Two-component environment-friendly coating

Abstract

The invention discloses a two-component environment-friendly coating, and relates to the technical field of coatings, the two-component environment-friendly coating is composed of powder and paste; the powder comprises a composite antirust material, calcium carbonate, aluminum oxide, iron oxide, magnesium carbonate and water; the paste comprises a composite antirust material, calcium carbonate, aluminum oxide, iron oxide, magnesium carbonate and water; the mass ratio of the powder to the paste is 1: 5; the composite antirust material comprises a core layer and a shell layer coating the surface of the core layer, the core layer is composed of graphdiyne and aluminum triphosphate, and the surface of the graphdiyne is coated with the aluminum triphosphate; the shell layer is formed by compounding graphene quantum dots and silicon dioxide nanoparticles; the small particle size of the silicon dioxide nanoparticles is 5-15 nm, and the large particle size of the silicon dioxide nanoparticles is 20-50 The mass ratio of the small-particle-size silicon dioxide nanoparticles to the large-particle-size silicon dioxide nanoparticles is 2: 1; by introducing a composite structure of double-particle-size silicon dioxide and graphene quantum dots, the anti-rust performance, the environment-friendly performance and the comprehensive performance of the coating are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly to a two-component environmental protection coating. Background Art

[0002] In the coating industry, traditional rust-inhibiting pigments such as chromates and molybdates have excellent anti-corrosion performance and are widely used in coatings. However, with the improvement of people's environmental awareness, people have begun to pay attention to and improve the environment. Traditional rust-inhibiting pigments contain heavy metals such as chromium and lead, which are likely to cause environmental pollution during the production and construction of coatings.

[0003] For example, in the Chinese patent with the application number CN202110019895.3, the invention provides a composite rust-inhibiting material, its preparation method, a coating, and a metal product. The composite rust-inhibiting material includes a core layer and a shell layer coated on the surface of the core layer; the core layer includes graphdiyne and aluminum tripolyphosphate, and the shell layer includes graphene. The preparation method of the composite rust-inhibiting material includes: mixing raw materials including an aluminum salt, oxidized graphdiyne, and water, and performing a first reaction to obtain a complex system; mixing materials including a phosphorus-containing substance and the complex system, and performing a second reaction to obtain a glue solution; mixing materials including graphene quantum dots and the glue solution, and performing a third reaction to obtain a composite intermediate; heating and reducing the composite intermediate in a non-oxidizing atmosphere to obtain the composite rust-inhibiting material. The coating includes the composite rust-inhibiting material described above. The metal product includes a rust-inhibiting coating, and the rust-inhibiting coating includes the coating described above. The composite rust-inhibiting material provided by this application has good rust-inhibiting effect and long service life.

[0004] The composite rust-inhibiting material in the above solution improves the rust-inhibiting effect, but there are still problems such as difficult control of shell layer defects leading to too fast penetration of corrosive media, and difficult regulation of the release rate of aluminum tripolyphosphate, which limits its long-term effectiveness and reliability. Summary of the Invention

[0005] By providing a two-component environmental protection coating in the embodiments of the present application, the technical problems in the prior art of difficult control of shell layer defects and difficult regulation of the release rate of aluminum tripolyphosphate in rust-inhibiting coatings are solved. By introducing a composite structure of double-sized silica nanoparticles and graphene quantum dots, and designing a multi-level protection structure, the rust-inhibiting performance, environmental protection performance, and comprehensive performance of the coating are improved.

[0006] The embodiments of the present application provide a two-component environmental protection coating, which is composed of a powder and a paste; The powder includes the following components in parts by weight: 2 parts of composite rust-inhibiting material, 93.8 parts of calcium carbonate, 0.1 part of aluminum oxide, 0.1 part of iron oxide, 4.4 parts of magnesium carbonate, and 0.6 part of water; The paste comprises the following components in parts by weight: 2 parts of a composite rust inhibitor, 62.9 parts of calcium carbonate, 0.3 part of aluminum oxide, 0.1 part of iron oxide, 3.9 parts of magnesium carbonate, and 32.8 parts of water; The mass ratio of the powder to the paste is 1:5; The composite rust inhibitor includes a core layer and a shell layer coated on the surface of the core layer; The core layer is composed of graphdiyne and aluminum tripolyphosphate, and the aluminum tripolyphosphate is coated on the surface of the graphdiyne; The shell layer is composed of a composite of graphene quantum dots and silica nanoparticles; The silica nanoparticles include small particles with a particle size of 5 - 15 nm and large particles with a particle size of 20 - 50 nm; the mass ratio of the small particles to the large particles of the silica nanoparticles is 2:1.

