Loudspeaker with improved ITR molecular sieve and electronic equipment

Abstract

The invention provides an ITR molecular sieve improved loudspeaker and electronic equipment. The rear cavity of the loudspeaker is filled with an ITR molecular sieve. The ITR molecular sieve comprises a skeleton and cations outside the skeleton; the framework comprises SiO2; the ITR molecular sieve contains uniform micropores, the micropore size is 0.4-0.62 nm, and the micropore volume is 0.09-0.24 cm < 3 > / g. The ITR molecular sieve is contained in the rear cavity of the loudspeaker, the sound compliance of air in the rear cavity is improved, the performance of the loudspeaker in a low-frequency band is improved, and the loudspeaker has long-term stability and low sensitivity to water vapor and temperature while having excellent acoustic performance.

Description

A speaker and electronic device improved by ITR molecular sieve Technical Field

[0001] This invention relates to a loudspeaker and electronic device improved by ITR molecular sieve, belonging to the field of loudspeaker device technology. Background Technology

[0002] Loudspeakers not only need to produce sound in a compact size, but also need to achieve excellent sound quality. Sound quality is closely related to various aspects of loudspeaker design and manufacturing, with the setting of the rear cavity volume being particularly crucial. Generally, reducing the rear cavity volume significantly weakens the low-frequency response, leading to a decrease in sound quality. Therefore, achieving high-quality sound under small rear cavity conditions remains a challenge. To address this, one approach is to fill the rear cavity with a gas whose acoustic compliance is superior to air, or to add materials such as melamine foam to the rear cavity to improve acoustic compliance. Alternatively, porous materials such as activated carbon, zeolite, and silica can be filled to increase the virtual rear cavity volume and improve acoustic compliance.

[0003] Currently, the International Molecular Sieve Association has identified over 260 molecular sieve structures, but their acoustic performance in micro-loudspeakers, or their relative merits, remains unclear. In recent years, research on the acoustic applications of molecular sieves has gradually progressed, but only the FER and MFI structures have achieved commercial application. Furthermore, research has found that structures such as MEL, DDR, EWT, ISV, ITN, ITH, SVR, IHW, BEA, MWT, and CHA may also have acoustic application potential, but their actual performance and stability remain uncertain. For example, although CN105013436A mentions that the BEA structure can be used in loudspeakers, this material still suffers from insufficient aging resistance.

[0004] Therefore, it is of great significance to provide a molecular sieve-modified loudspeaker that not only improves the performance of loudspeakers in the low-frequency range but also possesses long-term stability. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a loudspeaker and electronic device based on an ITR molecular sieve. This loudspeaker exhibits excellent acoustic performance, long-term stability, and low sensitivity to water vapor and temperature.

[0006] To achieve the above objectives, in a first aspect, the present invention provides an ITR molecular sieve-modified loudspeaker, wherein the rear cavity of the loudspeaker is filled with an ITR molecular sieve.

[0007] The ITR molecular sieve comprises a framework and extra-framework cations;

[0008] The framework contains SiO2;

[0009] The ITR molecular sieve contains uniform micropores with a size of 0.4-0.62 nm and a volume of 0.09-0.24 cm³. 3 / g.

[0010] If the micropore size of the ITR molecular sieve is less than 0.4 nm, it will hinder the diffusion of nitrogen in the pores due to its proximity to the size of nitrogen molecules (approximately 0.364 nm), thus slowing down the adsorption-desorption kinetics. If the micropore size of the ITR molecular sieve is greater than 0.62 nm, the physical adsorption between the pores and nitrogen molecules will be weakened, and the change in adsorption-desorption amount with pressure will not be significant enough, thus affecting its acoustic response performance. If the total micropore volume is insufficient, the crystallinity of the ITR material will be low, and the number of micropores available for gas adsorption will be limited, which will also significantly reduce its acoustic performance.

