| abstract |
【Task】 Provided a polyester film that has few foreign matters or coarse protrusions and oligomer precipitation in the film, and has good characteristics as a recording medium, especially a vapor-deposited magnetic recording medium, and processability to a vapor-deposited magnetic recording medium when used as a base substrate To do. [Solution] A biaxially stretched polyester film, wherein the polyester used in the film contains a titanium compound in an amount of 0.5 to 150 ppm in terms of titanium atom relative to the polyester, and a phosphorus compound in an amount of 0.1 to 400 ppm in terms of phosphorus atom relative to the polyester, antimony A biaxially stretched polyester film for recording media having a compound content of 30 ppm or less in terms of antimony atoms relative to polyester, a crystal size χc = 5 to 7 nm, and a plane orientation index χI = 5 to 8.5. [Selection figure] None |