Interior sound absorbing material

Abstract

To provide a sound absorbing material for a vehicle interior, which can provide a comfortable cabin space that is not only excellent in sound absorption characteristics for road noise echoing from outside the vehicle and conversation sounds in the cabin, but also excellent in visual and textural quality.SOLUTION: In an interior sound absorbing material in which a fiber layer and a base material layer are laminated and integrated, the fiber layer is a sheet-like material including a fiber web A composed of at least one type of main fiber and a resin binder. The basis weight of the fiber layer is 200 g / m2 or more, the thickness of the fiber layer is 1.35 mm or less, the average fiber diameter of the main fiber is 1 μm or more and 10 μm or less, and the average spatial size, which is an average value in the thickness direction of the fiber layer in a spatial size in a three-dimensional image of the fiber web A by X-ray CT, is 5 μm or more and 35 μm or less. The base material layer has an average spatial size that is at least twice the average spatial size of the fiber web A, and the thickness of the base material layer is 2 mm or more and 20 mm or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an interior sound-absorbing material. More specifically, the present invention is excellent in sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise entering from outside the vehicle or the conversation sound inside the vehicle cabin, and has a high surface quality (texture) of the surface that passengers touch, and also has high wear resistance. Therefore, not only the quietness that suppresses the reverberation of sound in the vehicle cabin and makes it easier to talk, but also a comfortable vehicle cabin space excellent visually and in texture can be provided. For example, the present invention relates to an interior sound-absorbing material that can be suitably used as an interior material for automobiles.

Background Art

[0002] When an automobile is running, various noises such as noise from the engine and drive system, road noise, and wind noise are generated. Conventionally, in order to suppress these noises and create a comfortable vehicle cabin space, sound-absorbing materials have been used for the purpose of suppressing noise emission. In recent years, with the progress of electrification of automobiles and the improvement of the quietness of the drive system, sounds that were not conventionally recognized as noise have come to be recognized as noise. The frequency of noise depends on each sound source, and a sound-absorbing material suitable for each sound source is used. However, although porous sound-absorbing materials widely used in in-vehicle applications, that is, non-woven fabrics and foams, exhibit excellent sound absorption rates in the high-frequency band, the sound absorption rate tends to decrease toward the low-frequency side. On the other hand, it is known that the sound insulation performance is improved in the entire frequency range by providing an additional layer on the surface of the porous material.

[0003] For example, Patent Document 1 below provides a laminated sound-absorbing material having excellent sound absorption in the low-frequency region, the mid-frequency region, and preferably also the high-frequency region. The laminated sound-absorbing material includes at least a fiber layer and a base material layer that is a porous layer. The fiber layer contains at least one fiber selected from the group consisting of polyvinylidene fluoride, nylon 6,6, polyacrylonitrile, polystyrene, polyurethane, polysulfone, polyvinyl alcohol, polyethylene terephthalate, polybutylene terephthalate, polyethylene, and polypropylene; is a layer composed of fibers having an average fiber diameter of 30 nm to 30 μm; and the basis weight of the fiber layer is 0.01 to 500 g / m 2 Preferably, it is 0.1 to 200 g / m 2 for even more preferred; the laminated sound-absorbing material is described, and the thickness of the base material layer is 3 to 60 mm; the fiber layer and the porous layer are fixed by at least one selected from the group consisting of melt partial adhesion, partial adhesion with an adhesive, sewing, stapling, clipping, fixing with an outer frame, fixing with a framework, welding of the edge portion, and bonding with a double-sided tape on the edge portion so as not to inhibit air permeability; the fiber layer has an average flow pore diameter of 1.0 to 60 μm; the fiber layer is arranged so as to be on the sound incident side; it is also described that the porous layer is a layer composed of at least one selected from the group consisting of a foamed resin, a non-woven fabric, and a woven fabric. Also, the effects are said to be high sound absorption rate in the low-frequency region, lightweight, and space-saving. However, Patent Document 1 does not describe that the fiber layer is a sheet-like material composed of at least one main fiber and a resin binder, nor does it describe the effect of the average space size of the fiber layer.

[0004] Further, Patent Document 2 below provides a non-woven fabric for a sound-absorbing material, a sound-absorbing material, and a method for manufacturing a non-woven fabric for a sound-absorbing material, which have excellent sound absorption performance in the low-frequency region and excellent productivity. It has a laminated structure of non-woven fabric A and non-woven fabric B. Non-woven fabric A contains fiber A having a modal value of the single fiber diameter of 0.05 to 0.80 μm and fiber B having a modal value of the single fiber diameter of 5.00 to 30.00 μm. The basis weight of the non-woven fabric B is 70 to 200 g / m 2and the fiber A and the fiber B are both polyester staple fibers; the thickness of the layer is 5 to 50 mm; the layer is laminated on one surface of the nonwoven fabric for the sound absorption material; are described. Further, the effects are said to be excellent in sound absorption performance (particularly, sound absorption performance in the low frequency range) and productivity. However, Patent Document 2 does not describe that it is a sound absorption material having a fiber layer and a base material layer, nor does it describe the effect of the average space size of the fiber layer.

[0005] Also, Patent Document 3 below provides a nonwoven fabric and a laminated nonwoven fabric suitable as a skin material of a composite sound absorption material that has good moldability and excellent morphological stability, and can exhibit a sufficient sound absorption imparting effect even in a thin low basis weight region. It is a laminated nonwoven fabric in which two or more nonwoven fabrics are laminated; it has a laminated structure in which at least one continuous long fiber layer (S) with an average fiber diameter of 10 μm or more and 30 μm or less and at least one ultrafine fiber layer (M) with an average fiber diameter of 0.3 μm or more and 7 μm or less are integrated; the basis weight of the ultrafine fiber layer (M) is 1 g / m 2 or more and 40 g / m 2 or less; the basis weight of the nonwoven fabric is 20 g / m 2 or more and 150 g / 2 or less, and the thickness is 2 mm or less; the component is polyethylene terephthalate; sound is incident from the skin material side; it is a composite sound absorption material in which the nonwoven fabric or laminated nonwoven fabric and a continuous bubble resin foam or fiber porous material as a sound absorption material are laminated; are described. The effects are good moldability and being thin and lightweight. However, Patent Document 3 does not describe that the fiber layer is a sheet-like material composed of at least one main fiber and a resin binder, and the basis weight of the fiber layer and the fiber diameter of the constituent fibers are different from those of the present invention, nor does it describe the effect of the average space size of the fiber layer.

