Modified nanometer aluminum oxide marine anticorrosive paint and preparation method thereof

Abstract

The invention discloses a modified nano aluminum oxide marine anticorrosive coating and a preparation method thereof, and the modified nano aluminum oxide marine anticorrosive coating comprises the following raw materials in parts by weight: 40-80 parts of epoxy resin, 5-15 parts of furan resin, 15-25 parts of modified nano aluminum oxide, 1-5 parts of modified glass flakes, 10-25 parts of a diluent, 20-70 parts of a curing agent and 0.05-0.2 part of an accelerant. 0.1 to 0.5 part of a defoaming agent and 0.1 to 0.5 part of a microbial preservative. The prepared modified nano aluminum oxide marine anticorrosive paint has good weather resistance and wear resistance and excellent acid, alkali and salt corrosion resistance, is particularly suitable for anticorrosive protection in a marine environment, and shows a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of marine anti-corrosion coatings, and particularly relates to a modified nano-aluminum oxide marine anti-corrosion coating and a preparation method thereof. Background Art

[0002] In today's maritime transportation field, metal materials play a crucial role and are the basic materials for constructing ships and related maritime facilities. However, due to their high reactivity, the vast majority of metals are prone to chemical reactions with the media in the surrounding environment, resulting in frequent metal corrosion problems. This not only seriously affects the service life and safety of metal components but also increases maintenance costs, posing a potential threat to the protection of the marine environment.

[0003] To solve the problem of metal corrosion, alloy materials are widely used in the anti-corrosion field. By changing the composition and microstructure of metals, alloys improve the corrosion resistance of metals to a certain extent. However, the oxide layer formed on their surface is relatively fragile and easily damaged by mechanical action, thus limiting their effectiveness in practical applications. Traditional anti-corrosion coatings mostly use synthetic plastics as the base material. Although such coatings can provide anti-corrosion protection to a certain extent, they have a high content of volatile organic compounds (VOCs), which have an adverse impact on the environment and human health, and their service life is relatively short. Heavy anti-corrosion coatings have been widely used in harsh marine environments due to their excellent anti-corrosion performance. However, when the existing heavy anti-corrosion coatings encounter changes in environmental temperature, the toughness of their coatings is prone to decrease. Especially in environments with a large number of microorganisms such as the seabed, the adsorption of microorganisms will seriously affect the anti-corrosion performance of the coatings, resulting in a significant reduction in the anti-corrosion life.

[0004] Currently, some researchers have attempted to improve the performance of anti-corrosion coatings through modified materials. For example, the Chinese invention patent with the publication number CN118421190A proposes a method of using a castor oil coupling agent to modify graphene oxide and cross-linking and curing it with isophorone diisocyanate to obtain a stable anti-corrosion coating. However, this invention has obvious defects. Since castor oil has a polyhydroxy structure and is prone to react with water groups, water molecules can invade and affect the final performance of the anti-corrosion coating. Another Chinese invention patent with the publication number CN115322648A proposes an anti-corrosion coating of a modified graphene-doped epoxy system. Although this coating improves the anti-corrosion performance to a certain extent, its process is relatively cumbersome, requiring a high-temperature environment to be maintained for curing, and the curing time needs to be precisely controlled. The strict process conditions make the preparation of this coating difficult, and even a slight change will affect the final anti-corrosion performance, which is not conducive to large-scale popularization and application.

[0005] Therefore, there is an urgent need to develop a more efficient, environmentally friendly, stable and well-adapted anti-corrosion technology to meet the needs of the maritime industry for metal anti-corrosion. Summary of the Invention

[0006] To solve the above technical problems, the object of the present invention is to provide a modified nano-aluminum oxide marine anti-corrosion coating and its preparation method. The marine anti-corrosion coating has good weather resistance, abrasion resistance, and resistance to acid, alkali, and salt corrosion.

[0007] The above object of the present invention is achieved by the following technical solutions:

[0008] A modified nano-aluminum oxide marine anti-corrosion coating, the modified nano-aluminum oxide marine anti-corrosion coating comprises the following raw materials in parts by weight: 40-80 parts of epoxy resin, 5-15 parts of furan resin, 15-25 parts of modified nano-aluminum oxide, 1-5 parts of modified glass flakes, 10-25 parts of diluent, 20-70 parts of curing agent, 0.05-0.2 parts of accelerator, 0.1-0.5 parts of defoaming agent, 0.1-0.5 parts of microbial preservative;

[0009] The modified nano-aluminum oxide is prepared by the following method: mixing nano-aluminum oxide with an alcohol solvent to obtain solution A, mixing silane coupling agent I with an organic alcohol aqueous solution to obtain solution B, and mixing solution A and solution B to react to obtain the modified nano-aluminum oxide;

[0010] The modified glass flakes are prepared by the following method: pre-treating glass flakes in a mixed solution of concentrated nitric acid and concentrated sulfuric acid, mixing silane coupling agent II with water to obtain a silane coupling agent mixed solution, and adding the pre-treated glass flakes to the silane coupling agent mixed solution to react to obtain the modified glass flakes.

