High-temperature-resistant anticorrosive paint and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant anticorrosive coating and a preparation method thereof, and relates to the technical field of coatings. The coating comprises a main agent and a curing agent, the mass ratio of the main agent to the curing agent is (7-10): 1; the main agent is prepared from the following components in parts by weight: 35 to 40 parts of epoxy resin, 10 to 15 parts of hyperbranched polyborosiloxane containing an epoxy group, 30 to 35 parts of functional filler, 3 to 5 parts of other functional aids, 3 to 5 parts of rare earth oxide, 3 to 5 parts of diluent, 0.3 to 0.5 part of bentonite and 0.8 to 1 part of wax slurry; the curing agent is at least one of a 2636 epoxy curing agent, 3, 3 '-diamino-4, 4'-difluorodiphenyl sulfone, benzotripolycyanamide and 9, 9-bis (4-aminophenyl) fluorene. The coating is better in high temperature resistance, more excellent in corrosion resistance, stronger in adhesive force and better in environmental protection property.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a high-temperature resistant anti-corrosion coating and its preparation method. Background Technology

[0002] In aerospace, petrochemical, metallurgical, and power industries, various equipment (such as engine components, reactors, furnaces, and pipelines) are exposed to harsh environments with high temperatures and corrosive media (such as acids, alkalis, salt spray, and high-temperature oxidizing atmospheres) for extended periods. Surface protection is therefore crucial for ensuring equipment lifespan and operational safety. High-temperature resistant anti-corrosion coatings, as efficient and economical surface protection materials, form a dense protective film on the substrate surface, isolating it from high-temperature oxidation and corrosive media, thereby extending the equipment's service life.

[0003] Traditional high-temperature resistant anti-corrosion coatings are mainly divided into organic and inorganic coatings. Organic coatings (such as silicone and polyimide coatings) have good flexibility and adhesion, but their long-term high-temperature resistance is limited. They are prone to thermal oxidative degradation at high temperatures, leading to coating cracking, peeling, and a sharp decline in anti-corrosion performance. Inorganic coatings (such as ceramic-based and metal-based coatings) have excellent high-temperature resistance, but suffer from poor flexibility, weak adhesion to the substrate, and difficult application. It is in this context that organic-inorganic composite coatings have emerged. These coatings can better balance high-temperature resistance and corrosion resistance, and their appearance has attracted widespread attention in the industry.

[0004] Existing organic-inorganic composite coatings generally suffer from poor compatibility and uneven dispersion between inorganic fillers and the organic phase, leading to the formation of pores and defects within the coating. At high temperatures, these defects become channels for the penetration of oxidizing media and corrosive ions, significantly reducing the coating's high-temperature corrosion resistance lifespan. Furthermore, the antioxidants in these coatings are mostly traditional organic antioxidants (such as hindered phenols), which are prone to volatilization and failure at high temperatures, failing to inhibit the thermal oxidative degradation of the coating in the long term. The anti-corrosion additives are mostly single-component (such as zinc powder and chromates), with a simple anti-corrosion mechanism, making them unsuitable for complex high-temperature corrosive environments.

[0005] To address the aforementioned issues, existing technology CN113717637B provides a high-temperature resistant anti-corrosion coating and its preparation method. This coating is prepared from the following components in the following mass parts: 5-10 parts flexible fast-drying resin, 10-30 parts A organosilicon resin, 10-20 parts B organosilicon resin, 10-30 parts aluminum silver paste, 10-20 parts filler, 10-20 parts composite environmentally friendly solvent, 0.2-1 part catalyst, 0.5-1 part rheology modifier, and 0.2-0.5 parts dispersant. This invention's high-temperature resistant anti-corrosion coating is a single-component coating that does not require pre-baking. After being subjected to 600℃ for 6 hours, it still exhibits excellent adhesion and salt spray resistance, demonstrating long-lasting anti-corrosion performance. However, there is room for improvement in its resistance to thermal cycling, corrosion protection in complex media, application compatibility, and environmental friendliness.

