CN116367071A - Vibrating diaphragm and sound generating device - Google Patents

Abstract

The invention discloses a vibrating diaphragm and a sound production device, wherein the vibrating diaphragm comprises a mixed hydrogenated carboxylated nitrile rubber film layer, the mixed hydrogenated carboxylated nitrile rubber film layer is formed by mixing 100 parts by mass of hydrogenated carboxylated nitrile rubber, a vulcanizing agent, a filler, an anti-aging agent and other auxiliary agents, and the saturation of a butadiene chain segment in the hydrogenated carboxylated nitrile rubber is more than 70%; wherein the vibrating diaphragm is placed for 500 hours at 160 ℃, and the elongation at break after being taken out and placed for 24 hours is more than or equal to 100 percent. According to the vibrating diaphragm provided by the embodiment of the invention, the mixing type hydrogenated carboxylated nitrile rubber film layer is adopted, and the saturation of the butadiene chain segment in the hydrogenated carboxylated nitrile rubber of the mixing type hydrogenated carboxylated nitrile rubber film layer is more than 70%, so that the high temperature resistance of the vibrating diaphragm can be improved, the vibrating diaphragm can be placed for 500 hours at 160 ℃, the breaking elongation after being taken out and placed for 24 hours is more than or equal to 100%, and the vibrating diaphragm can meet the requirements of a sounding device with higher power and higher heating degree.

Description

Vibrating diaphragm and sound generating device

Technical Field

The invention belongs to the technical field of electroacoustic equipment, and particularly relates to a vibrating diaphragm of a sound generating device and the sound generating device comprising the vibrating diaphragm.

Background

The prior sound generating devices of the wearing products such as earphone, intelligent watch, intelligent bracelet, VR and AR products adopt thermoplastic elastomer or rubber. Among them, for the thermoplastic elastomer, a thermoplastic polyurethane elastomer (TPU) and thermoplastic polyester elastomer (TPEE) composite diaphragm is mostly used. For rubber materials, hydrogenated nitrile rubber (HNBR) is mostly used.

Along with the increasing power of the sound generating device product, the heating value of the sound generating device is also gradually increased, so that the heat resistance requirement of the sound generating device on the vibrating diaphragm is also higher.

However, for TPU materials, their long term temperature resistance does not exceed 100 ℃; for TPEE composite membranes and HNBR, their long-term operating temperature also does not exceed 160 ℃; therefore, development of a new diaphragm with good high temperature resistance applied to a sound generating device is urgently needed.

Disclosure of Invention

An object of the present invention is to provide a diaphragm, which can solve the technical problem of poor high temperature resistance of the diaphragm of the sound generating device in the prior art.

It is still another object of the present invention to provide a sound generating apparatus having the above-mentioned diaphragm.

According to a first aspect of the present invention, there is provided a diaphragm comprising a hydrogenated carboxylated nitrile rubber film layer of a kneading type, the hydrogenated carboxylated nitrile rubber film layer being kneaded from 100 parts by mass of hydrogenated carboxylated nitrile rubber, a vulcanizing agent, a filler, an anti-aging agent and other auxiliaries, wherein the saturation of a butadiene segment in the hydrogenated carboxylated nitrile rubber is more than 70%; wherein the vibrating diaphragm is placed for 500 hours at 160 ℃, and the elongation at break after being taken out and placed for 24 hours is more than or equal to 100 percent.

Optionally, the content of the acrylonitrile group in the mixed hydrogenated carboxylated nitrile rubber film layer is 10-50 wt%.

Optionally, the content of carboxyl in the mixed hydrogenated carboxylated nitrile rubber film layer is 2-7wt%.

Optionally, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 2, antioxidant 6, antioxidant 4, antioxidant 1076, antioxidant 168, antioxidant RD, antioxidant AW, antioxidant DD, antioxidant BLE, antioxidant 4010, 4010NA, 4020, 4030, 4040, antioxidant DNP, antioxidant H, antioxidant A, antioxidant D, antioxidant SP, antioxidant 264, antioxidant 2246-S, antioxidant NBC, and antioxidant MB.

Optionally, the content of the anti-aging agent is 0.1 to 10 parts by mass.

Optionally, the vulcanizing agent adopts at least one of amine vulcanizing agent, epoxy vulcanizing agent, metal oxide and metal peroxide.

Optionally, the content of the vulcanizing agent is 1 to 20 parts by mass.

Optionally, the other auxiliary agents contain vulcanization accelerators, and the vulcanization accelerators adopt at least one of tertiary ammonium, substituted urea, phenols, imidazoles, acetylacetone metal salt and boron trifluoride complex.

Optionally, the content of the vulcanization accelerator is 0.1 to 8 parts by mass.

Optionally, the filler adopts at least one of carbon black, white carbon black, talcum powder, calcium carbonate, magnesium carbonate, dolomite, barium sulfate, zinc sulfide, aluminum powder, graphite, titanium dioxide, lithopone, phenolic resin, petroleum resin and styrene resin.

