| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject film capable of exhibiting excellent impact resistance, excellent hydrolysis resistance, excellent thermal decomposition resistance and good metal plate laminability and useful for metal containers, etc., by limiting the melting point, thickness and reducing viscosity difference of film in specific ranges, respectively. SOLUTION: This copolyester film (e.g. a polyester film comprising a copolyester obtained by copolymerizing ethylene terephthalate units with ethylene dicarboxylic acid component or neopentyl glycol component) has a melting point of 150-250 deg.C and a thickness of 3-50μm. A difference between a reducing viscosity after thermally treated at the melting point +30 deg.C for 60 sec and a reducing viscosity before thermally treated is <=0.05 deciliter/g. The film has preferably a reducing viscosity of 0.4-1.0 deciliter/g. |
