Polyurethane elastomer sound insulation pad

Abstract

The invention provides a polyurethane elastomer sound insulation pad, and relates to the technical field of sound insulation materials. The polyurethane elastomer sound insulation pad is prepared from components in parts by weight as follows: 50-100 parts of polyether polyol, 20-60 parts of isocyanate, 5-20 parts of a foaming agent, 1-5 parts of a catalyst, 10-30 parts of filler and 1-10 parts of an aid. Through the gradient density design, broadband noise is blocked, and meanwhile the composite material has the advantages of being light, flexible, good in weather resistance and the like. According to the preparation method, a multi-layer gradient foaming process is adopted, and a stable density gradient structure is formed by regulating and controlling the raw material ratio and foaming parameters. The problems that a traditional uniform-density sound insulation pad is low in sound insulation efficiency and large in weight under broadband noise are solved, and the sound insulation pad can be widely applied to the scene of building floating floor sound insulation.

Description

Technical Field

[0001] The invention relates to the technical field of sound insulation materials, in particular to a polyurethane elastomer sound insulation pad. Background Art

[0002] With the development of modern industry and transportation, noise pollution has become increasingly prominent. Sound insulation mats, as a commonly used noise reduction material, are widely used in the construction field. Traditional polyurethane sound insulation mats usually adopt a uniform density structure, and their sound insulation performance mainly depends on the surface density of the material (mass law), that is, the higher the density, the better the sound insulation effect. However, this uniform density structure has the following shortcomings:

[0003] 1. Low broadband sound insulation efficiency: Uniform density materials have a good effect on blocking noise of specific frequencies, but their comprehensive sound insulation capacity for broadband noise (especially low-frequency and high-frequency noise) is limited, making it difficult to meet the needs of complex noise environments.

[0004] 2. Heavy weight: In order to improve the sound insulation, the material density or thickness needs to be increased, which leads to a significant increase in the weight of the sound insulation pad, which is not conducive to the application of sound insulation scenarios in floating floor slabs of buildings.

[0005] 3. Poor flexibility: High-density polyurethane materials tend to be hard and lack flexibility, making them difficult to adapt to the paving of complex curved surfaces, and are prone to cracking due to vibration during long-term use.

[0006] To address these issues, existing technologies have developed gradient-structured sound insulation materials. These materials are typically segmented and layered, resulting in distinct interfaces that easily reflect sound. Furthermore, the density gradient cannot be adjusted, making broadband optimization difficult. Furthermore, the preparation process for existing gradient materials is complex and costly, making them difficult to scale up. Therefore, there is an urgent need to develop a new type of sound insulation mat with a rational structural design, simple preparation process, and the combined properties of broadband sound insulation and lightweight flexibility. Summary of the Invention

[0007] (1) Technical problems solved

[0008] In response to the shortcomings of the existing technology, the present invention provides a polyurethane elastomer sound insulation pad, which achieves broadband noise isolation through gradient density design, while solving the problems of heavy weight and poor flexibility of traditional sound insulation pads.

[0009] (2) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical scheme: a polyurethane elastomer sound insulation pad, comprising the following components by weight: 50-100 parts of polyether polyol, 20-60 parts of isocyanate, 5-20 parts of foaming agent, 1-5 parts of catalyst, 10-30 parts of filler, and 1-10 parts of auxiliary agent.

[0011] Preferably, the polyurethane elastomer sound insulation pad comprises the following components in parts by weight: 80 parts of polyether polyol, 40 parts of isocyanate, 10 parts of foaming agent, 3 parts of catalyst, 20 parts of filler, and 5 parts of auxiliary agent, wherein the polyether polyol is polyoxypropylene polyol or polytetramethylene glycol polyol, and the hydroxyl value is 20-500 mgKOH / g; the isocyanate is TDI, MDI or a mixture thereof, and the isocyanate index is 0.8-1.2.

[0012] Preferably, the foaming agent includes a physical foaming agent and a chemical foaming agent, and the mass ratio thereof is 1:0.5-2.

[0013] Preferably, the filler comprises 10-30% by weight of expanded graphite or hollow glass microspheres.

[0014] Preferably, the auxiliary agent includes a stabilizer and a flame retardant, wherein the flame retardant enables the combustion performance of the sound insulation mat to reach B1 level.

[0015] Preferably, the sound insulation pad has a density gradient distribution along the thickness direction, and the density from the first surface to the second surface shows a monotonically increasing or decreasing trend, or a gradient change of first increasing and then decreasing, or first decreasing and then increasing, and the density range is 50-800 kg / m 3 , density gradient change rate is 5-50kg / m 3 ·mm; the closed porosity of the sound insulation pad is ≥65%, and the average sound insulation in the frequency range of 125-4000Hz is ≥25dB.

