Disperse Yellow dyes

Disperse yellow dyes, 9 412 Dispersibility, of organic pigments,... 

Another compound of interest is adenine [73-24-5] or 6-aminopurine (53) derived from pheny1a 2oma1ononitri1e (92). The introduction of the dicyanostyryl moiety has led to the industriali2ation of several methine dyes such as the Cl Disperse Yellow [6684-20-4] (54) (93). The Cl Disperse Blue 354 [74239-96-6] (55) also represents a new class of anTinoarylneutrocyariine dyes with a brilliant blue shade (94). The dimer of malononitrile is also used for the synthesis of new dyes (95). 

This mixture is known as Quinoline Yellow A [8003-22-3] (Cl 47000) and is most widely used with polyester fibers (109). Upon sulfonation, the water-soluble Quinoline Yellow S or Acid Yellow 3 [8004-92-0] (Cl 47005) is obtained. This dye is used with wool and its aluminum salt as a pigment. Foron Yellow SE-3GL (Cl Disperse Yellow 64) is the 3-hydroxy-4-bromo derivative. Several other quinoline dyes are commercially available and find apphcations as biological stains and analytical reagents (110). 

The early yellow disperse dyes were based on phenolic coupling components, eg, Cl Disperse Yellow 3 (92) (diazotized 4-arninoacetanihde coupled to -cresol) which is still used today for the coloration of cellulose acetate and nylon fibers. 

Azo Dyes. The Colourindex classifications of dyes depend more on their historical eady use than on their stmctures, eg. Oil Orange is named Solvent Yellow 14, and a yellow for synthetic fibers is Disperse Yellow 23. 

Fig. 4. Carbocychc azo dyes. Disperse Yellow 3 [2832-40-8] (Cl 11855) (26) is used to dye polyester Reactive Orange 1 [6522-74-3] (Cl 17907) (27) is a cotton dye Direct Orange 26 [25188-23-2] (Cl 29150) (28) is a dye for paper Synacril Fast Red 2G [48222-26-0] (Cl 11085) (29) dyes acrylic fibers Acid...

Quinophthalones provide important dyes for the coloration of plastics (eg, Cl Solvent Yellow 33 (71), R = H [5662-03-3]) and for the coloration of polyester. For example. Cl Disperse Yellow 54 (71) R = OH, is the lea ding yellow dye for the transfer printing of polyester. 

The structures of a number of neutral and anionic polymethine dyes are illustrated in Figure 6.3. There are many types of neutral poly-methines, utilising a wide range of electron donor and acceptor groups. For example, C. I. Disperse Yellow 99 (114) and C. I. Disperse Blue 354... 

The synthesis of nitro dyes is relatively simple, a feature which accounts to a certain extent for their low cost. The synthesis, illustrated in Scheme 6.5 for compounds 140 and 141, generally involves a nucleophilic substitution reaction between an aromatic amine and a chloronitroaromatic compound. The synthesis of C. I. Disperse Yellow 14 (140) involves the reaction of aniline with l-chloro-2,4-dinitroaniline while compound 141 is prepared by reacting aniline (2 mol) with compound 144 (1 mol). 

Nitro dyes exhibit benzenoid-quinonoid tautomerism (1.25) and their colour is attributed mainly to the o-quinonoid form, since this can be stabilised by hydrogen bonding. The tautomeric o-nitrosonaphthols (1.26) readily form chelate complexes with metals. A few yellow nitro disperse dyes, including Cl Disperse Yellow 1 (1.25), and brown acid dyes remain of significance. The remaining nitro and nitroso colorants, such as (1.26) and its 1 3 iron (II) complex (1.27), are no longer of commercial interest. 

The resins used to make fluorescent pigments are usually toluenesulphonamide-melamine-formaldehyde matrices. The dyes used for this purpose include Cl Disperse Yellow 11, Rhodamine 6G (Cl Basic Red 1) and Rhodamine B (Cl Basic Violet 10). More details of the fluorescent dyes used have been given in a review by Christie [31]. 

Only a limited range of nitro, azo and anthraquinone disperse dyes exhibit adequate fastness to dry heat, light and weathering for application on polyester automotive fabrics. The structure of Cl Disperse Yellow 86 was modified to incorporate UV absorbers of the benzophenone, benzotriazole or oxalanilide types into the dye molecule. The derived dyes showed better fastness properties than the parent unsubstituted dye. Positioning of the photostabilising moiety within the dye molecule had little influence on the light fastness obtained, however. Built-in benzophenone residues were more effective than the other two types [177]. Nevertheless, several further monoazo and nitrodiphenylamine disperse dye... 

