Marine nanometer antifouling coating and preparation method thereof

Abstract

The application discloses marine nano antifouling paint and a preparation method thereof, relates to the technical field of marine paint, and comprises the following steps: preparing an atom transfer radical polymerization initiator anchoring zinc oxide; preparing a multifunctional nano antifouling intermediate; and preparing and curing the marine nano antifouling paint. The antifouling intermediate is permanently locked in the coating through a chemical bonding strategy, long-acting and non-toxic antifouling effects are realized, and the mechanical performance and stability of the coating are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of marine coatings, in particular to a marine nano-antifouling coating and a preparation method thereof. BACKGROUND

[0002] When a ship sails and stops in the marine environment, the surface of the ship body is easily attached by marine organisms, which is called biofouling. Biofouling can significantly increase the sailing resistance of the ship, resulting in a substantial increase in fuel consumption and increasing maintenance costs. In order to solve this problem, the surface of the ship body usually needs to be coated with marine antifouling coatings. In the existing coating system, epoxy resin is a commonly used base material, but it does not have antifouling function itself, so the antifouling performance of the coating mainly depends on the added antifouling agent. At present, a widely used type of antifouling coating relies on the exudation of toxic substances such as cuprous oxide to kill the attached marine organisms by releasing toxic ions.

[0003] However, the above prior art solutions have many defects. First, the coating relying on toxic antifouling agents such as cuprous oxide has high toxicity to non-target marine organisms, which seriously destroys the marine ecological balance and does not meet the increasingly stringent international environmental protection regulations. Second, in order to seek an environmentally friendly alternative, some technologies attempt to add nano-particles such as nano-zinc oxide to the coating in a physical way, but the effect of such physical mixing is not ideal. The nano-particles are easily agglomerated in the high molecular matrix and are difficult to disperse uniformly. More seriously, due to the lack of firm bonding, these nano-antifouling agents will quickly leak from the coating, resulting in a very short antifouling period. Third, another type of low surface energy coating has certain non-toxic antifouling effect, but it generally has the disadvantages of poor mechanical strength and easy scratching, and its antifouling effect will decrease significantly when the ship is static. SUMMARY

[0004] The purpose of the present application is to provide a marine nano-antifouling coating and a preparation method thereof, which solves the problems in the background art.

[0005] To solve the above technical problems, the present application provides a preparation method of a marine nano-antifouling coating, which comprises the following steps:

[0006] The vacuum-dried and activated nano-zinc oxide is dispersed in anhydrous toluene under ultrasonic assistance, a silane coupling agent containing an atom transfer radical polymerization initiator is added, and the mixture is refluxed and stirred to react. The product is centrifuged, washed and dried to obtain an atom transfer radical polymerization initiator anchored zinc oxide.

[0007] The atom transfer radical polymerization initiator anchoring zinc oxide is dispersed in a mixed solvent, sulfobetaine methacrylate monomer and glycidyl methacrylate monomer are added, and oxygen is removed by bubbling; a catalyst complex formed by cuprous bromide and N,N,N',N'',N''-pentamethyldiethylenetriamine is injected under nitrogen protection, and a surface-initiated polymerization reaction is carried out under magnetic stirring in a constant-temperature water bath, and the product is centrifuged, washed and dried to obtain a multifunctional nano-antifouling intermediate;

[0008] A component is prepared by dispersing and sanding bisphenol A epoxy resin, multifunctional nano-antifouling intermediate, pigment and filler by high-speed shearing;

[0009] An amine curing agent is used as a B component;

[0010] After A and B components are mixed in a predetermined ratio and left to deaerate, they are applied to a substrate and cured at room temperature; during curing, the amine curing agent reacts with the epoxy groups of the bisphenol A epoxy resin and the epoxy groups on the intermediate, so that the intermediate is covalently bonded to the epoxy resin network.