Optionally, the content of the filler is 5 to 100 parts by mass.

Optionally, the other auxiliary agent comprises at least one of stearic acid, an ultraviolet absorber and color paste.

Alternatively, the diaphragm is formed into a single-layer structure including only one layer of the mixed hydrogenated carboxylated nitrile rubber film layer; or the vibrating diaphragm is formed into a composite layer structure, and the vibrating diaphragm comprises at least one layer of the mixed hydrogenated carboxyl nitrile rubber film layer.

A sound generating device according to an embodiment of the second aspect of the invention, comprising a diaphragm according to any of the above embodiments.

According to the vibrating diaphragm and the sounding device provided by the embodiment of the invention, the mixing type hydrogenated carboxylated nitrile rubber film layer is adopted, and the saturation of the butadiene chain segment in the hydrogenated carboxylated nitrile rubber of the mixing type hydrogenated carboxylated nitrile rubber film layer is more than 70%, so that the high temperature resistance of the vibrating diaphragm can be improved, the vibrating diaphragm can be placed for 500 hours at 160 ℃, the breaking elongation after being taken out and placed for 24 hours is more than or equal to 100%, and the vibrating diaphragm can meet the requirements of the sounding device with higher power and higher heating degree.

Other features of the present invention and its advantages will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

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

FIG. 1 is a schematic diagram of a diaphragm according to an embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of a sound emitting device according to one embodiment of the present invention;

FIG. 3 is a partial cross-sectional view of a sound emitting device according to yet another embodiment of the present invention;

fig. 4 is a schematic diagram showing reliability analysis of the diaphragms prepared in example 1 and comparative example 1.

Reference numerals:

a diaphragm 10; a main body 11; a conductive portion 12;

a voice coil 20; a first diaphragm 21; the second diaphragm 22.

Detailed Description

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 the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.

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

Techniques, methods, and apparatus known to one 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 specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

The diaphragm and the sound generating device according to the embodiment of the invention are described in detail below with reference to the specific drawings. As shown in fig. 1 to 3, the sound generating device may be a speaker unit, and the speaker unit may include a magnetic circuit system, a diaphragm 10, and a voice coil 20 disposed on the diaphragm 10, where one end of the voice coil 20 far away from the diaphragm 10 is inserted into a magnetic gap of the magnetic circuit system. When the speaker unit works, current is supplied to the voice coil 20, and the voice coil 20 vibrates reciprocally under the action of magnetic force to drive the vibrating diaphragm 10 to vibrate and sound.

The vibrating diaphragm 10 according to the embodiment of the invention comprises a mixed hydrogenated carboxylated nitrile rubber film layer, wherein the mixed hydrogenated carboxylated nitrile rubber film layer is formed by mixing 100 parts by mass of hydrogenated carboxylated nitrile rubber, a vulcanizing agent, a filler, an anti-aging agent and other auxiliary agents, and the saturation of a butadiene chain segment in the hydrogenated carboxylated nitrile rubber is more than 70%; wherein, the vibrating diaphragm 10 is placed for 500 hours at 160 ℃, and the elongation at break after being taken out and placed for 24 hours is more than or equal to 100 percent.

In other words, the material of the diaphragm 10 according to the embodiment of the present invention may include hydrogenated carboxylated nitrile rubber, that is, the diaphragm 10 according to the embodiment of the present invention includes a compounded hydrogenated carboxylated nitrile rubber film layer, which may be compounded from hydrogenated carboxylated nitrile rubber, a vulcanizing agent, a filler, an anti-aging agent, and other additives, wherein the content of the hydrogenated carboxylated nitrile rubber may be 100 parts.

In the hydrogenated carboxylated nitrile rubber, the molecular formula of the hydrogenated carboxylated nitrile polymer is shown as the following formula (I):

in formula (I), a, b, c, d, e is a natural number, and the original polymerized monomer of X may be an ethylenically unsaturated monocarboxylic acid or an ethylenically unsaturated dicarboxylic acid. The ethylenically unsaturated monocarboxylic acid may be acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, cinnamic acid, etc. The ethylenically unsaturated dicarboxylic acid may be fumaric acid, maleic acid, glutaconic acid, allylmalonic acid, mesaconic acid, tolconic acid, itaconic acid, triconic acid, etc.

Since the inside of carboxylated nitrile rubber contains two butadiene structures, namely a 1,2 butadiene structure and a 1,4 butadiene structure, and hydrogenated carboxylated nitrile rubber (HXNBR) is synthesized by adopting a carboxylated nitrile rubber hydrogenation method, wherein 1,2 butadiene is easier to hydrogenate and 1,4 butadiene is harder to hydrogenate, the hydrogenation degree is = (a+c)/(a+b+c) ×100%, and the hydrogenation degree refers to the saturation degree of butadiene segments in the rubber.

