Diaphragm of a sound generating device, method for preparing the same, and sound generating device

Abstract

The present application discloses a diaphragm of a sound generating device, a preparation method thereof, and a sound generating device. The diaphragm includes a silicone-based polymer film layer, and the silicone-based polymer film layer contains two or more mechanical loss peaks, wherein the temperature of the peak value of at least one mechanical loss peak is between -50°C and 20°C, and the peak height of the mechanical loss peak is greater than 0.13. The diaphragm of the present application can make the damping of the diaphragm at high and low temperatures at a relatively high level, thereby greatly improving the damping of the diaphragm, reducing polarization during vibration, reducing product distortion, and improving the listening yield.

Description

Technical Field

[0001] The present application relates to the field of electroacoustic technology, and more specifically, to a diaphragm of a sound generating device, a preparation method thereof, and a sound generating device using the diaphragm. Background Art

[0002] Currently, the diaphragms of micro sound generating devices mostly use multi-layer composite materials and silicone-based elastomer materials. Among them, most multi-layer composite materials are used in combination with an intermediate layer by engineering plastics such as PEEK and PAR with good heat resistance but poor material resilience, or elastomer materials such as TPU and TPEE with poor high-temperature resistance. The silicone-based elastomer materials mostly adopt a single-layer structure. Compared with engineering plastics and thermoplastic elastomer materials, they have excellent thermal stability and high resilience. However, the glass transition temperature of the silicone-based elastomer is < -100 °C, and it has good structural flexibility and small frictional resistance between chain segments. Therefore, its damping change is relatively stable at -100 °C to 200 °C, with small damping and high distortion, and it cannot meet the requirements of high-quality sound of current speakers (the operating temperature of speakers is about -30 °C to 140 °C). Moreover, the surface of the silicone-based elastomer has fewer active groups, which affects its adhesiveness.

[0003] Therefore, it is necessary to study a new technical solution to meet the purpose that the overall damping of the diaphragm is at a relatively high level under high and low temperature conditions and the adhesive force is relatively high. Summary of the Invention

[0004] An object of the present invention is to provide a diaphragm of a sound generating device, which can solve the technical problems of low damping and insufficient adhesiveness of the existing diaphragms in the high-temperature region.

[0005] Another object of the present invention is to provide a preparation method of the above diaphragm.

[0006] Another object of the present invention is to provide a sound generating device composed of the above diaphragm.

[0007] In order to achieve the above objects, the present invention provides the following technical solutions.

[0008] According to an embodiment of the first aspect of the present invention, a diaphragm of a sound generating device, the diaphragm includes a silicone-based high polymer film layer, the silicone-based high polymer film layer includes two or more mechanical loss peaks, and the temperature of the peak value of at least one mechanical loss peak is between -50 °C and 20 °C, and the peak height of the mechanical loss peak is greater than 0.13.

[0009] According to some embodiments of the present invention, the silicone-based high polymer is composed of structural unit one and structural unit two,

[0010] wherein, the structural unit one is The structural unit two is At least one of them, R, R1, and R2 in Structural Unit 1 are each any one selected from methyl, vinyl, phenyl, and trifluoropropyl, R3 in Structural Unit 2 is a hydrogen group or methyl, and m and n are integers ≥ 1.

[0011] According to some embodiments of the present invention, in the organosilicon-based high polymer, the mass percentage of Structural Unit 2 is 2% - 50%.

[0012] According to some embodiments of the present invention, the adhesion force of the vibration film and the standard tape during the peel test at a peel angle of 180° is 100 g / 25 mm - 1000 g / 25 mm.

[0013] According to some embodiments of the present invention, the Young's modulus of the vibration film is 1 MPa - 50 MPa.

[0014] According to some embodiments of the present invention, the thickness of the vibration film is 50 μm - 300 μm.

[0015] A method for preparing a vibration film of a sound generating device according to an embodiment of the second aspect of the present invention includes the following steps: mixing silicone rubber and ester group-containing rubber, adding a vulcanizing agent, a compatibilizer, and an auxiliary agent to obtain a mixed material; subjecting the mixed material to high-temperature crosslinking molding to obtain an organosilicon-based high polymer film layer.

[0016] According to some embodiments of the present invention, the ester group-containing rubber is at least one of polyurethane rubber, acrylate rubber, and ethylene acrylate.

