| 摘要 |
PURPOSE:To obtain a rare earth based resin magnet having stability against a variety of chemicals and low magnetic field magnetization by specifying the ratio of ferromagnetic powder and the said resin using a specific composition of ferromagnetic powder and polyvinylidene fluoride. CONSTITUTION:The compounding ratio of strong magnetic powders having low magnetic field magnetization obtained by blowing high pressure inactive gas to melts of a rare earth element-transition metal element-boron based alloy and letting it to cool quickly, and poilyvinylidene fluoride is set to 70:30-95:5 (weight ratio). If the compounding ratio is lower than 70/30, the occupancy ratio of strong magnetic powders is small, causing insufficient magnetic characteristics. If it is more than 95/5, the forming process in forming raw material compounds to resin magnets becomes difficult. Rare earth based resin magnets obtained have stable corrosion resistance against a variety of chemicals such as organic acid, inorganic acid, salt, fatty acid, aromatic hydrocarbon, chlorine based hydrocarbon, alcohol, halogen solution, etc., and have excellent high coercive force and low magnetic field magnetization. |
