A coumarin-containing acrylic metal salt resin, a preparation method thereof and use thereof

Abstract

This invention relates to an acrylic metal salt resin containing a coumarin structure, its preparation method, and its uses. The acrylic metal salt resin has the following chemical structural formula (I): This coumarin-containing acrylic metal salt resin of the present invention possesses antifouling effects that combine antibacterial, fluorescent antifouling, and self-polishing antifouling properties, enhancing the antifouling performance of the resin. Real-sea antifouling tests show that the coating has a static real-sea antifouling effect of over 110 days. It is an environmentally friendly antifouling resin with a simple preparation process and readily available raw materials.

Description

[Technical Field]

[0001] This invention belongs to the field of functional polymer materials technology. More specifically, this invention relates to a coumarin-containing acrylic metal salt resin, a method for preparing the acrylic metal salt resin, and the uses of the acrylic metal salt resin. [Background Technology]

[0002] Instruments and equipment in marine environments inevitably face the problem of marine biofouling. Marine biofouling not only causes economic losses but can also pose a threat to life, making its prevention and control a common marine environmental issue of concern to all countries. Currently, applying antifouling coatings is the most economical and effective method to prevent marine biofouling. Among them, self-polishing antifouling coatings are widely used both domestically and internationally due to their strong surface self-renewal ability, long antifouling period, and high antifouling performance. Tributyltin (TBT) self-polishing coatings, a representative product of the 19th century, were widely used on ships due to their excellent antifouling properties. However, because TBT compounds are environmentally unfriendly to the marine environment, the International Maritime Organization and the Marine Environment Protection Committee announced a ban on the use of TBT compounds in the marine environment until 2008. At the same time, many countries strictly monitor the harm of antifouling coatings to the marine environment. Therefore, the development of environmentally friendly antifouling coatings has become a research focus, and various countries have proposed developing environmentally friendly Wuxi self-polishing antifouling coatings.

[0003] With increasing environmental awareness, the application of natural antifouling agents in marine antifouling has garnered growing attention. Natural antifouling agents, typically derived from natural resources such as plants, algae, and microorganisms, possess characteristics such as biocompatibility, non-toxicity / low toxicity, and environmental friendliness, effectively reducing their impact on marine ecosystems. However, despite their excellent antifouling properties, the complexity of their separation and extraction processes limits their large-scale application. Therefore, how to synthesize marine antifouling coatings containing environmentally friendly antifouling agents using simple and readily available methods has become a pressing issue for those skilled in the art.

[0004] In response to the technical deficiencies of current environmentally friendly marine antifouling coatings, the inventors, based on a summary of existing technologies, and through extensive experimental research and analysis, finally completed this invention. [Summary of the Invention]

[0005] The purpose of this invention is to provide a coumarin-structured acrylic metal salt resin.

[0006] Another object of the present invention is to provide a method for preparing the coumarin-containing acrylate metal salt resin.

[0007] Another object of the present invention is to provide the use of the coumarin-containing acrylate metal salt resin.

[0008] The present invention is achieved through the following technical solution.

[0009] This invention relates to an acrylic metal salt resin containing a coumarin structure.

[0010] The acrylic metal salt resin has the following chemical structural formula (I):

[0011]

[0012] In the formula: R1 is H, R2 is H; or R1 is CH3, R2 is H; or R1 is H, R2 is Cl;

[0013] R3 is H, -OCH3, -OH, or -Et2N;

[0014] X is Zn 2+ or Cu 2+ Metal ions;

[0015] n is a positive integer; m is 0 or a positive integer; x is 0 or a positive integer; y is a positive integer;

[0016] The number-average molecular weight of the aforementioned acrylic metal salt resin containing coumarin structure is 2,000 to 60,000, and its molecular weight distribution is 1.0 to 2.5.

[0017] The present invention also relates to a method for preparing the acrylate metal salt resin containing the coumarin structure.

[0018] The preparation steps of the preparation method are as follows:

[0019] A. Preparation of hydroxycoumarin compounds

[0020] In a round-bottom flask, resorcinol or 2-methylresorcinol and ethyl acetoacetate are dissolved by stirring at a molar ratio of 1:0.8-2.0 to obtain a mixed solution. Then, ZrCl4 is slowly added to the mixed solution at 15%-25% of their total molar amount. The mixture is stirred vigorously at room temperature for 20-40 min. Then, ice water is slowly added to precipitate the precipitate. The precipitate is filtered, and the resulting filter cake is recrystallized in an ethanol solution with a concentration of more than 90% by volume. After filtration and drying, 7-hydroxy-4-methylcoumarin or 7-hydroxy-4,8-dimethylcoumarin is obtained.

[0021] B. Preparation of coumarin compounds containing C=C double bonds

[0022] The hydroxycoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask at a molar ratio of 30–40:40–55:40–55:0.7–1.0. Then, acetone solvent was added to the reactants at a ratio of 10–20:150–200 (total mass of reactants in grams to acetone in milliliters). The mixture was then heated under reflux at 50–70°C for 15–24 h. After filtration, the collected filtrate was subjected to vacuum rotary evaporation at 40–50°C and a vacuum degree of -0.07–-0.1 kPa to obtain a coumarin compound containing a C=C double bond structure.

[0023] C. Preparation of coumarin acid compounds

[0024] Salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:20-25. Then, 350%-500% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and stirred until homogeneous. The mixture was then reacted at 100-120°C for 2-6 hours. The mixture was then filtered and dried to obtain the coumarin acid compound.

[0025] D. Synthesis of coumarin-containing acrylic prepolymers

[0026] Ethyl acrylate, butyl acrylate, acrylic acid, and a coumarin compound containing a C=C double bond structure are mixed uniformly in a molar ratio of 6:2:2:0.05-2.5 to obtain a monomer mixture. Then, 0.5%-3.2% of an initiator based on the weight of the monomer mixture is added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 100-230% of solvent, 10%-20% of the monomer mixture containing the initiator, and 0.3%-2.0% of chain transfer agent are added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture is controlled at 75℃-110℃. Then, the remaining monomer mixture containing the initiator is divided into 9-15 equal parts, and one part is added every 10-20 minutes. The reaction is carried out for 4-8 hours to obtain a viscous acrylic prepolymer containing a coumarin structure.

[0027] E. Synthesis of coumarin-containing acrylate metal salt resins

[0028] The coumarin-structured acrylic prepolymer obtained in step D is cooled to below 70°C. Then, a metal oxide or hydroxide and the coumarin acid compound obtained in step C are added. The amount of each added is 0.8 to 1.5 times the molar amount of acrylic acid in the coumarin-structured acrylic prepolymer, and the molar ratio of the metal oxide or hydroxide to the coumarin acid compound is 1:0.8 to 1.5. The mixture is thoroughly mixed, and then 150% to 200% of the solvent by weight of the mixture is added to the resulting mixture. The mixture is then reacted at 100°C to 130°C for 3 to 5 days to obtain a coumarin-structured acrylic metal salt resin.

[0029] According to a preferred embodiment of the present invention, in step A, 4-chlororesorcinol and ethyl acetoacetate are mixed at a molar ratio of 1:0.8-2.0 to obtain a mixed solution. Simultaneously, concentrated sulfuric acid, at a concentration of 100%-200% of the total volume of the mixed solution, is cooled to -10°C to 5°C using an ice-salt bath. The mixed solution is added to the concentrated sulfuric acid under stirring and reacted for 3-7 hours. Then, ice water is slowly added under stirring to precipitate the precipitate, which is then filtered. The resulting filter cake is dissolved in a 5%-10% NaOH solution by weight. The resulting solution is then extracted 2-5 times with ethyl acetate at a volume ratio of 1:1.5-3.0. The resulting aqueous phase is acidified to pH 5 with a concentration of 10%-20% sulfuric acid by weight under ice bath cooling to precipitate the precipitate, which is then filtered. The resulting filter cake is recrystallized in an ethanol solution with a concentration of 75% or higher by volume, filtered, and dried to obtain 6-chloro-7-hydroxy-4-methylcoumarin.

[0030] According to another preferred embodiment of the present invention, in step C, the salicylaldehyde compound is salicylaldehyde, 2-hydroxy-4-methoxybenzaldehyde, 4-(diethylamino)salicylaldehyde, or 2,4-dihydroxybenzaldehyde.

[0031] According to another preferred embodiment of the present invention, in step C, the coumarin acid compound is coumarin-3-carboxylic acid, 7-methoxycoumarin-3-carboxylic acid, 7-diethylaminocoumarin-3-carboxylic acid, or 7-hydroxycoumarin-3-carboxylic acid.

[0032] According to another preferred embodiment of the present invention, in step D, the initiator is one or more initiators selected from azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, methyl ethyl ketone peroxide, ammonium persulfate, or potassium persulfate.

