Plate-shaped acoustic components

Abstract

To provide a plate-like acoustic member with an improved acoustic characteristic.SOLUTION: A plate-like acoustic member 1 includes a pattern of a non-adhesive interface 20 extending in a surface direction on an inner part. The plate-like acoustic member includes two fiber-reinforced plastic layers 10 which are mutually laminated, and includes the pattern of the non-adhesive interface at a part between the two fiber-reinforced plastic layers. The plate-like acoustic member includes a non-adhesive layer at a part between the two fiber-reinforced plastic layers, and thereby the non--adhesive interface can be formed between the fiber-reinforced plastic layer and the non-adhesive layer.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present disclosure relates to a plate-shaped acoustic member. [Background technology]

[0002] Traditionally, wood has been used as an acoustic material, but in recent years, fiber-reinforced resin has been attracting attention as an alternative material to wood.

[0003] Patent Document 1 discloses a composite material for acoustic panels, which is characterized by including a resin matrix having voids and carbon fibers arranged in the resin matrix and oriented in one direction. In Patent Document 1, the "resin matrix having voids" refers to a base material made of foamed resin.

[0004] Patent Document 2 discloses a sound plate for musical instruments made of fiber-reinforced resin with reinforcing fibers oriented in one direction of the sound plate, characterized in that rod-shaped bodies having a lower Young's modulus than the fiber-reinforced resin that forms the sound plate are embedded in the fiber-reinforced resin parallel to the orientation direction of the reinforcing fibers, and the sum of the cross-sectional areas of the rod-shaped bodies in a cross section perpendicular to the orientation direction is 5 to 60% of the cross-sectional area of ​​the sound plate.

[0005] Patent Document 3 discloses a sound plate for musical instruments made of fiber-reinforced resin with reinforcing fibers oriented in one direction of the sound plate, characterized in that a rod-shaped body having a circular cross section and a Young's modulus lower than that of the fiber-reinforced resin forming the sound plate is embedded in the fiber-reinforced resin parallel to the orientation direction of the reinforcing fibers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-306062 A [Patent Document 2] Japanese Patent Application Publication No. 59-10996 [Patent Document 3] Japanese Patent Application Publication No. 63-46492 Summary of the Invention [Problem to be solved by the invention]

[0007] As disclosed in Patent Documents 1 to 3, acoustic members that employ fiber-reinforced plastics have been proposed as substitutes for acoustic members that employ wood.

[0008] However, acoustic components employing man-made materials, such as fiber-reinforced plastics, can have difficulty reproducing the sounds that acoustic components employing natural materials, such as wood, can produce.

[0009] Therefore, there is a demand for acoustic components made of artificial materials, such as fiber-reinforced plastics, to more closely reproduce the sounds that can be produced by acoustic components made of wood, i.e., to further improve the acoustic characteristics.

[0010] An object of the present disclosure is to provide a plate-shaped acoustic component with improved acoustic characteristics. [Means for solving the problem]

[0011] The present inventors have found that the above object can be achieved by the following means: Aspect 1 A plate-shaped acoustic component having an internal pattern of non-bonded interfaces extending in the planar direction. Aspect 2 2. The plate-shaped acoustic member according to claim 1, wherein the pattern is a star, a polygon, an arc, a circle, a concentric circle, a polka dot, a magatama, a Tomoe pattern, a petal, a diamond, a coin, a stripe, a wave, a bow, an H, a staircase, or a staggered pattern. Aspect 3 3. The plate-shaped acoustic member according to claim 1 or 2, having voids in at least a portion of the non-bonded interface. Aspect 4 4. The plate-shaped acoustic component according to any one of aspects 1 to 3, comprising two fiber-reinforced plastic layers laminated to each other, and having the pattern between the two fiber-reinforced plastic layers. Aspect 5 The plate-shaped acoustic component of embodiment 4 has a non-adhesive layer between two of the fiber-reinforced plastic layers, thereby forming the non-adhesive interface between the fiber-reinforced plastic layer and the non-adhesive layer. Aspect 6 A plate-shaped acoustic member having two fiber-reinforced plastic layers laminated to each other, and having a non-adhesive layer in a portion between the two fiber-reinforced plastic layers. Aspect 7 7. The plate-shaped acoustic member according to claim 5 or 6, wherein the non-adhesive layer is a non-adhesive film layer. Aspect 8 The fiber reinforced plastic layer contains reinforcing fibers and a matrix resin, (a) the matrix resin is a polar resin and the non-adhesive film layer is a layer of a non-polar resin; or (b) the matrix resin is a non-polar resin, and the non-adhesive film layer is a layer of a polar resin; 8. The plate-shaped acoustic member according to claim 7. Aspect 9: 9. The plate-shaped acoustic member according to claim 8, wherein the reinforcing fibers are carbon fibers. Aspect 10 10. The plate-shaped acoustic member according to claim 8 or 9, wherein the polar resin is an epoxy resin, an unsaturated polyester resin, a phenolic resin, a polyimide resin, a polyamide resin, or a combination thereof. Aspect 11 The plate-shaped acoustic component according to any one of aspects 8 to 10, wherein the non-polar resin is a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin, an acrylonitrile-butadiene-styrene resin, a fluororesin, or a combination thereof. Aspect 12 An acoustic device comprising the acoustic member according to any one of aspects 1 to 11. Aspect 13 13. The acoustic device according to claim 12, which is a speaker or an acoustic board. Aspect 14 A musical instrument comprising the plate-shaped acoustic member according to any one of aspects 1 to 11. Aspect 15 15. The musical instrument of embodiment 14, wherein the musical instrument is an acoustic musical instrument. Aspect 16 16. The instrument of claim 15, wherein the acoustic instrument is a plucked string instrument, a bowed string instrument, or a struck string instrument. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a plate-shaped acoustic component with improved acoustic characteristics. [Brief description of the drawings]