[0011] According to a specific embodiment of the present invention, preferably, the particle size of the ITR molecular sieve is 10 nm to 50 μm; more preferably, the particle size of the ITR molecular sieve is 100 nm to 10000 nm, and even more preferably 150-8000 nm.

[0012] According to a specific embodiment of the present invention, preferably, the framework comprises SiO2 and oxides of non-silicon element M, and the molar ratio of Si / M in the framework is 50 or more.

[0013] According to a specific embodiment of the present invention, preferably, ITR molecular sieves typically require cation exchange before use to obtain different ITR molecular sieves. Commonly used exchange agents include ammonium salts, alkali metal salts, or alkaline earth metal salts. Ammonium salts mainly include ammonium chloride, ammonium nitrate, ammonium sulfate, and ammonium carbonate; alkali metal salts mainly include lithium salts, sodium salts, potassium salts, and rubidium salts, and the anions of alkali metal salts include chloride ions, sulfate ions, and nitrate ions; alkaline earth metal salts mainly include magnesium salts, calcium salts, and barium salts, and the anions of alkali metal salts include chloride ions, sulfate ions, and nitrate ions.

[0014] According to a specific embodiment of the present invention, preferably, the non-silicon element M is selected from one or more combinations of aluminum, iron, boron, germanium, gallium, titanium, and zirconium. The non-silicon element M is a trivalent, tetravalent, or pentavalent ion. Trivalent ions mainly include, but are not limited to, aluminum, iron, and boron; tetravalent ions mainly include, but are not limited to, germanium, titanium, and zirconium; and pentavalent ions mainly include, but are not limited to, gallium. More preferably, the non-silicon element M is selected from aluminum and / or boron.

[0015] Typically, the framework of ITR molecular sieves is mainly composed of silicon dioxide and germanium dioxide. However, the germanium-containing framework is prone to hydrolysis with water vapor in the air, exhibiting poor stability. To improve performance, boron can be introduced to synthesize boron-containing ITQ-34. Furthermore, there are two main approaches to preparing aluminum-containing ITQ-34: one is to substitute boron-containing ITQ-34; the other is to synthesize it directly under optimized conditions.

[0016] If the Si / M molar ratio is below 50, the molecular sieve will significantly adsorb moisture from the air, occupying most of the micropores and resulting in a loss of low-frequency improvement. Furthermore, when synthesizing with non-germanium M elements, a low Si / M ratio will lead to synthesis difficulties or a significant decrease in the crystallinity of the resulting ITR structure.

[0017] According to a specific embodiment of the present invention, preferably, the extra-skeletal cation is selected from one or more combinations of hydrogen ions, alkali metal ions, and alkaline earth metal ions, more preferably alkali metal ions and / or alkaline earth metal ions.

[0018] According to a specific embodiment of the present invention, preferably, the content of the extra-skeletal cation is 0.01 wt.% to 1.5 wt.%.

[0019] According to a specific embodiment of the present invention, preferably, in the rear cavity, the ITR molecular sieve and binder are molded into spherical (spherical, ellipsoidal, ellipsoidal with a pit in the middle, etc.), granular (irregular granular, etc.), sheet-like, or block-like shapes to prevent the molecular sieve powder from entering the speaker monomer. The sheet-like and block-like molded materials can be filled first, and then the rear cavity can be assembled. The granular molded materials are generally filled after the rear cavity is assembled.

[0020] According to a specific embodiment of the present invention, preferably, the size of the spherical or granular shape is 50-1000 μm, more preferably 100-1000 μm.

[0021] According to a specific embodiment of the present invention, preferably, the thickness of the sheet is 100-1000 μm, and the length and width are 3-100 mm. The size of the sheet is determined according to the rear cavity of the speaker.

[0022] According to a specific embodiment of the present invention, preferably, the thickness of the block is 1-20 mm, and the length and width are 3-100 mm. The size of the block is determined according to the rear cavity of the speaker.