[0016] Preferably, the density gradient is a continuous gradient or a segmented gradient, wherein the segmented gradient has 2 to 10 layers and the density difference of each layer is 10 to 100 kg / m 3 , and the interface bonding between adjacent layers is achieved through a transition layer, and the thickness of the transition layer is 0.1-2mm.

[0017] Preferably, the sound insulation pad is a multi-layer composite structure, including a sound insulation layer, an elastic layer, a membrane layer and a sound absorption layer stacked in sequence, wherein the sound insulation layer is an EPDM film or a PE / EVA layer, the sound absorption layer is a flame-retardant PET cotton felt, and the membrane layer is a polyethylene film with rectangular holes distributed on the surface.

[0018] The present invention further discloses a method for preparing a polyurethane elastomer sound insulation pad, which is based on the polyurethane elastomer sound insulation pad described above and comprises the following steps:

[0019] Step 1: Preparation:

[0020] Prepare multiple sets of polyurethane raw material systems with different densities, and adjust the amount of blowing agent, filler content or isocyanate index to form a gradient in the theoretical foaming density of each set of raw materials;

[0021] Step 2: Injection:

[0022] Each group of raw materials is injected into the mold in sequence, and a dynamic gradient casting process or a layered casting process is adopted to form a density gradient along the thickness direction in the mold;

[0023] Step 3: Molding:

[0024] The foaming temperature is controlled to be 20-80° C. and the curing time is 1-24 hours. The foaming and curing are completed to obtain the polyurethane elastomer sound insulation pad.

[0025] Preferably, in the dynamic gradient casting process, the raw material injection speed is 0.1-5 m / s, and the pressure in the mold is 0.1-1 MPa.

[0026] (3) Beneficial effects

[0027] The present invention provides a polyurethane elastomer sound insulation pad, which has the following beneficial effects:

[0028] 1. The density gradient structure can block both low-frequency and high-frequency noise at the same time. The average sound insulation in the range of 125-4000Hz is ≥25dB, which is 10-15dB higher than that of traditional uniform density sound insulation pads.

[0029] 2. Compared with uniform density materials with the same sound insulation, the weight is reduced by 20-40%, and it has good flexibility (elongation at break ≥ 300%), and can adapt to paving on complex curved surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the preparation method of the present invention;

[0031] Figure 2 It is a schematic structural diagram of the sound insulation pad of the present invention.

[0032] Among them, 1. Sound insulation layer; 2. Elastic layer; 3. Membrane layer; 4. Sound absorption layer. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] Example 1:

[0035] An embodiment of the present invention provides a polyurethane elastomer sound insulation pad, comprising the following components in parts by weight: 50 parts of polyether polyol, 20 parts of isocyanate, 5 parts of foaming agent, 1 part of catalyst, 10 parts of filler (such as calcium carbonate, talc), and 1 part of auxiliary agent, wherein the polyether polyol is polyoxypropylene polyol with a hydroxyl value of 100 mgKOH / g; the isocyanate is MDI with an isocyanate index of 1.0.

[0036] The foaming agent is a physical foaming agent; the filler includes 20% by weight of expanded graphite; the auxiliary agent includes a stabilizer and a flame retardant, wherein the flame retardant enables the combustion performance of the sound insulation mat to reach B1 level.

[0037] The sound insulation pad has a density gradient distribution along the thickness direction. The density from the first surface to the second surface shows a monotonically increasing or decreasing trend, or a gradient change from increasing first to decreasing, or first decreasing to increasing. The density range is 100kg / m 3 , the density gradient change rate is 20kg / m 3 ·mm; the closed porosity of the sound insulation pad is ≥65%, and the average sound insulation within the frequency range of 125Hz is ≥25dB.

[0038] The density gradient is a continuous gradient or a segmented gradient, wherein the segmented gradient has two layers and the density difference of each layer is 10 kg / m 3 , and the interface bonding between adjacent layers is achieved through a transition layer, and the thickness of the transition layer is 0.1mm.

[0039] Further, such as Figure 2 As shown, the sound insulation pad is a multi-layer composite structure, including a sound insulation layer 1, an elastic layer 2, a membrane layer 3 and a sound absorption layer 4 stacked in sequence, wherein the sound insulation layer is an EPDM film, the sound absorption layer is a flame-retardant PET cotton felt, and the membrane layer is a polyethylene film with rectangular holes distributed on the surface.