[0013] [Figure 1A] FIG. 1A is a schematic diagram of a plate-shaped acoustic member 1 according to a first embodiment of the present disclosure, viewed from a planar direction. [Figure 1B] FIG. 1B is a schematic diagram of the plate-shaped acoustic member 1 according to the first embodiment of the present disclosure, viewed from the AA' cross section of FIG. 1A. [Figure 1C] FIG. 1C is a schematic diagram of the plate-shaped acoustic member 1 according to the first embodiment of the present disclosure, viewed from the BB' cross section of FIG. 1B. [Figure 2A] FIG. 2A is a graph showing the acoustic characteristics of a plate-shaped acoustic member made of Jacaranda. [Figure 2B] FIG. 2B is a graph showing the acoustic characteristics of a rosewood plate-shaped acoustic member. [Figure 2C] FIG. 2C is a graph showing the acoustic characteristics of a plate-shaped acoustic member made of Sitka spruce. [Figure 2D] FIG. 2D is a graph showing the acoustic characteristics of a plate-shaped acoustic member made of carbon fiber reinforced plastic that does not have a non-bonded interface. [Figure 2E] FIG. 2E is a graph showing the acoustic characteristics of a plate-shaped acoustic component using another carbon fiber reinforced plastic that does not have a non-bonded interface. [Figure 2F] FIG. 2F is a graph showing the acoustic characteristics of a plate-shaped acoustic component using yet another carbon fiber reinforced plastic that does not have a non-bonded interface. [Figure 3A] FIG. 3A is a schematic diagram showing a vertical stripe pattern of the non-bonded interface 20. As shown in FIG. [Figure 3B] FIG. 3B is a schematic diagram showing a wavy pattern of the non-bonded interface 20. As shown in FIG. [Figure 3C] FIG. 3C is a schematic diagram showing a step-like pattern of the non-bonded interface 20. As shown in FIG. [Figure 3D] FIG. 3D is a schematic diagram showing a staggered pattern of non-bonded interfaces 20. [Figure 3E] FIG. 3E is a schematic diagram showing an H-shaped pattern of the non-bonded interface 20. As shown in FIG. [Figure 3F] FIG. 3F is a schematic diagram showing an arched pattern of non-bonded interfaces 20. [Figure 4A] FIG. 4A is a schematic diagram showing a layer structure of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure. [Figure 4B] FIG. 4B is a schematic diagram of the plate-shaped acoustic member 2 according to the second embodiment of the present disclosure viewed from the planar direction. [Figure 4C] FIG. 4C is a schematic diagram of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure, viewed from the CC' cross section of FIG. 4B. [Figure 4D] FIG. 4D is a schematic diagram of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure, viewed from the cross section taken along line DD' of FIG. 4C. [Figure 4E] FIG. 4E is a schematic diagram of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure, viewed from the CC' cross section of FIG. 4B. [Diagram 5] FIG. 5 is a schematic diagram showing the layer structure of the plate-shaped acoustic member 3 of the first embodiment. [Figure 6A] FIG. 6A is a schematic diagram showing the position where a small piece was cut out from the plate-shaped acoustic member of Example 6 and used for high-resolution XCT imaging observation. [Figure 6B] FIG. 6B is a visualization of data obtained based on high-resolution XCT imaging observation of the plate-shaped acoustic member of Example 6. [Figure 7A]FIG. 7A is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Examples 1, 2, and 6 and Comparative Example 1. [Figure 7B] FIG. 7B is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Examples 3 to 5 and Comparative Example 1. [Figure 7C] FIG. 7C is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Comparative Examples 1 to 3. [Figure 7D] FIG. 7D is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Reference Examples 1, 4, and 5 and Comparative Example 1. [Figure 8] FIG. 8 is a graph showing partial overall (POA) values ​​in the range of 20 to 293 Hz for the plate-shaped acoustic members of Examples 1 to 6, Comparative Examples 1 to 3, and Reference Examples 1 to 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the present disclosure.

