| 摘要 |
PURPOSE:To obtain the powder of needled-shaped magnetic particles which are conformal to a resin by compressing and shearing needle-shaped particles wherein the surface of the particle is convered with an organic compound having a hydrophobic group, the major axis length is within a specified range, and iron is the main component, and spreading the particles with a spatula. CONSTITUTION:Needle-shaped particles wherein the surface of the particle is convered with an organic compound having a hydrophobic group, the major axis length is 0.1-0.3mum and iron is the main component are kneaded by compression, shearing and spatula spreading by using a wheel-type kneading machine of an attritor. Thus, the aggregation of the powder of the needle-shaped particles is released, and the powder of the needle-shaped magnetic powder is obtained. The liquid absorbing quantity of the obtained powder of the needle-shaped particles is measured by using a resin solution containing 20 weight % of styrene-acryl resin and xylene. Then, the liquid absorbing quantity of the powder of the needle-shaped magnetic particles indicates 18ml. Thus, the magnetic particle powder which is compatible to resin, is obtained. Namely, the gloss of the surface of a resin molded film containing the powder of the needle-shaped particles indicates 90% when the gloss is measured at the incident angle of 20 degrees. |
