An electrostatic charge image developer contains a carrier including a core and, on the core, a silicone resin-containing layer serving as a lower layer, and an acrylic resin-containing layer serving as an upper layer, or a carrier including a silicone resin-containing core and an acrylic resin-containing layer on the silicone resin-containing core; strontium titanate particles having an average primary particle size of 20 nm or more and 100 nm or less; and a toner. The percentage of a silicone resin exposed on a surface of the carrier is 0.5 area % or more and 20 area % or less.

Provided is a toner containing a toner particle including a binder resin, a wax, and a colorant. The softening point of the toner is at least 80 C. and not more than 140 C. The average circularity of the toner is at least 0.940. The integrated value of stress in the toner at 150 C. which is measured by using a tackiness tester is at least 78 g.Math.m/sec.

A decolorizable toner allows for easy distinguishing between a sheet which can be reused and a sheet which is hardly able to be reused from each other. The decolorizable toner includes a color developable compound, a color developing agent, a decolorizing agent, a magnetic material, and a binder resin. The color developable compound is a precursor compound of a dye. The color developing agent is an electron accepting compound which donates a proton to the color developable compound. The decolorizing agent is a compound which inhibits a coloring reaction between the color developable compound and the color developing agent.

A decolorizable toner allows for easy distinguishing between a sheet which can be reused and a sheet which is hardly able to be reused from each other. The decolorizable toner includes a color developable compound, a color developing agent, a decolorizing agent, a magnetic material, and a binder resin. The color developable compound is a precursor compound of a dye. The color developing agent is an electron accepting compound which donates a proton to the color developable compound. The decolorizing agent is a compound which inhibits a coloring reaction between the color developable compound and the color developing agent.

A toner having a toner particle including a binder resin and a wax, wherein the wax includes a specific diester compound; a proportion As of an area occupied by the wax in a region from a surface of the toner particle to 0.5 m is 15.0% or less; wax domains are observed in the cross section of the toner particle, and an average number of the domains per cross section of one toner particle is from 10 to 2000; when a mass concentration of a polyvalent metal element in the toner particle determined by fluorescent X-ray analysis is denoted by Mi (ppm), Mi is from 3.5 ppm to 1100 ppm; and when a mass concentration of a polyvalent metal element in the toner particle determined by X-ray photoelectron spectroscopy is denoted by Ms (ppm),

Mi>Ms.

A positively chargeable 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 toner mother particle includes a polyester resin having an acid value of at least 10.0 mgKOH/g, a compound having a quaternary ammonium cation group, and strontium titanate particles. The external additive includes no strontium titanate particles.

A decolorizable toner allows for easy distinguishing between a sheet which can be reused and a sheet which is hardly able to be reused from each other. The decolorizable toner includes a color developable compound, a color developing agent, a decolorizing agent, a magnetic material, and a binder resin. The color developable compound is a precursor compound of a dye. The color developing agent is an electron accepting compound which donates a proton to the color developable compound. The decolorizing agent is a compound which inhibits a coloring reaction between the color developable compound and the color developing agent.

A magnetic toner comprising a magnetic toner particle including a binder resin, a magnetic body and a crystalline polyester, wherein a storage elastic modulus E(40) [Pa] at 40 C. and a storage elastic modulus E(85) [Pa] at 85 C., which are obtained in a powder dynamic viscoelasticity measurement of the magnetic toner, satisfy the following formulas (1) to (3).

E(40)6.010.sup.9 (1)

E(85)5.510.sup.9 (2)

[E(40)E(85)]100/E(40) (3)

A magnetic toner comprising a magnetic toner particle including a binder resin, a magnetic body and a crystalline polyester, wherein the dielectric loss tangent at 100 kHz is 1.010.sup.2 or more, a variation coefficient CV3 of an occupied area ratio of the magnetic body when a cross section of the magnetic toner particle is divided by a square grid having a side of 0.8 m in cross-sectional observation of the magnetic toner particle using a transmission electron microscope TEM is from 30.0% to 80.0%, and where a storage elastic modulus of the magnetic toner at 40 C. is taken as E(40) [Pa] and a storage elastic modulus of the magnetic toner at 85 C. is taken as E(85) [Pa], the following formulas (1) and (2) are satisfied:

E(85)5.510.sup.9 (1)

[E(40)E(85)]100/E(40)30 (2)

A magnetic carrier comprising a magnetic carrier core and a resin coating layer formed on the surface of the magnetic carrier core, wherein the resin coating layer includes a polymer having a structure represented by the following formula (1), and a content ratio of the structure represented by the formula (1) is from 5% by mass to 95% by mass based on a resin component of the resin coating layer,

##STR00001## wherein, R.sup.1 is H or CH.sub.3, and X is a structure represented by the following formula (2):

(C.sub.mH.sub.2m)R.sup.2(C.sub.nH.sub.2n)OH (2) wherein, R.sup.2 is a hydrocarbon group being a cyclic structure having 4 to 8 carbon atoms, and m and n are integers of 0 to 4.