| 摘要 |
PROBLEM TO BE SOLVED: To provide a colored biaxial oriented polyester film for metal plate laminating molding process having excellent concealment property to a base metal sheet, exhibiting excellent molding processability without scraping, damaging and peeling a film when molding processing to a can after laminating to the metal sheet and further good in adhesiveness of an ink, even when used for the can requiring stringent processing.SOLUTION: There is provided a colored biaxial oriented polyester film for metal plate laminating molding process having two layers of: a surface layer (A layer) consisting of copolymer polyester with an intrinsic viscosity of 0.66 to 0.85 and the melting point of 215 to 230°C and having the content of colored pigment of 10 wt.% or less; and a back layer (B layer) consisting of a polymer polyester with the intrinsic viscosity of 0.46 to 0.66 and the melting point of 235 to 245°C and having the content of colored pigment of over 10 wt.% and 50 wt.% or less. Here, the melting point and the intrinsic viscosity of the copolymer polyester of the A layer and the B layer satisfy following formulae (1) to (2) and a breaking strength of polyester film is 100 Mpa or more and the B layer is laminated to a metal sheet face and ironing is conducted. TmB-TmA≤20°C---(1) IVA-IVB≥0.15---(2), where TmA and IVA represent the melting point and the intrinsic viscosity of the copolymer polyester of the A layer respectively and the TmB and IVB represent the melting point and the intrinsic viscosity of the copolymer polyester of the B layer respectively. |
