An electrostatic charge image developing toner includes toner particles containing a binder resin and a release agent; and an external additive containing fatty acid metal salt particles, wherein a non-attachment rate representing a percentage of the fatty acid metal salt particles not attached to the toner particles before ultrasonic desorption treatment is 45% or less and a weak attachment rate representing a percentage determined by subtracting the non-attachment rate from a percent of the fatty acid metal salt particles not attached to the toner particles after ultrasonic desorption treatment is 55% or more.

A part material for printing three-dimensional parts with an electrophotography-based additive manufacturing system, the part material including a composition having a high-performance thermoplastic material and a charge control agent. The part material is provided in a powder form having a controlled particle size, and is configured for use in the electrophotography-based additive manufacturing system having a layer transfusion assembly for printing the three-dimensional parts in a layer-by-layer manner.

An image forming apparatus includes a charging unit that includes a conductive member which contacts with a surface of an image holding member, and that applies only a DC voltage to the conductive member to charge the surface of the image holding member; and a cleaning unit that has a blade which contacts with the surface of an image holding member and cleans the surface with the blade after a toner image is transferred onto a recording medium, wherein a developer includes toner particles, silica particles treated with a silicone oil, and a carrier, a volume average particle diameter of the carrier is from 20 m to 35 m, and a quantity ratio of an elemental silicon derived from a silicone oil and an elemental silicon derived from silica which are present on the surface of the carrier is from 0.05 to 0.2.

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.

A toner comprises a toner particle comprising a core particle comprising a resin component, a shell coating the surface of the core particle, and a polyvalent metal. The resin component comprises a polyester resin, and the shell comprises an amino resin; in an electron image of a cross section of the toner acquired using a transmission electron microscope, a polyvalent metal content P(M) obtained by energy-dispersive x-ray analysis at the core/shell interface and in the vicinity of this interface is 0.0010 to 2.00 atomic %; and the surface storage elastic modulus of the toner at a load of 30 N at 25 C., according to nanoindentation measurement of the toner, is from 6.50 GPa to 12.00 GPa.

An image forming apparatus includes a rotatable image bearing member, a charging member, a developing member, a cleaning member, an accommodating portion, and a controller capable of executing an image forming operation and a supplying operation for supplying a metal soap, accommodated in the accommodating portion, onto a surface of the image bearing member by the developing member. The controller carries out control so that when the supplying operation is executed, a surface moving speed of the image bearing member is higher than a surface moving speed of the image bearing member when the image forming operation is executed.

An object of the present invention is to provide a toner being free of a problem of image non-uniformity or carrier attraction due to charging unevenness and enabling stable printing, even at continuous printing, in a high-speed development system susceptible to stress. In the toner for developing an electrostatic charge image of the present invention, as an external additive of the toner, a metal oxide-polymer composite particle containing a polymer-grafted metal oxide, and a composite oxide particle having a core-shell structure, with the core part containing titania and the shell part containing silica, are added as a first external additive and a second external additive, respectively.

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.

A toner includes toner particles which contain a binder resin, a colorant, a wax, and a resin A having an organic polysiloxane structure; the amount of Si atoms of the toner particles is 4.5 to 10.0; in an analysis of a cross-section of each toner particle, in a surface layer region R from the periphery of the cross-section of the toner particle to the inside at a distance of 10.0% of the particle diameter in the cross-section of the toner particle, the content of Si atoms derived from the organic polysiloxane structure is 90.0% or more with respect to the total amount of Si atoms contained in the toner particle; and in a line analysis along a straight line between the periphery of the surface layer region R and a gravity center of the cross-section, an intensity count of Si atoms in the toner particle satisfies formula Si.sup.0>Si.sup.1>Si.sup.2>Si.sup.30.

Provided is a method of producing a toner including a toner particle, the method including: a granulation step of mixing a polymerizable monomer composition containing a polymerizable monomer and an aqueous medium to form a suspension of particles of the polymerizable monomer composition; and a polymerization step of polymerizing the polymerizable monomer in each of the particles of the polymerizable monomer composition in the presence of a metal phosphate containing aluminum as a metal element to provide the toner particle, the content ratio of aluminum in the metal phosphate containing aluminum being 1.0 mol % or more and 95.0 mol % or less with respect to all metal elements, the metal phosphate containing aluminum being obtained by adding an aluminum compound to the aqueous medium and/or the suspension.