| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing the porous film in which the porous film having high strength while having adequate porosity can be produced in high productivity by continuous steps. SOLUTION: The method for producing the porous film comprises steps for melting and kneading a composition containing a polyolefin-based resin and a solvent and extruding and cooling the kneaded material to form a sheet-like molded product and carrying out heat-rolling and stretching treatment and desolvating treatment of the sheet-like molded product. In the method for producing the porous film, at least steps of extrusion, cooling, heat rolling and stretching treatment are continuously carried out in this order and the melt-kneading is carried out at 140-220°C and the cooling is carried out until the temperature attains a temperature being lower by 50°C than gel temperature of the kneaded material to the gel temperature at 8-50°C/min cooling rate. COPYRIGHT: (C)2007,JPO&INPIT |
