A drag-reducing surface self-renewing marine antifouling coating and its preparation method

Abstract

The present invention relates to a drag-reducing, surface-self-renewing marine antifouling coating and its preparation method, which relates to the technical field of marine antifouling coatings. The coating comprises components A and B. Component A comprises the following components by weight: 20-80 parts of a drag-reducing, surface-self-renewing marine antifouling resin, 1-5 parts of silicone oil, 0-20 parts of an antifouling agent, 1-20 parts of a pigment or filler, 0-5 parts of a thixotropic agent, 0-3 parts of a silane coupling agent, and 10-30 parts of a solvent; component B is an organic amine curing agent. Compared to the mainstream Wuxi self-polishing coatings currently on the market, the antifouling resin produced by the present invention has excellent low surface energy properties, making it difficult for mucus secreted by marine organisms to wet, spread, and adhere to the coating surface. Even if it adheres, it is not strong and can be easily desorbed by water scouring. The resin can achieve self-renewal of the coating surface through surface degradation, and the resin can improve the coating's adhesion to the substrate. The present invention has a simple operation method, and the resulting coating is environmentally friendly, low-cost, and suitable for a variety of marine applications.

Description

Technical Field

[0001] The present invention relates to the technical field of marine antifouling materials, in particular to a drag-reducing surface self-renewing marine antifouling coating and a preparation method thereof. Background Art

[0002] Marine organisms that cling to the bottoms of ships and other offshore structures are also known as marine fouling organisms and marine fouling organisms. Unlike sessile organisms on marine reefs, as well as farmed shellfish, algae, and burrowing organisms, these organisms are generally harmful. When attached to the surfaces of artificial structures, they can cause the following hazards: ① Increased resistance to ship navigation; ② Reduced diameter of seawater cooling pipes and condenser tubes of heat exchangers, or even complete blockage; ③ Promoted corrosion and crevice corrosion; ④ Caused malfunction of instruments and machinery at sea; ⑤ Increased cross-sectional area of ​​piles and columns of offshore structures, increasing the impact of waves and currents; ⑥ Blocked meshes, competing with farmed shellfish and algae for attachment and bait.

[0003] Marine antifouling coatings are the most economical and effective way to address marine fouling. They primarily prevent fouling by marine organisms through the gradual seepage of antifouling agents from the paint film. Currently, most of the market is monopolized by giants such as Jotun, Kansai, Hempel, Zhongtu International, Akzo Nobel, and Nippon Paint Japan. This is especially true in the high-end antifouling coatings sector, which features high technological content and high added value.

[0004] Silicone-based fouling-release coatings and polyacrylate-based self-polishing coatings are currently the best-performing and most widely used marine antifouling coatings. However, silicone-based fouling-release coatings suffer from low mechanical strength and poor adhesion to the substrate, and cannot completely inhibit the attachment of marine organisms under static conditions. Polyacrylate-based self-polishing coatings, primarily based on self-polishing resins based on zinc polyacrylate, copper, or silane esters, offer an antifouling effect of 3-5 years. However, these self-polishing resins contain only hydrolyzable side groups, and their surface self-renewal relies on strong water flow, resulting in suboptimal static antifouling capabilities.

[0005] In response to the above problems, the present invention provides a drag-reducing, surface-self-renewing marine antifouling coating and a preparation method thereof. The antifouling coating has excellent low surface energy characteristics. The low surface energy of the coating surface makes it difficult for mucus secreted by marine organisms to wet, spread and adhere to the coating surface. Even if it adheres, it is not firm and can be easily removed by the flushing effect of water flow when the ship is sailing. At the same time, the substrate surface also has biodegradable groups. Even if a small amount of fouling organisms are attached, the coating surface can be self-renewed by surface degradation, and exhibits a relatively good antifouling effect under both dynamic and static conditions. In addition, some epoxy groups are added to the resin itself, which can improve the adhesion of the coating to the substrate.

[0006] Therefore, there is a need for a drag-reducing surface self-renewing marine antifouling coating and a preparation method thereof. Summary of the Invention

[0007] The present invention aims to address the above-mentioned problems by providing a drag-reducing, surface-self-renewing marine antifouling coating and its preparation method. The antifouling coating exhibits excellent low surface energy properties. The low surface energy of the coating surface makes it difficult for mucus secreted by marine organisms to wet, spread, and adhere to the coating surface. Even if it adheres, it is not strong and can be easily removed by the scouring action of water during navigation. Furthermore, the substrate surface contains biodegradable groups. Even if a small amount of fouling organisms adhere, the coating surface can be self-renewed through surface degradation, demonstrating excellent antifouling effectiveness under both dynamic and static conditions. Furthermore, the resin itself contains some epoxy groups, which enhances the coating's adhesion to the substrate. The antifouling coating exhibits excellent low surface energy properties and certain backbone degradation properties, demonstrating excellent antifouling effectiveness under both dynamic and static conditions. Furthermore, the resin itself contains some epoxy groups, which enhances the coating's adhesion to the substrate. The present invention is simple to operate, and the resulting coating is environmentally friendly and low-cost. It is suitable for a variety of marine applications and has broad application prospects.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] The first object of the present invention is to provide a drag-reducing surface self-renewing marine antifouling coating, which comprises component A and component B.

[0010] Wherein component A comprises the following components in percentage by weight:

[0011]

[0012] Component B is an organic amine curing agent.

