SYNTHETIC RESIN BOTTLE BODY, AND PROCESS FOR PRODUCTION THEREOF

摘要

Disclosed is a bottle structure or a production process for achieving the improvement in heat resistance or productivity of a wide-mouth bottle produced by the biaxial stretching blow molding of a polyethylene terephthalate resin. Specifically disclosed is a synthetic resin bottle body produced by the biaxial stretching blow molding of a PET resin, wherein a cylindrical mouth part is so formed that the diameter of a test-tube-like preform is enlarged through a stretching step by biaxial stretching blow molding in the same manner as in the production of a body part, and wherein the temperature for the stretching and the temperature of a mold are set at predetermined temperatures falling within a thermal crystallization temperature for the PET resin, so that the density of the cylindrical mouth part becomes 1.368 g/cm3 or more or the ratio of the absolute value of a crystallization enthalpy (?Hc) that is calculated from an exothermic peak produced in accordance with crystallization in a constant raising temperature measurement of differential scanning calorimetry (DSC) of the cylindrical mouth part to a melting enthalpy (?Hm) that is calculated from an endothermic peak produced in accordance with melting of the cylindrical mouth part (i.e., (|?Hc|/?Hm)) becomes less than 0.1.