IRON OXIDE PARTICLE AND ITS PRODUCTION

PROBLEM TO BE SOLVED: To produce iron oxide particles used as a material powder for an electrostatic copying magnetic toner, a material powder for a carrier for electrostatic latent image development, a black pigment powder, etc., for coating materials, excellent in fluidity, dispersibility, handleability, hygroscopic stability, etc., to environmental changes and optionally regulating the resistance and to provide a method for producing the iron oxide particles. SOLUTION: The iron oxide particles are coated with a compound iron oxide layer of Al and Fe and then coated with an Al component. The iron oxide particles are produced by adding and mixing a water-soluble Al salt, a ferrous salt and an aqueous solution of an alkali with a slurry produced by a wet process and containing the iron oxide particles, carrying out oxidation at pH 5-12 and 60-98 deg.C, coating the iron oxide particles with a compound iron oxide layer of Al and Fe and further adding a water-soluble Al component thereto and then coating the coated iron oxide particles with the Al component at pH 3-10.