Sound-absorbing material and speaker using same

Information

  • Patent Grant
  • 11863932
  • Patent Number
    11,863,932
  • Date Filed
    Monday, December 27, 2021
    2 years ago
  • Date Issued
    Tuesday, January 2, 2024
    8 months ago
Abstract
Provided is a sound-absorbing material, including a metal-organic framework material having a microporous structure. The metal-organic framework material includes a coordinated metal M and organic framework materials (OFs) coordinated with the coordinated metal. The microporous structure includes a plurality of uniformly distributed micropores, and a diameter of each of the plurality of micropores is within a range of 0.3 nm to 1.2 nm. The sound absorbing material including the metal-organic framework material can be added into a speaker to increase the acoustic compliance of air in a rear cavity of the speaker, thereby improving the performance of the speaker in a low frequency range.
Description
TECHNICAL FIELD

The present disclosure relates to the field of heat dissipation technologies for speakers, and in particular, to a sound-absorbing material and a speaker using the same.


BACKGROUND

As technologies develop, electronic products have become thinner and lighter and people have higher and higher requirements for the use experience of electronic products. For speakers of electronic products, people hope to obtain better audio effects. The sound quality is related to every aspect of the speaker design and manufacturing process, especially to the size of a rear cavity of the speaker. Generally, size reduction of the rear cavity of the speaker will significantly reduce the low-frequency response, resulting in poor sound quality, so it is difficult to provide good sound quality in a case of a small rear cavity.


In order to solve the above technical problems, conventional methods are mainly as follows: 1. replacing the air in the rear cavity with a gas with better acoustic compliance; 2. filling the rear cavity with foam (such as melamine) to increase the acoustic compliance; and 3. filling the rear cavity with porous materials such as activated carbon, zeolite, silicon dioxide, and the like to increase the virtual volume of the back cavity and improve the acoustic compliance. Among them, the third method is the most effective. At present, the zeolite filled in the rear cavity is mainly of MFI, MEL, FER and BEA structure types, and there is no research report on metal-organic framework materials (MOFs).


SUMMARY

An objective of the present disclosure is to provide a sound-absorbing material and a speaker using the same to overcome the above technical problems. The addition of the sound-absorbing material into a rear cavity of the speaker can increase the acoustic compliance of the air in the rear cavity of the speaker, thereby improving the performance of the speaker in a low frequency range.


In order to achieve the above objective, the present disclosure provides a sound-absorbing material, including a metal-organic framework material having a microporous structure. The metal-organic framework material includes a coordinated metal M and organic framework materials (OFs) coordinated with the coordinated metal. The microporous structure includes a plurality of uniformly distributed micropores. A diameter of each of the plurality of micropores is within a range of 0.3 nm to 1.2 nm.


As an improvement, the diameter of the micropores is within a range of 0.4 nm to 1.0 nm.


As an improvement, Al is used as the coordinated metal M, and the OFs include isophthalic acid or 2-aminoterephthalic acid.


As an improvement, the metal-organic framework material is of a CAU-10 type or a CAU-1-NH2 type.


As an improvement, a particle size of the metal-organic framework material is within a range of 0.1 um to 5 um.


As an improvement, the sound-absorbing material further includes an adhesive, and the metal-organic framework material is formed into sound-absorbing particles after adding the adhesive.


As an improvement, the sound-absorbing particles are spherical and have a particle size of 20 um to 1.0 mm.


As an improvement, the adhesive includes one or more of an acrylic adhesive, a polyurethane adhesive or an epoxy resin adhesive.


As an improvement, a mass of the adhesive is 1% to 10% of a mass of the sound-absorbing material.


The present disclosure further provides a speaker, including a housing with an accommodating space, a sounding unit placed in the housing, and a rear cavity defined by the sounding unit and the housing. The rear cavity is filled with the sound-absorbing material as described above.


Compared with a related art, the sound-absorbing material and the speaker using the same, as disclosed in the present disclosure, have the following beneficial effects: the sound-absorbing material is arranged to include a metal-organic framework material of a microporous structure; the metal-organic framework material includes a coordinated metal M and OFs coordinated with the coordinated metal; the microporous structure includes a plurality of uniformly distributed micropores, and the diameter of the micropores is within a range of 0.3 nm to 1.2 nm. The sound-absorbing material is added to the rear cavity of the speaker, and the micropores with the diameter of 0.3 nm to 1.2 nm absorb and desorb air under the action of sound pressure, which can increase the acoustic compliance of the air in the rear cavity, thereby improving the low-frequency performance of the speaker.





