WO2021135874A1

WO2021135874A1 - Sound-absorbing granules, sound-producing device, and electronic equipment

Info

Publication number: WO2021135874A1
Application number: PCT/CN2020/134867
Authority: WO
Inventors: 潘泉泉; 姚阳阳; 牟雅静; 李春
Original assignee: 歌尔股份有限公司
Priority date: 2020-01-02
Filing date: 2020-12-09
Publication date: 2021-07-08
Also published as: CN111182419A; CN111182419B

Abstract

Sound-absorbing granules (1), a sound-producing device, and electronic equipment. The sound-absorbing granules comprise: activated carbon granules and a macromolecular polymer adhesive mixed with the activated carbon granules; the activated carbon granules comprise an activated carbon granule inner core (11) and a hydrophobic layer (12) coated on the outer surface of the activated carbon granule inner core (11); the hydrophobic layer (12) has a thickness of 0.1 μm to 10 μm; the activated carbon granule inner core (11) comprises three elements of carbon, hydrogen and oxygen; the activated carbon granule inner core (11) comprises a turbostratic structure formed by irregular stacking of two-dimensional graphite layer structures and/or molecular fragments of three-dimensional graphite microcrystals; and the activated carbon granule inner core (11) has a loose pore structure.

Description

Sound-absorbing particles, sound-producing devices and electronic equipment

Technical field

The present invention relates to the technical field of acoustics, and more specifically, to a sound-absorbing particle, a sound generating device and an electronic device.

Background technique

The sounding device is a device used in electronic equipment to convert electrical signals into sound signals. The resonant frequency of the sound emitting device is an important acoustic performance index, and reducing the resonant frequency of the sound emitting device helps to improve the acoustic effect of the sound emitting device.

The resonance frequency refers to the sounding device gradually increasing the vibration frequency from the low frequency range, and the vibration intensity reaches the strongest vibration, or, when the impedance characteristic of the sounding device is measured, when the impedance value reaches the maximum value for the first time, the corresponding vibration frequency is called the sounding The resonant frequency or resonant frequency of the device is f0.

How to reduce the F0 of the sound generating device to improve the acoustic performance of the sound generating device is a problem that needs to be solved in this field.

Summary of the invention

An object of the present invention is to provide a new technical solution for sound-absorbing particles, sound-producing devices and electronic equipment.

According to the first aspect of the present invention, there is provided a sound-absorbing particle, including:

Activated carbon particles and a high molecular polymer binder mixed with the activated carbon particles;

The activated carbon particles include an activated carbon particle core and a hydrophobic layer coated on the outer surface of the activated carbon particle core;

The thickness of the hydrophobic layer is 0.1 μm-10 μm;

The activated carbon particle core includes three elements: carbon, hydrogen, and oxygen;

The activated carbon particle core includes a chaotic layer structure formed by random accumulation of molecular fragments of a two-dimensional graphite layer structure and/or three-dimensional graphite crystallites;

The activated carbon particle core has a loose pore structure.

Optionally, the material of the hydrophobic layer includes one of zeolite, aerogel, and porous organic polymer.

Optionally, the thickness of the hydrophobic layer is 2 μm-6 μm.

Optionally, the pore structure includes nano-scale micropores and mesopores.

Optionally, the pore size of the micropores ranges from 0.6 nm to 1.3 nm, and the pore size of the mesopores ranges from 2 nm to 3.5 nm.

Optionally, the activated carbon particles are at least one of spherical, quasi-spherical, flake-shaped, and rod-shaped.

Optionally, the particle size of the activated carbon particles ranges from 0.1 μm to 100 μm.

Optionally, the sound-absorbing particles are configured to have an adsorption amount of nitrogen greater than or equal to 0.05 mmol/g.

According to a second aspect of the present invention, there is provided a sound generating device, including:

A housing, a containing cavity is formed in the housing;

A vibration component, the vibration component is arranged in the accommodating cavity, and the accommodating cavity is divided into a front acoustic cavity and a rear acoustic cavity;

The sound-absorbing particles according to any one of the above, wherein the sound-absorbing particles are arranged in the rear acoustic cavity.

According to a third aspect of the present invention, there is provided an electronic device including the above-mentioned sound emitting device.

