Composite sound-absorbing material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of sound-absorbing materials, and particularly relates to a composite sound-absorbing material as well as a preparation method and application thereof. The composite sound-absorbing material comprises a foaming base material and sound-absorbing particles, the sound-absorbing particles are dispersed in the foaming base material; the foaming base material is a polyurethane material; the sound-absorbing particles comprise at least one of a metal organic framework compound, activated carbon, aerogel, carbon nanotubes and graphene. The sound-absorbing particles are dispersed in the foaming base material, so that obvious concave-convex structures are formed around foam holes of the sound-absorbing material, and the sound wave transmission resistance can be increased. Besides, the sound-absorbing particles with specific types, specific surface areas and pore diameters and porous structures are adopted, the number of internal pore channels is large, multi-angle collision of airflow in the pore channels can be enhanced, and the composite sound-absorbing material has a good sound-absorbing effect at low and medium frequencies.

Description

Technical Field

[0001] The present invention belongs to the technical field of sound-absorbing materials, and particularly relates to a composite sound-absorbing material, a preparation method thereof, and an application thereof. Background Art

[0002] Noise pollution is a serious problem faced by today's society. When the short-term noise intensity is higher than 120 dB, it will cause sharp mechanical damage to the cochlear hair cells in the inner ear; when in a noisy environment for a long time and the average sound intensity level is higher than 85 dB, it will cause metabolic failure and obvious hearing loss. Highway or aircraft noise is the main source of noise in cities, with a noise level of 65 - 70 dB; the noise generated by household appliances such as washing machines and kitchen stoves during use is the main source of indoor noise in homes, with an average noise level of 45 - 70 dB.

[0003] Currently, foam sound-absorbing materials are usually used to reduce product noise. Traditional foam sound-absorbing materials have a narrow sound absorption frequency range, with good sound absorption effect for high-frequency noise, but poor sound absorption effect for medium and low-frequency bands. Therefore, their application range is very limited, especially for household appliances such as washing machines, dryers, and refrigerators.

[0004] Therefore, there is an urgent need to provide a composite sound-absorbing material that has a good sound absorption effect on medium and low-frequency band noises. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above prior art.

[0006] Therefore, a first aspect of the present invention provides a composite sound-absorbing material.

[0007] Specifically, a composite sound-absorbing material includes a foam substrate and sound-absorbing particles; the sound-absorbing particles are dispersed in the foam substrate; the foam substrate is a polyurethane material;

[0008] The sound-absorbing particles include at least one of metal-organic framework compounds (MOFs), activated carbon, aerogel, carbon nanotubes, and graphene.

[0009] Specifically, the sound-absorbing particles of the present invention are distributed within the foamed substrate, and each individual sound-absorbing particle is fully or partially embedded within the fibers of the foamed substrate. The presence of the uniformly dispersed sound-absorbing particles forms a protrusion, resulting in an obvious concave-convex structure around the pores of the sound-absorbing material. This structure can greatly increase the acoustic wave transmission resistance, converting the acoustic energy into the thermal energy of particle vibration, thereby greatly enhancing the sound-absorbing effect. In contrast, the cross-sectional structure of traditional polyurethane foamed sound-absorbing materials consists of pores formed by smooth fibers of different thicknesses, with smooth surfaces around the pores and no protrusions. This makes traditional polyurethane foamed sound-absorbing materials have good sound-absorbing effects in the high-frequency range, but relatively poor sound-absorbing effects in the mid-low frequency bands. Additionally, the present invention uses MOFs, activated carbon, aerogel, carbon nanotubes, and graphene as sound-absorbing particles, which have numerous internal pores. When acoustic waves enter the three-dimensional network-connected pores inside the sound-absorbing particles, the more the air flow branches are divided, the more the multi-angle collisions of the air flow in the pores can be enhanced, thereby strengthening the disordered reflection, refraction, and even backflow of acoustic waves, continuously dissipating the acoustic energy, enhancing the sound-absorbing effect, and at the same time avoiding the situation where when the pore diameter of the sound-absorbing particles is relatively large, the foamed substrate enters the pores, affecting the sound-absorbing effect of the entire material, enabling the composite sound-absorbing material to have a good sound-absorbing coefficient in the mid-low frequency range.

[0010] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is greater than or equal to 180 m 2 / g.

[0011] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is 1000 - 4000 m 2 / g.

[0012] According to some embodiments of the present invention, the particle size of the sound-absorbing particles is 90 - 11000 nm.

[0013] According to some embodiments of the present invention, the particle size of the sound-absorbing particles is 100 - 10000 nm.

[0014] Specifically, using sound-absorbing particles with a larger specific surface area results in more internal pores in the sound-absorbing particles, which can enhance the multi-angle collisions of the air flow in the pores and improve the sound-absorbing effect. In addition, when the particle size of the sound-absorbing particles is too small, the sound-absorbing particles cannot form an obvious concave-convex structure around the pores of the sound-absorbing material, which will weaken the acoustic wave transmission resistance and reduce the sound-absorbing effect in the mid-low frequency range; when the particle size is too large, phenomena such as powder falling and agglomeration are likely to occur, which will also reduce the sound-absorbing effect of the sound-absorbing material in the mid-low frequency range. By selecting the above specific particle size range for the sound-absorbing particles of the present invention, the acoustic wave transmission resistance can be enhanced, the agglomeration phenomenon can be reduced, and thus the sound-absorbing effect of the sound-absorbing material in the mid-low frequency range can be improved.

[0015] According to some embodiments of the present invention, the sound-absorbing particles have a porous structure.

[0016] According to some embodiments of the present invention, the pore diameter of the sound-absorbing particles is less than 2 nm.

[0017] According to some embodiments of the present invention, the pore diameter of the sound-absorbing particles is 0.7 - 1.2 nm.

[0018] Specifically, using sound-absorbing particles with a smaller pore diameter can result in more internal pores in the sound-absorbing particles, enhancing the multi-angle collision of airflows in the pores and improving the sound-absorbing effect. At the same time, it can prevent the foaming substrate from entering the pores when the pore diameter of the sound-absorbing particles is large, which affects the sound-absorbing effect of the entire material, enabling the composite sound-absorbing material to have a good sound-absorbing coefficient in the mid-low frequency range.

[0019] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 55%.

[0020] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 60%.

[0021] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 90%.

