Rust-containing rust-proof composition containing lanthanum aluminate as well as preparation method and application of rust-containing rust-proof composition

Abstract

The invention relates to the technical field of anti-rust coatings, in particular to an on-rust anti-rust composition containing lanthanum aluminate as well as a preparation method and application of the on-rust anti-rust composition. Belongs to the technical field of antirust coatings. The composition is a two-component system, a component A contains epoxy resin, surface-modified nano lanthanum aluminate, micaceous iron oxide and other functional fillers and auxiliaries, and a component B is an amine curing system. During use, the components are mixed according to the mass ratio of (4-6): 1. Nano lanthanum aluminate is subjected to surface modification through gamma-glycidyl ether oxypropyl trimethoxy silane and can react with a rust layer to generate a stable inert product, and the adhesive force of a coating is enhanced through chemical bonding. The composition can be directly coated on the rusty metal surface, sand blasting derusting is not needed, and the construction process is remarkably simplified. Experiments show that the adhesive force of the coating reaches 5.32 MPa, the salt mist resistance lasts for more than 2000 hours, and the coating has excellent anti-rust property, adhesive force and mechanical property and is suitable for long-acting corrosion prevention of large steel structures such as bridges and storage tanks.

Description

Technical Field

[0001] This invention relates to the field of rust-preventive coatings, and in particular to a rust-preventive composition containing lanthanum aluminate, its preparation method, and its application. Background Technology

[0002] Metal corrosion and rusting is a widespread and serious problem, causing enormous economic losses to industrial production, infrastructure, and daily life. Statistics show that global economic losses due to metal corrosion reach hundreds of billions of dollars annually. Among various rust prevention methods, rust-preventive coatings are the most widely used. Traditional rust-preventive coatings typically require rigorous rust removal treatment of the metal surface before application; however, this process not only consumes significant manpower, resources, and time but can also pollute the environment. For example, in some large steel structure projects, pretreatment methods such as sandblasting are not only costly but also generate dust and other pollutants that adversely affect air quality and the health of operators.

[0003] The emergence of rust-preventive coatings has provided a new solution to this problem. These coatings can be applied directly to rusted metal surfaces, simplifying the coating process and reducing costs. However, current rust-preventive coatings on the market still have many shortcomings in terms of rust prevention performance and adhesion. For example, while some rust-preventive coatings can temporarily inhibit rust development, their long-term protective effect is poor, easily leading to problems such as coating peeling and rust recurrence. Their insufficient adhesion means that when subjected to external impacts, vibrations, or changes in ambient temperature and humidity, the bond between the coating and the metal surface weakens, causing premature coating failure.

[0004] Therefore, developing a rust-preventive coating with excellent rust-preventive properties and high adhesion is of great practical significance. Summary of the Invention

[0005] (a) Technical problems to be solved To address the problems of insufficient rust prevention performance and poor adhesion of existing rust-preventive coatings, this invention provides a rust-preventive composition containing lanthanum aluminate, its preparation method, and its application, so as to significantly improve the rust prevention effect and coating adhesion.

[0006] (II) Technical Solution In a first aspect, this application provides a rust-preventive composition containing lanthanum aluminate, the composition being a two-component system comprising component A and component B, wherein component A comprises the following components by weight: Film-forming resin: 40–60 parts; Rust-preventive filler: 3.5–10 parts, including 0.5–5 parts of surface-modified nano-lanthanum aluminate, wherein the particle size of the lanthanum aluminate is 100–2000 nm; Dispersant: 0.5–2 parts; Defoamer: 0.2–0.8 parts; Organic solvent: 5–10 parts, wherein the organic solvent is selected from one or more mixtures of xylene, butanol, and ethyl acetate; Component B comprises the following components by weight: Amine curing agent: 15–18 parts; Curing accelerator: 1–3 parts; Reactive diluent: 3–8 parts.

[0007] Component A and component B are mixed during use.

[0008] The film-forming resin is epoxy resin, which has good adhesion and chemical corrosion resistance. It can form a tough protective film on the metal surface, effectively blocking the intrusion of corrosive media.

[0009] The solvent is one or a mixture of xylene, butanol, and ethyl acetate. These solvents can adjust the viscosity of the composition to give it good workability and ensure that it can be evenly covered on the metal surface during the coating process.

