High-adhesive-force anti-condensation coating for ring main unit and preparation method of high-adhesive-force anti-condensation coating

Abstract

The invention relates to the technical field of coatings, and provides a high-adhesive-force anti-condensation coating for a ring main unit and a preparation method of the high-adhesive-force anti-condensation coating. The high-adhesion anti-condensation coating for the ring main unit is prepared from the following components in parts by weight: 15 to 35 parts of polyurethane resin, 10 to 30 parts of acrylic resin, 15 to 30 parts of filler, 4 to 8 parts of curing agent, 0.5 to 1 part of thickening agent, 0.1 to 0.15 part of defoaming agent, 0.15 to 0.25 part of dispersing agent, 10 to 20 parts of flame retardant, 5 to 8 parts of propylene glycol methyl ether acetate and 2 to 3 parts of propylene glycol methyl ether. The filler comprises modified lignin-based carbon nanospheres. Through the technical scheme, the problem of insufficient adhesive force of the anti-condensation coating for the ring main unit in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a high-adhesion anti-condensation coating for ring main units and its preparation method. Background Technology

[0002] Ring main units (RMUs) are high-voltage switchgear used in power systems, widely applied in residential communities, industrial parks, and urban power distribution networks. Their core function is to achieve segmented control, fault isolation, and load distribution within the ring distribution network, ensuring the reliability and flexibility of power supply. The RMU houses high-voltage cables, connecting wires, and other transmission components. The metal and insulating materials of these components are highly sensitive to the humidity of the operating environment. However, during long-term use, influenced by weather and diurnal temperature variations, moisture can accumulate inside the RMU. This moisture buildup damages internal components, leading to component failure, reduced insulation, localized leakage, and impacting power supply stability. More seriously, it can cause cable insulation to crack and break, resulting in complete insulation failure of core components. This can lead to insulation breakdown during operation, generating arc discharge, burning internal components, and potentially causing internal fires and severe losses. In the protection of ring main units and cables against condensation, surface coating is a commonly used technique in the industry. However, existing superhydrophobic coatings suffer from poor adhesion, and the coating is prone to peeling and cracking due to equipment vibration, fluctuations in ambient temperature and humidity, or minor external forces. This leads to a continuous decline in the anti-condensation effect, making it difficult to ensure equipment safety in the long term. Therefore, exploring coatings that combine excellent anti-condensation performance with high adhesion can effectively extend the service life of ring main units and cables, ensuring the stable operation of the power system. Summary of the Invention

[0003] This invention proposes a high-adhesion anti-condensation coating for ring main units and its preparation method, which solves the problem of insufficient adhesion of anti-condensation coatings for ring main units in related technologies.

[0004] The technical solution of the present invention is as follows: This invention proposes a high-adhesion anti-condensation coating for ring main units, comprising the following components in parts by weight: 15-35 parts polyurethane resin, 10-30 parts acrylic resin, 15-30 parts filler, 4-8 parts curing agent, 0.5-1 part thickener, 0.1-0.15 parts defoamer, 0.15-0.25 parts dispersant, 10-20 parts flame retardant, 5-8 parts propylene glycol methyl ether acetate, and 2-3 parts propylene glycol methyl ether. The filler includes modified lignin-based carbon nanospheres; The preparation method of the modified lignin-based carbon nanospheres includes the following steps: After acid treatment, lignin-based carbon nanospheres were dispersed in an aqueous ethanol solution, and then diisopropylamine silane and diphenylmethylsilane fluorine were added. The mixture was stirred and dried to obtain modified lignin-based carbon nanospheres.

[0005] As a further technical solution, the preparation method of the lignin-based carbon nanospheres includes the following steps: Enzymatically hydrolyzed lignin was dissolved in a γ-valerol solution, sonicated, and centrifuged to obtain a saturated lignin solution. The saturated lignin solution was then dialyzed to obtain a lignin nanosphere solution. The lignin nanosphere solution was subjected to a hydrothermal reaction to obtain lignin nanospheres. The lignin nanospheres were then carbonized to obtain lignin-based carbon nanospheres.

[0006] As a further technical solution, the volume ratio of ethanol to water in the ethanol-water solution is 95:5~10.