[0013] More preferably, the A component comprises the following components:

[0014]

[0015] Furthermore, the structure of the drag-reducing surface self-renewing marine antifouling resin is shown in the following formula (I):

[0016]

[0017] Wherein, m, n are integers;

[0018] R represents a methyl group or a phenyl group;

[0019] R' represents a methyl group or an ethyl group;

[0020] R1 represents a degradable aliphatic polyester, specifically comprising one of the following structural formula (II):

[0021]

[0022] Among them, R4, R 5、 R6 is an alkyl group or an aryl group having 1 or more carbon atoms, and a, b, x, y, and z represent integers of 1 or more.

[0023] (II);

[0024] R2 and R3 represent the corresponding groups of epoxy resin. Taking bisphenol A epoxy resin as an example,

[0025] The structural formula represented by R2 is shown in the following formula (III):

[0026]

[0027] The structural formula represented by R3 is shown in the following formula (IV):

[0028]

[0029] Preferably, the drag-reducing surface self-renewing marine antifouling resin in component A can be prepared by the following steps:

[0030] a) adding a certain amount of organosilicon monomer and xylene solvent to a reactor, starting stirring, heating to between 60°C and 100°C, adding a certain amount of hydrolysis accelerator, and slowly dripping a certain amount of deionized water; after the titration is completed, continuing the hydrolysis reaction for 3-10 hours, then adding an excess of sodium carbonate, stirring to neutralize the reaction system, measuring the pH value to be ≥7, and filtering the reactants; removing the alcohol generated by the reaction by atmospheric distillation, and then distilling off a trace amount of alcohol, water, and xylene solvent under reduced pressure to obtain organosilicon oligomers;

[0031] b) reacting the prepared organosilicon oligomer, degradable aliphatic polyester polyol, epoxy resin and an appropriate amount of catalyst at 100-180° C. for 3-10 hours, stopping heating, cooling to below 80° C., diluting with xylene, and stirring uniformly to obtain a drag-reducing surface self-renewing marine antifouling resin.

[0032] 4. A drag-reducing, surface-self-renewing marine antifouling coating according to claim 3, characterized in that the organosilicon monomer in step a) comprises one or more of methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and tetraethoxysilane; or

[0033] The hydrolysis accelerator in step a) includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, p-toluenesulfonic acid, sodium hydroxide and potassium hydroxide; or,

[0034] The amount of deionized water added in step a) is 50-100% of the amount of water required for complete hydrolysis.

[0035] Preferably, the organosilicon monomer in step a) includes one or more of methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and tetraethoxysilane.

[0036] Preferably, the hydrolysis accelerator in step a) includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, p-toluenesulfonic acid, sodium hydroxide and potassium hydroxide;

[0037] More preferably, the hydrolysis promoter in step a) is one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid and p-toluenesulfonic acid.

[0038] Preferably, the amount of deionized water added in step a) is 50-100% of the amount of water required for complete hydrolysis.

[0039] Preferably, the reaction equation of the hydrolysis reaction in step a) is as follows:

[0040] Take the partial hydrolysis reaction of methyltrimethoxysilane as an example:

[0041]

[0042] The organosilicon oligomer generally contains methoxy or ethoxy groups, and its representative formula is shown in the figure below:

[0043]

[0044] Wherein, R represents a methyl group or a phenyl group; R' represents a methyl group or an ethyl group; and n is an integer greater than 1.

[0045] Preferably, the degradable aliphatic polyester polyol in step b) includes one or more of polylactic acid polyol, polylactic acid glycolic acid copolymer polyol, polycaprolactone polyol and polybutylene succinate polyol; the molecular weight of the degradable aliphatic polyester polyol is 300 to 10,000.

[0046] More preferably, the degradable aliphatic polyester polyol in step b) is polylactic acid glycolic acid polyol; the molecular weight of the degradable aliphatic polyester polyol is 500-2000.

[0047] Furthermore, the structural formula of the degradable aliphatic polyester polyol is as follows:

[0048]

[0049] Wherein, R4, R5, and R6 are alkyl or aryl groups with a carbon number of 1 or more, and a, b, x, y, and z represent integers of 1 or more.

[0050] Here, R4, R5, and R6 are alkyl groups or aromatic groups having 1 or more carbon atoms, and a, b, x, y, and z represent integers of 1 or more.

[0051] For ease of representation, the structural formula of the degradable aliphatic polyester polyol can be abbreviated as follows:

[0052] HO-R1-OH.

[0053] Preferably, the epoxy resin in step b) includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin;

[0054] Taking bisphenol A epoxy resin as an example, its structural formula is shown in the figure below:

[0055]

[0056] Where m is an integer,

[0057] For ease of representation, the epoxy resin structural formula may be abbreviated as follows:

[0058]

[0059] Where m is an integer,

[0060] More preferably, the epoxy resin in step b) is bisphenol A epoxy resin.

[0061] Preferably, the catalyst in step b) includes one or more of stannous octoate, stannous chloride, dibutyltin dilaurate, potassium hydroxide, and methanesulfonic acid; and the amount of the catalyst used is 0.01 to 2 wt% of the mass of all monomers.

[0062] Preferably, the reaction equation in step b) is as shown below:

[0063]

[0064] Wherein, m and n are integers;

[0065] R represents a methyl group or a phenyl group;

[0066] R' represents a methyl group or an ethyl group.

[0067] Preferably, the mass ratio of the organosilicon oligomer, the degradable aliphatic polyester polyol, and the epoxy resin is 30-90:5-30:5-30;

[0068] More preferably, the mass ratio of the organosilicon oligomer, the degradable aliphatic polyester polyol, and the epoxy resin is 60-80:10-20:10-20.

[0069] Preferably, the silicone oil in component A is one or more of methyl silicone oil, phenyl silicone oil, hydroxy silicone oil and amino silicone oil; and has a viscosity of 100 to 10,000 cs.

