Acoustic enhancement material with low surface tension, preparation method thereof, loudspeaker, and electronic device

Abstract

The present invention provides an acoustic enhancement material with low surface tension, a preparation method thereof, a loudspeaker, and an electronic device. The acoustic enhancement material with low surface tension is prepared by first mixing a porous powder material, an adhesive, a hydrophilic additive, a low surface tension additive, and water uniformly and then molding; wherein the mass ratio of water, porous powder material, adhesive, hydrophilic additive, and low surface tension additive is 100:80-120:4-12:0.04-2.4:0.2-3.6, and the amount of porous powder material, adhesive, hydrophilic additive, and low surface tension additive is calculated based on the absolute dry mass of the effective ingredient. The acoustic enhancement material has a relatively low surface tension, so its water absorption capacity is poor, the moisture content is low, and the acoustic performance is not affected by moisture, and even if the acoustic enhancement material is treated with high temperature and high humidity, its acoustic performance will not be significantly reduced.

Description

Technical Field

[0001] The invention relates to an acoustic enhancement material with low surface tension, a preparation method thereof, a loudspeaker and electronic equipment, and belongs to the field of materials, in particular to the technical field of electronic acoustic materials. Background Art

[0002] Mobile phones, tablets, laptops and other electronic products are becoming thinner and lighter, so the resonant cavity of the speaker system components they use, that is, the speaker back cavity, is getting smaller and smaller. As we all know, the smaller and smaller speaker resonant cavity will lead to an increase in resonant frequency and a decrease in low-frequency sound pressure sensitivity, while consumers have higher and higher requirements for the audio quality of electronic products such as mobile phones, tablets, laptops, etc. In order to solve the contradiction between the two, acoustic enhancement materials came into being.

[0003] At present, the conventional method to improve the audio quality of small-cavity speakers is to prepare porous powder materials that can efficiently absorb and release air molecules into sound-absorbing particles with an average particle size of 200-800μm through molding technology and fill them into the speaker cavity. However, this method also has certain shortcomings, including:

[0004] First, the acoustic performance of the sound-absorbing particles is greatly reduced after being treated with high temperature and high humidity;

[0005] Secondly, when the speaker is working, the sound-absorbing particles vibrate at a high frequency in the cavity and collide and rub against the inner wall of the cavity. At the same time, there will be collision and friction between the particles. Over time, the sound-absorbing particles will break and break into powder, damaging the speaker. At the same time, the loose and porous structure on the surface of the sound-absorbing particles disappears due to collision and friction, and its corresponding acoustic performance will be significantly reduced.

[0006] In this regard, some companies have made some attempts and efforts to research hydrophobic and / or enhanced sound-absorbing particles, as follows.

[0007] Prior art 1: Four invention patents CN111147987A, CN111163395A, CN111182419A and CN111163403A applied by Goertek Co., Ltd. These four invention patents all disclose a sound-absorbing particle, including activated carbon particles and a high molecular polymer adhesive mixed with the activated carbon particles, wherein the activated carbon particles include an activated carbon particle core and a hydrophobic layer coated on the outer surface of the activated carbon particle core; the material of the hydrophobic layer includes one of zeolite, aerogel, and porous organic polymer. These four invention patents can reduce the moisture entering the activated carbon particle core by arranging a hydrophobic layer outside the activated carbon particle core, thereby improving the sound absorption capacity of the sound-absorbing particles. Filling the sound-absorbing particles into a sound-generating device can be used to reduce the resonant frequency of the sound-generating device and improve the sound-generating performance of the sound-generating device. However, the preparation of hydrophobic activated carbon particles, i.e. coating the surface of activated carbon particles with one of zeolite, aerogel and porous organic polymer, is very difficult, and none of the four invention patents discloses the corresponding preparation method; in addition, the use of zeolite to prepare sound-absorbing particles is common knowledge in the industry, that is, the hydrophobicity of the sound-absorbing particles obtained by the four invention patents in prior art 1 should be similar to the hydrophobicity of the sound-absorbing particles prepared from pure zeolite, which means that the hydrophobicity of the sound-absorbing particles provided by prior art 1 is only better than that of the sound-absorbing particles prepared from pure activated carbon, that is, its water absorption is lower than that of the sound-absorbing particles prepared from pure activated carbon, but compared with the sound-absorbing particles prepared from pure zeolite, the hydrophobicity of the sound-absorbing particles provided by prior art 1 is not significantly improved.

