| abstract |
Soluble tetrakisazo dyes of formula: (in which X1, X2, X3 and X4 are H or SO3M; Y1, Y2, Y3 and Y4 are OH and NH2 and M is H or a colourless cation), are used for dyeing of natural or regenerated cellulose, esp. paper, and leather in deep black shades. Gives good solubility in water, good substantivity and high strength, esp. on paper, giving uniform black shades. |