[0022] Specifically, using sound-absorbing particles with a large porosity can result in many pores in the sound-absorbing particles, more air flow branches formed by the sound waves being split, and more multi-angle collisions of airflows in the pores, thereby strengthening the disordered reflection of sound waves and the continuous loss of sound energy, and improving the sound-absorbing effect of the sound-absorbing material in the mid-low frequency band.

[0023] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 2.2 - 55%.

[0024] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 2.5 - 50%.

[0025] Specifically, when the addition amount of the sound-absorbing particles is too much, agglomeration is likely to occur, and the dispersibility is poor, affecting the sound-absorbing effect of the product; when the addition amount is too little, the sound-absorbing particles cannot form enough concave-convex structures around the pores of the sound-absorbing material, thereby affecting the sound-absorbing effect. By exploring the mass ratio of the sound-absorbing particles, the sound-absorbing particles are evenly embedded in the fibers of the foaming substrate and there are enough concave-convex structures around the pores, thereby increasing the sound wave transmission resistance and improving the sound-absorbing effect in the mid-low frequency range.

[0026] Specifically, among the sound-absorbing particles, the thermal conductivity coefficients of activated carbon, carbon nanotubes, and graphene materials are relatively high. The thermal conductivity coefficient of activated carbon is 0.1 - 0.3 W / m·K; the thermal conductivity coefficient of graphene is greater than 200 W / m·K. The sound-absorbing particles with high thermal conductivity coefficients can quickly disperse the heat of the sound-absorbing material, improving the thermal stability of the sound-absorbing material. In addition, the thermal conductivity coefficient of aerogel is 0.012 - 0.02 W / m·K. Although its thermal conductivity coefficient is small, it has excellent heat insulation ability and a large thermal resistance, which can well block the external heat, thereby indirectly improving the heat resistance of the polyurethane sound-absorbing material. Therefore, the composite sound-absorbing material of the present invention has good heat resistance at the same time.

[0027] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound-absorbing material is 0.35 - 0.9.

[0028] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound-absorbing material is 0.4 - 0.85.

[0029] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound-absorbing material is 0.6 - 0.85.

[0030] According to some embodiments of the present invention, the sound absorption coefficient is the sound absorption coefficient at 20 - 2000 Hz.

[0031] According to some embodiments of the present invention, the sound absorption coefficient is the sound absorption coefficient at 450 - 1000 Hz.

[0032] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 55 - 105 parts of polyether polyol and 65 - 100 parts of isocyanate.

[0033] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 60 - 99 parts of polyether polyol and 70 - 90 parts of isocyanate.

[0034] Specifically, the polyurethane material prepared from polyether polyol and isocyanate is used as the foaming substrate of the sound-absorbing material. It has porosity, which helps to improve the sound absorption effect; and by reasonably matching the amounts of polyether polyol and isocyanate, the polyurethane material has a good foaming effect, thereby improving the sound absorption effect of the sound-absorbing material.

[0035] According to some embodiments of the present invention, the raw materials for preparing the polyurethane material further include at least one of a catalyst, a blowing agent, a crosslinking agent, a chain extender, and a stabilizer.

[0036] Specifically, the polyether polyol and isocyanate are foamed under the action of a catalyst, a cell opener, a crosslinking agent, a chain extender, and a stabilizer to obtain a high molecular polymer. The addition of the catalyst and stabilizer enables the foaming process to proceed faster and more stably; the addition of the crosslinking agent and chain extender increases the crosslinking degree of the molecular chain, endowing the foamed material with good mechanical properties; the addition of the cell opener can increase the open cell rate of the sound-absorbing material, improve the effective utilization rate of the sound-absorbing particles, allow sound waves to be fully segmented by the pores in the foamed cells and the sound-absorbing particles, enhance the multi-angle collision of sound waves in the pores, and improve the sound-absorbing effect of the sound-absorbing material in the medium and low frequency bands.

[0037] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 55-105 parts of polyether polyol, 65-100 parts of isocyanate, 0.1-11 parts of catalyst, 1.8-5.5 parts of cell opener, 1-5.5 parts of crosslinking agent, 0.9-11 parts of chain extender, and 0.1-3.5 parts of stabilizer.

[0038] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 60-99 parts of polyether polyol, 70-90 parts of isocyanate, 0.1-10 parts of catalyst, 2-5 parts of cell opener, 1-5 parts of crosslinking agent, 1-10 parts of chain extender, and 0.1-3 parts of stabilizer.

[0039] Specifically, by optimizing the dosage relationship of the polyether polyol, isocyanate, catalyst, cell opener, crosslinking agent, chain extender, and stabilizer, the polyurethane material has a good foaming effect, thereby improving the sound-absorbing effect of the sound-absorbing material.

[0040] According to some embodiments of the present invention, by weight, the composite sound-absorbing material contains 10-110 parts of sound-absorbing particles.

[0041] According to some embodiments of the present invention, by weight, the composite sound-absorbing material contains 11-100 parts of sound-absorbing particles.

[0042] Specifically, when the addition amount of the sound-absorbing particles is too much, agglomeration occurs; when the addition amount is too little, the sound-absorbing particles cannot form enough uneven structures around the pores of the sound-absorbing material, thereby affecting the sound-absorbing effect. By reasonably matching the content of the sound-absorbing particles, the sound-absorbing particles are evenly embedded in the fibers of the foamed substrate and there are enough uneven structures around the pores, thereby increasing the sound wave transmission resistance and improving the sound-absorbing effect.

[0043] According to some embodiments of the present invention, the catalyst is an amine catalyst.

[0044] According to some embodiments of the present invention, the crosslinking agent includes at least one of glycerol, trimethylolpropane, hexamethylenediamine, and amino alcohol.

[0045] According to some embodiments of the present invention, the chain extender includes at least one of ethylene glycol, diethylene glycol, and 1,4-butanediol.

[0046] According to some embodiments of the present invention, the cell opener includes an organic polymer cell opener.

[0047] According to some embodiments of the present invention, the stabilizer includes a silicone stabilizer.

[0048] Specifically, by reasonably matching the above types of isocyanates, catalysts, cell openers, crosslinkers, chain extenders, and stabilizers, good foaming effects can be achieved among the catalyst, cell opener, crosslinker, chain extender, stabilizer, isocyanate, and polyether polyol, thereby improving the sound absorption effect of the sound-absorbing material.

[0049] The second aspect of the present invention provides a method for preparing the composite sound-absorbing material described in the first aspect of the present invention.