As can be seen from the above formula of the degree of hydrogenation, the lower the content of b with higher degree of hydrogenation, which indicates that the double bond content of HXNBR of the examples of the present invention is lower. Since the saturation of the butadiene segment is greater than 70% in the hydrogenated carboxylated raw nitrile rubber of the embodiments of the present invention, the hydrogenation in the hydrogenated carboxylated raw nitrile rubber is greater than 70%. It can be seen that the double bond content of the HXNBR of the examples of the present invention is low. The content of double bonds in the molecular chain of the rubber affects the heat aging resistance and the like, and the heat aging resistance in the molecular weight of the rubber decreases with the increase of the content of double bonds. Therefore, in the examples of the present invention, as the hydrogenation degree increases, the double bond content decreases and the temperature resistance of HXNBR increases.

In addition, the hydrogenation degree of the HXNBR is more than 70%, the vibrating diaphragm 10 is placed for 500 hours at 160 ℃, the breaking elongation after being taken out and placed for 24 hours is more than or equal to 100%, that is, the vibrating diaphragm has good high temperature resistance due to the low double bond content in the HXNBR, the vibrating diaphragm 10 of the embodiment of the invention can be used at 160 ℃ for a long time, and the vibrating diaphragm product can still be kept normally after 500 hours of reliability at the temperature. It should be noted that if the hydrogenation degree of HXNBR is less than 70%, the material of the diaphragm 10 is resistant to temperature difference, and the requirement of the sound generating device cannot be met.

In addition, the diaphragm 10 according to the embodiment of the invention adopts the HXNBR rubber, and the HXNBR material has good comprehensive properties, such as good high temperature resistance, excellent mechanical properties, processability and the like, and the diaphragm 10 prepared from the HXNBR rubber has good acoustic properties.

In addition, for oil resistance, the mixing type hydrogenated carboxylated nitrile rubber film layer provided by the embodiment of the invention contains acrylonitrile, and the polarity of the acrylonitrile is strong, and the molecular structure arrangement is compact, so that the existence of the acrylonitrile has strong stability for nonpolar and low-polarity solvents, in particular for gasoline and aliphatic hydrocarbon oil solvents. That is, the oil resistance of the diaphragm 10 product obtained in the embodiment of the present invention can be improved by introducing acrylonitrile.

For ozone resistance, conventional nitrile rubber contains a large amount of unsaturated double bonds, and the unsaturated double bonds are easy to be subjected to oxidation reaction such as ozone, so that the chain is broken, and the conventional nitrile rubber is not resistant to ozone. Compared with the prior art, the HXNBR has lower double bond content, so that the diaphragm 10 product obtained by the embodiment of the invention can better resist ozone attack, namely the ozone resistance of the diaphragm 10 is improved.

As for mechanical properties, because the acrylonitrile also has strong polarity, when the acrylonitrile content is higher, the polarity of the material containing the acrylonitrile is stronger, and the hardness and the stretching stress are both improved, so that the mechanical properties are improved, that is, the vibrating diaphragm 10 product obtained by the embodiment of the invention has higher mechanical properties.

Therefore, according to the vibrating diaphragm 10 of the embodiment of the invention, the mixing type hydrogenated carboxylated nitrile rubber film layer is adopted, and the saturation of the butadiene chain segment in the hydrogenated carboxylated nitrile rubber of the mixing type hydrogenated carboxylated nitrile rubber film layer is more than 70%, so that the high temperature resistance of the vibrating diaphragm 10 can be improved, the vibrating diaphragm 10 can be placed for 500 hours at 160 ℃, the elongation at break after being taken out and placed for 24 hours is more than or equal to 100%, and the vibrating diaphragm 10 can meet the requirements of a sounding device with higher power and higher heating degree.

According to one embodiment of the invention, the content of the acrylonitrile group in the mixed hydrogenated carboxylated nitrile rubber film layer is 10-50 wt%, so that the diaphragm 10 prepared from the mixed hydrogenated carboxylated nitrile rubber film layer has oil resistance, air tightness, tensile strength, processability, cold resistance and rebound resilience.

It should be noted that, the nitrile group is a strong polar group, and has higher electronegativity, and if the acrylonitrile content is less than 10wt%, the molecular chain in the mixed hydrogenated carboxylated nitrile rubber film layer has better flexibility, low intermolecular force, low glass transition temperature, low tensile strength and poor rebound resilience, and can not meet the requirements of the diaphragm 10.

Along with the increase of the acrylonitrile content, the polarity of HXNBR is increased, the flexibility of molecular chains is also reduced, the interaction force among the molecular chains is increased, the glass transition temperature is increased, the content of double bonds in the molecular chains is reduced, the saturation degree is increased, the oil resistance, the air tightness and the relative density of the mixed hydrogenated carboxylated nitrile rubber film layer are improved, the vulcanization speed is increased, the tensile strength performance is improved, but the processability, the cold resistance and the rebound resilience performance are all reduced. Particularly, when the content of the acrylonitrile block is more than 50wt%, the cold resistance of the mixed hydrogenated carboxylated nitrile rubber film layer is poor, and the prepared diaphragm 10 is easy to harden and become brittle in a low-temperature extreme environment, so that the risk of rupture of the diaphragm is increased.