[0006] In addition, Patent Document 4 below provides a sound-absorbing material having excellent form stability, excellent sound absorption in a wide frequency range, and excellent processability and handleability, and a method for manufacturing the same. The sound-absorbing material is formed by attaching a non-woven fabric to the surface of a sheet-like fiber aggregate; contains a resin binder; and is composed of a sheet-like fiber aggregate in which base material fibers and ultrafine short fibers are intertwined with each other. The fiber diameter of the base material fibers is 15 to 50 μm, the fiber diameter of the ultrafine short fibers is 0.2 to 5 μm, and the ultrafine short fibers pass through a sieve having a nominal mesh size of 2 mm defined in JIS Z8801-1. The apparent density of the sound-absorbing material is 0.015 to 0.2 g / cm 3 ; and it is also described that the sound-absorbing material is formed by attaching a non-woven fabric to the surface of a sheet-like fiber aggregate. However, Patent Document 4 does not describe that the sound-absorbing material has a fiber layer and a base material layer, and the basis weight and apparent density of the fiber layer are different from those of the present invention, and the effect of the average space size of the fiber layer is not described either.

[0007] In addition, Patent Document 5 below discloses a sound-absorbing material having a structure of a non-ventilated resonance layer that is a foam or a film, and a manufacturing method thereof. The sound-absorbing material has a lightweight sound-absorbing layer with a thickness of 1 to 50 mm and a density of 0.01 to 0.2 g / cm 3 , preferably 0.03 to 0.08 g / cm 3 , and a non-ventilated resonance layer with a basis weight of 200 g / m 2 or less, preferably 100 g / m 2 or less, which is adhered to the sound-absorbing layer via an adhesive layer. The adhesive strength of the adhesive layer to the sound-absorbing layer and the non-ventilated resonance layer is set to 1 to 20 N / 25 mm, preferably 3 to 10 N / 25 mm, for 180-degree peeling with a peeling width of 25 mm, and the adhesive layer is adhered to 50 to 100%, preferably 80% to 100% of the entire interface between the sound-absorbing layer and the non-ventilated resonance layer. However, Patent Document 5 does not describe that the sound-absorbing material has a fiber layer and a ventilated base material layer, and the basis weight of the fiber layer and the like are different from those of the present invention, and the effect of the average space size of the fiber layer is not described either.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, although the conventional technology can improve the sound absorption performance by providing an additional layer on the porous material, it can hardly exert its effectiveness with respect to sound insulation performance. Also, in order to countermeasures noise leaking from the inside of the vehicle, such as the driving sound of the engine, to the outside, it has been known that it is effective to improve the sound insulation performance rather than the sound absorption performance of the soundproof material. However, when used as an interior material for automobiles, the configuration of the sound absorption material for achieving quietness, which is excellent in the sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise entering from outside the vehicle and the conversation sound inside the vehicle compartment, and can suppress the reverberation of sound inside the vehicle compartment and make it easier to talk, has not been studied. In view of the level of such conventional technology, the problem to be solved by the present invention is, for example, when used as an interior material for automobiles, excellent in the sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise entering from outside the vehicle and the conversation sound inside the vehicle compartment, and having high surface quality (texture) of the surface that the passenger touches and high wear resistance, so that not only the quietness that can suppress the reverberation of sound inside the vehicle compartment and make it easier to talk, but also a comfortable vehicle interior space excellent visually and in texture can be provided. Therefore, for example, it is to provide an interior sound absorption material that can be suitably used as an interior material for automobiles.

Means for Solving the Problems

[0010] As a result of intensive studies and repeated experiments to solve the above problems, the inventors of the present application unexpectedly found that the above problems can be achieved by configuring the interior sound-absorbing material as follows, and thus completed the present invention.

[0011] That is, the present invention is as follows. [1] An interior sound-absorbing material in which a fiber layer and a base material layer are laminated and integrated, The fiber layer is a sheet-like material including a fiber web A composed of at least one main fiber and a resin binder, The basis weight of the fiber layer is 200 g / m 2 or more and 400 g / m 2 or less, The thickness of the fiber layer is 0.65 mm or more and 1.35 mm or less, The average fiber diameter of the main fiber is 1 μm or more and 10 μm or less, In the three-dimensional image of the fiber layer by X-ray CT, the average value of the average space size in the thickness direction of the fiber layer, which is the diameter of the largest sphere that enters the space excluding the fibers and the resin binder constituting the fiber layer, is 5 μm or more and 35 μm or less, The base material layer has an average space size that is at least twice the average space size of the fiber web A, and The thickness of the base material layer is 2 mm or more and 20 mm or less, An interior sound-absorbing material, characterized by the above. [2] The interior sound-absorbing material according to [1], wherein the main fiber is a polyester fiber. [3] The interior sound-absorbing material according to [1] or [2], wherein the fiber layer further includes a scrim layer made of a woven or knitted fabric and / or a fiber web B composed of at least one main fiber and a resin binder. [4] The interior sound-absorbing material according to any one of [1] to [3], wherein the resin binder is a polyurethane resin or a heat-sealing resin. [5] The interior sound-absorbing material according to [4], wherein the heat-sealing resin is a polyester resin having a melting point 20 °C or more lower than the melting point of the main fiber. [6] The interior sound-absorbing material according to any one of [1] to [5], wherein the base material layer is a foam, a porous body, or a hollow structure. [7] The interior sound-absorbing material according to any one of [1] to [6], wherein when sound in the frequency range of 500 to 6400 Hz is incident from a sound source arranged on the fiber layer side of the interior sound-absorbing material, the integrated sound absorption rate in the frequency range of 1000 to 2000 Hz is 20% or more. [8] The interior sound-absorbing material according to any one of [1] to [7], wherein the adhesion rate of the resin binder in the fiber layer is 5% by mass or more and 25% by mass or less. [9] The interior material according to any one of [1] to [8], wherein the interior sound-absorbing material is arranged on a support material with the fiber layer side facing the inside of the living space.

