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

Abstract

The invention relates to the technical field of electro-acoustic conversion, and discloses a vibrating diaphragm for a sound production device, the sound production device and electronic equipment. The vibrating diaphragm comprises at least one thermoplastic polyurethane elastomer layer; the thermoplastic polyurethane elastomer layer is prepared from a blending material, and the blending material comprises a first thermoplastic polyurethane elastomer and a second thermoplastic polyurethane elastomer; the glass transition temperature of the first thermoplastic polyurethane elastomer is-60 to-30 DEG C, and the glass transition temperature of the second thermoplastic polyurethane elastomer is-25 to 10 DEG C; and the creep recovery rate of the thermoplastic polyurethane elastomer layer in 5 minutes is 60%-98%. As the thermoplastic polyurethane elastomer layer comprises thermoplastic polyurethane elastomers with different glass transition temperatures, the damping temperature range of the vibrating diaphragm can be effectively expanded, and the vibrating diaphragm can keep good damping in a wide use temperature range and a wide frequency interval.

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 the related art, speaker diaphragms in existing VR products, AR products, smart glasses, and headphones typically use thermoplastic polyurethane (TPU) materials. TPU materials have excellent mechanical properties, a wide service temperature range, easy processability, and low processing costs.

[0003] However, the existing TPU material has low damping. In order to improve the damping of the diaphragm, the modulus change rate of the diaphragm will increase, resulting in a decrease in F0 stability. Summary of the Invention

[0004] An object of the present invention is to provide a new technical solution for a diaphragm of a sound-generating device.

[0005] According to a first aspect of the present invention, a diaphragm for a sound-generating device is provided. The diaphragm comprises at least one thermoplastic polyurethane elastomer layer; the thermoplastic polyurethane elastomer layer is prepared from a blend of a first thermoplastic polyurethane elastomer and a second thermoplastic polyurethane elastomer; the first thermoplastic polyurethane elastomer has a glass transition temperature of -60 to -30°C, and the second thermoplastic polyurethane elastomer has a glass transition temperature of -25 to 10°C; and the thermoplastic polyurethane elastomer layer has a 5-minute creep recovery rate of 60% to 98%.

[0006] Optionally, the soft segment of the first thermoplastic polyurethane elastomer includes at least one of polycaprolactone, polybutylene adipate, polytetramethylene oxide, polyethylene oxide, polypropylene oxide, and copolymerized polyether, and the mass content of the soft segment of the first thermoplastic polyurethane elastomer is 35%-80%.

[0007] Optionally, the soft segment of the second thermoplastic polyurethane elastomer includes at least one of polyethylene adipate, butanediol-based polycarbonate, hexanediol-based polycarbonate, 2-methyl-1,3-propylene glycol-based polycarbonate, copolycarbonate, and copolyester, and the mass content of the soft segment of the second thermoplastic polyurethane elastomer is 20%-70%.

[0008] Optionally, the ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 30%-95%; And / or, the ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 5%-70%.

[0009] Optionally, the blended material further includes an antioxidant, and the antioxidant includes pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol ester, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4 ,6-trione, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, dilauryl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetra(β-thiopropyl laurate), 2,6-di-tert-butyl-p-cresol, and the antioxidant is added in an amount of 0.1phr-2phr in the blended material; And / or, the blended material further comprises an anti-hydrolysis agent, the anti-hydrolysis agent comprises at least one of polycarbodiimide, monomeric carbodiimide, and liquid modified carbodiimide, and the amount of the anti-hydrolysis agent added to the blended material is 0.5 phr-5 phr; And / or, the blended material further includes a UV absorber, the UV absorber including at least one of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 2-hydroxy-4-n-octyloxybenzophenone, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol), and polymethylpropyl-3-oxy-[4(2,2,6,6-tetramethyl)piperidinyl]siloxane, and the amount of the UV absorber added to the blended material is 0.1phr-2phr; And / or, the blended material further includes a processing aid, which includes at least one of polytalc, dimethylsiloxane, polyethylene wax, fatty acid ester, and fatty acid salt, and the amount of the processing aid added to the blended material is 0.1 phr-5 phr.

[0010] Optionally, the thickness of the thermoplastic polyurethane elastomer layer is 10 μm-150 μm; And / or, the density of the thermoplastic polyurethane elastomer layer is 1.10 g / cm 3 -1.30g / cm 3 .

[0011] Optionally, the Young's modulus of the thermoplastic polyurethane elastomer layer is 5 MPa-200 MPa; And / or, the hardness of the thermoplastic polyurethane elastomer layer is 70A-95A.

[0012] Optionally, the Young's modulus change rate of the thermoplastic polyurethane elastomer layer after heat treatment at 130° C. for 90s-300s is ≤50%; And / or, the Young's modulus change rate of the thermoplastic polyurethane elastomer layer after heat treatment at 130° C. for 90 seconds to 300 seconds and then constant heat treatment at a temperature of 85° C. and a humidity of 85% RH for 96 hours is ≤50%.

[0013] Optionally, the diaphragm is formed into a single-layer structure, and the diaphragm is composed of a layer of the thermoplastic polyurethane elastic layer; Alternatively, the diaphragm is formed into a composite layer structure, the diaphragm includes at least one layer of the thermoplastic polyurethane elastomer layer and a composite layer, the composite layer and the thermoplastic polyurethane elastomer layer are stacked, and the composite layer is at least one of an elastomer layer, an engineering plastic layer and a film layer.

