Wear-resistant multi-dimensional micro-nano structure super-hydrophobic coating and preparation method thereof

Abstract

The invention provides a wear-resistant multi-dimensional micro-nano structure super-hydrophobic coating and a preparation method thereof, and relates to the technical field of super-hydrophobic coatings. The wear-resistant super-hydrophobic coating with the multi-dimensional micro-nano structure comprises primer coated on the surface of a base material and finish paint attached to the primer, the preparation method comprises the following steps: step 1, uniformly mixing and dispersing the primer raw materials, and spraying the primer raw materials on the surface of the base material; step 2, uniformly mixing and dispersing finish paint raw materials, spraying the uniformly mixed and dispersed finish paint raw materials on the primer after the surface of the primer coating is dried, and curing at room temperature; wherein the primer raw materials comprise vinyl resin, organic silicon resin, an inorganic filler, a solvent, a curing agent and an auxiliary agent; the finishing paint is prepared from the following raw materials: super-hydrophobic modified nano silicon dioxide, organic silicon resin and a solvent; the super-hydrophobic modified nano silicon dioxide at least contains particles with two particle sizes; the super-hydrophobic coating is simple in process, convenient to construct, good in surface wear resistance and high in durability.

Description

Technical Field

[0001] The present invention relates to the technical field of super hydrophobic coatings, and in particular to a wear-resistant multi-dimensional micro-nano structure super hydrophobic coating and a preparation method thereof. Background Art

[0002] Inspired by the lotus effect, people have found that super-hydrophobic surfaces have good self-cleaning, oil-water separation, anti-ice fog and anti-corrosion properties, so super-hydrophobic materials have attracted much attention in recent years. The key to preparing super-hydrophobic surfaces is to construct fine hydrophobic micro-nano structures. However, it is this fine surface structure that makes it vulnerable to external damage and loses its super-hydrophobic ability, which is also the most important problem restricting its application.

[0003] Wear-resistant super-hydrophobic coating is a special material that not only has super-hydrophobic properties and reduces the adhesion of water droplets, but also has excellent wear resistance and can resist wear and tear in daily use. This material has broad application prospects in various application fields such as self-cleaning, anti-icing, and drag reduction. Researchers have been exploring ways to improve the wear resistance of super-hydrophobic coatings. For example, by adding special nanomaterials such as cerium dioxide (CeO2) to the coating, the wear resistance, temperature resistance, and chemical corrosion resistance of the coating can be improved. In addition, by optimizing the micro-nano structure of the coating, its wear resistance can also be enhanced to a certain extent.

[0004] The micro-nano structure of the super-hydrophobic surface is extremely vulnerable to external damage, and even a slightly stronger wind can destroy this micro-nano structure. At present, there are probably the following methods for improving the mechanical durability of super-hydrophobic surfaces: 1. Microstructure protection method; 2. Self-healing surface method; 3. Binder protection method. For example, Chinese invention patent CN202310123571.3 discloses a super-wear-resistant and weather-resistant shell-like structure super-hydrophobic coating and its preparation method, the specific scheme of which is to mix alkyd resin, acrylic acid and tetrafluoro resin, silane coupling agent and other fillers as primer, spray HMDS modified nano-silica dispersion on the surface as topcoat, and obtain a wear-resistant super-hydrophobic surface through multi-layer composite on the bottom surface. Chinese invention patent CN202111095677.4 discloses a wear-resistant and corrosion-resistant super-hydrophobic composite coating and its preparation method, which uses silane coupling agent KH560 to modify mica / silica composite powder, supplemented by epoxy resin and solvent to obtain a wear-resistant super-hydrophobic surface. Chinese invention patent CN202311312130.4 discloses a method for preparing a highly wear-resistant and water-impact resistant super-hydrophobic coating, which is prepared by mixing a nano-silica dispersion and an acrylic resin with a silane coupling agent and a solvent. The wear-resistant super-hydrophobic coating can be impacted more than 10 times by a 300ml water flow at a height of 1.2m.

