| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbonaceous acoustic plate excellent in property as an acoustic vibration plate or an acoustic matching plate.SOLUTION: A carbonaceous acoustic plate having bulk density continuously varying in a thickness direction is provided by mixing a resin as a carbon source with particles of a boring material which are dispersed to form pores during carbonization of the resin to disperse the particles in the resin, curing the resin for a time enough for the particles of the boring material contained in the dispersion liquid to precipitate or float to produce a desired vertical-direction difference in presence ratio, and firing and carbonizing the cured resin. |
