| 摘要 |
PROBLEM TO BE SOLVED: To prevent a shoulder part and a body part from being greatly deformed to an extent unable to be restored when a pressure inside a bottle changes.SOLUTION: A first circumferential groove 15 continuously extending over whole circumference is formed at a shoulder 12. A plurality of second circumferential grooves 16 continuously extending over whole circumference are formed at intervals in a vertical direction at a body 13. An outer diameter A at a groove of the first circumferential groove 15 is at least 85% and less than 100% of an outer diameter B at the groove bottom of the second circumferential groove 16. The first circumferential groove 15 is disposed downward from a neck ring 29 protruded at a connection part of a mouth 11 and a shoulder 12 at a position separated by at least 60% to at most 80% of a distance C in a vertical direction of the neck ring 29 and the lower end of the shoulder 12. The groove bottom of the first circumferential groove 15 extends gradually toward the outside in the radial direction of the bottle as it goes from the upper part toward the lower part. |
