The present invention relates to a high-whiteness, biaxially oriented polyester
film with at least a base layer made from polyester. The base layer of the polyester
film of the invention also comprises from 2 to 60% by weight of a cycloolefin copolymer
(COC), from 0.1 to 25% by weight of a white pigment, and, if desired, from 0 to
5% by weight of an optical brightener, based on the weight of the base layer. The
glass transition temperature of the COC here is to be within the range from 70
to 270 C. The film is particularly suitable for packing foods or other consumable
items which are sensitive to light and/or to air, or for use in industry, e.g.
for producing hot-stamping foils or as a label film, or for image-recording papers,
printed sheets, or magnetic recording cards, or for processing on high-speed machinery
for winding, metallizing, printing or laminating.
