A copper-free antifouling paint and a method for preparing the same

Abstract

This invention belongs to the field of antifouling coating technology, and relates to a copper-free antifouling coating and its preparation method. The coating comprises a specific mass fraction of a resin mixture, an antimicrobial agent, fillers, additives, and a solvent. The specific steps are as follows: A specific mass fraction of the resin mixture, pigments, fillers, additives, and solvent is mixed and then dispersed for the first time to obtain a resin and pigment / filler mixture solution; subsequently, a specific mass fraction of the antimicrobial agent is added to the resin and pigment / filler mixture solution, and a second dispersion is performed to finally obtain the copper-free antifouling coating. The coating exhibits excellent antifouling effect and adhesion performance, and its low surface energy further enhances its anti-biofouling ability; simultaneously, its degradation products are all small molecules with good biocompatibility, which can be naturally decomposed in the marine environment without the risk of secondary pollution, meeting the green development needs of marine antifouling materials.

Description

Technical Field

[0001] This invention belongs to the field of antifouling coating technology, and relates to a copper-free antifouling coating and its preparation method. Background Technology

[0002] Marine equipment and facilities, including ship hulls, docks, and drilling platforms, inevitably suffer from the adhesion and corrosion of marine fouling organisms during service. Specifically, the colonization of algae, barnacles, and shellfish significantly increases the surface roughness of marine equipment and facilities, impairing their hydrodynamic performance, accelerating material corrosion and deterioration, reducing their service durability, and resulting in high maintenance costs. It also triggers a series of marine ecological and environmental problems. Currently, applying antifouling coatings is a core technical means to solve the problems of marine biofouling and material corrosion, offering both economic benefits and practicality.

[0003] With the continuous advancement of marine development, eco-friendly antifouling technology has become a core demand for the industry. However, existing mainstream antifouling coatings generally suffer from high cuprous oxide content, typically accounting for 35% to 40% of the total content. Cuprous oxide is a non-degradable heavy metal-based antifouling agent that not only possesses inherent biotoxicity, easily causing irreversible damage to non-target organisms such as marine shellfish and algae, but also accumulates continuously in the marine environment, disrupting the balance of the marine food chain and posing ecological pollution risks.

[0004] Therefore, developing a high-performance copper-free antifouling coating is of vital practical significance and application value for promoting the green development of marine engineering equipment and protecting the marine ecological environment. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and propose a copper-free antifouling coating and its preparation method. The coating prepared by this method has excellent antifouling effect and adhesion performance, and its low surface energy characteristics can further enhance its anti-biofouling ability.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention discloses a copper-free antifouling coating, wherein the components of the coating are contained in the following parts by mass: Resin mixture: 43-59 parts Antimicrobial agent: 9-16 parts Pigments and fillers: 20-27 parts Additives: 0.8~1.2 parts Solvent: 10-13 parts.

[0007] Furthermore, the resin mixture comprises the following components in parts by weight: 35-45 parts of degradable hyperbranched zinc self-polishing resin and 8-14 parts of rosin resin.

[0008] Specifically, the degradable hyperbranched zinc self-polishing resin breaks through the dependence of traditional self-polishing coatings on sailing speed and seawater erosion, and can continuously and stably polish under both dynamic and static working conditions, while also having high polishing rate and efficient antifouling agent release characteristics.

[0009] Specifically, the rosin resin can participate in the coating surface renewal process through swelling, forming a synergistic effect with the hyperbranched zinc self-polishing resin, and further optimizing the antifouling performance.

[0010] Furthermore, the antimicrobial agent comprises the following components in parts by weight: 3-7 parts zinc pyrithione, 3-5 parts isothiazolinone, and 3-6 parts diuron.

[0011] Specifically, the zinc pyrithione is a highly efficient, low-toxicity, environmentally friendly antifouling and antibacterial agent.

[0012] Specifically, the isothiazolinone is a highly effective antifungal and antialgae agent. It is not only low in toxicity and environmentally friendly with long-lasting efficacy, but also has a significant inhibitory effect on bacteria and algae. In addition, its low solubility in water can slow down the release rate of the active ingredients.

