OPAQUE POLYESTER FILM AS SUBSTRATE WITH WHITE COATINGS ON BOTH SIDES

摘要

PPROBLEM TO BE SOLVED: To provide a white polyester film and its production process, wherein the polyester film is improved in hiding performance and is superior in visibility after imaging as a white polyester printing film. PSOLUTION: The film is a polyester film which has an opaque core layer 1 having a transmission optical density greater than 2.0 and white outer layers 2 and 4 on both surfaces thereof, provided that (i) the white outer layers 2 and 4 contain 15-25 wt.% of an inorganic filler per the weight of polyester in white outer layers 2 and 4, that (ii) the polyester film shows a whiteness ranging 80-120 units, that (iii) the polyester film shows an LSP*/SPvalue ranging 90-100 and that (iv) the polyester film shows at least 4.0 in transmission optical density. PCOPYRIGHT: (C)2011,JPO&INPIT