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 is of a single-layer structure, the vibrating diaphragm is prepared from a blending material, the blending material comprises ethylene-acrylate rubber and acrylate rubber, and the mass ratio of a polyethylene block to a polyacrylate block in the ethylene-acrylate rubber is 0.2-4; the hardness of the vibrating diaphragm is 45A-80A, the room temperature damping factor of the vibrating diaphragm is greater than or equal to 0.2, and the strain recovery rate of the vibrating diaphragm is greater than or equal to 90% when the tensile deformation is 10%. The vibrating diaphragm provided by the embodiment of the invention is prepared from the blending material containing ethylene-acrylate rubber and acrylate rubber. In the vibrating diaphragm, due to hydrogen bonds formed by ester groups and microscopic phase separation of materials, the damping performance of the vibrating diaphragm is improved. And the mass ratio of a polyethylene block to a polyacrylate block in the ethylene-acrylate rubber is 0.2-4, so that the vibrating diaphragm material has good toughness and rebound resilience.

Description

Technical Field

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

[0002] In the related art, the diaphragm of high-performance micro speakers is usually made of AEM rubber material. As consumers' demands for the sound quality and volume of speakers of electronic devices become higher and higher, the amplitude of the speaker diaphragm is getting larger and larger. The increase in amplitude makes the polarization and distortion of the speaker higher and higher during vibration, which puts higher requirements on the damping performance of the diaphragm material. However, the room temperature damping factor of the diaphragm made of AEM rubber material is low, the distortion is serious, and the resilience is poor, which makes it difficult to meet the use requirements of the speaker. 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 is formed into a single-layer structure, and the diaphragm is prepared from a blended material, the blended material includes ethylene-acrylate rubber and acrylate rubber, and the mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber is 0.2-4; The hardness of the diaphragm is 45A-80A, the room temperature damping factor of the diaphragm is greater than or equal to 0.2, and the strain recovery rate of the diaphragm when the tensile deformation is 10% is greater than or equal to 90%.

[0005] Optionally, the ethylene-acrylate rubber is a ternary structure, and its molecular formula is: , Wherein, x, y, z are natural numbers; R and R' are alkyl groups; The acrylic rubber contains carboxylic acid groups and / or epoxy groups in its molecular formula.

[0006] Optionally, the blended material further includes an amine cross-linking agent, and the amine cross-linking agent includes at least one of hexamethylenediamine, hexamethylenediamine salt, hexamethylenediamine carbamate, triethylenetetramine, 2,2'-methylenedianiline and di-o-tolylguanidine, and the mass proportion of the amine cross-linking agent in the blended material is 0.2%-5wt%.

[0007] Optionally, the ethylene-acrylate rubber is a binary structure, and its molecular formula is:

[0008] Wherein, x and y are natural numbers; R is an alkyl group.

[0009] Optionally, the blended material further includes a peroxide crosslinking agent, which includes at least one of 1,3-1,4-di(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, 4,4'-bis(tert-butylperoxy)valerate, 1,1'-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and 2,4-dichlorobenzoyl peroxide, and the mass proportion of the peroxide crosslinking agent in the blended material is 0.2%-5wt%.

[0010] Optionally, the elongation at break of the diaphragm at room temperature is greater than or equal to 110%; And / or, the retention rate of the elongation at break of the diaphragm after aging for 168 hours at a temperature of 150° C. is greater than or equal to 50%.

[0011] Optionally, the stress loss rate of the diaphragm is greater than or equal to 30%; And / or, the glass transition point of the diaphragm is -60°C-10°C.

[0012] Optionally, in the blended material, the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylate rubber is 5%-95%.

[0013] Optionally, the blended material further includes a reinforcing agent, which is at least one of white carbon black, talcum powder, carbon black, and calcium carbonate, and the mass proportion of the reinforcing agent in the blended material is 5wt%-60wt%.

[0014] Optionally, the blended material also includes an antioxidant, which includes at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD, and antioxidant WH-02, and the mass proportion of the antioxidant in the blended material is 0.2wt%-6wt%.

[0015] Optionally, the room temperature storage modulus of the diaphragm is 2MPa-50Mpa; And / or, the density of the diaphragm is 1.1 g / cm 3 -1.65g / cm 3 ; And / or, the thickness of the diaphragm is 20 μm-150 μm.

[0016] According to a second aspect of the present invention, a sound-generating device is provided, which includes the diaphragm described in the present invention.

[0017] According to a third aspect of the present invention, an electronic device is provided, which includes the sound generating device of the present invention.

[0018] The diaphragm of the embodiment of the present invention is made of a blended material including ethylene-acrylate rubber and acrylate rubber. The mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber is 0.2-4, so that the diaphragm can have both good toughness and resilience. The strain recovery rate of the diaphragm when the tensile deformation is 10% is greater than or equal to 90%. The diaphragm has good resilience, which can improve the acoustic effect of the sound-generating device. Moreover, the blended material used to make the diaphragm includes ethylene-acrylate rubber and acrylate rubber. The hydrogen bonds formed by the ester groups in the diaphragm and the microscopic phase separation of the material can greatly improve the damping performance of the diaphragm, so that the room temperature damping factor of the diaphragm is not less than 0.2, so that the polarization and distortion of the diaphragm at a larger amplitude can be significantly reduced, thereby improving the sound effect.

[0019] 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 attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0021] Figure 1 is a cross-sectional view of a diaphragm according to an embodiment of the present invention.

[0022] Figure 2 is a stereoscopic diagram of a sound-generating device according to an embodiment of the present invention.

[0023] Figure 3 is a cross-sectional view of a sound generating device according to an embodiment of the present invention.

[0024] Figure 4 3 are total harmonic distortion curves of the micro-speakers of the embodiment of the present invention, comparative example 1, and comparative example 2.

[0025] Reference numerals: 100. Sound-generating device; 10. Shell; 20. Diaphragm; 30. Voice coil; 40. Permanent magnet. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that 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 unless otherwise specifically stated.

[0027] 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.

[0028] 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 as part of the specification.

[0029] 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.

[0030] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] The diaphragm 20 according to the embodiment of the present invention is described in detail below with reference to the accompanying drawings.

