Vibrating diaphragm assembly, sound production device and electronic equipment

Abstract

The invention discloses a vibrating diaphragm assembly, a sound production device and electronic equipment. The vibrating diaphragm assembly comprises a vibrating diaphragm body and a globe roof, and the vibrating diaphragm body and the globe roof are integrally formed. The vibrating diaphragm body comprises an elastomer layer composed of a modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer, the modified polystyrene-poly (ethylene-butylene)-polystyrene block copolymer contains an epoxy group and a benzene ring, the molar ratio range of the epoxy group to the benzene ring is 0.05%-5%, and at the temperature of 20-30 DEG C, the molecular weight of the elastomer layer is 10-30%. And the ejection force of the vibrating diaphragm assembly is 5N-30N. Epoxy groups in the elastomer layer can react with free radicals on the surface of the globe top to form chemical bonds and generate strong adhesive force, the epoxy groups generate ring-opening reaction, and stronger adhesive force is obtained between the vibrating diaphragm body and the globe top through intermolecular covalent bonds, so that an adhesive does not need to be arranged between the vibrating diaphragm body and the globe top; therefore, the thickness and mass of the diaphragm assembly can be reduced, the vibration space of the diaphragm assembly is increased, and the sounding sensitivity of the sounding device is improved.

Description

Technical Field

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

[0002] With the development of electronic product technology, the market competition for electronic products is becoming increasingly fierce, so the requirements for speakers in electronic products are also getting higher and higher. In terms of structure, the speaker is required to meet the requirements of lightness, thinness, and high waterproof level. In terms of acoustic performance, the speaker needs to have good mid-frequency sensitivity, suitable F0 and Fh.

[0003] In the related art, the diaphragm assembly in the speaker adopts the structure of diaphragm + adhesive layer + dome. Due to the existence of the adhesive layer, not only the weight of the diaphragm assembly is increased, affecting the sound sensitivity, but also the thickness of the diaphragm assembly is increased, occupying the vibration space of the diaphragm assembly, affecting the sound effect. Moreover, the adhesive layer is prone to cracking under the high-frequency vibration of the speaker and the high water pressure, thus failing to meet the sound quality and waterproof requirements, affecting the market competitiveness of the product.

[0004] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the invention

[0005] An object of the present invention is to provide a new technical solution for a diaphragm assembly.

[0006] According to a first aspect of the present invention, a diaphragm assembly is provided. The diaphragm assembly comprises:

[0007] A diaphragm body and a dome, wherein the diaphragm body and the dome are integrally formed;

[0008] Among them, the diaphragm body includes an elastomeric layer composed of modified polystyrene-poly (ethylene-butylene) -polystyrene block copolymer, the modified polystyrene-poly (ethylene-butylene) -polystyrene block copolymer contains epoxy groups and benzene rings, the molar ratio of the epoxy groups to the benzene rings ranges from 0.05% to 5%, between 20°C and 30°C, and the ejection force of the diaphragm assembly is 5N-30N.

[0009] Optionally, the elongation at break of the elastomer layer is 100%-800%; and / or the Young's modulus of the elastomer layer is 15MPa-600MPa.

[0010] Optionally, the glass transition temperature of the elastomer layer is from -50°C to -15°C.

[0011] Optionally, the thickness of the elastomer layer is 10 μm-300 μm.

[0012] Optionally, the ejection force loss rate of the diaphragm assembly after being soaked in water for 24 hours is 0.1%-5%.

[0013] Optionally, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is formed by grafting a polystyrene-poly(ethylene-butylene)-polystyrene block copolymer with an active compound containing an epoxy group, wherein the active compound includes at least one of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane and 2,3-epoxypropyltrimethylammonium chloride.

[0014] Optionally, an initiator is added to the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer and the active compound containing an epoxy group, wherein the active compound containing an epoxy group is 0.1 parts by weight to 4 parts by weight, the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is 3 parts by weight to 30 parts by weight, and the initiator is 0.05 parts by weight to 1 part by weight.

[0015] Optionally, the initiator includes at least one of dibenzoyl peroxide, azobisisobutyronitrile and 1,1-bis-di-tert-butylcyclohexylperoxide.

[0016] Optionally, the density of the elastomer layer is 0.75 g / cm 3 -1.1g / cm 3 .

[0017] Optionally, the diaphragm body and the ball top are integrally hot-pressed or integrally injection-molded.

[0018] Optionally, the molding temperature of the diaphragm body and the dome is 80°C-200°C.

[0019] Optionally, the diaphragm body is formed as a single-layer structure, and the diaphragm body is composed of a layer of the elastomer layer; or, the diaphragm body is formed as a composite layer structure, and the diaphragm body includes the elastomer layer and a composite layer, and the composite layer includes engineering plastics and / or elastomer materials.

[0020] According to a second aspect of the present invention, a sound-generating device is provided, which includes a vibration system and a magnetic circuit system cooperating with the vibration system, the vibration system includes a voice coil and a diaphragm assembly as in the above embodiment, the diaphragm assembly is arranged on one side of the voice coil, and the magnetic circuit system can drive the voice coil to vibrate to drive the diaphragm assembly to produce sound.

[0021] According to a third aspect of the present invention, an electronic device is provided, which includes the sound generating device of the above embodiment.

