Pigment Surface Modification via Nucleophilic Treating Agents

Abstract

Employing chemical reactions that modify particle surfaces to impart desirable physical-chemical properties has enjoyed enormous commercial success. One example is the surface modification of pigment particles for inkjet inks. As the applications of pigmented inkjet inks continue to grow, there is a need to modify a wider range of pigment types. The existence of many classes of pigments with various functional groups has presented challenges for the development of a general chemistry that can react with any pigments. As a result, inventing new ways of modifying pigment surfaces is important. In this report, treating agents having nucleophilic groups were used to modify Pigment Green 36 (PG36). When PG36 was modified with nucleophiles bearing water-soluble groups, pigment particles became water dispersible. Dispersions showed excellent colloidal stability and the color properties of PG36 have not been affected. This paper will also discuss the versatility of this chemistry for introducing a wide range of functional groups onto pigment particles that possess leaving groups.