| 摘要 |
PURPOSE:To balance the mechanical properties of a gas-permeable film by a method in which gas is blown onto the outside of the tubular biaxially stretched film composed of a specific ethylene-alpha-olefin copolymer and an inorganic filler, and the gas is continuously blown into the film. CONSTITUTION:A tubular unstretched film composed of an ethylene-alpha-olefin copolymer having a density of 0.910-0.940g/cm<3>, a melt flow rate of 0.1-5g/ 10min, and Q value (represented by weight average molecular weight/number average molecular weight ratio) of 4 or more and 58-13vol% an inorganic filler is biaxially stretched along a mandrel of a conical trapezoidal form. Gas is then blown onto the outside of the film to cool the film and also the gas is continuously blown from the inside to the outside of the film in a piercing manner to obtain a gas-permeable film. |