[0014] According to a second aspect of the present invention, a sound-generating device is provided, which includes the diaphragm of the present invention.

[0015] According to a third aspect of the present invention, an electronic device is provided, which includes the sound-generating device of the present invention.

[0016] In an embodiment of the present invention, the diaphragm includes at least one thermoplastic polyurethane elastomer layer; this layer is made of a blended material. Because the thermoplastic polyurethane elastomer layer comprises thermoplastic polyurethane elastomers with different glass transition temperatures, it effectively expands the diaphragm's damping temperature range, maintaining good damping stability across a wide operating temperature range and frequency range. Furthermore, the 5-minute creep recovery rate of the thermoplastic polyurethane elastomer layer in this embodiment of the present invention is between 60% and 98%, maintaining the diaphragm's creep and damping within a reasonable range. 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

[0017] 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.

[0018] Figure 1 is a cross-sectional view of a diaphragm according to an embodiment of the present invention.

[0019] Figure 2 is a perspective view of a sound-generating device according to an embodiment of the present invention.

[0020] Figure 3 is a cross-sectional view of a sound generating device according to an embodiment of the present invention.

[0021] Figure 4 1 is a curve showing the change of six-point amplitude versus frequency of the diaphragm according to an embodiment of the present invention.

[0022] Figure 5 This is the curve of the six-point amplitude change of the proportional diaphragm as a function of frequency.

[0023] Reference numerals: 100. Sound-generating device; 10. Housing; 20. Diaphragm; 30. Voice coil; 40. Permanent magnet. DETAILED DESCRIPTION

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] According to one embodiment of the present invention, a diaphragm 20 for a sound-generating device is provided. The diaphragm 20 includes at least one thermoplastic polyurethane elastomer layer; the thermoplastic polyurethane elastomer layer is made from a blended material comprising a first thermoplastic polyurethane elastomer and a second thermoplastic polyurethane elastomer; the first thermoplastic polyurethane elastomer has a glass transition temperature of -60 to -30°C, and the second thermoplastic polyurethane elastomer has a glass transition temperature of -25 to 10°C; and the thermoplastic polyurethane elastomer layer has a 5-minute creep recovery rate of 60% to 98%.

[0031] Specifically, the diaphragm 20 is applied to a sound-generating device, such as a miniature sound-generating device. The diaphragm 20 serves as a part of a vibration system. The diaphragm 20 is a ring-shaped diaphragm or a flat diaphragm. Optionally, the diaphragm 20 includes a thermoplastic polyurethane elastomer layer. The thermoplastic polyurethane elastomer layer may be one layer or multiple layers. The thermoplastic polyurethane elastomer 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 an extruder. Blending is performed in the extruder and the mixture is evenly mixed to form a blended material.

[0032] Thermoplastic polyurethane elastomer (TPU) is an elastomer formed by the copolymerization of soft segments and hard segments. The hard segment is formed by the reaction of diisocyanate and chain extender. The range of soft segments is as follows. The blended material includes two thermoplastic polyurethane elastomers with different glass transition temperatures, namely a first thermoplastic polyurethane elastomer with a low glass transition temperature and a second thermoplastic polyurethane elastomer with a high glass transition temperature. The glass transition temperature of the first thermoplastic polyurethane elastomer is -60 to -30°C, and the glass transition temperature of the second thermoplastic polyurethane elastomer is -25 to 10°C. During preparation, the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer are added to an extruder. Blending is carried out in the extruder to finally form a blended material. The blended material can be used to prepare a thermoplastic polyurethane elastomer layer by casting or coating, and the thermoplastic polyurethane elastomer layer is then press-formed to prepare the diaphragm 20.

[0033] The glass transition temperature is tested by DSC according to GB / T 19466.1-2004 standard, with a heating rate of 20°C / min.

[0034] In this embodiment of the present invention, the diaphragm 20 includes at least one thermoplastic polyurethane elastomer layer; this layer is made of a blend of materials. Because the thermoplastic polyurethane elastomer layer comprises thermoplastic polyurethane elastomers with different glass transition temperatures, it effectively expands the damping temperature range of the diaphragm 20, maintaining good damping stability over a wide operating temperature range and amplitude range. Furthermore, the 5-minute creep recovery rate of the thermoplastic polyurethane elastomer layer in this embodiment of the present invention is between 60% and 98%, maintaining the diaphragm's creep and damping within a reasonable range.

[0035] The creep recovery rate is the percentage of the reduction in material strain to the strain at the time of unloading within a set time after the tensile load is unloaded. The creep recovery rate characterizes the ability of the material to recover from deformation after creep. If the creep recovery rate is too small, the thermoplastic polyurethane elastomer layer will have poor ability to recover from deformation after creep; if the creep recovery rate is too large, the damping performance of the thermoplastic polyurethane elastomer layer will decrease. The 5-minute creep recovery rate of the thermoplastic polyurethane elastomer layer of the embodiment of the present invention is 60%-98%, so that the diaphragm 20 has both good damping performance and strong ability to recover from deformation after creep.

[0036] Among them, the creep recovery rate test method can be based on GB / T 11546.1-2008 standard, with a stress of 0.1 MPa, a holding time of 5 minutes, a creep time of 10 minutes, and a recovery time of 5 minutes.

