Water-based polymer composite sound-absorbing and sound-insulating paint and preparation method thereof

Abstract

The present application belongs to the technical field of high polymer and functional coating, and particularly relates to a water-based high polymer composite sound-absorbing and sound-insulating coating and a preparation method thereof. The composite sound-absorbing and sound-insulating coating comprises the following components in parts by weight: 20-40 parts of a silicone-acrylate emulsion; 15-30 parts of porous sound-absorbing fillers; 20-40 parts of high-density sound-insulating fillers; 5-10 parts of a crosslinking acrylate coated butyl rubber core-shell emulsion; 1-8 parts of functional additives; and 10-25 parts of deionized water. The porous sound-absorbing fillers, the high-density sound-insulating fillers and the butyl rubber elastic damping material are used in combination, so that the sound-absorbing coefficient and the sound-insulating volume of the coating can be improved. The core-shell coating treatment of butyl rubber by the crosslinking acrylate can significantly improve the adhesion, flexibility and alkali resistance of the coating, and also has an improving effect on the acoustic performance of the coating.

Description

A water-based polymer composite sound-absorbing and sound-insulating coating and its preparation method Technical Field

[0001] This invention belongs to the field of polymer and functional coating technology, specifically relating to a water-based polymer composite sound-absorbing and sound-insulating coating and its preparation method. Background Technology

[0002] With the acceleration of urbanization, the expansion of industrial production, and the increase in traffic flow, noise pollution (such as indoor building noise, traffic noise, and industrial equipment noise) has become a significant issue affecting the living environment and production efficiency. Statistics show that the compliance rate of urban environmental noise in my country is less than 70%. Low-frequency noise (such as elevator noise, air conditioner outdoor units, and low-frequency vibrations from traffic) has a particularly significant impact on human health (such as sleep disorders and cardiovascular diseases) due to its long propagation distance and slow attenuation, creating an urgent need for efficient and convenient noise reduction materials.

[0003] Traditional noise reduction materials are mainly divided into sound-absorbing materials (such as glass wool, rock wool, and porous foam) and sound-insulating materials (such as sound insulation boards, metal sheets, and sealing strips), but they have significant drawbacks:

[0004] Sound-absorbing materials rely on porous structures to convert sound energy into heat energy through air viscosity resistance and friction. They have a good absorption effect on mid-to-high frequency sound waves (>1000Hz), but their low-frequency sound absorption ability is weak (low-frequency wavelengths are longer, requiring materials with large thickness or resonant structures). They also have problems such as complicated installation (requiring keel fixation), large space occupation (thickness is usually >50mm), easy generation of dust (such as glass wool), and poor environmental performance (some contain formaldehyde).

[0005] Sound insulation materials: Based on the "law of mass" (the higher the surface density, the better the sound insulation effect), such as concrete walls and lead plates, although they can block sound waves, are heavy (e.g., a 100mm thick concrete wall weighs approximately 240kg / m²). 2 It has high construction difficulty (requiring on-site pouring or splicing), poor flexibility (difficult to adapt to curved / irregular substrates), and cannot absorb sound waves (easily leading to sound reflection and secondary noise).

[0006] Sound-absorbing and sound-insulating coatings are composite materials composed of sound-insulating materials, sound-absorbing materials, and polymers. As a lightweight and convenient alternative to traditional noise reduction materials, sound-absorbing and sound-insulating coatings have broad application prospects due to their strong adaptability and small space occupation. Although sound-absorbing and sound-insulating coatings solve some of the pain points of traditional materials, their technological maturity is still relatively low. Existing products still have significant shortcomings in acoustic performance (it is difficult to achieve both sound absorption and sound insulation), physical and mechanical properties (weak adhesion, insufficient flexibility, poor water resistance; the substrate is prone to cracking due to thermal expansion and contraction, and blistering and peeling are prone to occur on damp substrates, resulting in loss of sound insulation and sealing), construction efficiency (requiring multi-layer structures and multi-layer coatings, making construction complex), and cost control (some products use nanoporous materials, such as aerogel, which are costly). Summary of the Invention

[0007] In view of the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a water-based polymer composite sound-absorbing and sound-insulating coating.

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned water-based polymer composite sound-absorbing and sound-insulating coating.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A water-based polymer composite sound-absorbing and sound-insulating coating, comprising the following components in parts by weight:

[0011] 20-40 parts of silicone-acrylic emulsion;

[0012] 15-30 parts of porous sound-absorbing filler;

[0013] 20-40 parts of high-density sound insulation filler;

[0014] 5-10 parts of cross-linked acrylate-coated butyl rubber core-shell emulsion;

[0015] Functional additives 1-8 parts;

[0016] 10-25 parts deionized water.

