Acoustically enhancing material and preparation method therefor, loudspeaker, and electronic device

Abstract

The present disclosure provides an acoustically enhancing material and a preparation method therefor, a loudspeaker, and an electronic device. The acoustically enhancing material comprises a fiber network formed by interlacing fibers and raw powders of a zeolite molecular sieve, wherein the raw powders of the zeolite molecular sieve are loaded into the three-dimensional network formed by the interlacing fibers; and besides the fibers, no binder components exist between the raw powders of the zeolite molecular sieve. The acoustically enhancing material does not contain any binder, thereby avoiding a variety of performance losses or stability losses caused by the process of binding zeolite particles by means of a high-molecular binder in the prior art; moreover, each unit space of the material can be filled with more raw powders of the zeolite molecular sieve, which can not only greatly improve the acoustic effect, and but also makes the material have a particularly wide usage temperature interval. By means of a solution for extreme conditions, the structure can remain stable from a low temperature (the temperature of liquid nitrogen, i.e., -196°C) to the maximum high temperature (200°C), and a variety of stringent stability requirements for loudspeakers can be met.

Description

An acoustic enhancement material, its preparation method, and a loudspeaker / electronic device.

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 202410936225.1, filed on July 12, 2024, and incorporates the entire contents of the aforementioned patent application as part of this application. Technical Field

[0003] This disclosure relates to an acoustic enhancement material and its preparation method, as well as loudspeakers and electronic devices, belonging to the field of materials technology, particularly the field of electroacoustic materials technology. Background Technology

[0004] With the development of technology, people have increasingly higher requirements for speakers, especially mobile phone speakers. The demand is not just for small size and sound output, but also for excellent sound quality. Sound quality is related to every aspect of speaker design and manufacturing, particularly the size of the speaker's rear cavity. Generally, reducing the size of the rear cavity significantly decreases the low-frequency response, resulting in poorer sound quality. Therefore, it is difficult to provide good sound quality with a very small rear cavity.

[0005] To address these issues, engineers proposed various solutions, such as: 1) using a gas with better acoustic compliance instead of air for the back cavity atmosphere; 2) filling the back cavity with traditional high-porosity, low-density porous materials, such as melamine foam, open-cell polyurethane sponge, and aerogel, to increase acoustic compliance; and 3) filling the back cavity with porous materials containing micropores (here, micropores refer to pores with a diameter of less than 2 nm as defined by the International Union of Pure and Applied Chemistry, not the micropores of microporous plates or macroscopic acoustic micropores commonly referred to in the acoustic field), such as activated carbon, zeolite, and silica, to increase the virtual back cavity volume and improve acoustic compliance. The third method was the most effective.

[0006] EP2424270 discloses an acoustic enhancement material, which is obtained by adding 1-20% of a polymer binder or glue to 0.5-2μm zeolite molecular sieve raw powder or particles to obtain zeolite particles containing pores with a size of 1-30μm. The addition of polymer binders or adhesives significantly affects the acoustic performance and stability of zeolite molecular sieve particles. To better leverage the acoustic enhancement performance of zeolite particles, the impact of polymer binders or adhesives needs to be minimized. Besides improving the quality of zeolite particles, it's crucial to use as little binder as possible to bond them together. Generally, the industry selects binders with superior bonding properties, such as acrylates, styrene-butadiene compounds, and polyurethanes. However, the bonding strength of polymer binders is related to their operating temperature range, making it difficult to find a binder with a particularly wide temperature range and excellent high and low temperature bonding performance. Furthermore, while many other high- or low-temperature resistant binders exist, their bonding performance is poor under low-dosage conditions that meet acoustic performance requirements, failing to achieve the desired bonding effect. Adding large amounts of such binders can guarantee bonding, but it significantly reduces the acoustic performance of the zeolite particles or raw powder, even completely eliminating acoustic enhancement performance and resulting in a negative enhancement effect, i.e., reducing the virtual volume of the back cavity, increasing the resonant frequency f0, and decreasing the low-frequency sound pressure level.

[0007] In addition, existing technologies disclose technical solutions that use inorganic binders or fully crystalline zeolite particles obtained by secondary crystallization of silica binders and then use them as binders. However, both inorganic binders and fully crystalline zeolite particles are brittle and will break into powder significantly during speaker vibration or drop stability tests, which cannot meet the actual product reliability requirements.

[0008] Therefore, providing a novel acoustic enhancement material and its preparation method, as well as loudspeakers and electronic devices, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] To address the aforementioned shortcomings and deficiencies, the present disclosure aims to provide an acoustic enhancement material, a method for preparing the same, and a loudspeaker or electronic device.

[0010] To achieve the above objectives, on the one hand, this disclosure provides an acoustic reinforcement material, wherein the acoustic reinforcement material includes a fiber network formed by interlacing fibers and zeolite molecular sieve powder, the zeolite molecular sieve powder being loaded in the three-dimensional network formed by interlacing fibers, and there are no binder components between the zeolite molecular sieve powders other than fibers.

[0011] In one specific embodiment of the acoustic reinforcement material disclosed herein, the fiber volume percentage is 0.1-15%, optionally 0.6-10%, based on the total volume of the acoustic reinforcement material as 100%. The lower fiber percentage results in a higher effective density, meaning more effective zeolite molecular sieve powder can be packed into a unit space, thus maximizing the efficient utilization of the speaker's rear cavity space. Simultaneously, this acoustic reinforcement material maintains structural stability using only a small amount of fiber as an auxiliary material.

[0012] As a specific embodiment of the acoustic reinforcement material disclosed herein, the average diameter of the fiber is 10nm-10μm, optionally 50nm-5μm, more preferably 100nm-3μm, and even more preferably 100nm-2μm; its aspect ratio is greater than 10, optionally greater than 30, and more preferably greater than 50.

[0013] Based on the average diameter data of the fibers above, it can be seen that the fibers used in this disclosure are ultrafine nanofibers, which is a general term for both ultrafine fibers and nanofibers. As is known in the art, ultrafine fibers generally refer to fibers with a diameter of less than 10 μm, while nanofibers generally refer to fibers with a diameter of less than 1000 nm (some sources define nanofibers as fibers with a diameter of less than 100 nm). This disclosure avoids the problem of surface blockage of zeolite particles caused by polymeric binders during the bonding process of zeolite particles, which leads to various performance losses, by using ultrafine nanofibers to replace binders.

[0014] In this disclosure, the average diameter of the ultrafine nanofibers is obtained by measuring with a scanning electron microscope and taking the range of the main distribution. For example, 2% of the fibers have a diameter of less than 200 nm, 3% of the fibers have a size of more than 5 μm, and the remaining majority (about 90%) of the fibers have a diameter distribution of 0.6-2.2 μm. In this case, the average diameter of the fibers is calculated mainly based on 90% of the fibers.

