| 摘要 |
PURPOSE:To obtain a resin magnet having excellent magnetic properties and high mechanical strength, by incorporating a polyamide copolymer in a part of or all of a polyamide resin which is mixed and kneaded with ferromagnetic powder to provide a resin magnet material. CONSTITUTION:Ferromagnetic powder is mixed and kneaded with matrix of a polyamide resin, a part of which or all of which contains a polyamide copolymer. The polyamide and the polyamide copolymer preferably take a form of powder in view of uniform distribution or the like. The ferromagnetic powder may be a hard ferrite such as barium ferrite or strontium ferrite, or rare-earth cobalt magnetic powder such as samarium or cobalt. Strontium ferrite, which has previously been mixed with a coupling agent and surface treated, is incorporated with the polyamide resin and mixed by a super mixer. The mixture is then kneaded by a biaxial extruder to shape into pellets. In this manner, the material is allowed to be in semicrystal state for a longer period of time while it is shaped within magnetic field. Thus, the orientation of the ferromagnetic powder is improved whereby resultant products are allowed to have high magnetic properties. |
