Process for the preparation of anticorrosive coatings and anticorrosive coatings

Abstract

The present application relates to heavy-duty anticorrosive coating technical field, disclose a kind of preparation anticorrosive coating method and anticorrosive coating.The method includes: (1) coupling agent and diluent are contacted first, obtain mixed solution I;(2) the mixed solution I and epoxy resin are contacted second, obtain mixed solution II;(3) mixed solution II and dispersing agent, defoaming agent, defoaming agent, rheological agent, antirust pigment, barium sulfate, titanium white, leveling agent are contacted third, obtain the anticorrosive coating;The rheological agent is mass ratio 1:0.2~3.75 of fumed silica I and organic clay;The specific surface area of fumed silica I is 150~190m 2 / g;The coupling agent is titanium alloy nano chelate.The anticorrosive coating provided by the present application has high coating density, good adhesion, high hardness, good wear resistance, flexibility and impact resistance, and excellent acid, alkali and salt resistance.

Description

Technical Field

[0001] This invention relates to the field of heavy-duty anti-corrosion coatings, specifically to a method for preparing an anti-corrosion coating and the anti-corrosion coating itself. Background Technology

[0002] Flue gas desulfurization (FGD) units are the most severely corroded parts of thermal power plants. To prevent corrosion, mainstream anti-corrosion products such as glass flake anti-corrosion coatings are conventionally used. However, glass flake anti-corrosion coatings contain a significant amount of flammable gases that evaporate at room temperature. In enclosed containers such as FGD towers, these gases can easily explode upon contact with a spark. Therefore, a Class A hot work permit is required for application, and cross-operation is prohibited. Fire trucks and firefighters must be on-site throughout the application process. Especially during maintenance and repair, a continuous water supply is required to ensure safety, and the flammable gases produced persist throughout the entire service life of the glass flake anti-corrosion coating. Fire accidents frequently occur in thermal power plants during construction or maintenance, resulting in casualties and property damage ranging from millions to hundreds of millions of yuan.

[0003] Glass flake anti-corrosion coatings require a relatively thick application, which can easily lead to uneven bonding strength, low elongation at break, poor resistance to external impacts, and poor flexibility. Under the influence of external forces such as vibrations during other operations, they are prone to large-area blistering and peeling. At temperatures exceeding 150℃, they are prone to cracking, allowing corrosive media to penetrate and cause further detachment. Furthermore, depending on the ambient temperature and application process, the curing time of glass flake anti-corrosion coatings requires adjustments to the amount of initiator and accelerator added.

[0004] Glass flake anti-corrosion coatings typically require an application temperature of at least 5°C. In environments exceeding 35°C, dimethylbenzene should be added as an inhibitor to prevent excessively rapid curing and ensure long-term corrosion protection. Furthermore, depending on the location within the desulfurization tower, a coating thickness of 2mm to 6mm is required for effective corrosion protection. This results in a long application period, high labor intensity, and significant environmental pollution and health risks for workers. Therefore, there is an urgent need to develop an anti-corrosion coating with a wide application temperature range, high coating density, good adhesion, high hardness, strong wear resistance, high flexibility, and good impact resistance.

[0005] As is well known, steel corrosion occurs when corrosive media penetrate the substrate through a coating, causing the substrate to corrode and rust. Coatings, as the simplest method to prevent metal corrosion, primarily function by forming a film that isolates the medium from the metal substrate.

[0006] However, coatings typically contain porosity, one type being structural pores, the size of which is related to the molecular structure of the coating film-forming substance. The average diameter of these structural pores is generally around 10 mm. -5 ~10 -7Within a 1 cm range, meaning the diffusion and penetration of medium molecules between the polymer macromolecular chains in the coating, this usually follows Fick's law and belongs to molecular-level diffusion. Another type is pinholes formed during the coating film-forming process due to solvent evaporation or uneven dispersion and stirring; these pores are larger, approximately 10 cm. -2 ~10 -4 cm, or capillary diffusion, refers to the diffusion of the medium within the coating due to various defects in its physical structure, such as micropores, cracks, and pores. It can be calculated using the capillary diffusion formula. However, the speed of capillary diffusion is thousands of times greater than diffusion at the molecular level. Therefore, when micropores exist within the coating causing capillary diffusion, the effect of capillary diffusion is significantly offset by the extremely high capillary diffusion coefficient, which greatly diminishes the effect of increasing coating thickness on extending diffusion time.