[0013] Specifically, the diuron has stable performance and combines systemic and contact action, enabling efficient control of target organisms in the ocean.

[0014] Furthermore, the pigments and fillers comprise the following components in parts by weight: 4-8 parts zinc oxide, 4-8 parts iron oxide red, 2-4 parts bentonite, and 5-10 parts talc.

[0015] Specifically, the zinc oxide is alkaline and has excellent tinting and hiding power, making it a widely used inorganic surfactant in the coatings industry.

[0016] Specifically, the iron oxide can improve the physical properties of the paint film.

[0017] Specifically, the bentonite is used to improve the water resistance and adhesion of the coating.

[0018] Specifically, the talc powder is used to improve the settling properties of the coating.

[0019] Furthermore, the additive comprises the following components in parts by weight: 0.7-0.9 parts chlorinated paraffin and 0.1-0.3 parts dispersant.

[0020] Specifically, the chlorinated paraffin is used to enhance the flexibility of the coating.

[0021] Specifically, the dispersant is used to uniformly disperse particles or powders in the coating, prevent particle agglomeration, and improve the rheological properties of the coating; the dispersant is preferably one or two of BYK-104S from BYK Corporation, Disponer 903 from Deqian Company, or Disponer 904S.

[0022] Furthermore, the solvent is one or two of toluene, xylene, or butyl ester.

[0023] Secondly, this invention discloses a method for preparing any of the aforementioned copper-free antifouling coatings, the specific steps of which are as follows: Step 1: Mix a specific mass of resin mixture, pigments, fillers, additives and solvent and then disperse for the first time to obtain a resin and pigment / filler mixed solution; Step 2: Add a specific mass fraction of antimicrobial agent to the resin and pigment / filler mixture solution, and then perform a second dispersion to finally obtain a copper-free antifouling coating.

[0024] Furthermore, in step one, the rotation speed of the first dispersion operation is 1500 r / min to 2500 r / min, and the time is 10 min to 20 min.

[0025] Specifically, the first dispersion uses a higher rotation speed, which can better disperse pigments and fillers such as bentonite and talc, ensuring that each component is evenly dispersed and free of coarse particles.

[0026] Furthermore, in step two, the rotation speed of the second dispersion operation is 300 r / min to 500 r / min, and the time is 30 min to 50 min.

[0027] Specifically, the second dispersion uses a lower rotation speed to avoid excessively high system temperature due to prolonged dispersion, thereby ensuring the stability of the coating.

[0028] Compared with the prior art, the present invention has the following beneficial effects: Firstly, regarding the coating components, this invention combines a biodegradable hyperbranched zinc self-polishing resin with rosin resin. The biodegradable hyperbranched zinc self-polishing resin, with its unique biodegradable hyperbranched structure, can create a fragmented structure on the coating surface. This allows for continuous surface renewal in seawater through polymer backbone degradation and branch hydrolysis. Secondly, the excellent hydrophobicity of rosin resin complements the biodegradable hyperbranched zinc self-polishing resin in both structure and function, effectively improving the coating's practicality and durability, and enhancing its antifouling performance. Furthermore, to enhance the coating's anti-biofouling ability, this invention incorporates three antimicrobial agents: zinc pyrithione, isothiazolinone, and diuron. These three antimicrobial agents possess both low toxicity and easy degradation in seawater, achieving not only highly efficient antifouling but also forming a comprehensive protective system. By repelling or killing target marine organisms, they prevent their attachment and colonization on the material surface, thereby avoiding marine biofouling damage to marine engineering facilities.

[0029] Secondly, during use, the structure of the resin mixture involving main chain degradation and side chain hydrolysis, along with the continuous release of antimicrobial agents, enables the coating to possess self-cleaning, self-polishing, and antibacterial / antimicrobial effects. Furthermore, the degradation products of the coating are all small molecules with good biocompatibility, which can be naturally decomposed in the marine environment without the risk of secondary pollution, thus meeting the green development needs of marine antifouling materials.

