Molded body, sound-absorbing material, and vibration-absorbing material

Abstract

The molded body has a plurality of hollow portions formed in the interior of a molded material, and a plurality of neck portions each provided in the plurality of hollow portions and communicating with the hollow portions, a part of the plurality of neck portions communicating with the surface and / or communicating with the hollow portions exposed at the surface, at least a part of the plurality of neck portions intercommunicating the plurality of hollow portions, and an inner surface of the neck portion being formed of the molded material itself.

Description

TECHNICAL FIELD

[0001] The present application relates to a shaped body, a sound absorbing material, and a vibration absorbing material. BACKGROUND

[0002] Conventionally, various shaped bodies have been known as shaped bodies. Patent Document 1 describes a sound absorbing material having a matrix resin forming a base material and a fibrous substance dispersed in the inside of the matrix resin. The matrix resin is composed of a continuous bubble foam including a thermoplastic resin.

[0003] The matrix resin has a plurality of bubbles in the inside, and the fibrous substance has a hollow portion that communicates the plurality of bubbles with each other. A sound absorbing mechanism similar to a Helmholtz resonance is constituted by the hollow portion, and the sound absorbing mechanism is used for sound absorption of low frequency sound. The fibrous substance is in a curved tube shape, and extends from one bubble to another bubble adjacent to the one bubble. One end and the other end of the fibrous substance protrude from a bubble wall surface that divides the bubbles, respectively.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-96637 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] The shaped body including the sound absorbing material is used for a transport machine such as an automobile, or a building such as a house. However, in the shaped body, it is required to further reduce noise, and the demand for noise reduction is increasing. For example, in the field of automobiles, more stringent noise limits than ever have been established in recent years, and it is required to further improve the sound absorbing performance required in the noise limits. In addition, if the shaped body is thickened, the sound absorbing performance and the vibration absorbing performance can be improved. However, in the case where the shaped body is thick, there is a concern that sufficient space cannot be ensured in the transport machine or the building. Thus, a shaped body capable of suppressing the size from being large while improving the sound absorbing performance and the vibration absorbing performance is desired.

[0009] An object of the present application is to provide a shaped body, a sound absorbing material, and a vibration absorbing material capable of improving the sound absorbing performance and the vibration absorbing performance, and suppressing the size from being large.

[0010] SOLUTION TO PROBLEM

[0011] The shaped body of the present application has: a plurality of hollow portions formed in the interior of a shaped material; and a plurality of neck portions each provided in the plurality of hollow portions and communicating with the hollow portions, a part of the plurality of neck portions communicating with a surface and / or a hollow portion exposed at the surface, at least a part of the plurality of neck portions interconnecting the plurality of hollow portions, an inner surface of the neck portion being formed of the shaped material itself.

[0012] Effects of the Invention

[0013] According to the present disclosure, it is possible to provide a shaped body, a sound absorbing material, and a vibration absorbing material that can improve sound absorbing performance and vibration absorbing performance and can suppress an increase in size. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a perspective view showing an exemplary shaped body of an embodiment.

[0015] Figure 2 is a view showing a hollow portion and a neck portion exposed at a surface of the shaped body of Figure 1 .

[0016] Figure 3 is a cross-sectional view of a shaped body schematically showing an internal configuration of the shaped body of Figure 1 .

[0017] Figure 4 is a cross-sectional view of a shaped body schematically showing an internal configuration of an exemplary shaped body of a modification.

[0018] Figure 5 is a perspective view schematically showing an appearance of a hollow portion and a neck portion of the shaped body of Figure 2 .

[0019] Figure 6 is an exemplary graph showing a relationship between a frequency of a sound wave and a normal incidence sound absorption rate for the shaped body, in terms of a material of a polyurethane foam of the shaped body.

[0020] Figure 7 is an exemplary graph showing a relationship between a frequency of a sound wave and a normal incidence sound absorption rate for the shaped body, in terms of a diameter of a neck portion.

[0021] Figure 8 is an exemplary graph showing a relationship between a diameter of a neck portion and a peak frequency of a sound wave.

[0022] Figure 9 is an exemplary graph showing a relationship between a frequency of a sound wave and a normal incidence sound absorption rate for the shaped body, in terms of a diameter of a hollow portion.

[0023] Figure 10is an exemplary graph showing the relationship between the frequency of the sound wave and the normal incidence sound absorption rate of the molded body for the molded body of the resin material.

[0024] Figure 11 (a) and Figure 11 (a) and (b) of FIG. 1 are perspective views showing the outer shape of an exemplary molded body.

[0025] Figure 12 is a cross-sectional view of a molded body schematically showing one example of the internal structure of the molded body of the modification.

[0026] Figure 13 (a) of FIG. 2 is an enlarged view showing one example of the rib between a pair of large pores, Figure 13 (b) of FIG. 2 is Figure 13 is an enlarged view of the portion indicated by "A" of (a) of FIG. 2.

[0027] Figure 14 (a) of FIG. 3 is a photograph of the observation result of the molded body of the comparative example, Figure 14 (b) of FIG. 3, Figure 14 (c) of FIG. 3 is a photograph of the observation result of the molded body of the embodiment.

[0028] Figure 15 (a) of FIG. 4, Figure 15 (b) of FIG. 4 is a schematic view showing the case where the needle-like member is inserted into the foamed body to form the neck portion.

[0029] Figure 16 is a cross-sectional view of a molded body schematically showing one example of the internal structure of the molded body of the modification.

[0030] Figure 17 (a) of FIG. 5, Figure 17 (b) of FIG. 5 is an enlarged cross-sectional view of a molded body schematically showing one example of the internal structure of the molded body.

[0031] Figure 18 is an enlarged cross-sectional view of a molded body schematically showing one example of the internal structure of the molded body of the comparative example.

[0032] Figure 19 (a) of FIG. 6 is a schematic view for explaining the protruding portion of the neck portion of the molded body of the embodiment and the modification, Figure 19 (b) of FIG. 6 is a schematic view for explaining the protruding portion of the neck portion of the molded body of the comparative example.

[0033] Figure 20 is a schematic view for explaining the setting range of the parameters. DETAILED DESCRIPTION

[0034] In the shaped body, a plurality of hollow portions are formed inside, and neck portions are formed in the plurality of hollow portions, respectively. Some of the plurality of neck portions communicate with the surface and / or communicate with the hollow portions exposed to the surface. At least some of the plurality of neck portions communicate the plurality of hollow portions with each other. Thus, if vibration energy including a sound wave is incident to the neck portions, intense vibration is generated, and the hollow portions located on the opposite side of the surface function as springs, whereby the vibration energy is viscously attenuated. Thus, by the neck portions and the hollow portions extending on the side opposite to the surface of the neck portions, higher sound absorbing performance and vibration absorbing performance can be exhibited. In the shaped body, the inner surface of the neck portions is formed of the shaped material itself. In this case, compared to a case where the neck portions are formed of other members dedicated thereto, or the like, the incidence of the vibration energy with respect to the hollow portions and the neck portions can be smoother. Thus, even if the size of the shaped body is not made large, the sound absorbing performance and the vibration absorbing performance can be improved. As a result, the size of the shaped body can be suppressed from being made large.

[0035] The hollow portions and the neck portions communicating with the hollow portions can also be integrally formed of the same shaped material. In this case, since the shaped body can be made of a single material, the production of the shaped body can be easily performed.

[0036] The shaped body can be a foamed body, and the hollow portions can be formed of cells in the interior of the foamed body, the cells being larger than the average diameter of the cells as a whole by 100% or more. In this case, the hollow portions having a sufficient size can be formed of the larger cells.

[0037] At least some of the neck portions can be formed of cells in the interior of the foamed body. In this case, even if a dedicated member or the like for providing the neck portions is not used, the neck portions can be easily formed.

[0038] At least some of the neck portions can have a shape in which a center line extends in a straight line. In this case, the vibration energy can be smoothly incident to the neck portions.

