| 摘要 |
PURPOSE:To obtain a fluorine group stretched film, which has excellent mechanical characteristics and can be changed into a thin-film, by simultaneously biaxial-stretching a non-stretched film consisting of an ethylene-tetrafluoroethylene copolymer under specific conditions. CONSTITUTION:A non-stretched film composed of an ethylene-tetrafluoroethylene copolymer is each biaxial-stretching simultaneously to twice or more in the longitudinal direction and the lateral direction within a temperature range of 90-160 deg.C or lower. As an ethylene-tetrafluoroethylene copolymer resin applied, one, the mole ratio of ethylene therein to fluoroethylene therein extends over 40:60-70:30, particularly preferebly, 45:55-60:40, is suitable from the viewpoints of film formability, extensibility, etc. An ultraviolet light screening agent, such as titanium oxide powder, carbon powder, etc. or an ultraviolet light absorber, such as anthracene, anthraquinone, etc. or a slip properties improving agent, such as silica, kaoline, etc. can also be added to the resin. |
