Soundproofing material

Abstract

One of the objectives is to achieve both sound absorption and sound insulation properties in a soundproofing material, regardless of the direction of sound incidence. In particular, one of the objectives is to achieve both sound absorption and sound insulation properties in a soundproofing material that comprises a porous material including a fiber base material formed by laminating fibers and a viscoelastic member using a viscoelastic material. [Solution] A soundproofing material 1 in which a viscoelastic member 3 is attached to the fibers 7 and installed in a part of the space 20 between the fibers 7 of a fiber base material 2, and the space 20 between the fibers 7 penetrates from the surface 21 to the back surface 22 opposite to the surface 21 of the fiber base material 2.

Description

[Technical Field]

[0001] This invention relates to a soundproofing material, and more specifically, to a soundproofing material using a fiber base material and a viscoelastic member. [Background technology]

[0002] Conventionally, soundproofing materials used in buildings, structures, automobiles, electrical and electronic equipment, etc., have been constructed to possess either or both functions: sound absorption, which absorbs sound energy and reduces reflected sound; and sound insulation, which reduces transmitted sound through sound reflection and absorption. Several soundproofing materials have been proposed that are constructed by bonding porous materials and viscoelastic materials. Specifically, sound-absorbing materials such as sound-absorbing sheets have been proposed, in which the surface of a breathable sheet made of a fibrous structure such as nonwoven fabric or a porous structure such as glass wool or synthetic resin foam is covered with a viscoelastic material such as rubber or flexible synthetic resin (Patent Document 1).

[0003] Furthermore, sound-absorbing materials have been proposed comprising a membrane made of rubber or acrylic resin containing an inorganic compound and / or carbon fibers, and a first porous layer laminated on the back side of the membrane, and a sound-absorbing material comprising a membrane made of rubber or acrylic resin containing an inorganic compound and / or carbon fibers, a first porous layer laminated on the back side of the membrane, and a second porous layer laminated on the front side of the membrane (Patent Document 2). It has also been proposed that the porous layer be composed of glass wool, rock wool, or a mixture thereof.

[0004] Furthermore, a sound-absorbing material has been proposed comprising a first membrane made of rubber or acrylic resin, a first porous layer laminated on the front side of the first membrane, a second porous layer laminated on the back side of the first membrane, a second membrane laminated on the front side of the first porous layer, and a third porous layer laminated on the front side of the second membrane (Patent Document 3). It has also been proposed that the porous layer be composed of glass wool, rock wool, or a mixture thereof.

[0005] Furthermore, the sound-absorbing material disclosed in Patent Document 1 has a configuration in which a viscoelastic material covers the entire surface of the sheet and penetrates into the interior of the surface portion of the sheet. The sound-absorbing materials disclosed in Patent Documents 2 and 3 have a configuration in which a membrane and a porous body layer are laminated with their entire surfaces in contact with each other, and a portion of the membrane enters into the pores of the porous body layer. In the portions in which the viscoelastic material or membrane penetrates or enters the sheet or porous body layer, the pores of the sheet or porous body layer are completely sealed. Consequently, when a viscoelastic member such as rubber is laminated, the porous member does not have pores penetrating between the surface on which the viscoelastic member is laminated and the surface on the opposite side, and the sound-absorbing material has a configuration in which there is no airflow between the surface on which the viscoelastic member is laminated and the surface on the opposite side. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 1-298052 [Patent Document 2] Japanese Patent Publication No. 2007-71962 [Patent Document 3] Japanese Patent Publication No. 2007-47567 [Overview of the project] [Problems that the invention aims to solve]

[0007] Thus, these conventional technologies were soundproofing materials constructed by laminating a viscoelastic material such as rubber with a porous material such as glass wool. However, viscoelastic materials have high sound insulation but almost no sound absorption, and porous materials have high sound absorption but poor sound insulation. Therefore, these soundproofing materials could only achieve either sound absorption or sound insulation depending on the direction from which the sound entered the soundproofing material, that is, whether the sound entered the soundproofing material from the viscoelastic material side or the porous material side. In particular, when a viscoelastic material with sound insulation properties was installed on the sound incidence side, the sound was reflected, making it difficult to exhibit sound absorption performance.

[0008] Therefore, as described in Patent Document 3, it has been proposed to compensate for the above-mentioned shortcomings of the conventional technology by making the viscoelastic material portion as thin as possible and layering multiple layers of a combination with a porous member. However, depending on the direction of sound incidence, it is only possible to achieve either sound absorption or sound insulation, and it has been difficult to achieve both sound absorption and sound insulation.

[0009] Therefore, one of the objectives of the present invention is to achieve both sound absorption and sound insulation properties of a soundproofing material, regardless of the direction of sound incidence to the soundproofing material. Another objective is to simultaneously improve both the sound absorption and sound insulation performance of a soundproofing material. Furthermore, one of the objectives is to achieve both sound absorption and sound insulation properties in a soundproofing material comprising a porous material including a fiber base material formed by laminating fibers and a viscoelastic member using a viscoelastic material. Furthermore, one of the objectives is to simultaneously improve both the sound absorption and sound insulation performance in a soundproofing material comprising a fiber base material and a viscoelastic member. [Means for solving the problem]

[0010] The present invention, as a means to solve the above-mentioned problems, is a soundproofing material characterized in that a viscoelastic member is attached to the fibers and installed in a part of the space between the fibers of a fibrous base material, and the space between the fibers penetrates from the surface of the fibrous base material to the back surface opposite to the surface.