[0015] <<Plate-shaped acoustic component>> The plate-shaped acoustic member of the present disclosure has therein a pattern of non-bonded interfaces extending in the planar direction.

[0016] The material of the plate-shaped acoustic member of the present disclosure may be an artificial material, such as a plastic, more specifically a fiber-reinforced plastic.

[0017] The shape of the plate-shaped acoustic member of the present disclosure is not particularly limited as long as it is plate-shaped, and may be flat or curved. The shape of the plate-shaped acoustic member of the present disclosure may be a plate having irregularities or may be wavy. Furthermore, the plate-shaped acoustic member of the present disclosure may have, for example, one or more holes penetrating the plate-shaped acoustic member in the thickness direction. The size and thickness of the plate-shaped acoustic member of the present disclosure are not particularly limited, and may be appropriately determined according to the specific product to which it is applied.

[0018] The phrase "having a non-bonded interface pattern extending in the planar direction" means that, inside the plate-shaped acoustic member, the materials constituting the plate-shaped acoustic member are in contact with each other or at least partially separated from each other, and are not bonded to each other, so that the materials constituting the plate-shaped acoustic member are discontinuous in the portions, i.e., the non-bonded interfaces extend in the planar direction in a certain pattern. Also, at least a portion of the non-bonded interfaces may have voids.

[0019] A more specific description will be given with reference to Figures 1A to C. Figures 1A to C are schematic diagrams showing an example of a plate-shaped acoustic member 1 according to a first embodiment of the present disclosure.

[0020] Fig. 1A is a schematic diagram showing a planar acoustic member 1 according to a first embodiment of the present disclosure. As shown in Fig. 1A, the planar acoustic member 1 according to the first embodiment of the present disclosure is formed from a fiber-reinforced plastic layer 10 and has a flat plate shape.

[0021] Fig. 1B is a schematic diagram of a plate-shaped acoustic member 1 according to the first embodiment of the present disclosure, viewed from the A-A' cross section of Fig. 1A. As shown in Fig. 1B, the plate-shaped acoustic member 1 according to the first embodiment of the present disclosure has a non-bonded interface 20 that spreads in the planar direction inside the fiber-reinforced plastic layer 10. Between the non-bonded interfaces 20, the fiber-reinforced plastic layer 10 is continuous, i.e., there are regions that are not non-bonded.

[0022] Fig. 1C is a schematic diagram of the plate-shaped acoustic member 1 according to the first embodiment of the present disclosure, viewed from the B-B' cross section of Fig. 1B. As shown in Fig. 1C, in the plate-shaped acoustic member 1 according to the first embodiment of the present disclosure, the non-bonded interfaces 20 form a pattern of multiple vertical stripes extending in the planar direction.

[0023] It should be noted that FIGS. 1A to 1C are not intended to limit the invention of the present disclosure.

[0024] Without being limited by the principle, the principle by which the plate-shaped acoustic member of the present disclosure has improved acoustic characteristics is as follows.

[0025] Examples of wood materials used for plate-shaped acoustic members include Jacaranda, rosewood, and Sitka spruce. Plate-shaped acoustic members made of these woods have the acoustic characteristics shown in Figs. 2A to 2C. The graphs of acoustic characteristics shown in Figs. 2A to 2C were obtained by contacting one side of the plate-shaped acoustic member with a vibrating tuning fork, collecting sound from the other side of the plate-shaped acoustic member with a microphone, and analyzing the frequency of the collected sound using acoustic analysis software. In the analysis, the peak of the tuning fork vibration, which is the main tone, around 440 Hz was eliminated by applying an equalizer to the acoustic software.

