Container cap

A container cap comprising a top panel wall and a skirt wall of a cylindrical shape hanging down from the circumferential edge of the top panel wall, the skirt wall being sectioned into a main portion over a weakened line that is extending in the circumferential direction and can be broken and a tamper-evidence hem under the weakened line, and the circumferential wall portion of at least the main portion of the skirt wall having linear protuberances protruding on the outer side of the circumferential wall portion and extending in the up-and-down direction of the main portion in a plural number along the whole circumferential direction of the main portion,

• wherein the protuberances include large protuberances having a large height and small protuberances having a height of protrusion from the outer surface of the circumferential wall portion smaller than that of the large protuberances, and the main portion has large protuberance regions forming a plurality of large protuberances and small protuberance regions forming a plurality of small protuberances, the large protuberance regions and the small protuberance regions being alternately arranged in the circumferential direction of the main portion, and
• wherein the inner surface of the circumferential wall portion of the main portion is internally threaded to come into engagement with the mouth-and-neck portion of the container, the internal thread forming a threaded portion having a screw thread and a plurality of missing portion where the screw thread is missing, the threaded portion being arranged on the inner surface of the circumferential wall portion of at least the small protuberance regions, and at least the large protuberance regions being arranged on the outer surface of the circumferential wall portion at the missing portions.