| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cap made of a synthetic resin capable of preventing the inner pressure of a container from excessively increasing. <P>SOLUTION: A cap main body 4 with a top board part 2 and a cylindrical part 3 hung from its peripheral edge part 2b is provided. A channel part 15 tearing the top board part 2 during an elevation in the inner pressure of the container is formed. The channel part 15 is formed so as to pass through approximately a central part 2c of the top board part 2. When the inner pressure of the container 20 is elevated caused by the fermentation or the like of a content liquid, the top board part 2 is expanded and deformed upward, and a tensile force applied on the top board part 2 is increased. The top board part 2 is torn along the channel part 15, and gas in the container 20 is vented outward through a gap generated by tearing of the top board part 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