[0011] Preferably, the mass fraction of nano-zinc oxide and silane coupling agent containing atom transfer radical polymerization initiator is: nano-zinc oxide (18-22) parts, silane coupling agent containing atom transfer radical polymerization initiator (3.5-4.5) parts.

[0012] Preferably, the mass fraction of atom transfer radical polymerization initiator anchoring zinc oxide, sulfobetaine methacrylate monomer and glycidyl methacrylate monomer is: atom transfer radical polymerization initiator anchoring zinc oxide (8-12) parts, sulfobetaine methacrylate monomer (27-33) parts, glycidyl methacrylate monomer (8-12) parts.

[0013] Preferably, when preparing the A component, the mass fraction of bisphenol A epoxy resin, multifunctional nano-antifouling intermediate and pigment and filler is: bisphenol A epoxy resin (650-750) parts, multifunctional nano-antifouling intermediate (130-170) parts, pigment and filler (130-170) parts.

[0014] Preferably, the mass mixing ratio of the A component to the B component is (1000):(180-220).

[0015] Preferably, the temperature for vacuum drying and activation is 90-110°C, and the time is 10-14 hours; the power for ultrasonic-assisted dispersion is 350-450W, and the time length is 25-35 minutes; the temperature for reflux stirring reaction is 100-120°C, and the time is 20-28 hours.

[0016] Preferably, the mixed solvent is a mixture of methanol and water; the length of time for bubble deoxygenation is 40-50 minutes; the temperature of the constant-temperature water bath is 30-40 DEG C; and the magnetic stirring reaction time is 20-28 hours.

[0017] Preferably, the rotation speed of high-speed shearing dispersion is 3500-4500 rpm, and the length of time is 25-35 minutes; the sand mill grinding time is 1.5-2.5 hours; the mechanical stirring rotation speed when mixing component A and component B is 150-250 rpm, and the length of time is 8-12 minutes; and the length of time for static deaeration is 10-20 minutes.

[0018] The third monomer is added at the same time as the sulfobetaine methacrylate monomer and the glycidyl methacrylate monomer, and the third monomer is a non-ionic strong hydrophilic monomer.

[0019] A long-chain crosslinking agent is also added, and the mass of the long-chain crosslinking agent accounts for 0.1%-5.0% of the total mass of the sulfobetaine methacrylate monomer and the glycidyl methacrylate monomer.

[0020] Preferably, when component A is prepared, rigid nano-filler is additionally added at the same time as the color filler.

[0021] The application also provides a marine nano-antifouling coating prepared by the above method.

[0022] Compared with the prior art, the application has the following beneficial effects:

[0023] The zwitterionic groups construct a dense hydration layer on the surface of the coating, effectively preventing the initial adsorption of proteins and bacteria, and thereby inhibiting the formation of a biological membrane, without relying on the exudation of toxic substances, so that non-toxic antifouling that is friendly to the environment is achieved, and the toxic harm to non-target organisms in the sea is avoided.

[0024] A multifunctional nano-antifouling intermediate is designed, which can be covalently bonded to the matrix resin network during curing of the coating through specific chemical reactions, so that the antifouling functional units are permanently fixed in the coating, fundamentally solving the problem of loss of antifouling active ingredients, and ensuring the long-term stability and effectiveness of the antifouling performance of the coating.

[0025] The functionalized nanoparticles not only provide antifouling performance, but also are uniformly dispersed in the epoxy resin network as crosslinking points, significantly enhancing the overall mechanical performance of the coating, improving the adhesion and hardness of the coating, and enabling the coating to resist physical impact and scratching during sailing and berthing, thereby ensuring the integrity and durability of the coating.