[0005] Although there are many methods for preparing wear-resistant super-hydrophobic coatings in the prior art and many performance improvements have been made, there are still defects. The main manifestation is that the existing wear-resistant super-hydrophobic coatings generally have complex processes, harsh construction conditions, high costs, and high maintenance costs, and it is difficult to achieve large-surface preparation, which restricts the further widespread application and development of wear-resistant super-hydrophobic coatings. Summary of the invention

[0006] The present invention aims to solve the problems in the prior art that the wear-resistant super-hydrophobic coating has complex process, harsh construction conditions, expensive cost, high maintenance cost, and is difficult to prepare on a large surface. The present invention provides a wear-resistant multi-dimensional micro-nano structure super-hydrophobic coating with simple process, low cost, convenient construction, good surface wear resistance and strong durability, and a preparation method thereof.

[0007] The technical solution adopted by the present invention is:

[0008] A method for preparing a wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating comprises the following steps:

[0009] Step 1. Mix and disperse the primer raw materials evenly and spray them on the surface of the substrate;

[0010] Step 2. Mix and disperse the topcoat raw materials evenly. After the primer coating is dry, spray the evenly mixed and dispersed topcoat raw materials on the primer and cure at room temperature;

[0011] The primer raw materials include vinyl resin, silicone resin, inorganic filler, solvent, curing agent and auxiliary agent; the topcoat raw materials include super-hydrophobic modified nano-silica, silicone resin and solvent; and the super-hydrophobic modified nano-silica contains at least two particle sizes of particles.

[0012] Furthermore, the primer raw materials include: 20% vinyl resin, 10% to 20% silicone resin, 15% to 35% inorganic filler, and the balance solvent A1, curing agent and auxiliary agent, calculated by weight percentage.

[0013] Furthermore, the inorganic filler includes an inorganic filler B1 and an inorganic filler B2, the inorganic filler B1 is hollow glass microspheres with a particle size of 20-50 μm, and the inorganic filler B2 is hollow glass microspheres with a particle size of 100-150 μm.

[0014] Furthermore, the inorganic filler comprises: 5% to 10% of inorganic filler B1 and 10% to 25% of inorganic filler B2, by weight percentage.

[0015] Furthermore, the topcoat and primer of the wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating are mutually inlaid structures, and the topcoat and primer form a multi-level rough structure from large micron structure C1, micron structure C2 to nanostructure C3.

[0016] Furthermore, the distance between the papillae of the large microstructure C1 is 50-150 μm, the distance between the papillae of the microstructure C2 is 1-5 μm, and the distance between the particles of the nanostructure C3 is 10-1000 nm.

[0017] Furthermore, the topcoat raw materials include: 10-20% silicone resin, 30-50% super-hydrophobic modified nano-silica, 2-4% organotin catalyst and the remainder solvent, calculated by weight percentage; the particle size of the nano-silica is 10-1000nm.

[0018] Furthermore, the topcoat raw materials include: 15-20% silicone resin, 30-50% super-hydrophobic modified nano-silica, 2-4% organotin catalyst and the remainder solvent, calculated by weight percentage.

[0019] Furthermore, the preparation method of the super hydrophobic modified nano-silica comprises:

[0020] An alcohol solvent, an alkaline catalyst, and a silicate are sequentially added into a reactor, the temperature is raised to 60±10°C and then kept constant, and the reaction is divided into two parts, respectively reacted for 24 hours and 72 hours, and two types of unmodified nano-silica with different particle sizes are obtained after filtration and drying. The dried nano-silica with two different particle sizes is mixed with an alcohol solvent and an ester solvent, polysiloxane with a molecular weight between 500 and 5w is added, and the reaction is carried out at 80±5°C for 5±0.5 hours to obtain super-hydrophobic nano-silica containing particles of two different particle sizes.

[0021] A wear-resistant multidimensional micro-nanostructure super-hydrophobic coating comprises a primer coated on the surface of a substrate and a topcoat attached to the primer; the preparation process of the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating comprises the preparation method of the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating as described above.