[0007] As a further technical solution, the mass of the diisopropylamine silane is 1.2% to 1.5% of the mass of the lignin-based carbon nanospheres.

[0008] As a further technical solution, the mass of the diphenylmethylsilane fluoride is 2% to 3% of the mass of the lignin-based carbon nanospheres.

[0009] As a further technical solution, the vacuum degree during drying is 0.09~0.095MPa, the temperature is 70~85℃, and the time is 2~4h.

[0010] As a further technical solution, the mass ratio of γ-valerolactone to water in the γ-valerolactone solution is 1:1 to 1.5.

[0011] In this invention, enzymatically hydrolyzed lignin is dissolved in a γ-valerolactone solution. The oxygen atoms in the γ-valerolactone molecule can form hydrogen bonds with the hydroxyl groups on the lignin molecule. At the same time, its molecular structure may have π-π interactions with the aromatic structure of lignin, thereby dispersing and dissolving the lignin molecules in the γ-valerolactone solution. In the γ-valerolactone solution, the mass ratio of γ-valerolactone to water can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, or 1:1.5, preferably 1:1.

[0012] As a further technical solution, the ultrasound duration is 30-40 minutes.

[0013] As a further technical solution, the centrifugation rate is 7000~8000 rpm and the time is 15~20 min.

[0014] As a further technical solution, the concentration of the lignin saturated solution is 36~37.5 mg / mL.

[0015] As a further technical solution, the dialysis bag used for dialysis has a molecular weight cutoff of 1000.

[0016] As a further technical solution, the dialysis time is 40-50 hours.

[0017] As a further technical solution, the temperature of the hydrothermal reaction is 150~165℃ and the time is 10~12h.

[0018] As a further technical solution, the carbonization temperature is 740~840℃, which can be 740℃, 760℃, 780℃, 800℃, 820℃, or 840℃, preferably 800℃.

[0019] As a further technical solution, the filler also includes mica powder.

[0020] As a further technical solution, the mass ratio of the modified lignin-based carbon nanospheres to mica powder is 1:1~2.

[0021] In this invention, modified lignin-based carbon nanospheres and mica powder are used in combination to prepare a coating with better anti-condensation effect and stronger adhesion.

[0022] As a further technical solution, the curing agent includes an isocyanate curing agent.

[0023] As a further technical solution, the thickener includes organic bentonite.

[0024] In this invention, insufficient coating viscosity can lead to sagging during application, preventing even coverage of the object's surface. The addition of a thickener increases the coating viscosity. The thickener can be an organically modified attapulgite, an organic derivative of sepiolite, or an organic bentonite, preferably an organic bentonite. The organic bentonite first absorbs water and swells in the coating, increasing the interlayer spacing. Then, the organic long chains interact with polymer molecules or solvent molecules in the coating through van der Waals forces, hydrogen bonds, etc., forming a three-dimensional network structure. This network structure hinders the flow of particles in the coating, thereby increasing the coating viscosity and achieving a thickening effect.

[0025] As a further technical solution, the defoamer includes defoamer YRXP-07A.

[0026] In this invention, the addition of defoamer effectively eliminates foam generated during the production and use of coatings, avoiding the adverse effects of foam on coating application such as poor leveling and porosity, and significantly improving the stability, gloss and surface smoothness of the coating.

[0027] As a further technical solution, the dispersant includes one or both of sodium dioctyl sulfosuccinate and pentaerythritol stearate.

[0028] In this invention, sodium dioctyl sulfosuccinate contains a hydrophilic sulfonyl group and a hydrophobic octyl group in its molecular structure. In coatings, it can effectively prevent the aggregation of filler particles and allow the filler to be uniformly dispersed in the coating system. Pentaerythritol stearate can form a lubricating film between the filler particles and the resin and other media in the coating. On the one hand, it reduces the friction between the particles and the media, and on the other hand, it also plays a steric hindrance role, preventing the agglomeration of filler particles, thereby making the filler more uniformly dispersed in the coating.

[0029] As a further technical solution, the flame retardant includes triphenyl phosphate.

