POLYESTER MULTI-LAYER MOLDED FORM

摘要

PURPOSE:To enhance gas barrier properties, transparency and moldability by constituting the multi-layer of a polyethylene terephthalate resin layer and a copolymerized polyester resin layer and specifying the ratio of polyester resin and the copolymerized polyester resin which constitute the multi-layer. CONSTITUTION:A polyethylene naphthalate (PET) layer is formed which incorporates both a polyethylene terephthalate resin layer and a copolymerized polyester resin layer formed of 40 - 90 mol% ethylene - 2,6 - naphthalate unit and 60 - 10 mol% ethylene isophthalate unit by at least one layer at a time. Two layers are constituted by forming an inner layer of the PET layer and forming an outer layer of copolymerized polyester resin. Three layers are preferably constituted by forming the innermost layer and the outermost layer of the PET layer and forming an intermediate layer of the copolymerized polyester layer. The rate of weight constituting respective layers is preferably regulated to 10 - 90 wt.% polyester resin and 90 - 10 wt.% copolymerized polyester resin by effect of gas barrier properties and constraint of stretching properties.