[0007] Furthermore, the preparation method of the composite rust inhibitor is specifically as follows: S1. Mix an aluminum salt, oxidized graphdiyne, and water, and stir to obtain a complex system; S2. Mix a phosphorus-containing substance with the complex system, stir, and react to generate a colloidal solution; S3. Mix graphene quantum dots and silica nanoparticles to form a particle mixture; S4. Mix the particle mixture with the colloidal solution, and carry out a condensation reaction to form a composite intermediate; S5. Heat and reduce the composite intermediate in a non-oxidizing atmosphere to obtain the composite rust inhibitor.

[0008] Furthermore, the mass ratio of the graphene quantum dots to the silica nanoparticles is 1:(0.5 - 1).

[0009] Furthermore, the large-sized silica is mesoporous silica, and the mesoporous pores are 2 - 5 nm.

[0010] Furthermore, the large-sized silica is also pre-loaded with aluminum tripolyphosphate.

[0011] Furthermore, the pre-loaded aluminum tripolyphosphate accounts for 10 - 20% of the mass of the large-sized silica.

[0012] Furthermore, the pre-loading is specifically as follows: Immerse the large-sized silica in a 5 - 10 wt% aluminum tripolyphosphate solution, ultrasonically disperse for 30 minutes, and vacuum dry at 60°C for 12 hours to complete the pre-loading.

[0013] Furthermore, the two-component environmentally friendly coating is applied in two layers, which are divided into a barrier layer and a slow-release layer.

[0014] Furthermore, the mass ratio of the large-sized silica to the small-sized silica in the barrier layer is 1:3, and the total addition amount and the mass ratio of the graphene quantum dots is 0.8:1.

[0015] Furthermore, the mass ratio of large - particle - size silica to small - particle - size silica in the slow - release layer is 2:1, and the total addition amount to the mass ratio of graphene quantum dots is 1:1.

[0016] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: First, by introducing silica nanoparticles, the technical problems that it is difficult to control the shell defects of the composite anti - rust material, resulting in too fast penetration of corrosive media and difficult to regulate the release rate of aluminum tripolyphosphate are solved. The silica nanoparticles fill the shell defects, form a tortuous diffusion path, delay the penetration of corrosive media, and at the same time form hydrogen bonds with graphene to enhance the interfacial binding force, improve the anti - rust performance of the coating, extend the durability of the anti - rust effect, and enhance the comprehensive performance and environmental performance of the coating; Second, by introducing silica nanoparticles with different particle sizes, the contradiction between the shell compactness and release rate control of the anti - rust coating is solved. Small - particle - size silica fills the defects and enhances the shell compactness; large - particle - size silica constructs a slow - release channel to maintain the active anti - rust function; a dual - particle - size synergistic mechanism is generated by introducing silica nanoparticles with different particle sizes; Third, by introducing large - particle - size mesoporous silica and pre - loading aluminum tripolyphosphate, the problems of long - term protection and release control of the anti - rust coating are solved. The mesoporous structure serves as a reservoir to achieve the reservoir - type slow release of aluminum tripolyphosphate, and forms a double passivation film with the core layer, enhancing the anti - rust effect; Fourth, through functional hierarchical design and particle - size ratio optimization, the problem of the limited function of a single - layer anti - rust coating is solved, and the synergistic effect of rapid initial barrier and long - term slow release in the later stage is achieved; the bottom - layer coating uses a high proportion of small - particle - size silica. Utilizing its high specific surface area and filling ability, it fills micropores and cracks to form a dense physical barrier layer, rapidly reducing the penetration rate of corrosive media and providing an effective barrier for initial protection. At the same time, the pre - loaded aluminum tripolyphosphate slowly releases pyrophosphate ions through mesopores to form a dense passivation film in the initial stage, inhibiting the penetration of corrosive media; the surface - layer coating uses a high proportion of large - particle - size mesoporous silica. Through pre - loading aluminum tripolyphosphate, the reservoir - type slow release of pyrophosphate ions is achieved. The mesoporous structure can control the release rate of aluminum tripolyphosphate to ensure the continuous repair of the passivation film, thereby extending the protection life of the coating. Detailed implementation manners

