| 摘要 |
PURPOSE:To obtain the titled powder having superior dispersibility under hydrophobic conditions by dispersing ferromagnetic powder of a metallic compound or the like in an acidic or basic electrolyte soln. of a prescribed pH, and treating the powder with a soln. prepared by mixing a surfactant which is reverse in electric charge to the surface of the powder with a hydrophilic solvent. CONSTITUTION:Ferromagnetic powder of a metallic compound such as Fe3O4 contg. Co is dispersed in an electrolyte soln. of 1.5-3.5 or 10.5-13.0pH, or ferromagnetic powder of a metal such as Fe or an alloy thereof is dispersed in an electrolyte soln. of 10.5-13.0pH. An aqueous soln. of HCl, H2SO4 or the like is used as the acidic electrolyte soln., and an aqueous soln. of NaOH, KOH or the like is used as the basic electrolyte soln. The surface of the ferromagnetic powder after the dispersion treatment is treated with a soln. prepared by mixing a surfactant which is reverse in electric charge to the surface of the powder with a hydrophilic solvent such as water to obtain desired novel surface-treated ferromagnetic powder. |
