| 摘要 |
PURPOSE:To obtain a film having excellent abrasion resistance and slipperiness with scarce dropout, by containing inert particles and fine silica particles in a polyester deposited in a reaction system. CONSTITUTION:A biaxially oriented polyester film obtained by containing 0.05-1.0wt.% inert particles and 0.001-5wt.% monodisperse fine silica particles having a volume shape coefficient satisfying the formula 0.4<=(V/D<3>)<=pi/6 [V is particle volume (mu<3>); D is the maximum diameter (mu) in the plane of projection], 0.1-5mu average particle diameter and <=5% deviation therefrom. The inert particles are particles respectively containing >=1.0wt.% calcium, lithium and phosphorus. The number of the n-order interference fringes is Hn (fringes/ cm<2>) obtained by measuring the film surface by a two-beam interference method satisfies the formula SIGMAHn<=20, n>=3 and Hn/Hn+1>=10. |