[0011] Furthermore, in the above-mentioned soundproofing material, the viscoelastic member is a soundproofing material installed from the surface to the back surface of the fibrous base material.

[0012] Furthermore, in the above-mentioned soundproofing material, the viscoelastic member is a soundproofing material installed over the entire fibrous base material.

[0013] Furthermore, in the above-mentioned soundproofing material, the viscoelastic member is a soundproofing material installed in a part of the fibrous base material.

[0014] Furthermore, in the above-mentioned soundproofing material, the amount of the viscoelastic member installed is 10 to 50% by mass relative to the mass of the soundproofing material.

[0015] Also, in the sound insulation material, the viscoelastic member is a sound insulation material composed of rubber, a thermoplastic elastomer, or a thermosetting elastomer other than rubber.

[0016] Also, in the sound insulation material, the average fiber diameter of the fibers of the fiber base material is 2 to 10 μm.

[0017] Also, in the sound insulation material, the density of the fiber base material is 10 to 100 kg / m 3 This is a sound insulation material.

[0018] Also, in the sound insulation material, the air permeability resistance is 10,000 to 60,000 Ns / m 4 This is a sound insulation material.

[0019] Also, in the sound insulation material, the fiber base material is a sound insulation material composed of glass wool, rock wool, or a mixture of glass wool and rock wool.

[0020] Also, a method for manufacturing a sound insulation material is provided, in which a space between fibers of a fiber base material is impregnated with a viscoelastic member solution in which a viscoelastic member is dissolved in a solvent, the viscoelastic member is attached to the fibers, a drying process is performed to remove the solvent of the viscoelastic member solution, and the viscoelastic member is installed in a part of the space between the fibers of the fiber base material so that the space between the fibers penetrates from the front surface of the fiber base material to the back surface opposite to the front surface.

Advantages of the Invention

[0021] As described above, the present invention makes it possible to achieve both sound absorption and sound insulation properties in a soundproofing material, regardless of the direction of sound incidence to the soundproofing material. Furthermore, it makes it possible to simultaneously improve both the sound absorption and sound insulation performance of the soundproofing material. In addition, in a soundproofing material comprising a porous material including a fiber base material formed by laminating fibers and a viscoelastic member using a viscoelastic material, it makes it possible to achieve both sound absorption and sound insulation properties. Furthermore, in a soundproofing material comprising a fiber base material and a viscoelastic member, it makes it possible to simultaneously improve both the sound absorption and sound insulation performance. [Brief explanation of the drawing]

[0022] [Figure 1] A schematic cross-sectional view showing one embodiment of the present invention. [Figure 2] Partial cross-sectional micrograph of an example of the present invention [Figure 3] A schematic cross-sectional view showing another embodiment of the present invention. [Figure 4] Graph showing the sound absorption coefficient when the sound is incident perpendicularly. [Figure 5] Graph showing sound transmission loss [Modes for carrying out the invention]

[0023] The soundproofing material of the present invention comprises a fibrous base material and a viscoelastic member, wherein the viscoelastic member is attached to the fibers and installed in a portion of the space between the fibers of the fibrous base material, and the space between the fibers of the fibrous base material penetrates from the surface to the back surface opposite to the surface, which is in the thickness direction of the soundproofing material. The surface and back surface of the fibrous base material constitute a first surface and a second surface opposite to the first surface, respectively, in the thickness direction of the soundproofing material. The soundproofing material is installed so that the space to be soundproofed and the space to be soundproofed are separated in the thickness direction, and the first surface and the second surface of the soundproofing material are installed facing each other in the use. Embodiments of the present invention will be described below.

[0024] The fibrous substrate is a component used to impart sound absorption and sound insulation properties to soundproofing materials, primarily serving as the skeletal structure of the soundproofing material. The fibrous substrate has substantially the same thickness as the soundproofing material, and its front and back surfaces are installed facing either the space to be soundproofed or the space that is soundproofed. The fibrous substrate is composed of multiple fibers laminated together, with spaces between the fibers, giving it a three-dimensional mesh structure. Furthermore, within the fibrous substrate, the spaces between the fibers are connected and branched, continuing from the front surface to the back surface opposite the front surface in the thickness direction of the fibrous substrate, penetrating from the front surface to the back surface and communicating with each other, thus creating a continuous three-dimensional mesh structure. Air can pass from the front surface to the back surface of the fibrous substrate. Thus, the fibrous substrate can be described as a porous component.

[0025] A fibrous base material is a component constructed by laminating fibers, and is not particularly limited, but can be made from glass wool, specifically molded products formed into cotton-like, plate-like, or tubular shapes by laminating glass wool by intertwining it (hereinafter also referred to as "glass wool molded products"), from rock wool, specifically molded products formed into cotton-like, plate-like, or tubular shapes by laminating rock wool by intertwining it, from a mixture of glass wool and rock wool, specifically molded products formed into cotton-like, plate-like, or tubular shapes by laminating glass wool and rock wool by intertwining them, from nonwoven fabrics, felt, or composites thereof. The fibers of the fibrous base material are not particularly limited, and depending on the type of fibrous base material, natural fibers, chemical fibers, inorganic fibers, organic fibers, or a mixture of one or more of these can be used. Examples of natural fibers include wool, cotton, silk, and hemp, while examples of chemical fibers include polyester fibers, acrylic fibers, glass fibers, polyamide fibers, and artificial mineral fibers. The method for converting chemical fibers into fibers is not particularly limited, and known methods such as the flame method, blowing method, centrifugal method, and spinning method can be used.

