Preparation method of noise-reducing and anti-corrosion multifunctional coating

Abstract

The invention discloses a preparation method of a noise-reducing anti-corrosion multifunctional coating, which comprises the following steps: mixing a polydimethylsiloxane prepolymer with a curing agent, casting on a glass sheet, curing, demolding to obtain a film substrate, and carrying out laser perforation treatment on the film substrate to obtain a low-frequency noise-reducing film substrate; taking the low-frequency noise reduction film substrate as a directional receiving plane, and performing electrostatic spinning treatment to obtain the low-frequency noise reduction film; uniformly mixing aliphatic isocyanate, polyether polyol, a chain extender, a catalyst, a conductive filler, a heat-conducting filler, porous titanium dioxide, a defoaming agent, a dispersing agent and a latent curing agent, and treating to obtain an anti-corrosion damping coating; the surface of a target base body is sequentially coated with the anti-corrosion damping coating, the low-frequency noise reduction film and the anti-corrosion damping coating, and the noise reduction and anti-corrosion multifunctional coating is obtained; the problems that in the prior art, due to separation of low-frequency noise reduction and anti-corrosion functions, construction is complex, cost is high, the effect is limited, and signal transmission quality and equipment durability are difficult to consider at the same time are solved.

Description

Technical Field

[0001] The present invention belongs to the field of anti-corrosion coatings, and particularly relates to a preparation method of a noise-reducing and anti-corrosion multifunctional coating. Background Art

[0002] In the power system, as an important carrier for electric energy transmission, cables are often interfered by low-frequency noises (such as external mechanical vibration noises, power frequency noises). These noises not only cause signal transmission distortion, but may also lead to unstable operation of equipment, and even accelerate cable aging and reduce service life. In addition, the environment where cables are laid in China is complex, and cables are easily corroded, further affecting their performance and safety. In the prior art, noise reduction often adopts increasing the thickness of the cable outer skin or using sound insulation cotton, but this not only increases the weight and cost of the cable, affects the installation convenience of the cable, but also cannot effectively reduce low-frequency noises. The anti-corrosion function is often achieved through corrosion-resistant coatings, but the existence of low-frequency noises will cause the adhesion between the coating and the substrate to decrease, resulting in coating cracking. In addition, low-frequency noises will affect the microstructure of the anti-corrosion coating, leading to voids in the coating and causing local corrosion. However, there are still few anti-corrosion coatings on the market that have both low-frequency noise reduction and anti-corrosion functions. Therefore, it is of great practical significance and application value to develop a multifunctional coating material that can not only effectively reduce low-frequency noises but also provide anti-corrosion protection.

[0003] Yuan et al. (Yuan Xu, Wang Wei, Du Cuiting, et al. A novel noise-reducing and anti-corrosion polyurethane elastomer coating material modified by MXene / porous TiO2 [J]. Surfaces and Interfaces, 2024, 48, 104256.) achieved the dual functions of noise reduction and anti-corrosion by adding fillers with co-grown layered MXene and porous TiO2 microspheres to the PU coating. The layered and porous structures of the fillers improved the noise reduction performance for noises greater than 1000 Hz, but were ineffective for low-frequency noises.

[0004] Chinese Patent "A Multifunctional Anti-Corrosion Coating and Its Preparation Method" (Application No.: CN202310123456.7, Publication No.: CN115678901A, Publication Date: April 15, 2023) discloses a multifunctional anti-corrosion coating and its preparation method, in which the anti-corrosion performance and self-healing ability of the coating are improved through nanocomposites and self-healing technology, but ubiquitous low-frequency noises will cause voids in the coating and lead to local corrosion.

[0005] The Chinese patent "A Heat-resistant Self-healing ACNTs / fGO@TiB2 / ZP / EP Anticorrosive Coating and Its Preparation Method and Coating" (Application No.: CN202411556953.6, Publication No.: CN119264771A, Publication Date: January 7, 2025) discloses a heat-resistant self-healing ACNTs / fGO@TiB2 / ZP / EP anticorrosive coating and its preparation method and coating. By adding the composite filler ACNTs / fGO@TiB2 / ZP, phosphate ions and iron ions can be released during corrosion to react and form complexes or chelates, filling the micropores and cracks of the coating, realizing the self-healing of the coating. However, low-frequency noise will affect the microstructure of the composite filler, reduce its stability, and affect the long-term durability of the coating.

