Composite coating material, method for producing and use thereof

Abstract

This invention relates to the field of composite materials, and discloses a composite coating, its preparation method, and its application. The raw materials for preparing the composite coating contain epoxy resin, carboxyl-terminated liquid nitrile rubber, polyurethane prepolymer, hydrophobic material, and hydrogen-blocking material. The method for preparing the composite coating includes the following steps: (1) mixing epoxy resin, carboxyl-terminated liquid nitrile rubber, diluent, and polyurethane prepolymer to obtain a mixture; (2) mixing the hydrophobic material, hydrogen-blocking material, and the mixture to obtain a dispersion; and (3) mixing the dispersion with a curing agent. The composite coating of this invention can mitigate the occurrence of metal hydrogen embrittlement by inhibiting significant hydrogen permeation.

Description

Technical Field

[0001] This invention relates to the field of composite materials, and more specifically to a composite coating, its preparation method, and its application. Background Technology

[0002] Hydrogen energy boasts advantages such as wide availability, high energy conversion efficiency, zero pollution, zero emissions, and renewability, making it an ideal carrier for promoting the large-scale development of renewable energy and holding a crucial position in the future energy landscape. However, in the presence of hydrogen, hydrogen embrittlement occurs in metallic materials due to hydrogen absorption and permeation, severely degrading their mechanical properties. This significantly impacts the service life and reliability of metal components in hydrogen-contaminated equipment, and in severe cases, may lead to hydrogen leaks and safety accidents. Therefore, improving the hydrogen-blocking performance of polymer-based coatings that can be applied to metal surfaces is currently a research challenge in this field.

[0003] Current research on epoxy resin hydrogen-barrier coatings mainly focuses on the interaction between molybdate corrosion inhibitors and silane coupling agents to form a hydrogen permeation barrier membrane, thereby achieving hydrogen permeation prevention (CN 107916045A). Epoxy resin (EP), as a traditional thermosetting polymer, possesses high tensile strength, Young's modulus, low creep, excellent dimensional stability, and thermal stability due to its high crosslinking density. However, the three-dimensional network structure formed by the high crosslinking density of EP also leads to disadvantages such as significant brittleness, low fracture toughness, and poor crack resistance, further reducing the hydrogen-barrier performance of epoxy resin coatings. Since epoxy resin coatings have poor hydrogen-barrier performance, they cannot effectively inhibit hydrogen embrittlement. Furthermore, research indicates that the presence of water vapor promotes hydrogen embrittlement in metallic materials.

[0004] Patent application CN 107916045 A discloses a hydrogen-blocking corrosion-resistant material and its preparation method. It mainly improves the self-healing ability and pitting corrosion resistance by adding molybdate and silane coupling agents and their interaction, and by depositing reduction products on the metal surface to form a thin film that prevents hydrogen diffusion, thus enhancing the hydrogen permeation barrier. This results in a material with good hydrogen permeation barrier performance. However, this method does not improve the hydrogen-blocking ability from the fundamental structural aspects of the matrix material.

[0005] Patent application CN 115181276 A discloses a modified epoxy resin and its preparation method, epoxy resin coatings and their preparation methods, and applications. This method grafts a fluoropolymer onto segments of an epoxy resin to obtain a modified epoxy resin, improving its hydrophobicity and thermal stability, and enhancing its corrosion resistance. It solves the technical problems of poor hydrophobicity, poor acid resistance, and unsatisfactory modification effects in existing epoxy resins, achieving the technical effect of improving the hydrophobicity and thermal stability of epoxy resins and giving them stronger corrosion resistance. However, this method does not address the hydrogen barrier properties of the material. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical problem of poor hydrogen barrier performance of existing hydrogen barrier coatings, and to provide a composite coating, its preparation method and application. This composite coating has good hydrogen barrier performance and can be applied to the spraying and coating of metal material surfaces in all hydrogen-exposed environments.

[0007] To achieve the above objectives, the present invention provides a composite coating, wherein the raw materials for preparing the composite coating contain epoxy resin, carboxyl-terminated liquid nitrile rubber, polyurethane prepolymer, hydrophobic material and hydrogen barrier material.

[0008] Preferably, the hydrogen permeation current density of the composite coating is 0.1-0.28 μA / cm². 2 .

[0009] Preferably, the hydrophobic material is SiO2 and / or graphene.

[0010] Preferably, the average particle size of the SiO2 is 50-800 nm.

[0011] Preferably, the graphene has 5-70 layers.

[0012] Preferably, the hydrogen barrier material is one or more of Al2O3, SiC and Ti3C2 nanosheets.

[0013] Preferably, the average particle size of the Al2O3 is 20 nm-1 μm.

[0014] Preferably, the average particle size of the SiC is 50-800 nm.

[0015] Preferably, the Ti3C2 nanosheets have 8-40 layers.

[0016] Preferably, the epoxy resin is selected from E51 and / or E44.

[0017] Preferably, the number-average molecular weight of the polyurethane prepolymer is 10,000-500,000.

[0018] Preferably, the polyurethane prepolymer is a polyether-type polyurethane and / or a polyester-type polyurethane.

[0019] Preferably, the raw materials used to prepare the composite coating also contain additives.

[0020] Preferably, the additive contains a curing agent and a diluent.

[0021] Preferably, the diluent is selected from one or more of xylene, n-butanol, and dimethylformamide.

[0022] Preferably, the curing agent is one or more of polyamide, triethylenetetramine, and 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[0023] A second aspect of the present invention provides a method for preparing a composite coating, the method comprising the following steps:

[0024] (1) Mix epoxy resin, carboxyl-terminated liquid nitrile rubber, diluent and polyurethane prepolymer to obtain a mixture;

[0025] (2) Mix the hydrophobic material, the hydrogen barrier material and the mixture to obtain a dispersion;

[0026] (3) Mix the dispersion and the curing agent.

