Patent attributes
A plastic cap, which is a highly producible one-piece type cap when molded, but becomes a two-piece type cap excellent in sealability and openability when used, and enables a small-diameter pouring opening to be formed, is provided. The plastic cap comprises: a cap body which is composed of a top plate section and a skirt section, has a pouring nozzle formed on an outer surface of the top plate section so as to surround an opening-scheduled portion, and is fitted and fixed to a container mouth; and a top lid composed of a top face, and a circumferential wall suspending from an outer peripheral edge of the top face. The top lid has, formed therein, a protrusion protruding downward from an inner surface of the top face and having an engaging portion on an outer surface thereof. The cap body has an inner plug formed therein. The inner plug is composed of an annular sidewall having an outer diameter enabling the annular sidewall to intimately contact an inner surface of the pouring nozzle; and a bottom formed at a lower part of the annular sidewall. The inner plug is formed integrally with the cap body via a breakable weakened portion at a position below a seal portion of the pouring nozzle having an inner diameter enabling the seal portion to intimately contact the inner plug. On an inner surface of the annular sidewall, an engaged portion vertically engageable with the engaging portion of the protrusion is formed.