According to an embodiment of the present disclosure, by providing a hydrophobic layer outside the core of the activated carbon particles, the water entering the core of the activated carbon particles can be reduced, and the sound absorbing ability of the sound absorbing particles can be improved. Filling the sound-absorbing particles into the sound-emitting device can be used to reduce the resonance frequency of the sound-generating device and improve the sound-generating performance of the sound-generating device.

Through the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, other features and advantages of the present invention will become clear.

Description of the drawings

The drawings incorporated in the specification and constituting a part of the specification illustrate the embodiments of the present invention, and together with the description are used to explain the principle of the present invention.

Fig. 1 is a cross-sectional view of activated carbon particles in an embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of a sound generating device applied to sound-absorbing particles in an embodiment of the present disclosure.

In the figure, 1 is a sound-absorbing particle, 11 is an activated carbon particle core, 12 is a hydrophobic layer, 2 is a shell, 21 is a front acoustic cavity, 22 is a rear acoustic cavity, and 3 is a vibration component.

Detailed ways

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless specifically stated otherwise, 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.

The following description of at least one exemplary embodiment is actually only illustrative, and in no way serves as any limitation to the present invention and its application or use.

The technologies, methods, and equipment known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be regarded as part of the specification.

In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiment may have different values.

It should be noted that similar reference numerals and letters indicate similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further discussed in the subsequent drawings.

According to an embodiment of the present invention, a sound-absorbing particle is provided. As shown in FIG. 1, the sound-absorbing particle includes: activated carbon particles and a high molecular polymer binder mixed with the activated carbon particles; The carbon particles include an activated carbon particle core and a hydrophobic layer 12 covering the outer surface of the activated carbon particle core; the thickness of the hydrophobic layer 12 is 0.1 μm-10 μm; the activated carbon particle core 11 includes carbon, hydrogen, and oxygen. The activated carbon particle core 11 includes a chaotic layer structure formed by the random accumulation of molecular fragments of a two-dimensional graphite layer structure and/or three-dimensional graphite crystallites; the activated carbon particle core 11 has a loose pore structure.

In this embodiment, activated carbon particles are formed by the activated carbon particle core 11 and the hydrophobic layer 12 coated on the outer surface of the activated carbon particle core, and the activated carbon particles and the polymer binder are mixed together to form sound-absorbing particles. The high molecular polymer adhesive has excellent properties such as high adhesion, flexibility, waterproof, impermeability, crack resistance, and aging resistance. A large number of activated carbon particles can be firmly bonded together to form particles. The activated carbon particles have an amorphous structure, and the amorphous structure can improve the adaptability of the activated carbon particles to different application scenarios. For example, the sound-absorbing particles can be used in different sound generating devices. And the effect of reducing the resonance frequency F0 of the sound generating device can be achieved, and the middle and low frequency sound quality of the sound generating device can be improved. Through the absorption and release of air by the sound-absorbing particles, the effective volume of the sound cavity in the sound device can be effectively expanded.

The high-molecular polymer adhesive has excellent bonding properties, and can gather multiple activated carbon particles together to form sound-absorbing particles. The formed sound-absorbing particles combine the sound-absorbing effects of the activated carbon particles, and form a three-dimensional pore structure in the sound-absorbing particles. It can improve the absorption and release ability of sound-absorbing particles to air.

In an embodiment, the activated carbon particles may be spherical, quasi-spherical, flake-shaped, rod-shaped, or the like.

For example, spherical activated carbon particles that are bonded together form macropores, which further improve the absorption and release ability of sound-absorbing particles to air. The sheet-shaped activated carbon particles can improve the structural stability of the activated carbon sound-absorbing particles and reduce the risk of powdering and damage. At the same time, the carbonization process of the sheet-shaped amorphous activated carbon particles is simple and the cost is low.

The preparation process of the sound-absorbing particles in the present disclosure is simple, easy to manufacture without increasing additional production costs, can be manufactured in large quantities, and is suitable for large-volume industrial production.

In the present disclosure, the hydrophobic layer 12 covers the outer surface of the core 11 of the activated carbon particles. The hydrophobic layer 12 itself has hydrophobicity, which can effectively prevent the activated carbon particle core 11 from adsorbing a large amount of water and reduce the water absorption rate of the sound-absorbing particles. Prevent moisture from entering the activated carbon particle core 11 to affect the sound absorbing effect of the sound absorbing particles.

