| 摘要 |
PURPOSE:To obtain the titled microspheres, by cooling a molten mixture consisting of a thermoplastic resin as a base, an incompatible component and a fine magnetic material powder, adding this to a polar solvent for the resin to form microspheres of the resin containing the fine magnetic material powder. CONSTITUTION:A thermoplastic resin A as a base is mixed with component B incompatible with A and a fine magnetic material powder C at such a mixing ratio that B forms a continuous phase and A forms a dispersed layer, the amount of A+B is 100pts.wt. and the amount of C is 1-1,000 and at a temperature higher than any of the melting points of A and B and lower than the melting point of C. The molten mixture is solidified by cooling and the solidified product is disintegrated by immersion in a solvent D which acts as a poor solvent for A but acts as a good solvent for B to dissolve B in solvent D and at the same time to produce a suspension containing dispersed microspheres of A containing fine powders C and fine powders C alone. The microspheres of A containing powder C is separated from this suspension to obtain the titled microspheres. |
