MULTI-LAYER PLASTIC SHEET HAVING GAS BARRIER PROPERTY

PURPOSE:To obtain the above sheet combining heat resistance with the gas barrier property by constituting the sheet of a central layer which consists of the partially saponified resin or its derivative made of an ethylene-vinyl acetate copolymer, an adhesive layer and an outermost layer consisting of resin composition wherein modified polyolefine is blended with thermoplastic polyester and specifying the rates of thickness of the central layer, the adhesive layer and the outermost layer. CONSTITUTION:The partially saponified resin or its derivative made of an ethylene-vinyl acetate copolymer is utilized for the central layer of a plastic sheet. Modified polyolefine is utilized for the adhesive layers of double sides. The resin composition is utilized for the outermost layer wherein 0.5 - 10pts.wt. modified polyolefine is blended with 100pts.wt. thermoplastic polyester having >=80mol% ethylene terephthalate unit. Thereby the plastic sheet good in gas barrier property can be obtained without deteriorating elastic modulus and heat resistance. The respective rates of thickness of the central layer, the adhesive layers and the outermost layer are regulated to 1 - 15%, 1 - 15% and 98 - 70%. Thereby the optimum plastic sheet is obtained.