[0006] It is evident that it is necessary to seek more effective methods to prepare high-temperature resistant and anti-corrosion coatings with better high-temperature resistance, superior corrosion resistance, stronger adhesion, and better environmental friendliness. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provide a high-temperature resistant anti-corrosion coating with better high-temperature resistance, superior anti-corrosion performance, stronger adhesion, and better environmental protection, as well as a method for preparing the same.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high-temperature resistant anti-corrosion coating, comprising a main agent and a curing agent; the mass ratio of the main agent to the curing agent is (7-10):1; the main agent comprises the following components by weight: 35-40 parts epoxy resin, 10-15 parts epoxy-containing hyperbranched polyborosiloxane, 30-35 parts functional filler, 3-5 parts other functional additives, 3-5 parts rare earth oxides, 3-5 parts diluent, 0.3-0.5 parts bentonite, and 0.8-1 parts wax paste; the curing agent is at least one of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene.

[0009] Preferably, the epoxy resin is of type SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25°C, and is provided by Jiangsu Sanmu.

[0010] Preferably, there are no special requirements for the source of the epoxy-containing hyperbranched polyborosiloxane. In one embodiment of the present invention, the epoxy-containing hyperbranched polyborosiloxane is prepared according to the preparation method of hyperbranched polyborosiloxane in Example 1 of Patent Document CN107868252B.

[0011] Preferably, the functional filler is a mixture of silicon micro powder, graphene nanosheets, and silicon nitride in a mass ratio of (3-5):(0.5-0.8):0.5.

[0012] Preferably, the silicon micropowder is silicon micropowder GSF-2.

[0013] Preferably, the graphene nanosheets have a diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm.

[0014] Preferably, the average particle size of the silicon nitride is 20-60 nm.

[0015] Preferably, the other functional additives are a mixture of coupling agents, dispersants, defoamers, and preservatives in a mass ratio of (3-5):(0.8-1.2):1:(1-2).

[0016] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0017] Preferably, the dispersant is the superdispersant Tech-6320; and the defoamer is the defoamer Defom 6800.

[0018] Preferably, the corrosion inhibitor is a compound of zinc molybdate and aluminum tripolyphosphate in a mass ratio of 2:3.

[0019] Preferably, the rare earth oxide is at least one of cerium oxide and yttrium oxide.

[0020] Preferably, the average particle size of the rare earth oxide is 60-100 nm.

[0021] Preferably, the diluent is a mixture of Ultra LITE 2020 and diluent MD-2013 in a mass ratio of 1:3.

[0022] Preferably, the bentonite is HFGEL-140; the wax slurry is a 3300 polyamide wax dispersion.

[0023] Preferably, the curing agent is a compound of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene in a mass ratio of 1:1:0.5:0.3.

[0024] Another objective of this invention is to provide a method for preparing the high-temperature resistant anti-corrosion coating, comprising the following steps: adding each component of the main agent to a mixing container and stirring evenly for later use; adding the curing agent to a mixing container and stirring evenly for later use; mixing the main agent and the curing agent in proportion to form a homogeneous phase, thereby obtaining the high-temperature resistant anti-corrosion coating.

[0025] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The high-temperature resistant anti-corrosion coating disclosed in this invention is composed of two parts: a main agent and a curing agent; the mass ratio of the main agent to the curing agent is (7-10):1; the main agent includes the following components by weight: 35-40 parts epoxy resin, 10-15 parts epoxy-containing hyperbranched polyborosiloxane, 30-35 parts functional filler, 3-5 parts other functional additives, 3-5 parts rare earth oxides, 3-5 parts diluent, 0.3-0.5 parts bentonite, and 0.8-1 parts wax paste; the curing agent is at least one of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene. Through the synergistic effect of the components, the resulting coating exhibits better high-temperature resistance, superior anti-corrosion performance, stronger adhesion, and better environmental friendliness.