[0006] The Chinese patent "A Preparation Method of a Granular Decorated Electrospun Anticorrosive Coating with Both Corrosion Warning and Self-healing Functions" (Application No.: CN202411328073.3, Publication No.: CN119372924A, Publication Date: January 28, 2025) discloses a preparation method of a granular decorated electrospun anticorrosive coating with both corrosion warning and self-healing functions. By introducing nanofibers with a core-shell structure into the epoxy resin matrix, the anticorrosive coating's functions of warning corrosion and self-healing are realized. However, the presence of low-frequency noise will damage the interfacial properties of the core-shell structure, thus affecting the overall structure and impairing the function of warning corrosion. Summary of the Invention

[0007] The purpose of the present invention is to provide a preparation method of a noise-reducing and anticorrosive multifunctional coating, which solves the problems of complex construction, high cost, limited effect, and difficulty in simultaneously considering signal transmission quality and equipment durability caused by the separation of low-frequency noise reduction and anticorrosive functions in the prior art.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is:

[0009] A preparation method of a noise-reducing and anticorrosive multifunctional coating is specifically implemented according to the following steps:

[0010] Step 1, prepare a low-frequency noise-reducing thin film matrix

[0011] After mixing the polydimethylsiloxane prepolymer and the curing agent, perform casting treatment on a flat glass sheet, and demold after curing treatment to obtain a thin film matrix. Perform laser perforation treatment on the thin film matrix to obtain a low-frequency noise-reducing thin film matrix;

[0012] Step 2, electrospin directionally to obtain a low-frequency noise-reducing thin film

[0013] Use the low-frequency noise-reducing thin film matrix obtained in Step 1 as the directional receiving plane, and perform electrospinning treatment to obtain a low-frequency noise-reducing thin film;

[0014] Step 3, prepare the anti-corrosion damping coating

[0015] Mix aliphatic isocyanate, polyether polyol, chain extender, catalyst, conductive filler, heat-conductive filler, porous titanium dioxide, defoamer, dispersant and latent curing agent evenly to obtain the anti-corrosion damping coating;

[0016] Step 4, compound to obtain the noise-reducing and anti-corrosion multi-functional coating

[0017] Apply the anti-corrosion damping coating obtained in Step 3 on the surface of the target substrate. After curing, cover the low-frequency noise-reducing film obtained in Step 2 on the target substrate coated with the anti-corrosion damping coating through lamination treatment. Subsequently, perform dip coating treatment and heat curing treatment on the target substrate in the polydimethylsiloxane solution. Then, apply the anti-corrosion damping coating obtained in Step 3 on the low-frequency noise-reducing film of the target substrate again. After drying treatment, obtain the noise-reducing and anti-corrosion multi-functional coating.

[0018] Further, the specific operation in Step 1 is as follows: After ultrasonically cleaning a flat glass slide in deionized water or ethanol for 30 min to remove impurities, mix the polydimethylsiloxane prepolymer and curing agent with a ratio of 10:1 evenly, remove air bubbles under vacuum for 30 min, then cast on the glass slide. Place the cast film on a spin coater, adjust the spin coater speed to 500 - 2000 rpm, the rotation time is 30 - 60 s, the curing temperature is 65 - 85 °C, and the curing time is 2 - 4 h. The method of laser perforation treatment is as follows: The perforation diameters are arranged in an increasing order according to the sizes of 10, 20, 30, 40, 50 μm, and the perforation spacings are arranged in an increasing order according to the lengths of 100, 200, 300, 400 μm.

[0019] Further, the electrospinning treatment method in Step 2 is as follows: Mix the piezoelectric polymer and the solvent evenly by stirring to obtain a spinning solution. Use the low-frequency noise-reducing film substrate obtained in Step 1 as the directional receiving plane. Under the conditions of a receiving distance of 15 - 18 cm, a spinning voltage of 21 - 23 kV, and a roller speed of 1500 - 2500 rpm, electrospin to obtain the low-frequency noise-reducing film.

[0020] Further, the spinning solution in Step 2 is composed of the following substances by mass percentage: 8% - 10% piezoelectric polymer, 90% - 92% solvent, and the total mass of the above components is 100%; the piezoelectric polymer is any one of polyvinylidene fluoride and polyvinylidene fluoride trifluoroethylene; the solvent is N, N-dimethylformamide, acetone, and the volume ratio of N, N-dimethylformamide to acetone is 3:2.

[0021] Further, the anti-corrosion damping coating in step 3 is composed of the following substances by mass percentage: 25%-35% aliphatic isocyanate, 5%-10% polyether polyol, 10%-15% chain extender, 0.2%-0.4% catalyst, 5%-10% conductive filler, 10%-20% thermal conductive filler, 8.7%-19.5% porous titanium dioxide, 0.2%-0.4% defoamer, 0.1%-0.5% dispersant, and 10%-15% latent curing agent. The total mass of the above components is 100%.

[0022] Further, the aliphatic isocyanate in step 3 is any one of isophorone diisocyanate or hexamethylene diisocyanate; the polyether polyol is any one of polypropylene glycol or polytetrahydrofuran diol; the chain extender is any one of polyoxypropylene diamine or polyether triamine; the catalyst is any one of dibutyltin dilaurate or stannous octoate; the conductive filler is any one of conductive carbon black, carbon nanotubes, or graphene; the thermal conductive filler is any one of nano-aluminum oxide or nano-boron nitride; the defoamer is any one of stearyl alcohol or oleyl alcohol; the dispersant is any one of polyacrylate or phosphate ester; the latent curing agent is any one of ketimine or 2-isopropyl-3-hydroxyethyl-1,3-oxazolidine.