[0022] The beneficial effects of the present invention are:

[0023] 1. The super-hydrophobic coating preparation method of the present invention is simple and easy to operate, convenient for large-scale promotion and application, and its water static contact angle can reach 160°, the rolling angle is less than 5°, and it can withstand 5m / s (6L / min) water flow impact for more than 20min. It can be applied to a variety of substrate surfaces, effectively improve its surface self-cleaning and anti-corrosion properties, and extend the service life of the substrate, thereby solving the problem that the wear-resistant super-hydrophobic coating in the prior art is complex in process, harsh in construction conditions, expensive in cost, and high in maintenance cost, and it is difficult to achieve the preparation of large surfaces;

[0024] 2. The super-hydrophobic coating of the present invention also relies on the characteristics of super-hydrophobic nanoparticles of different particle sizes in the topcoat to form a "micrometer-nanometer" hierarchical structure, and then through the combination of two inorganic fillers of different particle sizes, a multi-level micro-nano structure of "large micrometer-micrometer-nanometer" is further formed, constructing a multi-level long-term and effective protection mechanism, thereby improving the overall wear resistance and hydrophobicity of the super-hydrophobic coating;

[0025] 3. The present invention also utilizes the organic silicone resin in the primer in combination with a curing agent to cure and crosslink to form a flexible substrate, which can effectively mitigate external impact and reduce the loss of super-hydrophobic nanoparticles;

[0026] 4. The present invention also utilizes the modified nano-silicon dioxide particles in the topcoat to have the ability to produce chemical cross-linking with the topcoat and the primer at the same time, which can effectively avoid the coating failure caused by the shedding of the modified nano-silicon dioxide particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of the structure of a super-hydrophobic coating according to an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of water impact resistance test of an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0032] In the prior art, there are many methods for preparing wear-resistant super-hydrophobic coatings, but the existing wear-resistant super-hydrophobic coatings generally have complex processes, harsh construction conditions, high costs, high maintenance costs, and difficulty in achieving large-surface preparation.

[0033] The present invention provides a wear-resistant multidimensional micro-nanostructure super-hydrophobic coating and a preparation method thereof, which has simple process, low cost, convenient construction, good surface wear resistance and strong durability. The wear-resistant multidimensional micro-nanostructure super-hydrophobic coating provided by the present invention mainly comprises a primer coated on the surface of a substrate and a topcoat attached to the primer.

[0034] The raw materials of primer mainly include vinyl resin, silicone resin, inorganic filler, solvent A1, curing agent and additives, etc.; the raw materials of topcoat mainly include super-hydrophobic modified nano-silica, silicone resin and solvent, etc.

[0035] The organic silicone resin is one or more of urea polysiloxane resin, methyl polysiloxane resin, hydroxy polysiloxane resin and vinyl polysiloxane resin.

[0036] The inorganic filler includes an inorganic filler B1 with a particle size of 20 to 50 μm and an inorganic filler B2 with a particle size of 100 to 150 μm. The inorganic filler B1 and the inorganic filler B2 can be different inorganic fillers or the same inorganic filler. Preferably, the inorganic filler B1 and the inorganic filler B2 are hollow glass microspheres with different particle sizes.

[0037] The solvent A1 is at least one of volatile organic solvents such as ethyl acetate, ethanol, xylene, and carbon tetrachloride.

[0038] The auxiliary agent is at least three of a defoamer, a cosolvent, a dispersant, a catalyst, and an adhesion promoter. The auxiliary agent is mainly used to strengthen the combination of the resin and the inorganic particles in the primer, and the combination of the primer and the topcoat.

