Resin structure for musical instrument and method of manufacturing resin structure for musical instrument

Abstract

To provide a resin structure for a musical instrument capable of forming a musical instrument with excellent tone quality, a musical instrument constituting member and a musical instrument using the same.SOLUTION: A resin structure for a musical instrument, which is used as a musical instrument constituting member or a musical instrument, comprises a foamed portion made of a foam and a covering portion covering an entire surface of the foamed portion. The musical instrument constituting member and the musical instrument are made of the resin structure for the musical instrument.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin structure for a musical instrument used as a component of a musical instrument or as a musical instrument, and a method for producing a resin structure for a musical instrument. [Background technology]

[0002] Conventionally, there are resin structures for musical instruments that are used as musical instrument components or musical instruments in place of those made of natural materials such as wood. Examples of musical instruments for which such resin structures for musical instruments are used include the body of a recorder. Examples of musical instrument components for which such resin structures for musical instruments are used include mouthpieces and reeds for woodwind instruments such as saxophones and clarinets.

[0003] Cane reeds have traditionally been used for musical instruments such as saxophones and clarinets. However, cane reeds have the following problems (1) to (3). (1) One manufacturer states that the percentage of reeds used as materials for reed reeds is less than 10%. Therefore, reed reeds cannot be said to be making full use of the natural material reed, and it is difficult to fulfill the responsibility of manufacturing products that contribute to the realization of a sustainable society.

[0004] (2) Reed reeds vary widely in quality. For this reason, performers purchase many reed reeds, try them out one by one to check the tone and playability, and select and use only those that are of a satisfactory quality. Here, performers usually consider that only about 20% of the reed reeds that have been checked for tone and playability are deemed suitable for performance. Therefore, it must be said that the product yield of reed reeds is extremely low.

[0005] (3) Reed reeds have the disadvantage that moisture from the player's saliva and breath seeps into them, making them prone to deterioration and difficult to keep clean. In particular, reed reeds are vulnerable to dryness, so reeds inserted into the mouth for playing are often stored in moderate humidity conditions. This storage method makes them prone to mold. Furthermore, in recent years, there has been a demand for reeds that are easy to maintain hygienically, from the perspective of infection control.

[0006] Conventionally, musical instrument reeds are made of synthetic resin. Resin reeds have more stable quality than reed reeds. Resin reeds are also less prone to deterioration and easier to maintain hygienically than reed reeds. As for resin leads, for example, there are techniques described in Patent Documents 1-5. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 6,087,571 [Patent Document 2] Patent No. 6683689 [Patent Document 3] JP 2021-500466 A [Patent Document 4] JP 2017-134233 A [Patent Document 5] Patent Publication No. 2022-11035 Summary of the Invention [Problem to be solved by the invention]

[0008] Conventionally, musical instruments including a resin structure for a musical instrument as a constituent member of the musical instrument have been considered to have inferior tone quality compared to musical instruments using conventional musical instrument constituent members made of natural materials instead of the resin structure for a musical instrument. Also, musical instruments made of the resin structure for a musical instrument have been considered to have inferior tone quality compared to conventional musical instruments made of natural materials. For this reason, there is a demand for a resin structure for a musical instrument that can form a musical instrument with an excellent tone color, or a resin structure for a musical instrument that can be used as a musical instrument with an excellent tone color.

[0009] The present invention has been made in view of the above-mentioned problems, and has an object to provide a resin structure for a musical instrument that can form a musical instrument with an excellent tone color, a musical instrument component using the same, a resin structure for a musical instrument that can be used as a musical instrument with an excellent tone color, and a musical instrument using the same. Another object of the present invention is to provide a musical instrument constituent member capable of forming a musical instrument with an excellent tone color, or a method for manufacturing a resin structure for a musical instrument that can be used to form a musical instrument with an excellent tone color, a method for manufacturing a musical instrument constituent member, and a method for manufacturing a musical instrument. [Means for solving the problem]

[0010] A resin structure for a musical instrument according to one aspect of the present invention comprises a foamed portion made of a foam, and a covering portion covering the entire surface of the foamed portion. Effect of the Invention

[0011] The resin structure for a musical instrument of the present invention comprises a foamed portion made of a foam and a covering portion covering the entire surface of the foamed portion. Therefore, the resin structure for a musical instrument of the present invention can be used as a component for a musical instrument capable of forming a musical instrument with an excellent tone color, or as a musical instrument with an excellent tone color. Furthermore, according to the method for producing a resin structure for a musical instrument of the present invention, it is possible to produce a resin structure for a musical instrument of the present invention, which comprises a foamed portion made of a foam and a covering portion covering the entire surface of the foamed portion. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view illustrating a musical instrument reed, which is an example of the musical instrument resin structure of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the musical instrument reed shown in FIG. 1 taken along line AA'. [Diagram 3] 3 is a cross-sectional view of the musical instrument reed body shown in FIG. 1 taken along line BB'. [Figure 4] 1 shows photographs of the appearance of resin structure 1 and resin structure 2 used in Examples 1 to 8, the physical foams of Examples 1 to 8 produced in Examples 1 to 8, and a commercially available clarinet reed made of polypropylene (Legere European Cut, number 3.5). [Diagram 5] Fig. 5 shows acoustic spectra obtained by playing a clarinet using the physical foam of Example 2 as a clarinet reed. Fig. 5(a) shows the acoustic spectrum obtained by playing the note "Re (actual note D6)", Fig. 5(b) shows the acoustic spectrum obtained by playing the note "Re (actual note D5)", and Fig. 5(c) shows the acoustic spectrum obtained by playing the note "Re (actual note D4)". [Figure 6] Figure 6 shows the sound spectrum obtained by playing a clarinet using a commercially available polypropylene clarinet reed. Figure 6(a) shows the sound spectrum obtained by playing the pitch "Re (actual note D6)," Figure 6(b) shows the sound spectrum obtained by playing the pitch "Re (actual note D5)," and Figure 6(c) shows the sound spectrum obtained by playing the pitch "Re (actual note D4)." [Figure 7] Figure 7 shows the sound spectrum obtained by playing a clarinet using a commercially available cane clarinet reed. Figure 7(a) shows the sound spectrum obtained by playing the pitch "Re (actual note D6)", Figure 7(b) shows the sound spectrum obtained by playing the pitch "Re (actual note D5)", and Figure 7(c) shows the sound spectrum obtained by playing the pitch "Re (actual note D4)". [Figure 8] FIG. 8 is a photograph showing the appearance of resin structure 5 used in Example 11 and the physical foam of Example 11. [Figure 9] Fig. 9 shows acoustic spectra obtained by playing a clarinet in which a commercially available polypropylene clarinet reed is fixed to a mouthpiece made of the physical foam of Example 11. Fig. 9(a) shows acoustic spectra obtained by playing the note "Re (actual note D6)", Fig. 9(b) shows "Re (actual note D5)", and Fig. 9(c) shows "Re (actual note D4)". [Figure 10]Fig. 10 shows acoustic spectra obtained by playing a clarinet in which a clarinet reed made of the physical foam of Example 2 is fixed to a mouthpiece made of the physical foam of Example 11. Fig. 10(a) shows acoustic spectra obtained by playing the note "Re (actual note D6)," Fig. 10(b) shows "Re (actual note D5)," and Fig. 10(c) shows acoustic spectra obtained by playing the note "Re (actual note D4)." [Figure 11] Fig. 11 shows acoustic spectra obtained by playing a clarinet in which a commercially available cane clarinet reed is fixed to a mouthpiece made of the physical foam of Example 11. Fig. 11(a) shows acoustic spectra obtained by playing the note "Re (actual note D6)", Fig. 11(b) shows "Re (actual note D5)", and Fig. 11(c) shows "Re (actual note D4)". [Figure 12] FIG. 12 is a photograph showing the appearance of resin structure 6 used in Example 15 and the physical foam of Example 15. [Figure 13] Fig. 13 shows sound spectra obtained by playing a soprano recorder made of the physical foam of Example 15. Fig. 13(a) shows the sound spectrum obtained by playing the note "Re (actual note D6)", and Fig. 13(b) shows the sound spectrum obtained by playing the note "Re (actual note D5)". [Figure 14] Figure 14 shows sound spectra obtained by playing a commercially available soprano recorder of Comparative Example 3. Figure 14(a) shows the sound spectrum obtained by playing the note "Re (actual note D6)," and Figure 14(b) shows the sound spectrum obtained by playing the note "Re (actual note D5)." [Figure 15] FIG. 15 is a photograph showing the appearance of the resin structure 3 used in Experiments 1 to 4 and the physical foams of Experiments 1 to 4 produced in Experiments 1 to 4. As shown in FIG. [Figure 16] FIG. 16 is a photograph showing the appearance of the physical foams produced in Experiments 5 to 8. As shown in FIG. [Figure 17] FIG. 17 is a photograph showing the appearance of resin structure 7 used in Experiments 10 to 12 and the physical foams of Experiments 10 to 12 produced in Experiments 10 to 12. As shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Means for Solving the Problems The present inventors have conducted extensive research as described below in order to solve the above problems and provide a musical instrument constituent member capable of forming a musical instrument with an excellent tone color, or a resin structure for a musical instrument that can be used as a musical instrument with an excellent tone color.

[0014] First, in order to investigate the difference in tone (acoustic characteristics) between an instrument using a resin structure for a musical instrument and an instrument using a conventional natural material instead of a resin structure for a musical instrument, the harmonic composition of the sound of a woodwind instrument using a reed made of a conventional resin structure for a musical instrument and the sound of a woodwind instrument using a reed made of a reed were investigated. As a result, it was found that the sound of a woodwind instrument using a reed made of a resin structure for a musical instrument has significantly fewer high-order harmonics than the sound of a woodwind instrument using a reed made of a reed.

[0015] Therefore, in order to form a musical instrument reed that can produce a sound with a harmonic composition close to that of a reed reed, the inventors attempted to make the resin structure for a musical instrument itself similar to that of reed (cane), which is a natural material, and conducted extensive research as described below. The inventors of the present invention have attempted to form a structure simulating the fine porous structure of a reed by physically foaming the resin structure for a musical instrument, as a method for making the material of the resin structure for a musical instrument closer to that of a natural material, cane. However, when the resin structure for a musical instrument is physically foamed, there is a possibility that the dimensions of the resin structure will be unnecessarily changed.

