Diaphragm of sound-generating device and sound-generating device

Abstract

The present application discloses a diaphragm of a sound-generating device and a sound-generating device. The diaphragm includes at least one modified acrylic rubber membrane layer, which is prepared by mixing inorganic hollow microspheres, additives, and acrylic polymer to form a mixed rubber and then subjecting it to a cross-linking reaction. The particle size of the inorganic hollow microspheres is 1 μm to 60 μm, and the distribution density of the inorganic hollow microspheres in the modified acrylic rubber membrane layer is 0.15 g / cm 3 ~0.9g / cm 3 After the modified acrylic rubber membrane layer is immersed in an oily solvent at 150°C for 70 hours, the fracture strength decrease ratio of the modified acrylic rubber membrane layer is ≤30%, and the swelling ratio is ≤20%. The diaphragm of the present application is prepared by cross-linking a modified acrylic rubber membrane layer prepared by mixing inorganic hollow microspheres, additives, and acrylic polymer to form a rubber compound. This not only reduces the density of the diaphragm material and improves the mid-frequency sensitivity of the sound-generating device, but also makes the diaphragm material have excellent resistance to solvent swelling.

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 and a sound-generating device using the diaphragm. Background Art

[0002] Speakers are currently widely used in electronic products. Speakers consist of a vibration system and a magnetic circuit system. The vibration system consists of a bonded diaphragm and voice coil. As people's demands for sound quality and perception grow, rubber diaphragms are becoming increasingly popular. However, due to the high density of rubber, the diaphragm's mass increases, resulting in low mid-frequency sensitivity and reduced acoustic performance.

[0003] In addition, electronic products with sound-generating devices, such as mobile phones and bracelets, will inevitably come into contact with the skin during use. Cosmetics, sunscreen, and secreted oils applied on the skin surface will penetrate into the interior of the electronic products, causing the diaphragm to swell, affecting the performance and life of the product and reducing the user experience.

[0004] Therefore, a new technical solution is needed to solve the above problems. Summary of the Invention

[0005] One object of the present application is to provide a diaphragm for a sound-generating device.

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

[0007] In order to achieve the above objectives, this application provides the following technical solutions.

[0008] According to the diaphragm of the sound-emitting device of the first embodiment of the present application, the diaphragm includes at least one modified acrylate rubber membrane layer, which is prepared by mixing inorganic hollow microspheres, additives and acrylate polymer to form a mixed rubber and then undergoing a cross-linking reaction; wherein the particle size of the inorganic hollow microspheres is 1 μm to 60 μm, and the distribution density of the inorganic hollow microspheres in the modified acrylate rubber membrane layer is 0.15 g / cm 3 ~0.9g / cm 3 After the modified acrylate rubber film layer is immersed in an oily solvent at 150° C. for 70 hours, the fracture strength decrease ratio of the modified acrylate rubber film layer is ≤30%, and the swelling ratio is ≤20%.

[0009] According to some embodiments of the present application, the compressive strength of the inorganic hollow microspheres is ≥10 MPa.

[0010] According to some embodiments of the present application, the content of the inorganic hollow microspheres accounts for 5 wt % to 50 wt % of the total amount of the rubber mix.

[0011] According to some embodiments of the present application, the modified acrylate rubber film layer is aged in hot air at 140° C. for 168 hours, and the tensile strength decrease ratio of the modified acrylate rubber film layer is ≤45%, and the elongation at break decrease ratio is ≤60%.

[0012] According to some embodiments of the present application, the surface contact angle between the modified acrylate rubber film layer and water is ≥80°.

[0013] According to some embodiments of the present application, the loss factor of the modified acrylate rubber film layer at room temperature is greater than 0.12.

[0014] According to some embodiments of the present application, the glass transition temperature of the modified acrylate rubber film layer is ≤-10°C.

[0015] According to some embodiments of the present application, the density of the modified acrylate rubber film layer is 0.6 g / cm 3 ~1.1g / cm 3 .

[0016] According to some embodiments of the present application, the additives include a cross-linking agent, a reinforcing agent and an antioxidant, wherein the cross-linking agent is at least one of sulfur, carboxylic acid ammonium salts, organic peroxides and amine vulcanization systems; the reinforcing agent is at least one of carbon black, white carbon black, graphene oxide, montmorillonite, talc, clay, mica powder, feldspar powder, sodium alginate, magnetic powder and diatomaceous earth; the antioxidant is at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD and antioxidant WH-02.

[0017] According to some embodiments of the present application, the content of the cross-linking agent accounts for 1wt% to 5.5wt% of the rubber mix, the content of the reinforcing agent accounts for 5.5wt% to 70.5wt% of the rubber mix, and the content of the antioxidant accounts for 0.6wt% to 6.5wt% of the rubber mix.

[0018] According to some embodiments of the present application, the diaphragm is a single-layer structure, and the diaphragm is composed of a layer of the modified acrylic rubber membrane.

[0019] According to some embodiments of the present application, the diaphragm is a composite layer structure, and the diaphragm further includes a membrane layer made of at least one of a thermoplastic elastomer, an engineering plastic, and a thermosetting elastomer.

[0020] According to the second aspect of the embodiment of the present application, the sound-producing device includes a vibration system and a magnetic circuit system coordinated with the vibration system, the vibration system includes a diaphragm and a voice coil coupled to one side of the diaphragm, the magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to produce sound, and the diaphragm is the diaphragm according to the above-mentioned embodiment of the present application.

[0021] According to the third aspect of the present application, the sound-producing device includes a shell and a magnetic circuit system and a vibration system arranged in the shell. 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 produce sound. The two ends of the second diaphragm are respectively connected to the shell and the bottom of the voice coil. The second diaphragm is the diaphragm according to the above-mentioned embodiment of the present application.

[0022] According to the diaphragm of the sound-emitting device in the embodiment of the present application, a modified acrylic rubber membrane layer is prepared by cross-linking reaction after mixing inorganic hollow microspheres, additives and acrylic polymer to form a mixed rubber. This not only reduces the density of the diaphragm material and improves the mid-frequency sensitivity of the sound-emitting device, but also makes the diaphragm material have excellent aging resistance and solvent swelling resistance, effectively improving the service life of the diaphragm.