[10] The interior material according to [9], which is for an automobile. [Effect of the Invention]

[0012] When the sound-absorbing material according to the present invention is used, for example, as an interior material for an automobile, it has excellent sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise entering from outside the vehicle or the conversation sound inside the vehicle cabin. Also, the surface quality (texture) of the surface that the passengers touch is high, and the wear resistance is also high. Therefore, not only the reverberation of the sound in the vehicle cabin is suppressed, making it easier to have conversations, but also a comfortable vehicle cabin space that is excellent visually and in terms of texture can be provided. Thus, it can be suitably used, for example, as an interior material for an automobile. [Brief Description of the Drawings]

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0015] One embodiment of the present invention is an interior sound-absorbing material in which a fiber layer and a base material layer are laminated and integrated, The fiber layer is a sheet-like material including a fiber web A composed of at least one main fiber and a resin binder, The basis weight of the fiber layer is 200 g / m 2 or more and 400 g / m 2 or less, The thickness of the fiber layer is 0.65 mm or more and 1.35 mm or less, The average fiber diameter of the main fiber is 1 μm or more and 10 μm or less, In the three-dimensional image of the fiber web A by X-ray CT, the average value in the thickness direction of the fiber layer of the space size, which is the diameter of the largest sphere that enters the space excluding the fibers and the resin binder constituting the fiber layer, is 5 μm or more and 35 μm or less, The base material layer has an average space size that is twice or more the average space size of the fiber web A, and The thickness of the base material layer is 2 mm or more and 20 mm or less, characterized by being an interior sound-absorbing material.

[0016] The interior sound-absorbing material of this embodiment is an interior sound-absorbing material in which a fiber layer and a base material layer are laminated and integrated. In the fiber layer, it is a sheet-like material including a fiber web A composed of at least one main fiber and a resin binder, and the resin binder controls the space size described later. This is the characteristic.

[0017] (Fiber layer) As shown in FIGS. 1 and 2, a resin binder is attached around the main fiber with a fiber diameter within a predetermined range, and thereby a fiber layer including a fiber web A with the space size controlled is arranged on the sound source side, and a base material layer having a thickness within a predetermined range and an air layer having a larger space size is arranged. By doing so, the inventors, for example, when used as an interior material for an automobile, are excellent in the sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise entering from outside the vehicle and the conversation sound in the vehicle interior, and the surface quality (texture) of the surface that the passengers touch is high, and the wear resistance is also high. Therefore, not only the quietness in which the reverberation of the sound in the vehicle interior is suppressed and it becomes easier to talk, but also unexpectedly, it is possible to provide a comfortable vehicle interior space that is excellent visually and in texture, and the present invention has been completed. Therefore, the interior sound-absorbing material of this embodiment can be suitably used, for example, as an interior material for an automobile.

[0018] As shown in FIG. 1, the space size of the fiber web A can be controlled by controlling the fiber diameter and the fiber layer density, but in the present invention, it is characterized in that the space size is controlled by attaching a resin binder around the main fiber with a predetermined fiber diameter. The adhesion rate of the resin binder is preferably 5% by mass or more and 25% by mass or less, and more preferably 5% by mass or more and 15% by mass or less. As shown in Comparative Example 5 below, when there is no resin binder, the sound absorption characteristics in the frequency range of 1000 to 2000 Hz are reduced compared with the case where there is a resin binder.

[0019] The basis weight of the fiber layer is 200 g / m 2 or more and 400 g / m 2 or less, preferably 250 g / m 2 or more and 350 g / m 2as follows, more preferably 260 g / m 2 or more and less than 300 g / m 2 . If the basis weight of the fiber layer is less than 200 g / m 2 , the abrasion resistance and sound absorption characteristics will deteriorate. If the basis weight of the fiber layer exceeds 400 g / m 2 , there will be demerits such as weight increase and deterioration of processability.

[0020] The thickness of the fiber layer is 0.65 mm or more and 1.35 mm or less, preferably 0.8 mm or more and 1.25 mm or less. If the thickness of the fiber layer is less than 0.65 mm, the abrasion resistance and sound absorption characteristics will deteriorate. If the thickness of the fiber layer exceeds 1.35 mm, the weight will increase, it will take up space, and the processability will also deteriorate.

[0021] The average fiber diameter of the main fiber is 1 μm or more and 10 μm or less, preferably 1.5 μm or more and 6.0 μm or less. If the average fiber diameter of the main fiber is less than 1 μm, the abrasion resistance and sound absorption characteristics will deteriorate. On the other hand, if it exceeds 10 μm, the surface quality (texture) and sound absorption characteristics will deteriorate.

[0022] In the three-dimensional image of the fiber web A by X-ray CT, the average space size, which is the average value in the thickness direction of the fiber layer of the space size, which is the diameter of the largest sphere that enters the space excluding the fibers and the resin binder that constitute the fiber web A, is 5 μm or more and 35 μm or less, preferably 10 μm or more and 20 μm or less. If the average space size is less than 5 μm, the sound absorption characteristics and abrasion resistance will deteriorate. On the other hand, if it exceeds 35 μm, the sound absorption characteristics and surface quality will deteriorate.

[0023] As illustrated in FIG. 4, by setting the average space size of the fiber web A to 5 μm or more and 35 μm or less, and setting the space average size of the base material layer to 2 times or more the average space size of the fiber web A, it is possible to achieve excellent sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise entering from outside the vehicle and the conversation sound inside the vehicle cabin. Although not wishing to be bound by a specific theory, the inventors of the present application presume that the reason is that the principle of the air layer behind (the phenomenon that when an air layer is provided behind a material with sound absorption performance, the sound absorption peak shifts to a lower frequency. The greater the thickness, the greater the effect) is acting.

[0024] There is no limitation on the main fiber either, but fibers directly spun by the melt spinning method, fibers obtained by the wet spinning method, ultrafine fibers obtained by removing the sea component from sea-island fibers using copolymer polyester as the sea component and homopolymer polyester as the island component, etc. can be used. As the polyester-based fiber, polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactate, and their copolymers are preferably used. If it is a polyester-based fiber, it is rich in light resistance and recyclability.