[0017] According to some embodiments of the present invention, the vulcanizing agent is a peroxide.

[0018] According to some embodiments of the present invention, the compatibilizer is one or more of a silane coupling agent, organosilicon-modified polyurethane, maleic anhydride graft polymer, and polysiloxane graft polymer.

[0019] A sound generating device according to an embodiment of the third aspect of the present invention includes a vibration system and a magnetic circuit system that cooperates with the vibration system. The vibration system includes a vibration film and a voice coil bonded to one side of the vibration film. The magnetic circuit system drives the voice coil to vibrate to drive the vibration film to generate sound, and the vibration film is the vibration film according to the above embodiments of the present invention.

[0020] The sound generating device according to the embodiment of the fourth aspect of the present invention includes a housing, a magnetic circuit system and a vibration system provided in the housing. The vibration system includes a voice coil, a first diaphragm and a second diaphragm. The top of the voice coil is connected to the first diaphragm. The magnetic circuit system drives the voice coil to vibrate to drive the first diaphragm to generate sound. Both ends of the second diaphragm are respectively connected to the housing and the bottom of the voice coil. The second diaphragm is the diaphragm according to the above embodiment of the present invention.

[0021] By adopting a silicone-based polymer film layer containing two or more mechanical loss peaks, where the peak temperature of at least one mechanical loss peak is between -50°C and 20°C, and the peak height of the mechanical loss peak within this temperature range is greater than 0.13, the diaphragm of the sound generating device according to the embodiment of the present application can keep the damping of the diaphragm at a relatively high level under both high and low temperature conditions. Furthermore, the damping of the diaphragm can be greatly improved, which can reduce polarization during vibration, reduce product distortion, and improve the listening yield.

[0022] Other features and advantages of the present application will become clear from the following detailed description of the exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings incorporated in the specification and forming a part of the specification illustrate embodiments of the present application and, together with the description, are used to explain the principles of the present application.

[0024] Figure 1 It is a dynamic thermomechanical analysis test chart of the silicone-based polymer according to Embodiment 2 of the present invention;

[0025] Figure 2 It is a dynamic thermomechanical analysis test chart of the comparative sample and the silicone-based polymers of Embodiments 1 to 3 according to the present invention;

[0026] Figure 3 It is a comparative chart of THD curves of the sound generating devices of the comparative sample, Embodiment 2 and Embodiment 3 according to the present invention;

[0027] Figure 4 It is a schematic structural diagram of the sound generating device according to an embodiment of the present invention.

[0028] REFERENCE SIGNS

[0029] Loudspeaker vibration unit 100;

[0030] Surround part 11; Dome top 12. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way a limitation on the present application or its application or use.

[0033] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the specification.

[0034] In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments may have different values.

[0035] It should be noted that: Like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, further discussion thereof is not required in subsequent drawings.

[0036] The diaphragm of the sound generating device according to an embodiment of the present invention will be specifically described below with reference to the accompanying drawings.

[0037] The diaphragm of the sound generating device according to an embodiment of the present application, the diaphragm includes a silicone-based polymer film layer, the silicone-based polymer film layer contains two or more mechanical loss peaks, and the temperature of the peak value of at least one mechanical loss peak is between -50°C and 20°C, and the peak height of the mechanical loss peak is greater than 0.13.

[0038] In other words, the operating temperature of the speaker and the diaphragm on the speaker is mostly -30°C to 140°C, while the glass transition temperature of the single-component silicone-based elastomer is less than -100°C. That is to say, the damping of the single-component silicone-based elastomer is small in the temperature range of -30°C to 140°C, that is, the temperature region of the high damping value of the single-component silicone-based elastomer is more concentrated in the region with a lower temperature. The diaphragm of the present embodiment includes a silicone-based polymer film layer, the silicone-based polymer film layer contains two or more mechanical loss peaks, and the temperature of the peak value of at least one mechanical loss peak is between -50°C and 20°C, and the peak height of the mechanical loss peak is greater than 0.13. It can be seen that the high damping region of the silicone-based polymer film layer of the present embodiment is closer to the region of the common operating temperature of the speaker. In addition, since the peak height of the mechanical loss peak is greater than 0.13, the peak height of the mechanical loss peak represents the damping of the material, and thus it can be shown that the silicone-based polymer film layer has a high damping in the temperature range of -50°C to 20°C.