BRIEF DESCRIPTION OF DRAWINGS

In order to make the technical solutions of embodiments of the present disclosure more clear, drawings to be used for description of embodiments will be explained briefly as follows. It is appreciated that, drawings used in the following description are merely some embodiments of the present disclosure. Those skilled in the art also may obtain other drawings based on these drawings without paying creative efforts.



FIG. 1 is a schematic structural diagram of a speaker of the present disclosure; and



FIG. 2 is a comparison diagram of frequency response curves and impedance curves before and after addition of a sound-absorbing material in a rear cavity of a speaker of the present disclosure.





DESCRIPTION OF EMBODIMENTS

The technical solutions in embodiments of the present disclosure will be described clearly and completely below in connection with the drawings in the embodiments of the present disclosure, and it will be apparent that the embodiments described here are merely a part, not all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.


A speaker of the present disclosure includes a housing 1 with an accommodating space, a sounding unit 2 placed in the housing 1, and a rear cavity 3 defined by the sounding unit 2 and the housing 1. The rear cavity is filled with a sound-absorbing material.


The sound-absorbing material includes a metal-organic framework material of a microporous structure. The metal-organic framework material includes a coordinated metal M and organic framework materials (OFs) coordinated with the coordinated metal. The microporous structure includes a plurality of uniformly distributed micropores, and a diameter of the micropores is within a range of 0.3 nm to 1.2 nm. The micropores absorb and desorb air under the action of sound pressure, which can increase the acoustic compliance of the air in the rear cavity 3, thereby improving the low-frequency performance of the speaker.


In one embodiment, the diameter of the micropores is within a range of 0.4 nm to 1.0 nm.


It should be noted that, in this embodiment, Al is used as the coordinated metal M, and the OFs include isophthalic acid or 2-aminoterephthalic acid. For example, a CAU-10 type metal-organic framework material formed by a combination of the coordination metal Al and isophthalic acid in a certain arrangement has a number of uniformly distributed micropores inside with a diameter of 0.4 nm and 0.7 nm; a CAU-1-NH2 type metal-organic framework material formed by a combination of the coordinated metal Al and 2-aminoterephthalic acid in a certain arrangement has a number of uniformly distributed micropores inside with a diameter of 0.45 nm and 1.0 nm.


It should be noted that the sound-absorbing material may be metal-organic framework material powder or sound-absorbing particles, which are arranged in the rear cavity 3 in a filling manner. Generally, a particle size of the metal-organic framework material powder is small and within a range of 0.1 um to 5 um. Therefore, in actual applications, the sound-absorbing material usually further includes an adhesive. The metal-organic framework material is formed into sound-absorbing particles of a specific shape by adding the adhesive. The formed sound-absorbing particles are relatively large to be suitable as a sound-absorbing material. The adhesive may include one or more of an acrylic adhesive, a polyurethane adhesive and an epoxy resin adhesive.


It should be noted that, in this embodiment, the sound-absorbing material is formed as sound-absorbing particles, and the mass of the adhesive in the sound-absorbing particles is 1% to 10% of the mass of the sound-absorbing material.


The sound-absorbing particles can be spherical, irregular, blocky, and the like. It should be noted that, in one embodiment, the sound-absorbing particles are optionally spherical and have a particle size of 20 um to 1.0 mm.


It should be noted that the sound-absorbing particles can be prepared by spray drying, and the preparation method includes:

    • Mixing metal-organic framework material powder with an adhesive and a solvent to form a solution, the solvent mainly refers to water and common organic solvents (such as ethanol, methanol, acetone, tetrahydrofuran, and the like);
    • Causing the mixed solution to pass through a nozzle to form dispersed droplets, and desolvating and solidifying the dispersed droplets by heating to obtain product particles;
    • Sieving the product particles to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


It should be noted that, in order to facilitate the forming process of the sound-absorbing particles or to improve the performance of sound-absorbing particles, a small amount of an additive can be added to the mixed solution of the raw material, and the dose of the additive is usually less than 2%. The additive can be alkali, hydrogen peroxide, surfactant, or the like.


The implementation manners of the present disclosure will be explained below in conjunction with specific examples.


EXAMPLE 1

The sound-absorbing material of this example was sound-absorbing particles formed from a CAU-10 type metal-organic framework material and an adhesive.


The sound-absorbing material of this example was prepared as follows.


A metal-organic framework material powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


The mass of the adhesive is 3% of the mass of the sound-absorbing material.


EXAMPLE 2

The sound-absorbing material of this embodiment was sound-absorbing particles formed from a CAU-1-NH2 type metal-organic framework material and an adhesive.