[0015] As a specific embodiment of the acoustic reinforcement material disclosed herein, the diameter of the fiber (abbreviated as D) fiber The diameter of the zeolite molecular sieve raw powder is smaller than that of the zeolite molecular sieve powder (ab zeolite Optionally, the ratio of the fiber diameter to the diameter of the zeolite molecular sieve powder is less than 1:2, more preferably less than 1:4, and even more preferably less than 1:8. In this disclosure, within the same volume space, the finer the fiber diameter, the smaller the pores of the three-dimensional network formed by the interlacing of fibers, the larger the fiber specific surface area, the higher the strength, and the better the acoustic performance, while also reducing the coverage of the zeolite molecular sieve powder.

[0016] As a specific embodiment of the acoustic reinforcement material disclosed herein, the fiber includes inorganic fibers and / or organic fibers (including synthetic polymer fibers and natural fibers). Optionally, the fiber is a synthetic polymer fiber. This disclosure selects to use fibers with high strength and resistance to high and low temperatures, which further avoids the problem in the prior art where the adhesive fails to meet performance requirements in the harsh lifespan evaluation of loudspeakers, leading to stability loss.

[0017] As a specific embodiment of the acoustic reinforcement material disclosed herein, the fiber has a low-temperature resistance of no higher than -30°C and a high-temperature resistance of no lower than 200°C. For example, the service temperature range of polyimide fiber is -200 to 300°C, and it can still maintain high strength at a temperature of 300°C; the service temperature of polyester fiber is -70 to 230°C.

[0018] In this disclosure, the artificially synthesized polymer fibers can be one or a combination of various common artificially synthesized fibers, such as: polyester fibers, polypropylene fibers, polyethylene fibers, polyacrylonitrile fibers, polyvinylidene fluoride fibers, polyphenylene sulfide fibers, aramid (meta-aramid, para-aramid) fibers, polyimide (PI) fibers, PTFE fibers, polyamide fibers, polyamide-imide (PAI) fibers, aromatic polyamide fibers, polytetrafluoroethylene fibers, polybenzimidazole fibers, fluorinated polymer fibers, and polyetheretherketone (PEEK) fibers; more preferably, high and low temperature resistant polymer fibers, such as polyphenylene sulfide fibers, aramid fibers (meta-aramid), polyimide (PI) fibers, PTFE fibers, aromatic polyamide fibers, polybenzimidazole fibers, and fluorinated polymer fibers.

[0019] In one specific embodiment of the acoustic enhancement material disclosed herein, the zeolite molecular sieve raw powder can be a directly synthesized raw powder, which is a hydrophobic high-silica molecular sieve. The molecular sieve is mainly composed of a framework and extra-framework cations. The framework is mainly composed of oxides of silicon dioxide and non-silicon atoms M. The Si / M molar ratio is greater than 80, and can be greater than 100. If the Si / M molar ratio is less than 80, it will significantly adsorb moisture from the air, occupying the micropores of the molecular sieve, resulting in a significant deterioration in the acoustic enhancement effect, or even no acoustic enhancement effect. M can be selected from at least one of Al, Fe, B, Ti, Zr, Ga, Cr, Mo, etc., and can be more specifically Al. The extra-framework cations can be selected from at least one of H ions, alkali metal ions, alkaline earth metal ions, and transition metal ions, and can be more specifically Li, Na, K, Ba, Ca, Mg, Cμ, Zn, and Ag. Based on 100% of the total weight of the zeolite molecular sieve raw powder, the content of extra-framework cations is 0.02 wt.% to 1.2 wt.%.

[0020] As a specific embodiment of the acoustic enhancement material disclosed herein, the particle size of the zeolite molecular sieve raw powder is greater than 2 μm and less than or equal to 10 μm, optionally greater than 6 μm and less than or equal to 10 μm, and more preferably greater than 8 μm and less than or equal to 10 μm.

[0021] In this disclosure, the particle size of the zeolite molecular sieve raw powder can be determined by scanning electron microscopy (SEM) in conjunction with a laser particle size analyzer. When the raw powder morphology is spherical or near-spherical, the spherical diameter is used as the standard, and the average particle size is determined by the D50 of the raw powder size distribution measured by the laser particle size analyzer. When the raw powder morphology deviates significantly from spherical, the longest side dimension of the raw powder morphology is used as the measurement object, and the average size is confirmed by SEM. For example, for flake-shaped raw powder, the longest side of the flake is mainly 5-10 μm, the wide side is mainly 3-6 μm, and the thickness is mainly 0.5-2 μm. Based on the average main dimension of the long side of 5-10 μm, the average particle size is calculated to be around 7.5 μm.

[0022] As a specific embodiment of the acoustic enhancement material disclosed herein, the structure of the zeolite molecular sieve raw powder includes one or a combination of several of the following structures: MFI, MEL, BEA, FAU, FER, MOR, and DDR. Basic information about the structure of zeolite molecular sieves can be obtained from the International Zeolite Association website (http: / / www.iza-online.org).

[0023] As a specific embodiment of the acoustic enhancement material disclosed herein, the morphology of the zeolite molecular sieve raw powder includes one or a combination of several of the following: flake-shaped, strip-shaped, strip-shaped twins, spherical and quasi-spherical, and can be selected as a spherical hierarchical porous morphology formed by the accumulation of small crystallites.

[0024] This disclosure does not impose specific requirements on the morphology (macroscopic form) of the acoustic reinforcement material, which can be reasonably adjusted according to the size of the loudspeaker and the required shape. As a specific embodiment of the acoustic reinforcement material described above, the morphology of the acoustic reinforcement material includes one or a combination of several of the following: particles, flakes, blocks, and irregular shapes. In some embodiments of this disclosure, the flakes may be in the form of molecular sieve membranes, and the particles may be spherical particles.

[0025] In one specific embodiment of the acoustic reinforcement material disclosed herein, the acoustic reinforcement material has air-permeable channels with a diameter of 10-1000 μm, optionally 20-500 μm. The air-permeable channels in the acoustic reinforcement material disclosed herein can be regularly arranged or irregularly arranged, optionally regularly arranged.

[0026] On the other hand, this disclosure also provides a method for preparing the above-mentioned acoustic enhancement material, wherein the preparation method includes:

[0027] Step (1): Mix the zeolite molecular sieve powder and fiber evenly to obtain a uniform mixture;

[0028] Step (2): Prepare the mixture into a precursor or blank;

[0029] Step (3): Curing and cross-linking the precursor or blank to obtain the acoustic reinforcement material.

