Patent ID: 6974621

Claim:
A biaxially oriented polyester film having a base layer B, which is composed of at least 80% by weight of a thermoplastic polyester, and having two outer layers A and C, wherein a) the outer layer A has high surface smoothness and comprises substantially no external particles, b) the outer layer C comprises external particles and has, per mm 2 of film surface area, a number N C of elevations whose respective heights h are correlated via the following equation A h1 −B h1 ·log 10 h /μm≦log 10 ( N C /mm 2 ) (1) 0.01 μm≦h≦1 μm A h1 =0.05; B h1 =3.3, and c) the outer layer A has been provided with an acrylate-containing layer D.