| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a plastic cap having both superior characteristics of sealing and degassing performance. <P>SOLUTION: This plastic cap comprises a top plate part and a skirt part suspended down from the peripheral edge of the top plate, the inner surface of the top plate is formed with an inner ring close brought into contact with the inner surface of a wall part of a container opening part, and the inner surface of the skirt is formed with a thread engaged with a thread formed at the outer surface of the wall of the container opening part. This plastic cap is characterized in that the inner surface of the inner ring is formed with at least one fine notch extending from its extremity end in an upward direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
