| 摘要 |
<p>A carrier core material for an electrophotographic developer containing Li ferrite, maghemite, and Fe 3 O 4 , wherein a part thereof is substituted with Mn, a Li content is 1 to 2.5% by weight, a Mn content is 2 to 7.5% by weight, and a silicon content is 25 to 10,000 ppm, a compression breaking strength is 130 MPa or more, an SF-1 is 125 to 145, respective cumulative strengths of respective spinel crystal structure faces in X-ray diffraction satisfy a certain equation, a vacuum resistivity R 500 across a 2 mm gap when a measurement voltage of 500 V is applied is 1×10 6 to 5×10 9 ©, and a vacuum resistivity R 1000 across a 6.5 mm gap when a measurement voltage of 1,000 V is applied is 5×10 7 to 1×10 10 ©.</p> |
