Damping coating containing open hollow microspheres and application

Abstract

The invention discloses a damping coating containing open hollow microspheres and application, and relates to the technical field of damping materials. Volatile liquid is loaded in inner spaces of the open hollow microspheres to adjust the density of the microspheres, so that the problem that the hollow microspheres are not matched with the density of other components of a coating system in the dispersion process is solved, mixing difficulty and layering of a coating product caused by density difference are avoided, the storage stability of the damping coating is improved, and the service life of the damping coating is prolonged. The drying process of the coating and the uniformity of the formed film are kept; multiple interfaces and deformable units are introduced by utilizing the open hollow microbeads, when the material is vibrated, vibration energy can be additionally consumed not only by movement energy consumption of a macromolecular chain segment, interface friction between the hollow microbeads and a polymer matrix, but also by elastic deformation and recovery of a shell layer of the microbeads, and a loss factor of a high-damping coating is obtained; gas molecules in the open hollow microbeads can freely enter and exit from the openings in the vibration process, vibration energy is converted into translational energy, and the loss factor of the damping coating is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of damping materials technology, and particularly to the field of vibration reduction and noise reduction damping coating technology, specifically a damping coating containing open hollow microspheres and its application. Background Technology

[0002] Vibration damping and noise reduction materials dissipate mechanical vibration energy by converting it into heat energy, and their applications have permeated all aspects of modern industry and high technology. Different industries have different requirements for damping materials based on their unique vibration and noise characteristics and working environments. For example: In the aerospace industry, damping materials need to withstand extreme temperatures while meeting requirements such as lightweight design and high damping performance. In the automotive industry, NVH (noise, vibration, and harshness) control focuses on suppressing low-frequency engine vibrations and mid-to-high-frequency noise generated by motors and reducers; the core requirements are wide-bandwidth (covering mid-to-high frequencies) vibration reduction, lightweight design, and integration with the vehicle body structure. In the rail transportation industry, damping materials primarily serve to improve ride comfort and vehicle structural safety; the core requirements are high sound insulation, flame retardancy, long-term durability, and lightweight environmental friendliness. In the industrial and construction industries, damping materials protect building structures and living environments, as well as ensure the stable operation of industrial equipment; the core requirements are ease of construction, environmental friendliness, wide-bandwidth vibration reduction, and sound insulation. Although the requirements for damping materials vary across industries, the need for high damping performance and lightweight design has become a common goal.

[0003] In recent years, the use of damping coatings has become a major trend in vibration reduction and noise control. Damping coatings are fluid materials that can be directly applied and form a damping layer after curing. Compared with other forms of damping materials such as sheets and foams, their core advantages lie in their direct application, adaptability to complex irregular structures, and ability to achieve large-area seamless coverage. They are particularly suitable for situations where it is impossible or inconvenient to install prefabricated damping sheets. When the vibrating surface area to be treated is large, irregularly shaped, or needs to be combined with anti-corrosion coating processes, damping coatings are usually a better choice than prefabricated damping sheets. The following are some of the most typical and concentrated application areas of damping coatings: 1. In the field of industrial equipment and piping, such as large fan housings, water pumps, press machine housings, generator sets, conveying pipelines, chemical containers, etc., damping coatings are used to suppress vibration and radiated noise from sheet metal structures. Damping coatings are applied directly to the equipment surface to form a constrained damping layer, and are particularly effective at handling low-to-medium frequency vibrations and noise. Application is flexible. Main products include epoxy-based damping coatings, polyurethane damping coatings, and water-based acrylic damping coatings.

[0004] 2. In the transportation sector, such as ship bulkheads and decks, high-speed rail / subway car floors, bus body frames, and heavy-duty truck cabs, damping coatings are used to reduce structural vibration and improve ride comfort. They can adhere tightly to complex curved surfaces, are compatible with anti-corrosion coatings, and achieve integrated vibration reduction and noise reduction. Main products include high-damping polyurethane coatings and rubber-modified epoxy coatings.

[0005] 3. In the field of building engineering, such as commercial building floors, stadium / cinema floors, steel structure corridors, and equipment floor walls, damping coatings improve impact sound insulation and suppress solid-borne sound transmission. Through structures such as "flooring floors," they can effectively block the transmission of vibrations within the building structure. Main products include water-based damping coatings and high-solids elastic coatings.