[0030] This disclosure does not specify the exact method for uniformly mixing the zeolite molecular sieve powder and fiber in step (1) of the above preparation method, as long as it ensures that the two are uniformly mixed. For example, it can be mixed uniformly in a solvent, or directly mixed uniformly. The solvent used in the mixing process is selected according to the properties of the fiber and the zeolite molecular sieve powder. It can be water-soluble or oil-soluble, and a solvent with low toxicity and easy to remove completely can be selected. Examples of solvents include: water, methanol, ethanol, tetrahydrofuran, acetonitrile, ethyl acetate, acetone, butanol, isobutanol, tert-butanol, cyclohexanol, n-hexanol, isooctanol, n-octanol, octadecanol (C8-C10 alcohols), C12-C14 alcohols, lauryl alcohol, C16-C18 alcohols, ethylene glycol, etc. Alcohols, glycerol, 1,2-hexanediol, 1,6-hexanediol, butanediol, polyvinyl alcohol, toluene, xylene (including o-xylene, m-xylene, and p-xylene), trimethylbenzene, ethylbenzene, naphthalene, methylnaphthalene, dimethylnaphthalene, cyclohexane, n-heptane, isooctane, hexadecane, gasoline, kerosene, diesel, alkylbenzene, paraffin, petroleum ether, diphenyl ether, acetic acid, benzoic acid, lauric acid, oleic acid, palmitic acid, and dioctyl phthalate (DOP), etc., but the solvents are not limited to these.

[0031] This disclosure does not specify the exact method for preparing the precursor or blank from the mixture in step (2) of the above preparation method, as long as it ensures that a precursor or blank with the required shape for the loudspeaker is obtained. The specific method can be reasonably selected according to the shape requirements of the loudspeaker, the type and amount of fiber, and the amount and size of the zeolite molecular sieve powder. For example, traditional catalyst-related preparation processes can be used, such as: ball rolling, extrusion, spraying, pressing, oil column forming, etc.; porous ceramic preparation processes can also be used, such as: sol-gel process, freeze drying process, template process, foam process, mold extrusion forming of honeycomb ceramics, etc.; and new forming processes can also be used, such as: 3D printing, etc.

[0032] This disclosure does not specify the exact method for curing, crosslinking, and shaping the precursor or blank in step (3) of the above preparation method. The method can be reasonably selected based on differences in fiber properties, as long as it ensures that an acoustic reinforcement material can be obtained. For example, the precursor or blank can be cured, crosslinked, and shaped through chemical reaction crosslinking. Specific methods of chemical reaction crosslinking include, but are not limited to, thermosetting and hot-melt crosslinking.

[0033] In another aspect, this disclosure also provides a loudspeaker, including one or more acoustic sensors and one or more housings, wherein the one or more acoustic sensors and one or more housings are combined to form a loudspeaker rear cavity, wherein the above-mentioned acoustic reinforcement material is assembled in the loudspeaker rear cavity.

[0034] Furthermore, this disclosure also provides an electronic device in which the above-mentioned acoustic enhancement material is assembled in the rear cavity of the speaker.

[0035] As a specific embodiment of the above-mentioned electronic devices disclosed herein, the electronic devices include smartphones, TWS earphones, headphones, smart glasses, smartwatches, VR devices, AR devices, tablet computers, or thin and light laptops, etc.

[0036] Compared with the prior art, the beneficial technical effects that this disclosure can achieve include:

[0037] The acoustic reinforcement material disclosed herein comprises fibers and zeolite molecular sieve powder. The fibers are introduced and interwoven to form a web, which traps the zeolite molecular sieve powder. By using fibers instead of binders, the surface of the zeolite particles is prevented from becoming clogged during the bonding process of polymer binders in existing technologies, thus avoiding various performance losses. Furthermore, the use of fibers avoids the stability loss caused by binders failing to meet performance requirements in harsh lifespan evaluations of loudspeakers. Therefore, in the acoustic reinforcement material disclosed herein, the surface of the zeolite molecular sieve powder is almost never clogged, thereby maximizing the acoustic performance of the zeolite molecular sieve powder.

[0038] In summary, the acoustic reinforcement material provided in this disclosure does not contain any binders, thus avoiding various performance or stability losses caused by the bonding of zeolite particles with polymer binders in the prior art. Furthermore, this acoustic reinforcement material can fill more zeolite molecular sieve powder per unit space, which can not only significantly improve the acoustic effect (i.e., increase the virtual volume of the speaker's rear cavity, shifting the speaker's resonant frequency f0 to a lower frequency and increasing the speaker's low-frequency sound pressure level), but also ensure its structural stability by using only fibers as auxiliary materials. In addition, this acoustic reinforcement material has a particularly wide operating temperature range (it is an acoustic reinforcement material resistant to high and low temperatures), and in extreme cases, it can maintain structural stability from the cryogenic liquid nitrogen temperature (i.e., -196℃) to the highest temperature of 200℃, meeting various stringent stability requirements of speakers. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this disclosure or related technologies, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 is a scanning electron microscope (SEM) image of the MFI structure molecular sieve A2 used in Embodiment 1 of this disclosure.

[0041] Figure 2 is a scanning electron microscope (SEM) image of sample 1 provided in Embodiment 1 of this disclosure.

[0042] Figure 3 is a scanning electron microscope (SEM) image of the MFI structure molecular sieve B2 used in Embodiment 5 of this disclosure.

[0043] Figure 4 is a scanning electron microscope (SEM) image of sample 5 provided in Embodiment 5 of this disclosure.

[0044] Figure 5 is a comparison of the frequency response curves and impedance curves of the small cavity 1cc loudspeaker with and without sample 1 in Test Example 2 of this disclosure.

[0045] Figure 6 is a comparison of the frequency response curves of the large cavity loudspeaker with 15cc sample 9, control sample 4 and no sample added in Test Example 4 of this disclosure. Detailed Implementation

[0046] It should be noted that the term "comprising" and any variations thereof in the specification, claims, and accompanying drawings of this disclosure are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device.

[0047] The "range" disclosed in this disclosure is given in the form of a lower limit and an upper limit. There can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0048] In this disclosure, unless otherwise stated, the numerical range "ab" is a shortened representation of any combination of real numbers from a to b, where a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this disclosure, and "0-5" is simply a shortened representation of these numerical combinations.

[0049] Unless otherwise specified, all embodiments and optional embodiments mentioned in this disclosure can be combined to form new technical solutions.

[0050] Unless otherwise specified, all technical features and optional features mentioned in this disclosure can be combined to form new technical solutions.

[0051] In this disclosure, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are exemplified as being performed sequentially. For example, a method including steps (a) and (b) indicates that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, mentioning that a method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or may include steps (a), (c), and (b), or may include steps (c), (a), and (b), etc.

[0052] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with the accompanying tables, figures, and embodiments. The embodiments described below are only some, not all, embodiments of this disclosure, and are used merely to illustrate the disclosure, and should not be considered as limiting its scope. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0053] The molecular sieves used in the embodiments of this disclosure have a bulk density of 0.55-0.65 g / cm³. 3 Furthermore, in this embodiment of the disclosure, when the calculation involves parameters such as fiber diameter, particle diameter, fiber length, and density, if these parameters are given as numerical ranges, the average value of the two endpoints of the numerical range is used as the specific value of the corresponding parameter for calculation.

