Rosin-modified zinc acrylate self-polishing resin, antifouling coating having resin, and synthesis method

Abstract

Disclosed in the present invention are a rosin-modified zinc acrylate self-polishing resin, an antifouling coating having the resin, and a synthesis method. Firstly, under the action of an initiator, an acrylic monomer is synthesized into an acrylic prepolymer by means of a polymerization reaction; then a rosin resin is grafted onto a side chain of the acrylic prepolymer under the action of zinc oxide and benzoic acid to obtain a zinc acrylate resin containing rosin in the side chain; then the rosin-modified zinc acrylate resin is mixed, dispersed, and ground with an antifouling agent, a pigment and filler, an auxiliary agent, and a solvent to obtain a self-polishing antifouling coating based on the rosin-modified zinc acrylate resin. The rosin-modified zinc acrylate self-polishing resin prepared in the present invention has a high degree of polymerization, a concentrated molecular weight distribution, and good plasticity and flexibility. The self-polishing antifouling coating based on the rosin-modified zinc acrylate self-polishing resin comprises cuprous oxide as a primary antifouling agent and a composite organic antifouling agent, and has stable copper ion leaching rate and relatively good antifouling effects.

Description

Rosin-modified zinc acrylate self-polishing resin, antifouling coatings containing the resin, and synthesis method thereof. Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a rosin-modified zinc acrylate self-polishing resin, an antifouling coating containing the resin, and a synthesis method thereof. Background Technology

[0002] Marine biofouling has always been a major challenge for maritime navigation. Fouling organisms increase frictional resistance, accelerate hull corrosion, and can even cause pipe blockages and leaks, severely impacting hull lifespan and navigational performance. Antifouling coatings are considered the most effective solution to marine biofouling problems. Currently, acrylic antifouling coatings dominate the market. The acrylic coatings market is experiencing continuous growth, with a projected CAGR of 4.65% from 2023 to 2028. Antifouling coatings, as a significant sub-market, are also showing strong growth momentum.

[0003] Zinc-based acrylic self-polishing antifouling coatings offer 2-5 years of antifouling performance, are free of heavy metal ions, and exhibit stable polishing rates, making them a subject of extensive research. Generally, to improve the polishing rate of the antifouling film and accelerate its surface self-renewal, thereby enhancing antifouling performance, a certain amount of rosin resin is added to the formulation. However, because rosin resin is soluble in seawater, rapid dissolution of the rosin resin on the surface during the early stages of antifouling paint service leads to excessive leaching of cuprous oxide. Summary of the Invention

[0004] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a rosin-modified zinc acrylate self-polishing resin, an anti-fouling coating having the resin, and a synthesis method.

[0005] This invention is achieved through the following technical solution:

[0006] A method for synthesizing rosin-modified zinc acrylate self-polishing resin includes the following steps:

[0007] (I) Preparation of acrylic acid prepolymer

[0008] Acrylic acid prepolymers are synthesized from acrylic acid monomers through polymerization under the action of an initiator.

[0009] (II) Synthetic rosin-modified zinc acrylate resin

[0010] In the presence of zinc oxide and benzoic acid, rosin resin is grafted onto the side chain of acrylic acid prepolymer to obtain zinc acrylate resin with rosin-containing side chain, namely rosin-modified zinc acrylate self-polishing resin.

[0011] In the above technical solution, the initiator is azobisisobutyronitrile or azobisisovalerate.

[0012] In the above technical solution, the acrylic monomers are methyl methacrylate (MMA), ethyl acrylate (EA), methacrylic acid (MAA), hydroxyethyl methacrylate (HEMA), and acrylic resin (AA).

[0013] In the above technical solution, the specific method for preparing the acrylic prepolymer in step (I) is as follows:

[0014] (i) Weigh 20 to 30 parts of xylene and 60 to 90 parts of benzoic acid, add them to a four-necked flask equipped with a stirrer, condenser, thermometer and constant pressure dropping funnel, and heat to 100°C while stirring to obtain reaction solution A.