[0023] ITR molecular sieves are usually synthesized directly in powder form with a particle size of less than 10 μm. To facilitate their use in the rear cavity of loudspeakers, they are generally mixed with a binder and shaped into a specific form to prevent the powder from entering the loudspeaker monomers and affecting performance.

[0024] According to a specific embodiment of the present invention, preferably, the molecular sieve forming process typically includes the following components: ITR molecular sieve, solvent, binder, and additives. More preferably, the solvent mainly includes water and / or organic solvents, commonly used organic solvents such as ethanol, toluene, acetone, tetrahydrofuran, etc. The additives refer to auxiliary components added in small amounts (usually less than 5%).

[0025] According to a specific embodiment of the present invention, preferably, the adhesive is an inorganic adhesive or an organic polymer adhesive. More preferably, the inorganic adhesive includes activated alumina and / or silica sol; the organic polymer adhesive includes acrylates, epoxy resins, polyurethanes, etc.

[0026] Secondly, the present invention also provides an electronic device, wherein the electronic device includes the aforementioned speaker.

[0027] According to a specific embodiment of the present invention, preferably, the electronic device includes a smartphone, a TWS (True Wireless Stereo) headset, a headset, smart glasses, a smartwatch, a VR device, an AR device, a tablet computer, or a thin and light laptop computer, etc.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The speaker of this invention contains an ITR molecular sieve in the rear cavity, which improves the acoustic compliance of the air in the rear cavity, enhances the performance of the speaker in the low frequency range, and has excellent acoustic performance while also having long-term stability and low sensitivity to water vapor and temperature. Attached Figure Description

[0030] Figure 1 is the XRD pattern of the all-silicon ITR molecular sieve raw powder of Example 1.

[0031] Figure 2 is a comparison of impedance curves of the speaker rear cavity with and without ITR molecular sieve in Example 2.

[0032] Figure 3 is a comparison of the frequency response curves of the speaker rear cavity with and without ITR molecular sieve in Example 2.

[0033] Figure 4 is a low-temperature nitrogen adsorption characterization diagram of the aluminum-containing ITR molecular sieve raw powder of Example 2.

[0034] Figure 5 is a scanning electron microscope image of the morphology of the aluminum-containing ITR molecular sieve raw powder of Example 2. Detailed Implementation

[0035] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0036] All numerical specifications in this invention (e.g., temperature, time, concentration, and weight, including ranges for each) are generally approximate values ​​that may be changed (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are to be understood as being preceded by the term "about".

[0037] Example 1

[0038] This embodiment provides a method for preparing an all-silica ITR molecular sieve (ITQ-34) and its application in a loudspeaker, specifically including the following steps:

[0039] 1) Preparation of all-silica ITR molecular sieve (ITQ-34)

[0040] All-silica ITR molecular sieves were synthesized using tetraethyl orthosilicate (based on SiO2) as the silicon source, N,N'-diethyl-N,N,N',N'-tetramethylhexamethylene-diammonium hydroxide (Me4Et2-diquat-6) as the template agent, and hydrogen fluoride (concentration of 40%) as the mineralizing agent, with water as the catalyst. The molar ratio of SiO2, template agent, HF, and H2O was 1:0.25:1:1.

[0041] The specific steps are as follows:

[0042] 1 mol of tetraethyl orthosilicate, 0.25 mol of template agent, and water were stirred at room temperature for 8 h to hydrolyze the tetraethyl orthosilicate, yielding a transparent and homogeneous solution. Then, 1 mol of HF was added, and the mixture was stirred in a fume hood for 4 h. The excess residual ethanol and water were then slowly evaporated by heating the mixture to 80 °C in a water bath until the required silicon-to-water ratio of 1:1 was achieved. The mixture was then placed in a high-pressure hydrothermal reactor, and the hydrothermal reaction was carried out at 175 °C for 144 h (for detailed synthesis procedures, please refer to the literature J. Am. Chem. Soc. 2023, 145, 17284-17291). The crystallized reactants were washed with water, centrifuged, dried overnight at 110 °C, and calcined at 550 °C in air for 8 h to obtain the all-silicon ITR molecular sieve raw powder.

