A long-short chain liquid surface carbamate antifouling coating and its preparation method and application

Abstract

The present invention discloses a long-short chain liquid surface carbamate antifouling coating and its preparation method and application, wherein the preparation method comprises the following steps: dissolving dodecafluoroheptyl methacrylate, β-mercaptoethanol and a photoinitiator in a tetrahydrofuran solution to obtain solution A; then adding solution A to a three-necked flask, performing an ultraviolet light initiation reaction in a protective gas environment, and continuously stirring the process to finally obtain a fluorocopolymer B; then mixing monohydroxyl-terminated polydimethylsiloxane and polypropylene glycol and removing water to obtain solution C; finally chemically grafting the monohydroxyl-terminated polydimethylsiloxane flexible long chain and the fluorocopolymer flexible short chain onto the carbamate. The long-short chain liquid surface carbamate antifouling coating of the present invention can be cured at room temperature, is environmentally friendly, inhibits the adhesion of fouling organisms, and has good mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of marine antifouling coatings, and in particular to a long- and short-chain liquid surface carbamate antifouling coating, a preparation method thereof, and an application thereof. Background Art

[0002] Marine biofouling is a well-known problem. In the shortest possible time, ship hulls and other artificial underwater surfaces are inevitably occupied by various marine organisms. Marine biofouling has caused serious economic and environmental problems. Effectively controlling biofouling is crucial, and current antifouling coatings are an effective means of inhibiting biofouling. Among antifouling coatings, a smooth liquid-injected surface is a very typical antifouling coating, but the lubricant in the coating is easily exhausted; when it is damaged over a large area, the coating will lose a large amount of lubricant and lose its performance. Therefore, it is necessary to develop a technology for preparing an antifouling coating that does not release lubricant but has a lubricant-like surface. It can be coated on the surface of underwater equipment such as ships, water work platforms, underwater vehicles, etc., to inhibit biofouling.

[0003] In CN117089276A, the applicant disclosed a polyurethane washable antifouling coating based on an oxime-carbamate bond and its preparation method. The preparation method comprises the following steps: S1. After removing water from a polyether diol, the mixture is uniformly mixed with a diisocyanate and heated to 70-80°C to produce polymer A; S2. Polymer A, a solvent, a dioxime, and a dibutyltin dilaurate catalyst are weighed and mixed uniformly to produce polymer B; S3. Polymer B is coated on a substrate to form a sample, which is then left at room temperature and then heated to 60°C for curing to produce a coating. This antifouling coating exhibits excellent wear resistance. Based on the oxime-carbamate bond, the coating undergoes a hydrolysis reaction with seawater, meeting the requirements for washability and addressing the problem of marine organisms attaching to ship hull surfaces and causing alien species invasion. This antifouling coating is cured by heating to 60°C, where the antifouling dioxime is released, further inhibiting the attachment of fouling organisms. This concept differs from the present invention. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to propose a long- and short-chain liquid surface carbamate antifouling coating and its preparation method and application. The long- and short-chain liquid surface carbamate antifouling coating can be cured at room temperature, is environmentally friendly, can inhibit the adhesion of fouling organisms, and has good mechanical properties.

[0005] The technical solutions adopted are:

[0006] A method for preparing a long- and short-chain liquid surface carbamate antifouling coating comprises the following steps:

[0007] S1. dissolving dodecafluoroheptyl methacrylate, β-mercaptoethanol, and a photoinitiator in a tetrahydrofuran solution to obtain a solution A;

[0008] S2. Solution A was added to a three-necked flask, and the reaction was initiated by UV light in a protective gas environment with continuous stirring to obtain a fluorinated copolymer B;

[0009] S3. The monohydroxy-terminated polydimethylsiloxane and polypropylene glycol were mixed and water was removed to obtain a solution C;

[0010] S4 hexamethylene diisocyanate trimer was dissolved in a mixed solution of xylene and tetrahydrofuran to obtain a solution D;

[0011] S5. Add B to C at room temperature, and then slowly dropwise add D to C at room temperature while stirring continuously;

[0012] S6. After the addition is complete, the reaction mixture is heated to 80-85°C and stirred continuously to ensure sufficient reaction to obtain prepolymer E.

