Low-frequency damping material, preparation method and application thereof

Abstract

The present invention provides a low-frequency damping material, its preparation method, and application. The low-frequency damping material includes a vibration-damping substrate, a sound-absorbing filler, and a dispersant; the vibration-damping substrate includes acrylic emulsion, polyurethane resin, polyether polyol, silicone rubber emulsion, polyester resin, expanded graphite, hard particles, and carbon fiber; the sound-absorbing filler includes polyacrylonitrile fiber and ceramsite. The present invention achieves the effect of effectively blocking noise over a wide frequency range by rationally designing the damping material formula, and the sound absorption coefficient of the damping material is significantly improved. In addition, the stability of the material in high and low temperature environments is fully considered, so that it has excellent heat resistance and low temperature resistance, and the sound insulation effect of the material is stable and reliable. At the same time, it has higher customizability and adaptability, and can be flexibly designed and customized according to the needs of different application scenarios to meet the needs of different fields.

Description

Technical Field

[0001] The present invention relates to the technical field of damping materials, and in particular to a low-frequency damping material, a preparation method thereof, and applications thereof. Background Art

[0002] Low-frequency (20-1200Hz) damping materials are materials that effectively absorb low-frequency vibration and noise. Typically made from polymers, rubber, metal, or composite materials, they exhibit high internal friction and damping properties. Low-frequency damping materials can be used to mitigate low-frequency vibration and noise generated by the operation of mechanical equipment, automobiles, aircraft, and other equipment, improving equipment stability and comfort. Widely used in engineering and construction, they can effectively reduce environmental noise levels and enhance equipment performance.

[0003] Traditional low-frequency damping materials often have some defects, which are mainly manifested in the following aspects:

[0004] Frequency dependence: The sound insulation performance of traditional low-frequency damping materials varies at different frequencies, especially in the low-frequency range, where the sound insulation performance is poor. This is because the sound absorption mechanism of traditional low-frequency damping materials is mainly based on internal resonance and sound absorption, and low-frequency noise often requires higher mass and thickness to effectively block it.

[0005] Temperature sensitivity: Traditional low-frequency damping materials are susceptible to performance degradation in high or low temperature environments, resulting in reduced sound insulation. Especially in industrial environments, material stability under high or low temperature conditions becomes a key factor restricting their application.

[0006] Material structure limitations: Traditional low-frequency damping materials often have fixed structural forms, making it difficult to meet the needs of different application scenarios. For example, in complex engineering environments, the material needs to have higher flexibility and adaptability to facilitate customization and installation. Summary of the Invention

[0007] The main purpose of the present invention is to provide a low-frequency damping material, a preparation method and application thereof, so as to solve the problems of low-frequency damping materials in the prior art, such as high frequency dependence and temperature sensitivity, and large material structure limitations.

[0008] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a low-frequency damping material is provided, comprising a vibration-damping substrate, a sound-absorbing filler and a dispersant; the vibration-damping substrate comprises acrylic emulsion, polyurethane resin, polyether polyol, silicone rubber emulsion, polyester resin, expanded graphite, hard particles and carbon fiber; the sound-absorbing filler comprises polyacrylonitrile fiber and ceramsite.

[0009] Furthermore, the weight ratio of the vibration-damping substrate to the sound-absorbing filler is (2.4-11.8):1; and / or the weight ratio of the dispersant to the sound-absorbing filler is (0.08-0.2):1.

[0010] Furthermore, the vibration-damping substrate includes, by weight, 30 to 50 parts of acrylic emulsion, 10 to 20 parts of polyurethane resin, 5 to 15 parts of polyether polyol, 5 to 10 parts of silicone rubber emulsion, 5 to 10 parts of polyester resin, 1 to 5 parts of expanded graphite, 1 to 5 parts of hard particles and 1 to 3 parts of carbon fiber.

[0011] Furthermore, the sound-absorbing filler comprises 5 to 15 parts of polyacrylonitrile fibers and 3 to 20 parts of ceramsite, by weight.

[0012] Furthermore, the hard particles include sand and / or glass beads; and / or the dispersant includes polyvinyl alcohol and / or sodium dodecylbenzene sulfonate.

