Abstract: An electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus are provided which not only secure mechanical strength sufficiently but also bring a vast improvement in charge transport performance and which can well satisfy electrical properties. An electrophotographic photosensitive member is provided an outermost surface layer of which contains at least a charge transporting compound having chain polymerizable functional groups which is represented by the following general formula (1-1) or (1-2); the charge transporting compound having been polymerized or cross-linked and cured. Also provided are a process cartridge and an electrophotographic apparatus which have such a photosensitive member.

Abstract: A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 ?m to 12.0 ?m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 ?m to 4.0 ?m with respect to a volume-based particle diameter distribution, the medium diameter (D50) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 ?m or less with respect to a volume-based particle diameter.

Abstract: A toner exhibits excellent image characteristics, and also has an excellent charging property even if the toner is used in a cleaning-simultaneous-with-developing system having a direct injection charging mechanism. The toner includes toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 ?m to 12.0 ?m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 ?m to 4.0 ?m with respect to a volume-based particle diameter distribution, the medium diameter (D50) being smaller than the weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 ?m or less with respect to a volume-based particle diameter.

Abstract: According to the present invention, there is provided: an electrophotographic photosensitive member having a photosensitive layer on a support in which a surface layer of the electrophotographic photosensitive member comprises an acrylic polymer having a polyfluoroolefin unit and an alkylene oxide unit, and having a number-average molecular weight in a range of 2,000 to 20,000; a process cartridge and an electrophotographic apparatus both comprising the electrophotographic photosensitive member.

Abstract: An electrophotographic photosensitive member having a surface layer containing at least one of a charge-transporting material and conductive particles and a polymer obtained by polymerizing at least one selected from the group consisting of a polyhydroxymethylbisphenol monomer having a specific structure, a polyhydroxymethylbisphenol oligomer having a specific structure, a polyhydroxymethyltrisphenol monomer having a specific structure and a polyhydroxymethyltrisphenol oligomer having a specific structure; and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

Abstract: The present invention relates to an electrophotographic photosensitive member comprising a surface layer excellent in adhesiveness and abrasion resistance, having a hardness and a toughness, and not degrading the charge transport property. One aspect of the present invention provides an electrophotographic photosensitive member comprising a photosensitive layer on a conductive support, wherein a surface layer of the photosensitive member contains a crosslinked epoxy-modified resol type phenolic resin, and at least one of a charge transport material and a conductive fine particle.

Abstract: A phenolic compound having a plurality of substituted hydroxyphenyl groups and charge-transportable structure, the substituted hydroxyphenyl groups of which have a hydroxymethyl group; and a resol resin obtained by allowing a phenolic compound having hydroxyphenyl groups and charge-transportable structure, to react with formaldehyde in the presence of a basic catalyst, and having charge-transportable structure. Also disclosed are a cured product and an electrophotographic photosensitive member which make use of the above, and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

Abstract: An electrophotographic photosensitive member is disclosed in which a photosensitive layer and a protective layer are formed on a conductive substrate in that order. In this photosensitive member, when its surface is charged to −700 V under a 23° C./5% RH environment and irradiated with white light in a light quantity of 10 lux·sec, if the surface potential at the time 0.2 seconds have passed from the irradiation and the surface potential at the time 0.5 seconds have passed from the irradiation are defined as Vsl(0.2) and Vsl(0.5), respectively, the absolute value of Vsl(0.2) and the absolute value of Vsl(0.2)−Vsl(0.5) satisfy specific conditions.

Abstract: An electrophotographic apparatus and a process cartridge have a charge unit for charging the surface of a photosensitive member by direct injection of electrical charge from a contact charging member to the photosensitive member. The charging unit also functions as a unit for supporting residual toner on the surface of the photosensitive member after transfer, for normalizing the electrical charge of the residual toner, and for returning the normalized residual toner to the surface of the photosensitive member. A developing unit also functions as a unit for recovering the normalized residual toner returned to the surface of the photosensitive member. The absolute value of the difference in charged potential between a first rotation and a second rotation of the photosensitive member is higher than 5 V and lower than 70 V. The photosensitive member has a charge injection layer having a specific composition and the charging member supports charged particles having specific characteristics.

Abstract: In an electrophotographic photosensitive member comprising a conductive support, and provided thereon a charge generation layer, a charge transport layer and a protective layer in this order, the layer thickness a0 (&mgr;m) of the charge transport layer at the middle portion of the conductive support in its generatrix direction, the layer thickness b0 (&mgr;m) of the protective layer at the middle portion of the conductive support in its generatrix direction, the layer thickness a (&mgr;m) of the charge transport layer at a portion other than the middle portion and the layer thickness b (&mgr;m) of the protective layer at the portion other than the middle portion satisfy the following expression (1) in a region satisfying 0.8 (&mgr;m)≦(a0−a)≦3.0 (&mgr;m): b0×(a/a0)3≦b(&mgr;m)≦b0×(a/a0)1/4  (1). Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.

Abstract: In an electrophotographic photosensitive member comprising a cylindrical support, and provided thereon a photosensitive layer and a protective layer in this order, which cylindrical support has an outer diameter of less than 30 mm, the difference between a coefficient of thermal expansion &agr;1 measured from the top of the protective layer and a coefficient of thermal expansion &agr;2 measured after the protective layer has been removed, |&agr;1−&agr;2|, is more than 5.0×10−7° C.−1 to less than 1.0×10−4° C.−1, and the modulus of elastic deformation We % measured from the top of the protective layer is more than 30% to less than 60%. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.

