Biaxially oriented polyester film and production method therefor

Abstract

The invention provides a biaxially oriented polyester film, which exhibits excellent transparency, is easily subjected to secondary processing, and is produced using a polyester resin obtained without using an antimony compound as a polymerization catalyst, and a production method therefor. At least one surface of the biaxially oriented polyester film meets requirements (1) to (4): (1) a number of fine protrusions each having a height of less than 3 nm per area of 4×10−12 m2 is 250 or more and 600 or less; (2) a number of fine protrusions each having a height of 3 nm or more per area of 4×10−12 m2 is 300 or more and 600 or less; (3) an arithmetic mean height Sa is 0.010 μm or more and 0.025 μm or less; and (4) an antimony content in the film is 10 ppm or less.

Dependencies are inferred from the claim text.