[0039] Thus, by adopting a silicone-based polymer film layer that includes two or more mechanical loss peaks, where the temperature at the peak of at least one mechanical loss peak is between -50°C and 20°C and the peak height of the mechanical loss peaks within this temperature range is greater than 0.13, the diaphragm of the sound generating device according to the embodiments of the present application can keep the damping of the diaphragm at a relatively high level under both high and low temperature conditions. Furthermore, the damping during the vibration of the diaphragm of the speaker can be greatly improved, the polarization during the vibration process can be reduced, the product distortion can be decreased, and the listening yield can be enhanced.

[0040] According to an embodiment of the present application, the silicone-based polymer is composed of structural unit one and structural unit two.

[0041] Among them, structural unit one is Structural unit two is at least one of the above, where R, R1, and R2 in structural unit one are any one selected from methyl, vinyl, phenyl, and trifluoropropyl, R3 in structural unit two is a hydrogen group or a methyl group, and m and n are integers greater than or equal to 1.

[0042] That is to say, the silicone-based polymer is mainly composed of structural unit one and structural unit two, where structural unit one is R in structural unit one is methyl, vinyl, phenyl, or trifluoropropyl, R1 is methyl, vinyl, phenyl, or trifluoropropyl, R2 is methyl, vinyl, phenyl, or trifluoropropyl, and R, R1, and R2 can adopt the same or different groups, which is not limited here. m and n are integers greater than or equal to 1, and m and n can be the same or different, which is also not limited here. The number of structural unit one in the silicone-based polymer can be multiple. When the number of structural unit one is multiple, R, R1, and R2 in the same structural unit one can be the same or different, and the structures of different structural unit one can be the same or different. That is to say, the silicone-based polymer includes at least one structural unit one, and the R group in the silicone-based polymer includes at least one of methyl, vinyl, phenyl, and trifluoropropyl; similarly, the R1 group in the silicone-based polymer includes at least one of methyl, vinyl, phenyl, and trifluoropropyl, and the R2 group in the silicone-based polymer includes at least one of methyl, vinyl, phenyl, and trifluoropropyl, which will not be elaborated here. Among them, when any one of R, R1, or R2 selects phenyl, since the introduction of phenyl can increase the volume of the molecular side chain and increase the resistance to intramolecular rotation, the damping performance can be further improved.

[0043] It should be noted that the structural unit one contains Si-O bonds, while the surface of the silicone elastomer has fewer active groups, which will affect the adhesiveness. The silicone-based polymer in this embodiment further contains a structural unit two, and the ester group in the structural unit two can increase the active groups of the silicone-based polymer, thereby improving the subsequent adhesiveness of the diaphragm. That is to say, through the structural unit two, not only can the silicone-based polymer have good damping at high temperatures, but also the adhesiveness can be increased. Among them, the structural unit two in the silicone-based polymer includes at least one of them. The number of the structural unit two in the silicone-based polymer can be multiple, and the structures of different structural unit twos can be the same or different. For example, the structural unit two of the silicone-based polymer includes the following situations: Situation one, the structural unit two in the silicone-based polymer is composed of ; Situation two, the structural unit two of the silicone-based polymer is composed of ; Situation three, the structural unit two of the silicone-based polymer is jointly composed of . It should be noted that the above-mentioned multiple combinations are only illustrative descriptions of the structural unit two in the silicone-based polymer, and do not limit that the network polymer can only be composed of the above three situations.

[0044] In some specific embodiments of the present application, in the silicone-based polymer, the mass percentage of the structural unit two is 2% to 50%. For example, the mass percentage of the structural unit two is 2%, 5%, 10%, 20%, 30%, 40% or 50%, etc. If the mass percentage of the structural unit two is less than 2%, it is easy to cause the damping improvement effect to be not obvious; if the mass percentage of the structural unit two is greater than 50%, it is easy to cause the loss of the advantages of the high and low temperature resistance performance of a part of the structural unit one. Optionally, the mass percentage of the structural unit two in the mass of the silicone-based polymer film layer is 5% to 20%. By adopting the mass percentage of the structural unit two within this range, the silicone-based polymer film layer of this embodiment can easily have the advantages of improving the damping effect and high and low temperature resistance performance at the same time.