[0043] Figure 1 shows the XRD characterization of the all-silica ITR molecular sieve raw powder. As shown in the figure, the ITR structure has a moderate intensity diffraction peak at a 2θ of about 9.5 degrees, corresponding to the 111 plane.

[0044] 2) Add binder for granulation

[0045] All-silica ITR molecular sieve powder, water, and binder (acrylate latex, 50% solid content) were mixed in a mass ratio of 38:60:12 to form a slurry. This slurry was then spray-dried using a 400 µm nozzle (top temperature 180 °C, bottom temperature 140 °C, spray pressure 0.3 MPa) to obtain ITR particles. Particles with a diameter of 270-330 µm were obtained by sieving and designated as Sample 1 (average diameter 300 µm).

[0046] 3) Sample 1 was used for speaker testing.

[0047] Using a commercially available 1115 loudspeaker, sample 1 was filled into the rear cavity of a loudspeaker with a volume of 0.4 cubic centimeters (referred to as 0.4cc), 80% filling (normal filling volume). The acoustic performance test data are shown in Table 1.

[0048] Example 2

[0049] This embodiment provides a method for preparing an aluminum-containing ITR molecular sieve and its application in a loudspeaker, specifically including the following steps:

[0050] 1) Preparation of aluminum-containing ITR molecular sieves

[0051] Aluminum-containing ITR molecular sieves were synthesized using tetraethyl orthosilicate (SiO2) as the silicon source, N,N'-diethyl-N,N,N',N'-tetramethylhexamethylene-diammonium hydroxide (Me4Et2-diquat-6) as the template agent, aluminum isopropoxide as the aluminum source (Al2O3), hydrogen fluoride as the mineralizing agent, and ITQ-34 from Example 1 as the seed crystal, along with water. The molar ratio of SiO2, template agent, Al2O3, seed crystal, HF, and H2O was 1:0.25:0.003:0.03:1:5.

[0052] The specific steps are as follows:

[0053] 1 mol of tetraethyl orthosilicate, 0.25 mol of template agent (N,N'-diethyl-N,N,N',N'-tetramethylhexammonium hydroxide), and 0.003 mol of aluminum isopropoxide were stirred with water at room temperature for 8 h to obtain a transparent and homogeneous solution. Then, 1 mol of HF was added, and the mixture was stirred in a fume hood for 4 h. The excess residual ethanol and water were slowly evaporated by heating the mixture to 80 °C in a water bath. The silica-to-water ratio was adjusted to the required ratio of 1:5. The mixture was then placed in a high-pressure hydrothermal reactor, and the hydrothermal reaction temperature was 175 °C for 144 h. The crystallized reactants were washed with water, centrifuged, dried overnight at 110 °C, and calcined at 550 °C in air for 8 h to obtain aluminum-containing ITR molecular sieve raw powder.

[0054] The original powder pore structure characterization and low-temperature nitrogen adsorption-desorption characterization of this embodiment are shown in Figure 4, and the scanning electron microscope is shown in Figure 5.

[0055] Low-temperature nitrogen adsorption characterization: The surface area and pore size distribution were measured using a Micromeritics ASAP 2020 instrument at 77 K. The molecular sieve was mainly composed of micropores in the low-pressure zone and packed pores in the high-pressure zone, with a BET of 468 μm. 2 / g, the median micropore width in HK is 0.52 nm, and the micropore volume is 0.163 cm³. 3 / g.

[0056] 2) Add binder for granulation

[0057] Aluminum-containing ITR molecular sieves, water, and binder (acrylate latex, 50% solid content) were mixed in a mass ratio of 38:60:12 to form a slurry. This slurry was then spray-dried using a 400 µm nozzle (top temperature 180 °C, bottom temperature 140 °C, spray pressure 0.3 MPa) to obtain ITR particles. Particles with a diameter of 270-330 µm were obtained by sieving and designated as Sample 2 (average diameter 300 µm).