[0011] Among the raw materials of the modified nano-aluminum oxide marine anti-corrosion coating provided by the present invention, nano-aluminum oxide has the advantages of high hardness, large specific surface area, strong oxidation resistance, excellent chemical stability, and high mechanical strength. It can improve the hardness, abrasion resistance, and heat resistance of the coating, and at the same time can also increase the gloss and adhesion of the coating, effectively improving the overall performance of the coating. However, due to the presence of hydroxyl groups on its surface, its compatibility with organic substances is poor. Since silane coupling agents have both hydrophilic and hydrophobic ends, silane coupling agents are selected to modify alumina. In addition, glass flakes can form a maze effect to block the penetration of corrosive media, and furan rings can resist the attack of chemical substances such as acids, alkalis, and salts. The modified nano-aluminum oxide and modified glass flakes have a large number of amino and hydroxyl groups on their surfaces, which undergo a cross-linking reaction with the nucleophilic group oxygen anion of the furan resin. The three work together to obtain a modified nano-aluminum oxide marine anti-corrosion coating with good weather resistance, abrasion resistance, and resistance to acid, alkali, and salt corrosion.

[0012] The modified nano-aluminum oxide provided by the present invention has a special Si-O-Al network structure due to silicon-based crosslinking, which improves the toughness and hydrophobicity of the coating, and increases the modified glass flakes to improve the physical shielding performance of the coating. At the same time, the structures at both ends of the silane coupling agent enhance the compatibility with polar small molecules, making the internal space evenly dispersed, enhancing the impact resistance of the coating, and making the coating have good thermal stability and corrosion resistance.

[0013] Further, the epoxy resin is selected from one or more of epoxy resin E44 (epoxy equivalent is 0.41 - 0.47), epoxy resin E42 (epoxy equivalent is 0.25 - 0.3), and epoxy resin E51 (epoxy equivalent is 0.48 - 0.54).

[0014] Further, the furan resin is furfuryl alcohol urea resin.

[0015] Further, the molecular weight of the furan resin is 90 - 110 Da.

[0016] Further, the diluent is ethanol and / or butanol.

[0017] Further, the curing agent is selected from one or more of 593 amine curing agent, 650 polyamide curing agent, T31 curing agent, and DDS curing agent.

[0018] Further, the accelerator is DMP-30.

[0019] Further, the defoamer is selected from one or more of BYK-2000, BYK-054, and BYK-065.

[0020] Further, the microbial preservative is Kathon.

[0021] Further, the modified nano-aluminum oxide marine anti-corrosion coating further includes 0.1 - 8 parts of pigment and filler.

[0022] Further, the pigment and filler can be various inorganic color powders, such as iron oxide yellow, iron oxide red, iron oxide gray, iron oxide black, chromium oxide green, etc.

[0023] Further, the particle size of the nano-aluminum oxide is 0.2 - 1 micron.

[0024] Further, the alcohol solvent is selected from one or more of isopropyl alcohol, ethanol, and n-butanol.

[0025] Further, the silane coupling agent I is γ-aminopropyltriethoxysilane and / or γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0026] Further, the organic alcohol is selected from one or more of isopropyl alcohol, ethanol, and n-butanol.

[0027] Furthermore, the mass ratio of the nano-aluminum oxide to the alcohol solvent is (0.3 - 0.7):1; the mass ratio of the silane coupling agent I to the organic alcohol aqueous solution is (1 - 5):(10 - 15); the mass ratio of the organic alcohol to water in the organic alcohol aqueous solution is (5 - 7):1; the mass ratio of solution A to solution B is (1.5 - 2.5):1.

[0028] In a specific embodiment, the modified nano-aluminum oxide is prepared by the following method: mixing nano-aluminum oxide with an alcohol solvent, and obtaining solution A after ultrasonic treatment for 1 - 2 h; mixing the silane coupling agent I and the organic alcohol aqueous solution in a magnetic stirrer under a water bath condition of 55 - 65 °C to obtain solution B; uniformly adding solution B into solution A for mixing, and obtaining a modified nano-aluminum oxide solution after reacting for 4 - 5 h, and filtering and drying the modified nano-aluminum oxide solution to obtain the modified nano-aluminum oxide.

[0029] Furthermore, the volume ratio of concentrated nitric acid to concentrated sulfuric acid in the mixed solution of concentrated nitric acid and concentrated sulfuric acid is (0.8 - 1.2):1.

[0030] Furthermore, the concentration of the concentrated nitric acid is 60 - 65%, and the concentration of the concentrated sulfuric acid is 65 - 75%.

[0031] Furthermore, the mass ratio of the silane coupling agent II to water is 1:(4 - 6); the mass ratio of the silane coupling agent mixture to the pretreated glass flakes is (5 - 7):5.

[0032] Furthermore, in the preparation method of the modified glass flakes, the silane coupling agent II is γ-aminopropyltriethoxysilane and / or γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0033] In a specific embodiment, the modified glass flakes are prepared by the following method: putting the glass flakes into the mixed solution of concentrated nitric acid and concentrated sulfuric acid, stirring for 10 - 20 min for activation pretreatment, mixing the silane coupling agent II and water in a flask under a water bath condition of 55 - 65 °C for 1 - 2 h to obtain a silane coupling agent mixture, adding the pretreated glass flakes into the silane coupling agent mixture in the flask, and performing suction filtration and drying after reacting for 4 - 5 h to obtain the modified glass flakes.

