PROCESS FOR PRODUCING RARE EARTH BOND MAGNET, COMPOSITION FOR RARE EARTH BOND MAGNET, AND RARE EARTH BOND MAGNET

摘要

A process for producing a rare earth bond magnet comprising the steps of first mixing rare earth magnetic powder, a binding resin and an anti-oxidant at a predetermined ratio, kneading the mixture at a temperature higher than a thermal deformation temperature of the binding resin, granulating or classifying the kneadate to a mean particle diameter of, e.g., about 0.01 to 2 mm, press-molding the resulting granular material at a first temperature at which the binding resin is softened or molten, and cooling the resulting molded article under a pressure to a second temperature lower than at least the first temperature. Consequently, a rare earth bond magnet having a low porosity, high dimensional accuracy and excellent magnetic characteristics can be obtained.