| 摘要 |
PROBLEM TO BE SOLVED: To provide a carrier core material in which degradation of the carrier such as peeling off of coating resin due to long-term use can be significantly suppressed, stable charging performance is maintained, and the particles are free from cracks or chipping.SOLUTION: Disclosed is a carrier core material having, as a main component, a material represented by the composition formula MnMFeO(where M is at least one kind of metal selected from the group consisting of Mg, Ti, Cu, Zn and Ni, and 0<X, 0≤Y and 0<X+Y<1). At least one of Sr element and Ca element contains 0.1 mol% to 1.0 mol% as the total amount in terms of SrO or CaO. Out of grain appearing on the surface of carrier core material particles, the appearance frequency of grain whose length RSm is 8.0 μm or more is 2.0 number% or less.SELECTED DRAWING: Figure 1 |
