Diaphragm for sound production device, sound production device, and electronic device

Abstract

This invention discloses a diaphragm for a sound-generating device, a sound-generating device, and an electronic device. The diaphragm includes a modified nitrile rubber layer made of a blend material, which includes nitrile rubber and a damping modifier. The nitrile rubber has a binary structure, and its mass percentage in the blend material is ≥40%. The damping modifier includes at least one of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, and its mass percentage in the blend material is ≤40%. The modified nitrile rubber layer has a first glass transition temperature and a second glass transition temperature. The first glass transition temperature is -60°C to -40°C, and the second glass transition temperature is -30°C to -10°C. The diaphragm of this invention has two glass transition temperature regions within a temperature range of -60°C to 10°C. Within this temperature range, the diaphragm exhibits good damping performance, effectively reducing the THD of the sound-generating device and improving the listening quality.

Description

Technical Field

[0001] This invention relates to the field of electroacoustic conversion technology, and more specifically, to a diaphragm for a sound-generating device, a sound-generating device, and an electronic device. Background Technology

[0002] In related technologies, diaphragm materials are made of nitrile rubber (NBR). However, this type of diaphragm has poor resilience and is prone to deviating from its vibration position during long-term use, resulting in insufficient lower vibration space and issues such as voice coil undershoot during large amplitude vibrations. When used at lower temperatures (e.g., -60℃ to 10℃), the rigidity of the diaphragm material increases, and the damping loss factor is low in some temperature ranges, leading to high THD distortion and poor listening performance. Furthermore, at lower temperatures (e.g., -60℃ to 10℃), the elastic modulus of the diaphragm changes significantly, causing excessive fluctuations in the product's F0 (fiber oscillation). Summary of the Invention

[0003] One object of the present invention is to provide a new technical solution for a diaphragm for a sound-generating device.

[0004] According to a first aspect of the present invention, a diaphragm for a sound-generating device is provided. The diaphragm comprises a modified nitrile rubber layer, the modified nitrile rubber layer being prepared from a blend material comprising nitrile rubber and a damping modifier, the nitrile rubber having a binary structure, the nitrile rubber comprising ≥40% by mass in the blend material, and the damping modifier comprising at least one selected from methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, the damping modifier comprising ≤40% by mass in the blend material.

[0005] The modified nitrile rubber layer has a first glass transition temperature and a second glass transition temperature, the first glass transition temperature being -60℃ to -40℃ and the second glass transition temperature being -30℃ to -10℃. The ratio of the F0 of the diaphragm at 23℃ to the F0 at -20℃ is greater than or equal to 0.8 and less than 1. The loss factor of the diaphragm is ≥0.14 within the range of -60℃ to 10℃. The elastic recovery rate of the diaphragm under a tensile strain of 10% is ≥90%.

[0006] Optionally, the nitrile rubber includes a butadiene-acrylonitrile copolymer, the molecular structure of which is:

[0007] ,

[0008] Where a and b are integers and not both 0;

[0009] c is a natural number;

[0010] And / or, the nitrile rubber comprises hydrogenated butadiene-acrylonitrile copolymer, the molecular structure of which is:

[0011] ,

[0012] Where e and f are integers and not both 0;

[0013] g is a natural number;

[0014] h and i are integers and not both 0.

[0015] Optionally, the nitrile rubber includes butadiene-acrylonitrile copolymer, wherein the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is 10%-40%.

[0016] Optionally, the damping modifier comprises methyl vinyl phenyl silicone oil, the molecular structure of which is:

[0017] ,

[0018] Where m is an integer;

[0019] n and o are natural numbers;

[0020] R3 is any one of methyl, vinyl, or phenyl;

[0021] R4 is any one of methyl, vinyl, or phenyl;

[0022] And / or, the damping modifier includes an ethylene-propylene copolymer, the molecular structure of which is:

[0023] , or ,

[0024] Where s, t, u, v, w, x, y, and z are all natural numbers;

[0025] And / or, the damping modifier comprises a butadiene-styrene copolymer, the molecular structure of which is:

[0026]

[0027] Where a1 and c1 are integers and they are not both 0;

[0028] b1 is a natural number.

[0029] Optionally, the blended material further includes fillers, the fillers including at least one of silica, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica, the fillers having a mass percentage content of 20%-55% in the blended material.

[0030] Optionally, the blend material further includes a vulcanizing agent, which includes sulfur, and the sulfur content in the blend material is 0.3%-3% by mass.

[0031] Optionally, the blend material further includes a vulcanizing agent, which includes at least one of the following: 1,2-1,4-bis(tert-butylperoxyisopropylbenzene), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxyisopropylbenzene, 4,4-bis(tert-butylperoxy)valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, dilauryl peroxide, and cumene hydroperoxide; the vulcanizing agent has a mass percentage content of 0.5%-3% in the blend material.

[0032] Optionally, the blend material further includes an accelerator, which includes at least one of tetramethylthiuram disulfide, tetraethylthiuram disulfide, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, zinc dimethyl dithiocarbamate, diphenylguanidine, sulfenic acid accelerator, thiuram accelerator, zinc oxide, and stearic acid, wherein the accelerator has a mass percentage of 0.2%-5% in the blend material.

[0033] Optionally, the blend material further includes an antioxidant, which includes at least one selected from N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, N-phenyl-β-naphthylamine, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2,4-trimethyl-1,2-dihydroquinoline, 2-mercaptobenzimidazole, and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline; the antioxidant is present in the blend material at a mass percentage of 0.1%-3%.

[0034] Optionally, the tensile strength of the modified nitrile rubber layer is ≥9 MPa.

