Vibrating diaphragm for sound production device, sound production device and electronic equipment

Abstract

The invention discloses a vibrating diaphragm for a sound production device, the sound production device and electronic equipment, the vibrating diaphragm comprises a modified nitrile rubber layer prepared from a blending material, the blending material comprises nitrile rubber and a damping modifier, the nitrile rubber is of a binary structure, the mass percentage content of the nitrile rubber in the blending material is not less than 40%, and the damping modifier is not less than 10%. The damping modifier comprises at least one of methyl vinyl phenyl silicone oil, an ethylene-propylene copolymer and a butadiene-styrene copolymer, and the mass percentage content of the damping modifier in the blending material is less than or equal to 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 DEG C to-40 DEG C, and the second glass transition temperature is-30 DEG C to-10 DEG C. The vibrating diaphragm has two glass transition temperature regions within the temperature range of-60 DEG C to 10 DEG C, and the vibrating diaphragm has good damping performance within the temperature range, so that the THD (total harmonic distortion) of the sound production device is effectively reduced, and the audition yield is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electroacoustic conversion, and more particularly to a diaphragm for a sound-generating device, a sound-generating device, and an electronic device. Background Art

[0002] In related technologies, diaphragms are made of nitrile butadiene rubber (NBR). However, this type of diaphragm has poor resilience and can easily deviate from its vibration position over long periods of use, resulting in insufficient downward vibration space and a tendency for the voice coil to hit the bottom during large amplitudes. When used at lower temperatures (e.g., -60°C to 10°C), the diaphragm material's rigidity increases, and the damping loss factor decreases within certain temperature ranges, leading to high THD distortion and poor listening performance. Furthermore, at lower temperatures (e.g., -60°C to 10°C), the diaphragm's elastic modulus changes significantly, causing significant fluctuations in the product's F0. Summary of the Invention

[0003] An object of the present invention is to provide a new technical solution for a diaphragm of 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 includes a modified nitrile rubber layer, the modified nitrile rubber layer being prepared from a blended material, the blended material including nitrile rubber and a damping modifier, the nitrile rubber having a binary structure, the nitrile rubber comprising 40% or more by weight of the blended material, and the damping modifier comprising at least one of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, the damping modifier comprising 40% or less by weight of the blended material; 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, the second glass transition temperature is -30°C to -10°C, the ratio of the F0 of the diaphragm at 23°C to the F0 at -20°C is greater than or equal to 0.8 and less than 1, the loss factor of the diaphragm within -60°C to 10°C is ≥0.14, and the elastic recovery rate of the diaphragm under a tensile strain of 10% is ≥90%.

[0005] Optionally, the nitrile rubber includes a butadiene-acrylonitrile copolymer, and the molecular structure of the butadiene-acrylonitrile copolymer is: , Wherein, a and b are integers and are not 0 at the same time; c is a natural number; And / or, the nitrile rubber comprises a hydrogenated butadiene-acrylonitrile copolymer, and the molecular structure of the hydrogenated butadiene-acrylonitrile copolymer is: , Wherein, e and f are integers and are not 0 at the same time; g is a natural number; h and i are integers and cannot be 0 at the same time.

[0006] Optionally, the nitrile rubber includes a butadiene-acrylonitrile copolymer, and the mass percentage of the acrylonitrile segment in the butadiene-acrylonitrile copolymer is 10%-40%.

[0007] Optionally, the damping modifier includes methyl vinyl phenyl silicone oil, and the molecular structure of the methyl vinyl phenyl silicone oil is: , Wherein, m is an integer; n and o are natural numbers; R3 is any one of methyl, vinyl, and phenyl; R4 is any one of methyl, vinyl, and phenyl; And / or, the damping modifier comprises an ethylene-propylene copolymer, and the molecular structure of the ethylene-propylene copolymer is: 、 or , Among them, s, t, u, v, w, x, y, z are all natural numbers; And / or, the damping modifier comprises a butadiene-styrene copolymer, and the molecular structure of the butadiene-styrene copolymer is:

[0008] Wherein, a1 and c1 are integers and are not 0 at the same time; b1 is a natural number.

[0009] Optionally, the blended material further includes a filler, which includes at least one of silica, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica, and the mass percentage of the filler in the blended material is 20%-55%.

[0010] Optionally, the blended material further includes a vulcanizing agent, the vulcanizing agent includes sulfur, and the mass percentage of the sulfur in the blended material is 0.3%-3%.

[0011] Optionally, the blended material further includes a vulcanizing agent, which includes at least one of: 1,2-1,4-di(tert-butylperoxyisopropylbenzene)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxide isopropylbenzene, 4,4-bis(tert-butylperoxy) valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, diisopropylbenzene peroxide, dibenzoyl peroxide, tert-butyl perbenzoate, dilauroyl peroxide, and isopropylbenzene hydroperoxide; the mass percentage of the vulcanizing agent in the blended material is 0.5%-3%.

[0012] 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 dimethyldithiocarbamate, diphenylguanidine, sulfenic acid amine accelerator, thiuram accelerator, zinc oxide, and stearic acid, and the mass percentage of the accelerator in the blend material is 0.2%-5%.

[0013] Optionally, the blended material further includes an antioxidant, which includes at least one of 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 mass percentage of the antioxidant in the blended material is 0.1%-3%.