[0013] S7 was added to E curing agent polyaspartic acid ester, leveling agent, defoaming agent, and stirred to obtain a solution F;

[0014] S8. Apply F to the substrate surface and cure at room temperature for 2 hours to obtain a long- and short-chain liquid-phase surface urethane antifouling coating.

[0015] Furthermore, in S1, the mass ratio of dodecafluoroheptyl methacrylate and β-mercaptoethanol is 400:39; the mass of the photoinitiator is 3%-5% of the total mass of dodecafluoroheptyl methacrylate and β-mercaptoethanol; and the mass of tetrahydrofuran does not exceed 30% of the total mass.

[0016] Furthermore, the molar ratio of the fluorine copolymer B in S2, the hexamethylene diisocyanate trimer in S4, and the monohydroxy-terminated polydimethylsiloxane and polypropylene glycol in S3 is 0.1-0.5:1:0.3:0.25.

[0017] Furthermore, the mass ratio of xylene to tetrahydrofuran in S4 is 1:1, and the total amount of xylene and tetrahydrofuran is 30%-50% of the total mass of the fluorocopolymer B in S2, the solution C in S3, and the hexamethylene diisocyanate trimer in S4.

[0018] Furthermore, the mass of the defoamer and the leveling agent in S7 is 0.1% of the total mass of the S6 prepolymer and the S7 polyaspartic acid ester, respectively.

[0019] Further, in S3, water is removed at 100-110° C. for 2-3 hours.

[0020] Furthermore, in S5, the dropping speed is 50-150 g / h, and the dropping continues for 30-40 minutes.

[0021] Further, in S7, the mixture is stirred at 2000-2500 rpm for 5-10 minutes to obtain solution F.

[0022] In the present invention, the leveling agent and the defoaming agent can be selected from commercially available leveling agents and defoaming agents, including but not limited to, for example, the leveling agent is selected from one of the commercially available German BYK BYK-306, BYK-307, and BYK-330, and the defoaming agent is selected from one of the commercially available German BYK BY066N, BYK-141, BYK-071, and BYK-060N.

[0023] The liquid-phase functional urethane antifouling coating of the present invention is prepared by the above-mentioned preparation method.

[0024] The liquid-phase functional urethane antifouling coating prepared by the preparation method is used for surface protection of underwater equipment, including ships, water work platforms, and underwater vehicles. Specifically, the antifouling coating can be applied to the surfaces of underwater equipment, such as ships, water work platforms, and underwater vehicles, to inhibit biofouling.

[0025] In the above technical solution,

[0026] The present invention involves chemically grafting flexible monohydroxy-terminated polydimethylsiloxane long chains and hydroxy-fluorine copolymer short chains onto a carbamate antifouling coating. The numerous repetitive CF bonds and Si-O bonds allow the molecular chains to remain flexible at low temperatures. The grafted monohydroxy-terminated polydimethylsiloxane long chains and hydroxy-fluorine copolymer short chains exhibit liquid-like smoothness. The flexible chains grafted onto the surface possess a high migration rate, and the rapid perturbation of the flexible chains can inhibit the adhesion of biofouling. Furthermore, the introduction of a polydimethylsiloxane / fluorine copolymer double-layer protective structure enhances the ability to inhibit biofouling adhesion.

[0027] Wherein: (a) monohydroxy-terminated polydimethylsiloxane and (b) hydroxy fluorine copolymer have the following structural formula:

[0028]

[0029] In (a), n is the degree of polymerization, usually 10-1000, and R is methyl or ethyl.

[0030] In (b), a is the degree of polymerization, usually 10-1000.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention introduces environmentally friendly polydimethylsiloxane / fluorine copolymer flexible chains into polyurethane antifouling coatings, demonstrating promising applications. By grafting flexible chains with different molecular weights, the coating achieves a dual-layer protection, enhancing its antifouling properties while also being environmentally friendly.

