Flexible anti-fouling and drag-reducing composite coating with temperature responsiveness, its preparation method and application

Abstract

The present invention discloses a temperature-responsive flexible anti-fouling and drag-reducing composite coating, its preparation method and application. The flexible anti-fouling and drag-reducing composite coating comprises a base layer, a flexible buffer layer, an anti-fouling responsive layer and a hydrophobic surface layer formed in sequence on the surface of a substrate; wherein, the base layer comprises an adhesive resin, a positively charged polymer and particulate fillers; the flexible buffer layer comprises a flexible polymer resin, a negatively charged polymer, a polymer drag reducer and an anti-ultraviolet additive; the hydrophobic surface layer comprises a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating anti-fouling agents, pore-forming agents, anti-ultraviolet additives and superhydrophobic micro-nano particles. The temperature-responsive flexible anti-fouling and drag-reducing composite coating provided by the present invention has strong binding force with the substrate, and also has anti-fouling property, corrosion protection performance and drag-reducing performance; at the same time, the preparation method provided by the present invention has the advantages of wide application range and large-area coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine coating protection, and particularly relates to a flexible antifouling and drag reduction composite coating with temperature responsiveness, its preparation method and application. Background Art

[0002] With the acceleration of the industrialization process, antifouling and drag reduction have become problems to be solved urgently in many fields, especially in the marine transportation and water treatment industries. The problem of biological attachment (such as the attachment of mussels, algae and other organisms) on the surfaces of ships and marine structures is very common, and the resulting increase in frictional resistance has become the main reason for the reduction of operating efficiency and the increase of energy consumption. Therefore, the development of a new type of antifouling coating to cope with and adapt to different environmental conditions has been the focus of continuous attention in the industry. At present, the flexible drag reduction technology is a key research direction in the drag reduction technology. Its drag reduction mechanism relies on the flexible effect to suppress and absorb the wave change of water pressure and delay the transition from laminar flow to turbulent flow, so as to achieve an effective drag reduction effect. However, in practical applications, it is difficult to cope with complex and changeable environments only by the flexible mechanism, and it is also impossible to avoid the dilemma of losing the drag reduction performance due to the attachment of marine organisms under long-term seawater immersion. Through the multi-layer structure design, effectively integrating a variety of compounds with special functions together to achieve the goal of integrating the functions of antifouling, drag reduction and hydrophobicity with the synergistic enhancement of chemical control and physical repulsion is an innovative idea. Therefore, this temperature-responsive antifouling and drag reduction coating has broad application prospects and will bring major technological breakthroughs and economic benefits to the marine transportation and water treatment industries. Summary of the Invention

[0003] The main object of the present invention is to provide a flexible antifouling and drag reduction composite coating with temperature responsiveness, its preparation method and application, so as to overcome the deficiencies of the prior art.

[0004] To achieve the foregoing invention object, the technical solutions adopted by the present invention include:

[0005] An embodiment of the present invention provides a flexible antifouling and drag reduction composite coating with temperature responsiveness, which includes: a base layer, a flexible buffer layer, an antifouling response layer and a hydrophobic surface layer formed in sequence on the surface of a substrate;

[0006] Among them, the base layer includes an adhesive resin, a positively charged polymer, and particulate fillers; the flexible buffer layer includes a flexible polymer resin, a negatively charged polymer, a polymer drag reducer, and an anti-ultraviolet additive; the anti-fouling responsive layer includes a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, and an anti-ultraviolet additive; the hydrophobic surface layer includes a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, a pore-forming agent, an anti-ultraviolet additive, and superhydrophobic micro-nano particles; the positively charged polymer includes polyvinylamine and / or poly(dimethylaminoethyl methacrylate); the negatively charged polymer includes any one or a combination of two or more of polyvinyl alcohol acid, polyethersulfone, and sodium polystyrene sulfonate.

[0007] The embodiment of the present invention also provides a preparation method of the aforementioned flexible anti-fouling and drag-reducing composite coating with temperature responsiveness, which includes:

[0008] Applying a first base liquid containing at least an adhesive resin, a positively charged polymer, particulate fillers, and a diluent to the surface of a substrate and performing a first curing treatment to form a base layer with a multi-level micro-nano structure;

[0009] Applying a second base liquid containing at least a flexible polymer resin, a negatively charged polymer, a polymer drag reducer, an anti-ultraviolet additive, and a solvent to the surface of the base layer and performing a second curing treatment to form a flexible buffer layer;

[0010] Applying a third base liquid containing at least a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, an anti-ultraviolet additive, and a solvent to the surface of the flexible buffer layer and performing a third curing treatment to form an anti-fouling responsive layer;

[0011] And applying a fourth base liquid containing at least a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, a pore-forming agent, an anti-ultraviolet additive, superhydrophobic micro-nano particles, and a solvent to the surface of the anti-fouling responsive layer and performing a fourth curing treatment to form a hydrophobic surface layer, thereby obtaining a flexible anti-fouling and drag-reducing composite coating with temperature responsiveness.

[0012] The embodiment of the present invention also provides an application of the aforementioned flexible anti-fouling and drag-reducing composite coating with temperature responsiveness in the intelligent protection of the hull shell, pipelines, offshore platforms, or the surfaces of underwater structures.

[0013] The embodiment of the present invention also provides a method for reducing the navigation resistance of a vehicle, which includes: covering at least the surface of the vehicle in contact with a liquid with the aforementioned flexible anti-fouling and drag-reducing composite coating with temperature responsiveness.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] First, the base layer of the present invention has a unique design. It not only has a strong interfacial bonding force with the substrate and is firmly bonded to the substrate, but also uses the interaction between positively charged polymers and negatively charged polymers to generate a strong interfacial bonding with the flexible buffer layer, ensuring the stability and durability of the coating. Secondly, the introduction of the flexible buffer layer, with its excellent flexibility, mechanical buffering and deformation capabilities, significantly improves the drag reduction performance. The design of this layer enables the coating to better adapt to and cope with the water flow shear force, thereby reducing resistance and improving the propulsion efficiency of the ship. Furthermore, the flexible anti-fouling response layer in the present invention mainly functions to store and release anti-fouling agents. Under thermal response conditions, through the loose structural channels of the hydrophobic surface layer, the anti-fouling agents can slowly diffuse, effectively preventing the attachment of dirt and keeping the surface clean. This design not only improves efficiency but also extends the service life. In addition, the hydrophobic surface layer and the anti-fouling response layer use the same flexible polymer resin, which ensures a strong interfacial bonding between the two and is beneficial to the overall performance of the coating. At the same time, the hydrophobic structure naturally has the ability to reduce the attachment of pollution, further enhancing the anti-fouling performance of the coating. Finally, the four-layer structure of the present invention acts synergistically to achieve a multi-functional coating with thermal response, anti-fouling and hydrophobic integration. This design not only improves the drag reduction and anti-fouling performance of the coating, but also provides corrosion protection and physical barrier, comprehensively protecting the ship equipment. At the same time, the preparation method adopted by the present invention has the advantages of wide application range and suitability for large-area coating, providing an ideal solution for the upgrading of the ship propulsion system. In summary, the present invention has significant advantages and outstanding effects in technology, and will bring significant energy conservation, emission reduction and economic benefits to the ship industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of a flexible anti-fouling and drag reduction composite coating with temperature responsiveness in a typical implementation scheme of the present invention.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS: 1 - Substrate, 2 - Base layer, 3 - Flexible buffer layer, 4 - Anti-fouling response layer, 5 - Hydrophobic surface layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In view of the deficiencies of the prior art, through long-term research and a large number of practices, the inventors of this case have been able to propose the technical solution of the present invention. The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work fall within the scope of protection of the present invention.