[0014] Optionally, the tensile strength of the modified nitrile rubber layer is ≥9 MPa.

[0015] Optionally, the diaphragm is formed into a single-layer structure, and the diaphragm is composed of a layer of the modified nitrile rubber; Alternatively, the diaphragm is formed into a multi-layer structure, the diaphragm includes at least one layer of the modified nitrile rubber layer and a composite layer, the composite layer and the modified nitrile rubber layer are stacked, and the composite layer is at least one of an elastomer layer, an engineering plastic layer and a film layer.

[0016] Optionally, the mass percentage of the nitrile rubber in the blended material is ≥50%, and the damping modifier is in the blended material.

[0017] Optionally, the glass transition temperature of the nitrile rubber is -30°C to -10°C, and the glass transition temperature of the damping modifier is -70°C to -35°C.

[0018] According to a second aspect of the present invention, a sound-generating device is provided, which includes the diaphragm of the present invention.

[0019] According to a third aspect of the present invention, an electronic device is provided, which includes the sound-generating device described in the present invention.

[0020] In an embodiment of the present invention, the diaphragm includes a modified nitrile rubber prepared from a blended material, wherein the blended material includes nitrile rubber and a damping modifier. By adding the damping modifier, the modified nitrile rubber has two different glass transition temperature regions within the temperature range of -60°C to 10°C. The diaphragm has good damping performance within this temperature range, and the loss factor of the diaphragm within the range of -60°C to 10°C is ≥0.14, which can effectively reduce the THD of the sound-generating device and has a higher listening yield. The ratio of the F0 of the diaphragm 20 at 23°C to the F0 at -20°C in the embodiment of the present invention is ≥0.80, so that the modulus change of the diaphragm under high and low temperature conditions is smaller and smoother, and the vibration stability is stronger. In addition, when the mass percentage of nitrile rubber in the blend material is ≥40%, correspondingly, the mass percentage of the damping modifier in the blend material is ≤40%, so that the elastic recovery rate of the diaphragm under the condition of a tensile strain of 10% is ≥90%, the diaphragm has good rebound performance, and can maintain the set position during long-term vibration, ensuring that the diaphragm has ample space for up and down vibration and will not collide with the voice coil.

[0021] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0023] Figure 1 is a cross-sectional view of a diaphragm according to an embodiment of the present invention.

[0024] Figure 2 is a perspective view of a micro-speaker according to an embodiment of the present invention.

[0025] Figure 3 is a cross-sectional view of a microspeaker according to an embodiment of the present invention.

[0026] Figure 4 is a cross-sectional view of a large speaker according to an embodiment of the present invention.

[0027] Figure 5 3 are total harmonic distortion (THD) curves of the sound-generating devices of the embodiment of the present invention and the comparative example.

[0028] Reference numerals: 100. Sound-generating device; 10. Shell; 20. Diaphragm; 30. Voice coil; 40. Permanent magnet; 50. Cone; 60. Dust cover; 70. Damper; 80. Skeleton; 90. U iron. DETAILED DESCRIPTION

[0029] 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 of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0030] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0032] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0033] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0034] The following describes in detail the diaphragm 20 for a sound-generating device according to an embodiment of the present invention with reference to the accompanying drawings.

[0035] 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 blended material. The blended material includes nitrile rubber and a damping modifier. The nitrile rubber has a binary structure, and the mass percentage of the nitrile rubber in the blended material is ≥40%. The damping modifier includes at least one of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, and the mass percentage of the damping modifier in the blended 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, the second glass transition temperature is -30°C to -10°C, the ratio of the F0 of the diaphragm 20 at 23°C to the F0 at -20°C is greater than or equal to 0.80 and less than 1, the loss factor of the diaphragm 20 within -60°C to 10°C is ≥0.14, and the elastic recovery rate of the diaphragm 20 under a tensile strain of 10% is ≥90%.

[0036] Specifically, the diaphragm 20 is applied to a sound-generating device, such as a micro speaker or a large speaker. The diaphragm 20 serves as a part of a vibration system. The diaphragm 20 is a ring-shaped diaphragm or a flat diaphragm. The diaphragm 20 includes a modified nitrile rubber layer. The diaphragm 20 is a single-layer structure or a multi-layer structure. The modified nitrile rubber layer is prepared using a blended material. The preparation method is, for example, compression molding, air pressure molding, etc. The blended material is mixed by a plurality of materials. For example, a plurality of materials are added to a mixer. Blending is performed in the mixer and the mixture is evenly mixed to form a blended material.

[0037] Nitrile butadiene rubber (NBR) is a binary copolymer formed from acrylonitrile and butadiene monomers. Damping modifiers are used to improve the low-temperature damping properties of NBR. NBR molecular chains contain a large number of nitrile groups (-CN), which are polar groups that create strong interactions between the molecular chains. These strong interactions restrict the movement of the molecular chains, making it difficult for them to effectively relax and hysteresis when subjected to external forces, resulting in less energy dissipation. The loss factor of NBR is high only near its glass transition temperature (GTS), while it is lower in other ranges. In the embodiments of the present invention, the addition of a damping modifier allows the prepared modified NBR to have two GTSs. Specifically, the damping modifier is blended with NBR and cross-linked in a mold to form the diaphragm 20. The resulting cross-linked modified NBR layer has a first GTS of -60°C to -40°C and a second GTS of -30°C to -10°C.

