| abstract |
(57) [Abstract] [PROBLEMS] To provide a polyethylene-2,6-naphthalate film useful as a magnetic recording medium for high density recording, particularly as a metal tape base film. [Structure] Young's modulus [EM] in the vertical direction is 500 kg / mm 2 As described above, the Young's modulus in the lateral direction [ET] is 600 kg / mm 2 or more, and the Young's modulus in the lateral direction is the same as or larger than the Young's modulus in the longitudinal direction, and the load at 120 ° C. is 1 kg / mm 2. A biaxially oriented polyethylene-2,6-naphthalate film having a lateral elongation per mm 2 of 0 to 0.8%. |