| 摘要 |
PROBLEM TO BE SOLVED: To provide a ceramic sound absorption material which has weather resistance, excels in sound absorption rate in a region of frequency at which a person feels a sound loud, and provides excellent sound absorption effect for sound which comes from various directions and angles by providing specific communicating air holes, and specifying porosity and permeability, and providing specific non-through grooves on a face at right angles in the direction of thickness. SOLUTION: A main body of air hole diameter is provided with communicating air holes of 0.2 to 2000μm and is constituted by multiporous ceramics block 1 having porosity of 60% or more and permeability of 1cm<3> .cm/cm<2> .sec.cmH2 O or more, and a non-through groove 2 having the depth of 20mm or more is provided on one face at right angles in the direction of its thickness in such a manner that its opening rate becomes 9% or more. Here, it is preferable that the non-through grooves 2 having the width of 2 to 50mm are provided at substantially equal interval in a scope of opening rate of 9 to 65% and that the maximum value of sound absorption rate in a scope of frequencies of 100 to 2000Hz is 0.8 or more. Moreover, it is preferable that the porous ceramic block 1 is obtained by burning fireproof clay in which an air hole providing material is mixed and/or fireproof chamotte.
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