SYNTHETIC RESIN CAP, CLOSING DEVICE, AND BEVERAGE-CONTAINING CLOSING DEVICE

摘要

In the synthetic resin cap, an inner sealing projection that is fitted into the mouth and an outer sealing projection that abuts against the outer surface of the mouth are formed on the inner surface of the top plate section. The inner sealing projection is capable of being pressed against the inner surface of the mouth as a result of the bending elastic force of the inner sealing projection. The outer sealing projection has an inner surface, the inside diameter of which decreases towards the tip. The minimum inside diameter section of the outer sealing projection is able to abut against the outer surface of the mouth at a position that is separated from the open edge on the container body side. When said synthetic resin cap is not screwed on the mouth, the inside diameter of the minimum inside diameter section is configured to be larger than the outside diameter of the mouth.