[0032] According to a specific embodiment of the present invention, a diaphragm 20 for a sound-generating device is provided. The diaphragm 20 is formed into a single-layer structure, and the diaphragm 20 is prepared from a blended material, the blended material includes ethylene-acrylate rubber (i.e., AEM rubber) and acrylate rubber (i.e., ACM rubber), and the mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber is 0.2-4; The hardness of the diaphragm 20 is 45A-80A, the room temperature damping factor of the diaphragm 20 is greater than or equal to 0.2, and the strain recovery rate of the diaphragm 20 when the tensile deformation is 10% is greater than or equal to 90%.

[0033] In other words, the diaphragm 20 is used in a sound-generating device. Figure 1As shown, the diaphragm 20 is a part of the vibration system. The diaphragm 20 is a folded ring diaphragm or a flat diaphragm. The diaphragm 20 is a single-layer structure and does not need to be compounded with other membrane layers. This makes the preparation process of the diaphragm 20 simple. The diaphragm 20 is made of a blended material. The preparation method is, for example, compression molding, air pressure molding, etc. The blended material is mixed with a variety of materials. For example, a variety of materials are added to a mixer. Blending is carried out in a mixer and mixed evenly to form a blended material. In this embodiment, the blended material includes AEM rubber and ACM rubber. Among them, AEM rubber is an elastomer obtained by copolymerization with ethylene-acrylate as the main monomer. ACM rubber is an elastomer obtained by copolymerization with acrylate as the main monomer.

[0034] During the preparation, the AEM rubber and the ACM rubber are added to a mixer for mixing to form a blended material. The blended material is formed into a single-layer diaphragm 20 by compression molding or air pressure molding. The blended material is vulcanized during the molding process. Of course, the method for preparing the diaphragm 20 is not limited to the above embodiment, and those skilled in the art can select according to actual needs.

[0035] The blended material of the embodiment of the present invention includes ethylene-acrylate rubber (i.e., AEM rubber) and acrylate rubber (i.e., ACM rubber). The molecular formula of the acrylate rubber contains carboxylic acid groups and / or epoxy groups. In other words, the molecular formula of the acrylate rubber may contain only carboxylic acid groups, the molecular formula of the acrylate rubber may contain only epoxy groups, and the molecular formula of the acrylate rubber may contain both carboxylic acid groups and epoxy groups. The above two groups act as crosslinking points and react with the crosslinking agent during the crosslinking process, thereby vulcanizing and molding the blended material.

[0036] In an embodiment of the present invention, the hardness of the diaphragm 20 is 45A-80A, and the room temperature damping factor of the diaphragm 20 is greater than or equal to 0.2. This is because the diaphragm 20 is made of a blended material. The blended material includes ethylene-acrylate rubber and acrylate rubber. The hydrogen bonds formed by the ester groups in the diaphragm 20 and the microscopic phase separation of the materials improve the damping performance of the diaphragm 20, for example, the room temperature damping factor is greater than or equal to 0.2. Compared with a diaphragm made of pure AEM rubber, under the same hardness conditions, the room temperature damping factor of the diaphragm 20 of the embodiment of the present invention is significantly improved, for example, by more than 20%.

[0037] When the hardness of the diaphragm 20 of the present invention is greater than or equal to 45A, the room temperature damping factor of the diaphragm 20 is greater than or equal to 0.2. When the hardness of the diaphragm 20 is less than or equal to 80A, the diaphragm 20 can maintain sufficient toughness and is not prone to film breakage. Therefore, the room temperature damping factor of the diaphragm 20 of the embodiment of the present invention is greater than or equal to 0.2, and the hardness is 45A-80A, which makes the diaphragm 20 polarized and distorted at a larger amplitude, and is not prone to film breakage.

[0038] In addition, the mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber in the diaphragm 20 of the embodiment of the present invention is 0.2-4. The strain recovery rate of the diaphragm when the tensile deformation is 10% is greater than or equal to 90%. It should be noted that the polyethylene block can provide toughness in the diaphragm 20, and as the mass content of the polyethylene block increases, the resilience of the diaphragm 20 becomes better; when the mass content of the polyethylene block is too large, the polyethylene block is easy to crystallize, resulting in increased processing difficulty of the diaphragm 20, and reducing the resilience of the diaphragm 20, making it difficult to meet the use requirements of the diaphragm 20. When the mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber is 0.2-4, the diaphragm 20 can have both good toughness and resilience, so that the strain recovery rate of the diaphragm 20 when the tensile deformation is 10% is greater than or equal to 90%, and the diaphragm 20 has good resilience. Among them, the strain recovery rate of the diaphragm 20 when the tensile deformation is 10% can be tested using the ASTM D5026-23 standard.

[0039] Optionally, the hardness of the diaphragm 20 is 45A, 50A, 60A, 70A, 80A, etc. The room temperature damping factor is 0.2, 0.25, 0.3, 0.34, 0.4, 0.45, etc. The strain recovery rate when the tensile deformation is 10% is 90%, 92%, 94%, 95%, etc. Of course, the hardness of the diaphragm 20, the room temperature damping factor, and the strain recovery rate when the tensile deformation is 10% are not limited to the above embodiments, and those skilled in the art can make selections according to actual needs.

[0040] The diaphragm 20 of the embodiment of the present invention is made of a blended material including ethylene-acrylate rubber and acrylate rubber. The mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber is 0.2-4, so that the diaphragm 20 can have both good toughness and resilience. The strain recovery rate of the diaphragm 20 when the tensile deformation is 10% is greater than or equal to 90%. The diaphragm 20 has good resilience, which can improve the acoustic effect of the sound-generating device. Moreover, the blended material used to make the diaphragm 20 includes ethylene-acrylate rubber and acrylate rubber. The hydrogen bonds formed by the ester groups in the diaphragm 20 and the microscopic phase separation of the materials can greatly improve the damping performance of the diaphragm 20, so that the room temperature damping factor of the diaphragm 20 is not less than 0.2, so that the polarization and distortion of the diaphragm 20 under large amplitudes can be significantly reduced, thereby improving the sound-generating effect. The diaphragm 20 of the present invention is a single-layer structure with good mechanical properties. It can meet the use requirements without being compounded with other material layers. It has a simple structural design, is easy to manufacture, and saves costs.

