Super-hydrophobic gas-phase corrosion-inhibiting coating, and preparation method and application thereof

Abstract

The present application relates to a kind of super-hydrophobic gas phase corrosion inhibitor coating and its preparation method and application, belong to the technical field of anticorrosive coating.The coating includes super-hydrophobic material BN / GO@SiO2, multi-element gas phase corrosion inhibitor system and epoxy resin;The multi-element gas phase corrosion inhibitor system is composed of sodium benzoate, sodium gluconate and cyclohexylamine carbonate;The present application also provides a kind of preparation method of super-hydrophobic gas phase corrosion inhibitor coating.The super-hydrophobic gas phase corrosion inhibitor coating of the present application is used for the corrosion protection of electronic components.The super-hydrophobic gas phase corrosion inhibitor coating of the present application can be prepared into super-hydrophobic gas phase corrosion inhibitor coating with excellent hydrophobic, heat conduction and insulation after spraying.

Description

Technical Field

[0001] This invention relates to the technical field of anti-corrosion coatings, specifically to a superhydrophobic vapor phase corrosion inhibitor coating, its preparation method, and its application. Background Technology

[0002] For electronic components operating in high-salt and high-humidity environments, organic anti-corrosion coatings protect the metal by blocking corrosive media through the organic matrix and fillers. However, although organic coatings are one of the most widely used metal protection methods, their effective coverage is affected by the shape and defects of the metal. The coverage is significantly reduced when the protected metal substrate has sharp edges or points. Furthermore, the application of organic coatings can excessively affect the basic properties of the metal surface, potentially impacting the use of some precision instruments. In recent years, vapor phase corrosion inhibitors (VCI) have received widespread attention in the field of corrosion protection.

[0003] Vapor phase corrosion inhibitors are compounds that can spontaneously volatilize at room temperature and adsorb onto the outer surface of metals in the form of small molecules or particles to block corrosive media, thereby achieving corrosion inhibition. Organic polymer films or paper are typically chosen as effective carriers for vapor phase corrosion inhibitors. Compared to traditional organic anti-corrosion coatings, vapor phase corrosion inhibitor technology, as an alternative method of metal protection, can effectively solve the problems faced by coatings. Furthermore, through proper formulation, vapor phase corrosion inhibitors can achieve long-lasting corrosion inhibition performance comparable to coatings.

[0004] Hexagonal boron nitride (h-BN), a two-dimensional layered material with excellent thermal conductivity, has gradually gained widespread attention in the field of thermal conductive materials due to its unique layered structure, strong mechanical properties, and good chemical stability. h-BN possesses very high thermal conductivity, effectively dissipating heat generated inside devices and mitigating overheating problems. Furthermore, h-BN exhibits good electrical insulation properties, thus effectively preventing electrical short circuits and ensuring safe operation when used as a thermal conductive material in electronic devices. Especially under high-frequency operating conditions, the heat generated inside electronic devices is highly concentrated and difficult to dissipate. This necessitates that thermal conductive materials not only possess excellent thermal conductivity but also good electrical insulation properties to prevent heat accumulation from damaging the internal circuitry of the device.

[0005] How to rationally combine hexagonal boron nitride with vapor phase corrosion inhibition systems for application in electronic devices is an urgent problem to be solved. Summary of the Invention

[0006] To address the issue that existing anti-corrosion materials for electronic devices do not combine hexagonal boron nitride with a vapor phase corrosion inhibitor system, this invention provides a superhydrophobic vapor phase corrosion inhibitor coating, its preparation method, and its application to solve the aforementioned problem.

[0007] The technical solution of this invention is as follows: In a first aspect, the present invention provides a superhydrophobic vapor phase corrosion inhibitor coating, the coating comprising a superhydrophobic material BN / GO@SiO2, a multi-component vapor phase corrosion inhibitor system and an epoxy resin; the multi-component vapor phase corrosion inhibitor system is composed of sodium benzoate, sodium gluconate and cyclohexylamine carbonate.

[0008] Furthermore, the mass ratio of the superhydrophobic material BN / GO@SiO2, the multi-component vapor phase corrosion inhibitor system, and the epoxy system is 0.16:0.04:1.

[0009] Furthermore, the preparation method of the superhydrophobic material BN / GO@SiO2 is as follows: (1) Preparation of hydroxylated boron nitride powder: Boron nitride and sodium hydroxide solution were mixed and stirred at 120 ℃~130 ℃. After the reaction was completed, the solid and liquid were separated and the solid was dried to obtain hydroxylated boron nitride powder. (2) Preparation of BN / GO powder: GO aqueous dispersion and hydroxylated boron nitride powder prepared in step (1) are added to isopropanol, and then DMAOP (dimethyloctadecyl-(3-trimethoxysilylpropyl)ammonium chloride) is added. The amount of DMAOP added is the same as the amount of GO added. Then the reaction is stirred. After the reaction is completed, the solid and liquid are separated and the solid is dried to obtain BN / GO composite material. (3) Preparation of BN / GO@SiO2: The BN / GO composite material prepared in step (2) is dispersed in anhydrous ethanol, ammonia and TEOS (ethyl silicate) are added, and the mixture is stirred to react. After the reaction is completed, the solid and liquid are separated, and the solid is dried under vacuum to obtain BN / GO@SiO2. (4) Preparation of superhydrophobic corrosion inhibitor material BN / GO@SiO2: Take the BN / GO@SiO2 prepared in step (3) and disperse it in anhydrous ethanol, add HMDS (hexamethyldisilazane) and ammonia water, stir and react; after the reaction is completed, separate the solid and liquid, and dry to obtain superhydrophobic material BN / GO@SiO2.

[0010] Furthermore, in step (1), the concentration of the sodium hydroxide solution is 20 wt%, the amount of boron nitride added is 1 wt% of the mass of the sodium hydroxide solution, and the particle size of the boron nitride is 2~5 μm.

[0011] Furthermore, in step (2), the concentration of the GO aqueous dispersion is 8~12 mg / g; the mass ratio of GO to hydroxylated boron nitride powder is 0.02:1.

[0012] Furthermore, in step (3), the amount of ammonia is 10~12 ml / g based on the weight of BN / GO; the amount of TEOS is 0.2~0.3 g / g based on the weight of BN / GO.

[0013] Furthermore, in step (4), the amount of HMDS used is 48~52 ml / g based on the weight of BN / GO@SiO2; the amount of ammonia used is 48~52 ml / g based on the weight of BN / GO@SiO2.

[0014] Furthermore, the multi-component vapor phase corrosion inhibitor system is composed of 50 wt% sodium benzoate, 30 wt% sodium gluconate and 20 wt% cyclohexylamine carbonate.

[0015] Secondly, the present invention provides a method for preparing the above-mentioned superhydrophobic vapor phase corrosion inhibitor coating, comprising the following steps: The superhydrophobic material BN / GO@SiO2 and the multi-component vapor phase corrosion inhibitor system were dissolved in anhydrous ethanol, stirred evenly, and then epoxy resin was added and stirred evenly again to obtain the superhydrophobic vapor phase corrosion inhibitor coating.

[0016] Thirdly, the present invention provides an application of the above-mentioned superhydrophobic vapor phase corrosion inhibitor coating in the corrosion protection of electronic components.

