阅读说明：本技术 一种复合振膜、复合振膜的制备方法及发声装置 (Composite vibrating diaphragm, preparation method of composite vibrating diaphragm and sound production device ) 是由 周厚强 王婷 李春 于 2020-06-30 设计创作，主要内容包括：本申请公开了一种复合振膜、复合振膜的制备方法及发声装置。复合振膜包括胶膜层和支撑层,胶膜层采用橡胶材料与交联剂经交联反应制成,橡胶材料包括乙烯-丙烯酸酯二元共聚物和乙烯-丙烯酸酯-不饱和有机羧酸三元共聚物中的至少一种,按照质量份数计,橡胶材料的质量份数为100份,交联剂的质量份数为0.5份～10份,胶膜层的模量为1MPa～20MPa；支撑层采用热塑性弹性体制成。本申请的胶膜层具有高阻尼、高回弹,寿命长、耐油、耐候性等特点,胶膜层同支撑层粘结牢靠,胶膜层模量比常规丙烯酸胶膜/硅胶胶膜层高。在振膜成型过程中,胶膜层受挤压均匀变形,振膜各部位厚度均一,可靠性优。(The application discloses a composite vibrating diaphragm, a preparation method of the composite vibrating diaphragm and a sound production device. The composite vibrating diaphragm comprises a rubber diaphragm layer and a supporting layer, wherein the rubber diaphragm layer is prepared by a rubber material and a cross-linking agent through a cross-linking reaction, the rubber material comprises at least one of ethylene-acrylate binary copolymer and ethylene-acrylate-unsaturated organic carboxylic acid terpolymer, the rubber material comprises 100 parts by mass, the cross-linking agent comprises 0.5-10 parts by mass, and the modulus of the rubber diaphragm layer is 1-20 MPa; the supporting layer is made of thermoplastic elastomer. The utility model provides a glue film layer has high damping, high resilience, characteristics such as longe-lived, resistant oil, weatherability, and the glue film layer bonds with the supporting layer firmly, and the glue film layer modulus is higher than conventional acrylic acid glued membrane/silica gel glued membrane layer. In the vibrating diaphragm forming process, the film layer is extruded and uniformly deformed, the thickness of each part of the vibrating diaphragm is uniform, and the reliability is excellent.)

1. A composite diaphragm is characterized by comprising a film adhesive layer and a supporting layer;

the rubber film layer is prepared by a cross-linking reaction of a rubber material and a cross-linking agent, wherein the rubber material comprises at least one of ethylene-acrylate binary copolymer and ethylene-acrylate-unsaturated organic carboxylic acid terpolymer, the rubber material comprises 100 parts by mass, the cross-linking agent comprises 0.5-10 parts by mass, and the modulus of the rubber film layer is 1-20 MPa;

the supporting layer is made of thermoplastic elastomer.

2. The composite diaphragm of claim 1 wherein the cross-linking agent is a peroxide cross-linking agent.

3. The composite diaphragm of claim 2 wherein the peroxide crosslinking agent comprises at least one of 1,3-1, 4-di (t-butylperoxyisopropyl) benzene, dicumyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) -3-hexyne, n-butyl 4,4 '-bis (t-butylperoxy) valerate, 1' -bis (t-butylperoxy) -3,3,5 trimethylcyclohexane, and 2, 4-dichlorobenzoyl peroxide.

4. The composite diaphragm of claim 1, wherein the content of the unsaturated organic carboxylic acid in the ethylene-acrylate-unsaturated organic carboxylic acid terpolymer is (0.1-4.5)% of the terpolymer.

5. The composite diaphragm of claim 1, wherein the adhesive film layer further includes a filler; the filler is 3-60 parts by weight.

6. The composite diaphragm of claim 5 wherein the filler includes at least one of silica, silicate, carbonate, and amorphous carbon.

