01.10.05
A biaxially oriented, laminated polyethylene terephthalate film with at least two layers has been issued a patent. An irregularity in film thickness determined within 4 mm width at an arbitrary position in a transverse direction of the film is about 0.1 mm or less. Young's moduli in longitudinal and transverse directions of the film are in a range of about 3500 to about 10,000 MPa, respectively, and the ratio of both Young's moduli (longitudinal/transverse) is in a range of about 1.0 to 2.5