[0054] Example 1

[0055] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0056] Step (1): Take ultrafine nano-polyester short fibers A1 (polyester fibers, here selected as polyethylene terephthalate, PET material), with a fiber diameter between 0.5-3μm and a length between 300-1000μm; take MFI structure molecular sieve A2, with a Si / Al ratio of 200 and an average molecular sieve diameter between 7-10μm. The scanning electron microscope (SEM) image of the MFI structure molecular sieve A2 is shown in Figure 1.

[0057] Step (2): Place 0.37cm 3 (0.5g) The above polyester fibers were homogenized and dispersed at high speed in 100g of a 0.5wt.% polyvinyl alcohol viscous solution, and then 7.5cm³ of solution was added. 3 (4.5g) of the above zeolite powder, stir thoroughly and disperse evenly.

[0058] Step (3): The uniformly dispersed liquid obtained in step (2) is filtered by pressure to obtain a uniformly mixed fiber molecular sieve filter cake; the filter cake is then washed three times with 300g of deionized water to remove the residual small amount of polyvinyl alcohol.

[0059] Step (4): After removing residual moisture from the filter cake, perform heat treatment crosslinking. The heat treatment conditions are: under a nitrogen atmosphere, constant temperature treatment at 200℃ for 5 min, constant temperature treatment at 240℃ for 2 min, and constant temperature treatment at 247℃ for 1 min. After the heat treatment, the filter cake is completely shaped. The material thickness measured with vernier calipers is between 1.36 mm and 1.44 mm, the filter cake diameter is 90 mm, and the corresponding material density is 0.55-0.57 g / cm³. 3 Finally, based on the dimensions of the speaker tooling cavity, sample 1 was obtained by cutting.

[0060] Example 2

[0061] This embodiment provides an acoustic reinforcement material, which differs from Embodiment 1 in that the amount of polyester fiber used is 0.74 cm³. 3 (1g), the amount of zeolite powder used is 6.67cm. 3 (4g), after complete setting, the material thickness was measured with vernier calipers and found to be between 1.49mm and 1.61mm, the filter cake diameter was 90mm, and the corresponding material density was 0.49-0.52g / cm³. 3 Finally, sample 2 was obtained by cutting according to the rear cavity dimensions of the speaker tooling.

[0062] Example 3

[0063] This embodiment provides an acoustic reinforcement material, which differs from Embodiment 1 in that the amount of polyester fiber used is 1 cm. 3 (1.4g), the amount of zeolite powder used is 6cm 3 (3.6g), after complete setting, the material thickness was measured with vernier calipers and found to be between 1.58mm and 1.62mm, with a filter cake diameter of 90mm, corresponding to a material density of 0.48-0.50g / cm³. 3 Sample 3 was obtained by cutting the sample according to the dimensions of the speaker tooling.

[0064] Example 4

[0065] This embodiment provides an acoustic reinforcement material, which differs from Embodiment 1 in that the amount of polyester fiber used is 0.185 cm³. 3 (0.25g), the amount of zeolite powder used is 7.917cm. 3 (4.75g), after complete setting, the material thickness was measured with vernier calipers and found to be between 1.27mm and 1.35mm, the filter cake diameter was 90mm, and the corresponding material density was 0.58-0.62g / cm³. 3 Sample 4 was obtained by cutting according to the dimensions of the speaker tooling.

[0066] Example 5

[0067] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0068] Step (1): Take nano-polyester short fiber B1 (PET material), with a fiber diameter between 200-400nm and a length between 300-600μm; MFI structure molecular sieve B2, with a Si / Al ratio of 300 and an average molecular sieve diameter between 7-10μm. The scanning electron microscope (SEM) image of the MFI structure molecular sieve B2 is shown in Figure 3.

[0069] Step (2): Place 0.111cm 3 0.15 g of the above-mentioned polyester fiber was homogenized and dispersed at high speed in 100 g of a 0.5 wt.% polyvinyl alcohol viscous solution, and then 8.08 cm³ of the solution was added. 3 (4.85g) of the above zeolite powder was thoroughly stirred and dispersed.

[0070] Step (3): The uniformly dispersed liquid obtained in step (2) is filtered by pressure to obtain a uniformly mixed fiber molecular sieve filter cake. The filter cake is then washed three times with 300g of deionized water to remove any residual small amount of polyvinyl alcohol.

[0071] Step (4): After removing residual moisture from the filter cake, perform heat treatment crosslinking. The heat treatment conditions are: under a nitrogen atmosphere, constant temperature treatment at 200℃ for 5 min, constant temperature treatment at 240℃ for 2 min, and constant temperature treatment at 247℃ for 0.5 min. After the heat treatment, the filter cake is completely set. The material thickness measured with vernier calipers is between 1.25 mm and 1.30 mm, the filter cake diameter is 90 mm, and the corresponding material density is 0.60-0.63 g / cm³. 3 Sample 5 was obtained by cutting according to the dimensions of the speaker tooling.

[0072] Example 6

[0073] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0074] Step (1): Take 0.074cm 3 (0.1g) of polyester fiber A3 and 0.111cm 3 0.15 g of polyester fiber B3 was homogenized and dispersed at high speed in 100 g of a 0.5 wt.% polyvinyl alcohol viscous solution, and then 7.92 cm³ of [amount missing] was added. 3 (4.75g) The above-mentioned MFI structure molecular sieve B2 was thoroughly stirred and evenly dispersed.

[0075] Step (2): The uniformly dispersed hydraulic filter obtained in the previous step is used to obtain a uniformly mixed fiber molecular sieve filter cake. The filter cake is then washed three times with 300g of deionized water to remove any residual small amount of polyvinyl alcohol.

[0076] Step (3): After drying the filter cake to remove residual moisture, perform heat treatment crosslinking. The heat treatment conditions are: under nitrogen atmosphere, constant temperature treatment at 200℃ for 5 min, constant temperature treatment at 240℃ for 2 min, and constant temperature treatment at 247℃ for 0.5 min. After the heat treatment, the filter cake is completely shaped. The material thickness is measured with vernier calipers and is between 1.35 mm and 1.43 mm. The diameter of the filter cake is 90 mm, and the corresponding material density is between 0.55-0.58 g / cm3. The sample 6 is obtained by cutting according to the size of the speaker tooling.

[0077] Example 7

[0078] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0079] Step (1): Take polyester short fiber C1 (PET material), with a fiber diameter between 1.5-4.5μm and a length between 500-1000μm; MFI structure molecular sieve C2, with a Si / Al ratio of 350 and an average molecular sieve diameter between 5-8μm.

[0080] Step (2): Take 0.074cm 3 (0.1g) of polyester fiber C3 and 0.259cm 3 0.35 g of polyester fiber B3 was added and homogenized by high-speed stirring in 100 g of a 0.5 wt.% polyvinyl alcohol viscous solution, followed by the addition of 8.27 cm³ of [amount missing]. 3 (4.55g) of the above zeolite powder, stir thoroughly and disperse evenly.

[0081] Step (3): Take 10.5g of the uniformly dispersed liquid obtained in step (2) and filter it to obtain a uniformly mixed fiber molecular sieve membrane. Then wash the filter membrane three times with 300g of deionized water to remove the residual small amount of polyvinyl alcohol.

