| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain good electrostatic charge build-up performance and stable charges and image density without depending on the use environment by using a developer comprising a toner of specified color particles having specified volume average particle size and BET specific surface area and a magnetic carrier of a binder type carrier. SOLUTION: This developer consists of at least a toner of color particles having 3 to 7μm volume average particle size and a magnetic carrier. The color particles have >=5.0m<2> /g BET specific surface area and the carrier is a binder type carrier comprising a resin and a magnetic powder dispersed in the resin. Namely, by increasing the specific surface area of color particles which constitute a small particle toner and by using the binder type carrier as a carrier, excellent build-up property for electrification is obtd., this effect can be maintained for a long time, and environmental stability during formation of an image can be improved. The toner having a large specific surface area has more electrification sites with excellent charge holding property, which improves the charge producing rate.</p> |
