Patent ID: 8333509

Claim:
A bag container comprising a container body shaped by using a mold, the container body being made of synthetic resin and having a spout-forming portion and a filling inlet portion that project outward from a circumferential surface of the container body, contents of the bag container being enclosed therein by first filling the contents through the filling inlet portion to place the contents inside and then applying fusion-bond sealing to the filling inlet portion, wherein: before the filling inlet portion undergoes fusion-bond sealing, the filling inlet portion has, at a sealing base portion thereof that constitutes a boundary of a region for applying the fusion-bond sealing, a polygonal cross-sectional shape having an even number of corners, a tip-end-side cross-section-changing portion is provided on a tip-end side with respect to the sealing base portion, the tip-end-side cross-section-changing portion changing the cross-sectional shape of the filling inlet portion in such a design as to connect the sealing base portion to a cylindrical portion, and a plurality of flat triangular panels each having a shape of an isosceles triangle are provided on the container-body side with respect to the sealing base portion, the triangular panels being provided in a connected manner along a circumferential direction of the filling inlet portion, a base of each isosceles triangle being formed of one of the sides of the polygonal cross-sectional shape having the even number of corners and legs of that isosceles triangle being respectively formed of ridgelines located on both sides of the base, the ridgelines respectively starting from opposite ends of the base; and when the fusion-bond sealing is to be applied to the filling inlet portion, a pair of opposing corners of the polygonal cross-sectional shape, which has the even number of corners, of the sealing base portion before undergoing the fusion-bond sealing is positioned respectively on opposite edges of the filling inlet portion after having undergone the fusion-bond sealing by folding up a region on the tip-end side with respect to the sealing base portion in such a manner as to squash that region.