[0082] Step (4): After drying the above filter membrane to remove residual moisture, it is subjected to heat treatment crosslinking. The heat treatment conditions are: under nitrogen atmosphere, constant temperature treatment at 200℃ for 5 min, constant temperature treatment at 240℃ for 2 min, and constant temperature treatment at 247℃ for 0.5 min. After the heat treatment, the filter cake is completely shaped. The material thickness is measured to be between 140-160 μm and the diameter is 90 mm using a film thickness gauge. The sample 7 is curled according to the size of the speaker fixture (i.e., bent or rolled according to the size of the speaker fixture to be screened into the rear cavity) to adapt to the shape of the speaker rear cavity, and then subjected to corresponding tests. It can be understood that the sample 7 can also be cut and stacked into the rear cavity. In the sample 7, the volume ratio of fiber is 3.74%.

[0083] Example 8

[0084] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0085] Step (1): Take ultrafine polyimide fiber A4 (Polyimide, PI material), with a fiber diameter between 1-3μm, and cut it into short fibers with a length of 300-500μm. MFI structure molecular sieve D, Si / Al ratio is 150, and the average diameter of the molecular sieve is between 7-10μm.

[0086] Step (2): Take 0.714cm 3 1 g of ultrafine polyimide fiber A4 was homogenized and dispersed in 100 mL of ethanol by high-speed stirring, and then 13.85 cm⁻¹ was added. 3 (9g) The above MFI structure molecular sieve D was thoroughly stirred and evenly dispersed.

[0087] Step (3): Filter the uniformly dispersed liquid obtained in step (2) to obtain a uniformly mixed fiber molecular sieve filter cake.

[0088] Step (4): The filter cake is subjected to heat treatment for crosslinking. The heat treatment conditions are: vacuum conditions, constant temperature treatment at 400℃ for 5 minutes. After the heat treatment, the filter cake is completely shaped. The material thickness is measured with vernier calipers and is between 12.50 mm and 12.60 mm. The diameter of the filter cake is 90 mm and the material density is 0.36 g / cm³. 3 Nearby, sample 8 was obtained by cutting according to the tooling dimensions of a large cavity loudspeaker.

[0089] Example 9

[0090] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0091] Step (1): Take 0.714cm 31 g of ultrafine polyimide fiber A4 was homogenized and dispersed in 100 mL of ethanol by high-speed stirring, and then 13.85 cm⁻¹ was added. 3 (9g) of the above-mentioned MFI structure molecular sieve D was thoroughly stirred and evenly dispersed.

[0092] Step (2): The uniformly dispersed hydraulic filter obtained in step (1) is used to obtain a uniformly mixed fiber molecular sieve filter cake. After drying, a mixture of molecular sieve raw powder and polyimide fiber is obtained.

[0093] Step (3): Weigh 5g of the uniform mixture, add 2.5g of liquid paraffin, knead evenly, and then place it into an array-hole mold (pore diameter 0.3mm, pore density distribution of 1 hole per square millimeter, and uniform distribution) for molding; then demold, dewax, and then heat-treat for cross-linking. The heat treatment conditions are vacuum conditions, constant temperature treatment at 400℃ for 5min. After the heat treatment, the filter cake is completely shaped. The material thickness is measured with vernier calipers and is between 12.40mm and 12.50mm, the filter cake diameter is 90mm, and the material density is 0.37g / cm³. 3 Nearby, sample 9 was obtained by cutting according to the tooling dimensions of a large cavity loudspeaker.

[0094] Example 10

[0095] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0096] Step (1): Take nano-polyimide fiber B4 (Polyimide, PI material), with a fiber diameter between 500-800nm, and cut it into short fibers with a length of 300-500μm. MFI structure molecular sieve D, Si / Al ratio is 150, and the average diameter of the molecular sieve is between 7-10μm.

[0097] Step (2): Take 1.07cm 3 1.5 g of nano-polyimide fiber B4 was homogenized and dispersed in 100 mL of cyclohexane under high-speed stirring, and then 13.08 cm⁻¹ was added. 3 (8.5g) of the above-mentioned MFI structure molecular sieve D was thoroughly stirred and evenly dispersed.

[0098] Step (3): Take 2g of benzoic acid and recrystallize it in 20mL of cyclohexane by ultrasonication to obtain white needle-shaped benzoic acid needle crystals. Add the benzoic acid needle crystals to the fiber molecular sieve dispersion obtained after uniform dispersion in step (2) and further disperse it evenly. Then filter it by pressure to obtain a uniformly mixed fiber molecular sieve filter cake.

[0099] Step (4): The filter cake is subjected to heat treatment for crosslinking. The heat treatment conditions are: vacuum conditions, constant temperature treatment at 400℃ for 5 minutes. After the heat treatment, the filter cake is completely shaped. The material thickness is measured with vernier calipers and is between 12.55 mm and 12.59 mm. The diameter of the filter cake is 90 mm and the material density is 0.36 g / cm³. 3 Nearby, sample 10 was obtained by cutting according to the tooling dimensions of a large cavity loudspeaker.

[0100] Example 11

[0101] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0102] Step (1): Weigh 0.714cm 3 (1g) of nano-polyimide fiber B4, 0.714cm 3 (1g) of the micronized polyimide fiber A5 from Example 8 was homogenized and dispersed in 100mL of tert-butanol by high-speed stirring, and then 11.43cm was added. 3 (8g) of the above-mentioned MFI structure molecular sieve D and 200mL of water were thoroughly stirred and evenly dispersed.

[0103] Step (2): Filter the uniformly dispersed liquid obtained in step (1) to remove most of the liquid, and obtain a viscous slurry with a volume of about 30 mL. Pour the viscous slurry into a mold and freeze it directly.

[0104] Step (3): After freeze-drying to remove the solvent, perform heat treatment crosslinking. The heat treatment conditions are: vacuum conditions, constant temperature treatment at 400℃ for 5 minutes. After heat treatment, the sample is completely shaped. The material thickness measured with vernier calipers is between 12.65 mm and 12.69 mm, the filter cake diameter is 90 mm, and the material density is 0.35 g / cm³. 3 Nearby, sample 11 was obtained by cutting according to the tooling dimensions of a large cavity loudspeaker.

[0105] Example 12

[0106] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0107] Step (1): Take nano-polyimide fiber C3 (Polyimide, PI material), with a fiber diameter between 100-300nm, and ball mill it into short fibers with a length of less than 30-70μm.

