Sound-absorbing material

Abstract

The present disclosure pertains to a sound-absorbing material comprising: a first base material layer having a communication hole; and a composite layer provided on the first base material layer, wherein the composite layer includes at least one particle among a porous particle and a hollow particle, and a binder resin.

Description

Technical Field

[0001] The present invention relates to a sound-absorbing material, a sound-absorbing property-improving coating liquid, and a sound-absorbing property-improving sheet.

Background Art

[0002] A single-layer sound-absorbing structure made of a melt-blown nonwoven fabric is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of a single-layer sound-absorbing structure made of a nonwoven fabric, the sound-absorbing characteristics in the low-frequency region are particularly insufficient.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a sound-absorbing material having excellent sound-absorbing characteristics in the low-frequency region.

Means for Solving the Problems

[0006] The present invention provides a sound-absorbing material including a first base material layer having communication holes and a composite layer provided on the first base material layer, the composite layer including at least one of porous particles and hollow particles and a binder resin.

[0007] The present invention provides a sound-absorbing material including a first base material layer having communication holes and a composite sheet provided on the first base material layer, the composite sheet including a composite layer including at least one of porous particles and hollow particles and a binder resin on a support base material.

[0008] In one aspect, the sound-absorbing material may further include a second base material layer having communication holes under the first base material layer.

[0009] In one aspect, the sound-absorbing material may further include a third base material layer having communication holes on the composite layer.

[0010] In one aspect, the thickness of the sound-absorbing material may be 1 to 100 mm.

[0011] The present invention provides a sound-absorbing property-improving sheet including a composite layer containing at least one of porous particles and hollow particles and a binder resin on a support base material.

[0012] The present invention provides a sound-absorbing property-improving coating liquid containing at least one of porous particles and hollow particles, a binder resin, and a liquid medium.

[0013] In one aspect, the specific surface area of the particles may be 1 to 1000 m 2 / g.

[0014] In one aspect, the average particle diameter D50 of the particles may be 1 to 100 μm.

[0015] In one aspect, the bulk density of the particles may be 0.05 to 1.00 g / cm 3 .

[0016] In one aspect, the density of the first base material layer may be 0.005 to 0.30 g / cm 3 .

[0017] In one aspect, the air permeability resistance of the first base material layer may be 0.003 to 0.500 kPa·s / m.

Effects of the Invention

[0018] According to the present invention, it is possible to provide a sound-absorbing material excellent in sound-absorbing characteristics in the low-frequency region.

Brief Description of the Drawings

[0019]

Figure 1

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Figure 10

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Figure 12

Figure 13

Mode for Carrying Out the Invention

[0020] <Sound-absorbing material> FIG. 1 is a schematic cross-sectional view of a sound-absorbing material according to an embodiment. The sound-absorbing material 10 includes a first base material layer 2 having communication holes and a composite layer 1 provided on the first base material layer 2. The composite layer 1 contains at least one of porous particles and hollow particles and a binder resin.

[0021] FIG. 2 is a schematic cross-sectional view of a sound-absorbing material according to another embodiment. The sound-absorbing material 20 includes a first base material layer 2 having communication holes and a composite sheet 4 provided on the first base material layer 2. The composite sheet 4 includes a composite layer 1 containing at least one of porous particles and hollow particles and a binder resin on a support base material 3.

[0022] Sound (acoustic energy) incident from the composite layer side is dissipated as thermal energy when passing through the sound-absorbing material. Thereby, attenuation of sound is observed.

[0023] (Base material layer) Examples of the base material layer having communication holes include resin foams, nonwoven fabrics, polymer porous bodies, porous ceramics, etc. Among these, from the viewpoint of excellent sound absorption characteristics in the low frequency range, the base material layer may be a resin foam or a nonwoven fabric. When there are a plurality of base material layers, each base material layer may be composed of the same material or different materials.

[0024] Examples of the material of the resin foam include polyethylene resin, polypropylene resin, polyurethane resin, polyester resin, acrylic resin, polystyrene resin, melamine resin, silicone resin, natural rubber, synthetic rubber, etc. From the viewpoints of heat resistance, flame retardancy, etc., the material of the resin foam may be melamine resin.