[0033] According to another preferred embodiment of the present invention, in step D, the solvent is one or more solvents selected from toluene, xylene, n-butanol, butyl acetate or ethyl acetate.

[0034] According to another preferred embodiment of the present invention, in step D, the chain transfer agent is n-dodecyl mercaptan, tert-dodecyl mercaptan, or an aliphatic thiol chain transfer agent.

[0035] According to another preferred embodiment of the present invention, in step E, the divalent metal oxide is zinc oxide or copper oxide; the divalent metal hydroxide is zinc hydroxide or copper hydroxide; and the solvent is N,N-dimethylformamide or dimethyl sulfoxide solvent.

[0036] The present invention also relates to the use of the coumarin-containing structured acrylic metal salt resin or the coumarin-containing structured acrylic metal salt resin prepared according to the above preparation method in marine antifouling coatings.

[0037] The invention will now be described in more detail.

[0038] This invention relates to an acrylic metal salt resin containing a coumarin structure.

[0039] Coumarin is a typical natural compound widely found in fruits, vegetables, and grasses. Current research has found that benzopyranones of coumarin possess broad bioinhibitory properties, including antibacterial, antioxidant, and antiviral effects. Coumarin-3-carboxylic acid compounds, in particular, exhibit good inhibitory effects against almost all tested bacteria (plant pathogens), with inhibition rates reaching as high as 93.11%, showing potential for marine antifouling applications. See the literature "Antibacterial activities of coumarin-3-carboxylic acid against Acidovorax citrulli", journal "Frontiers in Microbiology", Vol. 14, No. 2023. Recent research indicates that the fluorescent properties of compounds can impart excellent antifouling properties to materials. Therefore, it is possible that superior antifouling performance can be achieved through the synergistic effect of fluorescence and inherent antibacterial properties. Introducing coumarin structures with both bioinhibitory and fluorescent properties into acrylic resins could lead to the development of novel, multifunctional, synergistic, environmentally friendly self-polishing antifouling resins.

[0040] According to the present invention, the acrylic metal salt resin has the following chemical structural formula (I):

[0041]

[0042] In the formula: R1 is H, R2 is H; or R1 is CH3, R2 is H; or R1 is H, R2 is Cl;

[0043] R3 is H, -OCH3, -OH, or -Et2N;

[0044] X is Zn 2+ or Cu 2+ Metal ions;

[0045] n is a positive integer; m is 0 or a positive integer; x is 0 or a positive integer; y is a positive integer;

[0046] The number-average molecular weight of the aforementioned acrylic metal salt resin containing coumarin structure is 2,000 to 60,000, and its molecular weight distribution is 1.0 to 2.5.

[0047] The number-average molecular weight and molecular weight distribution of the acrylic metal salt resin were determined by conventional gel permeation chromatography.

[0048] The present invention also relates to a method for preparing the acrylate metal salt resin containing the coumarin structure.

[0049] The preparation steps of the preparation method are as follows:

[0050] A. Preparation of hydroxycoumarin compounds

[0051] In this step, the basic reaction for preparing hydroxycoumarin compounds is as follows:

[0052]

[0053] In the formula: R1 is H, R2 is H; or R1 is CH3, R2 is H; or R1 is H, R2 is Cl;

[0054] In this invention, the hydroxycoumarin is 7-hydroxy-4-methylcoumarin, 7-hydroxy-4,8-dimethylcoumarin, or 6-chloro-7-hydroxy-4-methylcoumarin.

[0055] The specific preparation methods for 7-hydroxy-4-methylcoumarin or 7-hydroxy-4,8-dimethylcoumarin are as follows:

[0056] In a round-bottom flask, resorcinol or 2-methylresorcinol and ethyl acetoacetate are dissolved by stirring at a molar ratio of 1:0.8-2.0 to obtain a mixed solution. Then, ZrCl4 is slowly added to the mixed solution at 15%-25% of their total molar amount. The mixture is stirred vigorously at room temperature for 20-40 min. Then, ice water is slowly added to precipitate the precipitate. The precipitate is filtered, and the resulting filter cake is recrystallized in an ethanol solution with a concentration of more than 90% by volume. After filtration and drying, 7-hydroxy-4-methylcoumarin or 7-hydroxy-4,8-dimethylcoumarin is obtained.

[0057] In this invention, the molar ratio of resorcinol or 2-methylresorcinol to ethyl acetoacetate is 1:0.8 to 2.0. If the molar ratio of resorcinol or 2-methylresorcinol to ethyl acetoacetate is greater than 1:0.8, the reaction is incomplete and the reaction yield is low; if the molar ratio of resorcinol or 2-methylresorcinol to ethyl acetoacetate is less than 1:2.0, the excess ethyl acetoacetate does not participate in the reaction, resulting in resource waste. Therefore, a molar ratio of resorcinol or 2-methylresorcinol to ethyl acetoacetate of 1:0.8 to 2.0 is reasonable, preferably 1:1.0 to 1.8; more preferably 1:1.2 to 1.6.

[0058] The resorcinol, 2-methylresorcinol, and ethyl acetoacetate used in this invention are all products currently sold on the market, such as products sold by Shanghai Aladdin Biochemical Technology Co., Ltd. under the trade names resorcinol and 2-methylresorcinol, and products sold by Sinopharm Chemical Reagent Co., Ltd. under the trade name ethyl acetoacetate.

[0059] The main function of adding ZrCl4 to the mixture solution is to act as a catalyst for the reaction, thereby increasing the chemical reaction rate and the reaction yield.

[0060] After adding ZrCl4 to the mixture solution, it is necessary to use a conventional stirrer at a stirring speed of 300-600 rpm for 20-40 minutes. Within this range, if the stirring speed is below 300 rpm, the reactants will settle, resulting in an incomplete reaction; if the stirring speed is above 600 rpm, the reaction will proceed very vigorously. Therefore, a stirring speed of 300-600 rpm is suitable, preferably 400-500 rpm. Within this range, if the stirring time is less than 20 minutes, the reaction will be incomplete, resulting in a low yield; if the stirring time is longer than 40 minutes, it will increase reaction costs and waste resources. Therefore, a stirring time of 20-40 minutes is appropriate.

[0061] In this step, ice water is added to the reaction solution to allow the reactants to precipitate. The volume ratio of the reaction solution to ice water is generally 1:3–6. The mixture of reaction solution and ice water is allowed to stand at room temperature until the precipitate no longer increases. The precipitate is separated using a vacuum filtration device sold by Shanghai Ailang Instrument Co., Ltd. under the trade name "Water Flow Vacuum Pump". The resulting filter cake is recrystallized in an ethanol solution with a concentration of 90% or higher by volume. The main purpose of recrystallization is to obtain high-purity compounds. During recrystallization, the ratio of filter cake weight (grams) to ethanol solution volume (milliliters) is generally 1:10–20. After recrystallization, the filter cake is filtered using a filtration device sold by Shanghai Ailang Instrument Co., Ltd. under the trade name "Water Flow Vacuum Pump". The resulting filter cake is then dried to constant weight at 65°C using a drying device sold by Shanghai Yiheng Instrument Co., Ltd. under the trade name "Constant Temperature Blower Dryer". The dried product is analyzed by nuclear magnetic resonance hydrogen spectroscopy, and the results are listed in the appendix. Figure 1 With appendix Figure 2 In the middle, by the appendix Figure 1 With appendix Figure 2 The results listed confirm that the dried product is 7-hydroxy-4-methylcoumarin or 7-hydroxy-4,8-dimethylcoumarin compound.

[0062] The specific preparation method for the 6-chloro-7-hydroxy-4-methylcoumarin compound is as follows:

[0063] 4-Chlororesorcinol and ethyl acetoacetate were mixed at a molar ratio of 1:0.8–2.0 to obtain a mixture solution. Simultaneously, concentrated sulfuric acid (100%–200% of the total volume of the mixture solution) was cooled to -10°C–5°C using an ice-salt bath. The mixture solution was added to the concentrated sulfuric acid with stirring and reacted for 3–7 hours. Then, ice water was slowly added with stirring to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was dissolved in a 5%–10% (by weight) NaOH solution. The resulting solution was then extracted 2–5 times with ethyl acetate at a volume ratio of 1:1.5–3.0. The resulting aqueous phase was acidified to pH 5 with a 10%–20% (by weight) sulfuric acid solution under ice bath cooling, precipitating the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in an ethanol solution with a concentration of 75% or higher (by volume). After filtration and drying, 6-chloro-7-hydroxy-4-methylcoumarin compound was obtained.