[0015] (ii) Weigh 20 to 30 parts of methyl methacrylate (MMA), 150 to 200 parts of ethyl acrylate (EA), 5 to 10 parts of hydroxyethyl methacrylate (HEMA), 5 to 10 parts of methacrylic acid (MAA), 1 to 5 parts of acrylic acid (AA) and 3 to 5 parts of initiator, mix and stir evenly to obtain reaction solution B;

[0016] (iii) Add reaction solution B to reaction solution A at a uniform rate over 3 hours, and keep warm for 2 hours to obtain acrylic acid prepolymer.

[0017] In the above technical solution, the specific method for synthesizing rosin-modified zinc acrylate resin in step (II) is as follows:

[0018] (i) Weigh 80-120 parts of rosin liquid, 15-20 parts of benzoic acid, and 10-20 parts of zinc oxide, mix them thoroughly in a beaker, and then heat in an oven at 80°C for 1 hour to obtain reaction solution C.

[0019] (ii) Add reaction solution C to the acrylic prepolymer prepared in step (Ⅰ), raise the reaction temperature to 110°C, and keep it at 110°C for 3 hours to obtain rosin-modified zinc acrylate resin.

[0020] In the above technical solution, the rosin liquid is made by mixing rosin and xylene in a mass ratio of 1:1.

[0021] A rosin-modified zinc acrylate self-polishing resin is prepared by the aforementioned method.

[0022] A self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin, wherein the self-polishing antifouling coating comprises the following components and the weight parts of each component are as follows:

[0023] In the above technical solution, the antifouling agent includes organic antifouling agents and inorganic antifouling agents; the organic antifouling agent is any one or more of copper pyridinethione, copper pyridinethione, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-tert-butylamino-4-cyclopropylamino-6-methylthio-s-triazine, zinc ethylene didithiocarbamate, 4-bromo-2-(4-chlorophenyl)-5-trifluoromethylpyrrole-3-onitrile, N-(2,4,6-trichlorophenyl)maleimide, pyridine triphenylborane, or capsaicin; the inorganic antifouling agent is a copper-based antifouling agent, which is any one or more of copper, copper alloys, cuprous oxide, or cuprous thiocyanate.

[0024] In the above technical solution, the pigments and fillers include pigments and fillers. The pigments are any one or more of titanium dioxide, iron oxide red, zinc oxide, and iron oxide black. The fillers are any one or more of talc, calcium carbonate, precipitated barium sulfate, barite, silica fume, mica powder, kaolin, barium carbonate, magnesium silicate, or diatomaceous earth.

[0025] In the above technical solution, the additives include plasticizers and anti-settling thixotropic agents. The plasticizer is any one or more of chlorinated paraffin, dibutyl phthalate, dioctyl phthalate, epoxidized fatty acid esters, epoxidized soybean oil, dimethyl lauramide, sodium stearate, polybutyl acetate, or polyester-type polyurethane. The anti-settling thixotropic agent is any one or more of fumed silica, organobentonite, polyamide wax, or hydrogenated castor oil.

[0026] In the above technical solution, the solvent is any one or more of toluene, xylene, n-butanol, n-hexane or n-heptane.

[0027] A method for preparing a self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin is as follows: rosin-modified zinc acrylate resin is mixed with antifouling agent, pigments, fillers, additives, and solvent, dispersed at high speed, and ground to a fineness ≤80μm to prepare a self-polishing antifouling coating based on rosin-modified zinc acrylate resin.

[0028] The beneficial effects of this invention are:

[0029] This invention provides a rosin-modified zinc acrylate self-polishing resin, an antifouling coating containing this resin, and a synthesis method. Compared to conventional zinc acrylate antifouling coatings, which often have poor mechanical properties and require the addition of plasticizers to improve toughness and enhance mechanical properties, the rosin-modified zinc acrylate resin prepared in this invention increases the distance between polymer macromolecules and reduces the intermolecular forces, thereby improving the coating's toughness and acting as an internal plasticizer, providing excellent mechanical properties for the antifouling coating. Compared to conventional self-polishing antifouling coatings that directly add rosin to the formulation, the self-polishing antifouling coating prepared in this invention can overcome the problems of excessively fast polishing rate and excessive copper ion leaching in the early stages of antifouling coatings, achieving a stable polishing rate and copper ion leaching rate for the antifouling coating. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be further described below through specific embodiments.