[0026] Furthermore, the fibrous base material can be constructed by bonding fibers together using a binder. While not particularly limited, the binder can be a thermosetting resin such as phenolic resin, epoxy resin, or silicone resin, or a thermoplastic resin such as polyester, polyethylene, polypropylene, or polyamide. The amount of binder added varies depending on the density and application of the soundproofing material and the amount of viscoelastic material added, but it can be 0.5 to 18% by mass of the fibrous base material in terms of solid content, with 0.5 to 10% by mass being preferred. Note that the fibrous base material may also be constructed without a binder.

[0027] The length of the fibers in the fibrous substrate is not particularly limited and may be long fibers, short fibers, or a mixture of long and short fibers. The thickness of the fibers is also not particularly limited, but fibers with an average diameter of approximately 0.1 to 30 μm can be used, preferably 2 to 10 μm, and more preferably 3 to 7 μm. By setting the average fiber diameter to 2 to 10 μm, or even 3 to 7 μm, more fibers can be contained at the same density, allowing for the conversion of more sound into thermal energy and improving sound absorption performance. Furthermore, the air permeability resistance within the fibrous substrate increases, improving the energy attenuation effect, thus improving sound insulation without hindering sound absorption. Additionally, while a larger fiber diameter tends to allow viscoelastic materials to adhere more easily to the fibers, excessively large fiber diameters tend to narrow the spaces between fibers. The fibrous substrate may be composed of fibers of the same diameter, or it may be composed of a mixture of fibers of different diameters.

[0028] Furthermore, the density of the fiber base material is not particularly limited, but is typically between 5 and 300 kg / m³. 3 It can be set to approximately 10-100 kg / m 3 It is preferable to keep it to around 5 kg / m 3 If the density is less than 10 kg / m, the spaces between fibers are wider, the total amount of viscoelastic material adhering to the fibers decreases, and the spaces between fibers cannot be adequately sealed, resulting in a decrease in sound absorption and sound insulation performance. On the other hand, 10 kg / m 3 This is because, at this level, the viscoelastic material adheres more easily between the fibers, allowing it to adequately fill the spaces between the fibers. Also, 300 kg / m 3If it exceeds this value, it becomes difficult for the viscoelastic member to penetrate into the fiber base material. At the same time, as the spaces between the fibers are blocked by the fibers and the viscoelastic member, the sound absorption performance decreases. Also, 100 kg / m 3 By setting it as follows, it becomes easier for the viscoelastic member to penetrate into the fiber base material. At the same time, by maintaining the spaces between the fibers, high sound absorption performance can be maintained. With such a configuration, the sound waves incident on the soundproofing material can efficiently vibrate the fibers, convert the sound energy into thermal energy, and improve the sound absorption performance.

[0029] When the fiber base material is composed of glass wool, the average fiber diameter is not particularly limited, but it can be about 2 to 10 μm, and preferably 3 to 7 μm. By setting it to 3 to 7 μm, even at the same density, more fibers can be included, more sound can be converted into thermal energy, the sound absorption performance can be further improved, the ventilation resistance in the fiber base material increases, and the energy attenuation effect improves. Therefore, the sound insulation performance can be improved without inhibiting the sound absorption property. Also, when the fiber base material is composed of glass wool, the density of the fiber base material can be 10 to 50 kg / m 3 and can be about 15 to 40 kg / m 3 is preferred. By setting it to 15 to 40 kg / m 3 the sound absorption performance can be further improved, and at the same time, the sound insulation effect can also be improved.

[0030] The thickness of the fiber base material, that is, the length from the front surface to the back surface, is not particularly limited, but it can be about 5 to 150 mm. If the thickness is less than 5 mm, the performance as a sound absorption material is not sufficient. If the thickness exceeds 150 mm, problems in terms of cost and installation will occur. Incidentally, the width, length, and shape of the fiber base material are not particularly limited and can be configured according to the location and application where the soundproofing material is installed.

[0031] Furthermore, depending on the material of the fibers, the fiber base material may be given a flame retardant and / or a thermally conductive substance. By using such a configuration, flame retardancy and thermal conductivity can be imparted to the soundproofing material. When imparting flame retardancy to the fiber base material, the fibers can be made to contain a flame retardant substance such as a halogen-based resin, or the flame retardant substance can be attached to the fibers by coating or other means. Inorganic fibers such as glass wool and rock wool are flame retardant in their natural state, so it is not necessary to add a further flame retardant substance. Furthermore, when imparting thermal conductivity to the fiber base material, the fibers can be made to contain a thermally conductive substance such as carbon black, or the thermally conductive substance can be attached to the fibers by coating or other means. In addition, during fiber manufacturing or molding of the fiber base material, various additives other than flame retardants and thermally conductive substances, such as antifungal agents and insecticides, may be added to the inside or outside of the fibers as needed.

[0032] Furthermore, durability may be provided to the fiber substrate. Fiber substrates are difficult to return to their original shape when compressed, but the recovery performance can be improved by adding an elastomer such as rubber. Furthermore, environmental friendliness may be provided to the fiber substrate. When the fiber substrate is composed solely of fibers, there is a possibility that the fibers will scatter and pollute the environment, but by adding an elastomer such as rubber, environmental pollution can be prevented by reducing the scattering of fibers. Such durability and environmental friendliness can be provided by the present invention, in which a viscoelastic member using an elastomer such as rubber is installed on the fiber substrate.

