| 摘要 |
The present invention can provide small-diameter core material particles for electrophotographic carrier, the particles that can prevent occurrences of carrier adhesions and reduce toner spent, have excellent durability and cause little fluctuations in image density with a narrow particle diameter distribution, and an efficient, cost-effective production method thereof That is, the core material particles for electrophotographic carrier are particles wherein the weight average particle diameter, Dw, is in the range of 22µm to 32µm, the ratio of Dw to the number average particle diameter, Dp, satisfies the condition, 1<Dw/Dp<1.20, the content of particles smaller than 20µm in diameter is in the range of 0% by mass to 7% by mass and smaller than 36µm is in the range of 90% by mass to 100% by mass, and the BET specific surface area is in the range of 300cm 2 /g to 900cm 2 /g. |
