Water-based single-component high-temperature-resistant anticorrosive paint and preparation method thereof

Abstract

The invention provides a water-based single-component high-temperature-resistant anticorrosive coating and a preparation method thereof. The high-temperature-resistant anticorrosive coating is prepared from the following raw materials in parts by mass: 25 to 30 parts of nano silica sol, 10 to 15 parts of aluminum oxide sol, 15 to 18 parts of aluminum dihydrogen phosphate, 1 to 1.5 parts of graphene, 6 to 10 parts of inorganic efficient corrosion inhibitor, 10 to 15 parts of anti-rust pigment, 5 to 10 parts of filler, 6 to 8 parts of functional additive and 5 to 8 parts of deionized water, the total mass part of the raw materials is 100 parts; through scientific formula design, the protection of the coating in the whole temperature range from normal temperature to 1000 DEG C is realized by utilizing a nanotechnology, an in-situ ceramic phase change technology and a special chemical corrosion inhibition mechanism.

Description

Technical Field

[0001] This invention belongs to the field of functional coatings technology, specifically relating to a water-based single-component high-temperature resistant anti-corrosion coating and its preparation method. Background Technology

[0002] In modern industrial sectors such as petrochemicals, aerospace, and energy, metal structures are often subjected to extreme environments involving both high-temperature oxidation (400℃~1000℃) and chemical corrosion. Material failure can lead to significant economic losses and safety hazards. However, existing high-temperature resistant and anti-corrosion coating technologies have significant limitations: organic high-temperature resistant coatings, while performing reasonably well at room temperature, will peel off and fail above 300℃ due to resin thermal degradation and carbonization; while traditional inorganic coatings, although possessing excellent heat resistance, generally suffer from high film brittleness, poor adhesion, and high porosity, resulting in poor salt spray resistance (typically less than 500 hours), failing to solve the industry problem of "heat resistant but not corrosion resistant."

[0003] With increasingly stringent environmental regulations and the implementation of the "oil-to-water" policy, water-based coatings have become an inevitable trend in the development of coatings. However, the research and development of water-based high-temperature resistant anti-corrosion coatings faces more severe technical bottlenecks than solvent-based coatings. First, direct contact between water-based media and steel can easily cause flash rust, and the presence of highly active nanoparticles in single-component systems often leads to gelation or sedimentation during storage, making it difficult to guarantee stability. More importantly, during the transition from the room-temperature physical deposition state to the high-temperature ceramic sintering state (especially in the 400℃~600℃ range), due to the "time difference" and "volume difference" between the decomposition of organic additives and the sintering of inorganic components, the coating is prone to severe volume shrinkage and cracking, leading to complete failure of protection.

[0004] In summary, existing technologies lack a coating product that can simultaneously meet the requirements of long-lasting protection across the entire temperature range (room temperature to 1000℃), single-component water-based environmental friendliness, and high strength and toughness mechanical properties. Faced with the extreme demands of high-end industries for material protection, there is an urgent need to develop a novel water-based, single-component, high-temperature resistant anti-corrosion coating based on in-situ ceramic phase transformation mechanisms, incorporating nano-reinforcing materials and intelligent corrosion inhibition mechanisms, to address the aforementioned technical challenge of simultaneously achieving both temperature resistance and corrosion resistance. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a water-based, single-component, high-temperature resistant anti-corrosion coating and its preparation method, aiming to overcome the technical bottleneck of existing high-temperature coatings being "heat-resistant but not corrosion-resistant, and corrosion-resistant but not heat-resistant." Through scientific formulation design, utilizing nanotechnology, in-situ ceramic phase transformation technology, and a special chemical corrosion inhibition mechanism, this invention achieves full-temperature protection from room temperature to 1000℃.

[0006] The technical solution of this invention is: a water-based single-component high-temperature resistant anti-corrosion coating, comprising the following raw materials in parts by weight:

[0007] 25-30 parts by weight of nano-silica sol, 10-15 parts by weight of alumina sol, 15-18 parts by weight of aluminum dihydrogen phosphate, 1-1.5 parts by weight of graphene, 6-10 parts by weight of inorganic high-efficiency corrosion inhibitor, 10-15 parts by weight of anti-rust pigment, 5-10 parts by weight of filler, 6-8 parts by weight of functional additives, and 5-8 parts by weight of deionized water.