[0035] Optionally, the diaphragm is formed as a single-layer structure, and the diaphragm is composed of a single layer of the modified nitrile rubber;

[0036] Alternatively, the diaphragm may be formed as a multilayer structure, comprising at least one layer of the modified nitrile rubber and a composite layer, wherein the composite layer is stacked with the modified nitrile rubber layer, and the composite layer is at least one of an elastomer layer, an engineering plastic layer, and a film layer.

[0037] Optionally, the nitrile rubber in the blend contains ≥50% by mass, and the damping modifier is present in the blend.

[0038] Optionally, the glass transition temperature of the nitrile rubber is -30℃ to -10℃, and the glass transition temperature of the damping modifier is -70℃ to -35℃.

[0039] According to a second aspect of the present invention, a sound-generating device is provided. The sound-generating device includes the diaphragm described in the present invention.

[0040] According to a third party of the present invention, an electronic device is provided. This electronic device includes the sound-generating device described herein.

[0041] In this embodiment of the invention, the diaphragm comprises modified nitrile rubber prepared from a blend of materials, wherein the blend includes nitrile rubber and a damping modifier. By adding the damping modifier, the modified nitrile rubber exhibits two distinct glass transition temperature regions within a temperature range of -60℃ to 10℃. Within this temperature range, the diaphragm demonstrates excellent damping performance, with a loss factor ≥0.14 within the -60℃ to 10℃ range. This effectively reduces the THD of the sound-generating device, resulting in higher sound quality. In this embodiment of the invention, the ratio of F0 at 23℃ to F0 at -20℃ is ≥0.80, resulting in a smaller and smoother modulus change in the diaphragm under high and low temperature conditions, and stronger vibration stability. Furthermore, when the mass percentage of nitrile rubber in the blend is ≥40%, the corresponding mass percentage of the damping modifier in the blend is ≤40%, which makes the elastic recovery rate of the diaphragm ≥90% under the condition of tensile strain of 10%. The diaphragm has good resilience and can maintain the set position during long-term vibration, ensuring that there is sufficient space for the diaphragm to vibrate up and down and that there will be no collision with the voice coil.

[0042] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0043] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0044] Figure 1 This is a cross-sectional view of the diaphragm according to an embodiment of the present invention.

[0045] Figure 2 This is a perspective view of a miniature loudspeaker according to an embodiment of the present invention.

[0046] Figure 3 This is a cross-sectional view of a miniature loudspeaker according to an embodiment of the present invention.

[0047] Figure 4 This is a cross-sectional view of a large loudspeaker according to an embodiment of the present invention.

[0048] Figure 5 These are the total harmonic distortion (THD) curves of the sound-generating devices in the embodiments and comparative examples of the present invention.

[0049] Figure label:

[0050] 100. Sound-generating device; 10. Housing; 20. Diaphragm; 30. Voice coil; 40. Permanent magnet; 50. Cone; 60. Dust cover; 70. Spider; 80. Frame; 90. U-shaped iron. Detailed Implementation

[0051] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0052] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0053] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0054] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0056] The diaphragm 20 for a sound-generating device according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0057] According to one embodiment of the present invention, a diaphragm 20 for a sound-generating device is provided. The diaphragm 20 includes a modified nitrile rubber layer, which is prepared from a blend material comprising nitrile rubber and a damping modifier. The nitrile rubber has a binary structure, and the mass percentage of the nitrile rubber in the blend material is ≥40%. The damping modifier includes at least one selected from methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, and the mass percentage of the damping modifier in the blend material is ≤40%.

[0058] The modified nitrile rubber layer has a first glass transition temperature and a second glass transition temperature, the first glass transition temperature being -60℃ to -40℃ and the second glass transition temperature being -30℃ to -10℃. The ratio of F0 at 23℃ to F0 at -20℃ of the diaphragm 20 is greater than or equal to 0.80 and less than 1. The loss factor of the diaphragm 20 within the range of -60℃ to 10℃ is ≥0.14. The elastic recovery rate of the diaphragm 20 under a tensile strain of 10% is ≥90%.

[0059] Specifically, the diaphragm 20 is used in a sound-generating device, such as a miniature loudspeaker or a large loudspeaker. The diaphragm 20 is part of a vibration system. The diaphragm 20 can be a surround diaphragm or a planar diaphragm. The diaphragm 20 includes a modified nitrile rubber layer. The diaphragm 20 can have a single-layer or multi-layer structure. The modified nitrile rubber layer is prepared using a blend of materials. Preparation methods include, for example, compression molding or air compression molding. The blend is composed of multiple materials, for example, multiple materials are added to a mixer. The materials are blended in the mixer until homogeneous to form the blend.

[0060] Nitrile butadiene rubber (NBR) is a copolymer polymerized from acrylonitrile and butadiene monomers, exhibiting a binary structure. Damping modifiers are used to improve the low-temperature damping properties of NBR. The NBR molecular chain contains a large number of nitrile groups (-CN), which are polar groups, resulting in strong interactions between the molecular chains. These strong interactions restrict the movement of the molecular chains, making it difficult for them to relax effectively and hysteresis under external forces, thus reducing energy dissipation. NBR exhibits a high loss factor only near its glass transition temperature, while its loss factor is low in other ranges. In this embodiment of the invention, a damping modifier is added to prepare a modified NBR with two glass transition temperatures. Specifically, the damping modifier is blended with NBR and crosslinked in a mold to form a diaphragm 20. The resulting modified NBR layer has a first glass transition temperature of -60°C to -40°C and a second glass transition temperature of -30°C to -10°C.