Abstract: The present invention relates to an electrophotographic photosensitive member comprising a surface layer excellent in adhesiveness and abrasion resistance, having a hardness and a toughness, and not degrading the charge transport property.

Abstract: According to the present invention, there is provided: an electrophotographic photosensitive member having a photosensitive layer on a support in which a surface layer of the electrophotographic photosensitive member comprises an acrylic polymer having a polyfluoroolefin unit and an alkylene oxide unit, and having a number-average molecular weight in a range of 2,000 to 20,000; a process cartridge and an electrophotographic apparatus both comprising the electrophotographic photosensitive member.

Abstract: To provide a toner which exhibits excellent performances for image characteristics, and also has excellent performances for charging property even if the toner is used in a cleaning simultaneous with developing system having a direct injection charging mechanism. The toner of the present invention comprises toner particles and non-magnetic metallic-compound fine particles. The weight average particle diameter of the toner is 3.0 &mgr;m to 12.0 &mgr;m. The metallic-compound fine particles are conductive metallic-compound fine particles having a specific surface area (cm2/cm3) of 5×105 to 100×105; a medium diameter (D50) of 0.4 &mgr;m to 4.0 &mgr;m with respect to a volume-basis particle diameter distribution, the medium diameter (D50) being smaller than a weight average particle diameter of the toner; and a 90% particle diameter D90 of 6.0 &mgr;m or less with respect to a volume-basis particle diameter.

Abstract: An electrophotographic apparatus, includes: an electrophotographic photosensitive member and a charging device. The charging device includes a conductor particle-carrying member having an electroconductive and elastic surface, and conductor particles having a particle size of 10 nm-10 &mgr;m and carried on the carrying member so as to be disposed in contact with the photosensitive member, thereby directly injecting charges to the photosensitive member to charge the photosensitive member. The photosensitive member includes a photosensitive layer and a charge injection layer as a surface layer disposed in this order on a support, the charge-injection layer having a thickness d (&mgr;m) and an elastic deformation percentage We (OCL) (%) satisfying a relationship of formula (1) below with an elastic deformation percentage We (CTL) (%) of the photosensitive layer: −0.71×d+We(CTL)≦We(OCL)≦0.03×d3−0.89×d2+8.43×d+We(CTL)  (1).

Abstract: An electrophotographic photosensitive member having a surface layer containing at least one of a charge-transporting material and conductive particles and a polymer obtained by polymerizing at least one selected from the group consisting of a polyhydroxymethylbisphenol monomer having a specific structure, a polyhydroxymethylbisphenol oligomer having a specific structure, a polyhydroxymethyltrisphenol monomer having a specific structure and a polyhydroxymethyltrisphenol oligomer having a specific structure; and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.

Abstract: In an electrophotographic photosensitive member comprising a cylindrical support, and provided thereon a photosensitive layer and a protective layer in this order, which cylindrical support has an outer diameter of less than 30 mm, the difference between a coefficient of thermal expansion &agr;1 measured from the top of the protective layer and a coefficient of thermal expansion &agr;2 measured after the protective layer has been removed, |&agr;1−&agr;2|, is more than 5.0×10−7° C.−1 to less than 1.0×10−4° C.−1, and the modulus of elastic deformation We % measured from the top of the protective layer is more than 30% to less than 60%. Also disclosed are a process cartridge and an electrophotographic apparatus which have such an electrophotographic photosensitive member.

Abstract: An electrophotographic photosensitive member is disclosed in which a photosensitive layer and a protective layer are formed on a conductive substrate in that order. In this photosensitive member, when its surface is charged to −700 V under a 23° C./5% RH environment and irradiated with white light in a light quantity of 10 lux·sec, if the surface potential at the time 0.2 seconds have passed from the irradiation and the surface potential at the time 0.5 seconds have passed from the irradiation are defined as Vsl(0.2) and Vsl(0.5), respectively, the absolute value of Vsl(0.2) and the absolute value of Vsl(0.2)−Vsl(0.5) satisfy specific conditions.

Abstract: In an electrophotographic photosensitive member comprising a conductive support, and provided thereon a charge generation layer, a charge transport layer and a protective layer in this order, the layer thickness a0 (&mgr;m) of the charge transport layer at the middle portion of the conductive support in its generatrix direction, the layer thickness b0 (&mgr;m) of the protective layer at the middle portion of the conductive support in its generatrix direction, the layer thickness a (&mgr;m) of the charge transport layer at a portion other than the middle portion and the layer thickness b (&mgr;m) of the protective layer at the portion other than the middle portion satisfy the following expression (1) in a region satisfying 0.8 (&mgr;m)≦(a0−a)≦3.

Abstract: A phenolic compound having a plurality of substituted hydroxyphenyl groups and charge-transportable structure, the substituted hydroxyphenyl groups of which have a hydroxymethyl group; and a resol resin obtained by allowing a phenolic compound having hydroxyphenyl groups and charge-transportable structure, to react with formaldehyde in the presence of a basic catalyst, and having charge-transportable structure. Also disclosed are a cured product and an electrophotographic photosensitive member which make use of the above, and a process cartridge and an electrophotographic apparatus which have the electrophotographic photosensitive member.