Soundproofing material

Abstract

We provide soundproofing materials with a novel structure. [Solution] One aspect of the present invention provides a soundproofing material 10 comprising a plate-shaped or sheet-shaped package body 20 made of a non-permeable resin bag body 30 in which a plurality of foam chips 21 are packaged so that the inside is under negative pressure. Since the foam inside the bag body is divided into a plurality of chips, it is possible to suppress sound transmission in the foam, thereby improving the soundproofing performance of the soundproofing material. Moreover, since the plurality of chips are not bonded to each other, it is possible to block the sound transmission path between the chips and improve sound insulation.

Description

Technical Field

[0001] The present disclosure relates to sound insulating materials.

Background Art

[0002] Conventionally, sound insulating materials provided with foams have been known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a sound insulating material having a novel structure.

Means for Solving the Problems

[0005] One aspect of the present invention is a sound insulating material including a package body in a plate shape or a sheet shape formed by packaging a plurality of foam chips in a resin-made bag body having airtightness so that the inside thereof is in a negative pressure state.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a cross-sectional view of the sound insulating material of the first embodiment [Figure 2] FIG. 2A is a cross-sectional view of the foam chips supplied to the receiving portion of the formed sheet, FIG. 2B is a cross-sectional view of a pair of resin sheets overlapped with each other and heat-sealed at their outer edges, and FIG. 2C is a cross-sectional view of the bag body obtained by trimming a pair of resin sheets. [Figure 3] FIG. 3 is a cross-sectional view of the sound insulating material attached to the opposing surface shaped to the three-dimensional shape of the object. [Figure 4] FIG. 4A is a perspective view of the vehicle body to which the sound insulating material is attached, and FIG. 4B is a plan view of the sound insulating material. [Figure 5] Figure 5 is a cross-sectional view of a soundproofing material according to another embodiment. [Figure 6] Figure 6A is a cross-sectional view of the soundproofing material of the embodiment, and Figure 6B is a cross-sectional view of the soundproofing material of the comparative example. [Figure 7] Figure 7 is a graph showing the transmission loss of soundproofing materials in the example and comparative example. [Modes for carrying out the invention]

[0007] [First Embodiment] Figure 1 shows a soundproofing material 10 according to the first embodiment. The soundproofing material 10 comprises a plate-shaped or sheet-shaped package 20. The package 20 consists of a plurality of foam chips 21 packaged in a bag 30.

[0008] In the soundproofing material 10 of this embodiment, a sound insulation layer 40 is superimposed on one side (first surface 20A) of the package body 20. For example, the sound insulation layer 40 is attached to the package body 20 with an adhesive (e.g., double-sided tape). In this embodiment, the sound insulation layer 40 is laminated on only one side of the front and back surfaces of the package body 20, but it may be laminated on both the front and back surfaces of the package body 20. Note that the soundproofing material 10 can also be configured without the sound insulation layer 40.

[0009] The soundproofing material 10 is attached to an object 80 (for example, a noise source, something placed around a noise source, or something to which noise is transmitted), or it is placed opposite to it with a gap in between, and is used to reduce sound coming from the object 80. The object 80 may be, for example, installed in a vehicle or other vehicle, or installed in a building. For example, objects 80 installed in a vehicle include body panels (floor panels, roof panels, door panels, etc.), interior materials, and dashboard panels.

[0010] In this embodiment, the soundproofing material 10 has a side opposite to the sound insulation layer 40, that is, a second side 20B opposite to the first side 20A of the package body 20, facing the object 80. Alternatively, the soundproofing material 10 may be positioned with the sound insulation layer 40 facing the object 80.

[0011] The multiple chips 21 contained in the bag 30 may be the same shape, or they may include chips 21 of different shapes. Furthermore, these multiple chips 21 may be the same size, or they may include chips 21 of different sizes. The shape of the multiple chips 21 is not particularly limited and may be regular or irregular. For example, the chips 21 may be spherical, granular, or cylindrical, or polyhedral such as cubic, or multiple chips 21 of such shapes may be mixed together. Also, the chips 21 may be fragments such as crushed pieces. In the example of this embodiment, the chips 21 are crushed pieces. If the chips 21 are crushed pieces in this way, for example, crushed pieces can be obtained by crushing foam that has been used in a product once using a crusher, and thus they can be reused. Alternatively, scraps of foam generated in the production process may be reused (for example, crushed into crushed pieces) and used as chips 21.