[0010] In a further embodiment, the mass ratio of component A to component B is (4–6):1. In the resulting mixture, the surface-modified nano-lanthanum aluminate accounts for 1% to 5.2% of the total mass of the composition.

[0011] Mixing component A and component B at a mass ratio of (4–6):1 ensures both sufficient cross-linking and curing of the epoxy resin system and maintains good workability and mechanical strength of the coating. This content range is a key window for achieving excellent rust prevention and adhesion performance. Lanthanum aluminate, as a functional inorganic material with a perovskite structure, has a surface rich in active sites that can chemically react with iron hydroxyl oxide in the metal rust layer, transforming it into a thermodynamically more stable inert composite oxide, thereby passivating the rust layer and blocking the electrochemical corrosion pathway. After surface modification with γ-glycidoxypropyltrimethoxysilane, the surface of nano-lanthanum aluminate is grafted with epoxy active groups, which not only significantly improves its dispersion stability in the epoxy resin matrix and avoids defects caused by agglomeration, but also forms covalent bonds with the resin network during the curing process, constructing a chemical anchoring effect at the rust / coating interface and greatly enhancing adhesion. Experimental results show that when the lanthanum aluminate content is within the range of 1%–5.2%, the coating exhibits high density, strong interfacial adhesion, and long-term corrosion resistance—the salt spray test corrosion resistance exceeds 2000 hours, and the adhesion can reach over 5 MPa. However, if the content is too low, the ability to transform rust is insufficient; if it is too high, it disrupts the continuous resin phase, leading to coating embrittlement, blistering, or even cracking, thus weakening the protective effect. Therefore, this mass ratio range represents the optimal balance point for chemical activity, physical filling, and film-forming performance.

[0012] In a further embodiment, the surface-modified nano-lanthanum aluminate is treated with a silane coupling agent, and the treatment process includes the following steps: Step 1: Vacuum dry 100 parts of nano-lanthanum aluminate at 100–120°C for 2–4 hours to activate the surface hydroxyl groups; Step 2: Add 1–5 parts of silane coupling agent to a mixed solvent consisting of 85–90 parts of anhydrous ethanol and 10–15 parts of deionized water, adjust the pH to 4–5 with glacial acetic acid, stir and hydrolyze for 30–60 minutes to obtain silane hydrolysate. Step 3: Disperse the nano-lanthanum aluminate obtained in Step 1 in the silane hydrolysate, ultrasonically disperse for 20–40 minutes, and then stir and react at 60–80°C for 2–4 hours to graft the silane coupling agent onto the surface of lanthanum aluminate. Step 4: Separate the reaction product by centrifugation or vacuum filtration, wash it 2–3 times with anhydrous ethanol, and then vacuum dry it at 60–80°C for 6–12 hours to obtain surface-modified nano-lanthanum aluminate.

[0013] The reason we treat nano-lanthanum aluminate with this silane coupling agent is to enable it to truly integrate with epoxy resin, rather than simply mixing it in. Although the original nano-lanthanum aluminate has hydroxyl groups on its surface, its polarity is too strong, making it particularly prone to agglomeration in organic resins. Once it clumps together, it sinks to the bottom and cannot disperse, not only failing to provide rust prevention but also becoming a defect in the coating. The first step is high-temperature vacuum drying to remove surface adsorbed water and expose active hydroxyl groups. The second step is to prepare a silane hydrolysis solution. Adjusting the pH to 4-5 with glacial acetic acid is crucial, as only under these weakly acidic conditions can the silane be fully hydrolyzed into silanols without excessively rapid self-condensation. The third step involves allowing the activated lanthanum aluminate and these silanols to react fully under ultrasonic and heating conditions. The silanols then dehydrate and graft onto the surface of the lanthanum aluminate, forming stable Si–O–La / Al bonds. Meanwhile, the silane carries an epoxy group at the other end, effectively giving the inorganic particles a coating that allows them to cross-link with the resin. Finally, unreacted small molecules are washed away, and the mixture is dried to obtain an amphiphilic functional filler that is both attracted to inorganic rust layers and organic resins.

