| 摘要 |
A heating element (10) is obtained by laminating a heat generation layer (11), which contains an oxidizable metal, a water absorbent and water, and a water holding layer (12), which is formed of a water absorbent sheet (102). The content of the water absorbent is 0.3-20 parts by mass relative to 100 parts by mass of the oxidizable metal. The mass ratio of the water content to the content of the water absorbent in the heat generation layer (11), namely (water/water absorbent) is 0.8-13. The water content in the water holding layer (12) is 10-45% by mass of the maximum water absorption amount of the water holding layer (12). |