[0017] Preferably, the silicone-acrylic emulsion is prepared by the following method:

[0018] The emulsifier is added to a reaction vessel containing deionized water and heated and stirred to dissolve. Then, acrylate monomers, acrylic monomers, and silane coupling agent monomers are added and mixed and emulsified to obtain a monomer emulsion. Then, an initiator solution is added dropwise and the reaction is kept at a constant temperature to obtain a silicone-acrylic emulsion.

[0019] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the emulsifier is one or more of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and nonylphenol polyoxyethylene ether; the amount of emulsifier added is 3-6% of the mass of deionized water.

[0020] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the temperature of the heating, stirring, dissolving, and heat-preserving copolymerization reaction is 60-80℃.

[0021] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the acrylate monomer is one or more of methyl methacrylate, ethyl acrylate, and butyl acrylate; the amount of acrylate monomer added is 40-60% of the mass of the acrylate monomer.

[0022] The main function of the acrylate monomer in this invention is to coordinate the hardness and flexibility of the coating film and improve its water resistance.

[0023] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the acrylic monomer is one or both of acrylic acid and methacrylic acid.

[0024] The main function of the acrylic monomer in this invention is to improve the adhesion of the coating.

[0025] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the silane coupling agent monomer is one or two of methacryloyloxypropyltrimethoxysilane and vinyltriethoxysilane; the amount of silane coupling agent monomer added is 10-20% of the mass of the acrylic monomer.

[0026] The main functions of the silane coupling agent monomer of this invention are, on the one hand, to improve the interfacial bonding force with the sound-absorbing and sound-insulating filler through the hydrolyzed silanol groups, thereby preventing the coating from cracking or the filler from falling off; on the other hand, to improve the water resistance and strength of the coating through the micro-crosslinking of the hydrolyzed silanol groups.

[0027] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the solid content of the monomer emulsion is 40-60%.

[0028] Preferably, in the preparation of the above-mentioned silicone-acrylic emulsion, the initiator is potassium persulfate or ammonium persulfate, and the total amount of initiator added is 0.3-0.6% of the mass of the monomer emulsion.

[0029] Preferably, the porous sound-absorbing filler is one or more of expanded perlite, hollow glass microspheres, and porous ceramic powder with a particle size of 0.005-0.5 mm.

[0030] Preferably, the high-density sound-insulating filler is one or more of barite powder (BaSO4), ferrite powder (Fe3O4), and calcium carbonate powder (CaCO3) with a particle size of 1-10μm.

[0031] Preferably, the mass ratio of the porous sound-absorbing filler to the high-density sound-insulating filler is controlled at 1:1-2. Within this ratio range, the sound absorption effect of the porous structure is ensured, while the high-density filler increases the surface density (dry film density ≥ 1.2 g / cm³). 3This enhances sound insulation performance.

[0032] Preferably, the crosslinked acrylate-coated butyl rubber core-shell emulsion is prepared by the following method:

[0033] (1) Add acrylate monomers and diene crosslinking agents to an aqueous emulsifier solution and mix and emulsify to obtain a shell monomer pre-emulsion;

[0034] (2) Add the shell monomer pre-emulsion obtained in step (1) to the butyl latex and stir to mix and emulsify. Then add the initiator solution and heat to polymerize to obtain a cross-linked acrylate coated butyl rubber core-shell emulsion.

[0035] Preferably, in the preparation of the crosslinked acrylate-coated butyl rubber core-shell emulsion, the acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1:1-2; the diene crosslinking agent is one or more of isoprene, 1,4-pentadiene, 1,5-hexadiene, and 2,5-dimethyl-1,5-hexadiene.

[0036] Preferably, in the preparation of the crosslinked acrylate-coated butyl rubber core-shell emulsion, the amount of diene crosslinking agent added is 0.5-3% of the mass of the acrylate monomer.

[0037] The acrylate monomers and diene crosslinking agents used in this invention have good affinity with butyl latex particles. After emulsification, they can better coat the surface of butyl latex particles. Then, through in-situ polymerization and crosslinking, a shell is formed, resulting in a crosslinked acrylate-coated butyl rubber core-shell emulsion with good coating effect. The above-mentioned acrylate coating significantly improves the compatibility between butyl rubber particles and silicone-acrylic adhesive resin, which is beneficial for forming an "island structure" in the dried coating film where butyl rubber particles are dispersed in the silicone-acrylic film-forming resin. This reduces the continuous phase separation of butyl rubber, thereby significantly improving the dispersion effect of butyl rubber and reducing its impact on the overall uniformity of the coating film. The resulting composite coating has better damping performance and flexibility, and can achieve better sound absorption and insulation effects as well as stronger adhesion.