[0034] A preparation method of a modified nano-aluminum oxide marine anti-corrosion coating includes the following steps:

[0035] (1) Stirring a diluent and a microbial preservative to obtain mixture I;

[0036] (2) Adding the modified nano-aluminum oxide and the modified glass flakes to the mixture I obtained in step (1) to obtain mixture II;

[0037] (3) Add epoxy resin and furan resin to the mixture II obtained in step (2) to obtain mixture III;

[0038] (4) Add a curing agent, an accelerator, and an antifoaming agent to the mixture III obtained in step (3) to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

[0039] The preparation method of the modified nano-aluminum oxide marine anti-corrosion coating provided by the present invention is simple, fast, low-cost, and easy to industrialize.

[0040] Furthermore, step (4) also includes the step of adding pigments and fillers to the mixture III.

[0041] In a specific embodiment, the preparation method of the modified nano-aluminum oxide marine anti-corrosion coating includes the following steps:

[0042] (1) Add a diluent and a microbial preservative to a reaction vessel and stir well to obtain mixture I;

[0043] (2) Add modified nano-aluminum oxide and modified glass flakes to the mixture I obtained in step (1), and ultrasonically disperse for 10 - 15 min to obtain mixture II;

[0044] (3) Add epoxy resin and furan resin to the mixture II obtained in step (2), and stir and mix for 15 - 20 min to obtain mixture III;

[0045] (4) Add a curing agent, an accelerator, an antifoaming agent, and pigments and fillers to the mixture III obtained in step (3), and stir and age for 30 - 40 min to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

[0046] The beneficial effects of the present invention:

[0047] 1. By introducing nano-aluminum oxide with high hardness, large specific surface area, strong oxidation resistance, excellent chemical stability, and high mechanical strength, and modifying the nano-aluminum oxide, the obtained modified nano-aluminum oxide marine anti-corrosion coating has achieved significant improvements in hardness, abrasion resistance, and heat resistance. At the same time, the nano-aluminum oxide also enhances the gloss and adhesion of the coating, comprehensively optimizing the overall performance of the coating. In addition, combined with the maze effect formed by glass flakes, it effectively blocks the penetration of corrosive media, and the addition of furan resin further improves the anti-corrosion performance of the coating. The modified nano-aluminum oxide marine anti-corrosion coating prepared by the present invention has good weather resistance and abrasion resistance, as well as excellent resistance to acid, alkali, and salt corrosion, and is particularly suitable for anti-corrosion protection in marine environments, showing broad application prospects.

[0048] 2. The modified nano-aluminum oxide marine anti-corrosion coating provided by the present invention can form a coating that is tightly bonded to the substrate and has excellent compatibility. This not only facilitates the recoating operation of subsequent other coatings, but also effectively inhibits the attachment of microorganisms and algae through its unique low surface tension characteristics, while reducing the erosion of moisture in the air on the coating, thereby greatly enhancing the durability and protection performance of the coating in the marine environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a scanning electron microscope image before the modification of nano-aluminum oxide.

[0050] Figure 2 It is a scanning electron microscope image after the modification of nano-aluminum oxide.

[0051] Figure 3 It is a schematic diagram of a coating sample prepared by using the modified nano-aluminum oxide marine anti-corrosion coating of Examples 1-3; among them, the left coating sample is Example 1, the middle coating sample is Example 2, and the right coating sample is Example 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments 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.

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited are not intended to limit the present invention.

[0054] Unless otherwise specified, the experimental methods used in the following embodiments are all conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0055] Example 1

[0056] A modified nano-aluminum oxide marine anti-corrosion coating, the modified nano-aluminum oxide marine anti-corrosion coating comprises the following raw materials in parts by weight: 70 parts of epoxy resin E44, 15 parts of furfuryl alcohol urea resin, 15 parts of modified nano-aluminum oxide, 1 part of modified glass flake, 20 parts of ethanol, 40 parts of 593 amine curing agent, 0.05 part of accelerator DMP-30, 0.1 part of defoaming agent BYK-2000, 0.1 part of Kathon, and 1 part of chromium oxide green. Its preparation method comprises the following steps:

[0057] (1) Add 20 parts of ethanol and 0.1 part of Kathon into a reaction vessel and stir well to obtain Mixture I;

[0058] (2) Add 15 parts of modified nano-aluminum oxide and 1 part of modified glass flakes into Mixture I obtained in step (1), and disperse ultrasonically for 10 min to obtain Mixture II;

[0059] (3) Add 70 parts of epoxy resin E44 and 15 parts of furfuryl alcohol urea resin into Mixture II obtained in step (2), and stir and mix for 15 min to obtain Mixture III;

[0060] (4) Add 40 parts of 593 amine curing agent, 0.05 part of accelerator DMP-30, 0.1 part of defoamer BYK-2000 and 1 part of chromium oxide green into Mixture III obtained in step (3), and stir and age for 30 min to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

[0061] Among them, the modified nano-aluminum oxide is prepared by the following method: Add 20 parts of isopropanol and 10 parts of nano-aluminum oxide (particle size of 0.2 microns) into a reaction vessel, and mix ultrasonically for 1 h to obtain Solution A; Mix 2 parts of γ-aminopropyltriethoxysilane, 12 parts of absolute ethanol and 2 parts of pure water in a magnetic stirrer under the condition of a 60 °C water bath to obtain Solution B; Add Solution B into Solution A at a uniform rate of 1 drop per 3 s using a peristaltic pump and mix. After reacting for 4 h, a modified nano-aluminum oxide solution is obtained. After washing with water, washing with ethanol, filtering by suction and drying at 100 °C, the modified nano-aluminum oxide is obtained.

