US Patent 7144671 Adjuvants for negatively charged toners

Negative liquid electrographic toner compositions are provided comprising a liquid carrier having a Kauri-Butanol number less than about 30 mL and a plurality of negatively charged toner particles dispersed in the liquid carrier. The toner particles comprise a polymeric binder comprising at least one amphipathic graft copolymer comprising one or more S material portions and one or more D material portions. The toner composition additionally comprises a charge control adjuvant that is an acid or a base. These compositions have surprising bulk conductivity and charge per mass properties, particularly as the toner particles are depleted from the toner composition during printing operations.