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs; the terms used in the description of the present invention in this specification are only for the purpose of describing specific implementation manners and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0018] Example 1: A two-component environmentally friendly coating, which consists of a powder and a paste; The powder comprises the following components in parts by weight: 2 parts of a composite rust inhibitor, 93.8 parts of calcium carbonate, 0.1 part of aluminum oxide, 0.1 part of iron oxide, 4.4 parts of magnesium carbonate, and 0.6 part of water; The paste comprises the following components in parts by weight: 2 parts of a composite rust inhibitor, 62.9 parts of calcium carbonate, 0.3 part of aluminum oxide, 0.1 part of iron oxide, 3.9 parts of magnesium carbonate, and 32.8 parts of water; The mass ratio of the powder to the paste is 1:5; The composite rust inhibitor includes a core layer and a shell layer coated on the surface of the core layer; The core layer is composed of graphdiyne and aluminum tripolyphosphate, wherein the aluminum tripolyphosphate is coated on the surface of the graphdiyne, and the shell layer is composed of a composite of graphene quantum dots and silica nanoparticles; The preparation method of the composite rust inhibitor specifically includes the following steps: S1. Mix an aluminum salt, oxidized graphdiyne, and water, and stir to obtain a complexing system; Among them, the aluminum salt includes at least one of aluminum chloride, aluminum sulfate, aluminum nitrate, and aluminum hydroxide. The size of the oxidized graphdiyne is 1 nm - 100 nm, the oxygen content of the oxidized graphdiyne is 5 wt% - 20 wt%, the mass ratio of the aluminum salt to the oxidized graphdiyne is 1∶(1 - 5), and the stirring time is 10 min - 60 min; S2. Mix a phosphorus-containing substance with the complexing system, stir, and react to generate a colloidal solution; Among them, the phosphorus-containing substance includes at least one of phosphoric acid and phosphates, and the phosphates include at least one of sodium phosphate, ammonium phosphate, and sodium dihydrogen phosphate; the reaction temperature is 60°C - 120°C; the molar ratio of the aluminum salt to the phosphorus-containing substance is 1∶(2 - 5); S3. Mix graphene quantum dots and silica nanoparticles to form a particle mixture; Among them, the size of the graphene quantum dots is 1 - 20 nm, the oxygen content is 10 - 60 wt%, the particle size of the silica nanoparticles is 5 - 20 nm, and the mass ratio of the graphene quantum dots to the silica nanoparticles is 1:(0.2 - 1); the mass ratio of the aluminum salt to the graphene quantum dots is 1∶(4 - 6); S4. Mix the particle mixture with the colloidal solution, and carry out a condensation reaction to form a composite intermediate; Among them, the temperature of the condensation reaction is 250°C - 400°C; S5. Heat and reduce the composite intermediate in a non-oxidizing atmosphere to finally obtain the composite rust inhibitor; Among them, the non-oxidizing atmosphere includes at least one of hydrogen, nitrogen, and noble gases; the temperature of the heat reduction is 600°C - 900°C; The construction method of the coating, the specific steps are as follows: A1. Mix the powder and paste in a mass ratio of 1:5, and stir at low speed until uniform to form a two-component environmentally friendly coating; A2. Remove the oil stains, dust and loose particles on the construction surface to ensure dryness and no rust; A3. Use resin to paste a crack prevention bandage at the joint of the board to ensure that the bandage is flat and bubble-free; A4. Apply the mixed coating evenly on the board area by scraping and brushing to fill the sunken area and dry at room temperature; A5. Stir and mix the coating and putty powder in a mass ratio of 1:4, then scrape and brush all the board areas again and dry at room temperature; A6. After drying, polish the coating until the surface is flat, remove burrs and protrusions, and roll on latex paint without primer or other intermediate layers.

[0019] For the specific implementation of the technical solution of the above embodiment, experiments are carried out. Among them, the coating formula: the powder and paste are mixed in a ratio of 1:5; Condensation reaction temperature: 300 °C Heating reduction temperature: 800 °C Mass ratio of aluminum salt to graphene quantum dots: 1:5 Construction process: single-layer scraping and brushing thickness 1.5 mm, drying at room temperature for 6 hours; Test standard: salt spray test (GB / T 1771-2007), impedance test (72 h); The shell layer defect rate characterizes the integrity of the shell layer structure through the intensity ratio (D / G) of the D peak and G peak of Raman spectroscopy, and the coating porosity is measured by mercury intrusion method (%); the test results are shown in Table 1 below: Table 1