7. The composite diaphragm of claim 1, wherein the thickness of the adhesive film layer is 5um to 100 um.

8. The composite diaphragm of claim 1, wherein the hardness of the adhesive film layer is 25A to 75A.

9. The composite diaphragm of claim 1, wherein the adhesive film layer is formed by a calendering or coating process.

10. The composite diaphragm of claim 1, wherein the adhesive film layer and the supporting layer are attached to each other and are formed by air explosion molding.

11. The composite diaphragm of any one of claims 1 to 10, wherein the thermoplastic elastomer includes at least one of a polyester thermoplastic elastomer, a polyurethane thermoplastic elastomer, a polyolefin thermoplastic elastomer, a polystyrene thermoplastic elastomer, and a polyamide thermoplastic elastomer.

12. The composite diaphragm of any one of claims 1 to 10, wherein the composite diaphragm includes a glue layer and a support layer, and the glue layer and the support layer are bonded;

or the support layer comprises a first support layer and a second support layer; the first supporting layer and the second supporting layer are respectively attached to two sides of the adhesive film layer.

13. A sound-generating device comprising a magnetic circuit system and a vibration system cooperating with each other, said vibration system comprising a composite diaphragm as claimed in any one of claims 1 to 12.

14. A method of manufacturing a composite diaphragm, comprising:

step S1, mixing 100 parts by mass of rubber material and 0.5-10 parts by mass of cross-linking agent to prepare rubber film blank; wherein the rubber material comprises at least one of ethylene-acrylate binary copolymer and ethylene-acrylate-unsaturated organic carboxylic acid ternary copolymer;

step S2, adhering the glue film blank and a support layer made of thermoplastic elastomer to form a composite layer;

and step S3, heating and pressurizing the composite layer to form the composite diaphragm.

15. The method of manufacturing a composite diaphragm of claim 14, further comprising a step of drying the adhesive film blank at 80-100 ℃ between the step S1 and the step S2.

16. The method of manufacturing a composite diaphragm according to claim 14 or 15, wherein in step S3, the composite layer is air-blasted to form the diaphragm;

and in the gas explosion forming process, the rubber film blank is subjected to a crosslinking reaction and is shaped.

Technical Field

The application relates to the technical field of electroacoustic conversion, in particular to a composite diaphragm, a preparation method of the composite diaphragm and a sound production device

Background

Among the current sound generating mechanism, the vibrating diaphragm adopts compound vibrating diaphragm structure more. The existing elastomer diaphragm material adopts unique soft and hard section combination, has both thermal plasticity and good rebound resilience, has excellent cost performance, and is widely applied to composite diaphragm structures.

The existing vibrating diaphragm with a thermoplastic elastomer composite structure mostly adopts a composite structure of a thermoplastic elastomer and a conventional acrylic acid adhesive film/silica gel adhesive film, and because no reinforcing agent is contained in the conventional acrylic acid adhesive film/silica gel adhesive film, the modulus of the conventional adhesive film is small, and the conventional adhesive film is easy to extrude and flow at high temperature.

Referring to fig. 1, a composite diaphragm 1 'made of an existing elastomer is formed in a high-temperature gas explosion mode, a corrugated ring root 11' of the composite diaphragm 1 'is easily extruded, so that a glue layer of the corrugated ring root 11' is thinned, the uniformity of the overall thickness of the composite diaphragm is poor, and stress concentration is easily caused in the process of reliability verification, so that reliability failure is caused. Moreover, the long-term service temperature of the thermoplastic elastomer is not high, the heat dissipation capacity is limited due to limited module space, the temperature of the composite diaphragm is obviously increased along with the high-power and long-time vibration of the composite diaphragm, and the thermoplastic elastomer is easy to generate unrecoverable deformation, so that the service life of a product is influenced.

Disclosure of Invention

An object of the application is to provide a compound vibrating diaphragm, a preparation method of the compound vibrating diaphragm and a sound production device with the compound vibrating diaphragm, wherein each part of the compound vibrating diaphragm is uniform in thickness and excellent in reliability, and the compound vibrating diaphragm has the characteristics of high damping, high resilience, long service life, oil resistance, weather resistance and the like.