[0006] 4. In the military and aerospace fields, such as ship compartments, submarine hulls, aircraft auxiliary structures, and military vehicles, damping coatings are used to meet special environmental requirements (such as salt spray resistance, wide temperature range, and stealth capabilities). They achieve multi-functional composites including vibration reduction, sound insulation, corrosion protection, and stealth. Main products include wide-temperature-range damping coatings and multi-functional composite coatings.

[0007] However, achieving both lightweighting and improved damping performance in damping coatings remains a significant challenge. Current methods primarily involve replacing some solid fillers with hollow glass microspheres in the coating formulation, directly reducing the density of the cured coating. Furthermore, the addition of hollow microspheres introduces multiple interfaces and deformable units within the composite material. When the material is subjected to vibration, not only does the movement of the polymer chains consume energy, but the interfacial friction between the hollow microspheres and the polymer matrix, as well as the elastic deformation and recovery of the microsphere shells, also contribute to the additional energy dissipation. Additionally, hollow microspheres can enhance the coating's thermal and sound insulation properties.

[0008] In the technical direction of adding hollow glass microspheres to achieve lightweight damping coatings, CN115197623A uses 2-10 parts of modified hollow glass microspheres grafted with silane coupling agent to obtain damping coatings with a wide damping temperature range and high damping peak value. CN120365799A performs complex surface grafting modification on hollow glass microspheres to adjust the stiffness and damping characteristics of the coating and improve the loss factor of the damping coating. CN114672093A adds 5-20 parts of hollow glass microspheres and combines them with inorganic nanofillers to achieve a low-density and high-sound-insulating resin material by utilizing the hollow structure of the microspheres. CN111548721A discloses that the dispersant, defoamer, substrate wetting agent, catalyst, adhesion promoter, damping pigments and fillers, dehydrating agent and hollow microspheres in the formulation work together to achieve synergistic effects and prepare a sprayable damping coating for ships. CN113980554B discloses a method of treating hollow microspheres with silane coupling agent KH550 or KH560 or silane prepolymer and adding them to damping coatings to improve the compatibility between hollow microspheres and epoxy resin.

[0009] However, adding hollow glass microspheres to damping coatings to achieve lightweighting does present several common operational difficulties, particularly the limitation of Stokes' law, which states that the settling velocity of particles in a liquid is proportional to the density difference between the particles and the liquid. The core issue is that the density of hollow microspheres is lower than that of the coating system. Therefore, under buoyancy, the hollow microspheres tend to float on the coating surface. This not only severely affects the uniformity of the coating preparation process and its storage stability, but also, during coating drying, the floating and agglomeration of hollow microspheres significantly impacts film uniformity, thereby affecting the adhesion and impact resistance of the damping coating, ultimately impairing the strength and damping performance of the resulting coating.

[0010] To address the above pain points, this invention utilizes open hollow microspheres as fillers, which are added to the damping coating formulation to overcome the limitations imposed by the density difference of materials described by Stokes' Law on the coating mixing process, thereby preparing high-performance lightweight damping coatings. Summary of the Invention

[0011] The purpose of this invention is to provide a damping coating containing open hollow microspheres and its application, so as to solve the problems existing in the prior art.

[0012] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a damping coating containing open hollow microspheres, wherein the damping coating containing open hollow microspheres comprises a coating base, open hollow microspheres, a solvent and additives; The open hollow microspheres need to adsorb solvent before being added to the coating.

[0013] First, it's crucial to understand that the core difference between open-cell hollow microspheres and closed-cell hollow microspheres is that open-cell microspheres have interconnected pores in their outer shell. This interconnected structure ensures the exchange of substances, including liquids and gases, within and outside the microsphere. This invention utilizes this material exchange capability of open-cell hollow microspheres, combined with the restriction of gas movement within the microsphere's hollow structure, to prepare a high-performance damping coating.

[0014] The preparation of open-cell hollow microspheres involves first constructing a hollow spherical matrix, and then forming interconnected pores on the shell through physical or chemical means to create controllable open channels. The preparation processes for open-cell hollow microspheres vary considerably depending on the material. Currently, glass, ceramic, polymer, and fly ash-based open-cell hollow microspheres are available on the market.

[0015] Furthermore, the content of the open hollow microspheres is 0~70wt%, preferably 20~50wt%.

[0016] Furthermore, the solvent can be a single component or a multi-component mixture, depending on the damping coating system.

