Abstract: A toner for developing electrostatic images which is obtained by melt mixing at least a binder resin and a coloring agent, forming a powder material by pulverizing the obtained mixture after cooling and removing rough particles and fine particles from the formed powder material by classification, wherein inorganic fine particles having a roundness of 1.00 to 1.30, an average of the diameter of primary particles of 0.05 to 0.45 ?m and a ratio of a standard deviation to the average of the diameter of primary particles of 0.25 or smaller are added as an external additive, and a process for producing a toner for developing electrostatic images which comprises melt mixing at least a binder resin and a coloring agent, forming a powder material by pulverizing the obtained mixture after cooling, rounding the powder material by a heat treatment and adding the above inorganic fine particles to the rounded powder material.

Abstract: A toner for developing electrostatic images which is obtained by melt mixing at least a binder resin and a coloring agent, forming a powder material by pulverizing the obtained mixture after cooling and removing rough particles and fine particles from the formed powder material by classification, wherein inorganic fine particles having a roundness of 1.00 to 1.30, an average of the diameter of primary particles of 0.05 to 0.45 ?m and a ratio of a standard deviation to the average of the diameter of primary particles of 0.25 or smaller are added as an external additive, and a process for producing a toner for developing electrostatic images which comprises melt mixing at least a binder resin and a coloring agent, forming a powder material by pulverizing the obtained mixture after cooling, rounding the powder material by a heat treatment and adding the above inorganic fine particles to the rounded powder material.

Abstract: A non-magnetic mono-component toner which comprises a toner and barium titanate having a surface area of 0.5 to 5 m2/g as measured in accordance with a BET method in an amount of 0.2 to 5 parts by weight per 100 parts by weight of the toner.

Abstract: A non-magnetic mono-component toner includes a toner and barium titanate having a surface area of 0.5 to 3 m2/g as measured in accordance with a BET method in an amount of 0.2 to 5 parts by weight per 100 parts by weight of the toner. The toner can form images of a high density and suppress fog in the background simultaneously.