[0025] Examples of the fibers constituting the nonwoven fabric include organic fibers and inorganic fibers. Examples of the organic fibers include polyolefin fibers such as polyethylene (low density or high density), polypropylene, copolymerized polyethylene, copolymerized polypropylene, etc., polyester fibers such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc., acrylic fibers, polyurethane fibers, acetate fibers, polyamide fibers, nylon fibers, natural fibers such as rayon fibers, wool, etc. Examples of the inorganic fibers include glass fibers, metal fibers, ceramic fibers, carbon fibers, etc. The fibers constituting the nonwoven fabric can include one or more of these.

[0026] From the viewpoint of excellent sound absorption characteristics in the low frequency range, the thickness of the base material layer can be 0.1 to 50 mm, may be 0.5 to 20 mm, or may be 2.0 to 10 mm. When there are a plurality of base material layers, each base material layer may have the same thickness or different thicknesses. When there are a plurality of base material layers, from the viewpoint of excellent sound absorption characteristics in the low frequency range, the thickness of the base material layer on the sound incident side may be thinner than the thickness of the other base material layers.

[0027] From the viewpoint of excellent sound absorption characteristics in the low frequency range, the basis weight of the base material layer can be 10 to 1000 g / m 2 and may be 30 to 700 g / m 2 or may be 50 to 500 g / m 2 or may be 100 to 300 g / m 2 or may be. When there are a plurality of base material layers, each base material layer may have the same basis weight or different basis weights.

[0028] From the viewpoint of excellent sound absorption characteristics in the low frequency range, the density of the base material layer can be 0.005 to 1.0 g / cm 3 and may be 0.005 to 0.50 g / cm 3 or may be 0.005 to 0.30 g / cm 3 or may be 0.01 to 0.25 g / cm 3 or may be 0.01 to 0.10 g / cm 3 or may be. When there are a plurality of base material layers, each base material layer may have the same density or different densities.

[0029] From the viewpoint of excellent sound absorption characteristics in the low frequency range, the air permeability resistance of the base material layer can be 0.003 to 0.500 kPa·s / m, may be 0.004 to 0.300 kPa·s / m, may be 0.005 to 0.25 kPa·s / m, or may be 0.01 to 0.15 kPa·s / m. The air permeability resistance of the base material layer is measured by an air permeability tester (KES-F8) manufactured by Kato Tech Co., Ltd. etc.

[0030] (Composite layer) The composite layer contains at least one of porous particles and hollow particles, hereinafter collectively referred to as "sound-absorbing particles" in some cases.

[0031] Examples of the porous particles contained in the composite layer include inorganic porous particles, organic porous particles, and composite porous particles (organic-inorganic composite porous particles) containing both of their constituent materials.

[0032] Examples of the constituent materials of the inorganic porous particles include metal oxides (including composite oxides), hydroxides, nitrides, carbides, carbonates, borates, sulfates, silicates, phosphates, etc. Specifically, metal oxides such as silica, titanium oxide, zinc oxide, alumina, zirconium oxide, tin oxide, magnesium oxide, potassium titanate, hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, nitrides such as silicon nitride, titanium nitride, aluminum nitride, carbides such as silicon carbide, titanium carbide, carbonates such as calcium carbonate, magnesium carbonate, borates such as aluminum borate, magnesium borate, sulfates such as calcium sulfate, magnesium sulfate, silicates such as calcium silicate, magnesium silicate, phosphates such as calcium phosphate, etc. In addition, as the above constituent materials, glass, zeolite, aerogel, etc. can also be used.

[0033] Examples of the constituent materials of the organic porous particles include charcoal, activated carbon, polymer porous sintered bodies, resin foams, or resin porous bodies such as (meth)acrylate-based (e.g., crosslinked polymethyl methacrylate), styrene-based, silicone-based, nylon-based resins, etc.

[0034] Examples of the hollow particles contained in the composite layer include inorganic hollow particles, organic hollow particles, and composite hollow particles (organic-inorganic composite hollow particles) containing both of their constituent materials. The hollow particles may be single hollow particles having one pore inside the particles, or multi-hollow particles having a plurality of pores.

[0035] Examples of the constituent materials of the inorganic hollow particles include silica, glass, shirasu, perlite, alumina, fly ash, shale, obsidian, volcanic rock, and the like.