[0041] In a specific embodiment of the present invention, the ethylene-acrylate rubber is a ternary structure, and its molecular formula is: , Wherein, x, y, z are natural numbers; R and R' are alkyl groups.

[0042] Optionally, R' is a methyl group, an ethyl group or a butyl group. AEM rubber containing the above groups is widely available, and the preparation process of the diaphragm 20 is simple.

[0043] In the embodiment of the present invention, the ethylene-acrylate rubber of the ternary structure and the acrylate rubber containing carboxylic acid groups (-COOH) and / or epoxy groups can react with a crosslinking agent in the air and form the diaphragm 20 by air pressure molding. This simplifies the preparation process of the diaphragm 20 and saves production costs.

[0044] In a specific embodiment of the present invention, the blended material further includes an amine crosslinking agent, and the amine crosslinking agent includes at least one of hexamethylenediamine, hexamethylenediamine salt, hexamethylenediamine carbamate, triethylenetetramine, 2,2'-methylenedianiline and di-o-tolylguanidine. The mass proportion of the amine crosslinking agent in the blended material is 0.2%-5wt%.

[0045] Specifically, the amine crosslinking agent is a compound containing an amino functional group, which can undergo a crosslinking reaction with ACM rubber and AEM rubber to form a crosslinked structure, thereby curing the blended material and improving the mechanical properties, heat resistance and chemical resistance of the blended material. Optionally, the amine crosslinking agent may include any one or a mixture of hexamethylenediamine, hexamethylenediamine salt, hexamethylenediamine carbamate, triethylenetetramine, 2,2'-methylenedianiline and di-o-tolylguanidine. Those skilled in the art can choose according to actual needs. During preparation, after the AEM rubber and the ACM rubber are evenly mixed, an amine crosslinking agent is added. The ternary structure of ethylene-acrylate and acrylate containing carboxylic acid groups (-COOH) and / or epoxy groups can undergo a crosslinking reaction with the amine crosslinking agent in the air to cure and form, and finally form a diaphragm 20. It should be noted that the amine crosslinking agent can undergo a crosslinking reaction with AEM rubber and ACM rubber in the air, and the diaphragm 20 is formed by air pressure molding. Compared with other molding processes, air pressure molding significantly improves the output rate of the diaphragm 20 while maintaining a high yield, and the mold cost is relatively low, thereby reducing production costs.

[0046] When mixing, the mass of the amine cross-linking agent accounts for 0.2wt%-5wt% of the total mass of the blended material. It should be noted that the less the mass content of the amine cross-linking agent, the insufficient degree of cross-linking of the blended material, and the poor stability of the macromolecular network structure formed by the blended material. When the mass proportion of the amine cross-linking agent in the blended material is less than 0.2wt%, the degree of cross-linking of the diaphragm 20 is insufficient, and the stability of the macromolecular network structure is poor. If the mass content of the amine cross-linking agent is too high, the elongation at break of the diaphragm 20 is too low. Especially when the mass proportion of the amine cross-linking agent in the blended material is greater than 5wt%, the elongation at break of the diaphragm 20 is too low, and film breakage is prone to occur. When the mass content of the amine cross-linking agent in the blended material is 0.2wt%-5wt%, it can not only ensure that the diaphragm 20 has a sufficient degree of cross-linking, but also make the diaphragm 20 have a higher elongation at break.

[0047] Optionally, the mass proportion of the amine crosslinking agent in the blended material is 0.2wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, etc. Further, the mass proportion of the amine crosslinking agent in the blended material is 0.5wt%-3wt%. Of course, the mass proportion of the amine crosslinking agent in the blended material is not limited to the above embodiments, and those skilled in the art can make a selection according to actual needs.

[0048] In a specific embodiment of the present invention, the ethylene-acrylate rubber is a binary structure, and its molecular formula is:

[0049] Wherein, x and y are natural numbers; R is an alkyl group.

[0050] In the embodiment of the present invention, the binary structure of ethylene-acrylate rubber and acrylate rubber can react with a cross-linking agent to prepare the diaphragm 20 by compression molding.

[0051] In a specific embodiment of the present invention, the blended material further includes a peroxide crosslinking agent, which includes at least one of 1,3-1,4-di(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxideisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, 4,4'-bis(tert-butylperoxy)valeric acid n-butyl ester, 1,1'-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and 2,4-dichlorobenzoyl peroxide, and the mass proportion of the peroxide crosslinking agent in the blended material is 0.2%-5wt%.

[0052] Specifically, the peroxide crosslinking agent can generate free radicals on the main chain of the dimer, and the free radicals form crosslinking points, and the dimers are polymerized together through the crosslinking points to form a macromolecular network structure. Optionally, the peroxide crosslinking agent includes 1,3-1,4-di(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylperoxyisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, 4,4'-bis(tert-butylperoxy)valeric acid n-butyl ester, 1,1'-bis(tert-butylperoxy)-3,3,5 trimethylcyclohexane and 2,4-dichlorobenzoyl peroxide. The above-mentioned peroxide crosslinking agents can all generate free radicals on the main chain of the dimer to form a macromolecular network structure by crosslinking. During preparation, after the AEM rubber and the ACM rubber are evenly mixed, a peroxide crosslinking agent is added to form a blended material of the binary structured AEM rubber, ACM rubber and the peroxide crosslinking agent, and the blended material is molded in a mold to form the diaphragm 20 .

[0053] When mixing, the mass of the peroxide crosslinking agent accounts for 0.2wt%-5wt% of the total mass of the blended material. It should be noted that the less the mass content of the peroxide crosslinking agent, the insufficient degree of crosslinking of the blended material, and the poor stability of the macromolecular network structure formed by the blended material. When the mass proportion of the peroxide crosslinking agent in the blended material is less than 0.2wt%, the degree of crosslinking of the diaphragm 20 is insufficient, and the stability of the macromolecular network structure is poor. If the mass content of the peroxide crosslinking agent is too high, the elongation at break of the diaphragm 20 is too low. Especially when the mass proportion of the peroxide crosslinking agent in the blended material is greater than 5wt%, the elongation at break of the diaphragm 20 is too low, and film breakage is prone to occur. When the mass content of the peroxide crosslinking agent in the blended material is 0.2wt%-5wt%, it can not only ensure that the diaphragm 20 has a sufficient degree of crosslinking, but also make the diaphragm 20 have a higher elongation at break.

