Colour and constitution relationships in organic pigments:Part 6 Azonaphtharylamide Pigments

摘要

Colour and constitution relationships within a series of naphtholazo pigments have been established.The spectral properties of the pigments in solution correlate reasonably well with the results of optimised PPP-MO calculations,and the colouristic properties of the pigments in the solid and solution states show generally similar trends.Structure/property relationships,in terms of solvent resistance,lightfastness and thermal stability,have been established for the series of pigments in printing ink and industrial paint applications.X-ray powder diffraction studies demonstrate that the aqueous heat treatment used in the synthesis of the pigments provides enhanced crystallinity which generally leads in turn to improved colouristic and technical performance.