| 摘要 |
PURPOSE:To enable high dispersion in a short period of time, by impressing a revolving magnetic field from the outside of a container of paint of a dispersing device, exerting a rotational force to magnetic powder so that shearing forces acting on the magnetic powder are increased. CONSTITUTION:A three sets of coils 4 to impress revolving magnetic fields are disposed around a nonmagnetic container of paint 2 each coil being shifted at equal angular intervals of 90 deg. in a circumferential direction. When revolving magnetic fields are applied to magnetic paint in the container 2 from outside, rotational forces due to magnetic action as well as mechanical shearing forces act on the magnetic powder so that dispersion of the magnetic powder is enhanced, while the magnitude of the magnetic field is made smaller than the coercive force of the magnetic powder to prevent the occurrence of switching of magnetization. By application of the magnetic powder obtained as magnetic paint for manufacture of magnetic recording medium, excellent magnetic characteristics will be obtained. |