[0020] The technical solution in the above embodiment of the present application has at least the following technical effects or advantages: By introducing silica nanoparticles, the technical problems that it is difficult to control the shell layer defects of the composite rust preventive material, resulting in too fast penetration of corrosive media and difficult to regulate the release rate of aluminum tripolyphosphate, are solved. The silica nanoparticles fill the shell layer defects, form a tortuous diffusion path, delay the penetration of corrosive media, and at the same time form hydrogen bonds with graphene to enhance the interfacial binding force, improve the rust prevention performance of the coating, extend the durability of the rust prevention effect, and enhance the comprehensive performance and environmental protection performance of the coating; Silica nanoparticles are introduced as inert fillers and uniformly dispersed in the graphene film to fill the defective pores, forming tortuous diffusion paths to delay the penetration of corrosive media. At the same time, the hydroxyl groups on the silica surface form hydrogen bonds with the oxygen-containing functional groups of graphene quantum dots, enhancing the interfacial bonding force between the shell layer and the core layer, preventing delamination, and improving the overall structural stability. By adjusting the addition amount of silica, the porosity and diffusion resistance of the graphene film are regulated, enabling the pyrophosphate groups of aluminum tripolyphosphate to be released at a controllable rate, prolonging the timeliness of the formation of the passivation film, and improving the durability of the rust prevention effect. The shielding property of graphene and the chemical passivation property of aluminum tripolyphosphate achieve a dual rust prevention mechanism under the synergistic effect of silica. Silica nanoparticles can fill the defects in the graphene shell, reduce the pinholes and cracks in the shell, improve the compactness and integrity of the shell, and prevent corrosive media from penetrating through the shell to the substrate surface, thereby improving the rust prevention performance of the coating. The physical barrier effect of silica nanoparticles can delay the release rate of aluminum tripolyphosphate, enabling it to be released more uniformly onto the coating surface, forming a more stable and durable passivation film, and improving the long-term rust prevention effect of the coating. By enhancing the shell integrity and delaying the release of aluminum tripolyphosphate, the rust prevention performance of the coating is significantly improved. After introducing silica nanoparticles, the comprehensive properties of the coating such as corrosion resistance, adhesion, and weather resistance are improved, and the inert characteristics of silica nanoparticles prevent them from chemically reacting with other components in the coating, thus ensuring the stability and durability of the coating.

[0021] By reducing the excessive release of aluminum tripolyphosphate and lowering the content of free acidic substances in the coating, the environmental performance of the coating is further improved. By introducing silica nanoparticles, the rust prevention performance of the coating is improved, the service life of metal products is extended, and the maintenance and replacement costs caused by corrosion are reduced. The comprehensive properties of the coating such as corrosion resistance, adhesion, and weather resistance are improved, enabling it to be used in more severe environments and meeting a wider range of application requirements.

[0022] Example 2: In Example 1 above, by introducing silica nanoparticles, the technical problems of difficult control of the shell defects in the composite rust prevention material, resulting in too fast penetration of corrosive media and difficult regulation of the release rate of aluminum tripolyphosphate, are solved. Silica nanoparticles fill the shell defects, form tortuous diffusion paths, delay the penetration of corrosive media, and at the same time form hydrogen bonds with graphene to enhance the interfacial bonding force, improve the rust prevention performance of the coating, prolong the durability of the rust prevention effect, and enhance the environmental performance of the coating. To further improve the rust prevention performance of the coating, it is further improved on the basis of Example 1.

[0023] The silica nanoparticles include small-sized nanoparticles with a size of 5-15 nm and large-sized nanoparticles with a size of 20-50 nm; the mass ratio of the small-sized to the large-sized silica nanoparticles is 2:1; the mass ratio of the graphene quantum dots to the silica nanoparticles is 1:(0.5-1); Experiments were carried out on the basis of the experiments in Example 1. The difference from Example 1 is that the silica nanoparticles include small-sized nanoparticles with a size of 5-15 nm and large-sized nanoparticles with a size of 20-50 nm; the mass ratio of the small-sized to the large-sized silica nanoparticles is 2:1; the test results are shown in Table 2 below: Table 2