The preparation method of the sound-absorbing material in this was prepared as follows.


A metal-organic framework material powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


The mass of the adhesive is 3% of the mass of the sound-absorbing material.


COMPARATIVE EXAMPLE 1

The sound-absorbing material of this comparative example was sound-absorbing particles formed from a MIL-101(Cr) type metal-organic framework material and an adhesive. The MIL-101(Cr) type metal-organic framework material was formed by a combination of a coordinated metal Cr and terephthalic acid in a certain arrangement.


The sound-absorbing material of this comparative example was prepared as follows.


A metal-organic framework material powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


The mass of the adhesive is 3% of the mass of the sound-absorbing material.


COMPARATIVE EXAMPLE 2

The sound-absorbing material of this comparative example was sound-absorbing particles formed from a MIL-53(Al) type metal-organic framework material and an adhesive. The MIL-53(Al) type metal-organic framework material was formed by a combination of a coordinated metal Al and terephthalic acid in a certain arrangement.


The sound-absorbing material of this comparative example was prepared as follows.


A metal-organic framework material powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


The mass of the adhesive is 3% of the mass of the sound-absorbing material.


COMPARATIVE EXAMPLE 3

The sound-absorbing material of this comparative example was sound-absorbing particles formed from a MIL-100(Fe) type metal-organic framework material and an adhesive.


The MIL-100(Fe) type metal-organic framework material was formed by a combination of a coordinated metal Fe and trimesic acid in a certain arrangement.


The sound-absorbing material of this comparative example was prepared as follows.


A MOFs powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


A mass of the adhesive is 3% of the mass of the sound-absorbing material.


COMPARATIVE EXAMPLE 4

The sound-absorbing material of this comparative example was sound-absorbing particles formed from a Uio-66 type metal-organic framework material and an adhesive. The Uio-66 type metal-organic framework material was formed by a combination of a coordinated metal Zr and terephthalic acid in a certain arrangement.


The sound-absorbing material of this comparative example was prepared as follows.


A MOFs powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


The mass of the adhesive is 3% of the mass of the sound-absorbing material.


COMPARATIVE EXAMPLE 5

The sound-absorbing material of this comparative example was sound-absorbing particles formed from a MIL-101(Al)—NH2 type metal-organic framework material and an adhesive. The MIL-101(Al)—NH2 type metal-organic framework material was formed by a combination of a coordinated metal A and 2-aminoterephthalic acid in a certain arrangement.


The sound-absorbing material of this comparative example was prepared as follows.


A metal-organic framework material powder was mixed with an adhesive and a solvent to form a solution.


The mixed solution passed through a nozzle to form dispersed droplets, and then the dispersed droplets were dehydrated and solidified by heating to obtain product particles.


The product particles were sieved to select product particles with a particle size of 20 um to 1.0 mm as the sound-absorbing material.


The mass of the adhesive is 3% of the mass of the sound-absorbing material.


COMPARATIVE EXAMPLE 6

Melamine foam Basotec produced by BASF was selected as a sound-absorbing material.


The sound-absorbing materials of Examples 1 to 2 and Comparative Examples 1 to 6 were respectively filled in a rear cavity of a speaker for acoustic performance testing. The results are shown in Table 1. The speaker adopted was of a model 1115, the volume of its back cavity is 1 cc, and the environment temperature at which the testing was carried out was ambient temperature.


Table 1 Resonant frequency F0 before and after addition of a sound-absorbing material in the rear cavity of the speaker












TABLE 1






F0 before addition of a
F0 after addition of a
F0 change



sound-absorbing
sound-absorbing
before



material in the rear
material in the rear
and after



cavity/Hz
cavity/Hz
addition/Hz







Example 1
914
846
68


Example 2
912
834
78


Comparative
915
873
42


Example 1





Comparative
913
865
48


Example 2





Comparative
914
876
38


Example 3





Comparative
913
872
41


Example 4





Comparative
915
880
35


Example 5





Comparative
914
892
22


Example 6









According to Table 1, it can be concluded that after the rear cavity of the speaker is filled with the sound-absorbing materials of Examples 1 to 2, the resonant frequency F0 of the speaker can be further reduced, thus increasing more virtual acoustic volume.



FIG. 2 shows a comparison diagram of frequency response curves and impedance curves before and after addition of a sound-absorbing material, where curves I represent the sound pressure frequency response before the sound-absorbing material is added to the rear cavity 3, and curves II represent sound pressure frequency response after the sound-absorbing material is added to the rear cavity 3. It can be seen from FIG. 2 that after the addition of the sound-absorbing material, the resonant frequency of the speaker significantly shifts to a low frequency, the virtual acoustic volume increases, and the sound pressure value of the low frequency is improved at the same time.


