BICOMPONENT MOISTURE BARRIER POLY(ETHERIMIDE) ESTER FILMS

摘要

A bicomponent film of a hydrophilic copolyester having a WVTR of at least 3500 gm?mil/m2/24 hrs. of a poly(etherimide) ester elastomer containing about 25-60 weight percent ethylene oxide units, and a hydrophobic copolyester having a WVTR of 400-2500 gm?mil/m2/24 hrs. of a poly(etherimide) ester elastomer or a segmented copolyester elastomer having no more than about 20 weight percent ethylene oxide units in the hydrophobic elastomers, the bicomponent film having a separation ratio for water vapor of at least 1.2 as determined by ASTM/E 96-66 (Procedure BW).