[0013] Furthermore, the low-frequency damping material also includes one or more of an antioxidant, a molding agent and a hardener; preferably, by weight, the low-frequency damping material also includes 0.5 to 2 parts of an antioxidant, 0.5 to 2 parts of a molding agent and 0.5 to 2 parts of a hardener; more preferably, the antioxidant includes butyl hydroxybenzoate and / or bis(2,4-dimethylphenyl)trisiloxane; and / or the molding agent includes calcium stearate and / or polyacrylate; and / or the hardener includes an isocyanate crosslinker and / or hydrogen peroxide.

[0014] According to another aspect of the present invention, a method for preparing the low-frequency damping material of the present invention is provided, comprising the following steps: step S1, mixing acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion, and performing a first stirring to obtain a first mixture; step S2, adding polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles and carbon fiber to the first mixture, and adding a dispersant, and performing a second stirring to obtain a second mixture; step S3, molding the second mixture to obtain a molding material; and step S4, curing the molding material to obtain a low-frequency damping material.

[0015] Furthermore, in step S1, the first stirring temperature is 20-30°C, the time is 25-35 min, and the speed is 200-400 rpm; in step S2, the second stirring temperature is 20-30°C, first stirring at 100-200 rpm for 5-10 min, then stirring at 400-600 rpm for 10-15 min, and finally stirring at 200-300 rpm for 5-10 min to obtain a second mixture; in step S3, the molding method includes coating and / or casting, and the molding material includes a plate, sheet or plate-sheet composite material; in step S4, curing includes static curing and oven curing performed in sequence; preferably, the static curing temperature is 20-30°C, the time is 22-26 h; and / or the oven curing temperature is 55-65°C, and the time is 22-26 h.

[0016] Furthermore, step S3 further includes: adding an antioxidant, a molding agent and a hardener to the second mixture to obtain a pre-molded material, and molding the pre-molded material to obtain a molded material; preferably, the viscosity of the pre-molded material is 500 to 2000 Pa·s.

[0017] According to another aspect of the present invention, there is provided an application of the low-frequency damping material of the present invention in vibration and noise reduction.

[0018] Compared with the prior art, the present invention has at least the following technical effects:

[0019] Broadband Damping Effect: This invention achieves effective noise isolation across a wide frequency range through the rationally designed damping material formulation. In particular, the damping material's sound absorption coefficient is significantly improved at low frequencies, providing reliable technical support for the effective control of low-frequency noise.

[0020] Excellent temperature resistance: The composition design of the present invention fully considers the stability of the material in high and low temperature environments, so that it has excellent heat resistance and low temperature resistance. Under various extreme working conditions, the sound insulation effect of the material is stable and reliable and is not easily affected by external temperature changes.

[0021] Diversified structural customizability: By adjusting the formula, the present invention makes the material more customizable and adaptable. It can be flexibly designed and customized according to the needs of different application scenarios, and can realize the diversified application of the material to meet the needs of different fields. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0023] As described in the background of this invention, existing low-frequency damping materials suffer from high frequency dependence and temperature sensitivity, as well as significant material structural limitations. To address these issues, a typical embodiment of the present invention provides a low-frequency damping material comprising a vibration-damping substrate, a sound-absorbing filler, and a dispersant; the vibration-damping substrate comprises an acrylic emulsion, a polyurethane resin, a polyether polyol, a silicone rubber emulsion, a polyester resin, expanded graphite, hard particles, and carbon fibers; and the sound-absorbing filler comprises polyacrylonitrile fibers and ceramsite.

[0024] Among the above ingredients, acrylic emulsion acts as a base polymer, providing the material's basic structure and flexibility. It also acts as a binder, helping the material form a continuous structure after curing. Polyurethane resin can increase the material's hardness and durability, improve its tensile strength and elastic modulus, and also help increase its temperature resistance. Polyether polyols can increase the material's elasticity and toughness, improve its energy absorption capacity, and also help improve its fatigue resistance. Polyacrylonitrile fiber, as a sound-absorbing filler, can effectively absorb sound wave energy and reduce sound transmission, while also increasing the material's strength and toughness. Ceramic granules, as a sound-absorbing filler, can appropriately increase the material's mass and improve the scattering effect of sound waves, effectively reducing the propagation of low-frequency noise.