[0027] Preferably, step (1) includes the following specific steps:

[0028] (a) Epoxy resin and carboxyl-terminated liquid nitrile rubber were vacuum stirred and then mixed with a diluent to obtain solution A;

[0029] (b) The polyurethane prepolymer and solution A are stirred under vacuum to obtain a mixture.

[0030] Preferably, based on a total usage of 100% by weight of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer, the usage of polyurethane prepolymer is 5-80% by weight, the usage of carboxyl-terminated liquid nitrile rubber is 10-70% by weight, and the usage of epoxy resin is 10-85% by weight.

[0031] Preferably, the weight ratio of the diluent to the total amount of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer is 10-80:100.

[0032] Preferably, in step (a), the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 400-600 rpm, time 20-40 min;

[0033] Preferably, in step (b), the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 400-600 rpm, time 20-40 min.

[0034] Preferably, step (2) includes the following specific steps:

[0035] S1. Vacuum stir the hydrophobic material with the mixture;

[0036] S2. The material obtained in step S1 is mixed with the hydrogen barrier material under vacuum to obtain a dispersion.

[0037] Preferably, the weight ratio of the amount of hydrophobic material to the amount of the mixture is 1-10:100;

[0038] Preferably, the weight ratio of the amount of hydrogen barrier material to the amount of the mixture is 1-15:100.

[0039] Preferably, in step S1, the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 100-1000 rpm, time 20-40 min;

[0040] Preferably, in step S2, the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed of 3000-5000 rpm, time of 20-40 min.

[0041] Preferably, in step (3), the weight ratio of the amount of curing agent to the amount of dispersion is 5-50:100.

[0042] Preferably, in step (3), the mixing operation is vacuum stirring.

[0043] Preferably, the conditions for vacuum stirring include: a temperature of 30-120℃ and a vacuum degree of -0.5×10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed of 3000-5000 rpm, time of 20-40 min.

[0044] A third aspect of the present invention provides an application of the above-mentioned composite coating in hydrogen embrittlement protection of metallic materials.

[0045] This invention prepares a composite coating with good hydrogen barrier properties using epoxy resin, carboxyl-terminated liquid nitrile rubber, polyurethane prepolymer, hydrophobic material, and hydrogen barrier material as raw materials. Furthermore, the hydrogen barrier properties of the composite coating are controlled by adjusting the ratio of epoxy resin, polyurethane prepolymer, and carboxyl-terminated liquid nitrile rubber, the molecular weight of polyurethane prepolymer, the ratio of hydrophobic material and hydrogen barrier material and their size effect, vacuum stirring temperature, and stirring speed. Detailed Implementation

[0046] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0047] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0048] The present invention provides a composite coating, wherein the raw materials for preparing the composite coating contain epoxy resin, carboxyl-terminated liquid nitrile rubber, polyurethane prepolymer, hydrophobic material and hydrogen barrier material.

[0049] In this invention, due to the presence of hydrophobic materials, the resulting composite coating becomes hydrophobic, which can reduce the hydrogen embrittlement phenomenon caused by the coupling of hydrogen and water vapor on the metal surface, further reduce hydrogen absorption and hydrogen permeation, and help improve hydrogen barrier performance.

[0050] In a preferred embodiment, the hydrogen permeation current density of the composite coating of the present invention is 0.1-0.28 μA / cm². 2 .

[0051] More preferably, the hydrophobic material is SiO2 and / or graphene.

[0052] When the average particle size of SiO2 is different, its dispersion degree in the composite coating is different, which will affect the mechanical properties and hydrogen barrier properties of the composite coating. Therefore, in a preferred case, in order to improve the mechanical properties and hydrogen barrier properties of the obtained composite coating, the average particle size of SiO2 is 50-800nm.

[0053] In this invention, since the number of graphene layers varies, the path through which the gas passes will be different. When the number of graphene layers is large, it can extend the hydrogen transport path, thereby playing a significant role in blocking hydrogen. Therefore, in order to improve the hydrogen blocking performance, in a preferred embodiment, the number of graphene layers is 5-70.

[0054] More preferably, the hydrogen barrier material is one or more of Al2O3, SiC and Ti3C2 nanosheets.

[0055] In a preferred embodiment, the average particle size of the Al2O3 is 20 nm to 1 μm.

[0056] In a preferred embodiment, the average particle size of the SiC is 50-800 nm.

[0057] In this invention, the number of Ti3C2 nanosheets can vary. When the number of Ti3C2 nanosheets is different, the hydrogen barrier performance is different. The more layers there are, the longer the distance that hydrogen molecules need to pass through, and the better the hydrogen barrier performance. Therefore, in a preferred case, the number of Ti3C2 nanosheets is 8-40 layers.

[0058] Similarly, in this invention, when the average particle size of Al2O3 and SiC is different, their dispersion degree in the composite coating is different, which will affect the mechanical properties and hydrogen barrier properties of the composite coating. Therefore, in order to improve the performance of the composite coating, in a preferred case, the average particle size of Al2O3 and SiC is controlled within the above range.

[0059] Preferably, the epoxy resin is selected from E51 and / or E44.

[0060] More preferably, the number-average molecular weight of the polyurethane prepolymer is 10,000-500,000, specifically 10,000, 100,000, 200,000, 300,000, 400,000, or 500,000.

[0061] Preferably, the polyurethane prepolymer is a polyether-type polyurethane and / or a polyester-type polyurethane.

[0062] In this invention, in order to obtain a composite coating with better performance, the raw materials for preparing the composite coating also contain additives.

[0063] Preferably, the additive contains a curing agent and a diluent.

[0064] Preferably, the diluent is selected from one or more of xylene, n-butanol, and dimethylformamide.

[0065] Preferably, the curing agent is one or more of polyamide, triethylenetetramine, and 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[0066] In this invention, the composite coating prepared using the above-mentioned raw materials exhibits good hydrogen barrier properties, with a hydrogen permeation current density of 0.1-0.28 μA / cm². 2 .