[0020] Specifically, as an aspect of the technical solution of the present invention, a flexible anti-fouling and drag-reducing composite coating with temperature responsiveness includes: a base layer, a flexible buffer layer, an anti-fouling response layer, and a hydrophobic surface layer formed in sequence on the surface of a substrate;

[0021] Among them, the base layer includes an adhesive resin, a positively charged polymer, and particulate fillers; the flexible buffer layer includes a flexible polymer resin, a negatively charged polymer, a polymer drag reducer, and an anti-ultraviolet additive; the anti-fouling response layer includes a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, and an anti-ultraviolet additive; the hydrophobic surface layer includes a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, a pore-forming agent, an anti-ultraviolet additive, and superhydrophobic micro-nano particles; the positively charged polymer includes polyvinylamine and / or poly(dimethylaminoethyl methacrylate); the negatively charged polymer includes any one or a combination of two or more of polyvinyl alcohol acid, polyethersulfone, and sodium polystyrene sulfonate.

[0022] In the present invention, the function of the base layer is not only to have a strong interfacial bonding force with the substrate, but also to generate a strong interfacial bonding force with the flexible buffer layer through the positively charged polymer and the negatively charged polymer; the flexible buffer layer provides mechanical buffering and deformation ability with excellent flexibility and improves the drag-reducing performance; the main function of the flexible anti-fouling response layer is to provide storage and release of the anti-fouling agent. Under the thermal response, the anti-fouling agent is slowly diffused and released through the loose structure channels of the hydrophobic surface layer; the hydrophobic surface layer and the anti-fouling response layer use the same flexible polymer resin, which can ensure strong interfacial bonding. On the one hand, a porous structure is in-situ formed under the action of the pore-forming agent, providing a structural channel for the diffusion of the anti-fouling agent. On the other hand, the hydrophobic structure naturally has the ability to reduce the attachment of pollutants. Under the synergistic action of the four-layer structure, a multi-functional coating integrating thermal response, anti-fouling, and hydrophobicity is realized.

[0023] In some preferred embodiments, the thickness of the base layer is 20-60 μm.

[0024] In some preferred embodiments, the thickness of the flexible buffer layer is 0.1-0.5 mm.

[0025] In some preferred embodiments, the thickness of the anti-fouling response layer is 0.1-0.5 mm.

[0026] In some preferred embodiments, the thickness of the hydrophobic surface layer is 10 - 60 μm.

[0027] In some preferred embodiments, the method for preparing the temperature-responsive polymer microcapsules encapsulating an antifouling agent includes:

[0028] Emulsifying and polymerizing a temperature-responsive polymer monomer, an antifouling agent, a crosslinking agent, an initiator, and nucleating particles in a water-oil solution at 50 - 80 °C for 12 - 24 h to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0029] Furthermore, the temperature-responsive polymer monomer includes N-isopropylacrylamide, and is not limited thereto.

[0030] Furthermore, the antifouling agent includes any one or a combination of two or more of copper pyrithione, zinc pyrithione, and chitosan, and is not limited thereto.

[0031] Furthermore, the crosslinking agent includes any one or a combination of two or more of N,N'-methylenebisacrylamide (MBA), divinylbenzene, and diisocyanate, and is not limited thereto.

[0032] Furthermore, the initiator includes any one or a combination of two or more of potassium persulfate (KPS), azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (AIBME), and azodiisooctanenitrile, and is not limited thereto.

[0033] Furthermore, the nucleating particles include any one or a combination of two or more of gaseous hydrophobic SiO 2 , gaseous hydrophilic SiO 2 , TiO 2 , Al 2 O 3 , and is not limited thereto.

[0034] In some more specific embodiments, the structural schematic diagram of the temperature-responsive flexible antifouling and drag reduction composite coating is as Figure 1 shown, including a substrate 1, a base layer 2, a flexible buffer layer 3, an antifouling response layer 4, and a hydrophobic surface layer 5.

[0035] The present invention aims to invent a multi-layer composite structure coating that has both room temperature-responsive antifouling and elasticity, provides a flexible drag reduction function with a flexible elastic resin, provides antifouling property with room temperature-responsive antifouling capsules, and combines a hydrophobic surface layer to achieve physical isolation and corrosion protection performance. The provided temperature-responsive flexible antifouling and drag reduction functional coating has a significant drag reduction and antifouling effect, and also has excellent bonding strength, durability, corrosion protection, etc. At the same time, the preparation method adopted by the present invention has advantages such as a wide application range and large-area coating.

[0036] Another aspect of the embodiments of the present invention also provides a preparation method of the aforementioned flexible anti-fouling and drag-reducing composite coating with temperature responsiveness, which includes:

[0037] Applying a first base liquid containing at least an adhesive resin, a positively charged polymer, a particulate filler, and a diluent to the surface of a substrate and subjecting it to a first curing treatment to form a base layer with a hierarchical micro-nano structure;

[0038] Applying a second base liquid containing at least a flexible polymer resin, a negatively charged polymer, a polymer drag reducer, an anti-ultraviolet additive, and a solvent to the surface of the base layer and subjecting it to a second curing treatment to form a flexible buffer layer;

[0039] Applying a third base liquid containing at least a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, an anti-ultraviolet additive, and a solvent to the surface of the flexible buffer layer and subjecting it to a third curing treatment to form an anti-fouling response layer;

[0040] And, applying a fourth base liquid containing at least a flexible polymer resin, temperature-responsive polymer microcapsules encapsulating an anti-fouling agent, a pore-forming agent, an anti-ultraviolet additive, superhydrophobic micro-nano particles, and a solvent to the surface of the anti-fouling response layer and subjecting it to a fourth curing treatment to form a hydrophobic surface layer, thereby obtaining a flexible anti-fouling and drag-reducing composite coating with temperature responsiveness.

[0041] In some preferred embodiments, the preparation method specifically includes: applying the first base liquid to the surface of the substrate by spraying or brushing and subjecting it to a curing treatment at room temperature for 12 - 24 h to form the base layer.

[0042] In some preferred embodiments, the preparation method specifically includes: applying the second base liquid to the surface of the base layer by spraying or brushing and subjecting it to a curing treatment at room temperature for 4 - 12 h to form a flexible buffer layer.

[0043] In some preferred embodiments, the preparation method specifically includes: applying the third base liquid to the surface of the flexible buffer layer by spraying or brushing and subjecting it to a curing treatment at room temperature for 12 - 24 h to form the anti-fouling response layer.

[0044] In some preferred embodiments, the preparation method specifically includes: applying the fourth base liquid to the surface of the anti-fouling response layer by spraying or brushing and subjecting it to a curing treatment at room temperature for 12 - 24 h to form the hydrophobic surface layer.

[0045] In some preferred embodiments, the mass ratio of the adhesive resin, the positively charged polymer, the particulate filler, and the diluent in the first base liquid is 10 - 50:0.5 - 5:0.5 - 5:0 - 30.

[0046] In some preferred embodiments, the mass ratio of the flexible polymer resin, negatively charged polymer, polymer drag reducer, UV-resistant additive to the solvent in the second base liquid is 20~50: 0.5~5: 0.5~5: 0.5 - 5: 0~30.

[0047] In some preferred embodiments, the mass ratio of the flexible polymer resin, temperature-responsive polymer microcapsules encapsulating antifouling agent to the solvent in the third base liquid is 30~40: 1~5: 0~30.

[0048] In some preferred embodiments, the mass ratio of the flexible polymer resin, temperature-responsive polymer microcapsules encapsulating antifouling agent, pore former, UV-resistant additive, superhydrophobic micro-nano particles to the solvent in the fourth base liquid is 20~50: 0~5: 0~5: 0~2: 0~5: 0~30.