[0026] (2) The high-temperature resistant anti-corrosion coating disclosed in this invention uses epoxy resin and epoxy-containing hyperbranched polyborosiloxane as the resin matrix. Epoxy resin itself has good adhesion, mechanical properties and chemical stability, which can provide a solid foundation for the coating; while epoxy-containing hyperbranched polyborosiloxane, with its unique hyperbranched structure and polyborosiloxane segments, not only greatly improves the high-temperature resistance of the coating, enabling the coating to maintain a stable structure at high temperatures, but also improves the compatibility with inorganic fillers and inhibits the anti-corrosion failure caused by structural degradation at high temperatures. The combination of the two fundamentally solves the problem of poor compatibility and uneven dispersion of inorganic fillers and organic phases in traditional coatings, effectively reduces the formation of internal pores and defects in the coating, significantly enhances the density and integrity of the coating, and improves the anti-corrosion performance.

[0027] (3) The high-temperature resistant and anti-corrosion coating disclosed in this invention is composed of silicon micro powder, graphene nanosheets, and silicon nitride in a mass ratio of (3-5):(0.5-0.8):0.5. Silicon micro powder has high hardness, low expansion coefficient, and good chemical stability, which can enhance the mechanical strength and heat resistance of the coating. Graphene nanosheets, with their excellent barrier properties, ultra-high strength, and good conductivity, form a dense barrier network in the coating, effectively blocking the penetration of oxidizing media and corrosive ions. Silicon nitride, with its high hardness, high temperature resistance, and wear resistance, further enhances the overall performance of the coating. The three components work together to significantly improve the coating's high temperature resistance, corrosion resistance, and mechanical properties, far exceeding the effect of a single filler or a combination of ordinary fillers.

[0028] (4) The high-temperature resistant anti-corrosion coating disclosed in this invention addresses the core technical problems of traditional high-temperature resistant anti-corrosion coatings, such as insufficient long-term high-temperature stability, weak adhesion to the substrate, and short anti-corrosion life under complex media. It adopts a special curing system formed by compounding 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene in a mass ratio of 1:1:0.5:0.3, and precisely breaks through the problems through the synergistic effect of each component. The core mechanism of this compound system is to fully crosslink the active hydrogen atoms contained in the multi-components with the epoxy groups in the epoxy resin and the epoxy group-containing hyperbranched polyborosiloxane, and construct a three-dimensional network structure with density, heat resistance and flexibility, thereby fundamentally improving the protective performance of the coating. To address the issue of traditional coatings' easy degradation and failure at high temperatures, the 3,3'-diamino-4,4'-difluorodiphenyl sulfone in the compound system, with its fluorinated aromatic structure, forms a synergistic reinforcing effect with the Si-O and BO high-bond-energy segments of polyborosiloxane, significantly improving the thermal stability of the crosslinked network and inhibiting thermal oxidative degradation at high temperatures. This solves the problem of single curing agents being unable to simultaneously achieve room-temperature curing and high-temperature stability. Addressing the pain points of poor flexibility in inorganic coatings and easy cracking at high temperatures in organic coatings, the rigid fluorene ring and flexible amino segments of 9,9-bis(4-aminophenyl)fluorene optimize the rigid-flexible balance of the network structure, enabling the coating to adapt to the thermal expansion and contraction of the substrate at high temperatures, avoiding cracking and peeling caused by stress concentration. Simultaneously, its aromatic structure enhances the bonding force with the resin matrix, improving adhesion. To address the issue of corrosive media penetration caused by insufficient coating density, epoxy curing agent 2636 provides highly efficient curing activity, ensuring sufficient cross-linking reaction and reducing porosity caused by unreacted groups. Phenylated melamine further densifies the network structure through multifunctional cross-linking, enhancing the surface hardness and wear resistance of the coating, resisting external erosion, and blocking physical channels for corrosive media intrusion. Furthermore, this compound system exhibits excellent synergy with functional fillers, rare earth oxides, and other components. The well-developed cross-linked network firmly anchors the inorganic fillers, preventing gaps at the filler-resin interface, while simultaneously enhancing the uniform dispersion of rare earth oxides in the coating, fully leveraging their catalytic corrosion inhibition effects.