[0045] According to an embodiment of the present application, the adhesive force of the diaphragm and the standard tape in the peeling test at a peeling angle of 180° is 100 g / 25 mm to 1000 g / 25 mm. Among them, in the test, the standard tape used is the Nitto standard tape. In the adhesive force test, the following steps can be carried out: Stick a 25-mm-wide standard tape on the diaphragm material, ensure that there are no bubbles and impurities on the bonding surface, and after placing for 24 h, peel at 180° with a tensile machine, and the peeling rate is 300 mm / min to test the size of the adhesive force. Since the addition of the structural unit two can increase the active groups on the surface of the silicone-based polymer, such as increasing the ester group, etc., the bonding performance is improved, and the problem of poor bonding between the subsequent diaphragm of the speaker and the dome and the housing is improved.

[0046] In some specific embodiments of the present application, the Young's modulus of the diaphragm is 1 MPa to 50 MPa. For example, the Young's modulus is 1 MPa, 5 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, or 50 MPa, etc. In some specific embodiments of the present application, the thickness of the diaphragm is 50 μm to 300 μm. For example, the thickness is 50 μm, 60 μm, 70 μm, 1000 μm, 150 μm, 2000 μm, or 300 μm, etc. Since the resonant frequency F0 of the speaker is proportional to the thickness and modulus of the diaphragm, when the modulus of the diaphragm is relatively small, the required thickness is too large, which will lead to a smaller vibration space; while when the modulus of the diaphragm is too large, the required thickness is relatively small, which will lead to insufficient stiffness of the diaphragm.

[0047] The present application also discloses a method for preparing a diaphragm of a sound generating device, including the following steps: mixing silicone rubber and ester group-containing rubber, adding a vulcanizing agent, a compatibilizer, and an auxiliary agent to obtain a mixed material; cross-linking and molding the mixed material at a high temperature to obtain an organosilicon-based high polymer film layer. The auxiliary agent may include a reinforcing agent and an antioxidant. The reinforcing agent may be selected from silica, carbon-based materials, silicates, carbonates, etc. The antioxidant may be selected from pentaerythritol tetrakis[β-(3,5-di-tert-butyl,4-hydroxyphenyl)propionate] antioxidant, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,6-di-tert-butylphenol, etc. The auxiliary agent may also include a structure control agent, and the structure control agent may be selected from diols, diorganocyclosiloxanes, alkoxysilanes, hydroxyfluorosilicone oils, etc.

[0048] That is to say, the present application also discloses a method for manufacturing a diaphragm of a sound generating device. The manufacturing method may include the following steps: mixing silicone rubber, ester group-containing rubber, a vulcanizing agent, a compatibilizer, and other auxiliary agents, and curing and molding to obtain an organosilicon-based high polymer film layer. Since the organosilicon-based high polymer film layer is made by mixing silicone rubber and ester group-containing rubber, the organosilicon-based high polymer film layer contains two or more mechanical loss peaks. The temperature of the peak value of at least one mechanical loss peak may be between -50°C and 20°C, and the peak height of the mechanical loss peak corresponding to this temperature range may be greater than 0.13. By using the combination of silicone rubber and ester group-containing rubber, not only can the diaphragm have good damping properties in both high and low temperature regions, but also the adhesiveness can be ensured, and the assembly firmness performance of the diaphragm can be improved.

[0049] According to an embodiment of the present application, the ester group-containing rubber is at least one of polyurethane rubber, acrylate rubber (ACM), and ethylene acrylate (AEM). By using the above types of ester group-containing rubber, it is beneficial to have both adhesiveness and high damping in high and low temperature regions. In other words, the silicone-based polymer film layer can be composed of a damping modifier and a siloxane elastomer. The damping modifier is selected from rubbers with relatively good damping performance, including one or more of polyurethane rubber, ethylene acrylate rubber, acrylate rubber, etc. That is to say, by blending silicone rubber and ester group-containing rubber, the damping of the diaphragm material can be effectively improved within a wide temperature range, and the surface active groups increase, thereby improving the adhesiveness of the diaphragm material.