[0031] Example 1

[0032] A self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin, specifically:

[0033] (I) Preparation of acrylic acid prepolymer

[0034] Weigh 20 parts by mass of xylene and 60 parts by mass of benzoic acid, and add them to a four-necked flask equipped with a stirrer, condenser, thermometer and constant pressure dropping funnel. Stir and heat to 100°C to obtain reaction solution A.

[0035] Weigh 22 parts by mass of methyl methacrylate, 165 parts by mass of ethyl acrylate, 6 parts by mass of hydroxyethyl methacrylate, 5.5 parts by mass of methacrylic acid, 1.5 parts by mass of acrylic acid, and 3.5 parts by mass of initiator, mix and stir evenly to obtain reaction solution B.

[0036] The reaction solution B was added dropwise to the reaction solution A at a uniform rate over 3 hours, and the mixture was kept at this temperature for 2 hours to obtain the acrylic acid prepolymer.

[0037] (II) Synthetic rosin-modified zinc acrylate resin

[0038] Weigh 97 parts by mass of rosin liquid (rosin:xylene = 1:1), 20 parts by mass of benzoic acid, and 19 parts by mass of zinc oxide. Mix and stir evenly in a beaker and heat in an oven at 80°C for 1 hour to obtain reaction solution C. Add reaction solution C to the above four-necked flask (acrylic acid prepolymer) and raise the reaction temperature to 110°C. Keep at 110°C for 3 hours to obtain rosin-modified zinc acrylate resin.

[0039] (III) Synthesis of self-polishing antifouling coatings based on rosin-modified zinc acrylate resin

[0040] A self-polishing antifouling coating based on rosin-modified zinc acrylate resin was prepared by mixing 25 parts by weight of rosin-modified zinc acrylate resin, 40 parts by weight of cuprous oxide, 7 parts by weight of copper pyridinethione, 10 parts by weight of zinc oxide, 6 parts by weight of iron oxide red, 5 parts by weight of talc, 3 parts by weight of organobentonite, 1 part by weight of polyamide wax and 10 parts by weight of xylene, dispersing at high speed and grinding to a fineness ≤80μm.

[0041] Example 2

[0042] A self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin, specifically:

[0043] (I) Preparation of acrylic acid prepolymer

[0044] Same as in Example 1;

[0045] (II) Synthetic rosin-modified zinc acrylate resin

[0046] Same as in Example 1;

[0047] (III) Synthesis of self-polishing antifouling coatings based on rosin-modified zinc acrylate resin

[0048] A self-polishing antifouling coating based on rosin-modified zinc acrylate resin was prepared by mixing 25 parts by weight of rosin-modified zinc acrylate resin, 20 parts by weight of cuprous oxide, 7 parts by weight of copper pyridinethione, 15 parts by weight of zinc oxide, 10 parts by weight of iron oxide red, 15 parts by weight of talc, 3 parts by weight of organobentonite, 1 part by weight of polyamide wax and 10 parts by weight of xylene, dispersing at high speed and grinding to a fineness ≤80μm.

[0049] Example 3

[0050] A self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin, specifically:

[0051] (I) Preparation of acrylic acid prepolymer

[0052] Same as in Example 1;

[0053] (II) Synthetic rosin-modified zinc acrylate resin

[0054] Same as in Example 1;

[0055] (III) Synthesis of self-polishing antifouling coatings based on rosin-modified zinc acrylate resin

[0056] A self-polishing antifouling coating based on rosin-modified zinc acrylate resin was prepared by mixing 25 parts by weight of rosin-modified zinc acrylate resin, 40 parts by weight of cuprous oxide, 7 parts by weight of copper pyridinethione, 10 parts by weight of zinc oxide, 6 parts by weight of iron oxide red, 5 parts by weight of talc, 3 parts by weight of organobentonite, 1 part by weight of polyamide wax, 5 parts by weight of chlorinated paraffin and 10 parts by weight of xylene, dispersing at high speed and grinding to a fineness ≤80μm.

