Sound absorption microsphere, preparation method thereof and loudspeaker box

Abstract

The invention provides a sound absorption microsphere, a preparation method thereof and a loudspeaker box. The sound absorption microspheres are composed of a conductive molecular sieve and an antistatic adhesive, the conductive molecular sieve is a molecular sieve with conductive metal ions implanted in a skeleton, and the antistatic adhesive comprises an antistatic agent and an organic adhesive. Compared with the prior art, the conductive metal ions are implanted into the skeleton structure of the molecular sieve, Al species in the skeleton are replaced, the energy band structure of the molecular sieve is adjusted, and the charge transfer capacity is remarkably improved; meanwhile, the antistatic agent is added into the adhesive, so that the sound-absorbing microspheres prepared from the conductive molecular sieve and the antistatic adhesive are not easy to generate static electricity, and charges carried by the sound-absorbing microspheres can be led out to achieve an antistatic effect.

Description

Technical Field

[0001] This invention relates to the field of electroacoustic conversion technology, and in particular to a sound-absorbing microsphere and its preparation method, and a loudspeaker box. Background Technology

[0002] With the development of modern industry, the application scenarios of sound-absorbing materials are constantly expanding, and higher requirements are being placed on their performance. In actual use, the sound-absorbing microspheres in speaker enclosures often generate static electricity due to friction, induction, and other reasons. The accumulation of static electricity causes the sound-absorbing microspheres to attract dust and impurities, affecting the sound absorption effect and service life of the speaker enclosure.

[0003] Currently, common antistatic methods mainly include coating the material surface with an antistatic coating and adding antistatic agents. However, traditional antistatic coatings have problems such as poor adhesion to sound-absorbing microspheres and insufficient durability, making them prone to peeling and failure. Simply adding antistatic agents to adhesives can improve the antistatic properties of materials to some extent, but the dispersibility and stability of antistatic agents are difficult to guarantee, and excessive addition may adversely affect the sound absorption performance and physical and mechanical properties of sound-absorbing microspheres.

[0004] Molecular sieves, as porous materials with regular pore structures and large specific surface areas, are often used as fillers or framework materials for sound-absorbing microspheres. However, traditional molecular sieves have limited charge transport capabilities, and the Al species in their framework hinder charge conduction, resulting in poor electrical conductivity and difficulty in effectively dissipating static electricity accumulated on the surface of sound-absorbing microspheres. Therefore, how to improve the antistatic ability of sound-absorbing microspheres without significantly affecting their sound absorption performance has become a pressing technical problem in this field.

[0005] Therefore, it is necessary to provide a new sound-absorbing microsphere and its preparation method, as well as a loudspeaker box, to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a sound-absorbing microsphere, its preparation method, and a loudspeaker enclosure. The aim is to improve the antistatic ability of the sound-absorbing microsphere and solve the electrostatic problems existing in current sound-absorbing microspheres.

[0007] In a first aspect, the present invention provides a sound-absorbing microsphere, the sound-absorbing microsphere being made of a conductive molecular sieve and an antistatic adhesive, wherein the conductive molecular sieve is a molecular sieve with conductive metal ions implanted in its framework, and the antistatic adhesive includes an antistatic agent and an organic adhesive.

[0008] Preferably, the framework of the conductive molecular sieve is made of silicon oxide and conductive metal ions; wherein the molar ratio between silicon and metal elements is between 50 and 800.

[0009] Preferably, the conductive metal ions include one or more of Zn2+, Mg2+, Ag+, Fe3+ and Ga3+, and the molar ratio of the conductive metal ions to the total cations in the framework of the conductive molecular sieve is greater than 5%.

[0010] Preferably, the conductive molecular sieve includes one or more of the following: MFI structure, FER structure, and MEL structure.

[0011] Preferably, the antistatic adhesive comprises one or more of polyacrylate, polystyrene acrylate, polystyrene acetate, polystyrene butadiene resin, and polyurethane resin adhesive with added antistatic agent; wherein the antistatic agent accounts for 5%-20% of the mass of the organic adhesive.