[0030] This invention also proposes a method for preparing a high-adhesion anti-condensation coating for ring main units, comprising the following steps: Polyurethane resin and acrylic resin are mixed to obtain a matrix film-forming material; filler, dispersant, propylene glycol methyl ether acetate and propylene glycol methyl ether are added to the matrix film-forming material and mixed evenly, then thickener, flame retardant and defoamer are added to continue dispersion, and finally curing agent is added and stirred to obtain a high-adhesion anti-condensation coating for ring main units.

[0031] The working principle and beneficial effects of this invention are as follows: In this invention, the addition of modified lignin-based carbon nanospheres not only improves the adhesion of the anti-condensation coating but also enhances its anti-condensation effect. The lignin-based carbon nanospheres, prepared from lignin, possess abundant active sites. Further modification with diisopropylamine silane and diphenylmethylsilane fluorine results in the synergistic effect of the diisopropylamine silane's amino groups significantly enhancing adhesion, while the diphenylmethylsilane fluorine provides superhydrophobicity. Applying these modified lignin-based carbon nanospheres to the coating ultimately yields an anti-condensation coating suitable for ring main units and possessing high adhesion. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] In the following examples and comparative examples, Polyurethane resin: Model NP2600, manufacturer: Dongguan Jiurui Plastic Raw Materials Co., Ltd. Acrylic resin: Model KR9250, manufactured by Tianjin Kemike Chemical Trading Co., Ltd. Isocyanate curing agent: model Bayhydur BL5335, manufacturer: Shanghai Kaiyin Chemical Co., Ltd.; Enzymatic hydrolysis of lignin: Model number S11278854; Manufacturer: Hubei Xinyuhong Biomedical Technology Co., Ltd. Mica powder: particle size 325 mesh, manufactured by Tianjin Hongqiao District Tianbao Haotong Stone Processing Plant; Organic bentonite: Model BP-183, manufactured by Jinan Ruili Chemical Co., Ltd.

[0034] Example 1 A high-adhesion anti-condensation coating for ring main units comprises the following components in parts by weight: 15 parts polyurethane resin, 30 parts acrylic resin, 15 parts filler, 4 parts isocyanate curing agent, 1 part organic bentonite, 0.15 parts defoamer YRXP-07A, 0.15 parts sodium dioctyl sulfosuccinate, 10 parts triphenyl phosphate, 5 parts propylene glycol methyl ether acetate, and 3 parts propylene glycol methyl ether. The filler is a modified lignin-based carbon nanosphere; A method for preparing lignin-based carbon nanospheres includes the following steps: Enzymatically hydrolyzed lignin was dissolved in a 1:1 mass ratio of γ-valerol to water in a binary solvent. After ultrasonic dispersion for 30 min, the solution was centrifuged at 8000 rpm for 20 min to obtain a saturated lignin solution with a concentration of 37.5 mg / mL. The saturated solution was injected into deionized water to achieve a γ-valerol volume fraction of 9%. The mixed solution was then dialyzed in a dialysis bag (1000 molecular weight cutoff) for 48 h to remove residual γ-valerol, yielding a lignin nanosphere solution. The dialyzed lignin nanosphere solution was hydrothermally heated at 160 °C for 12 h to obtain lignin nanospheres. The lignin nanospheres were then carbonized in a tube furnace at 800 °C under nitrogen protection to obtain lignin-based carbon nanospheres. The preparation method of modified lignin-based carbon nanospheres includes the following steps: Lignin-based carbon nanospheres were soaked in 0.1 mol / L dilute nitric acid and then dried at 70°C for 8 hours. The dried lignin-based carbon nanospheres were dispersed in an ethanol-water solvent with a volume ratio of 95:5. Diisopropylamine silane and diphenylmethylsilane fluoride were added to the mixed solution, with the mass of diisopropylamine silane being 1.3% of the mass of the lignin-based carbon nanospheres and the mass of diphenylmethylsilane fluoride being 2.5% of the mass of the lignin-based carbon nanospheres. The mixture was stirred for another 2 hours to obtain a mixed solution. The mixture was then placed in a vacuum drying oven (vacuum degree 0.09 MPa, temperature 80°C, drying time 2.5 hours) to obtain modified lignin-based carbon nanospheres. A method for preparing a high-adhesion anti-condensation coating for ring main units includes the following steps: Polyurethane resin and acrylic resin were mixed in a mixer at 600 rpm to obtain a matrix film-forming material. Then, filler, sodium dioctyl sulfosuccinate, propylene glycol methyl ether acetate and propylene glycol methyl ether were added and mixed evenly. Organic bentonite, triphenyl phosphate and defoamer YRXP-07A were added and the mixture was further dispersed evenly. Finally, isocyanate curing agent was added and stirred to obtain a high-adhesion anti-condensation coating for ring main units.