[0064] In this preparation method, the molar ratio of 4-chlororesorcinol to ethyl acetoacetate is the same as that of resorcinol or 2-methylresorcinol to ethyl acetoacetate as described above, so it will not be repeated here.

[0065] The concentrated sulfuric acid used in this preparation method should be understood as a sulfuric acid solution with a concentration of 98% by weight.

[0066] In this preparation method, the amount of concentrated sulfuric acid used is 100% to 200% of the total volume of the mixture solution. If the amount of concentrated sulfuric acid is less than 100% of the total volume of the mixture solution, the reaction proceeds slowly and incompletely, and the reaction yield is low; if the amount of concentrated sulfuric acid is more than 200% of the total volume of the mixture solution, it leads to increased reaction costs and waste of resources; therefore, the amount of concentrated sulfuric acid used is 100% to 200% of the total volume of the mixture solution.

[0067] The mixture solution reacts with concentrated sulfuric acid at a temperature of -10℃ to 5℃ for 3 to 7 hours under stirring. If the reaction time between the mixture solution and concentrated sulfuric acid is less than 3 hours, the reaction is incomplete and the reaction yield is low; if the reaction time is longer than 7 hours, side reactions increase and the yield of the target product decreases. Therefore, a reaction time of 3 to 7 hours between the mixture solution and concentrated sulfuric acid is appropriate, preferably 4 to 6 hours.

[0068] The main purpose of precipitating the product of the reaction between the mixed solution and concentrated sulfuric acid in ice water is to terminate the reaction.

[0069] The filter cake obtained by vacuum filtration is dissolved in a 5%–10% (by weight) NaOH solution. The resulting solution is then extracted 2–5 times with ethyl acetate at a NaOH-ethyl acetate volume ratio of 1:1.5–3.0. The basic purpose of this extraction step is to transfer the NaOH to the ethyl acetate solution, leaving the product directly in the aqueous solution. When the number of extractions is 2–5, if the NaOH-ethyl acetate volume ratio is greater than 1:1.5, the product extraction will be incomplete; if the ratio is less than 1:3.0, it will result in resource waste. Therefore, a NaOH-ethyl acetate volume ratio of 1:1.5–3.0 is preferable. When the NaOH-ethyl acetate volume ratio is 1:1.5–3.0, if the number of extractions is less than 2, the product extraction will be incomplete; if the number of extractions is more than 5, it will be time-consuming and labor-intensive, resulting in resource waste. Therefore, a number of extractions of 2–5 is appropriate.

[0070] The aqueous phase obtained from the extraction was acidified to pH 5 with sulfuric acid at a concentration of 10%–20% by weight under ice bath cooling, precipitating a precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in an ethanol solution with a concentration of at least 75% by volume. After filtration and drying, the 6-chloro-7-hydroxy-4-methylcoumarin compound was obtained. The recrystallization, filtration, drying, and the equipment involved in this step have been described above and will not be repeated here.

[0071] The obtained dried matter was analyzed using the methods described above, and the results are listed in the appendix. Figure 3 , by appendix Figure 3The results listed confirm that the dried product is a 6-chloro-7-hydroxy-4-methylcoumarin compound.

[0072] B. Preparation of coumarin compounds containing C=C double bonds

[0073] The hydroxycoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask at a molar ratio of 30–40:40–55:40–55:0.7–1.0. Then, acetone solvent was added to the reactants at a ratio of 10–20:150–200 (total mass of reactants in grams to acetone in milliliters). The mixture was then heated under reflux at 50–70°C for 15–24 h. After filtration, the collected filtrate was subjected to vacuum rotary evaporation at 40–50°C and a vacuum degree of -0.07–-0.10 kPa to obtain a coumarin compound containing a C=C double bond structure.

[0074] In this step, the basic reaction for preparing coumarin compounds containing C=C double bonds is as follows:

[0075]

[0076] In the formula: R1 is H, R2 is H; or R1 is CH3, R2 is H; or R1 is H, R2 is Cl;

[0077] In this basic reaction, K2CO3 mainly plays the role of increasing the leaving ability of the leaving group in the substrate and enhancing the nucleophilicity of the nucleophile; 3-bromopropene mainly plays the role of providing a double bond as a reactant; and KI mainly plays the role of acting as a catalyst to change the transition state of the reaction, lower the activation energy of the reaction, and enable the reaction to proceed smoothly.

[0078] The molar ratio of the hydroxycoumarin compound, K₂CO₃, 3-bromopropene, and KI reactant is 30–40:40–55:40–55:0.7–1.0. When the amounts of K₂CO₃, 3-bromopropene, and KI reactant are within the aforementioned range, if the amount of the hydroxycoumarin compound is less than 30%, the reaction yield will be low due to the low reactant content; if the amount of the hydroxycoumarin compound is greater than 40%, the reactant content will be excessive, leading to resource waste. Therefore, an amount of 30–40% of the hydroxycoumarin compound is reasonable, and preferably 32–38%.

[0079] When the amounts of hydroxycoumarin compound, 3-bromopropene, and KI reactant are within the aforementioned range, if the amount of K2CO3 is less than 40, the reaction will be incomplete due to insufficient alkali to promote the reaction, resulting in a low reaction yield. If the amount of K2CO3 is greater than 55, some side reactions will occur, leading to a decrease in the reaction yield. Therefore, an amount of K2CO3 of 40-55 is suitable, preferably 44-52.

[0080] When the amounts of the hydroxycoumarin compound, K2CO3, and KI reactants are within the aforementioned range, if the amount of 3-bromopropene is less than 40, the reaction yield will be low due to the low reactant content; if the amount of 3-bromopropene is greater than 55, the reactant will be excessive, leading to a waste of resources. Therefore, an amount of 40 to 55 of 3-bromopropene is appropriate, preferably 42 to 48.

[0081] When the amounts of the hydroxycoumarin compound, K2CO3, and 3-bromopropene reactant are within the aforementioned range, if the amount of KI is less than 0.7, the catalyst will not provide adequate catalysis, preventing the reaction from proceeding smoothly and resulting in incomplete reaction and low yield. If the amount of KI is greater than 1.0, some side reactions will occur, thus affecting the yield of the reaction. Therefore, an amount of KI of 0.7 to 1.0 is appropriate, preferably 0.8 to 0.9.

[0082] Preferably, the molar ratio of the hydroxycoumarin compound, K2CO3, 3-bromopropene and KI reactant is 32-38:44-52:42-48:0.8-0.9.

[0083] In this step, the ratio of the total mass (grams) of the hydroxycoumarin compound, K₂CO₃, 3-bromopropene, and KI reactants to the volume (mL) of acetone is 10–20:150–200. When the total mass of the hydroxycoumarin compound, K₂CO₃, 3-bromopropene, and KI reactants is 10–20, if the amount of acetone used is less than 150, these reactants will not dissolve completely, resulting in a low reaction yield; if the amount of acetone used is more than 200, the concentration of these reactants will be too low, which will also lead to a lower reaction yield and waste of resources. Therefore, an amount of acetone of 150–200 is suitable, preferably 160–190.

[0084] When the amount of acetone used is 150-200, if the total mass of the reactants containing hydroxycoumarin, K2CO3, 3-bromopropene, and KI is less than 10, the concentration of these reactants will decrease significantly, leading to a significant decrease in the yield of the reaction. If the total mass of the reactants containing hydroxycoumarin, K2CO3, 3-bromopropene, and KI is greater than 20, these reactants cannot dissolve sufficiently, resulting in a low yield of the reaction. Therefore, a total mass of 10-20 of the reactants containing hydroxycoumarin, K2CO3, 3-bromopropene, and KI is appropriate, and preferably 12-18.

[0085] The reaction mixture of hydroxycoumarin compound, K2CO3, 3-bromopropene, and KI is heated under reflux in acetone solvent at a temperature of 50°C–70°C for 15–24 hours. In this step, if the reaction temperature is below 50°C within the specified range, the reaction will be incomplete, resulting in a significantly lower product yield. If the reaction temperature is above 70°C, side reactions will occur due to the high temperature, further reducing the yield of the target product. Therefore, a reaction temperature of 50°C–70°C is feasible, preferably 56°C–65°C. If the reaction time is less than 15 hours within the specified range, the reaction will be incomplete, leading to a significantly lower product yield. If the reaction time is longer than 24 hours, side reactions will occur, resulting in resource waste. Therefore, a reaction time of 15–24 hours is reasonable, preferably 18–22 hours.

[0086] After the heating and reflux reaction is completed, a vacuum filtration device sold by Shanghai Ailang Instrument Co., Ltd. under the trade name "Water Flow Vacuum Pump" is used for filtration. The collected filtrate is then vacuum evaporated using a vacuum rotary evaporator sold by Zhengzhou Keda Machinery Instrument Equipment Co., Ltd. under the trade name "Rotary Evaporator" at a temperature of 40℃~50℃ and a vacuum degree of -0.07~-0.10kPa.