[0025] In addition, the fiber layer can include a scrim layer made of a woven or knitted fabric. The scrim layer functions as a core material and is preferably a woven or knitted fabric from the viewpoints of stabilizing the production of the formed sheet in the papermaking process and imparting mechanical strength. The material of the scrim layer is preferably the same polymer system as the main fiber from the viewpoint of color matching in dyeing. In the case of a knitted fabric, a single knit knitted with 22 gauge or more and 28 gauge or less is preferred. In the case of a woven fabric, it is more suitable because higher dimensional stability and strength can be achieved than in a knitted fabric. The weave of the woven fabric may be plain weave, twill weave, damask weave, etc., but plain weave is preferred from the viewpoints of cost and process aspects such as entangling property.

[0026] The yarns constituting the fabric may be monofilaments or multifilaments. The single fiber fineness of the yarns is preferably 5.5 dtex or less in terms of easily obtaining a soft touch. As the form of the yarns constituting the fabric, raw multifilament yarns such as polyester and polyamide, or processed yarns subjected to false twisting are preferably twisted at a twist count of 0 to 3000 T / m. The multifilament may be a normal one. For example, 33 dtex / 6f, 55 dtex / 24f, 83 dtex / 36f, 83 dtex / 72f, 110 dtex / 36f, 110 dtex / 48f, 167 dtex / 36f, 166 dtex / 48f, etc. of polyester, polyamide, etc. are preferably used. The yarns constituting the fabric may be multifilament long fibers. The fabric density of the yarns in the fabric is preferably 30 to 150 threads / inch, more preferably 40 to 100 threads / inch, in terms of imparting flexibility and mechanical strength. In order to have good mechanical strength and an appropriate texture, the basis weight of the fabric is preferably 20 to 150 g / m 2 is preferred. Incidentally, the presence or absence of false twisting processing of the yarns constituting the fabric, the twist count, the single fiber fineness of the multifilament, the fabric density, etc. contribute not only to the entanglement with the fiber web and flexibility but also to mechanical properties such as seam strength, tear strength, tensile strength and elongation, stretchability, etc. Therefore, they may be appropriately selected according to the target physical properties and uses.

[0027] (Resin binder) There is no particular limitation on the resin binder either, but it can be a polyurethane resin or a heat-sealing resin. As the polyurethane resin, those obtained by the reaction of a polymer diol, an organic diisocyanate, and a chain extender are preferred. As the polymer diol, for example, diols such as polycarbonate-based, polyester-based, polyether-based, silicone-based, and fluorine-based can be adopted, and copolymers combining two or more of these may also be used. From the viewpoint of hydrolysis resistance, polycarbonate-based or polyether-based diols or a combination thereof are preferably used. Further, from the viewpoints of light resistance and heat resistance, polycarbonate-based, polyester-based, or a combination thereof diols are preferably used. Furthermore, from the viewpoint of cost competitiveness, polyether-based, polyester-based, or a combination thereof diols are preferably used. Polycarbonate-based diols can be produced by, for example, transesterification reaction of an alkylene glycol and a carbonate ester, reaction of phosgene or chloroformate ester and an alkylene glycol, etc.

[0028] Examples of the alkylene glycol include linear alkylene glycols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol; branched alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-methyl-1,8-octanediol; alicyclic diols such as 1,4-cyclohexanediol; aromatic diols such as bisphenol A; etc. These can be used alone or in combination of two or more.

[0029] Examples of the polyester-based diol include polyester diols obtained by condensing various low molecular weight polyols and polybasic acids.

[0030] As the low molecular weight polyol, for example, one or more selected from ethylene glycol, 1,2 - propylene glycol, 1,3 - propylene glycol, 1,3 - butanediol, 1,4 - butanediol, 2,2 - dimethyl - 1,3 - propanediol, 1,6 - hexanediol, 3 - methyl - 1,5 - pentanediol, 1,8 - octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane - 1,4 - diol, and cyclohexane - 1,4 - dimethanol can be used. In addition, an adduct obtained by adding various alkylene oxides to bisphenol A can also be used.

[0031] As the polybasic acid, for example, one or more selected from succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydroisophthalic acid can be mentioned.

[0032] Examples of the polyether - type diol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymer diols obtained by combining them.

[0033] The number - average molecular weight of the polymer diol is preferably 500 to 4000. By setting the number - average molecular weight to 500 or more, more preferably 1500 or more, it is possible to prevent the texture from becoming hard. Also, by setting the number - average molecular weight to 4000 or less, more preferably 3000 or less, the strength of the polyurethane resin can be maintained well.

[0034] Examples of the organic diisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, etc.; and aromatic diisocyanates such as diphenylmethane diisocyanate, tolylene diisocyanate, etc. These may be used in combination. Among them, from the viewpoint of light resistance, aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate are preferably used.

[0035] As the chain extender, amine-based chain extenders such as ethylenediamine and methylene bisaniline, and diol-based chain extenders such as ethylene glycol can be used. Further, a polyamine obtained by reacting a polyisocyanate with water can also be used as the chain extender.

[0036] The polyurethane resin can be used in the form of a solvent-type polyurethane resin in which the polyurethane resin is dissolved in an organic solvent such as N,N-dimethylformamide, or a water-dispersion-type polyurethane resin in which the polyurethane resin is emulsified with an emulsifier and dispersed in water. Among them, the water-dispersion-type polyurethane resin is preferable because it is easy to fill the polyurethane resin in a fine form into the fiber sheet, it is easy to obtain performances such as texture and mechanical properties even with a small amount of adhesion, and it is not necessary to use an organic solvent and the environmental load can be reduced. A heat-sealing resin having a melting point 20°C or more and 170°C or less lower than the melting point of the main body fiber is preferably a polyester resin, a polyamide resin, an acrylic resin, a polyolefin resin, etc. from the viewpoint of easy availability. As the polyester resin, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactate, copolymers thereof, etc. are preferably used. As the polyamide resin, nylon, copolymers thereof, etc. are preferably used. As the acrylic resin, polymers of acrylic esters or methacrylic esters, copolymers thereof, etc. are preferably used. As the polyolefin resin, polyethylene, polypropylene, polybutene, polystyrene, copolymers thereof, etc. are preferably used.

