POROUS MATERIAL, AND SOUND INSULATING MATERIAL AND VIBRATION-DAMPING MATERIAL USING THE POROUS MATERIAL

摘要

PROBLEM TO BE SOLVED: To obtain a porous material having sufficient sound insulating function and vibration-damping function not only in a higher frequency region but also in a lower frequency region, and to obtain a sound insulating material and a vibration-damping material using the porous material. SOLUTION: This porous material has the energy per unit area QA of 1×10<6> -4×10<7> erg which the material requires to be compressed with load to 50% thick; the ratio QL/QA of 20-45% here the QL is the energy of per unit area which is consumed inside the material when the material is compressed from the uncompressed state to the compressed loaded state of 50% thick and further returned to the uncompressed state; and an air permeability of 1-60 cc/cm<3> .sec.