[0108] Step (2): Weigh 1.43cm 3 (2g) Step (1) After ball milling, the PI short fibers are homogenized and dispersed in a 60mL mixture of tert-butanol and water by high-speed stirring, and then 40cm is added.3 (20g) of MFI molecular sieve C2 was uniformly dispersed to obtain a slurry;

[0109] Step (3): Spray dry the slurry obtained in step (2) with a 400μm nozzle (80℃ at the top of the tower, 100℃ at the bottom of the tower, spray pressure 0.4MPa) to granulate and obtain spherical particles;

[0110] Step (4): The spherical particles obtained in step (3) are placed in a nitrogen atmosphere furnace and subjected to heat treatment at 400℃ for 10 minutes for semi-melt crosslinking. After crosslinking, the particles are sieved through a sieve to obtain particles with a diameter of 270-330μm and a particle bulk volume of 43.5cm³. 3 This sample, denoted as Sample 12, has an average diameter of 300 μm.

[0111] Example 13

[0112] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0113] Step (1): Take ultrafine nano polyester short fibers (polyethylene terephthalate, PET material) with a fiber diameter between 0.2-0.4μm and a length between 300-1000μm; take MFI structure molecular sieve A2 with a Si / Al ratio of 200 and an average molecular sieve diameter between 7-10μm.

[0114] Step (2): Place 0.37cm 3 (0.5g) The above polyester fibers were homogenized and dispersed at high speed in 100g of a 0.5wt.% polyvinyl alcohol viscous solution, and then 7.5cm³ of solution was added. 3 (4.5g) of the above zeolite powder, stir thoroughly and disperse evenly.

[0115] Step (3): The uniformly dispersed liquid obtained in step (2) is filtered by pressure to obtain a uniformly mixed fiber molecular sieve filter cake; the filter cake is then washed three times with 300g of deionized water to remove the residual small amount of polyvinyl alcohol.

[0116] Step (4): After removing residual moisture from the filter cake, perform heat treatment crosslinking. The heat treatment conditions are: under a nitrogen atmosphere, constant temperature treatment at 200℃ for 5 min, constant temperature treatment at 240℃ for 2 min, and constant temperature treatment at 247℃ for 1 min. After the heat treatment, the filter cake is completely shaped. The material thickness measured with vernier calipers is between 1.36 mm and 1.44 mm, the filter cake diameter is 90 mm, and the corresponding material density is 0.55-0.57 g / cm³. 3Finally, sample 13 was obtained by cutting according to the rear cavity dimensions of the speaker tooling.

[0117] Example 14

[0118] This embodiment provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0119] Step (1): Take ultrafine nano polyester short fibers (polyethylene terephthalate, PET material) with a fiber diameter between 3-5 μm and a length between 300-1000 μm; take MFI structure molecular sieve A2 with a Si / Al ratio of 200 and an average molecular sieve diameter between 7-10 μm.

[0120] Step (2): Place 0.37cm 3 (0.5g) The above polyester fibers were homogenized and dispersed at high speed in 100g of a 0.5wt.% polyvinyl alcohol viscous solution, and then 7.5cm³ of solution was added. 3 (4.5g) of the above zeolite powder, stir thoroughly and disperse evenly.

[0121] Step (3): The uniformly dispersed liquid obtained in step (2) is filtered by pressure to obtain a uniformly mixed fiber molecular sieve filter cake; the filter cake is then washed three times with 300g of deionized water to remove the residual small amount of polyvinyl alcohol.

[0122] Step (4): After removing residual moisture from the filter cake, perform heat treatment crosslinking. The heat treatment conditions are: under a nitrogen atmosphere, constant temperature treatment at 200℃ for 5 min, constant temperature treatment at 240℃ for 2 min, and constant temperature treatment at 247℃ for 1 min. After the heat treatment, the filter cake is completely shaped. The material thickness measured with vernier calipers is between 1.36 mm and 1.44 mm, the filter cake diameter is 90 mm, and the corresponding material density is 0.55-0.57 g / cm³. 3 Between these steps, sample 14 was finally obtained by cutting according to the rear cavity dimensions of the speaker tooling.

[0123] Comparative Example 1

[0124] This comparative example provides an acoustic enhancement material, which is obtained by a method including the following specific steps:

[0125] Disassemble the speaker of a commercially available Apple X phone, remove the particles from the rear cavity and use them as acoustic enhancement material, denoted as Comparative Sample 1.

[0126] Comparative Example 2

[0127] This comparative example provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0128] Weigh 4g of styrene-acrylic emulsion adhesive (a commercially available high-adhesion adhesive with a solid content of 50%) and disperse it in a 60mL mixture of tert-butanol and water. Then add 40cm... 3 20g of MFI molecular sieve C was uniformly dispersed to obtain a slurry; the slurry was then spray-dried using a 400μm nozzle (80℃ at the top of the column, 100℃ at the bottom of the column, and a spray pressure of 0.4MPa) to obtain spherical particles; the particles were then sieved to obtain particles with a diameter of 270-330μm, which were designated as control sample 2, with an average diameter of 300μm.

[0129] Comparative Example 3

[0130] This comparative example provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0131] Step (1): Take commercially available traditional polyester short fibers with a fiber diameter of 15-25μm, cut the short fibers into 500-1000μm and MFI structure molecular sieve A2 with a Si / Al ratio of 200 and an average molecular sieve diameter between 7-10μm.

[0132] Step (2): Take 1.48cm of the above-mentioned commercially available traditional polyester fiber. 3 (2g), the amount of zeolite powder is 6.0cm. 3 (3g), all other operations were the same as in Example 1. After the filter cake was fully shaped, the material thickness was measured with vernier calipers and found to be between 1.57mm and 1.63mm. The filter cake diameter was 90mm, corresponding to a material density of 0.48-0.50g / cm³. 3 Between them, the comparison sample 3 was obtained by cutting according to the size of the speaker tooling.

[0133] Comparative Example 4

[0134] This comparative example provides an acoustic enhancement material derived from N'Bass particles used in commercially available Android flagship phones. These N'Bass particles have a size of approximately 300 μm and a bulk density of 0.39-0.40 g / cc.

[0135] Comparative Example 5

[0136] This comparative example provides an acoustic enhancement material, which is prepared by a method including the following specific steps:

[0137] Step (1): Take commercially available traditional polyester short fibers with a fiber diameter of 30-45μm, cut the short fibers into 500-1000μm and MFI structure molecular sieve A2 with a Si / Al ratio of 200 and an average molecular sieve diameter of 7-10μm.

[0138] Step (2): Take 1.48cm 3 (2g) of the above-mentioned conventional polyester fiber, 6.0cm 3 (3g) of zeolite powder was used, and other operations were the same as in Example 1. After the filter cake was fully shaped, the material thickness was measured with vernier calipers and found to be between 1.57mm and 1.63mm. The filter cake diameter was 90mm, corresponding to a material density of 0.48-0.50g / cm³. 3 Between these, a comparison sample 5 was obtained by cutting according to the dimensions of the speaker tooling.

[0139] Test Example 1

[0140] In this test example, scanning electron microscopy (SEM) analysis was performed on samples 1 and 5, respectively. The obtained SEM images are shown in Figures 2 and 4, respectively. As can be seen from Figures 2 and 4, both samples 1 and 5 consist of a fiber network formed by interlacing fibers and zeolite molecular sieve powder. The zeolite molecular sieve powder is loaded in the three-dimensional network formed by interlacing fibers, and there are no binder components between the zeolite molecular sieve powders except for the fibers.