[0070] Preferably, the antifouling agent in component A includes one or more of cuprous oxide, copper pyrithione, mancozeb, (4,5-dichloro-N-octyl-4-isothiazolin-3-one)isothiazolinone derivatives, and the like.

[0071] Preferably, the pigments and fillers in component A include one or more of nano-silicon dioxide, polytetrafluoroethylene, zinc oxide, calcium carbonate, talc, titanium dioxide, and red iron oxide.

[0072] Preferably, the thixotropic agent in component A includes one or more of organic bentonite, fumed silica, and polyamide wax.

[0073] Preferably, the silane coupling agent in component A includes one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane.

[0074] Preferably, the solvent in component A is one or more of toluene, xylene, n-butanol, ethyl acetate, butyl acetate, and methyl isobutyl ketone.

[0075] Preferably, the organic amine curing agent in component B includes one or more of diethylenetriamine, triethylenetetramine, ethylenediamine, hexamethylenediamine, diethylaminopropylamine and polyamide.

[0076] Preferably, the drag-reducing surface self-renewing marine antifouling coating is characterized in that the mass ratio of component A to component B is 1 to 100:1;

[0077] More preferably, the drag-reducing surface self-renewing marine antifouling coating is characterized in that the mass ratio of component A to component B is 20 to 50:1.

[0078] The second object of the present invention is to provide a method for preparing the drag-reducing surface self-renewing marine antifouling coating. The drag-reducing surface self-renewing marine antifouling coating can be prepared by the following method:

[0079] During coating, component A and component B are mixed to obtain a drag-reducing surface self-renewing marine antifouling coating.

[0080] Furthermore, the preparation of the A component comprises the following steps:

[0081] (1) According to the ratio, first mix the drag-reducing surface self-renewing marine antifouling resin with an appropriate amount of solvent and place it in a disperser. At a speed of 500-1000 r / min, add additives such as thixotropic agent, silane coupling agent, silicone oil, etc. and continue stirring for 10-30 minutes;

[0082] (2) Add pigments, fillers and antifouling agents in the order from liquid to powder and from small to large specific gravity, and continue to disperse at a speed of 500-3000 r / min for 30-60 minutes until the coating fineness is below 60 μm;

[0083] (3) Replenish the solvent according to the viscosity, continue stirring at a speed of 500 to 3000 r / min for 20 minutes, filter and package to obtain the drag-reducing surface self-renewing marine antifouling coating component A.

[0084] Compared with the prior art, the beneficial effects of the present invention are embodied in the following aspects:

[0085] (1) The developed drag-reducing surface self-renewing marine antifouling coating has a low surface energy, which makes it difficult for the mucus secreted by marine organisms to wet, spread and adhere to the coating surface. Even if it adheres, it is not firm and can be easily fallen off by the scouring effect of water when the ship is sailing.

[0086] (2) Resin degradation: The developed drag-reducing surface self-renewing marine antifouling resin contains biodegradable groups. Even if a small amount of fouling organisms are attached, the coating surface can be self-renewed by surface degradation.

[0087] (3) The developed drag-reducing surface self-renewing marine antifouling resin has some epoxy groups added to it, which can improve the adhesion of the coating to the substrate and effectively solve the problems of low mechanical strength and poor adhesion to the substrate of traditional low surface energy coatings.

[0088] (4) The developed drag-reducing surface self-renewing marine antifouling coating is green and environmentally friendly, and has a good antifouling effect even without adding antifouling agents.

[0089] (5) The developed drag-reducing surface self-renewing marine antifouling coating has abundant raw material sources, simple production process, and affordable price, and is easy to industrialize.

[0090] In summary, the drag-reducing, self-renewing marine antifouling coating provided by the present invention has a low surface energy, making it difficult for mucus secreted by marine organisms to wet, spread, and adhere to the coating surface. Even if it does adhere, it is not strong and can be easily removed by the scouring effect of water during navigation. Furthermore, the substrate surface contains biodegradable groups, so even if a small amount of fouling organisms adhere, the coating surface can be self-renewed through surface degradation. The coating exhibits good antifouling effectiveness under both dynamic and static conditions. More importantly, the present invention is simple to operate, low-cost, and suitable for industrial production.

[0091] Compared with the mainstream Wuxi self-polishing coatings on the market, most of them are acrylic resins, which generally only contain hydrolyzable side groups. Their surface renewal depends on the scouring of strong water flow, and the static antifouling effect is not ideal. The antifouling resin prepared by the present invention has excellent low surface energy characteristics. The low surface energy of the coating surface makes it difficult for the mucus secreted by marine organisms to wet, spread and adhere to the coating surface. Even if it adheres, it is not firm. When the ship is sailing, it can be easily desorbed by the scouring effect of the water flow. At the same time, the resin itself also has biodegradable groups. Even if a small amount of fouling organisms are attached, the self-renewal of the coating surface can be achieved by surface degradation. In addition, the resin itself is also added with some epoxy groups, which can improve the adhesion of the coating to the substrate. The operation method of the present invention is simple, the obtained coating is green and environmentally friendly, has low cost, can be applied to a variety of sea areas, and has a wide range of application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 Schematic diagram of the shallow sea immersion experiment of Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, Comparative Example 1 and Comparative Example 2 (corresponding from left to right), wherein (1) is Example 1, (2) is Example 2, (3) is Example 3, (4) is Example 4, (5) is Example 5, (6) is Example 6, (7) is Comparative Example 1, and (8) is Comparative Example 2. DETAILED DESCRIPTION

[0093] The present invention is described in detail below with reference to specific embodiments, but is by no means intended to limit the present invention. Any features, such as preparation methods, materials, structures, or composition ratios, that are not explicitly described in this technical solution are considered to be common technical features disclosed in the prior art.