[0023] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0025] Figure 1 1 is a test curve of vibration displacement of different parts of the diaphragm of the sound-generating device at different frequencies according to an embodiment of the present application;

[0026] Figure 2 is a graph showing changes in the fracture strain and elastic modulus of the diaphragm of the sound-generating device according to an embodiment of the present application as a function of the mass proportion of the inorganic hollow microspheres;

[0027] Figure 3 : is a mid-frequency Fr curve of the modified acrylic rubber membrane layer with different densities of the diaphragm of the sound-generating device according to an embodiment of the present application;

[0028] Figure 4 Schematic diagram of the overall structure of the sound-generating device according to an embodiment of the present application;

[0029] Figure 5 is a schematic diagram of a partial structure of a sound-generating device according to an embodiment of the present application;

[0030] Figure 6 is a cross-sectional view of a sound-generating device according to an embodiment of the present application;

[0031] Figure 7 1 is an exploded view of a sound-generating device according to an embodiment of the present application.

[0032] Reference numerals

[0033] Sound-generating device 100;

[0034] Housing 10; voice coil 11; first diaphragm 12; second diaphragm 13; magnetic circuit system 14;

[0035] Diaphragm 15 ; surround 151 ; dome 152 . DETAILED DESCRIPTION

[0036] 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.

[0037] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0038] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0039] 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.

[0040] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0041] The diaphragm of the sound-emitting device according to the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0042] According to the diaphragm of the sound-generating device of the embodiment of the present application, the diaphragm includes at least one modified acrylate rubber membrane layer, which is prepared by mixing inorganic hollow microspheres, additives, and acrylate polymer to form a mixed rubber and then cross-linking the mixed rubber. The particle size of the inorganic hollow microspheres is 1 μm to 60 μm, and the distribution density of the inorganic hollow microspheres in the modified acrylate rubber membrane layer is 0.15 g / cm 3 ~0.9g / cm 3After the modified acrylate rubber film layer is immersed in an oily solvent at 150°C for 70 hours, the fracture strength decrease ratio of the modified acrylate rubber film layer is ≤30%, and the swelling ratio is ≤20%.

[0043] The diaphragm of the sound-emitting device according to the embodiment of the present application can be composed of at least one modified acrylic rubber membrane layer. Specifically, the diaphragm in the present application can be a single-layer structure or a multi-layer composite structure. When the diaphragm is a single-layer structure, the diaphragm is made of a layer of modified acrylic rubber membrane layer of the present application. When the diaphragm is a multi-layer composite structure, the diaphragm includes at least one modified acrylic rubber membrane layer, and the diaphragm is composed of a modified acrylic rubber membrane layer and a membrane layer of other materials. Optionally, when the diaphragm contains multiple layers of modified acrylic rubber membrane layers, the two adjacent modified acrylic rubber membrane layers can be spaced apart, that is, a membrane layer of other materials can also be set between the two adjacent modified acrylic rubber membrane layers. Of course, the two adjacent modified acrylic rubber membrane layers can also be set in close contact with each other. The setting can be selected according to actual usage requirements, and the present application does not impose specific restrictions on this.

[0044] Specifically, the molecular structural formula of the acrylate polymer may be at least one of the following molecular structural formulas (I) and (II).

[0045] Formula (I)

[0046] In formula (I), m and n are natural numbers; R is an alkyl group; and X is a sulfurization active point epoxy group, active chlorine group, or carboxyl group.

[0047] Formula (II)

[0048] In formula (II), m and n are natural numbers; R and R' are alkyl groups.

[0049] The modified acrylate rubber membrane layer is made by adding inorganic hollow microspheres to an acrylate polymer. The inorganic hollow microspheres, additives, and acrylate polymer are kneaded to form a rubber mix, which, after vulcanization, forms the modified acrylate rubber membrane layer. In other words, the acrylate polymer forms acrylate rubber, which acts as a base material. After kneading the inorganic hollow microspheres and acrylate polymer, the inorganic hollow microspheres are evenly dispersed within the base material. By adding the inorganic hollow microspheres to the rubber, the density of the diaphragm material can be reduced, resulting in a low-density diaphragm material.

[0050] Under the condition that the acrylic rubber diaphragm material with the addition of inorganic hollow microspheres has the same hardness as conventional acrylic rubber diaphragm materials, the diaphragm of the present application has a lower diaphragm density, which can reduce the vibration quality of the vibration system. The mid-frequency region of the frequency response of a sound-generating device is the region where the vibration quality of the vibration system is controlled. The lower the vibration quality, the higher the mid-frequency sensitivity. By adding inorganic hollow microspheres to the acrylic polymer, the present application can effectively reduce the vibration quality of the vibration system.

[0051] Therefore, the mid-frequency sensitivity of a sound-generating device using the diaphragm of the present application is significantly improved compared to the mid-frequency sensitivity of a sound-generating device using a conventional acrylic rubber diaphragm material. In other words, the diaphragm of the sound-generating device of the present application can improve the mid-frequency response of the sound-generating device, thereby providing the sound-generating device with higher mid-frequency sensitivity.

[0052] It's important to note that frequency response (Fr) is used in electronics to describe the differences in an instrument's ability to process signals of varying frequencies. Like distortion, Fr is a very important parameter. Frequency response, also known as the gain curve, is the curve showing how gain changes with frequency. Any audio device or carrier (the object that records sound signals) has a frequency response curve.

[0053] Inorganic hollow microspheres are hollow, thin-walled, hard, and lightweight spheres with a high strength-to-density ratio. The addition of inorganic hollow microspheres to the diaphragm of the sound-generating device in this application effectively reduces the density and weight of the rubber, thereby reducing the overall weight of the diaphragm, lowering the vibration mass of the vibration system, and improving the sensitivity of the sound-generating device.

[0054] Inorganic hollow microspheres can be hollow glass microspheres, hollow ceramic microspheres, and the like. Hollow glass microspheres are composed of inorganic materials such as silicon dioxide, aluminum oxide, zirconium oxide, magnesium oxide, and sodium silicate, along with an enclosed gas. The main component of the hollow glass microsphere shell is borosilicate, which has the characteristics of high rigidity, good chemical stability, and a high melting point. When filled into rubber, it can effectively prevent rubber aging caused by light and heat, thereby improving the temperature resistance of the rubber material. Furthermore, hollow glass microspheres are excellent thermal insulation materials that can effectively block external heat and effectively slow down the damage to the internal network structure of the rubber caused by external heat.

[0055] In other words, adding inorganic hollow microspheres to ACM (acrylic ester) rubber forms a dense oxide layer on the rubber surface, hindering the penetration of oxygen molecules and effectively improving the ACM rubber's aging and temperature resistance. This means that low-density rubber diaphragm products containing inorganic hollow microspheres can maintain excellent acoustic performance even in harsh, high-temperature environments. Furthermore, the high compressive strength of the inorganic hollow microspheres prevents them from being crushed during the mixing process.