[0038] Preferably, in the preparation of the above-mentioned crosslinked acrylate-coated butyl rubber core-shell emulsion, the emulsifier aqueous solution is an aqueous solution of at least one emulsifier selected from sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and nonylphenol polyoxyethylene ether; the mass concentration of the emulsifier aqueous solution is 2-5%.

[0039] Preferably, in the preparation of the above-mentioned crosslinked acrylate-coated butyl rubber core-shell emulsion, the solid content of the shell monomer pre-emulsion is 40-60%; the solid content of the butyl latex is 40-50%; and the amount of the shell monomer pre-emulsion added is 30-50% of the mass of the butyl latex.

[0040] Preferably, in the preparation of the crosslinked acrylate-coated butyl rubber core-shell emulsion, the initiator is potassium persulfate or ammonium persulfate, and the total amount of initiator added is 0.5-1.0% of the mass of the shell monomer pre-emulsion.

[0041] Preferably, in the preparation of the crosslinked acrylate-coated butyl rubber core-shell emulsion, the temperature of the heating polymerization reaction is 60-80°C.

[0042] Preferably, the functional additives include at least one of the following: dispersants (such as sodium polyacrylate), defoamers (such as silicones), thickeners (such as hydroxyethyl cellulose), film-forming aids (such as dodecyl alcohol esters), and fungicides (such as isothiazolinone).

[0043] The preparation method of the above-mentioned water-based polymer composite sound-absorbing and sound-insulating coating includes the following preparation steps:

[0044] Dispersant and defoamer are added to deionized water and stirred until homogeneous. Then, porous sound-absorbing filler and high-density sound-insulating filler are added and stirred and ground. Next, silicone-acrylic emulsion and cross-linked acrylate-coated butyl rubber core-shell emulsion are added and mixed until homogeneous. Finally, film-forming aid and thickener are added to adjust the viscosity to 8000-12000 mPa·s. The mixture is then filtered and packaged to obtain a water-based polymer composite sound-absorbing and sound-insulating coating.

[0045] The functions and principles of each component of this invention are as follows:

[0046] Silicone-acrylic emulsion: a film-forming substance that provides coating mechanical properties and adhesion, is environmentally friendly, has good film-forming properties, and is highly compatible with fillers.

[0047] Cross-linked acrylate-coated butyl rubber core-shell emulsion: Introduces damping properties, dissipates vibration energy through internal friction, and enhances low-frequency sound insulation.

[0048] Porous sound-absorbing filler: Porous structure enhances sound energy reflection and scattering, and consumes sound energy through air viscosity resistance and heat conduction (mainly high-frequency sound absorption), resulting in excellent sound absorption performance.

[0049] High-density sound insulation filler: High-density inorganic filler, which blocks the transmission of sound waves through the mass law (mainly for mid-to-low frequency sound insulation).

[0050] Functional additives: These adjust the workability, stability, and durability of coatings. For example, dispersants prevent filler agglomeration and improve dispersion uniformity; defoamers eliminate air bubbles generated during preparation and application, preventing pinholes in the coating from affecting acoustic performance; thickeners adjust viscosity to 8000-12000 mPa·s (25℃, Brookfield viscometer), suitable for spray / roller coating; film-forming aids lower the minimum film-forming temperature (MFT) of the resin, ensuring the integrity of low-temperature film formation.

[0051] Sound absorption mechanism: Relying on the interconnected porous structure inside the coating (such as the pore size of porous sound-absorbing filler of 10-20μm), after the sound waves enter the pores, the sound energy is converted into heat energy through the viscous friction between air molecules and pore walls and the vibration loss of the material skeleton.

[0052] Sound insulation mechanism: The surface density of the coating is increased by using high-density sound insulation filler, and damping additives (such as butyl rubber) are used to suppress substrate vibration and reduce sound wave transmission.

[0053] Through the synergistic effect of the above components, a three-dimensional porous structure and a damping vibration reduction system are formed inside the coating, which can simultaneously achieve the dual effects of "sound absorption" and "sound insulation".

