The toner is a toner including a toner particle comprising a binder resin, a crystalline material, wherein, when a ratio of an area occupied by the crystalline material in a toner surface observed with a scanning electron microscope after ruthenium-staining the toner under a specific condition (1) is represented by S.sub.1 (%), a ratio of an area occupied by the crystalline material in the toner surface observed with the scanning electron microscope after ruthenium-staining the toner under a condition (2) is represented by S.sub.2 (%), and a dispersion diameter of a plurality of domains formed of the crystalline material on the toner surface observed with the scanning electron microscope after the ruthenium-staining the toner under the condition (2) is represented by R.sub.2 (nm), the following expressions (1), (2), and (3) are satisfied. $\begin{array}{cc}0.0S_{1}0.5& \left(1\right)\end{array}$$\begin{array}{cc}1.S_{2}10.& \left(2\right)\end{array}$$\begin{array}{cc}20R_{2}200& \left(3\right)\end{array}$

A process cartridge includes a toner, a regulating member, and a developing roller including a conductive substrate, an elastic layer, and a surface layer which includes a binder resin, a first resin particle having an elastic coefficient of 100 to 10,000 MPa, and a second resin particle having an elastic coefficient of 2 to 50 MPa and in which the outer surface has a first protruded portion and a second protruded portion 5.0 m or more lower than the first protruded portion and has an average maximum height of 6 to 18 m. The toner includes a toner particle and an external additive A that is a silica particle having a major diameter of 40 to 400 nm, a surface coverage of the toner particle by the external additive A is 3.0% or more, and a dispersion degree evaluation index D of the external additive A is 2.0 or less.

A toner includes toner particles, each including: a toner base particle including a binder resin, a colorant, and wax; and resin particles on a surface of the toner base particle, wherein Formulae 1 to 3 below are satisfied, where M is a volume average primary particle diameter (nm) of the resin particles, and L is a distance (nm) between the resin particles present next to one another on the surface of the toner base particle:
M<L;(Formula 1)
5 (nm)<M60 (nm); and(Formula 2)
0.40[M(nm)/L(nm)]<0.90.(Formula 3)

The present disclosure provides a toner that achieves both high image gloss and high image loadability. The toner includes a toner particle that includes: a styrene-acrylic resin having a unit represented by the formula (1); and an ester compound A, wherein the ester compound A is an ester compound represented by the formula (2) or the formula (3): and an absolute value of a difference between SPb (J/cm.sup.3).sup.1/2 that is an SP value of the styrene-acrylic resin and SPw1 (J/cm.sup.3).sup.1/2 that is an SP value of the ester compound A is 1.00 or larger and 2.00 or smaller.

A toner comprising a toner particle, wherein the toner particle comprises a binder resin, a resin A, and a resin B, the resin A comprises a substituted or unsubstituted silyl group in a molecule, a substituent of the substituted silyl group is at least one selected from the group consisting of an alkyl group having 1 or more carbon atoms, an alkoxy group having 1 or more carbon atoms, a hydroxy group, a halogen atom, and an aryl group having 6 or more carbon atoms, and the resin B comprises an azo group in a molecule.

An image forming apparatus includes a control portion to execute a first operation in which a charging voltage applying portion generates a first potential difference that generates an electrostatic force to move developer from a charging member to an image bearing member, a second operation in which a developing voltage applying portion generates a second potential difference that generates an electrostatic force to move developer from the image bearing member to a developer bearing member, and a third operation in which a transfer voltage having a polarity corresponding to the normal charging polarity of the developer by the transfer voltage applying portion is applied while the developer passes through a transfer portion where the developer is transferred to a developer member. A region on a surface of the image bearing member where the second potential difference is generated in the second operation includes a region where the first potential difference is generated in the first operation.

An image forming apparatus includes a control portion to execute a first operation in which a charging voltage applying portion generates a first potential difference that generates an electrostatic force to move developer from a charging member to an image bearing member, a second operation in which a developing voltage applying portion generates a second potential difference that generates an electrostatic force to move developer from the image bearing member to a developer bearing member, and a third operation in which a transfer voltage having a polarity corresponding to the normal charging polarity of the developer by the transfer voltage applying portion is applied while the developer passes through a transfer portion where the developer is transferred to a developer member. A region on a surface of the image bearing member where the second potential difference is generated in the second operation includes a region where the first potential difference is generated in the first operation.

A conventional process cartridge is developed.

A rotatable developing roller, a developing frame for rotatably supporting the developing roller, toner including toner particles and an external additive, a toner accommodating portion for accommodating the toner, a supplying roller for supplying the toner to a surface of the developing roller in contact with the surface of the developing roller, a regulating blade for regulating a layer thickness of the toner carried on the surface of the developing roller in contact with the surface of the developing roller, and an electrical contact electrically connected to the supplying roller and the regulating blade and capable of receiving electric power from an outside are provided, wherein the toner includes hydrotalcite particles as the external additive, and in line analysis in STEM-EDS mapping analysis of the toner, fluorine exits inside the hydrotalcite particles.

A resin composition includes: a resin having a first group capable of forming at least two hydrogen bonds; and a photoisomerization compound having a second group capable of forming at least two hydrogen bonds complementarily with the first group and having a moiety that is reversibly isomerized by light.

A process cartridge includes a toner and a developing roller. In the toner, a cohesion cluster containing fine silica particles and a binder component is present on surfaces of toner particles. Ratios of toner particles having the cohesion cluster before and after treatments with ultrasonic waves under specific conditions in terms of number % are within predetermined ranges. The developing roller has an Asker C hardness of 56 degrees or more and 75 degrees or less.