[0087] The product was dried at 65°C until constant weight using a drying device sold by Shanghai Yiheng Instrument Co., Ltd. under the trade name "Constant Temperature Blower Dryer". The dried product was analyzed using conventional nuclear magnetic resonance (NMR) 1H spectroscopy, and the results are listed in the appendix. Figure 4-6 , by appendix Figure 4-6 The results listed confirm that the dried product is 7-allyloxy-4-methylcoumarin, 7-allyloxy-4,8-dimethylcoumarin, and 6-chloro-7-allyloxy-4-methylcoumarin.

[0088] C. Preparation of coumarin acid compounds

[0089] Salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:20-25. Then, 350%-500% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and stirred until homogeneous. The mixture was then reacted at 100-120°C for 2-6 hours. The mixture was then filtered and dried to obtain the coumarin acid compound.

[0090] In this step, the basic reaction for preparing coumarin acid compounds is as follows:

[0091]

[0092] In the formula: R3 is H, -OCH3, -OH or -Et2N;

[0093] According to the present invention, the salicylaldehyde compound is salicylaldehyde, 2-hydroxy-4-methoxybenzaldehyde, 4-(diethylamino)salicylaldehyde, or 2,4-dihydroxybenzaldehyde, all of which are currently commercially available products, such as those sold by Shanghai Aladdin Biochemical Technology Co., Ltd. under the trade name salicylaldehyde, 2-hydroxy-4-methoxybenzaldehyde, 4-(diethylamino)salicylaldehyde, and 2,4-dihydroxybenzaldehyde. The Mischel acid used in this invention is a currently commercially available product, such as those sold by Shanghai Maclean Biochemical Technology Co., Ltd. under the trade name Mischel acid.

[0094] In this step, the molar ratio of salicylaldehyde to Michaelis acid is 20:20–25. If the molar ratio of salicylaldehyde to Michaelis acid is greater than 20:20, the reaction will be incomplete, and the yield of the reaction product will be significantly reduced; if the molar ratio of salicylaldehyde to Michaelis acid is less than 20:25, too much Michaelis acid will be used, resulting in resource waste. Therefore, a molar ratio of salicylaldehyde to Michaelis acid of 20:20–25 is appropriate.

[0095] The mass of the aqueous solvent should be 350%–500% of the total mass of the salicylaldehyde compound and Michaelis acid. If the mass of the aqueous solvent is less than 350%, the concentration of these reactants will be too high, the reaction will not proceed completely, and the yield of the reaction product will be significantly reduced. If the mass of the aqueous solvent is greater than 500%, the concentration of these reactants will be too low, and the yield of the reaction product will also be significantly reduced. Therefore, a mass of 350%–500% for the aqueous solvent is appropriate.

[0096] Salicylic aldehyde compounds react with Michaelis-Menten acid in an aqueous solvent at a temperature of 100–120°C for 2–6 hours. Within this range, if the reaction temperature is below 100°C, the reactants cannot react sufficiently, resulting in a lower product yield. If the reaction temperature is above 120°C, side reactions occur, significantly affecting the target product yield. Therefore, a reaction temperature of 100–120°C is suitable. Within this range, if the reaction time is less than 2 hours, the reactants do not react sufficiently, also reducing the product yield. If the reaction time is longer than 6 hours, side reactions occur, significantly affecting the target product yield. Therefore, a reaction time of 2–6 hours is suitable, preferably 2.8–5.1 hours.

[0097] After the reaction of salicylaldehyde compounds with Michaelis-Menten acid in an aqueous solvent is completed, the mixture needs to be filtered and dried until constant weight is achieved. The dried product is analyzed using conventional proton nuclear magnetic resonance spectroscopy, and the results are listed in the appendix. Figure 7-10 , by appendix Figure 7-10 The results listed confirm that the dried product is coumarin-3-carboxylic acid, 7-methoxycoumarin-3-carboxylic acid, 7-diethylaminocoumarin-3-carboxylic acid, or 7-hydroxycoumarin-3-carboxylic acid.

[0098] The filtration equipment used in this step is a product currently available on the market, such as the product sold by Shanghai Airong Instrument Co., Ltd. under the trade name Water Flow Air Pump.

[0099] The drying equipment used in this step is a product currently sold on the market, such as the product sold by Shanghai Yiheng Instrument Co., Ltd. under the trade name Constant Temperature Blower Dryer.

[0100] D. Synthesis of coumarin-containing acrylic prepolymers

[0101] Ethyl acrylate, butyl acrylate, acrylic acid, and a coumarin compound containing a C=C double bond structure are mixed uniformly in a molar ratio of 6:2:2:0.05-2.5 to obtain a monomer mixture. Then, 0.5%-3.2% of an initiator based on the weight of the monomer mixture is added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 100-230% of solvent, 10%-20% of the monomer mixture containing the initiator, and 0.3%-2.0% of chain transfer agent are added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture is controlled at 75℃-110℃. Then, the remaining monomer mixture containing the initiator is divided into 9-15 equal parts, and one part is added every 10-20 minutes. The reaction is carried out for 4-8 hours to obtain a viscous acrylic prepolymer containing a coumarin structure.

[0102] In this step, the basic reaction for preparing the coumarin-structured acrylic prepolymer is as follows:

[0103]

[0104] In the formula: R1 is H, R2 is H; or R1 is CH3, R2 is H; or R1 is H, R2 is Cl;

[0105] R3 is H, -OCH3, -OH, or -Et2N;

[0106] n is a positive integer; m is 0 or a positive integer; x is 0 or a positive integer; y is a positive integer;

[0107] The molar ratio of ethyl acrylate, butyl acrylate, acrylic acid, and coumarin compound containing a C=C double bond in the monomer mixture is 6:2:2:0.05–2.5. The ethyl acrylate, butyl acrylate, and acrylic acid used in this invention are commercially available products, sold by Datang Chemical Reagent Co., Ltd.

[0108] According to the present invention, the main purpose of adding an initiator to the monomer mixture is to decompose the acrylate base monomer, acrylic monomer, and coumarin-containing functional monomer into active species, thereby initiating free radical polymerization of these monomers. The initiator used in this invention is one or more initiators selected from azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, methyl ethyl ketone peroxide, ammonium persulfate, or potassium persulfate. These are all commercially available products, for example, those sold by Tianjin Damao Chemical Reagent Factory or Tianjin Hedong Hongyan Reagent Factory.

[0109] The amount of initiator added is 0.5% to 3.2% by weight of the monomer mixture. If the amount of initiator added is less than 0.5%, these monomers are difficult to polymerize to obtain acrylic prepolymer; if the amount of initiator added is more than 3.2%, the acrylic prepolymer will have a higher viscosity and shorter molecular chains, which is not conducive to the subsequent film formation of acrylic resin. Therefore, the amount of initiator added is appropriate at 0.5% to 3.2%, preferably 0.9% to 2.5%.

[0110] Then, based on the weight of the monomer mixture, 100-230% solvent, 10%-20% of the above-mentioned monomer mixture containing the initiator, and 0.3%-2.0% chain transfer agent are stirred and mixed evenly to obtain a reaction mixture, wherein: the solvent is one or more solvents selected from toluene, xylene, n-butanol, butyl acetate, or ethyl acetate, which are all currently commercially available products, such as those sold by Datang Chemical Reagent Co., Ltd.

[0111] The chain transfer agent is a dodecyl mercaptan, tert-dodecyl mercaptan, or aliphatic thiol chain transfer agent, which are all products currently sold on the market, such as those sold by Shanghai Aladdin Biochemical Technology Co., Ltd.

[0112] The reaction temperature of the reaction mixture is controlled at 75℃~110℃ so that the polymerization reaction can proceed smoothly and fully. Then, the remaining monomer mixture containing the initiator is divided into 9~15 parts and one part is added every 10~20 minutes. The purpose is to avoid agglomeration caused by excessive addition at one time or explosive polymerization caused by excessive local temperature.

[0113] After adding the remaining monomer mixture containing the initiator, the reaction needs to continue for 4 to 8 hours. If the reaction time is less than 4 hours, the prepolymerization reaction will be incomplete, and the yield of the prepolymerization product will be reduced; if the reaction time is longer than 8 hours, some side reactions will increase significantly, thus reducing the yield of the target product. Therefore, a reaction time of 4 to 8 hours is suitable, preferably 4.6 to 7.2 hours.

