A process of forming an image includes the steps of: developing an electrostatic latent image with a toner, the latent image being formed through charge of the surface of an electrostatic latent image carrier and exposure of the surface to light; and applying a lubricant onto the surface of the electrostatic latent image carrier. The toner includes a toner matrix particle and an external additive nanoparticle. The external additive nanoparticle comprises a silica-polymer composite nanoparticle. A percentage of atomic silicon present on the surface of the silica-polymer composite nanoparticle satisfies Condition A expressed by Expression: 15.0 atm %≦percentage of atomic silicon ({Si/(C+O+Si)}×100)≦30.0 atm %. The percentage of atomic silicon is determined from total amounts of atomic carbon, oxygen, and silicon present on the topmost surface of the silica-polymer composite nanoparticle and within 3 nm inwards from the topmost surface.

An electrostatic charge image developing toner includes toner particles containing a binder resin, and an external additive including silica particles having a compression aggregation degree is from 60% to 95% and a particle compression ratio is from 0.20 to 0.40, and resin particles containing a polymer obtained by polymerizing a (meth)acrylic acid ester monomer.

Pressure-responsive particles include pressure-responsive base particles and resin particles, in which the pressure-responsive base particles contain a styrene-based resin that contains styrene and other vinyl monomers as polymerization components and a (meth)acrylic acid ester-based resin that contains at least two kinds of (meth)acrylic acid esters as polymerization components, a ratio of a mass of the (meth)acrylic acid esters to a total mass of polymerization components is 90% by mass or more in the (meth)acrylic acid ester-based resin, the pressure-responsive particles have at least two glass transition temperatures, a difference between a lowest glass transition temperature and a highest glass transition temperature is 30° C. or higher, and a ratio of a mass of the resin particles to a total mass of the pressure-responsive particles is 0.05% by mass or more and 2.0% by mass or less.

Pressure-responsive particles include pressure-responsive base particles and silica particles, in which the pressure-responsive base particles contain a styrene-based resin that contains styrene and other vinyl monomers as polymerization components and a (meth)acrylic acid ester-based resin that contains at least two kinds of (meth)acrylic acid esters as polymerization components and in which a ratio of a mass of the (meth)acrylic acid esters to a total mass of polymerization components is 90% by mass or more, the pressure-responsive particles have at least two glass transition temperatures, a difference between a lowest glass transition temperature and a highest glass transition temperature is 30° C. or higher, and a ratio of a surface coating rate Cs2 by the silica particles after application of the following first stress to a surface coating rate Cs1 by the silica particles before application of stress satisfies a relationship of 0.4≤Cs2/Cs1≤0.8, first stress: 10 g of the pressure-responsive particles and 90 g of resin-coated ferrite particles are put in a V-shaped mixer with a rotary container having a volume of 0.5 L and rotated at a rotation speed of 40 rpm for 20 minutes at a temperature of 20° C. and a relative humidity of 50%.

A pressure sensitive adhesive particle includes a sea-island structure constituted by a sea containing a resin A and islands containing a resin B1 and a resin B2, in which a viscosity of the resin B1 at 100° C. is smaller than a viscosity of the resin B2 at 100° C.

A toner comprising a toner particle comprising a binder resin including a polyester resin, and a polyolefin resin having a sulfonic acid group, wherein the polyolefin resin having a sulfonic acid group is a polymer in which a vinyl polymer is bonded to a polyolefin, a content ratio of a monomer unit containing a sulfonic acid group in the vinyl polymer is from 1.0 mass % to 20.0 mass %, in a FT-IR spectrum obtained through measurement of a large particle size toner and a small particle size toner resulting from dividing, on a number basis, the toner into two substantially equal parts, a ratio of an intensity of a maximum absorption peak in a range from 1130 cm.sup.−1 to 1170 cm.sup.−1 with respect to an intensity of a maximum absorption peak in a range from 1713 cm.sup.−1 to 1723 cm.sup.−1 exhibits a specific relationship.

A toner contains a toner particle containing a resin component and a wax. The resin component contains a vinyl polymer A having a monomer unit A represented by the formula (A):

##STR00001##

In a luminance histogram created from STEM observation, the total pixel value C in luminance 0 to 9 and the total pixel value A in luminance 0 to 245 satisfy 0.000≤C/A≤0.250. When the pixel value in luminance 10 to 245 has a maximum value P at luminance X, luminance M-luminance N ranges from 120 to 235, wherein the luminance M denotes a luminance at which the pixel value falls below 20% of P for the first time from the luminance X to 245, and the luminance N denotes a luminance at which the pixel value falls below 20% of the P for the first time from the luminance X to 10.

A toner contains toner particles that include a binding resin, a crystalline resin, an ester wax and a dispersant. The binding resin includes an amorphous polyester resin, and the dispersant includes an acrylic copolymer resin or a hybrid resin of the amorphous polyester resin and a styrene resin. When an endothermic peak temperature that is derived from the ester wax in a temperature rise is represented by T1, an exothermic peak temperature that is derived from the ester wax in cooling is represented by T2, a peak temperature of the crystalline resin is represented by Tc and the endothermic peak temperature, the exothermic peak temperature and the peak temperature are measured with a differential scanning calorimeter, T2<Tc<T1 is satisfied, and T1 is greater than 65° C. and less than 85° C.

The present invention provides an aqueous pigment dispersion liquid being such that a pigment is finely dispersed, and the viscosity, and the particle diameters of the pigment are unlikely to fluctuate, being excellent in storage stability, and enabling preparation of an emulsion-polymerized toner having properly controlled particle diameters while improving the pigment utilization rate. The aqueous pigment dispersion liquid is an aqueous pigment dispersion liquid for an emulsion-polymerized toner containing a pigment, a dispersant, and an aqueous medium. The dispersant is a polymer containing a constitutional unit (A) derived from a monomer (A) such that a group containing a (meth)acryloyloxy group or the like is bonded to one end of a particular polyethylene glycol chain or the like, and a constitutional unit (B) derived from a monomer (B) having a carboxy group or the like, the polymer has a number average molecular weight in terms of polystyrene of 4,000 to 15,000, as measured by gel permeation chromatography, the polymer is contained in a state of being not ionized substantially, and the aqueous pigment dispersion liquid has a pH of 3.0 to 8.4.

A toner comprising a toner particle comprising a binder resin including a polyester resin, and a polyolefin resin having a sulfonic acid group, wherein the polyolefin resin having a sulfonic acid group is a polymer in which a vinyl polymer is bonded to a polyolefin, a content ratio of a monomer unit containing a sulfonic acid group in the vinyl polymer is from 1.0 mass % to 20.0 mass %, in a FT-IR spectrum obtained through measurement of a large particle size toner and a small particle size toner resulting from dividing, on a number basis, the toner into two substantially equal parts, a ratio of an intensity of a maximum absorption peak in a range from 1130 cm.sup.−1 to 1170 cm.sup.−1 with respect to an intensity of a maximum absorption peak in a range from 1713 cm.sup.−1 to 1723 cm.sup.−1 exhibits a specific relationship.