[0029] (5) The high-temperature resistant anti-corrosion coating disclosed in this invention utilizes rare earth oxides, which possess unique electronic structures and chemical activities. These oxides can reduce the activation energy of oxidation reactions, thus acting as catalytic corrosion inhibitors. Under high-temperature conditions, rare earth oxides such as cerium oxide and yttrium oxide can inhibit the oxidation process, slow down the thermal oxidative degradation rate of the coating, and improve the high-temperature resistance of the coating. Upon addition, they work synergistically with other components in the coating to impart excellent high-temperature resistance and anti-corrosion properties to the product.

[0030] (6) The high-temperature resistant anti-corrosion coating disclosed in this invention, with the addition of epoxy-containing hyperbranched polyborosiloxane, not only effectively improves the high-temperature resistance of the coating, but also enhances its anti-corrosion performance. Existing technologies only disclose its high-temperature resistance, but not its anti-corrosion performance, nor its application in the composition of this invention to form a high-temperature resistant anti-corrosion coating. When epoxy-containing hyperbranched polyborosiloxane enters the "family" of coatings, the compatibility issue with other components becomes prominent. This invention overcomes this core obstacle through the rational selection of the composition formula, achieving advantages such as better high-temperature resistance, superior anti-corrosion performance, and stronger adhesion. Furthermore, this invention uses a solvent-free system, reducing the environmental impact of organic solvents and improving environmental friendliness. Detailed Implementation

[0031] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0032] Example 1: A high-temperature resistant anti-corrosion coating, consisting of a main agent and a curing agent; the mass ratio of the main agent to the curing agent is 10:1; the main agent includes the following components by weight: 40 parts epoxy resin, 10 parts epoxy-containing hyperbranched polyborosiloxane, 30 parts functional filler, 3 parts other functional additives, 3 parts rare earth oxides, 3 parts diluent, 0.3 parts bentonite, and 0.8 parts wax paste.

[0033] The epoxy resin is SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25°C, and was provided by Jiangsu Sanmu; the epoxy-containing hyperbranched polyborosiloxane was prepared according to the preparation method of hyperbranched polyborosiloxane in Example 1 of patent document CN107868252B; the functional filler is a compound of silicon micropowder, graphene nanosheets, and silicon nitride in a mass ratio of 3:0.5:0.5; the silicon... The micro powder is silicon micro powder GSF-2; the graphene nanosheets have a sheet diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm; the silicon nitride has an average particle size of 20 nm; the other functional additives are coupling agents, dispersants, defoamers, and preservatives compounded in a mass ratio of 3:0.8:1:1; the coupling agent is silane coupling agent KH550; the dispersant is superdispersant Tech-6320; the defoamer is defoamer Defom. 6800; the corrosion inhibitor is a compound of zinc molybdate and aluminum tripolyphosphate in a mass ratio of 2:3; the rare earth oxide is cerium oxide; the average particle size of the rare earth oxide is 60nm; the diluent is a compound of Ultra LITE 2020 and diluent MD-2013 in a mass ratio of 1:3; the bentonite is HFGEL-140; the wax paste is 3300 polyamide wax dispersion; the curing agent is a compound of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene in a mass ratio of 1:1:0.5:0.3.

[0034] A method for preparing the high-temperature resistant anti-corrosion coating includes the following steps: adding each component of the main agent to a mixing container and stirring evenly for later use; adding the curing agent to a mixing container and stirring evenly for later use; mixing the main agent and the curing agent in proportion to form a homogeneous phase, thereby obtaining the high-temperature resistant anti-corrosion coating.