[0062] The modified glass flakes are prepared by the following method: Put 5 parts of glass flakes into a mixed solution of concentrated nitric acid (concentration of 60%) and concentrated sulfuric acid (concentration of 75%) with a volume ratio of 1:1, stir for 10 min for activation pretreatment. In a flask, mix 1 part of γ-aminopropyltriethoxysilane and 5 parts of pure water under the condition of a 60 °C water bath for 1 h to obtain a silane coupling agent mixed solution. Add the pretreated glass flakes into the silane coupling agent mixed solution in the flask, and after reacting for 4 h, filter by suction and dry to obtain the modified glass flakes.

[0063] Figure 1 It is a scanning electron microscope image of nano-aluminum oxide before modification.

[0064] Figure 2 It is a scanning electron microscope image of nano-aluminum oxide after modification. The modified nano-aluminum oxide has less powder agglomeration and more active sites than before modification, which is convenient for subsequent reaction with polymers.

[0065] Example 2

[0066] A modified nano-aluminum oxide marine anti-corrosion coating, and the modified nano-aluminum oxide marine anti-corrosion coating comprises raw materials in the following parts by weight: 80 parts of epoxy resin E51, 15 parts of furfuryl alcohol urea resin, 18 parts of modified nano-aluminum oxide, 2 parts of modified glass flakes, 20 parts of ethanol, 30 parts of T31 curing agent, 0.1 part of accelerator DMP-30, 0.2 part of defoamer BYK-054, 0.2 part of Kathon, and 1.5 parts of iron oxide ash. Its preparation method comprises the following steps:

[0067] (1) Add 20 parts of ethanol and 0.2 part of Kathon to a reaction vessel and stir well to obtain mixture I;

[0068] (2) Add 18 parts of modified nano-aluminum oxide and 2 parts of modified glass flakes to mixture I obtained in step (1), and perform ultrasonic dispersion for 10 min to obtain mixture II;

[0069] (3) Add 80 parts of epoxy resin E51 and 15 parts of furfuryl alcohol urea resin to mixture II obtained in step (2), and stir and mix for 15 min to obtain mixture III;

[0070] (4) Add 30 parts of T31 curing agent, 0.1 part of accelerator DMP-30, 0.2 part of defoamer BYK-054, and 1.5 parts of iron oxide ash to mixture III obtained in step (3), and stir and age for 30 min to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

[0071] Among them, the modified nano-aluminum oxide is prepared by the following method: Add 20 parts of ethanol and 10 parts of nano-aluminum oxide (particle size 0.3 μm) to a reaction vessel, and perform ultrasonic mixing for 1 h to obtain solution A; Mix 2 parts of γ-aminopropyltriethoxysilane, 12 parts of absolute ethanol, and 2 parts of pure water in a magnetic stirrer under a water bath condition of 60 °C to obtain solution B; Add solution B to solution A at a uniform rate of 1 drop per 3 s using a peristaltic pump for mixing. After reacting for 4 h, a modified nano-aluminum oxide solution is obtained. After washing the modified nano-aluminum oxide solution with water, washing with ethanol, filtering, and drying at 100 °C, the modified nano-aluminum oxide is obtained.

[0072] The modified glass flakes are prepared by the following method: Put 5 parts of glass flakes into a mixed solution of concentrated nitric acid (concentration 65%) and concentrated sulfuric acid (concentration 70%) with a volume ratio of 1:1, stir for 10 min for activation pretreatment. Mix 1 part of γ-aminopropyltriethoxysilane and 5 parts of pure water in a flask under a water bath condition of 60 °C for 1 h to obtain a silane coupling agent mixture solution. Add the pretreated glass flakes to the silane coupling agent mixture solution in the flask, and after reacting for 4 h, filter and dry to obtain the modified glass flakes.

[0073] Example 3

[0074] A modified nano-aluminum oxide marine anti-corrosion coating, the modified nano-aluminum oxide marine anti-corrosion coating comprising the following raw materials in parts by weight: 80 parts of epoxy resin E44, 15 parts of furfuryl alcohol urea resin, 20 parts of modified nano-aluminum oxide, 5 parts of modified glass flakes, 25 parts of ethanol, 70 parts of 650 polyamide curing agent, 0.2 part of accelerator DMP-30, 0.5 part of defoamer BYK-065, 0.5 part of Kathon, and 2 parts of iron oxide black. Its preparation method comprises the following steps:

[0075] (1) Add 25 parts of ethanol and 0.5 part of Kathon to a reaction vessel and stir well to obtain mixture I;

[0076] (2) Add 20 parts of modified nano-aluminum oxide and 5 parts of modified glass flakes to mixture I obtained in step (1), and ultrasonically disperse for 10 min to obtain mixture II;

