| 摘要 |
<P>PROBLEM TO BE SOLVED: To develop an electromagnetic wave absorbing material having the same noise reducing effect as a conventional electromagnetic wave absorbing material since an electromagnetic wave absorption sheet is not provided with sound absorption performance or noise reducing effect and, therefore, noise is increased when an insulation wall, installed conventionally and having sound absorbing performance, is removed and the electromagnetic wave absorbing sheet is installed. <P>SOLUTION: In the electromagnetic wave absorbing sheet constituted of a two-layer structure of a metallic reflection layer and an electromagnetic wave absorption layer, the electromagnetic wave absorption layer is prepared by mixing and dispersing 20-90wt% of magnetic material consisting of more than one kind selected from various ferrites and iron powders and 0.5-20wt% of dielectric material consisting of more than one kind selected from carbon, titanium oxide and zinc oxide into 5-60wt% of a binder resin. Further, the electromagnetic wave absorption sheet is provided with a thickness of not more than 10.0mm, and the electromagnetic wave absorbing material is provided with perforation of a porosity of 10-65% and is prepared by laminating a sound absorbing material thereon. <P>COPYRIGHT: (C)2004,JPO |