[0036] Examples of the constituent materials of the organic hollow particles include styrene resins such as crosslinked styrene-acrylic resins, (meth)acrylic resins such as crosslinked polymethyl methacrylate and acrylonitrile-acrylic resins, phenolic resins, fluorine-based resins, polyamide-based resins, polyimide-based resins, polycarbonate-based resins, polyether-based resins, polyvinylidene chloride-based resins, epoxy-based resins, urea-based resins, and the like.

[0037] The sound-absorbing particles may be used alone or in combination of two or more.

[0038] From the viewpoints of dispersibility in the composite layer and sound-absorbing characteristics in the low-frequency region, the average particle diameter D50 of the sound-absorbing particles can be 0.1 to 1000 μm, may be 1 to 100 μm, may be 1 to 50 μm, may be 3 to 50 μm, or may be 4 to 30 μm. The average particle diameter D50 of the sound-absorbing particles can be measured, for example, by the laser diffraction / scattering method.

[0039] From the viewpoints of dispersibility in the composite layer and sound-absorbing characteristics in the low-frequency region, the specific surface area of the sound-absorbing particles can be 1 to 2000 m 2 / g, may be 1 to 1000 m 2 / g, may be 2 to 1000 m 2 / g, or may be 4 to 1000 m 2 / g. Further, from the viewpoint of further improving the sound-absorbing performance, the specific surface area of the sound-absorbing particles may be 500 to 1000 m 2 / g, or may be 700 to 900 m 2 / g. In addition to dispersibility and sound-absorbing characteristics, from the viewpoint of high filling in the binder resin, the specific surface area of the sound-absorbing particles may be 1 to 200 m 2 / g, or may be 2 to 100 m 2It may be / g. The specific surface area can be measured by the BET method. As the measuring device, a gas adsorption amount measuring device (manufactured by Quantachrome Instruments Japan Co., Ltd., Autosorb-iQ (Autosorb is a registered trademark)) can be used.

[0040] The bulk density of the sound-absorbing particles can be 0.05 to 1.00 g / cm from the viewpoints of dispersibility in the composite layer and sound-absorbing characteristics in the low-frequency region. 3 and can be 0.10 to 0.80 g / cm. 3 It may be, and may be 0.10 to 0.75 g / cm. 3 It may be, and may be 0.15 to 0.60 g / cm. 3 It may be. The bulk density can be measured by the mercury intrusion method or the like. As the measuring device, a porosimeter (manufactured by Shimadzu Micromeritics, Autopore 9520 type) can be used.

[0041] The content of the sound-absorbing particles in the composite layer can be 10 to 99% by volume, based on the total mass of the composite layer, and may be 20 to 90% by mass, from the viewpoint of sound-absorbing characteristics in the low-frequency region.

[0042] The binder resin has a function of binding sound-absorbing particles. Examples of the binder resin include epoxy resins (e.g., epoxy ester resins), silicone resins, phenolic resins, urea resins, melamine resins, polyurethane resins, polyethylene resins, polypropylene resins, polystyrene resins, polyester resins, acrylic resins (polymers containing acrylic acid esters or methacrylic acid esters as main structural units), polyvinyl acetate resins, polyamide resins, polyimide resins, cellulose-based resins, polyvinyl-based resins, polyvinyl chloride-based resins (e.g., polyvinyl chloride resins, ethylene-vinyl chloride copolymer resins), and the like. Also, as the binder resin, acrylic acid-based resins (polymers containing acrylic acid, acrylate salts, methacrylic acid, and methacrylate salts as structural units), polyethylene oxide, polyethylene glycol, and the like can be used. Among these, from the viewpoints of heat resistance, flame retardancy, and toughness, silicone resins, acrylic resins, phenolic resins, polyester resins, and polyvinyl chloride-based resins can be preferably used.

[0043] Examples of the cellulose-based resins include hydroxypropyl methylcellulose, carboxymethylcellulose ammonium, hydroxyethyl methylcellulose, and the like. Examples of the polyvinyl-based resins include polyvinyl alcohol, polyvinyl pyrrolidone, and the like.

[0044] Examples of the acrylic acid-based resins include polyacrylic acid, acrylic acid copolymer polymers, polyacrylate salts, acrylate salt copolymer polymers, and the like.