[0007] In the above situations, increasing the coating thickness loses its meaning of "long-lasting". In other words, some coatings with low density cannot achieve long-lasting corrosion protection even if they are very thick. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing anti-corrosion coatings that cannot simultaneously achieve a wide range of application temperature, high coating density, good adhesion, high hardness, good wear resistance, flexibility and impact resistance. It also aims to break through the anti-corrosion strategy of over-reliance on increasing coating thickness and solve the safety problem of existing anti-corrosion coatings being prone to ignition throughout their entire service life.

[0009] To achieve the above objectives, a first aspect of the present invention provides a method for preparing an anti-corrosion coating, the method comprising: (1) The coupling agent and the diluent are brought into first contact to obtain mixed solution I; (2) The mixed solution I and the epoxy resin are brought into a second contact to obtain mixed solution II; (3) Mixed solution II is brought into a third contact with dispersant, defoamer, antifoaming agent, rheology modifier, anti-rust pigment, barium sulfate, titanium dioxide and leveling agent to obtain the anti-corrosion coating; The rheology modifier is a mixture of fumed silica I and organic clay in a mass ratio of 1:0.2–3.75; the specific surface area of ​​the fumed silica I is 150–190 m². 2 / g; the coupling agent is a titanium alloy nano-chelate; the epoxy equivalent of the epoxy resin is 196-212, the viscosity of the epoxy resin is 500-2000 mPa.s, and the molecular weight of the epoxy resin is 3000-3500.

[0010] A second aspect of the present invention provides an anti-corrosion coating prepared by the method described in the first aspect.

[0011] Compared with the prior art, the present invention has the following beneficial effects through the above technical solution: 1. The anti-corrosion coating of the present invention can be applied at temperatures ranging from -20℃ to 40℃. The anti-corrosion coating of the present invention has high coating density, good adhesion, high hardness, good wear resistance, flexibility and impact resistance, high elongation at break, low water vapor permeability coefficient and low chloride ion permeability. In harsh liquid environments such as desulfurization towers where the ambient temperature (50-80℃) is higher than normal temperature and corrosion is severe, only 0.5mm to 1mm of coating is needed to achieve a highly efficient anti-corrosion effect.

[0012] 2. The anti-corrosion coating of the present invention has a uniform and dense film structure, low water vapor permeability and low chloride ion permeability, and excellent anti-corrosion and anti-rust effect; it can withstand 170-190℃ and does not release any organic solvents that can evaporate at room temperature, making it safe and environmentally friendly. It has good adhesion, high hardness, good flexibility, impact resistance and wear resistance, and the dry film is weather-resistant and non-toxic.

[0013] 3. The anti-corrosion coating described in this invention is a heavy-duty anti-corrosion coating. The construction process is simple, and three sprays can achieve a thickness of 1mm, which can greatly improve construction efficiency and shorten the construction cycle. It has virtually no harm to construction personnel and the environment. It can be used for the anti-corrosion of food containers such as drinking water tanks. It is a non-hazardous chemical and an environmentally friendly heavy-duty anti-corrosion coating. It has no harm to the physical and mental health of construction personnel and is environmentally friendly.

[0014] 4. The anti-corrosion coating of the present invention organically combines chemical rust prevention, electrochemical rust prevention, passivation-type corrosion inhibition, and shielding rust prevention. The components in the coating do not need to undergo time-consuming, energy-consuming, and labor-intensive grinding to achieve a fully dispersed effect.

[0015] 5. The method for preparing anti-corrosion coatings described in this invention employs a different manufacturing process and equipment than ordinary coatings, which enables the components in the coating to be fully dispersed. After the coating film is cured, the pores are very small, the film is dense and uniform, and the anti-corrosion and anti-rust effects are significantly improved. The water vapor permeability coefficient and chloride ion permeability resistance are significantly reduced compared with other conventional coatings. Thus, the coating film has excellent corrosion resistance and can provide long-term protection to the substrate with a thin coating. It is an environmentally friendly heavy-duty anti-corrosion coating that meets the requirements of green energy saving and environmental protection. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the method for preparing anti-corrosion coatings according to the present invention. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] As previously described, a first aspect of the present invention provides a method for preparing an anti-corrosion coating, the method comprising: (1) The coupling agent and the diluent are brought into first contact to obtain mixed solution I; (2) The mixed solution I and the epoxy resin are brought into a second contact to obtain mixed solution II; (3) Mixed solution II is brought into a third contact with dispersant, defoamer, antifoaming agent, rheology modifier, anti-rust pigment, barium sulfate, titanium dioxide and leveling agent to obtain the anti-corrosion coating; The rheology modifier is a mixture of fumed silica I and organic clay in a mass ratio of 1:0.2–3.75; the specific surface area of ​​the fumed silica I is 150–190 m². 2 / g; the coupling agent is a titanium alloy nano-chelate; the epoxy equivalent of the epoxy resin is 196-212, the viscosity of the epoxy resin is 500-2000 mPa.s, and the molecular weight of the epoxy resin is 3000-3500.