[0141] Test Example 2

[0142] This test example measures the acoustic performance of samples 1-6, sample 12, and control samples 1-3 and control sample 5, including:

[0143] Using commercially available 1115 type loudspeakers, the tooling back cover cavity volume is 1 cubic centimeter (abbreviated as 1cc, there is about 0.8cc gap volume between the driver and the back cover), and the back cover cavity volume is 100% canned according to the measurement standard.

[0144] The acoustic performance testing was conducted using conventional methods existing in the field. For example, the acoustic performance of each sample and each comparison sample could be tested using the "Measuring Impedance" method shown in paragraphs 0049-0054 of Chinese patent application CN105049997A. Specifically, each sample and each comparison sample was tested according to the "Measuring Impedance" method to obtain an impedance spectrum. The curve in the impedance spectrum corresponds to the impedance curve, where the frequency corresponding to the highest point of the impedance curve is F0. When the loudspeaker is not loaded with each sample and each comparison sample, the measured F0 is marked as F. 0- 空腔 When the loudspeaker is loaded with each sample and each control sample, the measured F0 is labeled as F. 0-样品或对比样 Then the formula for calculating ΔF0 is: ΔF0=F 0-空腔 -F 0-样品或对比样 .

[0145] The acoustic performance data obtained in this test case are shown in Table 1 and Figure 5.

[0146] Test Example 3

[0147] This test example examines the drop structure stability of samples 1-6, sample 12, and control samples 1-3 and control sample 5, including:

[0148] Weigh 0.2g of the above-mentioned test sample and control sample respectively and place them into a 250g drop test fixture (approximately 160mm x 100mm x 90mm in length, width, and height, made of 316L stainless steel, with a 60mm diameter sample tank cover). o To increase the destructive power of the structure upon impact (by highlighting sharp edges), the sample was dropped 300 times from a height of 1.6m (100 times on each side and 25 times on each of the four sides). After the drop test, the sample was disassembled and the amount of powder shedding was observed to determine whether the material strength met the requirements. The experimental results are shown in Table 1.

[0149] Table 1 shows the resonant frequency F0 and the shedding of the acoustic reinforcement material before and after adding it to the rear cavity of the 1cc loudspeaker.

[0150] Note: Density is the average value of each sample.

[0151] As can be seen from Table 1, compared with the comparative sample 1 provided in Comparative Example 1, the low-frequency improvement performance of the samples provided in Examples 1, 4-6 of this disclosure, i.e., ΔF0 / Hz, can be reduced by more than 50Hz, and by up to 109Hz, with a significant improvement in acoustic performance.

[0152] Comparative Example 2, based on a commercially available molding formula, increased the amount of adhesive during the molding process to further enhance particle strength. As shown in Table 1, with the adhesive content increasing to over 9 wt.%, the acoustic performance significantly worsened compared to Comparative Example 1, with ΔF0 decreasing from 255.4 Hz to only 148.5 Hz, a deterioration of over 40%. This phenomenon is attributed to the fact that with the increase in adhesive content, the cured adhesive particles significantly clog the surface of the molecular sieve powder, resulting in insufficient air permeability and hindering the powder's ability to fully exert its effect, thus significantly worsening the acoustic performance. In contrast, this disclosure, by using a fiber mesh to enclose the molecular sieve powder, almost eliminates the phenomenon of significantly worsened acoustic performance due to fiber content clogging. For example, sample 12, under the same conditions, achieved an acoustic performance ΔF0 of 281.1 Hz, a 10% improvement over Comparative Example 1 and a significant improvement of approximately 90% over Comparative Example 2.

[0153] For sample 2, the fiber content was increased to 20 wt. (7.81 v / v%), and the acoustic performance was still better than that of control sample 1, and significantly better than that of control sample 2.

[0154] For Sample 3, the fiber content was increased to 28 wt.% (9.95 v / v%), and the acoustic effect was close to that of Comparative Sample 1, significantly better than Comparative Sample 2. The acoustic effect of Sample 3 was average, mainly because the fiber content was too high, resulting in a much lower proportion of molecular sieve powder, which in turn reduced the acoustic enhancement effect. Compared to Example 1, Example 14 had a ratio of molecular sieve powder to fiber average diameter of 2.125. At this point, the number of fibers in contact with a single powder was insufficient, resulting in poor fiber fixation of the powder and slight powder shedding. In contrast, the fiber diameter in Example 13 was 0.2-0.4 μm, and its ratio to the powder diameter was 28.3. Compared to Example 1, with the same volume, a large number of fibers firmly held the powder in place, resulting in good fixation. Furthermore, the small fiber diameter resulted in a small contact area on the powder surface, which did not affect the acoustic effect of the powder channels.

[0155] In this disclosure, the drop test uses relatively stringent tooling and conditions, with a height of 1.6m. As can be seen from the experimental results shown in Table 1, the strength of the samples provided in the embodiments of this disclosure is significantly better than that of comparative samples 1-3 and comparative sample 5, and almost all of them can pass the stringent drop evaluation.

[0156] For control sample 3, which uses traditional polyester fiber and has increased the fiber content to 40 wt%, the strength of control sample 3 is still relatively poor, with significant breakage and powder shedding, especially during the drop process where powder continuously leaks out and is basically unable to be caught. The reason for this is mainly due to the large diameter of the traditional polyester fiber, which is between 15-25 μm. The fiber diameter is basically larger than the diameter of the molecular sieve powder. This also confirms the results of control sample 5, that is, when the fiber diameter is larger than the diameter of the original powder particles, the powder shedding gradually becomes more serious with the increase of fiber diameter. The main reason is that as the fiber diameter increases, the size of the gaps in the network formed between the fibers also increases, which cannot effectively catch the original powder particles, causing continuous powder leakage during the drop process.

[0157] Test Example 4

[0158] This test example measures the acoustic performance of samples 8-11, sample 12, and control sample 4 in a large-cavity loudspeaker, including:

[0159] Acoustic performance tests were conducted using a commercially available portable Bluetooth speaker, model MW-P1C, with dimensions of 63mm×47mm×30mm, a 4Ω 3W speaker, a system frequency response of 120Hz-20KHz, and a rear cavity volume of 18cc, approximately 80% filled.

[0160] The acoustic performance testing was conducted using conventional methods existing in the field. For example, the acoustic performance of each sample and each comparison sample could be tested using the "Measuring Impedance" method shown in paragraphs 0049-0054 of Chinese patent application CN105049997A. Specifically, each sample and each comparison sample was tested according to the "Measuring Impedance" method to obtain an impedance spectrum. The curve in the impedance spectrum corresponds to the impedance curve, where the frequency corresponding to the highest point of the impedance curve is F0. When the loudspeaker is not loaded with each sample and each comparison sample, the measured F0 is marked as F. 0- 空腔 When the loudspeaker is loaded with each sample and each control sample, the measured F0 is labeled as F. 0-样品或对比样 Then the formula for calculating ΔF0 is: ΔF0=F 0-空腔 -F 0-样品或对比样 .