[0039] The plurality of hollow portions and the plurality of neck portions can constitute a wavelength absorbing unit, and the wavelength absorbing rate of the wavelength absorbing unit for a wavelength of 450 Hz or more and 10,000 Hz or less can be 0.4 or more. In this case, the sound wave energy and the vibration energy in a frequency band of 450 Hz or more and 10,000 Hz or less can be absorbed with higher efficiency.

[0040] The normal incidence sound absorbing rate per 10 mm thickness for a wavelength of 450 Hz or more and 10,000 Hz or less can be 0.4 or more. In this case, the sound wave energy and the vibration energy in a frequency band of 450 Hz or more and 10,000 Hz or less can be absorbed with higher efficiency.

[0041] The diameter of the neck portions can also be 10 μm or more and 1,000 μm or less. In this case, the sound wave energy and the vibration energy in a target frequency band can be more efficiently absorbed.

[0042] The volume of the hollow portion can also be 4.19 x 10 9 μm 3 The above and 3.82 x 10 11 μm 3 The following. In this case, the sound wave energy and vibration energy of the target frequency band can be more efficiently absorbed.

[0043] may be, in the case where the protruding portion is formed by causing the neck portion to protrude from the inner surface of the hollow portion, the protruding height of the protruding portion with respect to the inner surface of the hollow portion can be 100 μm or less. In this case, the incidence of vibration energy with respect to the hollow portion and the neck portion can be made smoother.

[0044] The shaped body described has: a main surface; a back surface provided opposite the main surface; and one or more side surfaces provided between the main surface and the back surface, a portion of the plurality of neck portions can be exposed at the main surface, or exposed at the hollow portion exposed at the main surface.

[0045] The sound absorbing material of the present application can also be the shaped body described. In this case, a sound absorbing material that has the same effect as the shaped body described can be provided.

[0046] The vibration absorbing member of the present disclosure can also be the shaped body described. In this case, a vibration absorbing material that has the same effect as the shaped body described can be provided.

[0047] The shaped body of the present application has: a plurality of hollow portions formed inside the shaped body; and a plurality of neck portions each provided in the plurality of hollow portions and communicating with the hollow portions, a portion of the plurality of neck portions communicating with the surface and / or with the hollow portion exposed at the surface, at least a portion of the plurality of neck portions communicating the plurality of hollow portions with each other, the neck portion extending from the inner surface of the divided hollow portion to the surface or the inner surface of the other hollow portion adjacent to the hollow portion.

[0048] In the shaped body, a plurality of hollow portions are formed inside, and neck portions are formed in the plurality of hollow portions, respectively. Some of the plurality of neck portions communicate with the surface and / or communicate with the hollow portions exposed on the surface. At least some of the plurality of neck portions communicate the plurality of hollow portions with each other. Thus, if vibration energy including a sound wave is incident to the neck portions, intense vibration is generated, and the hollow portions located on the opposite side of the surface function as springs, whereby the vibration energy is viscously attenuated. Thus, by the neck portions and the hollow portions extending on the opposite side of the surface from the neck portions, higher sound absorbing performance and vibration absorbing performance can be exhibited. In the shaped body, the neck portions extend from the inner surface dividing the hollow portions to the inner surface of the other hollow portions adjacent to the hollow portions. Thus, the neck portions can be formed not to protrude from the inner surface dividing the hollow portions, and thus, the incidence of the vibration energy with respect to the hollow portions and the neck portions can be made smoother. Thus, even without making the size large, the sound absorbing performance and the vibration absorbing performance can be improved. As a result, the size of the shaped body can be suppressed from being large.

[0049] The material of the hollow portions and the material of the neck portions can be the same as each other. In this case, since the shaped body can be made of a single material, the production of the shaped body can be easily performed.

[0050] In the shaped body, the ratio of the number of the neck portions to the number of the hollow portions can be 1.1 or more. In this case, by increasing the ratio of the number of the neck portions, the frictional action between the vibration including the sound wave and the neck portions can be enhanced, and thus, the sound wave energy and the vibration energy can be more efficiently absorbed.

[0051] The shaped body can also include a polyurethane foam at least in part. In this case, the shaped body having higher softness can be provided.

[0052] The shaped body can also include at least either one of a thermoplastic resin and a photocurable resin. In this case, the shaped body can be produced by a 3D printer or the like, and thus, the production of the shaped body can be more easily performed.

[0053] The air permeability can also be 0.4 cm 3 / (cm 2 ·s) or more and 200 cm 3 / (cm 2 ·s) or less. In this case, the sound absorbing performance and the vibration absorbing performance can be improved, and the desired air permeability can be ensured.

[0054] The thickness can also be 5 mm or more. In this case, the sound absorbing performance and the vibration absorbing performance can be further reliably improved.

[0055] According to the present disclosure, a shaped body, a sound absorbing material, and a vibration absorbing material capable of improving the sound absorbing performance and the vibration absorbing performance and suppressing the size from being large can be provided.

[0056] (Description of Embodiments)

[0057] Hereinafter, embodiments of the shaped body, sound-absorbing material, and vibration-absorbing material of the present application will be described with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and repetitive description will be appropriately omitted. In addition, the drawings are sometimes simplified or exaggerated in part for the sake of easy understanding, and the dimensional ratio and the like are not limited to the dimensional ratio described in the drawings.

[0058] First, the "shaped body" in the present disclosure indicates a shaped product shaped into a certain shape. The shaped body of the present application has a plurality of hollow portions and a plurality of neck portions. In the present disclosure, the "hollow portion" indicates a portion of the inside of the shaped body that forms a space.

[0059] The "neck portion" indicates a portion provided to each of the plurality of hollow portions and communicating with the hollow portion. The "neck portion" can communicate with the surface of the shaped body and / or with the hollow portion exposed at the surface. The shaped body can have a plurality of "neck portions", and at least a part of the plurality of neck portions can communicate the plurality of hollow portions with each other. For example, the volume of the gap of the "neck portion" is smaller than the volume of the hollow portion, and the "neck portion" can be a gap that links the plurality of hollow portions with each other.

[0060] In the present disclosure, a "wavelength absorption unit" can be formed by the hollow portion and the neck portion. The "wavelength absorption unit" indicates a portion that can selectively absorb sound or vibration of a specific wavelength, for example, constitutes a resonator-type sound-absorbing material. The "resonator-type sound-absorbing material" indicates a shaped body that absorbs sound of a target frequency (hereinafter, sometimes referred to as "target frequency") using a hole (for example, a neck portion) exposed at the surface of the shaped body and an expansion portion (for example, a hollow portion) that is further expanded than the hole at the portion opposite to the surface of the hole. When the sound wave energy of the target frequency is incident to the hole, the sound wave energy vibrates violently in the hole, and the air of the expansion portion located deep in the hole functions as a spring to viscously attenuate the sound wave energy, thereby being sound-absorbed. The "wavelength absorption unit" can be, for example, a Helmholtz resonator.

[0061] The relationship between the target frequency (resonance frequency) f0 (Hz), the diameter d (m) of the hole (for example, a neck portion), and the volume V (m 3 ) of the expansion portion (for example, a hollow portion) is represented by the following formula (1). In addition, S represents the cross-sectional area (m 2 ) of the opening exposed at the surface of the shaped body, and l represents the thickness (m) of the material, and C represents the sound velocity (m / s).

[0062]

[0063] For example, by using the above formula (1), it is possible to effectively absorb acoustic wave energy and vibration energy of a target frequency.

[0064] Figure 1 is a perspective view showing an example of a molded body 1. As one example, the molded body 1 is a sound absorbing material that absorbs acoustic wave energy. For example, the molded body 1 can also be a sound absorbing material that is provided for suppressing noise in a car interior or suppressing noise outside a car. In addition, the molded body 1 can also be a sound absorbing material that is provided for sound insulation of a building including a house. In this way, the molded body 1 as a sound absorbing material can be used for various purposes. In addition, the molded body 1 can also be a vibration absorbing material that absorbs vibration energy.

[0065] As shown in Figure 1 , the molded body 1 is in a cylindrical shape. However, the shape of the molded body 1 is not limited to a cylindrical shape, but can be appropriately changed. The molded body 1 is, for example, composed of a polyurethane foam having continuous cellularity. As one example, the molded body 1 can also be produced by polyurethane molding.