[0019] In some embodiments, the organic clay is HFGEL-205B organic clay produced by Zhejiang Fenghong New Material Co., Ltd.

[0020] In some embodiments, based on the total mass of the composition, the epoxy resin content is 50-55 wt%, the rheology modifier content is 0.9-4.0 wt%, the diluent content is 6-9 wt%, the anti-rust pigment content is 4-8 wt%, the barium sulfate content is 8-10 wt%, the titanium dioxide content is 6-10 wt%, the coupling agent content is 8-12 wt%, the dispersant content is 0.1-0.4 wt%, the defoamer content is 0.1-0.5 wt%, the antifoamer content is 0.05-0.5 wt%, and the leveling agent content is 0.4-1.0 wt%.

[0021] In some embodiments, the dispersant is a high molecular weight polycarboxylic acid and polysiloxane dispersant.

[0022] In some embodiments, the average particle size of the titanium alloy nanochelate is 15–30 nm.

[0023] Preferably, the titanium alloy nano-chelate is a titanium alloy nano-chelate with model number RT001 produced by Hunan Ruitian New Materials Co., Ltd.

[0024] In this invention, the stable ring structure of the titanium alloy nano-chelate exhibits significant chemical and thermal stability, and possesses a nanoparticle effect. When interacting with light, it generates a small-size effect, greatly reducing light scattering and shielding power, resulting in a "transparent" state. It also exhibits strong absorption of short-wavelength ultraviolet light, excellent heat resistance, weather resistance, and resistance to acids, alkalis, and salts. Furthermore, the coating is non-toxic, possesses good hydrophobicity, and exhibits good storage and dispersibility. It fully utilizes the functions of nanomaterials, such as the small-size maze effect, quantum effect, surface effect, and boundary effect, thereby saving energy and reducing carbon emissions. The titanium alloy nano-chelate acts as a key coupling agent in the coating system, chemically bonding or entangled with the weakly polar organic polymers (epoxy resin) in the coating, and reacting with the surface functional groups of the strongly polar, high-surface-energy inorganic materials (titanium alloy nano-chelate). This uniformly and fully "welds" together organic and inorganic materials with vastly different properties, forming a denser interpenetrating network polymer coating after curing.

[0025] In some embodiments, the defoamer is a modified polysiloxane.

[0026] In some embodiments, the modified polysiloxane is a polysiloxane modified with fumed silica II.

[0027] In some embodiments, the defoaming agent is an acrylate copolymer.

[0028] In some embodiments, the leveling agent is a fluorocarbon-modified polyacrylate copolymer.

[0029] In some embodiments, the epoxy resin is BQ-E800 epoxy resin produced by Foshan Beiqing New Materials Co., Ltd. In this preferred embodiment, the epoxy resin has low viscosity (500–2000 mPa·s) and good permeability, resulting in a corrosion-resistant coating with good workability and good adhesion to the substrate.

[0030] In this invention, the viscosity of the epoxy resin is the viscosity measured at 25°C.

[0031] In some embodiments, the epoxy resin has a large number of rotatable C-C and CO σ single bonds in its molecular backbone, as well as a flexible backbone (polyether chain). In this preferred case, the coating film prepared has good flexibility.

[0032] In some embodiments, the epoxy resin is a low-viscosity solvent-free epoxy resin that has been hyperbranched and modified, with three identical branches and a large included angle of 120 degrees between the three branches. This facilitates the reaction of the active groups of each component in the anti-corrosion coating to form polymer chains. The polymer chains can easily interpenetrate to form a hard and dense polymer film, which has excellent hardness, flexibility, impact resistance, and high elongation at break, as well as good resistance to corrosion from acids, alkalis, and salts.