[0054] Compared with the prior art, the beneficial effects of the present invention are:

[0055] (1) By combining "porous lightweight sound-absorbing filler" and "high-density sound-insulating filler", both high-frequency sound absorption and mid-to-low-frequency sound insulation are achieved, overcoming the shortcomings of traditional coatings that only have "single function of sound absorption or sound insulation". Butyl rubber elastic damping material is introduced, and the viscoelasticity of butyl rubber is used to consume vibration energy through internal friction, further improving low-frequency sound insulation. Acoustic performance is achieved through the synergistic effect of "porous sound absorption + high-density sound insulation + damping energy consumption".

[0056] (2) By applying an acrylate shell crosslinking coating to butyl rubber, the dispersion performance of butyl rubber in silicone propylene film-forming resin is improved, thereby improving the sound absorption and sound insulation effect while reducing the impact on adhesion.

[0057] (3) The composite coating of the present invention uses water as a solvent, has low VOC content, and has no irritating odor during construction, which meets the requirements of green building. Detailed Implementation

[0058] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0059] Example 1

[0060] A water-based polymer composite sound-absorbing and sound-insulating coating, comprising the following components in parts by weight:

[0061] Base material: 40 parts silicone-acrylic emulsion; 5 parts cross-linked acrylate-coated butyl rubber core-shell emulsion.

[0062] Composite porous sound-absorbing filler: 12 parts expanded perlite (particle size 0.1-0.5mm); 8 parts hollow glass microspheres (particle size 5-20μm).

[0063] Composite high-density sound insulation filler: 20 parts barite powder (BaSO4, particle size 5-10μm); 10 parts ferrite powder (Fe3O4, particle size 1-5μm).

[0064] Functional additives: Dispersant (sodium polycarboxylate) 1.0 part; Defoamer (organosilicon) 0.5 part; Thickener (hydroxyethyl cellulose) 0.8 part; Film-forming aid (dodecyl alcohol ester) 3.0 part; Preservative (isothiazolinone) 0.3 part.

[0065] 19.4 parts of deionized water.

[0066] The silicone-acrylic emulsion is prepared by the following method:

[0067] Sodium dodecylbenzenesulfonate and nonylphenol polyoxyethylene ether, emulsifiers, were added to a reactor containing deionized water at a mass ratio of 1:1 and heated to 60°C with stirring to dissolve. The total mass concentration of the emulsifiers was 4%. Then, methyl methacrylate, butyl acrylate, acrylic acid, and methacryloxypropyltrimethoxysilane, in a mass ratio of 30:20:100:15, were added and emulsified to obtain a monomer emulsion with a solid content of 50%. The temperature was then raised to 70°C, and an ammonium persulfate initiator solution was added dropwise for reaction. The total amount of ammonium persulfate added was 0.5% of the mass of the monomer emulsion, and the addition time was controlled at 1.5 h. After the addition was completed, the reaction was continued at the temperature for 3 h to obtain a silicone-acrylic emulsion.

[0068] The cross-linked acrylate-coated butyl rubber core-shell emulsion was prepared by the following method:

[0069] (1) Methyl methacrylate, butyl acrylate and isoprene crosslinking agent in a mass ratio of 40:60:2 were added to a mixed emulsifier aqueous solution of sodium dodecyl sulfonate and nonylphenol polyoxyethylene ether (SDS:NPEO = 2:1, total emulsifier mass concentration of 3%) and mixed and emulsified to obtain a shell monomer preemulsion with a solid content of 50%.

[0070] (2) The shell monomer pre-emulsion obtained in step (1) is added to butyl latex (commercially available, solid content 45%) at a mass ratio of 40:100 and stirred and emulsified. Then, the mixture is heated to 70°C and ammonium persulfate initiator solution is added dropwise and stirred to react. The total amount of ammonium persulfate added is 0.8% of the mass of the shell monomer pre-emulsion. The addition time is controlled to be 1 hour. After the addition is completed, the reaction is continued for 4 hours to obtain cross-linked acrylate coated butyl rubber core-shell emulsion.

[0071] The preparation method of the water-based polymer composite sound-absorbing and sound-insulating coating in this embodiment includes the following preparation steps:

[0072] S1. Premixing stage: Add deionized water (19.4 parts) to the dispersion vessel, turn on the stirrer (500 rpm), add dispersant (1.0 part) and defoamer (0.5 parts) in sequence, and stir for 5 minutes until completely dissolved.