[0054] Optionally, the mass proportion of the peroxide crosslinking agent in the blended material is 0.2wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, etc. Of course, the mass proportion of the peroxide crosslinking agent in the blended material is not limited to the above embodiments, and those skilled in the art can make a selection according to actual needs.

[0055] In a specific embodiment of the present invention, the elongation at break of the diaphragm at room temperature is greater than or equal to 110%; And / or, the retention rate of the elongation at break of the diaphragm after aging for 168 hours at a temperature of 150° C. is greater than or equal to 50%.

[0056] In this embodiment, the elongation at break of the diaphragm 20 is tested at room temperature. The elongation at break of the diaphragm 20 can be tested according to the ASTM D412-2016 standard. The elongation at break refers to the percentage of the length of the material when it breaks after being stretched to the length before stretching. The lower the elongation at break of a material, the worse the toughness of the material, and the more likely it is that the membrane will break. The diaphragm 20 of the embodiment of the present invention has an elongation at break greater than or equal to 110% due to the large polarity and intermolecular force of ACM rubber. The diaphragm 20 has good toughness and is not prone to membrane breakage.

[0057] The elongation at break retention rate refers to the degree of retention of the elongation at break of a material after aging relative to the initial elongation at break. Before the test, the diaphragm 20 was aged for 168 hours at 150°C. The elongation at break of the diaphragm 20 can be tested in accordance with the ASTM D412-2016 standard. It should be noted that the higher the elongation at break retention rate, the higher the temperature resistance and stability of the material; conversely, the lower the temperature resistance and stability of the material. In the diaphragm 20 of the embodiment of the present invention, since the ACM rubber of the blended material contains a large number of ester groups, a large number of hydrogen bonds are formed between molecules. A large number of hydrogen bonds make the intermolecular force large, so the elongation at break retention rate of the diaphragm 20 is significantly improved. The elongation at break retention rate of the diaphragm 20 after aging for 168 hours at 150°C is greater than or equal to 50%, so that the diaphragm 20 has high temperature resistance and high stability under long-term use, which meets its use requirements under extreme working conditions.

[0058] Optionally, the elongation at break of the diaphragm 20 after aging for 168 hours at 150° C. is 110%, 200%, 300%, etc. The elongation at break retention rate is 50%, 53%, 55%, 58%, 60%, 65%, etc. Of course, the elongation at break and the elongation at break retention rate are not limited to the above embodiments, and those skilled in the art can set them according to actual needs.

[0059] In a specific embodiment of the present invention, the stress loss rate of the diaphragm 20 is greater than or equal to 30%; And / or, the glass transition point of the diaphragm is -60°C-10°C.

[0060] Specifically, the diaphragm 20 of the embodiment of the present invention satisfies one of the above conditions or satisfies both of the above conditions at the same time. The stress loss rate refers to the ratio of the stress reduction of the material due to factors such as time, environment, and temperature during the stress process. The stress loss rate of the diaphragm 20 can be tested according to the ASTM D5026-15 standard. It should be noted that the higher the stress loss rate, the more complete the stress release of the diaphragm 20 during the molding process, and the lower the dimensional deformation of the diaphragm 20 when it is placed; conversely, the more incomplete the stress release of the diaphragm 20 during the preparation process, and the higher the dimensional deformation of the diaphragm 20 when it is placed. The diaphragm 20 of the embodiment of the present invention is prepared by the above-mentioned blended material, so that the stress loss rate of the diaphragm 20 is greater than or equal to 30%. This shows that the stress of the diaphragm 20 is completely released during the molding process, and the dimensional deformation of the diaphragm 20 is low when it is placed. Of course, the stress loss rate is not limited to the above embodiment, and those skilled in the art can set it according to actual needs.

[0061] The glass transition point (i.e., glass transition temperature, Tg) refers to the temperature at which a material changes from a glassy state to a highly elastic state. The glass transition point can be tested according to the ASTM D882 standard. In this embodiment, the glass transition point of the diaphragm 20 is -60°C-10°C, so that the diaphragm 20 can be used for a long time in a low temperature environment without the diaphragm 20 being broken due to vibration stretching.

[0062] Optionally, the stress loss rate is 30%, 33%, 35%, 38%, 40%, 45%, 50%, etc. The glass transition point of the diaphragm 20 is -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 10°C, etc. Of course, the glass transition point of the diaphragm 20 is not limited to the above embodiments, and those skilled in the art can select according to actual needs.

[0063] In a specific embodiment of the present invention, in the blended material, the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylate rubber is 5%-95%.

[0064] It should be noted that, since the ester content in ACM rubber is much higher than that in AEM rubber, there is a certain microscopic phase separation in the material, which significantly increases the damping property of the diaphragm 20 during movement. Therefore, as the ACM rubber content increases, the ester content in the blended material increases significantly, the hydrogen bond content between the molecular chains increases, the friction force increases during the movement of the molecular chains, the internal friction increases, and the damping property of the diaphragm 20 increases significantly. However, due to the poor molecular flexibility of ACM rubber, when there are too many hydrogen bonds, the toughness of the diaphragm 20 will decrease. In this embodiment, when the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylic rubber is 5%-95%, the diaphragm 20 has both high damping property and toughness.

[0065] Optionally, in the blended material, the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylic rubber is 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%. Further, in the blended material, the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylic rubber is 7%-75%. Of course, the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylic rubber is not limited to the above embodiments, and those skilled in the art can make a selection according to actual needs.

[0066] In a specific embodiment of the present invention, the blended material further includes a reinforcing agent, which is at least one of white carbon black, talcum powder, carbon black, and calcium carbonate, and the mass proportion of the reinforcing agent in the blended material is 5wt%-60wt%.