[0037] In some specific implementations of the present invention, the soft segment of the first thermoplastic polyurethane elastomer includes at least one of polycaprolactone, polybutylene adipate, polytetramethylene oxide, polyethylene oxide, polypropylene oxide, and copolymerized polyether, and the mass content of the soft segment of the first thermoplastic polyurethane elastomer is 35%-80%.

[0038] In this embodiment, the first thermoplastic polyurethane elastomer is selected from a thermoplastic polyurethane elastomer whose soft segment includes one or more of polycaprolactone, polybutylene adipate, polytetramethylene oxide, polyethylene oxide, polypropylene oxide, and copolymerized polyether. All of these materials meet the glass transition temperature requirements of the first thermoplastic polyurethane elastomer.

[0039] Furthermore, by adjusting the ratio of the soft segment to the hard segment in the first thermoplastic polyurethane elastomer, the performance of the first thermoplastic polyurethane elastomer can be further optimized. When the mass content of the soft segment in the first thermoplastic polyurethane elastomer is less than 35%, the corresponding hard segment content is too high, resulting in excessive hardness and poor elasticity of the diaphragm 20, as well as an excessively high glass transition temperature and insufficient low-temperature performance. When the mass content of the soft segment in the first thermoplastic polyurethane elastomer is greater than 80%, the soft segment transitions from a dispersed phase to a continuous phase, resulting in poor dimensional stability, high permanent deformation, poor heat resistance, insufficient hardness, poor mechanical properties, and a low glass transition temperature for the diaphragm 20. When the mass content of the soft segment in the first thermoplastic polyurethane elastomer is between 35% and 80%, the diaphragm 20 has a moderate glass transition temperature and hardness, while also maintaining moderate low-temperature and heat resistance.

[0040] Optionally, the mass content of the soft segment of the first thermoplastic polyurethane elastomer is 35%, 40%, 50%, 60%, 70%, or 80%, and those skilled in the art can make the selection according to actual needs.

[0041] In some specific embodiments of the present invention, the soft segment of the second thermoplastic polyurethane elastomer includes at least one of polyethylene adipate, butanediol-based polycarbonate, hexanediol-based polycarbonate, 2-methyl-1,3-propylene glycol-based polycarbonate, copolycarbonate, and copolyester, and the mass content of the soft segment of the second thermoplastic polyurethane elastomer is 20%-70%.

[0042] In this embodiment, the second thermoplastic polyurethane elastomer comprises a soft segment comprising one or more of polyethylene adipate, butanediol-based polycarbonate, hexanediol-based polycarbonate, 2-methyl-1,3-propylene glycol-based polycarbonate, copolycarbonate, and copolyester. All of these materials meet the glass transition temperature requirements of the second thermoplastic polyurethane elastomer.

[0043] Furthermore, when the soft segment content of the second thermoplastic polyurethane elastomer is less than 20% by weight, the hard segment content is correspondingly too high, resulting in excessive hardness and poor elasticity of the diaphragm 20, as well as an excessively high glass transition temperature and insufficient low-temperature performance. When the soft segment content of the second thermoplastic polyurethane elastomer is greater than 70% by weight, the soft segment transitions from a dispersed phase to a continuous phase, resulting in poor dimensional stability, high permanent deformation, poor heat resistance, insufficient hardness, poor mechanical properties, and a low glass transition temperature for the diaphragm 20. When the soft segment content of the second thermoplastic polyurethane elastomer is between 20% and 70%, the diaphragm 20 has a moderate glass transition temperature and hardness, while also maintaining moderate low-temperature and heat resistance.

[0044] Optionally, the mass content of the soft segment of the second thermoplastic polyurethane elastomer is 20%, 30%, 35%, 40%, 50%, 60%, 70%, etc., and those skilled in the art can make the selection according to actual needs.

[0045] In some specific embodiments of the present invention, the ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 30%-95%; And / or, the ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 5%-70%.

[0046] In this embodiment, the damping temperature range of the diaphragm 20 is related to the ratio of the high glass transition temperature component to the low glass transition temperature component. By limiting the ratio of the first thermoplastic polyurethane elastomer to the second thermoplastic polyurethane elastomer in the blended material, the diaphragm 20 can have a wider damping temperature range.

[0047] Specifically, when the ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is less than 30%, and accordingly, the ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is greater than 70%, in this case, the content of the first thermoplastic polyurethane elastomer is too low, the rate of change of the modulus of the diaphragm 20 with temperature is too high, and the F0 stability at low temperatures (-20°C to 0°C) is poor. When the ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is greater than 95%, and accordingly, the ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is less than 5%, in this case, the content of the second thermoplastic polyurethane elastomer is too low, the damping temperature range of the diaphragm 20 is narrow, and the room temperature damping factor of the diaphragm 20 is small, resulting in poor damping performance at room temperature (23°C). When the ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is 30%-95%; correspondingly, the ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is 5%-70%. Within this range, the diaphragm 20 has a wide damping temperature range, a high room temperature damping factor, and a good modulus change rate.

[0048] Optionally, the ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the masses of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 30%, 40%, 50%, 60%, 70%, 80%, 95%, etc. The ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the masses of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, etc. Those skilled in the art can adjust the ratio according to actual needs.