[0017] The beneficial effects of this invention are as follows: The superhydrophobic material BN / GO@SiO2 provided by this invention can be used in conjunction with a vapor phase corrosion inhibitor system to obtain a superhydrophobic vapor phase corrosion inhibitor coating through simple chemical synthesis. The coating, prepared by spraying, exhibits an adhesion greater than 10 MPa; salt spray resistance exceeding 240 h; damp heat resistance exceeding 240 h; contact angle > 150°; roll-off angle < 10°; thermal conductivity > 1.5 W / m·K; and coating resistivity > 10⁻⁶. 9 Ω·cm, circuit board insulation resistance > 10 8 The contact resistance change rate is less than 10%. The superhydrophobic vapor phase corrosion inhibitor coating of this invention can prepare a superhydrophobic vapor phase corrosion inhibitor coating with excellent hydrophobicity, thermal conductivity and insulation after spraying, and further research can be carried out on this basis. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 The figures are electrochemical impedance spectroscopy spectra of superhydrophobic materials BN / GO@SiO2 with different GO contents in Test Example 1 of this invention; in the figures, (a) is 8 wt% GO content; (b) is 6 wt% GO content; (c) is 4 wt% GO content; and (d) is 2 wt% GO content.

[0020] Figure 2This is the electrochemical impedance spectroscopy of the epoxy coating that was immersed for 7 days in Test Example 1 of this invention.

[0021] Figure 3 These are the EIS impedance spectrum and Tafel polarization curve of Test Example 2 of the present invention; in the figure, (a) is the EIS impedance spectrum of the coating with the vapor phase corrosion inhibitor added; (b) is the Tafel curve of the coating with the vapor phase corrosion inhibitor added; (c) is the EIS impedance spectrum of the coating without the vapor phase corrosion inhibitor added; and (d) is the Tafel curve of the coating without the vapor phase corrosion inhibitor added.

[0022] Figure 4 The figure shows the results of the 72-hour immersion test for resistance to damp heat in Test Example 4. In the figure, (a) is the surface condition of the coating before immersion, and (b) is the surface condition of the coating after immersion for 72 hours.

[0023] Figure 5 The figure shows the results of the 168h immersion test for resistance to damp heat in Test Example 4; in the figure, (a) is the surface condition of the coating before immersion, and (b) is the surface condition of the coating after immersion for 168h.

[0024] Figure 6 The figure shows the results of the accelerated corrosion test of salt spray test for 72 hours in test example 4; in the figure, (a) is the surface condition of the coating before accelerated corrosion, and (b) is the surface condition of the coating after 72 hours of accelerated corrosion.

[0025] Figure 7 The figure shows the results of the accelerated corrosion test after 168 hours of salt spray testing in Test Example 4. In the figure, (a) is the surface condition of the coating before accelerated corrosion, and (b) is the surface condition of the coating after 168 hours of accelerated corrosion.

[0026] Figure 8 This is a graph showing the test results of the superhydrophobic angle of the coating in Test Example 5.

[0027] Figure 9 This is a graph showing the thermal conductivity test results in Test Example 6.

[0028] Figure 10 This is a graph showing the change in resistance of the coating after immersion for 240 hours in test example 7.

[0029] Figure 11 The graph shows the on-resistance curve of the circuit board contact resistance in Test Example 8; in the graph, (a) is the on-resistance between the pin and the component, and (b) is the on-resistance between the on-points.

[0030] Figure 12 This is a graph showing the change in on-resistance of the blank circuit board after the salt spray test in Test Example 8. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0032] Example 1 A superhydrophobic material, BN / GO@SiO2, is prepared by the following method: (1) Preparation of hydroxylated boron nitride (BN-OH) powder: A 20 wt% sodium hydroxide solution was prepared, and 1 wt% hexagonal boron nitride (particle size 2~5 μm) powder was added. The mixture was stirred at 125 °C for 12 h to achieve high-temperature alkalization. Subsequently, water was added for dilution, followed by vacuum filtration and vacuum drying to obtain hydroxylated boron nitride powder (BN-OH).

[0033] (2) Preparation of BN / GO powder: 2 g of GO aqueous dispersion with a concentration of 10 mg / g and 1 g of BN-OH were uniformly dispersed in 100 ml of isopropanol. The mass fraction of GO relative to BN-OH was controlled at 2 wt%. An equal mass of DMAOP (dimethyloctadecyl-(3-trimethoxysilylpropyl)ammonium chloride) solution was prepared with isopropanol to a concentration of 1 wt%. The DMAOP solution was added to the mixed solution of GO and BN-OH and stirred for 12 h at 800 rpm using a mechanical stirrer. The uniformly mixed solution was vacuum filtered, and washed several times with anhydrous ethanol during the process. Then, it was vacuum dried to obtain the BN / GO composite material.

[0034] (3) Preparation of BN / GO@SiO2: 1 g of BN / GO was dispersed in 50 ml of anhydrous ethanol, 10 ml of ammonia and 0.2 g of TEOS were added, and the stirring time was controlled at 90 min. The solution was vacuum filtered, and repeatedly washed with anhydrous ethanol during the process. After vacuum drying, BN / GO@SiO2 was obtained.

[0035] (4) Preparation of superhydrophobic BN / GO@SiO2: 0.2 g of BN / GO@SiO2 was dispersed in 80 ml of anhydrous ethanol, 10 ml of HMDS and 10 ml of ammonia were added, and the mixture was stirred for 8-10 h. Then, the solution was vacuum filtered and repeatedly washed with anhydrous ethanol. After vacuum drying, the superhydrophobic material BN / GO@SiO2 was obtained.

[0036] Example 2 The preparation method is the same as in Example 1, except that the amount of GO added in step (2) is controlled to be 4 wt% relative to the mass fraction of BN-OH.

[0037] Example 3 The preparation method is the same as in Example 1, except that the amount of GO added in step (2) is controlled to be 6 wt% relative to the mass fraction of BN-OH.

[0038] Example 4 The preparation method is the same as in Example 1, except that the amount of GO added in step (2) is controlled to be 8 wt% relative to the mass fraction of BN-OH.

[0039] Example 5 A method for preparing a superhydrophobic vapor phase corrosion inhibitor coating is as follows: 2 g of the superhydrophobic material BN / GO@SiO2 prepared in Examples 1-4 and 0.5 g of the multi-component vapor phase corrosion inhibitor system (50 wt% sodium benzoate + 30 wt% sodium gluconate + 20 wt% cyclohexylamine carbonate) were dissolved in 5 ml of anhydrous ethanol and stirred thoroughly. Then, 12.5 g of epoxy resin was added and stirred thoroughly again to obtain the superhydrophobic vapor phase corrosion inhibitor coating.

[0040] The method of using superhydrophobic vapor phase corrosion inhibitor coating is to spray the superhydrophobic vapor phase corrosion inhibitor coating onto the surface of a carrier. The carrier can be a part of the circuit board surface without electronic components, or it can be an alloy that is easily corroded, such as a steel plate.

[0041] Test Example 1 Testing the performance of superhydrophobic materials BN / GO@SiO2 with different GO contents Take four portions of anhydrous ethanol, 5 ml each, and dissolve 2 g of the superhydrophobic material BN / GO@SiO2 prepared in Examples 1-4 in each portion. Stir thoroughly until homogeneous. Then add 12.5 g of epoxy resin to each solution and stir thoroughly again to obtain four single-component coatings with different GO contents.

[0042] Q235 steel sheets with dimensions of 20 mm × 20 mm × 5 mm were successively sanded with sandpaper of grits of 80, 200, 400, 800, and 1200. They were then ultrasonically treated with alcohol and acetone, respectively. Using the same spraying method, four single-component coatings with different GO contents were sprayed onto the surface of the Q235 steel sheets to prepare working electrodes. Electrochemical impedance spectroscopy (EIS) and Tafel polarization curve (PDP) tests were performed on the prepared working electrodes using the classic three-electrode mode to test the anti-corrosion performance of the coating.