[0026] By introducing a third monomer or rigid nanofiller, the introduced hydrophilic monomer can ensure that the coating still maintains a high efficient hydration layer and antifouling performance in low salinity or fresh water; and the addition of rigid filler further enhances the ability of the coating to resist extreme mechanical scratches, making the coating suitable for more complex and variable marine environments. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

[0028] Embodiment 1

[0029] In this embodiment, specific intermediate values are selected for the components and process parameters, and the specific steps include the following steps:

[0030] (1) Preparation of atom transfer radical polymerization initiator anchored zinc oxide:

[0031] 20.0 grams of nano-zinc oxide (purity 99.8%, particle size 30-50 nm) was vacuum dried and activated at 100°C for 12 hours; the activated nano-zinc oxide was added to 500 mL of anhydrous toluene, and ultrasonic-assisted dispersion was performed at a power of 400 W for 30 minutes to obtain a suspension; 4.0 grams of (3-(2-bromoisobutyrylamino)propyl)trimethoxysilane coupling agent (purity 95%) was added to the suspension, the mixture was warmed to 110°C and refluxed and stirred for 24 hours; after the reaction was completed, the product was collected by centrifugation, washed, and vacuum dried at 60°C for 24 hours to obtain atom transfer radical polymerization initiator anchored zinc oxide powder;

[0032] (2) Preparation of multifunctional nano-antifouling intermediate:

[0033] 10.0 grams of the powder prepared in step (1) was dispersed in 300 mL of a mixed solvent of methanol and water (1:1) and ultrasonicated for 15 minutes; 30.0 grams of sulfobetaine methacrylate monomer and 10.0 grams of glycidyl methacrylate monomer were added; high-purity nitrogen was bubbled for 45 minutes; in another container, 0.286 grams of cuprous bromide and 0.346 grams of N,N,N',N'',N''-pentamethyldiethylenetriamine were dissolved in 10 mL of deoxygenated methanol; under nitrogen protection, the catalyst complex was injected into the mixture; the reaction was magnetically stirred in a 35°C constant-temperature water bath for 24 hours; after the reaction was completed, the reaction was terminated by exposure to air, the product was collected by centrifugation, repeatedly washed, and vacuum dried at 40°C for 48 hours to obtain a multifunctional nano-antifouling intermediate;

[0034] (Three) Preparation and curing of marine nanometer antifouling coating:

[0035] Preparation of A component: 700 grams of bisphenol A epoxy resin was weighed as matrix material, 150 grams of multifunctional nanometer antifouling intermediate prepared in step (two) was added; a high-speed shearing disperser with a rotation speed of 4000 rpm was used for shearing for 30 minutes, and then transferred to a sand mill for grinding for 2 hours; 100 grams of anatase titanium dioxide and 50 grams of barium sulfate were added as pigments and fillers, and 5 grams of polyacrylate leveling agent was added, and stirred uniformly to obtain A component;

[0036] Preparation of B component: 200 grams of isophorone diamine was weighed as amine curing agent B component;

[0037] Application and curing: before application, A component and B component were mixed at a mass ratio of 1000:200, and mechanically stirred at a rotation speed of 200 rpm for 10 minutes; after standing and defoaming for 15 minutes, it was applied to the substrate, and cured at room temperature of 25°C for 7 days; during the curing process, the amine curing agent reacted with the glycidyl methacrylate epoxy groups on the intermediate and the epoxy resin, so that the intermediate was covalently bonded to the network structure.

[0038] Example 2

[0039] The components and process parameters of this example are selected as a specific lower value;

[0040] (One) Preparation of atom transfer radical polymerization initiator anchored zinc oxide:

[0041] Nanometer zinc oxide 18 parts, (3-(2-bromo isobutyryl amido) propyl) trimethoxysilane coupling agent 3.5 parts; activation: 90°C, 10 hours; ultrasonic: 350W, 25 minutes; reflux: 100°C, 20 hours;

[0042] (Two) Preparation of multifunctional nanometer antifouling intermediate:

[0043] Atom transfer radical polymerization initiator anchored zinc oxide 8 parts, sulfobetaine methacrylate monomer 27 parts, glycidyl methacrylate monomer 8 parts; oxygen removal: 40 minutes; reaction: 30°C, 20 hours;

[0044] (Three) Preparation and curing of marine nanometer antifouling coating:

[0045] A component: bisphenol A epoxy resin 650 parts, multifunctional nanometer antifouling intermediate 130 parts, pigments and fillers 130 parts; dispersion: 3500 rpm, 25 minutes; grinding: 1.5 hours;

[0046] B component: A:B component mixing ratio 1000:180; mixing stirring: 150 rpm, 8 minutes; defoaming: 10 minutes;

[0047] The curing mechanism is the same as in Example 1.