[0016] As seen in reeds made of natural materials, individual differences in materials and dimensions directly affect the performance of the reed. Resin reeds have the advantage of being of stable quality compared to reed reeds. Therefore, for example, subjecting a resin reed to a physical foaming operation that may cause changes in dimensions may lead to the loss of the stable performance of the resin reed. In addition, it is expected that a great deal of effort will be required to deform a resin reed by physical foaming and evaluate the allowable degree of deformation. Due to these circumstances, it is considered that a person skilled in the art would not have thought of forming a porous structure by physically foaming a resin structure for a musical instrument.

[0017] In response to this, the present inventors have conducted extensive research into conditions for physically foaming a resin structure, and have found that a resin structure for a musical instrument can be obtained by physically foaming a resin structure, the resin structure comprising a foamed portion made of a foam and a covering portion covering the entire surface of the foamed portion. Furthermore, the inventors have confirmed that by using a musical instrument reed made of such a musical instrument resin structure, it is possible to obtain a sound with a harmonic composition closer to the sound of a woodwind instrument when a reed made of a reed is used, compared to the sound of a woodwind instrument when a musical instrument reed made of a conventional musical instrument resin structure is used, and have arrived at the present invention.

[0018] The present invention includes the following aspects. [1] A resin structure for a musical instrument, comprising a foamed portion made of a foam and a covering portion covering the entire surface of the foamed portion.

[0019] [2] A musical instrument component comprising the resin structure for a musical instrument described in [1]. [3] The musical instrument component described in [2], which is a musical instrument reed or a musical instrument mouthpiece. [4] A musical instrument comprising the resin structure for a musical instrument described in [1]. [5] The instrument described in [4], which is a recorder.

[0020] [6] The resin structure for a musical instrument according to [1], which is made of a material for physical foaming. [7] The resin structure for a musical instrument according to [6], wherein the physical foaming material comprises one or more selected from the group consisting of polypropylene, acrylic resin, polyamide, ebonite, and acrylonitrile-butadiene-styrene (ABS) resin. [8] The resin structure for a musical instrument according to [6], wherein the physical foaming material is made of polypropylene.

[0021] [9] A method for producing the resin structure for a musical instrument according to [1], comprising the steps of: an impregnation step of impregnating the resin structure with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body; and a bubble generating step of placing the resin-impregnated body under conditions of a second pressure lower than the first pressure and a second temperature that is the same as or different from the first temperature, thereby physically changing the foaming agent to generate bubbles, thereby forming a physical foam consisting of a foamed portion made of a foam and a covering portion that covers the entire surface of the foamed portion.

[0022]

[10] The method for producing a resin structure for a musical instrument according to [9], wherein the physical foam has the same shape as the resin structure.

[11] The method for producing a resin structure for a musical instrument according to [9], wherein the foaming agent is carbon dioxide.

[12] The method for producing a resin structure for a musical instrument according to [9], wherein the foaming agent is supercritical fluid carbon dioxide.

[0023]

[13] The method for manufacturing a resin structure for a musical instrument described in [9], wherein mechanical properties of the resin structure for a musical instrument are controlled within a specific range by changing one or more conditions selected from the first pressure, the first temperature, and the second temperature.

[14] The method for producing a resin structure for a musical instrument as described in [9], wherein the density of the resin structure for a musical instrument is controlled within a specific range by changing one or more conditions selected from the first pressure, the first temperature, and the second temperature.

[0024]

[15] The method for manufacturing a resin structure for a musical instrument described in [9], wherein acoustic characteristics of the resin structure for a musical instrument are controlled within a specific range by changing one or more conditions selected from the first pressure, the first temperature, and the second temperature.

[16] The method for producing a resin structure for a musical instrument according to

[15] , wherein the acoustic characteristic is a harmonic composition of a sound of a musical instrument that includes the resin structure for a musical instrument.

[0025]

[17] The method for producing a resin structure for a musical instrument according to any one of

[13] to

[15] , further comprising changing the second temperature.

[0026]

[18] A method for producing a musical instrument component according to the item [2], comprising the steps of: an impregnation step of impregnating the resin structure with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body; A manufacturing method for a musical instrument component includes a bubble generating step of physically changing the foaming agent to generate bubbles by placing the resin-impregnated body under conditions of a second pressure lower than the first pressure and a second temperature that is the same as or different from the first temperature, thereby forming a physical foam consisting of a foamed portion made of a foam and a covering portion that covers the entire surface of the foamed portion.

[0027]

[19] A method for manufacturing a musical instrument according to [4], comprising the steps of: an impregnation step of impregnating the resin structure with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body; A method for manufacturing a musical instrument, comprising: a bubble generation step of placing the resin-impregnated body under conditions of a second pressure lower than the first pressure, and a second temperature that is the same as or different from the first temperature, thereby physically changing the foaming agent to generate bubbles, thereby forming a physical foam consisting of a foamed portion made of a foam and a covering portion that covers the entire surface of the foamed portion.

[0028] Hereinafter, the resin structure for a musical instrument, the component of a musical instrument, the musical instrument, the manufacturing method of the resin structure for a musical instrument, the manufacturing method of the component of a musical instrument, and the manufacturing method of a musical instrument according to the present embodiment will be described in detail with reference to the drawings as appropriate. The drawings used in the following description may show characteristic parts in an enlarged scale for the sake of convenience in order to make the features of the present invention easier to understand. Therefore, the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto, and may be appropriately modified and implemented within the scope of the present invention.

[0029] [Resin structures for musical instruments] In this embodiment, a musical instrument reed will be described as an example of the musical instrument resin structure of the present invention. Fig. 1 is a perspective view for explaining a musical instrument reed which is an example of the musical instrument resin structure of the present invention. Fig. 2 is a cross-sectional view taken along line AA' of the musical instrument reed shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line BB' of the musical instrument reed body shown in Fig. 1.

[0030] As shown in FIG. 1, the musical instrument reed 1 of this embodiment has a generally rectangular shape in plan view. The planar shape and thickness of the musical instrument reed 1 are appropriately determined according to the type of musical instrument to be played using the musical instrument reed 1. As shown in FIG. 1 and FIG. 2, the thickness of the musical instrument reed 1 gradually decreases from the generally central portion 1d in the length direction on the side not in contact with the mouthpiece (the upper surface side in FIG. 1 and FIG. 2) toward the edge portion 1c on the side that the player holds in the mouth. When the musical instrument reed 1 is a clarinet reed, the thickness of the generally central portion 1d in the length direction (heel thickness) is preferably within a range of, for example, 2 mm to 4 mm, and the thickness of the edge portion 1c on the side that the player holds in the mouth (tip thickness) is preferably within a range of 0.03 mm to 0.5 mm. In addition, the dimension of the region in the length direction of the musical instrument reed 1 where the thickness of the edge portion 1c is 0.5 mm or less can be 1 mm to 50 mm.

[0031] 2 and 3, the musical instrument reed 1 of this embodiment is composed of a foamed portion 1b made of a foam and a covering portion 1a covering the entire surface of the foamed portion 1b. Therefore, a woodwind instrument using the musical instrument reed 1 of this embodiment can produce a sound with a harmonic composition similar to that of a woodwind instrument using a reed reed, which is a natural material having a fine porous structure.

[0032] As shown in Fig. 2, the thickness of the foamed portion 1b of the musical instrument reed 1 varies depending on the thickness dimension of the musical instrument reed 1. In contrast, as shown in Fig. 2 and Fig. 3, the thickness of the covering portion 1a (the dimension from the surface of the musical instrument reed 1 to the interface between the covering portion 1a and the foamed portion 1b) is approximately constant regardless of the thickness dimension of the musical instrument reed 1. As shown in Fig. 2, the foamed portion 1b is not formed in places where the thickness dimension of the musical instrument reed 1 is less than twice the thickness of the covering portion 1a, and the edge portion 1c on the side that the player holds in the mouth is made up only of the covering portion 1a and does not have the foamed portion 1b.

[0033] The musical instrument reed 1 of this embodiment has a covering portion 1a covering the entire surface of the foamed portion 1b, and furthermore, the edge portion 1c on the side that the player holds in the mouth is made of only the covering portion 1a, so that moisture contained in the saliva or breath of the player is less likely to seep into the foamed portion 1b. For this reason, the musical instrument reed 1 of this embodiment is easier to manage hygienically than a reed made of reed. In addition, since the musical instrument reed 1 of this embodiment has the covering portion 1a covering the entire surface of the foamed portion 1b, hygiene management is easier than, for example, when the covering portion 1a is not formed on at least a part of the surface of the foamed portion 1b and the foamed portion 1b is exposed. Furthermore, since the covering portion 1a covers the entire surface of the foamed portion 1b, there is little dimensional change with the resin structure used as the material of the musical instrument reed 1, and it is estimated that the musical instrument reed 1 has appropriate rigidity and is excellent in playability and durability.

[0034] The musical instrument reed 1 of this embodiment is made of a physically foamable material that can be foamed by physical foaming. Examples of the material for physical foaming that can be used include resin materials such as polypropylene, acrylic resin, polyamide, ebonite, acrylonitrile-butadiene-styrene (ABS) resin, methacrylic resin, phenolic resin, epoxy resin, polyurethane, polyester, polycarbonate, polyacetal, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyethylene (HDPE), polyether sulfone, polyphenylene ether, etc. Among these, it is preferable to use a material for physical foaming that contains one or more resin materials selected from polypropylene, acrylic resin, polyamide, ebonite, and acrylonitrile-butadiene-styrene resin, since they can be easily foamed by physical foaming.

[0035] The physically foaming material forming the musical instrument reed 1 may consist of only a resin material, or may contain non-resin materials such as fillers together with the resin material, as necessary, to the extent that they can be foamed by physical foaming. Examples of the filler that may be contained in the physical foaming material include organic fillers or inorganic fillers such as plant fibers, cellulose nanofibers, carbon fibers, silica particles, and glass fibers.

