| 摘要 |
PURPOSE:To contrive an improvement in strength and heat resistance, by containing an ethylene chlorotrifluoroethylene copolymer at more than a specific rate. CONSTITUTION:After a film is produced by cooling thermoplastic resin containing more than 80mol% ethylene chlorotrifluoroethylene copolymer, whose mol ratio between ethylene and chlorotrifluoroethylene is 20:80-80:20, at a temperature range of (the fusion point -10 deg.C) - (the fusion point -100 deg.C) and a cooling rate of more than 80 deg.C/sec by extruding the same through a die by heating and fusing, the film is stretched biaxially more than two times as long as the same in each of a longitudinal and lateral directions at a time at the temperature range of more than 50 deg.C and less than 180 deg.C. Crystallization characteristic value DELTAT of a biaxially oriented fluorine stretched film obtained in this manner is more than 20 deg.C and less than 70 deg.C, tensile strength which has been only about 4kg/mm<2> on an unstretched film improves up to more than 13kg/mm<2>, and tensile modulus which has been about 120kg/mm<2> up to 180kg/mm<2>. |