[0114] E. Synthesis of coumarin-containing acrylate metal salt resins

[0115] The coumarin-structured acrylic prepolymer obtained in step D is cooled to below 70°C. Then, a metal oxide or hydroxide and the coumarin acid compound obtained in step C are added. The amount of each added is 0.8 to 1.5 times the molar amount of acrylic acid in the coumarin-structured acrylic prepolymer, and the molar ratio of the metal oxide or hydroxide to the coumarin acid compound is 1:0.8 to 1.5. The mixture is thoroughly mixed, and then 150% to 200% of the solvent by weight of the mixture is added to the resulting mixture. The mixture is then reacted at 100°C to 130°C for 3 to 5 days to obtain a coumarin-structured acrylic metal salt resin.

[0116] In this step, the basic reaction for preparing coumarin-containing acrylate metal salt resin is as follows:

[0117]

[0118] In the formula:

[0119] R1 is H, R2 is H; or R1 is CH3, R2 is H; or R1 is H, R2 is Cl;

[0120] R3 is H, -OCH3, -OH, or -Et2N;

[0121] X is Zn 2+ or Cu 2+ Metal ions;

[0122] n is a positive integer; m is 0 or a positive integer; x is 0 or a positive integer; y is a positive integer;

[0123] According to the present invention, the divalent metal oxide is zinc oxide or copper oxide; the divalent metal hydroxide is zinc hydroxide or copper hydroxide. The solvent is N,N-dimethylformamide or dimethyl sulfoxide.

[0124] The coumarin acid compound prepared by step C of the preparation method of the present invention is coumarin-3-carboxylic acid, 7-methoxycoumarin-3-carboxylic acid, 7-diethylaminocoumarin-3-carboxylic acid, or 7-hydroxycoumarin-3-carboxylic acid.

[0125] In this step, the amounts of metal oxide, metal hydroxide, and coumarin acid compound used are 0.8 to 1.5 times the molar amount of acrylic acid in the coumarin-structured acrylic acid prepolymer, respectively. If the amount of any one of these compounds is less than 0.8 times, a large amount of prepolymer will remain in the acrylic metal salt resin; if the amount of any one of these compounds is greater than 1.5 times, a large amount of by-reaction products will be present in the acrylic metal salt resin. Therefore, it is feasible to use an amount of 0.8 to 1.5 times for any one of these compounds.

[0126] Furthermore, the molar ratio of metal oxide or metal hydroxide to coumarin acid compound is 1:0.8–1.5. If the molar ratio of metal oxide or metal hydroxide to coumarin acid compound is greater than 1:0.8, the polymerization reaction will be incomplete; if the molar ratio is less than 1:1.5, a large amount of organic acid monomers will remain in the polymer solution. Therefore, a molar ratio of metal oxide or metal hydroxide to coumarin acid compound of 1:0.8–1.5 is reasonable.

[0127] The amount of solvent used is 150% to 200% of the weight of the mixture obtained in this step. If the amount of solvent is less than 150% of the weight of the mixture obtained in this step, it will hinder heat transfer within the system, thus affecting the smooth progress of the reaction. If the amount of solvent is more than 200% of the weight of the mixture obtained in this step, it will result in excessively low viscosity of the acrylic metal salt resin, affecting its film-forming properties. At the same time, excessive organic solvent will affect the environment and waste resources. Therefore, it is feasible to use 150% to 200% of the weight of the mixture obtained in this step.

[0128] The metal oxide, metal hydroxide, and coumarin acid compound are reacted in the solvent at a temperature of 100℃ to 130℃ for 3 to 5 days to obtain the coumarin-structured acrylate metal salt resin. When the reaction time is within the specified range, if the reaction temperature is below 100℃, the reaction rate is low and incomplete, resulting in a significantly reduced yield. If the reaction temperature is above 130℃, the resulting product has a low molecular weight, increased side reactions, and wasted resources. Therefore, a reaction temperature of 100℃ to 130℃ is reasonable, preferably 108℃ to 122℃. When the reaction temperature is within the specified range, if the reaction time is less than 3 days, the degree of polymerization of the reactants is low; if the reaction time is longer than 5 days, side reactions increase. Therefore, a reaction time of 3 to 5 days is suitable, preferably 3.5 to 4.5 days.

[0129] The product obtained from this preparation step was detected using conventional proton nuclear magnetic resonance spectroscopy and conventional Fourier transform infrared spectroscopy. The detection results are listed in the appendix. Figure 11-12 , by appendix Figure 11 With appendix Figure 12 The results listed confirm that the product is a coumarin-structured acrylate metal salt resin.

[0130] The present invention also relates to the use of the coumarin-containing structured acrylic metal salt resin or the coumarin-containing structured acrylic metal salt resin prepared according to the above preparation method in marine antifouling coatings.

[0131] According to the national standard "Test Method for Shallow Sea Immersion of Antifouling Paint Samples" (GB / T 5370-2007), the antifouling performance of the coumarin-structured acrylic metal salt resin of this invention was tested in Qingdao, Shandong Province. Specific test results are detailed in the following embodiments section. These test results clearly demonstrate that the coumarin-structured acrylic metal salt resin of this invention has an antifouling period of at least 110 days in a marine environment.

[0132] The beneficial effects of this invention are:

[0133] The coumarin-containing acrylate metal salt resin synthesized in this invention is an environmentally friendly antifouling resin with a simple preparation process and readily available raw materials. Furthermore, by grafting natural antifouling agents into the acrylate metal salt resin, a coumarin-containing acrylate metal salt resin is prepared, exhibiting antifouling effects that combine antibacterial, fluorescent antifouling, and self-polishing antifouling properties, thus enhancing the resin's antifouling performance. Through real-sea antifouling tests, this coating demonstrates a static real-sea antifouling effect of over 110 days. [Attached Image Description]

[0134] Figure 1 The NMR spectrum of 7-hydroxy-4-methylcoumarin is shown below.

[0135] Figure 2 The hydrogen NMR spectrum of 7-hydroxy-4,8-dimethylcoumarin;

[0136] Figure 3 The 1H NMR spectrum of 6-chloro-7-hydroxy-4-methylcoumarin;

[0137] Figure 4 The NMR spectrum of 7-allyloxy-4-methylcoumarin is shown below.

[0138] Figure 5 The 1H NMR spectrum of 7-allyloxy-4,8-dimethylcoumarin;

[0139] Figure 6 The 1H NMR spectrum of 6-chloro-7-allyloxy-4-methylcoumarin;

[0140] Figure 7 The 1H NMR spectrum of coumarin-3-carboxylic acid;

[0141] Figure 8 The 1H NMR spectrum of 7-methoxycoumarin-3-carboxylic acid;

[0142] Figure 9 The 1H NMR spectrum of 7-diethylaminocoumarin-3-carboxylic acid;

[0143] Figure 10 The 1H NMR spectrum of 7-hydroxycoumarin-3-carboxylic acid;

[0144] Figure 11 The 1H NMR spectrum of the metal salt of acrylic acid;

[0145] Figure 12 This is the Fourier transform infrared spectrum of the acrylic metal salt.

[0146] Figure 13 This is a real-world rendering of acrylic metal salts.

Detailed Implementation Methods

[0147] The invention will be better understood through the following examples.

[0148] Example 1: Preparation of acrylic metal salt resin containing coumarin structure according to the present invention

[0149] The implementation steps of this embodiment are as follows:

[0150] A. Preparation of hydroxycoumarin compounds

[0151] In a round-bottom flask, resorcinol and ethyl acetoacetate were dissolved by stirring at a molar ratio of 1:1:1.2 to obtain a mixed solution. Then, ZrCl4 was slowly added to the mixed solution at 18% of their total molar amount. The mixture was stirred vigorously at room temperature for 35 min. Then, ice water was slowly added to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in a 90% ethanol solution by volume. After filtration and drying, 7-hydroxy-4-methylcoumarin was obtained.

[0152] B. Preparation of coumarin compounds containing C=C double bonds

[0153] The 7-hydroxy-4-methylcoumarin, K2CO3, 3-bromopropene, and KI reactants prepared in step A were added to a round-bottom flask in a molar ratio of 35:48:48:0.9. Then, acetone solvent was added to the reactants in a ratio of 15:180 (total mass of reactants in grams) to acetone in milliliters. The mixture was then heated under reflux at 60°C for 20 hours, filtered, and the collected filtrate was subjected to vacuum rotary evaporation at 50°C and a vacuum degree of -0.07 kPa to obtain 7-allyloxy-4-methylcoumarin.

[0154] C. Preparation of coumarin acid compounds

[0155] Salicylaldehyde and Michaelis-Mears acid were added to a round-bottom flask at a molar ratio of 20:22. Then, 400% of the total mass of the salicylaldehyde compound and Michaelis-Mears acid was added as an aqueous solvent. The mixture was stirred and mixed evenly. The mixture was then reacted at 112°C for 4 hours. After filtration and drying, coumarin-3-carboxylic acid compound was obtained.