[0012] In this embodiment, the chips 21 are sized to overlap in the thickness direction of the package body 20 within the package body 20. For example, two or more chips 21 are contained within the bag body 30. The size of the chips 21 is preferably 10 to 50% of the thickness of the package body 20. For example, the size of the chips 21 is preferably 2 mm to 35 mm. In this case, the thickness of the package body 20 is preferably 5 to 60 mm. Here, the size of the chip 21 refers to the distance between the two furthest points on the outer surface of the chip 21. That is, if the chip 21 is spherical, the size of the chip 21 is its diameter, and if the chip 21 is cubic, the size of the chip 21 is the length of its diagonal.

[0013] The foam constituting the chip 21 may be non-permeable (for example, having a closed-cell structure) or permeable (for example, having a continuous-cell structure). For example, a plurality of chips 21 may include both closed-cell chips 21 and continuous-cell chips 21. The foam constituting the chip 21 may be made of a thermosetting resin such as polyurethane foam (for example, rigid polyurethane foam or flexible polyurethane foam), a thermoplastic resin such as polyolefin foam such as polyethylene foam or polypropylene foam, or a foam made of other resins. The foaming ratio of the foam constituting the chip 21 is preferably, for example, 5 to 100 times. Chips 21 made of different materials may be blended.

[0014] In this embodiment, the chips 21 are not bonded to each other. For example, adjacent chips 21 are in contact with each other, but a gap is formed between them.

[0015] In this embodiment, the bag 30 is made of resin and is non-permeable. The bag 30 may have a flat shape, for example, and may be a flat bag or a bag with a gusset. In this embodiment, the bag 30 is formed by overlapping a pair of resin sheets 31 and heat-sealing their outer edges together (see Figures 2A to 2C).

[0016] In this embodiment, the package body 20 is configured such that the inside of the bag body 30 is under negative pressure, and the bag body 30 is in close contact with the chip 21. Therefore, the bulkiness of the package body 20 can be reduced.

[0017] Note that the resin constituting the bag body 30 is not particularly limited. However, when the bag body 30 is formed by heat sealing as in this embodiment, a resin with good heat-sealing properties is preferred. Examples of the resin constituting the bag body 30 include polyolefin resins such as polyethylene resin and polypropylene resin. From the viewpoint of heat-sealing properties, it is preferably a thermoplastic resin. When the bag body 30 is composed of a pair of resin sheets 31, it is preferable that these resin sheets 31 are made of the same type of resin, but they can also be made of different types of resins.

[0018] Note that the package body 20 of this embodiment is formed, for example, as follows. First, as shown in FIG. 2A, a first resin sheet 31A, which is one of the pair of resin sheets 31, is formed into a shape (e.g., dish shape or container shape) having a receiving portion 32 for receiving a plurality of chips 21 by vacuum forming, press forming, or the like. Then, a plurality of chips 21 are accommodated in the receiving portion 32 of the first resin sheet 31A. Next, a second resin sheet 31B, which is the other resin sheet, is overlapped with the first resin sheet 31A in which a plurality of chips 21 are accommodated in the receiving portion 32, and a vacuum is drawn between these resin sheets 31. Then, in the vacuum-drawn state, the outer edge portions of the first resin sheet 31A and the second resin sheet 31B that are overlapped are heat-sealed. As a result, a plurality of chips 21 are encapsulated, and a bag body 30 with a negative pressure inside is formed, and the package body 20 is formed. Note that the outer edge portions of the pair of resin sheets 31 are appropriately trimmed (see FIG. 2C).

[0019] The sound insulation layer 40 is preferably airtight. Examples of the sound insulation layer 40 include a resin sheet. The sound insulation layer 40 may also be a fiber sheet such as a non-woven fabric or a pressed felt.