[0066] In addition, the molded body 1 can also be composed of a thermoplastic resin or a photocurable resin. In this case, the molded body 1 can be produced, for example, using a 3D printer or the like. For example, the molded body 1 can also be composed of polyvinyl chloride or metal. In addition, the molded body 1 can be produced by at least any one of irradiating laser light, inserting a needle-like member, blowing in a gas, and mixing a volatile component. In this way, the material and the production method of the molded body 1 are not particularly limited. In addition, a larger molded body can be produced, and the produced molded body can be cut to obtain a molded body having a desired size and shape.

[0067] The molded body 1 has a plurality of hollow portions 2 and a plurality of neck portions 3. The plurality of hollow portions 2 are, for example, dispersedly arranged in the inside of the molded body 1. "The plurality of hollow portions are dispersedly arranged" includes, for example, a state in which the plurality of hollow portions 2 are arranged in a staggered manner, a state in which the plurality of hollow portions 2 are arranged in a lattice shape, and a state in which the plurality of hollow portions 2 are arranged in a concentric circle shape, as shown in a cross-sectional view of the molded body 1. Figure 1 In addition, the hollow portion 2 can be exposed on all the faces of the molded body 1, can be exposed on a part of the faces of the molded body 1, or can not be exposed on any face. A part of the plurality of neck portions 3 can be communicated (exposed) with respect to the surface 1b of the molded body 1 and / or communicated (exposed) with respect to the hollow portion 2 exposed on the surface 1b. The hollow portion 2 can be regularly arranged or irregularly arranged in the inside of the molded body 1.

[0068] The neck portion 3 has an opening 3b, for example, on the inner surface 2b of the hollow portion 2. The opening 3b is, for example, circular in shape. However, the shape of the opening 3b is not limited to a circular shape, and can be an oblong shape or the like, and is not particularly limited. The openings 3b of the neck portions 3 can be regularly arranged on the inner surface 2b, or can be irregularly arranged.

[0069] In the present disclosure, the "inner surface" of the hollow portion means a surface that divides the inside of the hollow portion. The "opening" means an aperture that is exposed to the outside from a surface of an object. The inner surface 2b exposed by the surface 1b is, for example, semispherical in shape. However, the shape of the inner surface 2b is not limited to a semispherical shape, and is not particularly limited. For example, the sizes (areas) of the plurality of inner surfaces 2b exposed by the surface 1b are different from each other. That is, the sizes of the inner surfaces 2b exposed by the surface 1b are different from each other.

[0070] Figure 2 is a view that shows the inner surface 2b of the hollow portion 2 of the shaped body 1 and the opening 3b of the neck portion 3. As shown in Figure 2 , the hollow portions 2 can also be regularly arranged on the surface 1b, for example, in a staggered manner. In Figure 2 , three openings 3b are formed in one inner surface 2b.

[0071] In the plurality of neck portions 3, the diameters of the openings 3b can be the same as each other, for example. However, the diameters of the openings 3b can also be different from each other. In the case where the diameters of the openings 3b are different from each other, for example, if the diameter of the first opening 3b is assumed to be D (mm), the diameter of the second opening 3b can be D / 2 (mm), and the diameter of the third opening 3b can be D / 4 (mm). As one example, the value of D is 0.4, but is not particularly limited.

[0072] Figure 3 is a cross-sectional view that schematically shows the internal structure of the shaped body 1. As shown in Figure 3 , a plurality of hollow portions 2 and a plurality of neck portions 3 that communicate the plurality of hollow portions 2 with each other are formed in the inside 1f of the shaped body 1. The neck portion 3 extends from the inner surface 2b that divides the hollow portion 2 to the inner surface 2b of another hollow portion 2 adjacent to the hollow portion 2 (may also be the inner surface 2b of the hollow portion 2 exposed by the surface 1b), or the surface 1b (for example, in the case where the hollow portion 2 is formed in the surface 1b, is a region other than the region where the hollow portion 2 is formed). For example, the neck portion 3 extends from the inner surface 2b that divides the hollow portion 2 to the inner surface 2b of another hollow portion 2 adjacent to the hollow portion 2 or the surface 1b. In other words, the neck portion 3 does not extend to the inside of the hollow portion 2. However, in the inner surface 2b of the hollow portion 2, a slight step, a projection, or a bump or the like that does not significantly hinder the sound absorption performance and the vibration absorption performance can also be formed from the neck portion 3 toward the inside of the hollow portion 2. Furthermore, detailed description regarding this structure will be described later by comparing with the comparative example.

[0073] As one example, the shaped body 1 can be a porous sound absorbing material. In this case, in the shaped body 1, sound waves incident to the neck portion 3 are converted into heat energy to achieve sound absorption. At this time, the sound wave energy is attenuated by friction within the gap (neck portion 3) and is absorbed by the skeleton vibration of the shaped body 1 itself.

[0074] The plurality of hollow portions 2 and the plurality of neck portions 3 can also constitute a wavelength absorption unit 10 of the shaped body 1. The wavelength absorption unit 10 constitutes, for example, a resonator type sound absorbing material. In the wavelength absorption unit 10, the neck portion 3 exposed at the surface 1b of the shaped body 1 (the inner surface 2b of the hollow portion 2) and the hollow portion 2 further expanded than the neck portion 3 at a portion on the side opposite to the opening 3b of the neck portion 3 are used to absorb sound waves or vibrations of a target frequency.

[0075] For example, the material of the hollow portion 2 and the material of the neck portion 3 are the same as each other. As a specific example, the material of the hollow portion 2 and the material of the neck portion 3 can also include a thermoplastic resin or a photocurable resin. In this case, the production of the hollow portion 2 and the neck portion 3 can be easily performed using a 3D printer or the like.

[0076] However, the material of the hollow portion 2 and the material of the neck portion 3 can also be different from each other.

[0077] In the example of Fig. 1, the inner surface 2b of the hollow portion 2 is exposed at the surface 1b of the shaped body 1, but the opening 3b of the neck portion 3 can also be exposed at the surface 1b of the shaped body 1. For example, the hollow portion 2 and the neck portion 3 are each three-dimensionally formed. "Three-dimensionally formed" indicates, for example, a state of being arranged along a first direction of the shaped body, a second direction intersecting (as one example, orthogonal to) the first direction, and a third direction intersecting (as one example, orthogonal to) both the first direction and the second direction. In the present embodiment, for example, the hollow portion 2 and the neck portion 3 are arranged in a manner of being arranged along the first direction, the second direction, and the third direction, respectively. Figure 3 In the example of Fig. 1, the inner surface 2b of the hollow portion 2 is exposed at the surface 1b of the shaped body 1, but the opening 3b of the neck portion 3 can also be exposed at the surface 1b of the shaped body 1. For example, the hollow portion 2 and the neck portion 3 are each three-dimensionally formed. "Three-dimensionally formed" indicates, for example, a state of being arranged along a first direction of the shaped body, a second direction intersecting (as one example, orthogonal to) the first direction, and a third direction intersecting (as one example, orthogonal to) both the first direction and the second direction. In the present embodiment, for example, the hollow portion 2 and the neck portion 3 are arranged in a manner of being arranged along the first direction, the second direction, and the third direction, respectively.

[0078] Figure 3 In the example of Fig. 1, the inner surface 2b of the hollow portion 2 is exposed at the surface 1b of the shaped body 1, but the opening 3b of the neck portion 3 can also be exposed at the surface 1b of the shaped body 1. For example, the hollow portion 2 and the neck portion 3 are each three-dimensionally formed. "Three-dimensionally formed" indicates, for example, a state of being arranged along a first direction of the shaped body, a second direction intersecting (as one example, orthogonal to) the first direction, and a third direction intersecting (as one example, orthogonal to) both the first direction and the second direction. In the present embodiment, for example, the hollow portion 2 and the neck portion 3 are arranged in a manner of being arranged along the first direction, the second direction, and the third direction, respectively. Figure 5 is a perspective view schematically showing the appearance of the hollow portion 2 and the appearance of the neck portion 3. As shown in Figs. 1 and 2, for example, in the inside 1f of the shaped body 1, the hollow portion 2 is provided in a spherical shape, and the neck portion 3 is provided in a cylindrical hole shape. Figure 3 Figure 5 As one example, in the inside 1f of the shaped body 1, the hollow portion 2 is provided in a spherical shape, and the neck portion 3 is provided in a cylindrical hole shape.