It can be seen that in this embodiment, when the content of the acrylonitrile group in the hydrogenated carboxylated nitrile rubber film layer is 10wt% to 50wt%, the prepared diaphragm 10 can be made to have heat resistance, cold resistance, oil resistance, and the like. Alternatively, the content of acrylonitrile groups in the compounded hydrogenated carboxylated nitrile rubber film layer is 10wt%, 12wt%, 15wt%, 20wt%, 30wt%, 40wt%, 50wt%, etc.

According to one embodiment of the invention, the content of carboxyl in the mixed hydrogenated carboxylated nitrile rubber film layer is 2-7wt%, so that the prepared diaphragm 10 has good high temperature resistance, good mechanical property, high elongation at break and the like.

It should be noted that, when the content of carboxyl groups in the raw rubber of the hydrogenated carboxylated nitrile rubber is less than 2wt%, more crosslinking points cannot be provided due to the low content of carboxyl groups, so that the crosslinking density is low, the strength is low, the polarity is low, and the high temperature resistance is insufficient, so that the prepared diaphragm 10 is poor in high temperature resistance. When the carboxyl content is more than 6wt%, the polarity is large, the crosslinking density is high, the toughness of the material is reduced, the elongation at break is reduced, and the membrane rupture phenomenon is easy to occur in the vibration process of the vibrating membrane 10 product.

It can be seen that, in this embodiment, when the content of carboxyl in the mixed hydrogenated carboxylated nitrile rubber film layer is 2wt% -7 wt%, not only the diaphragm 10 can be ensured to have better high temperature resistance and mechanical properties, but also the phenomenon of rupture of the diaphragm in the vibration process can be avoided. Alternatively, the content of carboxyl groups in the kneaded hydrogenated carboxylated nitrile rubber film layer is 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, or the like.

In some embodiments of the invention, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 2, antioxidant 6, antioxidant 4, antioxidant 1076, antioxidant 168, antioxidant RD, antioxidant AW, antioxidant DD, antioxidant BLE, antioxidant 4010, 4010NA, 4020, 4030, 4040, antioxidant DNP, antioxidant H, antioxidant A, antioxidant D, antioxidant SP, antioxidant 264, antioxidant 2246-S, antioxidant NBC, antioxidant MB. In the present embodiment, by adding the above-described anti-aging agent, the effect of extending the service life of the diaphragm 10 can be achieved. For example, by using the age resistor RD, the high temperature aging resistance of the diaphragm 10 can be improved.

According to one embodiment of the invention, the content of the anti-aging agent is 0.1 to 10 parts by mass, and the anti-aging agent with the range can play a role in better prolonging the service life.

If the content of the antioxidant is less than 0.1 parts by mass, that is, the amount of the antioxidant added is too small, the effect of extending the service life cannot be obtained by too small amount of the antioxidant. If the content of the anti-aging agent is more than 10 parts by mass, the addition amount of the anti-aging agent is too much, and since the excessive anti-aging agent cannot be well miscible with the elastomer, it is difficult to uniformly disperse, so that the mechanical properties of the prepared diaphragm 10 are reduced, the elongation at break is reduced, and the anti-aging agent is easily precipitated to the surface over time.

The following test results are shown in table 1 below for the elongation at break before and after reliability of HXNBR film layers added with different amounts of anti-aging agent.

TABLE 1 reliability before and after elongation at break of HXNBR films with different amounts of anti-aging agent

The tensile strength testing method comprises the following steps: the raw materials of the diaphragm 10 with different anti-aging agent contents in the table 1 are taken, other components and addition amounts are the same, the standard distance is 30mm, the stretching rate is 300mm/min according to the test standard of ASTM-D882, the diaphragm is tested to be placed at 160 ℃ for 500 hours, and the diaphragm is taken out and then is placed for 24 hours to obtain the elongation at break.

As can be seen from Table 1, when the content of the anti-aging agent was 0.5 part by mass, 4 parts by mass and 8 parts by mass, the HXNBR film layer was left at 160℃for 500 hours, and after taking out, the elongation at break after standing for 24 hours was more than 100%, and the elongation at break was high. And when the content of the anti-aging agent is 0 part by mass and 20 parts by mass, the HXNBR film layer has lower elongation at break.

It can be seen that in this embodiment, by adopting the antioxidant in an amount of 0.1 to 10 parts by mass, the effect of better prolonging the service life can be achieved. Alternatively, the content of the antioxidant is 0.1 part by mass, 1 part by mass, 3 parts by mass, 5 parts by mass, 6 parts by mass, 10 parts by mass, or the like.

