BIAXIALLY POLYPROLYLENE FILM AND FILM CAPACITOR MADE THEREOF

摘要

PROBLEM TO BE SOLVED: To obtain a film excellent in voltage endurance, heat resistance and yield obtained when a metal layer is provided on a film and having excellent resistance to dielectric breakdown from a room temperature to a high temperature region of 105 deg.C and suitable for capacitors. SOLUTION: This biaxially polypropylene film has <=99% isotactic index and has the following characteristics (1), (2) and (3). (1): P1>99%, (2): P2 <=0.1% and (3): P3<=0.8% in which P1 represents a ratio of absorption peak derived from mmmmm among a pentad fraction obtained from<13> C-NMR of polypropylene and P2 represents a ratio of absorption peak derived from mmrr + mmrm + rmrr + rmrm and P3 represents a ratio of absorption peak derived from rrrr + mrrr + mrrm [(m) represents meso configuration of adjacent two recurring units in polypropylene molecular chain and (r) represent racemo configuration thereof].