[0057] Comparative Example 1

[0058] A self-polishing antifouling coating based on zinc acrylate self-polishing resin, specifically:

[0059] (I) Preparation of acrylic acid prepolymer

[0060] Same as in Example 1;

[0061] (II) Synthesis of Zinc Acrylate Resin

[0062] Weigh 20 parts by mass of benzoic acid and 20 parts by mass of zinc oxide, mix and stir them evenly in a beaker, and heat them in an oven at 80°C for 1 hour to obtain reaction solution C. Add reaction solution C to the above four-necked flask (acrylic acid prepolymer), and raise the reaction temperature to 110°C. Keep it at 110°C for 3 hours to obtain zinc acrylate resin.

[0063] (III) Synthesis of self-polishing antifouling coatings based on zinc acrylate resin

[0064] A self-polishing antifouling coating based on rosin-modified zinc acrylate resin was prepared by mixing 25 parts by weight of zinc acrylate resin, 40 parts by weight of cuprous oxide, 8 parts by weight of rosin, 7 parts by weight of copper pyridinethione, 10 parts by weight of zinc oxide, 6 parts by weight of iron oxide red, 5 parts by weight of talc, 3 parts by weight of organobentonite, 1 part by weight of polyamide wax, 5 parts by weight of chlorinated paraffin and 10 parts by weight of xylene, dispersing at high speed and grinding to a fineness ≤80μm.

[0065] Comparative Example 2

[0066] A self-polishing antifouling coating based on zinc acrylate self-polishing resin, specifically:

[0067] (I) Preparation of acrylic acid prepolymer

[0068] Same as in Example 1;

[0069] (II) Synthetic rosin-modified zinc acrylate resin

[0070] Same as Comparative Example 1;

[0071] (III) Synthesis of self-polishing antifouling coatings based on rosin-modified zinc acrylate resin

[0072] A self-polishing antifouling coating based on rosin-modified zinc acrylate resin was prepared by mixing 25 parts by weight of zinc acrylate resin, 40 parts by weight of cuprous oxide, 7 parts by weight of copper pyridinethione, 10 parts by weight of zinc oxide, 6 parts by weight of iron oxide red, 5 parts by weight of talc, 3 parts by weight of organobentonite, 1 part by weight of polyamide wax and 10 parts by weight of xylene, dispersing at high speed and grinding to a fineness ≤80μm.

[0073] Performance tests were conducted on the self-polishing antifouling coatings synthesized in the examples and comparative examples:

[0074] I. Impact Resistance Test

[0075] Test method: A coating film impact tester was used, referring to the standard specification "GB / T 1732-2020 Test Method for Impact Resistance of Coating Film". The sample was a 1mm tinplate with a coating thickness of 25±5μm, and the drop height was 50cm. The impact resistance of the coating film was tested. The test results are shown in Table 1.

[0076] II. Bending performance test

[0077] Referring to the ASTM D522 / D522M standard for paint film bending test, the sample was a 1mm tinplate with a coating thickness of 25±5μm. The tinplate coated with paint was bent around cylindrical mandrels of different diameters, and the paint film was observed to see if it cracked or peeled off from the substrate, thus evaluating the flexibility of the coating. The test results are shown in Table 1.

[0078] Table 1. Test results of impact resistance and flexural resistance

[0079] Comparing the test results of Examples 1-3 and Comparative Examples 1-2, Examples 1 and 2 used rosin-modified zinc acrylate resin, while Example 3 used rosin-modified zinc acrylate resin with added plasticizer (chlorinated paraffin). Examples 1-3 all passed the impact resistance test. Examples 1 and 2 showed cracking in the flexural resistance test, while Example 3 did not show cracking or peeling. Comparative Examples 1 and 2 used unmodified zinc acrylate resin. Comparative Example 1 added a plasticizer and passed the impact resistance test, but showed slight cracking in the flexural resistance test. Comparative Example 2 did not add a plasticizer, and the coating failed the impact resistance test, while peeling occurred in the flexural resistance test. The comparative results show that rosin-modified zinc acrylate resin can provide an internal plasticizing effect, improving the toughness of the coating.

