Abstract: A toner including a toner particle, a composite particle present on a surface of the toner particle, and a spherical silica fine particle. The composite particle includes a fine particle A containing an organic silicon compound as a binder component, and a fine particle B which is an inorganic fine particle. The fine particle B is present on a surface of the composite particle in a state where a part of the fine particle B is embedded in a surface of the fine particle A. The composite particle and the silica fine particle each have a predetermined particle diameter, proportions of bifunctional to tetrafunctional silicon atoms in the fine particle A satisfy predetermined requirements, and an average value of embedding ratios of the fine particle B to the fine particle A in the composite particle is 30% or greater and 90% or less.

Abstract: A toner includes toner particles each containing a binder resin and a release agent, and composite particles each present on a surface of each toner particle. The release agent has a penetration of 4 or less at 25° C. The composite particles include fine particles A each containing an organosilicon compound having a siloxane bond, the organosilicon compound serving as a binder component, and fine particles B formed of inorganic fine particles. Each fine particle B is partially embedded at the surface of each fine particle A. In the fine particles A, the proportions of di- to tetra-functional silicon atoms satisfy predetermined requirements. The fine particles B have a number-average diameter of primary particles of 0.01 ?m or more and 0.06 ?m or less. In the composite particles, the average value of embedding ratios of the fine particles B to the fine particles A is 30% or more and 90% or less.

Abstract: A toner contains toner particles and an external additive on the surfaces of the toner particles. The external additive includes composite fine particles that include fine particles A containing an organosilicon compound with siloxane bonds as a binder component and fine particles B at least partially embedded in the surfaces of the fine particles A with an embedding rate of 30% to 90% on average, and fine particles C including titanium oxide or titanic acid compound fine particles and having a volume resistivity of 2.0×109 to 2.0×1013 ?·cm and a number average diameter of primary particles of 10 to 100 nm. The organosilicon compound contains bifunctional, trifunctional, and tetrafunctional silane monomers with specific relationships. The number average diameter X of primary particles of the composite fine particles and the number average diameter Y of primary particles of fine particles C satisfy 1.0?X/Y?10.0.

Abstract: A toner including a toner particle and a composite particle present on a surface of the toner particle. The composite particle includes a fine particle A containing, as a binder component, an organic silicon compound, and a fine particle B which is an inorganic fine particle. The fine particle B is present in a state where a part of the fine particle B is embedded in a surface of the fine particle A. Proportions of silicon atoms in bifunctional to tetrafunctional silane monomers of the fine particle A satisfy predetermined relationships. A primary particle of the fine particle B has a number average particle diameter of 0.01 ?m or greater and 0.06 ?m or less. An average value of embedding ratios of the fine particle B to the fine particle A in the composite particle is 30% or greater and 90% or less.

Abstract: An external additive for toner comprising: a fine particle A containing, as a binder component, an organosilicon compound having a siloxane bond; and a fine particle B that is present on a surface of the fine particle A in a state of being at least partially embedded in the surface of the fine particle A, wherein the external additive for toner (i) has a number-average particle diameter of a primary particle of 0.03 ?m or more and 0.30 ?m or less, and (ii) has a Young's modulus of 10 GPa or more and 30 GPa or less, wherein content ratios, on a number basis, of the following unit (a), unit (b), and unit (c) in the fine particle A based on all silicon atoms present in the fine particle A satisfy the following expressions (1) and (2). (a)+(b)+(c)?0.80??(1) (b)+(c)?0.

Abstract: The external additive for toner includes an external additive particle containing: a fine particle A; and a plurality of fine particles B that are each present so as to partially protrude from a surface of the fine particle A, wherein the fine particle A (i) is a particle of an organosilicon compound having a siloxane bond, (ii) has a number-average particle diameter of 0.03 ?m or more and 0.30 ?m or less, and (iii) has an average circularity of 0.90 or more, wherein, when the number-average particle diameter of the fine particle A is represented by DA, and a number-average particle diameter of the plurality of fine particles B is represented by DB, DB/DA is 0.10 or more and 0.63 or less.

Abstract: The external additive for toner includes an external additive particle containing: a base particle A; and a plurality of convex forming particles B each configured to form a convex portion on a surface of the base particle A. The base particle A and the convex forming particles B are particles each containing a silicon compound having a siloxane bond, and a chemical bond is formed between the base particle A and each of the convex forming particles B. The base particle A and the convex forming particles B each have a total content of the following unit (a), unit (b), and unit (c) of 80 mass % or more and 100 mass % or less: where R1 and R2 each represent an alkyl group having 1 or more and 6 or less carbon atoms.

Abstract: The fine particle is a silicon-containing fine particle, wherein the number-average diameter of the fine particle is 0.05 ?m to 0.30 ?m; the proportion of the silicon atom with reference to the total of the elements is at least 20% according to fluorescent x-ray measurement of the fine particle; and, with respect to the silicon atom proportions measured in analysis by x-ray photoelectron spectroscopy while irradiating with Ar-K? radiation and etching, the proportions of silicon atoms having prescribed structures vary at prescribed depths.

Abstract: A two component developer comprising a toner and a specific magnetic carrier, wherein a toner particle in the toner comprises a surface layer comprising an organosilicon polymer, electrical conductivity of a filtrate obtained by filtering off the toner using a specific procedure is 1.0 to 2.5 ?S/cm, and when dC (atomic %) denotes carbon concentration, dO (atomic %) denotes oxygen concentration and dSi (atomic %) denotes silicon concentration, as measured by ESCA, at the surface of the toner particle, then the dC, the dO and the dSi satisfy the following formulae: 40.0?dC/(dC+dO+dSi)×100?60.0 10.0?dSi/(dC+dO+dSi)×100?26.0.

Abstract: The present disclosure provides a fine particle containing silicon, wherein the fine particle has a number-average particle diameter of a primary particle of 0.05 ?m or more and 0.20 ?m or less, wherein the fine particle contains a silicon atom at a ratio of 20% or more with respect to all elements in measurement by X-ray fluorescence.