Relations Between the Structure and Properties of Azo Disperse Dyes

Experiments with 60 azo disperse dyes have confirmed that, to be suitable for dyeing polyester fibre, the dye must have a solubility parameter very close to that of the fibre. However, this criterion alone is insufficient to ensure good substantivity. Good correlations have been found between the following properties: (i) molar attraction constant and molar volume (ii) molar attraction constant and sublimation temperature (iii) molar volume and barriness (iv) partition coefficient and migration, and (v) partition coefficient and unlevelness of dyed packages