A toner includes toner particles. The toner particles each include a toner mother particle and an external additive attached to the surface of the toner mother particle. The external additive includes specific external additive particles. The specific external additive particles have a number average primary particle diameter of at least 30 nm and no greater than 305 nm. The specific external additive particles include antimony-doped tin oxide particles or indium tin oxide particles. A ratio (M.sub.Sb/(M.sub.Sn+M.sub.Sb)) of a mass (M.sub.Sb) of an antimony atom to a total of the mass (M.sub.Sb) of the antimony atom and a mass (M.sub.Sn) of a tin atom in the antimony-doped tin oxide particles is at least 4% by mass and no greater than 46% by mass.

A pale-color toner includes toner particles. The toner particles each include a toner mother particle and an external additive attached to a surface of the toner mother particle. The external additive includes specific external additive particles. The specific external additive particles have a number average primary particle diameter of at least 30 nm and no greater than 305 nm. The specific external additive particles include antimony-doped tin oxide particles. A ratio (M.sub.Sb/(M.sub.Sn+M.sub.Sb)) of a mass (M.sub.Sb) of an antimony atom to a total of the mass (M.sub.Sb) of the antimony atom and a mass (M.sub.Sn) of a tin atom in the antimony-doped tin oxide particles is at least 4% by mass and no greater than 31% by mass.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that the net intensity of x-ray fluorescence from the Mg element in the toner is 0.10 kcps or more and 1.20 kcps or less; and at least one external additive including particles of a metal salt of a fatty acid.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that in an x-ray fluorescence analysis of the toner, the net intensity of the peak for the Mg element is 0.10 kcps or more and 1.20 kcps or less; and at least one external additive including particles of at least one compound represented by formula (1),

MTiO.sub.3  (1)

where M represents at least one selected from the group consisting of Ca, Sr, and Ba.

An electrostatic image developing toner includes an amorphous polyester resin and a crystalline polyester resin, wherein a Net intensity N.sub.Na of a Na element and a Net intensity N.sub.Cl of a Cl element, the Net intensities N.sub.Na and N.sub.Cl being determined by X-ray fluorescence analysis, satisfy 2.5≤N.sub.Cl/N.sub.Na≤260.0.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin; the Mg element in an amount such that the net intensity of x-ray fluorescence from the Mg element in the toner is 0.10 kcps or more and 1.20 kcps or less; and external additives including particles of at least one compound represented by formula (1) and particles of a metal salt of a fatty acid,

MTiO.sub.3   (1)

where M represents at least one selected from the group consisting of Ca, Sr, and Ba.

According to various embodiments, there is provided a toner composition and a developer. The toner composition includes toner particles including a resin, a colorant; and a surface additive applied to a surface of the toner particles. The surface additive includes polyaniline doped strontium titanate (SrTiO.sub.3).

Provided is a toner characterized by including at least a negatively-charged toner master particle, and an external additive externally added onto the surface of the toner master particle, wherein the external additive includes a fine powder and a small particle size silica having an average first particle diameter smaller than that of the fine powder, and wherein the fine powder is a composition containing at least aluminum hydroxide and silica and has a surface treated with silane.

According to one embodiment, a toner which has excellent low-temperature fixability, and also has excellent heat resistance even when the toner is reused, sufficiently maintains an electric charge amount, and hardly decreases an image density is provided. Also provided are a toner cartridge and an image forming apparatus, in each of which the toner is stored.

A toner according to an embodiment contains toner base particles and an external additive. The external additive contains silica particles A, B, and C having a particle diameter of 10 to 14 nm, 40 to 70 nm, and 90 to 150 nm, respectively.

A toner comprising a toner particle and a silica particle on a surface of the toner particle, wherein an area formed by a polyester resin and an area formed by a styrene-acrylic resin are present on the surface of the toner particle; the silica particle has the number-average particle diameter of 15 to 60 nm; the silica particle has the average pore diameter of 5.0 to 20.0 nm; and the silica particle has the total pore volume of 0.20 to 1.50 cm.sup.3/g.