Abstract: A soundproofing material including a porous body having a cell structure and including inorganic fibers other than asbestos, wherein an average cell diameter is more than 300 ?m and 1000 ?m or less, a bulk density is 0.007 to 0.024 g/cm3, and a flow resistivity is 170,000 to 2,000,000 Ns/m4.

Abstract: A soundproof member includes: a first elastic porous body layer; a first film layer; a second elastic porous body layer; and a second film layer, the layers arranged in the stated order from a sound source (S) side, wherein the first and second elastic porous body layer each have: a thickness of 0.5 mm or more and 10 mm or less; a bulk density of 45 kg/m3 or more and 550 kg/m3 or less; and a Young's modulus of 7,000 Pa or more and 28,000 Pa or less, and wherein a total (L1/?1+L2/?2) of a ratio (L1/?1) of the thickness L1 (mm) of the first elastic porous body layer to a viscous characteristic length ?1 (?m) thereof and a ratio (L2/?2) of the thickness L2 (mm) of the second elastic porous body layer (20) to a viscous characteristic length ?2 (?m) thereof is 0.11 or more.

Abstract: A soundproofing material including a porous body having a cell structure and including inorganic fibers other than asbestos, wherein an average cell diameter is more than 300 ?m and 1000 ?m or less, a bulk density is 0.007 to 0.024 g/cm3, and a flow resistivity is 170,000 to 2,000,000 Ns/m4.

Abstract: Inorganic fibers including the following composition, SiO2, Al2O3, MgO and CaO being main components, and the inorganic fibers being produced by a melting method: SiO2: 3.0 wt % or more and less than 48.0 wt %, Al2O3: more than 20.0 wt % and 80.0 wt % or less, MgO: 1.0 wt % or more and 50.0 wt % or less, CaO: 1.0 wt % or more and 50.0 wt % or less, and Fe2O3: 0.0 wt % or more and less than 1.0 wt %.

Abstract: Inorganic fibers including the following composition, SiO2, MgO and CaO being main components: SiO2: 73.6 wt % to 85.9 wt %, MgO: 9.0 wt % to 21.3 wt %, CaO: 5.1 wt % to 12.4 wt %, Al2O3: 0 wt % or more and less than 2.3 wt %, and Fe2O3: 0 wt % to 0.50 wt %.

Abstract: Inorganic fibers including the following composition, SiO2, MgO and CaO being main components: SiO2: 73.6 wt % to 85.9 wt %, MgO: 9.0 wt % to 21.3 wt %, CaO: 5.1 wt % to 12.4 wt %, Al2O3: 0 wt % or more and less than 2.3 wt %, and Fe2O3: 0 wt % to 0.50 wt %.

Abstract: Inorganic fibers including the following composition, SiO2, Al2O3, MgO and CaO being main components, and the inorganic fibers being produced by a melting method: SiO2: 3.0 wt % or more and less than 48.0 wt %, Al2O3: more than 20.0 wt % and 80.0 wt % or less, MgO: 1.0 wt % or more and 50.0 wt % or less, CaO: 1.0 wt % or more and 50.0 wt % or less, and Fe2O3: 0.0 wt % or more and less than 1.0 wt %.

Abstract: A composition for inorganic fibers having the following composition ratio and including no solvent: SiO2 1.0 to 54.5 wt %; Al2O3 less than 58.0 wt %; MgO 1.0 to 69.0 wt %; CaO 6.0 wt % or less; and the total of SiO2, Al2O3 and MgO exceeding 94.0 wt %.

Abstract: Inorganic fibers which contain Na2O, SiO2 and Al2O3 as main components and do not react with alumina at 600° C.