[0036] The musical instrument reed 1 of this embodiment is preferably made of a physical foaming material containing one or more resin materials selected from polypropylene, acrylic resin, and polyamide, and an organic or inorganic filler, because this is a material with a proven track record as an existing resin reed material. Furthermore, from the viewpoint that the musical instrument reed 1 of this embodiment can be easily manufactured, as needed, at musical instrument stores or the like by a method of physically foaming an existing resin reed, it is most preferable that the musical instrument reed 1 of this embodiment is made of a resin material containing polypropylene and is made of a physically foaming material that does not contain organic or inorganic fillers.

[0037] The musical instrument reed 1 of this embodiment preferably has a flexural modulus, which is a mechanical property of the musical instrument reed 1, within a range of 0.1 GPa to 20 GPa. When the musical instrument reed 1 has a flexural modulus of 0.1 GPa or more, the musical instrument reed 1 has appropriate rigidity and excellent durability. The musical instrument reed 1 more preferably has a flexural modulus of 1 GPa or more, and even more preferably has a flexural modulus of 3 GPa or more. Furthermore, since the flexural modulus of the musical instrument reed 1 is close to the flexural modulus of wood such as reed, it is preferably 20 GPa or less, and more preferably 15 GPa or less.

[0038] [Method of manufacturing resin structures for musical instruments] Next, as an example of a method for producing a resin structure for a musical instrument of the present invention, a method for producing a reed 1 for a musical instrument shown in FIG. 1 will be described. In the method for manufacturing a resin structure for a musical instrument of the present embodiment, the impregnation step and the bubble generating step are carried out in this order.

[0039] (Impregnation process) In the impregnation step, the resin structure is impregnated with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body. The resin structure is made of a resin material corresponding to the resin material forming the target musical instrument reed 1. It is preferable to use a resin structure having the shape of the target musical instrument reed 1. As the resin structure, a commercially available resin reed may be used, or a resin reed manufactured by a known method may be used.

[0040] The foaming material may be any known foaming material that can be used for physical foaming, and may be appropriately selected depending on the resin material that forms the intended musical instrument reed 1. For example, gaseous carbon dioxide, gaseous nitrogen, gaseous butane, supercritical fluid carbon dioxide, etc. may be used as the foaming material, and supercritical fluid carbon dioxide is preferably used since it is an easy-to-handle supercritical fluid.

[0041] The first pressure and the first temperature may be within a pressure range and a temperature range that allow the resin structure to be sufficiently impregnated with the foaming material. The first pressure and the first temperature can be appropriately determined depending on the type of resin material forming the resin structure, the shape of the resin structure, the type and amount of foam used, the shape of the musical instrument reed 1 as the target object, its mechanical properties and / or density, etc.

[0042] The higher the first pressure and the first temperature, the easier it is for the foaming material to be impregnated into the resin structure, promoting foaming in the bubble generation process and making it easier to obtain a musical instrument reed 1 with a small density and bending modulus. For example, when the resin structure has the shape of a musical instrument reed 1 made of polypropylene and the foaming material is supercritical fluid carbon dioxide, it is preferable that the first pressure is within the range of 7.4 MPa to 20 MPa and the first temperature is within the range of 32°C to 50°C.

[0043] The time for impregnating the resin structure with the foaming agent under the conditions of the first pressure and the first temperature may be any time long enough to allow the foaming agent to penetrate to the inside of the resin structure. The time for impregnating the foaming agent can be appropriately determined depending on the first pressure and the first temperature, the type of resin material forming the resin structure, the shape of the resin structure, the type and amount of foam used, etc. For example, when the resin structure has the shape of a musical instrument reed 1 made of polypropylene and the foaming agent is supercritical fluid carbon dioxide, the time for impregnating the resin structure with the foaming agent under the conditions of the first pressure and first temperature is preferably within a range of 12 hours to 168 hours, and more preferably within a range of 12 hours to 48 hours.

[0044] (Bubble generation process) In the bubble generating step, the resin-impregnated body is placed under conditions of a second pressure lower than the first pressure in the impregnation step and a second temperature the same as or different from the first temperature in the impregnation step. This physically changes the foaming agent to generate bubbles, forming a physical foam consisting of a foamed portion 1b made of a foam and a covering portion 1a covering the entire surface of the foamed portion 1b.

[0045] The second pressure is a pressure lower than the first pressure and can be, for example, normal pressure. The second temperature may be the same as or different from the first temperature, and may be any temperature at which bubbles are generated and at which the resin-impregnated body does not melt. If the second temperature is increased, many bubbles are more likely to be generated, and it becomes easier to obtain a musical instrument reed 1 with a small density and flexural modulus. If the second temperature is increased, the thickness of the covering portion 1a formed on the entire surface of the foamed portion 1b tends to become thinner. On the other hand, if the second temperature is too high, the resin-impregnated body becomes more likely to deform, making it difficult to obtain a musical instrument reed 1 having a desired shape.

[0046] The second temperature can be appropriately determined depending on the type of resin material forming the resin structure, the shape of the resin structure, the type and amount of foam used, and the shape, mechanical properties and / or density of the desired musical instrument reed 1. The second temperature is preferably within a range of 50°C to 150°C, for example, when the resin structure has the shape of musical instrument reed 1 made of polypropylene and the foaming material is carbon dioxide.

[0047] When the first temperature is lower than the second temperature and the resin-impregnated body is heated in the bubble generating step, the heating method used is not particularly limited as long as it can heat the resin-impregnated body. For example, when the first temperature is lower than the second temperature and the second temperature is 90° C. or lower, a method of immersing the resin-impregnated body in warm water or hot water can be used. Also, for example, when the first temperature is lower than the second temperature and the second temperature is higher than 90°C, a method can be used in which a heat press is used to minimize the pressure applied to the resin-impregnated body and heat the resin-impregnated body while avoiding deformation such as warping of the resin-impregnated body.

[0048] In the manufacturing method of this embodiment, it is preferable to use a method in which the resin structure is impregnated with a foaming agent in a pressure-resistant container such as a reactor under conditions of a predetermined first pressure and a predetermined first temperature, and then the impregnation step is performed, and the pressure in the pressure-resistant container is released to return the pressure in the pressure-resistant container to normal pressure, thereby setting the pressure inside the pressure-resistant container to a second pressure, and then the bubble generation step is started.

[0049] The bubble generation process of this embodiment preferably includes a temperature adjustment process in which, after starting the bubble generation process, the resin-impregnated body is heated at a predetermined heating rate or cooled at a predetermined cooling rate to a second temperature, and a foaming process in which the resin-impregnated body is foamed at the second temperature.

[0050] When the bubble generating step of this embodiment has a temperature adjusting step and a foaming step, a part of the foaming agent impregnated into the resin structure at the first pressure and the first temperature is preferentially released from the surface of the resin-impregnated body during the period from when the bubble generating step is started to when the foaming step is started (in other words, during the temperature adjusting step). As a result, at the stage when the foaming step is started (the stage when the resin-impregnated body is at the second temperature), the generation of bubbles inside the resin-impregnated body is promoted, and the foamed portion 1b and the covering portion 1a that covers the entire surface of the foamed portion 1b are easily formed.

[0051] When the second temperature profile is set under the above conditions, the time from the start of the bubble generation process to the start of the foaming process (in other words, the time during which the temperature adjustment process is performed) is, for example, preferably 15 seconds to 1440 minutes, and more preferably 15 seconds to 120 minutes. When the time during which the temperature adjustment process is performed is 300 seconds or more, the covering portion 1a having a sufficient thickness is easily formed on the entire surface of the foaming portion 1b. When the time during which the temperature adjustment process is performed is 300 seconds or less, the foaming agent impregnated into the resin structure at the first pressure and the first temperature can be prevented from being excessively released from the surface of the resin-impregnated body or from being physically changed. Therefore, a predetermined amount of bubbles can be generated inside the resin-impregnated body in the foaming process.

[0052] In the bubble generating step, it is preferable to hold the resin-impregnated body at the second temperature until gas is no longer generated from the resin-impregnated body, which allows sufficient bubble generation inside the resin-impregnated body.

[0053] The time from the start to the end of the bubble generating process can be appropriately determined depending on the first and second temperatures, the type of resin material forming the resin structure, the shape of the resin structure, the type and amount of foam used, the shape, mechanical properties and / or density of the target musical instrument reed 1, etc. The time from the start to the end of the bubble generating process can be within a range of 15 seconds to 1440 minutes, for example, and is preferably within a range of 5 minutes to 120 minutes.

[0054] For example, when manufacturing a clarinet reed made of polypropylene as a musical instrument reed 1, if the time from the start to the end of the bubble generation process is 15 seconds or more, a sufficient amount of bubbles can be generated inside the resin-impregnated body in the bubble generation process.

[0055] Moreover, it is preferable that the time from the start to the end of the air bubble generating step is short, from the viewpoint of efficiently manufacturing the musical instrument reed 1. For example, when a clarinet reed made of polypropylene is manufactured as the musical instrument reed 1, the above-mentioned time can be set to 5 minutes or less by setting the second temperature to a temperature at which air bubbles are efficiently generated and shortening the time for which the temperature adjustment step is performed using a known method.

[0056] In the manufacturing method of this embodiment, it is preferable that the shape of the physical foam formed by carrying out the cell generating step is the same as the shape of the resin structure used in the impregnation step. In this case, by using a resin structure having the shape of the desired musical instrument reed 1, the physical foam obtained by carrying out the bubble generating step can be used as is as the musical instrument reed 1. Therefore, compared to the case where, for example, machining or other processing is carried out to give the physical foam a predetermined shape, the musical instrument reed 1 can be manufactured easily and efficiently with fewer steps. In addition, by using, for example, a resin reed made of a synthetic resin that is commercially available as a musical instrument reed as the resin structure, it is possible to provide a musical instrument reed 1 whose mechanical properties such as bending elastic modulus and / or density are changed within a specific range according to the player's preference.

[0057] In this specification, the physical foam having the same shape as the resin structure means that a physical foam obtained by using a resin structure that can be used as a musical instrument component such as a resin reed or as a musical instrument and performing an impregnation step and a bubble generating step has a shape that is the same as or has only a slight difference from the resin structure. The physical foam having only a slight difference in shape from the resin structure means that the physical foam has a shape that can be used as a musical instrument component or as a musical instrument without any problems, simply by adjusting the shape of the physical foam to a feasible extent using a tool such as a file, and without processing the physical foam using a large-scale device such as a cutting machine.