[0094] The present invention provides a drag-reducing surface self-renewing marine antifouling coating, comprising component A and component B.

[0095] Component A contains the following components:

[0096]

[0097] Component B is an organic amine curing agent.

[0098] More preferably, the A component comprises the following components:

[0099]

[0100] In fact, among silicone monomers, trifunctional monomers (methyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, etc.) can provide cross-linking points, difunctional monomers (dimethyldimethoxysilane, dimethyldiethoxysilane, etc.) can provide a certain degree of flexibility, and the presence of phenyl groups can improve the heat resistance of the prepolymer and its miscibility with organic resins, but at the same time it will also reduce toughness; therefore, the three need to be combined to obtain a silicone prepolymer with excellent performance.

[0101] In fact, the amount of water used during the hydrolysis process directly reflects the degree of hydrolysis. The higher the water usage, the higher the degree of hydrolysis and the larger the molecular weight of the resulting silicone prepolymer. This may result in a low content of active alkoxy groups, or even no active alkoxy groups at all, making it difficult for them to react with hydroxyl groups and hindering further modification of the oligomer.

[0102] Furthermore, we conducted extensive seawater degradation experiments on common biodegradable materials. Taking PLA as an example, under industrial composting conditions (temperature 58±2°C, humidity 98%, and the presence of microorganisms), PLA strips lost 70% of their weight in approximately 50 days and completely degraded within 3-6 months. However, after a year of immersion in either freshwater or the ocean, no significant weight loss was observed, and GPC testing showed no significant change in molecular weight. While other biodegradable materials, such as PBAT and PBS, degrade faster than PLA in seawater, their weight loss after a year of immersion was only around 2%, indicating very slow degradation. Polyglycolic acid, on the other hand, degrades much faster in seawater, with samples losing over 50% of their weight in a single month in a marine environment. Therefore, poly(lactic-co-glycolic acid) copolymer polyols can be used to modulate the degradation rate of resins in the ocean.

[0103] Furthermore, the organosilicon prepolymer obtained by monomer hydrolysis still contains a certain amount of unhydrolyzed alkoxy groups, which can react with the active groups in degradable aliphatic polyester polyols and epoxy resins. Practice has shown that when organosilicon oligomers containing alkoxy groups react with these active groups, only the hydroxyl groups participate in the reaction, while the epoxy groups are largely inactive.

[0104] Furthermore, the surface energy of the marine antifouling coating prepared by the present invention is relatively low, generally less than 25mJ / m 2At this time, it is difficult for hard-shelled marine organisms such as barnacles to attach to its surface, and only a small amount of antifouling agent is needed, or even no antifouling agent is required, to achieve excellent antifouling effect.

[0105] Furthermore, pigments and fillers are important auxiliary materials for preparing marine antifouling coatings. They can give the coatings different colors and glossiness, and at the same time can effectively improve the physical properties of the antifouling coatings and reduce the cost of the antifouling coatings. However, an increase in the proportion of pigments and fillers will increase the surface energy of the coating surface. Therefore, the proportion of pigments and fillers used in the marine antifouling coatings prepared by the present invention should be minimized.

[0106] Furthermore, the addition of a thixotropic agent can improve the adhesion of the marine antifouling coating to the substrate.

[0107] Furthermore, adding an appropriate amount of curing agent (component B) can cause the drag-reducing surface self-renewing marine antifouling coating to undergo a certain degree of cross-linking, thereby increasing the adhesion and hardness of the coating and improving the physical properties of the coating.

[0108] In the following embodiments:

[0109] As a preferred embodiment, the drag-reducing surface self-renewing marine antifouling resin is used as the film-forming resin, and the component A of the drag-reducing surface self-renewing marine antifouling resin can be prepared by the following method:

[0110] (1) According to the ratio, first place the drag-reducing surface self-renewing marine antifouling resin as a film-forming resin solution in a disperser, add thixotropic agent, silane coupling agent and other additives at a speed of 500-1000 r / min, and continue stirring for 10-30 minutes.

[0111] (2) Add pigments, fillers and antifouling agents in the order from liquid to powder and from small to large specific gravity, and continue to disperse at a speed of 500-3000 r / min for 30-60 minutes until the paint fineness is below 60 μm.

[0112] (3) Replenish the solvent according to the viscosity, continue stirring at a speed of 500 to 3000 r / min for 20 minutes, filter and package to obtain the drag-reducing surface self-renewing marine antifouling coating component A.

[0113] Component B is a commercially available product and can be used directly by mixing when applying.

[0114] The surface energy testing method is: testing is performed with reference to the contact angle method in the ISO 8296 standard.

[0115] The present invention has no special restrictions on the raw materials used, and they can be commonly available on the market.

[0116] To further illustrate the present invention, the present invention will be further described below with reference to specific embodiments.

[0117] Poly(lactic-co-glycolic acid) copolymer polyol was purchased from Jiangsu Meijing New Materials Technology Co., Ltd. Fumed silica was purchased from Evonik Degussa. Organic bentonite was purchased from Zhejiang Fenghong New Materials Co., Ltd. Methyl silicone oil was purchased from Shenzhen Jipeng Silicone Fluoride Materials Co., Ltd.

[0118] Example 1:

[0119] This embodiment provides a drag-reducing surface self-renewing marine antifouling coating.

