Water-based anticorrosive coating for ships based on barium titanate / graphene / imonite clay composite filler and preparation method thereof

Abstract

The application discloses a ship anticorrosive coating based on barium titanate / graphene / imonite clay composite filler and a preparation method thereof. The anticorrosive coating is prepared by taking the barium titanate / graphene / imonite clay composite material as a filler and taking a water-based acrylic acid epoxy hybrid resin and an amino-modified polysiloxane resin as a matrix, and can significantly improve the hardness, wear resistance, impact resistance and adhesion of the coating, and has excellent ultraviolet resistance, high-temperature resistance, weather resistance, anti-aging properties such as powdering resistance, discoloration resistance, gloss loss resistance and cracking resistance, reduces the risk of coating damage, and prolongs the service life. The anticorrosive coating is especially suitable for the area below the waterline of a ship, a ballast tank and the bottom of a ship.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion coating technology, specifically relating to a marine anti-corrosion coating based on barium titanate / graphene / immon clay composite filler and its preparation method. Background Technology

[0002] Marine anti-corrosion coatings play a crucial role in ensuring safe ship operation, extending service life, and reducing maintenance costs. Factors in the marine environment such as high salt spray, humidity, microbial adhesion, and temperature fluctuations accelerate metal corrosion, leading to decreased structural strength, equipment malfunctions, and even safety accidents.

[0003] Traditional epoxy zinc-rich coatings protect the steel substrate through zinc powder sacrificial anodes, but their high zinc content often results in poor coating flexibility, making them prone to cracking due to hull deformation and insufficient long-term effectiveness. Polyurethane anti-corrosion coatings suffer from poor weather resistance and are susceptible to hydrolysis in humid and hot environments. Chinese patent CN111500147A improves the overall anti-corrosion performance of heavy-duty anti-corrosion coatings by adding graphene and reduces the zinc content. Chinese patent CN113201264A utilizes the layered chain structure of the special fibrous crystal morphology in attapulgite clay, which, under the action of activators, allows graphene powder to be adsorbed on the surface of the attapulgite clay, improving the coating's anti-corrosion performance and antibacterial effect. However, these technical solutions only consider improving one or two properties of the coating. For marine coatings used in marine environments, multiple functions such as corrosion prevention, antifouling, antibacterial properties, and weather resistance are needed to extend service life. Therefore, developing new anti-corrosion pigments and fillers that provide long-lasting corrosion protection, have stable performance, and meet environmental protection requirements has become an urgent problem to be solved in the development of anti-corrosion coatings. Summary of the Invention

[0004] Based on the problems pointed out in the background art, the present invention aims to provide a marine anti-corrosion coating based on barium titanate / graphene / immon clay composite filler and its preparation method.

[0005] This invention first provides a marine anti-corrosion coating based on a barium titanate / graphene / immon clay composite filler, comprising the following components by weight: 100 parts of waterborne acrylic-epoxy hybrid emulsion, 20-40 parts of amino-modified polysiloxane resin emulsion, 5-20 parts of barium titanate / graphene / nanoimmon clay composite nanoparticles, 3-10 parts of waterborne additives, and 10-30 parts of water.

[0006] If the amount of barium titanate / graphene / nano-immon clay composite nanoparticles added is too low, it will not be able to improve the adhesion of the coating to the substrate surface; while if the amount added is too high, it will affect the film-forming performance of the coating, reduce the film quality of the existing coating, and also greatly increase the production cost. Preferably, the marine anti-corrosion coating modified by barium titanate / graphene / nano-immon clay composite material includes the following components by weight: 100 parts of waterborne acrylic epoxy hybrid emulsion, 20-40 parts of amino-modified polysiloxane resin emulsion, 10-20 parts of barium titanate / graphene / nano-immon clay composite nanoparticles, 3-10 parts of waterborne additives, and 10-30 parts of water.

