Bio-based copper-free marine antifouling paint and preparation method thereof

Abstract

The invention belongs to the technical field of chemical coatings, and discloses a bio-based copper-free marine antifouling coating and a preparation method of the bio-based copper-free marine antifouling coating. Comprising the following components: 5 to 15 parts of bio-based polyester resin, 20 to 25 parts of deionized water, 1 to 3 parts of soybean saponin, 1.5 to 3.0 parts of ethylene glycol butyl ether, 0.5 to 1.5 parts of hydroxyethyl cellulose, 1.5 to 3.5 parts of a rheological additive, 0.2 to 0.4 part of a defoaming agent, 0.2 to 0.6 part of a dispersing agent, 15 to 30 parts of zinc oxide, 4 to 6 parts of iron oxide red, 6 to 10 parts of diuron, 15 to 30 parts of rosin emulsion and 10 to 20 parts of vinyl chloride-vinylidene chloride copolymer emulsion. 1-3 parts of a pH regulator and 3-6 parts of a coalescing agent. According to the bio-based copper-free marine antifouling paint, the antifouling effect is remarkably improved through combined use of polylactic acid and polyhydroxyalkanoate, and the obtained bio-based copper-free marine antifouling paint has the antifouling effects of broad spectrum, high efficiency and low toxicity through emulsification of rosin resin and the action of the vinyl chloride-vinylidene chloride copolymer emulsion and diuron.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical coatings, and in particular relates to a bio-based copper-free marine antifouling coating and a preparation method thereof, which is applied to antifouling projects such as ships, marine structures, pipelines, etc. in seawater and fresh water. Background Art

[0002] In today's world, with the rapid development of industries such as marine transportation, offshore wind energy, and offshore oil production, the number and scale of ships and marine engineering facilities are growing. However, a large number of marine organisms, such as seaweed, shellfish, and microorganisms, often adhere to the surface of these facilities. This phenomenon is called biofouling. Biofouling not only affects the appearance of the equipment, but more importantly, it will lead to a decline in equipment performance, increase energy consumption, and even cause structural damage, which also causes serious pollution to the environment. Therefore, it is particularly important to develop an efficient and environmentally friendly antifouling coating.

[0003] Traditional antifouling coatings mainly rely on compounds containing heavy metals (such as copper) as active ingredients, which inhibit or kill attached marine organisms by releasing toxic substances. However, during the use of such antifouling coatings, heavy metal elements will gradually be released into the marine environment, causing damage to aquatic ecosystems, threatening marine biodiversity, and may enter human food through the food chain, posing a potential risk to human health. In addition, the extraction and treatment process of heavy metals will also produce a large amount of harmful waste, causing secondary damage to the environment. Therefore, finding a new antifouling material that can effectively prevent fouling without causing negative impacts on the environment has become the focus of attention of researchers around the world.

[0004] Bio-based marine copper-free antifouling coatings are an innovative solution that emerged in this context. This type of coating uses natural renewable resources such as vegetable oils, chitosan, lignin, etc. to replace heavy metal components in traditional antifouling coatings. At the same time, scientists have modified these natural materials to give them good antifouling properties. Bio-based marine copper-free antifouling coatings can not only effectively prevent the attachment of marine organisms, but also do not produce toxic substances during the degradation process, and are environmentally friendly. In addition, due to its wide and sustainable source of raw materials, bio-based antifouling coatings are also more cost-effective in the long run.

[0005] Although bio-based marine copper-free antifouling coatings have many advantages, their research and development still faces some challenges. For example, how to improve their antifouling durability and ensure that they can maintain a stable effect even in harsh marine environments; how to optimize the formula and improve the mechanical properties and weather resistance of the coating to adapt to different types of marine facilities; and how to achieve large-scale production and reduce application costs. These issues require further in-depth research and exploration by scientific researchers. Summary of the invention

[0006] In view of the above deficiencies in the prior art, the object of the present invention is to provide a bio-based copper-free marine antifouling coating and a preparation method thereof, which is a low-toxic, high-efficiency, environmentally friendly, biodegradable antifouling coating.

