| 摘要 |
PROBLEM TO BE SOLVED: To provide a synthetic resin cap easily pulled out from a mold at molding, without risk of decreasing fastening force, and further, capable of keeping sufficient airtightness.SOLUTION: A synthetic resin cap includes a top plate part and a peripheral wall part suspended from the periphery of the top plate part and has a screw part formed screwably with a container mouth on an inner periphery surface of the periphery wall. The screw part is formed so as to be alternately arranged with a non-screw part not provided with a thread in the circumferential direction, and further, the lengths in the periphery direction of the screw part and the non-screw part are formed to be the same. |
