Patent ID: 6962740

Claim:
A biaxially oriented polyester film which has a base layer B composed of at least 80% by weight of a thermoplastic polyester, and has 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 of elevations N c which correlate by way of the following equation to their respective heights h 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 C has an acrylate-containing layer D.