[0026] In contrast, plate-shaped acoustic components made of artificial materials, such as various fiber-reinforced plastics, can be formed to have the acoustic characteristics shown in Figures 2D to 2F, respectively. Note that the acoustic characteristic graphs shown in Figures 2D to 2F were also subjected to the same frequency analysis as the acoustic characteristic graphs shown in Figures 2A to 2C.

[0027] As shown in Figures 2D-F, the plate-shaped acoustic members made of carbon fiber reinforced plastics with a given composition have peaks that are close to those shown in Figures 2A-C, respectively. This means that the acoustic characteristics of plate-shaped acoustic members made of wood such as Jacaranda, rosewood, and Sitka spruce can be reproduced to some extent by plate-shaped acoustic members made of artificial materials, such as fiber reinforced plastics, more specifically carbon fiber reinforced plastics that do not have a non-bonded interface.

[0028] However, there is a difference between the sound produced by a plate-shaped acoustic member that is actually made from an artificial material and the sound produced by a plate-shaped acoustic member that is actually made from wood.

[0029] One factor that is thought to be responsible for this is that the acoustic characteristics of plate-shaped acoustic components made from wood differ from those of plate-shaped acoustic components made from artificial materials, such as carbon fiber reinforced plastic, in terms of the presence or absence and the magnitude of peaks in the low-frequency range, for example, around 20 Hz to 300 Hz.

[0030] The plate-shaped acoustic member of the present disclosure has a non-bonded interface pattern that extends in the planar direction inside the plate-shaped acoustic member. This allows the plate-shaped acoustic member of the present disclosure to have acoustic properties similar to those of a plate-shaped acoustic member made of wood in the low-frequency range, for example, around 20 Hz to 300 Hz. This allows the plate-shaped acoustic member of the present disclosure to more accurately reproduce the sound that can be produced by an acoustic member made of wood, i.e., to further improve the acoustic properties.

[0031] This is thought to be due to, without being limited by any particular theory, the fact that the plate-shaped acoustic member has a pattern of non-bonded interfaces extending in the planar direction inside, making a portion of the inside of the plate-shaped acoustic member discontinuous, or the presence of voids in at least a portion of the non-bonded interfaces, which changes the elastic modulus and internal loss of the plate-shaped acoustic member itself.

[0032] The pattern of the non-bonded interface may or may not have regularity. The pattern of the non-bonded interface may be, for example, a star shape, a polygonal shape, an arc shape, a circle shape, a concentric circle shape, a polka dot pattern, a magatama shape, a Tomoe pattern, a petal shape, a diamond shape, a coin shape (a shape having a square hole inside a circle, particularly in the center), a vertical stripe shape, a wavy shape, a staircase shape, a staggered shape, an H shape, or an arch shape. FIGS. 3A to 3F show, in order, vertical stripe shape, wavy shape, staircase shape, staggered shape, an H shape, or an arch shape as an example of the pattern of the non-bonded interface 20. Note that FIGS. 3A to 3F show examples of the pattern of the non-bonded interface 20 that the plate-shaped acoustic member 1 according to the first embodiment of the present disclosure can have. Also, FIGS. 3A to 3F are cross-sectional views similar to FIG. 1C.

[0033] It should be noted that FIGS. 3A to 3F are not intended to limit the invention of the present disclosure.

[0034] By designing the pattern of the non-bonded interface, it is possible to adjust the position and magnitude of a desired peak in the low frequency region, for example, in the vicinity of 20 Hz to 300 Hz.

[0035] The plate-shaped acoustic member of the present disclosure may specifically have a configuration having two fiber-reinforced plastic layers laminated to each other and having a pattern of a non-bonded interface between the two fiber-reinforced plastic layers.

[0036] More specifically, the plate-shaped acoustic member of the present disclosure may have two fiber-reinforced plastic layers laminated together, and may have a non-adhesive layer between the two fiber-reinforced plastic layers, and a non-adhesive interface pattern may be formed between the fiber-reinforced plastic layer and the non-adhesive layer.

[0037] The non-adhesive layer is a layer that is not adhered to the fiber-reinforced plastic layer.

[0038] 4A-D are schematic diagrams of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure.

[0039] As shown in FIG. 4A, the plate-shaped acoustic member 2 according to the second embodiment of the present disclosure has a structure in which a non-adhesive layer 25 is inserted between two fiber-reinforced plastic layers 10 that are laminated to each other, and the two fiber-reinforced plastic layers 10 are bonded together as shown in FIG. 4B.

