Abstract: An electrophotographic dry toner comprising toner particles having externally added thereto fine particles of an inorganic compound having been surface treated with an amphoteric surface active agent. The toner is excellent in fluidity, anti-caking properties, charging properties, and environmental stability and provides excellent images free from defects such as black spots.

Abstract: A developer for developing an electrostatic latent image, said developer comprising (i) a toner containing at least a binder resin and a colorant, and (ii) substantially spherical silica fine particles having a bulk density of not less than 300 g/l; a process for producing the developer; and a process for forming a toner image using the developer. The developer exhibits satisfactory fluidity and satisfactory cleanability while retaining environmental stability and durability. The developer causes no toner filming on the surface of a photoreceptor, the surface of a carrier, or the surface of a charge-imparting member.

Abstract: An electrophotographic dry toner comprising a binder resin and a colorant, having externally added thereto an inorganic compound, preferably spherical silica particles, having been surface treated with at least one treating agent selected from the group consisting of a treating agent selected from a polyethylene, a fatty acid metal salt, and a solid alcohol containing from 20 to 60 carbon atoms. The toner is prepared by treating the inorganic compound with a dispersion or a solution of the treating agent in a solvent and adding the thus surface-treated inorganic compound to a toner. The toner exhibits satisfactory fluidity, satisfactory cleanability, excellent environmental stability, and excellent durability and causes no toner filming phenomenon on a photoreceptor, a carrier used in a two-component developer system, or a charging part used in a one-component developer system.

Abstract: A dry toner for developing an electrostatic latent image comprising toner particles and fine particles of a lubricant coated with an inorganic compound fine powder and an image formation method using the same. The toner is excellent in fluidity, cleaning properties, stability with environmental changes, and durability.

Abstract: A positively chargeable electrophotographic toner is disclosed, which is prepared by adding to toner particles silica fine particles having been surface treated with a homo-or copolymer comprising, as a monomer component, a dialkylaminoalkyl acrylate or a dialkylaminoalkyl methacrylate in the form of a quaternary ammonium salt. The toner has improved fluidity and improved anti-caking properties while exhibiting satisfactory charging properties and environmental stability and causing no image defects.

Abstract: A positively chargeable electrophotographic toner excellent in powder fluidity, circumstance dependency and durability is disclosed. The toner comprises a toner particle and a silica fine particle the surface of which is treated with a substantially water-insoluble or sparingly water-soluble quaternary ammonium salt compound.