[0025] Silicone rubber emulsion can improve the material's flexibility and weather resistance, especially enhancing its flexibility in low-temperature environments, while also helping to improve its aging resistance. Polyester resin can increase the material's adhesion and durability, improve its surface hardness and gloss, and also help to increase its chemical resistance. Expanded graphite can increase the material's thermal conductivity, improve its stability in high-temperature environments, and also help to improve its fire resistance. Hard particles can increase the material's hardness and wear resistance, increase its compressive strength, and also help to improve its surface texture. Carbon fiber can increase the material's strength and rigidity, improve its tensile strength and impact resistance, and also help to reduce its density and weight. Dispersants can improve the compatibility between the sound-absorbing filler and the resin matrix, promote uniform dispersion of the filler, and prevent filler agglomeration, thereby improving the material's mechanical properties and durability.

[0026] The above-mentioned components of the present invention work together to effectively block noise in a wide frequency range; at the same time, it has excellent heat resistance and low temperature resistance; and makes the material more customizable and adaptable to meet the needs of different fields.

[0027] To better balance vibration reduction and sound absorption effects, in a preferred embodiment, the weight ratio of the vibration-damping substrate to the sound-absorbing filler is (2.4-11.8):1; and / or the weight ratio of the dispersant to the sound-absorbing filler is (0.08-0.2):1. If the above weight ratio is too large, the sound absorption coefficient of the low-frequency damping material may be reduced due to the low content of the sound-absorbing filler and poor sound absorption effect. If the weight ratio is too small, the vibration reduction effect may be reduced, the mechanical strength and temperature resistance of the material may be reduced, or the compatibility of the vibration-damping substrate and the sound-absorbing filler may be reduced due to the reduction of the dispersant. Therefore, the present invention limits this ratio to within the above specific range.

[0028] In order to make the low-frequency damping material have lower frequency dependence and temperature sensitivity, as well as smaller material structure restrictions, in a preferred embodiment, the vibration-damping substrate includes, by weight, 30 to 50 parts of acrylic emulsion, 10 to 20 parts of polyurethane resin, 5 to 15 parts of polyether polyol, 5 to 10 parts of silicone rubber emulsion, 5 to 10 parts of polyester resin, 1 to 5 parts of expanded graphite, 1 to 5 parts of hard particles and 1 to 3 parts of carbon fiber.

[0029] Polyacrylonitrile fiber and ceramsite serve as the primary sound-absorbing fillers, and their content significantly impacts the low-frequency damping material's sound absorption coefficient, mechanical strength, and high-temperature resistance at different frequencies. In a preferred embodiment, the sound-absorbing filler comprises 5-15 parts polyacrylonitrile fiber and 3-20 parts ceramsite by weight, providing more effective sound absorption, further improving the low-frequency damping material's sound absorption coefficient, and synergizing with the vibration-damping base material to enhance mechanical strength and high-temperature resistance.

[0030] To further improve the mechanical strength and component compatibility of the low-frequency damping material, in a preferred embodiment, the hard particles include sand and / or glass beads; and / or the dispersant includes polyvinyl alcohol and / or sodium dodecylbenzenesulfonate.

[0031] In a preferred embodiment, the low-frequency damping material also includes one or more of an antioxidant, a molding agent, and a hardener. The antioxidant can delay the oxidative aging of the material during preparation and use, protect the basic properties of the material from oxidation, and extend the service life of the material. The molding agent can improve the processing performance of the material, reduce the friction resistance during processing, and improve the surface quality and molding accuracy of the material. The hardener can undergo a cross-linking reaction with the polymer matrix during the curing process of the material, thereby enhancing the hardness, strength and durability of the material and improving the stability and chemical resistance of the material. The above components can further improve the comprehensive properties of the material, such as flexibility, anti-aging performance, hardness, surface quality, etc., on the basis of enhancing the sound absorption effect of the original components.

[0032] To better utilize the comprehensive performance-enhancing effects of the aforementioned additional components, the low-frequency damping material preferably further comprises, by weight, 0.5-2 parts of an antioxidant, 0.5-2 parts of a molding agent, and 0.5-2 parts of a hardener. For similar reasons, more preferably, the antioxidant comprises butylated hydroxybenzoate and / or bis(2,4-dimethylphenyl)trisiloxane; and / or the molding agent comprises calcium stearate and / or polyacrylate; and / or the hardener comprises an isocyanate crosslinking agent and / or hydrogen peroxide.

