A part material for printing three-dimensional parts with an electrophotography-based additive manufacturing system, the part material including a composition having a semi-crystalline 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.

A developer having low-temperature fixability and storage stability, and capable of prolonging the service life is provided. A toner includes a coloring agent, an amorphous polyester, a crystal line polyester, ester wax containing multiple ester compounds, each having a carbon number selected from 32 to 54, and hydrophobic silica having an average primary particle diameter of 8 to 35 nm. When the ion intensity ratio of each ester compound having a different carbon number is expressed as percentage, the content (a) of the ester compound having a carbon number of (Cn) showing the maximum intensity ratio is from 20 to 55% by weight of the entire ester wax, the sum (g) of the content (e) of the ester compound having a carbon number of (Cn+2) and the content (f) of the ester compound having a carbon number of (Cn+4) satisfies the following formula: 0.065≦g/a≦0.200.

A toner includes a plurality of toner particles containing a binder resin and one or more microcapsules that contain a fragrant material. A ratio of a number of toner particles that contain at least one microcapsule in a region from a surface thereof to 1 μm in depth with respect to a total number of toner particles in the region is equal to or greater than 60%.

A toner includes a plurality of toner particles containing a binder resin and one or more microcapsules that contain a fragrant material. A ratio of a number of toner particles that contain at least one microcapsule in a region from a surface thereof to 1 μm in depth with respect to a total number of toner particles in the region is equal to or greater than 60%.

A toner having compatibility between transfer properties and cleaning properties is provided. A toner wherein a fine particle A containing a primary particle having a number average particle diameter (D1) of 80 nm or more and 400 nm or less is present on the surface of a toner particle at a coverage ratio of 5 to 40%, a fixing rate of 30 to 90% by mass, and a variation coefficient of 0.1 to 0.5 in a region of 0.5 πμm.sup.2.

According to one example of the present application, there is provided a toner for developing an electrostatic charge image, containing: a toner particle containing a binder resin; a particle adhering to a surface of the toner particle; and an elastomer particle containing one or more kinds of oil, wherein a volume particle size distribution index GSD.sub.T (D50.sub.T/D16.sub.T) on a small diameter side of the toner particle and a volume particle size distribution index GSD.sub.E (D50.sub.E/D16.sub.E) on a small diameter side of the elastomer particle satisfy Formula (1):
GSD.sub.E/GSD.sub.T≧1.  Formula (1):

A toner includes toner particles containing a binder resin, a colorant, and inorganic fine particles, in which in a depth profile of an element distribution in a depth region from the outermost surface of a particle to a depth of 500 nm the depth profile being obtained by an element analysis performed by X-ray photoelectron spectroscopy using the toner as a sample, two or more minimum points of a concentration of a carbon element in the depth region exist, a concentration of an inorganic element becomes a maximum value at a depth position corresponding to each of the minimum points, and the inorganic element is an element derived from the inorganic fine particle.

Image forming apparatus, including: image bearer; charging unit for electrically charging image bearer surface; developing unit for developing with toner, electrostatic latent image formed over image bearer by exposure unit for performing light exposure; transfer unit for transferring developed toner to receiving member; and cleaning unit for cleaning toner remaining over image bearer without being transferred, wherein the toner contains: external additives; and base particles made of at least binder resin and colorant, external additive content of the toner is from 4 to 7 parts by mass relative to 100 parts by mass of base particles, primary particles of at least one external additive have a number average particle diameter of 0.01 to 0.05 μm, cleaning unit includes an elastic-body blade having surface elastic modulus of from 15 to 25 N/mm.sup.2 and surface friction coefficient of from 0.5 to 0.7 at an abutment part thereof abutting on image bearer.

An image forming apparatus for developing an electrostatic latent image with developer includes a development part, a transfer part, and a fuser. The developer includes first developer with a first coloring agent of yellow and a first external additive, and second developer with a second coloring agent of a color other than yellow and a second external additive. A first peeling rate of the first external additive by a following formula (1) is smaller than a second peeling rate of the second external additive by a following formula (2),

the first peeling rate (%)=[1−(X1/Y1)]×100  (1)

the second peeling rate (%)=[1−(X2/Y2)]×100  (2) X1, Y1 are amounts (weight %) of the first external additive in the first developer after/before the ultrasonic waves are applied, X2, Y2 are amounts (weight %) of the second external additive in the second developer after/before the ultrasonic waves are applied.

An image forming apparatus for developing an image with developer includes a development part, a transfer part, and a fuser the medium. The developer is configured with a plurality of particles, an average circularity degree of the developer is ranged within 0.955 to 0.970, and a peeling rate (%) of the external additive by a following equation is 30.6% or less,

peeling rate (%)=[1 −(X/Y)]×100 . . .   (1) wherein X is an amount (weight %) of the external additive included in the developer after ultrasonic waves are applied, and Y is an amount (weight %) of the external additive included in the developer before the ultrasonic waves are applied.