For example, the thickness of the hydrophobic layer 12 may be 0.1 μm-10 μm. Within this thickness range, the hydrophobic layer 12 can provide sufficient water resistance, and effectively avoid the problem of reducing the sound absorption capacity of the sound-absorbing particles caused by a large amount of water entering the activated carbon particle core 11. For example, it is possible to prevent moisture from entering the transported pore structure in the activated carbon particle core 11. The loose pore structure can effectively achieve the sound absorption effect.

For example, the thickness of the hydrophobic layer 12 is 2 μm-6 μm. The thickness of the hydrophobic layer 12 has better waterproof ability within this thickness range, and the ability to prevent moisture from entering the core 11 of the activated carbon particles is improved. Improve the sound-absorbing reliability of sound-absorbing particles.

In an embodiment, the material of the hydrophobic layer 12 includes one of zeolite, aerogel, and porous organic polymer.

Zeolites, aerogels and porous organic polymers have excellent waterproof performance and do not affect the sound absorption performance of sound-absorbing particles. For example, a zeolite hydrophobic layer made of zeolite prevents a large amount of water from entering the sound-absorbing particles through the hydrophobic properties of the zeolite material. And, an aerogel water-repellent layer made of aerogel, and a porous organic polymer water-repellent layer made of a porous organic polymer.

The thickness of the hydrophobic layer 12 made of one of the aforementioned zeolite, aerogel, and porous organic polymer is set to be 0.1 μm-10 μm. Optionally, the thickness is set at 2 μm-6 μm. The water absorption rate of the sound-absorbing particles can be effectively reduced, and the resonance frequency F0 of the sound generating device applied to the sound-absorbing particles can be reduced.

For example, the mass ratio of the hydrophobic layer 12 in the sound-absorbing particles is 1-50%, and the mass ratio of the activated carbon particle core 11 in the sound-absorbing particles is 50-99%.

Specifically, the hydrophobic layer 12 is made of one of zeolite, aerogel, and porous organic polymer within the aforementioned set thickness range. And, set the mass percentage of the different above-mentioned materials in the sound-absorbing particles. The water absorption rate and resonance frequency F0 of the sound-absorbing particles can be reduced to more optimal values. For details, refer to the contents shown in Table 1 to Table 3. Tables 1 to 3 show the water absorption rate of the sound-absorbing particles under the mass fraction and thickness of the hydrophobic layer 12 of different materials obtained from the experiment, and the resonance frequency reduction effect of the sound generating device applied to the sound-absorbing particles.

Table 1

沸石包覆层质量(wt％)Mass of zeolite coating (wt%)	00	0.1～50.1～5	5～205～20	20～4020～40	30～5030～50
沸石包覆层厚度(um)Zeolite coating thickness (um)	00	0.1～20.1～2	2～42～4	2～62～6	4～104～10
F0降低效果(Hz)F0 reduction effect (Hz)	170170	165165	160160	158158	150150
吸水率(％)Water absorption rate (%)	35％35%	24％twenty four%	16％16%	5％5%	2％2%

Table 2

table 3

It can be seen from Table 1 to Table 3 that when the activated carbon particle core 11 is coated with a hydrophobic layer 12 made of any one of zeolite, aerogel and porous organic polymer, the thickness of the hydrophobic layer 12 and the hydrophobic layer 12 The increase in the percentage of mass. The water absorption rate of the sound-absorbing particles has been significantly reduced, and the resonance frequency F0 of the sound generating device applied to the sound-absorbing particles has been significantly reduced.

It can be seen that the sound-absorbing particles in the present disclosure can effectively reduce the water absorption rate and effectively reduce the resonance frequency F0 of the sound generating device to which the sound-absorbing particles are applied. Improve the low frequency performance of the sound device.

In one embodiment, the activated carbon particles are at least one of spherical, quasi-spherical, flake-shaped, and rod-shaped.

Activated carbon particles of different shapes are mixed together to form sound-absorbing particles with a pore structure between the activated carbon particles. Increase the sound-absorbing performance of sound-absorbing particles.

For example, activated carbon particles of different shapes are mixed with high molecular polymer binders to make sound-absorbing particles. The prepared sound-absorbing particles can be granular. The structural space of the sound device is limited, and the sound-absorbing particles are made into granules, which makes it easier to pack the sound-absorbing particles into the limited space.

For example, the sound-absorbing particles may be granular. It may be a kind of sound-absorbing particles, and the sound-absorbing particles include the above-mentioned sound-absorbing particles.

