| 摘要 |
<p>PROBLEM TO BE SOLVED: To hold excellent transparncy and to prevent deformation caused by filling a heated drink from occurring by making degree of crystallinity of a trunk part measured by means of X-rays analysis at a specified range and making degree of orientation of non-crystallized part of the trunk part measured by using a fluorescence photometer at a specified value or smaller. SOLUTION: Degree of crystallinity of a trunk part of a bottle measured by means of X-rays analysis is made in a range of 25-35%, pref. 26-32%. In addition, degree of orientation of non-crystallized part of the trunk part measured by using a fluorescence photometer is made to be at most 0.14, pref. in a range of 0.10-0.12. When each characteristic exists in this range, enough heat resistance can be ensured on the trunk part of the bottle. At the same time, even when a heated drink, etc., are filled into the bottle, as ratios of deformation, expansion and shrinkage are small, deformation of the trunk part of the bottle can be kept small. In addition, a bottle with excellent transparency can be obtd.</p> |
