| 摘要 |
<p>A multiple layer film comprises a first layer (12) of vinylidene chloride copolymer having a first softening temperature. A second polymeric sealant layer (14) has a second softening temperature no more than 20 DEG C less than the first softening temperature. A third layer (16) is between the first and second layers, the third layer having a third softening temperature greater than the first and second softening temperatures. A fourth layer (18) has a fourth softening temperature greater than the first and second softening temperatures. The first layer is positioned between the third and fourth layers. All the layers of the film are adhered respectively to each other. The composition of the second layer preferably comprises a polypropylene polymer, or other higher softening temperature polymer composition. The composition for the third layer is preferably selected from polycarbonates, polyamides, polypropylenes, and polyethylenes. The composition for the fourth layer is preferably selected from among polyesters, polycarbonates, polyamides, and polypropylenes. The films of the invention are useful for the fabrication of closed packages.</p> |