[0058] 3) Sample 2 was used for speaker testing.

[0059] Using a commercially available 1115 loudspeaker, sample 2 was filled into the rear cavity of a loudspeaker with a volume of 0.4 cubic centimeters (referred to as 0.4cc), 100% filled. The acoustic performance test data are shown in Table 1.

[0060] The acoustic effects are shown in Figure 2 (impedance test) and Figure 3 (sound pressure level test). The black line is the test curve of the empty module (without material filling), and the blue line is the test curve after filling with material. It can be seen that when sample 2 containing aluminum ITR molecular sieve is added to the rear cavity of the loudspeaker, the sound pressure value in the low frequency range is significantly improved, and the resonant frequency also shifts significantly to the low frequency range.

[0061] Example 3

[0062] This embodiment provides a method for preparing boron-containing ITR molecular sieves and their application in loudspeakers, specifically including the following steps:

[0063] 1) Preparation of boron-containing ITR molecular sieves

[0064] The only difference from Example 2 is that aluminum isopropoxide is replaced with boric acid as the boron source;

[0065] The molar ratio of SiO2, template agent, boric acid, seed crystal, HF, and H2O is 1:0.25:0.002:0.04:0.5:4.

[0066] The BET of the molecular sieve is 436 m. 2 / g, the median micropore size in HK is 0.51 nm, and the t-plot external surface area is 85 m². 2 / g, micropore volume is 0.15 cm³ 3 / g.

[0067] 2) Add binder for granulation

[0068] The only difference from Example 2 is that the aluminized ITR molecular sieve is replaced with the boron-containing ITR molecular sieve;

[0069] Sample 3 was obtained.

[0070] 3) Sample 3 was used for speaker testing.

[0071] The method is the same as in Example 2.

[0072] Example 4

[0073] This embodiment provides a method for preparing boron-containing ITR molecular sieves and their application in loudspeakers, differing from Embodiment 2 only in that:

[0074] The molar ratio of SiO2 to Al2O3 (i.e., the molar ratio of Si / Al) is 600.

[0075] Example 5

[0076] This embodiment provides a method for preparing boron-containing ITR molecular sieves and its application in loudspeakers, differing from Embodiment 3 only in that:

[0077] The molar ratio of SiO2 to boric acid (i.e., the molar ratio of Si / B) is 200.

[0078] Example 6

[0079] This embodiment provides a method for preparing boron-containing ITR molecular sieves and its application in loudspeakers, differing from Embodiment 3 only in that:

[0080] The boron-containing ITR molecular sieve obtained in Example 3 was exchanged with 2 M ammonium nitrate solvent at 80 °C for 6 h. The ratio of the mass of the molecular sieve solid to the mass of the ammonium nitrate aqueous solution was 1:10. After the exchange was completed, the sieve was washed with water 4 times, dried, and calcined to obtain the hydrogen-form ITR molecular sieve.

[0081] A binder was added for granulation, and the resulting particles were designated as sample 6.

[0082] Example 7

[0083] This embodiment provides a method for preparing boron-containing ITR molecular sieves and its application in loudspeakers, differing from Embodiment 3 only in that:

[0084] The boron-containing ITR molecular sieve obtained in Example 3 was exchanged with 2 M lithium chloride solvent at 80 °C for 6 h. The ratio of the solid mass of the molecular sieve to the mass of the lithium chloride aqueous solution was 1:10. After the exchange, the molecular sieve was washed with water 4 times, dried, and calcined to obtain the hydrogen-form ITR molecular sieve.

[0085] A binder was added for granulation, and the resulting particles were designated as sample 7.

[0086] Example 8

[0087] This embodiment provides a method for preparing boron-containing ITR molecular sieves and its application in loudspeakers, differing from Embodiment 3 only in that:

[0088] The boron-containing ITR molecular sieve obtained in Example 3 was exchanged with 2 M sodium chloride solvent at 80 °C for 6 h. The ratio of the mass of the molecular sieve solid to the mass of the sodium chloride aqueous solution was 1:10. After the exchange was completed, the sieve was washed with water 4 times, dried, and calcined to obtain the hydrogen-form ITR molecular sieve.