[0022] One technical effect of the present invention is that the epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the dome to form chemical bonds, thereby generating strong bonding force, so that the bonding force between the diaphragm body and the dome is strong, and the epoxy groups will produce a ring-opening reaction, so that the diaphragm body and the dome can obtain a higher bonding force through intermolecular covalent bonds, thereby improving the reliability of the diaphragm assembly, so that the diaphragm assembly is not easy to crack during high-frequency vibration, and can also have good waterproof performance. In addition, since there is a strong bonding force between the diaphragm body and the dome, there is no need to set an additional adhesive between the diaphragm body and the dome, and the diaphragm body and the dome can be integrally formed, thereby reducing the thickness and mass of the diaphragm assembly, which is beneficial to increasing the vibration space of the diaphragm assembly and improving the sound sensitivity of the sound-generating device.

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

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

[0025] Figure 1 It is a schematic diagram of the partial structure of a sound-generating device according to an embodiment of the present invention.

[0026] Figure 2 It is a schematic structural diagram of a diaphragm body according to an embodiment of the present invention.

[0027] Figure 3 It is a frequency loudness curve diagram of a diaphragm assembly according to an embodiment of the present invention.

[0028] Reference numerals:

[0029] 100. Sound-generating device; 110. Shell; 120. Diaphragm assembly; 121. Diaphragm body; 122. Dome; 130. Voice coil; 140. Permanent magnet. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0031] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0032] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0033] 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.

[0034] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] The present invention provides a diaphragm assembly 120, which can be used in a sound-generating device 100. Figures 1 to 3 As shown, the diaphragm assembly 120 includes a diaphragm body 121 and a ball top 122, and the diaphragm body 121 and the ball top 122 are integrally formed; wherein the diaphragm body 121 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups and benzene rings, and the molar ratio of the epoxy groups to the benzene rings ranges from 0.05% to 5%, and at 20°C to 30°C, the ejection force of the diaphragm assembly 120 is 5N-30N.

[0036] Specifically, the diaphragm body 121 and the ball top 122 are integrally formed. For example, the diaphragm body 121 is bonded to the ball top 122 during the injection molding process, and after cooling and solidification, the diaphragm body 121 and the ball top 122 are connected together; or, the diaphragm body 121 is heated and pressed together with the ball top 122 by hot pressing, and after cooling and solidification, the diaphragm body 121 and the ball top 122 are connected together. The above-mentioned one-piece molding method does not require the use of an adhesive, thus saving the step of bonding the diaphragm body 121 and the ball top 122. Since no adhesive is used, there is no need to set an adhesive layer between the ball top 122 and the diaphragm body 121, so the diaphragm assembly 120 can be made thinner and lighter.

[0037] The diaphragm body 121 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups. The epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the dome 122 to form chemical bonds, thereby generating a strong adhesive force, so that the diaphragm body 121 and the dome 122 have a strong adhesive force, and the epoxy groups will produce a ring-opening reaction, so that the diaphragm body 121 and the dome 122 obtain a higher adhesive force through intermolecular covalent bonds, thereby improving the reliability of the diaphragm assembly 120.

[0038] In one embodiment of the present invention, the molecular formula of the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (modified SEBS) is:

[0039] Modified SEBS contains epoxy groups and benzene rings, and the molar ratio of epoxy groups to benzene rings ranges from 0.05% to 5%. The benzene rings are generally located at the end of the modified SEBS, and the content of the end-capped benzene rings is fixed. Therefore, when the molar ratio of epoxy groups to benzene rings is too low, that is, the content of epoxy groups is too low, the content of intermolecular covalent bonds that the epoxy groups can produce ring-opening reactions is low, resulting in too low adhesion between the diaphragm body 121 and the ball top 122; and when the molar ratio of epoxy groups to benzene rings is too high, the content of epoxy groups is too high, and the temperature required for the integral molding of the diaphragm body 121 and the ball top 122 is high, resulting in reduced processing efficiency. Therefore, the molar ratio of epoxy groups to benzene rings ranges from 0.05% to 5%, so that the diaphragm body 121 and the ball top 122 can have a higher adhesion, and the temperature of the integral molding of the diaphragm body 121 and the ball top 122 can be avoided to be too high, which affects the processing efficiency.

[0040] For example, the molar ratio of epoxy groups to benzene rings can be 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4% or 5%, etc. The above values ​​can make the bonding force between the diaphragm body 121 and the ball top 122 higher and facilitate the integral molding of the diaphragm body 121 and the ball top 122.

[0041] In addition, between 20°C and 30°C, the ejection force of the diaphragm assembly 120 is 5N-30N. For example, the ejection force of the diaphragm assembly 120 can be 5N-30N at 20°C, 25°C or 30°C. The test method of the ejection force includes:

[0042] a) fixing the diaphragm assembly 120 by using a tool;

[0043] b) Install a top head below the dynamometer, and place the diaphragm assembly 120 and the top head of the dynamometer vertically;

[0044] c) Run the dynamometer so that the ejector head vertically contacts the ball top 122 and runs to the position where the diaphragm body 121 and the ball top 122 are separated or the diaphragm body 121 is damaged, and record the force value of the dynamometer at this time, which is the ejection force.

[0045] The ejection force indicates the size of the bonding force between the diaphragm body 121 and the ball top 122. When the ejection force is too low, the bonding force between the diaphragm body 121 and the ball top 122 is small, and the reliability of the diaphragm assembly 120 is too low. When the ejection force is too high, the diaphragm body 121 needs to contain more epoxy groups. The more epoxy groups there are, the higher the molding temperature of the diaphragm body 121 is, which reduces the processing efficiency of the diaphragm body 121. The ejection force of the diaphragm assembly 120 is 5N-30N, so that the reliability of the diaphragm assembly 120 is high and the processing efficiency of the diaphragm body 121 is high. For example, the ejection force of the diaphragm assembly 120 can be 5N, 10N, 15N, 20N, 25N or 30N, etc. The above values ​​can all make the reliability of the diaphragm assembly 120 high and the processing efficiency of the diaphragm body 121 high.