[0008] The total mass fraction of the raw materials is 100 parts.

[0009] Furthermore, the particle size of the nano-silica sol is 10-20 nm, and the solid content is 20-30%.

[0010] Furthermore, the alumina sol has a particle size of 10–100 nm and a solid content of 30–40%.

[0011] Furthermore, the graphene has a carbon-to-oxygen ratio greater than 5.

[0012] Furthermore, the silicate content in the inorganic high-efficiency corrosion inhibitor is not less than 50 wt%.

[0013] Furthermore, the anti-rust pigment is one or more of zinc phosphomolybdate, zinc phosphate, aluminum tripolyphosphate, and phytate.

[0014] Furthermore, the filler is one or more of titanium dioxide, precipitated barium sulfate, aluminum oxide, and calcium carbonate.

[0015] Furthermore, the functional additive is one or more of the following: dispersant, wetting agent, defoamer, thickener, anti-settling agent, and adhesion promoter.

[0016] The preparation method of the water-based single-component high-temperature resistant anti-corrosion coating as described in any of the preceding items includes the following steps:

[0017] Step 1: In a reactor with low-speed stirring, add dispersant, wetting agent, 1 / 2 of the defoamer, nano silica sol and alumina sol in the following proportions by mass, and stir.

[0018] Step 2: Continue to slowly add graphene, inorganic high-efficiency corrosion inhibitor, rust-preventive pigment, aluminum dihydrogen phosphate and filler to the reaction vessel in Step 1 to obtain a premix;

[0019] Step 3: Transfer the premix obtained in Step 2 to a sand mill for grinding to obtain grinding material. Grind the material to a fineness of ≤35μm under the condition that the cooling water is turned on to keep the material temperature below 50℃.

[0020] Step 4: Transfer the abrasive obtained in Step 3 to a color mixing tank, and add the anti-settling agent, adhesion promoter, and the remaining 1 / 2 defoamer in sequence under low-speed stirring. Stir to obtain a water-based single-component high-temperature resistant anti-corrosion coating.

[0021] Furthermore, in steps one and four, the low-speed stirring speed is 300-500 rpm, and the stirring time is 5 min;

[0022] In step three, the grinding speed is 1800-2400 rpm and the grinding time is 120 min;

[0023] In step four, the stirring time is 10 minutes.

[0024] The beneficial effects of this invention are:

[0025] (1) In-situ ceramicization phase transformation achieves ultra-strong heat resistance and crack resistance (breakthrough in heat resistance): This invention introduces aluminum dihydrogen phosphate as a high-temperature binder, initiating an in-situ ceramicization reaction above 500℃, "sintering" nano-silicon / aluminum sol, pigments, fillers, and graphene into a hard Al-Si-P composite ceramic skeleton, solving the problem of low strength of the high-temperature carbon layer in traditional coatings. Combined with the excellent in-plane thermal conductivity of graphene, it can quickly disperse the local thermal stress at the flame impact point, ensuring that the coating does not crack or peel off under high temperature of 1000℃ and alternating hot and cold temperatures, achieving structural integrity across the entire temperature range.

[0026] (2) The "capture-conversion" mechanism and the labyrinth effect work together to achieve long-term corrosion protection (breakthrough in corrosion resistance): The unique "capture-H" mechanism of inorganic high-efficiency corrosion inhibitors is used to achieve long-term corrosion protection (breakthrough in corrosion resistance). + The "OH- release" mechanism actively regulates the internal pH of the coating to 8-9, fundamentally inhibiting acidic hydrogen evolution corrosion and flash rust. Simultaneously, the rust-inhibiting pigments and corrosion inhibitors synergistically form a dense "heteropolyacid salt-iron silicate" composite passivation film on the substrate surface. Combined with the "maze effect" constructed from high aspect ratio graphene, the penetration path of corrosive media is significantly extended, enabling the coating to achieve salt spray resistance of over 2000 hours.

