A Review of the Classes, Structures, and Methods of Analysis of Synthetic Organic Pigments

Abstract

Synthetic organic pigments have been manufactured since the latter part of the 19th century. Thousands of these pigments have been introduced for a variety of applications, including paints, printing inks, and the coloration of plastics and textiles. Many synthetic organic pigments are azos, containing the azo linkage (−N=N−). Newer classes of synthetic organic pigments have been introduced to overcome limitations of poor lightfastness or solvent fastness(bleed resistance) exhibited by some of the earlier pigments. This paper reviews the major classes of synthetic organic pigments in terms of their structures, physical properties, and specific applications. These classes include arylide yellows, diarylide yellows, β-naphthols, naphthols, benzimidazolones, disazo condensation pigments, pyrazolones, nickel azo yellow, phthalocyanines, quinacridones, perylenes and perinones, isoindolinone and isoindoline pigments, triarylcarbonium pigments, diketopyrrolo-pyrrole pigments, thioindigoids, and several miscellaneous pigments. Current methods of analysis of these pigments are discussed.