POLYESTER BIAXIALLY STRETCHED FILM

摘要

PURPOSE:To provide the title film excellent in transparency and processability, stabilized in heat behavior after processing and suppressed in the lowering of the flatness of the film due to heat shrinkage such as unevenness or a curl. CONSTITUTION:A polyester biaxially stretched film is characterized by that at least two heat absorption peaks are observed other than a melting peak at the time of thermal analysis and the difference between the heat absorption peak of the highest temp. and that of the lowest temp. excepting the melting peak is within the range of 20-130 deg.C and the heat shrinkage factors in longitudinal and lateral directions at 150 deg.C are 0.8 to -0.5% and the presence probability (Ps) of org. particles in the surface layer of at least a single surface and the presence probability (Pc) of org. particles in the center part of the film become Ps>2Pc.