[0027] (3) Chemical bonding and nano-densification endow excellent mechanical properties (breakthrough in physical properties): The acidic groups of aluminum dihydrogen phosphate react with the active sites on the steel surface to generate iron phosphate chemical bonds, which significantly improves the adhesion of the coating (≥9MPa). At the same time, the tiny nano-silica sol (10-20nm) efficiently fills the gaps between the micron-sized pigments and fillers, forming a dense inorganic interpenetrating network, so that the coating hardness reaches 7H or higher, and has extremely strong scratch resistance and impact resistance.

[0028] (4) Environmentally friendly water-based single-component system, convenient construction and stable storage (process breakthrough): This invention adopts a pure water-based system with extremely low VOC content, making it green and environmentally friendly. Through a specific "step-by-step feeding + temperature-controlled grinding" process and the compounding of functional additives, the problem of easy agglomeration and sedimentation of inorganic nanomaterials is solved, achieving single-component packaging. Compared with two-component coatings, this product does not require on-site mixing, can be used immediately after opening the container, and has good storage stability, greatly reducing the difficulty and cost of construction and facilitating large-scale industrial promotion. Attached Figure Description

[0029] Figure 1 This is a flowchart of the preparation method of the water-based single-component high-temperature resistant anti-corrosion coating of the present invention. Detailed Implementation

[0030] Various exemplary embodiments of the invention will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the invention or its application or use. The invention can be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0031] The terms "first," "second," and similar words used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "comprising" mean that the element preceding the word encompasses the element listed after it, without excluding the possibility of encompassing other elements. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] Water-based, single-component, high-temperature resistant, and anti-corrosion coating, comprising the following raw materials in parts by weight:

[0033] 25-30 parts by weight of nano-silica sol, 10-15 parts by weight of alumina sol, 15-18 parts by weight of aluminum dihydrogen phosphate, 1-1.5 parts by weight of graphene, 6-10 parts by weight of inorganic high-efficiency corrosion inhibitor, 10-15 parts by weight of anti-rust pigment, 5-10 parts by weight of filler, 6-8 parts by weight of functional additives, and 5-8 parts by weight of deionized water.

[0034] Specifically, the particle size of nano-silica sol is 10–20 nm, with a solid content of 20–30%; the particle size of alumina sol is 10–100 nm, with a solid content of 30–40%. Nano-silica sol and alumina sol form a binary inorganic film-forming framework. Nano-silica sol (particle size 10–20 nm) is the basic film-forming material for coatings. Its extremely small particle size endows it with a large specific surface area and high surface energy. During the coating drying process, dehydration condensation reactions occur between the silanol groups (Si-OH) on the surface of the silica sol particles (Si-OH + HO-Si → Si-O-Si + H2O), forming a dense siloxane inorganic network. This constitutes the basis for the room-temperature hardness of the coating. The introduction of alumina sol (particle size 10–100 nm) constructs a "Si-Al" binary network. Alumina particles are usually positively charged, and through electrostatic interactions with negatively charged silica sol particles, they form a "carrying cell" structure, regulating the thixotropic properties of the coating. More importantly, at high temperatures, alumina is the key aluminum source for generating high-temperature resistant ceramic phases such as mullite (3Al2O3·2SiO2), which can effectively suppress the crystallization and glass transition of single silica at high temperatures and improve the thermal shock resistance of the coating.

[0035] Aluminum dihydrogen phosphate (Al(H2PO4)3) serves as both a high-temperature binder and a ceramicization initiator. It acts as a bridge between low-temperature and high-temperature performance. At low temperatures, as an acidic binder, it slightly etches the steel surface, increasing roughness, and forms chemical bonds with iron atoms, providing initial adhesion. During the intermediate temperature transition, in the 300–500°C range where organic additives decompose, aluminum dihydrogen phosphate undergoes a condensation reaction to generate aluminum polyphosphate, forming an inorganic polymer network that fills the voids left by the decomposition of organic matter, maintaining coating strength. At high temperatures, it acts as a flux and reactant in the high-temperature ceramicization reaction, promoting the sintering of silicon-aluminum oxides.

