| 摘要 |
PROBLEM TO BE SOLVED: To prepare a biaxially oriented laminated polyester film capable of providing a magentic recording medium to be provided with an excellent slit performance while suppressing the occurrence of a dropout due to a large sized foreign substance or an oligomer. SOLUTION: This biaxially oriented laminated polyester film comprises a layer A having a thickness of 2.5μm or more and an intrinsic viscosity of 0.62 or more and made of a polyester composition A using a germanium compound as a catalyst and a layer B laminated on one face of the layer A. The layer B has a thickness of 2μm or less, is made of a polyester composition B using a titanium compound and an antimony compound as catalysts, and contains the titanium compound of 1-15 ppm in terms of titanium element content, an antimony compound of 40-160 ppm in terms of antimony element content, a phosphorus compound of 10-200 ppm in terms of phosphorus element content and 0.001-1 wt.% of inert particles B having an average particle diameter of 50-1,000 nm. The layer B has an intrinsic viscosity of 0.59 or less, and the difference in intrinsic viscosity between the composition A and the composition B is 0.10 or less. COPYRIGHT: (C)2006,JPO&NCIPI |
