| 摘要 |
PURPOSE:To improve the gas barrier property at the breaking groove, make the cap easily openable, improve the efficiency of the manufacture, without leaving a metal foil on the cap after opening of the cap so as to make hygienic, and enable recycling the resin after use. CONSTITUTION:A metal foil 15 which is similar in shape to the enclosure of an endless breaking groove 6 and has a slightly larger area than the enclosure defined by the outer edge 17 of the bottom of the breaking groove is stuck to the inner side of the mouth wall 5 in a concentric arrangement with the breaking groove 6. The metal foil 15 extends beyond the outer edge 17 of the bottom of the breaking groove and forms on the outer side of the breaking groove a region which is narrow in breadth and at which the metal foil 15 removably sticks. |