[0045] The composite layer may contain, as other components, thickeners, fibrous substances, pigments, leveling agents, film-forming aids, and the like used during the preparation of the coating liquid described later.

[0046] From the viewpoints of the binding property of the sound-absorbing particles and the strength of the composite layer, the content of the binder resin in the composite layer can be 10 to 1000 parts by mass with respect to 100 parts by mass of the sound-absorbing particles, but it may also be 100 to 500 parts by mass.

[0047] The thickness of the composite layer can be 1 to 1000 μm, may be 5 to 500 μm, may be 10 to 250 μm, or may be 20 to 100 μm from the viewpoint of excellent sound absorption characteristics in the low frequency range. Further, from the viewpoint of excellent sound absorption characteristics in the low frequency range, the ratio of the thickness of the composite layer to the thickness of the base material layer (thickness of the base material layer / thickness of the composite layer) can be 1 to 20000, may be 10 to 10000, or may be 100 to 1000.

[0048] (Supporting base material) The composite layer may be provided on the supporting base material. The supporting base material can be used as a support for the composite layer when it is difficult to form the composite layer on the base material layer. Examples of the supporting base material include high-density non-woven fabrics, resin films, metal films, etc. The combination of the supporting base material and the composite layer provided on the supporting base material is called a composite sheet. Since the composite sheet can improve the sound absorption characteristics by laminating it on the target, it can be called a sound absorption improvement sheet.

[0049] Examples of the fibers constituting the non-woven fabric include the fibers exemplified in the section of the base material layer above.

[0050] The thickness of the supporting base material can be 1 to 500 μm, may be 5 to 250 μm, or may be 50 to 200 μm from the viewpoint of being able to support the composite layer and not inhibiting the sound absorption characteristics in the low frequency range.

[0051] The basis weight of the supporting base material can be 10 to 500 g / m 2 and may be 20 to 250 g / m 2 or may be 30 to 200 g / m 2 from the viewpoint of excellent sound absorption characteristics in the low frequency range.

[0052] The density of the supporting base material can be 0.01 to 1.0 g / cm 3 and may be 0.10 to 0.50 g / cm 3 or may be 0.20 to 0.50 g / cm 3 from the viewpoint of supporting the composite layer.

[0053] (Another base material layer) From the viewpoint of improving the sound absorption effect in the low - frequency range and adjusting the sound absorption frequency peak, the sound absorption material may further include another base material layer having communication holes. That is, the sound absorption material may include, in addition to the first base material layer and the composite layer, a second base material layer having communication holes further under the first base material layer, and may also include a third base material layer having communication holes further on the composite layer. The matters described in the section of the above - mentioned base material layer can be applied to these other base material layers.

[0054] (Adhesive layer) The sound absorption material may be provided with an adhesive layer between each of the above - mentioned layers as necessary. For example, the sound absorption material may be provided with an adhesive layer between the first base material layer and the second base material layer, between the support base material (composite sheet) and the first base material layer, etc. As the adhesive layer, there are polyester resin, vinyl acetate resin, ethylene - vinyl acetate copolymer resin, isobutene - maleic anhydride copolymer resin, acrylic copolymer resin, acrylic monomer, acrylic oligomer, vinyl chloride resin, urethane resin (including moisture - curable type), silylated urethane resin, epoxy resin, modified epoxy resin, polyolefin resins such as polyethylene resin, ionomer resin, silicone resin, modified silicone resin, synthetic rubbers such as styrene - butadiene rubber, chloroprene rubber, nitrile rubber, natural rubbers such as isoprene rubber, layers containing adhesive components such as water glass and silicate, or laminates having layers containing these adhesive components on both sides of a support body composed of paper, cloth, non - woven fabric, fiber, resin film, metal tape, etc. Further, the adhesive layer may be one having the above - mentioned layer containing the adhesive component or the above - mentioned laminate on both sides of a resin film (adhesive sheet). Each adhesive layer may be composed of the same material or different materials.

[0055] The thickness of the adhesive layer is not particularly limited, but can be 0.01 - 500 μm, and may be 1 - 250 μm. Each adhesive layer may have the same thickness or different thicknesses.

