| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sound absorber which has a sound absorption rate peak in a sufficiently low frequency band in a frequency(horizontal axis)-sound absorption rate(vertical axis) graph even when polyurethane form having relatively low cushion properties is used. <P>SOLUTION: There is provided a sound absorber 1 having a panel part 2 which is composed of polyurethane foam and a space formation part 3 which is coupled to the panel part on the opposite side of the panel part from a sound source side and forms a space part 4 made open to the opposite side, the polyurethane foam of the panel part 2 having a hysteresis loss rate of 70% or higher and an air permeation amount of 0.05-10 ml/cm<SP POS="POST">2</SP>/second(10 mm thickness), and the volume ratio of the space part 4 to the total volume of the sound absorber 1 and space part 4 being 8-80%. <P>COPYRIGHT: (C)2013,JPO&INPIT |