[0033] In some embodiments, the rust-inhibiting pigment is a silica ion-exchange type rust-inhibiting pigment.

[0034] In this invention, compared to commonly used rust-preventive pigments such as zinc phosphate and aluminum tripolyphosphate in coatings, the silica ion-exchange type rust-preventive pigment offers better rust prevention, higher cost-effectiveness, and is free of heavy metals. It can react with corrosive media to form a dense, insoluble passivation layer.

[0035] In some embodiments, the average particle size of the barium sulfate is 2500 to 3500 mesh.

[0036] In some embodiments, the barium sulfate is barium sulfate of model SM-5HBL produced by Xiangtan Shuangma Century New Materials Co., Ltd. The water extraction pH of the barium sulfate is 7-9, and it is environmentally friendly and non-toxic.

[0037] In some embodiments, the titanium dioxide is rutile titanium dioxide, and the average particle size of the rutile titanium dioxide is 2500-3000 mesh.

[0038] In some embodiments, the diluent is C 12-14 Alkyl glycidyl ether.

[0039] In this invention, by first contacting the coupling agent (titanium alloy nano-chelate) with the diluent and then contacting it with the epoxy resin, the components in the anti-corrosion coating can be fully dispersed.

[0040] In some embodiments, in step (1), the operation of the first contact includes: ultrasonic dispersion treatment for 10 to 15 minutes.

[0041] In some embodiments, in step (2), the operation of the second contact includes: stirring at a speed of 300-400 rpm for 10-15 min, followed by ultrasonic dispersion for 5-10 min.

[0042] In some embodiments, the operation of the third contact in step (3) includes stirring at a speed of 300-400 rpm for 3-5 minutes, followed by ultrasonic dispersion for 3-5 minutes.

[0043] In some implementations, step (3) includes the following specific steps: (31) The dispersant, the defoamer and the antifoaming agent are added to the mixed solution II respectively to perform the fourth contact; the operation of the fourth contact includes: stirring at 300 rpm to 400 rpm for 5 min to 10 min, and then ultrasonically dispersing for 3 min to 5 min; (32) Add the rheology modifier to the material obtained in step (31) and stir for 15 min to 20 min at a temperature of 0-40℃ and a speed of 400 rpm to 500 rpm. (33) Add the rust-preventive pigment, the barium sulfate and the titanium dioxide to the material obtained in step (32) in sequence, and stir for 20 min to 30 min at a temperature of 0-40℃ and a speed of 500 rpm to 1000 rpm. (34) Add the leveling agent to the material obtained in step (33) and make a third contact to obtain the anti-corrosion coating.

[0044] In some embodiments, the conditions for ultrasonic wave dispersion in the first contact, the second contact, the third contact, and the fourth contact each independently include: a frequency of 20-60 kHz and an output power of 800-1000 W.

[0045] In some implementations, the operation of the first contact, the second contact, the third contact, and the fourth contact is performed independently at 0-40°C.

[0046] The method for preparing the anti-corrosion coating of the present invention can also involve various post-processing operations known in the art, such as filtration. For example, the material after the third contact is filtered through a 100-150 mesh filter to obtain the anti-corrosion coating.

[0047] As previously stated, a second aspect of the present invention provides an anti-corrosion coating prepared by the method described in the first aspect.

[0048] In some embodiments, the anti-corrosion coating has an elongation at break of 20%–28% and a water vapor permeability coefficient of 3.9 × 10⁻⁶. -12 ~9.8×10 -12 g / (mspa), chloride ion permeability resistance is 2.9×10 -4 ~9.3×10 -4 mg / (cm 2 .d), adhesion is 9-11 MPa, hardness is 4H, flexibility is 1 mm, and impact strength is 50-100 kg·cm.

[0049] In other embodiments, the anti-corrosion coating has an elongation at break of 26%–28% and a water vapor permeability coefficient of 3.9 × 10⁻⁶. -12 ~4.2×10 -12 g / (mspa), chloride ion permeability resistance is 2.9×10 -4 ~3.2×10 -4 mg / (cm 2 .d), adhesion is 11MPa, hardness is 4H, flexibility is 1mm, and impact strength is 100kg.cm.

