JP7565580B2 - Sound insulation and sound absorption materials and sound insulation and sound absorption components - Google Patents

Description

The present invention relates to a sound insulation/absorption material that can reduce noise generated by automobiles, electrical appliances, etc., and to a sound insulation/absorption member that uses this sound insulation/absorption material.

Conventionally, sound-absorbing materials have been used as a method for reducing noise generated by automobiles, electrical appliances, etc. Various types of sound-absorbing materials are known, for example, thermally stable soundproofing materials such as those described in Patent Document 1.

The sound-absorbing material described in Patent Document 1 prevents sound reflection by absorbing noise generated by automobiles, electrical appliances, etc., and prevents sound from being transmitted to the outside. Another known soundproofing method is sound insulation, which blocks sound transmitted through the air and prevents sound from being transmitted to the outside.

As described in Patent Document 2, in order to improve the sound insulation effect, sound-absorbing material made of foamed resin (urethane, etc.) and a sound-insulating cover with a four-layer structure consisting of melamine foam material and cotton felt sandwiched between two layers of nonwoven fabric are used to improve the noise suppression effect of engines, etc.

Patent No. 3911548 Patent No. 5831281

However, although there have been conventional sound absorbing and insulating materials that provide a noise suppression effect, as shown in Patent Document 2, it is necessary to provide both a sound absorbing material and a sound insulating material, and there is no sound deadening material that provides both sound absorbing and sound insulating effects, so there has been a demand for sound absorbing and sound insulating materials that can provide both sound absorption and sound insulating effects.

The present invention was made in consideration of the above problems, and its main objective is to provide a sound-insulating/sound-absorbing material that can achieve both sound-blocking and sound-absorbing effects and has improved adaptability to automobiles, electrical appliances, etc.

The sound-insulating/sound-absorbing material of the present invention is characterized in that a fiber structure containing 50% or more nanofibers having a resin fiber diameter of 1000 nm or less and the remaining resin fiber diameter being microfibers having a resin fiber diameter of 10 μm or less is compressed at room temperature and has a compression set rate of 40% or more .

In addition, the sound-insulating/sound-absorbing material of the present invention is characterized in that a fiber structure containing 50% or more nanofibers having a resin fiber diameter of 1000 nm or less and the remaining microfibers having a resin fiber diameter of 10 μm or less is compressed at room temperature, and is formed by laminating at least a first sound-insulating/sound-absorbing material and a second sound-insulating/sound-absorbing material, the first sound-insulating/sound-absorbing material and the second sound-insulating/sound-absorbing material differ from each other in at least one of basis weight or porosity .

The sound-proofing/sound-absorbing member according to the present invention is characterized in that the above-mentioned sound-proofing/sound-absorbing material is molded into a predetermined shape.

The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute an invention.

The sound-insulating/sound-absorbing material of the present invention contains 50% or more nanofiber fibers with a resin fiber diameter of 1000 nm or less, and the remaining resin fiber diameter is a microfiber with a diameter of 10 μm or less. The fiber structure is compressed at room temperature, so it can achieve both sound-insulating and sound-absorbing effects, and because it does not contain metals, it can be made lighter and less costly.

1 is a perspective view of a sound insulation/absorbing member according to an embodiment of the present invention. 1 is a cross-sectional view of a sound insulation/absorbing material according to an embodiment of the present invention. 1A to 1C are schematic diagrams showing a method for producing a sound-insulating/sound-absorbing material according to an embodiment of the present invention. 1A is an enlarged view of a sound insulation/absorbing material according to an embodiment of the present invention, and FIG. 1B is an enlarged view of a conventional sound absorbing material. Graph showing the relationship between compression temperature and compression set rate. 1 is a graph comparing the sound absorption coefficient of the sound insulation/sound absorption material according to this embodiment with that of a conventional sound absorbing material. 5 is a graph showing the relationship between the transmission loss of the sound insulating/absorbing material according to the present embodiment and a sound absorbing material that is not compressed.