[0061] In other words, the modified nitrile rubber of this embodiment has two glass transition temperature regions within a temperature range of -60℃ to 10℃, allowing the diaphragm 20 to maintain a high loss factor over a wider temperature range. For example, the loss factor of the diaphragm 20 within the range of -60℃ to 10℃ is ≥0.14, which can effectively reduce the THD of the sound-generating device using this diaphragm 20, resulting in low distortion and high sound quality. Furthermore, because the diaphragm 20 has two glass transition temperature regions, the elastic modulus of the diaphragm 20 changes smoothly within this temperature range, avoiding large fluctuations in F0 caused by drastic changes in the elastic modulus. The ratio of the F0 of the diaphragm 20 at 23℃ to the F0 at -20℃ is greater than or equal to 0.80 and less than 1. Furthermore, since the damping modifier has a lower glass transition temperature, it has better resilience under near-room temperature conditions, resulting in good resilience performance of the diaphragm 20. The elastic recovery rate is ≥90% under a tensile strain of 10%, which allows the diaphragm 20 to remain in the designed position during long-term vibration, ensuring sufficient vertical vibration space for the diaphragm 20 and avoiding problems such as voice coil undershoot.

[0062] It should be noted that if the mass percentage of nitrile rubber in the blend is too low, the blend will be difficult to mix, and the elongation at break after vulcanization will be too low, making the film breakage phenomenon more likely to occur during reliability testing. When the mass percentage of nitrile rubber in the blend is ≥40%, the blend is easy to mix, and the resulting modified nitrile rubber has a high elongation at break.

[0063] Optionally, the nitrile rubber in the blend contains ≥50% by mass, and the damping modifier in the blend contains ≤30% by mass. Within this range, the blend is easy to mix, and the resulting modified nitrile rubber has a higher elongation at break and better overall damping in the low-temperature range.

[0064] Furthermore, the glass transition temperature of the damping modifier is typically lower than that of nitrile rubber, enabling the modified nitrile rubber to exhibit good damping properties within a temperature range of -60°C to 10°C. Optionally, the damping modifier includes any one or a mixture of several of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer. All of these substances can chemically react with nitrile rubber to form a cross-linked structure, resulting in a modified nitrile rubber layer with dual glass transition temperatures.

[0065] Furthermore, the ratio of the F0 value of the diaphragm 20 at 23°C to that at -20°C is greater than or equal to 0.80 and less than 1. The F0 value of the diaphragm 20 at 23°C characterizes the resonant frequency of the diaphragm 20 at room temperature. The closer the ratio of the F0 value of the diaphragm 20 at 23°C to that at -20°C is to 1, the better the vibration stability of the diaphragm 20 at different temperatures. The modulus stability of the modified nitrile rubber layer is significantly better than that of the nitrile rubber layer; better modulus stability results in better F0 stability of the speaker.

[0066] Optionally, the ratio of F0 at 23°C to F0 at -20°C of the diaphragm 20 is 0.80, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, etc. Those skilled in the art can select according to actual needs.

[0067] In this embodiment of the invention, the modified nitrile rubber is prepared from a blend material, which includes nitrile rubber and a damping modifier. This embodiment of the invention adds a damping modifier to the nitrile rubber, resulting in a modified nitrile rubber with two glass transition temperatures. The modified nitrile rubber layer obtained after crosslinking has a first glass transition temperature and a second glass transition temperature. The first glass transition temperature is -60℃ to -40℃, and the second glass transition temperature is -30℃ to -10℃. Therefore, the modified nitrile rubber of this embodiment of the invention has two glass transition temperature regions within the temperature range of -60℃ to -10℃, allowing the diaphragm 20 to maintain a high loss factor over a wide temperature range. The loss factor of the diaphragm 20 within the range of -60℃ to 10℃ is ≥0.14, which effectively reduces the THD of the sound-generating device using this diaphragm 20, resulting in low distortion and high sound quality. Furthermore, because the diaphragm 20 has two glass transition temperature regions, the elastic modulus of the diaphragm 20 changes smoothly within this temperature range, avoiding large fluctuations in F0 caused by drastic changes in the elastic modulus. For example, the ratio of the F0 of the diaphragm 20 at 23℃ to that at -20℃ is greater than or equal to 0.80 and less than 1, indicating that the diaphragm 20 has better vibration stability at different temperatures. Moreover, because the damping modifier has a lower glass transition temperature, it has better resilience at room temperature, resulting in good resilience performance of the diaphragm 20. Under a tensile strain of 10%, the elastic recovery rate is ≥90%, allowing the diaphragm 20 to maintain its designed position during long-term vibration, ensuring ample vertical vibration space and avoiding problems such as voice coil undershoot.

[0068] In some specific embodiments of the present invention, the glass transition temperature of the nitrile rubber is -30℃ to -10℃, and the glass transition temperature of the damping modifier is -70℃ to -35℃.

[0069] In this embodiment, the glass transition temperature of the nitrile rubber is in the range of -30℃ to -10℃, and the glass transition temperature of the damping modifier is -70℃ to -35℃. This embodiment of the invention, by adding a damping modifier, enables the prepared modified nitrile rubber to possess two glass transition temperatures. The first glass transition temperature is -60℃ to -40℃, and the second glass transition temperature is -30℃ to -10℃. In other words, the modified nitrile rubber of this embodiment has two glass transition temperature regions within the temperature range of -60℃ to 10℃, allowing the diaphragm 20 to maintain good damping performance over a wider temperature range.

