| 摘要 |
PROBLEM TO BE SOLVED: To form a satisfactory image with high transfer efficiency by incorporating magnetic powder treated with silane coupling into a toner. SOLUTION: This electrophotographic developer contains a carrier and a toner contg. a bonding resin, a colorant and magnetic powder treated with silane coupling. The amt. of the magnetic powder is preferably 0.1-2.0 pts.wt. to that of this developer and the resistance of the toner is preferably 5×10<9> -3×10<11> Ω.cm. In this pref. ranges, stable transfer efficiency can be maintained without increasing residue on transfer in the early stage and at the life end and the carrier does not stick. In the case of <0.1 pts.wt. of the magnetic powder, the effect of the added magnetic powder is not produced and transfer efficiency deteriorates. In the case of >2.0 pts.wt., the lowering of image density and the blurring of a solid part may be caused because the flowability of the developer deteriorates and it is difficult to feed the developer onto a developing roll. |
