Abstract: A silica particle includes: a quaternary ammonium salt, in which the following expressions are satisfied, 0.90?FBEFORE/FAFTER?1.10, and 5?FSINTERING/FBEFORE?20, in which FBEFORE represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing, which is obtained from a pore distribution curve in a nitrogen gas adsorption method, FAFTER represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles after washing, which is obtained from the pore distribution curve in the nitrogen gas adsorption method, and FSINTERING represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles before washing and after sintering at 600° C., which is obtained from the pore distribution curve in the nitrogen gas adsorption method.

Abstract: A silica particle includes: a quaternary ammonium salt, in which the following expressions are satisfied, 0.90?FBEFORE/FAFTER?1.10, and 5?FSINTERING/FBEFORE?20, in which FBEFORE represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing, which is obtained from a pore distribution curve in a nitrogen gas adsorption method, FAFTER represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles after washing, which is obtained from the pore distribution curve in the nitrogen gas adsorption method, and FSINTERING represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles before washing and after sintering at 600° C., which is obtained from the pore distribution curve in the nitrogen gas adsorption method.

Abstract: Resin particles include resin base particles and silica particles on surfaces of the resin base particles. The silica particles contain a quaternary ammonium salt and have hydrophobized surfaces. A difference (detection temperature A?detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning.

Abstract: Resin particles include resin base particles and silica particles on surfaces of the resin base particles. The silica particles contain a quaternary ammonium salt and have hydrophobized surfaces. A difference (detection temperature A?detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning.

Abstract: An electrostatic charge image developing toner has toner particles and silica particles that are added to an exterior of the toner particles and contain a nitrogen element-containing compound, in which in a case where A represents a pore volume of pores of the silica particles having a diameter of 1 nm or more and 50 nm or less determined from a pore size distribution curve obtained by a nitrogen adsorption method before baking at 350° C., and B represents a pore volume of pores of the silica particles having a diameter of 1 nm or more and 50 nm or less determined from a pore size distribution curve obtained by a nitrogen adsorption method after baking at 350° C., B/A is 1.2 or more and 5 or less, and B is 0.2 cm3/g or more and 3 cm3/g or less.

Abstract: 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 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.

Abstract: An electrostatic charge image developing toner contains toner particles and silica particles that are added to an exterior of the toner particles and contain a nitrogen element-containing compound containing a molybdenum element, in which in the silica particles, a ratio (Mo/Si) of Net intensity of the molybdenum element to Net intensity of a silicon element measured by X-ray fluorescence analysis is 0.035 or more and 0.35 or less.

Abstract: An organic substance-attached porous inorganic oxide particle including porous inorganic oxide particle and an organic substance attached to the surface of the porous inorganic oxide particle. The organic substance-attached porous inorganic oxide particle satisfies a formula below (Cf?Ce)/2>1 where Cf represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after the particle is washed, and Ce represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after two-minute surface etching of the particle.

Abstract: Silica particles contain a nitrogen element-containing compound containing a molybdenum element, in which a ratio (Mo/Si) of Net intensity of the molybdenum element to Net intensity of a silicon element measured by X-ray fluorescence analysis is 0.035 or more and 0.35 or less.

Abstract: Silica particles include a nitrogen-containing compound. When the volumes of pores having a diameter of 1 nm or more and 50 nm or less, the volumes being determined from a pore size distribution curve of the silica particles before and after the silica particles are baked at 350° C., the pore size distribution curve being obtained by nitrogen gas adsorption, are defined as A and B, respectively, B/A is 1.2 or more and 5 or less and B is 0.2 cm3/g or more and 3 cm3/g or less.

Abstract: Silica particles includes a nitrogen-containing compound. The ratio of the integral C of a signal observed at a chemical shift of ?50 ppm or more and ?75 ppm or less in a 29Si solid-state nuclei magnetic resonance (NMR) spectrum of the silica particles, the 29Si solid-state NMR spectrum being obtained by cross polarization/magic angle spinning (CP/MAS), to the integral D of a signal observed at a chemical shift of ?90 ppm or more and ?120 ppm or less in the 29Si solid-state NMR spectrum, that is, C/D, is 0.10 or more and 0.75 or less. The amount X of the nitrogen-containing compound extracted from the silica particles with a mixed solution of ammonia and methanol is 0.1% by mass or more. The amount X of the nitrogen-containing compound extracted and the amount Y of the nitrogen-containing compound extracted from the silica particles with water satisfy Y/X<0.3.

Abstract: Silica particles have silica base particles, a structure that covers at least a part of a surface of the silica base particles and is configured with a reaction product of a trifunctional silane coupling agent, and a nitrogen element-containing compound, in which a content of the nitrogen element-containing compound with respect to the silica particles is 0.005% by mass or more and 0.50% by mass or less in terms of N atoms, and the silica particles have a degree of hydrophobicity of 10% or more and 60% or less and a volume resistivity of 1×108?·cm or more and 1×1012.5 ?·cm or less.

Abstract: Resin particles include resin base particles and silica particles on surfaces of the resin base particles. The silica particles contain a quaternary ammonium salt and have hydrophobized surfaces. A difference (detection temperature A?detection temperature B) between a detection temperature A and a detection temperature B is more than 50° C., where the detection temperature A is a detection temperature from a pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles before cleaning, and the detection temperature B is a detection temperature from the pyrolysis product of the quaternary ammonium salt determined by pyrolysis mass spectrometry of the resin particles after cleaning.

Abstract: A silica particle includes: a quaternary ammonium salt, in which the following expressions are satisfied, 0.90?FBEFORE/FAFTER?1.10, and 5?FSINTERING/FBEFORE?20, in which FBEFORE represents a maximum frequency value of a pore diameter of 2 nm or less in the silica particles before washing, which is obtained from a pore distribution curve in a nitrogen gas adsorption method, FAFTER represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles after washing, which is obtained from the pore distribution curve in the nitrogen gas adsorption method, and FSINTERING represents a maximum frequency value of the pore diameter of 2 nm or less in the silica particles before washing and after sintering at 600° C., which is obtained from the pore distribution curve in the nitrogen gas adsorption method.

Abstract: An organic substance-attached porous inorganic oxide particle including porous inorganic oxide particle and an organic substance attached to the surface of the porous inorganic oxide particle. The organic substance-attached porous inorganic oxide particle satisfies a formula below (Cf?Ce)/2>1 where Cf represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after the particle is washed, and Ce represents the amount of carbon (atom %) measured by subjecting the surface of the particle to X-ray photoelectron spectroscopy (XPS) after two-minute surface etching of the particle.

Abstract: A silica particle has a compression and aggregation degree of from 60% to 95% and a particle compression ratio of from 0.20 to 0.40.

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 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: 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.