| 摘要 |
PURPOSE:To prevent the premature rupture of a container lid due to a doming phenomenon and permit the same to be ruptured very easily when a chemical is used by a method wherein the structure of a sealing member is made up of a main thin wall part and a plurality of reinforcing rib parts provided on this thin wall part extending radially and spaced circumferentially. CONSTITUTION:A sealing member 8 on a container lid 2 has a main thin wall part 28 and a plurality of reinforcing rib parts 30 provided on the main thin wall part 28 extending radially and spaced circumferentially. Preferably, the three rib parts 50 are formed circumferentially in an equally spaced relation. In this way, at the time of heat-treating a chemical container 32 at a high temperature, even if a radial stress is produced on the sealing member 28 due to the doming phenomenon of a top panel wall 10 of an inner lid 4 and a top panel wall 18 of an outer lid 6 the sealing member is retained in its shape without suffering premature rupture. When the chemical contained in the container is used, the outer lid 6 is pulled up forcibly with a curl 26 held between the fingers to produce stress concentration on the sealing member 8 so as to cause the progress of the rupture of the sealing member 28 take place very easily. |