[0036] Graphene has a carbon-to-oxygen ratio greater than 5; it possesses thermal management and labyrinth shielding properties. This invention limits the carbon-to-oxygen ratio of graphene to greater than 5 to ensure its excellent electrical and thermal conductivity and chemical stability. In the preferred formulation, the graphene sheets exhibit good layered orientation in the coating. The preferred addition amount (1-1.5 parts) precisely reaches the percolation threshold, constructing a dense "labyrinth" network. The path of corrosive media (water molecules, chloride ions, oxygen) through the coating is extended by tens of times, thereby significantly improving salt spray resistance. Graphene's high thermal conductivity plays an unexpected role in fireproofing. It can rapidly conduct and disperse the localized high heat at the flame impact point along the in-plane direction, reducing the hot spot temperature and preventing coating cracking caused by excessive local thermal stress, thus ensuring the integrity of the insulation layer. As a nano-reinforcing phase, graphene can effectively prevent the propagation of microcracks and improve the fracture toughness of the ceramic layer.

[0037] The inorganic high-efficiency corrosion inhibitor contains no less than 50 wt% silicate; it possesses intelligent "capture-conversion" and high-temperature sealing properties. The inorganic high-efficiency corrosion inhibitor (silicate content ≥ 50 wt%) selected in this invention is the core anti-corrosion component, and its mechanism of action is groundbreaking. Intelligent "capture-conversion" mechanism: Unlike traditional phosphates, this corrosion inhibitor has unique chemical activity. It can actively capture water molecules penetrating the paint film and acidic hydrogen ions (H+) generated by the corrosion reaction, generating hydroxide ions (OH–) through hydrolysis or ion exchange reactions. This keeps the microenvironment inside the paint film neutral or weakly alkaline (pH 8–9) for a long time. This mechanism fundamentally inhibits the hydrogen evolution reaction of steel corrosion under acidic conditions and prevents the "flash rust" common in water-based coatings. Ferric silicate passivation film: This corrosion inhibitor can chemically react with the metal substrate to form a complex, highly adhesive ferric silicate compound coating. This film is dense and insulating, passivating the metal surface and significantly increasing the corrosion potential. High-temperature sealing effect: Under high fire temperatures (>800℃), the calcium silicate component in the corrosion inhibitor softens and, as a high-temperature additive, reacts with phosphates, alumina, etc., to form a hard, airtight silicate glass phase or ceramic shell. This shell seals the micropores on the substrate surface, cuts off the oxygen supply, and prevents the steel from oxidizing.

[0038] The rust-inhibiting pigments are one or more of zinc phosphomolybdate, zinc phosphate, aluminum tripolyphosphate, and phytates; these pigments participate in synergistic passivation. The phosphate and molybdate ions released by pigments such as zinc phosphomolybdate and zinc phosphate work synergistically with the silicate ions released by the inorganic high-efficiency corrosion inhibitors. When trace amounts of moisture penetrate to the interface, they rapidly react with iron ions, forming a dense "heteropolyacid salt-ferric silicate" composite passivation film on the steel surface, reducing the corrosion current density to an extremely low level.

[0039] The filler is one or more of titanium dioxide, precipitated barium sulfate, alumina, and calcium carbonate; the filler has the function of volume filling and thermal expansion matching. Fillers such as titanium dioxide and barium sulfate not only reduce costs, but more importantly, they adjust the thermal expansion coefficient of the coating to match the steel substrate, thereby reducing the internal stress caused by thermal expansion and contraction.

[0040] Functional additives are one or more of the following: dispersants, wetting agents, defoamers, thickeners, anti-settling agents, and adhesion promoters. The functions of these functional additives are as follows:

[0041] Dispersants, through steric hindrance and electrostatic repulsion, enable nanoparticles (graphene, silica sol) and pigments and fillers to be stably dispersed in the aqueous phase, preventing agglomeration and ensuring coating uniformity.

[0042] Wetting agents reduce the surface tension of the system, enabling water-based coatings to effectively wet high surface energy metal substrates and prevent pinholes.

[0043] Defoamer breaks down air bubbles generated during stirring and grinding, ensuring a dense coating free of pinholes;

[0044] Thickeners adjust the rheological properties of coatings, provide thixotropy, and prevent sagging and sedimentation during vertical application and storage.

[0045] Anti-settling agent to prevent heavy pigments and fillers from settling to the bottom during storage;

[0046] Adhesion promoters, typically silane coupling agents, build molecular bridges between inorganic fillers and the substrate, enhancing interfacial bonding.