[0033] The method for manufacturing the fibrous substrate is not particularly limited. For example, it can be manufactured by known methods such as applying a binder to fibers by spraying or coating them using a spray device, accumulating the binder-coated fibers on a perforated conveyor, and then feeding them into a pair of upper and lower perforated conveyors, compressing and heating them to harden the binder; or by laminating fibers to form a plate-shaped substrate using a fleece machine, heating it in a heating furnace, and then compressing and molding it while cooling it in a press mold of the product shape.

[0034] The fibrous substrate may consist of a single layer of substrate made of the fibers described above, or it may be constructed by laminating multiple fibrous substrates made of different fiber types, fiber diameters, fiber shapes, and densities in the thickness direction. The laminated fibrous substrates can be bonded together using adhesives, heat welding, or other methods.

[0035] Viscoelastic members are components used to impart sound insulation and sound absorption properties to soundproofing materials, primarily for imparting sound insulation properties. Viscoelastic members can also function as binders for fibrous substrates. Viscoelastic members are composed of elastomers possessing flexibility, pliability, and rubber-like elasticity. As elastomers, rubber, thermoplastic elastomers, thermosetting elastomers other than rubber, and composites thereof can be used. Elastomers are preferred because they offer superior flexibility, pliability, and elasticity compared to other polymer materials, are inexpensive, and allow for the addition of various functions by changing the compounding composition. Among elastomers, rubber is preferred because it offers superior flexibility, pliability, and elasticity, and allows for the easy addition of various functions by changing the compounding composition.

[0036] Furthermore, any material other than elastomer that possesses sound-insulating properties and is similar to elastomers that have been conventionally used as soundproofing materials can be used as a viscoelastic member, as it will produce similar effects.

[0037] The rubber is not particularly limited and may be natural rubber or synthetic rubber, and may be either diene-based or non-diene-based rubber. Examples of synthetic rubbers include styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPM), and chlorosulfonated polyethylene (CSM). Depending on the form of the soundproofing material, a rubber compound can be used that has the necessary flexibility, pliability, and rubber-like elasticity.

[0038] Examples of thermoplastic elastomers, though not limited to those mentioned above, include copolymer ethylene vinyl acetate resin (EVA), polyvinyl chloride (PVC), and polyurethane-based thermoplastic elastomers. Examples of thermosetting elastomers, though not limited to those mentioned above, include thermosetting urethane elastomers.

[0039] Furthermore, viscoelastic members containing elastomers can be constructed by adding vulcanizing agents, vulcanization accelerators, antioxidants, corrosion inhibitors, anti-aging agents, pigments, flame retardants, thermally conductive substances, and other fillers. In particular, it is preferable to include flame retardants such as halogen-based resins and / or thermally conductive substances such as carbon black. By incorporating these substances, flame retardancy and / or thermal conductivity can be imparted to the viscoelastic member.

[0040] In soundproofing materials, a viscoelastic member is installed by adhering to the fibers in a portion of the spaces between the fibers of the fibrous base material. Because the viscoelastic member is installed only in a portion of the spaces between the fibers of the fibrous base material, it does not completely block the spaces between the fibers of the fibrous base material, and does not prevent the penetration of the spaces between the fibers from the surface to the back of the fibrous base material, in other words, from the first surface to the second surface of the soundproofing material.

[0041] Furthermore, as schematically shown in Figure 1, the soundproofing material 1 has a viscoelastic member 3 evenly distributed throughout the entire interior of the fiber base material 2, adhering to the fibers 7 from the surface 21 to the back surface 22 of the fiber base material 2, that is, from the first surface 4 to the second surface 5 opposite the first surface 4. In other words, the viscoelastic member installation area 9, where the viscoelastic member 3 is adhering to the fibers of the fiber base material 2, extends throughout the entire interior of the fiber base material 2 and throughout the entire interior of the soundproofing material 1, but the viscoelastic member 3 only fills a portion of the space 20 between the fibers 7 of the fiber base material 2. Note that in Figure 1, the viscoelastic member 3 is shown as a circle or ellipse, and the fibers 7 are shown as curves.

[0042] Furthermore, since the viscoelastic member 3 is installed by adhering to the fibers in a portion of the space 20 between the fibers of the fiber base material 2, the space 20 between the fibers is partially narrowed or partially blocked in some places. However, the space 20 between the fibers is branched and interconnected, forming a continuous three-dimensional network structure, so it is not completely blocked, and air can pass between the first surface 4 of the soundproofing material 1 and the second surface 5 on the opposite side of the first surface 4. In the places where the space 20 between the fibers is blocked, the viscoelastic member 3 adheres to multiple fibers in a film-like manner, or adheres to the fibers in a rod-like manner around the fibers in the longitudinal direction of the fibers and also adheres to adjacent fibers, thereby blocking a portion of the space 20 between the fibers.

[0043] Furthermore, the soundproofing material may be configured in which viscoelastic members are installed on the surface and / or back surface of the fibrous substrate, in other words, on the first and / or second surface of the soundproofing material. That is, the soundproofing material may be configured in which viscoelastic members are evenly installed throughout the entire surface, including the interior of the fibrous substrate and the outer surface including the surface and back surface. Also, depending on the manufacturing method of the soundproofing material, it may be unavoidable that viscoelastic members adhere to the outer surface of the fibrous substrate. Even when viscoelastic members adhere to the outer surface of the fibrous substrate in this way, the viscoelastic members adhere to the fibers, and there are no viscoelastic members present in a film-like or sheet-like form over the entire surface and / or back surface. Therefore, even on the outer surface of the fibrous substrate, although some areas may be blocked, the spaces between the fibers are not completely blocked, and air can pass between the first surface and the opposite second surface of the soundproofing material.