[0008] Prior art 2: Invention patent CN CN108059388A applied by AAC Technologies (Singapore) Ltd. This invention patent provides a method for making sound-absorbing particles, the method comprising: firstly preparing a mixed slurry with porous powder, water, adhesive and additives in a mass ratio of 1:(0.5-8):(0.01-0.16):(0.001-0.15); then subjecting the mixed slurry to spray molding, drying and screening treatments in sequence to obtain the sound-absorbing particles. The invention patent also provides sound-absorbing particles and a speaker box including the sound-absorbing particles. Compared with the related art, the sound-absorbing particles made by the sound-absorbing particle making method have high compressive strength. When the sound-absorbing particles have the same deformation as the sound-absorbing particles in the related art, the pressure on the sound-absorbing particles is greater than the pressure on the sound-absorbing particles in the related art. When the sound-absorbing particles of the present invention are used in a speaker box, it is not easy to produce powder, so that the acoustic performance of the speaker box is good and the stability is high. However, the additives used in the prior art 2 are all highly hydrophilic substances, such as Tween 20, Tween 80, polyethylene glycol, sorbitol, etc. Although in this field, adding a small amount of highly hydrophilic substances to the formula to improve the strength of the particles is a common method, the embodiment of the prior art 2 does not disclose experimental data related to the strength of the sound-absorbing particles; in addition, although the addition of highly hydrophilic substances can indeed improve the strength of the sound-absorbing particles to a certain extent, the introduction of highly hydrophilic substances will inevitably enhance the water absorption of the sound-absorbing particles, and the acoustic performance of the highly water-absorbing sound-absorbing particles will inevitably be greatly reduced after being treated with high temperature and high humidity.

[0009] Therefore, providing a new acoustic enhancement material with low surface tension and a preparation method thereof, as well as a loudspeaker and an electronic device has become a technical problem that urgently needs to be solved in the art. Summary of the invention

[0010] In order to solve the above-mentioned shortcomings and deficiencies, an object of the present invention is to provide an acoustic enhancement material with low surface tension.

[0011] Another object of the present invention is to provide a method for preparing the acoustic enhancement material with low surface tension.

[0012] Another object of the present invention is to provide a loudspeaker, in which the acoustic reinforcement material with low surface tension as described above is installed in the rear cavity of the loudspeaker.

[0013] Another object of the present invention is to provide an electronic device, wherein the speaker rear cavity of the electronic device is equipped with the acoustic enhancement material with low surface tension as described above.

[0014] In order to achieve the above objectives, on the one hand, the present invention provides an acoustic enhancement material with low surface tension, wherein the acoustic enhancement material with low surface tension is prepared by first mixing a porous powder material, an adhesive, a hydrophilic additive, a low surface tension additive and water uniformly and then molding;

[0015] Among them, the mass ratio of water, porous powder material, adhesive, hydrophilic additive and low surface tension additive is 100:80-120:4-12:0.04-2.4:0.2-3.6, and the dosage of porous powder material, adhesive, hydrophilic additive and low surface tension additive is calculated based on the absolute dry mass of the active ingredient.

[0016] As a specific embodiment of the acoustic enhancement material described above in the present invention, the mass ratio of water, porous powder material, adhesive, hydrophilic additive and low surface tension additive is 100:90-110:4.5-11:0.045-1.1:0.225-2.2.

[0017] Different low surface tension additives have different effects on reducing the surface tension of acoustic enhancement materials. Therefore, the amount of different low surface tension additives added is different. During on-site operations, their amount can be reasonably determined as needed, but it must be ensured that their amount is within the range required by this application.

[0018] As a specific embodiment of the acoustic enhancement material described above in the present invention, the porous powder material is a porous powder material with acoustic enhancement, including one or a combination of zeolite molecular sieve, activated silica, activated carbon, surface porous calcium carbonate and surface porous calcium silicate.

[0019] In order to enhance the acoustic enhancement effect of the acoustic enhancement material to a greater extent, as a specific embodiment of the acoustic enhancement material described above in the present invention, the zeolite molecular sieve includes one or a combination of MFI structure molecular sieve, FER structure molecular sieve, CHA structure molecular sieve, MEL structure molecular sieve, TON structure molecular sieve and MTT structure molecular sieve.

[0020] Among them, MFI structure molecular sieve, FER structure molecular sieve, CHA structure molecular sieve, MEL structure molecular sieve, TON structure molecular sieve and MTT structure molecular sieve are all conventional molecular sieves. The specific molecular sieve can be reasonably selected according to the actual operation needs and used in the present invention.

