A positively chargeable toner includes a plurality of toner particles each including a core and a shell layer disposed over a surface of the core. The core contains a polyester resin. The shell layer covers at least 40% and no greater than 80% of an area of the surface of the core, (4) is greater than 0 V. (6) is less than 0 V. A relationship represented by |(3)(4)|>|(6)(7)| is satisfied. (3), (4), (6), and (7) represent zeta potentials of the positively chargeable toner with the toner particles having no external additive. (3), (4), (6), and (7) are respectively measured in an aqueous medium at pH 3, pH 4, pH 6, and pH 7.

An electrostatic charge image developing toner includes a plurality of toner particles. Each of the plurality of toner particles includes a toner core and a shell layer covering the toner core. The shell layer contains a thermosetting resin. A content ratio of a toner component insoluble in tetrahydrofuran is at least 90 mass % relative to mass of the toner. Melt viscosity of the toner at 75 C. is at least 1.010.sup.4 Pa.Math.s and no greater than 1.010.sup.5 Pa.Math.s. The thermosetting resin is preferably a melamine resin or a urea resin. The toner core preferably contains a binder resin, and the binder resin has a softening point (Tm) of at least 85 C. and no greater than 95 C.

A two-component developer includes a toner and a carrier. The toner is a positively chargeable toner that is positively charged by friction with the carrier. The toner includes a plurality of toner particles each including a toner mother particle and a plurality of first resin particles. An anionic surfactant having higher negative chargeability than the first resin particles is present on surfaces of the first resin particles. The carrier includes a plurality of carrier particles each including a carrier mother particle and a plurality of second resin particles. A cationic surfactant having higher positive chargeability than the second resin particles is present on surfaces of the second resin particles. The first resin particles have a zeta potential lower than 0 mV at a pH of 5. The second resin particles have a zeta potential higher than 0 mV at a pH of 5.

The object of the present invention is to provide a toner for development of electrostatic images (hereinafter referred to as toner) which, while preventing dust during fixation, secures improved hot offset resistance and is excellent in providing good image quality. The invention relates to the toner that comprises a binder resin, a colorant and a wax, wherein the wax has, while in a state of being contained in the toner, a melting point of from 55 C. to 90 C., and the value Dt of the toner satisfies a specific formula.

A positively chargeable toner includes a plurality of toner particles each including a core and a shell layer disposed over a surface of the core. The core contains a polyester resin. The shell layer covers at least 40% and no greater than 80% of an area of the surface of the core, (4) is greater than 0 V. (6) is less than 0 V. A relationship represented by |(3)(4)|>|(6)(7)| is satisfied. (3), (4), (6), and (7) represent zeta potentials of the positively chargeable toner with the toner particles having no external additive. (3), (4), (6), and (7) are respectively measured in an aqueous medium at pH 3, pH 4, pH 6, and pH 7.

The present disclosure relates to a chemically prepared toner composition including a toner particle having a core including a first polymer binder, an styrene acrylate encapsulated wax latex, a pigment, and a shell formed around the core including a second polymer binder and method to make the same. The disclosed method of preparing the toner results in a change in the distribution of the components of the toner particle wherein the lower molecular weight resins, the pigment, and the wax are located away from the surface of the toner particle and the pigment is clinging to the edge of the wax domain.

The present disclosure relates to a chemically prepared toner composition including a toner particle having a core including a first polymer binder, an styrene acrylate encapsulated wax latex, a pigment, and a shell formed around the core including a second polymer binder and method to make the same. The disclosed method of preparing the toner results in a change in the distribution of the components of the toner particle wherein the lower molecular weight resins, the pigment, and the wax are located away from the surface of the toner particle and the pigment is clinging to the edge of the wax domain.

A toner, including: a colorant; and a binder resin, wherein a spreadability of the toner under a non-pressurized condition is 1.20 to 2.50, wherein a common logarithm of a storage modulus at 100 C. (G) of the toner is 4.0 [log Pa] to 5.0 [log Pa], and wherein a ratio of a loss modulus at 100 C. (G) to the storage modulus at 100 C. (G) of the toner (G/G=tan ) is 1.1 to 2.2.

Toner for developing electrostatic images including core particles that contain a colorant, a binder resin, and a wax, and exhibiting low-temperature fixability, high-temperature anti-offset property, image durability, flowability, high-temperature preservability, and low particle emission rate.

An image forming apparatus includes a plurality of developing member to form toner images, respectively, a transfer member to sequentially transfer the toner images onto a recording material and to overlappingly form toner on the recording material. A fixing member presses and heats the recording material on which the toner images are transferred and fixes the toner images on the recording material. A storage medium stores a usage history of the developing member. A controller controls a fixing temperature of the fixing member. The controller determines the fixing temperature based on a difference between the usage history of one of the developing member stored in the storage medium and the usage history of another of the developing member.