Patent ID: 6174655
Filing Date: 2001-01-16
Classification: C08J,C08K,G03C,Y10T

Abstract:
A biaxial oriented polyester film, comprising 0.001 to 0.05% by weight of spherical silica particles with a number average particle diameter (Xm) of 0.20 to 0.50 .mu.m and a particle size distribution represented by the following formula (1):0.1.ltoreq..vertline.d.sub.90 -Xm.vertline./.vertline.d.sub.10 -Xm.vertline..ltoreq.0.7 (1)wherein d.sub.10 represents a particle diameter (.mu.m) obtained when the number of the particles is summed from the particles with the smallest diameter toward the particles with larger diameters and the number reaches 10% of the total number of the particles, d.sub.90 represents a particle diameter obtained in the same manner as for d.sub.10 described above except that the particle diameter is obtained when the number of the particles reaches 90% of the total number of the particles, and Xm represents a number average particle diameter.