Patent ID: 8309230

Claim:
A multilayer barrier structure comprising: (a) a first nanocomposite layer including a first polymer and a first exfoliated filler wherein the first exfoliated filler is a silicate having an aspect ratio greater than 25 and wherein the layer exhibits an at least 50-fold reduction in gas permeability as compared with a coating formed from the first polymer alone; (b) a second nanocomposite layer including a second polymer and a second exfoliated filler wherein the second exfoliated filler is a silicate having an aspect ratio greater than 25 and wherein the layer exhibits an at least 50-fold reduction in gas permeability as compared with a coating formed from the second polymer alone; (c) at least one intermediate layer disposed between the first and second nanocomposite layers, the intermediate layer including a material selected from the group consisting of: synthetic elastomers, non-elastomeric synthetic polymers, natural non-elastomeric polymers, including films, fabrics, nonwovens, papers or foams comprising the aforesaid polymers, and further wherein the multilayer structure exhibits a breakthrough time at least 30% higher than it would be if the two barrier layers were combined in a single layer on one side of the intermediate layer.