Iron oxide particles and process for producing the same

摘要

Iron oxide particles comprising: 100 parts by weight of material iron oxide particles having a specific surface area represented by the formula (1): $wherein\; rho\; represents\; the\; specific\; gravity,\; d3\; represents\; the\; area-average\; particle\; diameter\; (0.1\; mu\; m/g,\; and\; the\; increment\; of\; said\; specific\; surface\; area\; with\; respect\; to\; the\; amount\; of\; aid\; fine\; particles\; being\; not\; less\; than\; 0.35.$