[0007] As one of the preferred solutions for the aforementioned anti-corrosion coatings, the preparation method of barium titanate / graphene / nano-immon clay composite nanopowder is as follows:

[0008] (1) Preparation of barium titanate / graphene / nano-immon clay composite material:

[0009] Nano-immon clay was ultrasonically dispersed in deionized water, stirred evenly, and allowed to swell completely. 0.2 g of tetradecyltrimethylammonium bromide (TTAB) was added under stirring, and stirring continued for 30 min. Then, 0.5 g of graphene oxide and 0.5 mL of 3-aminopropyltriethoxysilane (APTES) were added. The mixture was stirred and refluxed at 70-90 °C for 20-24 h. After the reaction was complete, the mixture was cooled to room temperature, and deionized water was added to adjust the concentration, resulting in a modified graphene / nano-immon clay suspension with a solid content of 12.5 mg / mL.

[0010] The mass ratio of nano-immon clay to graphene oxide is 2:0.5.

[0011] The amount of tetradecyltrimethylammonium bromide (TTAB) added is 10% of the mass of nano-immon clay.

[0012] The mass-to-volume ratio of tetradecyltrimethylammonium bromide to 3-aminopropyltriethoxysilane is 2 g: 5 mL.

[0013] (2) Dissolve tetrabutyl titanate in ethylene glycol methyl ether, add 30% ammonia solution to precipitate titanium ions, and collect the white precipitate, which is the titanium hydroxide precipitate.

[0014] (3) The modified graphene / nano-immon clay suspension, titanium hydroxide precipitate, ethylenediamine / ethanolamine mixed solvent (volume ratio 1:1), barium acetate, and NaOH powder were mixed and ultrasonically stirred for 30 min. The mixture was then transferred to a reaction vessel with a polytetrafluoroethylene liner, sealed, and kept at 180-200℃ for 12-14 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The reaction products were filtered and separated, washed with deionized water, and dried to obtain barium titanate / graphene / nano-immon clay composite nanopowder.

[0015] The molar ratio of tetrabutyl titanate to barium acetate is 1:1.

[0016] The volume ratio of the modified graphene / nano-immon clay suspension to the ethylenediamine / ethanolamine mixed solvent is 1:2.

[0017] The molar ratio of barium acetate to NaOH is 1:20.

[0018] Graphene oxide is obtained by oxidizing graphite and then exfoliating it. Oxidation methods include the Hummers method, the Staudenmaier method, or the Brodie method. The resulting graphene oxide sheets have a pleated beryllium structure, a high oxygen content, abundant functional groups, and good dispersibility.

[0019] As one of the preferred options for the aforementioned anti-corrosion coating, the solid content of the waterborne acrylic-epoxy hybrid emulsion is 35-55%, preferably 40%.

[0020] As one of the preferred options for the aforementioned anti-corrosion coatings, the amino-modified polysiloxane resin emulsion has a solid content of 40-50% and an amino value of 0.2-0.5 mmol / g solid content.

[0021] As one of the preferred options for the aforementioned anti-corrosion coating, the water-based additives include at least one of wetting and dispersing agents, film-forming aids, thickeners, leveling agents, defoamers, and pH adjusters.

[0022] The wetting and dispersing agent is an anionic wetting and dispersing agent, preferably a weakly anionic polymer.

[0023] The preferred thickener is an alkali-swellable anionic thickener.

[0024] The defoamer is a water-based silicone defoamer.

[0025] This invention also provides a method for preparing the above-mentioned marine anti-corrosion coating based on barium titanate / graphene / immon clay composite filler: Dispersant and water are mixed evenly, barium titanate / graphene / nanoimmon clay composite nanoparticles are added, and ball-milled until the particle size D50 ≤ 2 μm; under low-speed stirring, resin emulsion is added to the pre-dispersed filler slurry, and homogenized using a homogenizer; then, defoamer, thickener, and other additives are added, homogenized again, and the material is discharged.

[0026] The marine anti-corrosion coating based on barium titanate / graphene / immon clay composite filler provided by this invention can be used in heavy-duty anti-corrosion areas such as the waterline area, ballast tanks, and hull of ships.