[0120] Preparation of drag-reducing surface self-renewing marine antifouling resin:

[0121] a) adding 136 g (1 mol) of methyltrimethoxysilane, 240 g (2 mol) of dimethyldimethoxysilane, 198 g (1 mol) of phenyltrimethoxysilane, and 100 g of xylene solvent to a reaction kettle, starting stirring, heating to 80° C., adding 0.5 g of phosphoric acid, and then slowly adding 144 g (8 mol) of deionized water dropwise; after the titration is completed, continuing the reaction for 4 h, then adding an excess of sodium carbonate, stirring to neutralize the reaction system, measuring the pH value to be ≥7, and filtering the reactants; removing the alcohol generated by the reaction by atmospheric distillation, and then distilling off trace amounts of alcohol, water, and xylene solvent under reduced pressure to obtain an organosilicon oligomer;

[0122] b) 100 g of the organosilicon oligomer prepared in step A, 10 g of a polylactic acid glycolic acid copolymer polyol with a molecular weight of 2000, 20 g of bisphenol A epoxy resin E44, and 0.2 g of dibutyltin dilaurate were reacted at 150° C. for 5 h. Heating was stopped, the temperature was lowered to below 80° C., and xylene (20% of the total amount of the product) was added for dilution, and the mixture was stirred uniformly to obtain a drag-reducing, surface-self-renewing marine antifouling resin.

[0123] Prepare the marine antifouling coating component A (excluding antifouling agent) according to the following weight ratio:

[0124] Includes: 80g of drag-reducing surface self-renewing marine antifouling resin, 2g of methyl silicone oil with a viscosity of 100cs (silicone oil), 3g of red iron oxide (pigment filler), 0.5g of fumed silica (thixotropic agent), 1g of silane coupling agent γ-aminopropyltriethoxysilane (silane coupling agent), 10g of xylene (solvent), and 3.5g of n-butanol solvent (solvent).

[0125] The curing agent of component B is diethylenetriamine, and the amount used is 3wt% of component A.

[0126] The drag-reducing surface self-renewing marine antifouling coating is prepared by the following method:

[0127] Component A of the drag-reducing surface self-renewing marine antifouling resin can be prepared by the following method:

[0128] (1) According to the ratio, first mix 80g of drag-reducing surface self-renewing marine antifouling resin with 5g of xylene and 3.5g of n-butanol. Add thixotropic agent, silane coupling agent, silicone oil and other additives at a speed of 1000r / min and continue stirring for 20min.

[0129] (2) Add 3g of red iron oxide and continue dispersing at a speed of 2000r / min for 60min.

[0130] (3) According to the viscosity, the remaining 5 g of xylene solvent was added, and stirring was continued at a speed of 2000 r / min for 20 min. The mixture was filtered and packaged to obtain the drag-reducing surface self-renewing marine antifouling coating component A.

[0131] Component B is a commercially available product and can be directly mixed with component A for use during coating.

[0132] Example 2:

[0133] This embodiment provides a drag-reducing surface self-renewing marine antifouling coating.

[0134] Drag-reducing surface self-renewing marine antifouling resin is the same as in Example 1

[0135] Prepare the marine antifouling coating component A (excluding cuprous oxide) according to the following weight ratio:

[0136] The invention comprises: 75g of a drag-reducing, surface-self-renewing marine antifouling resin, 2g of methyl silicone oil (silicone oil) with a viscosity of 500cs, 4g of copper pyrithione (antifouling agent), 4g of red iron oxide (pigment filler), 0.5g of fumed silica (thixotropic agent), 1g of a silane coupling agent γ-glycidyloxypropyltrimethoxysilane (silane coupling agent), 8g of xylene (solvent) and 5.5g of methyl isobutyl ketone solvent (solvent).

[0137] The curing agent of component B is diethylenetriamine, and the amount used is 2wt% of component A.

[0138] The preparation of the drag-reducing surface self-renewing marine antifouling coating is basically the same as in Example 1, except that in step (2), the pigments and antifouling agents are added in the order of liquid to powder and from small to large specific gravity.

[0139] Example 3:

[0140] This embodiment provides a drag-reducing surface self-renewing marine antifouling coating.

[0141] Drag-reducing surface self-renewing marine antifouling resin is the same as in Example 1

[0142] Prepare the marine antifouling coating component A (containing a small amount of cuprous oxide) according to the following weight ratio:

[0143] The invention comprises: 65g of a drag-reducing surface self-renewing marine antifouling resin, 2g of methyl silicone oil with a viscosity of 500cs, 10g of cuprous oxide, 3g of copper pyrithione, 3g of red iron oxide, 0.5g of organic bentonite, 1g of a silane coupling agent γ-glycidyloxypropyltrimethoxysilane, 10g of xylene and 5.5g of butyl acetate solvent.

[0144] The curing agent of component B is diethylenetriamine, and the amount used is 1.8wt% of component A.

[0145] The preparation of the drag-reducing surface self-renewing marine antifouling coating is the same as that in Example 1, except that in step (2), the pigments and antifouling agents are added in the order of liquid to powder and from small to large specific gravity.

[0146] Example 4:

[0147] This embodiment provides a drag-reducing surface self-renewing marine antifouling coating.

[0148] Preparation of drag-reducing surface self-renewing marine antifouling resin:

[0149] a) adding 163.2 g (1.2 mol) of methyltrimethoxysilane, 216 g (1.8 mol) of dimethyldimethoxysilane, 118.8 g (0.6 mol) of phenyltrimethoxysilane, and 100 g of xylene solvent to a reaction kettle, starting stirring, heating to 75° C., adding 0.5 g of phosphoric acid, and then slowly adding 126 g (7 mol) of deionized water dropwise; after the titration is completed, continuing the reaction for 6 h, then adding an excess of sodium carbonate, stirring to neutralize the reaction system, measuring the pH value to be ≥7, and filtering the reactants; removing the alcohol generated by the reaction by atmospheric distillation, and then distilling off trace amounts of alcohol, water, and xylene solvent under reduced pressure to obtain an organosilicon oligomer;

[0150] b) 100 g of the organosilicon oligomer prepared in step A, 8 g of a polylactic acid glycolic acid copolymer polyol with a molecular weight of 1000, 15 g of bisphenol A epoxy resin E51, and 0.4 g of tetrabutyl titanate were reacted at 140° C. for 4 h. Heating was stopped, the temperature was lowered to below 80° C., and xylene (20% of the total amount of the product) was added for dilution, and the mixture was stirred uniformly to obtain a drag-reducing, surface-self-renewing marine antifouling resin.