[0017] Microspheres are immersed in a selected solvent. To ensure that the cavity of the open hollow microspheres is filled with a sufficient amount of the selected solvent, auxiliary treatment methods such as decompression assistance, ultrasonic assistance, boiling assistance, and high and low temperature cycling assistance can be used.

[0018] Furthermore, the additives include one or more of the following: solid fillers, pigments, plasticizers, dispersants, defoamers, leveling agents, thickeners, coupling agents, antioxidants, antifungal agents, and flame retardants.

[0019] Furthermore, the open hollow microspheres employ assisted adsorption when adsorbing solvents; the assisted adsorption includes the use of auxiliary agents and auxiliary treatment methods.

[0020] Furthermore, the auxiliary agent is a volatile amphiphilic organic solvent, and the volume ratio of the auxiliary agent to the solvent is 0~30%:1.

[0021] Furthermore, the auxiliary agent is a volatile amphiphilic organic solvent, and the volume ratio of the auxiliary agent to the solvent is 5~20%:1.

[0022] When using water as a solvent to fill open-cell hollow microspheres, the hydrophilicity and lipophilicity of the cavities of open-cell hollow microspheres made of different materials vary. If the microspheres cannot fully absorb water when directly immersed in water, a certain amount of volatile hydrophilic organic solvent (such as one or a mixture of small molecule alcohols, aldehydes, ketones, acids, etc.) can be used as an auxiliary agent. The auxiliary agent can be added directly to the water to fill the open-cell hollow microspheres. Alternatively, the cavity of the open-cell hollow microspheres can be moistened with the auxiliary agent before filling with water. Or, the cavity of the open-cell hollow microspheres can be filled with the auxiliary agent and then immersed in water to replace the water in the cavity. This process can be repeated several times until the water concentration in the cavity of the microspheres reaches the required level.

[0023] Furthermore, when the coating base is a solvent-free damping coating, the open hollow microspheres adsorb one of water or organic volatile solvents before being added.

[0024] Furthermore, the preparation method of the damping coating containing open hollow microspheres described above includes the following preparation steps: (1) Solvent is adsorbed by open hollow microspheres to obtain filled open hollow microspheres; (2) The open-hole hollow microspheres are added to the base material of the damping coating formulation in a certain proportion, and the additives are added. The mixture is stirred until it is uniform and matured to obtain the damping coating containing the open-hole hollow microspheres. (3) The damping coating containing open hollow microspheres is applied to the substrate surface by a coating process, including but not limited to: spraying, scraping, rolling, dipping, etc., and dried and cured to obtain the damping coating containing open hollow microspheres.

[0025] It is important to note that during the wet film drying and curing process, sufficient time must be ensured for the solvent filling the open hollow microspheres in the coating to completely evaporate. The thickness of a single coating layer should be sufficient to prevent sagging, wrinkling, and, during the drying process, to prevent pinholes, cracking, or orange peel-like shrinkage. If the damping coating obtained from a single coat does not meet the design thickness, it can be recoated. This involves applying another layer of coating after the first coat is surface dry, allowing it to dry and cure, and repeating this recoating process until the resulting coating meets the design requirements.

[0026] Furthermore, the application of any of the above-mentioned damping coatings containing open hollow microspheres includes the preparation of damping plates and damping shell materials with high loss factor, high heat insulation and sound insulation performance using a multi-layer coating process.

[0027] Furthermore, the application of any of the above-mentioned damping coatings containing open hollow microspheres also includes the preparation of high-performance damping preforms using a process of casting in a mold, drying and molding, and demolding.

[0028] Compared with the prior art, the beneficial effects achieved by the present invention are: 1. By loading (adsorbing) volatile liquids into the internal space of open hollow microspheres, the density of the microspheres can be adjusted, which solves the problem of density mismatch between hollow microspheres and coating system during dispersion, avoids mixing difficulties and product stratification caused by density difference, improves the storage stability of damping coatings, and maintains the uniformity of coating drying process and film formation.

[0029] 2. By utilizing open hollow microspheres containing volatile liquids, which can restore their complete hollow structure after drying, the porosity of the coating is increased, effectively reducing the overall weight of the damping coating.

[0030] 3. Multiple interfaces and deformable units are introduced into the coated composite material using open hollow microspheres. When the material is subjected to vibration, not only does the movement of polymer chain segments consume energy, but the interfacial friction between the hollow microspheres and the polymer matrix, as well as the elastic deformation and recovery of the microsphere shell, can also consume additional vibration energy, thus obtaining a loss factor for the high-damping coating.

