| 摘要 |
PURPOSE:To improve traveling durability, light-shielding properties and slit properties particularly in a laminated polyester film for a magnetic recording medium respectively by laminating a polyester layer containing specific inorganic particles and carbon black particles respectively and another polyester layer. CONSTITUTION:A polyester layer A containing inorganic particles (a) having Mohs hardness of seven or more and mean particle size of 0.05-0.5mum and carbon black particles (b), the mean particle size of an aggregate of which is 0.005-0.5mum, and another polyester layer B are laminated, thus constituting a film main body. The following various conditions are satisfied simultaneously. That is, 0.20<=CaA<=5.0. 0.70<=CbA<=3.0. CaA<+>B<=0.15. 0.60<=CbA<+>B<=2.0. T900<=30. 0.015<=Ra<4=0.045. RtA/RaA<=15. 0.002<=RaB<=0.015. Where CaA, CbA, CaA<+>B and CbA<+>B represent each content of (a) and (b) to A and A and B respectively, and T900 ray transmittance, RaA, and RaB the mean roughness of A and B and RtA the maximum projection height of A respectively. |
