Abstract: A titanium oxide aerogel particle includes a metallic compound that has a metal atom and a hydrocarbon group, the metallic compound being bonded to a surface of the aerogel particle via an oxygen atom. The titanium oxide aerogel particle has a BET specific surface area of 120 m2/g to 1000 m2/g, and has absorption at wavelengths of 450 nm and 750 nm.

Abstract: A resin particle composition includes resin particles, inorganic particles surface-treated with oil, and silica particles having a compression aggregation degree of 60% to 95% and a particle compression ratio of 0.20 to 0.40.

Abstract: A silica composite particle includes a silica particle and a compound in which a metal atom selected from the group consisting of Ti, Al, Zr, V, and Mg bonds to an organic group through oxygen, the silica particle being surface-treated with the compound. A coverage of a surface of the silica composite particle with the metal atom is 0.01 at % or more and 30 at % or less. When a binding energy peak of O1s in an oxide of the metal atom is assumed to be MO1s, a binding energy peak of O1s in SiO2 is assumed to be SO1s, and a binding energy peak of O1s in the silica composite particle is assumed to be MSO1s, the binding energy peaks being detected by X-ray photoelectron spectroscopy, the formula 0.000452×X2?0.059117×X+SO1s<MSOs?(SO1s?MO1s)/100×X+SO1s is satisfied.

Abstract: A resin particle composition includes resin particles, polishing agent particles having an average circle-equivalent diameter of 0.1 ?m to 3.0 ?m, and silica particles having a compression aggregation degree of 60% to 95% and a particle compression ratio of 0.20 to 0.40.

Abstract: An electrostatic image developing toner contains: toner particles, first silica particles having an average equivalent circle diameter of 10 nm to 120 nm and second silica particles having a compressive agglomeration degree of 60% to 95%, a particle compression ratio of 0.20 to 0.40 and an average equivalent circle diameter being greater than the average equivalent circle diameter of the first silica particles.

Abstract: An electrostatic charge image developing toner includes toner particles, silica particles having an average particle diameter of 80 nm to 200 nm, lubricant particles N which has negatively chargeable property, and lubricant particles P which has positively chargeable property, wherein a content (s) of the silica particles, a content (n) of the lubricant particles N, and a content (p) of the lubricant particles P satisfy relationships of Expression (1): 0.002?p/s?0.2; and Expression (2): 0.02?n/s?0.5.

Abstract: A toner for electrostatic image development includes toner particles; and an external additive containing silica particles and polytetrafluorethylene particles, the silica particles having a compression-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.

Abstract: Provided are methods of preparing silica particles having two maximum values in number particle size distribution, wherein in the two maximum values, a particle size ratio (a maximum value of a small-size side/a maximum value of a large-size side) between a maximum value of a large-size side and a maximum value of a small-size side is from 0.02 to 0.3, and a number ratio (a number of silica particles having a maximum value of the small-size side/number of silica particles having a maximum value of the large-size side) is from 1 to 100, and particles within a range of 10% from the large-size side of the silica particles have an average circularity of from 0.65 to 0.90 and an average shrinkage ratio of from 10 to 50.

Abstract: An electrostatic charge image developing toner includes: toner particles; first silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%; and second silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%, wherein, when an average primary particle diameter of the first silica particles is set as Da (nm) and an average primary particle diameter of the second silica particles is set as Db (nm), relationships of the following Expressions (A1) to (A3) are satisfied: Expression (A1): 80?Da?120, Expression (A2): 120?Db?200, and Expression (A3): 10?Db?Da?120.

Abstract: An electrostatic charge image developing toner includes toner particles containing a binder resin, and an external additive including silica particles having a compression aggregation degree is from 60% to 95% and a particle compression ratio is from 0.20 to 0.40, and resin particles containing a polymer obtained by polymerizing a (meth)acrylic acid ester monomer.

Abstract: An electrostatic charge image developing toner includes toner particles and an external additive that includes silica particles having a compression aggregation degree of 60% to 95% and a particle compression ratio of 0.20 to 0.40 and fatty acid metal salt particles.

Abstract: An electrostatic charge image developing toner containing: toner particles; and silica particles having a compaction aggregation degree of from 60% to 95% and a particle compaction ratio of from 0.20 to 0.40, an electrostatic charge image developer containing the electrostatic charge image developing toner, and a toner cartridge that accommodates the electrostatic charge image developing toner and is detachable from an image forming apparatus.

Abstract: An electrostatic charge image developing toner includes kneaded and pulverized toner particles that contain a binder resin and a release agent, the release agent being partially exposed, and an external additive that contains silica particles having a compression aggregation degree of from 60% to 95% and a particle compression ratio of from 0.20 to 0.40.

Abstract: An electrostatic charge image developer includes an electrostatic charge image developing toner that includes toner particles, and an external additive which is added to the toner particles and which includes silica particles whose compression aggregation degree is from 60% to 95% and particle compression ratio is from 0.20 to 0.40, and a carrier for developing an electrostatic charge image that includes a core particle and a resin coated layer which covers a surface of the core particle and that has a surface roughness Ra (based on JIS-B0601) of 0.5 ?m or less and a circularity of 0.975 or more.

Abstract: 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.

Abstract: An electrostatic charge image developing toner includes toner particles, silica particles having an average particle diameter of 80 nm to 200 nm, lubricant particles N which has negatively chargeable property, and lubricant particles P which has positively chargeable property, wherein a content (s) of the silica particles, a content (n) of the lubricant particles N, and a content (p) of the lubricant particles P satisfy relationships of Expression (1): 0.002?p/s?0.2; and Expression (2): 0.02?n/s?0.5.

Abstract: An electrostatic charge image developing toner includes: toner particles; first silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%; and second silica particles having an average circularity of 0.9 to 1.0, a particle size distribution index of 1.05 to 1.25, and a compression aggregation degree of 60% to 95%, wherein, when an average primary particle diameter of the first silica particles is set as Da (nm) and an average primary particle diameter of the second silica particles is set as Db (nm), relationships of the following Expressions (A1) to (A3) are satisfied: Expression (A1): 80?Da?120, Expression (A2): 120?Db?200, and Expression (A3): 10?Db?Da?120.

Abstract: An image forming apparatus includes a developing unit that contains an electrostatic charge image developer and develops an electrostatic charge image formed on the surface of an image holding member as a toner image by using the developer, wherein the developer contains a carrier and an electrostatic charge image developing toner that includes a toner particle and an external additive, the toner particles have an average circularity of from 0.98 to 1.00 and a number-particle diameter distribution index (lower GSD) on a small diameter side of 1.22 or more and contain at least a vinyl resin, and the external additive contains silica particles having a compression aggregation degree of 60% to 95% and a particle compression ratio of 0.20 to 0.40.

Abstract: An electrostatic image developing toner contains: toner particles, first silica particles having an average equivalent circle diameter of 10 nm to 120 nm and second silica particles having a compressive agglomeration degree of 60% to 95%, a particle compression ratio of 0.20 to 0.40 and an average equivalent circle diameter being greater than the average equivalent circle diameter of the first silica particles.

Abstract: An electrostatic charge image developer includes an electrostatic charge image developing toner that includes toner particles, and an external additive which is added to the toner particles and which includes silica particles whose compression aggregation degree is from 60% to 95% and particle compression ratio is from 0.20 to 0.40, and a carrier for developing an electrostatic charge image that has a core including a magnetic member in a binder resin for a core and a coating layer which covers a surface of the core and which includes a resin for a coating layer and has a surface roughness Ra of from 0.25 ?m to 0.4 ?m.