| 摘要 |
<p>PURPOSE:To prevent whitening and to enhance transparency, heat resistance and economicity by forming a multi-layer preform of the different saturated polyester resin layers of at least two layers and regulating oligomer content of the outer peripheral facing layer to the specified rate or below and molding the multi-layer preform into a bottle by a blow mold. CONSTITUTION:A preform made of saturated polyester resin is formed of the different saturated polyester resin layers (a), (b) of at least two layers. As the general-purpose saturated polyester resin (a) of the inner peripheral facing layer, polyethylene terephthalate is preferably utilized. Saturated polyester resin (b) of the outer peripheral facing layer is produced by reacting ethylene glycol or the ester forming derivative thereof with terephthalic acid or the ester forming derivative thereof in the conditions wherein oligomer content does not exceed 0.05wt.%. A bottle is obtained by molding this multi-layer preform in a blow mold. Further the multi-layer preform is obtained by supplying saturated polyester resin (a) and (b) to a molding machine such as an injection molding machine, an extruder, a compression molding machine and a blow molding machine.</p> |
