| 摘要 |
<p>The present invention is a multilayer polyester film comprising a layer A and a layer B which are laminated alternately, the layer A constituting the outermost layer on both sides of the film, wherein (1) the layer A comprises a polyester A, and the layer B comprises a polyester B, (2) the melting point of the polyester A is higher than the melting point of the polyester B by at least 15 DEG C, (3) the layer A is a layer having an oriented structure, and the layer B is a layer having a substantially unoriented structure, (4) the ratio (a/b) of the total thickness (a) of the layer A to the total thickness (b) of the layer B is 0.01 to 3, and (5) the in-plane tensile strength of the multilayer polyester film is 50 MPa or lower at a maximum, and the difference between its maximum value and minimum value is 20 MPa or smaller; and a method for producing the multilayer polyester film. According to the present invention, there is provided a film having excellent isotropy of in-plane tensile strength, excellent transparency, a low degree of thickness unevenness and excellent moldability.</p> |