[0007] To achieve the above objectives, the technical solutions adopted are:

[0008] One of the purposes of the present invention is to provide a bio-based copper-free marine antifouling coating, which comprises the following components in parts by weight:

[0009]

[0010]

[0011] Furthermore, the bio-based polyester resin is obtained by mixing polylactic acid (PLA) and polyhydroxyalkanoate (pHA) in a mass ratio of 2:3-3:2.

[0012] The beneficial effects of adopting the above further technical scheme are: PLA is usually brittle, while pHA has good toughness. The combination of the two can improve the overall mechanical properties of the coating and make it more durable in the marine environment; both PLA and pHA have good biodegradability, but pHA degrades slowly, which can be used as a "slow release" mechanism to enable the coating to continuously release antifouling components for a longer period of time and improve the overall antifouling durability; pHA has good antifouling performance. After combining with PLA, it can improve the antifouling ability of the coating and reduce the attachment of marine organisms; PLA has good fluidity, while pHA may have poor fluidity. The combination of the two can improve the processing performance of the coating and make it easier to apply and form; pHA has strong hydrophilicity, while PLA has good water resistance. The combined use can improve the water resistance and weather resistance of the coating to a certain extent and adapt to changes in the marine environment; pHA alone may cost more, while PLA is relatively cheap. By using it in combination, the material cost can be reduced while maintaining performance. The combination of the two can produce a synergistic effect and improve the overall performance of the antifouling coating.

[0013] Furthermore, the rosin emulsion is obtained by emulsifying the rosin resin.

[0014] Furthermore, at 20° C., the viscosity of an aqueous solution containing 2% by mass of the hydroxyethyl cellulose is 50,000-60,000 mPa.s.

[0015] Furthermore, the film-forming aid is alcohol ester dodecahydrate.

[0016] Furthermore, the rheological additive is polyamide wax powder.

[0017] Furthermore, the pH regulator is sodium hydroxide.

[0018] Furthermore, the dispersant is BASF 4560, and the defoaming agent is Digo 825.

[0019] The second object of the present invention is to provide a method for preparing the above-mentioned bio-based copper-free marine antifouling coating, comprising the following steps:

[0020] (1) After the bio-based polyester resin, deionized water, soybean saponin, and ethylene glycol butyl ether are uniformly mixed according to the selected weight proportions, hydroxyethyl cellulose is added according to the weight, and stirred at a low speed until it is completely dissolved;

[0021] (2) adding a dispersant, a rheological agent, and a defoaming agent according to selected weight portions to the material obtained in step (1), and stirring at a medium speed to uniformly mix;

[0022] (3) adding the zinc oxide, red iron oxide and diuron to the material obtained in step (2) in selected weight proportions, mixing and dispersing at high speed to a fineness of less than 50-80 μm;

[0023] (4) adding the rosin emulsion and vinyl chloride-vinylidene chloride copolymer emulsion according to the selected weight proportions to the material obtained in step (3), and stirring at a slow speed until uniform;

[0024] (5) slowly adding the pH adjuster according to the selected weight proportion to the material obtained in step (4), and stirring at a low speed to uniformly mix the mixture;

[0025] (6) Slowly add the film-forming aid according to the selected weight proportion to the material obtained in step (5), slowly stir for 15 minutes to obtain a uniform mixture, and then filter to obtain the mixture.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The bio-based copper-free marine antifouling paint of the present invention does not contain copper, which reduces the pollution to the marine environment; the bio-based polyester resin is used, such as a mixture of polylactic acid and polyhydroxyalkanoate, which can be decomposed by microorganisms under certain conditions, reducing the impact of waste on the environment, and the ratio of polylactic acid to polyhydroxyalkanoate is reasonably adjusted to achieve a better balance between antifouling performance, mechanical properties and processing performance; the rosin emulsion can be better dissolved in water by emulsifying the rosin resin, and it will slowly dissolve in seawater, and the toxic materials in the paint film can be steadily and gradually seeped into the seawater, and no saponification layer is generated during the dissolution process; the use of vinyl chloride-vinylidene chloride copolymer emulsion has strong polarity and excellent adhesion and seawater resistance due to the presence of vinyl chloride. The degradable organic antifouling system uses an environmentally friendly organic antifouling agent diuron, which has a broad-spectrum, high-efficiency and low-toxic antifouling effect. DETAILED DESCRIPTION

