BIAXIALLY ORIENTED POLYESTER FILM

摘要

PURPOSE:To obtain a biaxially oriented polyester film having uniform surface and excellent in operating properties represented by traveling property and winding characteristics and abrasion resistance. CONSTITUTION:The objective biaxially oriented polyester film is characterized by including (A) 0.05-3wt.% vaterite type calcium carbonate having 0.005-1mum average particle diameter and being <=2.00 in the distribution value of particle size defined in the following formula and (B) 0.001-0.2wt.% vaterite type calcium carbonate particles having 0.1-2mum average particle diameter larger than that of the particles A and being <=2.00 in the distribution value of particle size defined in the following formula: The distribution value of particle size = d25/d75. [d25 and d75 represent particle diameter (mum) obtained by measuring integrate volume of particle group from larger particle side and corresponding to 25% and 75% of total volume, respectively].