[0049] In some specific embodiments of the present invention, the blend material further includes an antioxidant, and the antioxidant includes tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol ester, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) At least one of oxazine-2,4,6-trione, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, dilauryl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetra(β-thiopropyl laurate), and 2,6-di-tert-butyl-p-cresol, wherein the antioxidant is added in an amount of 0.1phr-2phr to the blended material; And / or, the blended material further comprises an anti-hydrolysis agent, the anti-hydrolysis agent comprises at least one of polycarbodiimide, monomeric carbodiimide, and liquid modified carbodiimide, and the amount of the anti-hydrolysis agent added to the blended material is 0.5 phr-5 phr; And / or, the blended material further includes a UV absorber, the UV absorber including at least one of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 2-hydroxy-4-n-octyloxybenzophenone, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol), and polymethylpropyl-3-oxy-[4(2,2,6,6-tetramethyl)piperidinyl]siloxane, and the amount of the UV absorber added to the blended material is 0.1phr-2phr; And / or, the blended material further includes a processing aid, which includes at least one of polytalc, dimethylsiloxane, polyethylene wax, fatty acid ester, and fatty acid salt, and the amount of the processing aid added to the blended material is 0.1 phr-5 phr.

[0050] In the embodiment of the present invention, the antioxidant can inhibit the oxidative degradation of TPU during processing or long-term use, thereby improving the reliability of the diaphragm 20 . The blending material can be selected from any one of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-trione, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, dilauryl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetrakis(β-thiopropyl laurate), and 2,6-di-tert-butyl-p-cresol, or a mixture of multiple thereof. The antioxidant is added in an amount of 0.1-2 phr to the blended material, meaning that 0.1-2 parts by mass are added per 100 parts by mass of the total mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer. When the antioxidant is added in an amount less than 0.1 phr, the antioxidant's effect in inhibiting the oxidative degradation of the TPU is not significant. When the antioxidant is added in an amount greater than 2 phr, the antioxidant is prone to precipitation. When the antioxidant is added in an amount of 0.1-2 phr, the antioxidant's effect in inhibiting the oxidative degradation of the TPU is significant and is not prone to precipitation.

[0051] Optionally, the amount of antioxidant added to the blended material is 0.1 phr, 0.5 phr, 1 phr, 1.5 phr, 2 phr, etc., which can be set by those skilled in the art according to actual needs.

[0052] The anti-hydrolysis agent can improve the water resistance of TPU, prevent TPU from hydrolyzing in a humid environment, and improve the reliability of the diaphragm 20. Any one or a mixture of polycarbodiimide, monomeric carbodiimide, and liquid modified carbodiimide can be selected in the blending material. The amount of the anti-hydrolysis agent added to the blending material is 0.5phr-5phr, which means that 0.5-5 parts by mass are added to the total mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 100 parts by mass. When the amount of the anti-hydrolysis agent added to the blending material is less than 0.5phr, the effect of the anti-hydrolysis agent on improving the water resistance of TPU is not obvious. When the amount of the anti-hydrolysis agent added to the blending material is greater than 5phr, the anti-hydrolysis agent is easy to precipitate. When the amount of the anti-hydrolysis agent added to the blending material is 0.5phr-5phr, the effect of the anti-hydrolysis agent on improving the water resistance of TPU is significant and not easy to precipitate.

[0053] Optionally, the amount of the anti-hydrolysis agent added to the blended material is 0.5 phr, 1 phr, 2 phr, 3 phr, 4 phr, 5 phr, etc., and those skilled in the art can set it according to actual needs.

[0054] The ultraviolet absorber can slow down the aging of TPU under sunlight and / or UV radiation, thereby improving the reliability of the diaphragm 20. The blended material may include any one of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol, 2-hydroxy-4-n-octyloxybenzophenone, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), and polymethylpropyl-3-oxy-[4(2,2,6,6-tetramethyl)piperidinyl]siloxane, or a mixture of multiple thereof. The UV absorber is added in an amount of 0.1-2 phr to the blended material, meaning that 0.1-2 parts by mass are added to 100 parts by mass of the total mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer. When the UV absorber is added in an amount less than 0.1 phr to the blended material, the UV absorber does not significantly slow down the aging of the TPU under sunlight and / or UV irradiation. When the UV absorber is added in an amount greater than 2 phr to the blended material, the UV absorber is easily precipitated. When the UV absorber is added in an amount of 0.1-2 phr to the blended material, the UV absorber significantly slows down the aging of the TPU under sunlight and / or UV irradiation and is not easily precipitated.

[0055] Optionally, the amount of the ultraviolet absorber added to the blended material is 0.1 phr, 1 phr, 1.5 phr, 2 phr, etc., which can be set by those skilled in the art according to actual needs.

[0056] Processing aids can optimize the processing properties of TPU and adjust the viscosity of the TPU surface. Any one or a mixture of polytalc, dimethylsiloxane, polyethylene wax, fatty acid esters, and fatty acid salts can be selected from the blended material. The amount of processing aid added to the blended material is 0.1phr-5phr, which means that 0.1-5 parts by mass are added to the total mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 100 parts by mass. When the amount of processing aid added to the blended material is less than 0.1phr, the processing aid reduces the viscosity of the TPU surface, and the effect of optimizing the processing properties of TPU is not obvious. When the amount of processing aid added to the blended material is greater than 5phr, the processing aid is easy to precipitate. When the amount of processing aid added to the blended material is 0.1phr-5phr, the processing aid reduces the viscosity of the TPU surface, and the effect of optimizing the processing properties of TPU is significant and not easy to precipitate.

[0057] Optionally, the amount of the processing aid added to the blended material is 0.1 phr, 1 phr, 2 phr, 3 phr, 4 phr, 5 phr, etc., which can be set by those skilled in the art according to actual needs.