[0030] Third, this invention is a single-component self-curing coating that can be used alone without the need for additional curing agents, thus reducing manufacturing and labor costs. At the same time, since this antifouling coating is a single-component coating, it has the characteristics of simple construction process and can be adapted to various environmental processes such as spraying, brushing, and scraping. Attached Figure Description

[0031] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart of the preparation method of the present invention. Detailed Implementation

[0034] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0035] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Example 1 like Figure 1 As shown, this embodiment provides a method for preparing a copper-free antifouling coating, including the following steps: S1. First, weigh 35 parts by mass of the degradable hyperbranched zinc self-polishing resin and 8 parts by mass of rosin resin to obtain 43 parts by mass of the resin mixture; then weigh 8 parts by mass of zinc oxide, 8 parts by mass of iron oxide red, 3 parts by mass of bentonite and 8 parts by mass of talc to obtain 27 parts by mass of the pigment and filler; then weigh 0.7 parts by mass of chlorinated paraffin and 0.1 parts by mass of BYK-104S dispersant to obtain 0.8 parts by mass of the additive; then weigh 13 parts by mass of toluene as a solvent; after mixing the resin mixture, pigment and filler, additive and solvent, perform a first dispersion using a high-speed disperser to obtain a resin and pigment and filler mixed solution.

[0037] Specifically, the rotation speed of the first dispersion operation is 1500 r / min, and the time is 20 min.

[0038] S2. Weigh 5 parts by mass of zinc pyrithione, 6 parts by mass of diuron and 5 parts by mass of isothiazolinone to obtain 16 parts by mass of the antimicrobial agent; then, add the antimicrobial agent to the resin and pigment-filler mixture solution prepared in S1, and then perform a second dispersion using a high-speed disperser to finally obtain a copper-free antifouling coating.

[0039] Specifically, the second dispersion operation is performed at a rotation speed of 300 r / min for a duration of 30 min.

[0040] Example 2 The steps of this embodiment are the same as those in the preparation method described in Embodiment 1, except that: In S1, the degradable hyperbranched zinc self-polishing resin is 40 parts by mass, the rosin resin is 11 parts by mass, and the resin mixture is 51 parts by mass.

[0041] In S1, zinc oxide and iron oxide each have 4 parts by mass, bentonite has 2 parts by mass, talc has 10 parts by mass, and pigments and fillers have 20 parts by mass.

[0042] In S1, the chlorinated paraffin is 0.8 parts by mass, and the dispersant is a mixture of 0.1 parts by mass BYK-104S and 0.1 parts by mass Disponer 904S, that is, the auxiliary agent is 1 part by mass.

[0043] In S1, the solvent comprises 9 parts by mass of toluene and 3 parts by mass of butyl ester, that is, the solvent is 12 parts by mass.

[0044] In S1, the rotation speed of the first dispersion operation is 2000 r / min, and the time is 15 min.

[0045] In S2, the zinc pyrithione is 7 parts by mass, the diuron is 5 parts by mass, the isothiazolinone is 4 parts by mass, and the antimicrobial agent is 16 parts by mass.

[0046] In S2, the rotation speed of the second dispersion operation is 400 r / min, and the time is 40 min.

[0047] Example 3 The steps of this embodiment are the same as those in the preparation method described in Embodiment 1, except that: In S1, the degradable hyperbranched zinc self-polishing resin is 45 parts by mass, the rosin resin is 14 parts by mass, and the resin mixture is 59 parts by mass.

[0048] In S1, zinc oxide and iron oxide each have 6 parts by mass, bentonite has 4 parts by mass, talc has 5 parts by mass, and pigments and fillers have 21 parts by mass.

[0049] In S1, the chlorinated paraffin is 0.9 parts by mass, the dispersant is 0.3 parts by mass of Disponer 904S, that is, the auxiliary agent is 1.2 parts by mass.

[0050] In S1, the solvent comprises 8 parts by mass of xylene and 2 parts by mass of butyl ester, that is, the solvent is 10 parts by mass.

[0051] In S1, the rotation speed of the first dispersion operation is 2500 r / min, and the time is 10 min.