[0043] The reference electrode used in the three - electrode mode is a saturated silver chloride electrode, and the auxiliary electrode is a platinum mesh electrode (2 cm×2 cm). Before testing, four groups of samples need to be immersed in a 3.5% NaCl aqueous solution for different times (from 1 day to 7 days). During the test, the side of the working electrode coated with the coating needs to be in contact with the electrolyte, and the contact area is 1 cm 2 . The electrochemical workstation used is the CHI760E type electrochemical workstation of Shanghai Chenhua Instrument Co., Ltd., the electrolytic cell is the Beijing Jingke F029 type flat corrosion test electrolytic cell, and the analysis software is the chi760e software supporting the electrochemical workstation.

[0044] During the test, first, the open - circuit potential (OCP) of the working electrode needs to be measured. After the open - circuit potential is basically stable (usually 15 min), then the next step of electrochemical impedance spectroscopy (EIS) test is continued. When performing the electrochemical impedance spectroscopy test, the amplitude of the alternating current is 10 mV, and the frequency range is 10 -2 ~ 10 5 Hz. After a series of tests of open - circuit potential and electrochemical impedance spectroscopy with different immersion times (from 1 day to 7 days), finally, the Tafel polarization curve (PDP) test of the samples needs to be carried out. The specific experimental operation is as follows: The coated sample immersed in the 3.5% NaCl aqueous solution for 28 days is directly used for the Tafel polarization curve test. Scanning is carried out from the cathode direction to the anode direction, the scanning range is OCP ± 250 mV, and the scanning rate is 1 mV / s.

[0045] At the same time, a Q235 steel sheet sprayed only with epoxy resin is used as a control for the above - mentioned tests.

[0046] In the test of electrochemical impedance spectroscopy (EIS), we select the Bode plot as the final presentation form, and the specific results are as Figure 1 shown. In anti - corrosion research, the Bode plot can show the impedance of materials or coatings at different frequencies, and then the anti - corrosion performance can be inferred. If a higher impedance amplitude is seen in the low - frequency band, it means that the material or coating has a stronger blocking effect on the corrosion current and better anti - corrosion performance. High impedance values usually indicate that the coating effectively isolates the electrochemical reaction between the electrolyte and the substrate metal, thus delaying the corrosion process. If the impedance amplitude is low, especially in the low - frequency band, it indicates that the electrochemical stability of the coating or material is poor and the anti - corrosion performance is poor. Low impedance values usually mean that the coating has been damaged or the electrolyte contacts the metal surface, and the corrosion reaction may be more serious. Generally, the impedance modulus at the lowest measurement frequency (the impedance modulus at 0.01 Hz, |Z| 0.01HzThe impedance value can be used as a semi-quantitative indicator of the anti-corrosion performance of a coating; a higher impedance value generally indicates a better protective effect of the coating. For example, as the immersion time increases, |Z| 0.01Hz A decreasing value indicates a decline in the coating's corrosion resistance.

[0047] Depend on Figure 1 It can be seen that when the coating containing the superhydrophobic material BN / GO@SiO2 is immersed in a 3.5 wt% NaCl aqueous solution, its impedance modulus |Z| decreases with increasing immersion time. 0.01 Hz The overall trend is decreasing because corrosive media slowly penetrate to the coating / metal sheet interface, gradually deteriorating the coating's corrosion resistance. Regarding the impedance modulus |Z| 0.01 Hz Specific analysis revealed that, after 7 days of immersion, the coating with a GO content of 4 wt% exhibited the highest impedance modulus, at 7.652 × 10⁻⁶. 7 Ω·cm 2 While epoxy coatings soaked for 7 days (such as...) Figure 2 The impedance modulus of (as shown) is |Z|. 0.01 Hz =5.62×10 5 Ω·cm 2 Therefore, after a 7-day immersion period, the impedance modulus of the coating with a 4 wt% GO content is two orders of magnitude higher than that of the epoxy coating, indicating its superior anti-corrosion performance. This demonstrates that the coating's protective effect on the steel sheet is even better after adding the superhydrophobic material BN / GO@SiO2. This is because the filler can compensate for the inherent defects of the epoxy coating, blocking the penetration of corrosive media to the steel sheet surface, thus improving the anti-corrosion performance of the composite coating. Under the same immersion time, the impedance modulus of the coating with a 4 wt% GO content is always higher than that of other materials. This should be related to the morphology and structure of the material itself, presumably because the lamellar structure of the coating with a 4 wt% GO content is more complete and dense. Correspondingly, a high GO content in the composite material indicates an increased amount of DMAOP. According to previous research and literature review, excessive DMAOP addition leads to increased microscopic disorder in the composite material, resulting in more defects. This makes the composite coating more susceptible to corrosion when protecting the steel sheet. Conversely, insufficient DMAOP content prevents the formation of adequate chemical bonds between the composite material and the coating, leading to defects such as micropores and microcracks within the coating. Among this series of composite materials, the coating with a GO content of 4 wt% exhibits the best corrosion resistance. It also demonstrates the best compatibility between the composite material and the epoxy coating, improving coating density, reducing crack defects, and enhancing the barrier properties of the coating, thereby improving the overall corrosion resistance. Subsequent experiments all used the composite material with a GO content of 4 wt%.

[0048] Test Example 2 The Influence of Multi-component Vapor Phase Corrosion Inhibitors on the Corrosion Resistance of Coatings The superhydrophobic vapor phase corrosion inhibitor coating prepared in Example 5, with a GO content of 4 wt%, was used. Following the preparation method of the working electrode in Test Example 1, the superhydrophobic vapor phase corrosion inhibitor coating was sprayed onto the surface of a Q235 steel sheet. After obtaining the working electrode, electrochemical impedance spectroscopy (EIS) was performed to measure the corrosion resistance of the coating. Simultaneously, a single-component coating with a GO content of 4 wt% was sprayed onto the surface of the Q235 steel sheet as a control working electrode. To further analyze the corrosion resistance of different coatings, the potentiodynamic polarization curves of the coating samples after immersion in 3.5% NaCl aqueous solution for 7 days were tested. The Tafel polarization curves were then fitted, and the results are shown in Table 1 and... Figure 3 As shown.

[0049] Table 1 - Potentiodynamic polarization parameters of electrochemical impedance spectroscopy after immersion in 3.5 wt% NaCl aqueous solution for 7 days

[0050] As can be seen from the data in Table 1, the coating containing the vapor phase corrosion inhibitor system exhibits superior performance in multiple corrosion performance indicators. Specifically, the coating containing the vapor phase corrosion inhibitor system shows superior performance in corrosion current (IC). corr The corrosion current values ​​for the coating were significantly lower than those for the coating without a vapor phase corrosion inhibitor (a coating prepared by spraying a single-component paint with a GO content of 4 wt%), with the former having a corrosion current of 9.73 × 10⁻⁶. −11 A / cm², while the latter is 2.67 × 10⁻⁶. −8 A / cm². This indicates that coatings containing vapor-phase corrosion inhibitors can effectively suppress corrosion current and slow down the corrosion process of metals. Furthermore, the corrosion potential (E) of coatings containing vapor-phase corrosion inhibitors... corr The corrosion potential was also more positive, reaching -415 mV, far exceeding that of coatings without a vapor phase corrosion inhibitor. This indicates that the addition of the vapor phase corrosion inhibitor enhances the coating's corrosion resistance, making it more stable in corrosive environments and effectively preventing early coating failure. In terms of impedance modulus (R... p In terms of performance, coatings containing vapor phase corrosion inhibitors also showed significant advantages, with an impedance modulus of R. p =2.61×10 8 The impedance modulus (Ω·cm²) is significantly higher than that of coatings without a vapor phase corrosion inhibitor system. This higher impedance modulus indicates that the coating provides stronger electrochemical protection and better resistance to external corrosive agents. Furthermore, by calculating the annual corrosion rate (v... corr It was found that the annual corrosion rate of the coating containing the vapor phase corrosion inhibitor system was 4.44 × 10⁻⁶. −5mm / year, a figure that is only 3.6% of the annual corrosion rate of coatings without vapor phase corrosion inhibitors. This indicates that vapor phase corrosion inhibitors can significantly reduce the corrosion rate of coatings, delay the wear and degradation process of coatings, and thus effectively extend the service life of coatings.