[0070] In some specific embodiments of the present invention, the nitrile rubber comprises a butadiene-acrylonitrile copolymer, the molecular structure of which is:

[0071] ,

[0072] Where a and b are integers and not both 0;

[0073] c is a natural number;

[0074] And / or, the nitrile rubber comprises hydrogenated butadiene-acrylonitrile copolymer, the molecular structure of which is:

[0075] ,

[0076] Where e and f are integers and not both 0;

[0077] g is a natural number;

[0078] h and i are integers and not both 0.

[0079] Both types of nitrile rubber described above can be blended with damping modifiers to form modified nitrile rubber after crosslinking. Those skilled in the art can choose according to their actual needs.

[0080] In some specific embodiments of the present invention, the nitrile rubber includes butadiene-acrylonitrile copolymer, wherein the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is 18%-50%.

[0081] In this embodiment, the acrylonitrile segments in the butadiene-acrylonitrile copolymer contain nitrile groups, which are polar groups. These polar groups result in strong interactions between the molecular chains. When the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is less than 18%, the interactions between the molecular chains of the modified nitrile rubber are insufficient, resulting in low tensile strength and low damping. When the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is greater than 50%, the flexibility of the molecular chains within the modified nitrile rubber decreases, leading to decreased elasticity and increased brittleness. When the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is between 18% and 50%, the modified nitrile rubber possesses both sufficient tensile strength and suitable elasticity, making it less prone to film rupture.

[0082] Optionally, the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is 18%, 20%, 30%, 40%, 50%, etc., which can be selected by those skilled in the art according to actual needs.

[0083] In some specific embodiments of the present invention, the damping modifier comprises methyl vinyl phenyl silicone oil, the molecular structure of which is:

[0084] ,

[0085] Where m is an integer;

[0086] n and o are natural numbers;

[0087] R3 is any one of methyl, vinyl, or phenyl;

[0088] R4 is any one of methyl, vinyl, or phenyl;

[0089] And / or, the damping modifier includes an ethylene-propylene copolymer, the molecular structure of which is:

[0090] , or ,

[0091] Where s, t, u, v, w, x, y, and z are all natural numbers;

[0092] And / or, the damping modifier comprises a butadiene-styrene copolymer, the molecular structure of which is:

[0093]

[0094] Where a1 and c1 are integers and they are not both 0;

[0095] b1 is a natural number.

[0096] In this embodiment, all of the above-mentioned compounds can effectively modify nitrile rubber, giving the modified nitrile rubber two glass transition temperatures. Of course, the parameters of each molecular formula are not limited here, and those skilled in the art can select them according to actual needs.

[0097] In some specific embodiments of the present invention, the blended material further includes fillers, the fillers including at least one of silicon dioxide, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica, and the filler content in the blended material is 20%-55% by mass.

[0098] In this embodiment, the filler is used to improve the mechanical properties of the diaphragm 20, such as tensile strength and hardness. When preparing the diaphragm 20, the filler can be one or a mixture of several of the following: silica, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica.

[0099] During batching, the filler accounts for 20wt%-55wt% of the mass of the blended material.

[0100] It should be noted that the lower the filler content, the lower the tensile strength of the diaphragm 20, especially when the filler's mass percentage in the blend is less than 20 wt%, resulting in poor reinforcement of the diaphragm 20. Conversely, if the filler content is too high, for example, when the filler's mass percentage in the blend is greater than 55 wt%, the elongation at break of the diaphragm 20 will decrease significantly, and the material's toughness will be insufficient, making the diaphragm 20 prone to rupture during vibration. When the filler's mass percentage in the blend is between 20 wt% and 55 wt%, the diaphragm 20 possesses sufficient tensile strength, elongation at break, and toughness.

[0101] Optionally, the filler in the blended material may contain 20 wt%, 30 wt%, 40 wt%, 50 wt%, 55 wt%, etc. Of course, the mass percentage of the filler in the blended material is not limited to the above embodiments, and those skilled in the art can select according to actual needs.

[0102] In some specific embodiments of the present invention, the blend material further includes a vulcanizing agent, the vulcanizing agent including sulfur, and the sulfur content in the blend material is 0.3%-3% by mass.

[0103] In this embodiment, a vulcanizing agent, namely sulfur, is added to the blend material. The vulcanizing agent is used to cause the nitrile rubber and damping modifier to undergo a crosslinking reaction, thereby forming a network structure.

[0104] It should be noted that during the formulation process, the mass of sulfur accounts for 0.3wt%-3wt% of the total mass of the blended materials. It is important to note that a lower sulfur content results in insufficient cross-linking of the blended materials, leading to poor stability of the network structure. When the sulfur content in the blended materials is less than 0.3wt%, the diaphragm 20 exhibits insufficient cross-linking and poor network structure stability. Conversely, an excessively high sulfur content results in high hardness, poor toughness, low elongation at break, and susceptibility to aging at high temperatures. Particularly when the sulfur content in the blended materials exceeds 3wt%, the elongation at break of the diaphragm 20 becomes too low, making it prone to rupture. A sulfur content of 0.3wt%-3wt% in the blended materials ensures both sufficient cross-linking of the diaphragm 20 and a high elongation at break.

[0105] Optionally, the sulfur in the blended material has a mass percentage of 0.3 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, etc. Further, the sulfur in the blended material has a mass percentage of 1 wt%-2 wt%. Those skilled in the art can select the appropriate percentage based on actual needs.

[0106] In some specific embodiments of the present invention, the blend material further includes a vulcanizing agent, which includes at least one of the following: 1,2-1,4-bis(tert-butylperoxyisopropylbenzene), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxyisopropylbenzene, 4,4-bis(tert-butylperoxy)valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, dilauryl peroxide, and cumene hydroperoxide; the vulcanizing agent has a mass percentage content of 0.5%-3% in the blend material.

