A light-cured transparent antifouling coating and its preparation method and application

Abstract

The present invention discloses a photocurable transparent antifouling coating, its preparation method, and application. The preparation method comprises the following steps: S1. preparing a photocurable functional silicone resin; S2. reacting a diisocyanate monomer with a polyol to prepare an isocyanate-terminated polyurethane prepolymer; S3. mixing the isocyanate-terminated polyurethane prepolymer, a methacrylic acid hydroxyl monomer, and a polymerization inhibitor, and reacting them to prepare a methacrylic acid-terminated polyurethane prepolymer; S4. mixing the functional silicone resin with the methacrylic acid hydroxyl monomer-terminated polyurethane prepolymer, a methacrylic acid hydrophilic monomer, and a methacrylic acid hydrophobic monomer, stirring them, and ultrasonically vibrating them to obtain a resin solution; S5. adding a photoinitiator to the resin solution and ultrasonically vibrating it to obtain an antifouling resin; S6. applying the antifouling resin to the surface of a substrate and curing it. The antifouling coating prepared by the present invention has excellent antibacterial and diatom adhesion inhibition properties.

Description

Technical Field

[0001] The present invention relates to the field of marine antifouling coatings, and in particular to a light-cured transparent antifouling coating and a preparation method and application thereof. Background Art

[0002] Marine resources are an important component of a nation's resources, and the ability to develop and utilize them is a reflection of a nation's comprehensive national strength. Currently, the development of marine resources is hampered by issues such as reduced data collection and transmission efficiency caused by marine fouling on the visual windows of detection equipment, marine photovoltaic equipment, and underwater sensor surfaces. Therefore, there is a need to develop a transparent antifouling coating technology for the surface protection of underwater transparent equipment that is simple to prepare and has excellent antifouling properties.

[0003] However, current technologies often achieve antifouling effects by continuously shedding or releasing toxic molecules and polymers into the water. These releases can harm the ecological environment and human health, necessitating the development of antifouling coatings based on interfacial properties. Furthermore, current antifouling coatings are often cured at high temperatures, which limits their applicability. Therefore, the present invention has developed a photocurable, transparent interfacial antifouling coating that combines room-temperature photocuring with high optical clarity, making it suitable for protecting high-transparency underwater equipment.

[0004] Xiang Hongping et al. used epoxy-modified silicone resin A, epoxy-modified silicone resin B and sulfide in Chinese patent CN117363215A, "A photocurable paint, coating and its application", to prepare a long-lasting antibacterial coating with good mechanical properties and excellent corrosion resistance.

[0005] Chen Bo et al., in their Chinese patent CN117777822A, "A method for preparing a hydrophilic antibacterial and mildew-proof photocuring coating," used tannic acid, long-chain quaternary ammonium salts, and zinc chloride as the main raw materials to create a coating with excellent hydrophilic properties and long-lasting antibacterial and mildew-proof properties.

[0006] Sun Guanqing et al., in their Chinese patent CN116179059A, "A transparent photocurable coating and its preparation method", combined filler dispersion technology with photocuring technology to prepare a photocurable coating with good substrate adhesion, hardness, wear resistance and transparency.

[0007] The photocurable coatings prepared by the above methods are applicable, but the performance of each coating in inhibiting the adhesion of marine fouling needs further investigation and verification. Summary of the Invention

[0008] In view of this, in view of the urgent need for transparent coating preparation and application technology in the field of marine antifouling, and to solve the problem that underwater visual equipment and detection equipment are easily affected by fouling during the development of marine resources, the purpose of the present invention is to propose a light-cured transparent antifouling coating and its preparation method and application, which has good antibacterial and diatom adhesion inhibition properties.

[0009] The technical solutions adopted are:

[0010] A method for preparing a light-cured transparent antifouling coating of the present invention comprises the following steps:

[0011] S1. Preparation of functional silicone resin: TEOS, photoinitiator siloxane monomer and functional silicone monomer were reacted in a sol-gel system, and then the solvent was removed to prepare a photocurable functional silicone resin;

[0012] S2. reacting a diisocyanate monomer with a polyol to prepare an isocyanate group-terminated polyurethane prepolymer;

[0013] S3. The isocyanate group-terminated polyurethane prepolymer, a hydroxyl methacrylate monomer and a polymerization inhibitor are mixed and reacted to prepare a methacrylate group-terminated polyurethane prepolymer;

[0014] S4. Resin preparation: A functional silicone resin and a polyurethane prepolymer terminated with a methacrylic acid hydroxyl monomer, a methacrylic acid hydrophilic monomer, and a methacrylic acid hydrophobic monomer were mixed and stirred and ultrasonically shaken to obtain a resin solution;

[0015] S5. The photoinitiator is added to the resin solution obtained in S4, and ultrasonic oscillation is performed to obtain an antifouling resin;

[0016] S6. Applying the antifouling resin to the surface of the substrate and curing the resin to form a completely cured transparent antifouling coating.

