| 摘要 |
PROBLEM TO BE SOLVED: To obtain a film having improved impact resistance at a low temperature after a retort treatment by a method wherein a first layer made of polyester is laminated to a second layer of a mixture of polyester and polycarbonate and the crystallization time of a film is specified at a specific value. SOLUTION: A first layer made of polyester having mainly a repeating unit of ethylene terephthalate is laminated to a second layer which is formed from a composition comprising 20-60wt.% of polycarbonate substantially comprised of repeating units represented by the formula (wherein R1 , R2 show hydrogen atom and cycloalkyl group, respectively, R3 , R4 each show alkyl group, m, n are each 0, 1 or 2) and 40-80wt.% of polyester, and in which the polyester comprises 10-90wt.% polyester which mainly has a repeating unit of ethylene terephthalate and in which the concentration of end carboxylic acid is 10 equivalents/10<6> g or more and 10-90wt.% polyester which mainly has a repeating unit of butylene terephthalate and in which the concentration of end carboxylic acid is 20 equivalents/10<6> g or less. And a film has semi-crystallization time of 20-300 seconds at 160 deg.C. |
