| 摘要 |
<p>Provided is a method for producing a polyolefin microporous film having excellent long-term operating properties in that said method makes it possible to prevent the clogging of an extruder filter that occurs with long-term operation. The production method comprises the following steps (A) through (D): (A) a kneading step for kneading a polyolefin resin, plasticizer and antioxidant in order to form a kneaded product; (B) a molding step for processing the kneaded product after the kneading step in order to obtain a molded sheet; (C) a stretching step for stretching the molded sheet after the molding step in order to form a stretched product; and (D) a porous product forming step for extracting the plasticizer from the stretched product before and/or after the stretching step in order to form a porous product. Step (A) of the production method is a kneading step in which the polyolefin resin is kneaded with a plasticizer to which 0.05 to 5 mass% of antioxidant has been added with respect to the polyolefin resin.</p> |