[0023] Further, the conditions for uniform mixing in step 3 are: the mixing and stirring temperature is 80-95°C, and the stirring time is 1-3 h.

[0024] Further, the curing treatment conditions in step 4 are: room temperature curing for 10-30 min; the method of laminating treatment is: align and laminate the low-frequency noise reduction film with the target substrate coated with the cured anti-corrosion damping coating, and hot press at 60-100°C for 15-30 s; the method of dip coating treatment is: completely immerse the target substrate covered with the low-frequency noise reduction film in the polydimethylsiloxane solution, stay for 30-90 s, and then withdraw it at a speed of 5-10 mm / s; the heating and curing treatment conditions are: the heating temperature is 60-90°C, and the curing time is 1-3 h; the drying treatment conditions are: dry at room temperature for 10-30 min.

[0025] Further, the polydimethylsiloxane solution in step 4 is a solution obtained by mixing a polydimethylsiloxane prepolymer and a curing agent in a ratio of 10:1.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] A preparation method of a noise reduction and anti-corrosion multifunctional coating provided by the present invention can achieve efficient noise reduction of low-frequency noise in the range of 20 - 1000 Hz through the compounding of a low-frequency noise reduction film in the middle of the anti-corrosion coating. By using laser perforation, perforations with a fixed diameter and fixed spacing can be obtained on the flexible polydimethylsiloxane film. Then, through electrospinning, piezoelectric nanofibers with a fixed length and directional overlap are obtained on the surface of the perforated film. When low-frequency noise is incident, the overlapping piezoelectric nanofibers resonate due to frequency matching, thereby converting the low-frequency noise that is difficult to absorb into electrical energy through the piezoelectric effect. The conductive and heat-conductive fillers added to the anti-corrosion coating can convert it into heat energy dissipation from the inside to the outside in the overall coating. This method ensures that the coating has excellent anti-corrosion performance without adding additional low-frequency noise reduction equipment, solving the problems in the prior art such as complex construction, high cost, limited effect, and difficulty in simultaneously considering signal transmission quality and equipment durability caused by the separation of low-frequency noise reduction and anti-corrosion functions, and has broad application prospects in the fields of power transmission, rail transit, automobile manufacturing, and construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of a noise reduction and anti-corrosion multifunctional coating prepared by the present invention.

[0029] In the figure, 1 - anti-corrosion damping coating, 2 - low-frequency noise reduction film. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0031] A preparation method of a noise reduction and anti-corrosion multifunctional coating of the present invention is specifically implemented according to the following steps:

[0032] Step 1, prepare the matrix of the low-frequency noise reduction film

[0033] Mix the polydimethylsiloxane prepolymer and the curing agent evenly in a ratio of 10:1 to obtain a mixed solution. After ultrasonically cleaning a flat glass slide in deionized water or ethanol for 30 min to remove impurities, then pour the mixed solution after vacuum degassing for 30 min onto the flat glass slide. The rotation speed of the spin coater is 500 - 2000 rpm, and the rotation time is 30 - 60 s. After curing at a temperature of 65 - 85 °C for 2 - 4 h, demold to obtain the film matrix. Subsequently, perform laser perforation treatment on the film matrix to obtain the matrix of the low-frequency noise reduction film. The perforation diameters are arranged in an increasing order according to the sizes of 10, 20, 30, 40, 50 μm, and the perforation spacings are arranged in an increasing order according to the lengths of 100, 200, 300, 400 μm.

[0034] Step 2, obtain the low-frequency noise reduction film by directional electrospinning

[0035] The piezoelectric polymer and the solvent are mixed and stirred evenly to obtain a spinning solution, where the piezoelectric polymer is 8%-10% and the solvent is 90%-92%, and the total mass of the above components is 100%. The piezoelectric polymer is any one of polyvinylidene fluoride and polyvinylidene fluoride trifluoroethylene. The solvent is N,N-dimethylformamide and acetone, and the volume ratio of N,N-dimethylformamide to acetone is 3:2. Subsequently, the low-frequency noise reduction film matrix obtained in step 1 is used as the directional receiving plane, and under the conditions of a receiving distance of 15-18 cm, a spinning voltage of 21-23 kV, and a roller rotation speed of 1500-2500 rpm, electrospinning is carried out to obtain a low-frequency noise reduction film.

[0036] Step 3, prepare the anti-corrosion damping coating

[0037] The aliphatic isocyanate, polyether polyol, chain extender, catalyst, conductive filler, heat-conducting filler, porous titanium dioxide, defoaming agent, dispersant and latent curing agent are mixed evenly at a stirring temperature of 80-95 °C and a stirring time of 1-3 h to obtain the anti-corrosion damping coating; where the aliphatic isocyanate is 25%-35%, the polyether polyol is 5%-10%, the chain extender is 10%-15%, the catalyst is 0.2%-0.4%, the conductive filler is 5%-10%, the heat-conducting filler is 10%-20%, the porous titanium dioxide is 8.7%-19.5%, the defoaming agent is 0.2%-0.4%, the dispersant is 0.1%-0.5%, and the latent curing agent is 10%-15%, and the total mass of the above components is 100%.

