Heissschrumpfbarer Mehrschichtfilm

摘要

A polyamide resin-based heat-shrinkable multilayer film is caused to satisfy various properties required of a packaging material, especially a food packaging material, at high levels, and particularly exhibit a highest level of heat-shrinkability. The multilayer film comprises at least three layers including an outer surface layer (a) which comprises a polyester resin or a polyolefin resin; an intermediate layer (b) which comprises a mixture of 85 - 60 wt. % of an aliphatic polyamide resin, and 15 - 40 wt. % of an aromatic copolyamide resin which is a copolymer of aliphatic diamine/isophthalic acid and aliphatic diamine/terephthalic acid, and an inner surface layer (c) which essentially comprises a copolymer of ethylene and alpha -olefin having a density below 0.915. The heat-shrinkable multilayer film has been biaxially stretched and then heat-treated to have hot-water shrinkabilities at 80 DEG C of at least 30 % in each of longitudinal/transverse directions and at least 35 % in at least one of longitudinal/transverse directions.