[0089] A binder was added for granulation, and the resulting particles were designated as sample 8.

[0090] Comparative Example 1

[0091] The speaker of a commercially available Apple X phone was disassembled, and the comparative sample 1 particle was removed from the rear cavity for testing. The acoustic performance is shown in Table 1.

[0092] To evaluate the long-term stability of ITR molecular sieves in loudspeakers and test the weather resistance of the samples from the above examples and comparative examples, it is generally necessary to perform dual 85 coexistence tests (specific conditions: conducted in a clean high-temperature and high-humidity chamber, temperature 85 ℃, humidity 85%, time 120 hours) and VOCs resistance tests (specific conditions: 1 g of this material stored at room temperature and 1 g of UV-cured UV adhesive are placed in a 20 mL glass sample bottle, and coexisted at 85 ℃ for 120 h). The performance loss before and after the test is measured respectively, and the test results are shown in Table 1.

[0093] Table 1

[0094]

[0095] As can be seen from Table 1, the overall performance of the ITR molecular sieve of the present invention is improved by about 15 Hz compared with the comparative sample 1, and the low-frequency effect is significantly enhanced, indicating that the ITR molecular sieve of the present invention has significant progress in acoustic performance.

[0096] Furthermore, the ITR molecular sieve of this invention exhibits low sensitivity to water vapor and temperature. Considering the inherent errors in acoustic performance testing, it can be assumed that high temperature and high humidity environments have virtually no impact on the ITR molecular sieve. Additionally, VOC testing also indicates that the ITR molecular sieve of this invention is less sensitive to volatile organic compounds than existing zeolite molecular sieves. This is highly advantageous for its application in micro-lifting cavities, as the structural adhesives typically used in micro-lifting structures contain volatile organic compounds.

Claims

1. A loudspeaker improved with ITR molecular sieves, wherein, The rear cavity of the loudspeaker is filled with an ITR molecular sieve; the ITR molecular sieve comprises a framework and extra-framework cations; the framework comprises SiO2; the ITR molecular sieve contains uniform micropores with a micropore size of 0.4-0.62 nm and a micropore volume of 0.09-0.24 cm³. 3 / g.

2. The loudspeaker according to claim 1, wherein, The ITR molecular sieve has a particle size of 10 nm to 50 μm; and / or, the framework comprises SiO2 and oxides of non-silicon element M, wherein the molar ratio of Si / M in the framework is greater than 50.

3. The loudspeaker according to claim 2, wherein, The non-silicon element M is selected from one or more combinations of aluminum, iron, boron, germanium, gallium, titanium, and zirconium.

4. The loudspeaker according to claim 3, wherein, The non-silicon element M is selected from aluminum and / or boron.

5. The loudspeaker according to claim 1, wherein, The extra-framework cations are selected from one or more combinations of hydrogen ions, alkali metal ions, and alkaline earth metal ions.

6. The loudspeaker according to claim 1, wherein, The content of the extra-skeletal cations is from 0.01 wt.% to 1.5 wt.%.

7. The loudspeaker according to any one of claims 1-6, wherein, In the rear cavity, the ITR molecular sieve and binder are shaped into spherical, granular, sheet-like, or block-like forms.

8. The loudspeaker according to claim 7, wherein, The spherical or granular shape has a size of 50-1000 μm; and / or, the sheet-like shape has a thickness of 100-1000 μm and a length and width of 3-100 mm; and / or, the block-like shape has a thickness of 1-20 mm and a length and width of 3-100 mm.

9. The loudspeaker according to claim 8, wherein, The adhesive is an inorganic adhesive or an organic polymer adhesive.

10. An electronic device, wherein, The electronic device includes the speaker according to any one of claims 1-9.

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