[0049] In some preferred embodiments, the adhesive resin includes any one or a combination of two or more of modified epoxy resin, epoxy zinc-rich primer, acrylic polyurethane paint, amino organosilicon resin, polyurethane, fluorinated modified epoxy resin, and is not limited thereto.

[0050] In some preferred embodiments, the particulate filler includes any one or a combination of two or more of kaolin, talcum powder, mica powder, zinc oxide, titanium dioxide, silicon dioxide, glass microspheres, diatomaceous earth, and is not limited thereto.

[0051] In some preferred embodiments, the particle size of the particulate filler is 1~100 μm, and is not limited thereto.

[0052] In some preferred embodiments, the diluent includes any one or a combination of two or more of toluene, xylene, ethanol, ethyl acetate, butyl acetate, propylene glycol methyl ether, formamide, and is not limited thereto.

[0053] In some preferred embodiments, the flexible polymer resin includes any one or a combination of two or more of silicone resin, polyurethane, acrylic-modified silicone resin, polyurea, and is not limited thereto.

[0054] In some preferred embodiments, the polymer drag reducer includes any one or a combination of two or more of polyacrylamide, polyvinyl alcohol, sodium polyisopropacrylate, polyvinylpyrrolidone, and is not limited thereto.

[0055] In some preferred embodiments, the UV-resistant additive includes any one or a combination of two or more of 2-hydroxy-4-methoxybenzophenone, 2-(2H-benzotriazol-2-yl)-4,6-bis(2-methylmethylamino-ethyl)-phenol, 2-hydroxyphenol and its derivatives, octyl salicylate, and is not limited thereto.

[0056] In some preferred embodiments, the solvent includes any one or a combination of two or more of toluene, xylene, ethyl acetate, acetone, ethanol, butanol, and butyl acetate, and is not limited thereto.

[0057] In some preferred embodiments, the substrate includes any one or a combination of two or more of a steel substrate, an aluminum alloy substrate, and a copper alloy substrate, and is not limited thereto.

[0058] In some preferred embodiments, the pore-forming agent includes any one or a combination of two or more of sodium chloride, lactose, sucrose, ammonium bicarbonate, and sodium bicarbonate, and is not limited thereto.

[0059] In some preferred embodiments, the method for preparing the superhydrophobic micro-nano particles includes: mixing micro-nano particles, ammonia water, tetraethyl orthosilicate, a hydrophobic treatment modifier, and water and reacting for 6 to 24 h to obtain the superhydrophobic micro-nano particles; wherein, the hydrophobic treatment modifier includes any one or a combination of two or more of alkyl siloxane, alkyl chlorosilane, fluoroalkyl siloxane, alkyl organosilane, and perfluoroalkyl organosilane, and is not limited thereto.

[0060] Another aspect of the embodiments of the present invention also provides an application of the foregoing flexible antifouling and drag reduction composite coating with temperature responsiveness in the intelligent protection of the hull outer shell, pipelines, offshore platforms, or the surfaces of underwater structures.

[0061] Another aspect of the embodiments of the present invention also provides a method for reducing the navigation resistance of a vehicle, which includes: covering at least the surface of the vehicle in contact with the liquid with the foregoing flexible antifouling and drag reduction composite coating with temperature responsiveness.

[0062] The technical solutions of the present invention will be further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. These embodiments are implemented on the premise of the technical solutions of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0063] In the following embodiments, the experimental materials used can be purchased from conventional biochemical reagent companies without special instructions.

[0064] Example 1

[0065] (1) 68 wt.% epoxy zinc-rich primer, 2 wt.% polyvinylamine, and 7 wt.% kaolin were dissolved in xylene and mixed evenly to obtain a first base liquid; the base liquid was brush-coated on the surface of the steel substrate and cured at room temperature for 12 h to form a base layer;

[0066] (2) Dissolve 78 wt.% of a single-component highly elastic silicone resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of polyvinyl alcohol, and 3 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a second base liquid; in-situ brush coat this base liquid on the surface of the above-mentioned base layer, and cure it at room temperature for 8 h to form a flexible buffer layer;

[0067] (3) Dissolve 40 wt.% of a single-component highly elastic silicone resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a third base liquid; in-situ brush coat this base liquid on the surface of the above-mentioned flexible buffer layer, and cure it at room temperature for 12 h to form an antifouling-responsive layer;

[0068] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0069] Disperse 1.5 g of gaseous hydrophobic SiO 2 particles (30 nm) in 100 ml of deionized water to prepare an aqueous phase, add 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene to prepare an oil phase, then mix the two phases of water and oil at a volume ratio of 1 / 3, and carry out a high-speed stirring reaction at 50 °C for 12 h, centrifuge, and dry to obtain poly(N-isopropylacrylamide) microcapsule particles. Add 1 g of the above microcapsule particles to an ethanol solution of 40 g / L of zinc pyrithione, mix well, stir for 12 h, then centrifuge and dry to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0070] (4) Dissolve 30 wt.% of a single-component highly elastic silicone resin, 1 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, 1 wt.% of sodium chloride, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles in xylene, and uniformly mix them by mechanical stirring to obtain a fourth base liquid; in-situ brush coat this base liquid on the surface of the above-mentioned antifouling-responsive layer, and cure it at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating;

[0071] Among them, the preparation method of the superhydrophobic micro-nano particles is as follows:

[0072] Sequentially add 5 wt.% of SiO 2Nanoparticles (30 nm), 10 wt.% ammonia water, 5 wt.% deionized water, 4 wt.% tetraethyl silicate, and 2 wt.% perfluoroalkyl chlorosilane were added to anhydrous ethanol and reacted with continuous mechanical stirring for 8 h. After the reaction was completed, the solution was rotary evaporated to dryness to obtain superamphiphobic SiO 2 Nanoparticles.

[0073] Example 2

[0074] (1) 75 wt.% acrylic polyurethane paint, 2 wt.% polydimethylaminoethyl methacrylamide, and 7 wt.% zinc oxide were dissolved in ethyl acetate and mixed evenly to obtain a first base liquid; the base liquid was brushed on the surface of the steel substrate and cured at room temperature for 12 hours to form a base layer;

[0075] (2) 78 wt.% of a single-component flexible polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of polyvinyl alcohol, and 1 wt.% of 2-(2H-benzotriazine-2-yl)-4,6-bis(2-methylmethylamino-ethyl)-phenol were dissolved in ethyl acetate and uniformly stirred mechanically to obtain a second base liquid; the base liquid was applied in situ on the surface of the above-mentioned base layer and cured at room temperature for 8 hours to form a flexible buffer layer;

[0076] (3) 60 wt.% of a single-component flexible polyurethane resin, 4 wt.% of a temperature-responsive polymer microcapsule encapsulating an antifouling agent, and 2 wt.% of 2-(2H-benzotriazine-2-yl)-4,6-bis(2-methylmethylamino-ethyl)-phenol were dissolved in ethyl acetate and uniformly stirred mechanically to obtain a third base liquid; the base liquid was in situ brushed on the surface of the above-mentioned flexible buffer layer, and cured at room temperature for 12 hours to form an antifouling responsive layer;

[0077] The preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0078] 1.5 g of fumed hydrophobic SiO 2 The particles (30 nm) were dispersed in 100 ml of deionized water to prepare the water phase, and 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) were added to 50 ml of xylene to prepare the oil phase, and then the water and oil phases were mixed at a volume ratio of 1 / 3, stirred at high speed for 12 hours at 50°C, centrifuged, and dried to obtain poly (N-isopropylacrylamide) microcapsule particles. 1 g of the above microcapsule particles was added to a 40 g / L zinc pyridinethione ethanol solution and mixed thoroughly, stirred for 12 hours, centrifuged, and dried to obtain temperature-responsive polymer microcapsules encapsulating antifouling agents.