[0017] Further, in step S1, the photoinitiated siloxane monomer includes one or more of 3-(methacryloyloxy)propyl trimethoxysiloxane, vinyl trimethoxysiloxane, acryloxypropyl trimethoxysiloxane, acrylamidopropyl trimethoxysiloxane, methacryloxymethyl trimethoxysiloxane, 3-(N-allylamino)propyl trimethoxysiloxane, and acetoxypropyl trimethoxysiloxane;

[0018] The functional siloxane monomer includes one or more of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, pentafluorophenylpropyltrimethoxysiloxane, 2-(2-pyridyl)ethyltrimethoxysiloxane, and tetramethylguanidinopropyltrimethoxysiloxane.

[0019] Furthermore, in step S1, the mass ratio of tetraethyl orthosilicate, photoinitiated siloxane monomer and functional siloxane monomer is 1:(0.1-1):(0.3-1.2).

[0020] Furthermore, in step S2, the diisocyanate monomer includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate; the polyol includes one or more of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran; and the mass ratio of the diisocyanate monomer to the polyol is 1:(0.6-1).

[0021] Furthermore, in step S3, the hydroxyl methacrylate monomer includes one or both of hydroxyethyl methacrylate and hydroxypropyl methacrylate; and the mass ratio of the polyurethane prepolymer to the hydroxyl methacrylate monomer is 1:(0.2-0.5).

[0022] Furthermore, in step S4, the mass ratio of the functional silicone resin to the polyurethane prepolymer terminated with a methacrylic acid hydroxyl monomer, the methacrylic acid hydrophilic monomer, and the methacrylic acid hydrophobic monomer is: 1: (0.05-0.5): (0.1-0.5): (0.1-0.5).

[0023] Furthermore, in step S5, the photoinitiator includes one or more of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and hydroxycyclohexane phenone.

[0024] Furthermore, in step S6, the substrate includes one or more of a steel sheet, a glass, a polymethacrylate sheet, a polycarbonate sheet, a polyethylene terephthalate sheet, and a wood sheet; and / or the coating method is one of brushing, spin coating, blade coating, and dip coating.

[0025] Furthermore, in step S6, the curing time is 5-120 minutes.

[0026] The light-cured transparent antifouling coating of the present invention is prepared by the preparation method described in any one of the above schemes.

[0027] The above-mentioned light-cured transparent antifouling coating is used for surface protection of equipment and facilities including marine photovoltaic equipment, underwater detection instruments, underwater sensors, underwater vehicles and visual windows.

[0028] In the above technical solution,

[0029] Technical Description of Step S1: This method uses silanol groups from the hydrolysis of tetraethyl orthosilicate as crosslinking sites for silicone resins. It also introduces photoinitiable siloxane monomers as crosslinking sites during the photocuring process. Functional siloxane monomers can impart hydrophobic and antibacterial properties to the material. In the sol-gel system, the ester bonds in tetraethyl orthosilicate and the siloxane monomers undergo hydrolysis, producing silanol groups. These silanol groups then undergo dehydration and condensation to form a crosslinked silicone-based resin network with both photoinitiable and functional structures.

[0030] Technical Description of Step S2: The more reactive isocyanate group in the isocyanate reacts with the nucleophilic center in the hydroxyl group. This nucleophilic center in the hydroxyl group attacks the carbon atom in the isocyanate group, transferring the proton from the nitrogen atom to form a urethane structure. This step prepares an isocyanate-terminated polyurethane prepolymer.

[0031] Technical description of step S3: A polyurethane prepolymer terminated with a methacrylic acid group is prepared by reacting the hydroxyl groups in the methacrylic acid hydroxyl monomer with the remaining isocyanate groups in step S2.

[0032] Technical description of step S4: The functional silicone resin is fully mixed with other methacrylic acid monomers, and ultrasonic oscillation is used to achieve uniform dispersion of the raw materials.

