| 摘要 |
<p>PROBLEM TO BE SOLVED: To allow insoluble fine particles to scarcely elute in content and to improve the heat resistance by disposing straight-chain ethylene andα-olefin copolymer having specific physical properties as an innermost layer. SOLUTION: Straight-chain ethylene andα-olefin copolymer having physical properties described in paragraphs (a) to (f) obtained by copolymerizing ethylene and 3-20Cα-olefin in the presence of metallocene catalyst is used as an innermost layer. (a) Density: 0.910 to 0.945g/cm<3> , (b) melt flow rate: 0.5 to 50g/10min, (c) n-heptane extract at 50 deg.C: 0.8wt.% or less, (d) ash amount in the case of completely carbonizing at 650 deg.C in an electric furnace: 0.02wt.% or less, (e) a ratio of weight-average molecular weight obtaind by a gel permeation chromatography to number-average molecular weight: 3.0 or less, and (f) number of fine particles having 2μm or more measured after hot water sterilizing treatment at 110 deg.C/40min: 30 pieces/10ml or less.</p> |
