Mehrschichtige Polyesterfolie hoher optischer Dichte mit einer Gesamtdicke von maximal 60 µm mit zwei weißen Schichten und einer rußhaltigen Außenschicht
At least three-layered, biaxially oriented polyester film comprises: a carbon black filled covering layer with a thickness of 4-15 mu m and two titanium dioxide containing layers comprising a white covering layer containing titanium dioxide (at least 15 wt.%) and a base layer with a layer thickness of >= the sum of the covering layers thicknesses, comprising titanium dioxide (at least 4 wt.%). The carbon black containing covering layer comprises carbon black (3-15 wt.%). The standard viscosity of the film is at least 600. The weights of components are based on the respective layer. An independent claim is also included for producing the polyester film, comprising compressing the polymer or the polymer mixture of the individual layers in an extruder and liquefying to form a melt, molding the melt in a multilayer nozzle to form a flat melt film, pressing the flat melt film through a flat film die and drawing on a cooling roll and on at least one nip roll, where the formed film cools and solidifies, stretching the film simultaneously or sequentially in longitudinal and transverse directions, carrying out heat setting of the film, and coiling the film.