[0107] In this embodiment, a vulcanizing agent, which is a peroxide, is added to the blend material. The vulcanizing agent can be one or a mixture of more of the following: 1,2-1,4-bis(tert-butylperoxyisopropylbenzene), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxyisopropylbenzene, 4,4-bis(tert-butylperoxy)valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, dilauryl peroxide, and cumene hydroperoxide.

[0108] During formulation, the vulcanizing agent accounts for 0.5wt%-3wt% of the total mass of the blended materials. It should be noted that a lower vulcanizing agent content results in insufficient cross-linking of the blended materials, leading to poor stability of the network structure. When the vulcanizing agent's mass percentage in the blended materials is less than 0.5wt%, the diaphragm 20 exhibits insufficient cross-linking and poor network structure stability. Conversely, an excessively high vulcanizing agent content results in high hardness, poor toughness, and excessively low elongation at break of the diaphragm 20. Especially when the vulcanizing agent's mass percentage in the blended materials exceeds 3wt%, the elongation at break of the diaphragm 20 is too low, making it prone to rupture. A vulcanizing agent content of 0.5wt%-3wt% in the blended materials ensures both sufficient cross-linking of the diaphragm 20 and a high elongation at break.

[0109] In some specific embodiments of the present invention, the blend material further includes an accelerator, which includes at least one selected from tetramethylthiuram disulfide, tetraethylthiuram disulfide, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, zinc dimethyl dithiocarbamate, diphenylguanidine, sulfenic acid accelerator, thiuram accelerator, zinc oxide, and stearic acid. The accelerator has a mass percentage content of 0.2%-5% in the blend material.

[0110] In this embodiment, the accelerator can accelerate the vulcanization speed, shorten the vulcanization time, and lower the vulcanization temperature, thereby reducing the amount of vulcanizing agent used. One or more mixtures of the following can be added to the blend as accelerators: tetramethylthiuram disulfide, tetraethylthiuram disulfide, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, zinc dimethyl dithiocarbamate, diphenylguanidine, sulfenic acid accelerator, thiuram accelerator, zinc oxide, and stearic acid.

[0111] During formulation, the accelerator's mass percentage in the blend is 0.2 wt%-5 wt%. It should be noted that when the accelerator's addition is less than 0.2 wt%, its effect on accelerating vulcanization, shortening vulcanization time, and lowering vulcanization temperature is not significant. When the accelerator's addition is greater than 5%, the vulcanization reaction is too rapid, easily leading to uneven molecular network structure within the rubber, and the diaphragm 20 is prone to breakage. When the accelerator's mass percentage in the blend is 0.2 wt%-5 wt%, the vulcanization reaction rate of the blend is moderate.

[0112] Optionally, the accelerator in the blended material may be 0.2 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, etc., and those skilled in the art may set it according to actual needs.

[0113] In some specific embodiments of the present invention, the blend material further includes an antioxidant, which includes at least one selected from N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, N-phenyl-β-naphthylamine, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2,4-trimethyl-1,2-dihydroquinoline, 2-mercaptobenzimidazole, and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline; the antioxidant in the blend material is at a mass percentage of 0.1 wt% to 3 wt%.

[0114] During the use of polymer materials, over time, molecular chains break down, generating self-catalytically active free radicals. These free radicals can accelerate the aging of the polymer materials themselves. Adding an antioxidant to the diaphragm 20 can stop the generation of self-catalytically active free radicals in the blend material, thereby delaying the aging of the blend material and extending the service life of the diaphragm 20. When preparing the diaphragm 20, one or more of the following can be selected as antioxidants: N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, N-phenyl-β-naphthylamine, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2,4-trimethyl-1,2-dihydroquinoline, 2-mercaptobenzimidazole, and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline. The above-mentioned anti-aging agents are all miscible with nitrile rubber and damping modifiers, thereby preventing the diaphragm 20 from aging and extending the service life of the diaphragm 20.

[0115] When preparing the blend, the antioxidant accounts for 0.1wt%-3wt% of the mass of the blend material.

[0116] It should be noted that if the amount of antioxidant added to the blend is too small, for example, when the antioxidant's mass percentage in the blend is less than 0.1 wt%, it will not be able to prevent the diaphragm 20 from aging and extend its service life. If the amount of antioxidant added is too large, for example, when the antioxidant's mass percentage in the blend is greater than 3 wt%, the antioxidant will not be well miscible with nitrile rubber and damping modifier, resulting in the antioxidant not being uniformly dispersed in the blend and causing a decrease in the mechanical properties of the diaphragm 20. However, when the antioxidant's mass percentage in the blend is between 0.1 wt% and 3 wt%, the antioxidant can effectively extend the service life of the diaphragm 20, and the antioxidant can be uniformly dispersed in the blend, resulting in the prepared diaphragm 20 maintaining good mechanical properties.

[0117] Optionally, the antioxidant in the blended material may be 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, etc. Further, the antioxidant in the blended material may be 2 wt%-3 wt%. Of course, the mass percentage of the antioxidant in the blended material is not limited to the above embodiments, and those skilled in the art can select it according to actual needs.

[0118] In some specific embodiments of the present invention, the tensile strength of the modified nitrile rubber layer is ≥9MPa.

[0119] In this embodiment, tensile strength reflects the reliability of the diaphragm 20. When the tensile strength of the modified nitrile rubber is less than 9 MPa, the reliability of the diaphragm 20 is easily compromised, and the diaphragm 20 is prone to rupture after high temperature and humidity testing and aging testing. When the tensile strength of the modified nitrile rubber is ≥9 MPa, the reliability of the diaphragm 20 is good, and the diaphragm 20 is less likely to rupture after high temperature and humidity testing and aging testing.