[0156] D. Synthesis of coumarin-containing acrylic prepolymers

[0157] Ethyl acrylate, butyl acrylate, acrylic acid, and the 7-allyloxy-4-methylcoumarin prepared above were mixed uniformly in a molar ratio of 6:2:2:1.0 to obtain a monomer mixture. Then, 1.1% of azobisisobutyronitrile initiator based on the weight of the monomer mixture was added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 150% toluene solvent, 14% of the monomer mixture containing the initiator, and 1.3% n-dodecyl mercaptan chain transfer agent were added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture was controlled at 96°C. Then, the remaining monomer mixture containing the initiator was divided into 10 equal parts, and one part was added every 20 minutes. The reaction was carried out for 6 hours to obtain a viscous acrylic prepolymer containing the 7-allyloxy-4-methylcoumarin structure.

[0158] E. Synthesis of coumarin-containing acrylate metal salt resins

[0159] The coumarin-containing acrylic prepolymer obtained in step D was cooled to 60°C. Then, zinc oxide and the coumarin-3-carboxylic acid compound obtained in step C were added. The amount of each added was 1.0 times the molar amount of acrylic acid in the coumarin-containing acrylic prepolymer, and the molar ratio of zinc oxide to coumarin acid compound was 1:1.3. The mixture was mixed evenly, and then 150% of N,N-dimethylformamide solvent by weight of the mixture was added to the resulting mixture. The mixture was then reacted at 100°C for 4 days to obtain the coumarin-containing acrylic metal salt resin.

[0160] The antifouling performance of the coumarin-containing acrylic metal salt resin prepared in this embodiment was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 It has an antifouling cycle of over 110 days in marine environments.

[0161] Example 2: Preparation of acrylic metal salt resin containing coumarin structure according to the present invention

[0162] The implementation steps of this embodiment are as follows:

[0163] A. Preparation of hydroxycoumarin compounds

[0164] In a round-bottom flask, 2-methylresorcinol and ethyl acetoacetate were dissolved by stirring at a molar ratio of 1:0.8 to obtain a mixed solution. Then, ZrCl4 was slowly added to the mixed solution at 22% of their total molar amount. The mixture was stirred vigorously at room temperature for 20 min. Then, ice water was slowly added to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in a 92% ethanol solution by volume. After filtration and drying, 7-hydroxy-4,8-dimethylcoumarin compound was obtained.

[0165] B. Preparation of coumarin compounds containing C=C double bonds

[0166] The 7-hydroxy-4,8-dimethylcoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask in a molar ratio of 30:52:43:0.7. Then, acetone solvent was added to the reactants at a ratio of 18:200 (total mass of reactants in grams to acetone in milliliters). The mixture was then heated under reflux at 54°C for 24 hours, filtered, and the collected filtrate was subjected to vacuum rotary evaporation at 44°C and a vacuum degree of -0.09 kPa to obtain the 7-allyloxy-4,8-dimethylcoumarin compound.

[0167] C. Preparation of coumarin acid compounds

[0168] 2-Hydroxy-4-methoxybenzaldehyde salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:24. Then, 360% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and mixed evenly. The mixture was then reacted at 116°C for 3 hours. After filtration and drying, 7-methoxycoumarin-3-carboxylic acid compound was obtained.

[0169] D. Synthesis of coumarin-containing acrylic prepolymers

[0170] Ethyl acrylate, butyl acrylate, acrylic acid, and the 7-allyloxy-4,8-dimethylcoumarin compound prepared above were mixed uniformly in a molar ratio of 6:2:2:1.5 to obtain a monomer mixture. Then, 0.5% of azobisisobutyronitrile initiator based on the weight of the monomer mixture was added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 230% xylene solvent, 10% of the monomer mixture containing the initiator, and 0.5% tert-dodecyl mercaptan chain transfer agent were added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture was controlled at 75°C. Then, the remaining monomer mixture containing the initiator was divided into 9 equal parts, and one part was added every 15 minutes. The reaction was carried out for another 4 hours to obtain a viscous acrylic prepolymer containing the 7-allyloxy-4,8-dimethylcoumarin structure.

[0171] E. Synthesis of coumarin-containing acrylate metal salt resins

[0172] The coumarin-containing acrylic prepolymer obtained in step D was cooled to 68°C. Then, copper oxide and the 7-methoxycoumarin-3-carboxylic acid compound obtained in step C were added. The amount of each compound added was 0.8 times the molar amount of acrylic acid in the coumarin-containing acrylic prepolymer, and the molar ratio of copper oxide to coumarin acid compound was 1:1.0. The mixture was thoroughly mixed, and then 180% of dimethyl sulfoxide solvent by weight of the mixture was added to the resulting mixture. The mixture was then reacted at 105°C for 3 days to obtain the coumarin-containing acrylic metal salt resin.

[0173] The antifouling performance of the coumarin-containing acrylic metal salt resin prepared in this embodiment was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 It has an antifouling cycle of over 110 days in marine environments.

[0174] Example 3: Preparation of acrylic metal salt resin containing coumarin structure according to the present invention

[0175] The implementation steps of this embodiment are as follows:

[0176] A. Preparation of hydroxycoumarin compounds

[0177] In a round-bottom flask, resorcinol and ethyl acetoacetate were dissolved by stirring at a molar ratio of 1:1.6 to obtain a mixed solution. Then, ZrCl4 was slowly added to the mixed solution at 25% of their total molar amount. The mixture was stirred vigorously at room temperature for 28 min. Then, ice water was slowly added to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in a 94% ethanol solution by volume. After filtration and drying, 7-hydroxy-4-methylcoumarin compound was obtained.

[0178] B. Preparation of coumarin compounds containing C=C double bonds

[0179] The 7-hydroxy-4-methylcoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask in a molar ratio of 32:55:46:0.8. Then, acetone solvent was added to the reactants at a ratio of 20:190 (total mass of reactants in grams) to acetone in milliliters. The mixture was then heated under reflux at 58°C for 22 hours, filtered, and the collected filtrate was subjected to vacuum rotary evaporation at 42°C and a vacuum degree of -0.10 kPa to obtain the 7-allyloxy-4-methylcoumarin compound.

[0180] C. Preparation of coumarin acid compounds

[0181] 4-(diethylamino)salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:20. Then, 350% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and mixed evenly. The mixture was then reacted at 108°C for 4 hours. After filtration and drying, 7-diethylaminocoumarin-3-carboxylic acid compound was obtained.

[0182] D. Synthesis of coumarin-containing acrylic prepolymers

[0183] Ethyl acrylate, butyl acrylate, acrylic acid, and the 7-allyloxy-4-methylcoumarin compound prepared above were mixed uniformly in a molar ratio of 6:2:2:0.1 to obtain a monomer mixture. Then, 1.6% of dimethyl azobisisobutyrate initiator based on the weight of the monomer mixture was added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 100% n-butanol solvent, 16% of the monomer mixture containing the initiator, and 2.0% aliphatic thiol chain transfer agent were added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture was controlled at 82°C. Then, the remaining monomer mixture containing the initiator was divided into 12 equal parts, and one part was added every 10 minutes. The reaction was carried out for another 5 hours to obtain a viscous acrylic prepolymer containing the 7-allyloxy-4-methylcoumarin structure.

[0184] E. Synthesis of coumarin-containing acrylate metal salt resins

[0185] The coumarin-containing acrylic prepolymer obtained in step D was cooled to 65°C. Then, zinc hydroxide and the 7-diethylaminocoumarin-3-carboxylic acid compound obtained in step C were added. The amount of each compound added was 1.2 times the molar amount of acrylic acid in the coumarin-containing acrylic prepolymer, and the molar ratio of zinc hydroxide to coumarin acid compound was 1:0.8. The mixture was thoroughly mixed, and then 200% N,N-dimethylformamide solvent (by weight of the mixture) was added to the resulting mixture. The mixture was then reacted at 110°C for 5 days to obtain the coumarin-containing acrylic metal salt resin.

[0186] The antifouling performance of the coumarin-containing acrylic metal salt resin prepared in this embodiment was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 It has an antifouling cycle of over 110 days in marine environments.

[0187] Example 4: Preparation of acrylic metal salt resin containing coumarin structure according to the present invention

[0188] The implementation steps of this embodiment are as follows:

[0189] A. Preparation of hydroxycoumarin compounds

[0190] In a round-bottom flask, resorcinol and ethyl acetoacetate were dissolved by stirring at a molar ratio of 1:2.0 to obtain a mixed solution. Then, ZrCl4 was slowly added to the mixed solution at 15% of their total molar amount. The mixture was stirred vigorously at room temperature for 40 min. Then, ice water was slowly added to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in a 92% ethanol solution by volume. After filtration and drying, 7-hydroxy-4,8-dimethylcoumarin compound was obtained.

