A positively chargeable toner includes toner particles. The toner particles each include a toner mother particle containing a binder resin, and an external additive adhering to a surface of the toner mother particle. The external additive includes specific silica particles, specific titania particles, and specific crosslinked resin particles. The specific silica particles each include a silica base, and a first surface treatment layer present on a surface of the silica base. The first surface treatment layer has an alkyl group having a carbon number of at least 8 and no greater than 16, and an amino group. The specific titania particles each include a titania base, and a second surface treatment layer present on a surface of the titania base. The second surface treatment layer has an alkyl group having a carbon number of at least 3 and no greater than 8.

The toner for electrostatic charge development includes a toner particle including: a toner base particle containing a binder resin and a release agent; and an external additive containing titanium dioxide. The number fraction of the toner particle containing the titanium dioxide is 0.1% or more and 2.0% or less.

The toner for electrostatic charge development includes a toner particle including: a toner base particle containing a binder resin and a release agent; and an external additive containing titanium dioxide. The number fraction of the toner particle containing the titanium dioxide is 0.1% or more and 2.0% or less.

The purpose of the present invention is to provide a charge control agent for polymerized toners and particularly for color toners, which has a large charge amount and environmentally stable charging characteristics. Since a charge control agent including a pyrazolone derivative represented by a general formula (1) or a salt of the derivative as an active ingredient has a large charge amount and excellent environmental stability of charging, it has an excellent charge-imparting effect for use in polymerized toners and particularly in color toners: ##STR00001##
in the formula, R.sub.1, R.sub.2, and R.sub.3 each independently represent a substituted or unsubstituted C1 to C20 linear or branched alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group.

The purpose of the present invention is to provide a charge control agent for polymerized toners and particularly for color toners, which has a large charge amount and environmentally stable charging characteristics. Since a charge control agent including a pyrazolone derivative represented by a general formula (1) or a salt of the derivative as an active ingredient has a large charge amount and excellent environmental stability of charging, it has an excellent charge-imparting effect for use in polymerized toners and particularly in color toners: ##STR00001##
in the formula, R.sub.1, R.sub.2, and R.sub.3 each independently represent a substituted or unsubstituted C1 to C20 linear or branched alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group.

Provided is toner which has good low-temperature fixability, shelf stability and hot offset resistance, and which suppresses a decrease in glossiness of an image. The toner comprising colored resin particles containing a binder resin, a colorant, a softening agent and a charge control agent, and an external additive, wherein a glass transition temperature (Tg) specified from a temperature dependence curve of a loss tangent (tan ?) obtained by dynamic viscoelastic measurement of the toner, is 50? C. or more and less than 90? C.; the loss tangent (tan ?) at the glass transition temperature (Tg) is 1.70 or less; in a temperature range of 90? C. or more and 160? C. or less, a lowest temperature (Ta) with a loss tangent of 1.50 is more than 95? C. and less than 145? C.; and a storage elastic modulus (G) at the lowest temperature (Ta) is less than 56000 Pa.

A silica functionalized with a siloxane is of the general formula (I), [SiO.sub.4/2].sub.a [R.sup.1SiO.sub.3/2].sub.b [R.sup.3R.sup.1SiO.sub.2/2].sub.c [R.sup.1.sub.3SiO.sub.1/2].sub.d [O.sub.1/2R.sup.2].sub.e (I). The indices a, b, c, d, e each independently have integer values a from 0 to 100, b from 0 to 100, c from 0 to 50, d from 3 to 200, e from 0 to 50, with the proviso that the sum of a, b and c is at least 1 and for more than 50% of the siloxanes in the mixture the sum of a, b and c is ?4.

An electrostatic image developer includes: a toner A to which silica particles (A) containing an elemental nitrogen-containing compound containing elemental molybdenum are externally added; and a carrier B including a core material and a coating resin layer that covers the core material and contains inorganic particles. In the silica particles (A), the ratio N.sub.Mo/N.sub.Si of a Net intensity N.sub.Mo of elemental molybdenum that is measured by X-ray fluorescence analysis to a Net intensity N.sub.Si of elemental silicon that is measured by the X-ray fluorescence analysis is from 0.035 to 0.45 inclusive.

An electrostatic charge image developer includes: a toner A incorporating toner particles and silica particles (A) as an external additive, the toner particles containing a binder resin and resin particles, and the silica particles (A) containing a nitrogen-containing compound containing the element molybdenum; and a carrier B incorporating a core and a coating resin layer, the coating resin layer covering the core and containing inorganic particles, and the ratio N.sub.Mo/N.sub.Si is 0.035 or greater and 0.45 or less, where N.sub.Mo and N.sub.Si are measured net intensities for the element molybdenum and the element silicon, respectively, in the silica particles (A) in x-ray fluorescence analysis.

Provided is a toner comprising a toner particle comprising a binder resin and a. silica fine particle, wherein a total content of a polyvalent metal elements in the toner particle is 0.10 to 2.50 ?mol/g, a number-average particle diameter of a primary particle of the silica fine particle is 40 to 500 nm, and in the DD/MAS measurement of solid .sup.29Si-NMR of the silica fine particle, peak PD1 corresponding to a silicon atom represented by Si.sup.a in a structure represented by formula (1) and peak PD2 corresponding to a silicon atom represented by Si.sup.b in a structure represented by formula (2) are observed, and when an area of the peak PD1 is defined as SD1 and an area of the peak PD2 is defined as SD2, SD1 and SD2 satisfy: 1.2?(SD1+SD2)/SD1?10.0.