[0012] Preferably, the antistatic agent includes cationic antistatic agents, anionic antistatic agents, and nonionic antistatic agents.

[0013] Preferably, the particle size of the sound-absorbing microspheres is between 50 μm and 1000 μm.

[0014] Secondly, the present invention also provides a method for preparing sound-absorbing microspheres as described in any of the above embodiments, the method comprising the following steps: S1. Mix silicon compound, metal salt containing conductive metal ions, template agent, inorganic base and deionized water in a molar ratio of 800:0.5-5:5-20:50-100:10000-20000 and stir until homogeneous to obtain a mixed solution. S2. Heat the mixed solution to 90-100°C and maintain the heating for 24-76 hours to carry out a crystallization reaction to obtain initial crystals; S3. The initial crystals are separated and washed to obtain the initial molecular sieve; S4. The initial molecular sieve is then calcined at 480°C to remove the template agent, thereby obtaining the conductive molecular sieve. S5. Mix the antistatic agent and adhesive evenly at a mass ratio of 1-2:100 to obtain the antistatic adhesive; S6. Mix the antistatic adhesive, the conductive molecular sieve and deionized water in a mass ratio of 1-10:100:50-200 and stir evenly to obtain the original slurry. S7. The original slurry is shaped into microspheres by spraying or microfluidics to obtain microspherical slurry; S8. The microspherical slurry is dried and cured to obtain sound-absorbing microspheres.

[0015] Thirdly, the present invention also provides a loudspeaker, comprising a housing having a receiving space, a sound-emitting unit disposed within the housing, and a rear cavity formed by the sound-emitting unit and the housing, characterized in that the rear cavity is filled with sound-absorbing microspheres as described in the above embodiments.

[0016] Compared with the prior art, the present invention significantly improves the charge transport capacity by implanting conductive metal ions into the framework structure of the molecular sieve, replacing the Al species in the framework, and adjusting the band structure of the molecular sieve. At the same time, an antistatic agent is added to the adhesive, so that the sound-absorbing microspheres prepared by the conductive molecular sieve and the antistatic adhesive are not prone to static electricity and can discharge their own charge, thus achieving an antistatic effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 A flowchart illustrating the preparation method of the sound-absorbing microspheres provided in this embodiment of the invention; Figure 2 This is a schematic diagram of the structure of a loudspeaker provided in an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 This invention provides a sound-absorbing microsphere, which is made of a conductive molecular sieve and an antistatic adhesive. The conductive molecular sieve is a molecular sieve with conductive metal ions implanted in its framework, and the antistatic adhesive includes an antistatic agent and an organic adhesive.

[0020] This invention significantly improves charge transport capacity by implanting conductive metal ions into the framework structure of a molecular sieve, replacing Al species in the framework, and adjusting the band structure of the molecular sieve. At the same time, an antistatic agent is added to the adhesive, so that the sound-absorbing microspheres prepared by the conductive molecular sieve and the antistatic adhesive are not prone to static electricity and can discharge their own charge, thus achieving an antistatic effect. This significantly improves the antistatic performance of the sound-absorbing microspheres, resulting in better sound absorption. When filled into a loudspeaker 10, it can improve its acoustic performance.

[0021] In this embodiment, the framework of the conductive molecular sieve is made of silicon oxide and conductive metal ions; wherein the molar ratio between silicon and metal elements is between 50 and 800.

[0022] In this embodiment, the conductive metal ions include one or more of Zn2+, Mg2+, Ag+, Fe3+ and Ga3+, and the molar ratio of the conductive metal ions to the total cations in the framework of the conductive molecular sieve is greater than 5%.

[0023] In this embodiment, the conductive molecular sieve includes one or more of the following: MFI structure, FER structure, and MEL structure.

