METHOD FOR PREVENTING OXIDATION OF IRON OR IRON ALLOY POWDER

摘要

PURPOSE:To form a stable oxidation preventing film on the surface of the iron (alloy) powder to be used for a magnetic material or the like by dipping the iron (alloy) powder formed with an inorg. polymer film in an org. non-polar solvent dissolved with benzoic acid therein and subjecting the same to a dispersion treatment. CONSTITUTION:An inorg. polymer film of >=2.5% silicon oxide or the like based on the weight of Fe is formed on the surface of ferromagnetic iron powder or ferromagnetic iron alloy powder. The coated iron (alloy) powder is dipped in a non-polar org. solvent such as toluene or the like dissolved with benzoic acid or the deriv. therein and is subjected to a dispersion treatment. The benzoic acid or the deriv. thereof is adsorbed on the outside surface of the iron (alloy) by such treatment to form the stable oxidation preventing film thereon. The oxidation preventing film gives no adverse influences when the powder is made into paints or magnetic tapes.