[0046] In this embodiment, the material of the ball top 122 can be carbon fiber, aluminum, aluminum alloy or engineering plastic (Peek (polyetheretherketone) and PI (polyimide)), etc. The shape of the ball top 122 is circular, rectangular, oval, etc.

[0047] In the embodiment of the present invention, the epoxy group in the elastomer layer has high reactivity and can react with the free radicals on the surface of the dome to form a chemical bond, thereby generating a strong adhesive force, so that the adhesive force between the diaphragm body 121 and the dome 122 is strong, and the epoxy group will produce a ring-opening reaction, so that the diaphragm body 121 and the dome 122 obtain a higher adhesive force through the intermolecular covalent bond, thereby improving the reliability of the diaphragm assembly 120, so that the diaphragm assembly 120 is not easy to crack during high-frequency vibration, and can also have good waterproof performance. In addition, since there is a strong adhesive force between the diaphragm body 121 and the dome 122, there is no need to set an additional adhesive between the diaphragm body 121 and the dome 122, and the diaphragm body 121 and the dome 122 can be integrally formed, thereby reducing the thickness and mass of the diaphragm assembly 120, which is beneficial to improving the vibration space of the diaphragm assembly 120 and improving the sound sensitivity of the sound-generating device 100.

[0048] In a specific embodiment of the present invention, the molar content of the epoxy group accounts for 0.1%-1% of the elastomer layer. When the molar content of the epoxy group is too low, the content of intermolecular covalent bonds that the epoxy group can produce a ring-opening reaction is low, resulting in too low adhesion between the diaphragm body 121 and the ball top 122; and when the molar content of the epoxy group is too high, the temperature required for the integral molding of the diaphragm body 121 and the ball top 122 is high, resulting in reduced processing efficiency. Therefore, the molar content of the epoxy group in the range of 0.1%-1% can not only make the diaphragm body 121 and the ball top 122 have a higher adhesion, but also avoid the temperature of the integral molding of the diaphragm body 121 and the ball top 122 being too high to affect the processing efficiency.

[0049] For example, the molar content of the epoxy group in the elastomer layer can be 0.1%, 0.3%, 0.5%, 0.7% or 1%, etc. The above values ​​can make the bonding force between the diaphragm body 121 and the ball top 122 higher and facilitate the integral molding of the diaphragm body 121 and the ball top 122.

[0050] In a specific embodiment of the present invention, the elongation at break of the elastomer layer is 100%-800%; and / or the Young's modulus of the elastomer layer is 15MPa-600MPa.

[0051] In this embodiment, the modified SEBS is a thermoplastic elastomer, and its molecular structure is composed of a polystyrene hard segment and a polyolefin soft segment. This block copolymer structure enables the elastomer layer composed of the modified SEBS to have good elasticity, flexibility and high elongation at break. That is, the elongation at break of the elastomer layer can be 100%-800%. When the elongation at break of the elastomer layer is too low, the diaphragm body 121 is easily damaged during molding. When the elongation at break of the elastomer layer is too high, it helps to improve the sensitivity and response speed of the diaphragm body 121, which is beneficial to improving the performance of the sound-generating device 100. However, excessive elongation at break may also cause the diaphragm body 121 to be easily fatigued after long-term use, thereby affecting the durability and stability of the diaphragm assembly 120. The elongation at break of the elastomer layer is 100%-800%, which makes the diaphragm body 121 not easy to be damaged, and the diaphragm assembly 120 has high durability and stability.

[0052] For example, the elongation at break of the elastomer layer can be 100%, 150%, 200%, 300%, 400%, 500%, 600%, 700% or 800%, etc. The above values ​​can make the diaphragm body 121 not easily damaged and the diaphragm assembly 120 has high durability and stability.

[0053] Among them, when the elongation at break of the elastic layer is 150%-500%, it is beneficial to further improve the durability and stability of the diaphragm assembly 120.

[0054] In this embodiment, the Young's modulus of the elastomer layer is 15MPa-600MPa. When the Young's modulus of the elastomer layer is too low, the diaphragm body 121 is easily damaged during molding, and the F0 (the lowest vibration frequency of the diaphragm body at which the product can make sound) required by the product cannot be achieved. It can only be achieved by thickening, but the increase in thickness will lead to an increase in the mass of the diaphragm assembly 120, which will lose its vibration space and reduce the sensitivity of the mass control area. When the Young's modulus is too high, the flexibility and resilience of the material deteriorate. In order to obtain high loudness, the product requires the diaphragm body 121 to have a large displacement. At this time, the excessively high Young's modulus will inevitably bring adverse effects. The Young's modulus of the elastomer layer is 15MPa-600MPa, which makes the diaphragm body 121 not easy to be damaged, and has good flexibility and resilience.

[0055] For example, the Young's modulus of the elastomer layer may be 15MPa, 30MPa, 50MPa, 100MPa, 150MPa, 200MPa, 300MPa, 400MPa, 500MPa or 600MPa, etc. The above values ​​make the diaphragm body 121 not easily damaged and have good flexibility and resilience.

[0056] Among them, the Young's modulus of the elastomer layer can be 30 MPa-150 MPa, which is also beneficial to further improve the performance of the diaphragm assembly 120.

