| 摘要 |
PURPOSE:To provide a heat-shrinkable film holding a microporous structure even after heat shrinkage and excellent in air permeability. CONSTITUTION:A microporous biaxially oriented film composed of polyethylene whose intrinsic viscosity [eta] is 5dl/g or more is characterized by that an average pore size is 0.1-10mum, the tensile strength in all directions of the film is 1000kg/cm<2> or more and Gurley air permeability after heat shrinkage is 60-1800sec/100ml. |