[0058] In the manufacturing method of this embodiment, the shape of the physical foam formed by carrying out the bubble generating step is preferably the same as that of the resin structure used in the impregnation step, but it does not have to be the same shape. In this case, in order to give the physical foam obtained by carrying out the bubble generating step a predetermined shape, it may be processed, such as by cutting, within a range in which the foamed portion 1b is not exposed, before being used as the musical instrument reed 1.

[0059] In the manufacturing method of this embodiment, by changing one or more conditions selected from the first pressure in the impregnation step, the first temperature in the impregnation step, and the second temperature in the bubble generation step, it is possible to make the mechanical properties such as the flexural modulus and / or the density of the musical instrument reed 1 fall within a specific range. This makes it possible to make the acoustic characteristics of the musical instrument reed 1 fall within a specific range. For example, the acoustic characteristics of the musical instrument reed 1 can be the harmonic composition of the sound of a woodwind instrument that uses a musical instrument reed made of wood.

[0060] The musical instrument reed 1 of this embodiment is composed of a foamed portion 1b made of a foam and a covering portion 1a covering the entire surface of the foamed portion 1b. Therefore, the musical instrument reed 1 of this embodiment can form a woodwind instrument with an excellent tone. Specifically, a woodwind instrument using the musical instrument reed 1 of this embodiment can produce a sound with a harmonic composition that has many high-order harmonics similar to the sound of a woodwind instrument using a reed reed, which is a natural material having a fine porous structure. Specifically, a sound with a harmonic composition that includes many harmonics in the frequency range of 4 kHz or more, including higher-order harmonics of 16 kHz or more, and even harmonics exceeding 30 kHz can be produced.

[0061] Furthermore, since the manufacturing method of the musical instrument reed 1 of this embodiment includes an impregnation process and a bubble generation process, it is possible to manufacture the musical instrument reed 1 of this embodiment, which is composed of a foamed portion 1b made of a foam and a covering portion 1a covering the entire surface of the foamed portion 1b.

[0062] [Other examples] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments. The configurations and combinations thereof in the above-mentioned embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention.

[0063] For example, in the above-mentioned embodiment, a musical instrument reed, which is a musical instrument component, has been described as an example of a musical instrument component or a musical instrument resin structure used as a musical instrument, but the present invention is not limited to musical instrument reeds. Examples of musical instrument components in the present invention include mouthpieces for wind instruments, ligatures, guitar picks, xylophone soundboards, marimba soundboards, xylophone soundboards, vibraphone soundboards, and resin piano keyboards. In addition, examples of musical instruments made of the musical instrument resin structure include resin musical instruments such as resin recorders, resin flutes, resin trumpets, resin saxophones, resin clarinets, resin oboes, resin bassoons, resin trombones, resin stringed instruments, resin percussion instruments, and resin stringed percussion instruments.

[0064] When the musical instrument component of the present invention is a mouthpiece for a wind instrument, it is preferably made of a resin material such as polypropylene, acrylic resin, polyamide, ebonite, acrylonitrile butadiene styrene (ABS) resin, methacrylic resin, phenolic resin, epoxy resin, polyurethane, polyester, polycarbonate, polyacetal, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyethylene (HDPE), polyether sulfone, polyphenylene ether, etc. Among these, since performers prefer resins that have a long track record of use as commercial products, it is preferable to use any resin material selected from ebonite, phenolic resin, and acrylic resin.

[0065] Furthermore, when the musical instrument of the present invention is a resin recorder, it is preferable that the instrument is made of a resin material such as a physical foaming material, such as polypropylene, acrylic resin, polyamide, ebonite, acrylonitrile butadiene styrene (ABS) resin, methacrylic resin, phenolic resin, epoxy resin, polyurethane, polyester, polycarbonate, polyacetal, polyphenylene sulfide, polyethylene terephthalate, polybutylene terephthalate, polyether ether ketone, polyethylene (HDPE), polyethersulfone, polyphenylene ether, etc. Among these, it is preferable that the instrument is made of a resin material selected from acrylic resin, polyester, and ABS resin, since performers prefer resins that have a long track record of use as commercially available products. EXAMPLES

[0066] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0067] [Example 1] A physical foam for a clarinet reed was manufactured by the method described below. (Impregnation process) A pressure-resistant container (portable reactor (manufactured by Taiatsu Glass Industries Co., Ltd., capacity 200 mL, design pressure: 10 MPa, design temperature: 200°C)) was prepared. In addition, a commercially available translucent clarinet reed (Legere European Cut, number 4.5) made of polypropylene was prepared as the resin structure 1 (see FIG. 4).

[0068] Then, in the pressure-resistant container, the resin structure was impregnated with supercritical fluid carbon dioxide as a foaming agent for 24 hours under conditions of a first pressure of 7.5 MPa and a first temperature of 44° C. Carbon dioxide under the above-mentioned first pressure and first temperature conditions was in a supercritical state (critical pressure 7.4 MPa, critical temperature 31° C.). Thereafter, the leak valve of the pressure vessel was opened to release the pressure in the pressure vessel, and the inside of the pressure vessel was returned to room temperature and normal pressure to set the second pressure, and the bubble generation process was started.

[0069] (Bubble generation process) The resin-impregnated body was removed from the pressure vessel and immediately immersed in hot water to heat it to 90°C (second temperature), at which point numerous bubbles appeared on the surface of the resin-impregnated body. It took about one minute from the time the pressure in the pressure vessel was released to start the bubble generation process to the time the resin-impregnated body was heated to the second temperature. Heating was then continued until gas was no longer generated from the resin-impregnated body, and the resin-impregnated body was removed from the hot water to terminate heating and allowed to cool. By carrying out the above steps, as shown in FIG. 4, a physical foam of Example 1 was obtained, which consisted of a foamed portion 1b consisting of an opaque white portion and a translucent covering portion 1a covering the entire surface of the foamed portion 1b.

[0070] [Examples 2 to 4] The impregnation process was carried out in the same manner as in Example 1 to obtain a resin-impregnated body. Then, the resin-impregnated body was heated without applying pressure to the resin-impregnated body using a heat press machine (product name: heat press machine, manufactured by TUSY). The temperature (second temperature) at which the resin-impregnated body was heated was 100°C in Example 2, 110°C in Example 3, and 120°C in Example 4. When the resin-impregnated body was heated at the above temperatures, gas was generated from the resin-impregnated body at each temperature. In addition, the time from releasing the pressure in the pressure-resistant container to starting the bubble generating process to the second temperature was about 1 minute in each case. Thereafter, heating was continued until gas was no longer generated from the resin-impregnated body, and the resin-impregnated body was removed from the heat press machine, whereby heating of the resin-impregnated body was terminated and allowed to cool. By carrying out the above steps, the physical foams of Examples 2 to 4 were obtained, which consisted of a foamed portion 1b consisting of a milky white portion and a translucent covering portion 1a covering the entire surface of the foamed portion 1b, as shown in FIG. 4.

[0071] [Examples 5 to 8] As the resin structure 2, a commercially available translucent clarinet reed (Legere European Cut, number 4.0) made of polypropylene was prepared (see FIG. 4). Then, the impregnation step was carried out in the same manner as in Example 1, except that resin structure 2 was used, to obtain a resin-impregnated body.

[0072] Thereafter, the resin-impregnated body was heated in the same manner as in Example 2, except that the temperature (second temperature) at which the resin-impregnated body was heated was 100°C in Example 5, 120°C in Example 6, 140°C in Example 7, and 160°C in Example 8. As a result, gas was generated from the resin-impregnated body at each temperature. The time from releasing the pressure in the pressure-resistant container to starting the bubble generation process to reaching the second temperature was about 1 minute in each case. Thereafter, heating was continued until gas was no longer generated from the resin-impregnated body, and the resin-impregnated body was removed from the heat press machine, whereby heating of the resin-impregnated body was terminated and allowed to cool. By carrying out the above steps, the physical foams of Examples 5 to 8 were obtained, which consisted of a foamed portion 1b consisting of a milky white portion and a translucent covering portion 1a covering the entire surface of the foamed portion 1b, as shown in FIG. 4.

[0073] The physical foams of Examples 1 to 8 thus obtained were fixed to mouthpieces as clarinet reeds, and the reeds were attached to clarinets. A player played the clarinet to confirm whether it was playable or not.

[0074] As a result, it was possible to play the physical foams of Examples 1 to 6. However, the physical foams of Examples 7 and 8 were not playable in their original shapes due to poor shape.

[0075] Furthermore, when a player played the instruments, it was found that the playing feel of the physical foams of Examples 1 to 8, which used resin structures 1 and 2 with hardness numbers 4.5 (resin structure 1) and 4.0 (resin structure 2), was comparable to that of a commercially available polypropylene clarinet reed (Legere European Cut, number 3.5) (see (number 3.5) in FIG. 4 ). This is presumably because the physical foams of Examples 1 to 8 have foam portion 1b, which reduces their hardness.

[0076] FIG. 4 is a photograph showing the appearance of resin structure 1 and resin structure 2 used in Examples 1 to 8, the physical foams of Examples 1 to 8 produced in Examples 1 to 8, and a commercially available clarinet reed made of polypropylene (Legere European Cut, number 3.5).

[0077] [Example 9] Except for setting the temperature (second temperature) at which the resin-impregnated body was heated to 110°C, the same procedure as in Example 5 was followed to obtain the physical foam of Example 9, which consisted of a foamed portion 1b consisting of a cloudy portion and a translucent covering portion 1a covering the entire surface of the foamed portion 1b.

[0078] The apparent densities of the thus obtained physical foams of Examples 5 to 9 and the resin structure 2 were determined based on Archimedes' principle. The results are shown in Table 1.

[0079] [Table 1]

[0080] As shown in Table 1, it was confirmed that a physical foam having a low density can be obtained more easily by increasing the heating temperature (second temperature) of the resin-impregnated body. It was also found that if the heating temperature (second temperature) of the resin-impregnated body is made too high, the resin-impregnated body becomes more likely to deform, making it difficult to obtain a physical foam having a desired shape.