[0038] That is to say, the modified nitrile rubber of the embodiment of the present invention has two glass transition temperature regions within the temperature range of -60°C to 10°C, so that the diaphragm 20 maintains a high loss factor within a wider temperature range. For example, the loss factor of the diaphragm 20 within the range of -60°C to 10°C is ≥0.14, which can effectively reduce the THD of the sound-generating device using the diaphragm 20, with low distortion and high listening yield. In addition, since 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°C to the F0 at -20°C is greater than or equal to 0.80 and less than 1. Moreover, since the glass transition temperature of the damping modifier is lower, it has better resilience under conditions close to room temperature, so the diaphragm 20 has good resilience performance, and the elastic recovery rate under the condition of tensile strain of 10% is ≥90%, so that the diaphragm 20 can remain in the designed position during long-term vibration, ensuring that the diaphragm 20 has sufficient space for vibration up and down, avoiding problems such as bottoming of the voice coil.

[0039] It should be noted that if the mass percentage of nitrile rubber in the blend is too low, blending will be difficult, and the elongation at break of the vulcanized material will be too low, which can easily cause film breakage during reliability testing. When the mass percentage of nitrile rubber in the blend is ≥40%, blending is easy and the resulting modified nitrile rubber has a high elongation at break.

[0040] Optionally, the mass percentage of the nitrile rubber in the blended material is ≥50%, and the mass percentage of the damping modifier in the blended material is ≤30%. Within this range, the blended material is easily blended, and the resulting modified nitrile rubber has a higher elongation at break and better overall damping in the low temperature range.

[0041] Furthermore, the damping modifier typically has a lower glass transition temperature 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 of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, or a mixture thereof. 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.

[0042] In addition, the ratio of the F0 of the diaphragm 20 at 23°C to the F0 at -20°C is greater than or equal to 0.80 and less than 1. The F0 of the diaphragm 20 at 23°C represents the resonant frequency of the diaphragm 20 at room temperature. The F0 of the diaphragm 20 at -20°C represents the resonant frequency of the diaphragm 20 at -20°C. The closer the ratio of the F0 of the diaphragm 20 at 23°C to the F0 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. The better the modulus stability is, the better the F0 stability of the speaker is.

[0043] Optionally, the ratio of F0 of the diaphragm 20 at 23° C. to F0 at −20° C. is 0.80, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, etc. Those skilled in the art may make the selection according to actual needs.

[0044] In an embodiment of the present invention, a modified nitrile rubber is prepared from a blended material, wherein the blended material includes nitrile rubber and a damping modifier. In an embodiment of the present invention, a damping modifier is added to the nitrile rubber so that the prepared modified nitrile rubber has two glass transition temperatures. The modified nitrile rubber layer obtained after cross-linking has a first glass transition temperature and a second glass transition temperature, wherein the first glass transition temperature is from -60°C to -40°C, and the second glass transition temperature is from -30°C to -10°C. Therefore, the modified nitrile rubber of an embodiment of the present invention has two glass transition temperature regions within a temperature range of -60°C to -10°C, so that the diaphragm 20 maintains a high loss factor within a wider temperature range. The loss factor of the diaphragm 20 within the range of -60°C to 10°C is ≥0.14, which can effectively reduce the THD of the sound-generating device using the diaphragm 20, with low distortion and high listening yield. 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°C to the F0 at -20°C is greater than or equal to 0.80 and less than 1, indicating that the vibration stability of the diaphragm 20 at different temperatures is better. Furthermore, because the damping modifier has a lower glass transition temperature and exhibits better resilience at room temperature, the diaphragm 20 exhibits excellent resilience, with an elastic recovery rate of ≥90% under a tensile strain of 10%. This allows the diaphragm 20 to maintain its designed position during long-term vibration, ensuring ample space for the diaphragm 20 to vibrate upward and downward, and avoiding problems such as voice coil bottoming.

[0045] In some specific embodiments of the present invention, the glass transition temperature of the nitrile rubber is -30°C to -10°C, and the glass transition temperature of the damping modifier is -70°C to -35°C.

[0046] In this embodiment, the glass transition temperature of the nitrile rubber is in the range of -30°C to -10°C, and the glass transition temperature of the damping modifier is -70°C to -35°C. In the embodiment of the present invention, the modified nitrile rubber prepared by adding a damping modifier has two glass transition temperatures. The first glass transition temperature is -60°C to -40°C, and the second glass transition temperature is -30°C to -10°C. In other words, the modified nitrile rubber of the embodiment of the present invention has two glass transition temperature regions within the temperature range of -60°C to 10°C, so that the diaphragm 20 maintains a good damping effect within a wider temperature range.

[0047] In some specific embodiments of the present invention, the nitrile rubber includes a butadiene-acrylonitrile copolymer, and the molecular structure of the butadiene-acrylonitrile copolymer is: , Wherein, a and b are integers and are not 0 at the same time; c is a natural number; And / or, the nitrile rubber comprises a hydrogenated butadiene-acrylonitrile copolymer, and the molecular structure of the hydrogenated butadiene-acrylonitrile copolymer is: , Wherein, e and f are integers and are not 0 at the same time; g is a natural number; h and i are integers and cannot be 0 at the same time.