[0056] Furthermore, the particle size of the inorganic hollow microspheres can be selected within the range of 1 μm to 60 μm, preferably 5 μm to 30 μm. For example, the particle size of the inorganic hollow microspheres can be 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, or 60 μm. Inorganic hollow microspheres of different particle sizes can be selected according to the thickness of the diaphragm to ensure that the inorganic hollow microspheres are evenly dispersed in the substrate.

[0057] In addition, as the size of the inorganic hollow microspheres decreases, the distribution density of the inorganic hollow microspheres in the modified acrylic rubber film layer will increase. By selecting the appropriate size of the inorganic hollow microspheres, the distribution density of the inorganic hollow microspheres in the modified acrylic rubber film layer can be controlled at 0.15 g / cm 3 ~0.9g / cm 3 For example, the distribution density of inorganic hollow microspheres can be 0.15 g / cm 3 , 0.2g / cm 3 , 0.35g / cm 3 , 0.5g / cm 3 , 0.6g / cm 3 , 0.7g / cm 3 , 0.8g / cm 3 or 0.9g / cm 3 To ensure that the inorganic hollow microspheres can effectively reduce the density of the diaphragm, the distribution density of the inorganic hollow microspheres is preferably 0.35 g / cm 3 ~0.8g / cm 3 .

[0058] It should be noted that when small organic molecule solvents enter the rubber network, they increase the distance between the rubber molecular segments and weaken the entanglement between the rubber molecular chains, resulting in the volume expansion of the rubber material. Diaphragms made of ordinary rubber have poor solvent resistance, which is not conducive to maintaining the consistency of the mechanical properties of the diaphragm product. Because inorganic hollow microspheres are inorganic materials with high rigidity, they have excellent solvent resistance. Moreover, when inorganic hollow microspheres are added to ACM, the molecular chains of ACM and the inorganic hollow microspheres can form an entangled structure, which effectively reduces the free volume of the molecules and hinders the penetration of solvents. Therefore, the modified acrylic rubber film layer has excellent resistance to solvent swelling.

[0059] In other words, by introducing low-density inorganic hollow microspheres into acrylic rubber, the solvent swelling properties of the rubber diaphragm can be significantly improved. The inorganic hollow microspheres are a rigid inorganic material that effectively blocks solvent penetration into the rubber diaphragm, significantly enhancing the rubber diaphragm's solvent resistance. A diaphragm made with the modified acrylic rubber membrane layer of this application can ensure that a sound-generating device maintains stable acoustic performance even under harsh environmental conditions.

[0060] Specifically, after immersing the modified acrylate rubber film layer in IRM903# oil at 150°C for 70 hours, the fracture strength reduction ratio of the modified acrylate rubber film layer was ≤30%, and the swelling ratio was ≤20%. Table 1 shows the test results of the solvent resistance of modified acrylate rubber film layers with different contents of inorganic hollow microspheres. The inorganic hollow microspheres here are hollow glass microspheres. It should be noted that hollow glass microspheres are a type of inorganic hollow microspheres. The use of hollow glass microspheres or other inorganic hollow microspheres can equally reflect the role played by inorganic hollow microspheres in the material.

[0061] Test indicators: breaking strength, volume swelling ratio

[0062] Test method: Tested in accordance with GB / T 1690-2006, the test temperature is 150℃, the immersion time is 70h, and the test liquid is IRM903# oil.

[0063] The influence of the content of inorganic hollow microspheres in the diaphragm material on the solvent resistance of the diaphragm material is as follows:

[0064] Table 1

[0065]

[0066] As shown in Table 1, the fracture strength of the ACM rubber with zero hollow glass microspheres decreased by 35%, exceeding 30%, and the rubber volume swelling ratio was 25%, exceeding 20%. With increasing hollow glass microsphere addition, the fracture strength reduction and volume swelling ratio of the modified acrylic rubber film decreased significantly. This indicates that the addition of inorganic hollow microspheres effectively reduced the destructive effects of solvents on the rubber's internal network structure, thereby improving the solvent resistance of the modified acrylic rubber film.

[0067] In other words, by adding a certain amount of inorganic hollow microspheres to ACM rubber as the diaphragm material, the diaphragm material's resistance to solvent swelling can be effectively improved. This means that the modified acrylic rubber membrane layer exhibits superior solvent resistance compared to conventional acrylic rubber membrane layers, ensuring consistent mechanical properties of the diaphragm product. Sound-generating devices using this diaphragm can maintain stable acoustic performance even in harsher solvent environments.

[0068] It should be noted that the conventional acrylic rubber film layer is a film layer made of acrylic rubber without adding inorganic hollow microbeads.

[0069] Therefore, the diaphragm of the sound-emitting device according to the embodiment of the present application uses a modified acrylic rubber membrane layer as the diaphragm material, which is prepared by mixing inorganic hollow microspheres, additives and acrylic polymers to form a mixed rubber and then performing a cross-linking reaction. This not only reduces the density of the diaphragm material and improves the mid-frequency response of the sound-emitting device, but also makes the diaphragm material have excellent aging resistance and solvent swelling resistance, effectively improving the service life of the diaphragm and the acoustic stability of the sound-emitting device.

[0070] According to one embodiment of the present application, the compressive strength of the inorganic hollow microspheres is ≥10 MPa.

[0071] In other words, the high compressive strength of inorganic hollow microspheres not only prevents them from being crushed during the mixing process, but also effectively increases the tensile strength of the modified acrylic rubber membrane when added to the ACM rubber. The diaphragm's high mechanical strength prevents it from overstretching due to excessive driving forces in extreme environments, further ensuring its performance.

[0072] In some specific embodiments of the present application, the content of the inorganic hollow microspheres accounts for 5 wt % to 50 wt % of the total rubber mix.

[0073] In other words, a modified acrylic rubber membrane layer can be prepared by adding inorganic hollow microspheres accounting for 5wt% to 50wt% of the total amount of the mixed rubber to the acrylic polymer. As the amount of inorganic hollow microspheres added increases, the density of the modified acrylic rubber membrane layer decreases. By controlling the amount of inorganic hollow microspheres added, a diaphragm material with the desired performance can be obtained. The content of inorganic hollow microspheres can be any value between 5wt% and 50wt%, preferably, it can be 10wt% to 40wt%. For example, the content of inorganic hollow microspheres can be 5wt%, 10wt%, 15wt%, 20wt%, 30wt%, 40wt% or 50wt%.

