| abstract |
(57) [Abstract] [PROBLEMS] To provide a biaxially oriented polyethylene terephthalate film having excellent slitting property, scratch resistance, dimensional stability at high temperature, and high strength in the longitudinal direction, and a method for producing the same. [Structure] F 5 value in the longitudinal direction is in the range of 12 to 25 kg / mm 2 , thermal shrinkage in the longitudinal direction is 6% or less, and birefringence dn contributed by an amorphous portion represented by the following formula I. a is in the range 0.06 to 0.13, and the density is 1. A biaxially oriented polyethylene terephthalate film in the range of 383 to 1.394 g / cm 3 . [Equation 1] |