[0040] Fig. 4C is a schematic diagram of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure, viewed from the CC' cross section of Fig. 4B. As shown in Fig. 4C, in the plate-shaped acoustic member 2 according to the second embodiment of the present disclosure, a non-adhesive layer 25 is disposed between two fiber-reinforced plastic layers 10 that are laminated to each other. A pattern of a non-adhesive interface 20 is formed between the fiber-reinforced plastic layer 10 and the non-adhesive layer 25. In the portion between the two adjacent non-adhesive layers 25, the two fiber-reinforced plastic layers 10 are bonded to each other and integrated.

[0041] Fig. 4D is a schematic diagram of a plate-shaped acoustic member 2 according to a second embodiment of the present disclosure, viewed from the D-D' cross section of Fig. 4C. As shown in Fig. 4D, in the plate-shaped acoustic member 2 according to the second embodiment of the present disclosure, the non-adhesive layers 25 are arranged in a plurality of vertical stripes extending in the planar direction, whereby the non-adhesive interface 20 forms a vertical stripe pattern.

[0042] As shown in FIG. 4E, in the plate-shaped acoustic member 2 according to the second embodiment of the present disclosure, the fiber-reinforced plastic layer 10 and the non-adhesive layer 25 do not necessarily need to be in contact with each other, and for example, a gap 30 may exist in at least a portion between them.

[0043] It should be noted that FIGS. 4A to 4E are not intended to limit the invention of the present disclosure.

[0044] <Fiber reinforced plastic layer> The fiber-reinforced plastic layer is a layer of fiber-reinforced plastic containing reinforcing fibers and a matrix resin.

[0045] Fiber-reinforced plastics can be formed, for example, by impregnating reinforcing fibers into a matrix resin.

[0046] The thickness of the fiber reinforced plastic layer is not particularly limited, and may be, for example, 0.1 mm to 10.0 mm. The thickness of the fiber reinforced plastic layer may be 0.1 mm or more, 0.5 mm or more, 0.8 mm or more, or 1.0 mm or more, and may be 10.0 mm or less, 5.0 mm or less, 2.0 mm or less, or 1.0 mm or less. The thickness of the fiber reinforced plastic layer may be appropriately determined depending on the application of the plate-shaped acoustic member.

[0047] (Reinforced Fiber) The reinforcing fibers may be any fiber that can be used in fiber-reinforced plastics, such as glass fibers, carbon fibers, boron fibers, aramid fibers, or combinations thereof. The reinforcing fibers are preferably carbon fibers.

[0048] (Matrix resin) The matrix resin can be any resin that can be used in fiber reinforced plastics.

[0049] The matrix resin may be a polar resin or a non-polar resin. The polar resin may be an epoxy resin, an unsaturated polyester resin, a phenolic resin, a polyimide resin, a polyamide resin, or a combination thereof. The non-polar resin may be a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin, an acrylonitrile butadiene styrene resin, a fluororesin, or a combination thereof. Examples of the fluororesin include polytetrafluoroethylene (PTFE) and perfluoroalkoxyalkane (PFA).

[0050] <Non-adhesive Layer> The non-adhesive layer is a layer that is not bonded to the fiber-reinforced plastic layer.

[0051] The non-adhesive layer may be, for example, a non-adhesive film layer or a non-adhesive coating layer.

[0052] The non-adhesive film layer is a layer made of a film that does not have adhesion to the fiber-reinforced plastic layer. For example, when two laminated fiber-reinforced plastic layers are bonded together by the action of heat to form a plate-shaped acoustic member, the non-adhesive film layer can be a layer made of a material that does not bond to the fiber-reinforced plastic layer by the action of heat.

[0053] More specifically, when the matrix resin of the fiber-reinforced plastic layer is a polar resin, the non-adhesive film layer may be a layer made of a non-polar resin, whereas when the matrix resin of the fiber-reinforced plastic layer is a non-polar resin, the non-adhesive film layer may be a layer made of a polar resin.

[0054] The non-adhesive coating layer is a layer to which a material that does not have adhesive properties with respect to the fiber-reinforced plastic layer is applied.

[0055] The thickness of the non-adhesive layer is not particularly limited, and may be, for example, 1 μm to 100 μm. The thickness of the non-adhesive layer may be 1 μm or more, 5 μm or more, 10 μm or more, or 20 μm or more, and may be 100 μm or less, 80 μm or less, 50 μm or less, or 30 μm or less.