[0020] Figure 3 shows an example of the use of the sound insulation material 10. In this example, the opposing surface 80M of the object 80 to the sound insulation material 10 (in the example of this embodiment, the surface to which the sound insulation material 10 is attached) is shaped into a three-dimensional shape. For example, such an object 80 includes the dash panel 85 of the vehicle 90 shown in FIG. 4A. The dash panel 85 separates the power unit chamber 93 (see FIG. 3) where a driving motor, an engine, etc. are provided in the vehicle 90 from the passenger compartment 95. The vehicle 90 includes, for example, gasoline vehicles, electric vehicles such as electric vehicles, hybrid vehicles, plug-in hybrid vehicles, etc.

[0021] Thus, when the opposing surface 80M of the object 80 is shaped into a three-dimensional shape, for example, it is preferable to shape the sound insulation layer 40 into a shape corresponding to the shape of the opposing surface 80M of the object 80 (for example, shaping the sound insulation layer 40 with a mold by vacuum forming, press forming, etc.). Then, the package body 20 is overlapped and fixed (for example, adhered) to the shaped sound insulation layer 40. The sound insulation material 10 is attached, for example, so that the package body 20 abuts on the object 80 on the side opposite to the sound insulation layer 40. The package body 20 may be pre-shaped the bag body 30 (for example, the resin sheet 31) into a shape corresponding to the shape of the opposing surface 80M of the object 80 (for example, shaping the resin sheet 31 by vacuum forming, press forming, etc.). Further, the package body 20 can be made flexible by being composed of a resin bag body 30 and a plurality of divided foam chips 21, so that the flat package body 20 can be deformed into a shape corresponding to the opposing surface 80M by overlapping it with the sound insulation layer 40.

[0022] If a protrusion (for example, the steering wheel of a vehicle 90) is provided on the opposing surface 80M of the object 80, a through-hole 18 into which the protrusion is inserted may be formed in the package body 20 (see Figure 4B). By providing the through-hole 18 in this way, interference between the object 80 and the package body 20 can be suppressed. If a sound insulation layer 40 is provided, a through-hole into which the protrusion of the object 80 is inserted may also be formed in the sound insulation layer. If the bag body 30 is made of a pair of resin sheets 31, for example, the portions of the pair of resin sheets 31 that form the opening edges of the through-hole 18 are also heat-sealed.

[0023] In the soundproofing material 10 of this embodiment, the foam inside the bag 30 is divided into multiple chips 21, which makes it possible to suppress sound transmission in the foam and improve the soundproofing performance of the soundproofing material 10. Moreover, since the multiple chips 21 are not bonded to each other, it is possible to improve sound insulation by blocking the sound transmission path between the chips 21.

[0024] Furthermore, multiple chips 21 are arranged in overlapping positions in the thickness direction of the package body 20. In this way, the foam inside the bag body 30 is divided in the thickness direction of the package body 20, which makes it possible to improve the sound insulation in the thickness direction of the package body 20.

[0025] Furthermore, by including multiple chips 21 of different types (for example, chips of different sizes, different shapes, or chips of different sizes and shapes) within the bag 30, it becomes possible to form gaps between the chips 21 compared to when there are chips of the same size within the bag 30. This makes it possible to suppress the transmission of sound between the chips 21 and improve sound insulation. In addition, since the sound insulation layer 40 is superimposed on the package 20, the sound insulation performance of the soundproofing material 10 can be further enhanced.

[0026] Furthermore, since multiple chips 21 are packaged in the bag 30, handling of multiple chips 21 can be made easier. Also, because the bag 30 is non-permeable, the sound insulation effect can be enhanced. Moreover, because the inside of the bag 30 is under negative pressure, the package 20 is less bulky, making it easier to handle. When forming the package 20, the thickness of the package 20 can be adjusted to match the location where the soundproofing material 10 is placed by adjusting the vacuum inside the bag 30 (for example, by creating a vacuum so that the chips 21 can move within the bag 30).

[0027] Furthermore, since the sound insulation layer 40 is shaped to correspond to the outer surface shape of the object 80, it is possible to use the sound insulation layer 40 to make the shape of the resin bag 30 correspond to the outer surface shape of the object 80.

