PURPOSE: To obtain a plastic magnet having both excellent tenacity and heat resisting property by a method wherein the ratio of specific mixed binder of nylon 6 and nylon 46, and the magnetic powder, selected from the group of ferrite, samarium and neodymium magnetic materials, is specifically prescribed.
CONSTITUTION: The mixing weight ratio of nylon 6 and nylon 46 is 20 to 60 pts.wt. for the nylon 6 and 40 to 80 pts.wt. for the nylon 46. If the mixing ratio of the nylon 6 becomes smaller than the above, the tenacity of a binder decreases, the freely adjustment of the filling rate of magnetic powder becomes difficult, and therefore, this is considered undesirable. On the contrary to the above, if the mixture ratio of the nylon 46 becomes smaller than the above, the heat resistance such as soldering heat resistance decreases rapidly, and this is also undesirable. On the other hand, the magnetic powder having the average diameter of 0.5 to 10μm is used favorably, and also the quantity of the magnetic powder in a plastic magnet is to be within the range of 50 to 95wt.%. As a result, a plastic magnet having remarkably excellent heat-resisting property and the tenacity represented by a bending and breaking strain can be obtained.
TSUJI TOSHIO
HAYASE SHIGERU