[0035] Example 2: A high-temperature resistant anti-corrosion coating, composed of a main agent and a curing agent; the mass ratio of the main agent to the curing agent is 9:1; the main agent includes the following components by weight: 39 parts epoxy resin, 11 parts epoxy-containing hyperbranched polyborosiloxane, 32 parts functional filler, 3.5 parts other functional additives, 3.5 parts rare earth oxides, 3.5 parts diluent, 0.35 parts bentonite, and 0.85 parts wax paste.

[0036] The epoxy resin is SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25°C, and was provided by Jiangsu Sanmu; the epoxy-containing hyperbranched polyborosiloxane was prepared according to the preparation method of hyperbranched polyborosiloxane in Example 1 of patent document CN107868252B; the functional filler is a compound of silicon micropowder, graphene nanosheets, and silicon nitride in a mass ratio of 3.5:0.6:0.5; the silicon micropowder is... The silicon micropowder is GSF-2; the graphene nanosheets have a sheet diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm; the silicon nitride has an average particle size of 30 nm; the other functional additives are coupling agents, dispersants, defoamers, and preservatives compounded in a mass ratio of 3.5:0.9:1:1.3; the coupling agent is silane coupling agent KH560; the dispersant is superdispersant Tech-6320; and the defoamer is defoamer Defom6800.

[0037] The corrosion inhibitor is a compound of zinc molybdate and aluminum tripolyphosphate in a mass ratio of 2:3; the rare earth oxide is yttrium oxide; the average particle size of the rare earth oxide is 70 nm; the diluent is a compound of Ultra LITE 2020 and diluent MD-2013 in a mass ratio of 1:3; the bentonite is HFGEL-140; the wax paste is 3300 polyamide wax dispersion; the curing agent is a compound of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene in a mass ratio of 1:1:0.5:0.3.

[0038] A method for preparing the high-temperature resistant anti-corrosion coating includes the following steps: adding each component of the main agent to a mixing container and stirring evenly for later use; adding the curing agent to a mixing container and stirring evenly for later use; mixing the main agent and the curing agent in proportion to form a homogeneous phase, thereby obtaining the high-temperature resistant anti-corrosion coating.

[0039] Example 3: A high-temperature resistant anti-corrosion coating, consisting of a main agent and a curing agent; the mass ratio of the main agent to the curing agent is 8:1; the main agent includes the following components by weight: 38 parts epoxy resin, 13 parts epoxy-containing hyperbranched polyborosiloxane, 33 parts functional filler, 4 parts other functional additives, 4 parts rare earth oxides, 4 parts diluent, 0.4 parts bentonite, and 0.9 parts wax paste.

[0040] The epoxy resin is SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25℃, and is provided by Jiangsu Sanmu; the epoxy-containing hyperbranched polyborosiloxane is prepared according to the preparation method of hyperbranched polyborosiloxane in Example 1 of patent document CN107868252B; the functional filler is a mixture of silicon micro powder, graphene nanosheets, and silicon nitride in a mass ratio of 4:0.65:0.5; the silicon micro powder is silicon micro powder GSF-2; the graphene nanosheets have a sheet diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm; the silicon nitride has an average particle size of 40 nm; the other functional additives are a mixture of coupling agent, dispersant, defoamer, and preservative in a mass ratio of 4:1:1:1.5; the coupling agent is silane coupling agent KH570.

[0041] The dispersant is Tech-6320, a superdispersant; the defoamer is Defom 6800, a defoamer; the corrosion inhibitor is zinc molybdate and aluminum tripolyphosphate compounded in a mass ratio of 2:3; the rare earth oxide is cerium oxide; the average particle size of the rare earth oxide is 80 nm; the diluent is Ultra LITE 2020 and MD-2013 compounded in a mass ratio of 1:3; the bentonite is HFGEL-140; the wax paste is 3300 polyamide wax dispersion; the curing agent is 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene compounded in a mass ratio of 1:1:0.5:0.3.