[0052] In S2, zinc pyrithione, diuron, and isothiazolinone are each 3 parts by mass, meaning the antimicrobial agent is 9 parts by mass.

[0053] In S2, the rotation speed of the second dispersion operation is 500 r / min, and the time is 50 min.

[0054] Example 4 The steps of this embodiment are the same as those in the preparation method described in Embodiment 1, except that: In S1, the degradable hyperbranched zinc self-polishing resin is 42 parts by mass, the rosin resin is 12 parts by mass, and the resin mixture is 54 parts by mass.

[0055] In S1, the zinc oxide is 7 parts by mass, the iron oxide is 4 parts by mass, the bentonite is 3 parts by mass, the talc is 10 parts by mass, and the pigments and fillers are 24 parts by mass.

[0056] In S1, the chlorinated paraffin is 0.8 parts by mass, the dispersant is 0.3 parts by mass of BYK-104S, that is, the auxiliary agent is 1.1 parts by mass.

[0057] In S1, the solvent comprises 8 parts by mass of xylene and 3 parts by mass of butyl ester, that is, the solvent comprises 11 parts by mass.

[0058] In S2, the zinc pyrithione is 6 parts by mass, and the diuron and isothiazolinone are each 3 parts by mass, that is, the antimicrobial agent is 12 parts by mass.

[0059] Comparative Example 1 The comparative example follows the same preparation method as described in Example 1, except that: In S1, the resin mixture is replaced with 42 parts by weight of a degradable hyperbranched zinc self-polishing resin.

[0060] Comparative Example 2 The comparative example follows the same preparation method as described in Example 1, except that: In S1, the degradable hyperbranched zinc self-polishing resin is 39 parts by weight, the rosin resin is 11.2 parts by weight, that is, the resin mixture is 50.2 parts by weight.

[0061] In S1, zinc oxide and iron oxide each have 8 parts by mass, bentonite has 4 parts by mass, talc has 7 parts by mass, and the pigments and fillers have 27 parts by mass.

[0062] In S2, only 7 parts by weight of zinc pyrithione is used as an antimicrobial agent.

[0063] To further verify the actual performance of the present invention, a series of performance tests were conducted on the antifouling coatings prepared in Examples 1-3 and Comparative Examples 1 and 2. Specifically, adhesion performance was tested according to GB / T1720-2020, impact resistance was tested according to GB / T1732-2020, marine immersion performance was tested according to GB / T5370-2007, and storage stability was tested according to GB / T6753.3-1986. The specific test results are as follows: Table 1. Test Results of Copper-Free Antifouling Coatings Table 1 shows the performance test results of Examples 1-4 and Comparative Examples 1 and 2 of the copper-free antifouling coating of the present invention. Regarding conventional performance: Firstly, the surface energy of Examples 1-4 is 24.8-25.5 mN / m. This low surface energy ensures good antifouling effect while maintaining good wettability and interfacial adhesion to the substrate. Secondly, the cross-cut test results of Examples 1-4 are all Grade 1. According to GB / T1720-2020 standard, a Grade 1 result indicates excellent adhesion between the coating and the substrate, and the outermost layer of the paint film remains intact without peeling. Therefore, the coating obtained by applying the present invention can effectively resist external stress and is less prone to peeling or flaking, providing long-term protection. Thirdly, the flexibility of Examples 1-4 is between 1 and 2 mm, indicating excellent flexibility and crack resistance. Fourthly, according to GB / T1732-2020 standard, the impact resistance of Examples 1-4 can reach 45-50. cm, with excellent impact resistance, not easily cracked or detached under external impact, and good mechanical strength and toughness; fifthly, the sterilization rate is as high as 99.7% to 99.9%, indicating that the present invention still has efficient and environmentally friendly antifouling ability without relying on traditional toxic materials such as cuprous oxide.