[0027] The present invention has at least one of the following beneficial effects:

[0028] Nano-immon clay possesses a unique layered structure, effectively immobilizing corrosive ions (especially Cl-) through interlayer domains and surface adsorption. - This invention weakens the corrosive environment and provides an additional chemical protective layer at the microscopic level. By filling the gaps between graphene stacks within a nano-immon clay layered structure, the diffusion path of the corrosive medium is significantly extended; barium titanate is loaded in situ to improve the conductivity of graphene, further endowing the material with certain dielectric properties, which can generate a piezoelectric effect underwater, thereby dynamically inhibiting electrochemical corrosion and further improving the antifouling and anticorrosion performance of the coating.

[0029] Furthermore, barium titanate (BaTiO3), as a semiconductor material, typically has a more negative standard electrode potential than steel. When the coating is damaged (e.g., scratches, impact damage), BaTiO3, acting as a sacrificial anode, preferentially undergoes oxidation and corrosion dissolution. The resulting electrons migrate to the surface of the steel substrate, causing cathodic polarization and providing protection. This provides active protection for the damaged area of ​​the coating, overcoming the weakness of traditional shielding coatings that fail at the point of damage, and significantly improving the coating's self-healing ability and overall protective safety.

[0030] The marine anti-corrosion coating based on barium titanate / graphene / immon clay composite filler provided by this invention can significantly improve the coating's hardness, wear resistance, impact resistance, and adhesion, as well as its excellent UV resistance, high temperature resistance, and weather resistance. It also prevents the coating from chalking, discoloration, loss of gloss, cracking, and other aging properties, making it more able to withstand the mechanical wear, impact, and stress during the ship's navigation, berthing, and loading / unloading processes, reducing the risk of coating damage and extending its service life. Detailed Implementation

[0031] The present invention will be described in detail below with reference to the embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0032] Joncryl® PRO 1556, an acrylic epoxy hybrid emulsion, with a solids content of approximately 40%, manufactured by BASF.

[0033] Amino-modified polysiloxane resin emulsion, Shin-Etsu KF-8010, amino value approximately 0.3 mmol / g (solid content), solid content approximately 50%.

[0034] Wetting and dispersing agent TEGO® Dispers 755 W, active ingredient content 40%; thickener ASE-60; defoamer BYK-024. Example 1

[0035] A method for preparing a marine anti-corrosion coating based on a barium titanate / graphene / immonite clay composite filler includes the following steps:

[0036] (1) Preparation of barium titanate / graphene / nano-immon clay composite material:

[0037] 2g of nano-immon clay was ultrasonically dispersed in 100mL of deionized water, stirred for 30min, and allowed to swell for 4h. 0.2g of tetradecyltrimethylammonium bromide (TTAB) was added under stirring, and stirring was continued for 30min. Then, 0.5g of graphene oxide and 0.5mL of 3-aminopropyltriethoxysilane (APTES) were added. The mixture was stirred and refluxed at 90℃ for 24h. After the reaction was completed, it was cooled to room temperature, and deionized water was added to adjust the concentration to obtain a modified graphene / nano-immon clay suspension with a solid content of 12.5mg / mL.

[0038] Dissolve 1 mmol of tetrabutyl titanate in 5 mL of ethylene glycol methyl ether, add 30% ammonia solution to precipitate titanium ions, and collect the resulting white precipitate, which is titanium hydroxide precipitate.

[0039] 10 mL of modified graphene / nano-immon clay suspension, titanium hydroxide precipitate, 20 mL of ethylenediamine / ethanolamine mixed solvent (1:1 volume ratio), 1 mmol of barium acetate, and 0.8 g of NaOH powder were mixed and ultrasonically stirred for 30 min. The mixture was then transferred to a 50 mL reactor with a polytetrafluoroethylene liner, sealed, and kept at 200 °C for 12 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The reaction products were filtered to separate the products, washed with deionized water, and dried to obtain barium titanate / graphene / nano-immon clay composite nanopowder.