[0051] like Figure 3 As shown, after adding VCI to the coating, a 7-day immersion in a 3.5 wt% NaCl aqueous solution test revealed a significant improvement in the coating's electrochemical performance. Specifically, at the lowest frequency (0.01 Hz), the coating's impedance modulus did not decrease but instead increased to some extent. After 7 days of immersion, the |Z| of the VCI-containing coating... 0.01Hz The value reached 1.27 × 10 9 The impedance modulus of Ω·cm² is much higher than that of the coating without VCI, demonstrating its superior corrosion resistance.

[0052] With prolonged immersion time, the corrosion current of the VCI-containing coating decreased significantly, indicating that the protective effect of the coating gradually became apparent in corrosive environments, and the corrosion rate was significantly slowed down. Simultaneously, the corrosion potential was also more positive than that of the coating without VCI, indicating that the addition of VCI improved the coating's corrosion resistance, making it more robust after long-term immersion. These results demonstrate that vapor-phase corrosion inhibition systems can effectively improve the protective performance of coatings in corrosive media, showing significant application potential, especially in the design and optimization of protective coatings.

[0053] In conclusion, the addition of the vapor phase corrosion inhibitor system significantly improves the corrosion resistance of the coating, not only enhancing its corrosion resistance but also extending its service life. This result provides an important reference for the further optimization and development of vapor phase corrosion inhibitor coatings in corrosion-resistant applications.

[0054] Based on the preceding analysis, the addition of the vapor-phase corrosion inhibitor system and the two-dimensional corrosion protection mechanism of the superhydrophobic material BN / GO@SiO2 create a strong synergistic effect. The vapor-phase corrosion inhibitor system, through a dynamic protection mechanism of "evaporation-adsorption-inhibition," effectively compensates for the limitations of single-filler coatings that rely solely on physical barriers and permeability. Specifically, the vapor-phase corrosion inhibitor system not only forms a molecular-level protective layer on the coating surface but also provides additional corrosion inhibition protection when the coating is affected by environmental humidity, thus significantly improving the overall corrosion resistance of the coating. Depending on the external environment, we can categorize the film's state into two types: unwetted and wetted. In a normal environment, if the film is unwetted, it will envelop the metal surface, forming a closed protective space. In this case, the multi-element corrosion inhibitor system in the coating will be released to the metal surface through evaporation, forming a protective molecular film, thereby achieving corrosion inhibition. This corrosion-inhibiting molecular layer can effectively prevent the intrusion of external corrosive substances and delay the metal corrosion process. However, in a high-humidity environment, the film will become wetted, and corrosive droplets will gradually penetrate and permeate the film structure. At this point, the multi-component corrosion inhibitor system dissolves in the corrosive droplets and continues to migrate towards the metal surface with them, eventually forming a corrosion-inhibiting liquid film on the metal surface. During this process, the presence of the two-dimensional lamellar filler effectively controls the penetration of the corrosive droplets, resulting in a relatively slow penetration rate. This leads to a higher concentration of dissolved corrosion inhibitor in the coating when the droplets reach the metal surface. This higher concentration of corrosion inhibitor helps form a stable protective film on the metal surface, further improving the metal's corrosion resistance.

[0055] Throughout the penetration process, the corrosion inhibition effect is particularly significant in the early and middle stages. Due to the structure of the two-dimensional lamellar filler, corrosive droplets cannot penetrate rapidly, allowing the corrosion inhibitor to remain within the droplets for an extended period, maintaining a high concentration. When the droplets finally reach the metal surface, the formed corrosion-inhibiting film provides optimal protection for the metal. In the later stages, because a corrosion-inhibiting layer has already formed on the metal surface, a sufficient amount of the multi-element corrosion inhibition system effectively suppresses the corrosion reaction and significantly delays the metal corrosion process. This phenomenon is highly consistent with the impedance modulus results in electrochemical impedance spectroscopy, proving the effectiveness of this corrosion inhibition mechanism. The addition of the vapor-phase corrosion inhibition system not only complements the two-dimensional anti-corrosion mechanism of the filler but also enhances the corrosion resistance of the coating through a dynamic protection mechanism. This mechanism can continuously provide effective corrosion inhibition under different environmental conditions, based on changes in the film's state, thereby significantly extending the service life of the metal material.

[0056] In summary, when the coating thickness is approximately 50 μm, the corrosion current I... corr =9.73×10 -11 A / cm 2 The corrosion potential is higher E corr=-415 mV, with a larger impedance modulus R p =2.61×10 8 Ω·cm 2 And the annual corrosion rate is lower. corr =4.44×10 -5 The coating thickness is mm / year, and its corrosion inhibition performance is stronger than that of a single epoxy coating and a coating without a vapor phase corrosion inhibitor system. At this thickness, it can meet the anti-corrosion requirements.

[0057] Test Example 3 Adhesion test The adhesion of a coating not only determines the durability of its anti-corrosion effect but also directly affects the stability of its thermal conductivity. Coatings are typically applied to material surfaces to improve their corrosion resistance and thermal conductivity. However, if the adhesion between the coating and the surface of the material is insufficient, the coating may peel off or crack, thereby losing its anti-corrosion and thermal conductivity effects.

[0058] First, the anti-corrosion performance of a coating largely depends on its adhesion. If the coating is not firmly bonded to the metal surface, external corrosive media (such as water, salt, acid, alkali, etc.) can easily penetrate through the gaps between the coating and the metal surface, leading to corrosion of the metal and other substrates. A coating with strong adhesion can effectively prevent the intrusion of external corrosive media, slow down the corrosion process, and thus greatly improve the coating's anti-corrosion effect. Especially in harsh environments such as marine and chemical industries, the adhesion of the coating is particularly important, as it directly determines whether the material surface can remain uncorroded for a long period.

[0059] Secondly, the thermal conductivity of the coating is also significantly affected by adhesion. In many industrial applications, coatings not only need to provide corrosion protection but also maintain good thermal conductivity. For example, in high-temperature environments such as electronic equipment, engine components, and heat exchangers, the thermal conductivity of the coating is crucial. If the coating adhesion is insufficient, tiny air layers may form between the coating and the metal. These air layers have poor thermal conductivity, resulting in low heat transfer and affecting the heat dissipation effect of the equipment, thus reducing its performance and service life.

[0060] 1. The adhesion of the coating was tested according to standard GB / T 5210-2006 "Paints and Varnishes - Adhesion Test by Pull-Off Method". The specific implementation plan is as follows: 3M 420 adhesive was mixed evenly on a glass plate and applied evenly to the spindle. The spindle was then quickly adhered to the sample surface, and a weight was placed on top of the spindle to ensure firm adhesion. It was left to stand for 24 hours to dry and cure. The coating around the spindle was then cut with a cutter. After turning on the machine, the test standard "F20" (spindle diameter 20mm) was selected. The peak button was pressed, and the knob was turned to "ON". The quick-release sleeve on the quick-release sleeve was placed on the upper end of the spindle, and the quick-release sleeve was kept perpendicular to the sample. The handle on the digital manual pump was slowly pressed. When the spindle detached from the sample surface, the reading on the display was recorded, which is the adhesion of the coating on the test sample.

