| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat accumulator which neither reduces the mechanical strength of a package nor deteriorates its external appearance and also excels in the holding properties of the contents of a thermal storage medium. SOLUTION: The heat accumulator comprises a container having a multi-layer structure composed of at least two layers of a layer of a saponified product of an ethylene/vinyl acetate copolymer and a layer of a polyolefin based resin and, at the same, the layer of a saponified product of an ethylene/vinyl acetate copolymer being located in the thickness direction of the multi-layer structure within 60% from its inner side, and the container containing a thermal storage medium having a hydrocarbon as the major component. |