[0040] (2) Preparation of anti-corrosion coating:

[0041] The anti-corrosion coating comprises the following components by weight: 100 parts of waterborne acrylic-epoxy hybrid emulsion, 20 parts of amino-modified polysiloxane resin emulsion, 15 parts of barium titanate / graphene / nano-immon clay composite nanoparticles, 4.8 parts of waterborne additives, and 10 parts of water.

[0042] Mix the dispersant and water evenly, add the barium titanate / graphene / nano imidum clay composite nanoparticles, and ball mill for 4 hours until the particle size D50 ≤ 2μm; under low-speed stirring, add the resin emulsion to the pre-dispersed filler slurry, and homogenize at 3000 rpm for 20 minutes; then add the defoamer and thickener, homogenize at 2000 rpm for 20 minutes, and discharge the material. Example 2

[0043] The difference between this embodiment and Example 1 is that both tetrabutyl titanate and barium acetate are 0.5 mmol. Example 3

[0044] The difference between this embodiment and Example 1 is that 2 mmol of tetrabutyl titanate and barium acetate are used. Example 4

[0045] The difference between this embodiment and Embodiment 1 is that the anti-corrosion coating is composed of the following components by weight: 100 parts of water-based acrylic epoxy hybrid emulsion, 20 parts of amino-modified polysiloxane resin emulsion, 10 parts of barium titanate / graphene / nano-immon clay composite nanoparticles, 5 parts of water-based additives, and 10 parts of water. Example 5

[0046] The difference between this embodiment and Embodiment 1 is that the anti-corrosion coating is composed of the following components by weight: 100 parts of water-based acrylic epoxy hybrid emulsion, 20 parts of amino-modified polysiloxane resin emulsion, 20 parts of barium titanate / graphene / nano-immon clay composite nanoparticles, 3 parts of water-based additives, and 15 parts of water. Comparative Example 1

[0047] The difference between this example and Example 1 is that the filler is a barium titanate / graphene composite material, and the preparation method is the same as in Example 1. The difference is that no nano-immon clay was added. Comparative Example 2

[0048] The difference between this example and Example 1 is that the filler is a modified graphene / nano-immon clay suspension prepared according to the method of Example 1, which is then filtered and dried to obtain a modified graphene / nano-immon clay composite material. Comparative Example 3

[0049] The difference between this example and Example 1 is that the anti-corrosion coating is composed of the following parts by weight: 100 parts of water-based acrylic epoxy hybrid emulsion, 20 parts of amino-modified polysiloxane resin emulsion, 30 parts of barium titanate / graphene / nano-immon clay composite nanoparticles, 3 parts of water-based additives, and 15 parts of water.

[0050] The coatings prepared in the above examples and comparative examples were sprayed onto Q235 steel plates that had been sandblasted to Sa 2.5 grade. The dry film thickness was controlled at (50±5) μm. After curing under standard conditions (23±2℃, 50±5%RH) for 7 days, performance tests were conducted.

[0051] Impact resistance testing shall be conducted in accordance with GB / T 1732-2020 standard, with an impact strength of 50 kgf·cm; pencil hardness testing shall be conducted in accordance with GB / T 6739-2022 standard; adhesion testing shall be conducted in accordance with GB / T5210-2006 standard. Artificial weathering resistance shall be conducted in accordance with Cyclic A method in GB / T 1865-2009; seawater resistance shall be conducted in accordance with the immersion method in GB / T 9274-1998. Neutral salt spray resistance testing shall be conducted in accordance with GB / T1771-2007 standard.

[0052] Marine organism attachment experiment: Chlorella was selected for testing. An algal solution was prepared using artificial seawater. A steel plate coated with anti-corrosion paint was immersed in the algal solution and cultured for 3 months. After that, it was taken out and the presence of marine organisms on the coating surface was observed.