[0048] Example 3

[0049] The components and process parameters in this example are selected to be a particular higher value;

[0050] (1) Preparation of atom transfer radical polymerization initiator-anchored zinc oxide:

[0051] Nano zinc oxide 22 parts, (3-(2-bromoisobutyrylamido)propyl)trimethoxysilane coupling agent 4.5 parts; activation: 110°C, 14 hours; ultrasonic: 450W, 35 minutes; reflux: 120°C, 28 hours;

[0052] (2) Preparation of multifunctional nano antifouling intermediate:

[0053] Atom transfer radical polymerization initiator-anchored zinc oxide 12 parts, sulfobetaine methacrylate monomer 33 parts, glycidyl methacrylate monomer 12 parts; oxygen removal: 50 minutes; reaction: 40°C, 28 hours;

[0054] (3) Preparation and curing of marine nano antifouling paint:

[0055] A component: bisphenol A epoxy resin 750 parts, multifunctional nano antifouling intermediate 170 parts, pigment and filler 170 parts; dispersion: 4500 rpm, 35 minutes; grinding: 2.5 hours;

[0056] B component: A:B component mixing ratio 1000:220; mixing stirring: 250 rpm, 12 minutes; defoaming: 20 minutes;

[0057] The curing mechanism is the same as in Example 1.

[0058] Example 4

[0059] This example introduces a third monomer on the basis of Example 1; this example aims to optimize the antifouling performance of the paint in low salinity waters;

[0060] The parameters of steps (1) and (3) are the same as in Example 1;

[0061] Step (2) Preparation of multifunctional nano antifouling intermediate:

[0062] 10.0 grams of the powder prepared in step (one) was dispersed in 300 mL of a mixture of methanol and water (1 : 1); 25.0 grams of sulfobetaine methacrylate monomer, 10.0 grams of glycidyl methacrylate monomer, and additionally 5.0 grams of hydroxyethyl methacrylate as a third monomer were added;

[0063] Subsequent deoxygenation, catalyst preparation, initiation of polymerization, reaction (35 °C, 24 h), termination and purification steps were the same as in Example 1;

[0064] The resulting product was sulfobetaine methacrylate-co-glycidyl methacrylate-co-hydroxyethyl methacrylate, which still maintained a hydration layer in low salinity water by virtue of the hydrogen bonding water absorption of the hydroxyethyl methacrylate groups.

[0065] Example 5

[0066] This example introduces an internal crosslinking agent and a rigid filler on the basis of Example 1; this example aims to optimize the structural stability of the coating under extreme mechanical impact;

[0067] The parameters of step (one) were the same as in Example 1;

[0068] Preparation of multifunctional nano-antifouling intermediate in step (two):

[0069] The raw materials were the same as in Example 1, but 0.5 grams of diethylene glycol dimethacrylate was additionally added as a long-chain crosslinking agent (1.25% of the total mass of 40 grams of monomers) at the same time as the sulfobetaine methacrylate and glycidyl methacrylate monomers, to increase toughness; the subsequent steps were the same as in Example 1;

[0070] Preparation and curing of marine nano-antifouling paint in step (three):

[0071] Preparation of component A: the raw materials were the same as in Example 1, but 14 grams (2% of the weight of 700 grams of epoxy resin) of nano-silicon dioxide was additionally added as a rigid nano-filler at the same time as the 150 grams of pigment and filler (the specific components were the same as in Example 1); the subsequent steps were the same as in Example 1;

[0072] Preparation and curing of component B were the same as in Example 1;

[0073] The coating prepared by this method has improved scratch resistance and impact resistance due to the internal toughening of the polymer brush and the physical support of the rigid nano-filler.