[0079] The hollow portion 2 can also be a shape other than a spherical shape, and can be a cuboid shape, a cubic shape, a polyhedral shape, an oval shape, an ellipsoidal shape, an oblong shape, or a dome shape, or the like.​​

[0080] The neck portion 3 can also have a shape other than a cylindrical hole shape. The neck portion 3 can be any shape as long as it has a gap having a volume smaller than that of the hollow portion 2 and has two or more openings communicating with the gap. Thus, the neck portion 3 can have a hollow cylindrical shape (cylindrical hole shape), a hollow prism shape such as a hollow triangular prism, a hollow quadrangular prism, a hollow pentagonal prism, and the like, a hollow truncated cone shape, a hollow truncated pyramid shape such as a hollow triangular truncated pyramid, a hollow quadrangular truncated pyramid, a hollow pentagonal truncated pyramid, and the like, a spherical shape, an irregular hollow shape, or the like.

[0081] The neck portion 3 can have a meandering portion, a bent portion, a curved portion, or a bent portion, or can not have such a portion. The neck portion 3 can have a branch, or can not have a branch.

[0082] The opening 3b of the neck portion 3 is exposed, for example, at the inner surface 2b dividing the hollow portion 2. The neck portion 3 extends from the inner surface 2b dividing one hollow portion 2 to the inner surface 2b of another hollow portion 2 adjacent to the one hollow portion 2. The sizes of the plurality of neck portions 3 extending from the inner surface 2b can be the same as each other, or can be different from each other. Further, as shown in Figure 4 , the opening 3b of the neck portion 3 can not be exposed at the hollow portion 2, but can be exposed at the surface lb of the shaped body 1. In this case, any of the plurality of neck portions 3 communicates with the surface lb of the shaped body 1. In addition, in Figure 5 , an example in which the sizes (e.g., diameters) of the plurality of neck portions 3 are the same as each other is shown. However, the plurality of neck portions 3 can include a large-sized neck portion 3, a medium-sized neck portion 3, and a small-sized neck portion 3. In this way, the sizes of the neck portions 3 and the number of types of the sizes of the neck portions 3 can be appropriately changed.

[0083] As one example, the neck portion 3 does not have a portion protruding from the inner surface 2b. In addition, the hollow portion 2 can be formed in a hexagonal close-packed structure. In this case, as many hollow portions 2 as possible can be arranged inside the shaped body 1, and thus the sound absorbing performance and the vibration absorbing performance of the shaped body 1 can be further improved.

[0084] In addition, the plurality of neck portions 3 can extend radially from the spherical hollow portion 2. For example, the angle θ formed by one neck portion 3 extending from the hollow portion 2 and a neck portion 3 adjacent to the one neck portion 3 is 120°. However, the value of the angle θ is not particularly limited.

[0085] Next, with reference to Figure 12 , one example of a structure in a case where the shaped body 41 is a foamed body 45 in which a plurality of air holes are formed inside by foaming a molding material will be described. In this case, a plurality of air holes 42 (internal spaces in the molding material) are formed inside the molding resin using bubbles.

[0086] The hollow portion 2 is formed by some of the plurality of air holes 42 inside the foamed body 45. As shown in Figure 12 The hollow portion is formed by one large air hole 42 (referred to as large air hole 42A). At least a part of the neck portion 3 is formed by an air hole 42 inside the foamed body 45, and the neck portion 3 is formed by an air hole 42 (referred to as small air hole 42B) smaller than the large air hole 42A of the hollow portion 2.

[0087] Specifically, in a case where a small air hole 42B present between one large air hole 42A and other large air holes 42A communicates with each large air hole 42A, the small air hole 42B functions as the neck portion 3. Also, as shown by "A" in the drawing, a case where a pair of large air holes 42A communicate in a manner that a plurality of small air holes 42B are connected. In this case, one neck portion 3 can also be formed by a plurality of small air holes 42B. In a case where a small air hole 42B present between one large air hole 42A and the surface 41a of the molded body 41 (foamed body 45) communicates with the large air hole 42A and the surface 41a, the small air hole 42B also functions as the neck portion. Further, as shown by "B" in the drawing, there can also be a small air hole 42B that communicates with the large air hole 42A but does not communicate with other large air holes 42A or the surface 41a. In this case, the small air hole 42B can function as a part of the volume of the hollow portion 2.

[0088] Further, as shown in (a) of Figure 13 In a case where adjacent large air holes 42A are close to each other, a thin rib 43 is formed. At this time, as shown in (b) of Figure 13 In some cases, a fine air hole 42C smaller than the small air hole 42B is formed within the thin rib 43. By the collection of such fine air holes 42C, in a case where a pair of large air holes 42A communicate, a neck portion 3 can be formed by the collection of the fine air holes 42C.

[0089] As described above, the manufacturing method when the hollow portion 2 and the neck portion 3 are formed by mixing the large air hole 42A, the small air hole 42B, and the fine air hole 42C is described. In this case, for example, when foaming molding is performed, the hollow portion 2 and the neck portion 3 are formed by adjusting the amount of the defoaming agent added. That is, the defoaming agent is mixed in the molding resin of the foaming molding and is caused to diffuse in advance to the inside of the molding material. In a case where the foamed body 45 is molded by performing this adjustment, a site where the air bubbles are enlarged is formed due to the influence of the defoaming agent. As a result, the large air hole 42A is formed at random in a form of being mixed in the small air hole 42B.

[0090] Specifically, a defoaming agent is introduced into the molding resin to coalesce the fine bubbles, thereby forming larger bubbles capable of forming large cells 42A. As a method of introducing the defoaming agent, for example, a method of introducing the defoaming agent in advance into the polyol premix, or a method of introducing the defoaming agent on the isocyanate side can be cited. Further, there are emulsion types in which water is used as a dispersion medium in the defoaming agent, and a defoaming agent that cannot be introduced on the isocyanate side can be used. As a method of introducing such a defoaming agent, in addition to the above-described methods, a method of dropping the defoaming agent during foaming can be used.

[0091] As a type of defoaming agent, there are roughly solvent-based and water-based types. As a solvent-based type, a silicone-based type, a vegetable oil-based type, a polymer-based type, and the like can be used, but the effect of a silicone-based defoaming agent is high. Further, if the raw material of the polyurethane that is the molding resin is changed, there are cases in which another type of defoaming agent is effective.

[0092] For example, in the case of using a silicone-based defoaming agent "GC-302" manufactured by "Nissin Chemical Co., Ltd.", large cells 42A can be appropriately obtained. By using an introduction amount of 0.01 to 0.10 mass% in the system, large cells 42A are obtained. In the case in which the introduction amount is less than 0.01 mass%, sometimes the cells are not coalesced and a large cell cannot be obtained. In the case in which the introduction amount is more than 0.10 mass%, the cells are broken, and thus the foaming does not occur, and sometimes a polyurethane foam cannot be formed.

[0093] Figure 14 The photographs show the observation results of the foams using a microscope. Figure 14 (a) of FIG. 1 shows a foam of a comparative example. Figure 14 (b) of FIG. 1 shows a foam related to an embodiment. Figure 14 (c) of FIG. 1 shows a foam of an embodiment in which the defoaming agent is increased compared to Figure 14 The foams of the embodiments in which the defoaming agent is increased compared to (b) of FIG. 1. These are images obtained by photographing a length of 5.4 mm in the vertical direction x 7.2 mm in the horizontal direction. As the molding resin, that is, the polyurethane raw material of these foams, a material composed of an isocyanate-terminated prepolymer and a polyol premix including a plurality of polyoxyethylene polyoxypropylene glycols having different molecular weights, and an additive was used. As the defoaming agent, a silicone-based defoaming agent "GC-302" manufactured by "Nissin Chemical Co., Ltd." was used. In the foams, the introduction amount of the defoaming agent was 0.01 to 0.10 mass%. Figure 14 In the comparative example of (a) of FIG. 1, the introduction amount of the defoaming agent was set to 0.005 mass%. In the comparative example, the introduction amount of the defoaming agent was less than 0.01 mass%, and thus the cells were not coalesced and a large cell could not be obtained. Figure 14 In the embodiment of (b) of FIG. 1, the introduction amount of the defoaming agent was set to 0.05 mass%. In the embodiment, the introduction amount of the defoaming agent was 0.01 to 0.10 mass%, and thus a large cell was obtained. Figure 14 In the embodiment of (c) of FIG. 1, the introduction amount of the defoaming agent was set to 0.08 mass%.

