Microlayer extrusion coating and laminating for flexible packaging

摘要

The present development is a process for coating a substrate with a microlayered extrusion coating, or for producing a laminate from a first substrate, a microlayered extrudate and a second substrate. The present development also includes a microlayered extrusion coating used for laminating two or more plastic extrudates. The microlayered extrusion coating comprises a microlayer core comprising a plurality of layers of gas barrier material having a thickness of less than five microns per layer with alternating tie layers. The microlayer core is sandwiched between polymeric boundary layers which are further sandwiched between polymeric skin layers. The present microlayered extrudate surprisingly exhibits a gas barrier significantly better than conventional thicker single barrier layers and increased opacity in the extrudate using white pigmented LDPE enhances the printed graphics in a laminate structure using a printed substrate.

主权项

1. An extrudate for use in extrusion lamination or extrusion coating, said extrudate comprising a first microlayered core sandwiched between boundary layers and skin layers to form a structure comprising:
skin/boundary/microlayered core/boundary/skinwherein said skin layer and said boundary layer is selected from the group consisting of low density polyethylene, maleic anhydride, and combinations thereof, and wherein said microlayered core comprises at least one barrier microlayer selected from the group consisting of ethylene vinyl alcohol copolymer (EVOH), polyvinylidene dichloride (PVDC), vinylidene chloride/methyl acrylate copolymer, polyamide, polyester, high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), and combinations thereof, adhered to at least one tie microlayer selected from the group consisting of maleic anhydride, anhydride modified linear low density polyethylene, ethylene methacrylate, polyamide, and combinations thereof, and wherein the thickness of the barrier microlayer is less than about five microns and the thickness of the tie microlayer is less than about five microns.