To provide a low-cost electromagnetic wave absorbing building material in which electromagnetic wave absorbing performance for preventing communication failure is exhibited in a plurality of specified frequency bands by using an existing plaster building material.
A resistive coating layer 4 is laminated on one surface of a first plaster board 2a having a standard thickness d1, and a conductive layer 3 is laminated on the other surface. A second plaster board 2b having the standard thickness d1 is further laminated on the surface of the resistive coating layer 4, in this structure. A resistance value of the resistive coating layer 4 is set at 80 Ω/square or more and less than 280 Ω/square. In the electromagnetic wave absorbing building material 1 constituted in this way, when electromagnetic waves W in both frequency bands of 2.4 GHz and 5.2 GHz are made incident from the front surface side of the second plaster board 2b, the electromagnetic wave W is absorbed to the level where the communication failure is not caused.
SUGIMOTO HIROMICHI
AZUMA NOBUYUKI
OHBAYASHI CORP
NAIGAI TECHNOS KK
JP2004270143A | 2004-09-30 |
Takashi Noguchi
Kazuhiko Saishita