[0094] In the comparative example of (a) of FIG. 1, the introduction amount of the defoaming agent was set to 0.005 mass%. In the comparative example, the introduction amount of the defoaming agent was less than 0.01 mass%, and thus the cells were not coalesced and a large cell could not be obtained. Figure 14In the comparative example shown in (a), the pore 42 is not large enough to be equivalent to a large pore 42A, and it is impossible to confirm that the pore 42 can fully function as the cavity portion 2. On the other hand, in Figure 14 (b) Figure 14 In the embodiment shown in (c), it can be confirmed that a sufficiently large pore 42A is obtained that can function as the cavity 2. For example, in Figure 14 In (b), in the section indicated by "A", the combination of the Helmholtz-type cavity 2 and neck 3 can be confirmed. Furthermore, in Figure 14 (b) Figure 14 (c) shows only one cross-section. If viewed in three dimensions, the cavity 2 and the neck 3 are connected in a part that cannot be identified in the photograph.

[0095] Here, the formed foam 45 can be used directly as a sound-absorbing material, or it can be treated to form the neck 3. For example, laser irradiation, insertion of needle-like components, gas blowing, and mixing of volatile components can be performed. For example, as... Figure 15 As shown in (a), needle-shaped members 46 are inserted into the formed foam 45. Then, as... Figure 15 As shown in (b), by removing the needle-like member 46, a hole 47 is formed in the foam body 45 at the location where the needle-like member 46 was inserted. The result is as follows: Figure 16 As shown, a processing section 48 is formed extending within the foam body 45. A processing section 48 communicating with a pair of voids 2 (large pores 42A) is formed between them. This section functions as a neck 3 based on the processing section 48. Additionally, a processing section 48 is formed that communicates the voids 2 (large pores 42A) with a surface. This section also functions as a neck 3 based on the processing section 48.

[0096] Next, refer to Figures 17-19 The structure near the cavity 2 and neck 3 will be described in more detail. Figure 17 (a) is Figure 3 The neck 3 and based on the method shown Figure 16 Enlarged view of the neck 3 of the machining part 48. Figure 17 (b) is Figure 12 An enlarged view of the neck 3 based on small pores 42B, as shown in the diagram. Here, for comparison with this embodiment, Figure 18 The image shows an enlarged view of the neck 3 of the molded body of the comparative example.

[0097] like Figure 18As shown, in the molded body of the comparative example, the communication member 100 is mixed in the molding material. The communication member 100 is composed of a material different from the molding material such as a fiber member and is left in a state where the shape as a member is maintained after molding (does not disappear like a defoaming agent). The air holes 42 are formed by foaming in the inside of the molded body. In addition, by disposing the communication member between a pair of air holes 42, the pair of air holes 42 become in a state of communicating with each other. Thereby, the air holes 42 function as the hollow portion 2, and the communication member 100 functions as the neck portion 3. In such a structure, the hollow portion 2 is formed of the molding material, and the inner surface 2b of the hollow portion 2 is also formed of the molding material. On the other hand, the neck portion 3 is formed of the communication member 100, and the inner surface 3c of the neck portion 3 is also formed of the communication member 100 (the inner surface of the communication member). In addition, as shown in (b) of FIG. 10, the boundary surface BF is formed in a manner that can be observed between the molding material that forms the hollow portion 2 and the communication member 100 that forms the neck portion 3. This state does not correspond to a state where the material that forms the hollow portion 2 and the material that forms the neck portion 3 are integrally formed. Even if the material of the communication member 100 is the same or similar in composition to the molding material, the boundary surface BF is formed. That is, when the communication member 100 that is formed in advance is mixed in the molding material and molded, the boundary surface BF remains. This boundary surface BF can be confirmed even in a case where it is difficult to observe visually because the hardness of the material on the neck portion 3 side and the material on the hollow portion 2 side are different. Thus, regardless of the composition of the material of the communication member 100, such a boundary surface BF is formed in a manner that can be observed after molding. Figure 19

[0098] In contrast to this, in (a) of FIG. 11, Figure 17 Figure 17 In (b) of FIG. 11, Figure 19 In (b) of FIG. 11, Figure 18 ​​The connecting member 100 shown is not a member that is assumed to melt due to the heat during forming, and therefore cannot be considered as part of the forming material.

[0099] in addition, Figure 17 In the manner shown in (a), the neck 3 has a shape in which the center line CL1 extends in a straight line. In contrast, in the comparative example, since the connecting member 100 is mixed into the molding resin in a flowing state during molding, it solidifies in a shape where the connecting member 100 is randomly bent. Therefore, as... Figure 18 As shown, the center line CL2 of neck 3 curves instead of extending in a straight line. Furthermore, in Figure 17 In (a), a hollow cylindrical shape (cylindrical hole shape) neck 3 is shown as an example, but there are no particular limitations as long as the shape of the center line CL1 can be set to be straight. For example, the neck 3 can be: a hollow triangular prism, a hollow square prism, a hollow pentagonal prism, or other hollow prism shapes; a hollow frustum cone shape; a hollow frustum triangular pyramid, a hollow square pyramid, a hollow pentagonal pyramid, or other hollow frustum pyramid shapes; a sphere, etc. Even for these shapes, the center line CL1 can be set to extend in a straight line.

[0100] Here, as Figure 19 As shown in (b), in the comparative example, the connecting member constituting the neck 3 extends to a greater extent toward the inside of the cavity 2. In contrast, in this embodiment, as described above, the neck 3 does not extend toward the inside of the cavity 2. Furthermore, even if a neck is formed... Figure 19 Steps, protrusions, ridges, etc. (referred to as protrusions 54) as shown in (a) can also be suppressed to a small height that does not significantly impede sound absorption and vibration absorption performance.

[0101] Specifically, in the comparative example, the protrusion height H2 is greater than the range that affects performance, i.e., 100 μm. More specifically, if the protrusion height H2 in the comparative example is greater than 100 μm, and thus not ensured to be around 1 mm, the molding resin will flow into the connecting member 100, and the opening will be blocked by the molding resin. In this case, the opening to the cavity 2 cannot be maintained, and the neck 3 cannot be formed at all.

[0102] In contrast, in this embodiment, the protrusion height H1 of the protrusion 54 is suppressed to a range that does not affect performance, i.e., 100 μm or less. More preferably, the protrusion height H1 is suppressed to 0 μm or more and 80 μm or less. Furthermore, the definitions of heights H1 and H2 are not particularly limited, and can be determined using a cross-section near the neck 3 as described below. First, focus on the area near the opening of the neck 3 in the inner surface 2b of the cavity 2. In the presence of the protrusion 54, there is a base point SP on the inner surface 2b of the cavity 2 that rises toward the inside of the cavity 2. Extend the reference line SL from this base point SP toward the neck 3. At this time, at a certain contact point CTP of the neck 3, the tangent CTL relative to this contact point CTP is orthogonal to the reference line SL. Under this condition, the dimension of the highest part of the protrusion 54 relative to the reference line SL is defined as the "height of the protrusion". However, the definition of the height of the protrusion 54 is not limited to this, and other known methods can also be used. Furthermore, the absence of the protrusion 54 refers to the absence (or substantial absence) of the base point SP on the inner surface 2b of the cavity 2 near the opening of the neck 3.