[0151] Prepare the marine antifouling coating component A (excluding antifouling agent) according to the following weight ratio:

[0152] Includes: 80g of drag-reducing surface self-renewing marine antifouling resin, 2g of methyl silicone oil with a viscosity of 100cs (silicone oil), 3g of red iron oxide (pigment filler), 0.5g of fumed silica (thixotropic agent), 1.5g of silane coupling agent γ-glycidyloxypropyltrimethoxysilane (silane coupling agent), 10g of xylene (solvent), and 3g of n-butanol solvent (solvent).

[0153] The curing agent of component B is triethylenetetramine, and the amount used is 3wt% of component A.

[0154] The preparation of the drag-reducing surface self-renewing marine antifouling coating is the same as that in Example 1.

[0155] Example 5:

[0156] This embodiment provides a drag-reducing surface self-renewing marine antifouling coating.

[0157] Drag-reducing surface self-renewing marine antifouling resin is the same as in Example 4

[0158] Prepare the marine antifouling coating component A (excluding cuprous oxide) according to the following weight ratio:

[0159] The invention comprises: 75g of a drag-reducing, surface-self-renewing marine antifouling resin, 1.5g of methyl silicone oil (silicone oil) with a viscosity of 500cs, 4g of copper pyridinethione (antifouling agent), 4g of red iron oxide (pigment filler), 0.5g of fumed silica (thixotropic agent), 1g of a silane coupling agent γ-aminopropyltriethoxysilane (silane coupling agent), 8g of xylene (solvent) and 6g of methyl isobutyl ketone solvent (solvent).

[0160] The curing agent of component B is triethylenetetramine, and the amount used is 2wt% of component A.

[0161] The preparation of the drag-reducing surface self-renewing marine antifouling coating is the same as that in Example 1, except that in step (2), the pigments and antifouling agents are added in the order of liquid to powder and from small to large specific gravity.

[0162] Example 6:

[0163] This embodiment provides a drag-reducing surface self-renewing marine antifouling coating.

[0164] Drag-reducing surface self-renewing marine antifouling resin is the same as in Example 4

[0165] Prepare the marine antifouling coating component A (containing a small amount of cuprous oxide) according to the following weight ratio:

[0166] The invention comprises: 65 g of a drag-reducing, surface-self-renewing marine antifouling resin, 2 g of methyl silicone oil (silicone oil) with a viscosity of 500 cs, 10 g of cuprous oxide (antifouling agent), 3 g of copper pyridinethione (antifouling agent), 3 g of red iron oxide (pigment filler), 0.5 g of organic bentonite (thixotropic agent), 1 g of silane coupling agent γ-glycidyloxypropyltrimethoxysilane (silane coupling agent), 10 g of xylene (solvent) and 5.5 g of butyl acetate solvent (solvent).

[0167] The curing agent of component B is triethylenetetramine, and the amount used is 1.8wt% of component A.

[0168] The preparation of the drag-reducing surface self-renewing marine antifouling coating is the same as that in Example 1, except that in step (2), the pigments and antifouling agents are added in the order of liquid to powder and from small to large specific gravity.

[0169] Comparative Example 1:

[0170] This comparative example provides a marine antifouling coating.

[0171] Preparation of drag-reducing surface self-renewing marine antifouling resin:

[0172] a) adding 298 g (1.5 mol) of methyltrimethoxysilane, 240 g (2 mol) of dimethyldimethoxysilane, 99 g (0.5 mol) of phenyltrimethoxysilane, and an appropriate amount of xylene solvent to a reaction kettle, starting stirring, heating to 80° C., adding 0.5 g of phosphoric acid, and then slowly dripping 144 g (8 mol) of deionized water; after the titration is completed, continuing the reaction for 6 h, then adding excess sodium carbonate, stirring to neutralize the reaction system, measuring the pH value to be ≥7, and filtering the reactants; removing the alcohol generated by the reaction by atmospheric distillation, and then distilling off trace amounts of alcohol, water, and xylene solvent under reduced pressure to obtain an organosilicon oligomer;

[0173] b) 100 g of the organosilicon oligomer prepared in step A, 10 g of a polylactic acid glycolic acid copolymer polyol with a molecular weight of 2000, and 0.2 g of dibutyltin dilaurate were reacted at 150° C. for 5 h. The heating was stopped, the temperature was lowered to below 80° C., 20% xylene was added for dilution, and the mixture was stirred to obtain a drag-reducing, surface-self-renewing marine antifouling resin.

[0174] Prepare the marine antifouling coating components (containing a small amount of cuprous oxide) according to the following weight ratio:

[0175] The invention comprises: 65 g of a drag-reducing, surface-self-renewing marine antifouling resin, 2 g of methyl silicone oil (silicone oil) with a viscosity of 500 cs, 10 g of cuprous oxide (antifouling agent), 3 g of copper pyridinethione (antifouling agent), 3 g of red iron oxide (pigment filler), 0.5 g of organic bentonite (thixotropic agent), 1 g of silane coupling agent γ-glycidyloxypropyltrimethoxysilane (silane coupling agent), 10 g of xylene (solvent) and 5.5 g of butyl acetate solvent (solvent).

