To provide a radio wave absorber for effectively preventing radio wave interference by a scattered wave of a radio wave by providing the light reflecting function and the radio wave absorbing function for a road sign as road ancillary equipment.
This radio wave absorber 1 constitutes a radio wave absorbing layer 4 by laminating a dielectric layer 2 and a radio wave reflecting layer 3, and is integrally constituted by arranging a light reflecting layer 5 via an adhesive or others on a radio wave arrival directional X surface layer of this radio wave absorbing layer, that is, a surface of the dielectric layer 2. For the light reflecting layer 5, a material for passing the radio wave, for example, a Scotch light reflecting sheet (R) 6060 white made by the Sumitomo 3 M company is used. A material of the dielectric layer 2 is composed of a composition of blending, for example, conductive titanium oxide (FT-2000 made by the Ishihara Industry Co., Ltd.) and/or conductive carbon black (a commodity name (Ketjen Black) made by the Japan EC Co., Ltd.) with a base material. For the base material, a thermosetting resin (properly selected from, for example, an epoxy resin, polyurethane resin, a polyester resin, and a phenol resin) is used.
TOYODA MAKOTO
SO SATORU
Takashi Noguchi
Kazuhiko Saishita