Below, preferred embodiments for carrying out the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

Figure 1 is a perspective view of a sound insulation/sound absorption member according to an embodiment of the present invention, Figure 2 is a cross-sectional view of a sound insulation/sound absorption material according to an embodiment of the present invention, Figure 3 is a schematic diagram showing a manufacturing method of a sound insulation/sound absorption material according to an embodiment of the present invention, Figure 4 (a) is an enlarged view of a sound insulation/sound absorption material according to an embodiment of the present invention, (b) is an enlarged view of a conventional sound absorption material, Figure 5 is a graph showing the relationship between compression temperature and compression set rate, Figure 6 is a graph comparing the sound absorption rate of the sound insulation/sound absorption material according to this embodiment with that of a conventional sound absorption material, and Figure 7 is a graph showing the relationship between the transmission loss of the sound insulation/sound absorption material according to this embodiment and that of an uncompressed sound absorption material.

As shown in FIG. 1, the sound insulation/absorption member 1 according to this embodiment is formed by molding a sound insulation/absorption material 10, which will be described later, into a predetermined shape, and includes, for example, a hollow main body 2 and a flange portion 3 extending from the outer edge of the main body 2. The sound insulation/absorption member 1 according to this embodiment is formed by compressing the sound insulation/absorption material 10 at a predetermined pressure at room temperature.

As shown in FIG. 2, the sound-insulating/sound-absorbing material 10 according to this embodiment is constructed by laminating a first sound-insulating/sound-absorbing material 11 and a second sound-insulating/sound-absorbing material 12. Both the first sound-insulating/sound-absorbing material 11 and the second sound-insulating/sound-absorbing material 12 are constructed from a fiber structure containing 50% or more of so-called nanofiber fibers having a resin fiber diameter of 1000 nm or less, and the remaining resin fiber diameter being microfibers having a resin fiber diameter of 10 μm or less.

The resin fibers of the sound insulation/absorption material 10 according to this embodiment are made of polyester, polyamide, polyolefin, polyurethane, etc. Examples of polyesters that can be used include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polylactic acid. Examples of polyamides that can be used include nylon 6, nylon 66, and nylon 11. Examples of polyolefins that can be used include polyethylene, polypropylene, and polystyrene.

It is preferable that the nanofiber fibers having a resin fiber diameter of 1000 nm or less and the microfiber fibers having a resin fiber diameter of 10 μm or less are each composed of the same resin fiber. Furthermore, the nanofiber fibers and the microfiber fibers may be manufactured simultaneously using the same synthetic resin, or the nanofiber fibers and the microfiber fibers may be manufactured separately and then mixed together to form the nanofiber fibers and the microfiber fibers.

In addition, various nanofiber manufacturing methods, such as electrospinning and meltblowing, can be used to manufacture nanofiber fibers.

The first sound-insulating/sound-absorbing material 11 and the second sound-insulating/sound-absorbing material 12 are configured to differ from each other in at least one of the basis weight or porosity. For example, the basis weight of the first sound-insulating/sound-absorbing material 11 is formed to be greater than that of the second sound-insulating/sound-absorbing material 12.

As shown in FIG. 3, the sound insulation/absorption material 10 according to this embodiment is compressed at room temperature. In this specification, room temperature refers to a state in which the material is not heated during molding, and is preferably, for example, 10 to 35°C, and more preferably, 23°C ± 2°C.

As shown in FIG. 3, the sound insulation/absorption material 10 of this embodiment is preferably compressed by holding it for, for example, 24 hours using a pressure device 20. The pressure device 20 sandwiches the sound insulation/absorption material 10 of this embodiment between a pair of pressure plates 21, and compresses it in the axial direction of the bolt 23 by screwing a nut 22 onto a bolt 23 inserted through the pair of pressure plates 21. At this time, it is preferable that a force of about 270 N is applied to the sound insulation/absorption material 10 of this embodiment for compression.

The sound insulation/absorption material 10 according to this embodiment has a compression set rate of 30% or more, and more preferably 40% or more. As a result, when the material contains 50% or more resin fibers with a resin fiber diameter of less than 1000 nm, as shown in FIG. 4(a), the compression set rate at room temperature can be set to the above-mentioned value, and the fiber state does not collapse when compressed without heating, so that the effect of compression can be limited to a change in porosity.