[0014] The actual effect is very obvious. Without modification, the coating is prone to blistering and has poor adhesion; rust spreads easily after soaking in salt water. However, the modified lanthanum aluminate not only disperses evenly but also bridges the gap between the rust layer and the resin, chemically transforming the rust while covalently bonding the resin, essentially turning the originally fragile physical adhesion into chemical welding. In Example 2, we achieved an adhesion of 5.32 MPa and no blistering after 2000 hours of salt spray testing, all thanks to this surface modification step. Simply put, without modification, lanthanum aluminate is just for show; with modification, it becomes the key link in the entire rust-prevention system.

[0015] In a further embodiment, the silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

[0016] In a further embodiment, the rust-preventive filler also includes 3–5 parts of mica iron oxide. In a further embodiment, the amine curing agent is polyetheramine D-230; the curing accelerator is D0590; and the reactive diluent is phenyl glycidyl ether.

[0017] In a further embodiment, the dispersant is BYK-163; the defoamer is AFCONA-2727.

[0018] Secondly, this application provides a method for preparing a rust-preventive composition containing lanthanum aluminate, wherein the composition is a two-component system comprising component A and component B, which are mixed in a mass ratio of (4–6):1 when used. The preparation method includes the following steps: (1) Preparation of component A: The film-forming resin, dispersant, defoamer and organic solvent are mixed and stirred to form a uniform base material, and then the anti-rust filler is added and dispersed at high speed to obtain component A; (2) Preparation of component B: Mix and stir the amine curing agent, curing accelerator and reactive diluent evenly to obtain component B; (3) Before use, mix component A and component B at a mass ratio of (4–6):1, stir evenly, and let it mature for 20–30 min to obtain the composition.

[0019] In a further embodiment, in step (1), component A includes, by weight: 40–60 parts of film-forming resin, 0.5–2 parts of dispersant, 0.2–0.8 parts of defoamer, 5–10 parts of organic solvent, and 3.5–10 parts of rust-preventive filler; Mixing and stirring are performed at 300-500 r / min for 5-10 min to form a uniform base material; The rust-preventive filler contains 2–5 parts of surface-modified nano-lanthanum aluminate and 3–5 parts of mica iron oxide; The high-speed dispersion process is as follows: first, pre-disperse at 500–600 r / min for 5 min, then increase the speed to 1000–1200 r / min and continue dispersing for 20–30 min until the fineness is ≤25 μm; In step (2), component B comprises, by weight: 15–18 parts of amine curing agent, 1–3 parts of curing accelerator, and 3–8 parts of reactive diluent; The mixing speed is 300–500 r / min, and the time is 10–15 min.

[0020] This preparation method may seem to have few steps, but the parameters for each step are determined through repeated trials and are not arbitrarily set. Component A must truly disperse and stably disperse the nanofiller; component B must ensure the uniform activation of the curing system; and finally, the mixture should quickly form a dense, highly adhesive coating.

[0021] Component A is first mixed at a low speed with resin, additives, and solvent to form a base material. This step is a preparatory step, allowing the dispersant and defoamer to dissolve and activate, forming a stable liquid phase environment so that the filler added later is less likely to clump. Next, the rust-inhibiting filler is added, which is particularly crucial. We use surface-modified nano-lanthanum aluminate + flake mica iron oxide, one responsible for chemically transforming the rust layer, and the other providing physical shielding. However, nanoparticles naturally tend to clump together, so high-speed dispersion is essential. We first pre-disperse at 500–600 rpm for 5 minutes to initially wet the powder, then rapidly increase the speed to 1000–1200 rpm for 20–30 minutes, using strong shear force to completely break up the agglomerates until the fineness is ≤25 μm. If this step is skipped, the filler will not be properly dispersed, resulting in micropores and defects in the coating, directly reducing the rust-inhibiting effect.

[0022] Component B is relatively simple. The amine curing agent (such as D230), accelerator, and reactive diluent must be thoroughly stirred at 300–500 rpm for 10–15 minutes to ensure uniform distribution of the active ingredients. The reactive diluent, in particular, not only reduces viscosity but also participates in cross-linking, affecting the final network density.

