| 摘要 |
Polymeric film and multiple layer sheet structure consist of and include, respectively, a layer made from a blend of polyisobutylene and a polypropylene copolymer, the latter including 2 - 30 mole percent ethylene moieties and the blend layer containing at least 1.8 mole percent ethylene. Plural layer structures can have two, three or more layers, e.g. five to seven layers. One such structure comprises the following layers, taken in order: blend layer (12) - adhesive layer (16) - primer layer (18) - metal foil layer (14) - adhesive layer (20) - abuse resistant layer (22). This structure is useful for packaging oxidisable products, for the foil layer (14) is a barrier to gas transmission through the structure, and the blend layer is capable of forming heat seals useful in making an hermetically-closed package. |