[0024] In this embodiment, the antistatic adhesive includes one or more of polyacrylate, polystyrene acrylate, polystyrene acetate, polystyrene butadiene resin, and polyurethane resin adhesive with added antistatic agent; wherein the antistatic agent accounts for 5%-20% of the mass of the organic adhesive.

[0025] In this embodiment, the antistatic agent is an internally mixed antistatic agent, which includes cationic antistatic agents, anionic antistatic agents, and nonionic antistatic agents.

[0026] In this embodiment, the particle size of the sound-absorbing microspheres is between 50 μm and 1000 μm.

[0027] Please refer to Figure 2 This invention provides a loudspeaker 10, comprising a housing 1 with a receiving space, a sound-emitting unit 2 disposed within the housing 1, and a rear cavity 3 formed by the sound-emitting unit 2 and the housing 1, wherein the rear cavity 3 is filled with the aforementioned sound-absorbing microspheres. By filling the rear cavity 3 with sound-absorbing microspheres, the acoustic compliance of the air in the rear cavity 3 is increased, thereby improving the low-frequency performance of the loudspeaker 10. Simultaneously, the sound-absorbing microspheres provided by this invention are less prone to generating static electricity with each other, reducing static electricity generated by friction between the sound-absorbing microspheres and other components of the loudspeaker, thus significantly improving acoustic performance.

[0028] This invention also provides a method for preparing sound-absorbing microspheres, such as... Figure 1As shown, the preparation method includes the following steps: S1. Mix silicon compound, metal salt containing conductive metal ions, template agent, inorganic base and deionized water in a molar ratio of 800:0.5-5:5-20:50-100:10000-20000 and stir until homogeneous to obtain a mixed solution. S2. Heat the mixed solution to 90-100°C and maintain the heating for 24-76 hours to carry out a crystallization reaction to obtain initial crystals; S3. The initial crystals are separated and washed to obtain the initial molecular sieve; S4. The initial molecular sieve is then calcined at 480°C to remove the template agent, thereby obtaining the conductive molecular sieve. S5. Mix the antistatic agent and adhesive evenly at a mass ratio of 1-2:100 to obtain the antistatic adhesive; S6. Mix the antistatic adhesive, the conductive molecular sieve and deionized water in a mass ratio of 1-10:100:50-200 and stir evenly to obtain the original slurry. S7. The original slurry is shaped into microspheres by spraying or microfluidics to obtain microspherical slurry; S8. The microspherical slurry is dried and cured to obtain sound-absorbing microspheres.

[0029] In this embodiment, in order to better demonstrate the performance test of the sound-absorbing microspheres prepared by the present invention, the following Examples 2 and 3, Comparative Example 1 and Comparative Example 2 were conducted to obtain measurement results.

[0030] Example 2 This invention provides a method for preparing sound-absorbing microspheres, the method comprising the following steps: 1. Mix silica sol (silicon compound), magnesium chloride hexahydrate (metal salt containing conductive metal ions), ferric nitrate nonahydrate (metal salt containing conductive metal ions), tetrapropylammonium bromide (template agent), sodium hydroxide (inorganic base), and deionized water in a molar ratio of 800:1:2:10:50:10000 and stir until homogeneous. Place the mixed solution in a reaction vessel and heat at 90°C for 48 hours to carry out a crystallization reaction to obtain initial crystals.

[0031] 2. After filtering and drying the initial crystals obtained in the reactor in step 1, the dried sample was calcined at 480°C for 4 hours to remove the template agent, thus obtaining a conductive molecular sieve containing Mg and Fe ions. 3. Weigh 10g of acrylic adhesive, add 0.2g of antistatic adhesive using a dropper, and stir for 1 hour in a 50°C water bath to obtain the antistatic adhesive. 4. Weigh 1g of the antistatic adhesive from step 3, 10g of the conductive molecular sieve from step 2, and 10g of deionized water, and mix them thoroughly. 5. After the above mixture is thoroughly stirred, the slurry is filtered and then spray-granulated to obtain undried sound-absorbing microspheres; 6. Place the above sound-absorbing microspheres in a 100°C oven and dry for 2 hours to obtain the finished product, namely, antistatic sound-absorbing microspheres.