[0067] In this invention, the method for testing the hydrogen permeation current density is to conduct a hydrogen diffusion experiment using a Devnathan-Stachurski dual electrolyzer to obtain the hydrogen permeation current, and then to obtain the hydrogen permeation current density.

[0068] A second aspect of the present invention provides a method for preparing a composite coating, the method comprising the following steps:

[0069] (1) Mix epoxy resin, carboxyl-terminated liquid nitrile rubber, diluent and polyurethane prepolymer to obtain a mixture;

[0070] (2) Mix the hydrophobic material, the hydrogen barrier material and the mixture to obtain a dispersion;

[0071] (3) Mix the dispersion and the curing agent.

[0072] Preferably, step (1) includes the following specific steps:

[0073] (a) Epoxy resin and carboxyl-terminated liquid nitrile rubber were vacuum stirred and then mixed with a diluent to obtain solution A;

[0074] (b) The polyurethane prepolymer and solution A are stirred under vacuum to obtain a mixture.

[0075] In the method for preparing composite coatings described in this invention, adsorbed water may be present in raw materials such as epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer. During the preparation process, the adsorbed water will participate in the chemical reaction, thereby affecting the performance of the composite coating. Therefore, in order to obtain a composite coating with better performance, in a preferred case, all raw materials such as epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer need to be pre-dried in a vacuum oven, and the drying temperature is controlled at 50-100°C for 30-150 minutes. After drying, they are mixed to remove the adsorbed water from all raw materials.

[0076] Preferably, in order to further improve the performance of the composite coating, it is necessary to reasonably control the proportion of raw materials. Specifically, based on the total amount of epoxy resin, carboxyl-terminated liquid nitrile rubber and polyurethane prepolymer being 100% by weight, the amount of polyurethane prepolymer is 5-80% by weight, the amount of carboxyl-terminated liquid nitrile rubber is 10-70% by weight, and the amount of epoxy resin is 10-85% by weight.

[0077] Preferably, the weight ratio of the diluent to the total amount of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer is 10-80:100. Specifically, the weight ratio of the diluent to the total amount of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer can be 10:100, 20:100, 30:100, 40:100, 50:100, 60:100, 70:100, or 80:100.

[0078] In this invention, vacuum stirring is used to mix the raw materials. This not only makes the raw materials mix more thoroughly, but also avoids the generation of air bubbles during the mixing process, which would reduce the performance of the composite coating.

[0079] Preferably, in step (a), the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 400-600 rpm, time 20-40 min.

[0080] In a specific implementation, in step (a), the temperature of the vacuum stirring can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, or 120°C, and the vacuum degree of the vacuum stirring can be -0.5 × 10⁻⁶. 5 Pa, -0.6×10 5 Pa, -0.7×10 5 Pa, -0.8×10 5 Pa, -0.9×10 5 Pa or -1×10 5 Pa, the speed of the vacuum stirring can be 400 rpm, 450 rpm, 500 rpm, 550 rpm or 600 rpm, and the time of the vacuum stirring can be 20 min, 25 min, 30 min, 35 min or 40 min.

[0081] Preferably, in step (b), the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 400-600 rpm, time 20-40 min.

[0082] In a specific implementation, in step (b), the temperature of the vacuum stirring can be 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, or 120°C, and the vacuum degree of the vacuum stirring can be -0.5 × 10⁻⁶. 5 Pa, -0.6×10 5Pa, -0.7×10 5 Pa, -0.8×10 5 Pa, -0.9×10 5 Pa or -1×10 5 Pa, the speed of the vacuum stirring can be 400 rpm, 450 rpm, 500 rpm, 550 rpm or 600 rpm, and the time of the vacuum stirring can be 20 min, 25 min, 30 min, 35 min or 40 min.

[0083] Preferably, step (2) includes the following specific steps:

[0084] S1. Vacuum stir the hydrophobic material with the mixture;

[0085] S2. The material obtained in step S1 is mixed with the hydrogen barrier material under vacuum to obtain a dispersion.

[0086] More preferably, in order to improve the dispersibility of the hydrophobic material and the hydrogen barrier material so as to further improve the performance of the composite coating, the hydrophobic material and the hydrogen barrier material need to be modified with a silane coupling agent before mixing.

[0087] Therefore, in a preferred embodiment, in step S1, the hydrophobic material is stirred with methanol, water and silane coupling agent A for 0.5-1.5 hours, then filtered, the resulting solid is dried, and then vacuum stirred with the mixture.

[0088] In step S1, the ratio of the amount of hydrophobic material, methanol, water and silane coupling agent A is 1g:20-60mL:5-12mL:1-5mL.

[0089] In this invention, the modification of hydrophobic materials with silane coupling agents is a conventional treatment method in the art. The silane coupling agent A used is also a conventionally used silane coupling agent in the art. In specific embodiments, the silane coupling agent A is selected from one or more of KH560, KH550 and KH570.

[0090] Similarly, in a preferred embodiment, in step S2, the hydrogen barrier material is stirred with methanol, water and silane coupling agent B for 0.5-1.5 hours, then filtered, the resulting solid is dried, and then vacuum stirred with the material obtained in step S1 to obtain a dispersion.

[0091] In step S2, the ratio of the amount of hydrogen barrier material, methanol, water and silane coupling agent B is 1g:10-50mL:3-11mL:2-6mL.

[0092] In this invention, modifying the hydrogen barrier material with a silane coupling agent is a conventional treatment method in the art. The silane coupling agent B used is also a conventionally used silane coupling agent in the art. In a specific embodiment, the silane coupling agent B is selected from one or more of KH560, KH550 and KH570.

[0093] In a preferred embodiment of step S1, the weight ratio of the amount of hydrophobic material to the amount of the mixture is 1-10:100, specifically 1:100, 2:100, 3:100, 4:100, 5:100, 6:100, 7:100, 8:100, 9:100 or 10:100.

