| 摘要 |
PROBLEM TO BE SOLVED: To keep the molding workability, heat resistance, retort resistance and keeping taste and fragrance of a film and improve its impact resistance by a method wherein lubricants added respectively to an isophthalic acid copolymer polyester layer and to a polyester composition layer are specified. SOLUTION: This film includes inert particles (henceforth expressed as particles) on its both layers. Concretely, 0.01-3 wt.% of the particle A and 0.01-0.2 wt.% of the particle B are added to a copolymer polyester layer A made of an isophthalic acid copolymer polyester, while 0.03-0.5 wt.% of the particle C is added to a polyester composition layer B. The average particle diameter of the particle A is 0.05μm or more and below 0.6μm. That of the particle B is 0.3μm or more and 2.5μm or less. The ratio of the average particle diameter of the particle A to that of the particle B is 2.5 or more. The average particle diameter og the particle C is 0.8μm or more and below 2.5μm. By adding the above-mentioned lubricants, the slipperiness of the film is improved and it's molding workability and the like can be contrived to improve. |
