Gas Barrier Properties of Transparent Metal Oxide Coatings on PET Film

摘要

This paper presents an overview of an extensive investigation of the gas barrier properties of various metal oxides deposited by a range of techniques, on polyethylene terephthalate (PET) substrates. It has been observed that the gas barrier properties of an oxide/polymer film are strongly influenced by the coating thickness, materials and deposition method. It was found that sputtered coatings possessed lower permeability compared to evaporated layers and that ITO exhibited the highest resistance to oxygen permeation, whereas AlO_xN_y presented the best barrier to water vapor transmission. The deposition of barrier coatings onto a smoothing layer was found to result in almost a halving in water vapor transmission. It was also observed that the deposition of a topcoat on AlO_x/PET promotes an enhancement of the gas barrier properties, with the oxygen barrier improvement being greater than that for water vapor.