The above and other objects are achieved by the features of the independent claims. Further implementations are presented in the dependent claims, the description and the drawings.

In a first aspect, the application provides a composite diaphragm, which comprises a diaphragm layer and a supporting layer, wherein the diaphragm layer is prepared by a cross-linking reaction of a rubber material and a cross-linking agent, the rubber material comprises at least one of ethylene-acrylate binary copolymer and ethylene-acrylate-unsaturated organic carboxylic acid terpolymer, the rubber material comprises 100 parts by mass, the cross-linking agent comprises 0.5-10 parts by mass, and the modulus of the diaphragm layer is 1-20 MPa; the supporting layer is made of thermoplastic elastomer.

The crosslinking agent is a peroxide crosslinking agent.

Optionally, the peroxide crosslinking agent comprises at least one of 1,3-1, 4-di (t-butylperoxyisopropyl) benzene, dicumyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) -3-hexyne, n-butyl 4,4 '-bis (t-butylperoxy) valerate, 1' -bis (t-butylperoxy) -3,3,5 trimethylcyclohexane, and 2, 4-dichlorobenzoyl peroxide.

Optionally, the content of the unsaturated organic carboxylic acid in the ethylene-acrylate-unsaturated organic carboxylic acid terpolymer is (0.1-4.5)% of the terpolymer.

Optionally, the adhesive film layer further includes a filler; the filler is 3-60 parts by weight.

Optionally, the filler comprises at least one of silica, silicate, carbonate, amorphous carbon.

Optionally, the thickness of the adhesive film layer is 5 um-100 um.

Optionally, the hardness of the adhesive film layer is 25A-75A.

Optionally, the adhesive film layer is made by a calendaring or coating process.

Optionally, the glue film layer and the support layer are attached to each other, and the composite diaphragm is formed through gas explosion molding.

Optionally, the thermoplastic elastomer comprises at least one of a polyester thermoplastic elastomer, a polyurethane thermoplastic elastomer, a polyolefin thermoplastic elastomer, a polystyrene thermoplastic elastomer, and a polyamide thermoplastic elastomer.

Optionally, the composite diaphragm includes a glue film layer and a supporting layer, and the glue film layer and the supporting layer are bonded;

or the support layer comprises a first support layer and a second support layer; the first supporting layer and the second supporting layer are respectively attached to two sides of the adhesive film layer.

In a second aspect, the present application also provides a sound generating device, where the sound generating device includes a magnetic circuit system and a vibration system that are matched with each other, and the vibration system includes the above-mentioned diaphragm.

The present application also provides a method for manufacturing a composite diaphragm, including:

step S1, mixing 100 parts by mass of rubber material and 0.5-10 parts by mass of cross-linking agent to prepare rubber film blank; wherein the rubber material comprises at least one of ethylene-acrylate binary copolymer and ethylene-acrylate-unsaturated organic carboxylic acid ternary copolymer;

step S2, adhering the glue film blank and the supporting layer to form a composite layer;

and step S3, heating and pressurizing the composite layer to form the composite diaphragm.

Optionally, in step S1, a coating process is used to mix at least one of the ethylene-acrylate binary copolymer and the ethylene-acrylate-unsaturated organic carboxylic acid ternary copolymer with a cross-linking agent to prepare a sheet-shaped adhesive film blank.

Optionally, a process of drying the adhesive film blank is further included between the step S1 and the step S2, wherein the drying temperature is 80 ℃ to 100 ℃.

