MAGNETIC FLUID AND PROCESS FOR THE PRODUCTION THEREOF

摘要

A magnetic fluid which can work powerfully and at high precision under the action of an external magnetic field, is remarkably increased in the viscosity by applying an external magnetic field and regulating it, can be controlled in the viscosity easily and accurately, is excellent in the oxidation resistance of the particles and the dispersibility thereof, and exhibits satisfactorily large viscosity characteristics; and a process for the production of the same. The fluid is characterized in that magnetic metal particles covered with antioxidant films are stably dispersed in a solvent and that the stable dispersion is maintained, and the process is characterized by forming oxide films on the surfaces of starting oxide particles for the production of magnetic metal particles, reducing the resulting oxide particles to form magnetic metal particles covered with antioxidant films, and dispersing the magnetic metal particles covered with antioxidant films in a solvent stably.