Patent ID: 8652736

Claim:
An electrophotographic developer carrier core material that is obtained by mixing, and optionally calcining, a starting material comprising: (a) 0.5 μm to 2 μm diameter particles formed by pulverizing a mixture comprising magnetic oxide powder and resin, or silica particles with an average particle size of 1 μm to 10 μm mixed with 0.5 μm to 2 μm particles formed by pulverizing magnetic oxide powder; (b) a binder; (c) a dispersant; to form a mixed material, and sintering said mixed material, wherein 0.25≦A≦0.40 is satisfied where A is an apparent density/true density ratio of the electrophotographic developer carrier core material, the apparent density of the electrophotographic developer carrier core material is 2.0 g/cm 3 or less.