[0031] 4. By utilizing the fact that gas molecules inside the open hollow microspheres can freely enter and exit through the opening during vibration, the vibrational energy can be converted into translational energy, which greatly improves the loss factor of the damping coating.

[0032] 5. By utilizing the retention effect of open hollow microspheres on internal air molecules, the heat insulation and sound insulation performance of the damping coating is improved. Attached Figure Description

[0033] Figure 1 This is a scanning electron microscope image of the open hollow microspheres of the present invention.

[0034] Figure 2 This is a transmission electron microscope image of the open hollow sphere of the present invention.

[0035] Figure 3 This is a scanning electron microscope image of the damping coating containing open hollow spherical filler of the present invention. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] To more clearly illustrate the method provided by the present invention, the following embodiments are provided in detail. In the following embodiments, the testing methods for each indicator are as follows: I. The storage stability of the coating is checked by visual inspection for stratification: Visually inspect the coating for stratification, sedimentation, water layer, or caking. If the coating is uniform in consistency and has the same fluidity as when it was prepared after one week of storage, it is of excellent grade; if there is a small amount of sedimentation, and the fluidity can be restored by slight stirring, it is of good grade; if stratification or caking occurs, and the fluidity can be restored by stirring within 2 hours, it is of medium grade; if stratification or caking occurs, and the fluidity can be restored by stirring within 2-5 hours, it is of low grade; if stratification or caking occurs, and the fluidity can be restored by stirring for more than 5 hours, it is of low ready-to-use grade and is not suitable for storage.

[0038] II. Stability is mainly assessed by visual inspection of the wet film of the coating applied to the substrate to check for sagging, wrinkling, and uneven drying, pinholes, cracking, or orange peel-like defects. A coating without any of these defects is classified as Grade 1; a coating with a few minor defects that do not affect the overall coating is classified as Grade 2; a coating with localized defects that can be eliminated by recoating is classified as Grade 3; and a coating with significant overall defects is classified as Grade 4 (i.e., unqualified).

[0039] III. The drying time of the coating is compared with the surface drying time according to the method of GB / T1728-2020. At the same time, in order to ensure complete drying, the coating is naturally dried for one week after application and then the performance test is carried out.

[0040] IV. The uniformity of the damping coating after complete drying was observed using a scanning electron microscope to assess the dispersion of the open hollow microspheres.

[0041] V. The density of the damping coating after complete drying is determined by weighing. First, the substrate is weighed; then, the coating is weighed again after complete drying, and the difference between the two weights is the coating mass. The coating volume is calculated after accurately measuring the coating thickness and area. The density is obtained from the ratio of coating mass to volume.

[0042] VI. The sound insulation performance of the coating was measured according to the SAE J1400 method to obtain the sound transmission loss rating (STL) value for different coatings. The higher the STL (decibels), the better the overall sound insulation performance of the material.

[0043] VII. The thermal insulation performance of the coating is measured according to ISO 8301 method, and the thermal conductivity λ (W / mK) is measured by the heat flow meter method.

[0044] VIII. The damping performance of the damping coating was measured according to the method in GB / T 16406-1996, and the loss factor η was obtained.

[0045] IX. The adhesion of the coating was tested according to the method of GB / T 5210-2006 to obtain the adhesion strength value (MPa) and failure mode of the coating.

[0046] Examples 1-9 below are examples of open hollow microspheres used in water-based damping coating systems.

[0047] Example 1 (Comparative Example) Formulation (by weight): Component A: 36 parts butyl acrylate emulsion (48% solids content); Component B: 24 parts styrene-butadiene emulsion (52% solids content); Component C: 10 parts epoxy-modified acrylic emulsion (40% solids content). Solid additives: Component D: 30 parts phlogopite powder with a particle size of 40 mesh. Defoamer: Component E: 0.5% polyether-modified siloxane.

[0048] Damping coating preparation process: Maintain room temperature above 0 degrees Celsius. Mix components A and B while stirring at 25 rpm. Add component E and mix thoroughly. Add component C and continue stirring for 30 minutes. Then, adjust the stirring speed to 20 rpm. Add component D in three batches to the water-based resin mixture and stir for 30 minutes each time. Finally, adjust the stirring speed to 10 rpm and stir for another 30 minutes. Pack into sealed containers. Store at above 0 degrees Celsius for 7 days. Test after opening the container. A small amount of sediment may be present; slight stirring will restore fluidity. The coating's storage stability is rated as good.