[0067] In this embodiment, the reinforcing agent is used to improve the mechanical properties of the diaphragm 20, such as tensile strength, hardness, etc. When preparing the diaphragm 20, the reinforcing agent can be one or a mixture of white carbon black, talcum powder, carbon black, and calcium carbonate. Those skilled in the art can select according to actual needs.

[0068] It should be noted that the lower the content of the reinforcing agent, the lower the tensile strength of the diaphragm 20, especially when the mass proportion of the reinforcing agent in the blended material is less than 5wt%, the reinforcing effect on the diaphragm 20 is poor. If the content of the reinforcing agent is too high, for example, when the mass proportion of the reinforcing agent in the blended material is greater than 60wt%, the elongation at break of the diaphragm 20 will decrease significantly, and the toughness of the material is insufficient, resulting in the diaphragm 20 being prone to membrane breakage during vibration. When the mass proportion of the reinforcing agent in the blended material is 5wt%-60wt%, the diaphragm 20 has sufficient tensile strength, elongation at break and toughness.

[0069] Optionally, the mass proportion of the reinforcing agent in the blended material is 5wt%, 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, etc. Of course, the mass proportion of the reinforcing agent in the blended material is not limited to the above embodiments, and those skilled in the art can make a selection according to actual needs.

[0070] In a specific embodiment of the present invention, the blended material also includes an antioxidant, and the antioxidant includes at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD, and antioxidant WH-02, and the mass proportion of the antioxidant in the blended material is 0.2wt%-6wt%.

[0071] Specifically, during the use of polymer materials, as time goes by, the molecular chain breaks and generates autocatalytic active free radicals. Autocatalytic active free radicals can accelerate the aging of the polymer materials themselves. Adding an antioxidant to the diaphragm 20 can stop the generation of autocatalytic 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 mixtures of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD, and antioxidant WH-02 can be selected as antioxidants. The above antioxidants are all miscible with AEM rubber and ACM rubber, thereby preventing the diaphragm 20 from aging and extending the service life of the diaphragm 20.

[0072] It should be noted that in the blended material, the amount of antioxidant added is too small, for example, when the mass proportion of the antioxidant in the blended material is less than 0.2wt%, it is impossible to prevent the aging of the diaphragm 20 and extend the service life of the diaphragm 20. Too much antioxidant is added, for example, when the mass proportion of the antioxidant in the blended material is greater than 6wt%, the antioxidant cannot be well soluble with AEM rubber and ACM rubber, so that the antioxidant cannot be evenly dispersed in the blended material, resulting in a decrease in the mechanical properties of the diaphragm 20. When the mass proportion of the antioxidant in the blended material is 0.2wt%-6wt%, the antioxidant can effectively extend the service life of the diaphragm 20, and the antioxidant can be evenly dispersed in the blended material, and the prepared diaphragm 20 can maintain good mechanical properties.

[0073] Optionally, the weight percentage of the antioxidant in the blended material is 0.2wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, etc. Further, the weight percentage of the antioxidant in the blended material is 0.5wt%-2wt%. Of course, the weight percentage of the antioxidant in the blended material is not limited to the above embodiments, and those skilled in the art can select according to actual needs.

[0074] In a specific embodiment of the present invention, the room temperature storage modulus of the diaphragm 20 is 2MPa-50Mpa; And / or, the density of the diaphragm 20 is 1.1 g / cm 3 -1.65g / cm 3 ; And / or, the thickness of the diaphragm 20 is 20 μm-150 μm.

[0075] In the embodiment of the present invention, the diaphragm 20 satisfies any one, two or all three of the above conditions.

[0076] The room temperature storage modulus of the diaphragm 20 of the embodiment of the present invention is 2MPa-50Mpa. The storage modulus is used to characterize the ability of a material to resist elastic deformation. The room temperature storage modulus refers to the amount of energy stored in a material when it is subjected to an external force at room temperature. The room temperature storage modulus can be tested according to the ASTM D882 standard. It should be noted that when the room temperature storage modulus of the diaphragm 20 is too small, for example, less than 2MPa, the strength of the diaphragm 20 is too small, and polarization is prone to occur. When the room temperature storage modulus of the diaphragm 20 is too large, for example, greater than 50MPa, the hardness of the diaphragm 20 is too high, the elongation at break is low, and membrane rupture is prone to occur. When the room temperature storage modulus of the diaphragm 20 is 2MPa-50Mpa, the diaphragm 20 can have both good elasticity and hardness, and membrane rupture is not prone to occur.

[0077] Optionally, the room temperature storage modulus of the diaphragm 20 is 2MPa, 10MPa, 20MPa, 30MPa, 40MPa, 50MPa, etc. Of course, the room temperature storage modulus of the diaphragm 20 is not limited to the above embodiment, and those skilled in the art can set it according to actual needs.

[0078] The density of the diaphragm 20 in the embodiment of the present invention is 1.1 g / cm 3 -1.65g / cm 3 When the density of the diaphragm 20 is too high, for example, greater than 1.65 g / cm 3 When the density of the diaphragm 20 is too small, for example, less than 1.1 g / cm 3 When the density of the diaphragm 20 is 1.1 g / cm 3 -1.65g / cm 3 At the same time, the diaphragm 20 has moderate quality, good mid-frequency performance, and the processing technology of the diaphragm 20 is simple.

[0079] Optionally, the density of the diaphragm 20 is 1.1 g / cm 3 , 1.2g / cm 3 , 1.3g / cm 3 , 1.4g / cm 3 , 1.5g / cm 3 , 1.6g / cm 3 , 1.65g / cm 3 Of course, the density of the diaphragm 20 is not limited to the above embodiment, and those skilled in the art can set it according to actual needs.

[0080] The thickness of the diaphragm 20 of the embodiment of the present invention is 20μm-150μm. The diaphragm 20 is a single-layer structure. It should be noted that when the thickness of the diaphragm 20 is too low, for example, less than 20μm, the diaphragm 20 is easily deformed during processing, which is not conducive to the processing and molding of the diaphragm 20. When the thickness of the diaphragm 20 is too high, for example, greater than 150μm, the vibration space of the diaphragm 20 is affected, and the diaphragm 20 is easily rubbed against the shell. When the thickness of the diaphragm 20 is 20μm-150μm, it can not only ensure the convenience of processing of the diaphragm 20, but also save the vibration space of the diaphragm 20.