[0050] Specifically, the method for preparing the composite sound-absorbing material includes the following steps:

[0051] Mix the isocyanate with the sound-absorbing particles to obtain a first mixture; mix the remaining raw materials for preparing the polyurethane material except the isocyanate with the sound-absorbing particles to obtain a second mixture;

[0052] Mix the first mixture and the second mixture, and heat to obtain the composite sound-absorbing material;

[0053] The mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:(0.18 - 55).

[0054] Specifically, by adding the sound-absorbing particles separately and in the foaming process, problems such as uneven dispersion caused by adding the sound-absorbing particles later, easy powder falling, and the need to add additional binders to reduce the sound absorption effect can be avoided. The dispersion uniformity of the sound-absorbing particles can be improved, thereby enhancing the sound absorption effect. In addition, the present invention is not a simple physical mixture. A series of complex chemical reactions will occur after mixing. The polyether polyol reacts chemically after mixing to generate gas, thereby forming bubbles. mainly, the end groups in the polyether polyol molecules react with the foaming components in the isocyanate to generate gas, causing the polyether polyol to foam. The bubbles form open-cell bubbles under the action of the cell opener, the material volume expands, and the sound-absorbing particles in the system are pushed to be evenly distributed in the material.

[0055] According to some embodiments of the present invention, the mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:(0.2 - 50).

[0056] Specifically, the sound-absorbing particles in the first mixture and the second mixture of the present invention adopt specific proportions, which can fully exert the sound-absorbing function of the sound-absorbing particles.

[0057] According to some embodiments of the present invention, the first mixture is added to the second mixture for mixing.

[0058] According to some embodiments of the present invention, the mixing is carried out by stirring, the rotation speed of the stirring is greater than 2700 r / min, and the stirring time is 5 - 22 s.

[0059] According to some embodiments of the present invention, the rotation speed of the stirring is greater than 3000 r / min, and the stirring time is 5 - 20 s.

[0060] According to some embodiments of the present invention, the heating temperature is 25 - 65 °C, and the heating time is 9 - 22 min.

[0061] According to some embodiments of the present invention, the heating temperature is 30 - 60 °C, and the heating time is 10 - 20 min.

[0062] Specifically, adopting a suitable heating temperature and a relatively high stirring speed can make the foaming process proceed fully, and can improve the dispersion of the sound-absorbing particles. After foaming is completed, the sound-absorbing particles are evenly embedded in the fibers of the polyurethane foam substrate, so that there are obvious and evenly distributed concave and convex structures around the pores of the sound-absorbing material, increasing the acoustic wave transmission resistance and enhancing the sound-absorbing effect in the medium and low frequencies.

[0063] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is (0.9 - 5.5):1.

[0064] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is (1 - 5):1.

[0065] Specifically, the first mixture and the second mixture are added in appropriate proportions. On the one hand, it can fully exert the functions of each raw material component and maximize the sound-absorbing effect of the sound-absorbing material; on the other hand, it can make the sound-absorbing particles have an appropriate proportion in the composite sound-absorbing material, neither too much nor too little, avoiding agglomeration caused by too many sound-absorbing particles or insufficient concave and convex structures around the pores due to too few sound-absorbing particles, thereby reducing the sound-absorbing effect of the sound-absorbing material in the medium and low frequencies.

[0066] The third aspect of the present invention provides a household electrical appliance product.

[0067] Specifically, the household electrical appliance product includes the composite sound-absorbing material described in the first aspect of the present invention.

[0068] According to some embodiments of the present invention, the household electrical appliance product includes a washing machine, a dryer, a refrigerator, an air conditioner, and a dishwasher.

[0069] Specifically, the sound-absorbing material of the present invention has a good sound-absorbing effect in the medium and low frequencies. When it is applied to a washing machine, a dryer, a refrigerator, an air conditioner, and a dishwasher, it can achieve good sound absorption of medium and low frequency noises and reduce the damage of medium and low frequency noises to the human body. Specific Embodiments

[0070] In order to make those skilled in the art more clearly understand the technical solutions of the present invention, the following embodiments are listed for illustration. It should be noted that the following embodiments do not limit the protection scope required by the present invention.

[0071] Unless otherwise specified, the raw materials, reagents, or devices used in the following embodiments can be obtained from conventional commercial channels or can be obtained by existing known methods.

[0072] The first aspect of the embodiment of the present invention provides a composite sound-absorbing material, which includes a foaming substrate and sound-absorbing particles; the sound-absorbing particles are dispersed in the foaming substrate; the foaming substrate is a polyurethane material;

[0073] The sound-absorbing particles include at least one of a metal-organic framework compound, activated carbon, aerogel, carbon nanotubes, and graphene.

[0074] In the embodiment of the present invention, the sound-absorbing particles are distributed in the foaming substrate, and each single sound-absorbing particle is fully or partially embedded in the fibers of the foaming substrate. The existence of the uniformly dispersed sound-absorbing particles will form a protrusion, making the periphery of the pores of the sound-absorbing material have an obvious concave-convex structure. This structure can greatly increase the resistance to sound wave transmission and convert sound energy into the thermal energy of particle vibration, thereby greatly improving the sound-absorbing effect. The cross-sectional structure of the traditional polyurethane foamed sound-absorbing material is composed of pores formed by smooth fibers of different thicknesses, and the periphery of the pores is smooth without protrusions, so that the traditional polyurethane foamed sound-absorbing material has a good sound-absorbing effect in the high-frequency range, but has a poor sound-absorbing effect in the medium and low-frequency bands. In addition, the present invention uses MOFs, activated carbon, aerogel, carbon nanotubes, and graphene as sound-absorbing particles, which have more internal pores. When sound waves enter the three-dimensional network-connected pores inside the sound-absorbing particles, the more the air flow branches are divided, the more the multi-angle collision of the air flow in the pores can be enhanced, thereby strengthening the disordered reflection, refraction, and even backflow of sound waves, continuously losing sound energy, improving the sound-absorbing effect, and at the same time avoiding that when the pore diameter of the sound-absorbing particles is large, the foaming substrate will enter the pores, affecting the sound-absorbing effect of the whole material, so that the composite sound-absorbing material has a good sound-absorbing coefficient in the medium and low frequencies.

[0075] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is greater than or equal to 180 m 2 / g.

[0076] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is 1000 - 4000 m 2 / g.

[0077] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is 1800 m 2 / g.

[0078] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is 2200 m 2 / g.

[0079] According to some embodiments of the present invention, the specific surface area of the sound-absorbing particles is 2600 m 2 / g.

