Cationic Charge in the Coupling Component

Amino groups, amidine residues, trialkylammonium, and cyclic ammonium groups can serve as carriers of the cationic charge in the coupling components. 

Polyamines as Coupling Components. Chrysoidines are obtained by coupling dia-zonium salts of aniline, toluidines, or mixtures thereof to polyamine coupling components such as 1,3-phenylenediamine, 2,4- or 2,6- toluylenediamine, or mixtures of these diamines. These dyes confer muted yellow to orange shades to paper, leather, and polyacrylonitrile fibers. When they are mixed with malachite green and fuchsin, medium-fast black shades are obtained on polyacrylonitriles. A mixture of chrysoidine with Crystal Violet or Victoria Pure Blue is used to adjust the color of nigrosine hectograph inks [1]. 

Chrysoidine dye salts of dodecylbenzenesulfonic acid are soluble in glycols and glycol ethers and are used in the production of inks, printing inks, and varnishes [2], 

Vesuvin and Bismarck Brown products are obtained when rn -phenylenedia-mine, 2,4- and 2,6-diaminotoluene, or mixtures thereof are treated with nitrite in acidic solution, or when a mixture of the amines and nitrite is acidified. The final products consist of mixtures of monoazo, disazo, and polyazo dyes, with the dis-azo species probably predominating in commercial products. The dye is salted out immediately after its formation, and thereby the formation of polyazo dyes is prevented. 

Liquid Vesuvin dye solutions can be obtained by diazotization and coupling of aromatic diamines [3] or, if desired, also in mixture with aromatic monoamines [4] in carboxylic acid solutions. 

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