[0028] The present invention is described below in conjunction with examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] Example 1

[0030] A bio-based copper-free marine antifouling coating comprises the following components in parts by weight:

[0031] 15 parts of bio-based polyester resin (mixed with 7.5 parts each of polylactic acid and polyhydroxyalkanoate)

[0032]

[0033] The method for preparing the bio-based copper-free marine antifouling coating comprises the following steps:

[0034] (1) After the bio-based polyester resin, deionized water, soybean saponin, and ethylene glycol butyl ether are uniformly mixed according to the selected weight proportions, hydroxyethyl cellulose is added according to the weight, and stirred at a low speed until it is completely dissolved;

[0035] (2) adding a dispersant, a rheological agent, and a defoaming agent according to selected weight portions to the material obtained in step (1), and stirring at a medium speed to uniformly mix;

[0036] (3) adding the zinc oxide, red iron oxide and diuron to the material obtained in step (2) in selected weight proportions, mixing and dispersing at high speed to a fineness of less than 50-80 μm;

[0037] (4) adding the rosin emulsion and vinyl chloride-vinylidene chloride copolymer emulsion according to the selected weight proportions to the material obtained in step (3), and stirring at a slow speed until uniform;

[0038] (5) slowly adding the pH adjuster according to the selected weight proportion to the material obtained in step (4), and stirring at a low speed to uniformly mix the mixture;

[0039] (6) Slowly add the film-forming aid according to the selected weight proportion to the material obtained in step (5), slowly stir for 15 minutes to obtain a uniform mixture, and then filter to obtain the mixture.

[0040] Example 2

[0041] A bio-based copper-free marine antifouling coating comprises the following components in parts by weight:

[0042] 15 parts of bio-based polyester resin (6 parts of polylactic acid and 9 parts of polyhydroxyalkanoate)

[0043]

[0044] The preparation method of the bio-based copper-free marine antifouling coating is the same as that of Example 1.

[0045] Example 3

[0046] A bio-based copper-free marine antifouling coating comprises the following components in parts by weight:

[0047] Bio-based polyester resin 15 parts (polylactic acid 9 parts, polyhydroxyalkanoate 6 parts)

[0048]

[0049] The preparation method of the bio-based copper-free marine antifouling coating is the same as that of Example 1.

[0050] Comparative Example 1

[0051] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not contain diuron, and the other components and preparation method are the same as those of Example 1.

[0052] Comparative Example 2

[0053] The difference between Comparative Example 1 and Example 1 is that the vinyl chloride-vinylidene chloride copolymer emulsion is not contained, and the other components and preparation method are the same as those of Example 1.

[0054] Comparative Example 3

[0055] The difference between Comparative Example 1 and Example 1 is that unemulsified rosin is used, and the other components and preparation method are the same as those of Example 1.

[0056] Comparative Example 4

[0057] The difference between Comparative Example 4 and Example 1 is that among 15 parts of bio-based polyester resin, polylactic acid is 3 parts and polyhydroxyalkanoate is 12 parts, and the remaining components and preparation method are the same as those in Example 1.

[0058] Comparative Example 5

[0059] The difference between Comparative Example 5 and Example 1 is that among 15 parts of bio-based polyester resin, polylactic acid is 12 parts and polyhydroxyalkanoate is 3 parts, and the remaining components and preparation method are the same as those in Example 1.

[0060] Comparative Example 6

[0061] The difference between Comparative Example 6 and Example 1 is that it does not contain soybean saponin, and the other components and preparation method are the same as those of Example 1.

[0062] Comparative Example 7

[0063] The difference between Comparative Example 7 and Example 1 is that the 15 parts of bio-based polyester resins are all polylactic acid.