[0080] According to some embodiments of the present invention, the particle size of the sound-absorbing particles is 90 - 11000 nm.

[0081] According to some embodiments of the present invention, the particle size of the sound-absorbing particles is 100 - 10000 nm.

[0082] According to some embodiments of the present invention, the particle size of the sound-absorbing particles is 100 - 1000 nm.

[0083] According to some embodiments of the present invention, the particle size of the sound-absorbing particles is 300 - 700 nm.

[0084] In the embodiments of the present invention, sound-absorbing particles with a larger specific surface area are used, so that there are more internal pores in the sound-absorbing particles, which can enhance the multi-angle collision of air flow in the pores and improve the sound-absorbing effect. In addition, when the particle size of the sound-absorbing particles is too small, the sound-absorbing particles cannot form an obvious concave-convex structure around the pores of the sound-absorbing material, which will weaken the acoustic wave transmission resistance and reduce the sound-absorbing effect in the medium and low frequencies; when the particle size is too large, phenomena such as powder falling and agglomeration are likely to occur, which will also reduce the sound-absorbing effect of the sound-absorbing material in the medium and low frequencies. By selecting the above specific particle size range for the sound-absorbing particles of the present invention, the acoustic wave transmission resistance can be enhanced and the agglomeration phenomenon can be reduced, thereby improving the sound-absorbing effect of the sound-absorbing material in the medium and low frequencies.

[0085] According to some embodiments of the present invention, the sound-absorbing particles have a porous structure.

[0086] According to some embodiments of the present invention, the pore diameter of the sound-absorbing particles is less than 2 nm.

[0087] According to some embodiments of the present invention, the pore diameter of the sound-absorbing particles is 0.7 - 1.2 nm.

[0088] According to some embodiments of the present invention, the pore diameter of the sound-absorbing particles is 0.8 - 1.0 nm.

[0089] In the embodiments of the present invention, sound-absorbing particles with a smaller pore diameter are used, which can result in more internal pore channels in the sound-absorbing particles, enhance the multi-angle collision of air flow in the pores, improve the sound-absorbing effect, and at the same time avoid the foaming substrate entering the pores when the pore diameter of the sound-absorbing particles is large, which affects the sound-absorbing effect of the entire material, so that the composite sound-absorbing material has a good sound-absorbing coefficient in the medium and low frequencies.

[0090] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 55%.

[0091] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 60%.

[0092] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 90%.

[0093] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 95%.

[0094] According to some embodiments of the present invention, the porosity of the sound-absorbing particles is greater than 98%.

[0095] In the embodiments of the present invention, sound-absorbing particles with a large porosity are used, which can result in more pore channels in the sound-absorbing particles, more air flow branches into which the sound wave is divided, and more multi-angle collisions of the air flow in the pores, thereby strengthening the disordered reflection of the sound wave and the continuous loss of sound energy, and improving the sound-absorbing effect of the sound-absorbing material in the medium and low frequency bands.

[0096] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 2.2 - 55%.

[0097] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 2.5 - 50%.

[0098] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 15 - 25%.

[0099] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 18.75%.

[0100] According to some embodiments of the present invention, in the composite sound-absorbing material, the mass ratio of the sound-absorbing particles is 21.25%.

[0101] The sound-absorbing material in the embodiment of the present invention needs to meet the above-mentioned mass ratio, which can avoid the phenomenon of agglomeration when too much sound-absorbing particles are added, resulting in poor dispersion and affecting the sound-absorbing effect of the product; and can avoid the situation that when too little sound-absorbing particles are added, the sound-absorbing particles cannot form enough concave-convex structures around the pores of the sound-absorbing material, thereby affecting the sound-absorbing effect. By exploring the mass ratio of the sound-absorbing particles, the sound-absorbing particles are evenly embedded in the fibers of the foaming substrate and there are enough concave-convex structures around the pores, thereby increasing the resistance to sound wave transmission and improving the sound-absorbing effect of the material at medium and low frequencies.

[0102] Among the sound-absorbing particles of the embodiments of the present invention, the thermal conductivity of activated carbon, carbon nanotubes, and graphene materials is relatively high. The thermal conductivity of activated carbon is 0.1-0.3W / m·K; the thermal conductivity of graphene is greater than 0.1-0.3W / m·K; the sound-absorbing particles with high thermal conductivity can quickly disperse the heat of the sound-absorbing material and improve the thermal stability of the sound-absorbing material. In addition, the thermal conductivity of aerogel is 0.1-0.3W / m·K. Although its thermal conductivity is relatively small, it has excellent thermal insulation ability and large thermal resistance. It can well block external heat, thereby improving the heat resistance of polyurethane sound-absorbing materials in disguise.

[0103] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound absorbing material is 0.37-0.9.

[0104] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound absorbing material is 0.4-0.85.

[0105] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound absorbing material is 0.6-0.85.

[0106] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound absorbing material is 0.6.

[0107] According to some embodiments of the present invention, the sound absorption coefficient of the composite sound absorbing material is 0.83.

[0108] According to some embodiments of the present invention, the raw materials for preparing the polyurethane material include 55-105 parts of polyether polyol and 65-100 parts of isocyanate, by weight.

[0109] According to some embodiments of the present invention, the raw materials for preparing the polyurethane material include 60-99 parts of polyether polyol and 70-90 parts of isocyanate, by weight.

[0110] According to some embodiments of the present invention, the raw materials for preparing the polyurethane material include 69 parts of polyether polyol and 80 parts of isocyanate, calculated by weight.

[0111] According to some embodiments of the present invention, the raw materials for preparing the polyurethane material include 65 parts of polyether polyol and 80 parts of isocyanate, calculated by weight.

[0112] In the embodiments of the present invention, the polyurethane material prepared from polyether polyol and isocyanate is used as the foaming substrate of the sound-absorbing material. It has porosity, which helps to improve the sound-absorbing effect. And by reasonably matching the amounts of polyether polyol and isocyanate, the polyurethane material has good foaming effect, thereby improving the sound-absorbing effect of the sound-absorbing material.

[0113] According to some embodiments of the present invention, the raw materials for preparing the polyurethane material further include at least one of a catalyst, a cell opener, a crosslinking agent, a chain extender, and a stabilizer.