Two commercial disazo disperse dyes of relatively simple structure were selected for a recent study of photolytic mechanisms [180]. Both dyes were found to undergo photoisomerism in dimethyl phthalate solution and in films cast from a mixture of dye and cellulose acetate. Light-induced isomerisation did not occur in polyester film dyed with the two products, however. The prolonged irradiation of Cl Disperse Yellow 23 (3.161 X = Y = H) either in solution or in the polymer matrix yielded azobenzene and various monosubstituted azobenzenes. Under similar conditions the important derivative Orange 29 (3.161 X = N02, Y = OCH3) was degraded to a mixture of p-nitroaniline and partially reduced disubstituted azobenzenes. 

In order to facilitate satisfactory dye uptake, the molecular size of a disperse dye must be kept small monoazo structures are therefore exceptionally important, particularly in the coloration of polyester and cellulose triacetate. In the yellow shade area, molecular size generally poses no problem and the various available coupling components can all be used without making the molecule too large. A very simple example of the type of structure employed using a phenolic coupling component is Cl Disperse Yellow 3 (4-72). This dye is known to cause skin sensitisation when on nylon [85] and can also provoke an allergic reaction [86]. 

Heterocyclic coupling components are widely used in the disperse dye field for the production of yellow dyes. Numerous conventional dyes are based on simple pyrazolones, often combined with an o-nitroaniline diazo component, the o-nitro group being particularly favourable in ensuring good light fastness. Cl Disperse Yellow 8 (4-73), which uses a very simple pyrazolone coupling component, is an example. 

A very noticeable feature has been the use of a wider range of heterocyclic coupling components than in water-soluble azo dyes. An early example of this trend was Cl Disperse Yellow 5 (4.74), which used 4-hydroxy-1-methylcarbostyril as coupling component. It was in... 

Uncharged styryl (methine) disperse dyes were originally introduced to provide greenish yellow colours on cellulose acetate fibres. One such dye still in use is Cl Disperse Yellow 31 (6.226), which is made by condensing 4-(N-butyl-N-chloroethylamino)benzaldehyde with ethyl cyanoacetate. Suitable compounds for polyester usually contain the electron-accepting dicyanovinyl group, introduced with the aid of malononitrile. An increased molecular size leads to improved fastness to sublimation, as in the case of Cl Disperse Yellow 99 (6.227). A novel polymethine-type structure of great interest is present in Cl Disperse Blue 354 (6.228), which is claimed to be the most brilliant blue disperse dye currently available [85]. 

Quinophthalone (6.229) and its derivatives [86] also fall into the methine category, although they appear in the Colour Index under quinoline colouring matters. The parent compound was discovered in 1882 by Jacobsen, who condensed 2-methylquinoline (quinaldine) with phthalic anhydride. The product, quinoline yellow, is used as a solvent dye (Cl Solvent Yellow 33). The light fastness is improved by the presence of a hydroxy group in the quinoline ring system. Derivatives of this type provide greenish yellow disperse dyes for polyester. The moderate sublimation fastness of Cl Disperse Yellow 54 (6.230 R = H) is improved by the introduction of an adjacent bromine atom in Cl Disperse Yellow 64 (6.230 R = Br). 

Quinophthalones, made by the condensation of phthalic anhydride with quinaldine derivatives, are one snch gronp, exemplified by Cl Disperse Yellow 54 (2.17a) and Yellow 64 (2.17b) nsed for polyester, especially for transfer printing and also as solvent dyes. 

Direct Black 38 (see also Benzidine-based dyes) Direct Blue 6 (see also Benzidine-based dyes) Direct Brown 95 (see also Benzidine-based dyes) Disperse Blue 1 Disperse Yellow 3... 

The step 4 product (equivalent to 20 g solid polymer) was mixed with A -(2,4-dinitrophenyl)-l,4-phenylenediamine (Disperse Yellow 9 dye) (1 g) containing 20 ml water and smaller amounts of 2-pyrrolidone and ethylene glycol. The product was isolated containing at least a portion of the dye covalently bound to the latex particulates. 

Heterocyclic azo couplers have also featured prominently in disperse dye chemistry, especially in the production of yellows. Cl Disperse Yellow I (B-71MI11202) is in fact an azo dye prepared from benzenediazonium chloride and l-phenyl-3-methyl-5-pyrazolone, and pyrazolone couplers continue to appear in patents. However, the most important recent development has been the introduction of 2,6-dihydroxypyridine couplers in azo dyes such as (54). Although the couplers had been disclosed some time ago, their development by... 

There are few dyes in this class but two derivatives are among the most important yellow disperse dyes. The simplest example is Cl Disperse Yellow 54 (62), which is marketed by several companies, as is its brominated derivative Cl Disperse Yellow 64, which has slightly superior fastness properties. The simple molecule may be prepared (B-70MI11203) by condensation between chloroacetone and isatin, followed by fusion of the resulting 3-hydroxy-2-methylquinoline-4-carboxylic acid with phthalic anhydride. 

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