| 摘要 |
PURPOSE:To provide the developing roll which exhibits excellent leak resistance, maintains stable image densities in spite of an environmental change and effectively lessens the adverse influence on images. CONSTITUTION:This developing roll 20 is constituted by laminating and forming at least one layer of semiconductive coating layers 24 on the outer peripheral surface of a conductive base layer 22 forming a cylindrical surface. These semiconductive coating layers 24 are formed of a material which is prepd. by mixing an electron conductive material and ion conductive material with a binder resin and has 10<10> to 10<12>OMEGAcm volumetric resistivity (R) in the mixed state of the electron conductive material with the binder resin and has 10<7> to 10<12>OMEGAcm volumetric resistivity (R) in the mixed state of the ion conductive material mixed with the binder resin. |