[0077] (3) Add 80 parts of epoxy resin E44 and 15 parts of furfuryl alcohol urea resin to mixture II obtained in step (2), and stir and mix for 15 min to obtain mixture III;

[0078] (4) Add 70 parts of 650 polyamide curing agent, 0.2 part of accelerator DMP-30, 0.5 part of defoamer BYK-065, and 2 parts of iron oxide black to mixture III obtained in step (3), and stir and age for 30 min to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

[0079] Among them, the modified nano-aluminum oxide is prepared by the following method: Add 20 parts of isopropanol and 10 parts of nano-aluminum oxide (particle size 0.4 μm) to a reaction vessel, and ultrasonically mix and dissolve for 1 h to obtain solution A; Mix 2 parts of γ-aminopropyltriethoxysilane, 12 parts of absolute ethanol, and 2 parts of pure water in a magnetic stirrer at 60 °C in a water bath to obtain solution B; Add solution B to solution A at a uniform rate of 1 drop per 3 s using a peristaltic pump and mix. After reacting for 4 h, a modified nano-aluminum oxide solution is obtained. The modified nano-aluminum oxide solution is washed with water, washed with ethanol, filtered, and dried at 100 °C to obtain the modified nano-aluminum oxide.

[0080] The modified glass flakes are prepared by the following method: Put 5 parts of glass flakes into a mixed solution of concentrated nitric acid (concentration 60%) and concentrated sulfuric acid (concentration 75%) with a volume ratio of 1:1, stir for 10 min for activation pretreatment. In a flask, mix 1 part of γ-aminopropyltriethoxysilane and 5 parts of pure water at 60 °C in a water bath for 1 h to obtain a silane coupling agent mixture. Add the pretreated glass flakes to the silane coupling agent mixture in the flask, react for 4 h, then filter and dry to obtain the modified glass flakes.

[0081] Example 4

[0082] A modified nano-aluminum oxide marine anti-corrosion coating, and the modified nano-aluminum oxide marine anti-corrosion coating comprises raw materials in the following parts by weight: 40 parts of epoxy resin E44, 10 parts of furfuryl alcohol urea resin, 25 parts of modified nano-aluminum oxide, 5 parts of modified glass flakes, 10 parts of ethanol, 20 parts of 650 polyamide curing agent, 0.2 part of accelerator DMP-30, 0.5 part of defoamer BYK-065, 0.5 part of Kathon, and 1 part of iron oxide red. Its preparation method comprises the following steps:

[0083] (1) Add 10 parts of ethanol and 0.5 part of Kathon to a reaction vessel and stir well to obtain mixture I;

[0084] (2) Add 25 parts of modified nano-aluminum oxide and 5 parts of modified glass flakes to mixture I obtained in step (1), and perform ultrasonic dispersion for 10 min to obtain mixture II;

[0085] (3) Add 40 parts of epoxy resin E44 and 10 parts of furfuryl alcohol urea resin to mixture II obtained in step (2), and stir and mix for 15 min to obtain mixture III;

[0086] (4) Add 20 parts of 650 polyamide curing agent, 0.2 part of accelerator DMP-30, 0.5 part of defoamer BYK-065, and 1 part of iron oxide red to mixture III obtained in step (3), and stir and age for 30 min to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

[0087] Among them, the modified nano-aluminum oxide is prepared by the following method: Add 20 parts of isopropanol and 10 parts of nano-aluminum oxide (0.5 μm) to a reaction vessel, and perform ultrasonic mixing for 1 h to obtain solution A; Mix 2 parts of γ-aminopropyltriethoxysilane, 12 parts of absolute ethanol, and 2 parts of pure water in a magnetic stirrer under a water bath condition of 60 °C to obtain solution B; Add solution B to solution A at a uniform rate of 1 drop / 3 s using a peristaltic pump for mixing. After reacting for 4 h, a modified nano-aluminum oxide solution is obtained. After washing the modified nano-aluminum oxide solution with water, washing with ethanol, filtering, and drying at 100 °C, the modified nano-aluminum oxide is obtained.

[0088] The modified glass flakes are prepared by the following method: Put 5 parts of glass flakes into a mixed solution with a volume ratio of concentrated nitric acid (concentration 65%) to concentrated sulfuric acid (concentration 70%) of 1:1, and stir for 10 min for activation pretreatment. Mix 1 part of γ-aminopropyltriethoxysilane and 5 parts of pure water in a flask under a water bath condition of 60 °C for 1 h to obtain an aqueous silane coupling agent solution. Add the pretreated glass flakes to the aqueous silane coupling agent solution in the flask, and after reacting for 4 h, filter and dry to obtain the modified glass flakes.

[0089] Comparative Example 1

[0090] An anti-corrosion marine coating, which is basically the same as Example 3, except that modified nano-aluminum oxide is not added.

[0091] Comparative Example 2

[0092] An anti-corrosion marine coating, which is basically the same as Example 3, except that modified glass flakes are not added.

[0093] Comparative Example 3

[0094] An anti-corrosion marine coating, which is basically the same as Example 3, except that modified nano-aluminum oxide is replaced by silicon oxide.