[0039] The preparation process of the super-hydrophobic modified nano-silica is as follows: an alcohol solvent, an alkaline catalyst, and a silicate are sequentially added into a reactor, the temperature is raised to 50-70°C and then kept constant, the reaction is divided into two parts, and the reaction is performed for 24 hours and 72 hours respectively, and unmodified nano-silica of two particle sizes is obtained after filtration and drying; the dried nano-silica of two particle sizes is mixed with an alcohol solvent and an ester solvent, a polysiloxane with a molecular weight between 500 and 5w is added, and the reaction is performed at 80±5°C for 5±0.5 hours to obtain super-hydrophobic nano-silica containing particles of two particle sizes. In the preparation process, the alkaline catalyst is ammonia water; the alcohol solvent is one or more of methanol, ethanol, n-butanol, and propylene glycol, preferably ethanol; the silicate is one or two of tetrabutyl orthosilicate and tetraethyl orthosilicate, preferably ethyl orthosilicate; the ester solvent is one or more of butyl acetate, ethyl acetate, and dimethyl carbonate; and the polysiloxane includes one or more of urea polysiloxane, methyl polysiloxane, hydroxy polysiloxane, and vinyl polysiloxane.

[0040] Preferably, an organic tin catalyst may be added to the topcoat raw material, and the organic tin catalyst is one or more of stannous octoate, dibutyltin dilaurate, and dibutyltin diacetate.

[0041] The method for preparing the wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating provided by the present invention comprises:

[0042] Step 1. Mix and disperse the primer raw materials evenly, and use a spray gun to spray evenly on the surface of the substrate.

[0043] Step 2. Mix and disperse the topcoat raw materials evenly. After the primer is sprayed for 10 to 30 minutes, wait for the primer coating to dry on the surface; spray the evenly mixed and dispersed topcoat raw materials on the primer and cure at room temperature.

[0044] It should be pointed out that the step of evenly mixing and dispersing the topcoat raw materials only needs to be completed before spraying the topcoat, and there is no fixed order between the mixing and spraying steps of the primer raw materials.

[0045] The working principle of the present invention includes:

[0046] The present invention utilizes the organic silicon resin in the primer in combination with a curing agent to form a flexible substrate through curing and cross-linking, which can effectively mitigate external impact and reduce the loss of super-hydrophobic nanoparticles.

[0047] The present invention utilizes the ability of the modified nano silicon dioxide particles in the topcoat to produce chemical crosslinking with the topcoat and the primer at the same time, and can effectively avoid the coating failure caused by the shedding of the modified nano silicon dioxide particles.

[0048] And if Figure 1As shown in, the present invention also utilizes the characteristics of super-hydrophobic nanoparticles of different particle sizes in the topcoat, and the super-hydrophobic nanoparticles of different particle sizes can be dispersed and reassembled to form a hierarchical structure of "micrometer-nanometer", which is similar to the bionic structure of lotus leaves, and can improve the wear resistance and hydrophobicity of the coating at the same time. At the same time, the inorganic filler in the primer of the present invention also includes at least two different particle sizes, which can meet the conventional filler requirements, and also improve the surface micro-nano structure roughness of the primer, and then form a "large micron" structure layer. Thus after the super-hydrophobic topcoat is attached, the whole coating obtains a multi-level micro-nano structure of "large micron-micron-nanometer", and the papillary spacing of the large micron structure C1 produced by the primer is 50~150μm, and this large micron structure C1 includes interconnected framework structures, and a "pocket"-shaped gap is formed between the framework structures. The "pocket"-shaped gap can accommodate the nanostructure C3 with fragile mechanical properties, and the surface framework structure plays a role in protecting the shell, preventing the nanostructure from being removed by an abrasive larger than the frame size. The papillae spacing of the microstructure C2 under the large microstructure is 1~5μm, and the particle spacing of the nanostructure C3 is 10~1000nm. The strong hydrophobic and wear-resistant properties of the "micrometer-nanometer" hierarchical structure composed of the two can be maintained for a long time and are not easily damaged. Therefore, the three-layer multi-level micro-nano rough structure greatly improves the overall wear resistance and hydrophobicity of the superhydrophobic coating.

[0049] The wear-resistant multidimensional micro-nano structure super-hydrophobic coating prepared by the present invention has a water static contact angle of up to 160°, a rolling angle of less than 5°, and can withstand a 5 m / s (6 L / min) water flow impact for more than 20 minutes. It can be applied to the surfaces of various substrates, effectively improve their surface self-cleaning and anti-corrosion properties, and extend the service life of the substrate. The preparation method of the wear-resistant multidimensional micro-nano structure super-hydrophobic coating of the present invention is simple and easy to operate, and is convenient for large-scale promotion and application. It has good application prospects in the fields of anti-fouling, anti-icing, etc.

