| 摘要 |
PURPOSE:To improve the stability of the mouth part of a bottle and to remove the delamination of the bottom when the bottle is dropped by a method in which thermoplastic polyester is used for inner and outer layers, and excellent gas barrier resin is used for an intermediate layer, and then an adhesive layer is inserted between the inner and outer layers and the intermediate layer in the mouth part and the bottom part of the bottle. CONSTITUTION:The thermoplastic polyester layer 1 containing mainly polyethylene terephalate resin is used for inner and outer layers. The layer 2 of gas barrier resin is provided on the barrel part A of a bottle. Adhesive layers 22, 31 are further laminated between the polyester layers 11, 12 and gas barrier resin-layers 21, 32 of the mouth part B and the bottom part C of the bottle, thereby producing a multilayer preform. For the manufacture of said multilayer preform, the injection molding machine for coinjection which has three injection devices capable of controlling injection speed and injection pressure at least three stages, is used. As the definite example of said gas barrier resin, the saponified material of ethylene-vinylacetate copolymer, etc., are used, and as the adhesive resin, polyolefin or polyamide, etc., are used. |