[0073] S2. Filler dispersion stage: Keep the stirring speed at 1200 rpm, and slowly add expanded perlite (12 parts), hollow glass microspheres (8 parts), barite powder (20 parts), and ferrite powder (10 parts) in sequence. Disperse for 10 minutes after each filler is added, with a total dispersion time of 40 minutes.

[0074] S3. Mixing stage of base material and additives: Reduce the speed to 400 rpm, add silicone acrylic emulsion (40 parts) and cross-linked acrylate coated butyl rubber core shell emulsion (5 parts), and stir for 15 min; then add film-forming aid (3.0 parts), thickener (0.8 parts) and preservative (0.3 parts) in sequence, and stir for 20 min until the system is uniform.

[0075] S4. Filtration and Adjustment: Filter with a 100-mesh filter to remove agglomerated particles; test the viscosity. If it deviates from the target (8000-12000 mPa·s), fine-tune it by adding thickener or deionized water to obtain the water-based polymer composite sound-absorbing and sound-insulating coating.

[0076] The sound-absorbing and sound-insulating coating obtained in this embodiment has an average sound absorption coefficient (GB / T 18696.2-2002) of 0.65 (125-4000Hz), with a sound absorption coefficient >0.7 in the 500-2000Hz frequency range and a peak value (1000Hz) of 0.82. The weighted sound insulation (Rw) (GB / T 50121-2005, dry film thickness 2mm) is 34dB (100-3000Hz). The VOC content is ≤80g / L (GB18582-2020). The adhesion (GB / T 9286-2021 cross-cut test) is grade 0. The water resistance (GB / T 1733-1993, immersion 24h) shows no blistering or peeling. The alkali resistance (GB / T 9265-2009, saturated Ca(OH)2, 24h) shows no abnormalities. The flexibility (GB / T1731-2020, bending test) result is 2mm (no cracks in the coating).

[0077] Example 2

[0078] A water-based polymer composite sound-absorbing and sound-insulating coating, comprising the following components in parts by weight:

[0079] Base materials: 30 parts of silicone-acrylic emulsion (same as in Example 1); 7.5 parts of cross-linked acrylate-coated butyl rubber core-shell emulsion (same as in Example 1).

[0080] Porous sound-absorbing filler: 15 parts of expanded perlite (particle size 0.1-0.5mm).

[0081] High-density sound insulation filler: 20 parts of barite powder (BaSO4, particle size 5-10μm).

[0082] Functional additives: Dispersant (sodium polycarboxylate) 0.8 parts; Defoamer (organosilicon) 0.5 parts; Thickener (hydroxyethyl cellulose) 1.5 parts; Film-forming aid (dodecyl alcohol ester) 2.0 parts; Preservative (isothiazolinone) 0.2 parts.

[0083] 22.5 parts deionized water.

[0084] The preparation method of the water-based polymer composite sound-absorbing and sound-insulating coating in this embodiment is the same as that in Example 1.

[0085] The sound-absorbing and sound-insulating coating obtained in this embodiment has an average sound absorption coefficient of 0.58 (125-4000Hz), with a sound absorption coefficient >0.6 in the 500-2000Hz frequency range and a peak value (1200Hz) of 0.76. The weighted sound insulation (Rw) is 30dB (100-3000Hz). VOC content is ≤80g / L. Adhesion is grade 0. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 1mm (no cracks in the coating).

[0086] Example 3

[0087] A water-based polymer composite sound-absorbing and sound-insulating coating, comprising the following components in parts by weight:

[0088] Base materials: 20 parts of silicone-acrylic emulsion (same as in Example 1); 10 parts of cross-linked acrylate-coated butyl rubber core-shell emulsion (same as in Example 1).

[0089] Porous sound-absorbing filler: 30 parts of expanded perlite (particle size 0.1-0.5mm).

[0090] High-density sound insulation filler: 40 parts of barite powder (BaSO4, particle size 5-10μm).

[0091] Functional additives: Dispersant (sodium polycarboxylate) 1.6 parts; Defoamer (organosilicon) 0.4 parts; Thickener (hydroxyethyl cellulose) 0.3 parts; Film-forming aid (dodecyl alcohol ester) 4.0 parts; Preservative (isothiazolinone) 0.2 parts.

[0092] 13.5 parts deionized water.

[0093] The preparation method of the water-based polymer composite sound-absorbing and sound-insulating coating in this embodiment is the same as that in Example 1.