[0191] B. Preparation of coumarin compounds containing C=C double bonds

[0192] The 7-hydroxy-4,8-dimethylcoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask in a molar ratio of 36:40:52:1.0. Then, acetone solvent was added to the reactants at a ratio of 10:150 (total mass of reactants in grams) to acetone in milliliters. The mixture was then heated under reflux at 64°C for 20 h, filtered, and the collected filtrate was subjected to vacuum rotary evaporation at 48°C and a vacuum degree of -0.08 kPa to obtain the 7-allyloxy-4,8-dimethylcoumarin compound.

[0193] C. Preparation of coumarin acid compounds

[0194] 2,4-Dihydroxybenzaldehyde salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:25. Then, 490% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and mixed evenly. The mixture was then reacted at 104℃ for 5 hours. After filtration and drying, 7-hydroxycoumarin-3-carboxylic acid compound was obtained.

[0195] D. Synthesis of coumarin-containing acrylic prepolymers

[0196] Ethyl acrylate, butyl acrylate, acrylic acid, and the 7-allyloxy-4,8-dimethylcoumarin compound prepared above were mixed uniformly in a molar ratio of 6:2:2:0.5 to obtain a monomer mixture. Then, 2.2% of benzoyl peroxide initiator based on the weight of the monomer mixture was added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 125% butyl acetate solvent, 12% of the monomer mixture containing the initiator, and 0.8% n-dodecyl mercaptan chain transfer agent were added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture was controlled at 104°C. Then, the remaining monomer mixture containing the initiator was divided into 15 equal parts, and one part was added every 12 minutes. The reaction was carried out for 8 hours to obtain a viscous acrylic prepolymer containing the 7-allyloxy-4,8-dimethylcoumarin structure.

[0197] E. Synthesis of coumarin-containing acrylate metal salt resins

[0198] The coumarin-containing acrylic prepolymer obtained in step D was cooled to 62°C. Then, copper hydroxide and the 7-hydroxycoumarin-3-carboxylic acid compound obtained in step C were added. The amount of each compound added was 1.5 times the molar amount of acrylic acid in the coumarin-containing acrylic prepolymer, and the molar ratio of copper hydroxide to coumarin acid compound was 1:1.2. The mixture was thoroughly mixed, and then 190% of dimethyl sulfoxide solvent by weight of the mixture was added to the resulting mixture. The mixture was then reacted at 116°C for 3 days to obtain the coumarin-containing acrylic metal salt resin.

[0199] The antifouling performance of the coumarin-containing acrylic metal salt resin prepared in this embodiment was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 It has an antifouling cycle of over 110 days in marine environments.

[0200] Example 5: Preparation of acrylic metal salt resin containing coumarin structure according to the present invention

[0201] The implementation steps of this embodiment are as follows:

[0202] A. Preparation of hydroxycoumarin compounds

[0203] In a round-bottom flask, 4-chlororesorcinol and ethyl acetoacetate were mixed at a molar ratio of 1:2.0 to obtain a mixed solution. Simultaneously, 100% concentrated sulfuric acid (based on the total volume of the mixed solution) was cooled to -10°C using an ice-salt bath. The mixed solution was added to the concentrated sulfuric acid with stirring and reacted for 7 hours. Then, ice water was slowly added with stirring to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was dissolved in a 5% NaOH solution (by weight). The resulting solution was then extracted twice with ethyl acetate at a volume ratio of 1:1.5. The resulting aqueous phase was acidified to pH 5 with 20% sulfuric acid (by weight) under ice bath cooling, precipitating the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in an 80% ethanol solution (by volume). After filtration and drying, 6-chloro-7-hydroxy-4-methylcoumarin compound was obtained.

[0204] B. Preparation of coumarin compounds containing C=C double bonds

[0205] The 6-chloro-7-hydroxy-4-methylcoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask in a molar ratio of 40:43:55:0.8. Then, acetone solvent was added to the reactants in a ratio of 12:160 (total mass of reactants in grams to acetone in milliliters). The mixture was then heated under reflux at 70°C for 15 hours, filtered, and the collected filtrate was subjected to vacuum rotary evaporation at 46°C and a vacuum degree of -0.09 kPa to obtain the 6-chloro-7-allyloxy-4-methylcoumarin compound.

[0206] C. Preparation of coumarin acid compounds

[0207] 2-Hydroxy-4-methoxybenzaldehyde salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:23. Then, 500% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and mixed evenly. The mixture was then reacted at 120°C for 2 hours. After filtration and drying, 7-hydroxycoumarin-3-carboxylic acid compound was obtained.

[0208] D. Synthesis of coumarin-containing acrylic prepolymers

[0209] Ethyl acrylate, butyl acrylate, acrylic acid, and the 6-chloro-7-allyloxy-4-methylcoumarin compound prepared above were mixed uniformly in a molar ratio of 6:2:2:2.5 to obtain a monomer mixture. Then, 2.7% of benzoyl tert-butyl peroxide initiator was added based on the weight of the monomer mixture, and the mixture was mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 180% ethyl acetate solvent, 18% of the monomer mixture containing the initiator, and 1.0% tert-dodecyl mercaptan chain transfer agent were added based on the weight of the monomer mixture, and the mixture was stirred uniformly. The reaction temperature of the reaction mixture was controlled at 110°C. Then, the remaining monomer mixture containing the initiator was divided into 14 equal parts, and one part was added every 18 minutes. The reaction was carried out for another 6 hours to obtain a viscous acrylic prepolymer containing the 6-chloro-7-allyloxy-4-methylcoumarin structure.

[0210] E. Synthesis of coumarin-containing acrylate metal salt resins

[0211] The coumarin-containing acrylic prepolymer obtained in step D was cooled to 70°C. Then, copper oxide and the 7-methoxycoumarin-3-carboxylic acid compound obtained in step C were added. The amount of each added was 1.3 times the molar amount of acrylic acid in the coumarin-containing acrylic prepolymer, and the molar ratio of copper oxide to coumarin acid compound was 1:1.5. The mixture was stirred evenly, and then 170% of dimethyl sulfoxide solvent by weight of the mixture was added to the resulting mixture. The mixture was then reacted at 124°C for 4 days to obtain the coumarin-containing acrylic metal salt resin.

[0212] The antifouling performance of the coumarin-containing acrylic metal salt resin prepared in this embodiment was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 It has an antifouling cycle of over 110 days in marine environments.

[0213] Example 6: Preparation of acrylic metal salt resin containing coumarin structure according to the present invention

[0214] The implementation steps of this embodiment are as follows:

[0215] A. Preparation of hydroxycoumarin compounds

[0216] In a round-bottom flask, 4-chlororesorcinol and ethyl acetoacetate were mixed at a molar ratio of 1:1.2 to obtain a mixed solution. Simultaneously, concentrated sulfuric acid (200% by weight of the total volume of the mixed solution) was cooled to -5°C using an ice-salt bath. The mixed solution was added to the concentrated sulfuric acid with stirring and reacted for 7 hours. Then, ice water was slowly added with stirring to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was dissolved in a 10% NaOH solution. The resulting solution was then extracted five times with ethyl acetate at a volume ratio of 1:3.0. The resulting aqueous phase was acidified to pH 5 with 10% sulfuric acid under ice bath cooling to precipitate the precipitate. The precipitate was filtered, and the resulting filter cake was recrystallized in a 75% ethanol solution. After filtration and drying, 6-chloro-7-hydroxy-4-methylcoumarin compound was obtained.

[0217] B. Preparation of coumarin compounds containing C=C double bonds

[0218] The 6-chloro-7-hydroxy-4-methylcoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask in a molar ratio of 38:46:55:0.9. Then, acetone solvent was added to the reactants in a ratio of 14:170 (total mass of reactants in grams) to acetone in milliliters. The mixture was then heated under reflux at 68°C for 18 hours, filtered, and the collected filtrate was subjected to vacuum rotary evaporation at 40°C and a vacuum of -0.07 kPa to obtain the 6-chloro-7-allyloxy-4-methylcoumarin compound.

[0219] C. Preparation of coumarin acid compounds

[0220] 2,4-Dihydroxybenzaldehyde salicylaldehyde compound and Michaelis acid were added to a round-bottom flask at a molar ratio of 20:21. Then, 480% of the total mass of salicylaldehyde compound and Michaelis acid was added as an aqueous solvent. The mixture was stirred and mixed evenly. The mixture was then reacted at 100°C for 6 hours. After filtration and drying, 7-methoxycoumarin-3-carboxylic acid compound was obtained.