[0035] Example 2 A high-adhesion anti-condensation coating for ring main units comprises the following components in parts by weight: 35 parts polyurethane resin, 15 parts acrylic resin, 30 parts filler, 8 parts isocyanate curing agent, 0.8 parts organic bentonite, 0.1 parts defoamer YRXP-07A, 0.2 parts pentaerythritol stearate, 20 parts triphenyl phosphate, 8 parts propylene glycol methyl ether acetate, and 2 parts propylene glycol methyl ether. The filler is a modified lignin-based carbon nanosphere; A method for preparing lignin-based carbon nanospheres includes the following steps: Enzymatically hydrolyzed lignin was dissolved in a 1:1 mass ratio of γ-valerol to water in a binary solvent. After ultrasonic dispersion for 30 min, the solution was centrifuged at 8000 rpm for 20 min to obtain a saturated lignin solution with a concentration of 37.5 mg / mL. The saturated solution was injected into deionized water to achieve a γ-valerol volume fraction of 9%. The mixed solution was then dialyzed in a dialysis bag (1000 molecular weight cutoff) for 48 h to remove residual γ-valerol, yielding a lignin nanosphere solution. The dialyzed lignin nanosphere solution was hydrothermally heated at 160 °C for 12 h to obtain lignin nanospheres. The lignin nanospheres were then carbonized in a tube furnace at 800 °C under nitrogen protection to obtain lignin-based carbon nanospheres. The preparation method of modified lignin-based carbon nanospheres includes the following steps: Lignin-based carbon nanospheres were soaked in 0.1 mol / L dilute nitric acid and then dried at 70°C for 8 hours. The dried lignin-based carbon nanospheres were dispersed in an ethanol-water solvent with a volume ratio of 95:5. Diisopropylamine silane and diphenylmethylsilane fluoride were added to the mixed solution, with the mass of diisopropylamine silane being 1.3% of the mass of the lignin-based carbon nanospheres and the mass of diphenylmethylsilane fluoride being 2.5% of the mass of the lignin-based carbon nanospheres. The mixture was stirred for another 2 hours to obtain a mixed solution. The mixture was then placed in a vacuum drying oven (vacuum degree 0.09 MPa, temperature 80°C, drying time 2.5 hours) to obtain modified lignin-based carbon nanospheres. A method for preparing a high-adhesion anti-condensation coating for ring main units includes the following steps: Polyurethane resin and acrylic resin were mixed in a mixer at 600 rpm to obtain a matrix film-forming material. Then, filler, pentaerythritol stearate, propylene glycol methyl ether acetate and propylene glycol methyl ether were added and mixed evenly. Organic bentonite, triphenyl phosphate and defoamer YRXP-07A were added and the mixture was further dispersed evenly. Finally, isocyanate curing agent was added and stirred to obtain a high-adhesion anti-condensation coating for ring main units.

