Abstract
Latent pigment technologies of hydrogen-bonded pigments(pyrrolopyrroles and quinacridones)have been reviewed and their potential problems when applied to imaging and related areas are discussed. The present technology aims at solubilizing hydrogen-bonded pigments by blocking NH…O intermolecular hydrogen bonds through t-butoxycarbonylation of the NH group. Regeneration is then carried out by heat treatment to give “pigment nano particles” characterized by high transparency. However,the crystalline phase of the regenerated pigment is found to be,not always,the same phase as that of the parent pigment. As a result, the color of regenerated pigments is slightly different and the light-and heat-fastness is inferior to that of the parent pigments. In addition,CO2 evolved during the regeneration process is found to impair the transparency of pigmented layers.
