A magnetic toner is provided, which has a magnetic toner particle containing a binder resin, a wax, and a magnetic body, wherein, when Dn is a number-average particle diameter of the toner, CV1 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn 0.500 to +0.500, and CV2 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn 1.500 to 0.500, a relationship CV2/CV11.00 is satisfied; an average brightness of the toner in the range of Dn 0.500 to +0.500 is 30.0 to 60.0; and when, in a cross section of the toner observed using a transmission electron microscope, which is divided with a square grid having a side of 0.8 m, coefficient of variation CV3 of an occupied area percentage for the magnetic body is 40.0 to 80.0%.

A magnetic core material for electrophotographic developer, satisfying a value of Expression (1): a+b10+c+d+e+f, being from 200 to 1,400, when an amount of fluorine ion is denoted by a (ppm), an amount of chlorine ion is denoted by b (ppm), an amount of bromide ion is denoted by c (ppm), an amount of nitrite ion is denoted by d (ppm), an amount of nitrate ion is denoted by e (ppm), and an amount of sulfate ion is denoted by f (ppm), which are measured by combustion ion chromatography; and having a pore volume of from 30 to 100 mm.sup.3/g.

Provided is a magnetic toner having a toner particle containing a binder resin and a magnetic body, wherein the binder resin contains a polymer A having a first monomer unit and a second monomer unit, the first polymerizable monomer is at least one selected from the group consisting of the (meth)acrylic acid esters having C.sub.18-36 alkyl groups, a content of the first monomer unit and a content of the second monomer unit based on the total moles of all monomer units in the polymer A are respectively 5.0 to 60.0 mol % and 20.0 to 95.0 mol %, and assuming that an SP value of the first monomer unit and the second monomer unit are taken as SP.sub.11 (J/cm.sup.3).sup.0.5 and SP.sub.21(J/cm.sup.3).sup.0.5, respectively, 3.00(SP.sub.21SP.sub.11)25.00 is satisfied, and an oil absorption of the magnetic body is 5 to 40 ml/100 g.

Provided are a magnetic core material for electrophotographic developer and a carrier for electrophotographic developer, which are excellent in charge characteristics and strength and with which a satisfactory image free from defects can be obtained, and a developer containing the carrier.

A magnetic core material for electrophotographic developer, having a sulfur component content of from 50 to 700 ppm in terms of a sulfate ion and a BET specific surface area of from 0.06 to 0.25 m.sup.2/g.

A magnetic chemical toner comprising toner particles with high circularity (i.e., above 0.970) is described. The high circularity of the toner particles can maximize transfer efficiency and prevent toner waste during printing. The toner particles can comprise a polyester resin-based core. If desired, the toner particles can comprise a surface coating to modulate toner properties. Also described is a method of preparing the magnetic toner and a method of using the toner to print an image.

An electrostatic latent image developing toner includes toner particles each including a toner mother particle and an external additive. The toner mother particle includes a composite core and a shell layer. The composite core is a composite of a toner core, organic particles, and polyhedral magnetic particles. The organic particles each contain a releasing agent and adhere to a surface of the toner core. The magnetic particles include magnetic particles adhering to the surface of the toner core and magnetic particles adhering to surfaces of the organic particles. An amount of the magnetic particles is 0.5 parts by mass to 2.0 parts by mass relative to 100 parts by mass of the toner cores. In a cross-sectional image of each toner particle, an area of protruding portions of the magnetic particles, which protrude from the shell layer, accounts for 10% to 75% of an overall area of the magnetic particles.

A magnetic toner is provided, which has a magnetic toner particle containing a binder resin, a wax, and a magnetic body, wherein, when Dn is a number-average particle diameter of the toner, CV1 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn0.500 to +0.500, and CV2 is coefficient of variation of a brightness variance value of the toner in a particle diameter range of Dn1.500 to 0.500, a relationship CV2/CV1 1.00 is satisfied; an average brightness of the toner in the range of Dn0.500 to +0.500 is 30.0 to 60.0; and when, in a cross section of the toner observed using a transmission electron microscope, which is divided with a square grid having a side of 0.8 m, coefficient of variation CV3 of an occupied area percentage for the magnetic body is 40.0 to 80.0%.

An electrostatic latent image developing toner includes toner particles each including a toner mother particle and an external additive. The toner mother particle includes a composite core and a shell layer. The composite core is a composite of a toner core, organic particles, and polyhedral magnetic particles. The organic particles each contain a releasing agent and adhere to a surface of the toner core. The magnetic particles include magnetic particles adhering to the surface of the toner core and magnetic particles adhering to surfaces of the organic particles. An amount of the magnetic particles is 0.5 parts by mass to 2.0 parts by mass relative to 100 parts by mass of the toner cores. In a cross-sectional image of each toner particle, an area of protruding portions of the magnetic particles, which protrude from the shell layer, accounts for 10% to 75% of an overall area of the magnetic particles.

A plurality of toner particles each include a toner core, a shell layer covering a surface of the toner core, and a plurality of magnetic particles penetrating the shell layer. Each of the magnetic particles has an embedded portion and a protrusion portion. The embedded portions are embedded in the surface of the toner core. The protrusion portions are located further outward than the embedded portions in a radial direction of the toner particle and protrude outward from a surface of the shell layer in the radial direction of the toner particle. An average Heywood diameter X of the magnetic particles, a shell layer thickness Y, and an average value Z of protrusion heights of the respective magnetic particles satisfy relation (1) and relation (2) shown below.
0<Z(X/2)(1)
10 nmY50 nm(2)

Provided is a toner having a toner particle that contains a binder resin and a magnetic particle, wherein the magnetic particle satisfies the following stipulations (i) to (iii): (i) the magnetic particle has a prescribed shape and has a protruded portion on a plane portion thereof, (ii) the magnetic particle has a core particle that contains magnetite and has a coating layer, and (iii) the coating layer contains an iron-containing oxide and at least one of a silicon-containing oxide and an aluminum-containing oxide. In a molecular weight distribution measured on the tetrahydrofuran-soluble matter of the toner, the ratio (Mw/Mn) of a weight-average molecular weight to a number-average molecular weight is at least 10.0.