| abstract |
The present invention provides a sealing film having a layer formed of a polyester (A) containing terephthalic acid units, ethylene glycol units, diethylene glycol units, and other comonomer units, wherein the polyester (A) contains 25 to 50 mol% of terephthalic acid units, 25 to 49.5mol% of ethylene glycol units, 0.5 to 2.5 mol% of diethylene glycol units, and 2 to 25 mol% of other comonomer units having 5 or more carbon atoms, wherein the degree of crystallinity of the sealing film is less than 16%, and the sealing film is a stretched film having a shrinkage rate of 6% or more in the maximum shrinkage direction when left to stand at 125 ℃ for 20 seconds. The sealing film is excellent in mechanical properties, particularly tensile elongation, and also excellent in heat sealability and non-adhesiveness. |