[0037] The heat-sealing resin does not necessarily have to be composed of only a single polymer, and a plurality of types of polymers may be mixed. From the viewpoints of high adhesive strength and identity in dyeing, it is preferable that the polymer system is the same as that of the main body fiber. Also, additives may be mixed or adhered to this thermoplastic resin as long as the desired effects are achieved. Additives refer to titanium oxide, various antioxidants, light-resistant agents, antistatic agents, flame retardants, softeners, fastness improvers, pigments such as carbon black, dyes, etc. The thermoplastic resin has a melting point 20°C or more and 170°C or less lower than the melting point of the main body fiber, and preferably has a melting point 20°C or more and 170°C or less lower than the melting point of the main body fiber having the lowest melting point when there are two or more types of main body fibers. In addition, when the heat-sealing resin is a mixture of a plurality of types of polymers, it is necessary that the heat-sealing resin having the highest melting point has a melting point 20°C or more and 170°C or less lower than the melting point of the main body fiber having the lowest melting point. Regarding the melting point range, the abrasion resistance and appearance quality described in the present application can be achieved within the above range, but from the viewpoint of maintaining the appearance quality particularly well, the melting point of the heat-sealing resin is preferably 40°C or more and 150°C or less lower than the melting point of the main body fiber, and more preferably 40°C or more and 100°C or less lower than the melting point of the main body fiber.

[0038] (Base material layer) The base material layer is not particularly limited, and any foam, porous body, or hollow structure may be used as long as it has a spatial average size that is at least twice the average spatial size of the fiber web A. However, the thickness of the base material layer is 2 mm or more and 20 mm or less. If the thickness of the base material layer is less than 2 mm, the sound absorption characteristics will deteriorate. If the thickness of the base material layer is 20 mm or less, space can be saved, and the degree of freedom in design will be high when applying to various uses.

[0039] (Effect) When sound with a frequency of 500 to 6400 Hz is incident from a sound source arranged on the fiber layer side of the interior sound absorption material of the present embodiment, the integrated sound absorption rate at a frequency of 1000 to 2000 Hz is 20% or more, because the fiber layer and the base material layer satisfy the above requirements. The interior sound absorption material can exhibit excellent sound absorption characteristics. Such an effect is as shown in the following examples, but as shown in FIG. 4, it could not be achieved with conventional interior sound absorption materials.

[0040] Another embodiment of the present invention is an interior material arranged on a support material, preferably an interior material for an automobile, with the fiber layer side of the above-described interior sound absorption material facing the inside of the living space (the surface exposed to the outside during use = the side that a person touches). When the fiber layer has a three-layer structure including a scrim and when it is composed of the fiber web A and the fiber web B, the fiber web A side will be on the inside of the living space. As shown in Reference Examples 1 and 2 below, when a base material layer is arranged on the sound source side instead of a fiber layer, the desired sound absorption characteristics cannot be exhibited.

Examples

[0041] Hereinafter, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited to these examples. Regarding the samples according to the examples and comparative examples, each physical property, quality, etc. were evaluated by the following procedures and methods.

[0042] (1) Average diameter (μm) of the main (single) fiber constituting the fiber web A The average diameter (average fiber diameter) of the main (single) fibers constituting the fiber web A is obtained by photographing a cross-section in the thickness direction of the fiber layer at a magnification of 1500 times using a scanning electron microscope (SEM, "JSM-5610" manufactured by JEOL Ltd.), randomly selecting 100 fibers constituting the fiber web A, measuring the diameters of the cross-sections of the single fibers, and calculating the arithmetic mean value of the 100 measured values. Note that the outer surface is the surface that a person touches. In the case of a three-layer structure in which the fiber layer includes a scrim, and in the case of a two-layer structure composed of the fiber web A and the fiber web B, the deepest part of the fiber web A (that is, the part closest to the scrim side or the part closest to the fiber web B) is set as the observation region, and the fibers constituting the scrim and the fiber web B are excluded from the observation target, and the photographing is performed with a scanning electron microscope. When the observed shape of the cross-section of the single fiber is not circular, the outer peripheral distance on the straight line orthogonal to the midpoint of the longest diameter of the single fiber cross-section is defined as the fiber diameter. Figure 3 is a conceptual diagram for explaining how to obtain the fiber diameter. For example, when the cross-section A of the fiber is elliptical as shown in Figure 3, the outer peripheral distance c on the straight line b orthogonal to the midpoint p of the longest diameter a of the cross-section A in the observed image is defined as the fiber diameter (the subscript indicating that it is related to the nth fiber n is omitted.).

[0043] (2) Spatial size (μm) A three-dimensional image of the fiber layer is taken by X-ray CT, and the average value in the thickness direction of the diameter (μm) of the largest sphere that can enter the space excluding the fibers and PU resin blocks constituting the fiber layer is defined as the spatial size and obtained by the following procedure. (i) Rotate the image so that the xz-axis is in the plane and the y-axis is in the thickness direction on the screen, and trim the image into a rectangular parallelepiped. (ii) Apply a median filter under the condition of a radius of 2 pix. (iii) Apply the Otsu method to divide the region. Set the luminance value of the pixel so that the air is 0, the fibers of the nonwoven fabric, and the urethane resin are 255. (iv) For the pixels with a luminance value of 255 (fibers, PU resin), perform segmentation of the image processing method, and remove the structure with the number of pixels (pix) of the part with a continuous luminance value of 255 being 10000 or less as noise. (v) For the luminance value 0 (air), perform the thickness method of image analysis to obtain the spatial size. All pixels of the three-dimensional image have the value of the spatial size. (vi) Cut out the two-dimensional original image of the xz plane in the y-axis (thickness direction) with a thickness of 1 pix, and obtain the average and standard deviation of the spatial size on that plane. (vii) Perform the above (vi) for all y to obtain the profile in the thickness direction. In addition, when the sample has a scrim or contains the fiber web B, the deepest part of the fiber web A (that is, the part closest to the scrim side or the part closest to the fiber web B) is used as the observation region, and the fibers constituting the scrim and the fiber web B are excluded from the observation target, and imaging is performed with an X-ray CT device ("High-resolution 3D X-ray Microscope" manufactured by Rigaku Corporation). When the sample does not have a scrim, the central part of the thickness in the cross-section in the thickness direction is used as the center point of the observation region for imaging.