[0032] Example 3 This invention provides a method for preparing sound-absorbing microspheres, the method being as follows: 1. Mix silica sol, zinc sulfate heptahydrate (a metal salt containing conductive metal ions), potassium gallium sulfate dodecahydrate (a metal salt containing conductive metal ions), hexadecyltrimethylammonium salt (template agent), sodium hydroxide and deionized water in a molar ratio of 800:2:3:10:50:20000 and stir until homogeneous. Place the mixed solution in a reaction vessel and heat at 100°C for 72 hours to carry out a crystallization reaction. 2. After filtering and drying the reactants obtained in the reactor in step 1, the dried sample is calcined at 480°C for 4 hours to remove the template agent, thus obtaining a conductive molecular sieve containing Zn and Ga ions. 3. Weigh 10g of styrene-butadiene adhesive, add 0.2g of antistatic adhesive using a dropper, and stir for 1 hour in a 50°C water bath to obtain the antistatic adhesive. 4. Weigh 1g of the antistatic adhesive from step 3, 10g of the conductive molecular sieve from step 2, and 10g of deionized water, and mix them thoroughly. 5. Place the above-mentioned well-stirred slurry into the dispersed phase reservoir of the microfluidic device, and add 15 ml of microdroplet-generated oil into the continuous phase reservoir of the microfluidic device; 6. Set the temperature of the downstream section of the microchannel in the microfluidic device to -8°C, and set the flow rates of channel one (dispersed phase) and channel two (continuous phase) to 5 μL / min and 20 μL / min, respectively, and start sample preparation; 7. Collect the solidified molecular sieve particles using a low-temperature container; 8. Place the particles obtained in step 7 into a low-pressure vacuum environment until all the ice in the particles is removed by sublimation. Then place the particles into an oven and dry them at 120°C for 2 hours to obtain sound-absorbing microspheres.

[0033] Comparative Example 1 The preparation method of the ordinary sound-absorbing microsphere material provided in this comparative example is carried out according to the following steps. 1. Mix silica sol, aluminum sol, tetrapropylammonium bromide (template agent), sodium hydroxide and deionized water in a molar ratio of 800:3:10:50:10000 and stir until homogeneous. Place the mixed solution into a reaction vessel and heat at 90°C for 48 hours to carry out the crystallization reaction. 2. After filtering and drying the crystallization reaction product from step 1, the dried sample is calcined at 480°C for 4 hours to remove the template agent, thus obtaining the silica-alumina molecular sieve powder. 3. Weigh 1g of acrylic adhesive, 10g of silica-alumina molecular sieve from step 2, and 10g of deionized water, and mix them thoroughly. 4. After the above mixture is thoroughly stirred, the slurry is filtered and then spray-granulated to obtain undried sound-absorbing microspheres; 5. The above sound-absorbing microspheres were dried in a 100°C oven for 2 hours to obtain the control group finished sound-absorbing microspheres.

[0034] Comparative Example 2 The difference between this comparative example and Example 2 is that step 3 is omitted; all other steps are the same as in Example 2.

[0035] Specifically, the main purpose of this invention is to solve the problems of dry air in autumn and winter, and the difficulty in packaging and transferring sound-absorbing microspheres due to static electricity. Because the sound-absorbing microspheres are small in size, surface resistance cannot be measured normally. Therefore, this invention uses the following method to test the antistatic properties of the sound-absorbing microspheres: Weigh 1g of the sound-absorbing microspheres from Examples 2, 3, Comparative Example 1, and Comparative Example 2, place them in an electrostatic generator for 10 minutes, and then remove them. Pour the sound-absorbing microspheres densely onto a flat A4 paper and measure the number of sound-absorbing microspheres within a 1 square centimeter radius of the measurement center. The more sound-absorbing microspheres in the same area, the closer the distribution distance between the microspheres is, and the lower the static electricity they carry.

