BIAXIALLY ORIENTED POLYPROPYLENE FILM

摘要

PROBLEM TO BE SOLVED: To provide a biaxially oriented polypropylene film having two contradictory characteristics, i.e., high rigidity and low heat shrinkage and having better processing characteristics than those of conventional biaxially oriented polypropylene film because of higher tensile strength in the longitudinal direction. SOLUTION: The biaxially oriented polypropylene film is characterized in that it comprises mainly a highly stereoregular polypropylene having a mesopentad fraction of 97-99.5% and contains at least one of petroleum resins having substantially no polar group and/or terpene resins having substantially no polar group and that the sum of the modulus in tension in the longitudinal direction and that in the widthwise direction at ordinary temperature is at least 7.3 GPa.