Optionally, in step S3, performing gas explosion molding on the composite layer to form the diaphragm;

and in the gas explosion forming process, the rubber film blank is subjected to a crosslinking reaction and is shaped. Further features of the present application and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

The technical scheme provided by the application can achieve the following beneficial effects:

the glue film layer in this application has high damping, high resilience, characteristics such as longe-lived, resistant oil, weatherability, and the glue film layer bonds with the supporting layer firmly, and the glue film layer modulus is higher than conventional acrylic acid glued membrane/silica gel glued membrane layer. In the vibrating diaphragm forming process, the film layer is extruded and uniformly deformed, the thickness of each part of the vibrating diaphragm is uniform, and the reliability is excellent. The composite vibrating diaphragm has the advantages that the high-temperature resilience is improved, the composite vibrating diaphragm can be deformed and restored in the high-temperature vibrating process, and the acoustic performance is better.

Drawings

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.

FIG. 1 is a schematic diagram of a thickness of a composite diaphragm in the prior art;

FIG. 2 is a schematic thickness diagram of a composite diaphragm of the present application;

FIG. 3 is a schematic diagram of a first cross-sectional structure of a composite diaphragm;

FIG. 4 is a schematic diagram of a second cross-sectional structure of the composite diaphragm;

fig. 5 is a TMA performance test chart of a composite diaphragm of the prior art and a composite diaphragm of the present application.

In the figure, 1' a composite diaphragm; 11', folding ring root; 1. compounding a vibrating diaphragm; 11. the root of the folded ring; 12. a glue film layer; 13. a support layer; 131. a first support layer; 132. a second support layer.

Detailed Description

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

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

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

Referring to fig. 2 to 4, the application provides a composite diaphragm 1, including a rubber film layer 12 and a supporting layer 13, where the rubber film layer 12 is made of a rubber material and a cross-linking agent through a cross-linking reaction, the rubber material includes at least one of an ethylene-acrylate binary copolymer and an ethylene-acrylate-unsaturated organic carboxylic acid ternary copolymer, and the rubber material is 100 parts by mass, the cross-linking agent is 0.5 to 10 parts by mass, and the modulus of the rubber film layer is 1 to 20 MPa; the supporting layer is made of thermoplastic elastomer.

The vibrating diaphragm is of a composite structure of the film layer 12 and the supporting layer 13, and the film layer 12 adopts the binary copolymer and/or the ternary copolymer, so that the modulus of the film layer is improved. In the embodiment of the application, the adhesive film layer 12 is prepared by performing a crosslinking reaction on 100 parts by mass of a rubber material and 0.5-10 parts by mass of a crosslinking agent, so that the content of the crosslinking agent is increased, and the crosslinking degree is improved, thereby further increasing the modulus of the adhesive film layer 12, and enabling the adhesive film layer 12 to have the characteristics of high damping, high resilience, long-term service life, oil resistance, weather resistance and the like. When the mass part of the cross-linking agent is less than 0.5 part, the crosslinking density of the glue film layer 12 is easy to be small, the compression deformation is large, and the composite diaphragm 1 is easy to deform and lose efficacy in a larger diaphragm vibration process. When the mass part of the cross-linking agent is more than 10 parts, the cross-linking degree of the adhesive film layer 12 is too high, the elongation at break of the adhesive film layer 12 is reduced, the overall low-temperature reliability of the composite diaphragm 1 is poor, and the diaphragm breakage is easy to occur.

The adhesive film layer 12 and the supporting layer 13 are firmly bonded, and the modulus of the adhesive film layer 12 is 1 MPa-20 MPa which is higher than that of the common acrylic adhesive film/silica gel adhesive film in the prior art. Fig. 1 is a schematic diagram showing the thickness of a composite diaphragm in the prior art; referring to fig. 2, a thickness diagram of the composite diaphragm of the present application is shown. As is apparent from fig. 1 and 2, the edge portion 11 'of the composite diaphragm 1' in the prior art is easily squeezed, so that the glue layer of the edge portion 11 'becomes thinner, the uniformity of the overall thickness of the composite diaphragm 1' becomes worse, and stress concentration is easily caused in the process of verifying the reliability, thereby causing reliability failure. And in the compound vibrating diaphragm 1 forming process of this application, the glued membrane layer 12 receives the extrusion but evenly deforms, and it is slight that the extrusion of the ring root 11 is glued in the compound vibrating diaphragm forming process, and compound vibrating diaphragm thickness homogeneity is excellent, and the reliability is more excellent.