According to one embodiment of the present invention, the vulcanizing agent is at least one of an amine vulcanizing agent, an epoxy vulcanizing agent, a metal oxide, and a metal peroxide. Optionally, the amine cross-linking agent comprises at least one of hexamethylenediamine, hexamethylenediamine carbamate, triethylenetetramine, methylenedianiline, and di-o-toluene guanidine. Alternatively, the epoxy vulcanizing agent has no less than two functional groups, including phenolsAt least one of glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, linear aliphatic type epoxy resin, and alicyclic type epoxy resin. Optionally, the metal oxide vulcanizing agent comprises at least one of ZnO and MgO. Alternatively, the metal peroxide comprises ZnO ₂ With MgO (MgO) ₂ At least one of them.

Alternatively, the vulcanizing agent employs a peroxide, such as an organic peroxide. The diaphragm 10 product prepared by adopting peroxide for vulcanization and matching with promoters such as triallyl isocyanate, triallyl cyanurate and the like can also have good temperature resistance. By using peroxides as vulcanizing agent can be applied to HXNBR with fewer double bonds inside and can be applied to HXNBR with low hydrogenation degree types.

According to one embodiment of the present invention, the vulcanizing agent is contained in an amount of 1 to 20 parts by mass, which is advantageous in that the diaphragm 10 prepared has both strength and elongation at break. It should be noted that, when the content of the vulcanizing agent is less than 1 part by mass, the amount of generated crosslinking bonds is small, the reaction degree is low, the crosslinked network structure is not compact enough, and the strength of the obtained diaphragm 10 is low, so that the diaphragm 10 cannot be applied. When the content of the vulcanizing agent is more than 20 parts by mass, the crosslinking degree is made too high, so that the elongation at break of the diaphragm 10 is made too low, and the diaphragm 10 cannot be used. Alternatively, the content of the vulcanizing agent is 1 part by mass, 2 parts by mass, 5 parts by mass, 10 parts by mass, 15 parts by mass, 16 parts by mass, 20 parts by mass, or the like.

In some embodiments of the invention, the other auxiliary agent contains a vulcanization accelerator, wherein the vulcanization accelerator adopts at least one of tertiary ammonium, substituted urea, phenols, imidazoles, acetylacetone metal salt and boron trifluoride complex.

According to one embodiment of the present invention, the content of the vulcanization accelerator is 0.1 to 8 parts by mass, which is advantageous for improving the preparation efficiency of the diaphragm 10 and ensuring the appearance aesthetic property of the diaphragm 10. It should be noted that, when the content of the vulcanization accelerator is less than 0.1 part by mass, the acceleration efficiency tends to be low, and the reaction time is too long, so that the cost for manufacturing the diaphragm is high. When the content of the vulcanization accelerator is higher than 8 parts by mass, scorching is likely to occur when the hydrogenated carboxylated nitrile rubber is used for producing a diaphragm, and the storage time is too short, and the vulcanization accelerator and the hydrogenated carboxylated nitrile rubber have poor compatibility and are likely to migrate and separate out from the hydrogenated carboxylated nitrile rubber, that is, the appearance aesthetic property of the diaphragm 10 is affected. Alternatively, the content of the vulcanization accelerator is 0.1 part by mass, 1 part by mass, 2 parts by mass, 4 parts by mass, 5 parts by mass, 6 parts by mass, 8 parts by mass, or the like.

In some embodiments of the present invention, the filler is at least one of carbon black, white carbon black, talc, calcium carbonate, magnesium carbonate, dolomite, barium sulfate, zinc sulfide, aluminum powder, graphite, titanium dioxide, lithopone, phenolic resin, petroleum resin, and styrene resin.

The filler will be described below by taking carbon black as an example.

Carbon black is an amorphous structure in which particles form aggregates by physicochemical bonds with each other. The primary structure of carbon black is composed of aggregates, and van der Waals forces or hydrogen bonds exist between the aggregates, so that the aggregates can be aggregated into a space network structure, namely, a secondary structure of carbon black. The surface of carbon black has hydrogen, carboxyl, lactone, radical, quinone, and other groups that can undergo substitution, reduction, oxidation, and the like. When the carbon black is added into HXNBR, due to the strong interaction between the surface of the carbon black and a rubber interface, when the material is stressed, a molecular chain slides on the surface of the carbon black relatively easily, but is not easy to separate from the carbon black, and the elastomer and the carbon black form a strong bond capable of sliding, so that the mechanical strength is increased, and the mechanical property of the vibrating diaphragm can be improved.