[0057] In this embodiment, the elastomer layer can simultaneously satisfy the elongation at break of 100%-800% and the Young's modulus of the elastomer layer of 15MPa-600MPa. Alternatively, the elastomer layer can also satisfy one of the conditions of the elongation at break of 100%-800% and the Young's modulus of the elastomer layer of 15MPa-600MPa.

[0058] In a specific embodiment of the present invention, the glass transition temperature of the elastomer layer is -50°C to -15°C.

[0059] In this embodiment, the glass transition temperature (Tg) is the temperature at which the material changes from a glassy state to a highly elastic state. When the glass transition temperature of the elastomer layer is too low, the Young's modulus of the diaphragm body 121 will rise rapidly, causing the rigidity of the diaphragm body 121 to be too high, the F0 of the diaphragm assembly 120 to increase significantly, and the toughness of the diaphragm body 121 to decrease, which is prone to the risk of breakage. When the glass transition temperature is too high, the diaphragm body 121 may be more in the glassy state at low operating ambient temperatures, affecting the stability and reliability of the physical properties of the product. The glass transition temperature of the elastomer layer is -50°C to -15°C, which can make the diaphragm body 121 have high flexibility and good sensitivity in the high frequency band.

[0060] For example, the glass transition temperature of the elastomer layer can be -50°C, -40°C, -30°C, -25°C, -20°C or -15°C, etc. The above values ​​can make the diaphragm body 121 have high flexibility and good sensitivity in the high frequency band.

[0061] The glass transition temperature of the elastic layer may be -30° C. to -20° C. This is beneficial for further making the diaphragm body 121 have higher flexibility and better sensitivity in the high frequency band.

[0062] In a specific embodiment of the present invention, the thickness of the elastomer layer is 10 μm-300 μm.

[0063] In this embodiment, the thickness of the elastomer layer is 10μm-300μm. When the thickness of the elastomer layer is too thin, the rigidity of the diaphragm body 121 will be insufficient and the film making will be difficult. When the thickness of the elastomer layer is too thick, the mass of the diaphragm body 121 will increase, which will easily lead to a decrease in the sensitivity of the diaphragm body 121. Moreover, if the thickness of the elastomer layer is too large, it will occupy the vibration space of the diaphragm assembly 120, thereby affecting the sound effect of the sound-generating device 100. The thickness of the elastomer layer is 10μm-300μm, which can make the diaphragm body 121 have good rigidity, reduce the difficulty of film making, and help to reduce the mass of the diaphragm body 121 and improve the sensitivity of the diaphragm body 121.

[0064] For example, the thickness of the elastic layer can also be 10 μm, 20 μm, 50 μm, 100 μm, 150 μm, 200 μm or 300 μm, etc. The above values ​​can make the diaphragm body 121 have good rigidity, reduce the difficulty of film making, and help reduce the mass of the diaphragm body 121 and improve the sensitivity of the diaphragm body 121.

[0065] The thickness of the elastomer layer may be 20um-150um, which is beneficial to further make the diaphragm body 121 have good rigidity, reduce the difficulty of film making, reduce the mass of the diaphragm body 121, and improve the sensitivity of the diaphragm body 121.

[0066] In a specific embodiment of the present invention, the ejection force loss rate of the diaphragm assembly 120 after being soaked in water for 24 hours is 0.1%-5%. The ejection force loss rate means that the ejection force of the diaphragm assembly 120 at room temperature is F1, and the ejection force of the diaphragm assembly 120 after being soaked in water for 24 hours is F2, and the ejection force loss rate is (F1-F2) / F1. It should be noted that the diaphragm assembly 120 can be soaked in water for about 24 hours, for example, the soaking time can be 23 hours to 25 hours.

[0067] In this embodiment, the ejection force loss rate of the diaphragm assembly 120 after being soaked in water for 24 hours is 0.1%-5%, that is, the diaphragm assembly 120 has good waterproof performance. The ejection force loss rate of the diaphragm assembly 120 is low, which is mainly derived from the epoxy groups in the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer in the elastomer layer. The epoxy groups have good hydrophobicity and can effectively block the penetration of water. When the ejection force loss rate of the diaphragm assembly 120 is too high, the ejection force of the diaphragm assembly 120 is greatly reduced after being soaked in water, that is, the bonding force between the ball top 122 and the diaphragm body 121 will be too low. When the ejection force loss rate of the diaphragm assembly 120 is too low, it is necessary to increase the molar content of the epoxy group too much. If the molar content of the epoxy group is too high, the temperature required for the one-piece molding of the diaphragm body 121 and the ball top 122 will be higher, resulting in reduced processing efficiency. The ejection force loss rate of the diaphragm assembly 120 after being soaked in water for 24 hours is 0.1%-5%, which can ensure that the ball top 122 and the diaphragm body 121 still have a high adhesion force after the diaphragm assembly 120 is soaked in water, and can also avoid the temperature of the integral molding of the diaphragm body 121 and the ball top 122 being too high to affect the processing efficiency.

[0068] For example, the ejection force loss rate of the diaphragm assembly 120 after being soaked in water for 24 hours can be 0.1%, 0.5%, 1%, 2%, 3%, 4% or 5%, etc. The above values ​​can ensure that the diaphragm assembly 120 still has a high adhesion force between the ball top 122 and the diaphragm body 121 after being soaked in water, and can also avoid the temperature of the integral molding of the diaphragm body 121 and the ball top 122 being too high to affect the processing efficiency.

