PLASTIC CAP

PROBLEM TO BE SOLVED: To make dismounting work of a peripheral band from the container mouth compatible with secure closing work or a tamper-evident property by forming a weakened part in the peripheral band held on the container mouth when closing it and asymmetrically arranging a plurality of bridges on the weakened part. SOLUTION: This cap is formed of a top plate part 10 and a skirt part 20, and a peripheral band 40 or the like provided with a fixing means 100 fixed to the mouth of a container when closing it is disposed at the lower side of the skirt part 20. A vertically weakened part 90 for dismounting the cap is formed in the peripheral band 40 and a plurality of bridges 61, 62 are arranged asymmetrically and separately from each other on the weakened part 90. The weakened part 90 is formed of notches 91 and a plurality of connecting parts 92, 93 of which the thickness is made thin, and further, one side 92 of the connecting parts is disposed under the peripheral band 40. In this way, breakage due to concentrated stress is prevented when opening the cap, and the peripheral band 40 can easily and securely be removed from the container mouth.