[0033] Technical description of step S5: Add the photoinitiator to the resin dispersed in step 4, and evenly disperse the initiator in the resin by ultrasonic oscillation to obtain the antifouling resin.

[0034] Technical Description of Step S6: UV initiation uses light energy to induce electrons in the photoinitiator monomer molecules, causing them to transition to an excited state and form reactive free radicals. These free radicals then react with other monomer molecules to gradually form a high-molecular-weight polymer. The photoinitiator siloxane monomer serves as a crosslinking site, with one end located in the silicone resin structure and the other end in the methacrylate polymer structure.

[0035] The antifouling coating prepared by the above-mentioned preparation method can be applied to the surface protection of equipment such as visual windows of underwater vehicles, marine photovoltaic equipment and underwater sensors.

[0036] The light-curable, optically transparent marine antifouling coating prepared by the present invention uses ethyl orthosilicate as a cross-linking site for a silicone resin material, uses groups such as quaternary ammonium salts as antibacterial functional monomers, and uses photoinitiable 3-(methacryloyloxy)propyltrimethoxysiloxane as a cross-linking site for the silicone resin and a methacrylate resin. The mechanical properties of the coating are improved by introducing a polyurethane structure, and the amphiphilic groups of the methacrylate resin achieve efficient antifouling. During the process, a UV-induced photocuring reaction is used as a method for preparing the coating, thereby achieving convenient and efficient coating preparation.

[0037] The antifouling coating prepared by the present invention has dual antifouling effects: 1) structures such as quaternary ammonium salts in the coating achieve efficient inhibition of bacterial adhesion; 2) the introduction of amphiphilic chain segments in the coating achieves an antifouling effect of inhibiting diatom adhesion.

[0038] The results of the examples demonstrate that the antifouling coating prepared by the preparation method of the present invention has high optical transparency within the wavelength range of 350-800 nm, with a transmittance exceeding 85%. The results of the bacterial attachment inhibition experiment show that the coating can inhibit the attachment of bacteria by more than 90%. The results of the diatom inhibition experiment show that the coating can inhibit the attachment of diatoms by more than 90%.

[0039] The antifouling coating prepared by the present invention has high optical transparency, good mechanical properties and antifouling properties, can achieve rapid light curing, and is suitable for surface protection of underwater vehicles, marine photovoltaic equipment, sensors and detectors and other equipment and facilities. The coating of the present invention is cured by light curing, which expands the application field of coating technology; the resin preparation process of the present invention can only use anhydrous ethanol as a solvent, which can reduce the harm and impact of using organic solvents on the environment; the quaternary ammonium salt group antibacterial effect of the present invention and the amphiphilic interface antifouling synergistically achieve good antifouling effect; the polyurethane chain segment introduced by the present invention improves the mechanical properties of the coating.

[0040] Therefore, addressing the urgent need for transparent coating preparation and application technologies in the marine antifouling field, this invention uses a bactericidal silicone resin as the primary matrix, employs quaternary ammonium salts and other groups as antimicrobial active sites, and composites them with methacrylate materials to produce an amphiphilic transparent antifouling coating. This amphiphilic interface achieves high-efficiency antifouling, imparting the coating with excellent antimicrobial and diatom-inhibiting properties. The unique properties of light curing further expand the coating's application areas.

[0041] Compared with the prior art, the present invention has the following advantages:

[0042] 1. During the synthesis process of the present invention, only ethanol can be used as a solvent, which has the characteristics of low volatility and less harm to the environment;

[0043] 2. The coating curing process of the present invention is light-induced curing, which has the characteristics of high efficiency and low energy consumption;

[0044] 3. The coating of the present invention has the characteristics of high optical transparency;

[0045] 4. The coating of the present invention has good antibacterial activity and the ability to inhibit diatom adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1The transparency test results of the glass sheet, the coating prepared in Example 1, and the coating prepared in Example 2 under the UV-visible light spectrum are shown in the figure. According to the results in the figure, it can be seen that in the wavelength range of 350-800nm, the coatings have an optical transparency higher than 85%.