Referring to fig. 5, which is a TMA performance test chart of a composite diaphragm of the prior art and the composite diaphragm of the present application, it can be seen from fig. 5 that the composite diaphragm of the present application has a lower tensile expansion amount in the same temperature environment, so that the composite diaphragm 1 of the present application has a smaller deformation amount and a higher temperature resistance in a high-temperature environment generated in a high-power and long-time vibration process.

In addition, the adhesive film layer 12 of the present application adopts a chemical crosslinking method, so that the temperature resistance is improved, the long-term use temperature can reach 170-.

Specifically, the ethylene-acrylate binary copolymer may be represented by the following chemical formula:

wherein R is alkyl, and x and y are natural numbers.

The ethylene-acrylate-unsaturated organic carboxylic acid terpolymer may be represented by the following formula:

wherein R, R' is alkyl, and x, y and z are natural numbers.

The existing single-layer AEM vibrating diaphragm is generally vulcanized at high temperature, the vulcanizing temperature is 190-230 ℃, the vulcanizing time is 60-1000 s, and the vulcanizing temperature is higher and the vulcanizing time is shorter. The supporting layer 13 that this application composite diaphragm 1 adopted adopts thermoplastic elastomer to make, and thermoplastic elastomer temperature toleration is general, at 1 fashioned in-process of composite diaphragm, if forming temperature surpasses 180 ℃ can appear obvious composite diaphragm 1 and glue the die head problem, and the membrane in-process is got to the diaphragm, causes the diaphragm tensile easily, seriously influences the production yield. In this regard, the crosslinking agent used herein is a low-temperature vulcanizing agent, and may be, for example, a peroxide crosslinking agent. By adopting the peroxide crosslinking agent, a low-temperature vulcanizing agent vulcanizing system is realized, the vulcanizing temperature is 140-180 ℃, and the vulcanizing time is 30-300s, so that the deformation of the supporting layer 13 is prevented, and the product quality is improved.

Specifically, the peroxide crosslinking agent includes at least one of 1,3-1, 4-di (t-butylperoxyisopropyl) benzene, dicumyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane, t-butylcumyl peroxide, 2, 5-dimethyl-2, 5-bis (t-butylperoxy) -3-hexyne, n-butyl 4,4 '-bis (t-butylperoxy) valerate, 1' -bis (t-butylperoxy) -3,3,5 trimethylcyclohexane and 2, 4-dichlorobenzoyl peroxide.

In one possible embodiment, the unsaturated organic carboxylic acid content of the ethylene-acrylate-unsaturated organic carboxylic acid terpolymer is (0.1-4.5)% of the terpolymer.

In this embodiment, the unsaturated organic carboxylic acid in the terpolymer is the main crosslinking group, and increasing its proportion can increase the amount of reactive groups, thereby increasing the degree of crosslinking, and increasing the modulus and resilience of the film layer. When the content of the unsaturated organic carboxylic acid is lower than 0.1 percent of the terpolymer, the crosslinking monomer amount is small, the crosslinking density is low, the rebound resilience is poor, and the high-temperature vibration deformation failure is easy to occur; when the content of the unsaturated organic carboxylic acid is higher than 4.5 percent of the terpolymer, the amount of the crosslinking monomer is large, the crosslinking density is too high, the elongation at break is reduced, the low-temperature rebound resilience is poor, and the low-temperature reliability film rupture of the product is easily caused.

In one possible embodiment, the adhesive film layer may further include filler and auxiliary ingredients; the filler is 3-60 parts by weight. In this embodiment, the effect of increasing the elastic modulus of the adhesive film layer can be achieved by adding the filler to the adhesive film layer.

