| 摘要 |
PURPOSE:To form a copy image of high picture quality by using specific setting resin for the base material of a conductive layer and dispersing conductive particles in the base material. CONSTITUTION:The conductive roll is constituted by forming the conductive layer 12 on the outer periphery of a shaft body 11 along the circumference and the conductive layer 12 is formed by using the setting resin, derived from resin A between tert-butyl phenol novolak resin A and phenol novolak resin B and a setting agent, and dispersing conductive material particles in the base material. Namely, a material consisting principally of tert-butyl phenol novolak resin (tBu-phenol novolak) is used as the conductive resin material which constitutes the developing roll and when negative electrostatically charged toner is charged electrostatically to the negative polarity by using the developing roll which uses the roll, the electrosatic charging quantity of negative charges to the negative electrostatically charged toner is improved since the tert-buthy group is high in electron donative ability. Consequently, the picture quality increase effect of the copy image can be obtained. |