[0033] In another typical embodiment of the present invention, a method for preparing the low-frequency damping material of the present invention is also provided, comprising the following steps: step S1, mixing acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion and performing a first stirring to obtain a first mixture; step S2, adding polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles and carbon fiber to the first mixture, and adding a dispersant at the same time, and performing a second stirring to obtain a second mixture; step S3, molding the second mixture to obtain a molding material; step S4, curing the molding material to obtain a low-frequency damping material.

[0034] The present invention first mixes and stirs an acrylic emulsion, a polyurethane resin, a polyether polyol, a polyester resin, and a silicone rubber emulsion, and then evenly mixes the base polymer to obtain a first liquid mixture. Acoustic fillers such as polyacrylonitrile fiber and ceramsite, as well as expanded graphite, hard particles, and carbon fibers, are then added to the first mixture, along with a dispersant. After evenly stirring, a second mixture is obtained, which is then molded and cured to obtain the low-frequency damping material of the present invention. The above preparation method is simple and easy to operate. The resulting low-frequency damping material has low frequency dependence and temperature sensitivity, few material structure restrictions, and can be easily applied.

[0035] In a preferred embodiment, in step S1, the first stirring temperature is 20-30°C, the time is 25-35 minutes, and the speed is 200-400 rpm to fully mix the base material; in step S2, the second stirring temperature is 20-30°C, and the stirring is first carried out at 100-200 rpm for 5-10 minutes to avoid excessive dispersion of the added materials due to high-speed stirring, thereby affecting their effect; then, after the materials are basically mixed, the stirring speed can be increased to 400-600 rpm for 10-15 minutes to further ensure that the materials are fully mixed and achieve the desired uniformity; finally, when the stirring is about to end, the stirring speed can be reduced to 200-300 rpm for 5-10 minutes to reduce bubbles in the material and further improve the final properties of the material to obtain a second mixture. The above temperature can improve the fluidity of the liquid mixture and further promote the mutual dissolution and interaction of the components in the mixture; the above mixing time can further ensure that the components in the mixture are fully dissolved and mixed; the above stirring speed can better help accelerate the uniformity of the mixture and increase the dissolution rate, while avoiding excessive stirring speed to introduce too many bubbles and affect the quality of the mixture.

[0036] To make the low-frequency damping material more smoothly formed and better suited for most application scenarios, in a preferred embodiment, in step S3, the forming method includes coating and / or casting, and the forming material includes a plate, sheet, or plate-sheet composite material; in step S4, the curing includes static curing and oven curing, performed sequentially; preferably, the static curing temperature is 20-30°C for 22-26 hours; and / or the oven curing temperature is 55-65°C for 22-26 hours. Under these curing conditions, the low-frequency damping material can further form a continuous structure, thereby further improving the material's temperature resistance, mechanical strength, and flexibility.

[0037] In a preferred embodiment, step S3 further comprises: adding an antioxidant, a forming agent, and a hardener to the second mixture to obtain a preformed material, and molding the preformed material to obtain a molded material; preferably, the viscosity of the preformed material is 500 to 2000 Pa·s. In step S3, the antioxidant, forming agent, and hardener are added to the second mixture while continuously stirring to adjust the viscosity so that the mixture is suitable for subsequent processing, which can further improve the material's antioxidant properties, processing properties, and mechanical strength properties. The preformed material is then molded to obtain a molded material.

[0038] In another typical embodiment of the present invention, the application of the above-mentioned low-frequency damping material of the present invention in vibration reduction and noise reduction is also provided, such as as a vibration reduction and noise reduction material in mechanical equipment, automobiles, aircraft, engineering and construction fields, providing lower frequency dependence and temperature sensitivity, as well as smaller material structure restrictions, to play a vibration reduction and noise reduction role.

[0039] Typically, but not limited to, the weight ratio of the vibration damping substrate to the sound absorbing filler is 2.4:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 11.8:1 or a range consisting of any two of these values.

[0040] Typically, but not limited to, the weight ratio of the dispersant to the sound absorbing filler is 0.08:1, 0.1:1, 0.15:1, 0.2:1, or a range consisting of any two of these values.