[0033] 2. The antifouling coating of the present invention is chemically grafted onto a carbamate layer using long, flexible monohydroxy-terminated polydimethylsiloxane chains and short, flexible fluorocopolymer chains, giving the coating liquid-like slipperiness. The flexible chains grafted onto the surface possess a high migration rate, and the rapid perturbation of the flexible chains can inhibit the adhesion of biofouling. The low surface energy and slipperiness achieved by the monohydroxy-terminated polydimethylsiloxane and fluorocopolymer flexible chains inhibit the adhesion of fouling organisms. Controlling the content of the monohydroxy-terminated polydimethylsiloxane and fluorocopolymer chains with the hexamethylene diisocyanate trimer can control the antifouling properties of the coating.

[0034] 3. The flexible chains of the fluorocopolymer contain more hydrogen bonds, which can improve the mechanical properties of the coating. The mechanical properties of the coating can be controlled by adjusting the content of the flexible chains of the fluorocopolymer.

[0035] 4. The polymer resin (solution F) has good compatibility with the solvent and can be stored for a long time without deterioration or solidification, which facilitates the subsequent application of marine antifouling coatings or compounding into marine antifouling coatings.

[0036] 5. The polymer resin (Solution F) can be cured at room temperature in two hours. DETAILED DESCRIPTION

[0037] The present invention is described in detail below through specific examples, but the use and purpose of these exemplary embodiments are only used to illustrate the present invention and do not constitute any form of limitation on the actual protection scope of the present invention, nor do they limit the protection scope of the present invention to them.

[0038] Example 1

[0039] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0040] (1) 8 g of dodecafluoroheptyl methacrylate, 0.78 g of β-mercaptoethanol, 0.44 g of a photoinitiator, and 2.77 g of tetrahydrofuran were added to a three-necked flask. Nitrogen was continuously introduced during the process. The solution was UV-initiated and stirred continuously at a speed of 400 rpm to obtain a fluorinated copolymer.

[0041] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG (i.e., polypropylene glycol) were added to a three-necked flask and vacuum-dried at 110 °C for 2 hours.

[0042] (3) Add 11.99 g of fluorocopolymer to a three-necked flask, dissolve 60 g of hexamethylene diisocyanate trimer in 27.9 g of xylene and 27.9 g of tetrahydrofuran, and slowly add the solution dropwise to the three-necked flask at room temperature for 30 minutes. Stir continuously during the process at a stirring speed of 400 rpm.

[0043] (4) After the addition is complete, the reaction mixture is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction. Finally, a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0044] (5) Take 20g of prepolymer, add 7.98g of curing agent polyaspartic acid ester, 0.028g of leveling agent, and 0.028g of defoaming agent, and stir at 2000 rpm for five minutes.

[0045] (6) The resin was applied to the substrate surface and cured at room temperature for 2 hours to obtain a liquid-like functional polyurethane antifouling coating. This coating was named PFNP-10.

[0046] Do the following experiment:

[0047] 1. Laboratory static inhibition and desorption diatom experiment: The sample of Example 1 was evenly spread on a glass sheet with a size of 2.5 cm × 3.5 cm. A blank glass sheet was selected as a blank control. The sample sheet and the blank glass sheet were immersed in two model algae species (Dinophyceae and Nitzschia closterii) for 1 day, 3 days and 5 days respectively. After the samples were taken out, the unattached algae were removed. The algae attachment on the coating was photographed under an optical microscope. Five areas of each coating were randomly selected for photography. The average number of diatom cells on the blank glass sheet and the sample of Example 1 was calculated using the following formula (1):

[0048] (1)

[0049] Where K is the inhibition rate of diatom attachment, NB is the average number of diatom cells on the surface of the blank glass slide, and N1 is the average number of diatom cells on the surface of the sample.

[0050] 2. Mechanical properties experiment: The coating was tensile tested by a universal testing machine to measure its elongation at break. The test speed was 25 mm / min and three specimens were tested in parallel.

[0051] The inhibition rate of A. diversicolor after 5 days was calculated to be 59.67%, and the maximum breaking strength and breaking elongation were 2.87 MPa and 119.04% respectively.

[0052] Example 2

[0053] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0054] (1) 16 g of dodecafluoroheptyl methacrylate, 1.56 g of β-mercaptoethanol, 0.88 g of a photoinitiator, and 5.54 g of tetrahydrofuran were added to a three-necked flask. Nitrogen was continuously introduced during the process. The solution was UV-initiated and stirred continuously at a speed of 400 rpm to obtain a fluorinated copolymer.