[0023] When using the final product, mix A and B in a 4–6:1 ratio and allow it to cure for 20–30 minutes—this is called the induction period. This allows the epoxy and amine groups to begin reacting, slightly increasing the viscosity and resulting in less sagging and a more uniform film thickness during coating. Insufficient curing leads to a slow reaction and poor initial strength; excessive curing may cause gelation and render the product unusable.

[0024] The actual results are evident in the examples. Coatings produced using this process exhibit excellent workability and storage stability. When applied to rusty steel plates, they not only absorb loose rust but also form a dense, strong protective film. High adhesion, salt water resistance, and impact resistance are all thanks to this precisely controlled preparation process. Simply put, the formula is the skeleton, while the process is the flesh and blood—the same raw materials, but a different mixing method, can result in drastically different performance.

[0025] Thirdly, this application provides the application of the above-mentioned lanthanum aluminate-containing rust-preventing composition in rust-preventing coating of metal strips.

[0026] (III) Beneficial Effects Lanthanum aluminate, with its unique chemical structure, can react with rust on metal surfaces, transforming it into a stable inert compound, thereby effectively inhibiting further corrosion. Salt spray testing has verified that metal specimens coated with the composition of this invention can withstand corrosion for over 2000 hours, demonstrating excellent long-term corrosion protection.

[0027] Lanthanum aluminate not only improves coating density through physical filling, but also forms chemical bonds and strong interfacial adsorption between the rust layer and the epoxy matrix, significantly enhancing the bonding strength. Pull-off adhesion tests show that the coating adhesion can reach over 5 MPa, greatly enhancing the adhesion between the coating and the rusted metal substrate.

[0028] This invention simplifies the coating application process. The composition can be directly applied to rusted metal surfaces that have not been thoroughly derusted, eliminating the need for complex pretreatment steps such as sandblasting and pickling. This not only saves significant manpower, material resources, and time costs but also reduces environmental pollution such as dust and waste liquid. It is particularly suitable for engineering scenarios where complete rust removal is difficult, such as large steel structures, bridges, and storage tanks, demonstrating promising application prospects and widespread value. Experiments show that the coating adhesion reaches 5.32 MPa, and its salt spray resistance exceeds 2000 hours, exhibiting excellent rust prevention, adhesion, and mechanical properties, making it suitable for long-term corrosion protection of large steel structures such as bridges and storage tanks. Detailed Implementation

[0029] In the writing of this invention, the weight parts listed for component A and component B (e.g., 64.5 parts of component A and 24 parts of component B) are not absolute amounts for direct mixing, but rather relative proportions within each component, used to define the compositional structure of the components, and the whole is weighed as needed.

[0030] The rusty metal surface described in this application specifically refers to steel substrates (such as carbon steel and low-alloy steel) with rust (mainly composed of iron hydroxide, etc.), and is not applicable to other metals such as aluminum, copper, and zinc, or their corrosion products. The technical solution of this invention is designed specifically for the chemical properties of rust and is not applicable to non-ferrous metals.

[0031] Modification process The surface-modified nano-lanthanum aluminate is treated with a silane coupling agent, and the treatment process includes the following steps: Step 1: Vacuum dry 100 parts of nano-lanthanum aluminate at 100°C for 3 hours to activate the surface hydroxyl groups; Step 2: Add 2 parts of silane coupling agent to a mixed solvent consisting of 85 parts of anhydrous ethanol and 10 parts of deionized water, adjust the pH to 4.3 with glacial acetic acid, stir and hydrolyze for 42 minutes to obtain silane hydrolysate; Step 3: Disperse the nano-lanthanum aluminate obtained in Step 1 in the silane hydrolysate, ultrasonically disperse for 30 minutes, and then stir and react at 70°C for 2 hours to graft the silane coupling agent onto the surface of lanthanum aluminate. Step 4: Separate the reaction product by centrifugation or filtration, wash twice with anhydrous ethanol, and then vacuum dry at 70°C for 10 hours to obtain surface-modified nano-lanthanum aluminate. The silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

[0032] Example 1: This embodiment provides a rust-preventive composition containing lanthanum aluminate. Component A, by weight, comprises: 50 parts epoxy resin, 2 parts surface-modified nano-lanthanum aluminate (particle size 100 nm), 3 parts mica iron oxide, 1 part BYK163 dispersant, 0.5 parts AFCONA-2727 defoamer, and 8 parts organic solvent (xylene:butanol = 1:1). Component B, by weight, comprises: 16 parts polyetheramine D230, 2 parts curing accelerator D0590, and 6 parts phenyl glycidyl ether. Component A and component B are mixed at a mass ratio of 5:1.

