A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin, a release agent, and a coloring agent, and a cross-sectional image of the toner particles meets requirements (1) and (2): requirement (1), an average of ten or more domains, per toner particle, of the release agent have an area of 0.5% or more and 5.0% or less of the area of the toner particle; requirement (2), in a Voronoi tessellation generated from the centroids of the domains of the coloring agent, the mean area of the Voronoi cells is 0.020 μm.sup.2 or more and 0.060 μm.sup.2 or less, and the standard deviation of the areas of the Voronoi cells is 0.010 μm.sup.2 or less.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin, a release agent, and a coloring agent, and a cross-sectional image of the toner particles meets requirements (1) and (2): requirement (1), an average of ten or more domains, per toner particle, of the release agent have an area of 0.5% or more and 5.0% or less of the area of the toner particle; requirement (2), in a Voronoi tessellation generated from the centroids of the domains of the coloring agent, the mean area of the Voronoi cells is 0.020 μm.sup.2 or more and 0.060 μm.sup.2 or less, and the standard deviation of the areas of the Voronoi cells is 0.010 μm.sup.2 or less.

A toner is comprised of toner particles and external additive adhering to the surface of the toner particles. The toner particles are formed from a binder resin, an ester wax, and a colorant. The external additive comprises a titanium oxide and silica. A first adhesive strength between the external additive and the toner base particles is in a range of 90 to 100% when measured as a ratio of X-ray spectroscopic intensity of titanium for toner particles before and after a washing process, and a second adhesive strength between the external additive and the toner base particles is in a range of 50 to 80% when measured as a ratio of X-ray spectroscopic intensity of silicon measured for toner before and after another washing process.

A coating layer application device (200) for applying a coating layer, which is located on a transfer element, to a substrate, the coating layer (206) being formed from a coating material, in particular a thermosetting coating material, the coating layer (206) being curable and comprising an amorphous material, the coating layer application device comprising: a heating device (214, 220) being configured so as to (i) maintain the temperature of the coating layer (206) within a temperature range before removal of N the transfer element (204) from the coating layer (206), wherein within the temperature range the uncured coating material is in its supercooled liquid state; and/or (ii) partially cure the coating layer (206) during a contact of the coating layer (206) and the substrate (210) and before removal of the transfer element (204) from the coating layer, in particular by increasing the temperature of the coating layer (206) to a temperature at or above a curing temperature of the coating layer (206).

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin, a release agent, and a coloring agent, and a cross-sectional image of the toner particles meets requirements (1) and (2): requirement (1), an average of ten or more domains, per toner particle, of the release agent have an area of 0.5% or more and 5.0% or less of the area of the toner particle; requirement (2), in a Voronoi tessellation generated from the centroids of the domains of the coloring agent, the mean area of the Voronoi cells is 0.020 μm.sup.2 or more and 0.060 μm.sup.2 or less, and the standard deviation of the areas of the Voronoi cells is 0.010 μm.sup.2 or less.

A toner for developing an electrostatic charge image contains toner particles containing at least one binder resin, a release agent, and a coloring agent, and a cross-sectional image of the toner particles meets requirements (1) and (2): requirement (1), an average of ten or more domains, per toner particle, of the release agent have an area of 0.5% or more and 5.0% or less of the area of the toner particle; requirement (2), in a Voronoi tessellation generated from the centroids of the domains of the coloring agent, the mean area of the Voronoi cells is 0.020 μm.sup.2 or more and 0.060 μm.sup.2 or less, and the standard deviation of the areas of the Voronoi cells is 0.010 μm.sup.2 or less.

Provided is a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including: a developing unit including a toner; and an electrophotographic photosensitive member, wherein the toner includes a toner particle, the toner particle has a surface containing a polyvalent acid metal salt particle, and a surface layer of the electrophotographic photosensitive member contains at least one metal oxide particle among an aluminum oxide particle, a silicon dioxide particle, and a tin oxide particle.

A method of producing resin particles includes a first step of adding a monomer-containing emulsified liquid that contains a polymerizable monomer and an aqueous medium to an aqueous mother medium to polymerize the polymerizable monomer; and a second step of adding an aqueous medium for cooling to the aqueous mother medium after completion of the addition of the monomer-containing emulsified liquid to the aqueous mother medium.

A method of producing resin particles includes a first step of adding a monomer-containing emulsified liquid that contains a polymerizable monomer and an aqueous medium to an aqueous mother medium to polymerize the polymerizable monomer; and a second step of adding an aqueous medium for cooling to the aqueous mother medium after completion of the addition of the monomer-containing emulsified liquid to the aqueous mother medium.

The toner is characterized in that, wherein the binder resin is a resin satisfying at least one of the following specification (A) or (B): (A) the binder resin contains a crystalline resin having a unit (a) represented by the following formula (1) and a resin having a sulfide structure; and (B) the binder resin contains a crystalline resin having the sulfide structure and having the unit (a) represented by the following formula (1):

##STR00001##

wherein the colorant is any colorant selected from the specific group consisting of: carbon black and so on, wherein when the toner is subjected to measurement with a differential scanning calorimeter, a peak temperature of a maximum endothermic peak is present in a range of from 50° C. or more to 70° C. or less, and wherein the maximum endothermic peak has an endothermic quantity of 30 J/g or more and 70 J/g or less.