[0021] As a specific embodiment of the acoustic enhancement material described above in the present invention, the particle size of the zeolite molecular sieve is 0.5-10 μm.

[0022] As a specific embodiment of the acoustic enhancement material described above, the zeolite molecular sieve includes micropores with a pore size of 0.3-0.7 nm and mesopores with a pore size of 10-30 nm.

[0023] As a specific embodiment of the acoustic enhancement material described above in the present invention, the zeolite molecular sieve is ZSM-5 molecular sieve.

[0024] As a specific embodiment of the acoustic enhancement material described above in the present invention, the adhesive includes an organic adhesive and / or an inorganic adhesive; the organic adhesive includes one or a combination of polyacrylate, acrylic copolymer, polyurethane, polystyrene butadiene emulsion, polystyrene acrylate, polystyrene acetate emulsion, polyvinyl acetate emulsion, silicone resin and polybutadiene rubber emulsion; the inorganic adhesive includes one or a combination of silica sol, aluminum sol and pseudo-boehmite.

[0025] As a specific embodiment of the acoustic enhancement material described above, the hydrophilic additive includes one or a combination of ethylene glycol, propylene glycol, glycerol, polyethylene glycol, polypropylene glycol, and sorbitol, etc. When the hydrophilic additive is added during the preparation of the acoustic enhancement material, the strength of the obtained acoustic enhancement material with low surface tension can be significantly improved.

[0026] As a specific embodiment of the acoustic enhancement material described above, the low surface tension additive includes one or a combination of lubricants, silane coupling agents, and alkyl ketene dimer emulsions (AKD emulsions).

[0027] As a specific embodiment of the acoustic enhancement material described above in the present invention, the lubricant includes one or a combination of calcium stearate water-soluble emulsion, ammonium stearate water-soluble emulsion, sodium stearate water-soluble emulsion, potassium oleate emulsion, polyethylene wax water-soluble emulsion, silicone polymer emulsion, polyoxyethylene derivative water-soluble lubricant and fatty acid ester lubricant.

[0028] As a specific embodiment of the acoustic enhancement material described above, the silane coupling agent includes a methacryloxyalkyl silane coupling agent, etc. In some embodiments of the present invention, the methacryloxyalkyl silane coupling agent may be KH570, for example.

[0029] As a specific embodiment of the acoustic enhancement material described above in the present invention, the water includes one or a combination of deionized water, distilled water, reverse osmosis water, etc.

[0030] As a specific embodiment of the acoustic enhancement material described above in the present invention, the shape of the acoustic enhancement material includes microspheres (particles), blocks or sheets, etc.; wherein the size of the microspheres is 200-600 μm.

[0031] On the other hand, the present invention also provides a method for preparing the acoustic enhancement material with low surface tension as described above, wherein the preparation method comprises:

[0032] (1) mixing the porous powder material, the adhesive, the hydrophilic additive, the low surface tension additive and water uniformly to obtain a mixed slurry;

[0033] (2) After the mixed slurry is formed, it is dried and sieved in sequence to obtain the acoustic enhancement material with low surface tension.

[0034] As a specific embodiment of the preparation method described above in the present invention, step (1) specifically includes: accurately weighing the required porous powder material, adhesive, hydrophilic additive and low surface tension additive, and adding them to the required water, and then using conventional stirring, shearing, ultrasonic and other dispersion methods to uniformly disperse and mix the porous powder material, adhesive, hydrophilic additive and low surface tension additive to obtain a uniformly dispersed mixed slurry.

[0035] In the present invention, the surface tension of the mixed slurry is determined by the following method, and then the surface tension of the acoustic enhancement material is determined by the surface tension of the mixed slurry:

[0036] The mixed slurry is evenly coated on the printing paper with a scraper, and then the printing paper is placed in an oven at a temperature of 90°C to dry for 1 hour, and then pure water is dripped onto the dried coating to measure the contact angle. The larger the measured contact angle, the stronger the hydrophobicity of the coating and the lower the surface tension, so that it can be determined that the acoustic enhancement material prepared from the mixed slurry later also has a lower surface tension.

[0037] In the present invention, the contact angle of the coating made from the mixed slurry with the low surface tension additive with pure water is in the range of 90-130°, while the contact angle of the coating made from the mixed slurry without the low surface tension additive with pure water is in the range of 76-84°.

[0038] As a specific embodiment of the above preparation method of the present invention, wherein, in step (2), the drying is performed at 80-120° C. for 1-3 hours.