[0044] The amount of viscoelastic material installed on the fibrous substrate is 10% by mass or more and less than 75% by mass, preferably 10 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 25 to 50% by mass, relative to the mass of the soundproofing material. In other words, the mass ratio of the fibrous substrate to the viscoelastic material is 90:10 to less than 25:75, preferably 90:10 to 40:60, more preferably 90:10 to 50:50, and even more preferably 75:25 to 50:50. If the amount is less than 10% by mass, there is no significant difference in sound absorption and sound insulation performance compared to a soundproofing material composed only of a fibrous substrate without a viscoelastic material. However, if the amount is 10% by mass or more, depending on the sound frequency, and if it is 25% by mass or more, regardless of the sound frequency, it is superior to a soundproofing material composed only of a fibrous substrate without a viscoelastic material in terms of both sound absorption and sound insulation performance. Furthermore, if the mass percentage is 10% or more, then 25% or more is superior to 10% in terms of both sound absorption and sound insulation performance. Also, if the mass percentage is 50% or less, the higher the mass percentage, the better both sound insulation and sound absorption performance become. If the mass percentage is 60% or less, sound insulation performance improves, and sound absorption performance also improves slightly. If the mass percentage is 75% or more, the spaces between the fibers are almost completely filled, and depending on the sound frequency, the sound absorption performance may decrease compared to materials with a mass percentage of 25-50%. The amount of viscoelastic material installed on the fiber substrate can be determined by the concentration of the viscoelastic material in the solvent containing the viscoelastic material that is impregnated into the fiber substrate during the manufacture of the soundproofing material.

[0045] The airflow resistance in the thickness direction from the first to the second surface of the soundproofing material is important because if it is too high, sound absorption is poor, and if it is too low, sound insulation is poor. Therefore, measurements were taken according to the JIS L 1913 Frazier method (orifice diameter φ16 mm), and the range was 10,000 to 60,000 Ns / m. 4 It is preferable.

[0046] Microscopic images of partial cross-sections of soundproofing materials are shown in Figure 2. Figure 2(a) is a 100x magnification microscopic image of a partial cross-section of a soundproofing material in which the amount of viscoelastic material installed on the fibrous base material is 25% by mass relative to the mass of the soundproofing material. Figure 2(b) is a 100x magnification microscopic image of a partial cross-section of a soundproofing material in which the amount of viscoelastic material installed on the fibrous base material is 50% by mass relative to the mass of the soundproofing material. The fibrous base material is glass wool with an average fiber diameter of 4 μm and a density of 20 kg / m³. 3 The viscoelastic member is acrylonitrile butadiene rubber (NBR) in the formulation described in Table 1 below. In Figure 2, the fibers 7 that make up the fibrous base material 2 are linearly stretched, intertwined, and laminated, and the viscoelastic member 3 is attached to the fibers 7 in the spaces 20 between the fibers 7.

[0047] Furthermore, even when the viscoelastic member is installed throughout the entire interior of the fibrous substrate, that is, even when the entire interior of the fibrous substrate is the viscoelastic member installation area, the amount of viscoelastic member installed may be partially varied. When the amount of installation is partially varied, this includes configurations in which the amount of installation is varied in the thickness direction of the soundproofing material, in other words, from the first surface to the second surface, and configurations in which the amount of installation is varied in the vertical and / or horizontal direction of the first surface.

[0048] Alternatively, the viscoelastic member may be installed only in a portion of the thickness direction extending from the surface to the back of the fibrous substrate, so that only a portion of the thickness direction of the soundproofing material is designated as the viscoelastic member installation area. There are no particular limitations to such configurations, but for example, as shown in Figure 3, the viscoelastic member installation area 9 may be installed in a thickness portion 23 that does not reach from the first surface 4 of the soundproofing material 1 to the opposite second surface 5 (Figure 3(a)), installed only in the central portion 24 in the thickness direction of the soundproofing material 1 (Figure 3(b)), or installed from the first surface 4 and the second surface 5 of the soundproofing material 1 toward the center in the thickness direction, excluding the central portion 24 in the thickness direction (Figure 3(c)). Even with such configurations, air can still pass between the first surface 4 and the opposite second surface 5 of the soundproofing material 1.

[0049] Here, we will explain the manufacturing method of soundproofing material. Here, we will explain using the case in which glass wool molded product is used as the fibrous base material and rubber as the viscoelastic member as an example. First, glass wool molded product is manufactured. Glass wool molded product can be manufactured by known methods such as mixing glass and other raw materials, melting them, putting the molten raw materials into a fiberization device, and manufacturing glass wool by centrifugal force, attaching a binder to the glass wool, accumulating it on a perforated conveyor, and sending it to a pair of upper and lower perforated conveyors, compressing and heating it to harden the binder and form the product. Next, in addition to a vulcanizing agent, a vulcanization accelerator, a thickener, and other fillers are added to the raw rubber, and the mixture is stirred and kneaded to produce unvulcanized rubber.

[0050] Next, the rubber is dissolved in a solvent such as toluene to produce rubber cement as a viscoelastic material solution. The solvent is not particularly limited, but it is preferable to use one with good compatibility and a solubility parameter (SP value) close to that of the rubber being used. Note that the solvent is not limited to toluene, and various solvents can be used depending on the viscoelastic material. By changing the rubber concentration of the rubber cement, the amount of rubber adhering to the soundproofing material can be adjusted. For example, with the weight ratios of rubber to toluene in the formulations shown in Table 1 below, rubber 1:toluene 45, rubber 1:toluene 94, and rubber 1:toluene 247, soundproofing materials with weight ratios of glass wool to rubber of 50:50, 75:25, and 90:10 can be produced, respectively.