[0038] Among them, the aliphatic isocyanate is any one of isophorone diisocyanate or hexamethylene diisocyanate; the polyether polyol is any one of polypropylene glycol or polytetrahydrofuran glycol; the chain extender is any one of polyoxypropylene diamine or polyether triamine; the catalyst is any one of dibutyltin dilaurate and stannous octoate; the conductive filler is any one of conductive carbon black, carbon nanotubes, and graphene; the heat-conducting filler is any one of nano-aluminum oxide and nano-boron nitride. The defoaming agent is any one of stearyl alcohol or oleyl alcohol; the dispersant is any one of polyacrylate or phosphate dispersants; the latent curing agent is any one of ketimine or 2-isopropyl-3-hydroxyethyl-1,3-oxazolidine.

[0039] Step 4, compound to obtain a noise reduction and anti-corrosion multifunctional coating

[0040] Apply the anti-corrosion damping coating obtained in Step 3 on the surface of the target substrate. After curing at room temperature for 10 - 30 min, align and bond the low-frequency noise reduction film obtained in Step 2 with the target substrate with the cured anti-corrosion damping coating. Then, hot press at 60 - 100 °C for 15 - 30 s to cover the low-frequency noise reduction film on the anti-corrosion damping coating. Next, completely immerse the bonded target substrate in a polydimethylsiloxane solution with a ratio of polydimethylsiloxane prepolymer to curing agent of 10:1, stay for 30 - 90 s, and then withdraw it at a relatively fast speed of 5 - 10 mm / s. After curing at a heating temperature of 60 - 90 °C for 1 - 3 h, apply the anti-corrosion damping coating obtained in Step 3 on the low-frequency noise reduction film of the target substrate again. After drying at room temperature for 10 - 30 min, a noise reduction and anti-corrosion multi-functional coating is obtained.

[0041] Figure 1 Figure 4 is a schematic diagram of a noise reduction and anti-corrosion multi-functional coating prepared by the present invention. The low-frequency noise reduction film 2 is located in the middle layer of the noise reduction and anti-corrosion multi-functional coating. The upper and lower layers of the noise reduction and anti-corrosion multi-functional coating are anti-corrosion damping coatings 1. The low-frequency noise reduction film layer is formed by laser perforation with a fixed diameter and fixed spacing and the overlapping of piezoelectric nanofibers in the holes and the spacing. These overlapping piezoelectric fibers generate resonance due to frequency matching under the action of low-frequency noise, so that the difficult-to-absorb low-frequency noise can be converted into electrical energy through the piezoelectric effect. The conductive fillers and heat-conductive fillers added in the anti-corrosion coating are beneficial to the conversion of electrical energy into heat energy, thereby dissipating low-frequency noise.

[0042] The present invention obtains a film substrate with controllable thickness by controlling the rotation speed of the spin coater within the range of 500 - 2000 rpm, the rotation time of 30 - 60 s, the curing temperature of 65 - 85 °C, and the curing time of 2 - 4 h. By controlling the perforation diameter to increase in the order of 10, 20, 30, 40, 50 μm and the perforation spacing to increase in the order of 100, 200, 300, 400 μm, the overlapping length of subsequent piezoelectric nanofibers is controlled. By controlling the spinning voltage within the range of 21 - 23 kV and the roller rotation speed within the range of 1500 - 2500 rpm, the diameter and uniformity of the overlapping piezoelectric nanofibers are controlled. By controlling the overlapping length and fiber diameter of the piezoelectric nanofibers, the natural frequency of the overlapping fibers on the film substrate can resonate in the low-frequency band of 20 - 1000 Hz. By controlling the various ratios in the anti-corrosion damping coating, the damping of the anti-corrosion coating substrate can absorb medium and high-frequency noise, and the energy generated by the resonance of the low-frequency noise reduction film can be dissipated. By controlling the hot pressing of the low-frequency noise reduction film and the target substrate with the cured anti-corrosion damping coating at 60 - 100 °C for 15 - 30 s, their perfect fitting is controlled. By controlling the residence time of the fitted target substrate in the polydimethylsiloxane solution for 30 - 90 s, the extraction speed of 5 - 10 mm / s, the heating temperature of 60 - 90 °C, and the curing time of 1 - 3 h, the firm bonding of the low-frequency noise reduction film and the anti-corrosion damping coating is controlled. By controlling the re-coating of the anti-corrosion damping coating and drying at room temperature for 10 - 30 min, a multi-functional coating with noise reduction and anti-corrosion is obtained.