[0081] Optionally, the thickness of the diaphragm 20 is 20 μm, 40 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, etc. Of course, the thickness of the diaphragm 20 is not limited to the above embodiment, and those skilled in the art can set it according to actual needs.

[0082] 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.

[0083] In this example, the sound-generating device 100 may be a sound-generating device such as a speaker unit or a speaker assembly, and those skilled in the art may determine it according to actual conditions, and no specific limitation is made here.

[0084] 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, wherein the magnetic circuit system includes a permanent magnet 40, and the permanent magnet 40 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 arranged 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.

[0085] In this example, the diaphragm 20 may be a folded ring diaphragm. The folded ring diaphragm includes a central portion, a folded ring portion, and a fixed portion connected in sequence from the inside to the outside. 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.

[0086] In other examples, the diaphragm 20 may also be a planar diaphragm or other structures, which can be determined by those skilled in the art according to actual conditions and is not specifically limited here.

[0087] According to yet another embodiment of the present invention, an electronic device is provided.

[0088] 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 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 repeated here.

[0089] The diaphragm 20 and the sound generating device 100 of the present invention are described in detail below in conjunction with specific embodiments. It should be noted that the following description is only exemplary and does not specifically limit the present invention.

[0090] (I) Strain recovery rate of diaphragm 20 at 10% tensile deformation under different mass ratios of polyethylene block to polyacrylate block in AEM rubber The thickness of the diaphragm 20 is 85 μm. The diaphragm 20 is made of a blend of AEM rubber and ACM rubber, wherein the mass ratios of the polyethylene block to the polyacrylate block in the AEM rubber are 0.1, 0.2, 4, and 5, respectively. The test standard is ASTM D5026-23. The test sample with the same composition material as the diaphragm 20 is kept at 23° C. for 5 minutes. Then, the sample is instantly stretched to 10% and relaxed for 10 minutes. Next, the sample is restored for 5 minutes. The strain recovery rate at the end of the test is taken. The measured data are shown in Table 1. It should be noted that, considering the difference between the size of the diaphragm 20 and the sample size required by the corresponding test standard, a sample with the same composition material as the diaphragm 20 is selected for relevant tests to characterize the characteristics of the diaphragm. Since the sample is made of the same composition material as the diaphragm 20 itself, the relevant characteristics of the measured sample are consistent with the relevant characteristics of the diaphragm 20.

[0091] Table 1 - Strain recovery rate of the diaphragm when the tensile deformation is 10%

[0092] As can be seen from Table 1, when the mass ratio of the polyethylene block to the polyacrylate block in the AEM rubber is 0.1 and 5, the strain recovery rate of the diaphragm 20 at a tensile deformation of 10% is less than 90%, which cannot meet the actual use requirements. When the mass ratio of the polyethylene block to the polyacrylate block in the AEM rubber is 0.2 and 4, the strain recovery rate of the diaphragm 20 at a tensile deformation of 10% exceeds 90%. This is because the polyethylene block can provide toughness in the diaphragm 20. As the mass content of the polyethylene block increases, the resilience of the diaphragm 20 becomes better, and the strain recovery rate after stretching increases; when the mass content of the polyethylene block is too large, the polyethylene block is easy to crystallize, resulting in poor resilience of the diaphragm 20 and a decrease in the strain recovery rate after stretching.

[0093] (II) Retention rate of elongation at break of the diaphragm 20 of the embodiment of the present invention and the AEM rubber diaphragm of the same hardness after aging for 168 hours at 150°C The thickness of the diaphragm 20 and the AEM rubber diaphragm of the present invention is 85 μm. In the diaphragm 20 of the embodiment of the present invention, the mass content of ACM rubber (the ratio of the mass of ACM rubber to the total mass of ACM rubber and AEM rubber) is 10%. The hardness of the diaphragm 20 and the AEM rubber diaphragm of the present invention are 55A, 65A, and 75A, respectively. The elongation at break of the material is measured according to the ASTM D412-2016 standard. The sample shape of the diaphragm 20 and the AEM rubber diaphragm of the present invention is dumbbell-shaped. The tensile rate during the test is 500 mm / min, each group of samples is tested 5 times, and the test results are averaged over 5 times. The test results are shown in Table 2. It should be noted that, considering the difference between the size of the diaphragm 20 and the sample size required by the corresponding test standard, a sample with the same composition material as the diaphragm 20 is selected for relevant tests to characterize the characteristics of the diaphragm 20. Since the sample is made of the same composition material as the diaphragm 20 itself, the relevant characteristics of the measured sample are consistent with the relevant characteristics of the diaphragm 20.

[0094] Table 2 - Retention rate of elongation at break of the diaphragm and AEM rubber material of the embodiment of the present invention after aging for 168h at 150°C

[0095] As can be seen from Table 2, at the same hardness, the elongation at break retention rate of the diaphragm 20 of the embodiment of the present invention after aging for 168 hours at 150°C is greater than that of the AEM rubber diaphragm. This is because the diaphragm 20 of the embodiment of the present invention is made of a blend of ACM rubber and AEM rubber, wherein the ACM rubber contains a large number of ester groups, which makes the intermolecular force of the diaphragm 20 large, thereby greatly improving the temperature resistance of the diaphragm 20. Therefore, the elongation at break retention rate of the diaphragm 20 of the embodiment of the present invention after aging for 168 hours at 150°C is significantly higher than the elongation at break retention rate of the AEM rubber material after aging for 168 hours at 150°C.