[0094] In step S2, the weight ratio of the amount of hydrogen barrier material to the amount of the mixture is 1-15:100, more preferably 1-10:100, specifically 1:100, 3:100, 5:100, 7:100, 9:100 or 10:100.

[0095] In a preferred embodiment, the vacuum stirring conditions in step S1 include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 100-1000 rpm, time 20-40 min.

[0096] In a specific implementation, in step S1, the temperature of the vacuum stirring can be 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, or 120℃, and the vacuum degree of the vacuum stirring can be -0.5×10⁻⁶. 5 Pa, -0.6×10 5 Pa, -0.7×10 5 Pa, -0.8×10 5 Pa, -0.9×10 5 Pa or -1×10 5 Pa, the speed of the vacuum stirring can be 100 rpm, 200 rpm, 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm or 1000 rpm, and the time of the vacuum stirring can be 20 min, 25 min, 30 min, 35 min or 40 min.

[0097] In a preferred embodiment, the vacuum stirring conditions in step S2 include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5Pa, rotation speed of 3000-5000 rpm, time of 20-40 min.

[0098] In a specific implementation, in step S2, the temperature of the vacuum stirring can be 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, or 120℃, and the vacuum degree of the vacuum stirring can be -0.5×10⁻⁶. 5 Pa, -0.6×10 5 Pa, -0.7×10 5 Pa, -0.8×10 5 Pa, -0.9×10 5 Pa or -1×10 5 Pa, the speed of the vacuum stirring can be 3000 rpm, 3500 rpm, 4000 rpm, 4500 rpm or 5000 rpm, and the time of the vacuum stirring can be 20 min, 25 min, 30 min, 35 min or 40 min.

[0099] Preferably, in step (3), the weight ratio of the amount of curing agent to the amount of dispersion is 5-50:100, more preferably 20-50:100, specifically 20:100, 30:100, 40:100 or 50:100.

[0100] Preferably, in step (3), the mixing operation is vacuum stirring.

[0101] Preferably, in step (3), the conditions for vacuum stirring include: a temperature of 30-120℃ and a vacuum degree of -0.5×10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed of 3000-5000 rpm, time of 20-40 min.

[0102] In a specific implementation, in step (3), the temperature of the vacuum stirring can be 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, or 120℃, and the vacuum degree of the vacuum stirring can be -0.5×10⁻⁶. 5 Pa, -0.6×10 5 Pa, -0.7×10 5 Pa, -0.8×10 5 Pa, -0.9×10 5 Pa or -1×10 5Pa, the speed of the vacuum stirring can be 3000 rpm, 3500 rpm, 4000 rpm, 4500 rpm or 5000 rpm, and the time of the vacuum stirring can be 20 min, 25 min, 30 min, 35 min or 40 min.

[0103] In the method described in this invention, the stepwise addition of each raw material for reaction is beneficial to the formation of a polymer material with a high degree of cross-linking, which is more conducive to improving hydrogen barrier performance.

[0104] A third aspect of the present invention provides an application of the above-mentioned composite coating in hydrogen embrittlement protection of metallic materials.

[0105] This invention utilizes different dimensions of material structure design to control the ratio of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer, enabling chemical cross-linking and grafting reactions between the ternary matrix molecules. The ternary matrix further forms hydrogen bonds with hydrophobic particles and hydrogen-blocking micro / nano fillers, and finally, through further chemical reactions with the curing agent, significantly increases the cross-linking density of the coating. This results in a coating with a ternary interpenetrating network structure and significant hydrogen-blocking properties, effectively reducing hydrogen permeability and suppressing hydrogen embrittlement. Furthermore, the introduction of hydrophobic materials significantly reduces the enrichment of water molecules on the surface of hydrogen pipelines, further suppressing hydrogen embrittlement caused by the coupling of hydrogen and water vapor.

[0106] The composite coating of the present invention can mitigate the occurrence of metal hydrogen embrittlement by inhibiting significant hydrogen permeation, thereby improving the service life and reliability of metal components in hydrogen-contaminated equipment. It can be applied to the spraying and coating of metal material surfaces in all hydrogen-contaminated environments and has broad application prospects in the above-mentioned and related fields.

[0107] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0108] In the following examples, the epoxy resin was purchased from Jiangsu Nantong Xingchen Synthetic Materials Co., Ltd., the carboxyl-terminated liquid nitrile rubber was purchased from Shenzhen Masni Elastomer Co., Ltd., and the polyurethane prepolymer was purchased from Kejuya.

[0109] Example 1

[0110] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyether polyurethane) with a number average molecular weight of 10,000, hydrophobic material (SiO2 with an average particle size of 50 nm), hydrogen barrier material (Al2O3 with an average particle size of 20 nm) and curing agent (polyamide) in a vacuum oven and dry at 70°C for 80 min.

[0111] (2) The dried hydrophobic material was added to methanol and silane coupling agent A (KH550). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:20mL:5mL:1.25mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0112] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent B (KH560). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:40mL:10mL:2.5mL. The mixture was stirred for 1h, then filtered, and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0113] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and stir under vacuum (temperature 50℃, vacuum degree -1.0×10). 5 The mixture was stirred at 500 rpm for 20 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by (setting a rotation speed of 500 rpm and a time of 30 min) at Pa; wherein, based on a total weight of 100% for dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer, the content of dried polyurethane prepolymer was 5% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 10% by weight, and the content of dried epoxy resin was 85% by weight; wherein the weight ratio of the amount of dried diluent to the total weight of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 10:100.

[0114] (5) Add the silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100. Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 100 rpm, time of 30 min;

[0115] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100. Then, vacuum stir the mixture (temperature 30℃, vacuum degree -1.0×10). 5 The mixture was uniformly dispersed at 3000 rpm for 30 minutes (Pa) to obtain a dispersion.

[0116] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 25:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A1 is obtained.

