| 摘要 |
PROBLEM TO BE SOLVED: To provide: a ferrite carrier core material of resin filled type for electrophotographic developer, capable of maintaining high electrostatic charging performance for a long time while holding advantages of the carrier of resin filled type, obtaining a high grade quality of image, and reducing the number of defects of image; a ferrite carrier; and the electrophotographic developer by using this ferrite carrier. SOLUTION: The ferrite carrier core material of resin filled type for the electrophotographic developer is formed of porous ferrite particles. The composition of the porous ferrite particle is expressed by the formula (1): (MgO)x(Fe<SB>2</SB>O<SB>3</SB>)y, wherein a part of (MgO) and/or (Fe<SB>2</SB>O<SB>3</SB>) is substituted for SrO, x=10 mol% or more and less than 25 mol%, y=above 75 mol% and 90 mol% or less, x+y=100 mol%. The ferrite carrier is formed by filling voids in the ferrite carrier core material with resin. The electrophotographic developer using this ferrite carrier is provided. COPYRIGHT: (C)2011,JPO&INPIT |
