Abstract: A charging member includes a conductive mandrel, a semiconductive foamed elastic layer provided on the periphery of the mandrel, and a functional double-layer film provided on the periphery of the semiconductive foamed elastic layer. The semiconductive foamed elastic layer is a layer formed by making the mandrel and a semiconductive rubber composition standing uncured and unfoamed pass through a crosshead die of an extruder to set the composition on the periphery of the mandrel, followed by curing and foaming. The semiconductive rubber composition has a Mooney viscosity of from 15 to 30 and has a curing percentage of 40% or less when the foaming pressure reaches 50%. The functional double-layer film is a double-layer tube having a thin layer such that a tube formed out of only the layer is hard to use for covering. Also disclosed are a process cartridge and an electrophotographic apparatus which have such a charging member.

Abstract: The invention is a degradable polyurethane resin obtained by reacting 2,5-/2,6-diisocyanatomethylbicyclo[2.2.1]heptane and/or a modified compound thereof with polyol comprising a single compound, mixture or copolycondensate selected from the group consisting of (A) polyhydroxycarboxylate polyol, (B) aliphatic polyester polyol and (C) saccharides, or (D) straight or branched polyol formed by condensation of (A) and/or (B) with aliphatic polyhydric alcohol having functionality of three or more, and the polyurethane resin has hydralyzability and biodegradability, is excellent in rigidity and elasticity in combination with flexibility as compared with conventionally known biodegradable resin, and can provide formed articles having outstandingly high elasticity and elongation and other unprecedented properties.

Abstract: A charging member comprising a conductive mandrel, a semiconductive foamed elastic layer provided on the periphery of the mandrel, and a functional double-layer film provided on the periphery of the semiconductive foamed elastic layer. The semiconductive foamed elastic layer is a layer formed by making the mandrel and a semiconductive rubber composition standing uncured and unfoamed pass through a crosshead die of an extruder to set the composition on the periphery of the mandrel, followed by curing and foaming. The semiconductive rubber composition has a Mooney viscosity of from 15 to 30 and having a curing percentage of 40% or less when the foaming pressure reaches 50%. The functional double-layer film is a double-layer tube having a thin layer such that a tube formed out of only the layer is hard to use for covering. Also disclosed are a process cartridge and an electrophotographic apparatus which have such a charging member.

Abstract: A preparation process of isoimide comprising reacting a compound having one or more carboxyl group and one or more amide bond in the same molecule in the presence of a haloiminium salt and basic substance, and a preparation process of isoimide comprising reacting a compound having one or more carboxyl group with a compound having one or more amide bond in the presence of a haloiminium salt and basic substance are disclosed.

Abstract: A preparation process of solid polyhydroxycarboxylic acid comprising subjecting an organic solvent solution of polyhydroxycarboxylic acid to cooling.cndot.solidification and grinding. The preparation process can provide high molecular weight solid polyhydroxycarboxylic acid with ease and cheaply, can be converted with ease to a continuous system, and is useful in industry.