[0047] The coating prepared by this invention follows the protective principle of "staged, multi-mechanism synergy":

[0048] Phase 1: Room Temperature and Low Temperature Range (<300℃) – Physical Barrier and Electrochemical Passivation. In this phase, the coating relies on the dense inorganic network formed by the drying of nano-silicon / aluminum sol and the "maze effect" of graphene to block the penetration of water vapor and salt spray. Simultaneously, the highly efficient inorganic corrosion inhibitor maintains a weakly alkaline environment (pH 8–9) within the coating through a "capture-conversion" mechanism, and synergistically with anti-rust pigments to generate a "heteropolyacid salt-ferric silicate" composite passivation film on the steel substrate surface. The ferric phosphate chemical bonds formed by the reaction of the acidic groups of aluminum dihydrogen phosphate with the steel provide strong adhesion (≥9MPa), ensuring the coating does not peel off.

[0049] Phase Two: Intermediate Temperature Transition Zone (300℃~500℃) – Inorganic Framework Takes Over. As the temperature rises, organic additives decompose, creating micropores. At this point, aluminum dihydrogen phosphate begins to dehydrate and condense to form a polyphosphate glass phase, which promptly fills the pores and binds pigments and fillers, preventing coating chalking.

[0050] Phase Three: High-Temperature Zone (>500℃ to 1000℃) – In-situ Ceramization Phase Transformation + Thermal Barrier Protection. When the temperature rises to >500℃, an in-situ ceramization phase transformation occurs. Molten phosphate inorganic binders "sinter" together nano-silica sol particles, alumina, anti-rust pigments, fillers, and graphene sheets, generating a hard Al-Si-P composite ceramic framework in situ. This ceramic layer has extremely high strength, preventing the coating from detaching under the impact of turbulent flames and solving the problem of low carbon layer strength in traditional intumescent coatings. Simultaneously, at high temperatures, the calcium silicate in the inorganic high-efficiency corrosion inhibitor softens and reacts with surrounding components to form an airtight silicate glass-phase ceramic shell, sealing surface pores and cutting off oxygen supply. Graphene, utilizing its high thermal conductivity, rapidly disperses heat along the in-plane surface, eliminating localized thermal stress and preventing coating cracking.

[0051] To achieve the above objectives, such as Figure 1As shown, in some embodiments, a method for preparing a water-based single-component high-temperature resistant anti-corrosion coating according to any of the above embodiments is disclosed, comprising the following steps:

[0052] Step 1: In a reactor with low-speed stirring, add dispersant, wetting agent, 1 / 2 of the defoamer, nano silica sol and alumina sol in the following proportions by mass, and stir.

[0053] Step 2: Continue to slowly add graphene, inorganic high-efficiency corrosion inhibitor, rust-preventive pigment, aluminum dihydrogen phosphate and filler to the reaction vessel in Step 1 to obtain a premix;

[0054] Step 3: Transfer the premix obtained in Step 2 to a sand mill for grinding to obtain grinding material. Grind the material to a fineness of ≤35μm under the condition that the cooling water is turned on and the material temperature is below 50℃.

[0055] Step 4: Transfer the abrasive obtained in Step 3 to the color mixing tank, and add the anti-settling agent, adhesion promoter, and the remaining 1 / 2 defoamer in sequence under low-speed stirring. Stir to obtain a water-based single-component high-temperature resistant anti-corrosion coating.

[0056] Specifically, in steps one and four, the low-speed stirring speed is 300-500 rpm and the stirring time is 5 min; in step three, the grinding speed is 1800-2400 rpm and the grinding time is 120 min; in step four, the stirring time is 10 min.

[0057] The technical solution of the present invention will be further described below through more specific embodiments. The performance testing standards involved are as follows:

[0058] Pencil hardness was tested according to "GB / T 6739-2022 Determination of Hardness of Paints and Varnishes by Pencil Method"; adhesion was tested according to "GB / T 5210-2006 Adhesion Test of Paints and Varnishes by Pull-Off Method"; salt spray resistance was tested according to "GB / T1771-2007 Determination of Resistance to Neutral Salt Spray of Paints and Varnishes"; heat resistance was tested according to "GB / T 1735-2009 Determination of Heat Resistance of Paints and Varnishes". The sample was placed in a muffle furnace at 1000℃ for 2.5 hours, removed and allowed to cool naturally, and the surface was observed for cracking, peeling, blistering and other phenomena.