[0176] The preparation of the marine antifouling coating is the same as in Example 1, excluding the B component.

[0177] Comparative Example 2:

[0178] This comparative example provides a marine antifouling coating.

[0179] Preparation of drag-reducing surface self-renewing marine antifouling resin:

[0180] a) adding 163.2 g (1.2 mol) of methyltrimethoxysilane, 216 g (1.8 mol) of dimethyldimethoxysilane, 118.8 g (0.6 mol) of phenyltrimethoxysilane, and 100 g of xylene solvent to a reaction kettle, starting stirring, heating to 75° C., adding 0.5 g of phosphoric acid, and then slowly adding 126 g (7 mol) of deionized water dropwise; after the titration is completed, continuing the reaction for 6 h, then adding an excess of sodium carbonate, stirring to neutralize the reaction system, measuring the pH value to be ≥7, and filtering the reactants; removing the alcohol generated by the reaction by atmospheric distillation, and then distilling off trace amounts of alcohol, water, and xylene solvent under reduced pressure to obtain an organosilicon oligomer;

[0181] b) 50 g of the organosilicon oligomer prepared in step A, 8 g of a polylactic acid glycolic acid copolymer polyol with a molecular weight of 1000, 50 g of bisphenol A epoxy resin E51, and 0.4 g of tetrabutyl titanate were reacted at 140° C. for 4 h. The heating was stopped, the temperature was lowered to below 80° C., and xylene (20% of the total amount of the product) was added for dilution, and the mixture was stirred uniformly to obtain a drag-reducing, surface-self-renewing marine antifouling resin.

[0182] Prepare the marine antifouling coating component A (excluding antifouling agent) according to the following weight ratio:

[0183] Includes: 80g of drag-reducing surface self-renewing marine antifouling resin, 2g of methyl silicone oil with a viscosity of 100cs (silicone oil), 3g of red iron oxide (pigment filler), 0.5g of fumed silica (thixotropic agent), 1.5g of silane coupling agent γ-glycidyloxypropyltrimethoxysilane (silane coupling agent), 10g of xylene (solvent), and 3g of n-butanol solvent (solvent).

[0184] The curing agent of component B is triethylenetetramine, and the amount used is 9wt% of component A.

[0185] Coating adhesion refers to the ability of a coating to bond with the surface of the coated object. It is an important technical indicator and a prerequisite for a coating to possess a series of properties. Coatings with good adhesion are durable and have the properties required for use. Paint films with poor adhesion are prone to cracking, peeling, and becoming unusable. Therefore, coating adhesion strength is one of the important indicators for evaluating the quality of marine antifouling coatings. Coating adhesion strength is measured using a tensile method. Using a metal sheet coated with epoxy zinc-rich primer as the substrate, the eight marine antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were tested for adhesion strength according to ASTM D 4541. As shown in Table 1, the antifouling coatings prepared in Examples 1 to 6 and Comparative Example 2 all had adhesion strengths exceeding 1 MPa, meeting the requirements for use in marine antifouling coatings. In particular, the antifouling coating in Comparative Example 2, which has a higher epoxy resin content, has a greater adhesion strength exceeding 2 MPa. However, the antifouling coating prepared in Comparative Example 1, due to the lack of epoxy resin, has a lower adhesion strength and is unlikely to meet the requirements for use in marine antifouling coatings.

[0186] Table 1. Adhesion of coatings

[0187]

[0188]

[0189] The surface energy of marine antifouling coatings is an important factor affecting the drag reduction performance of marine antifouling coatings. Coatings with low surface energy can prevent the initial attachment of marine organisms and reduce the resistance generated during the navigation of ships, thereby achieving a drag reduction effect. The eight marine antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were tested for their surface energy by referring to the contact angle method in the ISO 8296 standard. As shown in Table 2, the surface energy of the antifouling coatings prepared in Examples 1 to 6 and Comparative Example 1 was all lower than 25 mJ / m 2 , has low surface energy characteristics, and can play a role in drag reduction. Among them, the content of inorganic filler in Example 4 and Example 6 is relatively high, and its surface energy is also improved; while in Comparative Example 2, due to the high proportion of epoxy resin, its surface energy is relatively high, and it is difficult to play a role in drag reduction.

[0190] Table 2. Surface energy of coatings

[0191] <![CDATA[Surface energy (mJ / m 2 )]]> Example 1 23.2±0.1 Example 2 23.6±0.1 Example 3 24.7±0.1 Example 4 22.8±0.1 Example 5 23.3±0.1 Example 6 24.3±0.1 Comparative Example 1 22.6±0.1 Comparative Example 2 28.8±0.1

[0192] The eight marine antifouling coatings prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were subjected to a shallow sea immersion test in accordance with the national standard GB / T5370-2007 "Shallow Sea Immersion Test Method for Antifouling Paint Samples". The test was conducted in Luomen sea area of ​​Zhoushan City. No antifouling agent was added to Examples 1 and 4, no cuprous oxide antifouling agent was added to Examples 2 and 5, and a small amount of cuprous oxide antifouling agent was added to Examples 3 and 6. The test period was from July 22, 2022 to July 19, 2023, with a period of one year.

[0193] The results are as follows Figure 1 As shown, after one year of shallow sea immersion testing, the surfaces of the samples of Examples 1 to 6 remained smooth, with little marine organism adhesion, except for slight color differences when the resins were different, and had good antifouling performance. However, in Comparative Example 1, although there was little marine organism adhesion due to poor adhesion, the coating showed shedding and blistering. In Comparative Example 2, due to the higher proportion of epoxy resin, its surface energy was higher, and the antifouling effect was less than ideal. The method of the present invention is simple to operate, low in cost, and suitable for industrial production.