[0033] The preparation method includes the following steps: (1) Preparation of component A: The film-forming resin, dispersant, defoamer and organic solvent are mixed and stirred to form a uniform base material. The mixing and stirring is carried out at 300 r / min for 5 min to form a uniform base material. Then, the rust-inhibiting filler is added and dispersed at high speed. The high-speed dispersion process is to first pre-disperse at 500 r / min for 5 min, and then increase the speed to 1000 r / min to continue dispersing for 20 min until the fineness is ≤25 μm; thus, component A is obtained. (2) Preparation of component B: The amine curing agent, curing accelerator and reactive diluent are mixed and stirred evenly. The mixing speed is 300 r / min and the time is 10 min.

[0034] Component B was obtained; (3) Before use, mix component A and component B at a mass ratio of 5:1, stir evenly and let it mature for 20 minutes to obtain the composition.

[0035] In this embodiment, the total mass of component A, calculated according to the formula, is 64.5 parts, and the total mass of component B is 24 parts. In actual use, components A and B need to be mixed at a mass ratio of 5:1. If component A is scaled up by 5 times, i.e., to 322.5 parts, the corresponding required mass of component B is 64.5 parts, and the final total mass of the mixture is 387.0 parts. At this point, the amount of lanthanum aluminate used is also scaled up by 5 times accordingly. The mass percentage of lanthanum aluminate in the final composition is 2.6%.

[0036] Example 2: In this embodiment, the preparation method is the same as above. Component A, by weight, includes: 40 parts epoxy resin, 3.5 parts surface-modified nano-lanthanum aluminate (particle size 1000 nm), 4 parts mica iron oxide, 0.8 parts BYK163, 0.3 parts AFCONA-2727, and 6 parts organic solvent (ethyl acetate); Component B includes: 15 parts polyetheramine D230, 1.5 parts D0590, and 5 parts phenyl glycidyl ether. The mass ratio of A to B is 4:1.

[0037] Take A = 54.6 × 4 = 218.4 parts, take component B as 54.6 parts, the total mass of the final mixture is 273.0 parts, and the mass percentage of lanthanum aluminate in the final composition is 5.13%. Example 3: This embodiment provides a rust-preventive composition with a low lanthanum aluminate content. Component A, by weight, includes: 55 parts epoxy resin, 0.85 parts surface-modified nano-lanthanum aluminate (particle size 500 nm), 4 parts mica iron oxide, 1 part BYK163 dispersant, 0.5 parts AFCONA-2727 defoamer, and 8 parts organic solvent (xylene and butanol mixed in a 1:1 ratio), with a total mass of 69.35 parts. Component B, by weight, includes: 16 parts polyetheramine D230, 2 parts curing accelerator D0590, and 6 parts phenyl glycidyl ether. In use, components A and B are mixed at a mass ratio of 5:1. The actual amount of modified lanthanum aluminate used is 0.85 × 5 = 4.25 parts, which accounts for 1.02% of the final composition by mass.

[0038] Comparative Example 1 Compared with Example 2, the surface-modified nano-lanthanum aluminate was omitted, while the remaining components, proportions, and preparation methods remained the same.

[0039] Comparative Example 2 The rust-preventive composition was prepared using the same method as in Example 2, except that lanthanum aluminate was replaced with an equal amount of zinc powder.

[0040] Comparative Example 3 Compared with Example 2, everything else remained the same, and lanthanum aluminate was not modified.

[0041] Comparative Example 4 Compared with Example 2, everything else remained the same, except for 2 parts of surface-modified nano-lanthanum aluminate (particle size of 100 nm) and 10 parts of mica iron oxide.