[0036] The measurement results obtained from Examples 2 and 3, Comparative Example 1 and Comparative Example 2 are shown below:

[0037] Acoustic measurement results show that, compared with Control Example 1 and Control Example 2, the number of sound-absorbing microspheres provided in Example 2 and Example 3 is greater, indicating that the closer the distribution distance between the sound-absorbing microspheres, the lower the static electricity they carry. Therefore, the sound-absorbing microspheres provided in Example 2 and Example 3 have better antistatic properties.

[0038] Compared with the prior art, the present invention significantly improves the charge transport capacity by implanting conductive metal ions into the framework structure of the molecular sieve, replacing the Al species in the framework, and adjusting the band structure of the molecular sieve. At the same time, an antistatic agent is added to the adhesive, so that the sound-absorbing microspheres prepared by the conductive molecular sieve and the antistatic adhesive are not prone to static electricity and can discharge their own charge, thus achieving an antistatic effect.

[0039] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A sound-absorbing microsphere, characterized in that, The sound-absorbing microspheres are made of conductive molecular sieves and antistatic adhesives. The conductive molecular sieves are molecular sieves with conductive metal ions implanted in their framework, and the antistatic adhesives include antistatic agents and organic adhesives.

2. The sound-absorbing microspheres as described in claim 1, characterized in that, The framework of the conductive molecular sieve is made of silicon oxide and conductive metal ions; wherein the molar ratio between silicon and metal elements is between 50 and 800.

3. The sound-absorbing microspheres as described in claim 2, characterized in that, The conductive metal ions include one or more of Zn2+, Mg2+, Ag+, Fe3+ and Ga3+, and the molar ratio of the conductive metal ions to the total cations in the framework of the conductive molecular sieve is greater than 5%.

4. The sound-absorbing microspheres as described in claim 1, characterized in that, The conductive molecular sieve includes one or more of the following structures: MFI structure, FER structure, and MEL structure.

5. The sound-absorbing microspheres as described in claim 1, characterized in that, The antistatic adhesive includes one or more of polyacrylate, polystyrene acrylate, polystyrene acetate, polystyrene butadiene resin, and polyurethane resin adhesive with added antistatic agent; wherein the antistatic agent accounts for 5%-20% of the mass of the organic adhesive.

6. The sound-absorbing microspheres as described in claim 1, characterized in that, The antistatic agent includes cationic antistatic agents, anionic antistatic agents, and nonionic antistatic agents.

7. The sound-absorbing microspheres as described in claim 1, characterized in that, The particle size of the sound-absorbing microspheres is between 50 μm and 1000 μm.

8. A method for preparing sound-absorbing microspheres as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: S1. Mix silicon compound, metal salt containing conductive metal ions, template agent, inorganic base and deionized water in a molar ratio of 800:0.5-5:5-20:50-100:10000-20000 and stir until homogeneous to obtain a mixed solution. S2. Heat the mixed solution to 90-100°C and maintain the heating for 24-76 hours to carry out a crystallization reaction to obtain initial crystals; S3. The initial crystals are separated and washed to obtain the initial molecular sieve; S4. The initial molecular sieve is then calcined at 480°C to remove the template agent, thereby obtaining the conductive molecular sieve. S5. Mix the antistatic agent and adhesive evenly at a mass ratio of 1-2:100 to obtain the antistatic adhesive; S6. Mix the antistatic adhesive, the conductive molecular sieve and deionized water in a mass ratio of 1-10:100:50-200 and stir evenly to obtain the original slurry. S7. The original slurry is shaped into microspheres by spraying or microfluidics to obtain microspherical slurry; S8. The microspherical slurry is dried and cured to obtain sound-absorbing microspheres.

9. A loudspeaker, comprising a housing having a receiving space, a sound-emitting unit disposed within the housing, and a rear cavity formed by the sound-emitting unit and the housing, characterized in that, The rear cavity is filled with sound-absorbing microspheres as described in any one of claims 1-7.

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