[0095] Comparative Example 4

[0096] An anti-corrosion marine coating, the anti-corrosion marine coating comprising the following raw materials in parts by weight: 80 parts of epoxy resin E42, 20 parts of furfuryl alcohol urea resin, 30 parts of modified nano-aluminum oxide, 3 parts of modified glass flakes, 25 parts of ethanol, 25 parts of 650 polyamide curing agent, 0.5 part of accelerator DMP-30, 0.5 part of defoamer BYK-065, 0.5 part of Kathon, 5 parts of iron oxide red, and a preparation method thereof comprising the following steps:

[0097] (1) Add 25 parts of ethanol and 0.5 part of Kathon to a reaction vessel and stir well to obtain Mixture I;

[0098] (2) Add 30 parts of modified nano-aluminum oxide and 3 parts of modified glass flakes to Mixture I obtained in step (1), and ultrasonically disperse for 10 min to obtain Mixture II;

[0099] (3) Add 80 parts of epoxy resin E42 and 20 parts of furfuryl alcohol urea resin to Mixture II obtained in step (2), and stir and mix for 15 min to obtain Mixture III;

[0100] (4) Add 25 parts of 650 polyamide curing agent, 0.5 part of accelerator DMP-30, 0.5 part of defoamer BYK-065, and 5 parts of iron oxide red to Mixture III obtained in step (3), and stir and age for 30 min to obtain the anti-corrosion marine coating.

[0101] Wherein, the modified nano-aluminum oxide is prepared by the following method: Add 20 parts of isopropanol and 10 parts of nano-aluminum oxide (particle size of 0.4 microns) to a reaction vessel, and ultrasonically mix and dissolve for 1 h to obtain Solution A; Mix 2 parts of γ-aminopropyltriethoxysilane, 12 parts of absolute ethanol, and 2 parts of pure water in a magnetic stirrer under a water bath condition of 60 °C to obtain Solution B; Add Solution B to Solution A at a uniform rate of 1 drop per 3 s using a peristaltic pump for mixing, and after reacting for 4 h, obtain a modified nano-aluminum oxide solution, and wash the modified nano-aluminum oxide solution with water, ethanol, filter by suction, and dry at 100 °C to obtain the modified nano-aluminum oxide.

[0102] The modified glass flakes are prepared by the following method: Put 5 parts of glass flakes into a mixed solution with a volume ratio of 1:1 of concentrated nitric acid (concentration 60%) and concentrated sulfuric acid (concentration 75%), stir for 10 min for activation pretreatment. In a flask, mix 1 part of γ-aminopropyltriethoxysilane and 5 parts of pure water at 60 °C in a water bath for 1 h to obtain a silane coupling agent mixed solution. Add the pretreated glass flakes to the silane coupling agent mixed solution in the flask, and after reacting for 4 h, filter and dry to obtain the modified glass flakes.

[0103] Comparative Example 5

[0104] A marine anti-corrosion coating, the marine anti-corrosion coating comprising the following raw materials in parts by weight: 20 parts of epoxy resin E44, 3 parts of furfuryl alcohol urea resin, 3 parts of modified nano-aluminum oxide, 1 part of modified glass flakes, 10 parts of ethanol, 10 parts of 650 polyamide curing agent, 0.01 part of accelerator DMP-30, 0.01 part of defoamer BYK-065, 0.5 part of Kathon, 3 parts of iron oxide red, and its preparation method comprises the following steps:

[0105] (1) Add 10 parts of ethanol and 0.5 part of Kathon to a reaction vessel and stir well to obtain mixture I;

[0106] (2) Add 5 parts of modified nano-aluminum oxide and 1 part of modified glass flakes to mixture I obtained in step (1), and ultrasonically disperse for 10 min to obtain mixture II;

[0107] (3) Add 20 parts of epoxy resin E44 and 3 parts of furfuryl alcohol urea resin to mixture II obtained in step (2), and stir and mix for 15 min to obtain mixture III;

[0108] (4) Add 10 parts of 650 polyamide curing agent, 0.01 part of accelerator DMP-30, 0.01 part of defoamer BYK-065 and 3 parts of iron oxide red to mixture III obtained in step (3), and stir and age for 30 min to obtain the marine anti-corrosion coating.

[0109] Among them, the modified nano-aluminum oxide is prepared by the following method: Add 20 parts of isopropanol and 10 parts of nano-aluminum oxide (particle size 0.4 μm) to a reaction vessel, and ultrasonically mix and dissolve for 1 h to obtain solution A; In a magnetic stirrer, mix 2 parts of γ-aminopropyltriethoxysilane, 12 parts of absolute ethanol and 2 parts of pure water at 60 °C in a water bath to obtain solution B; Add solution B to solution A at a rate of 1 drop / 3 s using a peristaltic pump and mix, and after reacting for 4 h, obtain a modified nano-aluminum oxide solution. Wash the modified nano-aluminum oxide solution with water, wash with ethanol, filter, and dry at 100 °C to obtain the modified nano-aluminum oxide.