Wherein the filler comprises at least one of silicon oxide, silicate, carbonate and amorphous carbon.

In one possible embodiment, a reinforcing agent may be added to the ethylene-acrylate binary copolymer and/or the ethylene-acrylate-unsaturated organic carboxylic acid terpolymer. The reinforcing agent can improve the hardness of the composite vibrating diaphragm and plays a role in reinforcing. Wherein, the strengthening agent can comprise at least one of carbon black, fumed silica and precipitated calcium carbonate. The carbon black may be at least one of N550FEF, N683APF, N774SRF-HMAS, N762SRF-LMNS, ISAF and MT.

In a possible implementation, in the composite diaphragm 1 provided in this embodiment of the present application, the thickness of the glue film layer 12 is 5um to 100 um. Wherein, the adhesive film layer 12 has the best combination property when the thickness is 5 um-100 um. When the thickness of glue film layer 12 is less than 5um, the damping of off-the-shelf compound vibrating diaphragm 1 is little, and THD (harmonic distortion) is high, and when the thickness of glue film layer 12 exceeded 100um, off-the-shelf compound vibrating diaphragm 1 weight was too big, and sensitivity worsened, consequently when the thickness of glue film layer 12 was less than 5um or when thickness exceeded 100um, the acoustic performance was all not good.

In one possible embodiment, the adhesive film layer 12 has a hardness of 25A to 75A. When the hardness of the adhesive film layer 12 is less than 25A, the hardness of the adhesive film layer 12 is too low, the molecular weight of the copolymer used in the adhesive film layer 12 is low, the filler is less, the crosslinking degree is low, and the adhesive film layer 12 is easily unrecoverable and deformable in the vibration process of the adhesive film layer 12, so that the composite diaphragm 1 fails. When the hardness of the adhesive film layer 12 is higher than 75A, the filler amount in the adhesive film layer 12 is large, the filler is easy to agglomerate and is uneven and defective points, the breaking elongation of the adhesive film layer 12 is reduced, and the film is easy to break and lose efficacy in low-temperature reliability verification. Therefore, when the hardness of the adhesive film layer 12 is designed to be 25A to 75A, the service life of the composite diaphragm 1 is prolonged, and the acoustic performance of the composite diaphragm 1 is improved.

In one possible embodiment, the adhesive film layer 12 is made by a calendaring or coating process.

When the calendering process is adopted, the material passes through a series of horizontal roller gaps which rotate oppositely, so that the material is subjected to extrusion and extension, and finally the flaky adhesive film layer 12 with set thickness, width and smooth surface is manufactured. Alternatively, the material may be formed into a paste polymer, and the sheet-like film layer 12 may be formed by a coating process.

In a possible embodiment, the adhesive film layer 12 and the supporting layer 13 are attached to each other and are air-blasted to form the diaphragm. Because the adhesive film layer 12 has a certain viscosity, when the adhesive film layer 12 and the supporting layer 13 are bonded, the two are further fixedly connected under the action of high temperature and high pressure in the gas explosion forming.

In one possible embodiment, the thermoplastic elastomer comprises at least one of a polyester thermoplastic elastomer, a polyurethane thermoplastic elastomer, a polyolefin thermoplastic elastomer, a polystyrene thermoplastic elastomer, a polyamide thermoplastic elastomer.

Optionally, referring to fig. 3, the composite diaphragm 1 includes a glue film layer 12 and a support layer 13, and the glue film layer 12 and the support layer 13 are bonded together. In this embodiment, the composite diaphragm 1 only includes two layers, which is light and thin, the adhesive film layer 12 is firmly bonded to the supporting layer 13, and the modulus of the adhesive film layer 12 is higher than that of the conventional acrylic adhesive film/silicone adhesive film layer 12. In the vibrating diaphragm forming process, the adhesive film layer 12 is extruded and uniformly deformed, the thickness of each part of the vibrating diaphragm is uniform, and the reliability is excellent.