[0043] The intermediate composite of the low-frequency noise reduction film and the anti-corrosion coating substrate in the multi-functional coating with noise reduction and anti-corrosion provides an efficient absorption mechanism and dissipation path for the absorption of low-frequency noise, enabling the multi-functional coating to not only resist the corrosion of the external environment during service but also absorb and dissipate the low-frequency noise interfering with the equipment. Based on the effectively anti-corrosion coating, the multi-functional coating with noise reduction and anti-corrosion solves the problems in the prior art such as complex construction, high cost, limited effect, and difficulty in simultaneously considering the signal transmission quality and equipment durability caused by the separation of noise reduction and anti-corrosion functions, and has broad application prospects in the fields of power transmission, rail transit, automobile manufacturing, and construction.

[0044] Example 1

[0045] Mix the polydimethylsiloxane prepolymer and the curing agent evenly at a ratio of 10:1 to obtain a mixed solution. After ultrasonically cleaning a flat glass slide in ethanol for 30 min to remove impurities, then cast the mixed solution after vacuum degassing for 30 min on the flat glass slide. The rotation speed of the spin coater is 2000 rpm and the rotation time is 30 s. After curing at a temperature of 65 °C for 4 h, demold to obtain a film substrate. Subsequently, laser perforate the film substrate in an arrangement with increasing perforation diameters (10, 20, 30, 40, 50 μm) and perforation spacings (100, 200, 300, 400 μm) to obtain a low-frequency noise reduction film substrate;

[0046] Mix 8% polyvinylidene fluoride, 92% N,N-dimethylformamide and acetone (the volume ratio of N,N-dimethylformamide to acetone is 3:2) and stir evenly to obtain a spinning solution. Use the low-frequency noise reduction film substrate as the directional receiving plane, and under the conditions of a receiving distance of 15 cm, a spinning voltage of 23 kV, and a roller rotation speed of 2000 rpm, electrospinning is carried out to obtain a low-frequency noise reduction film;

[0047] Mix 25% isophorone diisocyanate, 5% polytetrahydrofuran diol, 10% polyoxypropylene diamine, 0.2% dibutyltin dilaurate, 10% conductive carbon black, 20% nano-aluminum oxide, 19.5% porous titanium dioxide, 0.2% stearyl alcohol, 0.1% polyacrylate dispersant and 10% ketimine evenly at a stirring temperature of 80 °C and a stirring time of 3 h to obtain an anti-corrosion damping coating;

[0048] Cure the target substrate coated with the anti-corrosion damping coating at room temperature for 10 min. Align and bond the low-frequency noise reduction film with the target substrate cured with the anti-corrosion damping coating, and hot press at 100 °C for 15 s to cover the low-frequency noise reduction film on the anti-corrosion damping coating. Then completely immerse the bonded target substrate in a polydimethylsiloxane solution with a ratio of polydimethylsiloxane prepolymer to curing agent of 10:1, stay for 30 s, and then quickly extract it at a speed of 5 mm / s. After curing at a heating temperature of 60 °C for 3 h, coat the anti-corrosion damping coating on the low-frequency noise reduction film of the target substrate again, and dry at room temperature for 30 min to obtain a noise reduction and anti-corrosion multi-functional coating.

[0049] Example 2

[0050] Mix the polydimethylsiloxane prepolymer and the curing agent evenly at a ratio of 10:1 to obtain a mixed solution. After ultrasonically cleaning a flat glass slide in ethanol for 30 min to remove impurities, then cast the mixed solution after vacuum degassing for 30 min onto the flat glass slide. The rotation speed of the spin coater is 500 rpm and the rotation time is 60 s. After curing at a temperature of 85 °C for 2 h, demold to obtain a film substrate. Subsequently, laser perforate the film substrate in an arrangement where the perforation diameter (10, 20, 30, 40, 50 μm) and the perforation spacing (100, 200, 300, 400 μm) increase to obtain a low-frequency noise reduction film substrate;

[0051] Mix 9% poly(vinylidene fluoride-trifluoroethylene), 91% N,N-dimethylformamide and acetone (the volume ratio of N,N-dimethylformamide to acetone is 3:2) and stir evenly to obtain a spinning solution. Use the low-frequency noise reduction film substrate as the directional receiving plane, and under the conditions of a receiving distance of 18 cm, a spinning voltage of 21 kV, and a roller rotation speed of 1500 rpm, electrospinning is carried out to obtain a low-frequency noise reduction film;

[0052] Mix 35% hexamethylene diisocyanate, 10% polypropylene glycol, 10% polyether triamine, 0.4% stannous octoate, 5% carbon nanotubes, 10% nano boron nitride, 19.3% porous titanium dioxide, 0.2% oleyl alcohol, 0.1% phosphate dispersant and 10% 2-isopropyl-3-hydroxyethyl-1,3-oxazolidine evenly at a stirring temperature of 90 °C for 2 h to obtain an anti-corrosion damping coating;

[0053] Coat the anti-corrosion damping coating on the surface of the target substrate. After curing at room temperature for 30 min, align and bond the low-frequency noise reduction film with the target substrate with the cured anti-corrosion damping coating. Hot press at 60 °C for 30 s to cover the low-frequency noise reduction film on the anti-corrosion damping coating. Then completely immerse the bonded target substrate in a polydimethylsiloxane solution with a ratio of polydimethylsiloxane prepolymer to curing agent of 10:1 and stay for 60 s. Subsequently, withdraw it at a relatively fast speed of 10 mm / s. After curing at a heating temperature of 90 °C for 1 h, coat the anti-corrosion damping coating on the low-frequency noise reduction film of the target substrate again. After drying at room temperature for 30 min, a noise reduction and anti-corrosion multifunctional coating is obtained.

