| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyester film having coloring material sealability excellent under severe heating conditions.SOLUTION: The laminated polyester film includes a coating layer formed of a coating liquid including a polymer having a cation in a side chain on at least one surface of a multilayer polyester film which has at least three layers and containing a coloring material in an interlayer. After heating the film for 10 minutes at 180°C, a color difference value &Dgr;Eab between a liquid after extracting of the coating layer surface (250 cm) by the dimethylformamide of 10 mL and a liquid before extracting thereof by the dimethylformamide, is 10 or less. |
