| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyester film for a large capacity optical recording tape that enables high-density recording, the polyester film functioning as a base suitable to be used for a data recording tape, which is excellent in productivity of a base film and in recording characteristics with few errors, and particularly, enabling high-density optical recording.SOLUTION: A polyester film for an optical recording tape comprises a laminate film including a polyester layer (A) and a polyester layer (B), a skin layer (I) on a surface (A) of the polyester layer (A) opposite to the polyester layer (B), and a surface denoted as surface (B) of the polyester layer (B) opposite to the polyester layer (A). The polyester film satisfies the following conditions (a) to (e). (a) The skin layer (I) disposed on the surface (A) shows 7 or less of a ratio of (ten-point average surface roughness SRz on the skin layer (I))/(thickness of the skin layer (I)). (b) The skin layer (I) disposed on the surface (A) shows 15 or less of a ratio of (ten-point average surface roughness SRz on the skin layer (I))/(surface roughness SRz of the skin layer (I)). (c) The polyester layer (A) includes substantially no inert particles and has a thickness of 3.0 μm or more. (d) The polyester layer (B) includes inert particles (B) having an average particle diameter of 0.1 to 1.0 μm. (e) The surface (B) shows an average surface roughness SRz of 8 to 20 nm and a ten-point average roughness SRz of 300 nm or less. |