[0069] Among them, the output force loss rate of the diaphragm assembly 120 after being soaked in water for 24 hours ranges from 0.1% to 1%, which is beneficial to further ensure that the ball top 122 and the diaphragm body 121 still have a high adhesion force after the diaphragm assembly 120 is soaked in water, and can also avoid the temperature of the integral molding of the diaphragm body 121 and the ball top 122 being too high to affect the processing efficiency.

[0070] In this embodiment, the ejection force of the diaphragm assembly 120 after being baked at 130° C. for 6 hours is 10N-30N. That is, the diaphragm assembly 120 of the present invention can have good heat resistance.

[0071] In a specific embodiment of the present invention, the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is formed by grafting a polystyrene-poly(ethylene-butylene)-polystyrene block copolymer with an active compound containing an epoxy group, wherein the active compound includes at least one of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane and 2,3-epoxypropyltrimethylammonium chloride.

[0072] In this embodiment, polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (SEBS) is grafted with glycidyl methacrylate containing epoxy groups to form modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer (modified SEBS). That is,

[0073]

[0074] Among them, the grafting reaction is also called graft copolymerization or graft (co)polymerization. SEBS grafting is a free radical reaction, and the epoxy group is grafted onto the SEBS molecular chain in the form of monomers and oligomers, and the grafting position is on the unhydrogenated double bond.

[0075] Of course, the active compound containing epoxy groups may include one or more of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane and 2,3-epoxypropyltrimethylammonium chloride. Those skilled in the art may determine the actual situation, and no specific limitation is made here.

[0076] In a specific embodiment of the present invention, an initiator is added to the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer and the active compound containing an epoxy group, wherein the active compound containing an epoxy group is 0.1 parts by weight to 4 parts by weight, the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is 3 parts by weight to 30 parts by weight, and the initiator is 0.05 parts by weight to 1 part by weight.

[0077] In this embodiment, an initiator is added during the grafting reaction between polystyrene-poly(ethylene-butylene)-polystyrene block copolymer and an active compound containing epoxy groups. The initiator decomposes under heating or specific conditions to generate free radicals or other active species. These free radicals or active species can react with the main chain of SEBS to form active grafting points, thereby promoting the successful grafting of the epoxy groups of the side chains onto the main chain.

[0078] In this embodiment, the active compound containing epoxy groups is 0.1 parts by weight to 4 parts by weight, for example, the active compound can be 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight or 4 parts by weight, etc. The polystyrene-poly (ethylene-butylene)-polystyrene block copolymer is 3 parts by weight to 30 parts by weight, for example, the polystyrene-poly (ethylene-butylene)-polystyrene block copolymer can be 3 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight or 30 parts by weight, etc. The initiator is 0.05 parts by weight to 1 part by weight, for example, the initiator can be 0.05 parts by weight, 0.1 parts by weight, 0.3 parts by weight, 0.5 parts by weight, 0.7 parts by weight or 1 part by weight, etc. Of course, the specific ratio of the active compound, polystyrene-poly (ethylene-butylene)-polystyrene block copolymer and the initiator can be determined by those skilled in the art according to the actual situation, and is not specifically limited here.

[0079] In this embodiment, the initiator includes at least one of dibenzoyl peroxide, azobisisobutyronitrile and 1,1-bis-di-tert-butylcyclohexylperoxide. Those skilled in the art may determine the initiator according to actual conditions, and no specific limitation is made here.

[0080] In a specific embodiment of the present invention, the density of the elastomer layer is 0.75 g / cm 3 -1.1g / cm 3 .

[0081] In this embodiment, the density of the elastomer layer is 0.75 g / cm 3 -1.1g / cm 3 When the density of the elastomer is too low, the mechanical strength of the diaphragm body 121 will be reduced. During use, the diaphragm body 121 is easily damaged and difficult to meet the use requirements. If the density of the elastomer layer is too high, it will affect the acoustic performance of the diaphragm assembly 120. The density of the elastomer layer is 0.75g / cm 3 -1.1g / cm 3 , which can improve the mechanical strength of the diaphragm body 121 and avoid affecting the acoustic performance of the diaphragm assembly 120.

[0082] For example, the density of the elastomer layer may be 0.75 g / cm 3 , 0.8g / cm 3 , 0.9g / cm 3 , 1.0g / cm 3 or 1.1 g / cm 3 The above values ​​can both increase the mechanical strength of the diaphragm body 121 and avoid affecting the acoustic performance of the diaphragm assembly 120 .

[0083] The density of the elastomer layer can be 0.8 g / cm 3 -0.9g / cm 3 , which is beneficial to further improve the mechanical strength of the diaphragm body 121 while avoiding affecting the acoustic performance of the diaphragm assembly 120.

[0084] In a specific embodiment of the present invention, the diaphragm body 121 and the dome 122 are integrally formed by hot pressing or integrally formed by injection molding.

[0085] In this embodiment, the diaphragm body 121 can be integrally hot-pressed or integrally injection-molded with the dome 122. The molding temperature of the diaphragm body 121 and the dome 122 is 80°C-200°C. When the diaphragm body 121 and the dome 122 are molded, at the molding temperature, the epoxy group in the elastomer layer will produce a ring-opening reaction, thereby obtaining a higher adhesion through intermolecular covalent bonds. When the molding temperature is too low, the molding state of the diaphragm assembly 120 is poor, and when the molding temperature is too high, the diaphragm body 121 decomposes, which also affects the flatness of the diaphragm body 121.

