| 摘要 |
PROBLEM TO BE SOLVED: To improve impact resistance, especially, dent resistance by forming a polyester film of a laminate from a blend containing crystalline polyester and copolymer polyester being a specific component which are blended at a specified ratio, and setting the ester exchange ratios and intrinsic viscosities of the components of the blend to specific values. SOLUTION: A polyester film layer constituting a laminate is formed of a laminated film composed of a substrate layer constituted of a blend containing crystalline polyester (i) based on an ethylene terephthalate unit and copolymer polyester (ii) containing an ester unit derived from butylene glycol and aromatic dibasic acid and an ester unit derived from butylene glycol and aliphatic dibasic acid in a mol ratio of 90:10-50:50 in a wt. ratio of (i):(ii)=90:10-30:70. The ester exchange ratio E shown by formula of the component (i) in the blend is set to 0.5-20% and the intrinsic viscosity of the blend is set to 0.55 or more. |