[0039] The present invention does not make specific requirements on the molding method involved in step (2) of the preparation method described above. Those skilled in the art can reasonably select the molding method according to the actual operation needs, as long as the purpose of the present invention can be achieved. For example, when preparing acoustic enhancement material microspheres with low surface tension, the molding method can be spray drying, freeze molding, oil column molding, and rolling ball molding; when preparing acoustic enhancement material blocks with low surface tension or acoustic enhancement material sheets with low surface tension, the molding can be carried out by hot air drying.

[0040] In addition, the present invention does not make any specific requirements for the drying process involved in step (2) of the preparation method described above. The drying temperature and time can be reasonably adjusted according to the actual needs of the on-site operation, as long as the purpose of drying can be achieved.

[0041] The preparation method of the acoustic enhancement material with low surface tension provided by the present invention does not require special equipment and is simple to operate.

[0042] On the other hand, the present invention also provides a speaker, comprising one or more acoustic sensors and one or more shells, wherein the one or more acoustic sensors are combined with the one or more shells to form a speaker back cavity, wherein the speaker back cavity is equipped with the acoustic enhancement material with low surface tension as described above.

[0043] On the other hand, the present invention further provides an electronic device, wherein the above-mentioned acoustic enhancement material with low surface tension is installed in the rear cavity of the speaker of the electronic device.

[0044] As a specific embodiment of the electronic device described above in the present invention, the electronic device includes a smart phone, TWS earphones, headphones, smart glasses, smart watches, VR devices, AR devices, tablet computers or thin and light laptops, etc.

[0045] The present invention uses a low surface tension additive when preparing the acoustic enhancement material. During the drying process of the acoustic enhancement material, the low surface tension additive will spontaneously spread on the surface of the acoustic enhancement material due to its small surface tension, so that the surface tension of the acoustic enhancement material finally obtained is reduced due to the spreading of the low surface tension additive. At the same time, the low surface tension additive used in the present invention is a hydrophobic additive, so it will largely prevent moisture in the air from entering the interior of the acoustic enhancement material, thereby reducing the moisture in the acoustic enhancement material.

[0046] In addition, since the low surface tension additive can also serve as a particle lubricant for the acoustic enhancement material, this means that the surface of the acoustic enhancement material will become lubricated, so when the speaker works at high frequencies, the collision friction between the acoustic enhancement material, such as the acoustic enhancement material microspheres / particles and the inner wall of the speaker, and the collision friction between the acoustic enhancement material microspheres / particles, will be significantly reduced.

[0047] In summary, the acoustic enhancement material provided by the present invention has a lower surface tension, so its water absorption capacity is poor / water absorption performance is reduced, the moisture content is reduced, and the acoustic performance will not be affected by moisture. Even if the acoustic enhancement material is treated with high temperature and high humidity, its acoustic performance will not be significantly reduced. At the same time, due to the low surface tension of the sound-absorbing material and the lubricating properties, when the speaker is working, the acoustic enhancement material, such as the collision friction between the acoustic enhancement material microspheres / particles and the inner wall of the speaker cavity, and the collision friction between the acoustic enhancement material microspheres / particles, will be significantly reduced, thereby significantly reducing the risk of the acoustic enhancement material microspheres / particles breaking and crushing, and significantly reducing the risk of the loose porous structure of the surface of the acoustic enhancement material microspheres / particles disappearing due to collision friction. These loose porous structures on the surface will be maintained for a long time, thereby maintaining the acoustic performance of the acoustic enhancement material with low surface tension for a long time without reduction. Assembling it in the rear cavity of the speaker can significantly improve the acoustic reliability or stability of the acoustic enhancement material during the use of the speaker, thereby significantly improving the acoustic reliability or stability of the speaker.

[0048] In addition, when preparing the acoustic enhancement material, a low surface tension additive is added to the mixed slurry. The low surface tension additive has good compatibility with the three raw materials of porous powder material, adhesive and hydrophilic additive, does not change the properties of the mixed slurry, and makes the mixed slurry have better fluidity. In the subsequent mixed slurry molding process, the situation of the mixed slurry clogging the nozzle is significantly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 This is a schematic diagram of the situation on the mesh after the test sample 1# in Test Example 2 of the present invention has been slightly dropped.

[0051] Figure 2 This is a schematic diagram of the situation on the mesh after the reference sample 1# in Test Example 2 of the present invention has been slightly dropped. DETAILED DESCRIPTION

[0052] It should be noted that the term "comprises" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. 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 clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0053] "Scope" disclosed in the present invention is given in the form of lower limit and upper limit. It 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 limit and upper limit define the boundaries of a particular range. All ranges defined in this way are combinable, i.e. any lower limit can be combined with any upper limit to form a range. For example, for a specific parameter, a range of 60-120 and 80-110 is listed, and it is understood that a range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​listed are 1 and 2, and the maximum range values ​​listed are 3, 4 and 5, then the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.

