Cage complexes for charge direction in liquid toners

Abstract

Disclosed are negatively and positively charged liquid toners for electrophotography (EP). The charge on the toner particle is obtained by adding cage complex molecules, or clathrates/cryptates, to the liquid toner. The cage complex molecules have at least three chains, with at least one electron pair donor atom in each chain, for a total of at least three electron pair donor atoms (EPD's). Or, the cage complex molecules have at least two connected rings, with a total of at least three EPD's in the molecule including at least one EPD in each of the connected rings. For negatively charged toner particles, the clathrates/cryptates are distributed in the liquid dispersion, and metal cations are weakly associated with anionic functional groups on the toner particle. This way, the clathrates/cryptates in dispersion complex selectively with the cations and strip them from the toner particle, leaving a negatively charged particle. For positively charged toner particles, the clathrates/cryptates are covalently bound to the toner particles, and weakly associated metal cations are added with corresponding anionic species to the liquid dispersion. This way, the clathrates/cryptates on the toner particles complex selectively with the cations, and strip them from the dispersion, creating a positively charged particle.