Caps used for bottles with positive internal pressure and bottles with the caps attached

摘要

A cap (20) used for a bottle having a positive internal pressure, the cap (20) is provided with a female screw portion (21) for engaging with a male screw portion provided on the outer peripheral surface of the bottle mouth portion, and the female screw portion (21) is provided. A peripheral protrusion (22) that protrudes from the inner peripheral surface (25A) of the cap side wall (25) and extends spirally at least 360 degrees continuously is provided, and the peripheral protrusion (22) is a part in the radial direction. There is at least one notch (23) notched.