| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a sound absorbing material with both excellent sound absorption and excellent strength by laminating a plurality of inorganic sheets over one side of a continuous permeable hole foamed body in a condition where upper and lower small through holes are positionally shifted from each other. SOLUTION: A plurality of inorganic sheets 11 in which a large number of small through holes 12 are dispersively drilled over the whole surface in an approximately uniform manner, are laminated over one side of a continuous permeable hole foamed body 2 formed of the hardenable inorganic composition through adhesive layers 3, 3. Small through holes 12 in the upper and lower inorganic sheets 11 are positionally shifted from each other. An opening ratio of the small through holes 12 drilled in the inorganic sheets 11 is 30-80%, the thickness of the inorganic sheets 11 is 1-15mm, the number of laminated sheets is 2-10, and the total lamination height is 2-40mm. The hardenable inorganic composition preferably consists of Al2 O3 -SiO2 inorganic powder, alkali metal silicate, water and foaming agent. The sound absorbing material excellent in both sound absorption and strength can be obtained.</p> |