[0048] The two types of nitrile rubbers can be blended with a damping modifier and cross-linked to form a modified nitrile rubber. Those skilled in the art can select the one according to actual needs.

[0049] In some specific embodiments of the present invention, the nitrile rubber includes a butadiene-acrylonitrile copolymer, and the mass percentage of the acrylonitrile segment in the butadiene-acrylonitrile copolymer is 18%-50%.

[0050] In this embodiment, the acrylonitrile segment in the butadiene-acrylonitrile copolymer has a nitrile group, which is a polar group. The polar group enables a strong interaction force between the molecular chains. When the mass percentage of the acrylonitrile segment in the butadiene-acrylonitrile copolymer is less than 18%, the interaction force between the molecular chains of the modified nitrile rubber is insufficient, the tensile strength is low and the damping is small; when the mass percentage of the acrylonitrile segment in the butadiene-acrylonitrile copolymer is greater than 50%, the flexibility of the molecular chain in the modified nitrile rubber is reduced, resulting in a decrease in elasticity and an increase in brittleness. When the mass percentage of the acrylonitrile segment in the butadiene-acrylonitrile copolymer is 18%-50%, the modified nitrile rubber can have both sufficient tensile strength and appropriate elasticity, and is not prone to membrane rupture.

[0051] Optionally, the mass percentage of the acrylonitrile segment in the butadiene-acrylonitrile copolymer is 18%, 20%, 30%, 40%, 50%, etc., and those skilled in the art can select according to actual needs.

[0052] In some specific embodiments of the present invention, the damping modifier includes methyl vinyl phenyl silicone oil, and the molecular structure of the methyl vinyl phenyl silicone oil is: , Wherein, m is an integer; n and o are natural numbers; R3 is any one of methyl, vinyl, and phenyl; R4 is any one of methyl, vinyl, and phenyl; And / or, the damping modifier comprises an ethylene-propylene copolymer, and the molecular structure of the ethylene-propylene copolymer is: 、 or , Among them, s, t, u, v, w, x, y, z are all natural numbers; And / or, the damping modifier comprises a butadiene-styrene copolymer, and the molecular structure of the butadiene-styrene copolymer is:

[0053] Wherein, a1 and c1 are integers and are not 0 at the same time; b1 is a natural number.

[0054] In this embodiment, the above-mentioned several compounds can effectively modify the acrylonitrile-butadiene rubber so that the modified acrylonitrile-butadiene rubber has two glass transition temperatures. Of course, the parameters of each molecular formula are not limited here, and those skilled in the art can select according to actual needs.

[0055] In some specific embodiments of the present invention, the blended material further includes a filler, and the filler includes at least one of silica, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica, and the mass percentage of the filler in the blended material is 20%-55%.

[0056] In this embodiment, the filler is used to improve the mechanical properties of the diaphragm 20, such as tensile strength, hardness, etc. When preparing the diaphragm 20, the filler can be one or a mixture of multiple materials selected from the group consisting of silicon dioxide, carbon black, mineral whiskers, talc, diatomaceous earth, calcium carbonate, graphite, clay, and mica.

[0057] During compounding, the filler accounts for 20wt%-55wt% of the blended material.

[0058] It should be noted that the lower the filler content, the lower the tensile strength of the diaphragm 20, especially when the filler accounts for less than 20wt% by mass in the blended material, the reinforcement effect on the diaphragm 20 is poor. If the filler content is too high, for example, when the filler accounts for more than 55wt% by mass in the blended material, the elongation at break of the diaphragm 20 will drop significantly, and the toughness of the material will be insufficient, causing the diaphragm 20 to easily break during vibration. When the filler accounts for 20wt%-55wt% by mass in the blended material, the diaphragm 20 has sufficient tensile strength, elongation at break, and toughness.

[0059] Optionally, the mass proportion of the filler in the blended material is 20wt%, 30wt%, 40wt%, 50wt%, 55wt%, etc. Of course, the mass proportion of the filler in the blended material is not limited to the above embodiment, and those skilled in the art can select according to actual needs.

[0060] In some specific embodiments of the present invention, the blended material further includes a vulcanizing agent, the vulcanizing agent includes sulfur, and the mass percentage of the sulfur in the blended material is 0.3%-3%.

[0061] In this embodiment, a vulcanizing agent is added to the blended material, and the vulcanizing agent is sulfur. The vulcanizing agent is used to cause a cross-linking reaction between the nitrile rubber and the damping modifier, thereby forming a network structure.

[0062] It should be noted that when mixing, the mass of sulfur accounts for 0.3wt%-3wt% of the total mass of the blended material. It should be noted that the less the mass content of sulfur, the less cross-linking degree of the blended material, and the network structure stability formed by the blended material is poor. When the mass proportion of the sulfur in the blended material is less than 0.3wt%, the cross-linking degree of the diaphragm 20 is insufficient, and the network structure stability is poor. If the mass content of sulfur is too high, the hardness of the diaphragm 20 is large, the toughness is poor, the elongation at break is too low, and it is easy to age at high temperatures. Especially when the mass content of the sulfur in the blended material is greater than 3wt%, the elongation at break of the diaphragm 20 is too low, and film breakage is prone to occur. When the mass content of sulfur in the blended material is 0.3wt%-3wt%, it can ensure that the diaphragm 20 has sufficient cross-linking degree and can also make the diaphragm 20 have a higher elongation at break.