[0040] like Figure 1 As shown, an embodiment of the present invention further provides a method for preparing a polyurethane elastomer sound insulation pad, based on the polyurethane elastomer sound insulation pad described above, comprising the following steps:

[0041] Step 1: Preparation:

[0042] Prepare multiple sets of polyurethane raw material systems with different densities, and adjust the amount of blowing agent, filler content or isocyanate index to form a gradient in the theoretical foaming density of each set of raw materials;

[0043] Step 2: Injection:

[0044] Each group of raw materials is injected into the mold in sequence, and a dynamic gradient casting process or a layered casting process is used to form a density gradient along the thickness direction in the mold; wherein, in the dynamic gradient casting process, the raw material injection speed is 0.1m / s and the pressure in the mold is 0.1MPa;

[0045] Step 3: Molding:

[0046] The foaming temperature was controlled to be 20° C. and the curing time was 1 h. The foaming and curing were completed to obtain a polyurethane elastomer sound insulation pad.

[0047] Example 2:

[0048] An embodiment of the present invention provides a polyurethane elastomer sound insulation pad, comprising the following components in parts by weight: 80 parts of polyether polyol, 40 parts of isocyanate, 10 parts of a foaming agent, 3 parts of a catalyst, 20 parts of a filler (such as calcium carbonate or talc), and 5 parts of an additive, wherein the polyether polyol is polytetramethylene glycol polyol having a hydroxyl value of 100 mgKOH / g; the isocyanate is a mixture of TDI and MDI having an isocyanate index of 1.0.

[0049] Among them, the foaming agent includes a physical foaming agent and a chemical foaming agent, and the mass ratio thereof is 1:1; the filler includes 20% by weight of expanded graphite; the auxiliary agent includes a stabilizer and a flame retardant, among which the flame retardant makes the combustion performance of the sound insulation pad reach B1 level.

[0050] The sound insulation pad has a density gradient distribution along the thickness direction. The density from the first surface to the second surface shows a monotonically increasing or decreasing trend, or a gradient change from increasing first to decreasing, or first decreasing to increasing. The density range is 400kg / m 3 , the density gradient change rate is 30kg / m 3 ·mm; the closed porosity of the sound insulation pad is ≥65%, and the average sound insulation within the frequency range of 2000 Hz is ≥25dB.

[0051] The density gradient is a continuous gradient or a segmented gradient, wherein the segmented gradient has 5 layers and the density difference of each layer is 50 kg / m 3 , and the interface bonding between adjacent layers is achieved through a transition layer, and the thickness of the transition layer is 1mm.

[0052] Further, such as Figure 2 As shown, the sound insulation pad is a multi-layer composite structure, including a sound insulation layer 1, an elastic layer 2, a membrane layer 3 and a sound absorption layer 4 stacked in sequence, wherein the sound insulation layer is a PE / EVA layer, the sound absorption layer is a flame-retardant PET cotton felt, and the membrane layer is a polyethylene film with rectangular holes distributed on the surface.

[0053] like Figure 1 As shown, an embodiment of the present invention further provides a method for preparing a polyurethane elastomer sound insulation pad, based on the polyurethane elastomer sound insulation pad described above, comprising the following steps:

[0054] Step 1: Preparation:

[0055] Prepare multiple sets of polyurethane raw material systems with different densities, and adjust the amount of blowing agent, filler content or isocyanate index to form a gradient in the theoretical foaming density of each set of raw materials;

[0056] Step 2: Injection:

[0057] Each group of raw materials is injected into the mold in sequence, and a dynamic gradient casting process or a layered casting process is used to form a density gradient along the thickness direction in the mold. In the dynamic gradient casting process, the raw material injection speed is 3m / s and the pressure in the mold is 0.5MPa.

[0058] Step 3: Molding:

[0059] The foaming temperature was controlled to be 50° C. and the curing time was controlled to be 12 h. The foaming and curing were completed to obtain a polyurethane elastomer sound insulation pad.

[0060] Example 3:

[0061] An embodiment of the present invention provides a polyurethane elastomer sound insulation pad with a continuously increasing density gradient, comprising the following components in parts by weight:

[0062] Component A (low-density layer raw material): 100 parts of polyoxypropylene polyol (hydroxyl value 100 mgKOH / g), 30 parts of MDI, 15 parts of carbon dioxide foaming agent, 0.5 parts of stannous octoate catalyst, and 1 part of silicone oil stabilizer;

[0063] Component B (high-density layer raw material): 100 parts of polyoxypropylene polyol (hydroxyl value 100 mgKOH / g), 40 parts of MDI, 5 parts of carbon dioxide foaming agent, 0.5 parts of stannous octoate catalyst, 20 parts of calcium carbonate filler, and 1 part of silicone oil stabilizer.