[0051] Then, the entire glass wool molded product is completely immersed in rubber cement, impregnating the spaces between the fibers of the glass wool molded product with rubber, which is a viscoelastic material, and filling some of the spaces between the fibers of the glass wool molded product with the viscoelastic material, causing the rubber to adhere to the fibers. The time for immersing the glass wool molded product in rubber cement is not particularly limited, but it is preferable to immerse it for about 12 to 24 hours. If it is less than 12 hours, the rubber cement may not be sufficiently impregnated into the glass wool molded product, and if it is more than 24 hours, the amount of rubber cement impregnation does not change much. In addition, a higher rubber concentration in the rubber cement can increase the amount of rubber that adheres to the glass wool when the glass wool molded product is impregnated in rubber cement.

[0052] Next, the glass wool molded product is removed from the rubber cement. At this time, the amount of rubber cement remaining attached to the glass wool molded product and the amount of rubber cement removed from the glass wool molded product differ due to the difference in viscosity depending on the rubber concentration of the rubber cement, so the amount of rubber attached can be adjusted by changing the rubber concentration of the rubber cement. Then, through a drying process, specifically, the glass wool molded product is dried by applying hot air while alternately turning it over, and the solvent contained in the glass wool molded product is evaporated and removed. After the solvent has evaporated, the glass wool molded product with unvulcanized rubber attached is heated in a dry heat oven to vulcanize it. The heating temperature and heating time are determined according to the size of the fiber base material, etc., but for example, in the case of glass wool 300 mm long x 300 mm wide x 10 mm thick, it is vulcanized in a dry heat oven at 150°C for 30 minutes on each side, for a total of 60 minutes on both sides. In this way, a soundproofing material is completed in which rubber, which is a viscoelastic member, is impregnated into some of the gaps between the fibers of a molded glass wool material used as a fibrous base material, and the spaces between the fibers penetrate from the surface of the molded glass wool material to the back surface on the opposite side, thereby completely compounding and integrating the rubber and the porous material used as a fibrous base material, the molded glass wool material. Furthermore, by attaching the viscoelastic member to the fibers in this way, the viscoelastic member does not completely block the spaces between the fibers, thus maintaining breathability.

[0053] If the entire fiber substrate is a viscoelastic member installation area, and the amount of viscoelastic member installed is to be varied in certain areas, the fiber substrate can be manufactured by immersing each area of ​​the fiber substrate in rubber cement of a different concentration. Also, as shown in Figure 3, if only a portion of the thickness in the thickness direction of the soundproofing material is to be a viscoelastic member installation area, it is possible to manufacture the material by immersing only the portion of a single fiber substrate that will be the viscoelastic member installation area in rubber cement. Alternatively, multiple fiber substrates can be used, and the material can be manufactured by laminating fiber substrates that have been immersed in rubber cement and had viscoelastic members installed with fiber substrates that do not have viscoelastic members installed.

[0054] Thus, unlike the conventional technology in which the fiber base material and the viscoelastic member constitute completely separate layers and are not completely integrated, and in which one surface of the fiber base material is covered by the viscoelastic member, the soundproofing material of the present invention has the advantage of both the fiber base material and the viscoelastic member, namely the advantage of porous materials, which is good sound absorption performance, and the advantage of viscoelastic materials, which is good sound insulation performance. [Examples]

[0055] The sound absorption and sound insulation properties of soundproofing materials were evaluated. As an example, a soundproofing material composed of glass wool molded with rubber was used. As comparative examples, a soundproofing material composed solely of rubber (Comparative Example 1) and a soundproofing material composed solely of glass wool molded material (Comparative Example 2) were compared in terms of sound absorption and sound insulation. The glass wool molded material had an average fiber diameter of 4 μm and a density of 20 kg / m³. 3 The sample used was an Acrylia U-Board Pinless S (manufactured by Asahi Fiber Glass) formed into a cylindrical shape with a diameter of 40 mm and a thickness (height) of 10 mm. The average fiber diameter of the glass wool was calculated using an electron microscope, measuring the fiber diameter of each glass fiber with a ruler in a magnified image of 500 glass fibers. The density of the glass wool fiber base material was determined from the volume obtained by measuring the length, width, and thickness of the sample with a digital caliper, and the mass measured with an electronic balance.

[0056] The rubber used to adhere to the glass wool molded product was acrylonitrile butadiene rubber (NBR) and chlorosulfonated polyethylene (CSM), manufactured by compounding the raw materials listed in Tables 1 and 2. The CSM in Table 2 was compounded with carbon black, a thermally conductive substance, and antimony trioxide, a flame retardant substance.