[0059] Example 1

[0060] Raw material composition: 25 parts of nano silica sol (particle size 15nm, solid content 30%); 15 parts of alumina sol (particle size 20nm, solid content 30%); 15 parts of aluminum dihydrogen phosphate; 1 part of graphene (carbon-oxygen ratio > 5); 6 parts of inorganic high-efficiency corrosion inhibitor (Shanghai Junjiang JP-B803); 15 parts of anti-rust pigment (zinc phosphate); 10 parts of filler (titanium dioxide); 7 parts of deionized water; including 6 parts of functional additives, including 1 part of dispersant (BYK-190), 0.5 parts of wetting agent (BYK-346), 0.5 parts of defoamer (BYK-024), 1.5 parts of thickener (ASE-60), 1.5 parts of anti-settling agent (fumed silica), and 1 part of adhesion promoter (KH-560).

[0061] The water-based single-component high-temperature resistant anti-corrosion coating was prepared according to the preparation method in the above embodiment, with a grinding speed of 2000 rpm and a grinding fineness of 30 μm.

[0062] The coated pencil prepared in this embodiment has a hardness of 7H; a pull-off adhesion of 9.5MPa; a neutral salt spray resistance of 2100 hours; and no cracking or peeling of the coating surface during the heat resistance test, remaining intact.

[0063] Example 2

[0064] Raw material composition: 30 parts of nano-silica sol (particle size 10nm, solid content 25%); 10 parts of alumina sol (particle size 50nm, solid content 35%); 18 parts of aluminum dihydrogen phosphate; 1.5 parts of graphene; 10 parts of inorganic high-efficiency corrosion inhibitor (Shanghai Junjiang JP-B804); 10 parts of anti-rust pigment (aluminum tripolyphosphate); 8 parts of filler (precipitated barium sulfate); 5 parts of deionized water. Functional additives totaling 7.5 parts: 1.2 parts of dispersant, 0.6 parts of wetting agent, 0.6 parts of defoamer, 1.5 parts of thickener, 2 parts of anti-settling agent, and 1.6 parts of adhesion promoter.

[0065] The preparation method is the same as in Example 1.

[0066] The coated pencil prepared in this embodiment has a hardness of 8H; a pull-off adhesion of 10.2 MPa; a neutral salt spray resistance of 2300 hours; and no cracking or peeling of the coating surface during the heat resistance test, remaining intact.

[0067] Example 3

[0068] Raw material composition: 28 parts nano silica sol; 12 parts alumina sol; 16 parts aluminum dihydrogen phosphate; 1.2 parts graphene; 8 parts inorganic high-efficiency corrosion inhibitor (Shanghai Junjiang JP-B805); 12 parts anti-rust pigment (zinc phosphomolybdate); 8 parts filler (alumina powder); 6.8 parts deionized water. Functional additives totaling 8 parts: 1.5 parts dispersant (BYK-190), 0.8 parts wetting agent (BYK-346), 0.7 parts defoamer (BYK-024), 1.5 parts thickener (ASE-60), 2.0 parts anti-settling agent (fumed silica), and 1.5 parts adhesion promoter (KH-560).

[0069] The preparation method is the same as in Example 1.

[0070] The coated pencil prepared in this embodiment has a hardness of 8H; a pull-off adhesion of 9.8 MPa; a neutral salt spray resistance of 2200 hours; and in the heat resistance test, the coating surface showed no cracking or peeling and remained intact.

[0071] Example 4

[0072] Raw material composition: 26 parts nano-silica sol; 14 parts alumina sol; 17 parts aluminum dihydrogen phosphate; 1.1 parts graphene; 9 parts inorganic high-efficiency corrosion inhibitor (Shanghai Junjiang JP-B803); 13 parts rust-preventive pigment (phytate); 6 parts filler (calcium carbonate); 7.9 parts deionized water. Functional additives totaling 6 parts: 1.0 part dispersant (BYK-190), 0.5 part wetting agent (BYK-346), 0.5 part defoamer (BYK-024), 1.0 part thickener (ASE-60), 1.5 parts anti-settling agent (fumed silica), and 1.5 parts adhesion promoter (KH-560).

