Patent ID: 9719246
Date: 2017-08-01
CPC Classifications: B01D,C08L,E04B

Claim:
1. A vapor retarder membrane, comprising one active layer or an assembly of more than one active layer having a water vapor permeability that increases with surrounding relative humidity, wherein: said one active layer or assembly of more than one active layer comprises at least 90% by weight of a blend of ethylene/vinyl alcohol (EVOH) copolymer and of a copolyamide 6-6.6 (PA666) having a melting point below 210° C., an EVOH/PA666 weight ratio in said blend is 10/90-50/50, the total thickness of the one active layer or the assembly of more than one active layer is 20-100 μm, and the one active layer or the assembly of more than one active layer is at least 40% by weight of the vapor retarder membrane.