[0054] In the present invention, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and 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 the present invention, and "0-5" is just an abbreviation of these numerical combinations.

[0055] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in the present invention can be combined with each other to form a new technical solution.

[0056] In the present invention, unless otherwise specified, all technical features and preferred features mentioned in the present invention can be combined with each other to form a new technical solution.

[0057] In the present invention, if not specifically stated, the term "two" used in this specification means "at least two".

[0058] In the present invention, unless otherwise specified, all steps mentioned herein may be performed sequentially or randomly, but are preferably performed sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means 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.

[0059] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the attached table, drawings and examples. The following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to the normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0060] Example 1

[0061] This embodiment provides an acoustic enhancement material with low surface tension, which is prepared by a preparation method comprising the following specific steps:

[0062] Step 1: Preparation of mixed slurry

[0063] Accurately weigh 100 parts by weight of deionized water, 90 parts by weight of ZSM-5 molecular sieve, 4.5 parts by weight of polystyrene butadiene adhesive, 0.045 parts by weight of ethylene glycol, and 0.225 parts by weight of alkyl ketene dimer, wherein the parts of ZSM-5 molecular sieve, polystyrene butadiene adhesive, ethylene glycol, and alkyl ketene dimer are all parts by absolute dry weight of effective ingredients, and the average particle size of the ZSM-5 molecular sieve is 1.50 μm, including micropores with a pore size of 0.55 nm and mesopores with a pore size of 20 nm;

[0064] The ZSM-5 molecular sieve, polystyrene butadiene adhesive, ethylene glycol and alkyl ketene dimer are added into deionized water and mixed and stirred evenly to obtain a uniformly dispersed mixed slurry.

[0065] Step 2: Preparation of acoustic enhancement materials

[0066] The uniformly dispersed mixed slurry was spray-formed and dried at 110° C. for 3 h, and then sieved to obtain acoustic enhancement particles with an average particle size of 400 μm and low surface tension, which were marked as test sample 1#.

[0067] Example 2

[0068] This embodiment provides an acoustic enhancement material with low surface tension, which is prepared by a preparation method comprising the following specific steps:

[0069] Step 1: Preparation of mixed slurry

[0070] Accurately weigh 100 parts by weight of deionized water, 100 parts by weight of ZSM-5 molecular sieve, 7 parts by weight of polystyrene butadiene adhesive, 0.4 parts by weight of ethylene glycol, and 1.0 parts by weight of calcium stearate water-soluble emulsion lubricant, wherein the parts of ZSM-5 molecular sieve, polystyrene butadiene adhesive, ethylene glycol, and calcium stearate water-soluble emulsion lubricant are all parts by absolute dry weight of effective ingredients, and the average particle size of the ZSM-5 molecular sieve is 1.50 μm, including micropores with a pore size of 0.55 nm and mesopores with a pore size of 20 nm;

[0071] The ZSM-5 molecular sieve, polystyrene butadiene adhesive, ethylene glycol and calcium stearate water-soluble emulsion lubricant are added into deionized water and mixed and stirred evenly to obtain a uniformly dispersed mixed slurry.

[0072] Step 2: Preparation of acoustic enhancement materials

[0073] The uniformly dispersed mixed slurry was spray-formed and dried at 110° C. for 3 h, and then sieved to obtain acoustic enhancement particles with an average particle size of 400 μm and low surface tension, which were marked as test sample 2#.

[0074] Example 3

[0075] This embodiment provides an acoustic enhancement material with low surface tension, which is prepared by a preparation method comprising the following specific steps:

[0076] Step 1: Preparation of mixed slurry

[0077] Accurately weigh 100 parts by weight of deionized water, 55 parts by weight of ZSM-5 molecular sieve, 55 parts by weight of Silicalite-1 molecular sieve (which belongs to MFI structure molecular sieve and has an average particle size of 1.50 μm), 6 parts by weight of polystyrene butadiene adhesive, 5 parts by weight of polyacrylate adhesive, 1.1 parts by weight of polyethylene glycol, 2.0 parts by weight of calcium stearate water-soluble emulsion lubricant, and 0.2 parts by weight of silane coupling agent KH570, wherein the parts of ZSM-5 molecular sieve, MFI structure molecular sieve, polystyrene butadiene adhesive, polyacrylate adhesive, polyethylene glycol, calcium stearate water-soluble emulsion lubricant, and silane coupling agent KH570 are all parts by absolute dry weight of effective ingredients, and the average particle size of the ZSM-5 molecular sieve is 1.50 μm, including micropores with a pore size of 0.55 nm and mesopores with a pore size of 20 nm;

[0078] ZSM-5 molecular sieve, Silicalite-1 molecular sieve, polystyrene butadiene adhesive, polyacrylate adhesive, polyethylene glycol, calcium stearate water-soluble emulsion lubricant, and silane coupling agent KH570 are added to deionized water, mixed and stirred evenly to obtain a uniformly dispersed mixed slurry.