[0096] (III) Room temperature damping factor and elongation at break of the diaphragm 20 of the embodiment of the present invention at different ACM rubber mass contents The mass content of ACM rubber is the ratio of the mass of ACM rubber to the total mass of ACM rubber and AEM rubber. The thickness of the diaphragm 20 is 85 μm. The mass contents of ACM rubber are 5wt%, 7wt%, 40wt%, 75wt% and 95wt% respectively. The test standard for the room temperature damping factor of the diaphragm 20 is the ASTM D5026-23 standard. The elongation at break of the diaphragm 20 is tested in accordance with the ASTM D412-2016 standard. The test results of the room temperature damping factor and elongation at break of the diaphragm 20 are shown in Table 3. It should be noted that, considering the difference between the size of the diaphragm 20 and the sample size required by the corresponding test standard, a sample with the same composition material as the diaphragm 20 is selected for relevant tests to characterize the characteristics of the diaphragm 20. Since the sample is made of the same composition material as the diaphragm 20 itself, the relevant characteristics of the measured sample are consistent with the relevant characteristics of the diaphragm 20.

[0097] Table 3 - Room temperature damping factor and elongation at break of diaphragms

[0098] As can be seen from Table 3, the room temperature damping factor of the diaphragm 20 under the above ACM rubber mass content is greater than 0.2. This is mainly because the content of ester groups in ACM rubber is much higher than that in AEM rubber, and because the blended material includes ACM rubber and AEM rubber, the hydrogen bonds formed by the ester groups in the diaphragm 20 and the microscopic phase separation of the material improve the damping performance of the diaphragm 20. With the increase of the content of ACM rubber, the content of ester groups in the diaphragm 20 increases significantly, the content of hydrogen bonds between molecular chains increases significantly, the friction force and internal friction increase during the movement of the molecular chains, and the damping performance of the diaphragm 20 increases significantly. When the content of ACM rubber is too high, the content of AEM rubber will be too low, resulting in a decrease in the content of hydrogen bonds between molecular chains. Therefore, as can be seen from Table 3, with the increase of the content of ACM rubber, the room temperature damping factor of the diaphragm 20 first increases and then decreases.

[0099] In addition, the elongation at break of the diaphragm 20 under the above ACM rubber mass content is greater than 110%, and as the ACM rubber mass content increases, the elongation at break of the diaphragm 20 gradually decreases. This is because the molecular flexibility of ACM rubber is poor, so as the hydrogen bonds increase, the toughness of the diaphragm 20 decreases, thereby reducing the elongation at break of the diaphragm 20.

[0100] (IV) Elongation at break and tensile strength of diaphragm 20 at different silica mass contents The thickness of the diaphragm 20 is 85 μm, of which the mass content of ACM rubber (the ratio of the mass of ACM rubber to the total mass of ACM rubber and AEM rubber) is 35%. The mass contents of white carbon black in the blended materials are 5wt%, 37wt% and 60wt% respectively. The test standard for the elongation at break and tensile strength of the diaphragm 20 is ASTM D412-2016 standard. The measured elongation at break and tensile strength of different diaphragms 20 are shown in Table 4. It should be noted that, considering the difference between the size of the diaphragm 20 and the sample size required by the corresponding test standard, a sample with the same composition material as the diaphragm is selected for relevant tests to characterize the characteristics of the diaphragm. Since the sample is made of the same composition material as the diaphragm 20 itself, the relevant characteristics of the measured sample are consistent with the relevant characteristics of the diaphragm 20.

[0101] Table 4 - Elongation at break and tensile strength of diaphragm

[0102] As can be seen from Table 4, as the mass content of white carbon black increases, the elongation at break of the diaphragm 20 gradually decreases, and the tensile strength of the diaphragm 20 gradually increases. When the mass content of white carbon black is greater than 60wt%, the elongation at break of the diaphragm 20 is too low to meet the use requirements. When the mass content of white carbon black is less than 5wt%, the tensile strength of the diaphragm 20 is too low, and it also cannot meet the use requirements. This is because the main component of white carbon black is silicon dioxide. White carbon black is a white amorphous powder, and its surface contains relatively active hydroxyl groups. Due to the strong interaction between the surface of white carbon black and the interface of ACM rubber and AEM rubber, when the material is subjected to force, the molecular chain is easier to slide on the surface of white carbon black, but it is not easy to separate from it. In this way, the molecular chain and white carbon black form a strong bond that can slide, which increases the tensile strength of the diaphragm 20. However, the reinforcing agent, as a filler, occupies the space of the diaphragm 20, reducing the stretching space of the molecular chain. Therefore, as the mass content of white carbon black increases, the elongation at break of the diaphragm 20 gradually decreases.

[0103] (V) Total harmonic distortion of the sound-generating device of the embodiment of the present invention and the sound-generating device of the comparative example The sound-generating device of the embodiment of the present invention is a micro-speaker. The micro-speaker adopts the diaphragm 20 of the embodiment of the present invention, wherein the diaphragm 20 is a folded ring diaphragm. The folded ring diaphragm includes a central portion, a folded ring portion arranged around the central portion, and an edge portion arranged around the folded ring portion. A reinforcing layer is arranged at the central portion. The edge portion is connected to the shell. The thickness of the diaphragm 20 is 65 μm. The diaphragm 20 is made of a blended material consisting of AEM rubber and ACM rubber. The diaphragm 20 is rectangular as a whole. The ratio of the mass of ACM rubber to the total mass of ACM rubber and AEM rubber is 20%, the ratio of polyethylene block to polyacrylate in AEM rubber is 1, the hardness of the diaphragm 20 is 70.3A, the damping factor at room temperature is 0.3271, and the strain recovery rate at a tensile deformation of 10% is 95.8%. The F0 of the sound-generating device is 711 Hz. The total harmonic distortion (THD) curve of the micro-speaker is measured.

[0104] The diaphragm used in the sound-generating device of Comparative Example 1 is made of AEM rubber. The diaphragm is a single-layer structure with a thickness of 65 μm, a ratio of polyethylene block to polyacrylate of 0.1, a hardness of 70.3A, a damping factor of 0.2421 at room temperature, a strain recovery rate of 86.9% at a tensile deformation of 10%, and an F0 of 812 Hz for the micro-speaker. The total harmonic distortion (THD) curve of the micro-speaker was measured.

