| 摘要 |
PROBLEM TO BE SOLVED: To provide a laminated polyester film for a coating type magnetic recording tape, which adds sufficient electromagnetic conversion characteristics to an obtained magnetic recording tape even in a high-density recording region when used for a base film of the coating type magnetic recording tape, and also improves slit property and enables higher speed production.SOLUTION: A laminated polyester film for a coating type magnetic recording tape is a polyester film to be used for a base film of the coating type magnetic recording tape, including at least two layers, a layer A and a layer B. The layer A where a magnetic layer is formed, contains particles A of an average particle size of 0.05-0.15 μm in a range of 0.01-0.5 wt.%. The layer B where no magnetic layer is formed, contains particles B1 of an average particle size of 0.40-0.9 μm in a range of 0.001-0.020 wt.%, and particles B2 of an average particle size of 0.03-0.17 μm in a range of 0.15-0.8 wt.%. A ratio (tB/dB1) between a thickness of the layer B (tB) and the average particle size (dB1) of the particles B1 is in a range of 4.0-9.0. |