[0094] The sound-absorbing and sound-insulating coating obtained in this embodiment has an average sound absorption coefficient of 0.68 (125-4000Hz), with a sound absorption coefficient >0.7 in the 500-2000Hz frequency range and a peak value (900Hz) of 0.85. The weighted sound insulation (Rw) is 37dB (100-3000Hz). VOC content is ≤80g / L. Adhesion is rated as Grade 1. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 3mm (no cracks in the coating).

[0095] Example 4

[0096] A water-based polymer composite sound-absorbing and sound-insulating coating, compared with Example 1, differs in that the cross-linked acrylate-coated butyl rubber core-shell emulsion is prepared by the following method:

[0097] (1) Methyl methacrylate, butyl acrylate and 1,4-pentadiene crosslinking agent in a mass ratio of 50:50:0.5 were added to a mixed emulsifier aqueous solution of sodium dodecyl sulfonate and nonylphenol polyoxyethylene ether (SDS:NPEO = 2:1, total emulsifier mass concentration of 3%) and mixed and emulsified to obtain a shell monomer preemulsion with a solid content of 50%.

[0098] (2) The shell monomer pre-emulsion obtained in step (1) is added to butyl latex (commercially available, solid content 45%) at a mass ratio of 50:100 and stirred and mixed. Then, the mixture is heated to 70°C and ammonium persulfate initiator solution is added dropwise and stirred to react. The total amount of ammonium persulfate added is 0.8% of the mass of the shell monomer pre-emulsion. The addition time is controlled to be 1 hour. After the addition is completed, the reaction is continued for 4 hours to obtain cross-linked acrylate coated butyl rubber core-shell emulsion.

[0099] The sound-absorbing and sound-insulating coating obtained in this embodiment has an average sound absorption coefficient (GB / T 18696.2-2002) of 0.63 (125-4000Hz), with a sound absorption coefficient >0.7 in the 500-2000Hz frequency range and a peak value (1000Hz) of 0.81. The weighted sound insulation (Rw) is 32dB (100-3000Hz). VOC content is ≤80g / L. Adhesion is rated as Grade 1. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 2mm (no cracks in the coating).

[0100] Example 5

[0101] A water-based polymer composite sound-absorbing and sound-insulating coating, compared with Example 1, differs in that the cross-linked acrylate-coated butyl rubber core-shell emulsion is prepared by the following method:

[0102] (1) Methyl methacrylate, butyl acrylate and 2,5-dimethyl-1,5-hexadiene crosslinking agent in a mass ratio of 33.3:66.6:3 were added to a mixed emulsifier aqueous solution of sodium dodecyl sulfonate and nonylphenol polyoxyethylene ether (SDS:NPEO = 2:1, total emulsifier mass concentration of 3%) and mixed and emulsified to obtain a shell monomer preemulsion with a solid content of 50%.

[0103] (2) The shell monomer pre-emulsion obtained in step (1) is added to butyl latex (commercially available, solid content 45%) at a mass ratio of 30:100 and stirred and mixed. Then, the mixture is heated to 70°C and ammonium persulfate initiator solution is added dropwise and stirred to react. The total amount of ammonium persulfate added is 0.8% of the mass of the shell monomer pre-emulsion. The addition time is controlled to be 1 hour. After the addition is completed, the reaction is continued for 4 hours to obtain cross-linked acrylate coated butyl rubber core-shell emulsion.

[0104] The sound-absorbing and sound-insulating coating obtained in this embodiment has an average sound absorption coefficient of 0.64 (125-4000Hz), with a sound absorption coefficient >0.7 in the 500-2000Hz frequency range and a peak value (1000Hz) of 0.82. The weighted sound insulation (Rw) is 36dB (100-3000Hz). VOC content is ≤80g / L. Adhesion is grade 0. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 2mm (no cracks in the coating).

[0105] Example 6

[0106] A water-based polymer composite sound-absorbing and sound-insulating coating differs from Example 1 in that the crosslinked acrylate-coated butyl rubber core-shell emulsion is prepared by using the same amount of N,N'-methylenebisacrylamide crosslinking agent instead of isoprene crosslinking agent.

[0107] The sound-absorbing and sound-insulating coating obtained in this embodiment has an average sound absorption coefficient of 0.57 (125-4000Hz). The weighted sound insulation (Rw) is 29dB (100-3000Hz). The VOC content is ≤80g / L. Adhesion is rated as Grade 1. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. The flexibility test result was 2mm (no cracks in the coating).

[0108] The comparison between Example 6 and Example 1 shows that using a crosslinking agent with poor affinity for butyl latex particles reduces the coating effect on butyl rubber latex particles, resulting in a decrease in the overall uniformity of the coating film. Consequently, the sound absorption, sound insulation, and adhesion of the resulting coating are reduced to some extent.

