| 摘要 |
<p>PURPOSE: To provide an electrically insulating film having a low dielectric loss factor, high breakdown voltage and improved long term operability by incorporating a propylene polymer and a stabilizer in a base layer and an outer layer, incorporating a specific thermal oxidation temperature in a raw material, and limiting a content of an organic neutralizing agent. CONSTITUTION: A base layer of the multilayer film contains an extremely pure raw material which contains no lubricant and no ion forming component. This advantageously contains 50 ppm or less of a residual ash content, 10 ppm or less of a chlorine content and 0 to 0.10 wt.% of organic neutralizing agent or particularly calcium stearate. This raw material is stabilized by a stabilizer adapted to an idealized thermal oxidation temperature of a range of 260 to 300 deg.C. The raw material for the outer layer is similarly stabilized to have an idealized thermal oxidation temperature of a range of 240 to 300 deg.C. Stabilizations of both the materials are matched so that the film itself has an idealized thermal oxidation temperature of a range of 250 to 290 deg.C.</p> |
