| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cap having a straw insertion port which can satisfy the openability by a straw and the drop prevention of the opening region at a high level. <P>SOLUTION: This cap comprises a top plate section 2 and a skirt section 3 which vertically hangs from the peripheral edge of the top plate section 2. On the top plate section, the opening region 21 which is constituted of a circular main section 21a and a belt-shape added section 21b is specified by a breakable thinner line 22 having an arc-shape main section 22a and a pair of added sections 22b and 22b which extend from both ends of the arc-shape main section 22a. For the plastic cap, the opening region 21 can be displaced downward with the distal end edge 23 of the belt-shape added section 21b as a hinge by breaking the breakable thinner line 22. In the plastic cap, the breakable thinner line 22 is thinned from outside of the top plate section. At the same time, an annular thinner section 24 is formed at an annular section which is located outside of the opening region 21 and includes the distal end edge 23 of the belt-shape added section. The annular thinner section 24 is thinned from the inside of the top plate section for this cap made of a synthetic resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