[0042] A method for preparing the high-temperature resistant anti-corrosion coating includes the following steps: adding each component of the main agent to a mixing container and stirring evenly for later use; adding the curing agent to a mixing container and stirring evenly for later use; mixing the main agent and the curing agent in proportion to form a homogeneous phase, thereby obtaining the high-temperature resistant anti-corrosion coating.

[0043] Example 4: A high-temperature resistant anti-corrosion coating, consisting of a main agent and a curing agent; the mass ratio of the main agent to the curing agent is 7.5:1; the main agent includes the following components by weight: 37 parts epoxy resin, 14 parts epoxy-containing hyperbranched polyborosiloxane, 34 parts functional filler, 4.5 parts other functional additives, 4.5 parts rare earth oxides, 4.5 parts diluent, 0.45 parts bentonite, and 0.95 parts wax paste.

[0044] The epoxy resin is SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25°C, and was provided by Jiangsu Sanmu; the epoxy-containing hyperbranched polyborosiloxane was prepared according to the preparation method of hyperbranched polyborosiloxane in Example 1 of patent document CN107868252B; the functional filler is a compound of silicon micro powder, graphene nanosheets, and silicon nitride in a mass ratio of 4.5:0.75:0.5; the silicon micro... The powder is silicon micro powder GSF-2; the graphene nanosheets have a sheet diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm; the silicon nitride has an average particle size of 50 nm; the other functional additives are coupling agents, dispersants, defoamers, and preservatives compounded in a mass ratio of 4.5:1.1:1:1.8; the coupling agent is silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 compounded in a mass ratio of 1:2:1.

[0045] The dispersant is Tech-6320, a superdispersant; the defoamer is Defom 6800; the corrosion inhibitor is a mixture of zinc molybdate and aluminum tripolyphosphate in a mass ratio of 2:3; the rare earth oxide is a mixture of cerium oxide and yttrium oxide in a mass ratio of 3:5; the average particle size of the rare earth oxide is 90 nm; the diluent is a mixture of Ultra LITE 2020 and MD-2013 in a mass ratio of 1:3; the bentonite is HFGEL-140; the wax paste is a 3300 polyamide wax dispersion; the curing agent is a mixture of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene in a mass ratio of 1:1:0.5:0.3.

[0046] A method for preparing the high-temperature resistant anti-corrosion coating includes the following steps: adding each component of the main agent to a mixing container and stirring evenly for later use; adding the curing agent to a mixing container and stirring evenly for later use; mixing the main agent and the curing agent in proportion to form a homogeneous phase, thereby obtaining the high-temperature resistant anti-corrosion coating.

[0047] Example 5: A high-temperature resistant anti-corrosion coating, consisting of a main agent and a curing agent; the mass ratio of the main agent to the curing agent is 7:1; the main agent includes the following components by weight: 35 parts epoxy resin, 15 parts epoxy-containing hyperbranched polyborosiloxane, 35 parts functional filler, 5 parts other functional additives, 5 parts rare earth oxides, 5 parts diluent, 0.5 parts bentonite, and 1 part wax paste.

[0048] The epoxy resin is SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25℃, and is provided by Jiangsu Sanmu; the epoxy-containing hyperbranched polyborosiloxane is prepared according to the preparation method of hyperbranched polyborosiloxane in Example 1 of patent document CN107868252B; the functional filler is a compound of silicon micro powder, graphene nanosheets, and silicon nitride in a mass ratio of 5:0.8:0.5; the silicon micro powder is silicon micro powder GSF-2; the graphene nanosheets have a sheet diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm; the average particle size of the silicon nitride is 60 nm; the other functional additives are coupling agents, dispersants, defoamers, and preservatives compounded in a mass ratio of 5:1.2:1:2.

