US Patent 7186491 Negatively charged coated electrographic toner particles

Negatively charged coated toner particles are provided that comprise a plurality of polymeric binder particles that are substantially free of negatively charged pigment and a coating material comprising at least one negatively charged pigment coated on the outside surface of the polymeric binder particles. In one embodiment, a majority of the specific charge of the toner particles is contributed from the negatively charged pigment. In another embodiment, the toner particles are substantially free of additional charge director or charge control additive. Electrographic toner compositions comprising these particles are also provided.