[0064] test

[0065] The bio-based copper-free marine antifouling coatings prepared in Examples 1-3 and Comparative Examples 1-7 were tested for the marine biological coverage area of ​​the antifouling coatings. The test results are shown in Table 1.

[0066] Table 1. Test results of marine biological coverage area of ​​antifouling paints of Examples 1-3 and Comparative Examples 1-7

[0067]

[0068]

[0069] As can be seen from Table 1, the bio-based copper-free marine antifouling coating prepared by the present invention has a broad-spectrum, high-efficiency, low-toxic antifouling effect through the emulsification of soybean saponin, bio-based polyester resin, rosin resin, the use of vinyl chloride-vinylidene chloride copolymer emulsion, and the action of environmentally friendly organic antifouling agent diuron, and produces an excellent antifouling paint marine biological coverage effect. Comparing Example 1 with Comparative Example 4, it can be seen that polyhydroxyalkanoates have surface wettability, which helps to resist biological attachment. The increase in its content in Comparative Example 4 helps to improve the antifouling effect. However, due to the high cost of polyhydroxyalkanoates, the processing performance of the coating will deteriorate and affect the mechanical properties. Therefore, the content of polyhydroxyalkanoates cannot be increased indefinitely; comparing Example 1 with Comparative Example 5, the higher PLA content will make the coating harder, affecting its adhesion, thereby affecting the antifouling performance, and the PLA degradation rate is fast, which may cause the antifouling coating to degrade prematurely within the expected service life, making the antifouling coating ineffective; comparing Example 1 with Comparative Example 6, soybean saponin has the characteristics of a surfactant, which can reduce the surface tension of water and help the coating enhance the adhesion and biocompatibility of the coating. Comparing Example 1 with Comparative Example 7, it can be seen that combining polylactic acid with polyhydroxyalkanoates can produce a better antifouling effect than a single component.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bio-based copper-free marine antifouling coating, characterized in that: By weight, it includes the following components:

2. The bio-based copper-free marine antifouling coating according to claim 1, characterized in that: The bio-based polyester resin is obtained by mixing polylactic acid and polyhydroxyalkanoate in a mass ratio of 2:3-3:

2.

3. The bio-based copper-free marine antifouling coating according to claim 1, characterized in that: The rosin emulsion is obtained by emulsifying rosin resin.

4. The bio-based copper-free marine antifouling coating according to claim 1, characterized in that: At 20° C., the viscosity of the aqueous solution containing 2% by mass of the hydroxyethyl cellulose is 50000-60000 mPa.s.

5. The bio-based copper-free marine antifouling coating according to claim 1, characterized in that: The film-forming aid is alcohol ester dodecahydrate.

6. The bio-based copper-free marine antifouling coating according to claim 1, characterized in that: The rheological additive is polyamide wax powder.

7. The bio-based copper-free marine antifouling coating according to claim 1, characterized in that: The dispersant is BASF 4560, and the defoamer is Digo 825.

8. A method for preparing a bio-based copper-free marine antifouling coating according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) After the bio-based polyester resin, deionized water, soybean saponin, and ethylene glycol butyl ether are uniformly mixed according to the selected weight proportions, hydroxyethyl cellulose is added according to the weight, and stirred until it is completely dissolved; (2) adding a dispersant, a rheological agent, and a defoaming agent according to selected weight proportions to the material obtained in step (1) and stirring evenly; (3) adding the zinc oxide, red iron oxide and diuron to the material obtained in step (2) in selected weight proportions, mixing and dispersing to a fineness of less than 50-80 μm; (4) adding the rosin emulsion and vinyl chloride-vinylidene chloride copolymer emulsion according to selected weight proportions to the material obtained in step (3), and stirring evenly; (5) slowly adding the pH adjuster in selected weight proportions to the material obtained in step (4) and stirring the mixture evenly; (6) Slowly add the film-forming aid according to the selected weight proportion to the material obtained in step (5), stir for 15 minutes until uniform, and filter to obtain the product.

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