DOUBLE BAG

To provide a double bag which has an inner bag in which a fluid is sealed and an outer bag in which an endothermic agent or a heat dissipation agent and the inner bag are included, which has a structure that is easily manufactured, in which at least part of the inner bag included in the outer bag is openable prior to the outer bag when an external pressure is applied with an appropriate force, and which can generate an endothermic reaction or a heat dissipation reaction without obvious deviation in the entire outer bag.SOLUTION: A double bag 100 includes: an inner bag 10 including a first inner chamber 12 in which a fluid 101 is sealed; and an outer bag 20 for including the inner bag 10, and having a second inner chamber 22 in which an endothermic agent 102 or a heat dissipation agent reacting by coming into contact with the fluid 101 is sealed. A ratio of a long side inner dimension A3 of the inner bag 10 with respect to a short side inner dimension A1 of the inner bag 10 is greater than or equal to 1.5 times and smaller than or equal to 4 times. A ratio of a sealed amount (cc) of the fluid 101 with respect to maximum internal volume (cm) of the first inner chamber 12 of the inner bag 10 is greater than or equal to 70% and smaller than or equal to 95%. The inner bag 10 includes a slit 30 formed by being cut from a surface layer of a sheet 24 constituting the inner bag 10 to a middle part in the thickness direction.SELECTED DRAWING: Figure 1 【課題】流動体が封入された内袋、および吸熱剤または放熱剤と内袋とが内包された外袋を有する二重袋であって、製造容易な構造であるとともに、適度な力で外圧をかけた際に外袋に先んじて、当該外袋に内包された内袋の少なくとも一部が開口可能であり、外袋全体において顕著な偏りなく吸熱反応または放熱反応を生じさせ得る二重袋を提供する。【解決手段】二重袋１００は、流動体１０１が封入された第一内室１２を有する内袋１０と、内袋１０を内包するとともに、流動体１０１と接触することで反応する吸熱剤１０２または放熱剤が封入された第二内室２２を有する外袋２０と、を備え、内袋１０の短辺内寸Ａ１に対する内袋１０の長辺内寸Ａ３の比率が１．５倍以上４倍以下であり、内袋１０の第一内室１２の最大内容積（ｃｍ3）に対する流動体１０１の封入量（ｃｃ）の比率が７０％以上９５％以下であり、かつ、内袋１０は、内袋１０を構成するシート２４の表層から厚み方向中間部まで切り込まれてなるスリット３０を備える。【選択図】図１