According to one embodiment of the present invention, the filler content is 5 to 100 parts by mass, and the filler added in the above range can ensure a strong interaction between the carbon black and the rubber interface. If the amount of carbon black is less than 5 parts by mass, the tensile strength of the diaphragm 10 is low; if the amount of the carbon black is more than 100 parts by mass, the elongation at break of the diaphragm 10 is reduced. Therefore, the prepared mixed hydrogenated carboxylated nitrile rubber film layer can meet the use requirement of the vibrating diaphragm 10 when the content of the filler is 5-100 parts by mass. Further, the content of the filler may be 5 parts by mass, 10 parts by mass, 20 parts by mass, 30 parts by mass, 40 parts by mass, 50 parts by mass, 60 parts by mass, 70 parts by mass, 80 parts by mass, 90 parts by mass, 100 parts by mass, or the like.

In some embodiments of the present invention, the other auxiliary agents include at least one of stearic acid, an ultraviolet absorber, and color paste. By adding different auxiliary agents, the film layer can have different functions. For example, stearic acid as a mold release agent can improve lubricity during the rubber mixing process and mold release of the product during the production process. The color paste can dye rubber, the conventional HXNBR is colored rubber, so that the appearance attractiveness is lower, and the vibrating diaphragm 10 with different colors can be prepared by adding the color paste, so that the appearance attractiveness is improved. In addition, since unsaturated carbon-carbon double bonds in HXNBR are not completely hydrogenated and can be degraded under ultraviolet radiation, the film layer can have an ultraviolet absorption function by adding an ultraviolet absorber, and the prepared diaphragm 10 also has an ultraviolet absorption function.

Alternatively, the thickness of the compounded hydrogenated carboxylated nitrile rubber film is 25 μm to 300. Mu.m, and the preparation and use of the diaphragm 10 are facilitated by using the compounded hydrogenated carboxylated nitrile rubber film having a thickness in this range. Alternatively, the thickness of the compounded hydrogenated carboxylated nitrile rubber film layer is 25 μm, 30 μm, 50 μm, 100 μm, 150 μm, 160 μm, 200 μm, 300 μm, etc.

In some embodiments of the present invention, the diaphragm 10 is formed as a single-layer structure including only one layer of the compounded hydrogenated carboxylated nitrile rubber film; or, the diaphragm 10 is formed in a composite layer structure, and the diaphragm 10 includes at least one layer of a mixed hydrogenated carboxylated nitrile rubber film.

That is, the diaphragm 10 according to the embodiment of the present invention may be a single-layer film structure, or may be a film structure composed of a plurality of film layers, so long as the requirement that the diaphragm 10 contains at least one hydrogenated carboxylated nitrile rubber film layer is satisfied. Thus, the diaphragm 10 according to the embodiment of the present invention can meet the product requirements of different sound generating devices.

In addition, the vibrating diaphragm 10 provided by the invention can form a sound generating device with any structure. As shown in fig. 2, the sound generating device according to the embodiment of the invention includes a housing, a magnetic circuit system disposed in the housing, and a vibration system matched with the vibration system, wherein the vibration system includes a diaphragm 10 and a voice coil 20 combined on one side of the diaphragm 10, the magnetic circuit system drives the voice coil 20 to vibrate so as to drive the diaphragm 10 to generate sound, and the diaphragm 10 is the diaphragm 10 in the above embodiment. Specifically, when the sound generating device works, the voice coil 20 can vibrate up and down under the action of the magnetic field force of the magnetic circuit system after the voice coil 20 is electrified so as to drive the vibrating diaphragm 10 to vibrate, and sound can be generated when the vibrating diaphragm 10 vibrates. The sound generating device comprises a diaphragm 10 made according to the above described embodiments of the invention.

In other specific embodiments of the present invention, as shown in fig. 3, the sound generating device according to the embodiment of the present invention includes a housing, and a magnetic circuit system and a vibration system disposed in the housing, where the vibration system includes a voice coil 20, a first diaphragm 21 and a second diaphragm 22, the top of the voice coil 20 is connected to the first diaphragm 21, the magnetic circuit system drives the voice coil 20 to vibrate to drive the first diaphragm 21 to generate sound, two ends of the second diaphragm 22 are respectively connected to an external circuit and the bottom of the voice coil 20, and the second diaphragm 22 is a diaphragm of the above embodiment.

That is, the sound generating apparatus according to the embodiment of the present invention may further include two diaphragms, i.e., the first diaphragm 21 and the second diaphragm 22, which are manufactured by the above-described embodiments of the present invention, the first diaphragm 21 may be used for vibration sound generation, and the second diaphragm 22 may be used for balancing the vibration of the voice coil 20. Specifically, when the sound generating device works, the voice coil 20 can vibrate up and down under the action of the magnetic field force of the magnetic circuit system after the voice coil 20 is electrified so as to drive the first vibrating diaphragm 21 to vibrate, and sound can be generated when the first vibrating diaphragm 21 vibrates. The second diaphragm 22 can also vibrate up and down along with the voice coil 20, and since two ends of the second diaphragm 22 are respectively connected with an external circuit and the bottom of the voice coil 20, the second diaphragm 22 can balance the vibration of the voice coil 20, and can prevent the voice coil 20 from generating polarization, thereby improving the sound production effect of the sound production device.

