A resin particle contains a binder resin containing a polyester resin containing polyethylene terephthalate and a diol component of propylene glycol and a release agent containing an ester wax.

Mixtures are disclosed containing a plurality of charged pigment particles and a one or more charge control agents. At least one of the charge control agents has a chemical structure that includes a cationic head group, such as an ammonium cation or an iminium compound, and a non-ionic, polar functional group, other than an acyclic secondary amide group. The mixtures are useful as dispersions for forming electrophoretic media that may be incorporated into electrophoretic displays. Alternatively, the dispersions may be useful for forming electrophotographic toners and dispersions for other printing applications.

A toner for electrostatic charge image development has toner particles containing a binder resin including 90 mass % or more of an amorphous resin. In a differential molecular weight distribution curve of tetrahydrofuran soluble matter as measured by gel permeation chromatography, the toner has a maximum peak Ma in a molecular weight range of 2,500 or more and 8,000 or less, a minimum value Mm in a molecular weight range of more than 8,000 and less than 280,000, and a maximum peak Mb in a molecular weight range of 280,000 or more and 900,000 or less. When the area of the differential molecular weight distribution curve in a range of a molecular weight of 100 or more and less than the minimum value Mm is defined as A, and the area of the differential molecular weight distribution curve in a range of the minimum value Mm or more and a molecular weight of 10,000,000 or less is defined as B, the area ratio A/B is 5.5 or more and 10 or less.

An image-forming apparatus with strontium titanate used as an external additive for a toner is provided, wherein the image-forming apparatus is an electrophotographic apparatus that has the durability of an electrophotographic photosensitive member maintained and is superior in transferability even under low-temperature/low-humidity conditions. An electrophotographic apparatus is provided, the electrophotographic apparatus including: an electrophotographic photosensitive member having a surface layer containing a resin X as a binder resin; a charging unit; an exposing unit; a developing unit; and a transferring unit, wherein the toner contains strontium titanate as an external additive, and the resin X contains a structural unit represented by Formula (1).

A toner contains a crystalline polyester resin, a non-crystalline polyester resin A having a melting temperature ranging between 99 C. to 108 C., a non-crystalline polyester resin B having a melting temperature ranging between 140 C. to 150 C., an ester wax, and a colorant. A ratio of the crystalline polyester resin is 5% mass to 15% mass to a total T of the crystalline polyester resin, the non-crystalline polyester resin A, the non-crystalline polyester resin B, the ester wax, and the colorant. A ratio of the non-crystalline polyester resin A to the total T is between 50% mass to 60% mass. A ratio of the non-crystalline polyester resin B to the total T is between 20% mass to 30% mass.

A toner including: a toner particle containing a binder resin and a colorant; and a fine particle on a surface of the toner particle, wherein the fine particle is a solid and substantially hemispherical shape, and has a substantially flat surface and a curved surface, and wherein a number-average value of a longest diameter w of the substantially flat surface is 10 to 400 nm. An external additive for a toner that is a solid and substantially hemispherical shape, and has a substantially flat surface and a curved surface, wherein a number-average value of a longest diameter w of the substantially flat surface is 10 to 400 nm. A fine particle that is a solid and substantially hemispherical shape, and has a substantially flat surface and a curved surface, wherein a number-average value of a longest diameter w of the substantially flat surface is 10 to 400 nm.

An electrostatic latent image developing toner includes a plurality of toner particles each including a core and a shell layer. The shell layer is disposed over a surface of the core. The shell layer is substantially formed by a resin. The shell layer has a surface including a plurality of spot regions and a sheet region that is more hydrophobic than the spot regions. The spot regions each are more chargeable than the sheet region.

A developer having low-temperature fixability and storage stability, and capable of prolonging the service life is provided. A toner includes a coloring agent, an amorphous polyester, a crystal line polyester, ester wax containing multiple ester compounds, each having a carbon number selected from 32 to 54, and hydrophobic silica having an average primary particle diameter of 8 to 35 nm. When the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, the sum (g) of the content (e) of the ester compound having a carbon number of (Cn+2) and the content (f) of the ester compound having a carbon number of (Cn+4) satisfies the following formula: 0.065g/a0.200.

A magnetic one-component developer includes magnetic toner particles containing a binder resin and a magnetic powder, and silica particles having a compression and aggregation degree of 60% or more and 95% or less and a particle compression ratio of 0.20 or more and 0.40 or less.

A toner set for electrostatic image development includes a cyan toner, a magenta toner, and a yellow toner, wherein the Vicat softening temperatures of the toners are respectively in the range of from about 30 C. to about 60 C., and among the toners, the difference between the Vicat softening temperature of the toner having the highest Vicat softening temperature and the Vicat softening temperature of the toner having the lowest Vicat softening temperature is from about 1 C. to about 5 C.