[0024] The technical solutions in the embodiments of the present application at least have the following technical effects or advantages: By introducing silica nanoparticles with different particle sizes, the contradiction between the shell compactness and the release rate control of the rust-proof coating is solved. The small-sized silica fills the defects and enhances the shell compactness; the large-sized silica constructs a slow-release channel to maintain the active rust-proof function; by introducing silica nanoparticles with different particle sizes, a dual-particle-size synergistic mechanism is generated. The small-sized silica uses its similar size to the graphene quantum dots to fill the micropores and cracks in the shell, reduce the porosity, and enhance the shell compactness; reduce the sudden release of aluminum tripolyphosphate caused by shell defects and inhibit non-specific release; the large-sized silica forms pores as the directional diffusion path of pyrophosphate ions, constructs a slow-release channel, and maintains the active slow-release function to ensure the continuous and effective release of aluminum tripolyphosphate; by controlling the pore density and size, avoid the passivation failure caused by the complete closure of the shell, form a dynamic balance regulation, and achieve the balance between microscopic defect filling and macroscopic release channel construction through the dual-particle-size synergistic effect; The filling effect of the small-sized silica significantly reduces the porosity of the shell, enhances the physical barrier performance, effectively prevents the penetration of corrosive media, and the dense shell structure prolongs the diffusion path of the corrosive media, improving the rust-proof effect of the coating. The maintenance of the active rust-proof function enables the coating to still maintain excellent rust-proof effect in extreme corrosion environments; the directional pores formed by the large-sized silica provide a controllable release channel for aluminum tripolyphosphate, maintaining the active rust-proof function of the coating. The construction of the slow-release channel avoids the problems of excessive initial release or passivation failure caused by complete closure of the shell in the later stage of traditional coatings, improving the stability and reliability of the coating and prolonging the service life of the coating; the hydrogen bond network between silica and graphene quantum dots enhances the interfacial bonding strength between the shell and the core layer, preventing delamination, and the strengthened interfacial bonding improves the overall stability and durability of the coating, meeting the use requirements under different environmental conditions.

[0025] Example 3: In Example 2 above, by introducing silica nanoparticles with different particle sizes, the problem of difficult control of the compactness and release rate of the rust-proof coating shell was solved. Small particle size silica filled the defects and enhanced the compactness of the shell; large particle size silica constructed a slow-release channel to maintain the active rust-proof function; achieving a balance between microscopic defect filling and macroscopic release channel construction, improving the rust-proof performance, stability and environmental friendliness of the coating, extending the service life. To further improve the rust-proof performance of the coating, it was further improved on the basis of Example 2.

[0026] The large particle size silica is mesoporous silica, and the mesoporous pore size is 2 - 5 nm; the large particle size silica is pre-loaded with aluminum tripolyphosphate; the pre-loaded aluminum tripolyphosphate accounts for 10 - 20% of the mass of the large particle size silica; The pre-loading is specifically as follows: Immerse the large particle size silica in an aluminum tripolyphosphate solution with a concentration of 5 - 10 wt%, and ultrasonically disperse for 30 minutes; vacuum dry at 60 °C for 12 hours to allow the aluminum tripolyphosphate to be fully adsorbed in the mesopores; Based on Example 2, experiments were carried out with the mass ratio of graphene quantum dots to silica nanoparticles being 1:0.5; after testing, the salt spray life (h) was 4210, the coating impedance (Ω·cm²) was 47850, the shell defect rate (D / G peak ratio) was 0.61, and the coating porosity (%) was 5.9.

[0027] The technical solutions in the above embodiments of the present application at least have the following technical effects or advantages: By introducing large particle size mesoporous silica and pre-loading aluminum tripolyphosphate, the problem of long-term protection and release control of the rust-proof coating was solved. The mesoporous structure serves as a reservoir to achieve the reservoir-type slow release of aluminum tripolyphosphate, forming a double passivation film with the aluminum tripolyphosphate in the core layer, enhancing the rust-proof effect; Mesoporous silica has an extremely high specific surface area and pore volume, which can adsorb and store a large number of aluminum tripolyphosphate molecules to form a storage reservoir. The mesoporous size limits the diffusion rate of pyrophosphate ions, enabling it to be slowly released and avoiding passivation failure caused by excessive initial release; through the impregnation method, the aluminum tripolyphosphate solution is adsorbed and fixed by the capillary action of mesoporous silica to form a stable loading system. The physical adsorption between the functional groups on the mesoporous surface and the aluminum tripolyphosphate molecules further regulates the release rate to achieve long-term slow release; the core layer provides an initial basic passivation film to quickly neutralize the corrosive medium and protect the metal substrate. The pre-loaded large particle size silica in the shell acts as a long-term storage reservoir to continuously supplement pyrophosphate ions. Small particle size silica fills the defects of the graphene film to block the penetration of the corrosive medium and maintain the stability and integrity of the passivation film.