[0063] Optionally, the mass proportion of sulfur in the blended material is 0.3 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, etc. Further, the mass proportion of sulfur in the blended material is 1 wt%-2 wt%. Those skilled in the art can make the selection according to actual needs.

[0064] In some specific embodiments of the present invention, the blended material further includes a vulcanizing agent, which includes at least one of: 1,2-1,4-di(tert-butylperoxyisopropylbenzene)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxide isopropylbenzene, 4,4-bis(tert-butylperoxy) valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, diisopropylbenzene peroxide, dibenzoyl peroxide, tert-butyl perbenzoate, dilauroyl peroxide, and isopropylbenzene hydroperoxide; the mass percentage of the vulcanizing agent in the blended material is 0.5%-3%.

[0065] In this embodiment, a vulcanizing agent is added to the blended material, and the vulcanizing agent is a peroxide. The vulcanizing agent can be one of 1,2-1,4-di(tert-butylperoxyisopropylbenzene)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylisopropylbenzene peroxide, 4,4-bis(tert-butylperoxy)butyl valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, diisopropylbenzene peroxide, dibenzoyl peroxide, tert-butyl perbenzoate, dilauroyl peroxide, and cumene hydroperoxide, or a mixture of multiple thereof.

[0066] When mixing, the mass of the vulcanizing agent accounts for 0.5wt%-3wt% of the total mass of the blended material. It should be noted that the less the mass content of the vulcanizing agent, the insufficient degree of crosslinking of the blended material, and the poor stability of the network structure formed by the blended material. When the mass proportion of the vulcanizing agent in the blended material is less than 0.5wt%, the insufficient degree of crosslinking of the diaphragm 20 and the poor stability of the network structure. If the mass content of the vulcanizing agent is too high, the hardness of the diaphragm 20 is large, the toughness is poor, and the elongation at break is too low. Especially when the mass content of the vulcanizing agent in the blended material is greater than 3wt%, the elongation at break of the diaphragm 20 is too low, and film breakage is prone to occur. When the mass content of the vulcanizing agent in the blended material is 0.5wt%-3wt%, it can ensure that the diaphragm 20 has sufficient degree of crosslinking and can also make the diaphragm 20 have a higher elongation at break.

[0067] In some specific embodiments of the present invention, the blended 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 dimethyldithiocarbamate, diphenylguanidine, sulfenic acid amine accelerator, thiuram accelerator, zinc oxide, and stearic acid, and the mass percentage of the accelerator in the blended material is 0.2%-5%.

[0068] 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. The blend material can include a mixture of one or more of tetramethylthiuram disulfide, tetraethylthiuram disulfide, 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazolesulfenamide, N-tert-butyl-2-benzothiazolesulfenamide, zinc dimethyldithiocarbamate, diphenylguanidine, sulfenamide accelerator, thiuram accelerator, zinc oxide, and stearic acid as the accelerator.

[0069] When batching, the mass percentage of accelerator in the blend material is 0.2 wt%-5 wt%. It should be noted that when the addition of accelerator in the blend material is less than 0.2 wt%, accelerator accelerates vulcanization speed, shortens vulcanization time, and the effect of reducing vulcanization temperature is not obvious. When the addition of accelerator in the blend material is greater than 5%, the speed of vulcanization reaction is too fast, easily leading to the uneven network structure of rubber internal molecules, and diaphragm 20 is prone to fracture. When the mass percentage of accelerator in the blend material is 0.2 wt%-5 wt%, the vulcanization reaction speed of blend material is moderate.

[0070] Optionally, the mass percentage of the accelerator in the blended material is 0.2 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt %, 5 wt %, etc., which can be set by those skilled in the art according to actual needs.

[0071] In some specific embodiments of the present invention, the blend material further includes an antioxidant, which includes at least one of 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 mass percentage of the antioxidant in the blend material is 0.1 wt%-3 wt%.

[0072] During the use of polymer materials, over time, molecular chains break and autocatalytically active free radicals are generated. These autocatalytically active free radicals can accelerate the aging of the polymer material itself. Adding an antioxidant to the diaphragm 20 can halt the generation of autocatalytically active free radicals in the blended material, thereby delaying the aging of the blended material and extending the service life of the diaphragm 20. When preparing the diaphragm 20, one or more of a mixture of 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 can be selected as the antioxidant. The above-mentioned antioxidants are mutually soluble in the nitrile rubber and the damping modifier, thereby preventing the diaphragm 20 from aging and extending the service life of the diaphragm 20.

[0073] During the mixing process, the antioxidant accounts for 0.1wt%-3wt% of the blended material.

[0074] It should be noted that, in the blend material, if the amount of antioxidant added is too little, for example, when the mass proportion of the antioxidant in the blend material is less than 0.1wt%, it is impossible to prevent the diaphragm 20 from aging and extend the service life of the diaphragm 20. If the amount of antioxidant added is too much, for example, when the mass proportion of the antioxidant in the blend material is greater than 3wt%, the antioxidant cannot be well soluble with the nitrile rubber and the damping modifier, so that the antioxidant cannot be evenly dispersed in the blend material, resulting in a decrease in the mechanical properties of the diaphragm 20. When the mass proportion of the antioxidant in the blend material is 0.1wt%-3wt%, the antioxidant can effectively extend the service life of the diaphragm 20, and the antioxidant can be evenly dispersed in the blend material, and the prepared diaphragm 20 can maintain good mechanical properties.

