BIAXIALLY ORIENTED POLYPROPYLENE FILM

摘要

PROBLEM TO BE SOLVED: To obtain a biaxially oriented polypropylene film having excellent heat resistance, breakdown resistance characteristics and proper heat shrinkability useful as a film for a film for a capacitor. SOLUTION: This biaxially oriented polypropylene film has two or more endothermic peaks caused by melting when measured by a differential scanning calorimeter in which one of the peaks is higher than 160 deg.C and the other is in the range of 130-155 deg.C. The film has >=85 J/g total melt calorie and 0.02-0.2μm average surface roughness Ra of central line on at least one side of the film.