[0079] (4) Dissolve 30 wt.% of a single-component highly elastic silicone resin, 1 wt.% of temperature-responsive polymer microcapsules encapsulated with an antifouling agent, 2 wt.% of ammonium bicarbonate, 1 wt.% of 2-(2H-benzotriazol-2-yl)-4,6-bis(2-methylmethylaminoethyl)-phenol, and 5 wt.% of superhydrophobic micro-nano particles in ethyl acetate, and stir evenly by mechanical stirring to obtain a fourth base liquid; brush-coat this base liquid in situ on the surface of the above-mentioned antifouling response layer, and cure it at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating;

[0080] The preparation method of the superhydrophobic micro-nano particles is as follows:

[0081] Sequentially add 5 wt.% of diatomite nanoparticles (10 μm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of perfluoroalkyl organosilane to anhydrous ethanol, continuously stir and react mechanically for 8 h. After the reaction is completed, rotary evaporate and dry the solution to obtain super-biphobic diatomite nanoparticles.

[0082] Example 3

[0083] (1) Mix 70 wt.% of amino silicone resin, 2 wt.% of polydimethylaminoethyl methacrylate, and 7 wt.% of glass microspheres evenly in xylene to obtain a first base liquid; brush-coat this base liquid on the surface of a steel substrate and cure it at room temperature for 12 h to form a base layer;

[0084] (2) Dissolve 78 wt.% of a single-component highly elastic polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of polyisopropyl acrylate, and 3 wt.% of 2-hydroxy-4-methoxybenzophenone in butyl acetate, and stir evenly by mechanical stirring to obtain a second base liquid; brush-coat this base liquid in situ on the surface of the above-mentioned base layer and cure it at room temperature for 8 h to form a flexible buffer layer;

[0085] (3) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulated with an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and stir evenly by mechanical stirring to obtain a third base liquid; brush-coat this base liquid in situ on the surface of the above-mentioned flexible buffer layer and cure it at room temperature for 12 h to form an antifouling response layer;

[0086] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0087] Dissolve 1.5 g of gaseous hydrophobic SiO 2The aqueous phase was prepared by dispersing particles (30 nm) in 100 ml of deionized water. An oil phase was prepared by adding 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene. Then, the aqueous and oil phases were mixed at a volume ratio of 1 / 3 and stirred vigorously at 50 °C for 12 h. After centrifugation and drying, poly(N-isopropylacrylamide) microcapsule particles were obtained. 1 g of the above microcapsule particles was added to an ethanol solution of chitosan at 40 g / L and mixed thoroughly. After stirring for 12 h, the mixture was centrifuged and dried to obtain temperature-responsive polymer microcapsules encapsulated with antifouling agents.

[0088] (4) 30 wt.% of a one-component high-elastic polyurethane resin, 1 wt.% of temperature-responsive polymer microcapsules encapsulated with antifouling agents, 2 wt.% of sodium bicarbonate, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles were dissolved in xylene and stirred mechanically until homogeneous to obtain a fourth base liquid. The base liquid was brush-coated in situ on the surface of the above antifouling response layer and cured at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag-reducing functional coating.

[0089] The preparation method of the superhydrophobic micro-nano particles is as follows:

[0090] 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of n-octyltrifluoromethylsilane were successively added to anhydrous ethanol and continuously stirred mechanically for 8 h. After the reaction, the solution was rotary-evaporated to dryness to obtain super-hydrophobic and super-oleophobic TiO 2 nanoparticles.

[0091] Comparative Example 1 (compared with Example 3: temperature-responsive polymer microcapsules not added)

[0092] (1) 70 wt.% of an amino organosilicon resin, 2 wt.% of poly(dimethylaminoethyl methacrylate), and 7 wt.% of glass microspheres were dissolved in xylene and mixed evenly to obtain a first base liquid. The base liquid was brush-coated on the surface of a steel substrate and cured at room temperature for 12 h to form a base layer.

[0093] (2) 78 wt.% of a one-component high-elastic polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of poly(sodium isopropacrylate), and 3 wt.% of 2-hydroxy-4-methoxybenzophenone were dissolved in butyl acetate and stirred mechanically until homogeneous to obtain a second base liquid. The base liquid was brush-coated in situ on the surface of the above base layer and cured at room temperature for 8 h to form a flexible buffer layer.

[0094] (3) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and stir evenly by mechanical stirring to obtain a third base liquid; brush the base liquid in situ on the surface of the above-mentioned flexible buffer layer, and cure it at room temperature for 12 h to form an anti-fouling responsive layer;

[0095] (4) Dissolve 30 wt.% of a single-component highly elastic polyurethane resin, 2 wt.% of sodium bicarbonate, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles in xylene, and stir evenly by mechanical stirring to obtain a fourth base liquid; brush the base liquid in situ on the surface of the above-mentioned anti-fouling responsive layer, and cure it at room temperature for 24 h to obtain a temperature-responsive flexible anti-fouling and drag-reducing functional coating;

[0096] The preparation method of the superhydrophobic micro-nano particles is as follows:

[0097] Add 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of n-octyl perfluorosilane into anhydrous ethanol, continuously stir and react mechanically for 8 h. After the reaction is completed, rotary evaporate and dry the solution to obtain super-hydrophobic and super-oleophobic TiO 2 nanoparticles.

[0098] Performance characterization: The prepared composite coating does not have temperature-responsive anti-fouling and anti-fouling properties.

[0099] Comparative Example 2 (compared with Example 3: lacking a hydrophobic surface layer)

[0100] (1) Mix 70 wt.% of an amino organosilicon resin, 2 wt.% of poly(dimethylaminoethyl methacrylate), and 7 wt.% of glass microspheres evenly in xylene to obtain a first base liquid; brush the base liquid on the surface of a steel substrate and cure it at room temperature for 12 h to form a base layer;

[0101] (2) Dissolve 78 wt.% of a single-component highly elastic polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of polyisopropyl acrylate, and 3 wt.% of 2-hydroxy-4-methoxybenzophenone in butyl acetate, and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid in situ on the surface of the above-mentioned base layer, and cure it at room temperature for 8 h to form a flexible buffer layer;

[0102] (3) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a third base liquid; Brush this base liquid in situ on the surface of the above flexible buffer layer and cure it at room temperature for 12 h to form an antifouling response layer;

[0103] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0104] Disperse 1.5 g of gas-phase hydrophobic SiO 2 particles (30 nm) in 100 ml of deionized water to obtain an aqueous phase. Prepare an oil phase by adding 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene. Then mix the aqueous and oil phases at a volume ratio of 1 / 3, and carry out a high-speed stirring reaction at 50 °C for 12 h, centrifuge, and dry to obtain poly(N-isopropylacrylamide) microcapsule particles. Add 1 g of the above microcapsule particles to an ethanol solution of 40 g / L chitosan and mix well. After stirring for 12 h, centrifuge and dry to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0105] Performance characterization: The prepared composite coating has temperature-responsive antifouling properties, but poor hydrophobic effect and weak salt spray resistance.

[0106] Comparative Example 3 (compared with Example 3: lacking a flexible buffer layer)

[0107] (1) Dissolve 70 wt.% of an amino silicone resin, 2 wt.% of poly(dimethylaminoethyl methacrylate), and 7 wt.% of glass microspheres in xylene and mix them evenly to obtain a first base liquid; Brush this base liquid on the surface of the steel substrate and cure it at room temperature for 12 h to form a base layer;

[0108] (2) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a third base liquid; Brush this base liquid in situ on the surface of the above flexible buffer layer and cure it at room temperature for 12 h to form an antifouling response layer;

[0109] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0110] Disperse 1.5 g of gas-phase hydrophobic SiO 2The aqueous phase was prepared by dispersing particles (30 nm) in 100 ml of deionized water. An oil phase was prepared by adding 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene. Then, the aqueous and oil phases were mixed at a volume ratio of 1 / 3 and stirred vigorously at 50 °C for 12 h. After centrifugation and drying, poly(N-isopropylacrylamide) microcapsule particles were obtained. 1 g of the above microcapsule particles was added to an ethanol solution of chitosan at 40 g / L and mixed thoroughly. After stirring for 12 h, the mixture was centrifuged and dried to obtain temperature-responsive polymer microcapsules encapsulated with antifouling agents.

