Package packaging material comprising PLA film with moisture barrier layer by atomic layer deposition

摘要

Provided herein is a moisture barrier film for a package such as a cigarette or cigarette package. The film comprises polylactic acid ("PLA") that is both biodegradable and transparent. The film includes multiple layers of PLA with a base layer having a relatively high melting point compared to two outer layers having a relatively low melting point. The outer layer provides the film with heat sealing capability. The film is coated with a metal oxide layer consisting of aluminum oxide, titanium oxide and / or titanium oxide using an atomic layer deposition (“ALD”) coating process. The ALD coating on the PLA film provides a moisture vapor transmission rate of less than 4 g / m 2 / day after the film is creased to induce cracking of the ALD metal oxide layer.