[0080] III. Copper Ion Leakage Rate Test

[0081] The copper ion leaching rate was tested according to the national standard GB / T 6824-2008, "Determination of Copper Ion Leaching Rate of Antifouling Paint for Ship Bottom". Test cylinders coated with antifouling paint were immersed in a storage tank containing artificial seawater. At certain time intervals, each test cylinder was transferred to an independent leaching rate test container containing the same artificial seawater and rotated. After rotation, the cylinders were returned to the storage tank. The leachate from the test container was then collected and analyzed using atomic absorption spectrometry to determine the concentration of copper ions in the leachate, and the copper ion leaching rate of the antifouling paint was calculated. The cumulative leaching rates of the example and comparative samples were tested after 14 and 45 days, and the results are shown in Table 2.

[0082] Table 2. Test results of copper ion leaching rate

[0083] Examples 1-3 used rosin-modified zinc acrylate resin, with cuprous oxide contents of 37.38%, 18.83%, and 35.71%, respectively. Comparative Example 1 used zinc acrylate resin with added rosin, resulting in a cuprous oxide content of 33.33%. Comparative Example 2 used zinc acrylate resin with a cuprous oxide content of 37.38%. The copper ion leaching rates of Examples 1 and 3 were significantly lower than those of Comparative Examples 1 and 2, indicating that rosin-modified zinc acrylate resin can effectively control copper ion leaching and prevent excessive copper ion leaching. In Example 1, the cuprous oxide content was significantly higher than in Example 2, but the copper ion leaching rate test results were not significantly different, again indicating that rosin-modified zinc acrylate resin can effectively control copper ion leaching and is expected to reduce the amount of cuprous oxide used in antifouling coatings, thereby reducing coating costs. In Comparative Example 1, the cuprous oxide content was lower than in Comparative Example 2, but its copper ion leaching rate was significantly higher, indicating that adding rosin directly to the coating accelerates copper ion leaching.

[0084] IV. Shallow Sea Immersion Test

[0085] The test reference standard is GB / T 5370-2007, "Test Method for Shallow Sea Immersion of Antifouling Paint Samples". The immersion test was conducted in the waters off Zhoushan, Zhejiang Province, and the test period was one peak season for marine life.

[0086] Test results show that after one peak marine life season, samples from Examples 1-3 and Comparative Examples 1-2 did not exhibit any fouling organism attachment, demonstrating good antifouling performance. Comparative test results indicate that the rosin-modified zinc acrylate resin provided by this invention can effectively control the release of cuprous oxide in the antifouling coating; even with reduced cuprous oxide content, antifouling performance can still be guaranteed to a certain extent.

[0087] This invention grafts rosin resin onto zinc acrylate self-polishing resin in the form of side chains. On the one hand, this can overcome the problems of rapid polishing rate and excessive copper ion leaching caused by direct addition, and achieve "slow release" of copper ions. On the other hand, the addition of rosin resin can also play a role in internal plasticization, increasing the distance between polymer macromolecules and reducing the intermolecular forces, thereby increasing plasticity and improving the mechanical properties of antifouling coatings.

[0088] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method of synthesis of a rosin-modified zinc acrylate self-polishing resin, characterized by: Includes the following steps: (I) Preparation of acrylic acid prepolymer Acrylic acid prepolymers are synthesized from acrylic acid monomers through polymerization under the action of an initiator. (II) Synthetic rosin-modified zinc acrylate resin In the presence of zinc oxide and benzoic acid, rosin resin is grafted onto the side chain of acrylic acid prepolymer to obtain zinc acrylate resin with rosin-containing side chain, namely rosin-modified zinc acrylate self-polishing resin.

2. The rosin-modified zinc acrylate self-polishing resin according to claim 1, characterized in that: The initiator is azobisisobutyronitrile or azobisisovalerate.

3. The rosin-modified zinc acrylate self-polishing resin according to claim 1, characterized in that: The acrylic monomers are methyl methacrylate, ethyl acrylate, methacrylic acid, hydroxyethyl methacrylate, and acrylic resin.

