Sealant for polypropylene and easily openable hermetically sealed package including the same

摘要

A sealant for polypropylene consisting essentially of a composition comprising a high-pressure-processed low-density polyethylene (A) having a density of 910 to 930 kg/m³ and an MFR of 0.5 to 20 g/10 min; and an ethylene/α-olefin copolymer (B) having a density of 860 to less than 890 kg/m³, an MFR of 0.5 to 40 g/10 min and an Mw/Mn of 1.5 to 3, and/or a linear low-density polyethylene (C) having a density of 890 to 940 kg/m³ and an MFR of 0.2 to 30 g/10 min. In this composition, the component (A) is contained in an amount of 10 to 85% by weight, the component (B) in an amount of 50% by weight or less, and the component (B) and component (C) in a total amount of 15 to 90% by weight, based on the total weight of components (A), (B) and (C) . This composition exhibits an MFR of 1 to 15 g/10 min and a melt tension measured at 190°C of 5 to 100 mN. Further, there is provided an easily openable hermetically sealed package comprising a laminate having a double layer structure such that one side of a sealant layer consisting essentially of the above sealant is overlaid with a resin layer of polypropylene. The invention realizes a sealant for polypropylene, which enables reducing the neck-in at extrusion laminating, which is excellent in the bubble stability at inflation molding and which enables producing an easily openable hermetically sealed package exhibiting such a sealing strength as permits easily opening of a hermetically sealed package comprising polypropylene as an adherend. Thus, such an easily openable hermetically sealed package is provided by the invention.