Compared with a related art, the sound-absorbing material and the speaker using the same, as disclosed in the present disclosure, have the following beneficial effects: the sound-absorbing material is arranged to include a metal-organic framework material of a microporous structure; the metal-organic framework material includes a coordinated metal M and OFs coordinated with the coordinated metal; the microporous structure includes a plurality of uniformly distributed micropores, and the diameter of the micropores is within a range of 0.3 nm to 1.2 nm. The sound-absorbing material is added to the rear cavity of the speaker, and the micropores with the diameter of 0.3 nm to 1.2 nm absorb and desorb air under the action of sound pressure, which can increase the acoustic compliance of the air in the rear cavity, thereby improving the low-frequency performance of the speaker.


The above are only the embodiments of the present disclosure. It should be noted here that for those of ordinary skill in the art, improvements can be made without departing from the inventive concept of the present disclosure and these improvements all belong to the scope of the present disclosure.

Claims
  • 1. A sound-absorbing material, comprising a metal-organic framework material having a microporous structure, wherein the metal-organic framework material comprises a coordinated metal M and organic framework materials (OFs) coordinated with the coordinated metal, Al is used as the coordinated metal M, and the OFs comprise isophthalic acid or 2-aminoterephthalic acid, the metal-organic framework material is of a CAU-10 type or a CAU-1-NH2 type, the microporous structure comprises a plurality of uniformly distributed micropores, and a diameter of each of the plurality of micropores is within a range of 0.3 nm to 1.2 nm.
  • 2. The sound-absorbing material as described in claim 1, wherein the diameter each of the plurality of micropores is within a range of 0.4 nm to 1.0 um.
  • 3. The sound-absorbing material as described in claim 1, wherein a particle size of the metal-organic framework material is within a range of 0.1 um to 5 um.
  • 4. The sound-absorbing material as described in claim 1, further comprising an adhesive, wherein the metal-organic frame material is formed into sound-absorbing particles after adding the adhesive.
  • 5. The sound-absorbing material as described in claim 4, wherein the sound-absorbing particles are spherical and have a particle size of 20 um to 1.0 mm.
  • 6. The sound-absorbing material as described in claim 4, wherein the adhesive comprises one or more of an acrylic adhesive, a polyurethane adhesive or an epoxy resin adhesive.
  • 7. The sound-absorbing material as described in claim 4, wherein a mass of the adhesive is 1% to 10% of a mass of the sound-absorbing material.
  • 8. A speaker, comprising a housing with an accommodating space, a sounding unit placed in the housing, and a rear cavity defined by the sounding unit and the housing, wherein the rear cavity is filled with the sound-absorbing material as described in claim 1.
Priority Claims (1)
Number Date Country Kind
202111150702.4 Sep 2021 CN national
US Referenced Citations (28)
Number Name Date Kind
4657108 Ward Apr 1987 A
7448467 Wright Nov 2008 B2
7743877 Saiki Jun 2010 B2
7953240 Matsumura May 2011 B2
8184826 Matsumura May 2012 B2
8265330 Fukunishi Sep 2012 B2
8630435 Mellow Jan 2014 B2
8794373 Lin Aug 2014 B1
8885863 Takashima Nov 2014 B2
8942402 Yuasa Jan 2015 B2
9900675 Papakyriacou Feb 2018 B2
10419848 Choi Sep 2019 B2
10506333 Wang Dec 2019 B2
10939195 Dai Mar 2021 B2
11014820 Tang May 2021 B2
11109149 Feng Aug 2021 B2
11140475 Tang Oct 2021 B2
11206491 Zhou Dec 2021 B2
11488570 Feng Nov 2022 B2
11570544 Wang Jan 2023 B1
20070165895 Matsumura Jul 2007 A1
20070286449 Matsumura Dec 2007 A1
20110048844 Papakyriacou Mar 2011 A1
20170195781 Kang Jul 2017 A1
20200031678 Feng Jan 2020 A1
20200031679 Tang Jan 2020 A1
20200037066 Feng Jan 2020 A1
20220021966 Coakley Jan 2022 A1
Foreign Referenced Citations (5)
Number Date Country
106875934 Jun 2017 CN
113179470 Jul 2021 CN
216391309 Apr 2022 CN
216930316 Jul 2022 CN
115497445 Dec 2022 CN
Related Publications (1)
Number Date Country
20230096193 A1 Mar 2023 US