A toner contains a binder resin, a colorant, and an external additive that contains a titanium oxide fine particle hydrophobized with a silane coupling agent containing n-octyltriethoxy silane, wherein the titanium oxide fine particle contains rutile titanium oxide having a particle diameter of 10 to 35 nm.

An electrostatic image developing toner includes a toner particle including a binder resin and a release agent. When a cross section of the toner particle is observed, the toner particle satisfies a condition (A1) below: Condition (A1): the toner particle includes one or more domains of the release agent, the one or more domains having a diameter equal to 8% or more and 30% or less of the maximum diameter of the toner particle, the one or more domains having a geometric center at a depth of R/2 or less below the surface of the toner particle, where R represents the distance between the geometric center of the toner particle and the surface of the toner particle, the one or more domains being entirely included in an inside portion of the toner particle which extends below a depth of 50 nm from the surface of the toner particle.

A method of producing resin particles includes a first step of adding a monomer-containing emulsified liquid that contains a polymerizable monomer and an aqueous medium to an aqueous mother medium to polymerize the polymerizable monomer; and a second step of adding an aqueous medium for cooling to the aqueous mother medium after completion of the addition of the monomer-containing emulsified liquid to the aqueous mother medium.

An electrostatic charge image developing toner has toner particles and silica particles that are added to an exterior of the toner particles, contain a nitrogen element-containing compound, have a ratio C/D of 0.10 or more and 0.75 or less where C represents an integral value of signals observed in a range of chemical shift of 50 ppm or more and 75 ppm or less in a .sup.29Si solid-state nuclear magnetic resonance (NMR) spectrum obtained by a cross-polarization/magic angle spinning (CP/MAS) method and D represents an integral value of signals observed in a range of chemical shift of 90 ppm or more and 120 ppm or less in the same spectrum, have an extraction amount X of the nitrogen element-containing compound by a mixed solution of ammonia/methanol of 0.1% by mass or more, and satisfy Expression: Y/X<0.3 where X represents an extraction amount of the nitrogen element-containing compound by a mixed solution of ammonia/methanol and Y represents an extraction amount of the nitrogen element-containing compound by water.

Mixtures are disclosed containing a plurality of charged pigment particles and 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.

Used is an image forming apparatus including an image carrier and a developer carrier, in which a toner particle of the developer includes convex portions on a surface of a toner base particle, in a horizontal image converted from a cross-sectional image of the toner particle with STEM, when a convex maximum length D and a convex height H are equal to each other, and convex portions having a convex height H of 20 nm or more are defined as convex portions Y, a number-based average of convex widths W in the convex portions Y is at least 40 nm and not more than 200 nm, when a width of the horizontal image is defined as a circumferential length L, and a total of the convex widths W of the convex portions Y is indicated by W, W/L is 0.5 or more.

A fine particle of a silicon polymer, wherein the fine particle has pores; the total pore volume of the fine particle is 0.35 to 1.00 cm.sup.3/g; a number-average primary particle diameter of the fine particle is 0.05 to 0.30 m; the silicon polymer has a siloxane bond and an SiR.sup.1 bond; R.sup.1 represents an alkyl group having 1 to 6 carbon atoms; and designating, with reference to a chart obtained by .sup.29Si-NMR measurement of the fine particle, A as a total peak area corresponding to the silicon polymer, and B as a peak area corresponding to SiR.sup.1, A and B satisfy a following formula (1):
10.0B/A10045.0(1).

Toner contains toner particles. The toner particles contain a binder resin and a positively chargeable charge control agent. The most abundant resin in the binder resin in terms of mass is styrene-acrylic resin with an acid number of 7.0 mgKOH/g or more. The charge attenuation constant of the toner particles is 0.0200 or more in an environment of a temperature of 32.5 C. and a relative humidity of 80%.

A toner comprising: a toner particle comprising a binder resin and boric acid; and an external additive A having a primary particle major diameter of 80 to 200 nm, wherein in ATR-IR analysis of the toner particle in an ATR method using germanium as an ATR crystal, a peak corresponding to boric acid is detected, the average value of a shape factor SF-1 of the external additive A is 105 to 250, and the average value of a shape factor SF-2 of the external additive A is 102 to 250.

An external additive for a toner comprising a silica particle surface-treated with a polyhydric acid metal salt particle, wherein the polyhydric acid metal salt particle is particle of a salt of a polyhydric acid and a titanium compound, and a toner comprising a toner particle, and an external additive for a toner on the surface of the toner particle, wherein the external additive for a toner is the above external additive for a toner.