| 摘要 |
PROBLEM TO BE SOLVED: To solve the following problems: the use of carbon black is being restricted, for example, in EC because carbon black falls under materials (IARC group B) as subjects to regulation in terms of effect on the human body and environmental protection, and though magnetite is considered to be a substitute for carbon black, commercially available magnetite for a toner takes on a color tone tinted with red or has insufficient hiding power because it has a volume average particle diameter of 0.1-0.5μm. SOLUTION: This electrostatic charge image developing toner consists essentially of a binder resin and a colorant, and is held on a surface of a non-magnetic developing roll. The colorant is based on magnetite consisting of a plurality of groups of particles different from each other in particle size distribution. It is preferable that the magnetite consists of a group of particles having a volume average particle diameter of primary particles in the range of 0.2-0.5μm and a group of particles having a volume average particle diameter of primary particles in the range of 0.05-0.2μm. COPYRIGHT: (C)2004,JPO&NCIPI |
