Sound Absorbing Material and Structure Using the Same

Abstract

A sound absorbing material ( 1 a ) comprising a film ( 11 ) composed of a silicone rubber and a porous layer ( 12 ) (i.e., a first porous layer) laminated on the back surface of the film ( 11 ). The film ( 11 ) is made of a material which has flame retardancy and generates no noxious fume during combustion, such as a silicone rubber comprising only polysiloxane. The film ( 11 ) used is preferably one which has an oxygen index of 25 or higher, which exhibits a heat release value of combustion per unit volume of 8 MJ/m or less and which exhibits a heat release rate of combustion of [200 kW/m 2 ]·10 sec or less. The first porous layer ( 12 ) is formed from a material having flame retardancy, such as glass wool, rock wool or a mixture thereof. A structure ( 3 a ) can be formed by providing the sound absorbing material ( 1 a ) having the construction described above on a rigid wall ( 2 ) in parallel, with the first porous layer ( 12 ) facing to the rigid wall ( 2 ).

1 . A sound absorbing material comprising a film composed of a rubber, and a porous layer laminated on a back surface of said film. 
   
   
       2 . A sound absorbing material comprising a film composed of a rubber, a first porous layer laminated on a back surface of said film, and a second porous layer laminated on a front surface of said film. 
   
   
       3 . The sound absorbing material according to  claim 1 , wherein said rubber is a silicone rubber. 
   
   
       4 . The sound absorbing material according to  claim 1 , wherein said film has a heat release value of combustion of 8 MJ/m 2  or less. 
   
   
       5 . The sound absorbing material according to  claim 1 , wherein said film has a heat release value of combustion of [200 kW/m 2 ]·10 sec or less. 
   
   
       6 . The sound absorbing material according to  claim 1 , wherein said rubber is a rubber selected from the group consisting of natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, nitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, fluoro-rubber, chlorosulfonated polyethylene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, polysulfide rubber and polyolefin. 
   
   
       7 . The sound absorbing material according to  claim 1 , wherein said film includes a particulate inorganic compound. 
   
   
       8 . The sound absorbing material according to  claim 7 , wherein said inorganic compound comprises a compound selected from the group consisting of Si, Ca, Sr, Ba, and mixtures thereof. 
   
   
       9 . The sound absorbing material according to  claim 1 , wherein said porous layer is formed from a material having flame retardancy. 
   
   
       10 . The sound absorbing material according to  claim 1 , wherein said porous layer is formed from glass wool, rock wool, or a mixture thereof. 
   
   
       11 . The sound absorbing material according to  claim 1 , wherein said film is integrated with said porous layer. 
   
   
       12 . The sound absorbing material according to  claim 2 , wherein said film is integrated with either said first porous layer or said second porous layer. 
   
   
       13 . The sound absorbing material according to  claim 12 , wherein said film is integrated with said first porous layer and/or said second porous layer by adhesion. 
   
   
       14 . The sound absorbing material according to  claim 11 , wherein said film is integrated with said porous layer by adhesion. 
   
   
       15 . The sound absorbing material according to  claim 11 , wherein said film is integrated with said first porous layer and/or said second porous layer by silicone graft reaction. 
   
   
       16 . The sound absorbing material according to  claim 11 , wherein said film is integrated with said porous layer and/or said another porous layer by a portion of said film anchored within pores of said first porous layer and/or said second porous layer. 
   
   
       17 . A structure comprising a sound absorbing material according to  claim 1  and a rigid wall, wherein
 a porous layer of said sound absorbing material faces said rigid wall, and said sound absorbing material is arranged in parallel with said rigid wall.   
   
   
       18 . A structure comprising a sound absorbing material according to  claim 2  and a sound insulation board, wherein
 said first porous layer or said second porous layer of said sound absorbing material faces said sound insulation board, and said sound absorbing material is arranged in parallel with said sound insulation board.   
   
   
       19 . A structure comprising a sound absorbing material according to  claim 1  and a rigid wall, wherein
 said porous layer of said sound absorbing material faces said rigid wall through an air layer, and said sound absorbing material is arranged in parallel with said rigid wall.   
   
   
       20 . A structure comprising a sound absorbing material according to  claim 2  and a sound insulation board, wherein
 said second porous layer of said sound absorbing material faces said sound insulation board through an air layer, and said sound absorbing material is arranged in parallel with said sound insulation board.   
   
   
       21 . A structure comprising (1) a sound absorbing material according to  claim 1  and (2) a rigid wall or a sound insulation board, wherein
 said sound absorbing material has a heat release value of combustion of 8 MJ/m 2  or less, and a heat release rate of combustion of [200 kW/m 2 ]·10 sec or less.   
   
   
       22 . A structure comprising (1) a sound absorbing material according to  claim 2  and (2) a rigid wall or a sound insulation board, wherein
 said sound absorbing material has a heat release value of combustion of 8 MJ/m 2  or less, and a heat release rate of combustion of [200 kW/m 2 ]·10 sec or less.   
   
   
       23 . The sound absorbing material according to  claim 11 , wherein
 said film is integrated with said porous layer by silicone graft reaction.   
   
   
       24 . The sound absorbing material according to  claim 11 , wherein
 said film is integrated with said porous layer by a portion of said film anchored within pores of said porous layer.   
   
   
       25 . The sound absorbing material according to  claim 2 , wherein
 said first and second porous layers are formed of glass wool, rock wool, or a mixture thereof.