[0050] The anti-corrosion coating described in this invention is an environmentally friendly heavy-duty anti-corrosion coating. All components of the anti-corrosion coating are non-hazardous materials, and the entire construction process does not generate volatile organic solvents or dust at room temperature. It can effectively improve the working environment of coating construction personnel, ensure the health of workers, and protect the environment.

[0051] The present invention also discloses a material for preparing an anti-corrosion coating, the material comprising: the anti-corrosion coating and an epoxy curing agent; wherein the epoxy curing agent is a phenolic amine curing agent.

[0052] In some embodiments, the epoxy curing agent is a phenolic amine curing agent, model NC-558, manufactured by Cardlite Chemical (Zhuhai) Co., Ltd. The phenolic amine curing agent is benzyl alcohol-free.

[0053] Preferably, the mass ratio of the anti-corrosion coating to the epoxy curing agent is 1:0.2. In this preferred embodiment, the ratio of the anti-corrosion coating to the epoxy curing agent is fixed and will not change with temperature variations. Furthermore, no volatile organic solvents are released at room temperature. The coating can be recoated in 2 hours and fully dried in 8 hours at room temperature. The construction process is simple, and three spray coats can achieve a thickness of 1 mm. This significantly improves construction efficiency, shortens the overall anti-corrosion construction cycle, and enhances construction quality.

[0054] In this invention, the coating film formed by the interpenetration of polymers after the epoxy resin reacts with the epoxy curing agent (i.e., an amine curing agent containing active hydrogen) has a much higher density than the coating film formed by the reaction of ordinary asymmetric epoxy resin with epoxy curing agent. In other words, it can improve the crosslinking density of the coating film and improve its density and corrosion resistance.

[0055] In this invention, the active groups of the epoxy resin can better combine and react with the active groups of the titanium alloy nano-chelate containing many active dangling bonds and the epoxy curing agent containing active hydrogen to form a more uniform, dense, and well-adhesive micro-nano interpenetrating network structure of polymer coating film. This coating film perfectly adheres to every micropore on the surface of surface-treated metal and other substrates, forming an interwoven organic-inorganic hybrid chain segment with multiple barrier effects. This effectively blocks the corrosion of high-temperature oxidation, acids, alkalis, salts and organic solvents, and provides long-lasting resistance to ultraviolet aging.

[0056] This invention utilizes a silica ion-exchange type anti-rust pigment with a porous structure, which strongly inhibits blistering and rusting at damaged areas of the coating and possesses a strong adsorption capacity. The epoxy resin active groups react with an amine curing agent containing active hydrogen to form a dense interpenetrating network polymer, which, together with the porous ion-exchange silica, forms an even denser interpenetrating network coating. In corrosive environments, H₂O ionizes to release H₂. + and OH - It can strongly adsorb H in corrosive media + This makes the interface alkaline, and its alkaline components can neutralize the corrosive ions H+ that enter the paint film. + This improves the protective performance of the coating on the substrate, meaning it gives the coating excellent resistance to acids, alkalis, and salts. Simultaneously, SiO2 reacts with an alkaline environment to form SiO3. 2- Iron loses electrons at the anode and becomes Fe. 2+ Fe 2+ and SiO3 2- A dense and insoluble ferrous silicate is formed. This dense, insoluble ferrous silicate covers the surface of every micropore in the substrate, forming a dense passivation film. On the one hand, it significantly increases the adhesion between the coating and the metal substrate without the need for additional adhesion promoters; on the other hand, it prevents the penetration of corrosive media, inhibits the spread of rust and under-film corrosion at the site of paint film damage, and provides long-term protection for substrates in harsh environments.

[0057] In this invention, the silica ion-exchange type anti-rust pigment has a strong adsorption capacity. It reacts with the active groups of the epoxy resin and the active groups of the titanium alloy nano-chelate, as well as the epoxy curing agent containing active hydrogen, to form an interpenetrating network polymer, which together forms a more uniform and dense organic-inorganic hybrid segment interwoven coating film. This coating film has high hardness, good flexibility, and strong impact resistance, and therefore has a high elongation at break and good corrosion resistance.

[0058] The following combination Figure 1 The preferred embodiments of the method for preparing the anti-corrosion coating provided by the present invention will be described in further detail.

