| 摘要 |
PURPOSE:To produce an electrical insulating film greatly improved in voltage- resisting property and modulus of elasticity, by a method wherein, a high voltage is applied to a sheet of film of polytetrafluoroethylene fibers juxtaposed in parallel with the orientation axis of polyolefin matrix. CONSTITUTION:By using a mixture of 100pts.wt. of a powder-form crystalline polyolefin having an M.I. value of not less than 10 with 0.5-20pts.wt. of a powder-form non-baked polytetrafluoroethylene, a film is produced such that fibers of polytetrafluoroethylene are aligned in parallel to the axis of orientation of the polyolefin matrix. Thereafter, the film is compressed in a pressure-transmitting medium at a pressure of not lower than 300kg/cm<2>. Accordingly, since the phase of the non-baked polytetrafluoroethlyene is treated to attain a high density, an electrical insulating polyolefin film greatly improved in voltage- resisting property and modulus of elasticity can be produced. |