[0114] In the embodiments of the present invention, the polyether polyol and isocyanate are foamed under the action of a catalyst, a cell opener, a crosslinking agent, a chain extender, and a stabilizer to obtain a high molecular polymer. The addition of the catalyst and the stabilizer enables the foaming process to proceed faster and more stably. The addition of the crosslinking agent and the chain extender will increase the crosslinking degree of the molecular chain, making the foamed material have good mechanical properties. The addition of the cell opener can increase the open cell rate of the sound-absorbing material, improve the effective utilization rate of the sound-absorbing particles, enable the sound wave to be fully segmented by the pores in the foamed cells and the sound-absorbing particles, increase the multi-angle collision of the sound wave and the pores, and improve the sound-absorbing effect of the sound-absorbing material in the medium and low frequency bands.

[0115] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 55-105 parts of polyether polyol, 65-100 parts of isocyanate, 0.1-11 parts of catalyst, 1.8-5.5 parts of cell opener, 1-5.5 parts of crosslinking agent, 0.9-11 parts of chain extender, and 0.1-3.5 parts of stabilizer.

[0116] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 60-99 parts of polyether polyol, 70-90 parts of isocyanate, 0.1-10 parts of catalyst, 2-5 parts of cell opener, 1-5 parts of crosslinking agent, 1-10 parts of chain extender, and 0.1-3 parts of stabilizer.

[0117] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 69 parts of polyether polyol, 80 parts of isocyanate, 5 parts of catalyst, 3 parts of cell opener, 2 parts of crosslinking agent, 1 part of chain extender, and 0.5 part of stabilizer.

[0118] According to some embodiments of the present invention, by weight, the raw materials for preparing the polyurethane material include 65 parts of polyether polyol, 80 parts of isocyanate, 6 parts of catalyst, 3 parts of cell opener, 2 parts of crosslinking agent, 1 part of chain extender, and 0.5 part of stabilizer.

[0119] The embodiment of the present invention optimizes the usage relationship of polyether polyol, isocyanate, catalyst, cell opener, crosslinker, chain extender and stabilizer so that the polyurethane material has a good foaming effect, thereby improving the sound absorption effect of the sound-absorbing material.

[0120] According to some embodiments of the present invention, the composite sound-absorbing material comprises 10-110 parts by weight of sound-absorbing particles.

[0121] According to some embodiments of the present invention, the composite sound-absorbing material comprises 11-100 parts of sound-absorbing particles by weight.

[0122] According to some embodiments of the present invention, the composite sound-absorbing material comprises 35-45 parts by weight of sound-absorbing particles.

[0123] According to some embodiments of the present invention, the composite sound-absorbing material comprises 37.5 parts of sound-absorbing particles by weight.

[0124] According to some embodiments of the present invention, the composite sound-absorbing material comprises 42.5 parts of sound-absorbing particles by weight.

[0125] The embodiment of the present invention can avoid the phenomenon of agglomeration when too much sound-absorbing particles are added by reasonably matching the content of the sound-absorbing particles, and can also avoid the phenomenon that the sound-absorbing particles cannot form a sufficient concave-convex structure around the pores of the sound-absorbing material when too little sound-absorbing particles are added; the sound-absorbing particles are uniformly embedded in the fibers of the foaming substrate and have a sufficient concave-convex structure, thereby increasing the resistance to sound wave transmission, improving the sound absorption effect and making the sound absorption frequency range wider.

[0126] According to some embodiments of the present invention, MOFs include at least one of MOF-5 (Xi'an Qiyue Biotechnology Co., Ltd.), MIL-101 (Xi'an Ruixi Biotechnology Co., Ltd.), and MOF-177 (Xi'an Ruixi Biotechnology Co., Ltd.).

[0127] According to some embodiments of the present invention, the catalyst is an amine catalyst.

[0128] According to some embodiments of the present invention, the catalyst includes at least one of 33LV (Shanghai Sangjing Chemical Co., Ltd.), PC-5 (Jinan Qiyue Chemical Technology Co., Ltd.), 33LE (Xindian Chemical Materials (Shanghai) Co., Ltd.), ZF-10 (Xindian Chemical Materials (Shanghai) Co., Ltd.), and NX200 (Guangzhou Yourun Synthetic Materials Co., Ltd.).

[0129] According to some embodiments of the present invention, the catalyst includes at least one of 33LV and ZF-10.

[0130] According to some embodiments of the present invention, the cross-linking agent includes at least one of glycerol, trimethylolpropane, hexamethylenediamine, and amino alcohol.

[0131] According to some embodiments of the invention, the cross-linking agent is an amino alcohol.

[0132] According to some embodiments of the present invention, the chain extender includes at least one of ethylene glycol, diethylene glycol, and 1,4-butanediol.

[0133] According to some embodiments of the present invention, the chain extender is diethylene glycol.

[0134] According to some embodiments of the present invention, the cell opener comprises an organic polymer cell opener.

[0135] According to some embodiments of the present invention, the pore opening agent includes at least one of G501 (Dongguan Guangsiyuan Polyurethane Material Co., Ltd.), GSY-28 (Dongguan Guangsiyuan Polyurethane Material Co., Ltd.), SP-5 (Xiamen Aikema Chemical Co., Ltd.), Y-1900 (Dongguan Guangsiyuan Polyurethane Material Co., Ltd.), QG1121 (Shanghai Qiguang Industry and Trade Co., Ltd.), and Q100-A (Shanghai Qiguang Industry and Trade Co., Ltd.).

[0136] According to some embodiments of the present invention, the cell opener includes at least one of Y-1900 and SP-5.

[0137] According to some embodiments of the present invention, the stabilizer includes a silicone stabilizer.

[0138] According to some embodiments of the present invention, the stabilizer includes at least one of AK-8802 (Jining Tangyi Chemical Co., Ltd.), SY-6193 (Jiangxi Mitsukoshi New Materials Co., Ltd.), and Y-10366 (Jining Tangyi Chemical Co., Ltd.).

[0139] According to some embodiments of the invention, the stabilizer is AK-8802.

[0140] According to some embodiments of the present invention, the polyether polyol includes at least one of polyether polyol 141B (Shandong Xiangzhao New Materials Co., Ltd.), polyether polyol 303N (Hai'an Petrochemical Plant, Jiangsu Province), polyether polyol 4701 (Xindian Chemical Materials (Shanghai) Co., Ltd.), polyether polyol POP-H45 (Zibo Dexin Federal Chemical Industry Co., Ltd.), and polyether polyol 2000 (Nantong Qianhe Chemical Co., Ltd.).

