Electrophotographic member, process cartridge and electrophotographic apparatus

A process cartridge configured to be detachably attached to a main body of an electrophotographic image forming apparatus, the process cartridge comprising at least one electrophotographic member selected from the group consisting of a charging member, a development member and a cleaning member,

• the electrophotographic member comprises an electro-conductive substrate and a resin layer as a surface layer on the substrate, the resin layer comprising a urethane resin having a structure of formula (1), an anion and a resin particle, the resin layer further comprising carbon black
• where, R1 represents a hydrogen atom, or a monovalent hydrocarbon group having 1 to 12 carbon atoms, X1 to X3 independently represent a structure selected from the group consisting of formulae (X101) to (X103), or a monovalent hydrocarbon group having 1 to 12 carbon atoms, with the proviso that at least one of X1 to X3 is one of formulae (X101) to (X103)
• where R2 represents a linear or branched divalent hydrocarbon group, R3 represents a linear or branched divalent hydrocarbon group, R4 represents a linear or branched divalent hydrocarbon group, * represents a point of attachment to a nitrogen atom in formula (1), and ** represents a point of attachment to a carbon atom in a polymer chain forming the resin;
• and
• the electrophotographic member having a protrusion derived from the resin particle on an outer surface thereof, the resin particle comprising at least one of a urethane resin and a polyamide resin, wherein
• carbon black extracted from the resin layer has a BET specific surface area of 33 to 133 m2/g, and DBP absorption amount at a 70% torque value in DBP absorption measurement of 42 to 90 ml/100 g, and
• 1468≤Z2/Z1≤20175 and 0.056≤Z3/(Z2·Z4)≤0.813 when Z1 is an ionic equivalent (eq) of a resin of structural formula (1) contained in 1 part by mass of the resin layer, Z2 is a content (parts by mass) of the carbon black contained in 100 parts by mass of the resin layer, Z3 is a percentage (%) of the cross-sectional area of the resin particle in a cross-sectional area of the resin layer, and Z4 is d90 (μm) in a cumulative distribution of an area-equivalent diameter of the resin particle in the cross-sectional area of the resin layer.

An electrophotographic image forming apparatus, comprising:

• an electrophotographic photosensitive member;
• a charging member disposed such that the electrophotographic photosensitive member can be charged;
• a development member;
• and
• a cleaning member,
• at least one of the charging member, the development member and the cleaning member being an electrophotographic member comprising an electro-conductive substrate, with a resin layer as a surface layer on the substrate,
• the resin layer comprising a urethane resin having a structure of formula (1), an anion and a resin particle, the resin layer further comprising carbon black
• where R1 represents a hydrogen atom, or a monovalent hydrocarbon group having 1 to 12 carbon atoms, X1 to X3 independently represent a structure selected from the group consisting of formulae (X101) to (X103), or a monovalent hydrocarbon group having 1 to 12 carbon atoms, with the proviso that at least one of X1 to X3 is one of formulae (X101) to (X103)
• where R2 represents a linear or branched divalent hydrocarbon group, R3 represents a linear or branched divalent hydrocarbon group, R4 represents a linear or branched divalent hydrocarbon group, * represents a point of attachment to a nitrogen atom in formula (1), and ** represents a point of attachment to a carbon atom in a polymer chain forming the resin;
• and
• the electrophotographic member having a protrusion derived from the resin particle on an outer surface thereof, the resin particle comprising at least one of a urethane resin and a polyamide resin, wherein
• carbon black extracted from the resin layer has a BET specific surface area of 33 to 133 m2/g, and DBP absorption amount at a 70% torque value in DBP absorption measurement of 42 to 90 ml/100 g, and
• 1468≤Z2/Z1≤20175 and 0.056≤Z3/(Z2·Z4)≤0.813 when Z1 is an ionic equivalent (eq) of a resin of structural formula (1) contained in 1 part by mass of the resin layer, Z2 is a content (parts by mass) of the carbon black contained in 100 parts by mass of the resin layer, Z3 is a percentage (%) of the cross-sectional area of the resin particle in a cross-sectional area of the resin layer, and Z4 is d90 (μm) in a cumulative distribution of an area-equivalent diameter of the resin particle in the cross-sectional area of the resin layer.