[0064] The sound insulation pad has a density gradient distribution along the thickness direction. The density from the first surface to the second surface shows a monotonically increasing or decreasing trend, or a gradient change from increasing first to decreasing, or first decreasing to increasing. The density range is 400kg / m 3 , the density gradient change rate is 30kg / m 3 ·mm; the closed porosity of the sound insulation pad is ≥65%, and the average sound insulation within the frequency range of 2000 Hz is ≥25dB.

[0065] Further, such as Figure 2 As shown, the sound insulation pad is a multi-layer composite structure, including a sound insulation layer 1, an elastic layer 2, a membrane layer 3 and a sound absorption layer 4 stacked in sequence, wherein the sound insulation layer is an EPDM film, the sound absorption layer is a flame-retardant PET cotton felt, and the membrane layer is a polyethylene film with rectangular holes distributed on the surface.

[0066] An embodiment of the present invention further provides a method for preparing a polyurethane elastomer sound insulation pad with a continuously increasing density gradient, based on the polyurethane elastomer sound insulation pad with a continuously increasing density gradient as described above, comprising the following steps:

[0067] Using a two-component dynamic extruder, component A and component B were gradually transferred from a flow ratio of 1:0 to 0:1 (completed within 30 seconds), injected into a mold with a size of 300mm×300mm×10mm, and cured at 60℃ for 2h. The resulting sound insulation pad had a density of 80kg / m along the thickness direction. 3 Continuously increase to 300kg / m 3 , the gradient change rate is 22kg / m 3 ·mm.

[0068] Example 4:

[0069] An embodiment of the present invention provides a three-stage density gradient polyurethane elastomer sound insulation pad, comprising the following components in parts by weight:

[0070] Upper layer (low density): 100 parts of polytetramethylene glycol (hydroxyl value 200 mgKOH / g), 25 parts of TDI, 20 parts of pentane blowing agent, 0.3 parts of triethylenediamine catalyst, and 1 part of stabilizer;

[0071] Middle layer (medium density): 100 parts of polytetramethylene ether polyol, 35 parts of TDI, 10 parts of pentane foaming agent, 0.3 parts of catalyst, 10 parts of calcium carbonate filler, 1 part of stabilizer;

[0072] Lower layer (high density): 100 parts of polytetramethylene glycol, 45 parts of TDI, 5 parts of pentane foaming agent, 0.3 parts of catalyst, 20 parts of calcium carbonate filler, and 1 part of stabilizer.

[0073] The sound insulation pad has a density gradient distribution along the thickness direction. The density from the first surface to the second surface shows a monotonically increasing or decreasing trend, or a gradient change from increasing first to decreasing, or first decreasing to increasing. The density range is 800kg / m 3 , the density gradient change rate is 50kg / m 3 ·mm; the closed porosity of the sound insulation pad is ≥65%, and the average sound insulation within the frequency range of 4000 Hz is ≥25dB.

[0074] Further, such as Figure 2 As shown, the sound insulation pad is a multi-layer composite structure, including a sound insulation layer 1, an elastic layer 2, a membrane layer 3 and a sound absorption layer 4 stacked in sequence, wherein the sound insulation layer is a PE / EVA layer, the sound absorption layer is a flame-retardant PET cotton felt, and the membrane layer is a polyethylene film with rectangular holes distributed on the surface.

[0075] An embodiment of the present invention further provides a method for preparing a three-stage density gradient polyurethane elastomer sound insulation pad, based on the above-mentioned three-stage density gradient polyurethane elastomer sound insulation pad, comprising the following steps:

[0076] First, inject the upper layer material into the mold, wait for initial foaming (5 minutes), then inject the middle layer material, and then inject the lower layer material after 5 minutes, and cure at 40℃ for 4 hours. The resulting sound insulation pad has a thickness of 15mm and an upper layer density of 60kg / m 3 , middle layer 150kg / m 3 , lower layer 350kg / m 3 , the segmented density difference is 90kg / m 3 and 200kg / m 3 .

[0077] Comparative example: Uniform density polyurethane sound insulation pad:

[0078] The same raw materials as in Example 3 were used, and the amount of foaming agent was adjusted to make the density uniform at 180 kg / m 3 , prepare 10mm thick sound insulation pad.