[0103] Next, the various parameters of the molded articles in the embodiments described above will be explained. Furthermore, unless otherwise specified, the parameters are for... Figures 1-5 as well as Figures 12-19 The parameters mentioned in each implementation method.

[0104] (Size of the cavity)

[0105] For example, the diameter of the cavity 2 is 2000 μm or more and 9000 μm or less. The upper limit of the diameter of the cavity 2 can be 8000 μm, 7000 μm, or 6000 μm. The lower limit of the diameter of the cavity 2 can be 3000 μm, 4000 μm, or 5000 μm. As an example, the diameter of the cavity 2 is 5000 μm. However, the diameter of the cavity 2 is not limited to 5000 μm and can be appropriately changed according to the target frequency, etc.

[0106] Here, the method for determining the diameters of the cavity 2 and the neck 3 will be explained. The diameters can be determined by measuring the cavity 2 and the neck 3 based on images observed under a microscope. Furthermore, Figure 16 The cavity 2 and neck 3 shown may also have cross-sections that are not necessarily perfect circles. In this case, the area of ​​the cavity 2 that can be observed in the image is calculated. Then, an imaginary circle corresponding to this area is drawn, and the diameter of this circle is taken as the diameter of the cavity 2. For example, as shown... Figure 13In the case where the neck portion 3 is formed of a plurality of air holes 42, as shown, the sum of the areas of the plurality of air holes 42 is calculated from the observed image, and the diameter of a circle equivalent to the area is defined as the diameter of the neck portion 3. Further, the method of determining the diameter of each air hole is also the same as the above-described method.

[0107] For example, the volume of the hollow portion 2 is 4.19 x 10 9 μm 3 or more and 3.82 x 10 11 μm 3 or less. The upper limit of the volume of the hollow portion 2 can be 2.68 x 10 11 μm 3 , 1.80 x 10 11 μm 3 or 1.13 x 10 11 μm 3 . The lower limit of the volume of the hollow portion 2 can be 1.41 x 10 10 μm 3 , 3.35 x 10 10 μm 3 or 6.54 x 10 10 μm 3 . As one example, the volume of the hollow portion 2 is 4.19 x 10 9 μm 3 or more and 381.51 x 10 9 μm 3 or less. However, the volume of the hollow portion 2 is not limited to the above-described example, and can be appropriately changed according to the target frequency or the like.

[0108] In the case where the shaped body is a foamed body, it is particularly preferable that the following relationship be satisfied. That is, the hollow portion 2 is formed of air holes 42 of the interior of the foamed body, which are greater than the average diameter of the entire air holes 42 by 100% or more, preferably 300% or more, 2200% or more. The average diameter is calculated from "(the sum of the diameters of all the air holes in a unit volume) / (the number of all the air holes in a unit volume)". The air holes 42 in a unit volume include all the air holes 42 that form the hollow portion 2, the air holes 42 that form the neck portion 3, and the air holes 42 that neither form the hollow portion 2 nor form the neck portion 3. However, fine air holes 42C that are collapsed to the extent that they cannot be counted can be counted as one air hole 42.

[0109] (Size of neck portion)

[0110] For example, the diameter of the neck portion 3 is 10 μm or more and 1000 μm or less. The upper limit of the diameter of the neck portion 3 can be 900 μm, 800 μm, or 700 μm. The lower limit of the diameter of the neck portion 3 can be 20 μm, 30 μm, or 40 μm. As one example, the diameter of the neck portion 3 is 10 μm or more and 500 μm or less. However, the diameter of the neck portion 3 is not limited to the above examples, and can be appropriately changed according to the target frequency or the like.

[0111] (Relationship between the hollow portion and the neck portion)

[0112] The number of neck portions 3 extending from one hollow portion 2 is, for example, 2 or more and 24 or less. The upper limit of the number of neck portions 3 extending from one hollow portion 2 can be, for example, 15 or 13. The lower limit of the number of neck portions 3 extending from one hollow portion 2 can be, for example, 3, 4, 5, 6, 8, or 10. As one example, the number of neck portions 3 is 12. However, the number of neck portions 3 extending from one hollow portion 2 is not limited to the above examples, and can be appropriately changed.

[0113] For example, the inner surface 2b of the hollow portion 2 exposed at the surface lb is formed with 0 or more and 3 or less openings 3b.

[0114] In addition, the ratio of the number of neck portions 3 to the number of hollow portions 2 is, for example, 1 or more and 24 or less. However, the lower limit of the ratio can be 1.1, 3.0, 5.0, 7.0, or 11.0. In addition, the upper limit of the ratio can be 20.0, 16.0, 14.0, or 13.0. In this way, the ratio of the number of neck portions 3 to the number of hollow portions 2 can be appropriately changed. Furthermore, in a case where one neck portion 3 is formed by a collection of a plurality of small pores 42B or fine pores 42C, counting is performed as one neck portion 3. However, pores that are fine to the extent that they do not function as neck portions 3 can not be counted.

[0115] (Air permeability of the molded body)

[0116] The air permeability of the molded body is, for example, 0.4 cm 3 / (cm 2 ·s) or more and 200 cm 3 / (cm 2 ·s) or less.

[0117] In addition, the air permeability is measured in accordance with Japanese Industrial Standards JIS K 6400 using a Frazier air permeability tester (manufactured by TEST ST Co., Ltd., Switzerland).

[0118] (Wavelength absorbance)

[0119] The target frequency of the wavelength absorbing unit 10 is, for example, 450 Hz or more and 10,000 Hz or less. As one example, the target frequency of the wavelength absorbing unit 10 can be 250 Hz or more and 2,000 Hz or less, or 1,000 Hz or less. The wavelength absorption rate in the wavelength absorbing unit 10 is 0.4 or more for a wavelength of 450 Hz or more and 10,000 Hz or less. For example, when sound wave energy of the target frequency is incident on the neck portion 3, the sound wave energy is violently vibrated in the neck portion 3, and the air in the hollow portion 2 located on the inner side of the neck portion 3 functions as a spring to viscously attenuate the sound wave energy, whereby the sound wave energy is absorbed.

[0120] The wavelength absorption rate indicates the proportion of a wavelength of a specific frequency that is absorbed.

[0121] The wavelength absorption rate of 1.00 means that the reflection of the incident wave is 0%, and the wavelength absorption rate of 0.00 means that the incident wave is reflected by 100%.

[0122] (Perpendicular incidence sound absorption rate)

[0123] The target frequency of the perpendicular incidence sound absorption rate of the shaped body is the same as the frequency listed in the above-described wavelength absorption rate. The perpendicular incidence sound absorption rate per 10 mm thickness is preferably 0.4 or more, and preferably 0.6 or more for a wavelength of 450 Hz or more and 10,000 Hz or less. Further, the perpendicular incidence sound absorption rate described above specifies the value per 10 mm of the shaped body, but can also specify the value of the product itself, and can also specify the value per unit thickness in a unit area.

[0124] Here, as shown in FIG. 1, in the case where the hollow portions 2 and the neck portions 3 are regularly arranged, the above-described parameters are substantially uniform in the entire region of the portion that exhibits sound absorbing performance in the shaped body. On the other hand, as shown in FIG. 2, in the case where the hollow portions 2 and the neck portions 3 are formed in random sizes at random positions, the above-described parameters are sometimes made random in each region in the shaped body. Thus, the relationship between such a random structure and the above-described parameters will be described with reference to FIG. 3. Figure 5 Figure 12 Figure 16 Figure 20 Here, as shown in FIG. 1, in the case where the hollow portions 2 and the neck portions 3 are regularly arranged, the above-described parameters are substantially uniform in the entire region of the portion that exhibits sound absorbing performance in the shaped body. On the other hand, as shown in FIG. 2, in the case where the hollow portions 2 and the neck portions 3 are formed in random sizes at random positions, the above-described parameters are sometimes made random in each region in the shaped body. Thus, the relationship between such a random structure and the above-described parameters will be described with reference to FIG. 3. Figure 20 The wavelength absorption rate of 1.00 means that the reflection of the incident wave is 0%, and the wavelength absorption rate of 0.00 means that the incident wave is reflected by 100%.​​​

[0125] Next, the verification of the shaped body 1 configured as above is explained. Figure 6 is an exemplary graph showing the relationship between the frequency of the sound wave incident to the sound absorbing material not having the hollow portion 2 and the neck portion 3 and the normal incidence sound absorption rate, per material of the sound absorbing material. Figure 6 indicates the case where the semi-rigid polyurethane, the rigid polyurethane, the low air permeability soft polyurethane, and the high air permeability soft polyurethane are respectively used as the material of the sound absorbing material. In addition, the normal incidence sound absorption rate indicates the absorption rate of the sound wave when the sound wave hits in the direction perpendicular to the surface of the sound absorbing material. The normal incidence sound absorption rate is measured using a 4206-type sound tube (manufactured by SPECTRIS Corporation) with normal incidence sound absorption rate measuring software MS1021 (manufactured by SPECTRIS Corporation) in accordance with Japanese Industrial Standard JIS A 1405 with a back air layer of 0 mm. Figure 6 As is clear from the graph of FIG. 6, even if the hardness and the viscoelasticity of the material of the sound absorbing material change, the normal incidence sound absorption rate is almost constant (for example, less than 0.6) in the case where the frequency is 2000 Hz or less.