[0073] The preparation method is the same as in Example 1.

[0074] The coated pencil prepared in this embodiment has a hardness of 7H; a pull-off adhesion of 9.2 MPa; a neutral salt spray resistance of 2050 hours; and in the heat resistance test, the coating surface showed no cracking or peeling and remained intact.

[0075] Example 5

[0076] Raw material composition: 29 parts nano-silica sol; 11 parts alumina sol; 15 parts aluminum dihydrogen phosphate; 1.3 parts graphene; 7 parts inorganic high-efficiency corrosion inhibitor (Shanghai Junjiang JP-B804 and JP-B805 compounded in a 1:1 ratio); 12 parts rust-preventive pigment (zinc phosphate and aluminum tripolyphosphate in a 1:1 ratio); 8 parts filler (titanium dioxide and barium sulfate in a 1:1 ratio); 6.7 parts deionized water. Functional additives totaling 8 parts: 1.6 parts dispersant (BYK-190), 0.6 parts wetting agent (BYK-346), 0.8 parts defoamer (BYK-024), 1.5 parts thickener (ASE-60), 1.5 parts anti-settling agent (fumed silica), and 2.0 parts adhesion promoter (KH-560).

[0077] The preparation method is the same as in Example 1.

[0078] The coated pencil prepared in this embodiment has a hardness of 8H; a pull-off adhesion of 9.6MPa; a neutral salt spray resistance of 2250 hours; and no cracking or peeling of the coating surface during the heat resistance test, remaining intact.

[0079] Example 6

[0080] Raw material composition: 27 parts nano-silica sol; 13 parts alumina sol; 16.5 parts aluminum dihydrogen phosphate; 1.4 parts graphene; 8.5 parts inorganic high-efficiency corrosion inhibitor (Shanghai Junjiang JP-B805); 14 parts anti-rust pigment (zinc phosphomolybdate); 6.5 parts filler (alumina); 6.6 parts deionized water. 7 parts functional additives: 1.2 parts dispersant (BYK-190), 0.6 parts wetting agent (BYK-346), 0.6 parts defoamer (BYK-024), 1.3 parts thickener (ASE-60), 1.5 parts anti-settling agent (fumed silica), and 1.8 parts adhesion promoter (KH-560).

[0081] The preparation method is the same as in Example 1.

[0082] The coated pencil prepared in this embodiment has a hardness of 8H; a pull-off adhesion of 9.9 MPa; a neutral salt spray resistance of 2150 hours; and no cracking or peeling of the coating surface during the heat resistance test, remaining intact.

[0083] Comparative Example 1

[0084] The formulation is basically the same as in Example 1, except that graphene is not added and is replaced with the same mass fraction of precipitated barium sulfate. This verifies the role of graphene in thermal conductivity, crack resistance, and labyrinth effect corrosion prevention.

[0085] The coating prepared in this comparative example had a pencil hardness of 6H; the adhesion under the pull-off test decreased to 8.0 MPa; the neutral salt spray resistance was only 900 hours; and microcracks appeared on the coating surface during the heat resistance test. This indicates that the lack of graphene leads to a decrease in the thermal conductivity of the coating, an inability to disperse thermal stress, and the loss of the labyrinth effect, resulting in reduced density.

[0086] Comparative Example 2

[0087] The formulation is basically the same as in Example 1, except that Shanghai Junjiang JP-B803 inorganic high-efficiency corrosion inhibitor is not added, and ordinary deionized water is used instead in the same mass proportion. The capture-conversion mechanism and high-temperature pore-sealing effect of this corrosion inhibitor are verified.

[0088] The coating prepared in this comparative example had a pencil hardness of 6H; its pull-off adhesion decreased to 6.5 MPa; its neutral salt spray resistance was only 600 hours; and the coating surface showed severe corrosion in the heat resistance test. This indicates that the lack of an effective inorganic corrosion inhibitor prevented the formation of the crucial iron silicate passivation film and pH adjustment, leading to rapid coating failure in corrosive environments.

