| 摘要 |
PURPOSE:To obtain polyolefin film excellent in swelling resistance by a method wherein crosslinked silyl-modified polyolefin film having a gel fraction 30-70% and thicknesses 30-150mum is stretched at 80 deg.C or higher but at the temperature lower than the melting point and at the percent of stretch greater than that at the yield point and heat-treated at a temperature higher than the stretching temperature. CONSTITUTION:A cross-linked silyl-modified polyolefin film having a gel fraction 30-70% and thicknesses 30-150mu is stretched at 80 deg.C or higher but at the temperature lower than the melting poit and at the percent stretch greater than that at the yield point and heat-treated at the temperature higher than the orientation temperature. Thus, it is possible to obtain a polyolefin film having a dielectric constant, a small dielectric tangent, large dielectric breakdown and excellent swelling resistance. |
