| 摘要 |
PURPOSE:To improve gas barrier property of a polypropylene bottle by forming one end of a pipe made of a specific composition in a bottom, the other end in a neck portion, preliminarily heating it at the specific orientation suitable temperature, and molding in a blowing mold. CONSTITUTION:A pipe 1 is molded by using ethylene-vinyl alcohol copolymer containing 50mol% of ethylene component for a layer to become a gas barrier resin layer, polyproplene resin for inner and outer layers to become a base, by interposing an adhesive layer between the both resin layers, and by coextrusion method. The pipe is cut in a suitable length, fused and closed at one end to form a bottom 6, formed at the other end with a hole at the upper end and a neck 7 having a connecting portion on the outer periphery. The obtained preliminarily molded product 10 is preliminarily heated at suitable orienting temperature of 125 to 165 deg.C, and blow-molded axially and circumferentially in the blowing mold. The multilayer orientation polypropylene bottle obtained in this manner has excellent transparency and high gas barrier property. |