[0221] D. Synthesis of coumarin-containing acrylic prepolymers

[0222] Ethyl acrylate, butyl acrylate, acrylic acid, and the 6-chloro-7-allyloxy-4-methylcoumarin compound prepared above were mixed uniformly in a molar ratio of 6:2:2:2.0 to obtain a monomer mixture. Then, 3.2% of ammonium persulfate initiator based on the weight of the monomer mixture was added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 205% of a toluene and n-butanol mixture (weight ratio 4:1), 20% of the monomer mixture containing the initiator, and 1.6% of n-dodecyl mercaptan chain transfer agent were added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture was controlled at 90°C. Then, the remaining monomer mixture containing the initiator was divided into 13 equal parts, and one part was added every 14 minutes. The reaction was carried out for 7 hours to obtain a viscous 6-chloro-7-allyloxy-4-methylcoumarin structured acrylic prepolymer.

[0223] E. Synthesis of coumarin-containing acrylate metal salt resins

[0224] The coumarin-containing acrylic prepolymer obtained in step D was cooled to 66°C. Then, zinc hydroxide and the 7-hydroxycoumarin-3-carboxylic acid compound obtained in step C were added. The amount of each added was 1.4 times the molar amount of acrylic acid in the coumarin-containing acrylic prepolymer, and the molar ratio of zinc hydroxide to coumarin acid compound was 1:1.4. The mixture was stirred evenly, and then 160% of N,N-dimethylformamide solvent by weight of the mixture was added to the resulting mixture. The mixture was then reacted at 130°C for 5 days to obtain the coumarin-containing acrylic metal salt resin.

[0225] The antifouling performance of the coumarin-containing acrylic metal salt resin prepared in this embodiment was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 It has an antifouling cycle of over 110 days in marine environments.

[0226] Comparative Example 1: Preparation of Acrylic Metal Salt Resin

[0227] The implementation method of this comparative example is the same as implementation steps D and E of Example 1, except that 7-allyloxy-4-methylcoumarin compound is not used in implementation step D, and coumarin-3-carboxylic acid compound is not used in implementation step E.

[0228] The antifouling performance of the acrylic metal salt resin prepared in this comparative example was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 Its antifouling cycle in marine environments is far less than 110 days.

[0229] Comparative Example 2: Preparation of Acrylic Metal Salt Resin

[0230] The implementation method of this comparative example is the same as the implementation steps D and E of Example 3, except that 7-allyloxy-4-methylcoumarin compound is not used in implementation step D, and 7-diethylaminocoumarin-3-carboxylic acid compound is not used in implementation step E.

[0231] The antifouling performance of the acrylic metal salt resin prepared in this comparative example was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 Its antifouling cycle in marine environments is far less than 110 days.

[0232] Comparative Example 3: Preparation of Acrylic Metal Salt Resin

[0233] The implementation method of this comparative example is the same as that of Example 5 in steps D and E, except that step D does not use a compound containing 6-chloro-7-allyloxy-4-methylammonium oleoresin, and step E does not use a compound containing 7-hydroxycoumarin-3-carboxylic acid.

[0234] The antifouling performance of the acrylic metal salt resin prepared in this comparative example was tested according to the method described in this application specification. Its actual marine antifouling effect is shown in the appendix. Figure 13 Its antifouling cycle in marine environments is far less than 110 days.

[0235] Appendix Figure 13 These are actual marine antifouling effects of acrylic metal salt resin, as shown in the attached image. Figure 13 As can be seen from the actual marine antifouling conditions of Examples 1-6 and Comparative Examples 1-3, the antifouling period of the acrylate metal salt resin containing the coumarin structure in the actual marine environment exceeds 110 days, which is much longer than that of the acrylate metal salt resin without the coumarin structure.

Claims

1. A method for preparing an acrylic metal salt resin containing a coumarin structure, characterized in that... The preparation steps of the preparation method are as follows: A. Preparation of hydroxycoumarin compounds In a round-bottom flask, resorcinol or 2-methylresorcinol and ethyl acetoacetate are dissolved by stirring at a molar ratio of 1:0.8-2.0 to obtain a mixed solution. Then, ZrCl4 is slowly added to the mixed solution at 15%-25% of their total molar amount. The mixture is stirred vigorously at room temperature for 20-40 min. Then, ice water is slowly added to precipitate the precipitate. The precipitate is filtered, and the resulting filter cake is recrystallized in an ethanol solution with a concentration of more than 90% by volume. After filtration and drying, 7-hydroxy-4-methylcoumarin or 7-hydroxy-4,8-dimethylcoumarin is obtained. B. Preparation of coumarin compounds containing C=C double bonds The hydroxycoumarin compound prepared in step A, K2CO3, 3-bromopropene, and KI reactants were added to a round-bottom flask at a molar ratio of 30–40:40–55:40–55:0.7–1.

0. Then, acetone solvent was added to the reactants at a ratio of 10–20:150–200 (total mass of reactants in grams to acetone in milliliters). The mixture was then heated under reflux at 50–70°C for 15–24 h. After filtration, the collected filtrate was subjected to vacuum rotary evaporation at 40–50°C and a vacuum degree of -0.07–-0.10 kPa to obtain a coumarin compound containing a C=C double bond structure. C. Preparation of coumarin acid compounds Salicylic aldehyde compound and Michaelis-Menten acid are added to a round-bottom flask at a molar ratio of 20:20-25. The salicylic aldehyde compound is salicylic aldehyde, 2-hydroxy-4-methoxybenzaldehyde, 4-(diethylamino)salicylic aldehyde, or 2,4-dihydroxybenzaldehyde. Then, 350%-500% (based on the total mass of the salicylic aldehyde compound and Michaelis-Menten acid) of aqueous solvent is added, and the mixture is stirred until homogeneous. The mixture is then reacted at 100-120°C for 2-6 hours. After filtration and drying, the coumarin acid compound is obtained. The coumarin acid compound is coumarin-3-carboxylic acid, 7-methoxycoumarin-3-carboxylic acid, 7-diethylaminocoumarin-3-carboxylic acid, or 7-hydroxycoumarin-3-carboxylic acid. D. Synthesis of coumarin-containing acrylic prepolymers Ethyl acrylate, butyl acrylate, acrylic acid, and a coumarin compound containing a C=C double bond structure are mixed uniformly in a molar ratio of 6:2:2:0.05-2.5 to obtain a monomer mixture. Then, 0.5%-3.2% of an initiator based on the weight of the monomer mixture is added and mixed uniformly to obtain a monomer mixture containing the initiator. In a round-bottom flask, 100-230% of solvent, 10%-20% of the monomer mixture containing the initiator, and 0.3%-2.0% of chain transfer agent are added based on the weight of the monomer mixture and stirred uniformly. The reaction temperature of the reaction mixture is controlled at 75℃-110℃. Then, the remaining monomer mixture containing the initiator is divided into 9-15 equal parts, and one part is added every 10-20 minutes. The reaction is carried out for 4-8 hours to obtain a viscous acrylic prepolymer containing a coumarin structure. E. Synthesis of coumarin-containing acrylate metal salt resins The coumarin-structured acrylic prepolymer obtained in step D is cooled to below 70°C. Then, zinc oxide, copper oxide, zinc hydroxide, or copper hydroxide and the coumarin acid compound obtained in step C are added. The amount of each added is 0.8 to 1.5 times the molar amount of acrylic acid in the coumarin-structured acrylic prepolymer, and the molar ratio of zinc oxide, copper oxide, zinc hydroxide, or copper hydroxide to the coumarin acid compound is 1:0.8 to 1.

5. The mixture is thoroughly mixed, and then 150% to 200% of the solvent by weight of the mixture is added to the resulting mixture. The mixture is then reacted at 100°C to 130°C for 3 to 5 days to obtain a coumarin-structured acrylic metal salt resin.

2. The preparation method according to claim 1, characterized in that... In step D, the initiator is one or more initiators selected from azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, methyl ethyl ketone peroxide, ammonium persulfate, or potassium persulfate.

3. The preparation method according to claim 1, characterized in that... In step D, the solvent is one or more solvents selected from toluene, xylene, n-butanol, butyl acetate, or ethyl acetate.

4. The preparation method according to claim 1, characterized in that... In step D, the chain transfer agent is an aliphatic thiol chain transfer agent.

5. The preparation method according to claim 1, characterized in that... In step D, the chain transfer agent is n-dodecyl mercaptan or tert-dodecyl mercaptan.

6. The preparation method according to claim 1, characterized in that... In step E, the solvent is N,N-dimethylformamide or dimethyl sulfoxide.

7. The use of the coumarin-containing acrylic metal salt resin prepared by the preparation method according to any one of claims 2-6 in marine antifouling coatings.

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