[0081] [Example 10] The physical foam of Example 2 was used as a clarinet reed and fixed to a clarinet mouthpiece (product name: Vandoren B♭ Clarinet Mouthpiece Black Diamond 5, manufactured by Vandoren) and attached to the clarinet. A condenser microphone (DPA4011, manufactured by DPA) was placed at a position about 30 cm away from the finger holes of the clarinet (about 20 cm from the mouthpiece). The condenser microphone was then connected to an audio control console (SR51, manufactured by ADT) and an audio interface (DADman, manufactured by NTP Technology), and the playing sound was recorded using a DAW (Digital Audio Workstation (Pro Tools, manufactured by Avid)).

[0082] The wind sounds were recorded by a player playing a clarinet equipped with a clarinet reed made of the physical foam of Example 2. The player played the clarinet in three octaves of increasing pitch, starting from "Re (actual note D3)" in the low range, "Mi (actual note E3)," "Fa♯ (actual note F♯3)," "So (actual note G3)," "La (actual note A3)," "Si (actual note B3)," "Do♯ (actual note C♯4)," and "Re (actual note D4)," all the way up to "Re (actual note D6)," at a constant volume.

[0083] The wind sounds recorded in the DAW were then Fourier transformed (fft function) for each specific pitch using numerical analysis software (Mathworks, Matlab R2023b) to obtain an acoustic spectrum with frequency on the horizontal axis and sound pressure on the vertical axis. Fig. 5 shows acoustic spectra obtained by playing a clarinet using the physical foam of Example 2 as a clarinet reed. Fig. 5(a) shows the acoustic spectrum obtained by playing the note "Re (actual note D6)", Fig. 5(b) shows the acoustic spectrum obtained by playing the note "Re (actual note D5)", and Fig. 5(c) shows the acoustic spectrum obtained by playing the note "Re (actual note D4)".

[0084] From the acoustic spectrum shown in Fig. 5(a), it was confirmed that a sound having a harmonic composition including many harmonics of the pitch of "Re (actual note D6 (1189 Hz))" can be obtained by playing the pitch of "Re (actual note D6)" on a clarinet using the physical foam of Example 2. In particular, the acoustic spectrum shown in Fig. 5(a) shows that many high-order harmonics of 16 kHz or more (14th order or more) are included, and harmonics appear in a frequency range exceeding 30 kHz.

[0085] Furthermore, from the acoustic spectrum shown in FIG. 5(b), it was confirmed that by playing the note "Re (actual note D5 (588 Hz))" on a clarinet using the physical foam of Example 2, a sound with a harmonic composition containing many harmonics above 10 kHz (14th order or higher), and even higher harmonics exceeding 16 kHz, can be obtained. Furthermore, from the acoustic spectrum shown in FIG. 5(c), it was confirmed that by playing the note "Re (actual note D4 (292 Hz))" on a clarinet made using the physical foam of Example 2, a sound with a harmonic composition containing many high-order harmonics of 4 kHz or higher (14th order or higher) can be obtained.

[0086] [Comparative Example 1] Except for using a commercially available translucent clarinet reed (Legere European Cut, number 3.5) made of polypropylene (see (number 3.5) in FIG. 4 ) instead of the physical foam of Example 2, the same procedure as in Example 10 was used to record the sound of a performer playing a clarinet, and an acoustic spectrum was obtained with frequency on the horizontal axis and sound pressure on the vertical axis.

[0087] Figure 6 shows the sound spectrum obtained by playing a clarinet using a commercially available polypropylene clarinet reed. Figure 6(a) shows the sound spectrum obtained by playing the pitch "Re (actual note D6)," Figure 6(b) shows the sound spectrum obtained by playing the pitch "Re (actual note D5)," and Figure 6(c) shows the sound spectrum obtained by playing the pitch "Re (actual note D4)."

[0088] In addition, since the blowing feel of the physical foam of Example 2 is similar to that of a commercially available clarinet reed made of polypropylene (Legere European Cut, number 3.5) (see (number 3.5) in Figure 4), it is estimated that the hardness of the physical foam of Example 2 is reduced by having foam portion 1b, and that it has a hardness similar to that of a commercially available clarinet reed (Legere European Cut, number 3.5).

[0089] From the acoustic spectrum shown in Fig. 6(a), it was found that when the pitch "Re (actual note D6 (1189 Hz))" is played on a clarinet using a commercially available clarinet reed made of polypropylene, the signal intensity derived from the harmonics of the pitch "Re (actual note D6)" is clearly smaller, resulting in a sound with a harmonic composition with fewer harmonics, compared to when it is played on a clarinet using the physical foam of Example 2 (see Fig. 5(a)). In particular, the acoustic spectrum shown in Fig. 6(a) shows that high-order harmonics above 16 kHz (14th order or higher) hardly appear.

[0090] Furthermore, from the acoustic spectrum shown in FIG. 6(b), it was confirmed that when the pitch "Re (actual note D5 (588 Hz))" is played on a clarinet using a commercially available clarinet reed made of polypropylene, there are fewer high-order harmonics above 10 kHz (14th order or higher) and almost no harmonics above 16 kHz appear, compared to when the clarinet is played using the physical foam of Example 2 (see FIG. 5(b)).

[0091] Furthermore, from the acoustic spectrum shown in FIG. 6(c), it was confirmed that when the pitch of "Re (actual note D4 (292 Hz))" is played on a clarinet using a clarinet reed made of commercially available polypropylene, there are fewer high-order harmonics above 4 kHz (14th order or higher), almost no harmonics above 10 kHz, and there is a lot of noise, compared to when the note is played on a clarinet using the physical foam of Example 2 (see FIG. 5(c)).

[0092] [Comparative Example 2] Except for using a commercially available cane clarinet reed (product name: Reserve Evolution B♭ Clarinet, manufactured by D'Addario, number 3.5) instead of the physical foam of Example 2, the same procedure as in Example 10 was used to record the sound of a performer playing a clarinet, and an acoustic spectrum was obtained with frequency on the horizontal axis and sound pressure on the vertical axis.

[0093] Figure 7 shows the sound spectrum obtained by playing a clarinet using a commercially available cane clarinet reed. Figure 7(a) shows the sound spectrum obtained by playing the pitch "Re (actual note D6)", Figure 7(b) shows the sound spectrum obtained by playing the pitch "Re (actual note D5)", and Figure 7(c) shows the sound spectrum obtained by playing the pitch "Re (actual note D4)".

[0094] From the acoustic spectrum shown in Fig. 7(a), it was found that when the pitch "Re (actual note D6 (1189 Hz))" is played on a clarinet using a commercially available cane clarinet reed, a sound with a harmonic composition very similar to that obtained when the clarinet is played using the physical foam of Example 2 (see Fig. 5(a)) is obtained. The acoustic spectrum shown in Fig. 7(a) contains many high-order harmonics above 16 kHz (14th order or higher), similar to the acoustic spectrum shown in Fig. 5(a), and it is shown that harmonics appear in the frequency range exceeding 30 kHz.

[0095] Furthermore, from the acoustic spectrum shown in FIG. 7(b), it was confirmed that when the note "Re (actual note D5 (588 Hz))" was played on a clarinet using a commercially available cane clarinet reed, there were many high-order harmonics above 10 kHz (14th order or higher), and harmonics appeared in the frequency range above 16 kHz, just as in the case of playing on a clarinet using the physical foam of Example 2 (see FIG. 5(b)).

[0096] Furthermore, from the acoustic spectrum shown in FIG. 7(c), it was confirmed that when the note "Re (actual note D4 (292 Hz))" was played on a clarinet using a commercially available cane clarinet reed, many high-order harmonics above 4 kHz (14th order or higher) appeared, just as in the case of playing on a clarinet using the physical foam of Example 2 (see FIG. 5(c)). In addition, it was found that when the note "Re" (actual note D4 (292 Hz)) is played on a clarinet using a commercially available cane clarinet reed, almost no overtones above 10 kHz appear.

[0097] From the acoustic spectra shown in Figures 5 to 7, it was confirmed that by using the physical foam of Example 2, which consists of a foamed portion 1b made of a foam and a covering portion 1a covering the entire surface of the foamed portion 1b, it is possible to obtain a sound with a harmonic composition closer to the sound of a clarinet when a reed made of reed is used, compared to the sound of a clarinet when a clarinet reed made of commercially available polypropylene is used.

[0098] Furthermore, from the acoustic spectra shown in Figures 5 and 7, it was found that the sound of the clarinet using the physical foam of Example 2 has more high-order harmonics than the sound of the clarinet using a reed reed. This indicates that the clarinet using the physical foam of Example 2 may have better tone quality and / or playability than the clarinet using a reed reed, depending on the piece being played and the player's preferences. Therefore, the clarinet using the physical foam of Example 2 can broaden the range of expression for the player.

[0099] [Example 11] A physical foam for a clarinet mouthpiece was produced by the method described below. (Impregnation process) A pressure-resistant container (portable reactor (manufactured by Taiatsu Glass Industries Co., Ltd., capacity 200 mL, design pressure: 10 MPa, design temperature: 200°C)) was prepared. In addition, a commercially available clarinet mouthpiece made of ebonite (product name: Vandoren B♭ Clarinet Mouthpiece Black Diamond 5, manufactured by Vandoren) was prepared as the resin structure 5 (see FIG. 8).

[0100] Then, in the pressure-resistant container, the resin structure was impregnated with supercritical fluid carbon dioxide as a foaming agent for 24 hours under conditions of a first pressure of 7.5 MPa and a first temperature of 40° C. Carbon dioxide under the above-mentioned first pressure and first temperature conditions was in a supercritical state (critical pressure 7.4 MPa, critical temperature 31° C.). Thereafter, the leak valve of the pressure vessel was opened to release the pressure in the pressure vessel, and the inside of the pressure vessel was returned to room temperature and normal pressure to set the second pressure, and the bubble generation process was started.