[0049] Damping coating preparation: The obtained damping coating was applied to a pre-treated tinplate substrate using a scraping method. The tinplate substrate surface was pre-treated by sanding with 400# sandpaper and then cleaning with compressed air. The wet film thickness was 2-3 mm, and three substrate sizes were used: 203 mm × 305 mm for sound insulation testing; and 200 mm × 200 mm for heat insulation testing. These two samples could also be used for adhesion testing. The damping performance test sample size was 180 mm x 10 mm. The coating was allowed to dry naturally at room temperature. The wet film applied to the substrate showed no sagging or wrinkling. A small number of pinholes and cracks appeared during the drying process, but these did not affect the overall coating. The stability rating was 2. At a room temperature of 5 degrees Celsius in winter, the surface drying time was 8 hours.

[0050] The coating density and performance testing were conducted according to the standards described in Technical Specification V-IX. To ensure complete drying of the coating film, performance testing was performed 7 days after coating exposure when the room temperature was above 20 degrees Celsius, and 10 days after coating exposure when the room temperature was below 20 degrees Celsius. The filler was generally uniformly dispersed within the coating, with a small amount of agglomeration. The performance test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 2

[0051] The open-ended hollow glass microspheres were filled with a water / ethanol solution with a volume ratio of 95:5. After filtration, the water-filled glass microspheres were used as component F. The open-ended hollow glass microspheres were imported KOC and had a particle size of 50-80 μm.

[0052] The formulation was adjusted according to the formulation of Example 1, with component F replacing component D in the formulation of Example 1, while other components remained unchanged.

[0053] The damping coating was prepared using the same process as in Example 1. After storage at temperatures above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its fluidity as during preparation, indicating the coating was of superior quality after storage.

[0054] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0055] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with slight agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 3

[0056] The formula was adjusted according to the formula of Example 2, wherein the amount of component F was 10 parts, and the other components remained unchanged.

[0057] The damping coating was prepared using the same process as in Example 1. After storage at above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its flowability as during preparation, classifying it as excellent.

[0058] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0059] The testing process and indicators were the same as in Example 1. The filler was uniformly dispersed within the coating without agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 4

[0060] The formula was adjusted according to the formula of Example 2, wherein the amount of component F was 60 parts, and the other components remained unchanged.

[0061] The damping coating was prepared using the same process as in Example 1. After storage at temperatures above 0 degrees Celsius for 7 days, the container was opened for testing. A small amount of clumping occurred, but the fluidity was restored within 2 hours after stirring, indicating a medium-grade coating.

[0062] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate did not sag or wrinkle, but a small number of defects such as cracking and orange peel shrinkage appeared during the drying process. These defects can be eliminated by recoating. The stability is grade 3, and the surface drying time is 7 hours at a room temperature of 5 degrees Celsius in winter.

[0063] The testing process and indicators were the same as in Example 1. The filler was generally uniformly dispersed within the coating, with a small amount of agglomeration and resin voids. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 5

[0064] Open-ended hollow glass microspheres were filled with a water / ethanol solution with a volume ratio of 95:5. After filtration, water-filled glass microspheres were obtained and used as component G. The open-ended hollow glass microspheres were of imported type GL0237B and had a particle size of 1-20 μm.

[0065] The formulation was adjusted based on the formulation of Example 1, with component G replacing component D in the formulation of Example 1, while the other components remained unchanged.

[0066] The damping coating was prepared using the same process as in Example 1. After storage at above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its flowability as during preparation, classifying it as excellent.

[0067] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0068] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with a small amount of agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 6

[0069] Open-ended hollow glass microspheres were filled with a water / ethanol solution with a volume ratio of 95:5. After filtration, water-filled glass microspheres were obtained and used as component H. The open-ended hollow glass microspheres were domestically produced HCOC with a particle size of 100-200 μm.

[0070] The formulation was adjusted based on the formulation of Example 1, with component H replacing component D in the formulation of Example 1, while the other components remained unchanged.

[0071] The damping coating was prepared using the same process as in Example 1. After storage at temperatures above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its flowability as during preparation, and the coating stability was rated as excellent.