[0050] According to an embodiment of the present application, after mixing silicone rubber and ester group-containing rubber and undergoing treatment, a silicone-based polymer film layer is obtained. The silicone-based polymer film layer contains segment one and segment two, where segment one is Segment two is At least one of them. R, R1, and R2 in segment one are any one selected from methyl, vinyl, phenyl, and trifluoropropyl. R3 in segment two is a hydrogen group or a methyl group, and m and n are integers greater than or equal to 1.

[0051] According to an embodiment of the present application, the vulcanizing agent is a peroxide. The vulcanizing agent is mainly used to vulcanize the main polymer containing segment one. The vulcanizing agent can be selected from one or a mixture of several of 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, di-tert-butyl peroxide, and dicumyl peroxide. For the polymer containing segment two, its vulcanizing agent can be a peroxide or other types of vulcanizing agents, such as ammonia, sulfur, etc.

[0052] In some specific embodiments of the present application, the compatibilizer is one or more of a silane coupling agent, organosilicon-modified polyurethane, maleic anhydride-grafted polymer, and polysiloxane-grafted polymer. By adding a compatibilizer, the phase separation degree between segment one and segment two can be improved. Specifically, different compatibilizers can be selected according to different segment twos.

[0053] The present invention also discloses a sounding device, which includes a vibration system and a magnetic circuit system cooperating with the vibration system. The vibration system includes a diaphragm and a voice coil combined on one side of the diaphragm. The magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to emit sound. The diaphragm is the diaphragm of any of the above embodiments.

[0054] The present invention also discloses a sounding device, which includes a housing, a magnetic circuit system and a vibration system arranged in the housing. The vibration system includes a voice coil, a first diaphragm and a second diaphragm. The top of the voice coil is connected to the first diaphragm. The magnetic circuit system drives the voice coil to vibrate to drive the first diaphragm to generate sound. Both ends of the second diaphragm are respectively connected to the housing and the bottom of the voice coil, and the second diaphragm is the diaphragm of any of the above embodiments.

[0055] The diaphragm provided by the present invention can form a sounding device with any structure, such as the following typical sounding device: including a vibration system and a magnetic circuit system cooperating with the vibration system. The vibration system includes a diaphragm and a voice coil combined on one side of the diaphragm. When the sounding device works, after the voice coil is energized, under the action of the magnetic field force of the magnetic circuit system, the voice coil can vibrate up and down to drive the diaphragm to vibrate, and the diaphragm can generate sound when vibrating.

[0056] According to an embodiment of another aspect of the present invention, the sounding device may include a housing, a magnetic circuit system and a vibration system arranged in the housing. The vibration system may include a voice coil, a first diaphragm and a second diaphragm. The top of the voice coil is connected to the first diaphragm. The magnetic circuit system drives the voice coil to vibrate to drive the first diaphragm to generate sound. Both ends of the second diaphragm are respectively connected to the housing and the bottom of the voice coil. Among them, the second diaphragm may be the diaphragm in the above embodiments of the present invention.

[0057] That is to say, the first diaphragm can be used for vibrating and generating sound, and the second diaphragm can be used for balancing the vibration of the voice coil. Specifically, when the sounding device works, after the voice coil is energized, under the action of the magnetic field force of the magnetic circuit system, the voice coil can vibrate up and down to drive the first diaphragm to vibrate, and the first diaphragm can generate sound when vibrating. The second diaphragm can also vibrate up and down following the voice coil. Since both ends of the second diaphragm are respectively connected to the housing and the bottom of the voice coil, the second diaphragm can balance the vibration of the voice coil, and can prevent the voice coil from being polarized, thereby improving the sounding effect of the sounding device.

[0058] It should be noted that both the first diaphragm and the second diaphragm can adopt the diaphragm of the above embodiments of the present invention, or one of the first diaphragm and the second diaphragm can adopt the diaphragm of the above embodiments of the present invention. The present invention does not make specific restrictions on this.

[0059] Furthermore, those skilled in the art can make corresponding adjustments to the speaker vibration unit 100 according to the actual product requirements. For example, as Figure 4 shown, in a specific example of the present invention, the surround portion 11 bulges toward the voice coil side, the dome top 12 is located on the lower surface of the surround portion 11, and a centering washer is added to the vibration system. The sounding diaphragm is composed of the surround portion 11 and the dome top 12. The diaphragm prepared from the organosilicon-based polymer film layer can be located on the surround portion 11, or can be located on the surround portion 11 and the dome top 12.

