Disperse dye stable to dyeing, and its use for dyeing synthetic and semi-synthetic fibre materials
AssigneeCiba-Geigy Corporation
InventorsStefan Koller, Peter Eugster, Suresh C. Agarwal
Life of this patent
Estimating the term…
Abstract
It is possible by heating at temperatures of between 65.degree. and 200.degree. C. to convert the known .alpha.-modification of the azo dye of the formula ##STR1## which is unstable to dyeing, completely into the .beta.-modification which is stable to dyeing. The modification transformation can be performed either with the solid dye or with a suspension thereof in an organic, preferably aromatic, solvent. The novel dye modification is stable in dispersion under dyeing conditions, and shows no tendency to flocculate.
Claims7
A modification of the azo dye of the formula ##STR3## which modification is stable to dyeing and which is characterised by the X-ray diffraction pattern (CuK-.alpha. radiation) with the characteristic reflexes shown in FIG. 1, and by the d values of the interplanar spacings, calculated from the diffraction pattern:
- d [A]:
- 11.9 (s), 7.2 (vs), 3.61 (vs) and 3.39 (vs).
Dependencies are inferred from the claim text.