[0028] Aluminum tripolyphosphate coated on the surface of graphdiyne provides rapid initial passivation to form a basic passivation film to resist the intrusion of corrosive media. Aluminum tripolyphosphate pre-loaded in mesoporous silica continuously releases pyrophosphate radicals in the medium and long term to make up for the consumption of the core layer and maintain the effectiveness of the passivation film. Small particle size silica fills defects, reduces the penetration path of corrosive media, and enhances the physical barrier performance of the shell layer. Aluminum tripolyphosphate in the core layer and the shell layer together form a double passivation film to cover microcracks and defects on the metal surface and provide comprehensive chemical protection. The uniform distribution of mesoporous silica can disperse the stress inside the coating and improve the crack resistance and durability of the coating. The pre-loaded aluminum tripolyphosphate can continuously release pyrophosphate ions to form a stable passivation film, effectively preventing further erosion of corrosive media. The continuous existence and release of the passivation film can repair microcracks and damages on the coating surface and extend the service life of the coating. The regulation of mesopore size and surface functional groups enables aluminum tripolyphosphate to be released as needed, avoiding problems such as passivation failure caused by excessive initial release and insufficient later release. The pre-loading mechanism ensures the stability of the release rate and reduces release fluctuations caused by environmental factors. The uniform distribution of mesoporous silica and the strengthening effect of graphene quantum dots improve the flexibility of the coating, enabling it to better adapt to the deformation and vibration of the substrate.

[0029] Example 4: In Example 3 above, by introducing large particle size mesoporous silica and pre-loading aluminum tripolyphosphate, the problems of long-term protection and release control of the rust-proof coating are solved. The mesoporous structure acts as a reservoir to achieve reservoir-type slow release of aluminum tripolyphosphate, forming a double passivation film with the core layer and enhancing the rust-proof effect. To further improve the rust-proof performance of the coating, it is further improved on the basis of Example 3.

[0030] The two-component environmentally friendly coating is applied in two layers, divided into a barrier layer and a slow release layer; The mass ratio of large particle size silica to small particle size silica in the barrier layer is 1:3, and the mass ratio of the total addition amount to graphene quantum dots is 0.8:1; the mass ratio of large particle size silica to small particle size silica in the slow release layer is 2:1, and the mass ratio of the total addition amount to graphene quantum dots is 1:1; The construction method of applying the two-component environmentally friendly coating in two layers specifically comprises the following steps: In step A4, the mixed barrier layer coating is evenly troweled and applied to the plate area to fill the sunken area and dried at normal temperature to form a barrier layer; after the barrier layer is completely dried, the slow release layer coating is evenly troweled and applied and dried at normal temperature to form a slow release layer; Among them, the troweled thickness of the barrier layer is 1.0 mm and it is dried at normal temperature for 4 hours, and the troweled thickness of the slow release layer is 0.5 mm and it is dried at normal temperature for 5 hours; Based on Example 3, experiments were carried out with two coatings applied, namely the barrier layer and the sustained-release layer. After testing, the salt spray life (h) was 4820, the coating impedance (Ω·cm²) was 52430, the shell layer defect rate (D / G peak ratio) was 0.54, and the coating porosity (%) was 5.2.