[0042] Comparative Example 5 This embodiment provides a rust-preventive composition with a high content of lanthanum aluminate. Component A, by weight, comprises: 45 parts epoxy resin, 8.0 parts surface-modified nano-lanthanum aluminate (particle size 800 nm), 2 parts mica iron oxide, 1.5 parts BYK163 dispersant, 0.6 parts AFCONA-2727 defoamer, and 9 parts organic solvent (xylene:butanol = 1:1). Component B, by weight, comprises: 17 parts polyetheramine D230, 2.5 parts D0590, and 7 parts phenyl glycidyl ether. In use, components A and B are mixed at a mass ratio of 5:1.

[0043] Performance testing Rust prevention performance test: The rust prevention performance of the rust-resistant compositions prepared in Examples 1-3 and Comparative Examples 1-5 was tested by salt spray test.

[0044]

[0045] The performance test results above show that the rust-preventive composition containing surface-modified nano-lanthanum aluminate of the present invention exhibits significant advantages in adhesion, salt water resistance, and coating integrity. In Example 2, the lanthanum aluminate content was approximately 5.1%, and its adhesion reached 5.32 MPa, far superior to Comparative Example 1 (without lanthanum aluminate) and Comparative Example 2 (with zinc powder as a substitute), verifying the unique mechanism of lanthanum aluminate in chemically transforming rust and forming strong interfacial bonds. Example 1 achieved an adhesion of 2.8 MPa, showing a significant performance improvement; while Example 3 had an adhesion of 1.1 MPa, which, although better than the comparative examples, showed only a limited improvement, indicating that lanthanum aluminate needs to reach a certain threshold to exert its effective effect.

[0046] Comparative Example 3 used unmodified lanthanum aluminate. Although the filler type was the same, the lack of silane coupling agent modification resulted in poor dispersibility in the epoxy matrix and weak interfacial bonding with the rust layer. This manifested as decreased adhesion, significantly deteriorated salt water resistance, and the appearance of blistering and rust expansion, fully demonstrating the crucial role of surface modification in the function of lanthanum aluminate. In Comparative Example 4, the amount of mica iron oxide was too high. Although the physical shielding effect was enhanced, the excessive amount of lamellar filler hindered the effective contact between lanthanum aluminate and the rust layer, inhibiting its chemical conversion ability, resulting in both adhesion and corrosion resistance not reaching optimal levels. Although Comparative Example 5 used silane-modified nano-lanthanum aluminate, its content in the final composition was as high as about 10.1%, far exceeding the preferred range of this invention. Excessive lanthanum aluminate filler disrupted the continuity and cohesive strength of the epoxy resin matrix, leading to a significant decrease in the physical and mechanical properties of the coating. The impact resistance plummeted from 50 cm to 30 cm, obvious cracking occurred in the bending test, and the cross-cut adhesion rating deteriorated to level 3, indicating increased brittleness and loss of flexibility in the coating. Although lanthanum aluminate itself has the ability to chemically transform rust layers, high filler content leads to the following negative effects: The resin is excessively diluted, resulting in decreased film density and easier penetration by moisture and chloride ions; the tendency for nanoparticle aggregation increases, and even with surface modification, it is difficult to completely avoid micropores and interface defects; stress concentration within the coating accelerates environmental corrosion. Therefore, although its adhesion is still higher than Comparative Examples 1–3, its water resistance and salt water resistance are severely deteriorated, resulting in large-area blistering and rust expansion, and its overall protective performance is actually inferior to Examples 1 and 2.

[0047] The embodiments of this application will be described in further detail below with reference to the examples. The detailed description of the following embodiments is used to illustrate the principles of this application, but should not be used to limit the scope of this application. This application can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0048] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions and values ​​illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0049] It should be noted that, in the description of this application, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0050] Furthermore, the terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well.

[0051] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0052] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0053] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0054] The embodiments of this application have now been described in detail. To avoid obscuring the concept of this application, 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.

[0055] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A rust-preventive composition containing lanthanum aluminate, characterized in that, The composition is a two-component system, comprising component A and component B, wherein component A comprises the following components by weight: Film-forming resin: 40–60 parts; Rust-preventive filler: 3.5–10 parts, including 0.5–5 parts of surface-modified nano-lanthanum aluminate, wherein the particle size of the lanthanum aluminate is 100–2000 nm; Dispersant: 0.5–2 parts; Defoamer: 0.2–0.8 parts; Organic solvent: 5–10 parts, wherein the organic solvent is selected from one or more mixtures of xylene, butanol, and ethyl acetate; Component B comprises the following components by weight: Amine curing agent: 15–18 parts; Curing accelerator: 1–3 parts; Reactive diluent: 3–8 parts; When using, components A and B are mixed at a ratio of (4–6):

1.

