A charging roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The average of heights of contours of convex portions on a surface of the surface layer relative to an average cylindrical surface obtained by averaging surface irregularities of the surface layer is equal to or greater than 2.0 micrometers and is equal to or less than 8.4 micrometers. The average of intervals between apexes of the convex portions on the surface of the surface layer is equal to or greater than 6.7 micrometers and is equal to or less than 39.8 micrometers.

A resin sliding bearing includes: a bearing surface for slidingly bearing a shaft; and a hollow that communicates with the bearing surface through to a different surface of the bearing.

The present invention provides a grease composition or a lubricating oil composition which is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface of a rolling bearing, is excellent in durability in a high temperature and speed operation, and can be used for a long time. A grease-packed bearing (1) has an inner ring (2), an outer ring (3), and a plurality of rolling elements (4). A sealing member (6) for sealing a grease composition (7) is provided at openings (8a) and (8b) disposed at both axial ends of the inner ring (2) and the outer ring (3). The grease composition (7) includes a base grease composed of a base oil and a thickener and an additive added to the base grease. The additive contains at least one compound selected from among plant-derived polyphenolic compounds and compounds formed by decomposition thereof. The above-described compounds include tannin, gallic acid, ellagic acid, chlorogenic acid, caffeic acid, curcumin, quercetin, and quinic acid.

To provide a conductive member for an electrophotographic machine that is capable of preventing hardening degradation of a surface layer that is caused by an ionic conductive agent contained in a conductive rubber elastic body layer, allowing the surface layer to be improved in durability.

A conductive member 10 for an electrophotographic machine includes a conductive rubber elastic body layer 14 containing crossiinked rubber and an ionic conductive agent, and a surface layer 16 provided on an outer periphery of the conductive rubber elastic body layer 14, wherein the surface layer 16 contains a polymer and polyphenol. Examples of the polyphenol include a tannin, gallic acid, ellagic acid, pyrogallol, catechin, and chlorogenic acid.

A charging roller includes a conductive support, and a roller body to rotate about the conductive support. The roller body includes a conductive elastic layer to contact the conductive support, and a conductive resin layer located around the conductive elastic layer to form a surface of the roller body. The surface has ten-point average roughness Rzjis of approximately 20 μm to 30 μm. The conductive resin layer contains polyrotaxane.

A charging roll includes a core member, a rubber base material disposed around the core member, and a surface layer disposed around the rubber base material. The average of heights of contours of convex portions on a surface of the surface layer relative to an average cylindrical surface obtained by averaging surface irregularities of the surface layer is equal to or greater than 0.8 micrometers and is equal to or less than 2.1 micrometers. The average of intervals between apexes of the convex portions on the surface of the surface layer is equal to or greater than 6.6 micrometers and is equal to or less than 11.5 micrometers.

A joint for a composite frame includes a first composite rod, a first shell abutting the first composite rod, a second shell abutting the first composite rod and disposed opposite the first shell relative to the first composite rod. The first and second shells are joined together such that composite rod is fixed therebetween. A method of forming joints of composite frame includes forming a composite frame by interconnecting a plurality of composite rods formed by an Automated Fiber Placement (AFP) manufacturing method around a mandrel, applying a first shell to the plurality of composite rods at a first location where composite rods are interconnected, applying a second shell at the first location opposite the first shell relative to the composite rods, and joining the first and second shells together with the composite rods at the first location disposed between the first and second shells.

A charging roller includes a conductive support, and a roller body to rotate about the conductive support. The roller body includes a conductive elastic layer to contact the conductive support, and a conductive resin layer located around the conductive elastic layer to form a surface of the roller body. The surface has ten-point average roughness Rzjis of approximately 20 μm to 30 μm. The conductive resin layer contains polyrotaxane.

Provided is a charging roller that can achieve excellent image quality and prevent detachment of particles in its surface layer. A charging roller 1 comprises a shaft 2 and, on an outer circumferential side of the shaft 2, at least a base layer 3 and a surface layer 4, wherein the surface layer 4 contains a binder resin 41 and particles 42, and the particles 42 contain 50 mass% or more of a same component A as at least one selected from components constituting the binder resin 41, and a content of the particles in the surface layer is 30 parts to 120 parts by mass with respect to 100 parts by mass of the binder resin.

Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.