MANUFACTURE OF GAS BARRIER FILM THAT IS HEAT-SHRINKABLE AT LOW TEMPERATURE

摘要

PURPOSE:To obtain the titled film suitable for packaging perishable foods, by laminating an ethylene/vinyl acetate copolymer layer on each side of a vinylidene chloride copolymer layer through an adhesive layer, heating the laminate to a specified temperature after the laminate is cooled, and stretching biaxially the laminate by the inflation method. CONSTITUTION:Preferably, as an adhesive layer, an ethylene/vinyl acetate copolymer (mixture) whose MI is 2.5-10g/10min and whose vinyl acetate content is 13-25wt% is laminated on each side of a vinylidene chloride copolymer layer, then an ethylene/vinyl acetate copolymer whose MI is 0.2-1.5g/10min and whose vinyl acetate content is 15-25wt% is laminated on each side thereof by the co- extrusion method, and after the laminate the thickness of which vinylidene chloride copolymer layer is made to be 30% based on the whole thickness is cooled to 5-25 deg.C, the laminate is heated to 82-88 deg.C by hot water and is stretched to obtain the intended film whose heat shrinkage factor is 30% or more at 80 deg.C. USE:The film can be used for packaging foods that are different in shape and have to be stored for a longer period such as fishes, raw meat, etc.