The invention relates to biaxially orientated, co-extruded polyester films, which
have at least one base layer that contains a thermoplastic polyester, preferably
polyethylene terephthalate and approx. 2 to 60 wt.-% of a cycloolefin copolymer
that is preferably composed of norbornene and ethylene units and which have at
least one cover layer that is devoid of a COC and which optionally have additional
cover or intermediate layers and can contain conventional additives such as stabilisers
and anti-blocking agents. Said films are characterized in particular by a degree
of whiteness70%, an opacity55% and a gloss, (at least on one side)100
and are therefore suitable for numerous industrial applications. During the production
of the films in accordance with the co-extrusion process, up to 70 wt.-% of reclaimed
product can be used, without having a noticeable negative effect on the physical
properties of the film.