[0058] In some specific implementations of the present invention, the thickness of the thermoplastic polyurethane elastomer layer is 10 μm-150 μm; And / or, the density of the thermoplastic polyurethane elastomer layer is 1.10 g / cm 3 -1.30g / cm 3 .

[0059] In this embodiment, the thermoplastic polyurethane elastomer layer adopts a basic casting process to prepare the diaphragm 20. The thickness of the diaphragm 20 has an important influence on the performance of the diaphragm 20. When the thickness of the diaphragm 20 is too low, for example, less than 10μm, the film forming property and uniformity of the extrusion casting are poor, and the split vibration mode of the diaphragm 20 increases during vibration, and the distortion becomes higher. When the thickness of the diaphragm 20 is too high, for example, greater than 150μm, the vibration space of the diaphragm 20 is affected, the diaphragm 20 is easily bumped against the shell, and the mid-frequency sensitivity is reduced. When the thickness of the diaphragm 20 is 10μm-150μm, it can not only ensure the convenience of processing of the diaphragm 20, but also save the vibration space of the diaphragm 20 and ensure the acoustic performance.

[0060] Optionally, the thickness of the diaphragm 20 is 10 μm, 40 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, etc., and those skilled in the art can set it according to actual needs.

[0061] The density of the thermoplastic polyurethane elastomer layer has an important influence on the mid-frequency performance of the diaphragm 20. When the density of the thermoplastic polyurethane elastomer layer is too high, for example, greater than 1.30 g / cm 3When the density of the diaphragm 20 is too small, for example, less than 1.10 g / cm 3 When the density of the diaphragm 20 is 1.10 g / cm 3 -1.30g / cm 3 When the diaphragm 20 has moderate quality, the mid-frequency performance is good.

[0062] Optionally, the density of the diaphragm 20 is 1.10 g / cm 3 , 1.15g / cm 3 , 1.20g / cm 3 , 1.25g / cm 3 , 1.30g / cm 3 Those skilled in the art can make settings according to actual needs.

[0063] In some specific embodiments of the present invention, the Young's modulus of the thermoplastic polyurethane elastomer layer is 5 MPa-200 MPa; And / or, the hardness of the thermoplastic polyurethane elastomer layer is 70A-95A.

[0064] The Young's modulus of the thermoplastic polyurethane elastomer layer has an important influence on the vibration performance of the diaphragm 20. When the Young's modulus of the thermoplastic polyurethane elastomer layer is less than 5MPa, it is easy to cause the diaphragm 20 to resonate and split vibration, and the distortion is large. When the Young's modulus is low, the thickness of the diaphragm 20 needs to be increased to ensure that the mechanical properties of the diaphragm 20 meet the requirements. This limits the vibration space of the diaphragm 20 and easily causes the diaphragm 20 to collapse. When the Young's modulus of the thermoplastic polyurethane elastomer layer is greater than 200MPa, it is easy to cause the low-frequency loudness of the diaphragm 20 to be low, the vibration dive is insufficient, and a mid-frequency valley point is formed. When the Young's modulus of the thermoplastic polyurethane elastomer layer is 5MPa-200MPa, the diaphragm 20 is not easy to form resonance and split vibration, the distortion is small, and the low-frequency loudness is large, and the mid-frequency effect is good.

[0065] Optionally, the Young's modulus of the diaphragm 20 is 5 MPa, 50 MPa, 100 MPa, 150 MPa, 200 MPa, etc., and those skilled in the art can set it according to actual needs.

[0066] The hardness of the thermoplastic polyurethane elastomer layer has an important influence on the vibration performance of the diaphragm 20. When the hardness of the thermoplastic polyurethane elastomer layer is less than 70A, it is easy to cause the diaphragm 20 to resonate and split vibration, with large distortion, and when the hardness is low, the thickness of the diaphragm 20 needs to be increased to ensure that the mechanical properties of the diaphragm 20 meet the requirements, which limits the vibration space of the diaphragm 20 and easily causes the diaphragm 20 to collapse. When the hardness of the thermoplastic polyurethane elastomer layer is greater than 95A, it is easy to cause the low-frequency loudness of the diaphragm 20 to be low, the vibration dive is insufficient, and a mid-frequency valley point is formed. When the hardness of the thermoplastic polyurethane elastomer layer is 70A-95A, the diaphragm 20 is not easy to form resonance and split vibration, the distortion is small, and the low-frequency loudness is large, and the mid-frequency effect is good.

[0067] Optionally, the hardness of the diaphragm 20 is 70A, 75A, 80A, 85A, 90A, 95A, etc., and those skilled in the art can set it according to actual needs.

[0068] In some specific embodiments of the present invention, the Young's modulus change rate of the thermoplastic polyurethane elastomer layer after heat treatment at 130° C. for 90s-300s is ≤50%; And / or, the Young's modulus change rate of the thermoplastic polyurethane elastomer layer after heat treatment at 130° C. for 90 seconds to 300 seconds and then constant heat treatment at a temperature of 85° C. and a humidity of 85% RH for 96 hours is ≤50%.

[0069] In this embodiment, the thermoplastic polyurethane elastomer layer is heat-treated in a 130°C environment for 90s-300s. The Young's modulus change rate relative to the thermoplastic polyurethane elastomer layer before and after the treatment is calculated. A higher Young's modulus change rate indicates poor heat resistance of the diaphragm 20. If the Young's modulus change rate of the thermoplastic polyurethane elastomer layer in the embodiment of the present invention is ≤50%, the diaphragm 20 has good heat resistance.