[0086] For example, the molding temperature can be 80°C, 100°C, 120°C, 150°C, 180°C, or 200°C, etc. The above value ranges can all enable the diaphragm body 121 and the ball top 122 to produce a strong bonding force during molding, and the diaphragm assembly 120 is in a good molding state and the surface of the diaphragm body 121 is smooth.

[0087] Among them, the molding temperature of the diaphragm body 121 and the ball top 122 can be 100℃-150℃, which is conducive to further generating a stronger bonding force between the diaphragm body 121 and the ball top 122 during molding, and the molding state of the diaphragm assembly 120 is good, and the surface of the diaphragm body 121 is flat.

[0088] In this embodiment, when the diaphragm body 121 and the ball top 122 are integrally formed, the bonding time under hot pressing is 5s-60s to improve the stability of the bonding between the diaphragm body 121 and the ball top 122.

[0089] In a specific embodiment of the present invention, the diaphragm body 121 is formed as a single-layer structure, and the diaphragm body 121 is composed of a layer of the elastomer layer; or, the diaphragm body 121 is formed as a composite layer structure, and the diaphragm body 121 includes the elastomer layer and a composite layer, and the composite layer includes engineering plastics and / or elastomeric materials.

[0090] In this embodiment, the diaphragm body 121 may be a single-layer structure, that is, the diaphragm body 121 is composed of a single elastomer layer, and the single-layer elastomer layer is integrally formed with the dome 122. The single-layer diaphragm body 121 is thinner and lighter, which is conducive to the miniaturization design of the diaphragm assembly 120.

[0091] Alternatively, the diaphragm body 121 may also be a composite layer structure, that is, the diaphragm body 121 is composed of an elastomer layer and a composite layer. Among them, the composite layer may be one or both of engineering plastics and elastomer materials. By adding a composite layer, the diaphragm body 121 can combine the advantages of the elastomer layer and the composite layer, and can further improve the heat resistance, compression deformation resistance, aging resistance, etc. of the diaphragm body 121, and improve the mechanical properties of the diaphragm body 121. Engineering plastics include PEEK (polyetheretherketone) and PI (polyimide), etc., and elastomeric materials include TPU (thermoplastic polyurethane elastomer), TPEE (thermoplastic polyester elastomer) and rubber, etc. Of course, the specific material of the composite layer can be determined by those skilled in the art according to the actual situation, and no specific limitation is made here.

[0092] When the diaphragm body 121 is a composite layer structure, the diaphragm body 121 can be integrally formed with the sphere by hot pressing. The diaphragm body 121 includes an elastomer layer and a composite layer, and the elastomer layer is hot pressed and bonded to the spherical top 122 .

[0093] According to a second aspect of the present invention, a sound-generating device 100 is provided, the sound-generating device 100 comprising a vibration system and a magnetic circuit system matched with the vibration system, the vibration system comprising a voice coil 130 and a diaphragm assembly 120 as in the above embodiment, the diaphragm assembly 120 being arranged on one side of the voice coil 130, the magnetic circuit system being able to drive the voice coil 130 to vibrate so as to drive the diaphragm assembly 120 to generate sound. The sound-generating device 100 may be a speaker unit or a speaker module, etc.

[0094] like Figure 1 As shown, the sound-generating device 100 may include a housing 110, a magnetic circuit system and a vibration system, wherein the magnetic circuit system includes a permanent magnet 140, and the permanent magnet 140 is used to form a magnetic gap. The vibration system includes a diaphragm assembly 120 and a voice coil 130. The diaphragm assembly 120 and the permanent magnet 140 are both connected to the housing 110. The permanent magnet 140 is arranged on one side of the diaphragm assembly 120 along the vibration direction of the voice coil 130. One end of the voice coil 130 is connected to the diaphragm assembly 120, and the other end is located in the magnetic gap.

[0095] In this embodiment, the diaphragm assembly 120 includes a diaphragm body 121 and a dome 122, and the diaphragm body 121 and the dome 122 are integrally formed. The diaphragm body 121 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups. The epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the dome 122 to form chemical bonds, thereby generating strong adhesion, thereby making the adhesion between the diaphragm body 121 and the dome 122 stronger, and the epoxy groups will produce a ring-opening reaction, thereby obtaining a higher adhesion between the diaphragm body 121 and the dome 122 through intermolecular covalent bonds, thereby improving the reliability of the diaphragm assembly 120, so that the diaphragm assembly 120 is not easy to crack during high-frequency vibration, and can also have good waterproof performance. Furthermore, since there is a strong bonding force between the diaphragm body 121 and the ball top 122, there is no need for additional adhesive between the diaphragm body 121 and the ball top 122. The diaphragm body 121 and the ball top 122 can be integrally formed, thereby reducing the thickness and mass of the diaphragm assembly 120, which is beneficial to increasing the vibration space of the diaphragm assembly 120 and improving the sound sensitivity of the sound-emitting device.

[0096] Of course, the sound-generating device 100 of the present invention also includes at least all the beneficial effects of the above-mentioned embodiments, which will not be elaborated here.

[0097] According to a third aspect of the present invention, an electronic device is provided. The electronic device includes the sound-generating device 100 of the above embodiment. The electronic device may be a mobile phone, a smart watch or a computer. The electronic device of the present invention also includes at least all the beneficial effects of the above embodiment, which will not be described in detail here.

[0098] The diaphragm assembly 120 of the present invention is described in detail below with specific embodiments and comparative examples. It is worth noting that the following description is merely exemplary and does not specifically limit the present invention.

