| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyester film for paper base materials being hard coat films in a retardation film production process, the oligomer deposition amount of which hard coat film is reduced, the repeated usability of which hard coat film is improved and which hard coat film can allow the retardation film having very excellent flatness and thin thickness being the recent required quality without generating defects such as spot unevenness and without deforming the hard coat film to be obtained in high quality and with high stability.SOLUTION: The polyester film has a hard coat layer on one surface and 70-120 nm surface roughness (Ra) on the other surface thereof. A polyester layer constituting such surface has 0.67 or higher intrinsic viscosity and the total thickness of 70-155 μm. |