[0070] Alternatively, the thermoplastic polyurethane elastomer layer is placed at 130°C for a heat treatment for 90s-300s and then subjected to a constant wet heat treatment at a temperature of 85°C and a humidity of 85% RH for 96 hours. The Young's modulus change rate relative to the thermoplastic polyurethane elastomer layer before and after placement is calculated based on the change in Young's modulus before and after placement. The higher the Young's modulus change rate, the more unstable the long-term performance of the diaphragm 20 under high temperature and high humidity conditions, and the greater the deviation of F0 from the design value. The Young's modulus change rate of the thermoplastic polyurethane elastomer layer of the embodiment of the present invention is ≤50%, the long-term performance of the diaphragm 20 under high temperature and high humidity conditions is stable, and the F0 change is small.

[0071] It should be noted that after the high temperature treatment and / or high temperature and high humidity treatment, the Young's modulus of the diaphragm 20 may decrease or increase.

[0072] 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 thermoplastic polyurethane elastomer; Alternatively, the diaphragm 20 is formed into a multi-layer structure, and the diaphragm 20 includes at least one layer of the thermoplastic polyurethane elastomer layer and a composite layer, the composite layer and the thermoplastic polyurethane elastomer layer are stacked, and the composite layer is at least one of an elastomer layer, an engineering plastic layer and a film layer.

[0073] That is, the diaphragm 20 of the embodiment of the present invention can be a single-layer thermoplastic polyurethane elastomer layer. The diaphragm 20 has a simple structure and a simple manufacturing process.

[0074] Alternatively, the diaphragm 20 may have a multi-layer structure. Specifically, at least one thermoplastic polyurethane elastomer 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.

[0075] Optionally, the elastomer layer includes one or more of thermoplastic polyester elastomers, thermoplastic polyamide elastomers, polystyrene elastomers, and polyolefin thermoplastic 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 may be one or more layers.

[0076] According to another embodiment of the present invention, a sound generating device is provided. Figure 2-Figure 3 As shown, the sound-generating device 100 includes the diaphragm 20 of the above embodiment.

[0077] like Figure 2-Figure 3 As shown, 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.

[0078] 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.

[0079] 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.

[0080] According to yet another embodiment of the present invention, an electronic device is provided.

[0081] 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.

[0082] 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.

[0083] Example: The diaphragm 20 is a single-layer structure comprising a thermoplastic polyurethane elastomer layer. The diaphragm 20 is formed using pneumatic molding. The thermoplastic polyurethane elastomer layer is made from a blended material comprising a first thermoplastic polyurethane elastomer and a second thermoplastic polyurethane elastomer. The ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the masses of the first and second thermoplastic polyurethane elastomers is 20%. The diaphragm 20 has a thickness of 90 μm. The diaphragm 20 is a ring-shaped diaphragm.

[0084] The glass transition temperature of the first thermoplastic polyurethane elastomer is -37°C. The soft segment of the first thermoplastic polyurethane elastomer is polybutylene adipate with a molecular weight of 2100, and the hard segment is 4,4'-diphenylmethane diisocyanate and 1,4-butanediol. The molar ratio of polybutylene adipate: 4,4'-diphenylmethane diisocyanate: 1,4-butanediol is 1:2:1. The glass transition temperature of the second thermoplastic polyurethane elastomer is -22°C. The soft segment of the second thermoplastic polyurethane elastomer is polyethylene adipate with a molecular weight of 2000, and the hard segment is 4,4'-diphenylmethane diisocyanate and 1,4-butanediol. The molar ratio of polyethylene adipate: 4,4'-diphenylmethane diisocyanate: 1,4-butanediol is 2:5:3.

[0085] Comparative Example 1: Diaphragm 20 is a single-layer structure, produced by air compression molding of a single-component thermoplastic polyurethane elastomer. The soft segment of the thermoplastic polyurethane elastomer is polybutylene adipate with a molecular weight of 2000. The hard segment is composed of 4,4'-diphenylmethane diisocyanate and 1,4-butanediol. The molar ratio of polybutylene adipate: 4,4'-diphenylmethane diisocyanate: 1,4-butanediol is 1:2:1. The glass transition temperature of diaphragm 20 in Comparative Example 1 is -35°C. The thickness of diaphragm 20 is 73 μm.

[0086] Comparative Example 2: Diaphragm 20 is a single-layer structure, made by air compression molding of a single-component thermoplastic polyurethane elastomer. The soft segment of the thermoplastic polyurethane elastomer is polybutylene adipate with a molecular weight of 2100, and the hard segment is 4,4'-diphenylmethane diisocyanate and 1,4-butanediol. The molar ratio of polybutylene adipate: 4,4'-diphenylmethane diisocyanate: 1,4-butanediol is 1:2:1. The glass transition temperature of diaphragm 20 in Comparative Example 2 is -37°C. Diaphragm 20 has a thickness of 100 μm.

[0087] Comparative Example 3: Diaphragm 20 is a single-layer structure, produced by air compression molding of a single-component thermoplastic polyurethane elastomer. The soft segment of the thermoplastic polyurethane elastomer is polybutylene adipate with a molecular weight of 2000. The hard segment is composed of 4,4'-diphenylmethane diisocyanate and 1,4-butanediol. The molar ratio of polybutylene adipate: 4,4'-diphenylmethane diisocyanate: 1,4-butanediol is 2:5:3. The glass transition temperature of diaphragm 20 in Comparative Example 3 is -22°C. The thickness of diaphragm 20 is 65 μm.

