| 摘要 |
PURPOSE:To obtain a sufficient amount of polymer for holding a mechanical strength of molding, make high the density and improve magnetic characteristic by coating the polymer to the surface of magnetic powder of ferrite system through polymerization due to contact between such powder and monomer and then executing press molding under the magnetic field. CONSTITUTION:Single or two kinds of monomers, selected from the dienes such as butadiene, isoblene, chloroblene and monomers allowing radical polymerization or radical co-polymerization such as acrylonitrile, acrylamide and methacrylamide, and magnetic material powder of ferrite system are maintained under the close-contact condition in view of polymerization under the existence of catalyst for polymerization. Thereby, the magnetic material powder of ferrite system is coated by homopolymer or copolymere. Amount of monomer should desirably be in the range of 1-20% in terms of weight for the magnetic material powder of ferrite system. It is desirable for the obtained composition of magnetic material powder of ferrite system, in the case of executing magnetic field press by the wet method, to adjust the concentration so that the slurry in the constant concentration can be obtained. In this case, the slurry in moistened condition contains the solid matter concentration of 20-70wt%. |