[0059] In a preferred embodiment of the present invention, the titanium alloy nano-chelate and the diluent are ultrasonically dispersed for 10-15 minutes to obtain mixed solution I; the epoxy resin is added to mixed solution I and stirred at 300-400 rpm for 10-15 minutes, followed by ultrasonic dispersion for 5-10 minutes to obtain mixed solution II; the dispersant, the defoamer, and the antifoaming agent are added to mixed solution II and stirred at 300-400 rpm for 5-10 minutes, followed by ultrasonic dispersion for 3-5 minutes; the rheology modifier is added and stirred at 400-500 rpm for 15-20 minutes; the anti-rust pigment, the barium sulfate, and the titanium dioxide are added sequentially and stirred at 500-1000 rpm for 20-30 minutes; the leveling agent is added and stirred at 300-400 rpm for 3-5 minutes, followed by ultrasonic dispersion for 3-5 minutes, and then filtered to obtain the anti-corrosion coating.

[0060] The present invention will be described in detail below through embodiments.

[0061] For any raw materials or instruments whose manufacturers are not specified, they can all be obtained commercially. In the following examples, room temperature or ambient temperature refers to (25±2)℃.

[0062] Epoxy Resin I: Purchased from Foshan Beiqing New Materials Co., Ltd., model BQ-E800, epoxy equivalent of 196-212, viscosity of 500-2000 mPa.s at 25℃, and molecular weight of 3000-3500.

[0063] Epoxy Resin II: Purchased from Sinopec Hunan Petrochemical Co., Ltd., model CYD-128, epoxy equivalent 184~194, viscosity at 25℃ 11000~14000mPa.s, molecular weight 370~380.

[0064] Diluent: C 12-14 The alkyl glycidyl ether was purchased from Shandong Jilin Huakai Resin Co., Ltd.

[0065] Rust-preventing pigment: The silica ion-exchange type rust-preventing pigment was purchased from Xinji Yourong Chemical Technology Co., Ltd., model number YR-E3.

[0066] Barium sulfate: purchased from Xiangtan Shuangma Century New Materials Co., Ltd., model SM-5HBL, with an average particle size of 3000 mesh and a water extraction pH of 7-9.

[0067] Rutile titanium dioxide: purchased from Kemira, model CR828, with an average particle size of 2500 mesh.

[0068] Dispersant: Polycarboxylic acid and polysiloxane dispersant was purchased from Shanghai Shenzhu Chemical Technology Co., Ltd., product name SN-2204.

[0069] Defoaming agent: Acrylic ester copolymer purchased from Shanghai Shenzhu Chemical Technology Co., Ltd., product name SN-5331A.

[0070] Defoamer: The silicone-modified polysiloxane was purchased from Shanghai Shenzhu Chemical Technology Co., Ltd., and its product name is SN6368A.

[0071] Fumed silica I: purchased from Evonik Degussa, model R974, with a specific surface area of ​​160–180 m². 2 / g.

[0072] Organic clay: purchased from Zhejiang Fenghong New Material Co., Ltd., model number HFGEL-205B.

[0073] Leveling agent: Fluorocarbon modified polyacrylate copolymer was purchased from Shanghai Shenzhu Chemical Technology Co., Ltd., product name SN-3279.

[0074] Coupling agent I: Titanium alloy nano-chelate was purchased from Hunan Ruitian New Materials Co., Ltd., model RT001, with an average particle size of 15-30 nm.

[0075] Coupling agent II: The epoxy-modified silane coupling agent was purchased from Changsha Ruibote Technology Co., Ltd., model R560.

[0076] Thixotropic agent II: purchased from Guangdong Core New Materials Co., Ltd., model number PAMID D650.

[0077] Commercially available coating product: purchased from Hunan Ruitian New Materials Co., Ltd., model number RT002.

[0078] Epoxy curing agent: Phenolic amine curing agent was purchased from Cardley Chemical (Zhuhai) Co., Ltd., model NC-558.

[0079] The filter referred to below is the filter according to the Chinese standard.

[0080] The following examples were conducted at an ambient temperature of 23°C (accuracy ±2°C) and a relative humidity of 50%RH (accuracy ±5%).

[0081] In the following example, the total mass of the anti-corrosion coating is 100g, and wt% refers to the ratio of the mass (g) of a certain substance to the total mass (g) of the anti-corrosion coating.

