Patent ID: 7252916
Filing Date: 2007-08-07
Classification: G03G

Abstract:
1. An electro-photographic developing agent comprising: a binder resin; a coloring agent; a charge control agent; and an external additive comprising Ag particulates, wherein a first particle diameter of the Ag particulates is 10 to 500 nm, and wherein one of a)-e): a) the external additive further comprises at least one type of silica particles, wherein the at least one type of silica particles comprises at least a first silica particle and at least a second silica particle, wherein a first range of a diameter of the at least first silica particle is approximately 30 to 200 nm, and wherein a second, non-overlapping range of a diameter of the at least second silica particle is approximately 5 to 20 nm, b) the external additive further comprises at least one type of titanium oxide particle, wherein the at least one type of titanium oxide particle comprises at least a first titanium oxide particle and at least a second titanium oxide particle, wherein a first range of a diameter of the at least first titanium oxide particle is approximately 30 to 200 nm, and wherein a second, non-overlapping range of a diameter of the at least second titanium oxide particle is approximately 5 to 20 nm, c) the external additive further comprises at least one type of silicon carbide particles, wherein the at least one type of silicon carbide particles comprises at least a first silicon carbide particle and at least a second silicon carbide particle, wherein a first range of a diameter of the at least first silicon carbide particle is approximately 30 to 200 nm, and a second, non-overlapping range of a diameter of the at least second silicon carbide particle is approximately 5 to 20 nm, d) the external additive further comprises at least one type of alumina particles, wherein the at least one type of alumina particles comprises at least a first alumina particle and at least a second alumina particle, wherein a first range of a diameter of the at least first alumina particle is approximately 30 to 200 nm, and a second, non-overlapping range of a diameter of the at least second alumina particle is approximately 5 to 20 nm, or e) the external additive further comprises at least one type of polymer beads, wherein the at least one type of polymer beads comprises at least a first polymer bead and at least a second polymer bead, wherein a first range of a diameter of the at least first polymer bead is approximately 30 to 200 nm, and a second, non-overlapping range of the diameter of the at least second polymer bead is approximately 5 to 20 nm.