| abstract |
(57) [PROBLEMS] To provide a laminated biaxially oriented polyester film which is excellent in flatness, abrasion resistance, windability, etc. and is particularly useful for magnetic recording media. SOLUTION: A lubricant particle I is provided on one surface of a polyester layer B, A laminated biaxially oriented polyester film in which a polyester layer A containing II is laminated, wherein the agglomeration rates of the lubricant particles I and II are each greater than 0 (%) and less than 20%, and the average of the particles I is The particle size is 0.3 to 1.0 μm, the content is 0.005% by weight or more and less than 0.1% by weight, and the average particle size of the particles II satisfies the following formula (1) and the content is Is 0.1% by weight or more and less than 1.0% by weight, a laminated biaxially oriented polyester film. Here, dI is the average particle size of the lubricant particles I, and dII is the lubricant particles. It is the average particle size of II. |