After the spherical carbon particles are bonded to form sound-absorbing particles, a more uniform and finer pore structure can be formed between the carbon particles, thereby improving the acoustic performance of the sound-absorbing particles. The use of sheet-shaped carbon particles can improve the structural stability of sound-absorbing particles and reduce the risk of powdering and damage. At the same time, since the carbonization process of the flake-shaped amorphous activated carbon particles is simple and the cost is low, the flake-shaped amorphous activated carbon particles are preferred from the perspective of industrial application.

In the above example, the activated carbon particle core 11 includes three elements: carbon, hydrogen, and oxygen. Among the three elements of carbon, hydrogen, and oxygen in the activated carbon particle core 11, carbon accounts for the largest proportion. Possess a small amount. Increasing the proportion of carbon element can prevent the loose pore structure formed in the core 11 of the activated carbon particles from being too sparse. This prevents the pore size of the pore structure from becoming larger. When the pore size of the pore structure becomes larger, the cumulative pore volume of the sound-absorbing particles will decrease, and the ability of absorbing and air will decrease.

For example, the activated carbon particle core 11 includes a chaotic layer structure formed by random accumulation of molecular fragments of a two-dimensional graphite layer structure and/or three-dimensional graphite crystallites; the activated carbon particle core 11 has a loose pore structure.

There are a large number of irregular bonds on the edges of the two-dimensional graphite layer structure and the three-dimensional graphite crystallites. Irregular bonds can form tight connections between the two-dimensional graphite layer structure and the three-dimensional graphite crystallites, and interweave to form a pore structure. The valence electrons of carbon have sp2 hybrid orbitals and sp3 hybrid orbitals to form a hexagonal carbon network plane. The activated carbon particles accumulated in this random form can form a fine and abundant pore structure to meet the structural requirements of sound-absorbing particles for the pore structure.

The two-dimensional graphite layer structure included in the activated carbon particle core 11 and/or the disordered layer structure formed by the random accumulation of molecular fragments of three-dimensional graphite crystallites mainly affect the pore structure formed in the material. The more the content of the above two structures in the material, the more uniform the pore structure and the smaller the pore size of the pore structure after the material is processed through the carbonization process, so that the sound-absorbing particles can have a good effect of reducing the resonance frequency.

In one embodiment, the pore structure includes nano-scale micropores and mesopores.

The activated carbon particle core 11 has a large number of micropores and mesopores. A large number of micropores can increase the overall cumulative pore volume of the particles on the one hand, and on the other hand can increase the adsorption capacity of activated carbon particles for air molecules. A large number of small pores can absorb a large number of air molecules and improve the acoustic performance of the sound-absorbing particles made. When air molecules need to be quickly sucked into the micropores or quickly released from the micropores, the mesopores provide sufficient flow space for the air molecules, so that the air molecules can move quickly, and reduce air blockage and the situation in the micropores.

For example, the pore size of the micropore is in the range of 0.6 nm to 1.3 nm, and the pore size of the mesopore is in the range of 2 nm to 3.5 nm.

The pore diameter of the micropores is limited to the above-mentioned pore diameter range, so that the activated carbon particles can contain a sufficient and large number of micropores. The mesopores within the above-mentioned pore diameter range can avoid the decrease in the air absorption performance of the entire particles caused by the reduction of the accumulated pore volume of the activated carbon particles. Therefore, the above-mentioned pore size range of the micropores and mesopores can improve the sound absorption performance of the sound absorbing particles.

The inventors of the present invention have verified that filling the sound-absorbing particles of the present disclosure into the rear acoustic cavity 22 of the sound generating device can absorb and release air equivalent to expanding the volume of the rear acoustic cavity 22, which can make the rear acoustic cavity 22 more effective. The volume is expanded by N times, where N>1. In the rear acoustic cavity 22 of the sound generating device, the forced vibration of the sound-absorbing particles will consume the energy of the sound wave. This effect is equivalent to an increase in the acoustic compliance of the air in the volume of the rear acoustic cavity 22, thereby reducing the resonance frequency.

In one embodiment, the particle size of the activated carbon particles ranges from 0.1 μm to 100 μm.

By controlling the particle size of the activated carbon particle core 11 and by controlling the particle size of the sound-absorbing particles, the best packing density and the effect of reducing the resonance frequency can be achieved.