[0074] It should be noted that because the density of inorganic hollow microspheres is much lower than that of rubber, the density of the rubber material will decrease significantly as the amount of inorganic hollow microspheres added increases. Specifically, when the inorganic hollow microsphere content is low (less than 5wt%), the density of the diaphragm material is not significantly affected, and the diaphragm still has a relatively high density.

[0075] When the inorganic hollow microsphere content is too high (greater than 50wt%), the inorganic hollow microspheres contribute too much to the mass, reducing the rubber content, increasing the material modulus, and decreasing the fracture strain, causing the modified acrylic rubber membrane layer to lose its inherent soft elasticity. Due to its excessive mechanical strength, the maximum amplitude achievable by the prepared diaphragm under the same driving force is reduced, resulting in a lower low-frequency Fr of the sound-generating device. Furthermore, excessive addition of inorganic hollow microspheres significantly reduces the density of the modified acrylic rubber membrane layer, resulting in lower elongation at break and strength, making the diaphragm more susceptible to reliability issues such as collapse and rupture.

[0076] Therefore, by using a modified acrylic rubber membrane layer prepared by adding 5wt% to 50wt% of inorganic hollow microbeads to the total rubber mix as the diaphragm material, the density and strength of the diaphragm can be achieved at the same time, effectively ensuring the excellent mid-frequency and low-frequency performance of the diaphragm.

[0077] According to one embodiment of the present application, the modified acrylate rubber film layer is aged in hot air at 140° C. for 168 hours, and the tensile strength decrease ratio of the modified acrylate rubber film layer is ≤45%, and the elongation at break decrease ratio is ≤60%.

[0078] Specifically, the main component of the shell of inorganic hollow microspheres is borosilicate, which has the characteristics of high rigidity, good chemical stability and high melting point. After being filled into rubber, it can effectively prevent rubber aging caused by light and heat, thereby improving the temperature resistance of the rubber material. In addition, inorganic hollow microspheres are very excellent thermal insulation materials that can effectively block external heat and effectively slow down the damage of external heat to the internal network structure of the rubber. Adding it to ACM rubber can hinder the penetration of oxygen molecules and effectively improve the aging resistance of ACM rubber. Table 2 shows the reduction ratio of breaking strength and elongation at break of ACM rubber with different contents of inorganic hollow microspheres under the condition of aging for 168 hours in hot air at 140°C.

[0079] The influence of the content of inorganic hollow microspheres in the diaphragm material on the aging resistance of the diaphragm is as follows:

[0080] Test indicators: tensile strength after aging, elongation at break

[0081] The test method is to determine the tensile strength and elongation at break according to ASTM D412-2016. The specimen shape is dumbbell-shaped, the tensile rate is 500 mm / min, and each group of samples is tested 5 times to obtain the average value.

[0082] Table 2

[0083]

[0084] As shown in Table 2, when the hollow glass microsphere content is zero, the percentage decrease in tensile strength and elongation at break after aging of the diaphragm material is greater than the percentage decrease in tensile strength and elongation at break after aging of the diaphragm material containing a certain content of hollow glass microspheres. As the addition of inorganic hollow microspheres increases, the percentage decrease in tensile strength and elongation at break after aging of the diaphragm material gradually decreases, and the diaphragm material's anti-aging properties are improved. Therefore, low-density rubber diaphragm products containing inorganic hollow microspheres can maintain excellent acoustic performance even when used in harsh, high-temperature environments.

[0085] According to one embodiment of the present application, the surface contact angle between the modified acrylate rubber film layer and water is ≥80°.

[0086] It should be noted that the rubber film phenomenon is caused by the precipitation of small molecule compounding agents inside the rubber. During the high-temperature molding process of the rubber material diaphragm, the small molecule compounding agents inside the rubber migrate to the surface and adhere to the mold. Multiple molding will cause the accumulation of small molecule compounding agents on the mold to increase. On the one hand, it causes corrosion of the mold. On the other hand, the surface of the rubber diaphragm product forms a physical bond with the small molecule compounding agents accumulated on the mold. The combined effect of these two aspects causes severe rubber film. Rubber film is an unavoidable problem in the rubber processing process. Rubber film has a very large impact on the molding state of the diaphragm product. The film will cause poor dimensional stability of the rubber and cause corrosion to the mold. Severe film will cause extremely thin diaphragms to have reliability problems such as pulling deformation, film breakage and dimensional instability, resulting in poor molding of the diaphragm product.

[0087] Because mucosal properties are related to surface polar groups, the degree of mucosal properties of a diaphragm can be characterized by measuring the surface contact angle. The smaller the surface contact angle, the higher the mucosal properties of the diaphragm. To evaluate the mucosal properties of the modified acrylic rubber membrane layer, the applicant conducted surface contact angle tests on the surfaces of diaphragm materials produced under the same molding conditions and containing varying amounts of inorganic hollow microbeads.

[0088] It should also be noted that if the surface contact angle between a substance and water is less than 90°, it means that the surface of the substance is hydrophilic, that is, liquid can easily wet the substance, and the smaller the angle, the better the wettability; if the surface contact angle between a substance and water is greater than 90°, it means that the surface of the substance is hydrophobic, that is, liquid cannot easily wet the substance and can easily move on the surface.

[0089] Table 3 shows the surface contact angles of the diaphragm materials formed by adding different contents of inorganic hollow microspheres to the ACM rubber.

[0090] The effect of the content of inorganic hollow microspheres in the diaphragm material on the mucosal properties of the diaphragm is as follows:

[0091] The test method is: measuring the contact angle of rubber diaphragms with different hollow glass microbead contents and the corresponding mold surface after 30 molding cycles; testing is carried out according to the GGS1616 water drop angle standard, and ten points are measured for each sample to obtain the average value.

[0092] It should be noted that ACM conventional rubber + xwt% hollow glass microspheres refers to ACM conventional rubber with xwt% hollow glass microspheres added, that is, modified acrylic rubber film layers with different hollow glass microsphere contents, where x is 10, 30, or 40.

[0093] Table 3

[0094]

[0095] As shown in Table 3, the surface contact angle of the ACM rubber without hollow glass microspheres is 70°, less than 90°, indicating high mucosal properties. As the amount of hollow glass microspheres added to the ACM rubber increases, the surface contact angle of the rubber diaphragm product significantly increases, indicating that the mucosal properties of the modified acrylic rubber film have been significantly improved.