[0044] (3) Basis weight Each sample obtained by peeling off the fiber layer from the interior sound-absorbing material was cut into a 20 cm × 20 cm square to obtain a measurement sample. The weight of the measurement sample was measured with a scale, and the value obtained by multiplying the obtained numerical value by 25 was taken as the basis weight. The number of measurement samples was 3.

[0045] (4) Thickness The fiber layer was peeled off from the substrate layer of the interior sound-absorbing material and allowed to stand, and the thicknesses of the fiber layer and the substrate layer were measured with a vernier caliper, respectively. In addition, these thicknesses were corrected according to the thickness of the interior sound-absorbing material.

[0046] (5) Sound absorption characteristics The measurement was conducted in accordance with the vertical incidence sound absorption measurement method (in-tube method) of JIS A 1405 (1998). Three circular test pieces with a diameter of 30 mm were taken from the sample of the non-woven fabric for sound absorption material. As the test apparatus, an automatic vertical incidence sound absorption rate measuring instrument (model 10041A) manufactured by Electronic Measuring Instruments Co., Ltd. was used. The test piece (fiber layer) was attached to a base material layer with an arbitrary thickness, and it was attached to one end of the impedance tube for measurement with the test piece. Sound was incident from the fiber layer side. The sound absorption rate for each frequency was directly adopted as the numerical value of the measured sound absorption rate. (Data was acquired every 2 Hz. The maximum value of the sound absorption rate for each frequency is 1). Then, the total numerical value of the sound absorption rate from 1000 Hz to 2000 Hz obtained was adopted as the numerical value of the sound absorption characteristics. As the area ratio under the frequency-sound absorption rate curve illustrated in Fig. 4, the "integrated sound absorption rate from 1000 Hz to 2000 Hz when sound from 500 to 6400 Hz is incident from the sound source arranged on the fiber layer side of the interior sound absorption material" was obtained as a percentage.

[0047] (6) Surface quality (texture) For the sample, a total of 10 adults, 5 healthy adult males and 5 healthy adult females, were used as evaluators. The surface quality (texture) on the fiber layer side was judged according to the following 5-level evaluation criteria by visual inspection and sensory evaluation, and the most frequent evaluation was taken as the surface quality. When the number of evaluations was the same, the intermediate evaluation was taken as the evaluation score, and the surface quality was considered good (qualified) at level 4 or above. Level 5: Good touch (uniform fuzz), with a high-class feeling like genuine leather Level 4: Generally good touch and a high-class feeling Level 3: Neither good nor bad Level 2: Generally bad touch and no high-class feeling Level 1: Poor texture (uneven fuzz), no high-class feeling like genuine leather

[0048] (7) Abrasion resistance In accordance with JIS L 1096 (Method E, Martindale method), with a pressing load of 12 kPa (gf / cm 2) The abrasion test was carried out using a Martindale abrasion tester, and according to the number of times at the end point, the abrasion characteristics on the fiber layer side were judged based on the following five-level evaluation criteria. The abrasion resistance was considered good (qualified) when it was level 4 or above. When the fiber layer included a scrim, the end point refers to the number of abrasion times until the scrim becomes visible. When there is no scrim, it refers to the number of abrasion times until the back layer becomes visible. Level 5: 50,000 or more times at the end point Level 4: 40,000 or more times and less than 50,000 times at the end point Level 3: 30,000 or more times and less than 40,000 times at the end point Level 2: 10,000 or more times and less than 30,000 times at the end point Level 1: Less than 10,000 times at the end point

[0049] [Example 1] Polyethylene terephthalate fibers with an average single fiber diameter of 4.0 μm were produced by the melt spinning method and cut into lengths of 5 mm (hereinafter, the short fibers obtained by cutting polyethylene terephthalate fibers with an average single fiber diameter of 4.0 μm into lengths of 5 mm are also referred to as "PET ultra-fine short fibers"). The PET ultra-fine short fibers were dispersed in water and a fiber web A with a basis weight of 140 g / m was produced by the papermaking method. 2 In the same way, PET ultra-fine short fibers were dispersed in water and a fiber web B with a basis weight of 60 g / m was produced by the papermaking method. 2 The fiber web A, the fiber web B, and a scrim (plain weave) made of 166 dtex / 48f polyethylene terephthalate fibers with a basis weight of 95 g / m were laminated in the order of fiber web A / scrim / fiber web B to form a laminated sheet with a three-layer structure. 2 Next, a high-speed water flow using a straight-through flow injection nozzle was sprayed onto the laminated sheet from the outer surface side of the fiber web A at a pressure of 4 MPa and from the surface of the fiber web B at a pressure of 3 MPa. After the fiber layer was entangled with the scrim and crosslinked and integrated, it was dried at 100 °C using an air-through type pin tenter dryer to obtain a crosslinked sheet with a three-layer structure. Next, the outer surface of the complex sheet (the surface on the fiber web A side) was raised using 400-mesh sandpaper. Subsequently, an aqueous dispersion-type polyurethane resin impregnating solution containing 10% by mass of polyurethane resin solid content was impregnated into the complex sheet at a pickup rate of 100% (when the weight of the complex sheet after the raising treatment is set to 100, the total weight of the complex sheet and the polyurethane resin impregnating solution adhering to the complex sheet after dipping in the urethane impregnating solution and squeezing is 200). Then, it was dried by heating at 130 °C using a pin tenter dryer to obtain a sheet-like material filled with an aqueous dispersion-type polyurethane resin. The ratio of the aqueous dispersion-type polyurethane resin to the total fiber mass of this sheet-like material was 10% by mass. Next, the sheet-like material was dyed at 130 °C for 15 minutes using a flow dyeing machine with a blue disperse dye having a dye concentration of 5.0% owf ("Blue FBL" manufactured by Sumitomo Chemical Co., Ltd.), and subjected to reduction washing. Then, it was dried at 100 °C for 5 minutes using a pin tenter dryer to obtain a fiber layer having a three-layer structure. For the base material layer, a soft urethane foam "Molt Filter MF-30" (space size is approximately 100 μm to several 100 μm) manufactured by Inoac was used, cut to a thickness of 6 mm, and pasted to the fiber layer to produce a sound-absorbing material, and the sound-absorbing characteristics were measured.