[0028] [Other embodiments] In the above embodiment, a package body 20 matching the shape of the sound insulation layer 40 was laminated onto a sound insulation layer 40 formed into a three-dimensional shape. However, as shown in Figure 5, for example, multiple flat package bodies 20 may be arranged and laminated onto the sound insulation layer 40 formed into a three-dimensional shape. If the package bodies 20 laminated onto the sound insulation layer 40 are divided into multiple parts, the uneven positioning of the chips 21 within the bag 30 can be suppressed compared to when one large package body 20 is used.

[0029] Alternatively, for example, the bag 30 may be sealed in a grid pattern to divide the area in the package 20 where the chips 21 are contained into a grid pattern. In this way, the chips 21 can be sealed in each of the grid-divided areas in the package 20, and the uneven distribution of the chips 21 can be suppressed.

[0030] Multiple chips 21 can also be bonded together with a binder or the like.

[0031] The chip 21 can also be made of a sound-insulating material other than foam.

[0032] The package body 20 can also be in a shape other than a flat shape such as a plate or sheet. For example, the package body 20 may be in the shape of a block such as a cube.

[0033] The package body 20 can also be configured in a way that does not create a negative pressure state inside the bag body 30.

[0034] The bag 30 can also be made with a breathable structure.

[0035] [Confirmation experiment] The sound insulation performance was evaluated by measuring the transmission loss of the sound insulation material 10 from Examples 1 to 3 (see Figure 6A) and the sound insulation material 10V from Comparative Example 1 (see Figure 6B).

[0036] 1. Composition of soundproofing materials <Examples 1-3> The soundproofing material 10 in Examples 1 to 3 has a structure in which a sound insulation layer 40 is laminated on a package body 20, similar to the first embodiment described above, and the chips 21 are made of polyurethane foam. This polyurethane foam has an apparent density of 17 kg / m³ and has an open-cell structure. In Examples 1 to 3, the chips 21 are cut cubic pieces as shown in Figure 6A, but their sizes differ. The length of one side of the cubic chip is 20 mm in Example 1, 10 mm in Example 2, and 5 mm in Example 3. The package body 20 is plate-shaped, and its size is approximately 500 mm x approximately 500 mm x approximately 20 mm (thickness). The chips 21 are tightly packed into the bag body 30. In the thickness direction of the package body 20, the chips 21 are stacked in one layer in Example 1, two layers in Example 2, and three layers in Example 3. The bag body 30 is formed by heat-sealing a pair of resin sheets 31, each resin sheet 31 being made of polyethylene resin with a thickness of 0.04 mm. The sound insulation layer 40 is made of polypropylene resin with a basis weight of 3.4 kg / m². 2 It is so.

[0037] <Comparative Example 1> The soundproofing material 10V of Comparative Example 1 has a plate-shaped polyurethane foam 29 instead of a package body 20, and a sound insulation layer 40 is laminated on the polyurethane foam 29 (see Figure 6B). This polyurethane foam 29 is made of the same material as the chips 21 of Examples 1 to 3, but differs in that it is not divided into multiple chips 21. The size of the polyurethane foam 29 is approximately 500 mm x approximately 500 mm x approximately 20 mm (thickness). The sound insulation layer 40 is the same as in Examples 1 to 3.

[0038] 2. Test Method <Transmission loss> The transmission loss was measured in accordance with JIS A1441-1:2007. Specifically, a soundproofing material was placed on top of a steel plate 80A (500mm x 500mm x 0.8mm (thickness)) which was the object 80, and sound was incident from the steel plate 80A side. The soundproofing material was positioned so that the side opposite to the sound insulation layer 40 overlapped with the steel plate 80A.

[0039] 3. Test Results Figure 7 is a graph showing the transmission loss of the soundproofing material 10 of Examples 1-3 and the soundproofing material 10V of Comparative Example 1. As shown in Figure 7, it was confirmed that the soundproofing material 10 of Examples 1-3 had better transmission loss over a wide frequency range compared to the soundproofing material 10V of Comparative Example 1. This was particularly noticeable in the range of 800-3500 Hz. For the cubic chips 21 of 20 mm square, 10 mm square, and 5 mm square, the transmission loss was good for all sizes.

