| 摘要 |
PURPOSE:To obtain a stretched film excellent in heat resistance, mechanical strength, electrical properties, chemical resistance, etc., by stretching an unstretched film, which has been prepared from a 3-methylbutyl-1 (co)polymer having a specified melt viscosity, at or over a specified ratio. CONSTITUTION:3-Methylbuten-1 is polymerized or 3-methylbuten-1 and a polyene and/or an olefin of 2-12C are copolymerized to produce a poly-3-methylbutyl-1 having a melt viscosity of 1X10<4> poises or more measured at 330 deg.C and a shearing rate of 0.11/sec. This is formed into a film by a conentional film forming method such as a T-die method or the like, and the obtained unstretched film is stretched at a draw ratio of 2 or more by a conventional stretching manner to obtain the intended stretched film. USE:Magnetic recording base films, heat-resistant and electrical insulating film, various packaging materials, sheets, condenser films, etc. |
