| 摘要 |
PROBLEM TO BE SOLVED: To prepare a polyester film excellent in crease-maintaining property, form-maintaining property of a bag after bend-processing and handling property after the passage of time. SOLUTION: The polyester film is characterized by containing 20-80 wt. % polyester A component having at least ethylene terephthalate as a main recurring unit and 80-20 wt. % polyester B component having butylene terephthalate as a main recurring unit, consisting of the polyester having 230-255°C major melting point, having 1,280-1,320 kg/m<SP>3</SP>density at 25°C and≥2 J/g endothermic heat (ΔHe) at an enthalpy relaxation peak of the glass transition temperature obtained by a differential scanning calorimeter. COPYRIGHT: (C)2006,JPO&NCIPI |