[0075] Alternatively, the mass proportion of the antioxidant in the blend material is 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt% etc. Further, the mass proportion of the antioxidant in the blend material is 2wt%-3wt%. Of course, the mass proportion of the antioxidant in the blend material is not limited to the above embodiment, and those skilled in the art can select according to actual needs.

[0076] In some specific embodiments of the present invention, the tensile strength of the modified nitrile rubber layer is ≥9 MPa.

[0077] In this embodiment, the tensile strength can reflect 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 likely to deteriorate, and the diaphragm 20 is prone to rupture after high-temperature and high-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 unlikely to rupture after high-temperature and high-humidity testing and aging testing.

[0078] In some specific embodiments of the present invention, the diaphragm 20 is formed into a single-layer structure, and the diaphragm 20 is composed of a layer of the modified nitrile rubber layer; Alternatively, the diaphragm 20 is formed into a multi-layer structure, and the diaphragm 20 includes at least one layer of the modified nitrile rubber layer and a composite layer, the composite layer and the modified nitrile rubber layer are stacked, and the composite layer is at least one of an elastomer layer, an engineering plastic layer and a film layer.

[0079] That is to say, the diaphragm 20 of the embodiment of the present invention can be a modified nitrile rubber layer with a single-layer structure. The diaphragm 20 has a simple structure and a simple manufacturing process.

[0080] Alternatively, the diaphragm 20 may have a multi-layer structure. Specifically, at least one modified nitrile rubber layer and a composite layer are laminated together 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 multi-layer structure may have 2, 3, 4, 5, 6, 7, or other layers.

[0081] Optionally, the elastomer layer includes one or more of thermoplastic polyurethane elastomer, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, and thermoplastic polystyrene elastomer. The engineering plastic layer includes one or more of PEEK, PAR, PMI, PET, PEN, PA, PEI, and LCP. The film layer includes a silicone film and / or an acrylic film. The composite layer may be one or more layers.

[0082] According to another embodiment of the present invention, a sound generating device is provided. Figure 2-Figure 4 As shown, the sound-generating device 100 includes the diaphragm 20 of the above embodiment.

[0083] like Figure 2-Figure 3 As shown, the sound-generating device 100 is a micro-speaker. 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 is used to form a magnetic gap. The vibration system includes a diaphragm 20 and a voice coil 30. The diaphragm 20 and the permanent magnet 40 are both connected to the housing 10. The permanent magnet 40 is disposed on one side of the diaphragm 20 along the thickness direction. One end of the voice coil 30 is connected to the diaphragm 20, and the other end is located in the magnetic gap.

[0084] In this example, the diaphragm 20 may be a surround diaphragm. The surround diaphragm comprises a central portion, a surround portion, and a fixed portion, connected in sequence from the inside out. The fixed 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.

[0085] In other examples, the diaphragm 20 may also be a planar diaphragm or other structures. Those skilled in the art may determine this according to actual conditions, and no specific limitation is made here.

[0086] Figure 4 Another sound-generating device 100 according to an embodiment of the present invention is shown. The sound-generating device is a large loudspeaker.

[0087] The sound-generating device 100 may include a shell 10, a magnetic circuit system and a vibration system. The magnetic circuit system includes a permanent magnet 40 and a U iron 90. The permanent magnet 40 and the U iron 90 are used to form a magnetic gap. The vibration system includes a diaphragm 20, a cone 50, a skeleton 80, a voice coil 30 and a dust cover 60. The inner edge of the cone 50 is connected to one end of the skeleton 80. The dust cover 60 is provided on one end of the skeleton 80. The voice coil 30 is arranged around the other end of the skeleton 80. The diaphragm 20 is connected to the outer edge of the cone 50. The diaphragm 20 and the permanent magnet 40 are both connected to the shell 10. The permanent magnet 40 is provided on one side of the diaphragm 20 along the thickness direction. One end of the voice coil 30 is located in the magnetic gap. The shell 10 is provided with a spring 70. The spring 70 is connected to the middle part of the skeleton 80.

[0088] In this example, the diaphragm 20 may be a surround diaphragm. The surround diaphragm includes a central portion, a surround portion, and a fixed portion connected from the inside out. The fixed portion is used to connect to the housing 10. The central portion is connected to the outer edge of the cone 50.

[0089] In other examples, the diaphragm 20 may also be a planar diaphragm or other structures. Those skilled in the art may determine this according to actual conditions, and no specific limitation is made here.

[0090] According to yet another embodiment of the present invention, an electronic device is provided.

[0091] The electronic device is, for example, a mobile phone, a computer, a television, a speaker, an intercom, a VR device, an AR device, smart glasses, etc. The electronic device includes the sound-generating device 100 described in the above embodiment. Of course, the electronic device of the present invention also includes at least all the beneficial effects of the above embodiment, which will not be described in detail here.

[0092] The diaphragm 20 and the sound generating device 100 of the present invention are described in detail below with reference to specific embodiments. It should be noted that the following description is merely exemplary and does not specifically limit the present invention.