[0120] In some specific embodiments of the present invention, the diaphragm 20 is formed as a single-layer structure, and the diaphragm 20 is composed of a layer of the modified nitrile rubber;

[0121] Alternatively, the diaphragm 20 may be formed as a multilayer structure, comprising at least one layer of the modified nitrile rubber and a composite layer, wherein the composite layer is stacked with the modified nitrile rubber layer, and the composite layer is at least one of an elastomer layer, an engineering plastic layer, and a film layer.

[0122] In other words, the diaphragm 20 in this embodiment of the invention can be a single-layer modified nitrile rubber layer. The diaphragm 20 has a simple structure and a simple manufacturing process.

[0123] Alternatively, the diaphragm 20 can be a multi-layer structure. That is, at least one layer of modified nitrile rubber is stacked with a composite layer to form a multi-layer diaphragm 20. The composite layer is at least one of an elastomer layer, an engineering plastic layer, and a film layer. The number of layers in the multi-layer structure can be 2, 3, 4, 5, 6, 7, etc.

[0124] Optionally, the elastomer layer includes one or more of thermoplastic polyurethane elastomers, thermoplastic polyester elastomers, thermoplastic polyamide elastomers, and thermoplastic polystyrene elastomers. The engineering plastic layer includes one or more of PEEK, PAR, PMI, PET, PEN, PA, PEI, and LCP. The film layer is a silicone film and / or an acrylic film. The composite layer is one or more layers.

[0125] According to another embodiment of the present invention, a sound-generating device is provided. For example... Figures 2-4 As shown, the sound-generating device 100 includes the diaphragm 20 of the above embodiment.

[0126] like Figures 2-3 As shown, the sound-generating device 100 is a miniature loudspeaker. The sound-generating device 100 may include a housing 10, a magnetic circuit system, and a vibration system. The magnetic circuit system includes a permanent magnet 40, which forms a magnetic gap. The vibration system includes a diaphragm 20 and a voice coil 30. Both the diaphragm 20 and the permanent magnet 40 are connected to the housing 10. The permanent magnet 40 is disposed on one side of the diaphragm 20 along its thickness direction. One end of the voice coil 30 is connected to the diaphragm 20, and the other end is located within the magnetic gap.

[0127] In this example, the diaphragm 20 can be a surround diaphragm. The surround diaphragm includes a central portion, a surround portion, and a fixing portion connected sequentially from the inside out. The fixing portion is used to connect to the housing 10. A dome is provided on the central portion, and the voice coil 30 is connected to the central portion or the dome.

[0128] In other examples, the diaphragm 20 may also be a planar diaphragm or other structures, which can be determined by those skilled in the art according to the actual situation, and no specific limitation is made here.

[0129] Figure 4 Another sound-generating device 100 according to an embodiment of the present invention is shown. This sound-generating device is a large loudspeaker.

[0130] The sound-generating device 100 may include a housing 10, a magnetic circuit system, and a vibration system. The magnetic circuit system includes a permanent magnet 40 and a U-shaped iron 90, which form a magnetic gap. The vibration system includes a diaphragm 20, a cone 50, a frame 80, a voice coil 30, and a dust cover 60. The inner edge of the cone 50 is connected to one end of the frame 80. The dust cover 60 covers one end of the frame 80. The voice coil 30 is arranged around the other end of the frame 80. The diaphragm 20 is connected to the outer edge of the cone 50. Both the diaphragm 20 and the permanent magnet 40 are connected to the housing 10. The permanent magnet 40 is disposed on one side of the diaphragm 20 along its thickness direction. One end of the voice coil 30 is located within the magnetic gap. The housing 10 is provided with a spider 70. The spider 70 is connected to the middle of the frame 80.

[0131] In this example, the diaphragm 20 can be a folded ring diaphragm. The folded ring diaphragm includes a central portion, a folded ring portion, and a fixing portion connected sequentially from the inside to the outside. The fixing portion is used to connect to the housing 10. The central portion is connected to the outer edge of the cone 50.

[0132] In other examples, the diaphragm 20 may also be a planar diaphragm or other structures, which can be determined by those skilled in the art according to the actual situation, and no specific limitation is made here.

[0133] According to another embodiment of the present invention, an electronic device is provided.

[0134] Electronic devices include, for example, mobile phones, computers, televisions, speakers, walkie-talkies, VR devices, AR devices, and smart glasses. This electronic device includes the sound-generating device 100 described in the above embodiments. Of course, the electronic device of the present invention also includes at least all the beneficial effects of the above embodiments, which will not be elaborated upon here.

[0135] The diaphragm 20 and the sound-generating device 100 of the present invention will be described in detail below with reference to specific embodiments. It should be noted that the following description is merely exemplary and not a specific limitation of the present invention.

[0136] Example:

[0137] The diaphragm 20 is a single-layer folded ring diaphragm. The thickness of the diaphragm 20 is 110 μm. The diaphragm 20 includes a modified nitrile rubber layer. The modified nitrile rubber layer is prepared by compression molding of a blend material, which includes nitrile rubber and a damping modifier. The mass content of acrylonitrile segments in the nitrile rubber is 35%. The damping modifier is vinylphenyl silicone oil. The specific composition of the blend material is shown in Table 1.

[0138] Comparative example:

[0139] The diaphragm 20 is a single-layer folded ring diaphragm. The thickness of diaphragm 20 is 110 μm. Diaphragm 20 is prepared by compression molding of nitrile rubber. The mass content of acrylonitrile segments in the nitrile rubber is 35%. The specific composition of the blend material is shown in Table 1.