[0061] First test result: 11.308 MPa; Second test result: 11.837 MPa. Average adhesion: 11.573 MPa. The adhesion test results show that the coating has excellent adhesion properties, firmly adhering to the metal substrate, reducing the risk of peeling and cracking due to low adhesion, thus preventing the intrusion of corrosive media, effectively protecting the metal substrate, and extending its service life.

[0062] 2. Circuit board adhesion test The adhesion of the coating to the circuit board was tested according to the standard GB / T 5210-2006 "Paints and Varnishes - Pull-off Adhesion Test". The test area was selected as an area with fewer electronic components and a relatively flat surface on the circuit board (because the circuit board is not flat overall, the coating will flow during curing, resulting in an uneven appearance of the coating on the circuit board).

[0063] The adhesion was tested and found to be 10.41 MPa, indicating that the coating has excellent adhesion properties and can adhere firmly to the circuit board. However, the adhesion data is lower than that on the steel plate. Possible reasons are: (1) The coating on the circuit board was flowing during curing, resulting in an uneven coating. (2) There are obvious holes and solder joints on the circuit board, which can easily cause stress concentration in these areas, causing these areas to fall off or even break first, resulting in a lower adhesion test value.

[0064] Test Example 4 Damp heat and salt spray resistance tests 1. Damp heat resistance test Humidity and heat resistance testing is an important experimental method for evaluating the corrosion resistance of materials or coatings under high temperature and high humidity environments. By simulating extreme humid and heat conditions, this test can reveal the performance of coatings and metal materials in humid and hot environments. Humid and heat environments accelerate the corrosion process, especially significantly affecting metals and coatings, potentially leading to problems such as blistering, peeling, and cracking of coatings, and metal surfaces may also suffer from oxidative corrosion. Therefore, humidity and heat resistance testing can effectively assess the durability of coatings and materials under long-term exposure to high temperature and humidity conditions, helping to predict corrosion and failure risks in advance.

[0065] This test plays a crucial role in optimizing material design and improving corrosion resistance. For example, in fields such as marine applications, energy facilities, and construction, materials are frequently exposed to humid and hot environments, and traditional corrosion resistance tests may be insufficient to cope with extreme climatic conditions. Humidity and heat resistance testing accelerates the corrosion reaction, revealing material weaknesses and potential problems in a short time, thus providing necessary data to help select the most suitable combination of corrosion-resistant materials and coatings. Furthermore, humidity and heat resistance testing can also evaluate the synergistic effects of different materials or coatings. For instance, the combination of substrate and coating can significantly impact corrosion resistance, and testing can help determine which combinations perform better in humid and hot environments. This approach enhances material reliability, extends service life, and ensures its effectiveness in practical applications.

[0066] The resistance to immersion in NaCl aqueous solution was tested according to standard GB / T1740-2007 "Determination of Resistance to Damp Heat in Coatings". The specific implementation plan is as follows: The superhydrophobic vapor-phase corrosion inhibitor coating (GO content 4 wt%) prepared in Example 5 was coated onto a 20 mm × 20 mm × 5 mm Q235 steel sheet to obtain a sample. Before the test, the sample was placed in an environment with a temperature of 23 ℃ ± 2 ℃ and a relative humidity of 50 % ± 5% for at least 16 h. The sample was then immersed in a NaCl aqueous solution at a temperature of 23 ℃ ± 2 ℃ (NaCl concentration 5%) for 240 hours. The mass of the sample before and after damp heat immersion was measured using formula δ. s = (W s1 -W s0 ) / W s0 Calculate the mass loss rate δs, where W s1 and W s0 The figures represent the coating quality before and after wet heat immersion. A coating containing BN-KH@SiO2 was used as a control. BN-KH@SiO2 was obtained by first modifying BN with KH-560 silane coupling agent, then growing SiO2 on the modified surface, and finally performing hydrophobic modification. The surface condition of the prepared sample after immersion for 72 hours is shown below. Figure 4 As shown; the surface condition of the sample after soaking for 168 hours is as follows. Figure 5As shown in the table, the black sample is a coating containing BN / GO@SiO2, and the white sample is a coating containing BN-KH@SiO2. The weight loss of the coatings after 72h immersion test is shown in Table 2; the weight loss of the coatings after 168h immersion test is shown in Table 3; and the weight loss of the coatings after 240h immersion test is shown in Table 4.

[0067] Table 2 - Weight loss of coating after 72h immersion test

[0068] After 72 hours of immersion testing, no bubbles, peeling, or rust spots appeared on the coating surface, and the appearance remained consistent with that before the test. Further analysis of the weight loss of the coatings before and after wear during the immersion test revealed that all coatings experienced slight mass loss after 72 hours of immersion. The control coating, BN-KH@SiO2, showed a greater degree of weight loss with a slightly higher mass loss rate, but both remained at a very low rate.

[0069] Table 3-168h immersion test results of the coating weight loss

[0070] After 168 hours of immersion testing, the coating surfaces remained intact, with no bubbles, peeling, rust spots, or corrosion. Analysis of the mass loss revealed that the mass loss of both coatings was consistent with their 72-hour mass loss, indicating that the BN / GO@SiO2 coating exhibited the least weight loss. Furthermore, the mass loss rate continued to increase slightly.

[0071] Table 4 - Weight loss of the coating after 240h immersion test

[0072] After a 240-hour immersion test, the coating surfaces remained intact, with no bubbles, peeling, rust spots, or corrosion. However, the gloss of both coatings decreased compared to before the immersion test. Further analysis of the coating weight loss revealed that the weight loss of both coatings was relatively stable after the 240-hour immersion test. The coating weight did not decrease rapidly but rather showed a slow and stable downward trend, demonstrating that the coatings maintained a certain degree of stability during the 240-hour damp heat resistance test and indicating that the coatings still provided protection for the steel sheet.

[0073] 2. Salt spray resistance test Salt spray testing is an important experimental method for evaluating the corrosion resistance of materials or coatings, particularly suitable for simulating corrosive conditions that may be encountered in marine, coastal, or other saline environments. In these environments, atmospheric salt (especially sodium chloride) works in conjunction with moisture to significantly accelerate the corrosion process of metallic materials and coatings. Salt spray testing assesses a material's corrosion resistance in a closed salt spray environment by exposing it to the corrosion reaction caused by prolonged exposure to marine climates.

[0074] First, salt spray resistance testing can effectively predict a material's performance in a salt spray environment. By simulating exposure to salt spray and humid air in real-world use, salt spray testing accelerates corrosion reactions and exposes weaknesses in materials or coatings in advance. For example, metal surfaces often form corrosion products due to salt spray, while coatings may lose their protective effect due to salt spray penetration. Through salt spray resistance testing, the adhesion, impermeability, and durability of a coating can be assessed, thereby determining whether it can effectively prevent substrate corrosion in a salty environment.

[0075] Secondly, salt spray testing provides crucial information for material selection and optimization. In marine, coastal, or industrial environments, materials and coatings often face the corrosive effects of high concentrations of salt spray. Using unsuitable materials or coatings can lead to premature corrosion, impacting equipment lifespan and safety. Salt spray testing allows for the simulation of long-term salt spray exposure in a laboratory setting, enabling rapid screening of materials with superior corrosion resistance.

[0076] In addition, salt spray resistance testing can help evaluate the overall corrosion protection effect and service performance of coatings on metals. Through the test results, users can promptly identify coating defects and take measures to improve the coating formulation or construction process, thereby ensuring the long-term protective effect of the coating.

[0077] Compared to the natural environment, the chloride concentration in a salt spray chamber is several times or even tens of times higher, significantly increasing the corrosion rate and greatly shortening the time required to obtain results from salt spray tests on products. For example, a product sample might take a year to corrode under natural exposure conditions, but similar results can be obtained in just 24 hours under artificially simulated salt spray conditions.