[0093] Example: The diaphragm 20 is a single-layer ring-shaped 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 molded from a blended material comprising nitrile rubber and a damping modifier. The mass content of the acrylonitrile segment in the nitrile rubber is 35%. The damping modifier is vinylphenyl silicone oil. The specific ingredients of the blended material are shown in Table 1.

[0094] Comparative Example: Diaphragm 20 is a single-layer, ring-shaped diaphragm. Diaphragm 20 has a thickness of 110 μm. Diaphragm 20 is molded from nitrile rubber. The mass content of acrylonitrile segments in the nitrile rubber is 35%. The specific ingredients of the blend are shown in Table 1.

[0095] Table 1 - Ingredients of Example and Comparative Example Diaphragm 20

[0096] Performance testing: (1) The hardness (Shore A), tensile strength, tear strength, dissipation factor (-60°C to 10°C, taking the minimum value), and glass transition temperature of the diaphragm 20 of the embodiment and the comparative example 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 composed of the same material as the diaphragm 20 was selected for the relevant tests to characterize the characteristics of the diaphragm 20. Since the sample and the diaphragm 20 were composed of the same material, the relevant characteristics of the sample measured were consistent with the relevant characteristics of the diaphragm 20.

[0097] Among them, hardness (Shore A), tensile strength and tear strength are tested according to ASTM-D882 standard, and the test temperature is 23℃.

[0098] Dissipation factor, also known as damping factor, is the ratio of loss modulus to storage modulus. It is measured using a dynamic thermomechanical analyzer according to ASTM D5026-23. The frequency is 1 Hz and the strain is 0.2%.

[0099] The glass transition temperature was tested using a dynamic thermomechanical analyzer according to ASTM D5026-23, with a frequency of 1 Hz and a strain of 0.2%.

[0100] (2) The diaphragms 20 of the embodiment and the comparative example are assembled into a sound-generating device, which is a large loudspeaker. The two diaphragms 20 have the same size. The THD curves of the two sound-generating devices are tested. Figure 4 .

[0101] (3) Reliability test: The diaphragms 20 of the embodiment and comparative example were assembled into sound-generating devices. After the sound-generating devices were operated for 168 hours at 65°C and 95% humidity, the acoustic performance was tested and the listening yield rate was calculated. Calculation method: The HOHD curves of 10 sound-generating devices were tested and compared with the standard frame line. Products that exceeded the frame line were judged as NG and failed reliability. The diaphragms 20 of the embodiment and the comparative example were assembled into a sound-generating device, and the F0 of the sound-generating device was tested at 23° C. and −20° C., respectively. The ratio of the F0 at 23° C. and −20° C. was calculated.

[0102] Results and Analysis: (1) The test results of the hardness (Shore A), tensile strength, tear strength, loss factor (-60°C to 10°C, taking the minimum value), and glass transition temperature of the diaphragm 20 of the embodiment and the comparative example are shown in Table 2.

[0103] Table 2 - Performance test of embodiment and comparative example diaphragm 20

[0104] As can be seen from Table 2, the hardness of the diaphragm 20 of the embodiment of the present invention is the same as that of the diaphragm 20 of the comparative example, but the tensile strength, tear strength and loss factor of the diaphragm 20 of the embodiment of the present invention are all higher than those of the diaphragm 20 of the comparative example. This is mainly because the main components of the raw materials of the diaphragm 20 of the embodiment of the present invention and the diaphragm 20 of the comparative example are both nitrile rubber and the fillers are both carbon black, and the proportion of carbon black added is similar. The main components determine that the hardness of the diaphragm 20 of the embodiment is the same as that of the diaphragm 20 of the comparative example. The modified nitrile rubber of the diaphragm 20 of the embodiment of the present invention has two glass transition temperatures (i.e., -50°C and -17°C), and the diaphragm 20 maintains a high loss factor in the temperature range of -60°C to 10°C. The diaphragm 20 of comparative example 1 is made of nitrile rubber and has only one glass transition temperature, and cannot maintain a high loss factor in a wider temperature range.

[0105] (2) By Figure 4 It can be seen that within the range of 100Hz-1000Hz, the THD curve of the sound-emitting device of the embodiment of the present invention is generally lower than the THD curve of the sound-emitting device of the comparative example. This is because the vibration mold of the embodiment of the present invention is prepared by blending a damping modifier with nitrile rubber. The modified nitrile rubber layer obtained after cross-linking has a first glass transition temperature and a second glass transition temperature, 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 embodiment of the present invention has two different glass transition temperature regions within a wider temperature range, so that the diaphragm 20 maintains a good damping effect within a wider temperature range, can effectively reduce the THD of the sound-emitting device using the diaphragm 20, has low distortion, and has a high listening yield.

[0106] (3) After testing, the sound yield rate of the sound-generating device of the embodiment of the present invention reached 100%. The sound yield rate of the sound-generating device of the comparative example was 60%. The sound yield rate of the sound-generating device of the embodiment of the present invention was significantly higher than that of the sound-generating device of the comparative example.

[0107] The F0 of the diaphragm 20 of the embodiment of the present invention at 23°C is 60 Hz, and the F0 at -20°C is 71 Hz. The F0 of the diaphragm 20 of the comparative example is 61 Hz, and the F0 at -20°C is 94 Hz. The F0 at 23°C / F0 at -20°C of the sound-generating device of the embodiment of the present invention is 0.85, which is much higher than the F0 at 23°C / F0 at -20°C of the sound-generating device of the comparative example, which is 65.