[0056] 《Audio equipment》 The acoustic device of the present disclosure is an acoustic device having the plate-shaped acoustic member of the present disclosure.

[0057] Examples of the acoustic equipment include, but are not limited to, speakers, acoustic boards, and acoustic panels.

[0058] "musical instrument" The musical instrument of the present disclosure is a musical instrument having the plate-shaped acoustic member of the present disclosure.

[0059] The musical instruments may be acoustic musical instruments, more specifically, plucked string instruments, bowed string instruments, or struck string instruments. Examples of plucked string instruments include guitars, harps, and kotos. Examples of bowed string instruments include violins, violas, cellos, and double basses. Examples of struck string instruments include pianos. In addition, the musical instruments may be instruments other than acoustic instruments, such as electric instruments. Examples of electric instruments may be electric guitars, electric basses, electric pianos, electric violins, electric harps, and clavinets.

[0060] When the musical instrument of the present disclosure is a guitar, the plate-shaped acoustic member of the present disclosure may be applied to, for example, the top and / or back of the guitar body, etc. When the musical instrument of the present disclosure is a piano, the plate-shaped acoustic member of the present disclosure may be applied to, for example, the soundboard or sound bars of the piano, etc. EXAMPLES

[0061] Examples 1 to 6, Comparative Examples 1 to 4, and Reference Examples 1 to 6 Examples 1 to 6 As shown in Fig. 5, four carbon fiber reinforced plastic layers 110 (twill weave) made of epoxy resin and carbon fiber, each 100 mm long x 100 mm wide x 0.8 mm thick, were sandwiched in the center as indicated by the white arrow with a polypropylene (PP) resin film 120 as an intermediate layer to form a laminate. The polypropylene (PP) resin film 120 was cut and arranged to form a vertical striped pattern as shown in Fig. 3A.

[0062] The laminate was heated in a vacuum autoclave at about 120° C. to bond the carbon fiber reinforced plastic layers together, thereby forming the plate-shaped acoustic member of Example 1.

[0063] An ultrasonic flaw detection test confirmed that an intermediate layer with a vertical stripe pattern was inserted inside the plate-shaped acoustic component of Example 1.

[0064] The configuration of the plate-shaped acoustic member of Example 1 is summarized in Table 1 below.

[0065] Examples 2 to 6 The plate-shaped acoustic members of Examples 2 to 6 were formed in the same manner as in Example 1, except that the patterns of the intermediate layer were, respectively, as shown in Figures 3B to 3F, namely, wave-shaped, stepped, staggered, H-shaped, and bow-shaped patterns.

[0066] By ultrasonic inspection, it was confirmed that intermediate layers having wave-shaped, step-shaped, staggered, H-shaped, and bow-shaped patterns were inserted into the plate-shaped acoustic members of Examples 2 to 6, respectively.

[0067] The configurations of the plate-shaped acoustic members of Examples 2 to 6 are summarized in Table 1 below.

[0068] Comparative Example 1 A plate-shaped acoustic member of Comparative Example 1 was formed in the same manner as in Example 1, except that no intermediate layer was used.

[0069] The configuration of the plate-shaped acoustic member of Comparative Example 1 is summarized in Table 1 below.

[0070] Comparative Example 2 A plate-shaped acoustic member of Comparative Example 2 was formed in the same manner as in Example 1, except that the material for the intermediate layer was a polyamide 6 (PA6) film instead of a polypropylene (PP) resin film.

[0071] The intermediate layer had a vertical stripe pattern.

[0072] The configuration of the plate-shaped acoustic member of Comparative Example 2 is summarized in Table 1 below.

[0073] Comparative Example 3 A plate-shaped acoustic member of Comparative Example 3 was formed in the same manner as in Example 6, except that the material for the intermediate layer was a polyamide 6 (PA6) film instead of a polypropylene (PP) resin film.

[0074] The intermediate layer had an arched pattern.

[0075] The configuration of the plate-shaped acoustic member of Comparative Example 3 is summarized in Table 1 below.

[0076] Comparative Example 4 The plate-shaped acoustic member of Comparative Example 4 was formed in the same manner as in Example 1, except that a polypropylene (PP) resin film measuring 100 mm in length and 100 mm in width was sandwiched as an intermediate layer to form a laminate. The plate-shaped acoustic member of Comparative Example 4 was unable to bond the two central carbon fiber reinforced plastic layers despite being heated in a vacuum autoclave. This is because a polypropylene (PP) resin film of the same size as the carbon fiber reinforced plastic layers was sandwiched in the center.

