| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a self-standing polyester bottle of one-piece type structure in which some foot segments and valley segments are alternatively arranged and fragile breakage at the bottom segment is prevented. SOLUTION: There is provided a self-standing type pressure-proof bottle of double-axis extension in which some foot segments and some valley segments are alternatively installed, a degree of crystallization in one axial orientation and an enthalpy total amount in at least the valley segments within a radius corresponding to 40% of a barrel radius from the center of the bottom part are in relation satisfying the equations: Y<=(2.5×10-4)×(X-10.5)4 and 0<=X<10.5, wherein Y denotes an enthalpy total amount calculated as a heat absorbing peak value (J/g) when a specimen is measured within a range of Tg to Tg+25 deg.C measured with a differential scanning calorimeter, and X denotes a degree of orientating crystallization (%) measured by an X-ray refraction method within a range of 2θ=0 deg. to 100 deg..</p> |
