Gas barrier - Characteristic multilayer structure

摘要

PURPOSE:To realize a lightweight structure, which can withstand heat treatment and hot filling and has excellent transparency and gas-barrier performance by a structure wherein a mixed polyamide layer, which is produced through the polycondensation reaction of dicarboxylic acid consisting of specified components and m-xylylenediamine. CONSTITUTION:At least one layer is made of copolyamide, which is produced through the polycondensation reaction of dicarboxylic acid of 55-70mol.% of aliphatic dicarboxylic acid and 30-45mol.% of aromatic dicarboxylic acid consisting of isophthalic acid and terephthalic acid and n-xylylenediamine. At least one layer, which is made of another thermoplastic resin, is bonded to the layer just mentioned above in order to obtain a transparent, gas-barrier multi-layer structure. In this case, in the aromatic dicarboxylic acid, the component unit of the isophthalic acid is set within the range of 20-30mol.% and the component unit of the terephthalic acid is set within the range of 5-20mol.%.