[0109] Comparative Example 1

[0110] A water-based polymer composite sound-absorbing and sound-insulating coating, compared with Example 2, does not contain porous sound-absorbing filler, but increases the content of high-density sound-insulating filler to 35 parts, and the rest are the same.

[0111] The sound-absorbing and sound-insulating coatings obtained in this comparative example had an average sound absorption coefficient of 0.37 (125-4000Hz). The weighted sound insulation (Rw) was 26dB (100-3000Hz). VOC content was ≤80g / L. Adhesion was grade 0. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 1mm (no cracks in the coating).

[0112] Comparative Example 2

[0113] A water-based polymer composite sound-absorbing and sound-insulating coating, compared with Example 2, does not contain high-density sound-insulating filler, but increases the content of porous sound-absorbing filler to 35 parts, while the rest are the same.

[0114] The sound-absorbing and sound-insulating coatings obtained in this comparative example had an average sound absorption coefficient of 0.50 (125-4000Hz). The weighted sound insulation (Rw) was 20dB (100-3000Hz). VOC content was ≤80g / L. Adhesion was grade 0. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 1mm (no cracks in the coating).

[0115] Comparative Example 3

[0116] A water-based polymer composite sound-absorbing and sound-insulating coating, compared with Example 2, does not contain cross-linked acrylate-coated butyl rubber core-shell emulsion, but increases the content of silicone-acrylic emulsion to 37.5 parts, and the rest are the same.

[0117] The sound-absorbing and sound-insulating coatings obtained in this comparative example had an average sound absorption coefficient of 0.51 (125-4000Hz). The weighted sound insulation (Rw) was 22dB (100-3000Hz). VOC content was ≤80g / L. Adhesion was grade 0. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 2mm (no cracks in the coating).

[0118] Comparative Example 4

[0119] A water-based polymer composite sound-absorbing and sound-insulating coating, compared with Example 2, uses an equal amount of butyl latex (commercially available, solid content 45%) to replace the cross-linked acrylate-coated butyl rubber core-shell emulsion, the rest are the same.

[0120] The sound-absorbing and sound-insulating coatings obtained in this comparative example had an average sound absorption coefficient of 0.48 (125-4000Hz). The weighted sound insulation (Rw) was 24dB (100-3000Hz). VOC content was ≤80g / L. Adhesion was rated at level 2. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed blistering. Flexibility tests showed a thickness of 2mm (no cracks in the coating).

[0121] Comparative Example 5

[0122] A water-based polymer composite sound-absorbing and sound-insulating coating differs from Example 2 in that isoprene crosslinking agent was not added during the preparation of the crosslinked acrylate-coated butyl rubber core-shell emulsion.

[0123] The sound-absorbing and sound-insulating coatings obtained in this comparative example had an average sound absorption coefficient of 0.52 (125-4000Hz). The weighted sound insulation (Rw) was 25dB (100-3000Hz). VOC content was ≤80g / L. Adhesion was rated as Grade 1. Water resistance tests showed no blistering or peeling. Alkali resistance tests showed no abnormalities. Flexibility tests showed a thickness of 2mm (no cracks in the coating).

[0124] The comparison results between Comparative Examples 1-3 and the embodiments above show that the present invention, through the combined use of porous sound-absorbing filler, high-density sound-insulating filler, and butyl rubber elastic damping material, can synergistically improve the sound absorption coefficient and sound insulation of the coating. Furthermore, the addition of cross-linked acrylate-coated butyl rubber core-shell emulsion can also increase the flexibility of the coating.

[0125] The comparison results between Comparative Examples 4-5 and the Examples show that the coating obtained using unmodified butyl latex (Comparative Example 4) exhibits a significant decrease in sound absorption, sound insulation, adhesion, alkali resistance, and flexibility. This is because unmodified butyl rubber has poor compatibility with silicone-acrylic adhesive resin and poor adhesion to the substrate, easily leading to continuous phase separation during drying and film formation, affecting the overall uniformity of the coating and resulting in a comprehensive reduction in performance. Similarly, the use of uncrosslinked acrylate-modified butyl latex (Comparative Example 5) results in poor coating of butyl rubber particles, also leading to a significant decrease in sound absorption, sound insulation, adhesion, and flexibility.