Alternatively, referring to fig. 4, the support layer 13 includes a first support layer 131 and a second support layer 132; the first support layer 131 and the second support layer 132 are respectively attached to two sides of the adhesive film layer 12. In this embodiment, both sides of the adhesive film layer 12 are provided with a supporting layer, and the supporting layer has a protective effect on the adhesive film layer 12, so that the adhesive film layer 12 maintains good physical properties, thereby being beneficial to prolonging the service life of the product.

The embodiment of the application also provides a sound generating device simultaneously, and the sound generating device comprises a magnetic circuit system and a vibration system which are matched with each other, and the vibration system comprises the composite diaphragm.

The sound production device has the characteristics of good sound effect, small distortion and good waterproof effect.

In the embodiment of the present application, a method for manufacturing a composite diaphragm 1 is also provided, including:

step S1, mixing 100 parts by mass of rubber material and 0.5-10 parts by mass of cross-linking agent to prepare rubber film blank; wherein the rubber material comprises at least one of ethylene-acrylate binary copolymer and ethylene-acrylate-unsaturated organic carboxylic acid ternary copolymer;

step S2, adhering the glue film blank and the supporting layer 13 to form a composite layer;

and step S3, heating and pressurizing the composite layer to form the composite diaphragm 1.

In step S1, at least one of the ethylene-acrylate binary copolymer and the ethylene-acrylate-unsaturated organic carboxylic acid ternary copolymer is mixed with a crosslinking agent by a coating process to form a sheet-shaped adhesive film blank. In this step S1, no crosslinking reaction occurs.

The adhesive film blank is a sheet structure made by a calendaring or coating process, a drying process of the sheet adhesive film blank is further included between the step S1 and the step S2, the adhesive film blank can be dried by an oven, wherein, in order to prevent the crosslinking reaction of the adhesive film layer 12 in the drying process, the drying temperature of the oven is 80-100 ℃. When the drying temperature is lower than 80 ℃, the drying time of the adhesive film layer 12 is long, which is not beneficial to improving the production efficiency, and when the drying temperature is higher than 100 ℃, the adhesive film blank has the risk of cross-linking, so the drying temperature is designed to be 80-100 ℃, and the production efficiency and the manufacturing process requirements are considered.

Optionally, in step S3, performing gas explosion molding on the composite layer to form the diaphragm;

and in the gas explosion forming process, the rubber film blank is subjected to a crosslinking reaction and is shaped. In the forming process of the composite diaphragm 1, the adhesive film layer 12 can be uniformly deformed by extrusion, so that the thickness of each part of the composite diaphragm 1 is more uniform, and the reliability is better. And because the glue film layer 12 adopts a chemical crosslinking method, the temperature resistance is improved, the long-term use temperature can reach 170-.

The application also provides an assembling method of the sound generating device. The method comprises the following steps: the composite diaphragm 1 is directly bonded with at least one of a voice coil, a shell, a reinforcing layer and a magnetic yoke of a sound generating device. Direct bonding means bonding with other components by virtue of the adhesive property of the composite diaphragm 1 itself, rather than bonding with other components by an adhesive.

For example, a housing or a yoke is bonded to the composite diaphragm 1. The adhesive film layer 12 of the composite diaphragm 1 can be vulcanized under a set temperature condition and connected with other components. Since the composite diaphragm 1 itself has adhesive properties, it can be set to a set position directly before molding and bonded to other components. Then, vulcanization molding is performed. Through the mode, the bonding effect and the sealing effect of the composite vibration diaphragm 1 and other parts can be ensured, the waterproof performance of the sound production device is improved, the steps of assembling the composite vibration diaphragm 1 and other parts can be saved, the bonding agent is saved, and the assembling efficiency is improved.

Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present application. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present application. The scope of the application is defined by the appended claims.