| 摘要 |
PROBLEM TO BE SOLVED: To provide a microporous film that has uniform communication micropores having high water vapor permeability necessary for a sterilization treatment and the like, and that is useful as package bodies such as a pharmaceutical blister pack having the piercing strength enough to pack a syringe needle, a catheter, and the like.SOLUTION: The microporous film is formed from a thermoplastic resin composition containing a polypropylene resin and a polyolefin/polystyrene-based elastomer and has a sea-island structure comprising a sea part containing the polypropylene resin and an island part containing the polyolefin/polystyrene-based elastomer. A melt flow rate of the polyolefin/polystyrene-based elastomer is 1.0 g/10 minutes or lower, and a hole part is formed on the boundary between the sea part and the island part and in the sea part. The microporous film has 50-500 μm thickness and 20-200 seconds/100 cc air permeability and is formed by stretching in bi-axial directions. |