[0111] (3) 30 wt.% of a single-component high-elastic polyurethane resin, 2 wt.% sodium bicarbonate, 1 wt.% 2-hydroxy-4-methoxybenzophenone, and 5 wt.% superhydrophobic micro-nano particles were dissolved in xylene and stirred evenly by mechanical stirring to obtain a fourth base liquid; the base liquid was in-situ brush-coated on the surface of the above antifouling response layer and cured at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating;

[0112] The preparation method of the superhydrophobic micro-nano particles is as follows:

[0113] In sequence, 5 wt.% TiO 2 nanoparticles (50 nm), 10 wt.% ammonia water, 5 wt.% deionized water, 4 wt.% tetraethyl orthosilicate, and 2 wt.% n-octyl perfluorosilane were added to anhydrous ethanol, and continuously mechanically stirred for 8 h. After the reaction ended, the solution was rotary evaporated and dried to obtain super-hydrophobic and super-oleophobic TiO 2 nanoparticles.

[0114] Performance characterization: The prepared composite coating has temperature-responsive antifouling properties, but poor drag reduction effect.

[0115] Comparative Example 4 (compared with Example 3: lacking the base layer)

[0116] (1) 78 wt.% of a single-component high-elastic polyurethane resin, 2 wt.% sodium polystyrene sulfonate, 3 wt.% polyisopropyl acrylate, and 3 wt.% 2-hydroxy-4-methoxybenzophenone were dissolved in butyl acetate and stirred evenly by mechanical stirring to obtain a second base liquid; the base liquid was in-situ brush-coated on the surface of the above base layer and cured at room temperature for 8 h to form a flexible buffer layer;

[0117] (2) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a third base liquid; brush-coat this base liquid in situ on the surface of the above flexible buffer layer and cure it at room temperature for 12 h to form an antifouling-responsive layer;

[0118] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0119] Disperse 1.5 g of gas-phase hydrophobic SiO 2 particles (30 nm) in 100 ml of deionized water to prepare an aqueous phase. Add 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene to prepare an oil phase. Then mix the two phases of water and oil at a volume ratio of 1 / 3, and stir and react at a high speed at 50 °C for 12 h, centrifuge, and dry to obtain poly(N-isopropylacrylamide) microcapsule particles. Add 1 g of the above microcapsule particles to an ethanol solution of 40 g / L chitosan, mix well, stir for 12 h, then centrifuge and dry to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0120] (3) Dissolve 30 wt.% of a single-component highly elastic polyurethane resin, 1 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, 2 wt.% of sodium bicarbonate, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles in xylene, and uniformly mix them by mechanical stirring to obtain a fourth base liquid; brush-coat this base liquid in situ on the surface of the above antifouling-responsive layer and cure it at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag-reducing functional coating;

[0121] Among them, the preparation method of the superhydrophobic micro-nano particles is as follows:

[0122] Sequentially add 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of n-octyl perfluorosilane to anhydrous ethanol, continuously stir and react for 8 h. After the reaction is completed, rotary evaporate and dry the solution to obtain super-hydrophobic and super-oleophobic TiO 2 nanoparticles.

[0123] Performance characterization: The prepared composite coating has temperature-responsive antifouling properties, but has poor adhesion to the substrate and is easy to fall off.

[0124] Comparative Example 5 (compared with Example 3: lacking flexible polymer resin)

[0125] (1) Dissolve 70 wt.% amino silicone resin, 2 wt.% polydimethylaminoethyl methacrylate, and 7 wt.% glass microspheres in xylene and mix evenly to obtain the first base liquid; brush the base liquid on the surface of the steel substrate and cure it at room temperature for 12 h to form a base layer.

[0126] (2) Dissolve 78 wt.% amino silicone resin, 2 wt.% sodium polystyrene sulfonate, 3 wt.% polyisopropyl acrylate, and 3 wt.% 2-hydroxy-4-methoxybenzophenone in butyl acetate and mix evenly by mechanical stirring to obtain the second base liquid; brush the base liquid in situ on the surface of the above base layer and cure it at room temperature for 8 h to form a flexible buffer layer.

[0127] (3) Dissolve 40 wt.% amino silicone resin, 4 wt.% temperature-responsive polymer microcapsules encapsulated with antifouling agent, and 2 wt.% 2-hydroxy-4-methoxybenzophenone in xylene and mix evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ on the surface of the above flexible buffer layer and cure it at room temperature for 12 h to form an antifouling-responsive layer.

[0128] Among them, the preparation method of the temperature-responsive polymer microcapsules encapsulated with antifouling agent is as follows:

[0129] Disperse 1.5 g of gas-phase hydrophobic SiO 2 particles (30 nm) in 100 ml of deionized water to prepare an aqueous phase, add 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene to prepare an oil phase, then mix the two phases of water and oil at a volume ratio of 1 / 3, stir and react at a high speed at 50 °C for 12 h, centrifuge, and dry to obtain poly(N-isopropylacrylamide) microcapsule particles. Add 1 g of the above microcapsule particles to an ethanol solution of 40 g / L chitosan and mix well, stir for 12 h, then centrifuge and dry to obtain the temperature-responsive polymer microcapsules encapsulated with antifouling agent.

[0130] (4) Dissolve 30 wt.% amino silicone resin, 1 wt.% temperature-responsive polymer microcapsules encapsulated with antifouling agent, 2 wt.% sodium bicarbonate, 1 wt.% 2-hydroxy-4-methoxybenzophenone, and 5 wt.% superhydrophobic micro-nano particles in xylene and mix evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid in situ on the surface of the above antifouling-responsive layer and cure it at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating.

[0131] Among them, the preparation method of the superhydrophobic micro-nano particles is as follows:

[0132] 5 wt.% of TiO was added successively 2 nanoparticles (50 nm), 10 wt.% ammonia water, 5 wt.% deionized water, 4 wt.% tetraethyl orthosilicate, and 2 wt.% n-octyl perfluorosilane were added to absolute ethanol, and the mixture was continuously mechanically stirred for 8 h. After the reaction, the solution was rotary evaporated to dryness to obtain superhydrophobic and superoleophobic TiO 2 nanoparticles.

[0133] Performance characterization: The prepared composite coating has temperature-responsive antifouling property but no drag reduction effect.