[0088] The components of Comparative Example 2 are the same as those of the first thermoplastic polyurethane elastomer of the embodiment. The components of Comparative Example 3 are the same as those of the second thermoplastic polyurethane elastomer of the embodiment. The F0 of the embodiment diaphragm 20 and the diaphragms of Comparative Examples 1, 2, and 3 are the same.

[0089] Test items: (1) The temperature ranges in which the loss factors of the diaphragms 20 of the embodiment and comparative examples 1, 2, and 3 are greater than 0.1 and greater than 0.12 are tested respectively.

[0090] 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%.

[0091] (2) Testing The storage modulus of the diaphragms 20 of the embodiment and comparative examples 1, 2, and 3 were tested at -20°C and 20°C, and the storage modulus change rate was calculated.

[0092] The storage modulus was tested using a dynamic thermomechanical analyzer under the following test conditions: ASTM D5026-23 standard, tensile mode, heating rate of 3°C / min, and frequency of 1 Hz.

[0093] The calculation method of the storage modulus change rate at -20℃ / 20℃ is:

[0094] (3) Six-point amplitude test: The diaphragms 20 of the embodiment and comparative example 1 were assembled into a sound-generating device, and the displacement curves of five points on the edge and one point at the center of the diaphragm 20 were measured as a function of frequency. The diaphragms 20 of the embodiment and comparative example 1 were both rectangular surround diaphragms with similar dimensions.

[0095] Results and Analysis: (1) The test results of the diaphragm 20 of the embodiment and comparative examples 1, 2 and 3 are shown in Table 1. The damping factor of the diaphragm 20 of the embodiment and comparative examples 1, 2 and 3 changes with temperature as shown in Table 1. Figure 4 and Figure 5 shown.

[0096] Table 1 - Test results of the diaphragm 20 of Example and Comparative Examples 1, 2, and 3

[0097] From Table 1, Figure 4 and Figure 5It can be seen that although the -20℃ / 20℃ storage modulus change rate of the diaphragm 20 of the embodiment of the present invention is similar to that of the diaphragm of Comparative Example 1, the temperature range of the damping factor > 0.10 and the temperature range of the damping factor > 0.12 of the diaphragm 20 of the embodiment of the present invention are wider than those of the diaphragm of Comparative Example 1. Although the -20℃ / 20℃ storage modulus change rate of the diaphragm of Comparative Example 2 is smaller, the temperature range of the damping factor > 0.10 and the temperature range of the damping factor > 0.12 of the diaphragm of Comparative Example 2 are narrower. Although the temperature range of the damping factor > 0.10 and the temperature range of the damping factor > 0.12 of the diaphragm 20 of Comparative Example 3 are wider, the -20℃ / 20℃ storage modulus change rate is high and cannot meet the use requirements of the sound-generating device. Although the -20℃ / 20℃ storage modulus change rate of the diaphragm 20 of the embodiment of the present invention is higher than the -20℃ / 20℃ storage modulus change rate of the diaphragm 20 of Comparative Example 2, its value is relatively small and is at the general level of the industry, and still meets the use requirements of the sound-generating device. The temperature range of the damping factor > 0.10 and the temperature range of the damping factor > 0.12 of the diaphragm 20 of the embodiment of the present invention are extended to the low temperature zone compared with the temperature range of the damping factor > 0.10 and the temperature range of the damping factor > 0.12 of the diaphragm of Comparative Example 3. It can be seen that the diaphragm 20 of the embodiment of the present invention can have a lower -20℃ / 20℃ storage modulus change rate, and the temperature range of the damping factor > 0.10 and the temperature range of the damping factor > 0.12 of the diaphragm 20 are wider. The overall performance of the diaphragm of the embodiment of the present invention is better. This is mainly because the thermoplastic polyurethane elastomer layer of the diaphragm 20 of the embodiment is made of a blended material. Since the thermoplastic polyurethane elastomer layer includes thermoplastic polyurethane elastomers with different glass transition temperatures, the damping temperature range of the diaphragm 20 can be effectively expanded, and the diaphragm 20 can maintain good damping stability within a wider operating temperature range and a wider frequency range.

[0098] (2) Figure 4 1 is a curve showing the six-point amplitude variation with frequency of the diaphragm 20 according to an embodiment of the present invention. Figure 5 1 is a curve showing six-point amplitude variation with frequency of the diaphragm 20 in comparative example 1.

[0099] Depend on Figure 4 and Figure 5 As can be seen, the six-point amplitude curve of the embodiment of the present invention is more concentrated than the six-point amplitude curve of Comparative Example 1. This indicates that the diaphragm 20 of the embodiment of the present invention has good amplitude consistency. This is primarily due to the thermoplastic polyurethane elastomer layer of the diaphragm 20 of the embodiment being made of a blended material. Since the thermoplastic polyurethane elastomer layer includes a first thermoplastic polyurethane elastomer and a second thermoplastic polyurethane elastomer with different glass transition temperatures, the loss factor of the diaphragm 20 is high over a wide operating temperature range, resulting in good overall performance of the diaphragm 20 and good amplitude consistency at all locations.