[0041] Typically, but not limited to, the vibration damping substrate includes, by weight, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, or a range consisting of any two of their values, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts, or a range consisting of any two of their values, a polyurethane resin, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, or a range consisting of any two of their values, a polyether polyol, 5 parts, 8 parts, 10 parts, 12 parts, 10 parts, or a range consisting of any two of their values, a silicone rubber emulsion, 5 parts, 8 parts, 10 parts, 12 parts, 10 parts, or a range consisting of any two of their values, a polyester resin, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or a range consisting of any two of their values, expanded graphite, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, or a range consisting of any two of their values, hard particles, and 1 part, 2 parts, 3 parts, or a range consisting of any two of their values, of carbon fiber.

[0042] Typically, but not limiting, the sound-absorbing filler comprises, by weight, 5, 8, 10, 12, 15 parts of polyacrylonitrile fibers or a range consisting of any two of them and 3, 5, 10, 15, 18, 20 parts of ceramsite or a range consisting of any two of them.

[0043] Typically but not limiting, by weight, the low-frequency damping material further comprises 0.5 parts, 1 parts, 1.5 parts, 2 parts or a range consisting of any two of their values ​​of an antioxidant, 0.5 parts, 1 parts, 1.5 parts, 2 parts or a range consisting of any two of their values ​​of a molding agent, and 0.5 parts, 1 parts, 1.5 parts, 2 parts or a range consisting of any two of their values ​​of a hardener.

[0044] Typically but not limitatively, in step S1, the temperature of the first stirring is 20°C, 22°C, 24°C, 26°C, 28°C, 30°C or a range consisting of any two of them, the time is 25min, 26min, 28min, 30min, 32min, 34min, 35min or a range consisting of any two of them, and the speed is 200rpm, 250rpm, 300rpm, 350rpm, 400rpm or a range consisting of any two of them.

[0045] Typically but not limitatively, in step S2, the second stirring temperature is 20°C, 22°C, 24°C, 26°C, 28°C, 30°C or a range consisting of any two of them, and the mixture is first stirred at 100rpm, 120rpm, 140rpm, 160rpm, 180rpm, 200rpm or a range consisting of any two of them for 5min, 6min, 7min, 8min, 9min, 10min or a range consisting of any two of them, and then at 400rpm, 450rpm, 500rpm, 550rpm, 600rpm or a range consisting of any two of them for 10min, 11min, 12min, 13min, 14min, 15min or a range consisting of any two of them, and finally at 200rpm, 220rpm, 240rpm, 260rpm, 280rpm, 300rpm or a range consisting of any two of them for 5min, 6min, 7min, 8min, 9min, 10min or a range consisting of any two of them to obtain a second mixture.

[0046] Typically but not limitatively, in step S4, the static curing temperature is 20°C, 22°C, 24°C, 26°C, 28°C, 30°C or a range consisting of any two of them, and the time is 22h, 23h, 24h, 25h, 26h or a range consisting of any two of them; the oven curing temperature is 55°C, 56°C, 58°C, 60°C, 62°C, 64°C, 65°C or a range consisting of any two of them, and the time is 22h, 23h, 24h, 25h, 26h or a range consisting of any two of them.

[0047] Typically, but not limited to, the viscosity of the preform material is 500 Pa·s, 1000 Pa·s, 1500 Pa·s, 2000 Pa·s, or a range consisting of any two of these values.

[0048] The present application is further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application.

[0049] The material compositions of the following examples and comparative examples are shown in Table 1.

[0050] Example 1

[0051] Step S1, mixing corresponding parts by weight of acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion, and stirring at 300 rpm at 25° C. for 30 minutes to obtain a first mixture;

[0052] Step S2, adding corresponding parts by weight of polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles (glass beads) and carbon fiber to the first mixture in sequence, and adding corresponding parts by weight of a dispersant (polyvinyl alcohol), stirring at 25° C., first at 150 rpm for 8 min, then at 500 rpm for 12 min, and finally at 250 rpm for 8 min to obtain a second mixture;

[0053] Step S3, adding corresponding parts by weight of an antioxidant (butylated hydroxybenzoate), a forming agent (calcium stearate), and a hardener (isocyanate crosslinking agent) to the second mixture to obtain a preformed material with a viscosity of 865 Pa·s; coating and / or casting the preformed material to obtain a plate;

[0054] Step S4, curing the plate at 25° C. for 24 hours, and then putting it into an oven for curing at 60° C. for 24 hours to obtain a low-frequency damping material.

