Laminated packaging material for a container

摘要

A laminated packaging material for containers for liquids includes a thermoplastic material outermost layer, a paper substrate layer and a thermoplastic material innermost layer, the thermoplastic material innermost layer comprising a blend of a linear low density polyethylene (LLDPE) and a low density polyethylene (LDPE), the blend having a low swelling ratio in a range from 0.9 to 1.2. The blend further may have a melt flow index in a range from 5 to 20 dg/min. The LLDPE component of the blend is made by polymerization in the presence of a single site catalyst and has an average density a range from 0.86 to 0.92 g/mL and a peak melting point a range from 55 to 105° C. The thermoplastic material innermost layer prepared using such blends advantageously has a low layer thickness a range from 8 to 25 μm.

主权项

1. A laminated packaging material for containers for use with liquids, said packaging material comprising a thermoplastic material outermost layer, a paper substrate layer and a thermoplastic material innermost layer, the thermoplastic material innermost layer comprising a blend of a linear low density polyethylene (LLDPE) and a low density polyethylene (LDPE), wherein the LLDPE is prepared by polymerization in the presence of a metallocene catalyst, the blend having a swelling ratio in a range from 0.9 to 1.2 and an LLPDE content in a range from 30% to 80% (w/w) based on a total weight of LLDPE plus LDPE, wherein the LLPDE has a swelling ratio in a range from 0.9 to 1.1 and a narrow molecular weight distribution having a ratio of a weight average molar mass to a number average molar mass of less than or equal to 2.8, wherein the LLDPE comprises at least two types, one having an average density in a range from 0.86 to 0.89 g/mL, or below, and another having an average density in a range from above 0.89 to 0.92 g/mL and wherein the thermoplastic material outermost layer also comprises a blend of a linear low density polyethylene (LLDPE) and a low density polyethylene (LDPE), the blend having a swelling ratio in a range from 0.9 to 0.1.