| 摘要 |
PURPOSE:To prevent the electric conductivity of a molded item even at elevated temperature from deteriorating by a method wherein pellet-shaped master pellets, each of which is produced by coveringly and integrally forming a thermoplastic resin layer on the surface of electrically conductive filler consisting of copper fibers and low melting metal, are blended with thermoplastic pellets. CONSTITUTION:Master pellets are produced by coveringly forming a thermoplastic resin layer on the surface of electrically conductive filler material, which is formed by gathering long copper fibers and low melting metal, through the die of an extruder and, after that, by cutting the resultant electrically conductive filler material covered by the thermoplastic layer into pellets. There is no special limitation as for the shape of the section of the pellet and circular section, which is the ordinary sectional shape of the master pellet, flat section or the like may be acceptable. An electrically conductive resin composition is prepared by blending natural pellets consisting of thermoplastic resin only with the master pellets. The kind and amount of thermoplastic resin as the natural pellets to blend are properly selected in accordance with the characteristics requested by the electrically conductive resin composition and a molded item obtained. By employing the copper fibers and the low melting metal in combination, the junction points between the copper fibers are fused together by a low melting metal, resulting in forming a strong reticulate joining among the fibers and consequently developing no deterioration in thermal conductivity. |