[0078] A neutral salt spray corrosion test (using NaCl aqueous solution as the corrosive medium) was conducted on the joint according to the standard "Artificial Atmosphere Corrosion Test - Salt Spray Test" (GB / T 10125-2012). Kinetic curves of the relationship between weight loss due to salt spray corrosion and corrosion time were established through corrosion tests at different times.

[0079] Before the salt spray corrosion test, all specimens were cleaned of oil stains from their surfaces with alcohol, numbered, and hung in the salt spray corrosion chamber. The test surface of the specimen was at a 20° angle to the vertical direction. The reagents used in the test were sodium chloride (NaCl) solutions dissolved in distilled or deionized water with a conductivity not exceeding 20 μS / cm at 25℃±2℃, a concentration of 50 g / L±5 g / L, and a pH value between 6.5 and 7.2. The test temperature was 35℃±2℃, and the spray pressure was 0.0690-0.0828 MPa. The accelerated salt spray test lasted for 240 hours, with observation periods of 72 hours, 168 hours, and 240 hours. A wet-dry alternating spray method was used, employing a YW / R-250 salt spray test chamber from Shanghai Rongjun Experimental Instrument Co., Ltd. A coating containing BN-KH@SiO2 was used as a control. The control BN-KH@SiO2 used was the same as that used in the damp heat resistance test. The surface condition of the prepared sample after 72 hours of accelerated salt spray corrosion testing is as follows: Figure 6 As shown, the surface condition after 168 hours of accelerated salt spray corrosion testing is as follows. Figure 7 As shown in Table 5, the weight loss of the coating after 72h immersion test is shown in Table 6; the weight loss of the coating after 168h immersion test is shown in Table 7; and the weight loss of the coating after 240h immersion test is shown in Table 7.

[0080] Table 5-Weight loss of coatings after 72h salt spray test.

[0081] After 72 hours of accelerated salt spray corrosion testing, a comparison of the two coatings revealed that no rust or corrosion was observed on the surface; both remained virtually unchanged. Furthermore, due to the superhydrophobicity of the coating surface, water stains generated during the salt spray test were almost entirely absent from the coating surface. The superhydrophobicity of the coating ensured rapid water runoff, reducing the impact of the corrosive medium from the salt spray test. Further analysis of the weight loss of the coatings during the accelerated salt spray corrosion test showed that the BN / GO@SiO2 coating exhibited a lower weight loss rate and a lower mass loss rate. Both coatings maintained a remarkably low weight loss rate, indicating strong salt spray corrosion resistance.

[0082] Table 6-Weight loss of coating after 168h salt spray test

[0083] After 168 hours of accelerated salt spray corrosion testing, both coatings maintained high surface integrity, with no rust spots, blistering, or obvious corrosion marks. Thanks to the micro-nano hydrophobic structure of the coating surface, salt spray droplets quickly rolled off during dynamic scouring, leaving only a trace water film, significantly weakening the penetration driving force of the corrosive medium. Similarly, weight loss analysis showed that the BN / GO@SiO2 coating had a lower weight loss rate and mass loss rate. Both coatings maintained remarkably low weight loss rates, as low as 0.0061% and 0.0087%, respectively, indicating strong resistance to salt spray corrosion.

[0084] Table 7 - Weight loss of the coating after 240h salt spray test

[0085] After 240 hours of accelerated salt spray corrosion testing, both coatings still exhibited excellent salt spray stability, with no visible corrosion defects on the surface and almost no changes. Similarly, there was almost no water stains remaining on the coating surface, and the mass loss rate of the coatings remained at a very low level, at 0.0095% and 0.0154% respectively, indicating that the coatings have strong salt resistance.

[0086] Test Example 5 Hydrophobicity test Hydrophobicity testing assesses the anti-wetting ability of a coating by measuring the contact angle (θ) of a liquid on the coating surface. The contact angle of the coating surface is measured using a contact angle meter. The test results are as follows: Figure 8 As shown, the contact angle of the coating surface is 152.3° (>150°), indicating that the coating has superhydrophobic properties. This proves that the hydrophobic modification of the system using HMDS can fundamentally prevent metal corrosion failure. In high-humidity and high-salt environments, coatings are prone to absorbing moisture, which may lead to coating expansion, blistering, peeling, or corrosion. Coatings with strong hydrophobicity can effectively reduce moisture adsorption and reduce moisture penetration into the coating interior. Especially for metal substrates, moisture penetration can lead to problems such as substrate rusting and coating peeling. Hydrophobic coatings fundamentally improve corrosion resistance by reducing moisture penetration. Strong hydrophobic properties allow dust on the film surface to be quickly carried away by tiny droplets. On the one hand, this means that the time corrosive droplets stay on the film surface is greatly reduced, reducing the threat to the metal protected inside the film; on the other hand, when the film is in service in a corrosive environment, the film can use its self-cleaning ability to quickly clean some tiny dust particles on the surface with droplets, thereby preventing dust from gradually depositing on the film surface and causing wear, which would lead to a decrease in the hydrophobic properties of the film and shorten its service life.

[0087] Test Example 6 thermal conductivity Thermal conductivity is crucial in electronic device coatings, primarily due to its ability to improve heat dissipation, ensure temperature uniformity, prevent overheating damage, increase efficiency, and enhance thermal management. Selecting a coating with suitable thermal conductivity is a key step in electronic device design, especially in high-power electronic devices. A good thermally conductive coating can effectively extend the lifespan of the device and improve its overall performance. Therefore, thermal conductivity is an indispensable factor in the development and application of electronic device coatings.

[0088] Electronic devices generate a significant amount of heat during operation. If this heat cannot be effectively dissipated, the resulting temperature rise can lead to decreased device performance or even damage. Therefore, a coating with good thermal conductivity can help electronic devices quickly and effectively dissipate heat from the heat source, ensuring the normal operation of the equipment.

[0089] Sample preparation for thermal conductivity testing: The raw material was stirred for 1 hour using a power stirrer, then degassed in a vacuum oven for 20 minutes. The mixture was then poured into a 6 cm × 2.5 cm × 2 cm silicone mold, which was subsequently ultrasonicated for 10 minutes to ensure tight bonding between sample layers and avoid interfacial thermal resistance interference. The mold was then dried and cured in a 50 ℃ oven for 24 hours. After complete curing, the sample was smoothed and cut into two identical blocks. The thermal conductivity was tested using a Swedish HotDisk TPS2500S thermal conductivity meter. The test results are as follows: Figure 9 As shown.

[0090] Compared to traditional electronic device insulating coatings (such as epoxy resin, with a thermal conductivity of 0.2 W / (m·K)), which easily form thermal resistance barriers leading to increased chip junction temperature, the superhydrophobic vapor-phase corrosion inhibitor coating prepared in Example 5 forms a coating with a thermal conductivity of 1.566 W / (m·K), representing a 683% improvement in thermal conductivity. Modified boron nitride particles exhibit very high thermal conductivity, especially in the planar direction, which is significantly higher than in the vertical direction, while epoxy resin typically has lower thermal conductivity. Therefore, when boron nitride is added to the epoxy coating as a thermally conductive filler, it can form thermal conduction channels within the coating, significantly improving the overall thermal conductivity. Secondly, the structural characteristics of boron nitride also contribute to enhancing the coating's thermal conductivity. Boron nitride exists in a layered structure, which has good thermal conductivity. The weak interlayer bonding of boron nitride allows for rapid heat transfer within its plane. When boron nitride particles are uniformly distributed in the epoxy coating, they form a continuous thermally conductive network through which heat can be rapidly conducted, thereby improving the overall thermal conductivity of the coating. Furthermore, boron nitride exhibits excellent chemical and high-temperature stability, enabling it to maintain superior thermal conductivity over extended periods in high-temperature environments. This is particularly important for coating applications in high-temperature working environments. Epoxy coatings themselves are prone to performance degradation at high temperatures, such as thermal expansion and decreased hardness, while the addition of boron nitride effectively mitigates these problems, ensuring that the coating maintains good thermal conductivity even at high temperatures.

