The application of electronic and vibrational spectroscopic techniques to the identification of quinacridone pigments in vehicle paint systems

Abstract

Six red quinacridone pigments have been studied and characterised by electronic, infra–red and Raman spectroscopic techniques. The pigment colour can be correlated to the crystal structure rather than in terms of intramolecular substituent effects. Study of the pigments in paint formulations shows the complementary nature of these techniques; in particular, Raman spectra are very useful for pigment identification while infra–red spectroscopy is useful for characterising resins.