An electrostatically charged image developing toner includes a particulate toner matrix containing an external additive on the surface of the particulate toner matrix. The external additive includes silica particles A and silica particles B. The silica particles A have a number average primary-particle diameter in the range of 40 to 100 nm and an average circularity in the range of 0.50 to 0.90, and are surface-modified with silicone oil. The silica particles B have a number average primary-particle diameter of 25 nm or more and smaller than the number average primary-particle diameter of the silica particles A, and are surface-modified with alkylalkoxysilane having a specific structure or silazane.

There is provided a toner set including a yellow toner, a cyan toner and a magenta toner, the toners each comprising an external additive and colored resin particles comprising a binder resin, a colorant and a charge control agent. An absolute value of an average of q/d for any of the yellow, cyan and magenta toners is expressed by charge amount q (fC) and particle diameter d (m). It is obtained by measurement using an electric field detachment-type charge amount distribution measurement device. It is in a range of 2.0 to 6.5 fC/10 m, and a standard deviation (SD) of q/d is 13 fC/10 m or less. A difference between average values of q/d for any two of the yellow, cyan and magenta toners is 2.0 fC/10 m or less. A difference (SD) between standard deviations of q/d for the two toners is 5.0 fC/10 m or less.

There is provided a toner set including a yellow toner, a cyan toner and a magenta toner, the toners each comprising an external additive and colored resin particles comprising a binder resin, a colorant and a charge control agent. An absolute value of an average of q/d for any of the yellow, cyan and magenta toners is expressed by charge amount q (fC) and particle diameter d (m). It is obtained by measurement using an electric field detachment-type charge amount distribution measurement device. It is in a range of 2.0 to 6.5 fC/10 m, and a standard deviation (SD) of q/d is 13 fC/10 m or less. A difference between average values of q/d for any two of the yellow, cyan and magenta toners is 2.0 fC/10 m or less. A difference (SD) between standard deviations of q/d for the two toners is 5.0 fC/10 m or less.

To provide an efficient method for producing a negatively chargeable toner in which a carbon black (as a colorant) is well dispersed and which has high chargeability, has excellent transfer efficiency, prevent a white spot and provides an image with sufficient image density. Disclosed is a method for producing a negatively chargeable toner, the method including: a suspension step of obtaining a suspension in which droplets of a polymerizable monomer composition containing at least a polymerizable monomer, a carbon black, a softening agent and a charge control agent, which is a specific, sulfonic acid group-containing copolymer, are dispersed, by suspending the polymerizable monomer composition in an aqueous dispersion medium containing a dispersion stabilizer, and a step of obtaining colored resin particles by suspension polymerization using the suspension in the presence of a polymerization initiator.

To provide an efficient method for producing a negatively chargeable toner in which a carbon black (as a colorant) is well dispersed and which has high chargeability, has excellent transfer efficiency, prevent a white spot and provides an image with sufficient image density. Disclosed is a method for producing a negatively chargeable toner, the method including: a suspension step of obtaining a suspension in which droplets of a polymerizable monomer composition containing at least a polymerizable monomer, a carbon black, a softening agent and a charge control agent, which is a specific, sulfonic acid group-containing copolymer, are dispersed, by suspending the polymerizable monomer composition in an aqueous dispersion medium containing a dispersion stabilizer, and a step of obtaining colored resin particles by suspension polymerization using the suspension in the presence of a polymerization initiator.

A toner for electrostatic image development includes toner particles; and an external additive containing silica particles and polytetrafluorethylene particles, the silica particles having a compression-aggregation degree of 60% or more and 95% or less and a particle compression ratio of 0.20 or more and 0.40 or less.

A toner for developing an electrostatic latent image includes: toner base particles containing a hybrid crystalline polyester resin having a crystalline polyester polymerized segment and an amorphous polymerized segment chemically bonded to each other and an amorphous resin; and an external additive including fatty acid metal salt particles, wherein a volume median diameter of the fatty acid metal salt particles is from 3.0 to 5.0 m.

An external additive for a toner is described. An example external additive comprises tin oxide, aluminum oxide, and a silica-polymer composite.

The toner includes an external additive adhering to the surface of a toner particle. The external additive contains fine powder in which the surface of a core derived by addition of silica to strontium titanate is hydrophobized with a silane compound, and silica.

A production method of a toner having a toner particle that contains a binder resin and an external additive that is externally added to the toner particle, wherein the production method has a toner particle dispersion step of obtaining a toner particle dispersion by dispersing the toner particle and an inorganic dispersant in an aqueous medium; and an external addition step of externally adding the external additive to the toner particle through addition of the external additive to the toner particle dispersion.