[0141] According to some embodiments of the present invention, the polyether polyol includes at least one of polyether polyol 4701, polyether polyol POP-H45, and polyether polyol 2000.

[0142] According to some embodiments of the present invention, the isocyanate includes at least one of TDI-80 (Jinan Guangxun Trading Co., Ltd.), TDI-100 (Jinan Guangxun Trading Co., Ltd.), and PM200 (Jinan Mingxin Chemical Co., Ltd.).

[0143] According to some embodiments of the present invention, the isocyanate includes at least one of TDI-80 and PM200.

[0144] In the embodiments of the present invention, by reasonably matching the above-mentioned isocyanate, catalyst, blowing agent, crosslinking agent, chain extender, and stabilizer, the catalyst, blowing agent, crosslinking agent, chain extender, stabilizer, isocyanate, and polyether polyol have good foaming effects, thereby improving the sound absorption effect of the sound-absorbing material.

[0145] The second aspect of the embodiments of the present invention provides a preparation method of the composite sound-absorbing material of the first aspect of the present invention, including the following steps:

[0146] Mix the isocyanate with the sound-absorbing particles to obtain a first mixture; mix the raw materials for preparing the remaining polyurethane materials except the isocyanate with the sound-absorbing particles to obtain a second mixture;

[0147] Mix the first mixture and the second mixture, and heat to obtain the composite sound-absorbing material;

[0148] The mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:(0.18 - 55).

[0149] In the embodiments of the present invention, by adding the sound-absorbing particles separately and in the foaming process, it is possible to avoid the problems of uneven dispersion and easy powder falling caused by the post-addition of the sound-absorbing particles, and the need to add additional binders and other substances that reduce the sound absorption effect. It can improve the dispersion of the sound-absorbing particles, thereby enhancing the sound absorption effect. In addition, the present invention is not a simple physical mixture. A series of complex chemical reactions will occur after mixing. The polyether polyol reacts chemically after mixing to generate gas, thereby forming bubbles. mainly, the end groups in the polyether polyol molecules react with the foaming components in the isocyanate to generate gas, causing the polyether polyol to foam. The bubbles form open-cell bubbles under the action of the blowing agent, and the material volume expands, pushing the sound-absorbing particles in the system to be evenly distributed in the material.

[0150] According to some embodiments of the present invention, the mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:(0.2 - 50).

[0151] According to some embodiments of the present invention, the mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:0.7 - 1.3.

[0152] According to some embodiments of the present invention, the mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:0.89.

[0153] According to some embodiments of the present invention, the mass ratio of the sound-absorbing particles in the second mixture to the sound-absorbing particles in the first mixture is 1:1.14.

[0154] According to some embodiments of the present invention, the first mixture is added to the second mixture for mixing, and the mixing is carried out by stirring.

[0155] According to some embodiments of the present invention, the rotation speed of stirring is greater than 2700 r / min, and the stirring time is 5 - 22 s.

[0156] According to some embodiments of the present invention, the rotation speed of stirring is greater than 3000 r / min, and the stirring time is 5 - 20 s.

[0157] According to some embodiments of the present invention, the rotation speed of stirring is 5000 r / min, and the stirring time is 15 s.

[0158] According to some embodiments of the present invention, the heating temperature is 25 - 65 °C, and the heating time is 9 - 22 min.

[0159] According to some embodiments of the present invention, the heating temperature is 30 - 60 °C, and the heating time is 10 - 20 min.

[0160] According to some embodiments of the present invention, the heating temperature is 50 °C, and the heating time is 20 min.

[0161] In the embodiments of the present invention, using a suitable heating temperature and a relatively high stirring speed can make the foaming process proceed fully, and can improve the dispersion of the sound-absorbing particles. After foaming is completed, the sound-absorbing particles are evenly embedded in the fibers of the polyurethane foam substrate, making the foam holes of the sound-absorbing material have obvious concave and convex structures around, increasing the acoustic wave transmission resistance, and enhancing the sound absorption effect and the sound absorption frequency range.

[0162] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is (0.9 - 5.5):1.

[0163] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is (1 - 5):1.

[0164] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is (2.0 - 4.5):1.

[0165] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is (2.3 - 4.0):1.

[0166] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is 3:1.

[0167] According to some embodiments of the present invention, when the first mixture and the second mixture are mixed, the mass ratio of the second mixture to the first mixture is 4:1.

[0168] In the embodiments of the present invention, the first mixture and the second mixture are added in appropriate proportions. On the one hand, the functions of each raw material component can be fully exerted to maximize the sound absorption effect of the sound-absorbing material; on the other hand, the sound-absorbing particles can have an appropriate proportion in the composite sound-absorbing material, neither too much nor too little, avoiding agglomeration caused by too many sound-absorbing particles, or insufficient concave-convex structures around the pores due to too few sound-absorbing particles, thereby reducing the sound absorption effect of the sound-absorbing material.

[0169] The third aspect of the embodiments of the present invention provides a household electrical appliance product, including the composite sound-absorbing material of the first aspect of the present invention.

[0170] According to some embodiments of the present invention, the household electrical appliance product includes a washing machine, a clothes dryer, a refrigerator, an air conditioner, and a dishwasher.

[0171] The sound-absorbing material in the embodiments of the present invention has a good sound absorption effect in the medium and low frequencies. When it is applied to washing machines, clothes dryers, refrigerators, air conditioners, and dishwashers, it can achieve good sound absorption of medium and low frequency noises and reduce the damage of medium and low frequency noises to the human body.

[0172] Example 1

[0173] The raw materials for preparing the composite sound-absorbing material include component A and component B. By weight, component A includes 69 parts of polyether polyol POP-H45, 5 parts of catalyst 33LV, 3 parts of blowing agent Y-1900, 2 parts of crosslinking agent amino alcohol, 1 part of chain extender diethylene glycol, 0.5 part of stabilizer AK-8802, and 19.5 parts of sound-absorbing particles; component B includes 80 parts of isocyanate TDI-80 and 20 parts of sound-absorbing particles;

[0174] The sound-absorbing particles are silica-based aerogels with a specific surface area of 1800 m 2 / g, a pore diameter of less than 2 nm, a pore proportion of more than 95%, and a particle size of 90 - 100 nm;

[0175] In the composite sound-absorbing material, the mass ratio of component A to component B is 70:30.

