| 摘要 |
PURPOSE:To manufacture electric wires with high foam ratio by introducing not less than a specified pts. by wt. of at least one kind of fatty acid metal salts and metal oxides and not less than a specified pts. by wt. of thermally expansive fine hollow spheres into an extruding machine together with 100 pts. by wt. of polyolefin containing not less than a specified wt.% of maleic anhydride. CONSTITUTION:Together with 100 pts. by wt. of polyolefin containing 0.001wt.% or more maleic anhydride, not less than 0.05 pts. by wt. of at least one kind of fatty acid metal salts and metal oxides and not less than 5 pts. by wt. of thermally expansive fine hollow spheres are introduced into an extruding apparatus. After these substances are heated and kneaded, the outer circumference of a conductor is coated by extrusion of the mixture. Consequently, ionic bonds are formed between the maleic anhydride and the fatty acid metal salts and metal oxides and tension of molten polymer is raised, so that foams become fine and as a result, the outer diameter fluctuation at the time of extrusion is lessened and foaming is carried out to high degree. A foam insulated electric wire with low electrostatic capacity, low damping property, and high size presicion is thus obtained and the electric wire can be made easily thin or thick. |