[0047] Figure 2 Fluorescence microscope images of glass slides, coatings prepared in Example 1, and coatings prepared in Example 2 after being immersed in Ampelopsis pilosa for one day. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] Example 1

[0050] A method for preparing a light-cured transparent antifouling coating of the present invention comprises the following steps:

[0051] S1. Mix 2.08 g of ethyl orthosilicate, 1.50 g of 65% dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride, 1.39 g of 3-(methacryloyloxy)propyltrimethoxysiloxane, and 4 g of anhydrous ethanol. Add 1.40 g of 0.1 mol / L hydrochloric acid solution and react at 25°C for 12 h. The resulting solution is rotary evaporated at 50°C for 30 min to remove the anhydrous ethanol to obtain a silicone resin.

[0052] S2 55.5g of isophorone diisocyanate and 40g of polypropylene glycol polyol were mixed and stirred, heated to 80 ° C, a small amount of catalyst dibutyltin dilaurate was added, and the reaction was carried out for 2.5h to obtain an isocyanate group-terminated polyurethane prepolymer;

[0053] S3. The isocyanate group-terminated polyurethane prepolymer was cooled to 40°C, 41.6 g of hydroxyethyl methacrylate and 0.5 g of hydroquinone were slowly added, the temperature was raised to 55°C, and the reaction was carried out for 2.5 h to obtain a methacrylic acid group-terminated polyurethane prepolymer;

[0054] S4. 2.10 g of silicone resin, 0.13 g of a methacrylic acid group-terminated polyurethane prepolymer, 0.45 g of methacryloyloxypropyl-terminated polydimethylsiloxane, and 0.55 g of polyethylene glycol methyl ether methacrylate were mixed, stirred at room temperature for 1 h, and ultrasonically vibrated for 20 min;

[0055] S5. 0.1 g of photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone and 0.1 g of benzoin dimethyl ether were added to the resin obtained in S4 and ultrasonically vibrated for 20 min to obtain an antifouling resin;

[0056] S6. Apply the antifouling resin to the surface of the glass sheet by knife coating, and place the coated antifouling resin under a UV initiator for curing for 30 minutes.

[0057] The relevant properties and shapes of the tested coatings are as follows:

[0058] Test method for inhibiting the adhesion performance of bacteria (Escherichia coli, Staphylococcus aureus or Pseudomonas xiamenensis). Place a glass slide and a sample coated with the coating in Example 1 in a bacterial culture solution of the same concentration for 24 hours. After washing off the bacteria attached to the surface of the glass slide and the surface of the coating sample in Example 1, culture them on the surface of a solid culture medium for 24 hours. Calculate the number of bacterial colonies attached to the surface of the glass slide and the surface of the coating sample in Example 1, and use the number of bacterial colonies grown on the surface of the glass slide as a benchmark to calculate the reduction rate of bacterial attachment on the coating surface in Example 1, which is the bacterial attachment inhibition rate of the coating. The corresponding bacterial attachment inhibition rate is as follows:

[0059] Bacteria inhibition adhesion performance test results:

[0060] Xiamen Pseudoalteromonas inhibition rate: 96.3%

[0061] Staphylococcus aureus inhibition rate: 99.6%

[0062] E. coli inhibition rate: 96.0%

[0063] Test method for inhibiting diatom attachment. Figure 2 As shown, a glass slide and a sample coated with the coating in Example 1 were placed in a culture solution of the same concentration of Amphora diatoms for one day. The number of diatoms attached to the surface of the glass slide and the surface of the coating in Example 1 was observed and counted using a fluorescence microscope. The number of diatoms attached to the surface of the glass slide was used as a benchmark, and the reduction rate of diatom attachment on the coating surface was calculated, which was the diatom attachment inhibition rate of the coating. The corresponding diatom attachment inhibition rate was as follows:

[0064] Diatom inhibition adhesion performance test results:

[0065] Inhibition rate of double-browed algae: 92.9%

[0066] The test result of the coating adhesion on the glass sheet using the ASTM D4541-09 standard is 2.30 MPa.

[0067] The transmittance of the coating in the 350-800nm band was investigated by UV-visible light spectroscopy. The transmittance of the coating exceeded 85%, proving the high optical transmittance of the coating. Figure 1 .

[0068] Example 2

[0069] Referring to Example 1, the difference from Example 1 is that the mass of the methacrylic acid group-terminated polyurethane prepolymer added in S4 is 0.26 g.

