| 摘要 |
PURPOSE:To obtain a metallic magnetic fluid having excellent stability and durability by dispersing ferromagnetic metallic particles into a dispersion medium liquid under a colloidal state by using a dispersant of succinic acid polyamine or benzil polyamine. CONSTITUTION:A Langmuir membrane consisting of a surface active agent of dibenzil polyamine (DPA) is lined onto a dispersion medium liquid of alkyl naphthalene, Co is vacuum-deposited on the membrane, thus acquiring colloid composed of C fine particles coated with DPA, alkyl naphthalene and excess DPA. Colloid is diluted with lower hydrocarbon such as benzene, and secondary particles, the particle size of Co therein increases through heat treatment, are precipitated. The secondary particles are dried, thus obtaining semi-solid cake. Toluene and DPA are added to the cake, and a magnetic fluid employing toluene as a dispersion medium liquid is obtained through ultrasonic treatment. Succinic acid polyamine can also be used in place of DPA. |