[0077] The configuration of the plate-shaped acoustic member of Comparative Example 4 is summarized in Table 1 below.

[0078] <Reference examples 1 to 6> Flat plates of 100 mm length x 100 mm width made of spruce, mahogany, maple, ash, Jacaranda, and cedar were used as the plate-shaped acoustic members of Reference Examples 1 to 6, respectively.

[0079] The plates of Reference Examples 1 to 6 are summarized in Table 1 below.

[0080] [Table 1]

[0081] Evaluation of acoustic characteristics The acoustic characteristics of the plate-shaped acoustic members of Examples 1 to 6, Comparative Examples 1 to 3, and Reference Examples 1 to 6 were evaluated as follows.

[0082] A vibrating tuning fork was placed in contact with one side of the plate-shaped acoustic member, and sound was picked up by a microphone from the other side of the plate-shaped acoustic member. The picked-up sound was subjected to frequency analysis using acoustic analysis software.

[0083] The analysis results are shown in FIGS. 7A to 7D and 8.

[0084] 7A is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Examples 1, 2, and 6, and Comparative Example 1. FIG. 7B is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Examples 3 to 5, and Comparative Example 1.

[0085] 7A and 7B, the plate-shaped acoustic members of Examples to 6, which had a PP film with a predetermined pattern as an intermediate layer, had acoustic characteristics similar to those of the plate-shaped acoustic member of Comparative Example 1, which did not have an intermediate layer, at frequencies of 440 Hz or higher. On the other hand, in the vicinity of 20 Hz to 300 Hz, especially in the vicinity of 200 Hz, the plate-shaped acoustic member of Comparative Example 1 had a peak of 150 mPar or less, while the plate-shaped acoustic members of Examples 1 to 6 all had large peaks of 250 mPar or more.

[0086] FIG. 7C is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Comparative Examples 1 to 3.

[0087] As shown in Figure 7C, the plate-shaped acoustic members of Comparative Examples 2 and 3, which had a polyamide 6 (PA6) film with a predetermined pattern as an intermediate layer, both had acoustic properties similar to those of the plate-shaped acoustic member of Comparative Example 1, which did not have an intermediate layer, in the measured frequency range.

[0088] FIG. 7D is a graph showing the acoustic characteristics of the plate-shaped acoustic members of Reference Examples 1, 4, and 5 and Comparative Example 1.

[0089] As shown in Fig. 7D, the plate-shaped acoustic members of Reference Examples 1, 4, and 5, which are made of spruce, ash, and Jacaranda, respectively, had acoustic characteristics similar to those of the plate-shaped acoustic member of Comparative Example 1, which was made of four carbon fiber reinforced plastic layers, at frequencies of 440 Hz or more. On the other hand, in the vicinity of 20 Hz to 300 Hz, the plate-shaped acoustic member of Comparative Example 1 had a peak of 150 mPar or less, while the plate-shaped acoustic members of Reference Examples 1, 4, and 5 had multiple peaks of 200 mPar or more.

[0090] FIG. 8 is a graph showing partial overall (POA) values ​​in the range of 20 to 293 Hz for the plate-shaped acoustic members of Examples 1 to 6, Comparative Examples 1 to 3, and Reference Examples 1 to 6.

[0091] As shown in Fig. 8, the partial overall (POA) value between 20 and 293 Hz for the plate-shaped acoustic member of Comparative Example 1 was 82 or less. The plate-shaped acoustic members of Comparative Examples 2 and 3 also had almost similar values ​​(Comparative Example 2: 82 or less, Comparative Example 3: 83 or less), and there was no significant difference from that of the plate-shaped acoustic member of Comparative Example 1.

[0092] In contrast, the partial overall (POA) values ​​of the plate-shaped acoustic members of Examples 1 to 6 were all equal to or greater than 85. These values ​​are almost the same as those of the plate-shaped acoustic members of Reference Examples 1 to 6.

[0093] High-resolution XCT imaging observation Using a router and a diamond disk, the plate-shaped acoustic member of Example 6 was cut into a small piece (40 mm long x 5 mm wide) including the portion shown in FIG. 6A, ie, the portion where the intermediate layer was inserted.

[0094] The small piece was fixed to a specimen stand with wax and left to stand at room temperature. After the stress change in the wax disappeared, high-resolution XCT imaging was performed.