[0101] (Bubble generation process) The resin-impregnated body was removed from the pressure vessel and immediately immersed in boiling water to heat it to 100°C (second temperature), at which point numerous fine irregularities appeared on the surface of the resin-impregnated body. It took about one minute from the time the pressure in the pressure vessel was released to start the bubble generation process until the resin-impregnated body reached the second temperature. Heating was then continued until gas was no longer being generated from the resin-impregnated body, and the resin-impregnated body was removed from the warm water to terminate heating and allowed to cool. By carrying out the above steps, a physical foam of Example 11 was obtained, which was composed of a foamed portion and a covering portion covering the entire surface of the foamed portion, as shown in FIG.

[0102] 8 is a photograph showing the appearance of resin structure 5 used in Example 11 and the physical foam of Example 11. In the physical foam of Example 11, many dense air bubbles were formed inside, and many minute air bubble-derived irregularities were observed on the surface.

[0103] [Example 12] A commercially available translucent clarinet reed (Legere European Cut, No. 4.5) made of polypropylene, which is the resin structure 1, was fixed to the clarinet mouthpiece, which is the physical foam of Example 11, and attached to the clarinet. A condenser microphone (Sony, ECM-100N) was placed at a position about 30 cm away from the finger holes (about 20 cm from the mouthpiece) of the clarinet. The condenser microphone was then connected to an audio interface (RME, Babyface Pro FS), and the blowing sound was recorded using Audacity (developed by The Audacity Team).

[0104] The blowing sounds were recorded by a player playing a clarinet equipped with a clarinet mouthpiece made of the physical foam of Example 11. The player played the note "Re" in four ranges, increasing the pitch in the order from "Re (actual note D3)" in the low range to "Re (actual note D4)," "Re (actual note D5)," and so on, up to "Re (actual note D6)," at a constant volume using the clarinet.

[0105] The wind sounds recorded in Audacity were then Fourier transformed (fft function) for each specific pitch using numerical analysis software (Mathworks, Matlab R2023b) to obtain an acoustic spectrum with frequency on the horizontal axis and sound pressure on the vertical axis. Fig. 9 shows acoustic spectra obtained by playing a clarinet in which a commercially available polypropylene clarinet reed is fixed to a mouthpiece made of the physical foam of Example 11. Fig. 9(a) shows acoustic spectra obtained by playing the note "Re (actual note D6)", Fig. 9(b) shows "Re (actual note D5)", and Fig. 9(c) shows "Re (actual note D4)".

[0106] From the acoustic spectrum shown in Fig. 9(a), it was found that by playing the pitch "Re (actual note D6 (1189 Hz))" with a clarinet in which a commercially available clarinet reed made of polypropylene is fixed to a mouthpiece made of the physical foam of Example 11, a sound with a harmonic composition similar to that obtained when a clarinet reed made of the physical foam of Example 2 is fixed to a clarinet mouthpiece made of commercially available ebonite (see Fig. 5(a)) is played. Moreover, the acoustic spectrum shown in Fig. 9(a) contains many more high-order harmonics of 16 kHz or more (14th order or more) than the acoustic spectrum shown in Fig. 5(a), and it is shown that harmonics appear in a frequency range exceeding 30 kHz.

[0107] From the acoustic spectrum shown in Figure 9(b), it was confirmed that when the pitch of "Re (actual note D5 (588 Hz))" was played with a clarinet in which a commercially available clarinet reed made of polypropylene was fixed to a mouthpiece made of the physical foam of Example 11, the sound produced was similar to the sound produced when a clarinet reed made of the physical foam of Example 2 was played with a clarinet in which a commercially available clarinet mouthpiece made of ebony (see Figure 5(b)), containing many high-order harmonics of 10 kHz or more (14th order or more), and that harmonics appeared in a frequency range exceeding 16 kHz, which was more pronounced than in the acoustic spectrum shown in Figure 5(b).

[0108] From the acoustic spectrum shown in Figure 9(c), it was confirmed that when the pitch of "Re (actual note D4 (292 Hz))" was played with a clarinet in which a commercially available clarinet reed made of polypropylene was fixed to a mouthpiece made of the physical foam of Example 11, a significantly greater number of high-order harmonics above 4 kHz (14th order or higher) appeared than when the note was played with a clarinet in which a clarinet reed made of the physical foam of Example 2 was fixed to a clarinet mouthpiece made of commercially available ebony (see Figure 5(c)).

[0109] [Example 13] The clarinet was played in the same manner as in Example 12, except that a clarinet reed made of the physical foam of Example 2 was fixed to a clarinet mouthpiece made of the physical foam of Example 11 instead of a commercially available polypropylene clarinet reed (manufactured by Legere, Legere European Cut, number 4.5). The sound of a performer playing the clarinet was recorded, and an acoustic spectrum was obtained with frequency on the horizontal axis and sound pressure on the vertical axis.

[0110] Fig. 10 shows acoustic spectra obtained by playing a clarinet in which a clarinet reed made of the physical foam of Example 2 is fixed to a mouthpiece made of the physical foam of Example 11. Fig. 10(a) shows acoustic spectra obtained by playing the note "Re (actual note D6)," Fig. 10(b) shows "Re (actual note D5)," and Fig. 10(c) shows acoustic spectra obtained by playing the note "Re (actual note D4)."

[0111] From the acoustic spectrum shown in Fig. 10(a), it was found that by playing the note "Re (actual note D6 (1189 Hz))" with a clarinet in which the clarinet reed made of the physical foam of Example 2 is fixed to a mouthpiece made of the physical foam of Example 11, a sound with a harmonic composition similar to that obtained when the clarinet reed made of the physical foam of Example 2 is played with a clarinet in which a clarinet mouthpiece made of commercially available ebonite is fixed (see Fig. 5(a)). Moreover, the acoustic spectrum shown in Fig. 10(a) contains many more high-order harmonics of 16 kHz or more (14th order or more) than the acoustic spectrum shown in Fig. 5(a), and it is shown that harmonics appear in a frequency range exceeding 30 kHz.

[0112] From the acoustic spectrum shown in Figure 10(b), it was confirmed that when the pitch of "Re (actual note D5 (588 Hz))" was played on a clarinet in which the clarinet reed made of the physical foam of Example 2 was fixed to a mouthpiece made of the physical foam of Example 11, the pitch contained a significantly greater number of high-order harmonics of 10 kHz or more (14th order or more) than when the pitch was played on a clarinet in which the clarinet reed made of the physical foam of Example 2 was fixed to a clarinet mouthpiece made of commercially available ebonite (see Figure 5(b)), and harmonics appeared in the frequency range above 16 kHz.

[0113] From the acoustic spectrum shown in Figure 10(c), it was confirmed that when the pitch of "Re (actual note D4 (292 Hz))" was played on a clarinet in which the clarinet reed made of the physical foam of Example 2 was fixed to a mouthpiece made of the physical foam of Example 11, many high-order harmonics above 4 kHz (14th order or higher) appeared, as in the case of playing on a clarinet in which the clarinet reed made of the physical foam of Example 2 was fixed to a clarinet mouthpiece made of commercially available ebonite (see Figure 5(c)), and that few harmonics appeared in the frequency range above 16 kHz.

[0114] [Example 14] The clarinet was played in the same manner as in Example 12, except that a commercially available cane clarinet reed (Vandoren, V.12 reed, number 3 1 / 2) was fixed to the physical foam clarinet mouthpiece of Example 11 instead of a commercially available polypropylene clarinet reed (Legere, Legere European Cut, number 4.5). The sound of the performer playing the clarinet was recorded, and an acoustic spectrum was obtained with the horizontal axis representing frequency and the vertical axis representing sound pressure.

[0115] Fig. 11 shows acoustic spectra obtained by playing a clarinet in which a commercially available cane clarinet reed is fixed to a mouthpiece made of the physical foam of Example 11. Fig. 11(a) shows acoustic spectra obtained by playing the note "Re (actual note D6)", Fig. 11(b) shows "Re (actual note D5)", and Fig. 11(c) shows "Re (actual note D4)".

[0116] From the acoustic spectrum shown in Fig. 11(a), it was confirmed that by playing the note "Re (actual note D6 (1189 Hz))" with a clarinet in which a commercially available cane clarinet reed is fixed to a mouthpiece made of the physical foam of Example 11, a sound with a harmonic composition containing many harmonics of the note "Re (actual note D6)" can be obtained. In particular, the acoustic spectrum shown in Fig. 11(a) shows that many high-order harmonics above 16 kHz (14th order or higher) are included, and harmonics appear in a frequency range exceeding 30 kHz.

[0117] From the acoustic spectrum shown in Figure 11(b), it was confirmed that by playing the note "Re (actual note D5 (588 Hz))" on a clarinet in which a commercially available cane clarinet reed is fixed to a mouthpiece made of the physical foam of Example 11, a sound with a harmonic composition containing many harmonics above 10 kHz (14th order or higher), and even higher harmonics exceeding 16 kHz, can be produced.

[0118] However, as shown in Figure 11(b), when a clarinet with a commercially available clarinet reed made of cane fixed to a mouthpiece made of the physical foam of Example 11 was played with a clarinet with a clarinet reed made of the physical foam of Example 2 fixed to a mouthpiece made of the physical foam of Example 11, there were fewer high-order harmonics above 16 kHz and no harmonics in the frequency range above 30 kHz were detected, compared to when the note "Re (actual note D5 (588 Hz))" was played with a clarinet with a clarinet reed made of the physical foam of Example 2 fixed to a mouthpiece made of the physical foam of Example 11 (see Figure 10(b)).

[0119] From the acoustic spectrum shown in Figure 11(c), it was confirmed that when the pitch of "Re (actual note D4 (292 Hz))" was played on a clarinet in which a commercially available clarinet reed made of cane was fixed to a mouthpiece made of the physical foam of Example 11, many high-order harmonics above 4 kHz (14th order or higher) appeared, as in the case of playing on a clarinet in which a clarinet reed made of the physical foam of Example 2 was fixed to a clarinet mouthpiece made of commercially available ebonite (see Figure 5(c)), and that few harmonics appeared in the frequency range above 16 kHz.