[0079] Step 2: Preparation of acoustic enhancement materials

[0080] The uniformly dispersed mixed slurry was spray-formed and dried at 110° C. for 3 h, and then sieved to obtain acoustic enhancement particles with an average particle size of 400 μm and low surface tension, which were marked as test sample 3#.

[0081] Comparative Example 1

[0082] This comparative example provides an acoustic enhancement material, which differs from Example 1 only in that 0.225 parts by weight of alkyl ketene dimer is not added when preparing the acoustic enhancement material. The acoustic enhancement material prepared in this comparative example is marked as reference sample 1#.

[0083] Comparative Example 2

[0084] This comparative example provides an acoustic enhancement material, which differs from Example 2 only in that 1.0 parts by weight of calcium stearate water-soluble emulsion lubricant is not added when preparing the acoustic enhancement material. The acoustic enhancement material prepared in this comparative example is marked as reference sample 2#.

[0085] Comparative Example 3

[0086] This comparative example provides an acoustic enhancement material, which differs from Example 3 only in that 2.0 parts by weight of calcium stearate water-soluble emulsion lubricant and 0.2 parts by weight of silane coupling agent KH570 are not added when preparing the acoustic enhancement material. The acoustic enhancement material prepared in this comparative example is marked as reference sample 3#.

[0087] Test Example 1

[0088] This test example is based on the technical contents of sections 7.4, 7.8.3, and 7.8.4 of the group standard "Porous Sound-Absorbing Particles for Micro Speakers" (standard number: T / CECA 78-2022) to test samples 1#-test samples 3# and reference samples 1#-reference samples 3#. The resonance frequency offset value △f0, moisture content, and high temperature and high humidity storage △f' HTHR The test was carried out and the specific results are shown in Table 1 below.

[0089] Table 1

[0090] Moisture content / % △f0 / Hz <![CDATA[△f’ HTHR / Hz]]> Test sample 1# 1.42 135 1 Test sample 2# 1.08 129 0 Test sample 3# 0.71 122 -1 Reference sample 1# 1.90 134 -6 Reference sample 2# 2.11 128 -10 Reference sample 3# 1.98 122 -12

[0091] It can be seen from the experimental data in Table 1 above that the moisture content of test samples 1# to test samples 3# prepared using low surface tension additives in Examples 1 to 3 of the present invention is significantly lower than the moisture content of reference samples 1# to reference samples 3# prepared without using low surface tension additives in the corresponding comparative examples, which indicates that the low surface tension additive can prevent moisture from entering the acoustic enhancement particles.

[0092] It can also be seen from the Δf0 data in Table 1 above that the addition of the low surface tension additive does not have a negative impact on the acoustic performance of the acoustic enhancement particles. Specifically, the Δf0 of the test samples 1# to 3# prepared using the low surface tension additive in Examples 1 to 3 of the present invention is substantially consistent with the Δf0 of the reference samples 1# to 3# prepared without the low surface tension additive in the corresponding comparative examples.

[0093] From the above table 1, △f' HTHR The data also show that after high temperature and high humidity treatment, the acoustic performance of test samples 1# to test sample 3# prepared using low surface tension additives in Examples 1 to 3 of the present invention has almost no change. However, the acoustic performance of reference samples 1# to reference sample 3# prepared without using low surface tension additives in the corresponding comparative examples is reduced to a certain extent after high temperature and high humidity treatment.

[0094] Among them, △f' HTHR =f02'-f01', f02' is the acoustic performance data of the test sample or reference sample after high temperature and high humidity treatment, f01' is the acoustic performance data of the test sample or reference sample before high temperature and high humidity treatment, the temperature of high temperature and high humidity treatment is 85°C, the humidity is 85%, and the treatment time is 96h.