[0036] Example 3 A high-adhesion anti-condensation coating for ring main units comprises the following components in parts by weight: 30 parts polyurethane resin, 10 parts acrylic resin, 24 parts filler, 5 parts isocyanate curing agent, 0.5 parts organic bentonite, 0.12 parts defoamer YRXP-07A, 0.1 parts sodium dioctyl sulfosuccinate, 0.15 parts pentaerythritol stearate, 15 parts triphenyl phosphate, 7 parts propylene glycol methyl ether acetate, and 2.5 parts propylene glycol methyl ether. The filler is a modified lignin-based carbon nanosphere; A method for preparing lignin-based carbon nanospheres includes the following steps: Enzymatically hydrolyzed lignin was dissolved in a 1:1 mass ratio of γ-valerol to water in a binary solvent. After ultrasonic dispersion for 30 min, the solution was centrifuged at 8000 rpm for 20 min to obtain a saturated lignin solution with a concentration of 37.5 mg / mL. The saturated solution was injected into deionized water to achieve a γ-valerol volume fraction of 9%. The mixed solution was then dialyzed in a dialysis bag (1000 molecular weight cutoff) for 48 h to remove residual γ-valerol, yielding a lignin nanosphere solution. The dialyzed lignin nanosphere solution was hydrothermally heated at 160 °C for 12 h to obtain lignin nanospheres. The lignin nanospheres were then carbonized in a tube furnace at 800 °C under nitrogen protection to obtain lignin-based carbon nanospheres. The preparation method of modified lignin-based carbon nanospheres includes the following steps: Lignin-based carbon nanospheres were soaked in 0.1 mol / L dilute nitric acid and then dried at 70°C for 8 hours. The dried lignin-based carbon nanospheres were dispersed in an ethanol-water solvent with a volume ratio of 95:5. Diisopropylamine silane and diphenylmethylsilane fluoride were added to the mixed solution, with the mass of diisopropylamine silane being 1.3% of the mass of the lignin-based carbon nanospheres and the mass of diphenylmethylsilane fluoride being 2.5% of the mass of the lignin-based carbon nanospheres. The mixture was stirred for another 2 hours to obtain a mixed solution. The mixture was then placed in a vacuum drying oven (vacuum degree 0.09 MPa, temperature 80°C, drying time 2.5 hours) to obtain modified lignin-based carbon nanospheres. A method for preparing a high-adhesion anti-condensation coating for ring main units includes the following steps: Polyurethane resin and acrylic resin were mixed in a mixer at 600 rpm to obtain a matrix film-forming material. Then, filler, sodium dioctyl sulfosuccinate, pentaerythritol stearate, propylene glycol methyl ether acetate and propylene glycol methyl ether were added and mixed evenly. Organic bentonite, triphenyl phosphate and defoamer YRXP-07A were added and the mixture was further dispersed evenly. Finally, isocyanate curing agent was added and stirred to obtain a high-adhesion anti-condensation coating for ring main units.

[0037] Example 4 The only difference between this embodiment and Embodiment 3 is that the filler consists of 8 parts of modified lignin-based nanocarbon spheres and 16 parts of mica powder.

[0038] Example 5 The only difference between this embodiment and Embodiment 3 is that the filler consists of 12 parts modified lignin-based nanocarbon spheres and 12 parts mica powder.

[0039] Comparative Example 1 The only difference between this comparative example and Example 3 is that the filler is mica powder.

[0040] Comparative Example 2 The only difference between this comparative example and Example 3 is that no filler is added.

[0041] Comparative Example 3 The only difference between this comparative example and Example 3 is that the modified lignin-based carbon nanospheres are replaced with lignin-based carbon nanospheres.

[0042] The coatings obtained in Examples 1-5 and Comparative Examples 1-3 were sprayed onto the substrate surface, cured, and then tested according to the following method to form a coating with a thickness of 35 μm: 1. Contact angle test: According to standard ISO19403-2-2017, sample size 10cm×10cm; 2. Adhesion test: According to standard GB / T 5210-2006 "Paints and Varnishes - Pull-off test", the coating thickness is 35μm; The test results are shown in Table 1: Table 1. Performance test results of the coatings prepared in Examples 1-5 and Comparative Examples 1-3

[0043] 1. Compared with Comparative Examples 1-3, the coatings prepared in Examples 1-3 have a higher contact angle, indicating that the coatings prepared using modified lignin-based nanocarbon spheres have a good anti-condensation effect. Furthermore, the coatings have excellent adhesion when applied to galvanized steel sheets, stainless steel sheets, and rubber, thus preparing an anti-condensation coating with high adhesion for ring main units.

