| 摘要 |
<p>PURPOSE:To obtain a foodstuff packing material which has high heat resistance and is adaptable for even retort pouches, by a method wherein the subject material contains an aluminum foil layer polypropylene layer and is constituted of a using modified polypropylene composition. CONSTITUTION:A modified polypropylene composition is a polypropylene composition modified by unsaturated carboxylic acid satisfying the following conditions (a), (b). The condition (a) shall contain 5-20% low-density polyethylene whose molecular weight distribution represented by a ratio between weight-average molecular weight and number-average molecular weight is at least 5. The condition (b) shall contain at least 40wt.% propylene--ethylene copolymer having content of 1-8wt.% ethylene component. That is, the used modified polypropylene composition is composed basically of three components of polypropylene modified by the unsaturated carboxylic acid, low-density polyethylene and propylene- ethylene copolymer. Then at the time of manufacturing of the multi-layer laminated material containing the aluminum foil layer and polypropylene layer, extrusion sand laminate molding is performed.</p> |