[0056] The thickness of the sound-absorbing material can be 1 to 100 mm, may be 2 to 50 mm, or may be 5 to 30 mm from the viewpoints of expressing sound-absorbing characteristics, workability of the material, space saving, etc.

[0057] The sound-absorbing characteristics of the sound-absorbing material can be adjusted according to the composition of each layer and the mode of lamination. The normal incidence sound absorption rate of the sound-absorbing material measured in accordance with JIS A 1405-1 can be, for example, as follows.

[0058] In the case of a sound-absorbing material having a base material layer and a composite layer, the normal incidence sound absorption rate can be 0.4 or more at any frequency of 1000 Hz or less, specifically, for example, at least any one of 500 Hz, 750 Hz, and 1000 Hz, and may be 0.5 or more. The normal incidence sound absorption rate can be 0.25 or more at 750 Hz, and may be 0.3 or more. The normal incidence sound absorption rate can be 0.1 or more at 500 Hz, and may be 0.15 or more.

[0059] In the case of a sound-absorbing material having a base material layer and a composite sheet, the normal incidence sound absorption rate can be 0.5 or more at any frequency of 1000 Hz or less, specifically, for example, at least any one of 500 Hz, 750 Hz, and 1000 Hz, and may be 0.6 or more. The normal incidence sound absorption rate can be 0.2 or more at 750 Hz, and may be 0.4 or more. The normal incidence sound absorption rate can be 0.1 or more at 500 Hz, and may be 0.2 or more.

[0060] <Method for manufacturing sound-absorbing material> The sound-absorbing material 10 shown in FIG. 1 can be manufactured by applying a coating liquid for forming the composite layer 1 on the first base material layer 2. When the sound-absorbing material further includes a second base material layer under the first base material layer, the two layers may be adhered by an adhesive layer, or may be laminated without being adhered. Further, when the sound-absorbing material further includes a third base material layer on the composite layer, the two layers may be adhered using the coating liquid for forming the composite layer, or may be laminated without being adhered.

[0061] The sound-absorbing material 20 shown in FIG. 2 can be manufactured by laminating a composite sheet 4 obtained by applying a coating liquid for forming a composite layer on a support base material 3 and a first base material layer 2. In this case, the composite sheet and the first base material layer may be adhered by an adhesive layer, or they may be laminated without being adhered.

[0062] The laminate constituting the sound-absorbing material may be used in a state of being housed in a housing.

[0063] The coating liquid for forming the composite layer contains sound-absorbing particles, a binder resin, and a liquid medium. Since this coating liquid can improve the target sound-absorbing characteristics, it can be called a sound-absorbing property-improving coating liquid.

[0064] The binder resin is as exemplified in the section on the above composite layer. When the binder resin is a thermosetting resin, the coating liquid may further contain a curing agent. The curing agent is not particularly limited and may be appropriately changed according to the type of thermosetting resin. For example, when the thermosetting resin is an epoxy resin, a known epoxy resin curing agent can be used as the curing agent. Examples of the epoxy resin curing agent include amine-based curing agents, acid anhydride-based curing agents, polyamide-based curing agents, etc., and amine-based curing agents and polyamide-based curing agents can be preferably used from the viewpoint of reactivity.

[0065] Examples of the liquid medium include water and organic solvents. The organic solvent is not particularly limited as long as it can disperse the sound-absorbing particles. For example, aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p - cymene; aliphatic hydrocarbons such as hexane, heptane, and pentane; ethers such as diethyl ether, tetrahydrofuran, and 1,4 - dioxane; alcohols such as methanol, ethanol, isopropanol (isopropyl alcohol), butanol, ethylene glycol, diethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4 - hydroxy - 4 - methyl - 2 - pentanone; esters such as methyl acetate, ethyl acetate, and butyl acetate; amides such as N,N - dimethylformamide, N,N - dimethylacetamide, and N - methylpyrrolidone, etc. Among these, from the viewpoints of volatility, boiling point, etc., alcohols and ketones can be used, and alcohols can be particularly preferably used. Alcohols and ketones are suitable for use even when combined with these components because they are easily mixed with water, aqueous resins, etc.

[0066] The coating liquid may contain, as other components, a thickener, fibrous substances, pigments, leveling agents, film - forming aids, etc.