[0050] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with specific embodiments, but the content of the present invention is not limited to the following embodiments.

[0051] Example 1

[0052] First, by weight percentage, 20% of vinyl resin, 10% of silicone resin, 5% of 20-50 μm hollow glass microspheres (inorganic filler B1), 10% of 100-150 μm hollow glass microspheres (inorganic filler B2), 15% of ethanol (solvent A1), 30% of cosolvent (auxiliary agent), 6% of catalyst (auxiliary agent), 2% of dispersant (auxiliary agent), 2% of curing agent, at room temperature 800 r / min for 30 minutes, to obtain a primer for standby use. In this embodiment, the cosolvent is ethyl acetate, the catalyst is styrene, the dispersant is BYK-130, and the curing agent is methyl ethyl ketone peroxide.

[0053] Next, prepare super-hydrophobic modified nano-silica. The preparation process is as follows: add alcohol solvent, alkaline catalyst, and silicate in a mass ratio of 70:10:20 to the reactor in turn, heat to 50°C and keep constant temperature, react for 24h and 72h respectively, and obtain unmodified nano-silica of two particle sizes after filtration and drying; take the dried nano-silica, mix alcohol and ester solvents, add polysiloxane with a molecular weight between 500 and 5w, and react at 75°C for 4.5h to obtain super-hydrophobic nano-silica.

[0054] Then, by weight percentage, 10% hydroxy polysiloxane resin, 30% super hydrophobic modified nano-silica, 2% dibutyltin dilaurate (organotin catalyst) and 58% ethyl acetate (solvent) were dispersed at 1200 r / min for 30 minutes at room temperature to obtain a topcoat for use.

[0055] Finally, use a 5-8Mpa air spray gun to evenly spray the primer on the tinplate substrate. After the primer is dry for 20 minutes, spray the topcoat on the primer. After waiting for 3 hours at room temperature, a wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating sample is obtained.

[0056] Example 2

[0057] First, by weight percentage, 20% of vinyl resin, 20% of silicone resin, 5% of 20-50 μm hollow glass microspheres (inorganic filler B1), 10% of 100-150 μm hollow glass microspheres (inorganic filler B2), 15% of ethanol (solvent A1), 20% of cosolvent (auxiliary agent), 6% of catalyst (auxiliary agent), 2% of dispersant (auxiliary agent), 2% of curing agent, dispersed at room temperature at 800 r / min for 30 minutes, and a primer was obtained for standby use. In this embodiment, the cosolvent is ethyl acetate, the catalyst is styrene, the dispersant is BYK-130, and the curing agent is methyl ethyl ketone peroxide.

[0058] Next, prepare super-hydrophobic modified nano-silica. The preparation process is as follows: add alcohol solvent, alkaline catalyst, and silicate in a mass ratio of 70:10:20 to the reactor in sequence, heat to 70°C and keep constant temperature, react for 24h and 72h respectively, filter and dry to obtain unmodified nano-silica of two particle sizes; take the dried nano-silica, mix alcohol and ester solvents, add polysiloxane with a molecular weight between 500~5w, and react at 80°C for 5h to obtain super-hydrophobic nano-silica.

[0059] Then, by weight percentage, 15% hydroxy polysiloxane resin, 30% super hydrophobic modified nano-silica, 4% dibutyltin dilaurate (organotin catalyst) and 51% ethyl acetate (solvent) were dispersed at 1200 r / min for 30 minutes at room temperature to obtain a topcoat for use.

[0060] Finally, use a 5-8Mpa air spray gun to evenly spray the primer on the tinplate substrate. After the primer is dry for 20 minutes, spray the topcoat on the primer. After waiting for 3 hours at room temperature, a wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating sample is obtained.