It should be noted that the first diaphragm 21 and the second diaphragm 22 may be used in combination with the diaphragm 10 according to the above embodiment of the present invention, or one of the first diaphragm 21 and the second diaphragm 22 may be used with the diaphragm 10 according to the above embodiment of the present invention, which is not particularly limited.

The electronic device according to the embodiment of the present invention includes the sound generating device of the above embodiment, and the sound generating device adopts the diaphragm of the above embodiment, and since the diaphragm according to the above embodiment of the present invention has the above technical effects, the electronic device according to the embodiment of the present invention also has the corresponding technical effects, that is, the diaphragm 10 has high temperature resistance, which can meet the requirements of the sound generating device having higher power and a higher heating degree.

The diaphragm 10 and the sound generating device of the present invention will be described in detail with reference to specific embodiments.

Example 1

Raw hydrogenated carboxylated nitrile (HXNBR) rubber (content 100 parts by mass), bisphenol A epoxy resin (vulcanizing agent, epoxy value 435g/eq, content 6 parts by mass), modified imidazole (vulcanization accelerator, content 1 part by mass), carbon black (filler, content 50 parts by mass) and antioxidant 264 (antioxidant, content 3 parts by mass) were kneaded. Wherein, in the hydrogenated carboxylated nitrile rubber, the saturation of the butadiene chain segment is 85 percent.

Comparative example 1

Raw hydrogenated carboxylated nitrile (HXNBR) rubber (content 100 parts by mass), bisphenol A epoxy resin (vulcanizing agent, epoxy value 435g/eq, content 6 parts by mass), modified imidazole (vulcanization accelerator, content 1 part by mass), carbon black (filler, content 50 parts by mass) and antioxidant 264 (antioxidant, content 3 parts by mass) were kneaded. Wherein, in the hydrogenated carboxylated nitrile rubber, the saturation of the butadiene chain segment is 40 percent.

Comparative example 2

Hydrogenated Nitrile Butadiene (HNBR) crude rubber (content 100 parts by mass), dicumyl peroxide (DCP) (vulcanizing agent, content 4 parts by mass), TAIC (vulcanization accelerator, content 1 part by mass), carbon black (filler, content 50 parts by mass), and antioxidant 264 (antioxidant, content 3 parts by mass) were kneaded. Wherein, in the hydrogenated nitrile rubber, the saturation of the butadiene chain segment is 85 percent.

Comparative example 3

A TPU film having a hardness of 80A and a thickness of 70. Mu.m.

The single-layer diaphragms and diaphragms of 0.1mm were produced by vulcanizing each of example 1, comparative example 1 and comparative example 2 at 200℃for 10 minutes and at a pressure of 3 MPa.

Wherein, example 1, comparative example 2 and comparative example 3 were all prepared based on the similar F0 of the diaphragms when preparing the diaphragms.

The diaphragms prepared in example 1, comparative example 2 and comparative example 3 were subjected to strength test before and after reliability and acoustic performance test, respectively, as follows.

Among them, the high temperature reliability conditions (corresponding to the high temperature resistant conditions) are as follows:

the material was placed at 160 ℃ for 500h, taken out and left to stand for 24h, and then tested for strength before and after reliability.

The diaphragm is placed at 150 ℃, then a power-on test is carried out, the voltage is 2.4v, the time is 500h, and the acoustic performance is tested after the diaphragm is taken out. The test results obtained are shown in table 2 below.

TABLE 2 intensity of the diaphragm before and after reliability

As can be seen from table 2, the strength of the diaphragm of example 1 before high temperature reliability was 32MPa and the strength after high temperature reliability was 25MPa, and it was found that the strength of the diaphragm of example 1 after high temperature reliability was reduced by 7Ma.

Whereas the diaphragm of comparative example 1 had a strength of 26MPa before high temperature reliability and a strength of 6MPa after high temperature reliability, it was found that the diaphragm of comparative example 1 had a strength decrease of 20Ma after high temperature reliability. The diaphragm of comparative example 2 had a strength of 27MPa before high temperature reliability and 7MPa after high temperature reliability, and it was found that the diaphragm of comparative example 2 had a strength decrease of 20Ma after high temperature reliability. The diaphragm of comparative example 3 had a strength of 50MPa before high temperature reliability and a strength of 2MPa after high temperature reliability, and it was found that the diaphragm of comparative example 3 had a strength decrease of 48Ma after high temperature reliability.