[0117] Example 2

[0118] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyether polyurethane) with a number average molecular weight of 500,000, hydrophobic material (graphene with 5-30 layers), hydrogen barrier material (SiC with an average particle size of 50 nm) and curing agent (triethylenetetramine) in a vacuum oven and dry at 80°C for 120 min.

[0119] (2) The dried hydrophobic material was added to methanol and silane coupling agent A (KH550). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:30mL:10mL:2mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0120] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent B (KH550). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:40mL:8mL:5mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0121] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and perform vacuum stirring (temperature 40℃, vacuum degree -1.0×10). 5 The mixture was stirred at 500 rpm for 30 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by operating at 500 rpm for 30 minutes (Pa). The total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 100% by weight. The content of dried polyurethane prepolymer was 80% by weight, dried carboxyl-terminated liquid nitrile rubber was 10% by weight, and dried epoxy resin was 10% by weight. The weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 80:100.

[0122] (5) Add the silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100. Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 1000 rpm, time of 30 min;

[0123] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 1:100. Then, vacuum stir the mixture (temperature 30℃, vacuum degree -1.0×10). 5 After uniform dispersion (at 5000 rpm for 30 min), a dispersion was obtained.

[0124] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 50:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A2 is obtained.

[0125] Example 3

[0126] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyester polyurethane) with a number average molecular weight of 200,000, hydrophobic materials (graphene with 30-50 layers and SiO2 with an average particle size of 800 nm), hydrogen barrier materials (SiC with an average particle size of 800 nm and Al2O3 with an average particle size of 1 μm) and curing agents (triethylenetetramine and polyamide) in a vacuum oven and dry at 50°C for 150 min.

[0127] (2) The dried hydrophobic material was added to methanol and silane coupling agent A (KH560). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:60mL:10mL:3mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0128] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent B (KH560). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:20mL:11mL:6mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0129] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and stir under vacuum (temperature 60℃, vacuum degree -1.0×10). 5 The mixture was stirred at 600 rpm for 30 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by operating at 500 rpm for 30 minutes (Pa). The total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 100% by weight. The content of dried polyurethane prepolymer was 65% by weight, dried carboxyl-terminated liquid nitrile rubber was 10% by weight, and dried epoxy resin was 25% by weight. The weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 30:100.

[0130] (5) Add silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 8.5:100 (of which the weight ratio of the silane coupling agent-modified graphene to the mixture is 0.5:100, and the weight ratio of the silane coupling agent-modified SiO2 to the mixture is 8:100). Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 300 rpm, time of 30 min;

[0131] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100 (where the weight ratio of the amount of silane coupling agent modified SiC to the amount of the mixture is 2:100, and the weight ratio of the amount of silane coupling agent modified Al2O3 to the amount of the mixture is 8:100). Then, vacuum stir the mixture (temperature is 30℃, vacuum degree is -1.0×10). 5 After uniform dispersion (at 5000 rpm for 30 min), a dispersion was obtained.

[0132] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 35:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A3 is obtained.

[0133] Example 4

[0134] (1) Epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyester polyurethane) with a number average molecular weight of 300,000, hydrophobic material (Ti3C2 nanosheets with 15-40 layers and SiO2 with an average particle size of 100 nm), hydrogen barrier material (SiC with an average particle size of 100 nm and Al2O3 with an average particle size of 500 nm) and curing agent (polyamide) were placed in a vacuum oven and dried at 100°C for 40 min.

[0135] (2) The dried hydrophobic material was added to methanol and silane coupling agent A (KH570). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:45mL:12mL:1mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0136] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent B (KH570). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:10mL:10mL:2mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0137] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and stir under vacuum (temperature 50℃, vacuum degree -1.0×10). 5 The mixture was stirred at 500 rpm for 20 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by operating at 500 rpm for 30 minutes (Pa). The total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 100% by weight. The content of dried polyurethane prepolymer was 15% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 70% by weight, and the content of dried epoxy resin was 15% by weight. The weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 60:100.

[0138] (5) Add silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100 (where the weight ratio of the silane coupling agent-modified Ti3C2 nanosheets to the mixture is 8:100, and the weight ratio of the silane coupling agent-modified SiO2 to the mixture is 2:100). Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 500 rpm, time of 30 min;

[0139] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100 (of which the weight ratio of the amount of silane coupling agent modified SiC to the amount of the mixture is 7:100, and the weight ratio of the amount of silane coupling agent modified Al2O3 to the amount of the mixture is 3:100). Then, vacuum stir the mixture (temperature is 30℃, vacuum degree is -1.0×10). 5 After uniform dispersion (at 4000 rpm for 30 min), a dispersion was obtained.

[0140] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 28:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A4 is obtained.

[0141] Example 5

[0142] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyester polyurethane) with a number average molecular weight of 100,000, hydrophobic material (SiO2 with an average particle size of 150 nm), hydrogen barrier material (SiC with an average particle size of 350 nm) and curing agent (polyamide) in a vacuum oven and dry at 90°C for 140 min.

[0143] (2) The dried hydrophobic material was added to methanol and silane coupling agent A (KH560). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:20mL:12mL:4mL. The mixture was stirred for 1 hour, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0144] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent B (KH570). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:35mL:4mL:6mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0145] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and stir under vacuum (temperature 50℃, vacuum degree -0.7×10). 5 The mixture was stirred at 500 rpm for 20 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by operating at 500 rpm for 30 minutes (Pa). The total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 100% by weight. The content of dried polyurethane prepolymer was 20% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 60% by weight, and the content of dried epoxy resin was 20% by weight. The weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 30:100.

[0146] (5) Add the silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100. Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 300 rpm, time of 30 min;

[0147] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100. Then, vacuum stir the mixture (temperature 30℃, vacuum degree -1.0×10). 5 The mixture was uniformly dispersed at 3000 rpm for 30 minutes (Pa) to obtain a dispersion.

[0148] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 28:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A5 is obtained.

