| 摘要 |
Provided is a colored biaxially stretched polyester film for bonding and molding to a metal sheet, which is a colored biaxially stretched polyester film formed from two layers, a front surface layer (layer A) that is formed from a copolyester having an intrinsic viscosity between 0.66 and 0.85 and a melting point between 215 and 230ºC and that has a colored pigment content of 10 wt% or less and a back surface layer (layer B) that is formed from a copolyester having an intrinsic viscosity between 0.46 and 0.66 and a melting point between 235 and 245ºC and that has a colored pigment content exceeding 10 wt% but not exceeding 50 wt%, wherein the copolyesters of layers A and B have a melting point and an intrinsic viscosity that satisfy the following formulas (1) and (2), the polyester film has a tearing strength of 100 Mpa or greater, and blocking performance, moldability, and the like are excellent. TmB - TmA = 20ºC --- (1) IVA - IVB = 0.15 --- (2) (TmA and IVA are the melting point and intrinsic viscosity, respectively, of the copolyester of layer B and TmB and IVB are the melting point and intrinsic viscosity, respectively, of the copolyester of layer B.) |