4. The rosin-modified zinc acrylate self-polishing resin according to claim 1, characterized in that: The specific method for preparing the acrylic acid prepolymer in step (I) is as follows: (i) Weigh 20 to 30 parts of xylene and 60 to 90 parts of benzoic acid, add them to a four-necked flask equipped with a stirrer, condenser, thermometer and constant pressure dropping funnel, and heat to 100°C while stirring to obtain reaction solution A. (ii) Weigh 20 to 30 parts of methyl methacrylate, 150 to 200 parts of ethyl acrylate, 5 to 10 parts of hydroxyethyl methacrylate, 5 to 10 parts of methacrylic acid, 1 to 5 parts of acrylic acid and 3 to 5 parts of initiator, mix and stir evenly to obtain reaction solution B. (iii) Add reaction solution B to reaction solution A at a uniform rate over 3 hours, and keep warm for 2 hours to obtain acrylic acid prepolymer.

5. The rosin-modified zinc acrylate self-polishing resin according to claim 1, characterized in that: The specific method for synthesizing rosin-modified zinc acrylate resin in step (II) is as follows: (i) Weigh 80-120 parts of rosin liquid, 15-20 parts of benzoic acid, and 10-20 parts of zinc oxide, mix them thoroughly in a beaker, and then heat in an oven at 80°C for 1 hour to obtain reaction solution C. (ii) Add reaction solution C to the acrylic prepolymer prepared in step (Ⅰ), raise the reaction temperature to 110°C, and keep it at 110°C for 3 hours to obtain rosin-modified zinc acrylate resin.

6. The rosin-modified zinc acrylate self-polishing resin according to claim 5, characterized in that: The rosin liquid is made by mixing rosin and xylene in a mass ratio of 1:

1.

7. A rosin-modified zinc acrylate self-polishing resin, characterized in that: Prepared by the method described in any one of claims 1 to 6.

8. A self-polishing and anti-fouling coating based on the rosin-modified zinc acrylate self-polishing resin according to claim 7, characterized in that: The components and their weight parts of the self-polishing antifouling coating are as follows:

9. The self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin according to claim 8, characterized in that: The antifouling agent includes organic and inorganic antifouling agents; the organic antifouling agent is any one or more of copper pyrithione, copper pyrithione, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-tert-butylamino-4-cyclopropylamino-6-methylthio-s-triazine, zinc ethylene didithiocarbamate, 4-bromo-2-(4-chlorophenyl)-5-trifluoromethylpyrrole-3-onitrile, N-(2,4,6-trichlorophenyl)maleimide, pyridine triphenylborane, or capsaicin; the inorganic antifouling agent is a copper-based antifouling agent, which is any one or more of copper, copper alloys, cuprous oxide, or cuprous thiocyanate. The pigments and fillers include pigments and fillers. The pigments are any one or more of titanium dioxide, iron oxide red, zinc oxide, and iron oxide black. The fillers are any one or more of talc, calcium carbonate, precipitated barium sulfate, barite, silica fume, mica powder, kaolin, barium carbonate, magnesium silicate, or diatomaceous earth. The additives include plasticizers and anti-settling thixotropic agents. The plasticizer is any one or more of chlorinated paraffin, dibutyl phthalate, dioctyl phthalate, epoxidized fatty acid esters, epoxidized soybean oil, dimethyl lauramide, sodium stearate, polybutyl acetate, or polyester-type polyurethane. The anti-settling thixotropic agent is any one or more of fumed silica, organobentonite, polyamide wax, or hydrogenated castor oil. The solvent is any one or more of toluene, xylene, n-butanol, n-hexane, or n-heptane.

10. A method for preparing a self-polishing antifouling coating based on rosin-modified zinc acrylate self-polishing resin as described in claim 9, characterized in that: Specifically, the process involves mixing rosin-modified zinc acrylate resin with antifouling agents, pigments, fillers, additives, and solvents, dispersing and grinding at high speed to obtain a self-polishing antifouling coating based on rosin-modified zinc acrylate resin.

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