[0176] Preparation method of composite sound-absorbing material, comprising the following steps:

[0177] (1) Add the raw material components of component A and component B into a stirrer respectively, and mix them evenly at room temperature to obtain a first mixture and a second mixture respectively;

[0178] (2) Adjust the rotation speed of the stirrer to 5000 r / min, add the second mixture obtained in step (1) into the first mixture, stir for 15 s, pour the mixed material into a mold with a heating temperature of 50 °C, and demold after 20 min to obtain a composite sound-absorbing material. In the composite sound-absorbing material, silica-based aerogel is evenly dispersed in the polyurethane foam substrate.

[0179] Example 2

[0180] The raw materials for preparing the composite sound-absorbing material include component A and component B. By weight, component A includes 65 parts of polyether polyol 4701, 6 parts of catalyst PC-5, 3 parts of blowing agent Y-1900, 2 parts of cross-linking agent amino alcohol, 1 part of chain extender diethylene glycol, 0.5 part of stabilizer AK-8802, and 22.5 parts of sound-absorbing particles; component B includes 80 parts of isocyanate TDI-80 and 20 parts of sound-absorbing particles;

[0181] The sound-absorbing particles are coconut shell activated carbon with a specific surface area of 2600 m 2 / g, a pore diameter less than 2 nm, a pore proportion greater than 97%, and a particle size of 800 - 1000 nm;

[0182] In the composite sound-absorbing material, the mass ratio of component A to component B is 75:25.

[0183] Preparation method of composite sound-absorbing material, comprising the following steps:

[0184] (1) Add the raw material components of component A and component B into a stirrer respectively, and mix them evenly at room temperature to obtain a first mixture and a second mixture respectively;

[0185] (2) Adjust the rotation speed of the stirrer to 5000 r / min, add the second mixture obtained in step (1) into the first mixture, stir for 15 s, pour the mixed material into a mold with a heating temperature of 50 °C, and demold after 20 min to obtain a composite sound-absorbing material. In the composite sound-absorbing material, coconut shell activated carbon is evenly dispersed in the polyurethane foam substrate.

[0186] Example 3

[0187] The raw materials for preparing the composite sound-absorbing material include component A and component B. By weight, component A includes 69 parts of polyether polyol POP-H45, 8 parts of catalyst ZF-10, 2 parts of blowing agent SP-5, 2 parts of crosslinking agent amino alcohol, 1 part of chain extender diethylene glycol, 0.5 part of stabilizer AK-8802, and 17.5 parts of sound-absorbing particles; component B includes 80 parts of isocyanate PM200 and 20 parts of sound-absorbing particles.

[0188] The sound-absorbing particles are carbon nanotubes with a specific surface area of 1000 m 2 / g, a pore diameter less than 2 nm, a pore proportion greater than 95%, and a particle size of 300 - 700 nm.

[0189] In the composite sound-absorbing material, the mass ratio of component A to component B is 80:20.

[0190] The preparation method of the composite sound-absorbing material includes the following steps:

[0191] (1) Add the raw material components of component A and component B into a stirrer respectively, and mix them evenly at room temperature to obtain the first mixture and the second mixture respectively.

[0192] (2) Adjust the stirrer speed to 5000 r / min, add the second mixture obtained in step (1) into the first mixture, stir for 15 s, pour the mixed material into a mold with a heating temperature of 50 °C, and demold after 20 min to obtain the composite sound-absorbing material. In the composite sound-absorbing material, the carbon nanotubes are evenly dispersed in the polyurethane foam substrate.

[0193] Example 4

[0194] The raw materials for preparing the composite sound-absorbing material include component A and component B. By weight, component A includes 70 parts of polyether polyol POP-H45, 5 parts of catalyst 33LV, 3 parts of blowing agent Y-1900, 2 parts of crosslinking agent amino alcohol, 1 part of chain extender diethylene glycol, 0.5 part of stabilizer AK-8802, and 18.5 parts of sound-absorbing particles; component B includes 80 parts of isocyanate TDI-80 and 20 parts of sound-absorbing particles.

[0195] The sound-absorbing particles are MIL-101 MOF with a specific surface area of 2200 m 2 / g, a pore diameter of 0.7 - 1.2 nm, a pore proportion greater than 93%, and a particle size of 100 - 150 nm.

[0196] In the composite sound-absorbing material, the mass ratio of component A to component B is 70:30.

[0197] The preparation method of the composite sound-absorbing material includes the following steps:

[0198] (1) Add the raw material components of component A and component B into a stirrer respectively, and mix them evenly at room temperature to obtain the first mixture and the second mixture respectively;

[0199] (2) Adjust the stirrer speed to 5000 r / min, add the second mixture obtained in step (1) into the first mixture, stir for 15 s, pour the mixed material into a mold heated to 50 °C, and demold after 20 min to obtain a composite sound-absorbing material. In the composite sound-absorbing material, MIL-101 MOF is evenly dispersed in the polyurethane foam substrate.

[0200] Example 5

[0201] The raw materials for preparing the composite sound-absorbing material include component A and component B. By weight, component A includes 200069 parts of polyether polyol, 5 parts of catalyst 33LV, 3 parts of blowing agent Y-1900, 2 parts of cross-linking agent amino alcohol, 1 part of chain extender diethylene glycol, 0.5 part of stabilizer AK-8802, and 19.5 parts of sound-absorbing particles; component B includes 80 parts of isocyanate TDI-80 and 20 parts of sound-absorbing particles;

[0202] The sound-absorbing particles are MOF-5 with a specific surface area of 2500 m 2 / g, a pore diameter of 0.8 - 1 nm, a pore proportion greater than 98%, and a particle size of 100 - 150 nm;

[0203] In the composite sound-absorbing material, the mass ratio of component A to component B is 70:30.

[0204] The preparation method of the composite sound-absorbing material includes the following steps:

[0205] (1) Add the raw material components of component A and component B into a stirrer respectively, and mix them evenly at room temperature to obtain the first mixture and the second mixture respectively;

[0206] (2) Adjust the stirrer speed to 5000 r / min, add the second mixture obtained in step (1) into the first mixture, stir for 15 s, pour the mixed material into a mold heated to 50 °C, and demold after 20 min to obtain a composite sound-absorbing material. In the composite sound-absorbing material, MOF-5 is evenly dispersed in the polyurethane foam substrate.

[0207] Example 6

[0208] The difference between Example 6 and Example 2 is only that in Example 6, an equal amount of coconut shell activated carbon with a specific surface area of 200 m 2 / g is used to replace the coconut shell activated carbon with a specific surface area of 2600 m 2 / g, and the others are the same as in Example 2.