[0120] [Example 15] A physical foam soprano recorder was manufactured by the method described below. (Impregnation process) A pressure-resistant container (portable reactor (manufactured by Taiatsu Glass Industries Co., Ltd., capacity 200 mL, design pressure: 10 MPa, design temperature: 200° C.) was prepared. In addition, a commercially available soprano recorder (product name: YRS-20GB, manufactured by Yamaha Corporation) made of ABS resin was prepared as the resin structure 6 (see FIG. 12 ).

[0121] Then, in a pressure-resistant container, the resin structure was impregnated with carbon dioxide as a foaming agent for 24 hours under conditions of a first pressure of 4.0 MPa and a first temperature of 25° C. Carbon dioxide under the above-mentioned first pressure and first temperature conditions was not in a supercritical state (critical pressure 7.4 MPa, critical temperature 31° C.). Thereafter, the leak valve of the pressure vessel was opened to release the pressure in the pressure vessel, and the inside of the pressure vessel was returned to room temperature and normal pressure to set the second pressure, and the bubble generation process was started.

[0122] (Bubble generation process) When the resin-impregnated body was taken out of the pressure vessel and brought to 25°C (second temperature) by immersing it in water at 25°C, numerous bubbles appeared on the surface of the resin-impregnated body. It took about 1 minute from the time the pressure in the pressure vessel was released to start the bubble generation process until the resin-impregnated body reached the second temperature. Thereafter, the resin-impregnated body was immersed in water at 25°C until gas no longer evolved from the resin-impregnated body, and then the resin-impregnated body was taken out of the water. By carrying out the above steps, a physical foam of Example 15 was obtained, which was composed of a foamed portion and a covering portion covering the entire surface of the foamed portion, as shown in Fig. 12. Fig. 12 is a photograph showing the appearance of resin structure 6 used in Example 15 and the physical foam of Example 15.

[0123] [Example 16] A condenser microphone (ECM-100N, manufactured by Sony Corporation) was placed at a position about 30 cm away from the finger holes (about 20 cm from the mouthpiece) of a soprano recorder made of the physical foam of Example 15. The condenser microphone was then connected to an audio interface (Babyface Pro FS, manufactured by RME Corporation), and the sound of the instrument being played was recorded using Audacity (developed by The Audacity Team).

[0124] The wind sounds were recorded by a player playing a soprano recorder made of the physical foam of Example 15. The player played the scales of "Re (actual note D5)" in the low range and "Re (actual note D6)" in the high range at a constant volume using the soprano recorder made of the physical foam of Example 15.

[0125] The wind sounds recorded in Audacity were then Fourier transformed (fft function) for each pitch using numerical analysis software (Mathworks, Matlab R2023b) to obtain an acoustic spectrum with frequency on the horizontal axis and sound pressure on the vertical axis. Fig. 13 shows sound spectra obtained by playing a soprano recorder made of the physical foam of Example 15. Fig. 13(a) shows the sound spectrum obtained by playing the note "Re (actual note D6)", and Fig. 13(b) shows the sound spectrum obtained by playing the note "Re (actual note D5)".

[0126] From the acoustic spectrum shown in Fig. 13(a), it was confirmed that by playing the note "Re (actual note D6 (1189 Hz))" on a soprano recorder made of the physical foam of Example 15, a sound with a harmonic composition containing many harmonics of the note "Re (actual note D6)" was obtained. In particular, it was confirmed that the acoustic spectrum shown in Fig. 13(a) contains high-order harmonics of 16 kHz or more (14th order or more).

[0127] Also, from the acoustic spectrum shown in Fig. 13(b), it was confirmed that by playing the note "Re (actual note D5 (588 Hz))" on a soprano recorder made of the physical foam of Example 15, a sound with a harmonic composition containing many harmonics of the note "Re (actual note D5)" was obtained. Also, like the acoustic spectrum in Fig. 13(a), it was confirmed that the acoustic spectrum shown in Fig. 13(b) also contains high-order harmonics of 16 kHz or more (14th order or more).

[0128] [Comparative Example 3] Except for using a soprano recorder made of a commercially available ABS resin (product name: YRS-20GB, manufactured by Yamaha Corporation) as resin structure 6 instead of the soprano recorder made of the physical foam of Example 15, the same procedure as in Example 15 was used to record the sound played by a performer, and an acoustic spectrum was obtained with frequency on the horizontal axis and sound pressure on the vertical axis. Figure 14 shows sound spectra obtained by playing a commercially available soprano recorder of Comparative Example 3. Figure 14(a) shows the sound spectrum obtained by playing the note "Re (actual note D6)," and Figure 14(b) shows the sound spectrum obtained by playing the note "Re (actual note D5)."

[0129] From the acoustic spectrum shown in Figure 14(a), it was confirmed that by playing the pitch "Re (actual note D6 (1189 Hz))" on the commercially available soprano recorder of Comparative Example 3, a sound with a harmonic composition that includes harmonics of the pitch "Re (actual note D6)" up to about 16 kHz (14th order) can be obtained. Furthermore, from the acoustic spectrum shown in Figure 14(b), it was confirmed that by playing the pitch "Re (actual note D5 (588 Hz))" on the commercially available soprano recorder of Comparative Example 3, a sound with a harmonic composition that includes harmonics of the pitch "Re (actual note D5)" up to about 16 kHz (14th order) can be obtained.

[0130] On the other hand, in the acoustic spectrum of Figure 13(a) using the soprano recorder of Example 15, the intensity of the second harmonic is weaker and peaks appear at closer intervals in the frequency range above 8 kHz, compared to the acoustic spectrum of Figure 14(a) using the soprano recorder of Comparison Example 3. Moreover, the acoustic spectrum of Fig. 13(b) using the soprano recorder of Example 15 and the acoustic spectrum of Fig. 14(b) using the soprano recorder of Comparative Example 3 had similar shapes at frequencies below 10 kHz. However, in the acoustic spectrum of Fig. 13(b), the decrease in peak intensity with increasing frequency was slightly slower in the frequency range of about 10 kHz to 16 kHz than in the acoustic spectrum of Fig. 14(b).

[0131] From these findings, it was found that at least the harmonic composition of the played sound could be changed by foaming the soprano recorder of Comparative Example 3, which is the resin structure 6, to make the soprano recorder of Example 15, which is a physical foam. It was also confirmed that, for the soprano recorder, although the effect was less than that of the reed and mouthpiece, by making it a physical foam, it became possible to make it contain more harmonic sounds.

[0132] [Experiment 1] (Impregnation process) A pressure-resistant container (portable reactor (manufactured by Taiatsu Glass Industries Co., Ltd., capacity 200 mL, design pressure: 10 MPa, design temperature: 200° C.) was prepared. In addition, as the resin structure 3, a flat plate made of acrylic resin with a length of 9 mm, a width of 30 mm, and a thickness of 3 mm was prepared.

[0133] Then, in the pressure-resistant container, the resin structure was impregnated with supercritical fluid carbon dioxide as a foaming agent for 24 hours under conditions of a first pressure of 5 MPa and a first temperature of 0° C. Thereafter, the leak valve of the pressure-resistant container was opened to release the pressure in the pressure-resistant container, and the inside of the pressure-resistant container was brought to room temperature and normal pressure to set the second pressure, and the bubble generation process was started.

[0134] (Bubble generation process) The resin-impregnated body was removed from the pressure vessel and immediately immersed in warm water to heat it to 40°C (second temperature), at which point numerous bubbles appeared on the surface of the resin-impregnated body. It took about one minute from the time the pressure in the pressure vessel was released to start the bubble generation process until the resin-impregnated body reached the second temperature. Heating was then continued until no more gas was generated from the resin-impregnated body, and the resin-impregnated body was removed from the warm water to terminate heating and allowed to cool. By carrying out the above steps, a physical foam of Experiment 1 was obtained, which consisted of a foamed portion consisting of a milky white portion and a translucent covering portion covering the entire surface of the foamed portion, as shown in FIG.

[0135] [Experiment 2 to Experiment 4] Except for setting the heating temperature (second temperature) of the resin-impregnated body to 20° C. in Experiment 2, 60° C. in Experiment 3, and 80° C. in Experiment 4, physical foams in Experiments 2 to 4 were obtained in the same manner as in Experiment 1, each of which had a foamed portion consisting of a cloudy part and a translucent covering portion covering the entire surface of the foamed portion, as shown in Fig. 15. Fig. 15 is a photograph showing the appearance of the resin structure 3 used in Experiments 1 to 4, and the physical foams of Experiments 1 to 4 produced in Experiments 1 to 4.

[0136] The apparent densities of the physical foams of Experiments 1 to 4 and the resin structure 3 thus obtained were determined based on Archimedes' principle. The results are shown in Table 2.

[0137] [Table 2]

[0138] As shown in Table 2, it was confirmed that increasing the heating temperature (second temperature) of the resin-impregnated body makes it easier to obtain a physical foam with a low density. In addition, as shown in Fig. 15, it was found that if the heating temperature (second temperature) of the resin-impregnated body is made too high, the resin-impregnated body becomes more likely to deform, making it difficult to obtain a physical foam having a desired shape. As shown in Fig. 15, deformation of the resin-impregnated body was particularly noticeable in Experiment 3, in which the heating temperature of the resin-impregnated body was 60°C, and Experiment 4, in which the heating temperature of the resin-impregnated body was 80°C.

[0139] [Experiment 5] (Impregnation process) A pressure-resistant container (portable reactor (manufactured by Taiatsu Glass Industries Co., Ltd., capacity 200 mL, design pressure: 10 MPa, design temperature: 200°C)) was prepared. In addition, as the resin structure 4, a flat plate of length 9 mm, width 30 mm, and thickness 3 mm made of glass fiber reinforced polyamide (PAMXD6-GF50 (product name: Reny), manufactured by Mitsubishi Engineering Plastics Corporation) containing 50 mass % glass fiber was prepared.

[0140] Then, in the pressure-resistant container, the resin structure was impregnated with supercritical fluid carbon dioxide as a foaming agent for 24 hours under conditions of a first pressure of 7.5 MPa and a first temperature of 44° C. Carbon dioxide under the above-mentioned first pressure and first temperature conditions was in a supercritical state (critical pressure 7.4 MPa, critical temperature 31° C.). Thereafter, the leak valve of the pressure vessel was opened to release the pressure in the pressure vessel, and the inside of the pressure vessel was returned to room temperature and normal pressure to set the second pressure, and the bubble generation process was started.

