| 摘要 |
Multi-layer, heat-sealable polypropylene films are disclosed which possess good coefficient of friction, and thus good machinability, and which are also capable of forming good bonds with water based adhesives. The film structures consist essentially of (A) an outer heat sealable layer coextensively adherent to the upper surface of core layer (B), said outer layer (A) being formed from a polymer composition (a) consisting essentially of heat sealable resin compounded with one or more slip additives which are incompatible with polypropylene, (B) a core layer derived from a polymer composition (b) consisting essentially of an isotactic polypropylene compounded with one or more slip additives which are incompatible with polypropylene, and (C) an outer layer coextensively adherent to the lower surface of core layer (B), said outer layer (C) being formed from a polymer composition consisting essentially of isotactic polypropylene in the substantial absence of slip additives; wherein the total amount of slip additive in said film structure is effective to provide the outer surface of outer layer (A) with a coefficient of friction sufficient for high speed heat sealing packaging operations but insufficient to cause substantial hazing of said structure.
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