[0061] Example 3

[0062] First, by weight percentage, 20% of vinyl resin, 14% of silicone resin, 5% of 20-50 μm hollow glass microspheres (inorganic filler B1), 10% of 100-150 μm hollow glass microspheres (inorganic filler B2), 15% of ethanol (solvent A1), 26% of cosolvent (auxiliary agent), 6% of catalyst (auxiliary agent), 2% of dispersant (auxiliary agent), 2% of curing agent, at room temperature 800 r / min for 30 minutes, to obtain a primer for standby use. In this embodiment, the cosolvent is ethyl acetate, the catalyst is styrene, the dispersant is BYK-130, and the curing agent is methyl ethyl ketone peroxide.

[0063] Next, prepare super-hydrophobic modified nano-silica. The preparation process is as follows: add alcohol solvent, alkaline catalyst, and silicate in a mass ratio of 70:10:20 to the reactor in sequence, heat to 60°C and keep constant temperature, react for 24h and 72h respectively, filter and dry to obtain unmodified nano-silica of two particle sizes; take the dried nano-silica, mix alcohol and ester solvents, add polysiloxane with a molecular weight between 500 and 5w, and react at 85°C for 5h to obtain super-hydrophobic nano-silica.

[0064] Then, according to weight percentage, 20% hydroxy polysiloxane resin, 50% super hydrophobic modified nano-silica, 2% dibutyltin dilaurate (organotin catalyst) and 28% ethyl acetate (solvent) were dispersed at 1200 r / min for 30 minutes at room temperature to obtain a topcoat for use.

[0065] Finally, use a 5-8Mpa air spray gun to evenly spray the primer on the tinplate substrate. After the primer is dry for 20 minutes, spray the topcoat on the primer. After waiting for 3 hours at room temperature, a wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating sample is obtained.

[0066] Example 4

[0067] First, by weight percentage, 20% of vinyl resin, 20% of silicone resin, 10% of 20-50 μm hollow glass microspheres (inorganic filler B1), 25% of 100-150 μm hollow glass microspheres (inorganic filler B2), 10% of ethanol (solvent A1), 5% of cosolvent (auxiliary agent), 6% of catalyst (auxiliary agent), 2% of dispersant (auxiliary agent), 2% of curing agent, at room temperature 800 r / min for 30 minutes, to obtain a primer for standby use. In this embodiment, the cosolvent is ethyl acetate, the catalyst is styrene, the dispersant is BYK-130, and the curing agent is methyl ethyl ketone peroxide.

[0068] Next, prepare super-hydrophobic modified nano-silica. The preparation process is as follows: add alcohol solvent, alkaline catalyst, and silicate in a mass ratio of 70:10:20 to the reactor in sequence, heat to 70°C and keep constant temperature, react for 24h and 72h respectively, filter and dry to obtain unmodified nano-silica of two particle sizes; take the dried nano-silica, mix alcohol and ester solvents, add polysiloxane with a molecular weight between 500 and 5w, and react at 80°C for 5.5h to obtain super-hydrophobic nano-silica.

[0069] Then, by weight percentage, 10% hydroxy polysiloxane resin, 30% super hydrophobic modified nano-silica, 2% dibutyltin dilaurate (organotin catalyst) and 58% ethyl acetate (solvent) were dispersed at 1200 r / min for 30 minutes at room temperature to obtain a topcoat for use.

[0070] Finally, use a 5-8Mpa air spray gun to evenly spray the primer on the tinplate substrate. After the primer is dry for 20 minutes, spray the topcoat on the primer. After waiting for 3 hours at room temperature, a wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating sample is obtained.

[0071] Comparative Example 1

[0072] A domestic brand of super-hydrophobic coating: DSAN-S2001-DL (III) D-energy-absorbing super-hydrophobic super-self-cleaning anti-icing new material (double layer). This coating has been widely used in the State Grid.