[0044] 2. Compared with Examples 1 to 5, the coatings prepared in Examples 4 to 5 have a larger contact angle and stronger adhesion to galvanized steel plates, stainless steel plates and rubber. This indicates that the coatings prepared by combining modified lignin-based nanocarbon balls and mica powder have better anti-condensation effect and stronger adhesion.

[0045] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-adhesion anti-condensation coating for ring main units, characterized in that, The product comprises the following components in parts by weight: 15-35 parts polyurethane resin, 10-30 parts acrylic resin, 15-30 parts filler, 4-8 parts curing agent, 0.5-1 part thickener, 0.1-0.15 parts defoamer, 0.15-0.25 parts dispersant, 10-20 parts flame retardant, 5-8 parts propylene glycol methyl ether acetate, and 2-3 parts propylene glycol methyl ether. The filler includes modified lignin-based carbon nanospheres; The preparation method of the modified lignin-based carbon nanospheres includes the following steps: After acid treatment, lignin-based carbon nanospheres were dispersed in an aqueous ethanol solution, and then diisopropylamine silane and diphenylmethylsilane fluorine were added. The mixture was stirred and dried to obtain modified lignin-based carbon nanospheres.

2. The high-adhesion anti-condensation coating for ring main units according to claim 1, characterized in that, The preparation method of the lignin-based carbon nanospheres includes the following steps: Enzymatically hydrolyzed lignin was dissolved in a γ-valerol solution, sonicated, and centrifuged to obtain a saturated lignin solution. The saturated lignin solution was then dialyzed to obtain a lignin nanosphere solution. The lignin nanosphere solution was subjected to a hydrothermal reaction to obtain lignin nanospheres. The lignin nanospheres were then carbonized to obtain lignin-based carbon nanospheres.

3. The high-adhesion anti-condensation coating for ring main units according to claim 1, characterized in that, The volume ratio of ethanol to water in the ethanol-water solution is 95:5~10; The mass of the diisopropylamine silane is 1.2% to 1.5% of the mass of the lignin-based carbon nanospheres; The mass of the diphenylmethylsilane fluorine is 2% to 3% of the mass of the lignin-based carbon nanospheres; The vacuum degree during drying is 0.09~0.095MPa, the temperature is 70~85℃, and the time is 2~4h.

4. The high-adhesion anti-condensation coating for ring main units according to claim 2, characterized in that, The mass ratio of γ-valerolactone to water in the γ-valerolactone solution is 1:1 to 1.5; The ultrasound session lasted 30-40 minutes. The centrifugation rate is 7000~8000 rpm, and the time is 15~20 min; The concentration of the lignin saturated solution is 36~37.5 mg / mL; The dialysis time is 40-50 hours; The hydrothermal reaction is carried out at a temperature of 150~165℃ for 10~12 hours. The carbonization temperature is 740~840℃.

5. The high-adhesion anti-condensation coating for ring main units according to claim 1, characterized in that, The filler also includes mica powder.

6. The high-adhesion anti-condensation coating for ring main units according to claim 5, characterized in that, The mass ratio of the modified lignin-based carbon nanospheres to mica powder is 1:1~2.

7. The high-adhesion anti-condensation coating for ring main units according to claim 1, characterized in that, The curing agent includes an isocyanate curing agent; The thickener includes organobentonite.

8. The high-adhesion anti-condensation coating for ring main units according to claim 1, characterized in that, The defoamer includes defoamer YRXP-07A.

9. The high-adhesion anti-condensation coating for ring main units according to claim 1, characterized in that, The dispersant includes one or both of sodium dioctyl sulfosuccinate and pentaerythritol stearate; The flame retardant includes triphenyl phosphate.

10. A method for preparing a high-adhesion anti-condensation coating for ring main units, used to prepare the high-adhesion anti-condensation coating for ring main units according to any one of claims 1 to 9, characterized in that, The following steps are involved: Polyurethane resin and acrylic resin are mixed to obtain a matrix film-forming material; filler, dispersant, propylene glycol methyl ether acetate and propylene glycol methyl ether are added to the matrix film-forming material and mixed evenly, then thickener, flame retardant and defoamer are added to continue dispersion, and finally curing agent is added and stirred to obtain a high-adhesion anti-condensation coating for ring main units.

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