[0141] (Bubble generation process) When the resin-impregnated body was removed from the pressure-resistant container and heated to 200°C (second temperature) without applying pressure using a heat press (product name: heat press machine, manufactured by TUSY), bubbles appeared on the surface of the resin-impregnated body. It took about 1 minute from the time the pressure in the pressure-resistant container was released to start the bubble generation process until the resin-impregnated body reached the second temperature. Thereafter, heating was continued until gas was no longer generated from the resin-impregnated body, and the resin-impregnated body was removed from the heat press to end heating and allow to cool. By carrying out the above steps, a physical foam of Experiment 5 was obtained, which consisted of a foamed portion and a covering portion covering the entire surface of the foamed portion, as shown in FIG.

[0142] [Experiment 6 to Experiment 8] Physical foams in Experiments 6 to 8, each consisting of a foamed portion and a covering portion covering the entire surface of the foamed portion, were obtained in the same manner as in Experiment 5, except that the temperature (second temperature) to which the resin-impregnated body was heated was 230°C in Experiment 6, 260°C in Experiment 7, and 110°C in Experiment 8. Fig. 16 is a photograph showing the appearance of the physical foams produced in Experiments 5 to 8.

[0143] As shown in Fig. 16, in Experiment 8, in which the heating temperature (second temperature) of the resin-impregnated body was set to 110°C, no deformation of the resin-impregnated body was observed, and in Experiment 5, in which the heating temperature of the resin-impregnated body was set to 200°C, almost no deformation of the resin-impregnated body was observed. In contrast, in Experiment 6, in which the heating temperature of the resin-impregnated body was set to 230°C, and in Experiment 7, in which the heating temperature of the resin-impregnated body was set to 280°C, the deformation of the resin-impregnated body was noticeable.

[0144] [Experiment 9] A physical foam for Experiment 9 was obtained in the same manner as in Experiment 5, except that the temperature (second temperature) to which the resin-impregnated body was heated was 220°C, and the physical foam consisted of a foamed portion and a covering portion covering the entire surface of the foamed portion.

[0145] The flexural modulus of elasticity of the thus obtained physical foams of Experiments 5 to 7 and 9, and Resin Structure 4 was determined by the method described below. The results are shown in Table 3. "Flexural modulus" Rectangular specimens with a thickness of 2 mm, width of 5 mm, and length of 33 mm were taken from each of the physical foams and resin structure 4 in Experiments 5 to 7 and 9. Using a 5kN load cell and a plastic three-point bending test fixture, the relationship between bending stress and bending strain of the specimens at a test speed of 2 mm / min, i.e., the stress-strain curve, was measured using a bench-top precision universal testing machine (product name: Autograph AGS-X (manufactured by Shimadzu Corporation)). The bending modulus was calculated from the initial gradient of the obtained stress-strain curve using the software (TRAPEZIUM X) attached to the bench-top precision universal testing machine.

[0146] [Table 3]

[0147] As shown in Table 3, it was confirmed that by increasing the heating temperature (second temperature) of the resin-impregnated body, a physical foam having a small flexural modulus can be easily obtained.

[0148] [Experiment 10] (Impregnation process) A pressure-resistant container (portable reactor (manufactured by Taiatsu Glass Industries Co., Ltd., capacity 200 mL, design pressure: 10 MPa, design temperature: 200°C)) was prepared. In addition, as the resin structure 7, three rod-shaped materials with a diameter of 12 mm and a length of 80 mm were taken from a rod-shaped material (manufactured by Narica) made of ebonite with a diameter of 12 mm.

[0149] Then, in the pressure vessel, the resin structure was impregnated with supercritical fluid carbon dioxide as a foaming agent for 24 hours under conditions of a first pressure of 7.5 MPa and a first temperature of 40° C. Carbon dioxide under the above-mentioned first pressure and first temperature conditions was in a supercritical state (critical pressure 7.4 MPa, critical temperature 31° C.). Thereafter, the leak valve of the pressure vessel was opened to release the pressure in the pressure vessel, and the inside of the pressure vessel was brought to room temperature and normal pressure to set the second pressure, and the bubble generation process was started.

[0150] (Bubble generation process) When the resin-impregnated body was removed from the pressure vessel and heated to 100°C (second temperature) by immersing it in boiling water, numerous fine irregularities appeared on the surface of the resin-impregnated body. It took about one minute from the time the pressure in the pressure vessel was released to start the bubble generation process until the resin-impregnated body reached the second temperature. Thereafter, heating was continued until gas was no longer generated from the resin-impregnated body, and the resin-impregnated body was removed from the warm water to end heating and allowed to cool. By carrying out the above steps, a physical foam of Experiment 10 was obtained, which consisted of a foamed portion and a covering portion covering the entire surface of the foamed portion, as shown in FIG.

[0151] [Experiment 11, Experiment 12] In the bubble generation step, the resin-impregnated body was not immersed in boiling water, but instead was heated to 150°C (second temperature) in experiment 11 and to 200°C (second temperature) in experiment 12 without applying pressure to the resin-impregnated body removed from the pressure-resistant container using a heat press (product name: Heat Press Machine, manufactured by TUSY Corporation). Except for this, physical foams in experiments 11 and 12 were obtained in the same manner as in experiment 10, consisting of a foamed portion and a covering portion 1a covering the entire surface of the foamed portion, as shown in Figure 17. In experiments 11 and 12, heating the resin-impregnated body in the bubble generation step also caused numerous fine irregularities to appear on the surface of the resin-impregnated body.

[0152] FIG. 17 is a photograph showing the appearance of resin structure 7 used in Experiments 10 to 12 and the physical foams of Experiments 10 to 12 produced in Experiments 10 to 12. As shown in FIG. As shown in Figure 17, in experiment 10, in which the second temperature was 100°C, no deformation was observed in the resin-impregnated body, but the surface became rough due to the formation of air bubbles inside. In contrast, in experiment 11, in which the second temperature was 150°C, and experiment 12, in which the second temperature was 200°C, the formation of air bubbles was observed in the resin-impregnated body, but only slightly. Also, deformation was observed in the resin-impregnated body in experiment 12. [Explanation of symbols]

[0153] 1 resin structure for musical instrument (reed for musical instrument), 1a covering portion, 1b foam portion, 1c edge portion, 1d approximately center portion in the longitudinal direction.

Claims

1. A resin structure for a musical instrument, comprising: a foamed portion made of a foam; and a covering portion covering the entire surface of the foamed portion.

2. A musical instrument constituent member comprising the resin structure for a musical instrument according to claim 1.

3. 3. The musical instrument component according to claim 2, which is a musical instrument reed or a musical instrument mouthpiece.

4. A musical instrument comprising the resin structure for a musical instrument according to claim 1.

5. 5. The musical instrument of claim 4 which is a recorder.

6. 2. The resin structure for a musical instrument according to claim 1, which is made of a material for physical foaming.

7. 7. The resin structure for a musical instrument according to claim 6, wherein the material for physical foaming includes at least one material selected from the group consisting of polypropylene, acrylic resin, polyamide, ebonite, and acrylonitrile-butadiene-styrene resin.

8. 7. The resin structure for a musical instrument according to claim 6, wherein the physical foaming material is made of polypropylene.

9. A method for producing the resin structure for a musical instrument according to claim 1, comprising the steps of: an impregnation step of impregnating the resin structure with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body; and a bubble generating step of placing the resin-impregnated body under conditions of a second pressure lower than the first pressure and a second temperature that is the same as or different from the first temperature, thereby physically changing the foaming agent to generate bubbles, thereby forming a physical foam consisting of a foamed portion made of a foam and a covering portion that covers the entire surface of the foamed portion.

10. 10. The method for producing a resin structure for a musical instrument according to claim 9, wherein the physical foam has the same shape as the resin structure.

11. 10. The method for producing a resin structure for a musical instrument according to claim 9, wherein the foaming agent is carbon dioxide.

12. 10. The method for producing a resin structure for a musical instrument according to claim 9, wherein the foaming agent is supercritical fluid carbon dioxide.

13. 10. The method for producing a resin structure for a musical instrument according to claim 9, wherein mechanical properties of the resin structure for a musical instrument are controlled to fall within specific ranges by changing one or more conditions selected from the first pressure, the first temperature, and the second temperature.

14. 10. The method of manufacturing a resin structure for a musical instrument according to claim 9, wherein a density of the resin structure for a musical instrument is controlled to be within a specific range by changing one or more conditions selected from the first pressure, the first temperature, and the second temperature.

15. 10. The method of manufacturing a resin structure for a musical instrument according to claim 9, wherein acoustic characteristics of the resin structure for a musical instrument are controlled to fall within a specific range by changing one or more conditions selected from the first pressure, the first temperature, and the second temperature.

16. 16. The method for producing a resin structure for a musical instrument according to claim 15, wherein the acoustic characteristic is a harmonic composition of a sound of a musical instrument including the resin structure for a musical instrument.

17. The method for manufacturing a resin structure for a musical instrument according to any one of claims 13 to 15, wherein the second temperature is changed.

18. A method for manufacturing a musical instrument component according to claim 2, comprising the steps of: an impregnation step of impregnating the resin structure with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body; A manufacturing method for a musical instrument component includes a bubble generating step of physically changing the foaming agent to generate bubbles by placing the resin-impregnated body under conditions of a second pressure lower than the first pressure and a second temperature that is the same as or different from the first temperature, thereby forming a physical foam consisting of a foamed portion made of a foam and a covering portion that covers the entire surface of the foamed portion.

19. A method for manufacturing a musical instrument according to claim 4, comprising the steps of: an impregnation step of impregnating the resin structure with a foaming agent under conditions of a first pressure and a first temperature to form a resin-impregnated body; A method for manufacturing a musical instrument, comprising: a bubble generation process in which the resin-impregnated body is placed under conditions of a second pressure lower than the first pressure, and a second temperature that is the same as or different from the first temperature, thereby physically changing the foaming agent to generate bubbles, thereby forming a physical foam consisting of a foamed portion made of a foam and a covering portion that covers the entire surface of the foamed portion.

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