[0100] In summary, since the diaphragm 20 of the embodiment includes a thermoplastic polyurethane elastomer layer; the thermoplastic polyurethane elastomer layer is made of a blended material, and since the thermoplastic polyurethane elastomer layer includes thermoplastic polyurethane elastomers with different glass transition temperatures, the damping temperature range of the diaphragm 20 can be effectively expanded. The diaphragm 20 can maintain good damping stability within a wide operating temperature range and a wide amplitude range. Moreover, the diaphragm 20 of the embodiment of the present invention can have a low -20°C / 20°C storage modulus change rate, and the temperature range of the diaphragm 20 with a damping factor greater than 0.10 and a temperature range with a damping factor greater than 0.12 are relatively wide. In addition, the diaphragm 20 of the embodiment of the present invention has good amplitude consistency.

[0101] 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.

[0102] 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 at least one thermoplastic polyurethane elastomer layer; the thermoplastic polyurethane elastomer layer is prepared from a blended material, and the blended material includes a first thermoplastic polyurethane elastomer and a second thermoplastic polyurethane elastomer; the glass transition temperature of the first thermoplastic polyurethane elastomer is -60 to -30°C, and the glass transition temperature of the second thermoplastic polyurethane elastomer is -25 to 10°C; the 5-minute creep recovery rate of the thermoplastic polyurethane elastomer layer is 60%-98%.

2. The diaphragm according to claim 1, wherein The soft segment of the first thermoplastic polyurethane elastomer includes at least one of polycaprolactone, polybutylene adipate, polytetramethylene oxide, polyethylene oxide, polypropylene oxide, and copolymerized polyether, and the mass content of the soft segment of the first thermoplastic polyurethane elastomer is 35%-80%.

3. The diaphragm according to claim 1, wherein The soft segment of the second thermoplastic polyurethane elastomer includes at least one of polyethylene adipate, butanediol-based polycarbonate, hexanediol-based polycarbonate, 2-methyl-1,3-propylene glycol-based polycarbonate, copolycarbonate, and copolyester, and the mass content of the soft segment of the second thermoplastic polyurethane elastomer is 20%-70%.

4. The diaphragm according to claim 1, wherein: The ratio of the mass of the first thermoplastic polyurethane elastomer to the sum of the mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 30%-95%; And / or, the ratio of the mass of the second thermoplastic polyurethane elastomer to the sum of the mass of the first thermoplastic polyurethane elastomer and the second thermoplastic polyurethane elastomer is 5%-70%.

5. The diaphragm according to claim 1, wherein: The blend material also includes an antioxidant, which includes pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate octadecyl alcohol ester, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionamide], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6 -triketone, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, tris(2,4-di-tert-butylphenyl)phosphite, bis(2,4-dicumylphenyl)pentaerythritol diphosphite, dilauryl thiodipropionate, distearyl thiodipropionate, pentaerythritol tetra(β-thiopropyl laurate), 2,6-di-tert-butyl-p-cresol, wherein the antioxidant is added in an amount of 0.1phr-2phr in the blended material; And / or, the blended material further comprises an anti-hydrolysis agent, the anti-hydrolysis agent comprises at least one of polycarbodiimide, monomeric carbodiimide, and liquid modified carbodiimide, and the amount of the anti-hydrolysis agent added to the blended material is 0.5 phr-5 phr; And / or, the blended material further includes a UV absorber, the UV absorber including at least one of 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 2-hydroxy-4-n-octyloxybenzophenone, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol), and polymethylpropyl-3-oxy-[4(2,2,6,6-tetramethyl)piperidinyl]siloxane, and the amount of the UV absorber added to the blended material is 0.1phr-2phr; And / or, the blended material further includes a processing aid, which includes at least one of polytalc, dimethylsiloxane, polyethylene wax, fatty acid ester, and fatty acid salt, and the amount of the processing aid added to the blended material is 0.1 phr-5 phr.

6. The diaphragm according to claim 1, wherein: The thickness of the thermoplastic polyurethane elastomer layer is 10 μm-150 μm; And / or, the density of the thermoplastic polyurethane elastomer layer is 1.10 g / cm 3 -1.30g / cm 3 .

7. The diaphragm according to claim 1, wherein: The Young's modulus of the thermoplastic polyurethane elastomer layer is 5MPa-200MPa; And / or, the hardness of the thermoplastic polyurethane elastomer layer is 70A-95A.

8. The diaphragm according to claim 1, wherein: The Young's modulus change rate of the thermoplastic polyurethane elastomer layer after heat treatment at 130° C. for 90 seconds to 300 seconds is ≤50%; And / or, the Young's modulus change rate of the thermoplastic polyurethane elastomer layer after heat treatment at 130° C. for 90 seconds to 300 seconds and then constant heat treatment at a temperature of 85° C. and a humidity of 85% RH for 96 hours is ≤50%.

9. The diaphragm according to any one of claims 1 to 8, characterized in that: The diaphragm is formed into a single-layer structure, and the diaphragm is composed of a layer of the thermoplastic polyurethane elastomer; Alternatively, the diaphragm is formed into a multi-layer structure, the diaphragm includes at least one layer of the thermoplastic polyurethane elastomer layer and a composite layer, the composite layer is stacked with the thermoplastic polyurethane elastomer layer, and the composite layer is at least one of an elastomer layer, an engineering plastic layer and a film layer.

10. A sound-generating device, characterized in that: Comprising a diaphragm as described in any one of claims 1-9.

11. An electronic device, characterized in that: Comprising the sound-generating device as claimed in claim 10.

Images