[0054] Example 3

[0055] Mix the polydimethylsiloxane prepolymer and the curing agent evenly at a ratio of 10:1 to obtain a mixed solution. After ultrasonically cleaning a flat glass slide in ethanol for 30 min to remove impurities, then cast the mixed solution after vacuum defoaming for 30 min on the flat glass slide. The rotation speed of the spin coater is 1500 rpm, and the rotation time is 60 s. After curing at a temperature of 70 °C for 3 h, demold to obtain a film substrate. Subsequently, laser perforate the film substrate according to the arrangement pattern of increasing perforation diameters (10, 20, 30, 40, 50 μm) and perforation spacings (100, 200, 300, 400 μm) to obtain a low-frequency noise reduction film substrate;

[0056] Mix 10% polyvinylidene fluoride, 90% N,N-dimethylformamide and acetone (the volume ratio of N,N-dimethylformamide to acetone is 3:2) and stir evenly to obtain a spinning solution. Use the low-frequency noise reduction film substrate as the directional receiving plane, and under the conditions of a receiving distance of 18 cm, a spinning voltage of 21 kV, and a roller rotation speed of 2500 rpm, electrospinning to obtain a low-frequency noise reduction film;

[0057] Mix 30% isophorone diisocyanate, 8% polytetrahydrofuran diol, 15% polypropylene glycol, 0.3% stannous octoate, 8% graphene, 14.4% nano-aluminum oxide, 8.7% porous titanium dioxide, 0.1% oleyl alcohol, 0.5% polyacrylate dispersant and 15% ketimine evenly at a stirring temperature of 95 °C for 1 h to obtain an anti-corrosion damping coating;

[0058] Coat the anti-corrosion damping coating on the surface of the target substrate. After curing at room temperature for 30 min, align and attach the low-frequency noise reduction film to the target substrate with the cured anti-corrosion damping coating, and hot press at 100 °C for 15 s to cover the low-frequency noise reduction film on the anti-corrosion damping coating. Then completely immerse the attached target substrate in a polydimethylsiloxane solution with a ratio of polydimethylsiloxane prepolymer to curing agent of 10:1 for 60 s, and then quickly extract it at a speed of 5 mm / s. After curing at a heating temperature of 80 °C for 2 h, coat the anti-corrosion damping coating on the low-frequency noise reduction film of the target substrate again, and dry at room temperature for 10 min to obtain a noise reduction and anti-corrosion multifunctional coating.

[0059] Example 4

[0060] Mix the polydimethylsiloxane prepolymer and the curing agent evenly at a ratio of 10:1 to obtain a mixed solution. After ultrasonically cleaning a flat glass slide in ethanol for 30 min to remove impurities, then cast the mixed solution after vacuum defoaming for 30 min on the flat glass slide. The rotation speed of the spin coater is 1000 rpm, and the rotation time is 40 s. After curing at a temperature of 70 °C for 2 h, demold to obtain a film substrate. Subsequently, laser perforate the film substrate according to the arrangement with increasing perforation diameters (10, 20, 30, 40, 50 μm) and perforation spacings (100, 200, 300, 400 μm) to obtain a low-frequency noise reduction film substrate;

[0061] Mix 10% polyvinylidene fluoride trifluoroethylene, 90% N,N-dimethylformamide and acetone (the volume ratio of N,N-dimethylformamide to acetone is 3:2) and stir evenly to obtain a spinning solution. Use the low-frequency noise reduction film substrate as the directional receiving plane, and under the conditions of a receiving distance of 15 cm, a spinning voltage of 22 kV, and a roller rotation speed of 2000 rpm, electrospinning to obtain a low-frequency noise reduction film;

[0062] Mix 28.8% hexamethylene diisocyanate, 10% polypropylene glycol, 10% polyoxypropylene diamine, 0.4% stannous octoate, 10% conductive carbon black, 20% nano boron nitride, 10.4% porous titanium dioxide, 0.3% oleyl alcohol, 0.1% polyacrylate dispersant and 10% ketimine evenly at a stirring temperature of 85 °C for 2 h to obtain an anti-corrosion damping coating;

[0063] After curing the target substrate coated with the anti-corrosion damping coating at room temperature for 30 min, align and attach the low-frequency noise reduction film to the target substrate with the cured anti-corrosion damping coating, and hot press at 80 °C for 20 s to cover the low-frequency noise reduction film on the anti-corrosion damping coating. Then completely immerse the attached target substrate in a polydimethylsiloxane solution with a ratio of polydimethylsiloxane prepolymer to curing agent of 10:1, stay for 90 s, and then quickly extract it at a speed of 10 mm / s. After curing at a heating temperature of 60 °C for 3 h, coat the anti-corrosion damping coating on the low-frequency noise reduction film of the target substrate again, and dry at room temperature for 20 min to obtain a noise reduction and anti-corrosion multifunctional coating.