[0074] Comparative Example 1

[0075] A blank epoxy coating sample was prepared, the components of which only included bisphenol A epoxy resin 1000 parts and amine curing agent 200 parts, without any antifouling agent; curing was carried out according to the curing conditions of step (three) in Example 1.

[0076] Comparative Example 2

[0077] A traditional cuprous oxide antifouling coating panel was prepared with a commercially available C09D5 / 16 type paint, in which cuprous oxide served as the antifouling agent and functioned through an exudation mechanism.

[0078] Comparative Example 3

[0079] A coating panel with physically added nano-zinc oxide was prepared; for the A component, 700 grams of bisphenol A epoxy resin was weighed, 150 grams of non-functionalized bare nano-zinc oxide (purity 99.8%, particle size 30-50 nm) was added, and 150 grams of color filler and 5 grams of leveling agent were added; the B component and curing conditions were the same as in Example 1; in this comparative example, the nano-zinc oxide was only physically mixed with the epoxy resin.

[0080] Effect verification

[0081] To verify the technical effects of the preparation method of the marine nano-antifouling coating according to the present application, the coating panels prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance tests.

[0082] Antifouling long-term effectiveness test (real sea panel hanging):

[0083] The panels were hung in the South China Sea for 12 months of real sea testing; the percentage of biofouling area at different time points was recorded;

[0084] Antifouling agent stability test (immersion and release):

[0085] The panels were immersed in a 3% NaCl solution to simulate seawater environment; the concentration of zinc ions (Zn2+) in the immersion solution was detected at the 12th week;

[0086] Mechanical property test:

[0087] The pencil hardness and adhesion of the cured coating were tested;

[0088] Specific scenario test:

[0089] Low salinity test (only Example 4): the panels of Example 1 and Example 4 were simultaneously placed in a freshwater environment for 6 months of berthing, and the biofilm adhesion was observed;

[0090] Scratch resistance test (only Example 5): using a standard scratch resistance tester, the panels of Example 1 and Example 5 were subjected to the same load for scratching, and the scratch width and loss of coating adhesion were compared.

[0091] Test result summary table

[0092] ​

[0093] Effect Analysis:

[0094] Antifouling and stability (Comparative Example 1, Comparative Examples 1, 2, and 3):

[0095] The antifouling effects of Comparative Example 1 and Comparative Example 2 were not ideal; the data of Comparative Example 3 ( The precipitation of up to 8.5 mg / L confirmed the violent burst release and rapid loss of the antifouling agent;

[0096] In contrast, the actual marine fouling area over 12 months in Examples 1-5 was all <8%, and The precipitation concentrations were all below 0.1 mg / L; this confirms the preparation method of the present invention, which forms sulfobetaine methacrylate antifouling groups through surface-initiated polymerization in step (II) and curing mechanism in step (III). The glycidyl methacrylate groups react with amine curing agents to successfully covalently bond the multifunctional nano antifouling intermediate to the epoxy resin network, solving the loss problem and achieving long-lasting non-toxic antifouling.

[0097] Parameter range (comparative examples 1, 2, and 3):

[0098] Both Examples 2 and 3 exhibited good antifouling and anti-leakage properties, proving that the defined process parameters and component ranges are reasonable and effective;

[0099] Specific scenarios (comparative examples 1, 4, and 5):

[0100] Example 4, by introducing hydroxyethyl methacrylate, demonstrated that its antifouling effect in low-salinity waters was significantly better than that in Example 1, proving the effectiveness of the full salinity adaptive design.

[0101] Example 5, by introducing internal crosslinking and rigid fillers, exhibits superior scratch resistance compared to Example 1, demonstrating that this method significantly improves the robustness of the coating against mechanical scratches encountered during ship navigation and berthing.