[0055] Examples 2 to 7

[0056] The difference from Example 1 is that the material composition is different, see Table 1 for details.

[0057] Example 8

[0058] The difference from Example 1 is that

[0059] In step S1, corresponding weight portions of acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion are mixed and stirred at 20° C. at a speed of 200 for 35 minutes to obtain a first mixture;

[0060] In step S2, corresponding parts by weight of polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles (glass beads) and carbon fiber are added to the first mixture in sequence, and corresponding parts by weight of dispersant (polyvinyl alcohol) are added at the same time. The mixture is stirred at 20°C, first at 100 rpm for 10 min, then at 400 rpm for 15 min, and finally at 200 rpm for 10 min to obtain a second mixture.

[0061] Example 9

[0062] The difference from Example 1 is that

[0063] In step S1, corresponding weight portions of acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion are mixed and stirred at 400° C. for 25 minutes to obtain a first mixture;

[0064] In step S2, corresponding parts by weight of polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles (glass beads) and carbon fiber are added to the first mixture in sequence, and corresponding parts by weight of dispersant (polyvinyl alcohol) are added at the same time. The mixture is stirred at 30°C, first at 200 rpm for 5 minutes, then at 600 rpm for 10 minutes, and finally at 300 rpm for 5 minutes to obtain a second mixture.

[0065] Example 10

[0066] The difference from Example 1 is that in step S4, the plate is cured at 20° C. for 26 hours and then put into an oven for curing at 55° C. for 26 hours to obtain a low-frequency damping material.

[0067] Example 11

[0068] The difference from Example 1 is that in step S4, the plate is cured at 30° C. for 22 hours and then put into an oven for curing at 65° C. for 22 hours to obtain a low-frequency damping material.

[0069] Example 12

[0070] Step S1, mixing corresponding parts by weight of acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion, and stirring at 300° C. and 25° C. for 30 minutes to obtain a first mixture;

[0071] Step S2, adding corresponding weight parts of polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles (sand) and carbon fiber to the first mixture in sequence, and adding corresponding weight parts of dispersant (sodium dodecylbenzenesulfonate), stirring at 25° C., first at 150 rpm for 8 min, then at 500 rpm for 12 min, and finally at 250 rpm for 8 min to obtain a second mixture;

[0072] Step S3, adding corresponding parts by weight of an antioxidant (bis(2,4-dimethylphenyl)trisiloxane), a molding agent (polyacrylate), and a hardener (hydrogen peroxide) to the second mixture to obtain a preformed material having a viscosity of 945 Pa·s; coating and / or casting the preformed material to obtain a sheet material;

[0073] Step S4, curing the sheet material at 25° C. for 24 hours, and then putting it into an oven for curing at 60° C. for 24 hours to obtain a low-frequency damping material.

[0074] Comparative Example 1

[0075] The difference from Example 1 is that the material does not contain polyether polyol.

[0076] Comparative Example 2

[0077] The difference from Example 1 is that the material does not contain polyacrylonitrile fibers.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that the material does not contain ceramsite.

[0080] Comparative Example 4

[0081] The difference from Example 1 is that the material contains 20 parts of polyacrylonitrile fiber and 25 parts of ceramsite.

[0082] Comparative Example 5

[0083] The difference from Example 1 is that the material contains 3 parts of polyacrylonitrile fiber and 1 part of ceramsite.

[0084] The damping materials prepared in the above examples and comparative examples were tested for sound absorption coefficient, tensile strength, and heat resistance. The results are shown in Table 2.

[0085] Test method:

[0086] Sound absorption coefficient: GB / T18696.2-2002 Acoustic impedance tubes - Measurement of sound absorption coefficient and acoustic impedance - Part 2 - Transfer function method Tensile strength: GB / T 528-2009 Vulcanized rubber or thermoplastic rubber - Determination of tensile stress-strain properties Heat resistance: GB / T3512-2014 Vulcanized rubber or thermoplastic rubber - Hot air accelerated aging and heat resistance test

[0087] Table 1

[0088]

[0089] Table 2

[0090]

[0091]

[0092] As can be seen from the above, compared with the comparative example, the embodiments of the present invention achieve the effect of effectively blocking noise in a wide frequency range by rationally designing the damping material formula, and the sound absorption coefficient of the damping material is significantly improved; and the stability of the material in high and low temperature environments is fully considered, so that it has excellent heat resistance and low temperature resistance, and the sound insulation effect of the material is stable and reliable; at the same time, it has higher customizability and adaptability, and can be flexibly designed and customized according to the needs of different application scenarios to meet the needs of different fields.