[0070] Bacteria inhibition adhesion performance test results:

[0071] Xiamen Pseudoalteromonas inhibition rate: 93.9%

[0072] Staphylococcus aureus inhibition rate: 99.1%

[0073] E. coli inhibition rate: 96.2%

[0074] Diatom inhibition adhesion performance test results:

[0075] Inhibition rate of double-browed algae: 93.7%

[0076] The test result of the coating adhesion on the glass sheet using the ASTM D4541-09 standard is 2.22MPa.

[0077] The transmittance of the coating in the 350-800nm band was investigated by UV-visible light spectroscopy. The transmittance of the coating exceeded 85%, proving the high optical transmittance of the coating. Figure 1 .

[0078] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a light-cured transparent antifouling coating, characterized in that: The following steps are involved: S1. Preparation of functional silicone resin: reacting tetraethyl orthosilicate, a photoinitiator siloxane monomer, and a functional siloxane monomer in a sol-gel system, followed by removal of the solvent to prepare a photocurable functional silicone resin; the functional siloxane monomer comprises one or more of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, pentafluorophenylpropyltrimethoxysiloxane, 2-(2-pyridyl)ethyltrimethoxysiloxane, and tetramethylguanidinopropyltrimethoxysiloxane; S2. reacting a diisocyanate monomer with a polyol to prepare an isocyanate group-terminated polyurethane prepolymer; S3. The isocyanate group-terminated polyurethane prepolymer, a hydroxyl methacrylate monomer and a polymerization inhibitor are mixed and reacted to prepare a hydroxyl methacrylate monomer-terminated polyurethane prepolymer; S4. Resin preparation: A functional silicone resin and a polyurethane prepolymer terminated with a methacrylic acid hydroxyl monomer, a methacrylic acid hydrophilic monomer, and a methacrylic acid hydrophobic monomer were mixed and stirred and ultrasonically shaken to obtain a resin solution; S5. The photoinitiator is added to the resin solution obtained in S4, and ultrasonic oscillation is performed to obtain an antifouling resin; S6. Applying the antifouling resin to the surface of the substrate and curing the resin to form a completely cured transparent antifouling coating.

2. The method for preparing a light-curable transparent antifouling coating according to claim 1, characterized in that: In step S1, the photoinitiated siloxane monomer includes one or more of 3-(methacryloyloxy)propyltrimethoxysiloxane, vinyltrimethoxysiloxane, acryloxypropyltrimethoxysiloxane, acrylamidopropyltrimethoxysiloxane, methacryloxymethyltrimethoxysiloxane, and 3-(N-allylamino)propyltrimethoxysiloxane.

3. The method for preparing a light-curable transparent antifouling coating according to claim 1, wherein: In step S1, the mass ratio of tetraethyl orthosilicate, photoinitiated siloxane monomer and functional siloxane monomer is 1:(0.1-1):(0.3-1.2).

4. The method for preparing a light-curable transparent antifouling coating according to claim 1, wherein: In step S2, the diisocyanate monomer includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate; the polyol includes one or more of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran; and the mass ratio of the diisocyanate monomer to the polyol is 1:(0.6-1).

5. The method for preparing a light-curable transparent antifouling coating according to claim 1, wherein: In step S3, the hydroxyl methacrylate monomer includes one or both of hydroxyethyl methacrylate and hydroxypropyl methacrylate; and the mass ratio of the polyurethane prepolymer to the hydroxyl methacrylate monomer is 1:(0.2-0.5).

6. The method for preparing a light-curable transparent antifouling coating according to claim 1, wherein: In step S4, the mass ratio of the functional silicone resin to the polyurethane prepolymer terminated with a methacrylic acid hydroxyl monomer, the methacrylic acid hydrophilic monomer, and the methacrylic acid hydrophobic monomer is: 1: (0.05-0.5): (0.1-0.5): (0.1-0.5).

7. The method for preparing a light-curable transparent antifouling coating according to claim 1, wherein: In step S5, the photoinitiator includes one or more of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and hydroxycyclohexane phenone.

8. The method for preparing a light-curable transparent antifouling coating according to claim 1, wherein: In step S6, the substrate includes one or more of a steel sheet, a glass, a polymethacrylate sheet, a polycarbonate sheet, a polyethylene terephthalate sheet, and a wood sheet; and / or the coating method is one of brushing, spin coating, blade coating, and dip coating.

9. A light-cured transparent antifouling coating, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the photocurable transparent antifouling coating according to claim 9 in surface protection of equipment and facilities including marine photovoltaic equipment, underwater detection instruments, underwater vehicles and visual windows.

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