[0055] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110 °C for 2 hours.

[0056] (3) Add 23.98 g of fluorocopolymer to a three-necked flask, dissolve 60 g of hexamethylene diisocyanate trimer in 30.3 g of xylene and 30.3 g of tetrahydrofuran, and slowly add the solution dropwise to the three-necked flask at room temperature for 30 minutes. Stir continuously during the process at a stirring speed of 400 rpm.

[0057] (4) After the addition is complete, the reaction mixture is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction. Finally, a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0058] (5) Take 20g of prepolymer, add 7.27g of curing agent polyaspartic acid ester, 0.027g of leveling agent, and 0.027g of defoaming agent, and stir at 2000 rpm for five minutes.

[0059] (6) The resin was applied to the substrate surface and cured at room temperature for 2 hours to obtain a liquid-like functional polyurethane antifouling coating. This coating was named PFNP-20.

[0060] The inhibition rate of A. diversicolor after 5 days was calculated to be 72.54%, and the maximum breaking strength and breaking elongation were 3.74 MPa and 267.83% respectively.

[0061] Example 3

[0062] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0063] (1) 24 g of dodecafluoroheptyl methacrylate, 2.34 g of β-mercaptoethanol, 1.32 g of photoinitiator, and 8.31 g of tetrahydrofuran were added to a three-necked flask. Nitrogen was continuously introduced during the process. The solution was UV-initiated and stirred continuously at a speed of 400 rpm to obtain a fluorinated copolymer.

[0064] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110 °C for 2 hours.

[0065] (3) Add 35.97 g of fluorocopolymer to a three-necked flask, dissolve 60 g of hexamethylene diisocyanate trimer in 32.7 g of xylene and 32.7 g of tetrahydrofuran, and slowly add the solution dropwise to the three-necked flask at room temperature for 30 minutes. Stir continuously during the process at a stirring speed of 400 rpm.

[0066] (4) After the addition is complete, the reaction mixture is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction. Finally, a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0067] (5) Take 20g of prepolymer, add 6.27g of curing agent polyaspartic acid ester, 0.026g of leveling agent, and 0.026g of defoaming agent, and stir at 2000 rpm for five minutes.

[0068] (6) The resin was applied to the substrate surface and cured at room temperature for 2 hours to obtain a liquid-like functional polyurethane antifouling coating. This coating was named PFNP-30.

[0069] The inhibition rate of A. diversicolor was calculated to be 79.16% after 5 days, and the maximum breaking strength and elongation at break were 4.55 MPa and 275.76%.

[0070] Example 4

[0071] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0072] (1) 32 g of dodecafluoroheptyl methacrylate, 3.12 g of β-mercaptoethanol, 1.76 g of photoinitiator, and 11.08 g of tetrahydrofuran were added to a three-necked flask. Nitrogen was continuously introduced during the process. The solution was UV-initiated and stirred continuously at a speed of 400 rpm to obtain a fluorinated copolymer.

[0073] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110 °C for 2 hours.

[0074] (3) Add 47.96 g of fluorocopolymer to a three-necked flask, dissolve 60 g of hexamethylene diisocyanate trimer in 35.11 g of xylene and 35.11 g of tetrahydrofuran, and slowly add the solution dropwise to the three-necked flask at room temperature for 30 minutes with continuous stirring at a speed of 400 rpm.

[0075] (4) After the addition is complete, the reaction mixture is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction. Finally, a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0076] (5) Take 20g of prepolymer, add 5.55g of curing agent polyaspartic acid ester, 0.025g of leveling agent, and 0.037g of defoaming agent, and stir at 2000 rpm for five minutes.

[0077] (6) The resin was applied to the substrate surface and cured at room temperature for 2 hours to obtain a liquid-like functional polyurethane antifouling coating. This coating was named PFNP-40.

[0078] The inhibition rate of A. diversicolor after 5 days was calculated to be 88.52%, and the maximum breaking strength and breaking elongation were 6.4 MPa and 356.8% respectively.