[0091] The coating can quickly conduct heat from hot areas (such as the CPU) to the heatsink or casing, effectively preventing performance throttling or thermal failure caused by overheating. The high thermal conductivity of the coating enables efficient heat dissipation in a small space, which is especially important for space-constrained electronic products (such as circuit boards and chips). Efficient heat conduction reduces reliance on additional heat dissipation devices, saves space, reduces weight, and helps maintain the temperature of electronic components within a stable range. This prevents excessive temperature fluctuations from affecting the overall performance and stability of the system, reducing failures caused by temperature instability.

[0092] Test Example 7 Coating resistivity The resistivity of coatings plays a crucial role in electronic components. It directly affects component performance and is vital for efficiency, stability, and reliability. Resistivity is a physical quantity that measures a material's resistance to the flow of electric current, and it is a key parameter determining a material's conductivity and insulation properties. In electronic components, the level of coating resistivity directly influences the device's behavior and operating conditions.

[0093] In electronic components, the resistivity of the coating often determines its effectiveness in isolating current, thereby preventing problems such as short circuits, signal interference, or leakage. For demanding circuits, such as high-voltage devices or precision signal transmission circuits, high-resistivity coatings are particularly important. Coatings with high resistivity (resistivity > 10⁹ Ω·cm, such as insulating varnish and epoxy resin) can effectively block the flow of current, preventing short circuits or signal interference, and ensuring the safe and stable operation of equipment.

[0094] Especially in circuit boards, chip packages, and other electronic components, high-resistivity coatings are often used to isolate current flow between adjacent wires, preventing signal crosstalk or short circuits. In high-density integrated circuits (ICs), due to the compact design of the circuits, the distance between signal lines can be very small. Signal crosstalk can cause malfunctions in electronic components and even impair the stability of the entire system. In such cases, using a high-resistivity coating can effectively isolate these wires, reduce the impact of electrical noise, and thus improve the reliability and performance of the circuit.

[0095] Furthermore, for some high-voltage devices, the resistivity of the coating plays a crucial protective role. Applying a high-resistivity insulating coating to the surface of these devices ensures that the breakdown voltage remains at a high level under high-voltage conditions, preventing discharge and breakdown. Discharge and breakdown not only damage electronic components but can also lead to more serious safety hazards. By applying a high-resistivity coating, the risk of arc discharge can be effectively reduced, ensuring the safe operation of devices under high-voltage conditions.

[0096] High resistivity coatings play a crucial role in the function and reliability of electronic components. By appropriately selecting and applying high resistivity coatings, the electrical isolation, protection, and anti-interference capabilities of components can be effectively improved, ensuring the stability and safety of equipment under various operating conditions. Therefore, the optimization and control of resistivity are critical factors that cannot be ignored in the design, application, and production of surface coatings for electronic components.

[0097] The UT511 insulation resistance tester was used to measure the insulation resistance of a coating sprayed onto a metal substrate after immersion in a 3.5 wt% NaCl aqueous solution for 0 h, 72 h, 168 h, and 240 h. The alligator clips of the insulation resistance tester were used to clamp both ends of the coating. The instrument's ▲ button was pressed to select the resistance measurement range. Due to the high resistivity of the coating, the 1000 V range was selected. The red test lead was then inserted into the "LINE" input port, and the black test lead into the "EARTH" input port. Continuous measurement was then selected by pressing the TIME button. After the timer was no longer displayed on the LCD screen, the TEST button was pressed for 1 second to start continuous measurement, outputting the insulation resistance test voltage. The red test light illuminated, and the high voltage indicator flashed on the LCD screen for 0.5 seconds. After the test was completed, the TEST button was pressed to turn off the insulation resistance test voltage; the red test light went out, and the high voltage indicator disappeared.

[0098] Based on the relationship between resistivity and resistance, R = ρL / S, where R represents resistance, ρ represents resistivity, L represents the wire length (in this test example, the straight-line distance between the two alligator clips, which is 0.38 cm), and S represents the cross-sectional area (in this test example, the cross-sectional area of ​​the coating), the prepared coating thickness was approximately 0.9 mm to facilitate measurement and reduce experimental errors. See the detailed test results below. Figure 10 .

[0099] Depend on Figure 10 As can be seen, the coating system exhibited excellent insulation stability during the 240-hour immersion test in a 3.5 wt% NaCl aqueous solution. The insulation resistance of the coating remained consistently at 10 GΩ (1×10⁻⁶) after immersion. 10 Ω) or higher, exceeding the minimum threshold for insulating materials (1×10 9 The calculated resistivity remains at 7.1 × 10⁻⁶ Ω. 9 Above Ω·cm. This high insulation performance is sustained by the following synergistic mechanisms: First, the dense network formed by epoxy resin and boron nitride filler, due to the strong insulation properties of boron nitride particles and epoxy resin, blocks ion migration channels and increases resistivity; Second, the composite modified BN sheets strengthen the interfacial bonding through chemical bonding, inhibiting the propagation of microcracks under immersion tests and maintaining long-term stability of resistivity.

[0100] Test Example 8 Changes in circuit board insulation resistance and contact resistance 1. Circuit board insulation resistance Insulation resistance is one of the most fundamental insulation performance indicators of printed circuit boards (PCBs), playing a crucial role in electrical performance evaluation. Insulation resistance effectively reflects the insulation quality of a PCB, especially considering the electrical insulation requirements of the working environment. Good insulation resistance prevents unnecessary current leakage or short circuits, ensuring the normal operation and safety of the circuit. During PCB design and manufacturing, the coating used directly impacts insulation resistance. These measurements reveal whether the insulation performance of different areas meets design specifications and safety standards, further ensuring the stability and reliability of the PCB during use. Low insulation resistance in these areas may indicate a risk of electrical leakage, affecting normal circuit operation and potentially leading to malfunctions or damage. Therefore, accurately measuring and controlling the insulation resistance of various parts of the PCB not only helps evaluate the effectiveness of coatings and other insulating materials but also helps optimize the design, avoiding potential problems caused by poor insulation performance.

[0101] The UT511 insulation resistance tester was used to measure the insulation resistance of a circuit board surface that had been coated and immersed in a 3.5 wt% NaCl aqueous solution for 240 h. The alligator clips of the insulation resistance tester were used to clamp both ends of the coating. The instrument's ▲ button was pressed to select the resistance measurement range. Due to the high resistivity of the coating, the 1000V range was selected. The red test lead was then inserted into the "LINE" input port, and the black test lead into the "EARTH" input port. Continuous measurement was then selected by pressing the TIME button. After the timer was no longer displayed on the LCD screen, the TEST button was pressed and held for 1 second to start continuous measurement. The insulation resistance test voltage was output, the red test light illuminated, and the high voltage indicator flashed on the LCD screen for 0.5 seconds. After the test was completed, the TEST button was pressed to turn off the insulation resistance test voltage; the red test light went out and the high voltage indicator disappeared.

[0102] The test results showed that the insulation resistance of the circuit board reached 10 GΩ (10 10 Insulation resistance of 10 GΩ or higher is of great significance in high-voltage, high-humidity, high-frequency, or high-density scenarios. Firstly, an insulation resistance of 10 GΩ or higher effectively prevents leakage current hazards, ensuring human safety and equipment protection. Secondly, in humid, hot, or salt spray environments, high insulation resistance represents strong resistance to ion migration, ensuring long-term reliability. Furthermore, in high-frequency communication and high-density interconnect designs, an insulation resistance of 10 GΩ reduces signal attenuation and heat accumulation risks, significantly extending equipment lifespan and reducing maintenance costs.