[0082] Example 1 This embodiment uses the formulation in Table 1 and prepares the anti-corrosion coating according to the following method: (1) The coupling agent and the diluent were brought into contact for the first time (the frequency of the WH1200B ultrasonic processor was adjusted to 20 kHz and the output power was 1000 W, and the ultrasonic dispersion was performed for 10 min) to obtain mixed solution I; (2) Add epoxy resin to mixed solution I for a second contact (stir at 300 rpm for 10 min, adjust the frequency of WH1200B ultrasonic processor to 20 kHz and the output power to 1000 W, and perform ultrasonic dispersion treatment for 5 min) to obtain mixed solution II; (3) Add dispersant, defoamer and antifoaming agent to mixed solution II respectively, and perform the fourth contact (stir at 300 rpm for 5 min, adjust the frequency of WH1200B ultrasonic processor to 20 kHz and the output power to 1000 W, and perform ultrasonic dispersion treatment for 3 min); add rheology modifier, stir at 400 rpm for 15 min; add rust-preventive pigment, barium sulfate and titanium dioxide in sequence, stir at 500 rpm for 20 min; add leveling agent, and perform the third contact (stir at 300 rpm for 3 min, adjust the frequency of WH1200B ultrasonic processor to 20 kHz and the output power to 1000 W, and perform ultrasonic dispersion treatment for 3 min), filter with a 120 mesh filter to obtain anti-corrosion coating.

[0083] Examples 2-6 use a similar method to Example 1, but with different formulations, as detailed in Table 1.

[0084] Table 1: Raw material ratios for Examples 1-6

[0085] Example 7 The method was similar to that in Example 1, except that the amount of the anti-rust pigment was 11 wt% and the amount of barium sulfate was 7 wt%.

[0086] The remaining steps and methods are the same as in Example 1, and the anti-corrosion coating-7 is obtained.

[0087] Example 8 The method is similar to that in Example 1, except that the operation of the first contact is different. Specifically, as follows: (1) Make the coupling agent and diluent into first contact (stir at 300 rpm for 10 min). The remaining steps and methods are the same as in Example 1, and the anti-corrosion coating-8 is obtained.

[0088] Comparative Example 1 The procedure was carried out using a method similar to that in Example 1, except that the order in which the epoxy resin, diluent, and coupling agent were added was different. Details are as follows: (1) The epoxy resin and the diluent were brought into contact for the first time (the frequency of the WH1200B ultrasonic processor was adjusted to 20 kHz and the output power was 1000 W, and the ultrasonic dispersion was performed for 10 min) to obtain mixed solution I; (2) Add coupling agent to mixed solution I for a second contact (stir at 300 rpm for 10 min, adjust the frequency of WH1200B ultrasonic processor to 20 kHz and the output power to 1000 W, and perform ultrasonic dispersion treatment for 5 min) to obtain mixed solution II; The remaining steps and methods are the same as in Example 1, and the anti-corrosion coating-D1 is obtained.

[0089] Comparative Example 2 The procedure was carried out using a method similar to that in Example 1, except that thixotropic agent II was used to replace fumed silica I by mass.

[0090] The remaining steps and methods are the same as in Example 1, and the anti-corrosion coating-D2 is obtained.

[0091] Comparative Example 3 Commercially available coating products were used as the anti-corrosion coating - D3.

[0092] Comparative Example 4 The procedure was carried out using a method similar to that in Example 1, except that coupling agent II was used in place of the titanium alloy nano-chelate.

[0093] The remaining steps and methods are the same as in Example 1, and the anti-corrosion coating-D4 is obtained.

[0094] Comparative Example 5 The procedure was carried out using a method similar to that in Example 1, except that epoxy resin I was replaced with epoxy resin II of equal mass.

[0095] The remaining steps and methods are the same as in Example 1, and the anti-corrosion coating-D5 is obtained.

[0096] Test Example 1 The prepared anti-corrosion coatings (i.e., anti-corrosion coating-1 to anti-corrosion coating-8, anti-corrosion coating-D1, anti-corrosion coating-D2, anti-corrosion coating-D4, and anti-corrosion coating-D5) were weighed with epoxy curing agent at a mass ratio of 1:0.2, placed in the same container, and stirred for 3 minutes. The coating films were then prepared according to the relevant national standards, and the following performance tests were conducted. The test results are shown in Tables 2 and 3. Weigh the anti-corrosion coating-D3 and the matching curing agent at a mass ratio of 1:0.02, place them in the same container and stir for 3 minutes. Then, prepare the coating film according to the relevant national standards and conduct the following performance tests. The test results are shown in Table 3.