[0149] Example 6

[0150] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyether polyurethane) with a number average molecular weight of 500,000, hydrophobic materials (graphene with 20-60 layers and SiO2 with an average particle size of 80 nm), hydrogen barrier materials (SiC with an average particle size of 50 nm and Al2O3 with an average particle size of 50 nm) and curing agents (polyamide and triethylenetetramine) in a vacuum oven and dry at 90°C for 150 min.

[0151] (2) The dried hydrophobic material was added to methanol and silane coupling agent A (KH550). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:25mL:8mL:4.5mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0152] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent B (KH560). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:24mL:6mL:5.5mL. The mixture was then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0153] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and perform vacuum stirring (temperature 40℃, vacuum degree -0.6×10). 5 The mixture was stirred at 450 rpm for 35 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by (setting a rotation speed of 500 rpm and a time of 30 min) at Pa; wherein the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber and dried polyurethane prepolymer was 100% by weight, the content of dried polyurethane prepolymer was 10% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 10% by weight, and the content of dried epoxy resin was 80% by weight; wherein the weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber and dried polyurethane prepolymer was 80:100.

[0154] (5) Add silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100 (where the weight ratio of the silane coupling agent-modified graphene to the mixture is 5:100, and the weight ratio of the silane coupling agent-modified SiO2 to the mixture is 5:100). Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 300 rpm, time of 30 min;

[0155] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100 (where the weight ratio of the amount of silane coupling agent modified SiC to the amount of the mixture is 5:100, and the weight ratio of the amount of silane coupling agent modified Al2O3 to the amount of the mixture is 5:100). Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 After uniform dispersion (at 5000 rpm for 30 min), a dispersion was obtained.

[0156] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 30:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A6 is obtained.

[0157] Example 7

[0158] The method of Example 6 was implemented, except that the number average molecular weight of the polyurethane prepolymer was 150,000, the average particle size of SiO2 in the hydrophobic material was 100 nm, the average particle size of Al2O3 in the hydrogen barrier material was 1 μm, and in step (4), the weight ratio of the amount of the dried diluent to the total amount of the dried epoxy resin, the dried carboxyl-terminated liquid nitrile rubber and the dried polyurethane prepolymer was 30:100; thus, composite coating A7 was obtained.

[0159] Example 8

[0160] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyester polyurethane) with a number average molecular weight of 150,000, hydrophobic materials (graphene with 20-60 layers and SiO2 with an average particle size of 100 nm), hydrogen barrier materials (SiC with a particle size of 50 nm and Al2O3 with a particle size of 50 nm) and curing agents (polyamide and triethylenetetramine) in a vacuum oven and dry at 80°C for 80 min.

[0161] (2) The dried hydrophobic material was added to methanol and silane coupling agent (KH560). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:20mL:5mL:1.25mL. The mixture was stirred for 1h, then filtered and the resulting solid was dried to obtain silane coupling agent modified hydrophobic material.

[0162] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent (KH560). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:40mL:10mL:2.5mL. The mixture was stirred for 1h, then filtered, and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0163] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and perform vacuum stirring (temperature 70℃, vacuum degree -1.0×10). 5 The mixture was stirred at 550 rpm for 30 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by operating at 500 rpm for 30 minutes (Pa). The total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 100% by weight. The content of dried polyurethane prepolymer was 10% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 20% by weight, and the content of dried epoxy resin was 70% by weight. The weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 30:100.

[0164] (5) Add silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100 (where the weight ratio of the silane coupling agent-modified graphene to the mixture is 6:100, and the weight ratio of the silane coupling agent-modified SiO2 to the mixture is 4:100). Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 300 rpm, time of 30 min;

[0165] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100 (where the weight ratio of the amount of silane coupling agent modified SiC to the amount of the mixture is 5:100, and the weight ratio of the amount of silane coupling agent modified Al2O3 to the amount of the mixture is 5:100). Then, vacuum stir the mixture (temperature is 30℃, vacuum degree is -1.0×10). 5 After uniform dispersion (Pa, rotation speed 4000 rpm, time 30 min), a dispersion was obtained;

[0166] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 35:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A8 is obtained.

[0167] Example 9

[0168] The method of Example 8 was implemented, except that the average particle size of SiO2 in the hydrophobic material was 50 nm, the number of graphene layers was 30-50, and in step (5), the weight ratio of the amount of silane coupling agent modified hydrophobic material to the amount of mixture was 10:100 (wherein the weight ratio of the amount of silane coupling agent modified graphene to the amount of mixture was 4:100, and the weight ratio of the amount of silane coupling agent modified SiO2 to the amount of mixture was 6:100), to obtain composite coating A9.

[0169] Example 10

[0170] The method of Example 3 was implemented, except that the average particle size of SiO2 in the hydrophobic material was 50 nm, the number of graphene layers was 15-70, and in step (4), the weight ratio of the amount of the dried diluent to the total amount of the dried epoxy resin, the dried carboxyl-terminated liquid nitrile rubber and the dried polyurethane prepolymer was 40:100; thus, composite coating A10 was obtained.

[0171] Example 11

[0172] The method of Example 3 was implemented, except that the number average molecular weight of the polyurethane prepolymer was 300,000, and in step (4), the weight ratio of the amount of the dried diluent to the total amount of the dried epoxy resin, the dried carboxyl-terminated liquid nitrile rubber and the dried polyurethane prepolymer was 20:100; thus, composite coating A11 was obtained.

[0173] Example 12

[0174] (1) Epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyester polyurethane) with a number average molecular weight of 500,000, hydrophobic materials (graphene with 30-70 layers and SiO2 with an average particle size of 50 nm), hydrogen barrier materials (SiC with an average particle size of 50 nm and Al2O3 with an average particle size of 100 nm) and curing agents (polyamide and triethylenetetramine) were placed in a vacuum oven and dried at 55°C for 105 min.