[0049] The coupling agent is silane coupling agent KH550; the dispersant is superdispersant Tech-6320; the defoamer is defoamer Defom 6800; the corrosion inhibitor is zinc molybdate and aluminum tripolyphosphate compounded in a mass ratio of 2:3; the rare earth oxide is cerium oxide; the average particle size of the rare earth oxide is 100 nm; the diluent is Ultra LITE2020 and diluent MD-2013 compounded in a mass ratio of 1:3; the bentonite is HFGEL-140; the wax paste is 3300 polyamide wax dispersion; the curing agent is 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene compounded in a mass ratio of 1:1:0.5:0.3.

[0050] A method for preparing the high-temperature resistant anti-corrosion coating includes the following steps: adding each component of the main agent to a mixing container and stirring evenly for later use; adding the curing agent to a mixing container and stirring evenly for later use; mixing the main agent and the curing agent in proportion to form a homogeneous phase, thereby obtaining the high-temperature resistant anti-corrosion coating.

[0051] Comparative Example 1 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of epoxy resin is used instead of the epoxy-containing hyperbranched polyborosiloxane.

[0052] Comparative Example 2 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of epoxy-containing hyperbranched polyborosiloxane is used instead of epoxy resin.

[0053] Comparative Example 3 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of 2636 epoxy curing agent is used instead of 3,3'-diamino-4,4'-difluorodiphenyl sulfone.

[0054] Comparative Example 4 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of 2636 epoxy curing agent is used instead of 9,9-bis(4-aminophenyl)fluorene.

[0055] Comparative Example 5 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of 3,3'-diamino-4,4'-difluorodiphenyl sulfone is used instead of 9,9-bis(4-aminophenyl)fluorene.

[0056] Comparative Example 6 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of 9,9-bis(4-aminophenyl)fluorene is used instead of 3,3'-diamino-4,4'-difluorodiphenyl sulfone.

[0057] Comparative Example 7 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that no rare earth oxides are added.

[0058] Comparative Example 8 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of silicon micropowder is used instead of graphene nanosheets.

[0059] Comparative Example 9 This example provides a high-temperature resistant anti-corrosion coating and its preparation method, which is basically the same as that in Example 5, except that an equal amount of silicon micro powder is used instead of silicon nitride.

[0060] To further illustrate the beneficial technical effects of the high-temperature resistant anti-corrosion coatings involved in the embodiments of this application, relevant performance tests were conducted on the high-temperature resistant anti-corrosion coatings involved in Example 5 and Comparative Examples 1-9. The test results are shown in Table 1. The test method is as follows: The coatings prepared in the above examples and comparative examples were coated on the surface of a sample (steel plate) to obtain a coating film with a thickness of 80 μm. The coating was cured at 100°C for 30 min and then cured at 120°C for 1 h to obtain the coating film. The performance of the coating film was then tested. (1) Adhesion test: The test rating shall be carried out in accordance with GB / T 9286-1998.

[0061] (2) High temperature cycling performance test: The test piece is placed in a muffle furnace and heated to 620°C. It is kept at the temperature for 6 hours, then taken out and cooled to room temperature of 20°C. It is cycled 10 times and observed whether there are cracks and bubbles. If there are no cracks or bubbles, the high temperature cycling performance is qualified. If cracks and / or bubbles are generated, the high temperature cycling performance is not qualified.

[0062] (3) Neutral salt spray test: The test was conducted in accordance with GB / T 10125-2021 “Artificial Atmosphere Corrosion Test Salt Spray Test”, using 5% NaCl solution, at a temperature of 35℃, with continuous spraying, and the time (h) when rust spots (area ≥ 5%) appeared on the coating was recorded. (4) Resistance to acid and alkali corrosion: Refer to GB / T 9274-1988 "Determination of resistance to liquid media for paints and varnishes", immerse in 5% H2SO4 solution and 5% NaOH solution respectively, keep at 70℃ for 1000h, and determine the weight loss rate (%) of the coating.

