PROBLEM TO BE SOLVED: To provide a medical instrument having excellent gas permeability, flexibility, transparency and adhesiveness, capable of regulating the gas permeability, forming an inflation and radiation sterilizing and particularly suitable for a blood component stock container (blood platelet stock bag) or the like.SOLUTION: The medical instrument comprises a laminate 2 made of at least three layers. The laminate 2 has at least one functional layer 3 between an innermost layer 5 and an outermost layer 4. A main component of the layer 3 is a polyethylene or ethylene-&alpha-olefin copolymer to be polymerized by a metallocene catalyst having a density of 0.890 g/cm3 or less. A thickness constitution ratio of the layer 3 is 50 to 90% to the entire thickness of the laminate 2.COPYRIGHT: (C)2002,JPO【課題】ガス透過性および柔軟性、透明性、接着性に優れ、かつガス透過性を調整可能であり、インフレーション成形及び放射線滅菌が可能な、特に血液成分保存容器(血小板保存バッグ)等に好適な医療用具を提供すること。【解決手段】少なくとも三層よりなる積層体2より構成され、最内層5と最外層4の間に少なくとも一層の機能層3を有し、該機能層3の主成分が、密度0.890g/cm3以下のメタロセン触媒により重合されるポリエチレンまたはエチレン-α-オレフィン共重合体であり、該機能層3の肉厚構成比が積層体2全体の肉厚に対して50%から90%である医療用具。