[0040] [Note] The following describes the features extracted from the above embodiment, explaining their effects and other aspects as needed. For ease of understanding, corresponding configurations in the above embodiment will be indicated in parentheses as appropriate, but these features are not limited to the specific configurations indicated in parentheses.

[0041] For example, the following set of features can be considered to have been conceived with the objective of "providing a soundproofing material with a novel structure," given the background technology that "conventionally, soundproofing materials comprising foam are known (see, for example, Japanese Patent Publication No. 2014-28515)."

[0042] [Feature 1] A soundproofing material (soundproofing material 10) comprising a plate-shaped or sheet-shaped package (package 20) which is made of a non-permeable resin bag (bag 30) in which a plurality of foam chips (chips 21) are packaged so that the inside is in a negative pressure state.

[0043] [Feature 2] The soundproofing material described in Feature 1, wherein the plurality of foam chips are not bonded to each other.

[0044] [Feature 3] The soundproofing material according to feature 1 or 2, wherein the foam chips are arranged in multiple layers in the thickness direction of the package body.

[0045] [Feature 4] The soundproofing material according to any one of the features 1 to 3, further comprising a sound insulation layer (sound insulation layer 40) superimposed on one side of the aforementioned package body.

[0046] [Feature 5] The package body is attached to the object (object 80) by contacting it on the side opposite to the one side, The sound insulation layer is shaped to correspond to the outer surface shape of the object, as described in Feature 4.

[0047] [Feature 6] The soundproofing material according to feature 5, which has a through hole that penetrates the package body in the thickness direction and into which the protruding part of the object is inserted.

[0048] Feature 1 provides a soundproofing material with a novel structure. Since multiple foam chips are packaged in a bag, handling of the multiple foam chips is made easy. Because the bag is non-permeable, the sound insulation effect can be enhanced. Since the foam inside the bag is divided into multiple chips, sound transmission in the foam can be suppressed, thereby improving the soundproofing performance of the soundproofing material. Because the inside of the bag is under negative pressure, the package is less bulky, making it easier to handle.

[0049] In Feature 2, since the multiple foam chips are not bonded to each other, it is possible to improve sound insulation by blocking the sound transmission path between the foam chips.

[0050] In Feature 3, multiple foam chips are arranged in overlapping layers along the thickness of the package. By dividing the foam inside the bag along the thickness of the package in this way, it is possible to improve the sound insulation in the thickness direction of the package.

[0051] Feature 4 makes it possible to enhance the sound insulation performance of the soundproofing material by using a sound insulation layer.

[0052] In Feature 5, since the sound-insulating layer is shaped to correspond to the outer surface shape of the object, it is possible to use the sound-insulating layer to make the shape of the resin bag correspond to the opposite shape of the object.

[0053] As shown in Feature 6, the package may have through holes into which the protruding parts of the object are inserted. Providing such through holes helps to suppress interference between the object and the package. If a sound insulation layer is provided, through holes into which the protruding parts of the object are inserted may also be formed in the sound insulation layer.

[0054] While this specification and drawings disclose specific examples of the technology included in the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and changes to these examples, as well as parts of the examples taken individually. [Explanation of Symbols]

[0055] 10 Soundproofing materials 18 Through holes 20 packages 20A, Page 1 20B 2nd side 21 chips 30 Bag body 31 Resin sheet 31A First resin sheet 31B Second resin sheet 32 Receptor part 40 Sound insulation layer 80 Objects 80A Steel Plate 80M Opposing side 85 Dash Panel 90 vehicles 93 Power Unit Room 95 Cabin

Claims

1. A soundproofing material comprising a plate-shaped or sheet-shaped package body made of a non-permeable resin bag in which multiple foam chips are packaged so that the inside is under negative pressure.

2. The soundproofing material according to claim 1, wherein the plurality of foam chips are not bonded to each other.

3. The soundproofing material according to claim 1, wherein the foam chips are arranged in multiple layers in the thickness direction of the package body.

4. The soundproofing material according to any one of claims 1 to 3, further comprising a sound insulation layer superimposed on one side of the package body.

5. The package body is attached to the object by contacting it on the side opposite to the aforementioned one side. The soundproofing material according to claim 4, wherein the sound insulation layer is shaped to correspond to the outer surface shape of the object.

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