[0126] The normal incidence sound absorption rate indicates the proportion of the sound wave of a specific frequency that is absorbed when it is incident perpendicularly.

[0127] The wavelength absorption rate of 1.00 means that the reflection of the incident wave is 0%, and the wavelength absorption rate of 0.00 means that the incident wave is reflected by 100%.

[0128] Figure 7 is an exemplary graph showing the relationship between the frequency of the sound wave incident to the shaped body 1 having the hollow portion 2 and the neck portion 3 with a thickness of 10 mm and the normal incidence sound absorption rate, per diameter of the neck portion 3. In Figure 7 In the graph of FIG. 8, the case where the diameter of the hollow portion 2 is set to 5000 μm and the diameter of the neck portion 3 is set to 50 μm, 100 μm, 200 μm, and 400 μm, respectively, is shown.

[0129] Figure 8 is an exemplary graph showing the relationship between the diameter of the neck portion 3 and the peak value of the frequency with the highest sound absorption rate when the thickness of the shaped body 1 is set to 10 mm and the diameter of the hollow portion 2 is set to 5000 μm. As is clear from the graph of FIG. 9, in the case where the diameter of the neck portion 3 is 50 μm and the diameter of the hollow portion 2 is 5000 μm, the sound wave of the frequency around 1000 Hz can be absorbed. Figure 7 and Figure 8 As is clear from the graphs of FIGS. 8 and 9, in the case of the shaped body 1 having the hollow portion 2 and the neck portion 3, when the diameter of the neck portion 3 is 50 μm and the diameter of the hollow portion 2 is 5000 μm, the sound wave of the frequency around 1000 Hz can be absorbed.

[0130] Further, by changing the diameter of the neck portion 3, it is possible to absorb sound waves of frequencies corresponding to the calculated values of the formula (1). That is, it is known that by changing the diameter of the neck portion 3, it is possible to absorb sound waves of a larger range of target frequencies. In the case where the shaped body 1 has a continuous bubble property, in particular, it is also possible to absorb sound waves of a wavelength region around the target frequency.

[0131] Further, Figure 8 The measured values and the calculated values in the case where the thickness of the shaped body 1 is 10 mm are shown. It is known that in the case where the thickness of the shaped body 1 is 10 mm, the measured values exceed the calculated values. However, it is known that in the case where the thickness of the shaped body 1 is 15 mm, the measured values are approximately consistent with the calculated values.

[0132] Figure 9 is an exemplary graph showing the relationship between the frequency of sound waves incident to the shaped body 1 having the hollow portion 2 and the neck portion 3 and the normal incidence sound absorption rate. In Figure 9 , the case where the diameter of the neck portion 3 is set to 400 μm and the diameter of the hollow portion 2 is set to 5000 μm, 6000 μm, and 7000 μm, respectively, is shown. As Figure 9 indicated, it is known that even if the diameter of the hollow portion 2 changes in the range of 5000 μm or more and 7000 μm or less, the normal incidence sound absorption rate does not fluctuate as when the diameter of the neck portion 3 changes.

[0133] Figure 10 is a graph showing the relationship between the frequency of sound waves incident to the shaped body 1 having the hollow portion 2 and the neck portion 3 and the normal incidence sound absorption rate, in terms of the material of the shaped body 1. The molding of the shaped body was performed using a 3D printer device (3D system Co., Ltd., product name: Projet MJP 5500X), and as the resin for molding, #100, #250, or #400 (all are model numbers) was used. Figure 10 The model number "#100" in indicates the case where the shaped body 1 is composed of acrylonitrile-butadiene-styrene resin (ABS: Acrylonitrile Butadiene Styrene) resin, and the model number "#250" and the model number "#400" indicate the case where the shaped body 1 is composed of a mixture of ABS and an elastomer. In the model number "#250" and the model number "#400", the mixing ratio of ABS and the elastomer is different from each other. As Figure 10 indicated, it is known that in the shaped body 1, even if the mixing ratio of ABS and the elastomer changes, the sound absorption characteristics do not greatly change. Thus, in the shaped body 1, it is shown that even if the material changes, the sound absorption characteristics do not greatly fluctuate.

[0134] Next, the effect of the shaped body of the present embodiment will be described. As Figure 3 and Figure 4As exemplified, in the shaped body, a plurality of hollow portions 2 are formed inside, and a neck portion 3 is formed in each of the plurality of hollow portions 2. Some of the plurality of neck portions 3 communicate with the surface lb and / or with the hollow portion 2 exposed at the surface lb. At least some of the plurality of neck portions 3 communicate the plurality of hollow portions 2 with each other. Thus, when vibration energy including a sound wave is incident to the neck portion 3, intense vibration is generated, and the hollow portion 2 located on the opposite side (inside) of the surface lb functions as a spring, whereby the vibration energy is viscously attenuated. Thus, by the neck portion 3 and the hollow portion 2 extending on the side opposite to the surface lb of the neck portion 3, higher sound absorbing performance and vibration absorbing performance can be exerted.

[0135] In this shaped body, the inner surface 3c of the neck portion 3 is formed by the shaped material itself. In this case, compared to the case where the neck portion 3 is formed by a dedicated other member (such as the communication member 100 of the present embodiment), the incidence of the vibration energy with respect to the hollow portion 2 and the neck portion 3 can be smoother. Thus, even without making the size of the shaped body large, the sound absorbing performance and the vibration absorbing performance can be improved. As a result, the size of the shaped body can be suppressed from being large. Figure 18

[0136] The shaped body is a foamed body, and the hollow portion 2 can be formed by the cells 42 inside the foamed body, which are 100% or more larger than the average diameter of the entire cells 42.

[0137] At least some of the neck portions 3 can be formed by the cells 42 inside the foamed body.

[0138] At least some of the neck portions 3 can have a shape in which the center line CL1 extends in a straight line.

[0139] In the shaped body 1, the neck portion 3 extends from the inner surface 2b of the hollow portion 2 to the inner surface 2b of the other hollow portion 2 adjacent to the hollow portion 2. Thus, the neck portion 3 can be formed not to protrude from the inner surface 2b of the hollow portion 2, and thus the incidence of the vibration energy with respect to the hollow portion 2 and the neck portion 3 can be smoother. Thus, in the shaped body 1, even without making the size large, the sound absorbing performance and the vibration absorbing performance can be improved. As a result, the size of the shaped body 1 can be suppressed from being large.

[0140] More specifically, in the case where the protruding portion 54 is formed by the neck portion 3 protruding from the inner surface of the hollow portion 2, the protruding height of the protruding portion 54 with respect to the inner surface 2b of the hollow portion 2 can be 100 μm or less. In this case, the incidence of the vibration energy with respect to the hollow portion 2 and the neck portion 3 can be smoother.

