Yellow reactive dyes

Yellow reactive dyes Yellow-tip index Yerba santa Yersinia Yersinia pestis Yield stresses Yittnum Ylang-ylang Ylang-ylang oil... 

Although it has been reported (138) that decolorization of wastewater containing reactive azo dyes with sodium hydrosulfite is possible only to a limited extent, others have demonstrated good reduction (decolorization). For example, using zinc hydrosulfite for the decolorization of dyed paper stock (139) resulted in color reduction of 98% for azo direct dyes (139). A Japanese patent (140) describes reducing an azo reactive dye such as Reactive Yellow 3 with sodium hydrosulfite into its respective aromatic amines which ate more readily adsorbable on carbon than the dye itself. This report has been confirmed with azo acid, direct, and reactive dyes (22). 

The pyridone coupling components (4-8), which came into use in the 1960s chiefly for the preparation of greenish yellow disperse and reactive dyes, are made by the condensation of an alkylamine with ethyl acetoacetate and ethyl cyanoacetate. Coupling occurs at the position indicated by the arrow in Scheme 4-13. 

The new range of Lanasol CE (Ciba) metal-free reactive dyes for wool has been developed to offer the option of replacing chrome dyes in full depths by cost-effective alternatives. These five dyes (yellow, red, blue, navy and black) are based on the a-... 

Not all homobifunctional reactive dyes that react with cellulose by the nucleophilic addition mechanism are marketed as sulphatoethylsulphones. Thus the bluish red structure 7.74 contains two chloroethylsulphone precursor groups attached via a diethylamine residue and an activated chlorotriazine grouping to the H acid coupling component. The azopyrazolone yellow structure 7.75 depends for its reactivity on sulpha toe thylsulphonamide precursor groups located separately at the diazo and coupler extremities of the molecule. 

These dyes are invariably monoazo compounds with the reactive system attached to the diazo component, owing to the ready availability of monosulphonated phenylenediamine intermediates. Pyrazolone couplers are most commonly used, as in structure 7.82 (where Z is the reactive grouping), and this is particularly the case for greenish yellow vinylsulphone dyes. Catalytic wet fading by phthalocyanine or triphenodioxazine blues is a characteristic weakness of azopyrazolone yellows (section 3.3.4). Pyridones (7.83), barbituric acid (7.84) and acetoacetarylide (7.85 Ar = aryl) coupling components are also represented in this sector, with the same type of diazo component to carry the reactive function. 

RP-HPLC was also employed for the investigation of the hydrolysis behaviour of two fluorotriazine reactive dyes Cibacron blue F-R and Cibacron yellow F-4G. Chromatographic measurements were performed in an ODS column (50 X 4.6 mm i.d. particle size 5 /jm) at room temperature. The mobile phase was ACN-0.05 M ammonium acetate buffer containing 1 mM acetyhrimethylammonium bromide (47 53, v/v). Flow rates were 0.8 and 0.6 ml/min depending on the dyes to be separated. Dyes were detected at 275 nm. The hydrolysis of dyes was investigated both in the absence and presence of... 

Notes Col. 1. — (i) PE-PSSA polystyrene sulphonic acid grafted onto a polyethylene matrix and containing indicated amounts of divinyl benzene 120) (ii) Ionac MC-3470 (Ionac Corp., USA) powdered mixture of PSSA ion exchanger and inert polymer compressed hot with embedded mesh of supporting material120) (iii) Cellophane PUT 600/23 sheet (British Cellophane Ltd.) washed to remove plasticizer110) (iv) Dye A C. I. Direct Blue 1 (tetrasulphonate substantive dye)110 (v) Dye B Procion Yellow HA (disulphonate reactive dye, I.C.I. Ltd.)121. ... 

A reactive dye inclusion compound 1 (Figure 12) was prepared by condensing disodium salt of 7-[4-(methylamino)phenylazo]-2,4-naphthalenedisulfonic acid with cyanuric chloride and sodium 3-aminobenzenesulfonate (1 1 1) in the presence of hexaMs(2,3,6-tri-0-methyl)-a-cyclodextrin [41], Solutions of the bright yellow rotaxane 1 are more resistant to chemical bleaching than the uncomplexed dye. This compound anchored to mercerized cotton 2 also showed more photofading resistance [42],... 

It has been found that many of the reactive dyes have not the highest degree of fastness to natural weathering. When exposed over prolonged periods to the atmosphere they fade more rapidly than normal laboratory fastness tests would predict. Procion Yellow H-A, Procion Yellow M-6G, Procion Yellow M-R, and Procion Yellow H-SG are all deemed to be of borderline fastness to weathering. They are, nevertheless, in many cases superior to vat dyes because they do not induce accelerated oxidation of the cellulose on exposure to light. The deeper the shade the less apparent is the alteration due to weathering. 

Portland cement Mixing T1O2 with Portland cement in the ratio 1 1 or 1 2 by grinding. Adding distilled water. Pasting semisolid mass to the inner surface of round tile plates (12 cm diameter) or Petri dish (15.5 X 1.8 cm). Dyeing for 24 h Degradation of Alphazurine EG and reactive yellow 17 dyes in aqueous solution [523, 525]... 

B. NeppoUan, S. R. Kanel, H. C. Choi, M. V. Shankar, Banunathi Arabindoo, V. Murugesan, Photocatal3dic degradation of reactive yellow 17 dye in aqueous... 

A selection of representative chemical structures from the vast range of reactive dyes now available commercially is illustrated in Figure 8.5. Reactive dyes may be prepared, in principle, from any of the chemical classes of colorant by attaching a fibre-reactive group to an appropriate molecule. In common with most application classes of textile dyes and pigments, most reactive dyes belong to the azo chemical class, especially in the yellow, orange and red shade areas. Examples are typified by the structurally related red monoazo reactive dyes, the dichlorotriazine 8.28a, Cl Reactive Red 1, the... 

Reactive dye solutions Azo dye (Reactive Yellow 84) Organic compounds Dye wastewater Phenolic solutions... 

SPF fibres are usually light yellow in colour. They are stable with both hydrogen peroxide and reduction bleaching. A whitening or brightening treatment may be necessary for purer whiteness (Fig. 13.7). When bleaching an SPF blended with another fibre, care must be taken to use a method suitable for both fibres. Either acid or reactive dyes may be used dye fastness compares well with that of silk. ... 

Poly(hydroxyethyl methacrylate)-dye copolymers —The color additives formed by reaction of one or more of the following reactive dyes with poly(hydroxyethyl methacrylate), so that the sulfate group (or groups) or chlorine substituent of the dye is replaced by an ether linkage to poly(hydroxyethyl methacrylate) The dyes that may be used alone or in combination are Reactive Black 5 [17095-24-8] Reactive Blue 21 [73049-92-0] Reactive orange 78 [68189-39-9] Reactive Yellow 16 [60958-41-0] Reactive Blue 19 [2580-78-1] Reactive Blue 4 [4499-01-8] Cl Reactive Red 11 [12226-08-3] Cl Reacive Yellow 86 [61951-86-8] Cl reactive Blue 163 [72847-56-4]. 

Chlorosulfonic acid may also be used in the manufacture of (amino-alkyl)-phenyl reactive dyes thus the hydroxyethyl sulfone 44 was reacted with chlorosulfonic acid to yield the sulfate 45. The latter was subsequently condensed with cyanuric chloride 46 and the azo-5-pyrazolone 47 to yield the golden-yellow dye 48 (Scheme 10). ... 

---