| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ferrite carrier core material for electrophotographic developer with little fluctuation caused due to environmental changes in its electric properties including a charge amount, with which a desired stable charge amount is obtained, a ferrite carrier and method for producing them, and an electrophotographic developer containing the ferrite carrier. <P>SOLUTION: A ferrite carrier core material for electrophotographic developer having a Cl concentration, measured using an elution method, of 0.1-100 ppm, of a ferrite carrier core material consisting of ferrite particles having an apparent density of 2.30-2.80 g/cm<SP POS="POST">3</SP>, a BET specific surface area of 0.09-0.70 m<SP POS="POST">2</SP>/g, and an average circularity of 0.90 or more; a ferrite carrier for electrophotographic developer which is obtained by coating the ferrite core material with a resin; method for producing them; and an electrophotographic developer containing the ferrite carrier are adopted. <P>COPYRIGHT: (C)2012,JPO&INPIT |