[0105] The diaphragm used in the sound-generating device of comparative example 2 is made of ACM rubber. The diaphragm is a single-layer structure, with a thickness of 65 μm, a hardness of 70.4A, a damping factor of 0.2846 at room temperature, a strain recovery rate of 84.7% when the tensile deformation is 10%, and the F0 of the micro-speaker is 810 Hz. The total harmonic distortion (THD) curve of the micro-speaker is measured.

[0106] The structures and dimensions of the sound-generating devices of Comparative Examples 1 and 2 are the same as those of the sound-generating device of the embodiment of the present invention. The outer dimensions of the diaphragms of Comparative Examples 1 and 2 are the same as those of the diaphragm 20 of the embodiment of the present invention.

[0107] According to the above, when the hardness is similar, the diaphragm 20 of the embodiment of the present invention has a higher strain recovery rate and a higher room temperature damping factor when the tensile deformation is 10% than the diaphragms of Comparative Examples 1 and 2. The F0 of the micro-speakers of the embodiment of the present invention, Comparative Examples 1 and 2 is basically the same, that is, the low-frequency loudness of the three is basically the same. The THD curves of the micro-speakers of the embodiment of the present invention, Comparative Examples 1 and 2 are shown in FIG. Figure 4 As shown. The horizontal axis is frequency, unit: Hz; the vertical axis is THD, unit: %. Figure 4It can be seen that the total harmonic distortion of the micro-speaker of the embodiment of the present invention is lower than that of the micro-speakers of Comparative Examples 1 and 2. The listening effect of the micro-speaker of the embodiment of the present invention is better.

[0108] In summary, the diaphragm 20 of the embodiment of the present invention is made of a blended material including ethylene-acrylate rubber and acrylate rubber. Since the blended material includes ACM rubber and AEM rubber, the diaphragm 20 has hydrogen bonds formed by ester groups and microscopic phase separation of the material, thereby improving the damping performance of the diaphragm 20. The room temperature damping factor of the diaphragm 20 reaches 0.3271, which is significantly higher than the room temperature damping factors of the diaphragms 20 of Comparative Examples 1 and 2, thereby effectively suppressing the polarization and distortion of the diaphragm 20.

[0109] In addition, the ratio of the polyethylene block to the polyacrylate in the embodiment of the present invention is 1, so that the strain recovery rate of the diaphragm at a tensile deformation of 10% reaches 95.8%, which is significantly higher than the strain recovery rate under the same test conditions of Comparative Examples 1 and 2. This is mainly because the polyethylene block can provide toughness in the diaphragm 20, thereby improving the resilience of the diaphragm 20 and improving the strain recovery rate of the diaphragm 20 at a tensile deformation of 10%.

[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 example, it will be appreciated 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 will be appreciated by those skilled in the art that the above embodiments may be modified 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 is formed into a single-layer structure, and the diaphragm is prepared from a blended material, wherein the blended material includes ethylene-acrylate rubber and acrylate rubber, and the mass ratio of the polyethylene block to the polyacrylate block in the ethylene-acrylate rubber is 0.2-4; The hardness of the diaphragm is 45A-80A, the room temperature damping factor of the diaphragm is greater than or equal to 0.2, and the strain recovery rate of the diaphragm when the tensile deformation is 10% is greater than or equal to 90%.

2. The diaphragm according to claim 1, characterized in that: The ethylene-acrylate rubber is a ternary structure, and its molecular formula is: ， Wherein, x, y, z are natural numbers; R and R' are alkyl groups; The acrylic rubber contains carboxylic acid groups and / or epoxy groups in its molecular formula.

3. The diaphragm according to claim 2, characterized in that: The blended material also includes an amine crosslinking agent, which includes at least one of hexamethylenediamine, hexamethylenediamine salt, hexamethylenediamine carbamate, triethylenetetramine, 2,2'-methylenedianiline and di-o-tolylguanidine, and the mass proportion of the amine crosslinking agent in the blended material is 0.2%-5wt%.

4. The diaphragm according to claim 1, characterized in that: The ethylene-acrylate rubber is a binary structure, and its molecular formula is: Wherein, x and y are natural numbers; R is an alkyl group.

5. The diaphragm according to claim 4, characterized in that: The blended material also includes a peroxide crosslinking agent, which includes at least one of 1,3-1,4-di(tert-butylperoxyisopropyl)benzene, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, tert-butylisopropylbenzene peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, 4,4'-bis(tert-butylperoxy)valerate, 1,1'-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and 2,4-dichlorobenzoylperoxide, and the mass proportion of the peroxide crosslinking agent in the blended material is 0.2%-5wt%.

6. The diaphragm according to claim 1, characterized in that: The elongation at break of the diaphragm at room temperature is greater than or equal to 110%; And / or, the retention rate of the elongation at break of the diaphragm after aging for 168 hours at a temperature of 150° C. is greater than or equal to 50%.

7. The diaphragm according to claim 1, characterized in that: The stress loss rate of the diaphragm is greater than or equal to 30%; And / or, the glass transition point of the diaphragm is -60°C-10°C.

8. The diaphragm according to claim 1, characterized in that: In the blended material, the ratio of the mass of the acrylic rubber to the total mass of the acrylic rubber and the ethylene-acrylate rubber is 5%-95%.

9. The diaphragm according to claim 1, characterized in that: The blended material also includes a reinforcing agent, which is at least one of white carbon black, talcum powder, carbon black, and calcium carbonate. The weight proportion of the reinforcing agent in the blended material is 5wt%-60wt%.

10. The diaphragm according to claim 1, characterized in that: The blended material also includes an antioxidant, which includes at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD, and antioxidant WH-02, and the weight proportion of the antioxidant in the blended material is 0.2wt%-6wt%.

11. The diaphragm according to claim 1, characterized in that: The room temperature storage modulus of the diaphragm is 2MPa-50Mpa; And / or, the density of the diaphragm is 1.1 g / cm 3 -1.65g / cm 3 ; And / or, the thickness of the diaphragm is 20 μm-150 μm.

12. A sound-generating device, characterized in that: Comprising a diaphragm as described in any one of claims 1-11.

13. An electronic device, characterized in that: Comprising the sound-generating device as claimed in claim 12.

Images