| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a bag body maintaining excellent hermeticity over the long run. <P>SOLUTION: In a bag body 1 decompressing and sealing a core taken as a filling 2, a covering material 3 is formed of a protective layer, an aluminum foil 6 and a thermally welded layer 7. The protective layer is made up of a plurality of films such as a surface protective layer 4 and inside protective layer 5. When viewing a cross section in which at least a part of a sealing part 8 having outer peripheral parts of the covering material 3 thermally welded to each other is cut in a plane normal to a peripheral edge, the thermally welded layer 7 situated in the sealing part 8 contains at least one recess. A thin wall part 9 in which thickness of the thermally welded layer 7 is thinner than a peripheral part of the deepest part is formed in the deepest part of the recess. By so doing, a rupture of the sealing part 8 and a crack in the thin wall part 9 for suppressing an amount of atmospheric gas entering through the sealing part 8 from an end surface of a peripheral edge of the covering material 3 are hardly occur. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