[0141] The material of the hollow portion 2 and the material of the neck portion 3 can be the same as each other. In this case, since the shaped body 1 can be made of a single material, the production of the shaped body 1 can be easily performed.​

[0142] The shaped body is a foamed body, and the hollow portions 2 can be formed of cells 42 in the interior of the foamed body that are greater than 100% of the average diameter of the cells 42 as a whole. In this case, the hollow portions 2 having a sufficient size can be formed using the larger cells 42.

[0143] At least a portion of the neck portions 3 can be formed of the cells 42 in the interior of the foamed body. In this case, the neck portions 3 can be easily formed even without using a dedicated member or the like for providing the neck portions 3.

[0144] At least a portion of the neck portions 3 can have a shape in which the center line CL1 extends in a straight line. In this case, the vibration energy can be smoothly incident on the neck portions 3.

[0145] The ratio of the number of the neck portions 3 to the number of the hollow portions 2 of the shaped body 1 can be 1.1 or more. In this case, by increasing the number ratio of the neck portions 3, the frictional action between the vibration containing the sound wave and the neck portions 3 can be enhanced, and thus the sound wave energy and the vibration energy can be more efficiently absorbed.

[0146] The plurality of hollow portions 2 and the plurality of neck portions 3 can constitute the wavelength absorption unit 10, and the wavelength absorption rate in the wavelength absorption unit 10 of a wavelength of 450 Hz or more and 10,000 Hz or less can also be 0.4 or more. In this case, the sound wave energy and the vibration energy of the frequency band of 450 Hz or more and 10,000 Hz or less can be absorbed with higher efficiency.

[0147] The normal incidence sound absorption rate per 10 mm thickness of 450 Hz or more and 10,000 Hz or less can be 0.4 or more. In this case, the sound wave energy and the vibration energy of the frequency band of 450 Hz or more and 10,000 Hz or less can be absorbed with higher efficiency.

[0148] The diameter of the neck portions 3 can be 10 μm or more and 1,000 μm or less. In this case, the sound wave energy and the vibration energy of the target frequency band can be more efficiently absorbed.

[0149] The volume of the hollow portions 2 can also be 4.19 x 10 9 μm 3 to 3.82 x 10 11 μm 3 or less. In this case, the sound wave energy and the vibration energy of the target frequency band can be more efficiently absorbed.

[0150] The shaped body 1 can contain a polyurethane foamed body in at least a portion thereof. In this case, the shaped body 1 having higher softness can be provided.

[0151] The molded body 1 may contain at least one of thermoplastic resin and photocurable resin. In this case, the molded body 1 can be manufactured using a 3D printer or the like, thus making the manufacture of the molded body 1 easier.

[0152] The breathability is 0.4cm. 3 / (cm 2 ·s) or above and 200cm 3 / (cm 2 Below ·s). In this case, sound absorption and vibration absorption performance can be improved, and the desired air permeability can be ensured.

[0153] As described above, in this invention, the shape of the molded body can be appropriately changed. For example... Figure 11 As illustrated in (a), the molded body of the present invention can also be a rectangular plate-shaped molded body 21. The molded body 21, for example, has a main surface 22 for the incidence of sound waves or vibrations, one or more (four in one example) side surfaces 23 facing a direction different from the main surface 22, and a back surface 24 facing the side opposite to the main surface 22. In this case, the molded body 21 comprises a main surface 22, a back surface 24 disposed opposite to the main surface 22, and a side surface 23 disposed between the main surface 22 and the back surface 24. For example, a portion of the plurality of necks 3 may be exposed on the main surface 22, or exposed in the aforementioned cavity 2 exposed on the main surface 22.

[0154] The thickness T1 of the molded body 21 is, for example, 5 mm or more and 10 mm or less. However, the upper limit of the thickness T1 can also be a value other than 10 mm, and the lower limit of the thickness T1 can also be a value other than 5 mm. Furthermore, when the thickness T1 is 5 mm or more, the absorption of sound waves or vibrations by the molded body 21 can be more effective. In addition, in the molded body 21 having the aforementioned cavity 2 and neck 3, the absorption of sound waves or vibrations can be effectively achieved even when the thickness T1 is set to 10 mm or less. Moreover, by making the thickness T1 10 mm or less, the size of the molded body 21 can be made more compact.

[0155] like Figure 11 As illustrated in (b), the molded body of this disclosure can be a disc-shaped molded body 31 having a main surface 32 for sound waves or vibrations to be incident upon, a side surface 33 facing a direction different from the main surface 32, and a back surface 34 facing the opposite side to the main surface 32. The thickness T2 of the molded body 31 can, for example, be set to be the same as the thickness T1 of the molded body 21. As described above, the shape and size of the molded body of the present invention can be appropriately varied.

[0156] The sound absorbing material of the present embodiment can be the shaped body 1. In addition, the vibration absorbing material of the present embodiment can be the shaped body 1. In this case, a sound absorbing material or a vibration absorbing material that has the same effects as described above can be provided.

[0157] The embodiments of the shaped body, the sound absorbing material, and the vibration absorbing material of the present application have been described above. However, the present disclosure is not limited to the above-described embodiments. The present disclosure can be variously modified within the scope of the gist recited in the claims. That is, the shape, size, number, material, function, and arrangement of each portion of the shaped body, the sound absorbing material, and the vibration absorbing material can be appropriately modified within the scope of the above-described gist.

[0158] Explanation of Reference Signs

[0159] 1, 21, 31, 41, shaped body; 1b, surface; 1c, end surface; 1d, side surface; 1f, inside; 2, hollow portion; 2b, inner surface; 3, neck portion; 3b, opening; 10, wavelength absorbing unit; 22, 32, main surface; 23, 33, side surface; 24, 34, back surface; 42, air hole; 54, protruding portion; θ, angle.

Claims

1. A shaped body, wherein the shaped body has: a plurality of hollow portions formed in the interior of a shaped material; and a plurality of neck portions each provided in the plurality of hollow portions and communicating with the hollow portions, a part of the plurality of neck portions communicates with a surface and / or communicates with the hollow portions exposed to the surface, at least a part of the plurality of neck portions communicates the plurality of hollow portions with each other, an inner surface of the neck portion is formed of the shaped material itself, in a case where a projection is formed by causing the neck portion to project from an inner surface of the hollow portion, a projection height of the projection with respect to the inner surface of the hollow portion is 100 μm or less, a base point of the projection standing to an inner side of the hollow portion exists on the inner surface of the hollow portion, and the projection height of the projection is not 0.

2. The shaped body according to claim 1, wherein the hollow portion and the neck portion communicating with the hollow portion are integrally formed of the same shaped material.

3. The shaped body according to claim 1 or 2, wherein the shaped body is a foamed body, the hollow portion is formed of a cell in the interior of the foamed body, the cell being 100% or more larger than an average diameter of the entire cell.

4. The shaped body according to claim 3, wherein at least a part of the neck portion is formed of a cell in the interior of the foamed body.

5. The shaped body according to claim 1 or 2, wherein at least a part of the neck portion has a shape in which a center line extends in a straight line.

6. The shaped body according to claim 1 or 2, wherein the plurality of hollow portions and the plurality of neck portions constitute a wavelength absorption unit, a wavelength absorption rate of 450 Hz or more and 10,000 Hz or less in the wavelength absorption unit is 0.4 or more.

7. The shaped body according to claim 1 or 2, wherein a normal incidence sound absorption rate per 10 mm of thickness of 450 Hz or more and 10,000 Hz or less is 0.4 or more.

8. The shaped body according to claim 1 or 2, wherein a diameter of the neck portion is 10 μm or more and 1,000 μm or less.

9. The shaped body according to claim 1 or 2, wherein The volume of the hollow part is 4.19 x 10 9 μm 3 Above and 3.82 x 10 11 μm 3 Below.

10. The shaped body according to claim 1 or 2, wherein the shaped body has: a main surface; a back surface provided opposite to the main surface; and one or more side surfaces provided between the main surface and the back surface, a part of the plurality of neck portions is exposed at the main surface or the hollow portion exposed at the main surface.

11. A sound absorbing material, wherein the sound absorbing material is the shaped body according to any one of claims 1 to 10.

12. A vibration absorbing material, wherein the vibration absorbing material is the shaped body according to any one of claims 1 to 10.

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