| 摘要 |
PURPOSE:To obtain the titled open cell porous film having improved heat and chemical resistance, etc., by entangling fibers having an island-in-sea structure from a tetrafluoroethylene copolymer and a specific polyolefin, and removing the polyolefin with a solvent. CONSTITUTION:(A) A tetrafluoroethylene copolymer and (B) a polyolefin having <=2 melt index are melt extruded under heating, extruded and spun to give fibers having an island-in-sea structure containing the copolymer as an island component and the polyolefin as a sea component are entangled. The polyolefin is then removed with a solvent to afford the aimed open cell porous tetrafluoroethylene copolymer film. The entangled material is preferably heat-treated at a temperature above the melting point of the polyolefin and below the melting point of the tetrafluoroethylene copolymer under (no) pressure, and then the polyolefin is removed with the solvent. |