[0110] The modified glass flakes are prepared by the following method: 5 parts of glass flakes are placed in a mixture of concentrated nitric acid (concentration 60%) and concentrated sulfuric acid (concentration 75%) in a volume ratio of 1:1, and stirred for 10 minutes for activation pretreatment; 1 part of γ-aminopropyltriethoxysilane and 5 parts of pure water are mixed in a flask under 60°C water bath conditions for 1 hour to obtain a silane coupling agent mixture; the pretreated glass flakes are added to the silane coupling agent mixture in the flask, and after reacting for 4 hours, the mixture is filtered and dried to obtain the modified glass flakes.

[0111] Comparative Example 6

[0112] A marine anticorrosive coating, comprising the following raw materials in parts by weight: 100 parts of epoxy resin E44, 20 parts of furfuryl alcohol urea-formaldehyde resin, 40 parts of aluminum oxide, 5 parts of glass flakes, 25 parts of ethanol, 40 parts of 650 polyamide curing agent, 0.5 parts of accelerator DMP-30, 0.5 parts of defoamer BYK-065, 0.5 parts of kason, and 2 parts of red iron oxide. The preparation method thereof comprises the following steps:

[0113] (1) Add 25 parts of ethanol and 0.5 parts of kason to a reaction vessel and stir thoroughly to obtain a mixture I;

[0114] (2) adding 30 parts of nano-alumina and 5 parts of glass flakes to the mixture I obtained in step (1), and performing ultrasonic dispersion for 10 minutes to obtain a mixture II;

[0115] (3) adding 100 parts of epoxy resin E44 and 20 parts of furfuryl alcohol urea-formaldehyde resin to the mixture II obtained in step (2), stirring and mixing for 15 minutes to obtain a mixture III;

[0116] (4) Add 40 parts of 650 polyamide curing agent, 0.5 parts of accelerator DMP-30, 0.5 parts of defoaming agent BYK-065 and 2 parts of red iron oxide to the mixture III obtained in step (3), stir and age for 30 minutes to obtain the marine anti-corrosion coating.

[0117] Test Case

[0118] The modified nano-alumina marine anti-corrosion coatings of Examples 1-4 and the marine anti-corrosion coatings of Comparative Examples 1-6 are used to prepare coating samples, and the preparation method comprises the following steps:

[0119] (1) Polishing the sample to be coated with sandpaper;

[0120] (2) Wash the treated sample repeatedly with ethanol until the surface is smooth and wipe clean;

[0121] (3) Using a line coating machine to evenly coat the prepared marine anti-corrosion coating on the sample;

[0122] (4) Place the sample plate coated with the marine anti-corrosion coating in a vacuum drying oven (60 °C, 1 h) until the coating is completely cured to obtain a coated sample plate.

[0123] The coated sample plates prepared with the modified nano-aluminum oxide marine anti-corrosion coatings of Examples 1-3 are as Figure 3 shown. The left coated sample plate is Example 1, the middle coated sample plate is Example 2, and the right coated sample plate is Example 3.

[0124] Perform hardness tests, impact resistance tests, salt spray tests, acid and alkali resistance tests, abrasion resistance tests, and flexibility tests on the coated sample plates prepared with the modified nano-aluminum oxide marine anti-corrosion coatings of Examples 1-4 and the marine anti-corrosion coatings of Comparative Examples 1-4. The test methods are as follows:

[0125] Hardness test:

[0126] 1. Place the hardness tester flat on the coated sample plate (if the coated sample plate is smaller than the hardness tester, place the coated sample plate in front of the hardness tester and place the shim under the front end of the hardness tester) to keep the hardness tester horizontal;

[0127] 2. Use a blade to cut open the pencil lead so that the protruding part of the pencil lead is about 3-5 mm, and grind it flat with sandpaper. Then insert the pencil into the instrument and fix it tightly after the pencil lead contacts the test piece;

[0128] 3. Hold the center of the two wheels with the thumb and middle finger. Push the hardness tester forward about 2-3 cm from the back and then move it away. Then wipe off the pencil marks with an eraser;

[0129] 4. Determine the hardness by checking whether there are scratches on the coated sample plate. Perform the test on at least three positions on the coated sample plate and take the average value. The pencil grades cover various hardnesses from 6H to 6B, where 6H represents the hardest and 6B represents the softest.

[0130] Impact resistance test:

[0131] 1. Check whether the center of the punch rod is consistent with the center of the concave hole of the pillow cushion block, whether the positioning mark is aligned with the zero line, lower the weight hammer, and observe whether the engraved line on the positioning mark coincides with the zero line. Adjust the positioning mark if there is a deviation;

[0132] 2. Place the coated sample plate on the pillow cushion block with the paint film facing up and make the impact point in the middle of the coated sample plate. If the same coated sample plate is used for several tests, the distance between the edges of each impact point should be not less than 15 mm;

[0133] 3. According to the regulations in the product standard, fix the height by means of the controller screw. Press the control screw and the weight hammer will freely fall on the punch rod, and the punch rod will transmit the impact force to the coated sample plate on the pillow cushion block;

[0134] 4. Lift the plumb bob. The hook on the plumb bob will be automatically hooked by the controller. Take out the sample plate and observe it with a four - fold magnifying glass or by eye. When there are no cracks, wrinkles, or peeling on the paint film, the height from which the plumb bob drops can be increased, and continue to measure the impact strength of the paint film until the paint film is damaged or the paint film can withstand the impact of the plumb bob at a height of 40 cm.

