| 摘要 |
PURPOSE:To improve oxidation-resisting property and also to improve water-resisting property, temp. and moisture resisting property, salt-water resisting property, chemical resisting property and the like by a method wherein a polymerized coating, consisting of either of natural Japanese laquer or synthetic laquer or a mixture of both, is provided on the surface of the title permanent magnet. CONSTITUTION:Either natural Japanese laquer or synthetic laquer or a mixture thereof can be used as a Japanese laquer composition. Natural Japanese laquer is suitable as the laquer to be used, and among them, urushiol is especially considered advantageous when it is used as a coating material, because it has the largest number of non-saturation double coupling which can be brought into a state of oxidative polymerization. The viscosity of the above- mentioned laquer is decreased by diluting it, the diameter of dispersion particles is finely controlled by agitating it intensely, and besides, when various dry-hardening accelerators are added, a coating material, with which uniform coating can be conducted, is obtained. A coating operation is conducted by dipping a magnet into the above-mentioned coating material, and when heat treatment is performed for dry-hardening, a polymerized thin film having high corrosion-preventing effect can be obtained. Also, pertaining to synthetic laquer, various kinds of laquer-like substances are developed, and any of them can be used. |