In contrast, when conventional sound-absorbing materials are compressed without heating, the compression set is low, as shown in Comparative Example 1 in Figure 5, and a molded body cannot be obtained. On the other hand, when compressed with heating, the fibers that form the support of the fiber structure melt due to the heat, and the fibers change into a film-like shape, as shown in Figure 4 (b). It was confirmed that, due to this phenomenon, although a molded body can be produced, the sound-absorbing and sound-proofing performance cannot be achieved.

As shown in FIG. 5, the example of the sound insulation/absorption material 10 according to this embodiment has a significantly improved compression set rate compared to Comparative Example 1 of a conventional sound absorbing material. For example, it can be confirmed that the compression set rate at room temperature (approximately 23°C in FIG. 5) is improved over the compression set rate at a compression temperature of approximately 85°C in Comparative Example 1. This confirms that the compression set rate of the sound insulation/absorption material 10 according to this embodiment can exhibit performance that is better than that of conventional materials without the need for heating.

As shown in FIG. 6, the example of the sound-insulating/sound-absorbing material 10 according to this embodiment does not undergo heat compression, and therefore has an improved sound absorption coefficient. In contrast, the comparative example 1 of the conventional sound-absorbing material undergoes heat compression, and as shown in FIG. 4(b), the fibers melt, causing the sound absorption coefficient to deteriorate, resulting in a low sound-absorbing effect.

As shown in FIG. 7, the transmission loss of the sound-insulating/sound-absorbing material 10 according to this embodiment is generally improved compared to Comparative Example 2 in which compression is not performed, and it has been confirmed that the improved transmission loss can improve the shielding properties without increasing the basis weight by compression. In addition, the sound-insulating/sound-absorbing material 10 according to this embodiment is formed by laminating the first sound-insulating/sound-absorbing material 11 and the second sound-insulating/sound-absorbing material 12, which have different basis weights and porosities, and therefore it is possible to form a sound-insulating/sound-absorbing material that can achieve both sound insulation and sound absorption by suppressing the further synergistic effect of increasing the basis weight and the decrease in sound absorption rate due to lamination. In addition, the sound-insulating/sound-absorbing material according to this embodiment is composed only of compressed resin fibers without containing metal, so that it can be made lighter and its adaptability to automobiles, electrical products, etc. can be improved.

In addition, the above embodiment of the present invention has been described with respect to a case where two layers, the first sound insulating/absorbing material 11 and the second sound insulating/absorbing material 12, are laminated, but the number of layers may be one layer or three or more layers. Also, the first sound insulating/absorbing material 11 and the second sound insulating/absorbing material 12 may each be made of the same material. It is clear from the claims that such modified or improved forms are also included within the technical scope of the present invention.

1 Sound-insulating/sound-absorbing material, 2 Main body, 3 Flange, 10 Sound-insulating/sound-absorbing material, 11 First sound-insulating/sound-absorbing material, 12 Second sound-insulating/sound-absorbing material, 20 Pressure device, 21 Pressure plate, 22 Nut, 23 Bolt.

Claims (3)

A fiber structure containing 50% or more nanofibers having a resin fiber diameter of 1000 nm or less and the remaining microfibers having a resin fiber diameter of 10 μm or less is compressed at room temperature ,
A sound-insulating/sound-absorbing material characterized in that it has a compression set rate of 40% or more . A fiber structure containing 50% or more nanofibers having a resin fiber diameter of 1000 nm or less and the remaining microfibers having a resin fiber diameter of 10 μm or less is compressed at room temperature,
At least a first sound insulating/absorbing material and a second sound insulating/absorbing material are laminated together,
The first sound-insulating/absorbing material and the second sound-insulating/absorbing material are different from each other in at least one of basis weight or porosity . 3. A sound insulating/absorbing member, comprising the sound insulating/absorbing material according to claim 1 or 2 molded into a predetermined shape.

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