[0102] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a marine nano-antifouling coating, characterized in that, include: Vacuum-dried and activated nano-zinc oxide was dispersed in anhydrous toluene with ultrasonic assistance, and a silane coupling agent containing an atom transfer radical polymerization initiator was added. The mixture was refluxed and stirred. The product was centrifuged, washed, and dried to obtain atom transfer radical polymerization initiator-anchored zinc oxide. Zinc oxide anchored by atom transfer radical polymerization initiator was dispersed in a mixed solvent, and sulfobetaine methacrylate monomer and glycidyl methacrylate monomer were added. Oxygen was removed by bubbling. A catalyst complex formed by cuprous bromide and N,N,N',N'',N''-pentamethyldiethylenetriamine was injected under nitrogen protection. Surface-initiated polymerization was carried out by magnetic stirring in a constant temperature water bath. The product was centrifuged, washed, and dried to obtain a multifunctional nano antifouling intermediate. Component A was prepared by high-speed shear dispersion and sand milling of bisphenol A epoxy resin, multifunctional nano antifouling intermediate, pigments, fillers and leveling agents; An amine-based curing agent is used as component B. Mix components A and B in a predetermined ratio, allow to stand to degas, and then apply to the substrate for curing at room temperature. During curing, the amine curing agent reacts with the epoxy groups on the bisphenol A epoxy resin and the intermediates, causing the intermediates to covalently bond to the epoxy resin network.

2. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, The mass fractions of nano zinc oxide and silane coupling agent containing atom transfer radical polymerization initiator are: 18-22 parts of nano zinc oxide and 3.5-4.5 parts of silane coupling agent containing atom transfer radical polymerization initiator.

3. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, The mass fractions of the atom transfer radical polymerization initiator anchored zinc oxide, sulfobetaine methacrylate monomer, and glycidyl methacrylate monomer are as follows: 8-12 parts of the atom transfer radical polymerization initiator anchored zinc oxide, 27-33 parts of sulfobetaine methacrylate monomer, and 8-12 parts of glycidyl methacrylate monomer.

4. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, When preparing component A, the mass fractions of bisphenol A epoxy resin, multifunctional nano antifouling intermediate, and pigments and fillers are as follows: 650-750 parts of bisphenol A epoxy resin, 130-170 parts of multifunctional nano antifouling intermediate, and 130-170 parts of pigments and fillers.

5. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, The mass mixing ratio of component A to component B is 1000:180-220.

6. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, The vacuum drying activation temperature is 90-110°C, and the time is 10-14 hours; the ultrasonic-assisted dispersion power is 350-450W, and the duration is 25-35 minutes; the reflux stirring reaction temperature is 100-120°C, and the time is 20-28 hours.

7. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, The mixed solvent is a mixture of methanol and water; the bubbling deoxygenation time is 40-50 minutes; the temperature of the constant temperature water bath is 30-40°C; and the magnetic stirring reaction time is 20-28 hours.

8. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, The high-speed shear dispersion is performed at a speed of 3500-4500 rpm for 25-35 minutes; the grinding time in the sand mill is 1.5-2.5 hours; the mechanical stirring speed when mixing component A and component B is 150-250 rpm for 8-12 minutes; and the standing degassing time is 10-20 minutes. In addition to adding sulfobetaine methacrylate monomer and glycidyl methacrylate monomer, a third monomer is also added, which is a nonionic, strongly hydrophilic monomer. Long-chain crosslinking agents are also added, with the mass of the long-chain crosslinking agent accounting for 0.1%-5.0% of the total mass of sulfobetaine methacrylate monomer and glycidyl methacrylate monomer.

9. The method for preparing marine nano-antifouling coating according to claim 1, characterized in that, When preparing component A, rigid nanofillers are added in addition to pigments and fillers.

10. A marine nano-antifouling coating, characterized in that, It is prepared by the method for preparing marine nano antifouling coating according to any one of claims 1-9.

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