[0050] [Example 2] A sound-absorbing material was obtained in the same manner as in Example 1, except that the basis weight of the fiber web A was changed to 160 g / m 2 .

[0051] [Example 3] A sound-absorbing material was obtained in the same procedure as in Example 1, except that the urethane foam thickness of the base material layer was changed to 10 mm.

[0052] [Example 4] A sound-absorbing material was obtained in the same procedure as in Example 2, except that the urethane foam thickness of the base material layer was changed to 10 mm.

[0053] [Example 5] Using polyethylene terephthalate fibers having an average single fiber diameter of 5.8 μm, the basis weight of the fiber web A was 120 g / m2 An acoustic material was obtained in the same manner as in Example 1, except that it was changed to

[0054] [Example 6] The basis weight of the fiber web A was changed to 100 g / m 2 , and the basis weight of the scrim was changed to 70 g / m 2 An acoustic material was obtained in the same manner as in Example 1, except for the change.

[0055] [Example 7] An acoustic material was obtained in the same procedure as in Example 1, except that the urethane foam thickness of the base material layer was changed to 3.8 mm.

[0056] [Example 8] An acoustic material was obtained in the same procedure as in Example 1, except that the urethane foam thickness of the base material layer was changed to 2.0 mm.

[0057] [Example 9] An acoustic material was obtained in the same manner as in Example 1, except that polyethylene terephthalate fibers with an average single fiber diameter of 9.0 μm were used.

[0058] [Example 10] An acoustic material was obtained in the same manner as in Example 1, except that polyethylene terephthalate fibers with an average single fiber diameter of 2.5 μm were used.

[0059] [Example 11] An acoustic material was obtained in the same manner as in Example 1, except that polyethylene terephthalate fibers with an average single fiber diameter of 1.5 μm were used.

[0060] [Example 12] Using the PET ultra-fine short fibers of Example 1 as the main fibers, a heat-fusing resin was used as the resin binder. As the heat-fusing resin, all-melt type heat-fusible short fibers (Castben 8000 manufactured by Unitika Ltd.) composed of polyethylene terephthalate copolymer with a melting point of 180 °C, having an average single fiber diameter of 10.1 μm and a length of 5 mm were used. These short fibers were dispersed in water so that the weight ratio of main fibers: heat-fusible short fibers was 90:10 to prepare a slurry. From this slurry, a sheet with a basis weight of 140 g / m was made by the papermaking method 2A fiber web A for the surface was produced. Similarly, using the PET ultra-fine short fibers of Example 1 as the main fibers, a heat-fusing resin was used as the resin binder. As the heat-fusing resin, all-melt type heat-fusible short fibers (Castben 8000 manufactured by Unitika Ltd.) made of a polyethylene terephthalate copolymer with a melting point of 180°C, having an average diameter of 10.1 μm and a length of 5 mm for single fibers were used. These short fibers were dispersed in water so that the weight ratio of main fibers: heat-fusible short fibers was 90:10 to prepare a slurry. From this slurry, a fiber web B with a basis weight of 60 g / m 2 was produced by a papermaking method. A fiber web A, a fiber web B, and a scrim (plain weave) with a basis weight of 95 g / m 2 made of 166 dtex / 48f polyethylene terephthalate fibers were laminated in the order of fiber web A / scrim / fiber web B to form a laminated sheet having a three-layer structure. Next, a high-speed water flow using a straight-through flow injection nozzle was sprayed onto the laminated sheet from the outer surface side of the fiber web A at a pressure of 4 MPa and from the surface of the fiber web B at a pressure of 3 MPa. After entangling and integrating the fiber webs with the scrim, it was dried at 100°C using an air-through type pin tenter dryer to obtain an entangled sheet having a three-layer structure. Next, the outer surface (the surface on the fiber web A side) of the entangled sheet was raised using 400-mesh sandpaper, and then heat treatment was performed at 190°C using a pin tenter dryer to perform a heat-fusing treatment on the heat-fusible short fibers to obtain a fiber layer having a three-layer structure. After the dyeing process, the sound-absorbing material was obtained in the same procedure as in Example 1.

[0061] [Example 13] In the urethane impregnation step, a sound-absorbing material was produced in the same manner as in Example 1 except that the pickup rate of the polyurethane resin was set to 60% of that in Example 1, and the sound-absorbing characteristics were measured.

[0062] [Example 14] In the urethane impregnation step, a sound-absorbing material was produced in the same manner as in Example 1 except that the pickup rate of the polyurethane resin was set to 2.2 times that in Example 1, and the sound-absorbing characteristics were measured.

[0063] [Example 15] The PET ultra-fine short fibers described in Example 1 were dispersed in water, and a fiber web A with a basis weight of 290 g / m 2 was produced by a papermaking method. A high-speed water stream using a straight-through injection nozzle was injected from the outer surface side of the fiber web A at a pressure of 4 MPa and from the opposite side at a pressure of 3 MPa, and dried at 100 °C using an air-through pin tenter dryer to obtain a single-layer sheet-like material. Next, the sheet-like material was raised using 400-mesh sandpaper. Also, in the urethane impregnation step, the pickup rate of the polyurethane resin was made 2.2 times that of Example 1. In the subsequent steps, a sound-absorbing material was produced in the same manner as in Example 1, and the sound-absorbing characteristics were measured.