2. The rust-preventive composition containing lanthanum aluminate according to claim 1, characterized in that, In the resulting mixture, the surface-modified nano-lanthanum aluminate accounts for 1% to 5.2% of the total mass of the composition.

3. The rust-preventive composition containing lanthanum aluminate according to claim 1, characterized in that, The surface-modified nano-lanthanum aluminate is treated with a silane coupling agent, and the treatment process includes the following steps: Step 1: Vacuum dry 100 parts of nano-lanthanum aluminate at 100–120°C for 2–4 hours to activate the surface hydroxyl groups; Step 2: Add 1–5 parts of silane coupling agent to a mixed solvent consisting of 85–90 parts of anhydrous ethanol and 10–15 parts of deionized water, adjust the pH to 4–5 with glacial acetic acid, and stir for 30–60 minutes to hydrolyze and obtain silane hydrolysate; Step 3: Disperse the nano-lanthanum aluminate obtained in Step 1 in the silane hydrolysate, ultrasonically disperse for 20–40 minutes, and then stir and react at 60–80°C for 2–4 hours to graft the silane coupling agent onto the surface of lanthanum aluminate. Step 4: Separate the reaction product by centrifugation or vacuum filtration, wash it 2–3 times with anhydrous ethanol, and then vacuum dry it at 60–80°C for 6–12 hours to obtain surface-modified nano-lanthanum aluminate.

4. The rust-preventive composition according to claim 3, characterized in that, The silane coupling agent is γ-glycidoxypropyltrimethoxysilane.

5. The rust-preventive composition containing lanthanum aluminate according to claim 1, characterized in that, The rust-preventive filler also includes 3–5 parts of mica iron oxide.

6. The rust-preventive composition containing lanthanum aluminate according to claim 1, characterized in that, The amine curing agent is polyetheramine D-230; the curing accelerator is D0590; and the reactive diluent is phenyl glycidyl ether.

7. The rust-preventive composition containing lanthanum aluminate according to claim 1, characterized in that, The dispersant is BYK-163; the defoamer is AFCONA-2727.

8. A method for preparing a rust-preventive composition containing lanthanum aluminate, characterized in that, The composition is a two-component system, comprising component A and component B, which are mixed in a mass ratio of (4–6):1 when used. The preparation method includes the following steps: (1) Preparation of component A: The film-forming resin, dispersant, defoamer and organic solvent are mixed and stirred to form a uniform base material, and then the anti-rust filler is added and dispersed at high speed to obtain component A; (2) Preparation of component B: Mix and stir the amine curing agent, curing accelerator and reactive diluent evenly to obtain component B; (3) Before use, mix component A and component B at a mass ratio of (4–6):1, stir evenly, and let it mature for 20–30 min to obtain the composition.

9. The preparation method according to claim 8, characterized in that, In step (1), component A comprises, by weight: 40–60 parts of film-forming resin, 0.5–2 parts of dispersant, 0.2–0.8 parts of defoamer, 5–10 parts of organic solvent, and 3.5–10 parts of rust-preventive filler; The mixing process involves stirring at 300-500 r / min for 5-10 min to form a uniform base material. The rust-preventive filler comprises 0.5–5 parts of surface-modified nano-lanthanum aluminate and 3–5 parts of mica iron oxide; The high-speed dispersion process is as follows: first, pre-disperse at 500–600 r / min for 5 min, then increase the speed to 1000–1200 r / min and continue dispersing for 20–30 min until the fineness is ≤25 μm; In step (2), component B comprises, by weight: 15–18 parts of amine curing agent, 1–3 parts of curing accelerator, and 3–8 parts of reactive diluent; The mixing speed is 300–500 r / min, and the time is 10–15 min.

10. The use of the lanthanum aluminate-containing rust-preventing composition according to any one of claims 1–7 in the rust-preventing coating of metal strips.

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