[0053] Table 1 Coating performance test results

[0054]

[0055] The comparison of Examples 1-3 shows that the hardness of the coating increases with the increase of barium titanate loading. The absence of nano-immonite clay or graphene in the filler will affect the coating performance. Excessive filler addition results in poor film-forming properties and consequently, poor impact resistance.

[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler, characterized in that, The composition by weight includes the following components: 100 parts of waterborne acrylic epoxy hybrid emulsion, 20-40 parts of amino-modified polysiloxane resin emulsion, 5-20 parts of barium titanate / graphene / nano-immon clay composite filler, 3-10 parts of waterborne additives, and 10-30 parts of water.

2. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 1, characterized in that, The composition by weight includes the following components: 100 parts of waterborne acrylic epoxy hybrid emulsion, 20-40 parts of amino-modified polysiloxane resin emulsion, 10-20 parts of barium titanate / graphene / nano-immon clay composite filler, 3-10 parts of waterborne additives, and 10-30 parts of water.

3. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 1, characterized in that, The preparation method of the barium titanate / graphene / nano-immonite clay composite filler includes the following steps: (1) Disperse nano-immon clay in deionized water by ultrasonication, stir evenly and let it stand to fully swell; add tetradecyltrimethylammonium bromide under stirring, continue stirring, then add graphene oxide and 3-aminopropyltriethoxysilane, stir and reflux at 70-90℃ for 20-24h, cool to room temperature after the reaction is completed, add deionized water to adjust the concentration, and obtain a modified graphene / nano-immon clay suspension with a solid content of 12.5mg / mL; (2) Dissolve tetrabutyl titanate in ethylene glycol methyl ether, add 30% ammonia solution to precipitate titanium ions, and collect the white precipitate, which is the titanium hydroxide precipitate. (3) The modified graphene / nano-immon clay suspension, titanium hydroxide precipitate, ethylenediamine / ethanolamine mixed solvent (volume ratio 1:1), barium acetate, and NaOH powder were mixed and ultrasonically stirred until homogeneous. The mixture was then sealed and kept at 180-200℃ for 12-14 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The reaction products were then filtered, washed, and dried to obtain barium titanate / graphene / nano-immon clay composite filler.

4. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 3, characterized in that, In step (1), the mass ratio of nano-immon clay to graphene oxide is 2:0.5; the amount of tetradecyltrimethylammonium bromide added is 10% of the mass of nano-immon clay; and the mass-volume ratio of tetradecyltrimethylammonium bromide to 3-aminopropyltriethoxysilane is 2g:5mL.

5. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 3, characterized in that, The molar ratio of tetrabutyl titanate to barium acetate is 1:1; the volume ratio of modified graphene / nano-immon clay suspension to ethylenediamine / ethanolamine mixed solvent is 1:2; and the molar ratio of barium acetate to NaOH is 1:

20.

6. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 1, characterized in that, The solid content of the waterborne acrylic epoxy hybrid emulsion is 35-55%.

7. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 1, characterized in that, The solid content of the amino-modified polysiloxane resin emulsion is 40-50%, and the amino value is 0.2-0.5 mmol / g.

8. The marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler according to claim 1, characterized in that, Water-based additives include at least one of wetting and dispersing agents, film-forming aids, thickeners, leveling agents, defoamers, and pH adjusters.

9. The method for preparing the marine anti-corrosion coating based on barium titanate / graphene / immonite clay composite filler as described in claim 8, characterized in that, Wetting and dispersing agent and water are mixed evenly, and barium titanate / graphene / nano-immon clay composite filler is added. The mixture is ball-milled until the particle size D50 ≤ 2μm to obtain a pre-dispersed filler slurry. Under low-speed stirring, waterborne acrylic epoxy hybrid emulsion and amino-modified polysiloxane resin emulsion are added to the pre-dispersed filler slurry and homogenized. Then, defoamer and thickener are added, homogenized again, and the mixture is discharged.

10. The application of the marine anti-corrosion coating based on barium titanate / graphene / immon clay composite filler as described in claim 1 in the area below the waterline and in the ballast tanks of a ship.

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