[0194] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A drag-reducing surface self-renewing marine antifouling coating, characterized in that: The marine antifouling paint comprises component A and component B, Wherein component A comprises the following components in percentage by weight: Drag-reducing surface self-renewal marine antifouling resin 20~80%, Silicone oil 1~5%, Antifouling agent 0~20%, Pigments and fillers 1~20%, Thixotropic agent 0~5%, Silane coupling agent: 0~3%, Solvent 10~30%; Component B is an organic amine curing agent; The structure of the drag-reducing surface self-renewing marine antifouling resin is shown in the following formula (I): (I)； Wherein, m, n are integers; R represents a methyl group or a phenyl group; R' represents a methyl group or an ethyl group; R1 represents a degradable aliphatic polyester, specifically comprising one of the following structural formula (II): (II); Among them, R4, R5, and R6 are alkyl groups or aromatic groups with a carbon number of 1 or greater, and a, b, x, y, and z represent integers of 1 or greater; among them, R2 and R3 represent corresponding groups of epoxy resin.

2. The drag-reducing surface self-renewing marine antifouling coating according to claim 1, characterized in that: The preparation of the drag-reducing surface self-renewing marine antifouling resin comprises the following steps: a) Mixing and stirring the organosilicon monomer and xylene solvent, heating, adding a hydrolysis accelerator, and beginning to dropwise add deionized water; after titration is complete, continuing the reaction, then adding an excess of sodium carbonate, stirring to neutralize the reaction system, and measuring the pH value to be ≥7, filtering the reactants; removing the alcohol generated by the reaction by atmospheric distillation, and then distilling off the alcohol, water, and xylene solvent under reduced pressure to obtain an organosilicon oligomer; b) heating the prepared organosilicon oligomer, degradable aliphatic polyester polyol, epoxy resin and catalyst to react, cooling, diluting with xylene, and stirring uniformly to obtain a drag-reducing surface self-renewing marine antifouling resin.

3. The drag-reducing surface self-renewing marine antifouling coating according to claim 2, characterized in that: The organosilicon monomer in step a) includes one or more of methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane and tetraethoxysilane; or The hydrolysis accelerator in step a) includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, p-toluenesulfonic acid, sodium hydroxide and potassium hydroxide; or, The amount of deionized water added in step a) is 50-100% of the amount of water required for complete hydrolysis.

4. The drag-reducing surface self-renewing marine antifouling coating according to claim 2, characterized in that: The degradable aliphatic polyester polyol in step b) comprises one or more of polylactic acid polyol, polylactic acid glycolic acid copolymer polyol, polycaprolactone polyol and polybutylene succinate polyol; the molecular weight of the degradable aliphatic polyester polyol is 300-10000; or, The epoxy resin in step b) includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin and bisphenol S epoxy resin; or The catalyst in step b) comprises one or more of stannous octoate, stannous chloride, dibutyltin dilaurate, potassium hydroxide, and methanesulfonic acid; the amount of the catalyst is 0.01-2 wt% of the mass of all monomers; or, The mass ratio of the organosilicon oligomer, the degradable aliphatic polyester polyol, and the epoxy resin in step b) is 30-90:5-30:5-30.

5. The drag-reducing surface self-renewing marine antifouling coating according to claim 1, characterized in that: The silicone oil in component A is one or more of methyl silicone oil, phenyl silicone oil, hydroxy silicone oil and amino silicone oil; the viscosity is 100~10000cs; The antifouling agent in component A includes one or more of cuprous oxide, copper pyrithione, mancozeb, and (4,5-dichloro-N-octyl-4-isothiazolin-3-one)isothiazolinone derivatives; or The pigments and fillers in component A include one or more of nano-silicon dioxide, polytetrafluoroethylene, zinc oxide, calcium carbonate, talc, titanium dioxide and red iron oxide; or The thixotropic agent in component A includes one or more of organic bentonite, fumed silica and polyamide wax; or The silane coupling agent in component A includes one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane; or The solvent in component A is one or more of toluene, xylene, n-butanol, ethyl acetate, butyl acetate and methyl isobutyl ketone.

6. The drag-reducing surface self-renewing marine antifouling coating according to claim 1, characterized in that: The organic amine curing agent in component B includes one or more of diethylenetriamine, triethylenetetramine, ethylenediamine, hexamethylenediamine, diethylaminopropylamine and polyamide.

7. The drag-reducing surface self-renewing marine antifouling coating according to claim 1, characterized in that: The mass ratio of component A to component B is 1~100:

1.

8. A method for preparing a drag-reducing surface self-renewing marine antifouling coating according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: During coating, component A and component B are mixed to obtain a drag-reducing surface self-renewing marine antifouling coating.

9. The method for preparing a drag-reducing surface self-renewing marine antifouling coating according to claim 8, characterized in that: The preparation of the A component comprises the following steps: (1) First, according to the ratio, the drag-reducing surface self-renewing marine antifouling resin is mixed with the solvent, and then the thixotropic agent, silane coupling agent and silicone oil are added at a speed of 500-1000 r / min, and the stirring is continued for 10-30 minutes; (2) Add pigments, fillers and antifouling agents and continue dispersing at a speed of 500-3000 r / min for 30-60 minutes; (3) Replenish the solvent according to the viscosity, continue stirring at a speed of 500-3000 r / min for 20 min, filter and package to obtain component A of the drag-reducing surface self-renewing marine antifouling coating.

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