[0089] Comparative Example 3

[0090] The formulation is basically the same as in Example 1, except that aluminum dihydrogen phosphate is not added, and the same mass fraction of nano-silica sol is used instead. This verifies the key role of aluminum dihydrogen phosphate in high-temperature ceramicization phase transition and bonding.

[0091] The coating prepared in this comparative example had a pencil hardness of only 4H; its adhesion under the pull-off test dropped significantly to 3.0 MPa; its resistance to neutral salt spray was only 500 hours; and in the heat resistance test, the coating experienced severe cracking and peeling. This indicates that the lack of aluminum dihydrogen phosphate as a high-temperature binder prevents the in-situ ceramization phase transformation from being initiated, leading to structural collapse of the coating at high temperatures.

[0092] The data above show that the coatings prepared in Examples 1-6 of this invention are significantly superior to the comparative examples in terms of hardness, adhesion, salt spray resistance, and heat resistance. Comparative Example 1 demonstrates the importance of graphene for salt spray resistance and high-temperature crack resistance; Comparative Example 2 demonstrates the core role of inorganic high-efficiency corrosion inhibitors in "capture-conversion" corrosion protection and high-temperature pore sealing; Comparative Example 3 demonstrates that aluminum dihydrogen phosphate is an indispensable component for achieving in-situ ceramic phase transformation. This invention successfully achieves high-performance coatings.

[0093] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the embodiments.

[0094] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0095] The embodiments described above only illustrate some implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A water-based, single-component, high-temperature resistant, and corrosion-resistant coating, characterized in that: The raw materials include the following parts by weight: 25-30 parts by weight of nano-silica sol, 10-15 parts by weight of alumina sol, 15-18 parts by weight of aluminum dihydrogen phosphate, 1-1.5 parts by weight of graphene, 6-10 parts by weight of inorganic high-efficiency corrosion inhibitor, 10-15 parts by weight of anti-rust pigment, 5-10 parts by weight of filler, 6-8 parts by weight of functional additives, and 5-8 parts by weight of deionized water. The total mass fraction of the raw materials is 100 parts.

2. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The nano-silica sol has a particle size of 10-20 nm and a solid content of 20-30%.

3. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The alumina sol has a particle size of 10–100 nm and a solid content of 30–40%.

4. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The graphene has a carbon-to-oxygen ratio greater than 5.

5. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The silicate content in the inorganic high-efficiency corrosion inhibitor is not less than 50 wt%.

6. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The rust-preventive pigment is one or more of zinc phosphomolybdate, zinc phosphate, aluminum tripolyphosphate, and phytate.

7. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The filler is one or more of titanium dioxide, precipitated barium sulfate, aluminum oxide, and calcium carbonate.

8. The water-based single-component high-temperature resistant anti-corrosion coating according to claim 1, characterized in that: The functional additive is one or more of the following: dispersant, wetting agent, defoamer, thickener, anti-settling agent, and adhesion promoter.

9. A method for preparing a water-based, single-component, high-temperature resistant, and anti-corrosion coating as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: In a reactor with low-speed stirring, add dispersant, wetting agent, 1 / 2 of the defoamer, nano silica sol and alumina sol in the following proportions by mass, and stir. Step 2: Continue to slowly add graphene, inorganic high-efficiency corrosion inhibitor, rust-preventive pigment, aluminum dihydrogen phosphate and filler to the reaction vessel in Step 1 to obtain a premix; Step 3: Transfer the premix obtained in Step 2 to a sand mill for grinding to obtain grinding material. Grind the material to a fineness of ≤35μm under the condition that the cooling water is turned on to keep the material temperature below 50℃. Step 4: Transfer the abrasive obtained in Step 3 to a color mixing tank, and add the anti-settling agent, adhesion promoter, and the remaining 1 / 2 defoamer in sequence under low-speed stirring. Stir to obtain a water-based single-component high-temperature resistant anti-corrosion coating.

10. The method for preparing the water-based single-component high-temperature resistant anti-corrosion coating according to claim 9, characterized in that: In steps one and four, the low-speed stirring speed is 300-500 rpm and the stirring time is 5 min. In step three, the grinding speed is 1800-2400 rpm and the grinding time is 120 min; In step four, the stirring time is 10 minutes.

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