[0099] Embodiment 1: The diaphragm body 121 is composed of an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The molar ratio of epoxy groups to benzene rings in the elastomer layer is 5:1000. The dome 122 is an aluminum composite material. The diaphragm body 121 and the dome 122 are integrally hot-pressed at a temperature of 160°C and a hot-pressing time of 20 seconds.

[0100] Embodiment 2: The diaphragm body 121 is composed of an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer. The molar ratio of epoxy groups to benzene rings in the elastomer layer is 1:100. The dome 122 is an aluminum composite material. The diaphragm body 121 and the dome 122 are integrally hot-pressed at a temperature of 160°C and a hot-pressing time of 20 seconds.

[0101] Comparative Example 1: The diaphragm body is composed of a layer of TPU film (thermoplastic polyurethane elastomer), the dome is an aluminum composite material, and the bonding layer between the diaphragm body and the dome is an acrylic film. The bonding layer is annular and has a thickness of 25μm. First, one side of the bonding layer is bonded to the dome, and then the other side of the bonding layer is pressed onto the diaphragm body at room temperature for 20s.

[0102] Table 1 Performance data of the diaphragm assembly of Examples 1, 2 and Comparative Example 1

[0103] Example 1 Example 2 Comparative Example 1 Thickness of diaphragm assembly / μm 120 120 145 Thickness of the diaphragm body / μm 40 40 40 Thickness of dome / um 80 80 80 Thickness of adhesive layer / μm / / 25 Ejection force / N 12.45 15.76 8.23 Ejection force after soaking in water for 24 hours / N 12.01 15.23 5.26

[0104] As shown in Table 1, the thickness of the diaphragm body and the dome 122 of the diaphragm assembly 120 in Examples 1 and 2 and Comparative Example 1 is the same, the thickness of the diaphragm body is 40 μm, and the thickness of the dome 122 is 80 μm. The overall thickness of the two diaphragm assemblies 120 in Examples 1 and 2 is 120 μm. The thickness of the adhesive layer in Comparative Example 1 is 25 μm, and the overall thickness is 145 μm. Since the diaphragm assemblies 120 in Examples 1 and 2 are integrally formed, there is no adhesive layer, which makes the thickness of the diaphragm assemblies 120 in Examples 1 and 2 significantly smaller than the thickness of the diaphragm assembly 120 in Comparative Example 1.

[0105] At 20°C-30°C, the ejection force of the diaphragm assembly 120 of Example 1 is 12.45 N, the ejection force of the diaphragm assembly 120 of Example 2 is 15.76 N, and the ejection force of the diaphragm assembly 120 of Comparative Example 1 is 8.23 ​​N. It can be seen that the diaphragm body 121 in Examples 1 and 2 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, and the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups. The epoxy groups in the elastomer layer are highly reactive and can react with free radicals on the surface of the ball top 122 to form chemical bonds, thereby generating stronger bonding force, thereby strengthening the bonding between the diaphragm body 121 and the ball top 122. The epoxy groups will also produce a ring-opening reaction, thereby achieving a higher bonding force between the diaphragm body 121 and the ball top 122 through intermolecular covalent bonds, thereby enabling the diaphragm assembly 120 to have a greater ejection force.

[0106] In addition, the molar ratio of epoxy groups to benzene rings in the diaphragm body 121 of Example 1 is 5:1000, and the molar ratio of epoxy groups to benzene rings in the diaphragm body 121 of Example 2 is 1:100. It can be seen that since the molar ratios of epoxy groups to benzene rings in the diaphragm body 121 of the above two embodiments are both within the range of 0.05%-5%, the diaphragm body 121 and the ball top 122 can have a higher bonding force, and the diaphragm assembly 120 has a high ejection force.

[0107] After the diaphragm assembly 120 was immersed in water for 24 hours, the ejection force of each diaphragm assembly 120 was measured, wherein the ejection force of the diaphragm assembly 120 of Example 1 was 12.01N, and the ejection force loss rate was (12.45-12.01) / 12.45=3.53%. The ejection force of the diaphragm assembly 120 of Example 2 was 15.23N, and the ejection force loss rate was (15.76-15.23) / 15.76=3.36%. The ejection force of the diaphragm assembly 120 in Comparative Example 1 was 5.26N, and the ejection force loss rate was (8.23-5.26) / 8.23=36.08%. It can be seen that the diaphragm body 121 and the ball top 122 of the embodiment 1 and the embodiment 2 of the present invention are integrally formed, and there is a large bonding force between the elastic layer and the ball top 122, thereby reducing the ejection force loss rate of the diaphragm assembly 120, and the ejection force loss rate of the diaphragm assembly 120 can be made between 0.1% and 5%. However, the ejection force loss rate of the diaphragm assembly 120 formed by bonding the ball top 122 to the TPU diaphragm body through the adhesive layer is relatively large.

[0108] The diaphragm assembly 120 in Example 1 and Comparative Example 1 was assembled into the same type of sound-generating device 100, and the frequency response curves of the two sound-generating devices 100 were measured. The frequency response curves are shown in FIG. Figure 3 As shown in the figure, the horizontal axis represents the vibration frequency, unit: Hz; the vertical axis represents the loudness, unit: dB.

[0109] like Figure 3 As shown, between 800 Hz and 7500 Hz, the response value of the sound-generating device 100 in Example 1 is about 1.5 dB higher than the response value of the sound-generating device 100 in Comparative Example 1. It can be seen that since the diaphragm assembly 120 in Example 1 has no adhesive layer, the diaphragm assembly 120 has a light weight and a small thickness. In the same vibration space, the amplitude of the diaphragm assembly 120 is larger, thereby significantly improving the sound quality of the sound-generating device 100. The sound-generating device 100 prepared by the diaphragm assembly 120 of Example 1 has a higher sensitivity, a louder sound, and a better sound reproduction.