[0175] (2) The dried hydrophobic material was added to methanol and silane coupling agent (KH560). The ratio of the dried hydrophobic material, methanol, water and silane coupling agent A was 1g:28mL:11mL:5mL. The mixture was stirred for 1 hour, then filtered and the resulting solid was dried to obtain the silane coupling agent modified hydrophobic material.

[0176] (3) The dried hydrogen barrier material was added to methanol and silane coupling agent (KH550). The ratio of the dried hydrogen barrier material, methanol, water and silane coupling agent B was 1g:19mL:10mL:5mL. The mixture was stirred for 1 hour, stirred, filtered, and the resulting solid was dried to obtain the silane coupling agent modified hydrogen barrier material.

[0177] (4) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and stir under vacuum (temperature 76℃, vacuum degree -1.0×10). 5 The mixture was stirred at 500 rpm for 20 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5A mixture was obtained by (setting a rotation speed of 500 rpm and a time of 30 min) at Pa; wherein, based on a total weight of 100% for dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer, the content of dried polyurethane prepolymer was 65% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 10% by weight, and the content of dried epoxy resin was 25% by weight; wherein the weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 40:100.

[0178] (5) Add silane coupling agent-modified hydrophobic material to the mixture. The weight ratio of the silane coupling agent-modified hydrophobic material to the mixture is 10:100 (where the weight ratio of the silane coupling agent-modified graphene to the mixture is 5:100, and the weight ratio of the silane coupling agent-modified SiO2 to the mixture is 5:100). Then, perform vacuum stirring (temperature 30℃, vacuum degree -1.0×10). 5 Pa, rotation speed of 300 rpm, time of 30 min;

[0179] (6) Add silane coupling agent modified hydrogen barrier material to the material obtained in step (5). The weight ratio of the amount of silane coupling agent modified hydrogen barrier material to the amount of the mixture is 10:100 (where the weight ratio of the amount of silane coupling agent modified SiC to the amount of the mixture is 2:100, and the weight ratio of the amount of silane coupling agent modified Al2O3 to the amount of the mixture is 8:100). Then, vacuum stir the mixture (temperature is 30℃, vacuum degree is -1.0×10). 5 After uniform dispersion (at 5000 rpm for 30 min), a dispersion was obtained.

[0180] (7) Add the dried curing agent to the dispersion. The weight ratio of the dried curing agent to the dispersion is 35:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating A12 is obtained.

[0181] Comparative Example 1

[0182] This comparative example does not use carboxyl-terminated liquid nitrile rubber, polyurethane prepolymer, diluent, hydrophobic materials, or hydrogen barrier materials. Epoxy resin hydrogen barrier coating D1 is prepared directly using epoxy resin and curing agent as raw materials. The specific preparation method is as follows:

[0183] (1) Place the epoxy resin (E51) and curing agent (triethylenetetramine and polyamide) in a vacuum oven and dry them at 70°C for 80 min.

[0184] (2) Add the dried curing agent to the dried epoxy resin (the weight ratio of the dried curing agent to the dried epoxy resin is 25:100) and perform vacuum stirring (temperature 60℃, vacuum degree -1.0×10). 5 After mixing evenly at 600 rpm for 30 minutes (Pa), epoxy resin hydrogen barrier coating D1 is obtained.

[0185] Comparative Example 2

[0186] The method described in Example 1 is followed, except that hydrophobic and hydrogen-blocking materials are not used. The specific operation is as follows:

[0187] (1) Place epoxy resin (E51), carboxyl-terminated liquid nitrile rubber, diluent (xylene), polyurethane prepolymer (polyether polyurethane) with a number average molecular weight of 10,000 and curing agent (polyamide) in a vacuum oven and dry at 70°C for 80 min.

[0188] (2) Add the dried epoxy resin to the dried carboxyl-terminated liquid nitrile rubber and perform vacuum stirring (temperature 50℃, vacuum degree -1.0×10). 5 The mixture was stirred at 500 rpm for 20 minutes (Pa), then the dried diluent was added and mixed thoroughly to obtain solution A. Solution A was then added to the dried polyurethane prepolymer and vacuum stirred (temperature 30℃, vacuum degree -1.0×10⁻⁶). 5 A mixture was obtained by (setting a rotation speed of 500 rpm and a time of 30 min) at Pa; wherein, based on a total weight of 100% for dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer, the content of dried polyurethane prepolymer was 5% by weight, the content of dried carboxyl-terminated liquid nitrile rubber was 10% by weight, and the content of dried epoxy resin was 85% by weight; wherein the weight ratio of the amount of dried diluent to the total amount of dried epoxy resin, dried carboxyl-terminated liquid nitrile rubber, and dried polyurethane prepolymer was 30:100.

[0189] (3) Add the dried curing agent to the mixture. The weight ratio of the dried curing agent to the dispersion is 5:100. Then, vacuum stir (temperature 30℃, vacuum degree -1.0×10). 5 After homogenization at 3000 rpm for 30 minutes (Pa), composite coating D2 is obtained.

[0190] Comparative Example 3

[0191] The method was implemented according to Example 1, except that carboxyl-terminated liquid nitrile rubber was not used. That is, in step (4), the dried epoxy resin was added to the dried diluent and mixed evenly to obtain solution A; solution A was added to the dried polyurethane prepolymer and vacuum stirred (temperature 30°C, vacuum degree -1.0×10⁻⁶). 5 The mixture was prepared by mixing at 500 rpm for 30 minutes (Pa), and the total amount of dried epoxy resin and dried polyurethane prepolymer was 100% by weight. The content of dried polyurethane prepolymer was 10% by weight and the content of dried epoxy resin was 90% by weight. The weight ratio of the amount of dried diluent to the total amount of dried epoxy resin and dried polyurethane prepolymer was 30:100. Composite coating D3 was obtained.

[0192] Test Example 1

[0193] Composite coatings A1-A12 and D1-D3 were uniformly applied to 316 steel sheets with dimensions of 3cm×3cm and left to cure at room temperature (25℃) to obtain coatings of the same thickness. Hydrogen diffusion experiments were conducted on the obtained coatings using a Devnathan-Stachurski dual electrolytic cell to obtain the hydrogen permeation current and the range of hydrogen permeation current density variation.