[0126] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A water-based polymer composite sound-absorbing and sound-insulating coating, characterized in that... The following components are included by weight: 20-40 parts of silicone-acrylic emulsion; 15-30 parts of porous sound-absorbing filler; 20-40 parts of high-density sound-insulating filler; 5-10 parts of cross-linked acrylate-coated butyl rubber core-shell emulsion; 1-8 parts of functional additives; 10-25 parts of deionized water; the cross-linked acrylate-coated butyl rubber core-shell emulsion is prepared by the following method: (1) adding acrylate monomer and diene cross-linking agent to an emulsifier aqueous solution and mixing and emulsifying to obtain a shell monomer pre-emulsion; (2) adding the shell monomer pre-emulsion obtained in step (1) to butyl latex and stirring and mixing and emulsifying, and then adding an initiator solution and heating to polymerize to obtain a cross-linked acrylate-coated butyl rubber core-shell emulsion.

2. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 1, characterized in that... The silicone-acrylic emulsion is prepared by the following method: an emulsifier is added to a reaction vessel containing deionized water and heated and stirred to dissolve it. Then, acrylate monomers, acrylic monomers and silane coupling agent monomers are added and mixed and emulsified to obtain a monomer emulsion. Then, an initiator solution is added dropwise and the copolymerization reaction is carried out under heat to obtain the silicone-acrylic emulsion.

3. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 2, characterized in that: The emulsifier is one or more of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and nonylphenol polyoxyethylene ether; the amount of emulsifier added is 3-6% of the mass of deionized water; the temperature of the heating, stirring, dissolving, and heat-preserving copolymerization reaction is 60-80℃.

4. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 2, characterized in that: The acrylate monomer is one or more of methyl methacrylate, ethyl acrylate, and butyl acrylate; the amount of acrylate monomer added is 40-60% of the mass of the acrylate monomer; the acrylate monomer is one or two of acrylic acid and methacrylic acid; the silane coupling agent monomer is one or two of methacryloxypropyltrimethoxysilane and vinyltriethoxysilane; the amount of silane coupling agent monomer added is 10-20% of the mass of the acrylate monomer.

5. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 2, characterized in that: The monomer emulsion has a solid content of 40-60%; the initiator is potassium persulfate or ammonium persulfate, and the total amount of initiator added is 0.3-0.6% of the mass of the monomer emulsion.

6. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 1, characterized in that: The porous sound-absorbing filler is one or more of expanded perlite, hollow glass microspheres, and porous ceramic powder with a particle size of 0.005-0.5 mm; the high-density sound-insulating filler is one or more of barite powder, ferrite powder, and calcium carbonate powder with a particle size of 1-10 μm; the mass ratio of the porous sound-absorbing filler to the high-density sound-insulating filler is controlled at 1:1-2; the functional additives include at least one of dispersant, defoamer, thickener, film-forming aid, and mildew inhibitor.

7. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 1, characterized in that: In the preparation of crosslinked acrylate-coated butyl rubber core-shell emulsion, the acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1:1-2; the diene crosslinking agent is one or more of isoprene, 1,4-pentadiene, 1,5-hexadiene, and 2,5-dimethyl-1,5-hexadiene; the amount of the diene crosslinking agent added is 0.5-3% of the mass of the acrylate monomer.

8. The water-based polymer composite sound-absorbing and sound-insulating coating according to claim 1, characterized in that: In the preparation of crosslinked acrylate-coated butyl rubber core-shell emulsion, the emulsifier aqueous solution is an aqueous solution of at least one emulsifier selected from sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and nonylphenol polyoxyethylene ether; the mass concentration of the emulsifier aqueous solution is 2-5%; the solid content of the shell monomer pre-emulsion is 40-60%; the solid content of the butyl latex is 40-50%; the amount of shell monomer pre-emulsion added is 30-50% of the mass of the butyl latex; the initiator is potassium persulfate or ammonium persulfate, and the total amount of initiator added is 0.5-1.0% of the mass of the shell monomer pre-emulsion; the temperature of the heating polymerization reaction is 60-80℃.

9. The preparation method of the water-based polymer composite sound-absorbing and sound-insulating coating according to claim 6, characterized in that: The preparation steps include: adding dispersant and defoamer to deionized water and stirring to mix evenly; then adding porous sound-absorbing filler and high-density sound-insulating filler and stirring and grinding; then adding silicone acrylic emulsion and cross-linked acrylate-coated butyl rubber core-shell emulsion and mixing evenly; finally adding film-forming aid and thickener to adjust the viscosity to 8000-12000 mPa·s; filtering and packaging to obtain water-based polymer composite sound-absorbing and sound-insulating coating.