[0072] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0073] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with a small amount of agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 7

[0074] The open-cell hollow fly ash microspheres were filled with a water / ethanol solution with a volume ratio of 95:5, and the resulting water-filled cenospheres were filtered and used as component J. The open-cell hollow fly ash microspheres were domestically produced HNOC cenospheres with a particle size of 100-200 μm.

[0075] The formulation was adjusted according to the formulation of Example 1, with component J replacing component D in the formulation of Example 1, while the other components remained unchanged.

[0076] The damping coating was prepared using the same process as in Example 1. After storage at above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its flowability as during preparation, classifying it as excellent.

[0077] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0078] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with a small amount of agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 8

[0079] Acrylic polymer open-cell hollow microspheres were filled with a water / ethanol solution at a volume ratio of 90:10, and the resulting water-filled acrylic microspheres were filtered and used as component K. The acrylic polymer open-cell hollow microspheres were domestically produced HPOC with a particle size of 10-50 μm.

[0080] The formulation was adjusted based on the formulation of Example 1, with component K replacing component D in the formulation of Example 1, while the other components remained unchanged.

[0081] The damping coating was prepared using the same process as in Example 1. After storage at above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its flowability as during preparation, classifying it as excellent.

[0082] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 9 hours at a room temperature of 5 degrees Celsius in winter.

[0083] The testing process and indicators were the same as in Example 1. The filler was uniformly dispersed within the coating without agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1. Example 9

[0084] The ceramic open-ended hollow microspheres were filled with a water / ethanol solution with a volume ratio of 95:5. After filtration, the water-filled ceramic microspheres were used as component L. The ceramic open-ended hollow microspheres were domestically produced HCOC with a particle size of 5-20 μm.

[0085] The formulation was adjusted according to the formulation of Example 1, with component L replacing component D in the formulation of Example 1, while the other components remained unchanged.

[0086] The damping coating was prepared using the same process as in Example 1. After storage at above 0 degrees Celsius for 7 days, the container was opened for testing. The paste was uniform and consistent in its flowability as during preparation, classifying it as excellent.

[0087] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0088] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with a small amount of agglomeration. The test results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 1.

[0089] Examples 10-12 below are examples of open hollow microspheres used in solvent-based damping coating systems.

[0090] Example 10 (Comparative Example) Formulation (by weight): Solvent is a mixture comprising: 6 parts xylene, 4 parts butanediol monomethyl ether, 10 parts butyl acetate, 20 parts ethyl acetate, and 60 parts butanone. Resin component M (polybutyl methacrylate / laurate acrylate) 36 parts, resin component N (polyurethane) 8 parts, and resin component O (alkyd resin) 6 parts. Solid additive: Component D is 30 parts of phlogopite powder with a particle size of 40 mesh.

[0091] Damping coating preparation process: First, add the solvent to a mixing tank equipped with a reflux device according to the specified ratio. After mixing, heat to 60 degrees Celsius and add resin component M while stirring at 25 rpm. After complete dissolution, add resin component N, and then resin component O. Stir at medium speed to ensure the resin is completely dissolved or uniformly dispersed in the solvent, forming a homogeneous main agent solution. Increase the mixer speed to 35 rpm and add solid additive component D in three batches to the main agent solution, ensuring thorough dispersion and wetting. Use shear force to break up powder clumps, allowing the resin solution to coat each solid additive particle. This process will continue for 4 hours until the system is uniformly dispersed. Cool to room temperature while stirring, and then stir at 10 rpm for 30 minutes. Store in sealed containers for 7 days before opening and testing. The coating separates into layers; the lower layer is viscous with sediment at the bottom. Stirring for 30 minutes restores its fluidity. The coating's storage stability is medium.

[0092] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 6 hours at a room temperature of 5 degrees Celsius in winter.

[0093] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with a small amount of agglomeration. The results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 2. Example 11

[0094] Open-ended hollow glass microspheres were filled with a butyl acetate / butanediol monomethyl ether solution at a volume ratio of 90:10. After filtration, solvent-filled glass microspheres were obtained and used as component P. The open-ended hollow glass microspheres were imported KOC and had a particle size of 50-80 μm.

[0095] The formulation was adjusted based on the formulation of Example 10, replacing component D in the formulation of Example 10 with component P, while keeping the other components unchanged.

[0096] The coating preparation process is the same as in Example 10. After 7 days of sealed storage in containers, the containers were opened for testing. The coating did not show obvious stratification, but there was a small amount of sediment. The fluidity was restored with slight stirring, and the storage stability of the coating was rated as good.

