| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyester film which does not cause problems in terms of processing and appearance and can be used suitably for lamination and a design sheet. SOLUTION: In the laminated, biaxially oriented polyester film, the melting point Tm1 of a thicker layer (layer A) and the melting point Tm2 of a thinner layer (layer B) satisfy formulas: Tm1≥246°C and Tm1-Tm2>15°C, respectively, and the sum of the strengths is 350 MPa or below when the elongations in the longitudinal direction and in the width direction are 100%. Even when a structure which is laminated without being directly heat-laminated by a method such as dry lamination or a composite structure which is laminated with another plastic film or sheet, metal foil or the like is cold stretch-formed or cold protrusion-formed, a defect such as a pinhole, a crack, or delamination does not occur. When the structure is molded or heat-sealed at a temperature below its melting point, the laminated polyester film resistant to whitening can be formed. COPYRIGHT: (C)2007,JPO&INPIT |