[0064] In addition, in the shallow sea cladding test, Examples 1 to 4 showed excellent long-term antifouling performance—no biological attachment was observed on the paint film surface within 3 months; at 6 months, Example 1 remained clean, while the other examples only showed a small amount of silt; at 12 months, all examples had only a small amount of algae on the surface, with no barnacles or other shellfish attached, which met the GB / T5370-2007 standard.

[0065] In contrast, Comparative Example 2 showed a large number of barnacles and algae at 6 months, and the surface was completely covered by marine life at 12 months, with a much lower antifouling effect than the Example.

[0066] In the storage stability test, the sedimentation degree of the coating of the present invention was level 8 and the viscosity change was level 6, both of which meet the GB / T6753.3-1986 standard, demonstrating good storage stability.

[0067] Correspondingly, in Comparative Example 1, the resin mixture was replaced with a single-component degradable hyperbranched zinc self-polishing resin. The remaining components and preparation steps were the same as in Example 1. Table 1 shows that its surface energy was 28 mN / m, its cross-cut adhesion test score was 3, its flexibility was 3 mm, and its impact resistance was 40 cm. Therefore, its antifouling performance, adhesion, and impact resistance are all inferior to those of this invention. In summary, the combination of degradable hyperbranched zinc self-polishing resin and rosin resin can effectively improve the practicality and durability of the coating, and enable the coating to better perform its antifouling properties.

[0068] The key difference between Comparative Example 2 and Example 1 is that only a single zinc pyrithione component was used to replace the original antimicrobial agent component described in this invention. As shown in Table 1, Comparative Example 2 had a bactericidal rate of only 85%, and biofouling appeared on the film surface after 3 months of use in shallow seas. Therefore, its bactericidal ability and marine immersion performance are inferior to those of this invention. In summary, the three antimicrobial agents used in this invention—zinc pyrithione, isothiazolinone, and diuron—can effectively repel or kill target marine organisms, preventing their attachment and colonization on material surfaces, thereby avoiding marine biofouling damage to marine engineering facilities.

[0069] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0070] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A copper-free antifouling coating, characterized in that, The components of the coating are contained in the following parts by weight: Resin mixture: 43-59 parts Antimicrobial agent: 9-16 parts Pigments and fillers: 20-27 parts Additives: 0.8~1.2 parts Solvent: 10-13 parts.

2. The copper-free antifouling coating according to claim 1, characterized in that, The resin mixture comprises the following components in parts by weight: 35-45 parts of degradable hyperbranched zinc self-polishing resin and 8-14 parts of rosin resin.

3. The copper-free antifouling coating according to claim 1, characterized in that, The antimicrobial agent comprises the following components in parts by weight: 3-7 parts zinc pyrithione, 3-5 parts isothiazolinone, and 3-6 parts diuron.

4. The copper-free antifouling coating according to claim 1, characterized in that, The pigments and fillers comprise the following components by mass: 4-8 parts zinc oxide, 4-8 parts iron oxide red, 2-4 parts bentonite, and 5-10 parts talc.

5. The copper-free antifouling coating according to claim 1, characterized in that, The additive comprises the following components in parts by weight: 0.7-0.9 parts chlorinated paraffin and 0.1-0.3 parts dispersant.

6. The copper-free antifouling coating according to claim 1, characterized in that, The solvent is one or two of toluene, xylene, or butyl ester.

7. A method for preparing a copper-free antifouling coating according to any one of claims 1 to 6, characterized in that, The specific steps are as follows: Step 1: Mix a specific mass of resin mixture, pigments, fillers, additives and solvent and then disperse for the first time to obtain a resin and pigment / filler mixed solution; Step 2: Add a specific mass fraction of antimicrobial agent to the resin and pigment / filler mixture solution, and then perform a second dispersion to finally obtain a copper-free antifouling coating.

8. The method for preparing a copper-free antifouling coating according to claim 7, characterized in that, In step one, the rotation speed of the first dispersion operation is 1500 r / min to 2500 r / min, and the time is 10 min to 20 min.

9. The method for preparing a copper-free antifouling coating according to claim 7, characterized in that, In step two, the rotation speed of the second dispersion operation is 300 r / min to 500 r / min, and the time is 30 min to 50 min.

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