[0095] Test Example 2

[0096] In this test example, the test sample 1# and the reference sample 1# were subjected to micro drop tests according to the technical contents recorded in Section 7.8.5 of the group standard "Porous Sound-Absorbing Particles for Micro Speakers" (Standard No.: T / CECA 78-2022). The specific results are shown in Tables 2 and Figure 1-Figure 2 shown.

[0097] Table 2

[0098] Slight decline results Test sample 1# No powder loss Reference sample 1# Loss of fans

[0099] contrast Figure 1 and Figure 2 It can be clearly seen that after a slight drop, the test sample 1# prepared using a low surface tension additive in Example 1 of the present invention is very clean on the mesh without obvious powder, while after a slight drop, the reference sample 1# prepared without a low surface tension additive in Comparative Example 1 has obvious powder particles in the mesh holes of the mesh.

[0100] Test Example 3

[0101] In this test example, the mixed slurries obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were evenly coated on printing paper using a scraper, and then the printing paper was placed in an oven at 90°C for 1 hour for drying, and then pure water was dripped onto the dried coating to measure the contact angle. The larger the measured contact angle, the stronger the hydrophobicity of the coating and the lower the surface tension, so that it can be determined that the acoustic enhancement material subsequently prepared from the mixed slurry also has a lower surface tension.

[0102] In this test example, the contact angles of the coatings prepared from the mixed slurries obtained in Examples 1 to 3 and Comparative Examples 1 to 3 with pure water were 98°, 104°, 110°, 82°, 82°, and 84°, respectively.

[0103] It can be seen that compared with Comparative Examples 1 to 3, the coating prepared from the mixed slurry obtained in Examples 1 to 3 has a larger contact angle with pure water, which means that the acoustic enhancement material prepared from the mixed slurry added with a low surface tension additive in Examples 1 to 3 of the present invention naturally has a lower surface tension.

[0104] In summary, the embodiments of the present invention use a low surface tension additive when preparing an acoustic enhancement material. During the drying process of the acoustic enhancement material, the low surface tension additive will spontaneously spread on the surface of the acoustic enhancement material due to its small surface tension, so that the surface tension of the final acoustic enhancement material is reduced due to the spreading of the low surface tension additive. At the same time, the low surface tension additives used in the embodiments of the present invention are all hydrophobic additives, so they will largely prevent moisture in the air from entering the interior of the acoustic enhancement material, thereby reducing the moisture content of the acoustic enhancement material.

[0105] In addition, since the low surface tension additive can also serve as a particle lubricant for the acoustic enhancement material, this means that the surface of the acoustic enhancement material will become lubricated, so when the speaker works at high frequencies, the collision friction between the acoustic enhancement material, such as the acoustic enhancement material microspheres / particles and the inner wall of the speaker, and the collision friction between the acoustic enhancement material microspheres / particles, will be significantly reduced.

[0106] In summary, the acoustic enhancement material provided by the embodiment of the present invention has a low surface tension, so its water absorption capacity is poor / water absorption performance is reduced, the moisture content is reduced, and the acoustic performance will not be affected by moisture. Even if the acoustic enhancement material is treated with high temperature and high humidity, its acoustic performance will not be significantly reduced. At the same time, due to the low surface tension of the sound-absorbing material and the lubricating properties, when the speaker is working, the acoustic enhancement material, such as the collision friction between the acoustic enhancement material microspheres / particles and the inner wall of the speaker cavity, and the collision friction between the acoustic enhancement material microspheres / particles, will be significantly reduced, thereby significantly reducing the risk of the acoustic enhancement material microspheres / particles breaking and crushing, and significantly reducing the risk of the loose porous structure of the surface of the acoustic enhancement material microspheres / particles disappearing due to collision friction. These loose porous structures on the surface will be maintained for a long time, thereby maintaining the acoustic performance of the acoustic enhancement material with low surface tension for a long time without reduction. Assembling it in the rear cavity of the speaker can significantly improve the acoustic reliability or stability of the acoustic enhancement material during the use of the speaker, thereby significantly improving the acoustic reliability or stability of the speaker.

[0107] In addition, when preparing the acoustic enhancement material, a low surface tension additive is added to the mixed slurry. The low surface tension additive has good compatibility with the three raw materials of porous powder material, adhesive and hydrophilic additive, does not change the properties of the mixed slurry, and makes the mixed slurry have better fluidity. In the subsequent mixed slurry molding process, the situation of the mixed slurry clogging the nozzle is significantly reduced.

[0108] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the protection scope of the patent of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with each other and with each other, and with each other.

