A resin particle contains resin containing a tetrahydrofuran insoluble portion containing a non-linear polymer in which a non-linear prepolymer is cross-linked with a metal ion, wherein the resin particle has a carbon-14 concentration of 5.4 pMC or greater, wherein the tetrahydrofuran insoluble portion has a glass transition temperature of from −60 to lower than 0 degrees C. as measured by differential scanning calorimetry.

A toner comprises a toner particle containing an amorphous polyester, wherein the amorphous polyester contains an amorphous polyester 1, the amorphous polyester contains a tin compound and a titanium compound, a Sn/Ti abundance ratio between Sn and Ti in the amorphous polyester according to x-ray fluorescence analysis is 20/80 to 80/20, and a weight-average molecular weight Mw1 of the amorphous polyester 1 according to measurement by gel permeation chromatography (GPC) is Mw1<7,000.

A pressure sensitive adhesive includes: composite resin particles that contain a styrene resin containing, as polymerization components, styrene and a vinyl monomer other than styrene, and a (meth)acrylate resin containing, as a polymerization component, a (meth)acrylate; and an aqueous solvent containing water, in which a mass ratio of the styrene resin to the (meth)acrylate resin (styrene resin:(meth)acrylate resin) is 80:20 to 20:80, a difference between the lowest glass transition temperature and the highest glass transition temperature of the composite resin particles is 30° C. or more, a melt viscosity of the composite resin particles at 100° C. is 4000 Pa.Math.s or more and 20000 Pa.Math.s or less, and, in a melt viscosity range of the composite resin particles of 4000 Pa.Math.s or more and 20000 Pa.Math.s or less, a slope of a logarithm of the melt viscosity of the composite resin particles relative to a temperature of the composite resin particles is −0.08 or more and −0.04 or less.

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.

Disclosed herein is a toner composition, developer and additive for a toner composition. The toner composition includes toner particles having at least one resin, an optional colorant, an optional wax, and a crosslinked polymer particle on at least a portion of an external surface of the toner particles. The crosslinked polymeric particle on a surface of the toner particles includes at least a hydrophobic monomer comprising a non-fluorinated monomer having a carbon to oxygen (C/O) ratio of 3 or greater or a fluorinated monomer. The crosslinked polymer particle includes a second monomer comprising two or more vinyl groups present in an amount from about 8 wt % to about 40 wt % of the copolymer, a metal oxide and optionally a charge control agent monomer.

A toner including at least a crystalline resin as a binder resin, wherein a tetrahydrofuran soluble content of the toner includes 5.0% or more as a peak area of a component having a molecular weight of 100,000 or greater in a molecular weight distribution measured by gel permeation chromatography, and the tetrahydrofuran soluble content of the toner has a weight-average molecular weight of 20,000 to 60,000.

A toner for developing an electrostatic image includes a toner particle. The toner particle includes a binder resin and a black colorant. The binder resin includes a crystalline resin component. A toner layer formed through a deposition of the toner on a glass sheet in an amount of 6.5 g/m.sup.2 exhibits a light transmittance of 1 to 3% at a wavelength of 690 nm after applying heat at a temperature of 185° C. for five seconds to the toner layer from a position 100 μm away from a surface of the toner layer.

An electrostatic-image developing toner includes toner particles each including a polyester resin and a styrene (meth)acrylic resin. In a micro-compression test where a load of 0.2 mN is applied to the toner particles at a loading rate of 0.098 mN/sec, the median of a distribution of the ratios (%) of deformations of the toner particles to the diameters of the toner particles is 8.0 or more and 18.0 or less, and a variation in the distribution of the ratios of deformations of the toner particles to the diameters of the toner particles is 0.02 or more and 0.40 or less.

A toner comprising a toner particle that includes a binder resin, wherein in dynamic viscoelasticity measurement of the toner, the storage elastic modulus of the toner at 70° C. is from 0.10 MPa to 3.00 MPa, and in nanoindentation measurement of the toner, the surface storage elastic modulus of the toner at 25° C. under 150 μN of load is from 2.80 GPa to 4.50 GPa.

Novel support material formulations, characterized as providing a cured support material with improved dissolution rate, while maintaining sufficient mechanical strength, are disclosed. The formulations comprise a water-miscible non-curable polymer, a first water-miscible, curable material and a second, water-miscible material that is selected capable of interfering with intermolecular interactions between polymeric chains formed upon exposing the first water-miscible material to curing energy. Methods of fabricating a three-dimensional object, and a three-dimensional object fabricated thereby are also disclosed.