| 摘要 |
PROBLEM TO BE SOLVED: To provide a stopper that is neither removed nor sprung out even if an inner pressure is rapidly increased, and enables its opening work to be smoothly carried out.SOLUTION: A synthetic resin stopper 1 comprises an inner cylinder 5 vertically installed at a top wall 3 and inserted into and fitted to the inside of a container mouth part and an outer cylinder 7 vertically installed at the top wall 3 in a concentric manner with the inner cylinder 5 to cover the outside part of the container mouth part. The outer cylinder 7 comprises a cut-out part 17 cut and removed from the stopper 1 and a plurality of residual parts 19 having locking parts 23 locking an engagement part of the container mouth part, provided at intervals in a circumferential direction, and left while being not cut out. The locking parts 23 of the outer cylinder 7 can be detached from the engagement part of the container mouth part by picking up and pulling the residual part 19 upward by a finger after the cut-out part 17 is removed. |