[0093] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A low-frequency damping material, characterized in that: including vibration-damping substrates, sound-absorbing fillers, and dispersants; The vibration-damping substrate comprises, by weight, 30 to 50 parts of acrylic emulsion, 10 to 20 parts of polyurethane resin, 5 to 15 parts of polyether polyol, 5 to 10 parts of silicone rubber emulsion, 5 to 10 parts of polyester resin, 1 to 5 parts of expanded graphite, 1 to 5 parts of hard particles, and 1 to 3 parts of carbon fiber. The sound-absorbing filler comprises polyacrylonitrile fiber and ceramsite; in parts by weight, the sound-absorbing filler comprises 5 to 15 parts of the polyacrylonitrile fiber and 3 to 20 parts of the ceramsite; The weight ratio of the vibration-damping substrate to the sound-absorbing filler is (2.4-11.8):

1.

2. The low-frequency damping material according to claim 1, characterized in that: The weight ratio of the dispersant to the sound-absorbing filler is (0.08-0.2):

1.

3. The low-frequency damping material according to claim 1 or 2, characterized in that: The hard particles include sand and / or glass beads; and / or The dispersant includes polyvinyl alcohol and / or sodium dodecylbenzene sulfonate.

4. The low-frequency damping material according to claim 1 or 2, characterized in that: The low-frequency damping material further comprises one or more of an antioxidant, a shaping agent and a hardening agent.

5. The low-frequency damping material according to claim 4, characterized in that: In parts by weight, the low-frequency damping material further includes 0.5 to 2 parts of the antioxidant, 0.5 to 2 parts of the molding agent and 0.5 to 2 parts of the hardener.

6. The low-frequency damping material according to claim 5, characterized in that: The antioxidant includes butyl hydroxybenzoate and / or bis(2,4-dimethylphenyl)trisiloxane; and / or the forming agent includes calcium stearate and / or polyacrylate; and / or the hardening agent includes an isocyanate crosslinking agent and / or hydrogen peroxide.

7. The method for preparing the low-frequency damping material according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step S1, mixing acrylic emulsion, polyurethane resin, polyether polyol, polyester resin and silicone rubber emulsion, and performing a first stirring to obtain a first mixture; Step S2, adding polyacrylonitrile fiber, ceramsite, expanded graphite, hard particles and carbon fiber to the first mixture, adding a dispersant, and performing a second stirring to obtain a second mixture; Step S3, molding the second mixture to obtain a molding material; Step S4: solidifying the molding material to obtain the low-frequency damping material.

8. The preparation method according to claim 7, characterized in that In step S1, the first stirring temperature is 20-30°C, the time is 25-35 min, and the speed is 200-400 rpm; In step S2, the second stirring temperature is 20-30° C., the stirring is first performed at 100-200 rpm for 5-10 min, then at 400-600 rpm for 10-15 min, and finally at 200-300 rpm for 5-10 min to obtain the second mixture; In step S3, the molding method includes coating and / or casting, and the molding material includes a plate, a sheet, or a plate-sheet composite material; In the step S4, the curing includes static curing and oven curing performed sequentially.

9. The preparation method according to claim 8, characterized in that The temperature of the static curing is 20-30° C., and the time is 22-26 h; and / or the temperature of the oven curing is 55-65° C., and the time is 22-26 h.

10. The preparation method according to claim 7 or 8, characterized in that: The step S3 further includes: adding an antioxidant, a molding agent, and a hardener to the second mixture to obtain a pre-molded material, and molding the pre-molded material to obtain the molded material.

11. The preparation method according to claim 10, characterized in that: The viscosity of the preform material is 500-2000 Pa·s.

12. Use of the low-frequency damping material according to any one of claims 1 to 6 in vibration and noise reduction.

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