[0060] The diaphragm of the sound generating device of the present invention will be specifically described below in conjunction with specific embodiments.

[0061] In the diaphragm materials of the following Examples 1 to 3 and the comparative sample, methyl vinyl phenyl silicone rubber compound is selected as the silicone rubber containing structural unit one Among them, the compatibilizer in Examples 1 to 3 is selected as silane coupling agent.

[0062] Example 1

[0063] Select methyl vinyl phenyl silicone rubber compound as the silicone rubber containing structural unit one, select polyurethane compound as the ester group-containing rubber containing structural unit two, and peroxide accounting for 1% of the total weight of raw materials is used as the vulcanizing agent. The peroxide selected is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane as the vulcanizing agent.

[0064] The steps for preparing the sound generating device, i.e., the speaker, include:

[0065] First, add 2,5-dimethyl-2,5-di-tert-butylperoxyhexane to the methyl vinyl phenyl silicone rubber compound, then add the compatibilizer, and then mix evenly on a two-roll mill.

[0066] Then, add the plasticized polyurethane compound containing structural unit two accounting for 10% of the total weight of raw materials to obtain a silicone-based polymer. The mechanical loss peak of the obtained silicone-based polymer is at -33°C. By selecting the plasticized polyurethane compound, sticking to the roll during the mixing of the two can be prevented.

[0067] Subsequently, mix evenly on a two-roll mill to produce the diaphragm material.

[0068] Finally, the obtained diaphragm material is processed at 180°C for 200 s using a compression molding process to form the diaphragm and assemble it into the speaker.

[0069] Example 2

[0070] Select methyl vinyl phenyl silicone rubber compound as the silicone rubber containing structural unit one, select polyurethane compound as the ester group-containing rubber containing structural unit two, and peroxide accounting for 1% of the total weight of raw materials is used as the vulcanizing agent. The peroxide selected is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane.

[0071] The steps for preparing the sound generating device, i.e., the speaker, include:

[0072] First, add 2,5-dimethyl-2,5-di-tert-butylperoxyhexane to the methyl vinyl phenyl silicone rubber compound, then add the compatibilizer, and then mix evenly on a two-roll mill.

[0073] Then, add the plasticated polyurethane compound containing structural unit two, which accounts for 30% of the total weight of the raw materials, to obtain a silicone-based polymer. By selecting the plasticated polyurethane compound, sticking of the rollers during mixing can be prevented. Subsequently, mix evenly on a two-roll mill to produce the diaphragm material.

[0074] Subsequently, mix evenly on a two-roll mill to produce the diaphragm material.

[0075] Finally, the obtained diaphragm material is processed at 180 °C for 200 s using a compression molding process to form the diaphragm and assemble it into a speaker.

[0076] Example 3

[0077] Select methyl vinyl phenyl silicone rubber compound as the silicone rubber containing structural unit one, select ethylene acrylate compound as the ester group-containing rubber containing structural unit two, and use a peroxide accounting for 1% of the total weight of the raw materials as the vulcanizing agent. The peroxide selected is 2,5-dimethyl-2,5-di-tert-butylperoxyhexane.

[0078] The steps for preparing the sound generating device, i.e., the speaker, include:

[0079] First, add 2,5-dimethyl-2,5-di-tert-butylperoxyhexane to the methyl vinyl phenyl silicone rubber compound, then add the compatibilizer, and subsequently mix evenly on a two-roll mill.

[0080] Then, add the plasticated ethylene acrylate compound containing structural unit two, which accounts for 30% of the total weight of the raw materials, to obtain a silicone-based polymer. The mechanical loss peak of the obtained silicone-based polymer is at -29 °C. By selecting the plasticated ethylene acrylate compound, sticking of the rollers during mixing can be prevented. Subsequently, mix evenly on a two-roll mill to produce the diaphragm material.

[0081] Subsequently, mix evenly on a two-roll mill to produce the diaphragm material.

[0082] Finally, the obtained diaphragm material is processed at 180 °C for 200 s using a compression molding process to form the diaphragm and assemble it into a speaker.