Claims

1. An acoustic enhancement material with low surface tension, characterized in that: The acoustic enhancement material with low surface tension is prepared by first mixing a porous powder material, an adhesive, a hydrophilic additive, a low surface tension additive and water uniformly and then molding the mixture; The mass ratio of water, porous powder material, adhesive, hydrophilic additive and low surface tension additive is 100:80-120: 4-12:0.04-2.4:0.2-3.6, and the amount of porous powder material, adhesive, hydrophilic additive and low surface tension additive is calculated based on the absolute dry mass of the active ingredient; Wherein, the low surface tension auxiliary agent includes any one of a lubricant or an alkyl ketene dimer emulsion, or includes a combination of a lubricant and a silane coupling agent; Wherein, the hydrophilic auxiliary agent includes one or a combination of ethylene glycol, propylene glycol, glycerol, polyethylene glycol, polypropylene glycol and sorbitol; The lubricant includes one or a combination of calcium stearate water-soluble emulsion, ammonium stearate water-soluble emulsion, sodium stearate water-soluble emulsion, potassium oleate emulsion, polyethylene wax water-soluble emulsion, polyoxyethylene derivative water-soluble lubricant and fatty acid ester lubricant.

2. The acoustic enhancement material according to claim 1, characterized in that: The porous powder material includes one or a combination of zeolite molecular sieve, activated silicon dioxide, activated carbon, surface porous calcium carbonate and surface porous calcium silicate.

3. The acoustic enhancement material according to claim 2, characterized in that: The zeolite molecular sieve includes one or a combination of MFI structure molecular sieve, FER structure molecular sieve, CHA structure molecular sieve, MEL structure molecular sieve, TON structure molecular sieve and MTT structure molecular sieve.

4. The acoustic enhancement material according to claim 2, characterized in that: The particle size of the zeolite molecular sieve is 0.5-10 μm.

5. The acoustic enhancement material according to claim 2, characterized in that: The zeolite molecular sieve comprises micropores with a pore size of 0.3-0.7 nm and mesopores with a pore size of 10-30 nm.

6. The acoustic enhancement material according to any one of claims 2 to 5, characterized in that: The zeolite molecular sieve is ZSM-5 molecular sieve.

7. The acoustic enhancement material according to claim 1, characterized in that: The adhesive includes an organic adhesive and / or an inorganic adhesive; wherein the organic adhesive includes one or a combination of polyacrylate, acrylic copolymer, polyurethane, polystyrene butadiene emulsion, polystyrene acrylate, polystyrene acetate emulsion, polyvinyl acetate emulsion, silicone resin and polybutadiene rubber emulsion; wherein the inorganic adhesive includes one or a combination of silica sol, alumina sol and pseudo-boehmite.

8. The acoustic enhancement material according to claim 1, characterized in that: The silane coupling agent includes a methacryloxyalkyl silane coupling agent.

9. The acoustic enhancement material according to claim 1, characterized in that: The water includes one or a combination of deionized water, distilled water and reverse osmosis water.

10. The acoustic enhancement material according to claim 1, characterized in that: The shape of the acoustic enhancement material includes microspheres, blocks or sheets; wherein the size of the microspheres is 200-600 μm.

11. The method for preparing an acoustic enhancement material with low surface tension according to any one of claims 1 to 10, characterized in that: The preparation method comprises: (1) The porous powder material, the adhesive, the hydrophilic additive, the low surface tension additive and water are uniformly mixed to obtain a mixed slurry; (2) After the mixed slurry is formed, it is dried and sieved in sequence to obtain the acoustic enhancement material with low surface tension.

12. The preparation method according to claim 11, characterized in that: The preparation method also includes: firstly using a scraper to evenly apply the mixed slurry on printing paper, then placing the printing paper in an oven at a temperature of 90°C to dry for 1 hour, then dripping pure water onto the dried coating and measuring the contact angle, wherein the contact angle ranges from 90° to 130°.

13. The preparation method according to claim 11 or 12, characterized in that: In step (2), the drying is performed at 80-120° C. for 1-3 hours.

14. A speaker, 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 speaker back cavity, characterized in that: The loudspeaker rear cavity is equipped with the acoustic enhancement material with low surface tension as described in any one of claims 1 to 10.

15. An electronic device, characterized in that: The acoustic enhancement material with low surface tension according to any one of claims 1 to 10 is installed in the speaker rear cavity of the electronic device.

16. The electronic device according to claim 15, characterized in that: The electronic device includes a smart phone, a TWS headset, a head-mounted headset, smart glasses, a smart watch, a VR device, an AR device, a tablet computer or a thin and light laptop computer.

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