[0079] Experimental example:

[0080] The performance of the sound insulation pads prepared in Example 3, Example 4 and the comparative example was tested, and the results are shown in the following table:

[0081] Group Average sound insulation (dB) Weight (kg / ㎡) Elongation at break (%) Example 3 28 2.5 350 Example 4 28 2.8 320 Comparative Example 22 3.6 190

[0082] In summary, the sound insulation mat prepared by the present invention can effectively improve sound insulation performance, achieve a high average sound insulation value over a wide frequency range, and has a high closed-cell ratio, which can better prevent sound propagation. At the same time, the density gradient design and the use of a multi-layer composite structure reduce the weight of the sound insulation mat, improve the elongation at break, and enhance the flexibility and durability of the material while ensuring the sound insulation effect. In addition, the preparation method provided by the present invention is flexible and diverse, and sound insulation mats with different density gradients and structures can be prepared according to different needs. It has strong practicality and operability and can be widely used in places where floating floor slabs in buildings are soundproofed.

[0083] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A polyurethane elastomer sound insulation pad, characterized by: The invention comprises the following components in parts by weight: 50-100 parts of polyether polyol, 20-60 parts of isocyanate, 5-20 parts of foaming agent, 1-5 parts of catalyst, 10-30 parts of filler and 1-10 parts of auxiliary agent.

2. The polyurethane elastomer sound insulation pad according to claim 1, characterized in that: The invention comprises the following components in parts by weight: 80 parts of polyether polyol, 40 parts of isocyanate, 10 parts of foaming agent, 3 parts of catalyst, 20 parts of filler and 5 parts of auxiliary agent, wherein the polyether polyol is polyoxypropylene polyol or polytetramethylene glycol polyol, and the hydroxyl value is 20-500 mgKOH / g; the isocyanate is TDI, MDI or a mixture thereof, and the isocyanate index is 0.8-1.

2.

3. The polyurethane elastomer sound insulation pad according to claim 2, characterized in that: The foaming agent includes a physical foaming agent and a chemical foaming agent, and the mass ratio thereof is 1:0.5-2.

4. The polyurethane elastomer sound insulation pad according to claim 2, characterized in that: The filler comprises 10-30% by weight of expanded graphite or hollow glass microspheres.

5. The polyurethane elastomer sound insulation pad according to claim 2, characterized in that: The auxiliary agent includes a stabilizer and a flame retardant, wherein the flame retardant enables the combustion performance of the sound insulation mat to reach B1 level.

6. The polyurethane elastomer sound insulation pad according to any one of claims 1 to 5, characterized in that: The sound insulation pad has a density gradient distribution along the thickness direction. The density from the first surface to the second surface shows a monotonically increasing or decreasing trend, or a gradient change of first increasing and then decreasing, or first decreasing and then increasing. The density range is 50-800 kg / m 3 , density gradient change rate is 5-50kg / m 3 ·mm; the closed porosity of the sound insulation pad is ≥65%, and the average sound insulation in the frequency range of 125-4000Hz is ≥25dB.

7. The polyurethane elastomer sound insulation pad according to claim 6, characterized in that: The density gradient is a continuous gradient or a segmented gradient, wherein the number of segments is 2-10 layers, and the density difference of each layer is 10-100 kg / m 3 , and the interface bonding between adjacent layers is achieved through a transition layer, and the thickness of the transition layer is 0.1-2mm.

8. The polyurethane elastomer sound insulation pad according to claim 6, characterized in that: The sound insulation pad is a multi-layer composite structure, including a sound insulation layer, an elastic layer, a membrane layer and a sound absorption layer stacked in sequence, wherein the sound insulation layer is an EPDM film or a PE / EVA layer, the sound absorption layer is a flame-retardant PET cotton felt, and the membrane layer is a polyethylene film with rectangular holes distributed on the surface.

9. A method for preparing a polyurethane elastomer sound insulation pad, based on the polyurethane elastomer sound insulation pad according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Preparation: Prepare multiple sets of polyurethane raw material systems with different densities, and adjust the amount of blowing agent, filler content or isocyanate index to form a gradient in the theoretical foaming density of each set of raw materials; Step 2: Injection: Each group of raw materials is injected into the mold in sequence, and a dynamic gradient casting process or a layered casting process is adopted to form a density gradient along the thickness direction in the mold; Step 3: Molding: The foaming temperature is controlled to be 20-80° C. and the curing time is 1-24 hours. The foaming and curing are completed to obtain the polyurethane elastomer sound insulation pad.

10. The method for preparing a polyurethane elastomer sound insulation pad according to claim 9, characterized in that: In the dynamic gradient casting process, the raw material injection speed is 0.1-5 m / s, and the pressure in the mold is 0.1-1 MPa.

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