| 摘要 |
PROBLEM TO BE SOLVED: To improve the fire resistance of an electromagnetic-wave absorbing building-material, by providing on its electromagnetic-wave reflecting layer an inorganic building-material layer having a specific coefficient of moisture permeability on whose two surfaces water-resistant portions are formed, and by forming a resistance-film layer on the inorganic building-material layer. SOLUTION: On an electromagnetic-wave reflecting layer 3, there is provided such an inorganic building-material layer 1 as a fiber-reinforced cement, calcium silicate, or gypsum plate wherein its coefficient of moisture permeability is not larger than 2.0×108 g/Pa.s.m and water-resistant portions are formed on both its surfaces. Then, on the inorganic building-material layer 1, there is provided a resistance-film layer 2 comprising a structure of distributing in an organic binder such a conductive material as a carbon powder, carbon fibers, a metallic powder, and metallic fibers, or a structure wherein a conductive film is formed by forming an indium oxide tin film on an organic film through sputtering, etc. As a result, the fire resistance of an electromagnetic-wave absorbing building-material can be improved, and its stable electromagnetic-wave absorbing characteristic independent of the variation of the humidity of the external can be obtained.
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