[0134] Comparative Example 6

[0135] Compared with Example 3: The antifouling-responsive layer lacks temperature-responsive polymer microcapsules encapsulating antifouling agents;

[0136] (1) 70 wt.% amino organosilicon resin, 2 wt.% poly(dimethylaminoethyl methacrylate), and 7 wt.% glass microspheres were dissolved in xylene and mixed evenly to obtain the first base liquid; the base liquid was brushed on the surface of the steel substrate and cured at room temperature for 12 h to form a base layer;

[0137] (2) 78 wt.% one-component high-elastic polyurethane resin, 2 wt.% sodium polystyrene sulfonate, 3 wt.% poly(isopropenyl acrylate), and 3 wt.% 2-hydroxy-4-methoxybenzophenone were dissolved in butyl acetate and mechanically stirred evenly to obtain the second base liquid; the base liquid was in-situ brushed on the surface of the above base layer and cured at room temperature for 8 h to form a flexible buffer layer;

[0138] (3) 40 wt.% one-component high-elastic polyurethane resin and 2 wt.% 2-hydroxy-4-methoxybenzophenone were dissolved in xylene and mechanically stirred evenly to obtain the third base liquid; the base liquid was in-situ brushed on the surface of the above flexible buffer layer and cured at room temperature for 12 h to form a connection layer;

[0139] (4) 30 wt.% one-component high-elastic polyurethane resin, 1 wt.% temperature-responsive polymer microcapsules encapsulating antifouling agents, 2 wt.% sodium bicarbonate, 1 wt.% 2-hydroxy-4-methoxybenzophenone, and 5 wt.% superhydrophobic micro-nano particles were dissolved in xylene and mechanically stirred evenly to obtain the fourth base liquid; the base liquid was in-situ brushed on the surface of the above antifouling-responsive layer and cured at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating;

[0140] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is:

[0141] 1.5 g of gaseous hydrophobic SiO 2The aqueous phase was prepared by dispersing particles (30 nm) in 100 ml of deionized water. An oil phase was prepared by adding 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene. Then, the aqueous and oil phases were mixed at a volume ratio of 1 / 3 and stirred vigorously at 50 °C for 12 h. After centrifugation and drying, poly(N-isopropylacrylamide) microcapsule particles were obtained. 1 g of the above microcapsule particles was added to an ethanol solution of chitosan at 40 g / L and mixed thoroughly. After stirring for 12 h, the mixture was centrifuged and dried to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0142] The preparation method of the superhydrophobic micro-nano particles is as follows:

[0143] 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% ammonia water, 5 wt.% deionized water, 4 wt.% tetraethyl orthosilicate, and 2 wt.% n-octyltrifluoromethylsilane were successively added to anhydrous ethanol, and the mixture was continuously stirred mechanically for 8 h. After the reaction, the solution was rotary evaporated to dryness to obtain superhydrophobic and superoleophobic TiO 2 nanoparticles.

[0144] Performance: The antifouling life of the coating is short, and the antifouling property of the coating is greatly weakened.

[0145] Comparative Example 7

[0146] Compared with Example 3: The temperature-responsive polymer microcapsules encapsulating an antifouling agent are missing in the hydrophobic surface layer;

[0147] (1) 70 wt.% of amino organosilicon resin, 2 wt.% of poly(dimethylaminoethyl methacrylate), and 7 wt.% of glass microspheres were dissolved in xylene and mixed evenly to obtain the first base liquid; the base liquid was brush-coated on the surface of the steel substrate and cured at room temperature for 12 h to form a base layer;

[0148] (2) 78 wt.% of one-component high-elastic polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of polyisopropyl acrylate, and 3 wt.% of 2-hydroxy-4-methoxybenzophenone were dissolved in butyl acetate and stirred mechanically to obtain the second base liquid; the base liquid was in-situ brush-coated on the surface of the above base layer and cured at room temperature for 8 h to form a flexible buffer layer;

[0149] (3) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a third base liquid; brush-coat this base liquid in situ on the surface of the above flexible buffer layer, and cure it at room temperature for 12 h to form an antifouling-responsive layer;

[0150] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0151] Disperse 1.5 g of gas-phase hydrophobic SiO 2 particles (30 nm) in 100 ml of deionized water to prepare an aqueous phase, add 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene to prepare an oil phase, then mix the two phases of water and oil at a volume ratio of 1 / 3, and stir and react at a high speed at 50 °C for 12 h, centrifuge, and dry to obtain poly(N-isopropylacrylamide) microcapsule particles. Add 1 g of the above microcapsule particles to an ethanol solution of 40 g / L of chitosan, mix well, stir for 12 h, then centrifuge and dry to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0152] (4) Dissolve 30 wt.% of a single-component highly elastic polyurethane resin, 2 wt.% of sodium bicarbonate, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles in xylene, and uniformly mix them by mechanical stirring to obtain a fourth base liquid; brush-coat this base liquid in situ on the surface of the above antifouling-responsive layer, and cure it at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating;

[0153] Among them, the preparation method of the superhydrophobic micro-nano particles is as follows:

[0154] Sequentially add 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of n-octyl perfluorosilane to anhydrous ethanol, continuously stir and react for 8 h, and after the reaction is completed, rotary evaporate and dry the solution to obtain superhydrophobic and superoleophobic TiO 2 nanoparticles.

[0155] Performance: The antifouling property and responsiveness of the coating are poor in the initial state, and the overall antifouling property is weakened:

[0156] Comparative Example 8

[0157] Compared with Example 3: Lack of ultraviolet-resistant additive;

[0158] (1) 70 wt.% amino silicone resin, 2 wt.% polydimethylaminoethyl methacrylamide, and 7 wt.% glass microbeads were dissolved in xylene and mixed evenly to obtain a first base liquid; the base liquid was brushed on the surface of a steel substrate and cured at room temperature for 12 hours to form a base layer;

[0159] (2) dissolving 78 wt.% of a single-component high-elastic polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, and 3 wt.% of sodium polyisoacrylate in butyl acetate, and uniformly stirring the mixture mechanically to obtain a second base liquid; applying the base liquid in situ on the surface of the above-mentioned base layer, and curing the base liquid at room temperature for 8 hours to form a flexible buffer layer;

[0160] (3) 40 wt.% of a single-component high-elastic polyurethane resin and 4 wt.% of a temperature-responsive polymer microcapsule encapsulating an antifouling agent were dissolved in xylene and uniformly stirred mechanically to obtain a third base liquid; the base liquid was in-situ brushed on the surface of the above-mentioned flexible buffer layer, and cured at room temperature for 12 hours to form an antifouling responsive layer;

[0161] The preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0162] 1.5 g of fumed hydrophobic SiO 2 The particles (30 nm) were dispersed in 100 ml of deionized water to prepare the water phase, and 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) were added to 50 ml of xylene to prepare the oil phase. The water and oil phases were mixed at a volume ratio of 1 / 3, stirred at high speed for 12 hours at 50°C, centrifuged, and dried to obtain poly (N-isopropylacrylamide) microcapsule particles. 1 g of the above microcapsule particles was added to a 40 g / L chitosan ethanol solution and mixed thoroughly. After stirring for 12 hours, centrifuged and dried to obtain temperature-responsive polymer microcapsules encapsulating antifouling agents.

[0163] (4) 30 wt.% of a single-component high-elastic polyurethane resin, 1 wt.% of a temperature-responsive polymer microcapsule encapsulating an antifouling agent, 2 wt.% of sodium bicarbonate, and 5 wt.% of superhydrophobic micro-nanoparticles are dissolved in xylene and uniformly stirred mechanically to obtain a fourth base liquid; the base liquid is in situ brushed on the surface of the above-mentioned antifouling response layer, and cured at room temperature for 24 hours to obtain a temperature-responsive flexible antifouling and drag-reducing functional coating;

[0164] The preparation method of super hydrophobic micro-nano particles is as follows:

[0165] 5 wt.% TiO 2Nanoparticles (50 nm), 10 wt.% ammonia water, 5 wt.% deionized water, 4 wt.% tetraethyl orthosilicate, and 2 wt.% n-octyl perfluorosilane were added to anhydrous ethanol, and the mixture was continuously stirred mechanically for 8 h. After the reaction, the solution was rotary evaporated to dryness to obtain superhydrophobic and superoleophobic TiO 2 nanoparticles.

[0166] Performance: The anti-ultraviolet performance of the coating is poor, and yellowing and powdering are likely to occur.

[0167] Comparative Example 9

[0168] Compared with Example 3: The positively charged polymer (polydimethylaminoethyl methacrylate) and the negatively charged polymer (sodium polystyrene sulfonate) are missing.