[0067] From the viewpoints of dispersibility, viscosity of the coating liquid, etc., the content of the sound - absorbing particles in the coating liquid can be 1 to 50% by mass, but it may also be 5 to 50% by mass.

[0068] From the viewpoints of the binding property of the sound - absorbing particles, the strength of the composite layer, etc., the content of the binder resin in the coating liquid can be 50 to 5000 parts by mass with respect to 100 parts by mass of the sound - absorbing particles, but it may also be 100 to 1000 parts by mass.

[0069] <Applications of the sound - absorbing material> The above sound-absorbing material is excellent in sound absorption characteristics in the low-frequency region. Therefore, the above sound-absorbing material can be suitably used in applications such as automobiles, railway vehicles, aircraft, ships, buildings such as houses, electronic devices, and precision machinery. Here, the low-frequency region can be defined as a region where the frequency is 1000 Hz or less, and it may be a region of 800 Hz or less, a region of 750 Hz or less, or a region of 500 Hz or less.

Example

[0070] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0071] <Preparation of materials> (Base material layer) The base material layer shown in Table 1 was prepared.

[0072]

Table 1

[0073] (Supporting base material) The supporting base material shown in Table 2 was prepared.

[0074]

Table 2

[0075] (Sound-absorbing particles) The following particles were prepared as sound-absorbing particles. The details of each particle are shown in Tables 3 and 4. Particle 1 (manufactured by JIOS AEROGEL CORPORATION, product name: AeroVa) Particle 2 (manufactured by AGC Si-Tech Co., Ltd., product name: Sunsfair H-121) Particle 3 (manufactured by Sekisui Chemical Co., Ltd., product name: Tech Polymer MBP-8) Particle 4 (manufactured by Sekisui Chemical Co., Ltd., product name: Tech Polymer) Particle 5 (manufactured by 3M, product name: iM30K)

[0076] [Table 3]

[0077] [Table 4]

[0078] (Coating liquid for forming composite layer) 10 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-30000), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 200 parts by mass of pure water, 250 parts by mass of acrylic emulsion (manufactured by DIC Corporation, product name: DV-759EF, solid content 40 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 1.

[0079] 5 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-30000), 20 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 350 parts by mass of pure water, 500 parts by mass of acrylic emulsion (manufactured by DIC Corporation, product name: DV-759EF, solid content 40 wt%), 100 parts by mass of Particle 1, and 300 parts by mass of Particle 5 were mixed to obtain Coating Liquid 2.

[0080] 10 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-30000), 40 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 700 parts by mass of pure water, 1000 parts by mass of acrylic emulsion (manufactured by DIC Corporation, product name: DV-759EF, solid content 40 wt%), 100 parts by mass of Particle 1, and 900 parts by mass of Particle 5 were mixed to obtain Coating Liquid 3.

[0081] 50 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., product name: MP-30000), 200 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 3500 parts by mass of pure water, 5000 parts by mass of acrylic emulsion (manufactured by DIC Corporation, product name: DV-759EF, solid content 40 wt%), 100 parts by mass of Particle 1, and 4500 parts by mass of Particle 5 were mixed to obtain Coating Liquid 4.

[0082] 15 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., product name: MP-4000), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 530 parts by mass of pure water, 270 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 5.

[0083] 20 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., product name: MP-4000), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 530 parts by mass of pure water, 770 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 6.

[0084] 30 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., product name: MP-4000), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 630 parts by mass of pure water, 1750 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 7.

[0085] 10 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-4000), 15 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 320 parts by mass of pure water, 170 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 2 were mixed to obtain Coating Liquid 8.

[0086] 10 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-4000), 15 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 320 parts by mass of pure water, 170 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 3 were mixed to obtain Coating Liquid 9.

[0087] 10 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-4000), 15 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 320 parts by mass of pure water, 170 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 4 were mixed to obtain Coating Liquid 10.

[0088] 5 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-4000), 10 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 10 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 180 parts by mass of pure water, 90 parts by mass of ethylene-vinyl chloride copolymer resin emulsion (manufactured by Sumika Chemtex Corporation, product name: Sumie Lite 1010, solid content 50 wt%), and 100 parts by mass of Particle 5 were mixed to obtain Coating Liquid 11.