[0057] Unvulcanized rubber was produced by mixing the raw materials listed in Tables 1 and 2, stirring, and kneading them. Each was then dissolved in toluene to produce rubber cement. The rubber cement was prepared in three different concentrations based on the weight ratio of rubber to toluene: rubber 1:toluene 45, rubber 1:toluene 94, and rubber 1:toluene 247. Specifically, 27.5g of rubber per 1425ml of toluene (rubber cement A), 13.2g of rubber per 1425ml of toluene (rubber cement B), and 5.0g of rubber per 1425ml of toluene (rubber cement C). The entire glass wool molded product was then completely immersed in the rubber cement for 12 hours to impregnate the glass wool molded product with the rubber cement, allowing the rubber to adhere to the glass wool fibers and filling some of the spaces between the glass wool fibers with the viscoelastic material. Next, the glass wool molded material was removed from the rubber cement, excess rubber cement was removed from the glass wool molded material, and the glass wool molded material was dried by applying hot air while alternately turning it over to evaporate the solvent contained in the rubber cement contained in the glass wool molded material. After the solvent evaporated, the glass wool molded material with unvulcanized rubber attached was placed in a gear oven (hot air dryer) and heated at 150°C for 30 minutes on each side, for a total of 60 minutes on both sides, to vulcanize and obtain soundproofing material. The weight of the soundproofing material obtained after vulcanization was measured and compared with the weight of the glass wool molded material before filling with viscoelastic material to confirm that the weight ratio of the glass wool molded material to rubber was the predetermined ratio. The soundproofing materials using rubber cement A, rubber cement B, and rubber cement C had weight ratios of glass wool to rubber of 50:50, 75:25, and 90:10, respectively, meaning they contained 50 mass%, 25 mass%, and 10 mass% of viscoelastic material, respectively. Furthermore, the soundproofing material is cylindrical with a diameter of 40 mm and a thickness (height) of 10 mm, and is the same shape and size as the glass wool molded material before the rubber was attached.

[0058] The soundproofing material made with rubber cement A using the rubber formulation shown in Table 1 was designated as Example 1, the soundproofing material made with rubber cement B using the rubber formulation shown in Table 1 was designated as Example 2, the soundproofing material made with rubber cement C using the rubber formulation shown in Table 1 was designated as Example 3, the soundproofing material made with rubber cement A using the rubber formulation shown in Table 2 was designated as Example 4, the soundproofing material made with rubber cement B using the rubber formulation shown in Table 2 was designated as Example 5, and the soundproofing material made with rubber cement C using the rubber formulation shown in Table 2 was designated as Example 6.

[0059] The soundproofing material composed solely of rubber (Comparative Example 1) used rubber manufactured by a known method of stirring, kneading, heating, and vulcanizing the raw materials according to the formulations in Table 1 or Table 2, and then formed into a cylindrical shape with a diameter of 40 mm and a thickness (height) of 10 mm. The soundproofing material composed solely of rubber according to the formulation in Table 1 was designated as Comparative Example 1-1, and the soundproofing material composed solely of rubber according to the formulation in Table 2 was designated as Comparative Example 1-2. In addition, the soundproofing material composed solely of molded glass wool was made using the same glass wool used in the example, with an average fiber diameter of 4 μm and a density of 20 kg / m³. 3 Comparative Example 2 used an Acrylia U-Board Pinless S (manufactured by Asahi Fiberglass) formed into a cylindrical shape with a diameter of 40 mm and a thickness (height) of 10 mm. Thus, both the soundproofing material in the example and the soundproofing material in the comparative example are cylindrical in shape with a diameter of 40 mm and a thickness (height) of 10 mm, and are identical in shape and size.

[0060] [Table 1]

[0061] [Table 2]

[0062] The evaluation method involved assessing the sound absorption coefficient in the pipe using normal incidence sound absorption coefficient measurement, and assessing the sound insulation coefficient by assessing the transmission loss in the pipe using sound transmission loss measurement. The measurement method used a normal incidence sound absorption coefficient measurement system (manufactured by Nippon Acoustic Engineering Co., Ltd.). The normal incidence sound absorption coefficient was evaluated according to JIS A 1405-2, and the normal incidence transmission loss was evaluated according to ASTM E2611. In the examples, sound was incident from both the first surface (front) and the second surface (back) of the soundproofing material for evaluation.

[0063] The results are shown in the graphs in Figures 4 and 5. Figure 4 shows the normal incidence sound absorption coefficient, with Figure 4(a) showing the results when sound is incident from the first surface (front) of the soundproofing material of Examples 1 to 3, Figure 4(b) showing the results when sound is incident from the second surface (back) of the soundproofing material of Examples 1 to 3, Figure 4(c) showing the results when sound is incident from the first surface (front) of the soundproofing material of Examples 4 to 6, and Figure 4(d) showing the results when sound is incident from the second surface (back) of the soundproofing material of Examples 4 to 6. Figure 5 shows the sound transmission loss, with Figure 5(a) showing the results when sound is incident from the first surface (front) of the soundproofing material of Examples 1 to 3, Figure 5(b) showing the results when sound is incident from the second surface (back) of the soundproofing material of Examples 1 to 3, Figure 5(c) showing the results when sound is incident from the first surface (front) of the soundproofing material of Examples 4 to 6, and Figure 5(d) showing the results when sound is incident from the second surface (back) of the soundproofing material of Examples 4 to 6.

[0064] As is clear from the graph in Figure 4, the sound-absorbing materials of the examples have a higher sound absorption coefficient than the sound-absorbing materials made only of rubber (Comparative Examples 1-1 and 1-2). In particular, the sound absorption coefficient becomes higher as the frequency increases, and the sound absorption coefficient increases as the rubber content ratio increases. Specifically, in Examples 1 to 2 and Examples 4 to 6, which use rubber blended with a thermally conductive substance, there is no significant difference from the sound-absorbing material made only of glass wool (GW) (Comparative Example 2) up to about 400 Hz. However, at frequencies above 400 Hz, the sound absorption coefficient becomes higher as the frequency increases, and as the rubber content ratio increases, compared to the sound-absorbing material made only of glass wool (Comparative Example 2). Furthermore, while the soundproofing material of Example 3 shows no significant difference from the soundproofing material composed solely of glass wool (Comparative Example 2) up to approximately 500 Hz, it can be seen that at frequencies above 500 Hz, and especially as the frequency increases, the sound absorption coefficient becomes higher than that of the soundproofing material composed solely of glass wool (Comparative Example 2).