[0064] Comparative Example 1

[0065] The difference between Comparative Example 1 and Example 1 is that the film substrate in Step 1 was not subjected to laser perforation treatment.

[0066] Comparative Example 2

[0067] The difference between Comparative Example 2 and Example 1 is that Step 2 was not carried out.

[0068] Comparative Example 3

[0069] The difference between Comparative Example 3 and Example 1 is that in Step 4, the anti-corrosion damping coating was not recoated.

[0070] Comparative Example 4

[0071] The difference between Comparative Example 4 and Example 1 is that the anti-corrosion damping coating in Step 3 did not add conductive fillers.

[0072] Comparative Example 5

[0073] The difference between Comparative Example 4 and Example 1 is that the anti-corrosion damping coating in Step 3 did not add porous titanium dioxide.

[0074] Comparative Example 6

[0075] The difference between Comparative Example 4 and Example 1 is that the anti-corrosion damping coating in Step 3 did not add heat-conducting fillers.

[0076] Table 1 shows the comparison of the average sound absorption coefficient α of Example 1 and Comparative Examples 1-6 in the frequency bands of 50-1000 Hz and 1000-6400 Hz, and the average corrosion rate performance in 96 h.

[0077] Table 1

[0078]

[0079] As can be seen from Table 1, the low-frequency noise reduction film in Example 1 is composed of a laser-perforated PDMS film with a fixed diameter and a fixed pitch, and piezoelectric nanofibers lapped in the holes and pitches. The lapped fibers are fixed at both ends like nano-strings. When low-frequency noise in the range of 20-1000 Hz enters, the lapped piezoelectric nanofibers resonate due to frequency matching, thus converting the low-frequency noise that is difficult to absorb into electrical energy through the piezoelectric effect. Since the low-frequency noise reduction film is located in the middle layer of the anti-corrosion coating, the conductive fillers and heat-conducting fillers added in the anti-corrosion coating are beneficial to convert the electrical energy generated into heat energy and dissipate it. In addition, the microvoids between these lapped fibers and the porous titanium dioxide in the anti-corrosion coating are all beneficial to the absorption of medium and high-frequency noise, and the addition of these fillers can also fill the defects in the coating and effectively prevent the coating from being eroded by the external environment.

[0080] Therefore, Example 1 has excellent noise reduction performance in the low-frequency and mid-high frequency bands, as well as a low corrosion rate. Compared with Comparative Example 1, the thin film substrate in Step 1 was not subjected to laser perforation treatment. Therefore, the electrospun fibers in Step 2 were arranged in a continuous long fiber orientation on the thin film, rather than the fixed-length fibers with both ends fixed in Example 1. That is, the natural frequency of the fibers in Comparative Example 1 could not match the low-frequency, so the sound absorption performance in the 20 - 1000 Hz low-frequency band decreased significantly. Compared with Comparative Example 2, the thin film substrate was not used as the receiving plane for fiber collection, and the low-frequency could not be matched, so the low-frequency sound absorption performance was extremely poor. Compared with Comparative Example 3, the anti-corrosion damping coating was not reapplied, making the low-frequency noise reduction thin film the upper surface of the entire coating. The low-frequency noise reduction performance was still excellent, but it had a large number of through holes, reducing the anti-corrosion performance. Compared with Comparative Example 4, no conductive filler was added to the anti-corrosion damping coating, making the electric potential generated by the resonance of the low-frequency noise reduction thin film unable to conduct, reducing the sound absorption performance in the low-frequency band. Compared with Comparative Example 5, no porous titanium dioxide was added to the anti-corrosion damping coating, resulting in a decrease in the noise absorption performance in the mid-high frequency band that depends on porous sound absorption. Compared with Comparative Example 6, no heat-conducting filler was added to the anti-corrosion damping coating. Since the noise dissipation in the mid-high frequency band mainly depends on viscous loss and porous sound absorption to convert the incident sound wave into heat energy, and in addition, the electro-acoustic conversion generated by resonance is ultimately dissipated through heat, the absence of heat-conducting filler caused the overall noise absorption performance of the coating to decrease in the low, mid, and high frequency bands.