[0110] In summary, the diaphragm assembly 120 of Example 1 and Example 2 includes an integrally formed diaphragm body 121 and a dome 122. Compared with the diaphragm body of Comparative Example 1, the diaphragm body 121 of the diaphragm assembly 120 of both Examples 1 and 2 includes an elastomer layer composed of a modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer, wherein the modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer contains epoxy groups and benzene rings, and the molar ratio of the epoxy groups to the benzene rings is in the range of 0.05%-5%. The epoxy groups in the elastomer layer have high reactivity and can react with free radicals on the surface of the dome 122 to form chemical bonds, thereby generating a strong adhesive force, thereby making the adhesion between the diaphragm body 121 and the dome 122 stronger, and the epoxy groups will produce a ring-opening reaction, thereby obtaining a higher adhesive force between the diaphragm body 121 and the dome 122 through intermolecular covalent bonds, thereby enabling the diaphragm assembly 120 to have a greater ejection force, and after soaking in water for 24 hours, the elastomer layer of the diaphragm body 121 of Example 1 and Example 2 and the dome 122 still have a large adhesive force, thereby reducing the ejection force loss rate of the diaphragm assembly 120, and enabling the ejection force loss rate of the diaphragm assembly 120 to be between 0.1% and 5%. In addition, the sound-generating device 100 prepared by the diaphragm assembly 120 of Example 1 has higher sensitivity, louder sound, and better sound reproduction than the sound-generating device 100 prepared by the diaphragm assembly 120 of Comparative Example 1. Since the thickness and mass of the diaphragm assembly 120 of Examples 1 and 2 are smaller than the thickness and mass of the diaphragm assembly 120 of Comparative Example 1, the thickness of the diaphragm assembly 120 of Examples 1 and 2 is smaller, and thus has a larger amplitude, thereby improving the sensitivity, loudness and sound charging and discharging effect of the sound-emitting device 100.

[0111] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0112] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A diaphragm assembly, It is characterized in that include: A diaphragm body and a dome, wherein the diaphragm body and the dome are integrally formed; Among them, the diaphragm body includes an elastomeric layer composed of modified polystyrene-poly (ethylene-butylene) -polystyrene block copolymer, the modified polystyrene-poly (ethylene-butylene) -polystyrene block copolymer contains epoxy groups and benzene rings, the molar ratio of the epoxy groups to the benzene rings ranges from 0.05% to 5%, between 20°C and 30°C, and the ejection force of the diaphragm assembly is 5N-30N.

2. The diaphragm assembly according to claim 1, It is characterized in that The elongation at break of the elastomer layer is 100%-800%; And / or, the Young's modulus of the elastomer layer is 15 MPa-600 MPa.

3. The diaphragm assembly according to claim 1, It is characterized in that The glass transition temperature of the elastomer layer is -50°C to -15°C.

4. The diaphragm assembly according to claim 1, It is characterized in that The thickness of the elastic layer is 10 μm-300 μm.

5. The diaphragm assembly according to claim 1, It is characterized in that The ejection force loss rate of the diaphragm assembly after being soaked in water for 24 hours is 0.1%-5%.

6. The diaphragm assembly according to claim 1, It is characterized in that The modified polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is formed by grafting a polystyrene-poly(ethylene-butylene)-polystyrene block copolymer with an active compound containing an epoxy group, wherein the active compound comprises at least one of glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane and 2,3-epoxypropyltrimethylammonium chloride.

7. The diaphragm assembly according to claim 6, It is characterized in that An initiator is added to the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer and the active compound containing an epoxy group, wherein the active compound containing an epoxy group is 0.1 parts by weight to 4 parts by weight, the polystyrene-poly(ethylene-butylene)-polystyrene block copolymer is 3 parts by weight to 30 parts by weight, and the initiator is 0.05 parts by weight to 1 part by weight.

8. The diaphragm assembly according to claim 7, It is characterized in that The initiator includes at least one of dibenzoyl peroxide, azobisisobutyronitrile and 1,1-bis-di-tert-butylcyclohexylperoxide.

9. The diaphragm assembly according to claim 1, It is characterized in that The density of the elastomer layer is 0.75 g / cm 3 -1.1g / cm 3 .

10. The diaphragm assembly according to claim 1, It is characterized in that The diaphragm body and the ball top are integrally formed by hot pressing or integrally injection molding.

11. The diaphragm assembly according to claim 10, It is characterized in that The molding temperature of the diaphragm body and the dome is 80°C-200°C.

12. The diaphragm assembly according to any one of claims 1 to 9, It is characterized in that The diaphragm body is formed into a single-layer structure, and the diaphragm body is composed of a layer of the elastic body; Alternatively, the diaphragm body is formed as a composite layer structure, the diaphragm body includes the elastomer layer and the composite layer, and the composite layer includes engineering plastics and / or elastomer materials.

13. A sound-generating device, It is characterized in that It includes a vibration system and a magnetic circuit system matched with the vibration system, the vibration system includes a voice coil and a diaphragm assembly as described in any one of claims 1-12, the diaphragm assembly is arranged on one side of the voice coil, and the magnetic circuit system can drive the voice coil to vibrate to drive the diaphragm assembly to make sound.

14. An electronic device, It is characterized in that Comprising the sound-generating device as claimed in claim 13.

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