[0031] The technical solutions in the embodiments of the present application at least have the following technical effects or advantages: Through the functional layer design and the optimization of the particle size ratio, the problem of the limited function of a single coating of the rust-proof paint is solved, and the synergistic effect of rapid initial barrier and long-term sustained release in the later stage is achieved; The bottom coating uses a high proportion of small particle size silica. Utilizing its high specific surface area and filling ability, it fills micropores and cracks to form a dense physical barrier layer, rapidly reducing the penetration rate of corrosive media and providing an effective barrier for initial protection. At the same time, the pre-loaded aluminum tripolyphosphate slowly releases pyrophosphate radicals through mesopores, forming a dense passivation film in the initial stage to inhibit the penetration of corrosive media; the surface coating uses a high proportion of large particle size mesoporous silica. Through the pre-loading of aluminum tripolyphosphate, reservoir-type sustained release is achieved. The mesoporous structure can control the release rate of aluminum tripolyphosphate to ensure the continuous repair of the passivation film, thereby extending the protection life of the coating; The high proportion of small particle size silica in the bottom layer enhances the denseness and initial protection ability of the coating. Through physical barrier action, the occurrence of corrosion is rapidly inhibited, and the penetration of corrosive media is reduced; the high proportion of large particle size silica in the surface layer focuses on the sustained release function. Through the mesoporous reservoir effect, the continuous release of pyrophosphate radicals is achieved to maintain the long-term stability of the passivation film; the bottom layer barrier reduces the penetration pressure of corrosive media, and the surface layer sustained release extends the life of the passivation film, forming a protection mechanism of physical barrier, chemical passivation and continuous repair to achieve full protection; the functional layer design and the optimization of the particle size ratio improve the coating in terms of denseness, flexibility and crack resistance, enhancing the comprehensive protection performance of the coating, enabling the paint to be applicable to corrosive environments such as chemical industry, and expanding the scope of application; the synergistic effect of the bottom layer barrier and the surface layer sustained release forms an intelligent gradient function system, solving the performance limitation between rapid passivation and long-term sustained release of a single coating.

[0032] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A two-component environmentally friendly coating, characterized in that: It is composed of powder and paste; The powder includes the following components in parts by weight: 2 parts of composite anti-rust material, 93.8 parts of calcium carbonate, 0.1 parts of aluminum oxide, 0.1 parts of iron oxide, 4.4 parts of magnesium carbonate, and 0.6 parts of water; The paste includes the following components in parts by weight: 2 parts of composite anti-rust material, 62.9 parts of calcium carbonate, 0.3 parts of aluminum oxide, 0.1 parts of iron oxide, 3.9 parts of magnesium carbonate, and 32.8 parts of water; The mass ratio of powder to paste is 1:5; The composite anti-rust material comprises a core layer and a shell layer covering the surface of the core layer; The core layer is composed of graphyne and aluminum tripolyphosphate, and the aluminum tripolyphosphate is coated on the surface of graphyne; The shell is composed of a composite of graphene quantum dots and silica nanoparticles; The silicon dioxide nanoparticles include small particles with a diameter of 5-15 nm and large particles with a diameter of 20-50 nm; the mass ratio of the small particles to the large particles is 2:

1.

2. The two-component environmentally friendly coating according to claim 1, characterized in that: The preparation method of the composite anti-rust material is specifically as follows: S1. Mixing aluminum salt, graphene oxide and water, and stirring to obtain a complex system; S2. mixing the phosphorus-containing substance with the complexing system, stirring, and reacting to form a glue; S3. mixing graphene quantum dots with silica nanoparticles to form a particle mixture; S4. mixing the particle mixture with the glue solution, condensing the mixture to form a composite intermediate; S5. Heat and reduce the composite intermediate in a non-oxidizing atmosphere to obtain a composite anti-rust material.

3. The two-component environmentally friendly coating according to claim 1, characterized in that: The mass ratio of graphene quantum dots to silica nanoparticles is 1:(0.5-1).

4. The two-component environmentally friendly coating according to claim 1, characterized in that: Large particle size silica is mesoporous silica, and the mesopores are 2-5nm.

5. The two-component environmentally friendly coating according to claim 4, characterized in that: The large particle size silica is also preloaded with aluminum tripolyphosphate.

6. The two-component environmentally friendly coating according to claim 5, characterized in that: The pre-loaded aluminum tripolyphosphate accounts for 10-20% of the mass of the large particle size silica.

7. The two-component environmentally friendly coating according to claim 5, characterized in that: The pre-loading is specifically performed by immersing the large-particle silicon dioxide in a 5-10wt% aluminum tripolyphosphate solution, ultrasonically dispersing for 30 minutes, and vacuum drying at 60°C for 12 hours to complete the pre-loading.

8. The two-component environmentally friendly coating according to claim 4, characterized in that: The two-component environmentally friendly paint is applied in two layers, which are divided into a barrier layer and a slow-release layer.

9. The two-component environmentally friendly coating according to claim 8, characterized in that: The mass ratio of large-particle silica to small-particle silica in the barrier layer is 1:3, and the mass ratio of the total addition amount to the graphene quantum dots is 0.8:

1.

10. The two-component environmentally friendly coating according to claim 8, characterized in that: The mass ratio of large-particle silica to small-particle silica in the sustained-release layer is 2:1, and the mass ratio of the total added amount to the graphene quantum dots is 1:1.

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