[0161] The acoustic performance data obtained from this test example are shown in Table 2 and Figure 6 below.

[0162] Table 2 shows the resonant frequencies F0 before and after adding acoustic reinforcement material to the rear cavity of a 18cc large-cavity loudspeaker.

[0163] As can be seen from the experimental data in Table 2, adding N'Bass particles (used in the small cavity of a mobile phone, i.e., control sample 4) to the large cavity resulted in a significant effect when the filling volume was 5cc. Further increasing the filling volume, while still having some effect, resulted in a noticeably weaker effect. This is mainly because the N'Bass particles are only about 300μm in size, which is very small. As the filling volume increases, the thickness also increases, leading to greater resistance for the gas to travel from the upper layer to the bottom layer of particles with the sound waves. Consequently, the lower layer of N'Bass particles cannot fully exert their effect. Furthermore, acoustic reinforcement material blocks manufactured using conventional processes, due to their excessive thickness, experience increasingly greater resistance to sound waves traveling to the central area of ​​the material block, making it difficult to improve the acoustic performance.

[0164] Based on the characteristics of large-cavity loudspeakers, it is necessary to develop acoustic reinforcement materials with low flow resistance to match them. In this regard, Examples 8-11 and 12 of this disclosure provide low-flow-resistance porous bulk acoustic reinforcement materials to match this requirement. As shown in Table 2, under the same conditions, the acoustic performance of Samples 8-11 and 12 is significantly improved compared to Comparative Sample 4. In particular, the acoustic performance is even more significant after introducing more permeable channels through different preparation methods. The best result with a filling volume of 15cc is more than 50% higher than that of Comparative Sample 4.

[0165] Test Example 5

[0166] This test example refers to the acoustic performance test method in Test Example 2. The F0 / Hz of samples 1-6 and samples 13-14 before and after the heat resistance test is measured respectively, and ΔF0 / Hz is calculated accordingly. The experimental data are shown in Table 3 below.

[0167] This test example also refers to the method in Test Example 3 to test the drop structure stability of samples 1-6 and samples 13-14 after the heat resistance test, and the experimental results are shown in Table 3 below.

[0168] In this test example, the heat resistance test was conducted at a temperature of 200℃ for 1 hour.

[0169] Table 3 shows the addition of acoustic reinforcement material to the rear cavity of a 1cc loudspeaker and the examination of its resonant frequency F0 before and after heat resistance testing, as well as the shedding of powder from the acoustic reinforcement material during drop tests.

[0170] Normally, the operating temperature of the speaker's rear cavity is below 200℃. Therefore, in this test example, speakers with rear cavities filled with samples 1-6 and 13-14 were subjected to a heat resistance test at 200℃ for 1 hour. Subsequently, the corresponding acoustic performance data and material strength drop and powder shedding were measured, as shown in Table 3 above. As can be seen from Table 3, the morphology of the samples provided in this embodiment remained unchanged after the 200℃ heat resistance test, the acoustic performance showed minimal change, and the strength did not decrease. This proves that the acoustic reinforcement material provided in this embodiment can operate stably at 200℃.

[0171] The above description is merely a specific embodiment of this disclosure and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this disclosure can be freely combined and used.

Claims

1. An acoustic enhancement material, characterized in that, The acoustic enhancement material comprises a fiber network formed by interlacing fibers and zeolite molecular sieve powder. The zeolite molecular sieve powder is loaded in the three-dimensional network formed by interlacing fibers, and there are no binder components between the zeolite molecular sieve powders except for the fibers.

2. The acoustic enhancement material according to claim 1, characterized in that, With the total volume of the acoustic reinforcement material being 100%, the volume percentage of the fiber is 0.1-15%, preferably 0.6-10%.

3. The acoustic enhancement material according to claim 1, characterized in that, The average diameter of the fiber is 10nm-10μm, preferably 50nm-5μm, and more preferably 100nm-3μm; its aspect ratio is greater than 10, preferably greater than 30, and more preferably greater than 50.

4. The acoustic enhancement material according to claim 1, characterized in that, The ratio of the diameter of the fiber to the diameter of the zeolite molecular sieve powder is less than 1:2, preferably less than 1:4, and more preferably less than 1:

8.

5. The acoustic enhancement material according to any one of claims 1-3, characterized in that, The fiber includes inorganic fibers and / or organic fibers, and preferably, the fiber is a synthetic polymer fiber.

6. The acoustic enhancement material according to any one of claims 1-3, characterized in that, The fiber is resistant to low temperatures not exceeding -30℃ and high temperatures not lower than 200℃.

7. The acoustic enhancement material according to claim 1, characterized in that, The particle size of the zeolite molecular sieve raw powder is greater than 2 μm and less than or equal to 10 μm, preferably greater than 6 μm and less than or equal to 10 μm, and more preferably greater than 8 μm and less than or equal to 10 μm.

8. The acoustic enhancement material according to claim 1 or 7, characterized in that, The structure of the zeolite molecular sieve raw powder includes one or a combination of several of MFI, MEL, BEA, FAU, FER, MOR and DDR.

9. The acoustic enhancement material according to claim 1 or 7, characterized in that, The morphology of the zeolite molecular sieve raw powder includes one or a combination of several of the following: flake-shaped, strip-shaped, strip-shaped twins, spherical, and quasi-spherical.

10. The acoustic enhancement material according to any one of claims 1-4 and 7, characterized in that, The morphology of the acoustic enhancement material includes one or a combination of several of the following: granular, flake-like, block-like, and irregular shapes.

11. The acoustic enhancement material according to any one of claims 1-4 and 7, characterized in that, The acoustic enhancement material has a breathable channel with a diameter of 10-1000 μm, preferably 20-500 μm.

12. A method for preparing the acoustic enhancement material according to any one of claims 1-11, characterized in that, The preparation method includes: Step (1): Mix the zeolite molecular sieve powder and fiber evenly to obtain a uniform mixture; Step (2): Prepare the mixture into a precursor or blank; Step (3): The precursor or blank is cured, crosslinked and shaped to obtain the acoustic enhancement material.

13. A loudspeaker, comprising one or more acoustic sensors and one or more housings, wherein the one or more acoustic sensors and the one or more housings are combined to form a rear cavity of the loudspeaker, characterized in that, The rear cavity of the loudspeaker is fitted with the acoustic enhancement material according to any one of claims 1-11.

14. An electronic device, characterized in that, The electronic device is equipped with the acoustic enhancement material according to any one of claims 1-11 in the rear cavity of the speaker.

15. The electronic device according to claim 14, characterized in that, The electronic devices include smartphones, TWS earphones, headphones, smart glasses, smartwatches, VR devices, AR devices, tablets, or thin and light laptops.

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