[0096] Specifically, low-density inorganic hollow microspheres are smooth, rigid inorganic fillers. When added to rubber, they can reduce the rubber's inherent adhesiveness while also effectively mitigating the surface migration of small molecule compounds within the rubber, thereby improving the rubber's sticking properties. This ensures the quality of the diaphragm's molding.

[0097] According to one embodiment of the present application, the tensile strength of the modified acrylate rubber film layer is 3 MPa to 35 MPa.

[0098] In some specific embodiments of the present application, the tear strength of the modified acrylic rubber film layer is 15 N / mm to 85 N / mm.

[0099] That is to say, the low-density rubber diaphragm material formed by adding inorganic hollow microbeads to the acrylate polymer can have a tensile strength that is controlled within the range of 3MPa to 35MPa, and a tear strength that is controlled within the range of 15N / mm to 85N / mm. For example, the tensile strength of the modified acrylate rubber membrane layer can be 3MPa, 6MPa, 10MPa, 16MPa, 20MPa, 25MPa, 30MPa or 35MPa. The tear strength of the modified acrylate rubber membrane layer can be 15N / mm, 30N / mm, 45N / mm, 50N / mm, 70N / mm, 80N / mm or 85N / mm. That is, the modified acrylate rubber membrane layer can have suitable mechanical properties, and the diaphragm prepared therefrom is not prone to problems such as membrane breakage during the use of the sound-generating device, effectively ensuring the reliability of the diaphragm.

[0100] According to one embodiment of the present application, the room temperature storage modulus of the modified acrylic rubber membrane layer is 0.5 MPa to 35 MPa. By adding inorganic hollow microspheres to an acrylic polymer to form a low-density rubber diaphragm material, the room temperature storage modulus of the modified acrylic rubber membrane layer can be within the range of 0.5 MPa to 35 MPa, ensuring good resilience of the diaphragm.

[0101] In other words, the diaphragm made with this modified acrylic rubber membrane layer has excellent damping performance and resilience, effectively suppressing polarization during the vibration and sound generation process, and achieving greater consistency in the vibration system. The vibration consistency of each part of the diaphragm of this application is improved, effectively reducing distortion in the sound-generating device.

[0102] In some specific embodiments of the present application, the hardness of the modified acrylic rubber film layer is 35A to 80A.

[0103] It should be noted that the sound-producing device can be a loudspeaker. The loudspeaker includes a vibration system and a magnetic circuit system that cooperates with the vibration system. The vibration system includes the diaphragm provided in this application, which can be a ring-shaped diaphragm or a flat diaphragm. Loudspeakers using the diaphragm provided in this application have advantages such as good sound quality and durability.

[0104] In some specific embodiments of the present application, when the hardness of the diaphragm material is controlled within the range of 35A to 80A and the room temperature storage modulus is within the range of 0.5MPa to 35MPa, the F0 of the speaker can reach 500Hz to 1500Hz, thereby enabling the speaker to have excellent low-frequency performance.

[0105] In some specific embodiments of the present application, the glass transition temperature of the modified acrylate rubber film layer is ≤-10°C.

[0106] That is to say, by adding inorganic hollow microbeads to an acrylate polymer to form a low-density rubber diaphragm material, and then adjusting the amount of inorganic hollow microbeads added, the glass transition temperature of the diaphragm can be controlled to ≤-10°C. For example, -10°C, -13°C, -15°C, etc. Preferably, the glass transition temperature of the modified acrylate rubber membrane layer can be ≤-15°C. A lower glass transition temperature can enable the diaphragm to maintain good rubber elasticity in a low-temperature environment, thereby making the sound-generating device exhibit a more comfortable listening experience and further improving the acoustic performance of the sound-generating device.

[0107] Therefore, by adding inorganic hollow microbeads to the ACM rubber, the glass transition temperature of the modified acrylate rubber membrane layer of the present application can be controlled to ≤-10°C, so that the modified acrylate rubber membrane layer can maintain a high elastic state at room temperature, and the diaphragm has good resilience. When the operating temperature of the diaphragm is lower than 0°C, the speaker diaphragm can always maintain good rubber elasticity during operation, so that the speaker can exhibit higher sound quality. At the same time, it reduces the risk of damage to the speaker diaphragm in a low temperature environment and has higher reliability. In addition, a diaphragm with a lower glass transition temperature can make the modulus consistency of the diaphragm material high when the diaphragm material works above the glass transition temperature, and the F0 of the diaphragm prepared from the diaphragm material has better stability in the entire temperature range.

[0108] In some specific embodiments of the present application, the loss factor of the modified acrylate rubber film layer at room temperature is greater than 0.12.

[0109] Specifically, the strength of inorganic hollow microspheres is relatively high. After the inorganic hollow microspheres are filled into the rubber, the hardness of the rubber will be appropriately increased. Therefore, at the same hardness, the reinforcing agent content of low-density rubber is much less than that of ordinary rubber. Its rubber content is increased, the intermolecular interference increases, the internal friction resistance is large, and it has excellent damping performance. The loss factor of the diaphragm of the present application at room temperature is greater than 0.12. Preferably, the loss factor of the modified acrylic rubber film layer is greater than 0.14. Therefore, the diaphragm prepared from the diaphragm material with a higher damping value has a lower impedance curve, which can improve the damping property of the diaphragm. The vibration system can effectively suppress the polarization phenomenon during the vibration and sound generation process, and the consistency of the vibration system is better.

[0110] Furthermore, the loss factor can be adjusted in conjunction with the diaphragm thickness to further optimize diaphragm performance. Generally, a higher loss factor indicates better material damping. Improving the damping of the diaphragm material helps reduce polarization during vibration, lowering product distortion and improving audio yield. For example, the loss factor can be 0.12, 0.14, 0.15, 0.16, 0.17, or 0.18.

[0111] It should be noted that the loss factor test method can be a conventional test method, for example: obtained by dynamic mechanical testing (DMA), measured according to ASTM D5026-15 standard, tensile fixture, test temperature range of -50°C to 100°C, and heating rate of 3°C / min.

[0112] Therefore, by controlling the loss factor of the modified acrylic rubber membrane layer at room temperature, the diaphragm of the present application has excellent damping performance, such as Figure 1As shown, the diaphragm can be a rectangular surround diaphragm. The horizontal axis represents frequency (Hz), and the vertical axis represents loudness displacement (mm). Tests were performed at the edge and center of the diaphragm to obtain test curves of vibration displacement at different frequencies for different parts of the diaphragm.