[0095] High-resolution XCT imaging observation was performed using a high-resolution 3D X-ray microscope (nano3DX, Rigaku Corporation). The X-ray source was Cu (17.5 keV), the X-ray lens was L270, the X-ray tube voltage and tube current were 40 kV-30 mA, the CT imaging range was 0 to 180°, the exposure time was 8 seconds, and the number of images was 1100.

[0096] The obtained data was reconstructed on a computer and then converted into images at 0.54 μm / voxel using the image processing software ImageJ to obtain sequence data of the fragment direction at the imaging site.

[0097] The obtained sequence data was used to perform visualization and image analysis using the image analysis software AVIZO. In addition, different filter processing was applied for void extraction, PP film extraction, and carbon fiber extraction, and 3D data for each element extraction was created.

[0098] From the obtained imaging data, the voids, the PP film, and the carbon fibers were separated into elements and visualized as shown in Figure 6B.

[0099] As shown in Fig. 6B, in the plate-shaped acoustic member of Example 6, the carbon fiber reinforced plastic layer and the PP film layer were clearly distinguishable, and a non-adhesive interface was formed between these layers. In addition, a gap layer with a thickness of about 1 μm was formed between these layers.

[0100] It is not clear whether the vibration of the layer itself, with a void of just 1 μm, has a significant effect on the acoustic vibration of the plate-shaped acoustic component. However, it is believed that the effect of the non-bonded interfaces formed inside the plate-shaped acoustic component, or the combination of non-bonded interfaces and voids, changes the elastic modulus and internal loss of the entire plate-shaped acoustic component, thereby changing the acoustic characteristics of the plate-shaped acoustic component. [Explanation of symbols]

[0101] 1~3 Plate-shaped acoustic components 10 Fiber-reinforced plastic layer 20 Non-adhesive interface 25 Non-adhesive layer 30 void 110 Carbon fiber reinforced plastic layer 120 Polypropylene (PP) resin film

Claims

1. It has a non-adhesive interface pattern that extends in the surface direction. The method includes the steps of: providing a laminate of two fiber-reinforced plastic layers laminated together; and providing the pattern between the two fiber-reinforced plastic layers; A non-adhesive layer is provided between two of the fiber-reinforced plastic layers, thereby forming the non-adhesive interface between the fiber-reinforced plastic layer and the non-adhesive layer; The non-adhesive layer is a non-adhesive film layer. Plate-shaped acoustic component.

2. 2. The plate-shaped acoustic member according to claim 1, wherein the pattern is a star shape, a polygon shape, an arc shape, a circle shape, a concentric circle shape, a polka dot shape, a magatama shape, a Tomoe pattern, a petal shape, a diamond shape, a coin shape, a striped shape, a wavy shape, a bow shape, an H shape, a staircase shape, or a staggered shape.

3. 3. The plate-shaped acoustic member according to claim 1, wherein at least a portion of the non-bonded interface has a void.

4. The laminate has two fiber-reinforced plastic layers laminated to each other, and has a non-adhesive layer between the two fiber-reinforced plastic layers, The non-adhesive layer is a non-adhesive film layer. Plate-shaped acoustic component.

5. The fiber reinforced plastic layer contains reinforcing fibers and a matrix resin, (a) the matrix resin is a polar resin and the non-adhesive film layer is a layer of a non-polar resin; or (b) the matrix resin is a non-polar resin, and the non-adhesive film layer is a layer of a polar resin; The plate-shaped acoustic member according to any one of claims 1 to 4.

6. 6. The plate-shaped acoustic member according to claim 5, wherein the reinforcing fibers are carbon fibers.

7. 7. The plate-shaped acoustic member according to claim 5, wherein the polar resin is an epoxy resin, an unsaturated polyester resin, a phenolic resin, a polyimide resin, a polyamide resin, or a combination thereof.

8. The non-polar resin is a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin, an acrylnitrile butadiene styrene resin, a fluororesin, or a combination thereof, according to any one of claims 5 to 7. The plate-shaped acoustic member according to claim 5.

9. An acoustic device comprising the plate-shaped acoustic member according to any one of claims 1 to 8.

10. 10. The acoustic device according to claim 9, which is a speaker or an acoustic plate.

11. A musical instrument comprising the plate-shaped acoustic member according to any one of claims 1 to 8.

12. 12. The musical instrument of claim 11, which is an acoustic musical instrument.

13. 13. The musical instrument of claim 12, wherein the acoustic musical instrument is a plucked, bowed, or struck string instrument.

Images