[0063] Table 1. Performance test results of high-temperature resistant anti-corrosion coatings

[0064] As shown in Table 1, the high-temperature resistant and anti-corrosion coating prepared in Example 5 of this invention exhibits significantly better adhesion, high-temperature cycling performance, and anti-corrosion performance than the comparative examples. The combined use of epoxy resin, epoxy-containing hyperbranched polyborosiloxane, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 9,9-bis(4-aminophenyl)fluorene, rare earth oxides, graphene nanosheets, and silicon nitride is beneficial in improving the above-mentioned properties.

[0065] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-temperature resistant anti-corrosion coating, characterized in that, It consists of two parts: a main agent and a curing agent; the mass ratio of the main agent to the curing agent is (7-10):1; the main agent includes the following components by weight: 35-40 parts epoxy resin, 10-15 parts epoxy-containing hyperbranched polyborosiloxane, 30-35 parts functional filler, 3-5 parts other functional additives, 3-5 parts rare earth oxides, 3-5 parts diluent, 0.3-0.5 parts bentonite, and 0.8-1 parts wax paste; the curing agent is at least one of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene.

2. The high-temperature resistant anti-corrosion coating according to claim 1, characterized in that, The epoxy resin is of type SM618, with an epoxy equivalent of 184-200 g / eq and a viscosity of 10000-25000 mPa·s at 25°C.

3. The high-temperature resistant anti-corrosion coating according to claim 1, characterized in that, The functional filler is a compound of silicon micro powder, graphene nanosheets, and silicon nitride in a mass ratio of (3-5):(0.5-0.8):0.

5.

4. The high-temperature resistant anti-corrosion coating according to claim 3, characterized in that, The silicon micropowder is silicon micropowder GSF-2; the graphene nanosheets have a diameter of 1-10 μm, a thickness of 2-3 nm, and a D50 particle size of 5 μm; the silicon nitride has an average particle size of 20-60 nm.

5. The high-temperature resistant anti-corrosion coating according to claim 1, characterized in that, The other functional additives are coupling agents, dispersants, defoamers, and preservatives compounded in a mass ratio of (3-5):(0.8-1.2):1:(1-2).

6. The high-temperature resistant anti-corrosion coating according to claim 5, characterized in that, The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the dispersant is superdispersant Tech-6320; the defoamer is defoamer Defom 6800; and the corrosion inhibitor is a mixture of zinc molybdate and aluminum tripolyphosphate in a mass ratio of 2:

3.

7. The high-temperature resistant anti-corrosion coating according to claim 1, characterized in that, The rare earth oxide is at least one of cerium oxide and yttrium oxide; the average particle size of the rare earth oxide is 60-100 nm.

8. The high-temperature resistant anti-corrosion coating according to claim 1, characterized in that, The diluent is a mixture of Ultra LITE2020 and diluent MD-2013 in a mass ratio of 1:3; the bentonite is HFGEL-140; and the wax paste is a 3300 polyamide wax dispersion.

9. The high-temperature resistant anti-corrosion coating according to claim 1, characterized in that, The curing agent is a compound of 2636 epoxy curing agent, 3,3'-diamino-4,4'-difluorodiphenyl sulfone, benzo-melamine, and 9,9-bis(4-aminophenyl)fluorene in a mass ratio of 1:1:0.5:0.

3.

10. A method for preparing a high-temperature resistant anti-corrosion coating according to any one of claims 1-9, characterized in that, The process includes the following steps: adding each component of the main agent to a mixing container and stirring until homogeneous; adding the curing agent to a mixing container and stirring until homogeneous; and mixing the main agent and curing agent in proportion to form a homogeneous phase, thus obtaining a high-temperature resistant anti-corrosion coating.

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