Solvents for the outlet restriction for pigmented inks and for inks based on dyes

摘要

Two classes of solvents, organic esters and diols and triols, help to reduce bleed between black (pigment-containing) inks and color (water-soluble dye-based) inks when used in formulating inks that contain self-dispersed pigments. The solvents help self-dispersed pigments to agglomerate by producing successful mutual collisions when the electrostatic potential is reduced with positively charged color inks. It appears that these solvents may be changing the dielectric constant of the ink, thereby reducing the repulsion potential of the pigment particles themselves.