| 摘要 |
PURPOSE:To contrive improvements in transparency and gas barrier properties, by a method wherein a preform obtained by laminating resin each of polyethylene naphtholate, polyethylene terephthalate and the polyethylene naphtholate in this order is heated and orientation blow molding is performed so that an orientation index becomes a specific value. CONSTITUTION:It is preferable that polyethylene naphtholate resin A or C contains at least 60mol% ethylene-2,6-naphtholate unit derived from 2,6-naphthalene dicarboxylic acid and ethylene glycol. Polyethylene terephthalate resin B is manufactured from raw materials of terephthalic acid or its ester forming derivative. A multilayer preform 7 obtained by laminating the resin A, resin B and resin C in this order is manufactured by, for example, co-injection, which is heated from the outside and a hollow part up to an appropriate temperature of orientation, an orientation blow molding having an orientation index of at least 130cm is performed and a bottle 1 is manufactured. |