As can be seen, the diaphragms in example 1 are optimal in temperature resistance and minimal in degree of strength change before and after high temperature reliability, as compared with examples 1 and comparative examples 1 to 3. The strength of the comparative example 1 and the comparative example 2 is seriously reduced after high-temperature reliability, and only 6MPa or 7MPa is remained, which is far lower than that of the example 1, so that the risk of membrane rupture is high in the subsequent use. In addition, the temperature resistance to the diaphragm product is further improved by the addition of the carboxyl group in example 1. And comparative example 3 has a strength of only 2MPa after high temperature reliability, very low strength, almost complete failure,

as shown in fig. 4, comparing the THD of the diaphragm of example 1 with the THD of the diaphragm of comparative example 1 before and after reliability, it can be seen that the THD of example 1 is lower and the THD of example 1 after high temperature reliability is still lower than the THD of comparative example 1, and the acoustic performance and the temperature resistance are superior. This is because the high degree of hydrogenation of example 1 makes the high temperature resistance of the diaphragm of example 1 good, and the elongation at break and the strength change before and after the high temperature reliability of the diaphragm of example 1 are small, and it can be seen that the high temperature damages the internal structure of the material of example 1 little, so that the performance change before and after the high temperature reliability of the diaphragm of example 1 is small, and further the THD change corresponding to example 1 is small.

In summary, the diaphragm according to the embodiment of the invention comprises a mixed hydrogenated carboxylated nitrile rubber film layer, wherein the saturation of a butadiene segment in hydrogenated carboxylated nitrile rubber of the mixed hydrogenated carboxylated nitrile rubber film layer is more than 70%; the vibrating diaphragm is placed for 500 hours at 160 ℃, and the elongation at break after being taken out and placed for 24 hours is more than or equal to 100 percent, so that the vibrating diaphragm has good mechanical property, acoustic property and high temperature resistance.

While certain specific embodiments of the 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 invention. 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 invention. The scope of the invention is defined by the appended claims.

Claims (14)

1. The vibrating diaphragm is characterized by comprising a mixed hydrogenated carboxylated nitrile rubber film layer, wherein the mixed hydrogenated carboxylated nitrile rubber film layer is formed by mixing 100 parts by mass of hydrogenated carboxylated nitrile rubber, a vulcanizing agent, a filler, an anti-aging agent and other auxiliary agents, and the saturation of a butadiene chain segment in the hydrogenated carboxylated nitrile rubber is more than 70%; wherein the vibrating diaphragm is placed for 500 hours at 160 ℃, and the elongation at break after being taken out and placed for 24 hours is more than or equal to 100 percent.

2. The diaphragm of claim 1, wherein the acrylonitrile group content in the compounded hydrogenated carboxylated nitrile rubber film layer is 10 to 50wt%.

3. The diaphragm of claim 1, wherein the carboxyl group content in the compounded hydrogenated carboxylated nitrile rubber layer is 2-7 wt%.

4. The diaphragm of claim 1, wherein the antioxidant is selected from at least one of antioxidant 1010, antioxidant 2, antioxidant 6, antioxidant 4, antioxidant 1076, antioxidant 168, antioxidant RD, antioxidant AW, antioxidant DD, antioxidant BLE, antioxidant 4010, 4010NA, 4020, 4030, 4040, antioxidant DNP, antioxidant H, antioxidant a, antioxidant D, antioxidant SP, antioxidant 264, antioxidant 2246-S, antioxidant NBC, antioxidant MB.

5. The diaphragm of claim 4, wherein the content of the anti-aging agent is 0.1 to 10 parts by mass.

6. The diaphragm of claim 1, wherein the vulcanizing agent is at least one of an amine vulcanizing agent, an epoxy vulcanizing agent, a metal oxide, and a metal peroxide.

7. The diaphragm of claim 6, wherein the vulcanizing agent is contained in an amount of 1 to 20 parts by mass.

8. The diaphragm of claim 1, wherein the other auxiliary agent contains a vulcanization accelerator, and the vulcanization accelerator is at least one of tertiary ammonium, substituted urea, phenols, imidazoles, acetylacetonate metal salt, and boron trifluoride complex.

9. The diaphragm of claim 8, wherein the vulcanization accelerator is contained in an amount of 0.1 to 8 parts by mass.

10. The diaphragm of claim 1, wherein the filler is at least one of carbon black, white carbon, talc, calcium carbonate, magnesium carbonate, dolomite, barium sulfate, zinc sulfide, aluminum powder, graphite, titanium dioxide, lithopone, phenolic resin, petroleum resin, and styrene resin.

11. The diaphragm of claim 10, wherein the filler is present in an amount of 5 to 100 parts by mass.

12. The diaphragm of claim 1, wherein the other auxiliary agent comprises at least one of stearic acid, an ultraviolet absorber, and color paste.

13. The diaphragm of any one of claims 1 to 12, wherein the diaphragm is formed as a single-layer structure including only one layer of the kneaded hydrogenated carboxylated nitrile rubber film layer;

or the vibrating diaphragm is formed into a composite layer structure, and the vibrating diaphragm comprises at least one layer of the mixed hydrogenated carboxyl nitrile rubber film layer.

14. A sound generating device comprising a diaphragm as claimed in any one of claims 1 to 13.

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