Oxygen barrier laminate structure

PURPOSE: To obtain a paper board structure, which does not permeate gas and prevents pollutants from entering by a method wherein the extrusion of the laminate of an outer layer made by coating the outer surface of a substrate with a heat sealable low density polyethylene polymer, a polymer layer combined with an oxygen barrier layer and an interior product contacting layer made of a heat-sealable low density polyethylene polymer is executed under the temperature having a specified range. CONSTITUTION: On one side of a paper board substrate 12, a low density polyethylene (henceforth expressed as LDPE) polymer 10 covering is applied. The layer 10 is a glossy layer contacting with the outside air and made of an extrusion coating grade LDPE. A combination layer of a polyamide type polymer resin 14 and a caulking polymer resin 16 such as an ionomer type resin is simultaneously extruded onto the inner side portion of the paper board 12. On the combination layer, an oxygen impermeable material layer 18 such as an aluminum foil or the like is provided. On the outside layer of this foil, a second layer made of a caulking polymer resin 20 such as an ionomer type resin is coated. Further, on the second layer, a second layer made of a LDPE polymer 22 is coated. This layer heat-seals the whole laminate structure at its heat-sealing temperature range of 250-500°F. COPYRIGHT: (C)1990,JPO