| 摘要 |
PURPOSE:To obtain a porous film having a feeling of flexibility, excellent water vapor permeability, leakage resistance, strength and adhesion to tapes, by making a composition containing a polyolefin resin, a filler and a specific polyester into a film and drawing the film. CONSTITUTION:A composition consisting of (A) 100 pts.wt. polyolefin resin (preferably linear low-density polyethylene), (B) 50-250 pts.wt filler, one having preferably <=30mu average particle diameter and subjected to surface treatment with a fatty acid (metallic salt) and (C) 5-50 pts.wt. polyester which consists of C1: a polybasic acid, C2: a polyhydric alcohol containing three or more OH groups and/or polyhydric alcohol containing one or more ether bonds and C3: 8-22C monobasic acid and/or 6-22C monohydric alcohol and has <=5 deg.C melting point and preferably 800-4,000 average molecular weight is molded in a molten state into a film, which is drawn (preferably stretched at 1.5-3times draw ratio) to give a porous film. |