[0083] Comparative Example

[0084] Select the same methyl vinyl phenyl silicone rubber compound containing structural unit one as in the example, add 2,5-dimethyl-2,5-di-tert-butylperoxyhexane accounting for 1% of the total weight of the raw materials as the vulcanizing agent and mix evenly to produce the diaphragm material. Finally, use a compression molding process to process at 180 °C for 200 s to form the diaphragm and assemble it into a speaker.

[0085] Table 1 Performance comparison of diaphragm raw materials used in the examples and the comparative example

[0086]

[0087] First, the comparative example will be compared with Example 1. In both the comparative example and Example 1, methyl vinyl phenyl silicone rubber is used as the rubber compound containing structural unit one, and polyurethane rubber compound is further added in Example 1 as the rubber compound containing structural unit two. From the test results in Table 1, it can be seen that the modulus of the comparative example is 17 MPa, and that of the sample in Example 1 is 16 MPa. That is to say, even though the rubber containing structural unit two is added in Example 1, the change in the overall modulus of the rubber compound is not significant. Under the condition of a temperature of -30°C, the loss factor of the comparative example is 0.17, and that of Example 1 is 0.27. Under the condition of a temperature of 23°C, the loss factor of the comparative example is 0.16, and that of Example 1 is 0.17. It can be seen that adding the rubber containing structural unit two in Example 1 can improve the loss factors at low and high temperatures. In addition, the adhesive force of the glue in the comparative example is 120 g / 25 mm, and that of Example 1 is 280 g / 25 mm. It can be seen that due to the addition of structural unit two in Example 1, the adhesive force between the diaphragm product and the glue in Example 1 increases significantly.

[0088] Secondly, the comparative example will be compared with Example 3. In both the comparative example and Example 3, methyl vinyl phenyl silicone rubber is used as the rubber compound containing structural unit one, and ethylene acrylate rubber is further used in Example 3 as the rubber compound containing structural unit two. From the test results in Table 1, it can be seen that the modulus of the comparative example is 17 MPa, and that of the sample in Example 3 is 14 MPa. That is to say, even though the rubber containing structural unit two is added in Example 3, the change in the overall modulus of the rubber compound is not significant. Under the condition of a temperature of -30°C, the loss factor of the comparative example is 0.17, and that of Example 3 is 0.38. Under the condition of a temperature of 23°C, the loss factor of the comparative example is 0.16, and that of Example 3 is 0.2. It can be seen that adding the rubber containing structural unit two in Example 3 can improve the loss factors at low and normal temperatures. In addition, the adhesive force of the glue in the comparative example is 120 g / 25 mm, and that of Example 3 is 507 g / 25 mm. It can be seen that due to the addition of structural unit two in Example 3, the adhesive force between the product in Example 3 and the glue increases significantly.

[0089] Thus, it can be seen that whether polyurethane rubber or ethylene acrylate rubber is used as the raw material containing structural unit two, the change in the overall modulus of the rubber compound is not significant, the loss factors at low and normal temperatures are both improved, and the adhesive force between the obtained diaphragm and the glue increases significantly.

[0090] Next, Example 1 and Example 2 were compared. In Example 1, 10% polyurethane rubber was used as the rubber compound containing structural unit two, and in Example 2, 30% polyurethane rubber was used as the rubber compound containing structural unit two. From the test results, it can be seen that the adhesive strength of the glue in Example 1 was 280 g / 25 mm, while that in Example 3 was 537 g / 25 mm. Thus, it can be seen that the more the content of structural unit two added, the more ester groups, the active groups, in the diaphragm, and the greater the adhesive strength between the diaphragm and the glue, effectively improving the problem of weak adhesion of silicone-based polymers.

[0091] Next, Example 1 to Example 3 and the comparative example were subjected to dynamic thermomechanical analysis (DMA) tests, and the test results are as Figure 1 and Figure 2 shown.

[0092] It can be Figure 1 seen that for the silicone-based polymer in Example 2 subjected to dynamic thermomechanical analysis (DMA) test, as Figure 1 shown, the obtained silicone-based polymer contains two mechanical loss peaks, and one of the mechanical loss peaks has a peak temperature of about -33°C and a peak height of about 0.5.

