Patent ID: 7514380

Claim:
An article comprising a substrate and a selectively permeable membrane wherein the article is selectively permeable to moisture having a moisture vapor transmission rate, measured according to ASTM F2298, of at least 1800 g/m 2 /24 h; the substrate comprises textile or porous sheet material; the membrane comprises or is produced from a composition that comprises or is produced from an organic acid-modified ionomer and optionally a non-ionomeric polymer; the organic acid-modified ionomer comprises one or more E/X/Y copolymers and an organic acid or salt thereof where E is derived from ethylene, X is derived from at least one C 3 -C 8 α,β-ethylenically unsaturated carboxylic acid, and Y is derived from a softening comonomer; at least 60% of the acid moiety in the E/X/Y copolymer and organic acid is neutralized with an alkali metal; and the softening comonomer includes an alkyl (meth)acrylate.