METHOD FOR PRODUCING POROUS FILM, POROUS FILM, METHOD FOR PRODUCING LAMINATED POROUS FILM, LAMINATED POROUS FILM, AND SEPARATOR FOR BATTERY

摘要

PPROBLEM TO BE SOLVED: To provide a method for producing a porous film without causing any thin portion in the porous film to be obtained, and to provide a porous film and a laminated porous film obtained by the method, and a separator for a battery using the porous film or the laminated porous film. PSOLUTION: The method for producing a porous film includes: a sheet-forming step of kneading a mixture containing a polyolefin-based resin (A), a micropore-forming agent (B), and sodium stearate and/or sodium laurate (C) by 0.5 to 2 pts.wt. with respect to 100 pts.wt. of the component (B), molding the resin kneaded material (D) thus obtained into a sheet form to obtain a sheet (E); and a porous film forming step of at least stretching the sheet (E) to obtain a porous film (G). PCOPYRIGHT: (C)2010,JPO&INPIT