[0081] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example. The protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A method for preparing a noise reduction and anti-corrosion multifunctional coating, characterized in that: Follow the steps below to implement it: Step 1: Prepare low-frequency noise reduction film substrate After mixing the polydimethylsiloxane prepolymer and the curing agent, the mixture is cast on a flat glass sheet, and after curing, the film substrate is demoulded to obtain a film substrate, and the film substrate is laser perforated to obtain a low-frequency noise reduction film substrate; Step 2: Directed electrospinning to obtain low-frequency noise reduction film The low-frequency noise reduction film substrate obtained in step 1 is used as a directional receiving plane, and a low-frequency noise reduction film is obtained after electrospinning treatment; Step 3: Preparation of anti-corrosion damping coating The aliphatic isocyanate, polyether polyol, chain extender, catalyst, conductive filler, thermal conductive filler, porous titanium dioxide, defoamer, dispersant and latent curing agent are uniformly mixed to obtain an anti-corrosion damping coating; Step 4: Compound to obtain noise reduction and anti-corrosion multifunctional coating The anti-corrosion damping coating obtained in step 3 is coated on the surface of the target substrate. After curing treatment, the low-frequency noise reduction film obtained in step 2 is laminated and covered on the target substrate coated with the anti-corrosion damping coating. The target substrate is then dipped in a polydimethylsiloxane solution and heat-cured. The anti-corrosion damping coating obtained in step 3 is then coated again on the low-frequency noise reduction film of the target substrate. After drying treatment, a noise reduction and anti-corrosion multifunctional coating is obtained.

2. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 1, characterized in that: The specific method in step 1 is: after ultrasonicating a flat glass sheet in deionized water or ethanol for 30 minutes to remove impurities, mix the polydimethylsiloxane prepolymer and curing agent in a ratio of 10:1 evenly, vacuum degas for 30 minutes and then cast on the glass sheet, place the cast film on a glue spreader, adjust the glue spreader speed to 500-2000rpm, the rotation time to 30-60s, the curing temperature to 65-85°C, the curing time to 2-4h, and the laser perforation treatment method is: the perforation diameter is arranged in ascending order of 10, 20, 30, 40, 50μm, and the perforation spacing is arranged in ascending order of 100, 200, 300, 400μm.

3. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 1, characterized in that: The electrospinning process in step 2 is as follows: the piezoelectric polymer and the solvent are mixed and stirred evenly to obtain a spinning solution, the low-frequency noise reduction film substrate obtained in step 1 is used as a directional receiving plane, and the low-frequency noise reduction film is obtained by electrospinning at a receiving distance of 15-18 cm, a spinning voltage of 21-23 kV, and a roller speed of 1500-2500 rpm.

4. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 3, characterized in that: The spinning solution in step 2 is composed of the following substances in terms of mass percentage: 8%-10% piezoelectric polymer, 90%-92% solvent, and the total mass of the above components is 100%; the piezoelectric polymer is any one of polyvinylidene fluoride and polyvinylidene fluoride trifluoroethylene; the solvent is N,N-dimethylformamide and acetone, and the volume ratio of N,N-dimethylformamide and acetone is 3:

2.

5. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 1, characterized in that: The anti-corrosion damping coating in step 3 is composed of the following substances in percentage by mass: 25%-35% aliphatic isocyanate, 5%-10% polyether polyol, 10%-15% chain extender, 0.2%-0.4% catalyst, 5%-10% conductive filler, 10%-20% thermal conductive filler, 8.7%-19.5% porous titanium dioxide, 0.2%-0.4% defoamer, 0.1%-0.5% dispersant and 10%-15% latent curing agent, and the total mass of the above components is 100%.

6. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 5, characterized in that: The aliphatic isocyanate in step 3 is any one of isophorone diisocyanate or hexamethylene diisocyanate, the polyether polyol is any one of polypropylene glycol or polytetramethylene glycol, the chain extender is any one of polyoxypropylene diamine or polyether triamine, the catalyst is any one of dibutyltin dilaurate and stannous octoate, the conductive filler is any one of conductive carbon black, carbon nanotubes, and graphene, the thermal conductive filler is any one of nano-alumina and nano-boron nitride, the defoamer is any one of stearyl alcohol or oleyl alcohol, the dispersant is any one of polyacrylates or phosphates, and the latent curing agent is any one of ketimine or 2-isopropyl-3-hydroxyethyl-1,3-oxazolidine.

7. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 1, characterized in that: The mixing conditions in step 3 are as follows: the mixing and stirring temperature is 80-95° C. and the stirring time is 1-3 h.

8. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 1, characterized in that: In step 4, the curing treatment conditions are: curing at room temperature for 10-30 minutes; the laminating treatment method is: aligning and laminating the low-frequency noise reduction film with the target substrate with cured anti-corrosion damping coating, and hot pressing at 60-100°C for 15-30 seconds; the dipping treatment method is: completely immersing the target substrate covered with the low-frequency noise reduction film in the polydimethylsiloxane solution, staying for 30-90 seconds, and then pulling it out at a speed of 5-10mm / s; the heating curing treatment conditions are: heating temperature of 60-90°C, curing time of 1-3h; the drying treatment conditions are: drying at room temperature for 10-30 minutes.

9. The method for preparing a noise reduction and anti-corrosion multifunctional coating according to claim 1 or 8, characterized in that: The polydimethylsiloxane solution in step 4 is a solution in which a polydimethylsiloxane prepolymer and a curing agent are mixed in a ratio of 10:1.

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