| 摘要 |
A multilayer, heat-sealable film includes at least a first outer layer and a second, heat-sealable inner layer having a first surface adhered to the outer layer and a second, opposed surface adapted to be heat sealed to and peeled from another surface. The first outer layer comprises a mixture of a polypropylene and a second polymer immiscible in the polypropylene, with the polypropylene constituting over 50% by weight of the mixture. The second layer is free of polybutylene and is formed predominantly of polymers from the group consisting of propylene-ethylene copolymers, ethylene-propylene-butene-1 terpolymers and propylene-butene-1 copolymers, wherein the propylene in the copolymers and terpolymers constitutes over 50%, by weight, of such copolymers and terpolymers. The films have a peel strength of less than 250 g/in. with peel separation taking place at the interface between the second layer and the first outer layer and/or through the first outer layer. The films of this invention are stand-alone films that can be employed by themselves and/or can be laminated to one or more additional outer films to form a composite film structure.
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