[0113] The effect of adding inorganic hollow microspheres to the diaphragm material on the damping properties of the diaphragm is as follows:

[0114] like Figure 1 As shown, Figure 1 The curves in the figure are concentrated, indicating that the vibration consistency of the various parts of the diaphragm of the sound-generating device of the present application is better. During the vibration process, the diaphragm swings less, and the sound quality and listening stability are better. Loudspeakers using the diaphragm of the present application not only have a good vibration system consistency due to the diaphragm's excellent damping performance, effectively suppressing transient distortion of the loudspeaker, but also achieve high-fidelity effects on the loudspeaker's electrical signals.

[0115] According to one embodiment of the present application, the density of the modified acrylate rubber film layer is 0.6 g / cm 3 ~1.1g / cm 3 .

[0116] That is to say, by adding inorganic hollow microspheres to the acrylic polymer to form a low-density rubber diaphragm material, and then by adjusting the amount of inorganic hollow microspheres added, the density of the diaphragm material can be controlled at 0.6g / cm 3 ~1g / cm 3 For example, the density of the modified acrylic rubber film layer can be 0.6 g / cm 3 , 0.7g / cm 3 , 0.8g / cm 3 , 0.9g / cm 3 , 1g / cm 3 or 1.1 g / cm 3 Therefore, through the above setting, the weight of the modified acrylic rubber membrane layer can be reduced by 30%-50%, which can achieve a good weight reduction effect and greatly improve the sound sensitivity of the diaphragm.

[0117] Table 4 shows the density of modified acrylic rubber films with different addition amounts of inorganic hollow microspheres. Hollow glass microspheres are selected as the inorganic hollow microspheres here. It should be noted that hollow glass microspheres are a type of inorganic hollow microspheres. Whether hollow glass microspheres or other inorganic hollow microspheres are used, the role of inorganic hollow microspheres in the material can be equally demonstrated.

[0118] As shown in Table 4, with the increase of the addition amount of hollow glass microspheres, the density of the acrylic rubber film layer gradually decreases.

[0119] By measuring the modulus and fracture strain of the modified acrylic rubber film layer with different contents of inorganic hollow microspheres, a graph showing the change of the elastic modulus and fracture strain of the modified acrylic rubber film layer with the mass proportion of the inorganic hollow microspheres can be obtained. Figure 2 As shown in the figure, as the amount of inorganic hollow microspheres added increases, the elastic modulus gradually increases and the fracture strain gradually decreases. When the mass proportion of the added inorganic hollow microspheres is too high, the rubber content is reduced, the modulus is too high, and the fracture strain is too low, causing the modified acrylic rubber film layer to lose its inherent soft elasticity. Due to its poor mechanical properties, it is easy to cause reliability problems such as film breakage during processing.

[0120] The influence of the content of inorganic hollow microspheres in the diaphragm material on the density of the diaphragm is as follows:

[0121] Determination method: Direct determination by density balance

[0122] Table 4

[0123]

[0124] The influence of the content of inorganic hollow microspheres in the diaphragm material on the intermediate frequency Fr of the diaphragm is as follows:

[0125] like Figure 3 As shown in the figure, by testing the mid-frequency Fr of sound-generating devices with diaphragms of different densities, it was found that as the diaphragm density increased, the mid-frequency sensitivity of the sound-generating device gradually decreased. In other words, the diaphragm material formed of acrylic rubber with inorganic hollow microspheres can reduce the diaphragm density and improve the mid-frequency performance of the sound-generating device.

[0126] It should be noted that when the density of low-density rubber is low (less than 0.5g / cm 3 ), the content of inorganic hollow microspheres is high, the prepared diaphragm has low elongation at break and strength, and is prone to reliability problems such as collapse and rupture. When the content of inorganic hollow microspheres is low, the diaphragm density is high (>1g / cm 3 ), when the prepared diaphragm is of the same thickness, the mid-frequency sensitivity of the rubber diaphragm is not significantly improved compared with the conventional diaphragm.

[0127] According to one embodiment of the present application, the additives include a cross-linking agent, a reinforcing agent, and an antioxidant.

[0128] Among them, the cross-linking agent is at least one of sulfur, carboxylic acid ammonium salt, organic peroxide and amine vulcanization systems; the reinforcing agent is at least one of carbon black, white carbon black, graphene oxide, montmorillonite, talc, clay, mica powder, feldspar powder, sodium alginate, magnetic powder and diatomaceous earth; and the antioxidant is at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD and antioxidant WH-02.

[0129] In some specific embodiments of the present application, the content of the crosslinking agent accounts for 1wt% to 5.5wt% of the rubber mix, the content of the reinforcing agent accounts for 5.5wt% to 70.5wt% of the rubber mix, and the content of the antioxidant accounts for 0.6wt% to 6.5wt% of the rubber mix.

[0130] The crosslinking agent content accounts for 1wt% to 5.5wt% of the rubber mix, preferably 1wt% to 3wt%. The amount of crosslinking agent used directly determines the degree of crosslinking. When the crosslinking agent content in the system is less than 1wt%, the rubber has a low degree of crosslinking, low mechanical strength, and the mechanical properties of the material cannot meet product requirements. When the crosslinking agent content exceeds 5.5wt%, the rubber has a high degree of crosslinking, low elongation at break, insufficient toughness, and is prone to brittle fracture during long-term use.

[0131] Antioxidants account for 0.6% to 6.5% of the rubber mix. Over time, rubber molecular chains break, generating free radicals that accelerate aging. Adding antioxidants can inhibit the generation of autocatalytic free radicals within rubber products. Too little antioxidant will not extend the product's service life, while too much will cause poor miscibility with the elastomer, making it difficult to disperse evenly, leading to a decrease in the material's mechanical properties. Furthermore, the antioxidant tends to leach onto the surface over time.

[0132] The reinforcing agent accounts for 5.5% to 70.5% of the rubber compound. The reinforcing agent interacts with the rubber molecular chains through entanglement, van der Waals forces, or hydrogen bonds, forming an interface. When the material is subjected to stress, the molecular chains easily slide on the reinforcing agent surface but are difficult to separate from the reinforcing agent. The rubber molecules and the reinforcing agent form a strong bond that allows sliding, increasing the mechanical strength. However, excessive reinforcing agent significantly increases the tensile strength of the material and sharply reduces the elongation at break, which cannot meet product requirements.