[0089] 15 parts by mass of polyethylene oxide (manufactured by Sumitomo Seika Chemical Co., Ltd., product name: PEO-3), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 530 parts by mass of pure water, 270 parts by mass of an aqueous epoxy ester resin (manufactured by DIC Corporation, product name: Waterzol EFD-5560, solid content 40 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 12.

[0090] 15 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-4000), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 30 parts by mass of diethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 530 parts by mass of pure water, 270 parts by mass of a silicone emulsion (manufactured by Shin-Etsu Chemical Co., Ltd., product name: POLON-MF-56, solid content 40 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 13.

[0091] 15 parts by mass of hydroxypropyl methylcellulose (manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., product name: MP-4000), 30 parts by mass of isopropyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 530 parts by mass of pure water, 270 parts by mass of a urethane emulsion (manufactured by Sanyo Chemical Industries, Ltd., product name: Permalin UA-368, solid content 50 wt%), and 100 parts by mass of Particle 1 were mixed to obtain Coating Liquid 14.

[0092] (Adhesive layer) The following adhesive layers were prepared. Double-sided tape: 3M Japan Ltd., PGD-100, thickness 0.12 mm Spray glue: 3M Japan Ltd., Spray Glue 77

[0093] (Production of sound-absorbing material) Sound-absorbing materials having the configurations shown in each table were produced. The composite layers 1 to 14 were obtained by applying Coating Liquids 1 to 14 to a base material layer or a support base material to a predetermined thickness using a film applicator and drying the resulting coating film at 60 °C for 10 to 60 minutes.

[0094] Regarding the mode in which the base material layers are joined via the composite layer, after applying a coating liquid onto the base material layer, another base material layer was laminated, and heat treatment was performed under the above conditions.

[0095] In the table, the normal incidence sound absorption rate was measured according to the following. Sound was incident from the layer side described above in the table. Apparatus name: Type 4206 impedance tube (Brüel & Kjær) Measurement method: Normal incidence sound absorption rate (conforming to JIS A 1405-1) Measurement range: 50 to 1600 Hz

[0096] [Table 5]

[0097] [Table 6]

[0098] [Table 7]

[0099] [Table 8]

[0100] [Table 9]

[0101] [Table 10]

[0102] [Table 11]

[0103]

Table 12

[0104]

Table 13

[0105]

Table 14

[0106] Figures 3 to 13 are diagrams showing the perpendicular incidence sound absorption rates of the respective examples and comparative examples. As shown in the figures, it can be seen that the sound absorption materials of the examples are excellent in sound absorption characteristics in the low frequency range.

Explanation of Reference Signs

[0107] 1... composite layer, 2... first base material layer, 3... support base material, 4... composite sheet, 10, 20... sound absorption material.

Claims

1. A sound-absorbing material comprising a first base material layer having communication holes and a composite sheet provided on the first base material layer, wherein the composite sheet comprises a composite layer containing at least one of porous particles and hollow particles and a binder resin on a support base material. The specific surface area of the particles is 1 to 1000 m ２ / g, and The bulk density of the particles is 0.05 to 1.00 g / cm ３ and The sound-absorbing material, wherein the support base material is a non-woven fabric, a resin film or a metal film.

2. The sound-absorbing material according to Claim 1, wherein the density of the support base material is 0.01 to 1.0 g / cm3.

3. The sound-absorbing material according to Claim 1 or 2, further comprising a second base material layer having communication holes under the first base material layer.

4. The sound-absorbing material according to any one of Claims 1 to 3, further comprising a third base material layer having communication holes on the composite layer.

5. The sound-absorbing material according to any one of Claims 1 to 4, having a thickness of 1 to 100 mm.

6. The sound-absorbing material according to any one of Claims 1 to 5, wherein the average particle diameter D50 of the particles is 1 to 100 μm.

7. The density of the first base material layer is 0.005 to 0.30 g / cm ３ The sound absorbing material according to any one of claims 1 to 6, wherein the sound absorbing material is as described above.

8. The sound-absorbing material according to any one of Claims 1 to 7, wherein the air permeability resistance of the first base material layer is 0.003 to 0.500 kPa·s / m.

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