[0169] (1) 70 wt.% amino organosilicon resin and 7 wt.% glass microspheres were dissolved in xylene and mixed evenly to obtain the first base liquid; the base liquid was brushed on the surface of the steel substrate and cured at room temperature for 12 h to form a base layer;

[0170] (2) 78 wt.% one-component high-elastic polyurethane resin, 3 wt.% polyisopropyl acrylate, and 3 wt.% 2-hydroxy-4-methoxybenzophenone were dissolved in butyl acetate and stirred mechanically evenly to obtain the second base liquid; the base liquid was in-situ brushed on the surface of the above base layer and cured at room temperature for 8 h to form a flexible buffer layer;

[0171] (3) 40 wt.% one-component high-elastic polyurethane resin, 4 wt.% temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% 2-hydroxy-4-methoxybenzophenone were dissolved in xylene and stirred mechanically evenly to obtain the third base liquid; the base liquid was in-situ brushed on the surface of the above flexible buffer layer and cured at room temperature for 12 h to form an antifouling response layer;

[0172] Among them, the preparation method of the temperature-responsive polymer microcapsules of the antifouling agent is as follows:

[0173] 1.5 g of gaseous hydrophobic SiO 2The aqueous phase was prepared by dispersing particles (30 nm) in 100 ml of deionized water. An oil phase was prepared by adding 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene. Then, the aqueous and oil phases were mixed at a volume ratio of 1 / 3 and stirred vigorously at 50 °C for 12 h. After centrifugation and drying, poly(N-isopropylacrylamide) microcapsule particles were obtained. 1 g of the above microcapsule particles was added to an ethanol solution of chitosan at 40 g / L and mixed thoroughly. After stirring for 12 h, centrifugation and drying were carried out to obtain temperature-responsive polymer microcapsules encapsulated with antifouling agents.

[0174] (4) 30 wt.% of a single-component high-elastic polyurethane resin, 1 wt.% of temperature-responsive polymer microcapsules encapsulated with antifouling agents, 2 wt.% of sodium bicarbonate, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles were dissolved in xylene and stirred evenly by mechanical stirring to obtain a fourth base liquid. The base liquid was in-situ brush-coated on the surface of the above antifouling response layer and cured at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag-reducing functional coating;

[0175] The preparation method of the superhydrophobic micro-nano particles is as follows:

[0176] 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of n-octyl perfluorosilane were successively added to anhydrous ethanol and continuously stirred mechanically for 8 h. After the reaction, the solution was rotary evaporated to dryness to obtain superhydrophobic and superoleophobic TiO 2 nanoparticles.

[0177] Performance: The adhesion of the coating becomes poor and it is prone to peeling.

[0178] Comparative Example 10

[0179] Compared with Example 3: The pore-forming agent (sodium bicarbonate) is missing.

[0180] (1) 70 wt.% of an amino organosilicon resin, 2 wt.% of poly(dimethylaminoethyl methacrylate), and 7 wt.% of glass microspheres were dissolved in xylene and mixed evenly to obtain a first base liquid. The base liquid was brush-coated on the surface of a steel substrate and cured at room temperature for 12 h to form a base layer;

[0181] (2) Dissolve 78 wt.% of a single-component highly elastic polyurethane resin, 2 wt.% of sodium polystyrene sulfonate, 3 wt.% of sodium polyisopropenoate, and 3 wt.% of 2-hydroxy-4-methoxybenzophenone in butyl acetate, and uniformly mix them by mechanical stirring to obtain a second base liquid; in-situ brush coat this base liquid on the surface of the above base layer, and perform a curing treatment at room temperature for 8 h to form a flexible buffer layer;

[0182] (3) Dissolve 40 wt.% of a single-component highly elastic polyurethane resin, 4 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, and 2 wt.% of 2-hydroxy-4-methoxybenzophenone in xylene, and uniformly mix them by mechanical stirring to obtain a third base liquid; in-situ brush coat this base liquid on the surface of the above flexible buffer layer, and perform a curing treatment at room temperature for 12 h to form an antifouling-responsive layer;

[0183] Among them, the preparation method of the temperature-responsive polymer microcapsules encapsulating the antifouling agent is as follows:

[0184] Disperse 1.5 g of gaseous hydrophobic SiO 2 particles (30 nm) in 100 ml of deionized water to prepare an aqueous phase. Add 10 ml of N-isopropylacrylamide (NIPAM), 0.5 ml of N,N'-methylenebisacrylamide (MBA), and 0.2 ml of azobisisobutyronitrile (AIBN) to 50 ml of xylene to prepare an oil phase. Then mix the two-phase of water and oil at a volume ratio of 1 / 3, and carry out a high-speed stirring reaction at 50 °C for 12 h, centrifuge, and dry to obtain poly(N-isopropylacrylamide) microcapsule particles. Add 1 g of the above microcapsule particles to an ethanol solution of 40 g / L of chitosan and mix well, stir for 12 h, then centrifuge and dry to obtain temperature-responsive polymer microcapsules encapsulating an antifouling agent.

[0185] (4) Dissolve 30 wt.% of a single-component highly elastic polyurethane resin, 1 wt.% of temperature-responsive polymer microcapsules encapsulating an antifouling agent, 1 wt.% of 2-hydroxy-4-methoxybenzophenone, and 5 wt.% of superhydrophobic micro-nano particles in xylene, and uniformly mix them by mechanical stirring to obtain a fourth base liquid; in-situ brush coat this base liquid on the surface of the above antifouling-responsive layer, and perform a curing treatment at room temperature for 24 h to obtain a temperature-responsive flexible antifouling and drag reduction functional coating;

[0186] Among them, the preparation method of the superhydrophobic micro-nano particles is as follows:

[0187] Sequentially add 5 wt.% of TiO 2 nanoparticles (50 nm), 10 wt.% of ammonia water, 5 wt.% of deionized water, 4 wt.% of tetraethyl orthosilicate, and 2 wt.% of n-octyl perfluorosilane to anhydrous ethanol, continuously carry out a mechanical stirring reaction for 8 h. After the reaction ends, rotary evaporate and dry the solution to obtain superhydrophobic and superoleophobic TiO2 Nanoparticles

[0188] Performance: The coating fails to form a porous structure, resulting in a deterioration of the superhydrophobic performance. Moreover, the release channels of the antifouling agent become smaller, leading to a slow release of the antifouling agent and a decline in the antifouling property.

[0189] The performance tests of the composite coatings provided in the comparative examples and examples of the present invention were carried out. The adhesion test standard was GB / T5210-2006, and the salt spray test standard was GB / T10125-1997. The specific test results are shown in Table 1 below:

[0190] Table 1 Performance of the coatings prepared in Examples 1-3 and Comparative Examples 1-10

[0191] ;

[0192] In addition, the inventors of this case also referred to the foregoing examples and conducted tests with other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0193] It should be understood that the technical solutions of the present invention are not limited to the limitations of the above specific embodiments. Any technical deformation made according to the technical solutions of the present invention without departing from the spirit of the present invention and the scope protected by the claims falls within the protection scope of the present invention.

Claims

1. A temperature-responsive flexible antifouling and drag-reducing composite coating, characterized in that: include: A base layer, a flexible buffer layer, an antifouling response layer and a hydrophobic surface layer are sequentially formed on the surface of the substrate; Wherein, the base layer comprises an adhesive resin, a positively charged polymer and a particle filler; the flexible buffer layer comprises a flexible polymer resin, a negatively charged polymer, a polymer drag reducer and an anti-ultraviolet additive; the anti-fouling response layer comprises a flexible polymer resin, a temperature-responsive polymer microcapsule encapsulating an anti-fouling agent and an anti-ultraviolet additive; the hydrophobic surface layer comprises a flexible polymer resin, a temperature-responsive polymer microcapsule encapsulating an anti-fouling agent, a porogen, an anti-ultraviolet additive and super-hydrophobic micro-nanoparticles; the positively charged polymer is selected from polyvinyl alcoholamine and / or polydimethylaminoethyl methacrylamide; the negatively charged polymer is selected from any one or a combination of two or more of polyvinyl alcohol acid, polyether sulfone and sodium polystyrene sulfonate; the flexible polymer resin is selected from any one or a combination of two or more of silicone resin, polyurethane, acrylic modified silicone resin and polyurea; The preparation method of the temperature-responsive polymer microcapsules encapsulating the antifouling agent comprises: subjecting the temperature-responsive polymer monomer, the antifouling agent, the cross-linking agent, the initiator, and the nucleating particles to emulsification polymerization in a water-oil solution at 50-80° C. for 12-24 hours, thereby preparing the temperature-responsive polymer microcapsules encapsulating the antifouling agent; wherein the temperature-responsive polymer monomer is selected from N-isopropylacrylamide.

