| 摘要 |
<p>PURPOSE:To maintain sealing and dropping strengths, transparency and flexibility even at the time of sterilization at a specific temperature or higher by incorporating normal chain ethylene.alpha-olefin copolymer of specific density in an outer layer, an intermediate layer and an inner layer of a polyolefin multilayer film and mixing polypropylene in the inner layer and a specific % of high density polyethylene in the entire layer. CONSTITUTION:A multilayer film is formed of polyolefin resin. Its multilayer contains normal chain ethylene.alpha-olefin copolymer having a density of 0.920-0.950g/cm<3>, an intermediate layer contains at least one layer of the same copolymer having a density of 0.920g/cm<3> or less, an inner layer contains a mixture of the same copolymer having a density of 0.940g/cm<3> or less with 20-40wt.% of polypropylene, the entire layer contains high density polyethylene having a density of 0.960g/cm<3> or more, the outer layer and the intermediate layer contain 15-55wt.% and the inner layer contains 5-50wt.% of it. In this case, the outer layer needs transparency, flexibility, mechanical strength and heat resistance. The intermediate layer uses resin having high flexibility, impact resistance and transparency, and the inner layer can endure against sterilization at a high temperature.</p> |