[0103] 2. Circuit board contact resistance Contact resistance is a crucial indicator of the electrical performance of printed circuit boards (PCBs). Its magnitude and stability directly impact signal transmission and serve as a direct basis for evaluating the quality of component contacts. Increased on-resistance leads to more energy being converted into heat, increasing power loss and potentially causing short circuits. In high-frequency circuits, increased on-resistance can result in signal loss and distortion, severely degrading signal quality and even preventing proper signal reception or transmission. Particularly in communication and data transmission, signal attenuation affects system reliability and stability, deteriorating electrical connections and causing poor component contact, potentially leading to intermittent component failures. Furthermore, in electronic applications, excessive on-resistance can cause premature discharge or rapid overheating, significantly shortening component lifespan.

[0104] To measure the effect of coating on the contact resistance of a circuit board, the contact resistance between pins and components, and between conductive points, was measured under different salt spray accelerated corrosion cycles. A UT620C micro-ohmmeter was used. During testing, the coating at the contact point needed to be scraped off with tweezers before measurement, and then recoated afterward. The test results are as follows. Figure 11 As shown.

[0105] Depend on Figure 11 The results show that under simulated marine salt spray testing, the on-resistance of the circuit board generally follows the same pattern with the corrosion cycle, gradually increasing with the increase of the corrosion cycle. In the early stage of corrosion, the on-resistance exhibits a sudden increase, with the increase in on-resistance between pins and components reaching 0.8 mΩ and between conductive points reaching 0.4 mΩ. Subsequently, the increase decreases, showing a slow upward trend. At 240 hours of salt spray testing, the increase in on-resistance between pins and components reaches 1.34 mΩ, a change of approximately 2.73%, and the increase in on-resistance between conductive points reaches 1.14 mΩ, a change of approximately 1.65%. Combining the test results with previous research, the sudden increase in resistance in the early stage is due to the rapid erosion caused by the salt spray test, leading to an increase in the resistivity of the circuit board. Subsequently, the vapor-phase corrosion inhibitor system contained in the coating plays a role, forming an inhibitory film on the coating surface, preventing further corrosion and thus reducing the upward trend in resistance. This test result effectively demonstrates the dynamic protective effect of the vapor-phase corrosion inhibitor system.

[0106] After subjecting a blank circuit board to a 240-hour salt spray test, the contact resistance between its pins and components, and between conductive points, was measured. The results are as follows: Figure 12 As shown.

[0107] from Figure 12The test results show that after 240 hours of salt spray, obvious rust appeared at the circuit board connections. The increase in on-resistance between pins and components reached 8.7 mΩ, and the increase in on-resistance between conductive points was 6.7 mΩ, with both showing a clear upward trend. After 240 hours of salt spray, the change in on-resistance between pins and components was approximately 16.7%, and the change in on-resistance between conductive points was approximately 10.2%, both representing an increase of about 6 times compared to the change after the coating was applied.

[0108] In summary, the coating prepared by this invention through simple chemical synthesis and spraying technology exhibits the following properties: adhesion greater than 10 MPa; salt spray resistance exceeding 240 h; damp heat resistance exceeding 240 h; contact angle > 150°; roll-off angle < 10°; thermal conductivity > 1.5 W / m·K; and coating resistivity > 10⁻⁶. 9 Ω·cm, circuit board insulation resistance > 10 8 With a contact resistance change rate of less than 10%, a superhydrophobic vapor phase corrosion inhibitor coating with excellent hydrophobicity, thermal conductivity, and insulation was prepared, and further research can be carried out on this basis.

[0109] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A superhydrophobic vapor phase corrosion inhibitor coating, characterized in that, The invention includes the superhydrophobic material BN / GO@SiO2, a multi-component vapor phase corrosion inhibitor system, and an epoxy resin. The multi-component vapor phase corrosion inhibitor system is composed of sodium benzoate, sodium gluconate, and cyclohexylamine carbonate. The superhydrophobic material BN / GO@SiO2 is prepared by reacting boron nitride hydroxylated with GO and DMAOP to obtain a composite material; then reacting it with ammonia and TEOS to obtain BN / GO@SiO2; and finally reacting it with HMDS and ammonia to obtain the superhydrophobic material BN / GO@SiO2.

2. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 1, characterized in that, The mass ratio of the superhydrophobic material BN / GO@SiO2, the multi-component vapor phase corrosion inhibitor system, and the epoxy system is 0.16:0.04:

1.

3. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 1, characterized in that, The preparation method of the superhydrophobic material BN / GO@SiO2 is as follows: (1) Preparation of hydroxylated boron nitride powder: Boron nitride and sodium hydroxide solution were mixed and stirred at 120 ℃~130 ℃. After the reaction was completed, the solid and liquid were separated and the solid was dried to obtain hydroxylated boron nitride powder. (2) Preparation of BN / GO composite material: GO aqueous dispersion and hydroxylated boron nitride powder prepared in step (1) are added to isopropanol, and then DMAOP is added, wherein the amount of DMAOP added is the same as the amount of GO added; then the reaction is stirred, and after the reaction is completed, the solid and liquid are separated, and the solid is dried to obtain BN / GO composite material; (3) Preparation of BN / GO@SiO2: The BN / GO composite material prepared in step (2) is dispersed in anhydrous ethanol, ammonia and TEOS are added, and the mixture is stirred to react. After the reaction is completed, the solid and liquid are separated, and the solid is dried under vacuum to obtain BN / GO@SiO2. (4) Preparation of superhydrophobic corrosion inhibitor material BN / GO@SiO2: Take the BN / GO@SiO2 prepared in step (3) and disperse it in anhydrous ethanol, add HMDS and ammonia water, stir and react; after the reaction is completed, separate the solid and liquid, and dry to obtain superhydrophobic material BN / GO@SiO2.

4. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 3, characterized in that, In step (1), the concentration of sodium hydroxide solution is 20 wt%, the amount of boron nitride added is 1 wt% of the mass of sodium hydroxide solution, and the particle size of boron nitride is 2~5 μm.

5. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 3, characterized in that, In step (2), the concentration of the GO aqueous dispersion is 8~12 mg / g; the mass ratio of GO to hydroxylated boron nitride powder is 0.02:

1.

6. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 3, characterized in that, In step (3), the amount of ammonia is 10~12 ml / g based on the weight of BN / GO; the amount of TEOS is 0.2~0.3 g / g based on the weight of BN / GO.

7. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 3, characterized in that, In step (4), the amount of HMDS used is 48~52 ml / g based on the weight of BN / GO@SiO2; the amount of ammonia used is 48~52 ml / g based on the weight of BN / GO@SiO2.

8. The superhydrophobic vapor phase corrosion inhibitor coating as described in claim 3, characterized in that, The multi-component vapor phase corrosion inhibitor system consists of 50 wt% sodium benzoate, 30 wt% sodium gluconate and 20 wt% cyclohexylamine carbonate.

9. A method for preparing the superhydrophobic vapor-phase corrosion inhibitor coating as described in claim 1, characterized in that, Includes the following steps: The superhydrophobic material BN / GO@SiO2 and the multi-component vapor phase corrosion inhibitor system were dissolved in anhydrous ethanol, stirred evenly, and then epoxy resin was added and stirred evenly again to obtain the superhydrophobic vapor phase corrosion inhibitor coating.

10. The application of the superhydrophobic vapor phase corrosion inhibitor coating as described in claim 1 in the corrosion protection of electronic components.

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