Automotive sound-absorbing material

Abstract

A thin and light-weight automotive sound-absorbing material with a superior sound-absorbing property, which can be used, for example, for automotive insulator to keep the interior of an automobile quiet. This automotive sound-absorbing material has a laminate structure comprising a sound-absorbing layer, an intermediate layer, and a sound-absorbing layer. The intermediate layer comprises a film made of thermoplastic resin with a thickness of 10 to 100μ, on which small pores are uniformly opened in such a manner that the aperture ratio would be 0.05 to 5%. The sound-absorbing layers comprise an aggregate of fibers such as felt, glass wool, etc. or porous synthetic resin layer, such as urethane foam, etc.

1 . An automotive sound-absorbing material having a laminated structure composed of a sound-absorbing layer, an intermediate layer, and a sound-absorbing layer, wherein the intermediate layer comprises a film with a thickness of 10 to 100μ, on which small pores are uniformly opened in such a manner that the aperture ratio would be 0.05 to 5%. 
   
   
       2 . The automotive sound-absorbing material according to  claim 1 , wherein the intermediate layer is a film made of thermoplastic resin. 
   
   
       3 . The automotive sound-absorbing material according to  claim 1 , wherein the sound-absorbing layer comprises an aggregate of fibers. 
   
   
       4 . The automotive sound-absorbing material according to  claim 1 , wherein the sound-absorbing layer comprises a porous synthetic resin layer. 
   
   
       5 . The automotive sound-absorbing material according to  claim 2 , wherein an adhesive layer comprising low-melting resin is laminated to at least one side of the film made of thermoplastic resin, and the adhesive layer is heated and fused to the sound-absorbing layer. 
   
   
       6 . The automotive sound-absorbing material according to  claim 5 , wherein the adhesive layer is a low-melting resin with a melting point of 200° C. or lower. 
   
   
       7 . The automotive sound-absorbing material according to  claim 1 , wherein the sound-absorbing layer has a thickness of 0.5 to 40 mm and a basis weight of 100 to 1500 g/m 2 , and the intermediate layer is a film made of thermoplastic resin to which small pores with diameters of 0.5 to 5 mm are formed with a pitch of 3 to 30 mm.