[0133] According to one embodiment of the present application, the diaphragm is a single-layer structure, and the diaphragm is composed of a modified acrylic rubber membrane layer.

[0134] In some specific embodiments of the present application, the diaphragm is a composite layer structure, and the diaphragm further includes a membrane layer made of at least one of a thermoplastic elastomer, an engineering plastic, and a thermosetting elastomer.

[0135] That is to say, when the diaphragm is a composite diaphragm, it includes at least one layer of modified acrylic rubber membrane layer, that is, it can include one layer of modified acrylic rubber membrane layer, or it can include multiple layers of modified acrylic rubber membrane layers. The multiple layers of modified acrylic rubber membrane layers can be arranged adjacent to each other or at intervals. The specific setting method can be selected according to the specific design requirements of the sound-emitting device.

[0136] Among them, the thermoplastic elastomer is at least one of thermoplastic polyester elastomer, thermoplastic polyurethane elastomer, thermoplastic polyamide elastomer and silicone elastomer, the engineering plastic is at least one of polyetheretherketone, polyarylate, polyetherimide, polyimide, polyphenylene sulfide, polyethylene naphthalate, polyethylene terephthalate and polybutylene terephthalate; the thermosetting elastomer is at least one of natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), chlorinated nitrile rubber (HNBR), ethylene-propylene rubber (EPDM), silicone rubber (Q), fluorosilicone rubber, fluororubber (FPM), polyurethane rubber (AU), acrylate rubber (ACM), ethylene-acrylate rubber (AEM), ethylene-vinyl acetate rubber (EVM), chlorosulfonated polyethylene rubber (CSM), epichlorohydrin rubber (CO) and polysulfide rubber.

[0137] Furthermore, when the diaphragm is a composite diaphragm, the composite diaphragm may be composed of a film layer made of at least one of a thermoplastic polyester elastomer, a thermoplastic polyurethane elastomer, a thermoplastic polyamide elastomer, and a silicone elastomer, and a modified acrylic rubber film layer. The raw materials for the plastic polyurethane elastomer, thermoplastic polyamide elastomer, and silicone elastomer can be a variety of materials and can be selected based on specific needs. The composite diaphragm composed of a film layer made of a plastic polyurethane elastomer, a thermoplastic polyamide elastomer, and a silicone elastomer and a modified acrylic rubber film layer has excellent mechanical properties, ensuring a certain mechanical strength while also having a high damping value.

[0138] In summary, the diaphragm of the sound-emitting device according to the embodiment of the present application is prepared by using a modified acrylic rubber film layer as a raw material, and has excellent damping performance and rebound resilience. The vibration system can effectively suppress the polarization phenomenon during the vibration sound-emitting process, and the consistency of the vibration system is better, which effectively suppresses the transient distortion of the sound-emitting device. Moreover, by controlling the amount of added inorganic hollow microbeads, the density of the diaphragm is reduced, and the intermediate frequency Fr of the sound-emitting device is improved, so that the diaphragm has excellent aging resistance and solvent resistance, so that the sound-emitting device made using the diaphragm of the present application has good acoustic performance.

[0139] It should be noted that the diaphragm provided herein can be incorporated into any sound-generating device, such as the following typical sound-generating device: 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 coupled to one side of the diaphragm. When the sound-generating device is in operation, the voice coil is energized and, under the influence of the magnetic field of the magnetic circuit system, vibrates up and down, driving the diaphragm to vibrate. This vibration of the diaphragm produces sound.

[0140] According to an embodiment of the second aspect of the present application, a sound-producing device includes a vibration system and a magnetic circuit system coordinated with the vibration system. The vibration system includes a diaphragm and a voice coil coupled to one side of the diaphragm. The magnetic circuit system drives the voice coil to vibrate, thereby driving the diaphragm to produce sound. The diaphragm is the diaphragm of the aforementioned embodiment. Specifically, when the sound-producing device is in operation, after power is applied to the voice coil, the magnetic force of the magnetic circuit system causes the voice coil to vibrate up and down, driving the diaphragm to vibrate. The vibration of the diaphragm produces sound.

[0141] like Figure 4 and Figure 5 As shown, the sound-generating device includes a diaphragm 15 prepared according to the above-described embodiment of the present application. The diaphragm 15 can be composed of a rim portion 151 and a dome portion 152. A modified acrylic rubber membrane layer can be applied to the rim portion 151 of the diaphragm. Those skilled in the art can make corresponding adjustments based on actual product requirements, such as increasing the rim portion 151 toward the voice coil 11, positioning the dome portion 152 on the lower surface of the rim portion 151, and adding a centering support to the vibration system.

[0142] like Figure 6 and Figure 7 As shown, the sound-producing device 100 according to the third embodiment of the present application includes a shell 10 and a magnetic circuit system 14 and a vibration system arranged in the shell 10. The vibration system includes a voice coil 11, a first diaphragm 12 and a second diaphragm 13. The top of the voice coil 11 is connected to the first diaphragm 12. The magnetic circuit system 14 drives the voice coil 11 to vibrate to drive the first diaphragm 12 to produce sound. The two ends of the second diaphragm 13 are respectively connected to the bottom of the shell 10 and the voice coil 11. The second diaphragm 13 is the diaphragm of the above embodiment.

[0143] That is, the sound-generating device 100 according to the embodiment of the present application may further include two diaphragms prepared according to the above-described embodiment of the present application, namely, a first diaphragm 12 and a second diaphragm 13. The first diaphragm 12 can be used to vibrate and produce sound, and the second diaphragm 13 can be used to balance the vibration of the voice coil 11. Specifically, when the sound-generating device 100 is in operation, after the voice coil 11 is energized, the magnetic field force of the magnetic circuit system 14 causes the voice coil 11 to vibrate up and down, thereby driving the first diaphragm 12 to vibrate. The vibration of the first diaphragm 12 can produce sound. The second diaphragm 13 can also vibrate up and down following the voice coil 11. Since the two ends of the second diaphragm 13 are respectively connected to the housing 10 and the bottom of the voice coil 11, the second diaphragm 13 can balance the vibration of the voice coil 11, prevent polarization of the voice coil 11, and thus improve the sound quality of the sound-generating device 100.

[0144] It should be noted that the first diaphragm 12 and the second diaphragm 13 may simultaneously adopt the diaphragms of the above embodiment of the present application, or one of the first diaphragm 12 and the second diaphragm 13 may adopt the diaphragm of the above embodiment of the present application. The present application does not impose any specific restrictions on this.