[0097] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is Grade 1, and the surface drying time is 8 hours at a room temperature of 5 degrees Celsius in winter.

[0098] The testing process and indicators were the same as in Example 1. The filler was basically uniformly dispersed within the coating, with a small amount of agglomeration. The results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 2. Example 12

[0099] Acrylic polymer open-cell hollow microspheres were filled with a butyl acetate / butanediol monomethyl ether solution at a volume ratio of 90:10. After filtration, solvent-filled acrylic microspheres were obtained and used as component Q. The acrylic polymer open-cell hollow microspheres were domestically produced HPOC with a particle size of 10-50 μm.

[0100] The formulation was adjusted based on the formulation of Example 10, with component Q replacing component D in the formulation of Example 10, while the other components remained unchanged.

[0101] The coating preparation process is the same as in Example 10. After 7 days of sealed storage in containers, the containers were opened for testing. The paste was uniform and consistent in its fluidity as during preparation, classifying it as superior.

[0102] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is rated as Grade 1, and the surface drying time is 9 hours at a room temperature of 5 degrees Celsius in winter.

[0103] The testing process and indicators were the same as in Example 1. The filler was uniformly dispersed within the coating without agglomeration. The results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 2.

[0104] Examples 13-15 below are examples of open hollow microspheres used in two-component damping coating systems.

[0105] Example 13 (Comparative Example) Two-component formulation (by weight), ready-to-use damping coating. Component X is 4 parts hydroxyl-terminated polyethylene glycol, and component Y is 1 part HDDI (hexamethylene diisocyanate dimer) / MDI (diphenylmethane diisocyanate) mixture (HDDI / MDI=9:1). Solid additive component: Component D is 3 parts phlogopite powder with a particle size of 40 mesh.

[0106] Damping coating preparation process: Add component D to the mixing tank, add component Y to component D while stirring, and after fully wetting and mixing, add component X and mix thoroughly. After stirring for 30 minutes, immediately apply it to the tinplate.

[0107] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is rated as Grade 1, and the surface drying time is 2 hours at a room temperature of 5 degrees Celsius in winter.

[0108] The testing process and indicators were conducted according to sections III-IX of the above technical specifications. The filler was generally uniformly dispersed within the coating, with a small amount of agglomeration. The results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 3. Example 14

[0109] The formulation was adjusted according to the formulation of Example 13, with component P replacing component D, while the other components remained unchanged.

[0110] The preparation process of the damping coating is the same as in Example 13.

[0111] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is rated as Grade 1, and the surface drying time is 2 hours at a room temperature of 5 degrees Celsius in winter.

[0112] The testing process and indicators were the same as in Example 13. The filler was uniformly dispersed within the coating without agglomeration. The results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 3. Example 15

[0113] The formulation was adjusted according to the formulation of Example 13, with component Q replacing component D, while the other components remained unchanged.

[0114] The preparation process of the damping coating is the same as in Example 13.

[0115] The damping coating preparation process is the same as in Example 1. The wet film coated on the substrate showed no sagging or wrinkling, and no defects such as unevenness, pinholes, cracking, or orange peel shrinkage occurred during the drying process. The stability in use is rated as Grade 1, and the surface drying time is 4 hours at a room temperature of 5 degrees Celsius in winter.

[0116] The testing process and indicators were the same as in Example 13. The filler was uniformly dispersed within the coating without agglomeration. The results for coating density, sound insulation, heat insulation, damping, and adhesion are listed in Table 3.

[0117] Example 16 is an example of preparing a damping pad using a water-based damping coating containing open hollow microspheres via a repeated coating method. Example 16

[0118] A 500mm x 500mm nonwoven fabric was laid flat in a dish. The water-based damping coating obtained in Example 2 was poured into the dish. After the coating was completely adhered to both sides of the nonwoven fabric, the excess coating was poured off. The nonwoven fabric saturated with coating was transferred to a PFTFE polytetrafluoroethylene plate and dried at room temperature. After surface drying, another layer of the damping coating obtained in Example 2 was scraped onto each of the two surface-dried coatings. After surface drying, a second coating was applied. After complete drying, a damping plate with a thickness between 5-10mm was obtained. It was laser-cut into the required shape, and the sound transmission loss rating (STL) was tested to be 34 dB, and the thermal conductivity λ (W / mK) was 0.08.

