An electrophotographic photoreceptor includes a conductive substrate and a single-layer photosensitive layer on the conductive substrate. The photosensitive layer includes a binder resin, at least one selected from a hydroxygallium phthalocyanine pigment and a chlorogallium phthalocyanine pigment, a hole transporting material, and an electron transporting material and has a Martens hardness Hm of 170 N/mm.sup.2 or more and 200 N/mm.sup.2 or less.

A compound has a structure represented by the following formula (C1): ##STR00001##
wherein R.sub.a1, R.sub.a2, R.sub.a3, R.sub.a41, R.sub.a42, R.sub.a43, R.sub.a44, R.sub.a45, R.sub.a5, R.sub.a6, R.sub.a7, R.sub.a8, R.sub.a9, R.sub.a10, and R.sub.a11 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, an aralkyl group, an aryl group, a cyano group, a halogen atom, or a group obtained by combining two or more of the above groups, and a combination of R.sub.a1 and R.sub.a2, R.sub.a41 and R.sub.a42, R.sub.a42 and R.sub.a43, R.sub.a43 and R.sub.a44, R.sub.a44 and R.sub.a45, R.sub.a5 and R.sub.a6, R.sub.a8 and R.sub.a9, or R.sub.a10 and R.sub.a11 each independently may form a ring.

An electrophotographic photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, in which the charge transport layer contains a charge transport material, at least one of a polyester resin that has a constitutional unit having an aromatic ring or a polycarbonate resin that has a constitutional unit having an aromatic ring, and a compound (1) represented by Formula (1) and having a melting point of 40° C. or higher,

##STR00001## in Formula (1), Ar represents an aromatic ring that may have a substituent, L represents a single bond, an oxygen atom, or a sulfur atom, R represents an alkyl group having 1 or more and 10 or less carbon atoms, an aryl group having 6 or more and 20 or less carbon atoms, or an aralkyl group having 7 or more and 20 or less carbon atoms, and n represents an integer of 1 or greater.

An image forming unit includes a photoreceptor and a charging member that comes into contact with a surface of the photoreceptor and charges the photoreceptor, in which the photoreceptor includes a conductive substrate, and a lamination type photosensitive layer disposed on the conductive substrate and including a charge generation layer and a charge transport layer, the charge transport layer contains at least one of a polyester resin that has a constitutional unit having an aromatic ring or a polycarbonate resin that has a constitutional unit having an aromatic ring, the charging member includes a support member and an elastic layer disposed on the support member, and the elastic layer has a storage elastic modulus G′ of 5.0 MPa or less at a frequency of 100 Hz in dynamic viscoelasticity measurement under a temperature condition of 24° C.

There is provided an electrophotographic photoreceptor including: a conductive support; and a photosensitive layer and a protective layer containing a cured product obtained by curing a curable compound, which are sequentially disposed on the conductive support. An area ratio A/B is 0.0045 or less, where A is an absorbance area at a wavelength of 1647 cm.sup.−1 to 1627 cm.sup.−1 and B is an absorbance area of a peak at a wavelength of 1800 cm.sup.−1 to 1647 cm.sup.−1 in an infrared absorption spectrum measurement of the protective layer. The photosensitive layer contains at least a hole transport material (HTM) and a radical acceptor compound. The electrophotographic photoreceptor is an electrophotographic photoreceptor including a protective layer with a high curing degree and having good initial electrical characteristics, excellent strong exposure characteristics, and excellent transfer repeatability.

The present disclosure provides an electrophotographic photosensitive member having excellent dispersibility of fluorine atom-containing resin particles, and excellent durability, with an occurrence of a ghost suppressed. In the electrophotographic photosensitive member having a surface layer, the surface layer includes a fluorine atom-containing resin particle, a binder material, a charge transport substance, and a polymer A having a specific structural unit, wherein the binder material is a thermoplastic resin, and a film thickness of the surface layer is 35 μm or larger and 50 μm or smaller.

Provided is an electrophotographic photosensitive member including a surface layer, wherein the surface layer contains a fluorine atom-containing resin particle, a binder material, and a polymer having specific structural units.

The present disclosure provides an electrophotographic photosensitive member having a surface layer that is excellent in dispersibility of a fluorine atom-containing resin particle and suppresses a potential fluctuation at the time of repeated use. The electrophotographic photosensitive member having the surface layer, wherein the surface layer includes the fluorine atom-containing resin particle, a binder material, and a polymer A having a specific structural unit.

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.

The present invention provides an electrophotographic photoreceptor including at least a laminated photoreceptive layer in which a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance are laminated in this order on a substrate, where the charge generating substance is a titanyl phthalocyanine showing diffraction peaks at least at Bragg angles (2θ±0.2°) 7.3°, 9.4°, 11.6°, 24.2° and 27.3° in an X-ray diffraction spectrum using CuKα ray, and the laminated photoreceptive layer includes an optical absorption spectrum that has a maximum absorption at 800 to 850 nm and where a ratio Abs.sub.860 nm/Abs.sub.780 nm of a peak intensity at 860 nm (Abs.sub.860 nm) to a peak intensity at 780 nm (Abs.sub.780 nm) is 0.6 or more to 1.2 or less when a minimum absorbance at 400 to 800 nm is calibrated to 0.