[0145] The diaphragm of the sound-generating device of the present application is described in detail below with reference to specific embodiments.

[0146] Comparative Example 1

[0147] The formula is shown in Table 5 in parts by mass. After mixing according to the formula, a cross-linking reaction is performed to form a diaphragm material.

[0148] Table 5

[0149]

[0150] Example 1

[0151] The formula, calculated by mass, is shown in Table 6. After mixing according to the formula, a cross-linking reaction is performed to form the diaphragm material. The hollow glass microspheres have a size of 18 μm.

[0152] Table 6

[0153]

[0154] Test indicators: tensile strength, elongation at break, swelling ratio and density

[0155] Table 7 shows the performance test results of the diaphragm materials of Comparative Example 1 and Example 1, reflecting the effect of adding inorganic hollow microspheres on the tensile strength, elongation at break, swelling ratio and density of the diaphragm materials.

[0156] Test method:

[0157] (1) Tensile properties The tensile strength and elongation at break were determined according to ASTM D412-2016. The specimens were dumbbell-shaped and the tensile rate was 500 mm / min. Each group of samples was tested 5 times and the average value was taken.

[0158] (2) The oil resistance volume change rate and mass change rate of rubber are tested in accordance with GB / T1690-2006. The test temperature is 150℃, the immersion time is 70h, and the test liquid is IRM903# oil.

[0159] The physical properties of conventional ACM rubber and the ACM rubber with hollow glass microspheres added in this application are compared as follows:

[0160] Table 7

[0161]

[0162] As can be seen in Table 7, the addition of hollow glass microspheres significantly increases the tensile strength of the modified ACM rubber and significantly reduces its elongation at break. This means that the modified ACM rubber membrane layer of this application has excellent mechanical properties, fully meeting the mechanical requirements of diaphragm processing, and is less likely to experience reliability issues such as membrane breakage during use.

[0163] Furthermore, due to the low density of the inorganic hollow microspheres, the density of the modified acrylate rubber film layer formed by adding them to the acrylate polymer is significantly reduced. Furthermore, the swelling ratio of the modified acrylate rubber film layer in Example 1 of the present application is significantly lower than that of the conventional acrylate rubber film layer in Comparative Example 1. Therefore, the rubber film layer in this example exhibits superior solvent resistance compared to a rubber film layer without the addition of inorganic hollow microspheres.

[0164] That is to say, the density of the diaphragm of the present application is greatly reduced compared with conventional diaphragms, which not only improves the mid-frequency sensitivity of the sound-emitting device, but also the swelling ratio of the diaphragm of the present application is smaller than that of conventional diaphragms, indicating that it has better solvent resistance. After applying it to the speaker, it can still maintain excellent acoustic performance in more harsh environments (high-temperature solvents).

[0165] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above embodiments may 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. A diaphragm of a sound-generating device, characterized in that: The diaphragm includes at least one modified acrylate rubber membrane layer, which is prepared by mixing inorganic hollow microspheres, additives and acrylate polymer to form a mixed rubber and then performing a cross-linking reaction; The particle size of the inorganic hollow microspheres is 1 μm to 60 μm, and the distribution density of the inorganic hollow microspheres in the modified acrylate rubber film layer is 0.15 g / cm 3 ~0.9g / cm 3 After the modified acrylate rubber film layer is immersed in an oily solvent at 150°C for 70 hours, the fracture strength decrease ratio of the modified acrylate rubber film layer is ≤30%, the swelling ratio is ≤20%, the content of the inorganic hollow microspheres accounts for 5wt% to 50wt% of the total amount of the rubber mix; the compressive strength of the inorganic hollow microspheres is ≥10MPa.

2. The diaphragm of the sound-generating device according to claim 1, wherein: The modified acrylate rubber film layer is aged in hot air at 140° C. for 168 hours, and the tensile strength decrease ratio of the modified acrylate rubber film layer is ≤45%, and the elongation at break decrease ratio is ≤60%.

3. The diaphragm of the sound-generating device according to claim 1, wherein: The surface contact angle between the modified acrylic rubber film layer and water is ≥80°.

4. The diaphragm of the sound-generating device according to claim 1, wherein: The loss factor of the modified acrylate rubber film layer at room temperature is greater than 0.

12.

5. The diaphragm of the sound-generating device according to claim 1, wherein: The glass transition temperature of the modified acrylic rubber film layer is ≤-10°C.

6. The diaphragm of the sound-generating device according to claim 1, characterized in that The density of the modified acrylic rubber film layer is 0.6 g / cm 3 ~1.1g / cm 3 .

7. The diaphragm of the sound-generating device according to claim 1, characterized in that The additives include cross-linking agents, reinforcing agents and antioxidants, The cross-linking agent is at least one of sulfur, carboxylic acid ammonium salt, organic peroxide and amine vulcanization systems; the reinforcing agent is at least one of carbon black, white carbon black, graphene oxide, montmorillonite, talc, clay, mica powder, feldspar powder, sodium alginate, magnetic powder and diatomaceous earth; and the antioxidant is at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD and antioxidant WH-02.

8. The diaphragm of the sound-generating device according to claim 7, characterized in that: The content of the cross-linking agent accounts for 1wt% to 5.5wt% of the rubber mix, the content of the reinforcing agent accounts for 5.5wt% to 70.5wt% of the rubber mix, and the content of the antioxidant accounts for 0.6wt% to 6.5wt% of the rubber mix.

9. The diaphragm of the sound-generating device according to claim 1, characterized in that: The diaphragm is a single-layer structure, and the diaphragm is composed of a layer of the modified acrylic rubber membrane.

10. The diaphragm of the sound-generating device according to claim 1, wherein: The diaphragm is a composite layer structure, and the diaphragm further comprises a membrane layer made of at least one of thermoplastic elastomer, engineering plastic and thermosetting elastomer.

11. A sound-generating device, characterized in that: It includes a vibration system and a magnetic circuit system coordinated with the vibration system, the vibration system includes a diaphragm and a voice coil coupled to one side of the diaphragm, the magnetic circuit system drives the voice coil to vibrate to drive the diaphragm to make sound, and the diaphragm is the diaphragm described in any one of claims 1-10.

12. A sound-generating device, characterized in that: It includes a shell and a magnetic circuit system and a vibration system arranged in the shell, 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 make sound, the two ends of the second diaphragm are respectively connected to the shell and the bottom of the voice coil, and the second diaphragm is the diaphragm according to any one of claims 1 to 10.

Images