Laminate structure useful as liquid impermeable moisture vapor permeable membrane

摘要

A substantially liquid impermeable moisture vapor permeable laminate structure comprising: (i) a substrate layer comprising a woven or non-woven material, (ii) a moisture vapor control layer attached to said substrate, (iii) a tie layer comprising one or more copolymers comprising from about 30 to about 90 weight percent ethylene co-monomer units and from about 10 to about 70 weight percent vinyl acetage co-monomer units, and (iv) a layer comprising one or more copolyetherester(s) in an amount of at least 50 weight percent based on the total amount of polymer in the layer. The moisture vapor transmission rate (MVTR) in the direction away from the copolyetherester-containing layer and tie layer and towards the substrate is preferably greater than the MVTR in the direction away from the substrate layer and towards the tie layer and copolyetherester-containing layer.