[0093] It can be Figure 2 seen that compared with the comparative example without adding structural unit two, adding polyurethane rubber containing structural unit two in Example 1 and Example 2, the overall mechanical loss factor of the rubber compounds in Example 1 to Example 3 has a significant increase, especially the improvement effect is more obvious at temperatures below 0°C, and the improvement effect is more significant with the increase of the proportion of added structural unit two. After adding ethylene acrylate rubber containing structural unit two in Example 3, the overall mechanical loss factor of the rubber also has a significant increase, which helps to reduce the distortion performance of the product.

[0094] Next, the THD curves of the sound-producing devices assembled from the comparative example, Example 2, and Example 3 were tested and compared. That is to say, the performances of the assembled products of the comparative example, Example 2, and Example 3 were tested. It can be Figure 3 seen that the distortion effects of the products in Example 2 and Example 3 are significantly improved.

[0095] All in all, according to the diaphragm of the sound-producing device in the embodiments of the present application, by using a silicone-based polymer film layer containing two or more mechanical loss peaks, at least one of the mechanical loss peaks has a peak temperature between -50°C and 20°C, and the peak height of the mechanical loss peak in this temperature range is greater than 0.13. Using this silicone-based polymer film layer can effectively improve the damping of the diaphragm material in a wide temperature range, and increase the surface active groups, thereby improving the adhesion of the diaphragm material.

[0096] Although some specific embodiments of the present application have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration purposes and not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. The diaphragm of a sound generating device, characterized in that, The diaphragm includes a silicone-based polymer film layer, the silicone-based polymer film layer includes two or more mechanical loss peaks, the temperature of the peak value of at least one mechanical loss peak is between -50°C and 20°C, and the peak height of the mechanical loss peak is greater than 0.13; The silicone-based polymer is composed of structural unit one and structural unit two; Among them, the structural unit 1 is , the structural unit 2 is and at least one of them. R, R1, and R2 in the structural unit 1 are any one selected from methyl, vinyl, phenyl, and trifluoropropyl. R3 in the structural unit 2 is a hydrogen group or a methyl group. m and n are integers greater than or equal to 1; In the silicone-based polymer, the mass percentage of the structural unit two is 2% to 50%.

2. The diaphragm of the sound generating device according to claim 1, characterized in that, The adhesion force of the diaphragm in the peeling test with a standard tape at a peeling angle of 180° is 100 g / 25 mm to 1000 g / 25 mm.

3. The diaphragm of the sound generating device according to claim 1, wherein, The Young's modulus of the diaphragm is 1 MPa to 50 MPa.

4. The diaphragm of the sound generating device according to claim 1, characterized in that The thickness of the diaphragm is 50 μm to 300 μm.

5. A method for preparing a diaphragm of a sound generating device according to any one of claims 1-4, characterized in that, It includes the following steps: Mix silicone rubber with ester group-containing rubber, add a vulcanizing agent, a compatibilizer, and an auxiliary agent to obtain a mixed material; Crosslink and mold the mixed material at a high temperature to obtain a silicone-based polymer film layer.

6. The method for preparing the diaphragm of the sound generating device according to claim 5, characterized in that, The ester group-containing rubber is at least one of polyurethane rubber, acrylate rubber, and ethylene acrylate.

7. The method for preparing the diaphragm of the sound generating device according to claim 5, wherein The vulcanizing agent is a peroxide.

8. The preparation method of the diaphragm of the sound generating device according to claim 5, characterized in that, The compatibilizer is one or more of a silane coupling agent, silicone-modified polyurethane, maleic anhydride grafted polymer, and polysiloxane grafted polymer.

9. A sound generating device, characterized in that, It includes a vibration system and a magnetic circuit system that cooperates with the vibration system. The vibration system includes a diaphragm and a voice coil bonded to one side of the diaphragm. The magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to generate sound. The diaphragm is the diaphragm according to any one of claims 1-4.

10. A sound generating device, characterized in that, It includes a housing and a magnetic circuit system and a vibration system provided in the housing. The vibration system includes a voice coil, a first diaphragm, and a second diaphragm. The top of the voice coil is connected to the first diaphragm. The magnetic circuit system drives the voice coil to vibrate to drive the first diaphragm to generate sound. Both ends of the second diaphragm are connected to the housing and the bottom of the voice coil respectively. The second diaphragm is the diaphragm according to any one of claims 1-4.

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