A toner comprising: a toner particle containing a binder resin and a colorant, and an inorganic fine particle A and B present on the surface of the toner particle, wherein the inorganic fine particle A is a silica fine particle having a number-average particle diameter (D1) of primary particles in a specific range, the inorganic fine particle B has a number-average particle diameter (D1) of primary particles in a specific range, and is at least one fine particle selected from a group consisting of a silica fine particle, a titanium oxide fine particle, and an alumina fine particle, A total fixing ratio of the inorganic fine particle A and B is 75% or more, and an inter-particle force Fp(A) and an inter-particle force Fp(B) are within specific numerical ranges and satisfy a specific relationship.

Provided is a toner having good endurance stability and good low-temperature fixability in high-speed printing, and having good resistance to the adhesion of printed paper. The toner is a magnetic toner having, on the surface of toner particle containing a binder resin and an ester compound as a releasing agent, inorganic fine particle “a” and organic-inorganic composite fine particle having a volumetric specific heat of from 2,900 kJ/(m.sup.3.Math.° C.) to 4,200 kJ/(m.sup.3.Math.° C.), in which a coverage A of the surface of the toner particle with the inorganic fine particle “a” is 45.0% or more and 70.0% or less.

Provided are cobalt ferrite particles having a micrometer-order average particle diameter and similar particle diameters. When a cobalt ferrite precursor is treated at a high temperature and a high pressure, an oxidation reaction is caused in the presence of a complexing agent, thereby obtaining intended cobalt ferrite magnetic particles.

A toner includes toner particles. The toner particles each include a toner mother particle containing a binder resin and a releasing agent. The binder resin includes a polyester resin and a vinyl resin. The vinyl resin includes a specific vinyl unit. A relationship 1.30≤Wabs/Wps≤2.00 is satisfied where Wabs represents an absolute molecular weight at a largest peak on an absolute molecular weight distribution curve of the binder resin as measured by size-exclusion chromatography using a multi-angle laser light scattering detector, and Wps represents a relative molecular weight at a largest peak on a relative molecular weight distribution curve of the binder resin in terms of polystyrene as measured by size-exclusion chromatography using a differential refractive index detector.

A toner includes toner particles. The toner particles each include a toner mother particle containing a binder resin and a releasing agent. The binder resin includes a polyester resin and a vinyl resin. The vinyl resin includes a specific vinyl unit. A relationship 1.30≤Wabs/Wps≤2.00 is satisfied where Wabs represents an absolute molecular weight at a largest peak on an absolute molecular weight distribution curve of the binder resin as measured by size-exclusion chromatography using a multi-angle laser light scattering detector, and Wps represents a relative molecular weight at a largest peak on a relative molecular weight distribution curve of the binder resin in terms of polystyrene as measured by size-exclusion chromatography using a differential refractive index detector.

Provided are magnetic particles (cobalt ferrite) having a micrometer-order average particle diameter and similar particle diameters. A cobalt ferrite precursor is heated in the presence of a sulfite, thereby obtaining intended cobalt ferrite magnetic particles.

The toner is a toner including a toner particle comprising a binder resin, a crystalline material, wherein, when a ratio of an area occupied by the crystalline material in a toner surface observed with a scanning electron microscope after ruthenium-staining the toner under a specific condition (1) is represented by S.sub.1 (%), a ratio of an area occupied by the crystalline material in the toner surface observed with the scanning electron microscope after ruthenium-staining the toner under a condition (2) is represented by S.sub.2 (%), and a dispersion diameter of a plurality of domains formed of the crystalline material on the toner surface observed with the scanning electron microscope after the ruthenium-staining the toner under the condition (2) is represented by R.sub.2 (nm), the following expressions (1), (2), and (3) are satisfied.

[00001]$\begin{array}{cc}0.0\le S_1\le 0.5& \left(1\right)\\ 1.0\le S_2\le 10.0& \left(2\right)\\ 20\le R_2\le 200& \left(3\right)\end{array}$

There is provided a toner containing: a toner particle containing a binder resin, a releasing agent, and a colorant; and an iron oxide particle present on a surface of the toner particle, in which the iron oxide particle has a surface containing a compound having a specific structure.

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.