Toner particles in a developer include first strontium titanate particles attached to the surface of each toner mother particle thereof. The first strontium titanate particles have a content ratio of 0.3 to 0.9 parts by mass to 100.0 parts by mass of the toner mother particles. In the developer, coat layers of carrier mother particles of first carrier particles contain barium titanate particles and a coating resin including silicone resin. The barium titanate particles have a content ratio of 2 to 47 parts by mass to 100 parts by mass of the coating resin. Second strontium titanate particles attached to the surfaces of the carrier mother particles have a diameter of 15 to 85 nm.

A magnetic toner includes toner particles. The toner particles each include a toner core and a shell layer covering a surface of the toner core. The toner cores contain a polyester resin and a magnetic powder. The magnetic powder includes specific magnetic particles. The shell layers contain a specific vinyl resin.

An electrostatic charge image developing toner includes: a toner particle and a strontium titanate particle that is externally added to the toner particle, in which an average primary particle diameter of the strontium titanate particle that is present on a surface of the toner particle is 30 nm or more and 100 nm or less, and average primary particle circularity is 0.82 or more and 0.94 or less, and in which circularity that becomes 84% of accumulation of the primary particle is greater than 0.92.

A toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.010.sup.4 N, of from 200 MPa to 1,100 MPa.

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.

A toner including a toner particle having a core-shell structure that has a core formed from a resin 1 and a shell formed from a resin 2 on the surface of the core, wherein the resin 1 contains more than 50 mass % of an ester group-containing olefin-based copolymer, the ester group-containing olefin-based copolymer has a monomer unit Y1 represented by formula (1) below, and at least one type of monomer unit Y2 selected from the group consisting of monomer units represented by formula (2) and formula (3) below, the ester group concentration in the ester group-containing olefin-based copolymer is from 2 mass % to 18 mass %, and the resin 2 is an amorphous resin having a Tg value of from 50 C. to 70 C. ##STR00001##

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 toner comprising a binder resin and a colorant, wherein the toner has a Martens hardness, as measured at a maximum load condition of 2.010.sup.4 N, of from 200 MPa to 1,100 MPa.

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 toner comprising: a toner particle containing a binder resin and a colorant; and an external additive, wherein the external additive is a composite particle having an organic substance and an organosilicon polymer coating layer on the surface of the organic substance, and when a curve for the variation (dE/dT) in the storage elastic modulus E of the toner with respect to temperature T [ C.] is obtained on the basis of a curve of the temperature Tthe storage elastic modulus E [Pa] of the toner, as determined by powder dynamic viscoelasticity measurements of the toner, the relative minimum value on the lowest temperature side between the onset temperature and 90 C. is 1.3510.sup.8 or less.