[0140] Table 1 - Ingredients of Diaphragm 20 for Examples and Comparative Examples

[0141]

[0142] Performance testing:

[0143] (1) The hardness (Shore A), tensile strength, tear strength, loss factor (-60℃ to 10℃, minimum value) and glass transition temperature of the diaphragm 20 in the examples and comparative examples were tested respectively. It should be noted that, considering the difference between the size of the diaphragm 20 and the sample size required by the corresponding test standard, a sample with the same constituent material as the diaphragm 20 was selected for relevant tests to characterize the properties of the diaphragm 20. Since the sample and the diaphragm 20 itself have the same constituent material, the relevant properties of the sample are consistent with the relevant properties of the diaphragm 20.

[0144] Hardness (Shore A), tensile strength, and tear strength were tested according to ASTM-D882 standard at a test temperature of 23℃.

[0145] The loss factor, also known as the damping factor, is the ratio of the loss modulus to the storage modulus. It is tested using a dynamic thermomechanical analyzer according to the ASTM D5026-23 standard. The frequency is 1 Hz and the strain is 0.2%.

[0146] The glass transition temperature was tested using a dynamic thermomechanical analyzer, according to the ASTM D5026-23 standard, at a frequency of 1 Hz and a strain of 0.2%.

[0147] (2) The diaphragms 20 of the examples and comparative examples were assembled into a sound-generating device, which was a large loudspeaker. The two diaphragms 20 were of the same size. The THD curves of the two sound-generating devices were tested. See details. Figure 4 .

[0148] (3) Reliability testing:

[0149] The diaphragm 20 from the examples and comparative examples was assembled into the sound-generating device. After the sound-generating device operated for 168 hours at 65°C and 95% humidity, its acoustic performance was tested, and the listening yield was calculated. Calculation method: The HOHD curves of 10 sound-generating devices were tested and compared with the standard frame line. Products exceeding the frame line were judged as NG (Not Good) and their reliability failed.

[0150] The diaphragm 20 of the examples and comparative examples were assembled into the sound-generating device, and the F0 of the sound-generating device at 23°C and -20°C was tested respectively. The ratio of F0 at 23°C and -20°C was calculated.

[0151] Results and Analysis:

[0152] (1) The test results of the hardness (Shore A), tensile strength, tear strength, loss factor (-60℃ to 10℃, minimum value) and glass transition temperature of the diaphragm 20 in the examples and comparative examples are shown in Table 2.

[0153] Table 2 - Performance Tests of Diaphragm 20 in Examples and Comparative Examples

[0154] As shown in Table 2, the hardness of the diaphragm 20 in the embodiments of the present invention is the same as that of the diaphragm 20 in the comparative example. However, the tensile strength, tear strength, and loss factor of the diaphragm 20 in the embodiments of the present invention are all higher than those of the diaphragm 20 in the comparative example. This is mainly because the main component of the raw materials of the diaphragm 20 in the embodiments of the present invention and the diaphragm 20 in the comparative example are both nitrile rubber and carbon black, with similar carbon black addition ratios. The main components determine that the hardness of the diaphragm 20 in the embodiments of the present invention is the same as that of the diaphragm 20 in the comparative example. The modified nitrile rubber of the diaphragm 20 in the embodiments of the present invention has two glass transition temperatures (i.e., -50℃ and -17℃), and the diaphragm 20 maintains a high loss factor in the temperature range of -60℃ to 10℃. The diaphragm 20 in Comparative Example 1 is made of nitrile rubber and has only one glass transition temperature, which cannot maintain a high loss factor in a wider temperature range.

[0155] (2) By Figure 4 As can be seen, within the 100Hz-1000Hz range, the THD curve of the sound-generating device of this embodiment is generally lower than that of the comparative sound-generating device. This is because the diaphragm of this embodiment is prepared by blending a damping modifier with nitrile rubber. The modified nitrile rubber layer obtained after crosslinking has a first glass transition temperature and a second glass transition temperature, where the first glass transition temperature is -50℃ and the second glass transition temperature is -17℃. In other words, the modified nitrile rubber of this embodiment has two different glass transition temperature regions over a wide temperature range, enabling the diaphragm 20 to maintain good damping effect over a wide temperature range, effectively reducing the THD of the sound-generating device using this diaphragm 20, resulting in low distortion and high sound quality.

[0156] (3) After testing, the sound-emitting device of the present invention achieved a sound quality rate of 100%. The sound quality rate of the comparative sound-emitting device was 60%. The sound quality rate of the present invention is significantly higher than that of the comparative sound-emitting device.

[0157] In this embodiment of the invention, the diaphragm 20 has an F0 of 60 Hz at 23°C and an F0 of 71 Hz at -20°C. In the comparative embodiment, the diaphragm 20 has an F0 of 61 Hz and an F0 of 94 Hz at -20°C. The ratio of the F0 at 23°C to the F0 at -20°C in this embodiment of the invention is 0.85, which is significantly higher than the ratio of the comparative embodiment's F0 at 23°C to the F0 at -20°C, which is 65.

[0158] This indicates that the sound-generating device of the present invention exhibits excellent long-term reliability. This is primarily because the diaphragm of the present invention is prepared by blending a damping modifier with nitrile rubber. The modified nitrile rubber layer obtained after crosslinking has a first glass transition temperature and a second glass transition temperature, where the first glass transition temperature is -50°C and the second glass transition temperature is -17°C. In other words, the modified nitrile rubber of the present invention has two glass transition temperature regions over a relatively wide temperature range, resulting in a smoother modulus change and higher damping of the diaphragm.