[0073] Comparative Example 2

[0074] First, by weight percentage, 20% of vinyl resin, 20% of silicone resin, 5% of 20-50 μm hollow glass microspheres (inorganic filler B1), 10% of 100-150 μm hollow glass microspheres (inorganic filler B2), 15% of ethanol (solvent A1), 20% of cosolvent (auxiliary agent), 6% of catalyst (auxiliary agent), 2% of dispersant (auxiliary agent), 2% of curing agent, dispersed at room temperature at 800 r / min for 30 minutes, and a resin-based primer dispersion was obtained for standby use. In this embodiment, the cosolvent is ethyl acetate, the catalyst is styrene, the dispersant is BYK-130, and the curing agent is methyl ethyl ketone peroxide.

[0075] Next, prepare super-hydrophobic modified nano-silica. The preparation process is as follows: add alcohol solvent, alkaline catalyst, and silicate in a mass ratio of 70:10:20 to the reactor in sequence, heat to 70°C and keep constant temperature, react for 24h and 72h respectively, filter and dry to obtain unmodified nano-silica of two particle sizes; take the dried nano-silica, mix alcohol and ester solvents, add polysiloxane with a molecular weight between 500~5w, and react at 80°C for 5h to obtain super-hydrophobic nano-silica.

[0076] Then, by weight percentage, 70% of the super-hydrophobic modified nano-silica and 30% of ethyl acetate (solvent) were dispersed at 1200 r / min for 30 minutes at room temperature to obtain a topcoat dispersion for use.

[0077] Finally, the prepared super-hydrophobic silica topcoat dispersion was poured into the prepared resin-based base paint dispersion (mass ratio of topcoat: primer = 5:1), mixed and stirred for 30 minutes, and then the tinplate sheet was used as the substrate. The mixed paint was evenly sprayed on the tinplate sheet with an air spray gun at room temperature of 25°C. After natural curing, a comparative coating sample was obtained.

[0078] Experimental analysis

[0079] All coating samples were subjected to comparative tests on super-hydrophobicity, long-term water flow impact resistance, short-term water flow impact resistance, and finger friction resistance, and the results are shown in Table 1. The water impact resistance test was set up as follows: Figure 2 As shown, the nozzle diameter is 5mm, the spray distance is 20cm, the water flow rate for long-term water flow impact resistance is set to 5m / s (6L / min), and the short-term water flow impact resistance is set to 8m / s (9L / min).

[0080] / Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Water contact angle 158 158 161 158 158 153 Short-term resistance to water flow impact for 10s Water contact angle (after impact) 141 138 158 152 104 123 Long-term water shock resistance 20min water contact angle 101 123 145 124 103 124 Finger friction resistance 300 times without any problem 300 times without any problem 600 times without any problem 600 times without any problem After 200 times, the contact angle is less than 150° After 20 times, the contact angle is less than 150°

[0081] Table 1

[0082] After the short-term water flow impact resistance test, the hydrophobic properties of the coatings of Comparative Examples 1 and 2 deteriorated significantly, indicating that most of the super-hydrophobic modified nano-silica contained in the coatings had fallen off, proving that the bonding strength between the topcoat material and the primer was poor; Comparative Example 2 had the worst resistance to finger friction, which indicates that the super-hydrophobic coating prepared by physical intercalation without the addition of hydroxyl polysiloxane resin has poor wear resistance and is difficult to meet practical applications.

[0083] Comparing Example 1 and Example 2, it is found that the change in the primer resin content does not actually affect the super-hydrophobic property of the coating, and the durability of the super-hydrophobic property is also independent of the primer resin content. The primer resin mainly plays a bonding role with the substrate.

[0084] Comparing Example 2 and Example 4, it is found that the change of the addition amount of hollow glass microspheres in the primer can significantly affect the short-term water flow impact resistance of the coating. This is mainly because the hollow glass microspheres can form a "large micron structure" after curing on the coating surface, that is, spherical mastoids of different sizes, and there are grooves between the mastoids, which play a role in protecting the super-hydrophobic nano-topcoat. However, under long-term water flow impact, the nanoparticles still fall off and no longer have super-hydrophobic properties.

