Rhodamine B base [509-34-2] (Solvent Red 49 Cl 45170 1). The phosphotungstomolybdic acid salt of (17) is Pigment Violet 1 [1326-03-0] Cl45170 2). Pigment Red 173 [12227-77-9] Cl45170 3) is the corresponding aluminum salt. 

Solvent Red 43 [15086-94-9] 45380 2 Hilton-Davis Chemical Group of Sterling Dmg, Inc. Sun Chemical Cotp. 

OIL SOLUBLE AZO DYES The oil soluble, water-iasoluble, azo dyes dissolve ia oils, fats, waxes, etc. Generally, yellow, orange, red, and brown oil colors are azo stmctures and greens, blues, and violets are primarily anthraquiaones (see Dyes, anthraquinone). Blacks are usually nigrosiaes and iaduhnes of the aziae type (see Azinedyes). An example is Oil Red [85-83-6] (127) (Cl Solvent Red 24 Cl 26105). Uses iaclude the coloring of hydrocarbons, waxes, oils, candles, etc. 

Citms Red No. 2 (8) Cl Solvent Red 80 [6358-53-8] 12156 skins of oranges that are not intended or used for processing only 2.0 ppm max, based on the weight of the whole fmit... 

Anthraquinone Dyes. These dyes have much supeiioi weatheiabihty and heat stabihty compared with the azos, but at higher cost. Typical examples ate Solvent Red 111, Disperse Violet 1, Solvent Blue 56, and Solvent Green 3. 

The anthraquinones are useful in acrylics and are compatible with polystyrene and ceUulosics. Solvent Red 111 has a special affinity for poly(methyl methacrylate) as the red in automobile taillights exposure for a year in Florida or Arizona produces only a very slight darkening. Acid types are usehil for phenohcs (see Dyes, anthraquinone). 

Sudan IV [Solvent Red 24, l-(4-o-tolylazo-o-tolylazo)-2-naphthol] [85-83-6] M 380.5, m -184 (dec), Cl 26105, Xmax 520nm, pK jt -9.0. Crystd from EtOH/water or acetone/water. 

These unexacting requirements make the simplest unsulphonated azo structures, often monoazo types, quite acceptable [80]. Typical of the least polar members of this class are Cl Solvent Yellow 2 (4-68), Cl Solvent Orange 1 (4.69) and Cl Solvent Red 17 (4.70). Simple azo structures carrying sulphonamide, sulphone or carboxylate ester groups are used where a somewhat more polar, less soluble dye is needed. Simple disazo compounds (4-amino-azobenzene— 2-naphthol, for example) are used as red solvent dyes. Probably the only structural feature worthy of note in this class is the occasional adoption of structures carrying long alkyl chains to enhance solubility, as in the case of the disazo dye Cl Solvent Yellow 107 (4.71). 

Supercritical fluid extraction (SFE), microwave-assisted extraction (MAE) and Soxhlet extraction under various experimental conditions were applied for spiked poly(vinyl) chloride samples. Extracted dyes were separated in an ODS column (250 X 4.6 mm i.d. particle size 5 jum) using methanol as the mobile phase. Dyes are well separated by this method as demonstrated in Fig. 3.59. The optimal parameters of the extraction methods are compiled in Table 3.23. Recoveries depended on both the type of extraction method and the chemical structure of the dye. It was found that the highest recovery can be obtained by MAE and the extraction efficacy was the lowest for Solvent red 24 [129],... 

Fig. 3.59. HPLC-UV chromatogram at 230 nm for the analysis of azo dyes, (a) Disperse red 1 (b) Solvent yellow 14 (c) Solvent red 24. Reprinted with permission from M. C. Garrigos el al. [129].

Under U.S. regulations. Grades No. 1, No. 1 Low Sulfur, No. 2, No. 2 Low Sulfur, and No. 4 (Light) are required by 40 CFR Part 80 to contain a sufficient amount of the dye Solvent Red 164 so its presence is visually apparent. At or beyond terminal storage tanks, they are required by 26 CFR Part 48 to contain the dye Solvent Red 164 at a concentration spectrally equivalent to 3.9 lb per thousand barrels of the solid dye standard Solvent Red 26. 

Red Dye These dyes are dilutions of C.I. Solvent Red 164 utilized throughout the petroleum industry to identify specific fuels and oils. The dyes are termed 2-Naphthalenol (phenylazo) azo alkyl derivatives. ... 

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