[0209] Comparative Example 1

[0210] The difference between Comparative Example 1 and Example 1 is only that no sound-absorbing particulate silica aerogel is added in Comparative Example 1, and the others are the same as in Example 1.

[0211] Comparative Example 2

[0212] The difference between Comparative Example 2 and Example 3 is only that no sound-absorbing particulate carbon nanotube is added in Comparative Example 2, and the others are the same as in Example 3.

[0213] Comparative Example 3

[0214] The difference between Comparative Example 3 and Example 4 is only that an equal amount of molecular sieve with a specific surface area of 300 m 2 / g and a pore diameter of 0.75 nm is used to replace the MIL-101 MOF in Example 4, and the others are the same as in Example 4.

[0215] Comparative Example 4

[0216] The difference between Comparative Example 4 and Example 5 is only that an equal amount of molecular sieve with a pore diameter of 5 nm is used to replace the MOF-5 in Example 5, and the others are the same as in Example 5.

[0217] Performance test

[0218] The sound absorption coefficients of the composite sound-absorbing materials prepared in Examples 1-6 and Comparative Examples 1-4 were measured at 750 Hz, and the results are shown in Table 1.

[0219] Among them, the sound absorption coefficient was measured according to the following test method:

[0220] GB / T 18696.1-2004 Acoustics - Measurement of sound absorption coefficient and acoustic impedance in impedance tubes - Part 1: Standing wave ratio method.

[0221] Table 1: Sound absorption coefficients of the composite sound-absorbing materials prepared in Examples 1-6 and Comparative Examples 1-4

[0222]

[0223] As can be seen from Table 1, the composite sound-absorbing materials prepared in the examples of the present invention have a relatively high sound absorption coefficient at 750 Hz, indicating that the composite sound-absorbing materials of the present invention have good sound absorption effects under medium and low frequency conditions.

[0224] Since no sound-absorbing particulate silica aerogel is added in Comparative Example 1, the sound absorption coefficient of Comparative Example 1 at 750 Hz is significantly lower than that of Example 1, that is, the sound absorption effect of Example 1 at 750 Hz is significantly better than that of Comparative Example 1.

[0225] In Comparative Example 2, since no sound-absorbing particulate carbon nanotubes were added, the sound absorption coefficient of Comparative Example 2 at 750 Hz was significantly lower than that of Example 3, that is, the sound absorption effect of Example 3 at 750 Hz was significantly better than that of Comparative Example 2.

[0226] Comparative Example 3 used a molecular sieve with a specific surface area of 300 m 2 / g and a pore diameter of 0.75 nm, making the sound absorption coefficient of Comparative Example 3 at 750 Hz significantly lower than that of Example 4, that is, the sound absorption effect of Example 4 at 750 Hz was significantly better than that of Comparative Example 3.

[0227] Comparative Example 4 used an equal amount of molecular sieve with a pore diameter of 5 nm, making the sound absorption coefficient of Comparative Example 4 at 750 Hz significantly lower than that of Example 4, that is, the sound absorption effect of Example 5 at 750 Hz was significantly better than that of Comparative Example 4.

[0228] It can be seen that adding sound-absorbing particles during the foaming process of the sound-absorbing material of the present invention can improve the sound absorption effect of the composite sound-absorbing material in the mid-low frequency range, and the sound absorption coefficient can be as high as 0.83.

[0229] The sound-absorbing material of the present invention has a good sound absorption effect in the mid-low frequency range. When the composite sound-absorbing material of the present invention is applied to household appliances such as washing machines, dryers, refrigerators, air conditioners, and dishwashers, it can achieve good sound absorption of mid-low frequency noise and reduce the damage of mid-low frequency noise of household appliances to the human body.

[0230] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A composite sound-absorbing material, comprising a foaming substrate and sound-absorbing particles; Features: The sound-absorbing particles are dispersed in the foam substrate; the foam substrate is a polyurethane material; The sound-absorbing particles include at least one of metal organic framework compounds, activated carbon, aerogel, carbon nanotubes, and graphene.

2. The composite sound-absorbing material according to claim 1, It is characterized in that The specific surface area of ​​the sound-absorbing particles is greater than or equal to 180 m 2 / g, and / or, the particle size of the sound-absorbing particles is 90-11000nm.

3. The composite sound-absorbing material according to claim 1, It is characterized in that The sound-absorbing particles have a porous structure, the pore size of the sound-absorbing particles is less than 2 nm, and / or the porosity of the sound-absorbing particles is greater than 55%.

4. The composite sound-absorbing material according to claim 1, It is characterized in that In the composite sound-absorbing material, the mass proportion of the sound-absorbing particles is 2.2-55%.

5. The composite sound-absorbing material according to claim 1, It is characterized in that In parts by weight, the raw materials for preparing the polyurethane material include 55-105 parts of polyether polyol and 65-100 parts of isocyanate.

6. The composite sound-absorbing material according to claim 5, It is characterized in that The raw materials for preparing the polyurethane material also include at least one of a catalyst, a pore opening agent, a cross-linking agent, a chain extender, and a stabilizer.

7. The composite sound-absorbing material according to claim 6, It is characterized in that By weight, the raw materials for preparing the polyurethane material include 55-105 parts of polyether polyol, 65-100 parts of isocyanate, 0.1-11 parts of catalyst, 1.8-5.5 parts of cell opener, 1-5.5 parts of crosslinker, 0.9-11 parts of chain extender and 0.1-3.5 parts of stabilizer.

8. The composite sound-absorbing material according to claim 5, It is characterized in that The composite sound-absorbing material contains 10-110 parts of sound-absorbing particles by weight.

9. A method for preparing the composite sound-absorbing material according to any one of claims 5 to 8, It is characterized in that The following steps are involved: Mixing isocyanate with sound-absorbing particles to obtain a first mixture; mixing the remaining raw materials for preparing the polyurethane material except the isocyanate with the sound-absorbing particles to obtain a second mixture; The first mixture and the second mixture are mixed and heated to obtain the composite sound absorbing material; The mass ratio of the sound absorbing particles in the second mixture to the sound absorbing particles in the first mixture is 1:(0.18-55).

10. A household appliance, It is characterized in that The composite sound-absorbing material comprises the composite sound-absorbing material according to any one of claims 1 to 8.

11. The household appliance according to claim 10, It is characterized in that The household appliances include washing machines, dryers, refrigerators, air conditioners and dishwashers.

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