[0085] Comparing Implementation Case 2 and Implementation Case 3, it is found that the increase in the amount of silicone resin added in the topcoat can significantly improve the short-term and long-term water impact resistance of the coating, and improve the finger friction resistance. This is because the silicone resin has a strong cross-linking effect with the substrate and the super-hydrophobic modified particles, and can firmly adsorb the super-hydrophobic nanoparticles to form micron-sized clusters. Nano-sized particles are distributed on the micron-sized clusters to form a "micron-nano" hierarchical structure. This structure can protect the fragile nanoparticles, so it has excellent wear resistance and water flow impact resistance.

[0086] In summary, the wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coatings of Examples 1 to 4 prepared according to the present invention all have excellent super-hydrophobicity, water flow impact resistance, abrasion resistance and other properties.

[0087] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a wear-resistant multidimensional micro-nanostructure super-hydrophobic coating, characterized in that: The following steps are involved: Step 1. Mix and disperse the primer raw materials evenly and spray them on the surface of the substrate; Step 2. Mix and disperse the topcoat raw materials evenly. After the primer coating is dry, spray the evenly mixed and dispersed topcoat raw materials on the primer and cure at room temperature; The primer raw materials include vinyl resin, silicone resin, inorganic filler, solvent, curing agent and auxiliary agent; the topcoat raw materials include super-hydrophobic modified nano-silica, silicone resin and solvent; and the super-hydrophobic modified nano-silica contains at least two particle sizes of particles.

2. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 1, wherein: The primer raw materials include: 20% vinyl resin, 10%-20% silicone resin, 15%-35% inorganic filler, and the balance solvent A1, curing agent and auxiliary agent, calculated by weight percentage.

3. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 1, wherein The inorganic filler includes an inorganic filler B1 and an inorganic filler B2. The inorganic filler B1 is hollow glass microspheres with a particle size of 20 to 50 μm, and the inorganic filler B2 is hollow glass microspheres with a particle size of 100 to 150 μm.

4. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 3, wherein: The inorganic filler comprises: 5% to 10% of inorganic filler B1 and 10% to 25% of inorganic filler B2, calculated by weight percentage.

5. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating as claimed in claim 3, characterized in that, The topcoat and primer of the wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating are mutually inlaid structures, and the topcoat and primer form a multi-level rough structure from large micron structure C1, micron structure C2 to nano structure C3.

6. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 5, characterized in that: The distance between the papillae of the large micron structure C1 is 50-150 μm, the distance between the papillae of the micron structure C2 is 1-5 μm, and the distance between the particles of the nano structure C3 is 10-1000 nm.

7. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 1, wherein: The topcoat raw materials include: 10-20% silicone resin, 30-50% super-hydrophobic modified nano-silicon dioxide, 2-4% organic tin catalyst and the remainder solvent, calculated by weight percentage; the particle size of the nano-silicon dioxide is 10-1000nm.

8. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 7, wherein: The topcoat raw materials include: 15-20% silicone resin, 30-50% super-hydrophobic modified nano-silica, 2-4% organotin catalyst and the remainder solvent, calculated by weight percentage.

9. The method for preparing the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating according to claim 1, wherein: The preparation method of the super hydrophobic modified nano silicon dioxide comprises: An alcohol solvent, an alkaline catalyst, and a silicate are sequentially added into a reactor, the temperature is raised to 60±10°C and then kept constant, and the reaction is divided into two parts, respectively reacted for 24 hours and 72 hours, and two types of unmodified nano-silica with different particle sizes are obtained after filtration and drying. The dried nano-silica with two different particle sizes is mixed with an alcohol solvent and an ester solvent, polysiloxane with a molecular weight between 500 and 5w is added, and the reaction is carried out at 80±5°C for 5±0.5 hours to obtain super-hydrophobic nano-silica containing particles of two different particle sizes.

10. A wear-resistant multi-dimensional micro-nanostructure super-hydrophobic coating, characterized in that: It includes a primer coated on the surface of a substrate and a topcoat attached to the primer; the preparation process of the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating includes the preparation method of the wear-resistant multidimensional micro-nanostructure super-hydrophobic coating as described in any one of claims 1 to 9.

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