2. The flexible antifouling and drag-reducing composite coating according to claim 1, characterized in that: The thickness of the base layer is 20-60 μm; and / or the thickness of the flexible buffer layer is 0.1-0.5 mm; and / or the thickness of the antifouling response layer is 0.1-0.5 mm; and / or the thickness of the hydrophobic surface layer is 10-60 μm.

3. The flexible antifouling and drag-reducing composite coating according to claim 1, characterized in that: The antifouling agent is selected from any one of copper pyrithione, zinc pyrithione, and chitosan, or a combination of two or more thereof; And / or, the cross-linking agent is selected from any one or a combination of two or more of N,N'-methylenebisacrylamide, divinylbenzene, and diisocyanate; And / or, the initiator is selected from any one or a combination of two or more of potassium persulfate, azobisisobutyronitrile, dimethyl azobisisobutyrate, and azobisisoheptanenitrile; And / or, the nucleating particles are selected from any one or a combination of two or more of gas-phase hydrophobic SiO2, gas-phase hydrophilic SiO2, TiO2, and Al2O3.

4. The method for preparing a temperature-responsive flexible antifouling and drag-reducing composite coating according to any one of claims 1 to 3, characterized in that: include: Applying a first base liquid containing at least an adhesive resin, a positively charged polymer, a particle filler, and a diluent to the surface of the substrate and subjecting the substrate to a first curing treatment to form a base layer having a multi-level micro-nano structure; Applying a second base liquid containing at least a flexible polymer resin, a negatively charged polymer, a polymer drag reducer, an anti-ultraviolet additive and a solvent to the surface of the base layer and performing a second curing treatment to form a flexible buffer layer; Applying a third base liquid comprising at least a flexible polymer resin, a temperature-responsive polymer microcapsule encapsulating an antifouling agent, an anti-ultraviolet additive and a solvent to the surface of the flexible buffer layer and subjecting the third base liquid to a third curing treatment to form an antifouling responsive layer; And, a fourth base liquid comprising at least a flexible polymer resin, a temperature-responsive polymer microcapsule encapsulating an antifouling agent, a porogen, an anti-ultraviolet additive, super-hydrophobic micro-nanoparticles and a solvent is applied to the surface of the antifouling response layer and subjected to a fourth curing treatment to form a hydrophobic surface layer, thereby obtaining a flexible antifouling and drag-reducing composite coating with temperature responsiveness.

5. The preparation method according to claim 4, characterized in that: Specifically include: Applying the first base liquid to the surface of the substrate by spraying or brushing and curing at room temperature for 12 to 24 hours to form the base layer; and / or, applying the second base liquid to the surface of the base layer by spraying or brushing and curing it at room temperature for 4 to 12 hours to form a flexible buffer layer; and / or, applying a third base liquid to the surface of the flexible buffer layer by spraying or brushing and curing the base liquid at room temperature for 12 to 24 hours to form the antifouling response layer; And / or, the fourth base liquid is applied to the surface of the antifouling response layer by spraying or brushing and cured at room temperature for 12 to 24 hours to form the hydrophobic surface layer.

6. The preparation method according to claim 4, characterized in that: The mass ratio of the adhesive resin, the positively charged polymer, the particle filler and the diluent in the first base liquid is 10-50: 0.5-5: 0.5-5: 0-30; and / or, the mass ratio of the flexible polymer resin, the negatively charged polymer, the polymer drag reducer, the anti-ultraviolet additive and the solvent in the second base liquid is 20-50:0.5-5:0.5-5:0.5-5:0-30; And / or, the mass ratio of the flexible polymer resin, the temperature-responsive polymer microcapsules encapsulating the antifouling agent, and the solvent in the third base liquid is 30-40:1-5:0-30; And / or, the mass ratio of the flexible polymer resin, the temperature-responsive polymer microcapsules encapsulating the antifouling agent, the porogen, the anti-ultraviolet additive, the super-hydrophobic micro-nanoparticles and the solvent in the fourth base liquid is 20-50:0-5:0-5:0-2:0-5:0-30.

7. The preparation method according to claim 4, characterized in that: The adhesive resin is selected from any one or a combination of two or more of modified epoxy resin, epoxy zinc-rich primer, acrylic polyurethane paint, amino silicone resin, polyurethane, and fluorinated modified epoxy resin.

8. The preparation method according to claim 4, characterized in that: The particle filler is selected from any one or a combination of two or more of kaolin, talc, mica powder, zinc oxide, titanium dioxide, silicon dioxide, glass beads, and diatomaceous earth; and / or the particle size of the particle filler is 1-100 μm.

9. The preparation method according to claim 4, characterized in that: The diluent is selected from any one of toluene, xylene, ethanol, ethyl acetate, butyl acetate, propylene glycol methyl ether, and formamide, or a combination of two or more thereof.

10. The preparation method according to claim 4, characterized in that: The polymer drag reducer is selected from one or a combination of two or more of polyacrylamide, polyvinyl alcohol, sodium polyisoacrylate, and polyvinyl pyrrolidone.

11. The preparation method according to claim 4, characterized in that: The anti-ultraviolet additive is selected from any one or a combination of two or more of 2-hydroxy-4-methoxybenzophenone, 2-(2H-benzotriazine-2-yl)-4,6-bis(2-methylmethylamino-ethyl)-phenol, 2-hydroxyphenols and their derivatives, and octyl salicylate.

12. The preparation method according to claim 4, characterized in that: The solvent is selected from any one of toluene, xylene, ethyl acetate, acetone, ethanol, butanol, and butyl acetate, or a combination of two or more thereof.

13. The preparation method according to claim 4, characterized in that: The substrate is selected from any one of a steel substrate, an aluminum alloy substrate, and a copper alloy substrate, or a combination of two or more thereof.

14. The preparation method according to claim 4, characterized in that: The porogen is selected from any one of sodium chloride, lactose, sucrose, ammonium bicarbonate, and sodium bicarbonate, or a combination of two or more thereof.

15. The preparation method according to claim 4, characterized in that: The preparation method of the super-hydrophobic micro-nano particles comprises: mixing micro-nano particles, ammonia water, tetraethyl silicate, a hydrophobic treatment modifier and water for 6 to 24 hours to obtain the super-hydrophobic micro-nano particles; wherein the hydrophobic treatment modifier is selected from any one of alkyl siloxanes, alkyl chlorosilanes, fluoroalkyl siloxanes, alkyl organic silanes, and perfluoroalkyl organic silanes, or a combination of two or more thereof.

16. Use of the temperature-responsive flexible antifouling and drag-reducing composite coating according to any one of claims 1 to 3 in intelligent protection of the surface of a ship hull, a pipeline, an offshore platform or an underwater structure.

17. A method for reducing the navigation resistance of a navigation body, characterized in that: include: At least the surface of the navigation body in contact with the liquid is covered with a temperature-responsive flexible antifouling and drag-reducing composite coating as claimed in any one of claims 1 to 3.

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