[0097] The testing methods involved are as follows: Elongation at break: determined according to the national standard GB / T1040.2-2022.

[0098] Hardness: Measured according to the national standard GB / T6739-2022.

[0099] Flexibility: Measured according to the national standard GB / T1731-2020.

[0100] Abrasion resistance: Tested according to the national standard GB / T1768-2006.

[0101] Impact resistance: Tested according to the national standard GB / T20624.1-2006.

[0102] Water vapor transmission coefficient: determined according to procedure A in ASTM E96 / E96M-22a ε1 method.

[0103] Resistance to chloride ion penetration: determined according to the method in Appendix B.2 of JT / T695-2007.

[0104] Boiling water resistance: Tested according to the national standard GB / T9274-1988.

[0105] Adhesion: Measured according to the national standard GB / T5210-2006.

[0106] Heat resistance: Tested according to the national standard GB / T1735-2009.

[0107] Table 2

[0108] Table 3

[0109] The results above show that the anti-corrosion coating prepared by the method described in this invention has good film adhesion, high hardness, good flexibility, high elongation at break, good wear resistance, low water vapor permeability coefficient and low chloride ion penetration resistance, and good coating density.

[0110] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing an anti-corrosion coating, characterized in that, The method includes: (1) The coupling agent and the diluent are brought into first contact to obtain mixed solution I; (2) The mixed solution I and the epoxy resin are brought into a second contact to obtain mixed solution II; (3) Mixed solution II is brought into a third contact with dispersant, defoamer, antifoaming agent, rheology modifier, anti-rust pigment, barium sulfate, titanium dioxide and leveling agent to obtain the anti-corrosion coating; The rheology modifier is a mixture of fumed silica I and organic clay in a mass ratio of 1:0.2–3.75; the specific surface area of ​​the fumed silica I is 150–190 m². 2 / g; The coupling agent is a titanium alloy nano-chelate; The epoxy resin has an epoxy equivalent of 196 to 212, a viscosity of 500 to 2000 mPa·s, and a molecular weight of 3000 to 3500.

2. The method according to claim 1, characterized in that, Based on the total mass of the composition, the epoxy resin content is 50-55 wt%, the rheology modifier content is 0.9-4.0 wt%, the diluent content is 6-9 wt%, the anti-rust pigment content is 4-8 wt%, the barium sulfate content is 8-10 wt%, the titanium dioxide content is 6-10 wt%, the coupling agent content is 8-12 wt%, the dispersant content is 0.1-0.4 wt%, the defoamer content is 0.1-0.5 wt%, the antifoamer content is 0.05-0.5 wt%, and the leveling agent content is 0.4-1.0 wt%.

3. The method according to claim 1, characterized in that, The average particle size of the titanium alloy nano-chelate is 15–30 nm. And / or, the defoamer is a modified polysiloxane.

4. The method according to claim 1, characterized in that, The defoaming agent is an acrylate copolymer; And / or, the leveling agent is a fluorocarbon-modified polyacrylate copolymer.

5. The method according to any one of claims 1-4, characterized in that, The rust-preventive pigment is a silica ion-exchange type rust-preventive pigment.

6. The method according to any one of claims 1-4, characterized in that, The average particle size of the barium sulfate is 2500–3500 mesh.

7. The method according to any one of claims 1-4, characterized in that, The titanium dioxide is rutile titanium dioxide, and the average particle size of the rutile titanium dioxide is 2500-3000 mesh. And / or, the diluent is C 12-14 Alkyl glycidyl ether.

8. The method according to any one of claims 1-4, characterized in that, In step (1), the operation of the first contact includes: ultrasonic dispersion treatment for 10 to 15 minutes; And / or, in step (2), the operation of the second contact includes: stirring at a speed of 300-400 rpm for 10-15 min, followed by ultrasonic dispersion for 5-10 min.

9. The method according to any one of claims 1-4, characterized in that, In step (3), the operation of the third contact includes: stirring at a speed of 300-400 rpm for 3-5 minutes, followed by ultrasonic dispersion for 3-5 minutes.

10. An anti-corrosion coating prepared by the method according to any one of claims 1-9.

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