[0194] The detection method was as follows: After fixing the coated sample, the anolyte solution was prepared as a 0.2 mol / L NaOH solution, and the cathode solution was prepared as a 3.5% NaCl solution. The reference electrode type for the main channel was Hg / HgO (1M NaOH), and the reference electrode for the secondary channel was SCE (mercury / calomel-saturated KCl). The results are shown in Table 1.

[0195] Table 1

[0196]

[0197]

[0198] As can be seen from the results in Table 1, the composite coating obtained in the embodiments of the present invention has a low hydrogen permeation current density. The lower the hydrogen permeation current density, the lower the hydrogen permeability and the stronger the hydrogen permeation resistance. This indicates that the high cross-linking density ternary interpenetrating network structure formed by grafting in the present invention can significantly improve the hydrogen permeation resistance of the coating matrix material. The cross-linking density of the material is increased by the compounding of micro-nano-scale functional fillers and their chemical interaction with the ternary interpenetrating matrix, which prolongs the hydrogen transport path and plays a significant role in hydrogen blocking. The resulting composite coating is simple to prepare and has a significant hydrogen blocking effect, and can be widely used for coating and protecting any hydrogen-exposed metal surface.

[0199] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite coating, characterized in that, The raw materials for preparing the composite coating include epoxy resin, carboxyl-terminated liquid nitrile rubber, polyurethane prepolymer, silane coupling agent modified hydrophobic material, and silane coupling agent modified hydrogen barrier material. The hydrophobic material is SiO2 and / or graphene, wherein the average particle size of the SiO2 is 50-800 nm and the number of graphene layers is 5-70. The hydrogen barrier material is one or more of Al2O3, SiC and Ti3C2 nanosheets, wherein the average particle size of Al2O3 is 20nm-1μm, the average particle size of SiC is 50-800 nm, and the number of layers of Ti3C2 nanosheets is 8-40. The epoxy resin is selected from E51 and / or E44; The number-average molecular weight of the polyurethane prepolymer is 10,000-500,000; The polyurethane prepolymer is a polyether-type polyurethane and / or a polyester-type polyurethane; The raw materials for preparing the composite coating also contain additives, which include curing agents and diluents; The diluent is selected from one or more of xylene, n-butanol and dimethylformamide; The curing agent is one or more of polyamide, triethylenetetramine, and 3,3'-dichloro-4,4'-diaminodiphenylmethane.

2. The composite coating according to claim 1, characterized in that, The hydrogen permeation current density of the composite coating is 0.1-0.28 μA / cm. 2 .

3. A method for preparing the composite coating according to claim 1 or 2, characterized in that, The method includes the following steps: (1) Mix epoxy resin, carboxyl-terminated liquid nitrile rubber, diluent and polyurethane prepolymer to obtain a mixture; (2) The silane coupling agent modified hydrophobic material, the silane coupling agent modified hydrogen barrier material and the mixture are mixed to obtain a dispersion; (3) Mix the dispersion and the curing agent; Based on a total usage of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer of 100% by weight, the usage of polyurethane prepolymer is 5-80% by weight, the usage of carboxyl-terminated liquid nitrile rubber is 10-70% by weight, and the usage of epoxy resin is 10-85% by weight. The weight ratio of the amount of the silane coupling agent modified hydrophobic material to the amount of the mixture is 1-10:

100. The weight ratio of the amount of the silane coupling agent modified hydrogen barrier material to the amount of the mixture is 1-15:

100.

4. The method according to claim 3, characterized in that, The specific steps of step (1) include: (a) Epoxy resin and carboxyl-terminated liquid nitrile rubber were vacuum stirred and then mixed with a diluent to obtain solution A; (b) The polyurethane prepolymer and solution A are stirred under vacuum to obtain a mixture.

5. The method according to claim 3 or 4, characterized in that, The weight ratio of the diluent to the total amount of epoxy resin, carboxyl-terminated liquid nitrile rubber, and polyurethane prepolymer is 10-80:

100.

6. The method according to claim 4, characterized in that, In step (a), the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, speed 400-600 rpm, time 20-40 min.

7. The method according to claim 4, characterized in that, In step (b), the conditions for vacuum stirring include: a temperature of 30-120°C and a vacuum degree of -0.5 × 10⁻⁶. 5 Pa ~ -1×10 5 Pa, speed 400-600 rpm, time 20-40 min.

8. The method according to claim 3, characterized in that, The specific steps of step (2) include: S1. Vacuum stir the silane coupling agent modified hydrophobic material with the mixture; S2. The material obtained in step S1 is mixed with the silane coupling agent-modified hydrogen barrier material under vacuum to obtain a dispersion.

9. The method according to claim 8, characterized in that, In step S1, the conditions for vacuum stirring include: a temperature of 30-120℃ and a vacuum degree of -0.5×10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 100-1000 rpm, time 20-40 min.

10. The method according to claim 8, characterized in that, In step S2, the conditions for vacuum stirring include: a temperature of 30-120℃ and a vacuum degree of -0.5×10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 3000-5000 rpm, time 20-40 min.

11. The method according to claim 3, characterized in that, In step (3), the weight ratio of the amount of curing agent to the amount of dispersion is 5-50:

100.

12. The method according to claim 3 or 11, characterized in that, In step (3), the mixing operation is vacuum stirring.

13. The method according to claim 12, characterized in that, The conditions for vacuum stirring include: a temperature of 30-120℃ and a vacuum degree of -0.5×10⁻⁶. 5 Pa ~ -1×10 5 Pa, rotation speed 3000-5000 rpm, time 20-40 min.

14. The application of the composite coating according to claim 1 or 2 or the composite coating obtained by the method according to any one of claims 3-13 in the protection of metallic materials against hydrogen embrittlement.

Images