[0135] Salt spray test:

[0136] 1. Connect the power supply of the salt spray test machine and the connection of the air compressor pipe. Pour pure water into the water inlet of the salt spray test machine, exceeding the low - water - level card slot.

[0137] 2. Connect the drain pipe and the exhaust pipe in the salt spray test machine, and then add water to the isolation water tank up to the position of the backing plate to avoid salt spray leakage as much as possible.

[0138] 3. Pour the salt water in the test chamber into the salt solution replenishment bottle to ensure that it exceeds the water level line.

[0139] 4. Place the coated sample plate on the shelf, set the required time and temperature for the experiment (3000 h, 35 °C), and then press the power supply. The salt spray chamber starts the test.

[0140] Acid - alkali resistance test:

[0141] Place the coated sample plate in the prepared acid - base reagent (50 g / L), and observe and record its changes after 240 h.

[0142] Abrasion resistance test:

[0143] Fix the coated sample plate on the ink decolorization machine, set the corresponding pressure (20 ± 0.2 N) until the paint film peels off.

[0144] Flexibility test:

[0145] Fix the coated sample plate on the cylindrical bending table, bend the sample repeatedly with force until it breaks, and record the vertical side distance from the bending center to both ends of the coated sample plate.

[0146] The test results are shown in Table 1:

[0147] Table 1

[0148]

[0149]

[0150] It can be seen from Table 1 that the doping amount of modified nano - alumina significantly affects the performance of the anti - corrosion coating. Adding too much will cause agglomeration of nano - materials, and adding too little will lead to insufficient connectivity, thus affecting the anti - corrosion performance; although silicon dioxide has excellent physical properties, its anti - corrosion performance is far less prominent than that of modified nano - alumina.

[0151] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. Those skilled in the art should understand that other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A modified nano-aluminum oxide marine anti-corrosion coating, characterized in that, The modified nano-aluminum oxide marine anti-corrosion coating comprises raw materials in the following parts by weight: 40-80 parts of epoxy resin, 5-15 parts of furan resin, 15-25 parts of modified nano-aluminum oxide, 1-5 parts of modified glass flakes, 10-25 parts of diluent, 20-70 parts of curing agent, 0.05-0.2 part of accelerator, 0.1-0.5 part of defoamer, and 0.1-0.5 part of microbial preservative; The modified nano-aluminum oxide is prepared by the following method: mixing nano-aluminum oxide with an alcohol solvent to obtain solution A, mixing silane coupling agent I with an organic alcohol aqueous solution to obtain solution B, and mixing solution A and solution B and reacting to obtain the modified nano-aluminum oxide; The modified glass flakes are prepared by the following method: putting the glass flakes into a mixed solution of concentrated nitric acid and concentrated sulfuric acid for pretreatment, mixing silane coupling agent II with water to obtain a silane coupling agent mixed solution, and adding the pretreated glass flakes into the silane coupling agent mixed solution and reacting to obtain the modified glass flakes.

2. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, wherein, The epoxy resin is selected from one or more of epoxy resin E44, epoxy resin E42, and epoxy resin E51; the furan resin is furfuryl alcohol urea formaldehyde resin.

3. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that, The diluent is ethanol and / or butanol; the curing agent is selected from one or more of 593 amine curing agent, 650 polyamide curing agent, T31 curing agent, and DDS curing agent.

4. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that, The accelerator is DMP-30; the defoamer is selected from one or more of BYK-2000, BYK-054, and BYK-065; the microbial preservative is Kathon.

5. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that, The modified nano-aluminum oxide marine anti-corrosion coating further comprises 0.1-8 parts of pigment and filler.

6. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that, The particle size of the nano-aluminum oxide is 0.2-1 micron.

7. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that, The silane coupling agent I is γ-aminopropyltriethoxysilane and / or γ-(2,3-epoxypropoxy)propyltrimethoxysilane; the silane coupling agent II is γ-aminopropyltriethoxysilane and / or γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

8. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that, The mass ratio of the nano-aluminum oxide to the alcohol solvent is (0.3-0.7):1; the mass ratio of the silane coupling agent I to the organic alcohol aqueous solution is (1-5):(10-15); the mass ratio of the organic alcohol to water in the organic alcohol aqueous solution is (5-7):1; the mass ratio of solution A to solution B is (1.5-2.5):

1.

9. The modified nano-aluminum oxide marine anti-corrosion coating according to claim 1, characterized in that The mass ratio of the silane coupling agent II to water is 1:(4-6); the mass ratio of the silane coupling agent mixed solution to the pretreated glass flakes is (5-7):

5.

10. A method for preparing the modified nano-aluminum oxide marine anti-corrosion coating according to any one of claims 1-9, characterized in that, Comprising the following steps: (1) Stirring the diluent and the microbial preservative to obtain mixture I; (2) Adding the modified nano-aluminum oxide and the modified glass flakes into the mixture I obtained in step (1) to obtain mixture II; (3) Adding the epoxy resin and the furan resin into the mixture II obtained in step (2) to obtain mixture III; (4) Adding the curing agent, the accelerator, and the defoamer into the mixture III obtained in step (3) to obtain the modified nano-aluminum oxide marine anti-corrosion coating.

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