| 摘要 |
PROBLEM TO BE SOLVED: To provide a plastic bottle which achieves weight saving of a mouth plug part without changing an existing device and a shape of a cap, a preform, and a filling body.SOLUTION: A substantially cylindrical mouth plug part comprises: an outer screw 13 having an upper end part and a lower end part, and projecting outward from the upper end part to the lower end part in a spiral form; a coupler; a support ring; and a lower coupler. The outer screw 13 has: an upper surface straight part 13d on the upper side, which is linear in a cross-sectional view; an undersurface straight part 13e on the lower side, which is linear in a cross-sectional view; and an apical surface straight part 13f on the outside, which is linear in a cross-sectional view. A vertical width wD between a first intersection V1, which is an intersection between an extension line L3 from the upper surface straight part 13d and an extension line L5 from the apical surface straight part 13f, and a second intersection V2, which is an intersection between an extension line L4 from the undersurface straight part 13e and the extension line L5, is 0.4 mm or more and 0.9 mm or less.SELECTED DRAWING: Figure 9 |