For example, the sound-absorbing particles are configured to have an adsorption amount of nitrogen greater than or equal to 0.05 mmol/g. This ensures that the sound-absorbing particles have sufficient adsorption and desorption performance for air to meet the needs of the equivalent expansion cavity space.

According to an embodiment of the present invention, there is provided a sounding device, as shown in FIG. 2, the sounding device includes: a housing 2 with a receiving cavity formed in the housing 2; a vibration assembly 3, the vibration assembly 3 It is arranged in the accommodating cavity, and the accommodating cavity is divided into a front acoustic cavity 21 and a rear acoustic cavity 22; as in the above-mentioned sound-absorbing particles 1, the sound-absorbing particles 1 are arranged in the rear acoustic cavity 22.

In this embodiment, the sound-absorbing particles 1 may be granular. The sound-absorbing particles 1 are placed in the containing cavity provided in the sound generating device. The sound-absorbing particles 1 can be encapsulated in the accommodating cavity by mesh cloth. The vibrating component 3 is used to produce sound in the sound generating device. During the occurrence of the vibrating component 3, the sound-absorbing particles 1 in the accommodating cavity will adsorb and release the gas that changes due to sound in the sound generating device, so as to achieve the enlarged acoustic cavity 22 The volume, the effect of reducing the resonance frequency.

The sound-absorbing particles 1 provided by the present disclosure can be applied to different types of sound-producing devices such as earphones, earpieces, speakers, and sound boxes. Putting the sound-absorbing particles 1 into the back acoustic cavity 22 of the sound generating device is equivalent to virtually expanding the volume of the back acoustic cavity 22, and it is also equivalent to increasing the damping of the sound generating device, thereby reducing the resonance intensity. Finally, the resonance frequency of the sound emitting device can be reduced, and the effect of improving the acoustic performance of the sound emitting device can be achieved.

According to an embodiment of the present disclosure, there is provided an electronic device including the above-mentioned sound emitting device.

The sound generating device in the electronic device has the performance of reducing the resonance frequency of the above-mentioned sound generating device. The acoustic performance of the sound generating device in the electronic equipment is improved. Improve the usability of electronic equipment. For example, the electronic device may be a mobile phone, a tablet computer, or other electronic devices.

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

Claims

A sound-absorbing particle, characterized in that it comprises:

Activated carbon particles and a high molecular polymer binder mixed with the activated carbon particles;

The activated carbon particles include an activated carbon particle core and a hydrophobic layer coated on the outer surface of the activated carbon particle core;

The thickness of the hydrophobic layer is 0.1 μm-10 μm;

The activated carbon particle core includes three elements: carbon, hydrogen, and oxygen;

The activated carbon particle core includes a chaotic layer structure formed by random accumulation of molecular fragments of a two-dimensional graphite layer structure and/or three-dimensional graphite crystallites;

The activated carbon particle core has a loose pore structure.
The sound-absorbing particles according to claim 1, wherein the material of the hydrophobic layer includes one of zeolite, aerogel, and porous organic polymer.
The sound-absorbing particles according to claim 1, wherein the thickness of the hydrophobic layer is 2 μm-6 μm.
The sound-absorbing particles according to claim 1, wherein the pore structure comprises nano-scale micropores and mesopores.
The sound-absorbing particles according to claim 4, wherein the pore diameter of the micropores is in the range of 0.6 nm to 1.3 nm, and the pore diameter of the mesopores is in the range of 2 nm to 3.5 nm.
The sound-absorbing particles according to claim 1, wherein the shape of the activated carbon particles includes at least one of a spherical shape, a quasi-spherical shape, a flake shape, and a rod shape.
The sound-absorbing particles according to claim 1, wherein the particle size of the activated carbon particles ranges from 0.1 μm to 100 μm.
The sound-absorbing particles according to claim 1, wherein the sound-absorbing particles are configured to have an adsorption amount of nitrogen greater than or equal to 0.05 mmol/g.
A sound generating device, characterized in that it comprises:

A housing, a containing cavity is formed in the housing;

A vibration component, the vibration component is arranged in the accommodating cavity, and the accommodating cavity is divided into a front acoustic cavity and a rear acoustic cavity;

The sound-absorbing particles according to any one of claims 1-8, the sound-absorbing particles are arranged in the rear acoustic cavity.
An electronic device, characterized by comprising the sound emitting device according to claim 9.