合成树脂盖、封闭装置和容器包装饮料

Original abstractThe present invention provides a synthetic resin cap comprising: a cap body ( 4 ) having a top plate portion ( 2 ) and a cylinder portion ( 3 ) hanging from a circumferential edge portion ( 2 b ) thereof; an annular inside seal projection ( 12 ) to be fitted to a container mouth portion ( 21 ); a connector portion ( 15 ) formed between the top plate portion ( 2 ) and the inside seal projection ( 12 ); and an outside thin wall portion ( 16 ) formed on the top plate portion ( 2 ), and provides a closing device using thereof, and a container-packed beverage. When the internal pressure of the container has risen, the top plate portion ( 2 ) is deformably swelled upward, and an inward tensile force is applied to the inside seal projection ( 12 ) by the connector portion ( 15 ). Since the outside thin wall portion ( 16 ) undergoes bending deformation, the portion positioned inside the outside thin wall portion ( 16 ) to undergo significant bulging deformation upward, and the slope of the top plate portion ( 2 ) at the portion where the inside seal projection ( 12 ) is formed is increased. Thus, the inside seal projection ( 12 ) is displaced inward, and gas in the container may be easily discharged to the outside.