[0108] This shows that the long-term reliability of the sound-emitting device of the embodiment of the present invention is excellent. This is mainly because the vibration mold of the embodiment of the present invention is prepared by blending a damping modifier with nitrile rubber. The modified nitrile rubber layer obtained after cross-linking has a first glass transition temperature and a second glass transition temperature, 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 embodiment of the present invention has two glass transition temperature regions within a wider temperature range, so that the modulus change of the diaphragm is smoother and the damping is higher.

[0109] In summary, the vibration mold of the embodiment of the present invention is prepared by blending a damping modifier with nitrile rubber. The modified nitrile rubber layer obtained after cross-linking has a first glass transition temperature and a second glass transition temperature, 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 embodiment of the present invention has two glass transition temperature regions within a wider temperature range, so that the diaphragm 20 maintains good damping performance within a wider temperature range, can effectively reduce the THD of the sound-generating device using the diaphragm 20, has a higher listening yield, and makes the modulus change of the diaphragm 20 within this temperature range more gentle and the damping higher.

[0110] The above embodiments focus on 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. Considering the simplicity of the text, they will not be repeated here.

[0111] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present 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 blended material. The blended material includes nitrile rubber and a damping modifier. The nitrile rubber has a binary structure, and the mass percentage of the nitrile rubber in the blended material is ≥40%. The damping modifier includes at least one of methyl vinyl phenyl silicone oil, ethylene-propylene copolymer, and butadiene-styrene copolymer, and the mass percentage of the damping modifier in the blended 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, the second glass transition temperature is -30°C to -10°C, the ratio of the F0 of the diaphragm at 23°C to the F0 at -20°C is greater than or equal to 0.80 and less than 1, the loss factor of the diaphragm within -60°C to 10°C is ≥0.14, and the elastic recovery rate of the diaphragm under a tensile strain of 10% is ≥90%.

2. The diaphragm according to claim 1, wherein The nitrile rubber includes a butadiene-acrylonitrile copolymer, and the molecular structure of the butadiene-acrylonitrile copolymer is: ， Wherein, a and b are integers and are not 0 at the same time; c is a natural number; And / or, the nitrile rubber comprises a hydrogenated butadiene-acrylonitrile copolymer, and the molecular structure of the hydrogenated butadiene-acrylonitrile copolymer is: ， Wherein, e and f are integers and are not 0 at the same time; g is a natural number; h and i are integers and cannot be 0 at the same time.

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

4. The diaphragm according to claim 1, wherein The damping modifier includes methyl vinyl phenyl silicone oil, and the molecular structure of the methyl vinyl phenyl silicone oil is: ， Wherein, m is an integer; n and o are natural numbers; R3 is any one of methyl, vinyl, and phenyl; R4 is any one of methyl, vinyl, and phenyl; And / or, the damping modifier comprises an ethylene-propylene copolymer, and the molecular structure of the ethylene-propylene copolymer is: 、 or , Among them, s, t, u, v, w, x, y, z are all natural numbers; And / or, the damping modifier includes a butadiene-styrene copolymer, and the molecular structure of the butadiene-styrene copolymer is: Wherein, a1 and c1 are integers and are not 0 at the same time; b1 natural number.

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

6. The diaphragm according to claim 1, wherein: The blended material further includes a vulcanizing agent, which includes sulfur. The mass percentage of the sulfur in the blended material is 0.3%-3%.

7. The diaphragm according to claim 1, wherein: The blended material also includes a vulcanizing agent, which includes at least one of 1,2-1,4-di(tert-butylperoxyisopropylbenzene)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxide isopropylbenzene, 4,4-bis(tert-butylperoxy) valerate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, bis(2,4-dichloro)benzoyl peroxide, diisopropylbenzene peroxide, dibenzoyl peroxide, tert-butyl perbenzoate, dilauroyl peroxide, and isopropylbenzene hydroperoxide; the mass percentage of the vulcanizing agent in the blended material is 0.5%-3%.

8. The diaphragm according to claim 1, wherein: The blended material also 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 dimethyldithiocarbamate, diphenylguanidine, sulfenic acid amine accelerator, thiuram accelerator, zinc oxide, and stearic acid. The mass percentage of the accelerator in the blended material is 0.2%-5%.

9. The diaphragm according to claim 1, wherein: The blended material also includes an antioxidant, which includes at least one of 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 mass percentage of the antioxidant in the blended material is 0.1%-3%.

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

11. The diaphragm according to any one of claims 1 to 10, characterized in that: The diaphragm is formed into a single-layer structure, and the diaphragm is composed of a layer of the modified nitrile rubber; Alternatively, the diaphragm is formed into a multi-layer structure, the diaphragm includes at least one layer of the modified nitrile rubber layer and a composite layer, the composite layer and the modified nitrile rubber layer are stacked, 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 to 10, characterized in that: The mass percentage of the nitrile rubber in the blended material is ≥50%, and the mass percentage of the damping modifier in the blended material is ≤30%.

13. The diaphragm according to any one of claims 1 to 10, characterized in that: The glass transition temperature of the nitrile rubber is -30°C to -10°C, and the glass transition temperature of the damping modifier is -70°C to -35°C.

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

15. An electronic device, characterized in that: Comprising the sound-generating device as claimed in claim 14.

Images