| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing roller with appropriate positive charging property on its top surface without spoiling characteristics such as original stiffness and elasticity with just a small amount of amino group by having the amino group exist on the surface brought into contact with developer in order to give negative charging property to toner contained in the developer. SOLUTION: The developing roller is provided with an energized shaft and elastic layer and one or more layer(s) of coating layer(s) on the outer periphery of the shaft sequentially and develops an electrostatic latent image on an electrostatic latent image carrier by negative charge developer carried on its surface. The coating layer which is the surface layer contains positive charge control resin composed of a copolymer obtained by polymerizing a specific (meta) acrylate esther monomer and amino group containing monomer. When the surface is measured by a time-of-flight secondary ion mass spectrometer, percentage of maximum ionic strength derived from the amino group to total ion strength up to molecular weight 1850 is 0.5% or more. COPYRIGHT: (C)2007,JPO&INPIT |
