MANUFACTURE OF COBALT CONTAINING MAGNETIC IRON OXIDE POWDER

摘要

PURPOSE:To obtain a cobalt containing magnetic iron oxide powder improved in the characteristics by reacting to produce and to absorb specific diamine salt compound to the surfaces of cobalt containing magnetic iron oxide particles of high specific surface area by a special treating method. CONSTITUTION:Cobalt containing magnetic iron oxide particles having specific surface area of 35m<2>/g or higher of BET value are reacted with aqueous soluble compound of aqueous soluble compound of diamine and fatty acid in aqueous slurry in iron particles to absorb the reacted product on the surfaces of the iron particles. The aqueous soluble compound of diamine is represented by the general formula of R<1>NH(CH2) (where R<1> is alkyl, alkenyl or aryl group having 6 or more carbons, and n is integer number of 1-10). The aqueous soluble compound of the fatty acid is represented by the general formula of R<2>COOH (where R<2> is alkyl, alkenyl or aryl having 6 or more carbons).