[0064] [Comparative Example 1] As the sea component, polyethylene terephthalate copolymerized with 8 mol% of sodium 5-sulfoisophthalate was used, and as the island component, polyethylene terephthalate was used. With a composite ratio of 20% by mass of the sea component and 80% by mass of the island component, a sea-island composite fiber with 16 islands / 1f and an average fiber diameter of 18 μm was obtained. The obtained sea-island composite fiber was cut into a fiber length of 51 mm to be used as a staple, and a fiber web A was formed through a card and a cross lapper, and a sheet-like material was obtained by needle punching treatment. The obtained sheet-like material was immersed in 95 °C hot water for shrinkage and dried at 100 °C for 5 minutes using a pin tenter dryer to obtain a single-layer fiber web with a basis weight of 580 g / m 2 . The obtained web was immersed in a 10 g / L sodium hydroxide aqueous solution heated to a temperature of 95 °C and treated for 25 minutes to perform a sea-removing treatment to remove the sea component of the sea-island composite fiber, and a sheet-like material in which 16 single fibers of the island component were exposed as a fiber bundle was obtained. The average diameter of the single fibers of the fibers constituting the sheet-like material after sea removal was 4 μm. Next, an aqueous dispersion type polyurethane resin impregnating solution containing 10% of polyurethane resin solid content was impregnated into the sheet-like material at a pickup rate of 300%, and hot air drying was performed at 130°C for 5 minutes using a hot air dryer to obtain a sheet-like material filled with the aqueous dispersion type polyurethane resin. The ratio of the aqueous dispersion type polyurethane resin to the total fiber mass of this sheet-like material was 30% by mass. Thereafter, using a half-cutting machine having an endless band knife, the sheet-like material was half-cut perpendicularly to the thickness direction, and after the non-half-cut surface was raised using 400-mesh sandpaper, it was dyed at 130°C for 15 minutes using a liquid flow dyeing machine with a blue disperse dye having a dye concentration of 5.0% owf (「BlueFBL」manufactured by Sumitomo Chemical Co., Ltd.), and reduction washing was performed. Thereafter, drying was performed at 100°C for 5 minutes using a hot air dryer to obtain a single-layer fiber layer. Other procedures were the same as in Example 1 to produce a sound-absorbing material and measure its sound-absorbing characteristics.

[0065] [Comparative Example 2] A sound-absorbing material was obtained in the same manner as in Example 1 except that polyethylene terephthalate fibers having an average single fiber diameter of 13 μm were used.

[0066] [Comparative Example 3] The basis weight of fiber web A was changed to 80 g / m 2 , the basis weight of fiber web B was changed to 30 g / m 2 , and the scrim basis weight was changed to 50 g / m 2 , and a sound-absorbing material was obtained in the same manner as in Example 1.

[0067] [Comparative Example 4] A sound-absorbing material was obtained in the same procedure as in Example 1 except that the urethane foam thickness of the base material layer was changed to 1 mm.

[0068] [Comparative Example 5] A complex sheet having a three-layer structure was obtained in the same manner as in Example 1. Using this complex sheet as a fiber layer, it was laminated with the base material layer of Example 1 to obtain a sound-absorbing material. In Comparative Example 5, the raising treatment, the polyurethane impregnation step, and the dyeing step were not performed.

[0069] [Reference Example 1] During the measurement of the sound absorption characteristics, it was the same as in Example 1 except that the sound incidence was on the base material layer side.

[0070] [Comparative Example 2] An acoustic material was obtained in the same procedure as in Example 1 except that the urethane foam thickness of the base material layer was changed to 10 mm. Further, during the measurement of the sound absorption characteristics, the sound incidence was on the base material layer side.

[0071] [Table 1] [Industrial Applicability]

[0072] When the acoustic material according to the present invention is used as, for example, an interior material for automobiles, it is excellent in the sound absorption characteristics in the frequency range of 1000 to 2000 Hz, which is the reverberation sound of road noise invading from outside the vehicle or the conversation sound inside the vehicle cabin. Also, the surface quality (texture) of the surface that the passengers touch is high, and the wear resistance is also high. Therefore, not only the quietness in which the reverberation of the sound in the vehicle cabin is suppressed and it becomes easier to have a conversation, but also a comfortable vehicle cabin space excellent visually and in texture can be provided. For example, it can be suitably used as an interior material for automobiles. [Explanation of Signs]

[0073] (Signs in Figure 3) A n Fiber cross-section ( n Regarding the fibers of this mesh) a n Longest diameter p n Longest diameter a n Midpoint of b n Midpoint p n The straight line perpendicular to the longest diameter a at n Straight line c Straight line b n Outer peripheral distance c on = fiber diameter (Signs in Figure 5) 1 Fiber layer of interior acoustic material 11 Scrim 12 Fiber web A 13 Fiber web B

Claims

1. An interior sound-absorbing material in which a fiber layer and a base material layer are laminated and integrated, The fiber layer is a sheet-like material including a fiber web A composed of at least one type of subject fiber and a resin binder, The fiber layer has a basis weight of 200 g / m ２ More than 400g / m ２ is as follows: The thickness of the fiber layer is 0.65 mm or more and 1.35 mm or less, The average fiber diameter of the main fiber is 1 μm or more and 10 μm or less, In a three-dimensional image of the fiber web A by X-ray CT, an average spatial size, which is an average value in the thickness direction of the fiber layer of a spatial size that is a diameter of a maximum sphere that can fit in a space excluding the fibers constituting the fiber layer and the resin binder, is 5 μm or more and 35 μm or less, The base material layer has an average space size that is at least twice the average space size of the fiber web A, and the thickness of the base material layer is 2 mm or more and 20 mm or less. An interior sound absorbing material characterized by:

2. 2. The interior sound-absorbing material according to claim 1, wherein the main fiber is a polyester fiber.

3. 3. The interior sound-absorbing material according to claim 1 or 2, wherein the fiber layer further comprises a scrim layer made of a woven or knitted fabric and / or a fiber web B composed of at least one type of subject fiber and a resin binder.

4. 3. The interior sound-absorbing material according to claim 1, wherein the resin binder is a polyurethane resin or a heat-sealable resin.

5. 5. The interior sound-absorbing material according to claim 4, wherein the heat-fusible resin is a polyester resin having a melting point that is at least 20° C. lower than the melting point of the main fiber.

6. The interior sound-absorbing material according to claim 1 or 2, wherein the base layer is a foam, a porous body, or a hollow structure.

7. 3. The interior sound-absorbing material according to claim 1, wherein when a sound having a frequency of 500 to 6400 Hz is incident from a sound source arranged on the fiber layer side of the interior sound-absorbing material, the integrated sound absorption coefficient at a frequency of 1000 to 2000 Hz is 20% or more.

8. 3. The interior sound-absorbing material according to claim 1, wherein the adhesion rate of the resin binder in the fiber layer is from 5% by mass to 25% by mass.

9. 3. An interior material comprising the interior sound-absorbing material according to claim 1 or 2, disposed on a support material with the fiber layer side facing the interior of a room space.

10. The interior material according to claim 9, which is for an automobile.

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