[0065] Furthermore, as is clear from the graph in Figure 5, the soundproofing material of the examples has higher sound insulation than the soundproofing material made only of glass wool (Comparative Example 2). Specifically, in Examples 1 to 2 and Examples 4 to 6 which use rubber blended with a thermally conductive substance, the sound insulation is higher than that of Comparative Example 2 regardless of frequency. In Example 3, which does not use a thermally conductive substance, there is no significant difference from the soundproofing material made only of glass wool (Comparative Example 2) at frequencies above approximately 400-800 Hz, but at lower frequencies, especially as the frequency decreases, the sound insulation is higher than that of the soundproofing material made only of glass wool (Comparative Example 2).

[0066] From the above, it is clear that the soundproofing material in the example is capable of achieving both sound absorption and sound insulation properties. Furthermore, it is clear that it is possible to simultaneously improve both the sound absorption and sound insulation performance of the soundproofing material.

[0067] Thus, in the embodiments of the present invention, a soundproofing material comprising a fibrous base material and a viscoelastic material is made possible in which sound absorption and sound insulation properties, which cannot be achieved by each material alone, are simultaneously realized. [Industrial applicability]

[0068] As described above, the present invention makes it possible to achieve both sound absorption and sound insulation properties of a soundproofing material regardless of the direction of sound incidence to the soundproofing material. Therefore, it is suitable as a soundproofing material for use in buildings, structures, automobiles, electrical and electronic equipment, etc., and can be used in the construction industry, various manufacturing industries, etc. [Explanation of symbols]

[0069] 1. Soundproofing material 2. Fiber base material 20 Space between fibers 21 Surface of the fibrous substrate 22 Back surface of the fiber base material 3. Viscoelastic members 4. First surface of soundproofing material 5. Soundproofing material, second side 7 fibers 9. Viscoelastic member installation area

Claims

1. A soundproofing material characterized in that a viscoelastic member is attached to the fibers and installed in a portion of the space between the fibers of a fibrous base material, and the space between the fibers penetrates from the surface of the fibrous base material to the back surface opposite to the surface.

2. The soundproofing material according to claim 1, characterized in that the viscoelastic member is installed extending from the surface to the back surface of the fibrous base material.

3. The soundproofing material according to claim 1, characterized in that the viscoelastic member is installed over the entire fibrous base material.

4. The soundproofing material according to claim 1, characterized in that the viscoelastic member is installed in a part of the fibrous substrate.

5. The soundproofing material according to any one of claims 1 to 4, characterized in that the amount of the viscoelastic member installed is 10 to 50% by mass relative to the mass of the soundproofing material.

6. The soundproofing material according to any one of claims 1 to 4, characterized in that the viscoelastic member is made of rubber, a thermoplastic elastomer, or a thermosetting elastomer other than rubber.

7. The soundproofing material according to claim 5, characterized in that the viscoelastic member is made of rubber, a thermoplastic elastomer, or a thermosetting elastomer other than rubber.

8. The soundproofing material according to any one of claims 1 to 4, characterized in that the average fiber diameter of the fibers in the fibrous base material is 2 to 10 μm.

9. The soundproofing material according to claim 5, characterized in that the average fiber diameter of the fibers in the fibrous base material is 2 to 10 μm.

10. The density of the aforementioned fiber base material is 10 to 100 kg / m³. ３ The soundproofing material according to any one of claims 1 to 4, characterized in that it is the soundproofing material described in any one of claims 1 to 4.

11. The density of the aforementioned fiber base material is 10 to 100 kg / m³. ３ The soundproofing material according to claim 5, characterized in that it is the same as the soundproofing material according to claim 5.

12. The density of the aforementioned fiber base material is 10 to 100 kg / m³. ３ The soundproofing material according to claim 8, characterized in that it is the same as the present invention.

13. Air permeability resistance is 10,000 to 60,000 Ns / m ４ The soundproofing material according to any one of claims 1 to 4, characterized in that it is the soundproofing material described in any one of claims 1 to 4.

14. Air permeability resistance is 10,000 to 60,000 Ns / m ４ The soundproofing material according to claim 5, characterized in that it is the same as the soundproofing material according to claim 5.

15. The soundproofing material according to any one of claims 1 to 4, characterized in that the fibrous base material is composed of glass wool, rock wool, or a mixture of glass wool and rock wool.

16. The soundproofing material according to claim 5, characterized in that the fibrous base material is composed of glass wool, rock wool, or a mixture of glass wool and rock wool.

17. The soundproofing material according to claim 6, characterized in that the fibrous base material is composed of glass wool, rock wool, or a mixture of glass wool and rock wool.

18. The soundproofing material according to claim 8, characterized in that the fibrous base material is composed of glass wool, rock wool, or a mixture of glass wool and rock wool.

19. A method for manufacturing a soundproofing material, characterized by impregnating the spaces between the fibers of a fibrous substrate with a viscoelastic member solution obtained by dissolving a viscoelastic member in a solvent, attaching the viscoelastic member to the fibers, drying to remove the solvent from the viscoelastic member solution, and installing the viscoelastic member in a portion of the spaces between the fibers of the fibrous substrate so that the spaces between the fibers penetrate from the surface of the fibrous substrate to the back surface opposite to the surface.

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