An electrophotographic photoreceptor includes: a conductive holder; and at least a charge producing layer and a charge transport layer disposed on the conductive holder in order. The charge transport layer contains at least a binder resin, a charge transport agent and a p-type metal oxide particle.

An electrophotographic photoreceptor includes an electroconductive substrate, an organic photosensitive layer on the electroconductive substrate and an inorganic protective layer on the organic photosensitive layer, wherein a layer that forms a surface of the organic photosensitive layer contains a charge transporting material, a binder resin, and a silica particle; the inorganic protective layer contains a group 13 element, an oxygen atom, and a hydrogen atom; a sum of element constitution ratios of the group 13 element, the oxygen atom, and the hydrogen atom to all elements constituting the inorganic protective layer is equal to or more than 90 atomic %; and an element composition ratio (oxygen atom/group 13 element) of the oxygen atom and the group 13 element is 1.0 or more and less than 1.5.

The present invention relates to an electrophotographic photoreceptor comprising, on a conductive base: a charge generation layer; and a charge transport layer having a film thickness of 15 μm to 40 μm, wherein the charge transport layer is an outermost layer, and the charge transport layer contains an inorganic filler and a hydrocarbon compound represented by the following Formula (1).

Provided is an electrophotographic photoconductor including an outermost surface layer containing inorganic compound microparticles that have a number mean primary particle diameter of 10-40 nm and are dispersed uniformly into the outermost surface layer at a proportion of 7-18% by mass in the outermost surface layer, wherein in slicing the outermost surface layer in its stacking direction with a thickness of 70 nm, observing a strip-shaped sample piece thus obtained in scanning transmission electron microscopy, converting a cross-sectional image thus obtained to an 8-bit binary image, and observing any 50 regions from regions having a 5 μm×5 μm observation field of view in the binary image, the following formula is met: 0.5≤S.sub.Ave/N≤2.0, and wherein a maximum gap region has a size of 1.0 μm or less when represents a space with absence of the inorganic compound microparticles converted to an equivalent circle diameter.

An object of the present invention is to provide an electrophotographic photoreceptor which can prevent an increase in potential even using a fluorine resin in a charge transport layer, and can achieve both electrical properties and abrasion resistance, and present invention relates to a lamination type electrophotographic photoreceptor, in which a charge transport layer of the lamination type electrophotographic photoreceptor contains a compound having an E_homo of −4.550 eV or more based on structure optimization calculation by density functional calculation B3LYP/6-31G (d, p) and fluorine resin particles, and a content of the fluorine resin particles is 3% by weight to 20% by weight based on a total mass of the charge transport layer.

Provided is a process cartridge removably mountable onto a main body of an electrophotographic apparatus, the process cartridge comprising an electrophotographic photosensitive member, a toner, and a developing member configured to supply the toner to the electrophotographic photosensitive member, wherein, in filter fitting analysis in STEM-EDS analysis, a hydrotalcite particle comprises fluorine, and wherein, when a number-average primary particle diameter of a particle A is represented by “m” [nm], a content ratio of the particle A with respect to the surface layer is represented by “p” [vol %], and a number-average primary particle diameter of the hydrotalcite particle is represented by “h” [nm], the “m”, the “p”, and the “h” satisfy the following expressions, respectively:

5≤m≤300  Expression (1);

5≤p≤40  Expression (2); and

60≤h≤1,000  Expression (3).

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer on the conductive substrate. The electrophotographic photoreceptor has an outermost surface layer that contains fluorine-containing resin particles and a fluorine-containing graft polymer. The fluorine-containing resin particles contain 0 or more and 30 or less carboxy groups per 10.sup.6 carbon atoms. The outermost surface layer has a dielectric constant of 3.75 or more and 3.90 or less. The contact angle of pure water on the outermost surface layer is 90° or more.

An object of the present invention is to provide an electrophotographic photoreceptor which can prevent an increase in potential even using a fluorine resin in a charge transport layer, and can achieve both electrical properties and abrasion resistance, and present invention relates to a lamination type electrophotographic photoreceptor, in which a charge transport layer of the lamination type electrophotographic photoreceptor contains a compound having an E_homo of −4.550 eV or more based on structure optimization calculation by density functional calculation B3LYP/6-31G (d, p) and fluorine resin particles, and a content of the fluorine resin particles is 3% by weight to 20% by weight based on a total mass of the charge transport layer.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer on the conductive substrate. The electrophotographic photoreceptor has an outermost surface layer that contains fluorine-containing resin particles and a fluorine-containing graft polymer. The fluorine-containing resin particles contain 0 or more and 30 or less carboxy groups per 10.sup.6 carbon atoms. The outermost surface layer has a dielectric constant of 3.75 or more and 3.90 or less. The contact angle of pure water on the outermost surface layer is 90° or more.

Provided is an electrophotographic photosensitive member, which has high abrasion resistance and is resistant to being deeply flawed. Specifically, provided is an electrophotographic photosensitive member comprising a support and a surface layer formed on the support, wherein the surface layer comprises at least inorganic particles having pores in surfaces thereof, wherein at least a resin in the surface layer penetrates the pores, and wherein when vibration having a frequency of 0.5 Hz is applied to the surface layer at 28° C., the loss tangent tan δ of the dynamic viscoelasticity of the surface layer is from 0.005 to 0.05.