| 摘要 |
PROBLEM TO BE SOLVED: To provide a sound absorbing pipe which effectively absorbs noise in a low-frequency range even in the absence of a rigid wall and satisfies standards of a noncombustibility test of the Building Standard Law. SOLUTION: A sound absorbing material 1a of the present invention comprises a cylindrical rigid container 2a having a closed part 21 at one end, a first low-frequency sound absorbing material 33 provided at an outer periphery of the container 2a, and a second low-frequency sound absorbing material 44 charged in the container 2a. The container 2a is formed of a cylindrical pipe made of, for example, stainless steel. The first low-frequency sound absorbing material 3 has a first film 31 made of silicone rubber containing an inorganic compound and a first porous material layer 32 laminated on the back side (on a container 2a side) of the first film 31. The second low-frequency wave sound absorbing material 4 has a second film 41 made of silicone rubber containing an inorganic compound and a second porous material layer 42 laminated on the back side (on an opening part side of the container 2a) of the second film 41. COPYRIGHT: (C)2007,JPO&INPIT
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