Sperrschicht aus Copolyamid sowie deren Verwendung

摘要

Copolyamide barrier layers which are durable hot-water stable and transparent. The copolyamide is amorphous and partially aromatic, and comprises (a) 50 molar parts of substituted or unsubstituted aromatic dicarboxylic acids which are replaced by up to 60% by weight of at least one additional dicarboxylic acid selected from the group consisting of cycloaliphatic dicarboxylic acids having 8 to 24 carbon atoms, araliphatic dicarboxylic acids having 8 to 18 carbon atoms, and mixtures thereof, and (b) 50 molar parts of hexamethylene diamine, which is replaced by up to 60% by weight of at least one additional diamine, selected from the group consisting of substituted or unsubstituted aliphatic diamines having 4 to 20 carbon atoms, substituted cycloaliphatic diamines having 6 to 24 carbon atoms, araliphatic diamines having 8 to 18 carbon atoms, and mixtures thereof, the acid groups and amino groups being present substantially in equimolar proportions. These barrier layers are useful in reusable multilayer packaging elements, each of which contains at least one such barrier layer.