The toner contains a toner particle having a core-shell structure including: a core containing a binder resin and a colorant; and a shell, wherein the toner contains a crystalline material, and the shell contains an amorphous thermoplastic resin; and when SP values of the crystalline material and the amorphous thermoplastic resin, which are calculated by the Fedors method, are defined as SPc (J/cm.sup.3).sup.0.5 and SPa (J/cm.sup.3).sup.0.5, respectively, the SPc and the SPa (J/cm.sup.3) satisfy a particular relationship, and when the toner is observed by SEM after the toner has been subjected to ruthenium staining that treats the toner in an atmosphere of RuO.sub.4 gas having 500 Pa for 15 minutes, a ratio S2 (%) of an area occupied by the crystalline material per area of the toner satisfies a particular relationship.

The toner contains a toner particle having a core-shell structure including: a core containing a binder resin and a colorant; and a shell, wherein the toner contains a crystalline material, and the shell contains an amorphous thermoplastic resin; and when SP values of the crystalline material and the amorphous thermoplastic resin, which are calculated by the Fedors method, are defined as SPc (J/cm.sup.3).sup.0.5 and SPa (J/cm.sup.3).sup.0.5, respectively, the SPc and the SPa (J/cm.sup.3) satisfy a particular relationship, and when the toner is observed by SEM after the toner has been subjected to ruthenium staining that treats the toner in an atmosphere of RuO.sub.4 gas having 500 Pa for 15 minutes, a ratio S2 (%) of an area occupied by the crystalline material per area of the toner satisfies a particular relationship.

A toner contains toner particles that include a binding resin, a crystalline resin, an ester wax and a dispersant. The binding resin includes an amorphous polyester resin, and the dispersant includes an acrylic copolymer resin or a hybrid resin of the amorphous polyester resin and a styrene resin. When an endothermic peak temperature that is derived from the ester wax in a temperature rise is represented by T1, an exothermic peak temperature that is derived from the ester wax in cooling is represented by T2, a peak temperature of the crystalline resin is represented by Tc and the endothermic peak temperature, the exothermic peak temperature and the peak temperature are measured with a differential scanning calorimeter, T2<Tc<T1 is satisfied, and T1 is greater than 65° C. and less than 85° C.

A toner comprising a toner particle, wherein the toner has G1 of from 5.0×10.sup.−13 to 1.0×10.sup.−10, and a ratio G2/G1 of G2 to G1 is from 0.10 to 0.60, when a conductivity of the toner measured at a frequency of 0.01 Hz under a pressure of 1,000 kPa is designated by G1 in S/m, and a conductivity of the toner measured at a frequency of 0.01 Hz under a pressure of 100 kPa is designated by G2 in S/m.

A toner includes toner particles. The toner particles each include a toner mother particle containing a binder resin and an external additive attached to a surface of the toner mother particle. The external additive includes fluorine-containing particles. The fluorine-containing particles include a fluorine atom at least in surface layers thereof. The amount of the fluorine-containing particles is at least 0.10 parts by mass and no greater than 0.50 parts by mass relative to 100 parts by mass of the toner mother particles. When ultrasonication is performed, a residual amount ratio of remaining fluorine-containing particles is at least 0% by mass and no greater than 20% by mass relative to the amount of the fluorine-containing particles attached to the toner mother particles before the ultrasonication.

The present disclosure provides a toner excellent in low-temperature fixability and excellent in durability under harsh environments of high-temperature and high-humidity, and a method for producing the toner. The toner can contain: a toner particle containing a binder resin, wax, and an inorganic oxide particle; and an external additive, wherein the inorganic oxide particle contains, as a main component, an oxide of at least one element selected from the group consisting of Si, Mg, Al, Ti, and Sr; when a thin piece obtained by cutting the toner with a microtome is observed with a transmission electron microscope (TEM), the major axis A of the inorganic oxide particle is 0.10 to 3.00 μm; and in a wettability test of the toner with respect to a methanol/water mixed solvent, a methanol concentration at a transmittance of light having a wavelength of 780 nm of 50% is 5.0 to 30.0% by volume.

A toner set capable of eliminating unclearness in a color boundary of an image in which a color image and a black image are printed side by side. The toner set includes at least: a black toner for forming a black image; and a color toner for forming a color toner image. The black toner is a toner comprising a black toner particle containing a black colorant formed of carbon black or iron oxide, a binder resin, and a releasing agent, and an external additive. The color toner is a toner comprising a color toner particle containing a color organic colorant, a binder resin, and a releasing agent. A ratio in surface roughness (Sa) between the toners is 1.30≤ surface roughness Sa(C) of color toner/surface roughness Sa(Bk) of black toner ≤4.00. The surface roughness Sa(C) of the color toner is 10 nm to 30 nm.

A toner comprising a toner particle and an external additive, wherein the external additive comprises a silica particle and a hydrotalcite particle containing fluorine which is present in cross sections of the hydrotalcite particle, wherein, when a content of the hydrotalcite particle containing the fluorine and a content of the silica particle to 100 parts by mass of the toner particle are defined as Wh and Ws respectively, Wh and Ws are in specific ranges, and a sum of areas of peaks which are present in a range of −140 to 100 ppm of a chemical shift of the silica particle obtained by a solid-state .sup.29Si-NMR DD/MAS method is defined as S, the area of the peak of a D unit and Q unit are defined as D and Q respectively, the Wh, the Ws, S, the D, and the Q satisfy a specific relationship.

A toner containing a toner particle that contains a binder resin and a crystalline material, wherein, in measurement of powder dynamic viscoelasticity of the toner, when T(A)° C. is taken as an onset temperature for a storage elastic modulus E′ obtained at a ramp rate of 20° C./min, EA′(100) Pa is taken as a storage elastic modulus at 100° C. obtained at a ramp rate of 20° C./min, and T(B)° C. is taken as an onset temperature for a storage elastic modulus E′ obtained at a ramp rate of 5° C./min, T(A)−T(B) is 3.0° C. or less, T(A) is from 45.0° C. to 70.0° C., and EA′(100) is from 4.0×10.sup.9 Pa to 6.5×10.sup.9 Pa.

An electrostatic image developing toner includes an amorphous polyester resin, a crystalline polyester resin, and C.I. Pigment Red 57:1, wherein a Net intensity N.sub.Mg of an Mg element, the Net intensity N.sub.Mg of being determined by X-ray fluorescence analysis, is 0.10 kcps or more and 0.40 kcps or less.