[0079] Example 5

[0080] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0081] (1) 8 g of dodecafluoroheptyl methacrylate, 0.78 g of β-mercaptoethanol, 0.44 g of a photoinitiator, and 2.77 g of tetrahydrofuran were added to a three-necked flask. Nitrogen was continuously introduced during the process. The solution was UV-initiated and stirred continuously at a speed of 400 rpm to obtain a fluorinated copolymer.

[0082] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110 °C for 2 hours.

[0083] (3) Add 11.99 g of fluorocopolymer to a three-necked flask, dissolve 60 g of hexamethylene diisocyanate trimer in 27.9 g of xylene and 27.9 g of tetrahydrofuran, and slowly add the solution dropwise to the three-necked flask at room temperature for 30 minutes. Stir continuously during the process at a stirring speed of 400 rpm.

[0084] (4) After the addition is complete, the reaction mixture is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction. Finally, a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0085] (5) Take 20g of prepolymer, add 4.92g of curing agent polyaspartic acid ester, 0.024g of leveling agent, and 0.037g of defoaming agent, and stir at 2000 rpm for five minutes.

[0086] (6) The resin was applied to the substrate surface and cured at room temperature for 2 hours to obtain a liquid-like functional polyurethane antifouling coating. This coating was named PFNP-50.

[0087] The inhibition rate of A. diversicolor after 5 days was calculated to be 92.19%, and the maximum breaking strength and breaking elongation were 5.52 MPa and 300.06%.

[0088] 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 long- and short-chain liquid surface urethane antifouling coating, characterized in that: The steps include: S1. Dissolve dodecafluoroheptyl methacrylate, β-mercaptoethanol, and a photoinitiator in tetrahydrofuran to obtain solution A; the mass ratio of dodecafluoroheptyl methacrylate to β-mercaptoethanol is 400:39; the mass of the photoinitiator is 3%-5% of the total mass of dodecafluoroheptyl methacrylate and β-mercaptoethanol; S2. Solution A was added to a three-necked flask, and the reaction was initiated by UV light in a protective gas environment with continuous stirring to obtain a fluorinated copolymer B; S3. The monohydroxy-terminated polydimethylsiloxane and polypropylene glycol were mixed and water was removed to obtain a solution C; S4 hexamethylene diisocyanate trimer was dissolved in a mixed solution of xylene and tetrahydrofuran to obtain a solution D; S5. Add B to C at room temperature, and then slowly dropwise add D to C at room temperature while stirring continuously; S6. After the addition is complete, the reaction mixture is heated to 80-85°C and stirred continuously to ensure sufficient reaction to obtain prepolymer E. S7 was added to E curing agent polyaspartic acid ester, leveling agent, defoaming agent, and stirred to obtain a solution F; S8. Apply F to the substrate surface and cure at room temperature for 2 hours to obtain a long- and short-chain liquid-phase surface urethane antifouling coating.

2. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: The molar ratio of the fluorine copolymer B in S2, the hexamethylene diisocyanate trimer in S4, and the monohydroxy-terminated polydimethylsiloxane and polypropylene glycol in S3 is 0.1-0.5:1:0.3:0.

25.

3. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: The mass ratio of xylene to tetrahydrofuran in S4 is 1:1, and the total amount of xylene and tetrahydrofuran is 30%-50% of the total mass of the fluorocopolymer B in S2, the solution C in S3 and the hexamethylene diisocyanate trimer in S4.

4. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: The mass of the defoamer and leveling agent in S7 is 0.1% of the total mass of the S6 prepolymer and S7 polyaspartic acid ester, respectively.

5. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S3, water is removed at 100-110° C. for 2-3 hours.

6. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S5, the dropping speed is 50-150 g / h, and the dropping is continued for 30-40 minutes.

7. The method for preparing a long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S7, the mixture was stirred at 2000-2500 rpm for 5-10 minutes to obtain solution F.

8. A long- and short-chain liquid surface urethane antifouling coating, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the long- and short-chain liquid surface urethane antifouling coating prepared by the preparation method according to any one of claims 1 to 7 in the surface protection of underwater equipment including ships, water work platforms, and underwater vehicles.

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