[0119] Example 17 is an example of preparing a hemispherical damping soundproof cover using a casting method with open hollow microspheres. Example 17

[0120] A release agent was applied to the inner surface of a hemispherical shell (8mm thick, 200mm in diameter) mold. The damping coating prepared in Example 15 was poured into the mold. After curing for 24 hours, the shell was demolded and allowed to cure for another 7 days at room temperature. The edges of the shell were then ground smooth. The sound insulation performance test was conducted in a quiet laboratory with a noise level not exceeding 30 decibels. A sound source (60 decibels for a mobile phone ringtone) was placed inside the resulting shell with the opening facing upwards. The detector measured the sound intensity at 62 decibels from 300mm directly above. Then, another shell was used to cover the lower shell with its opening facing downwards, ensuring a tight seal. The seams of the shells were wrapped with 2mm thick double-sided tape. The detector measured the sound intensity of the mobile phone ringtone at 21 decibels.

[0121] Example of effect Tables 1 to 3 present the performance analysis results of embodiments 1 to 15 of the present invention.

[0122] Table 1: Performance Test Results of Waterborne Damping Coatings Obtained in Examples 1-9

[0123] Table 2: Test Results of Coating Performance of Oil-Based Damping Coatings Obtained in Examples 10-12

[0124] Table 3: Performance Test Results of Two-Component Damping Coatings in Examples 13-15

[0125] A comparison of the experimental data from Examples 1 and 2-9, Examples 11 and 11-12, and Examples 13 and 14-15 reveals that the present invention effectively reduces the overall weight of the damping coating and improves its damping performance, heat insulation performance, and sound insulation performance by adding open hollow microspheres to the damping coating and allowing the open hollow microspheres to adsorb the corresponding solvent before addition.

[0126] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A damping coating containing open hollow microspheres, characterized in that, The damping coating containing open hollow microspheres includes a coating base, open hollow microspheres, a solvent, and additives; The open hollow microspheres need to adsorb solvent before being added to the coating.

2. The damping coating containing open hollow microspheres according to claim 1, characterized in that, The content of the open hollow microspheres is 0~70wt%, preferably 20~50wt%.

3. The damping coating containing open hollow microspheres according to claim 1, characterized in that, The solvent is selected according to the damping coating system and can be a single component or a mixture of multiple components.

4. The damping coating containing open hollow microspheres according to claim 1, characterized in that, The additives include one or more of the following: solid fillers, pigments, plasticizers, dispersants, defoamers, leveling agents, thickeners, coupling agents, antioxidants, antifungal agents, and flame retardants.

5. The damping coating containing open hollow microspheres according to claim 3, characterized in that, When open hollow microspheres adsorb solvents, assisted adsorption is employed; the assisted adsorption includes the use of auxiliary agents and auxiliary treatment methods.

6. The damping coating containing open hollow microspheres according to claim 5, characterized in that, The auxiliary agent is a volatile amphiphilic organic solvent, and the volume ratio of the auxiliary agent to the solvent is 0~30%:1, preferably 5~20%:1; the auxiliary treatment method is one or more of the following: decompression assistance, ultrasonic assistance, boiling assistance, or high and low temperature cycle assistance.

7. The damping coating containing open hollow microspheres according to claim 3, characterized in that, When the coating base is a solvent-free damping coating, the open hollow microspheres adsorb one of water or organic volatile solvent before being added.

8. The method for preparing the coating of the damping coating containing open hollow microspheres according to any one of claims 1-7, characterized in that, The preparation steps include the following: (1) Solvent is adsorbed by open hollow microspheres to obtain filled open hollow microspheres; (2) The open-hole hollow microspheres are added to the base material of the damping coating formulation in a certain proportion, and the additives are added. The mixture is stirred until it is uniform and matured to obtain the damping coating containing the open-hole hollow microspheres. (3) The damping coating containing open hollow microspheres is applied to the substrate surface using a coating process, and after drying and curing, a damping coating containing open hollow microspheres is obtained.

9. The application of the damping coating containing open hollow microspheres according to any one of claims 1-8, characterized in that, This includes the use of multi-layer coating processes to prepare damping plates and damping shell materials with high loss factors, high heat insulation and sound insulation properties.

10. The application of the damping coating containing open hollow microspheres according to claims 1-8, characterized in that, It also includes the preparation of high-performance damping preforms using processes such as casting in molds, drying and molding, and demolding.

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