[0159] In summary, the diaphragm of this embodiment is prepared by blending a damping modifier with nitrile rubber. The modified nitrile rubber layer obtained after crosslinking has a first glass transition temperature and a second glass transition temperature, where the first glass transition temperature is -50°C and the second glass transition temperature is -17°C. That is, the modified nitrile rubber of this embodiment has two glass transition temperature regions over a wide temperature range, allowing the diaphragm 20 to maintain good damping performance over a wide temperature range. This effectively reduces the THD of the sound-generating device using the diaphragm 20, resulting in higher sound quality, and also makes the modulus change of the diaphragm 20 more gradual and the damping higher within this temperature range.

[0160] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0161] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A diaphragm for a sound-generating device, characterized in that, The diaphragm includes a modified nitrile rubber layer, which is prepared from a blend material. The blend material includes nitrile rubber and a damping modifier. The nitrile rubber has a binary structure and its mass percentage in the blend material is ≥40%. The damping modifier includes at least one of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, and its mass percentage in the blend material is ≤40%. The modified nitrile rubber layer has a first glass transition temperature and a second glass transition temperature, the first glass transition temperature being -60℃ to -40℃ and the second glass transition temperature being -30℃ to -10℃. The glass transition temperature of the damping modifier is -70℃ to -35℃. The ratio of the F0 of the diaphragm at 23℃ to the F0 at -20℃ is greater than or equal to 0.80 and less than 1. The loss factor of the diaphragm is ≥0.14 within the range of -60℃ to 10℃. The elastic recovery rate of the diaphragm under a tensile strain of 10% is ≥90%.

2. The diaphragm according to claim 1, characterized in that, The nitrile rubber includes a butadiene-acrylonitrile copolymer, the molecular structure of which is: ， Where a and b are integers and not both 0; c is a natural number; And / or, the nitrile rubber comprises hydrogenated butadiene-acrylonitrile copolymer, the molecular structure of which is: ， Where e and f are integers and not both 0; g is a natural number; h and i are integers and not both 0.

3. The diaphragm according to claim 2, characterized in that, The nitrile rubber includes butadiene-acrylonitrile copolymer, wherein the mass percentage of acrylonitrile segments in the butadiene-acrylonitrile copolymer is 10%-40%.

4. The diaphragm according to claim 1, characterized in that, The damping modifier includes methyl vinyl phenyl silicone oil, and the molecular structure of the methyl vinyl phenyl silicone oil is as follows: ， Where m is an integer; n and o are natural numbers; R3 is any one of methyl, vinyl, or phenyl; R4 is any one of methyl, vinyl, or phenyl; And / or, the damping modifier includes an ethylene-propylene copolymer, the molecular structure of which is: , or , Where s, t, u, v, w, x, y, and z are all natural numbers; And / or, the damping modifier comprises a butadiene-styrene copolymer, the molecular structure of which is: Where a1 and c1 are integers and they are not both 0; b1 is a natural number.

5. The diaphragm according to claim 1, characterized in that, The blended material further includes fillers, which include at least one of silicon dioxide, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica, and the filler has a mass percentage content of 20%-55% in the blended material.

6. The diaphragm according to claim 1, characterized in that, The blended material further includes a vulcanizing agent, which includes sulfur, and the sulfur content in the blended material is 0.3%-3% by mass.

7. The diaphragm according to claim 1, characterized in that, The blend material further includes a vulcanizing agent, which includes at least one of the following: 1,2-1,4-bis(tert-butylperoxyisopropylbenzene), 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxyisopropylbenzene, 4,4-bis(tert-butylperoxy)valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, dilauryl peroxide, and cumene hydroperoxide; the vulcanizing agent has a mass percentage content of 0.5%-3% in the blend material.

8. The diaphragm according to claim 1, characterized in that, The blend material further includes an accelerator, which includes at least one of tetramethylthiuram disulfide, tetraethylthiuram disulfide, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, zinc dimethyl dithiocarbamate, diphenylguanidine, sulfenic acid accelerator, thiuram accelerator, zinc oxide, and stearic acid. The accelerator has a mass percentage content of 0.2%-5% in the blend material.

9. The diaphragm according to claim 1, characterized in that, The blend material further includes an antioxidant, which includes at least one selected from N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, N,N'-diaryl-p-phenylenediamine, N-phenyl-β-naphthylamine, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2,4-trimethyl-1,2-dihydroquinoline, 2-mercaptobenzimidazole, and 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline; the antioxidant is present in the blend material at a mass percentage of 0.1%-3%.

10. The diaphragm according to claim 1, characterized in that, The tensile strength of the modified nitrile rubber layer is ≥9 MPa.

11. The diaphragm according to any one of claims 1-10, characterized in that, The diaphragm is formed as a single-layer structure, and the diaphragm is composed of a single layer of modified nitrile rubber; Alternatively, the diaphragm may be formed as a multilayer structure, comprising at least one layer of the modified nitrile rubber and a composite layer, wherein the composite layer is stacked with the modified nitrile rubber layer, and the composite layer is at least one of an elastomer layer, an engineering plastic layer, and a film layer.

12. The diaphragm according to any one of claims 1-10, characterized in that, The nitrile rubber in the blend contains ≥50% by mass, and the damping modifier in the blend contains ≤30% by mass.

13. The diaphragm according to any one of claims 1-10, characterized in that, The glass transition temperature of the nitrile rubber is -30℃ to -10℃.

14. A sound-generating device, characterized in that, Includes the diaphragm as described in any one of claims 1-13.

15. An electronic device, characterized in that, Includes the sound-generating device as described in claim 14.

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