Active and passive synergistic anti-icing composite coating structure as well as preparation method and application thereof

Abstract

The invention discloses an active and passive synergistic anti-icing composite coating structure as well as a preparation method and application thereof. The composite coating structure comprises an adhesive layer, a carbon nano tube electric heating layer and an anti-icing layer, the anti-icing layer is formed through a cross-linking curing reaction; wherein the first polyisocyanate retains at least two isocyanate groups, the second polyisocyanate has at least three isocyanate groups, the polyaspartic acid ester resin has a plurality of first aminated end groups, the organic silicon resin has a second aminated end group, and a polyurea cross-linked structure is formed through reaction. According to the invention, an anti-icing layer formed by cross-linking polymerization of four units is combined with a carbon nanotube electric heating layer, a carbon nanotube film with certain thickness and pipe diameter distribution enables a polyurea coating covering the surface of the film to form a certain micro-nano coarse structure, and a fluorosilicone component with low surface energy in polymer resin is combined; the surface of the polyurea coating has excellent water repellency and easy deicing performance, and an efficient anti-icing and deicing system is cooperatively formed.

Description

Technical Field

[0001] The present invention relates to the field of surface protection technology, and in particular to an active and passive coordinated anti-icing composite coating structure, and a preparation method and application thereof. Background Art

[0002] Icing is a common natural phenomenon that occurs in low-temperature environments. However, in the fields of transportation, aerospace, wind power energy, etc., icing on the substrate surface can cause great harm and safety hazards. For example, ice on the surface of wind turbine blades can cause the wind turbine power to drop or even be damaged, causing certain economic losses and affecting the service life of the equipment; with the operation of wind turbine blades, large pieces of ice falling off the blades can also cause potential safety hazards. In addition, the icing phenomenon also seriously threatens the safe operation of outdoor equipment and facilities such as aircraft, power facilities, and bridge cables. In particular, icing on transmission lines can make repairs difficult and power outages long, causing even greater economic losses and social impacts.

[0003] The current anti-icing strategies are divided into two categories: active anti-icing and passive anti-icing, mainly including physical addition of antifreeze, mechanical deicing, photothermal deicing, electric deicing, and preparation of anti-icing coatings. Among them, active anti-icing technology is to provide additional heat sources by external devices to increase the surface temperature to achieve the purpose of blocking ice or melting. This method is effective and reliable, but it has a large weight and energy consumption requirement for the device, is costly, and requires the installation and external connection of heating elements; passive anti-icing technology generally refers to anti-icing coatings that do not require additional energy. The surface of the material contains special physical or chemical structures that can effectively reduce the contact area between water droplets and the coating surface. It can not only prolong the freezing time, but also allow the ice layer to fall off by itself under the action of external forces (such as vibration, wind, self-gravity, etc.). This method is low-cost, low-energy, and easy to implement. It is an ideal and valuable anti-icing method. However, the current anti-icing coatings have a significant performance degradation in complex environments due to changes in the surface physical structure and chemical groups of the material itself, making it difficult to achieve a long-term anti-icing effect. Moreover, it is difficult to prevent icing in extremely low temperatures or long-term freezing environments.

[0004] Carbon nanotubes have excellent electrical and thermal conductivity, can quickly generate heat when current passes through, have a fast reaction speed, and the generated heat is quickly conducted through the high thermal conductivity of carbon nanotubes, which can evenly heat the entire carbon nanotube film. In addition, the heating effect can be controlled and the desired temperature can be reached by adjusting the current or voltage. Compared with traditional active heating methods, carbon nanotube films have a fast heating rate, short response time, high heat conversion efficiency, uniform heat distribution, and are easy to be integrated into the structure. They are also lightweight and strong. The Chinese invention patents with publication numbers CN 114524080 A and CN 103813554 A respectively use carbon nanotube films for active heating deicing or defrosting of aircraft wings and automobile glass, but the carbon nanotube films in the patents are not combined with passive anti-icing coating technology, and are purely active deicing. The Chinese invention patent with publication number CN 116751506 A proposes to use polyurea coating for anti-icing coating, but the polyurea structure in the patent is not suitable for active deicing, and the separate anti-icing coating in the patent invention can only passively prolong the formation time of the ice layer, and cannot actively de-ice. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide an active and passive coordinated anti-icing composite coating structure, and a preparation method and application thereof.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0007] In a first aspect, the present invention provides an active and passive synergistic anti-icing composite coating structure, which includes a glue layer, a carbon nanotube electric heating layer and an anti-icing layer stacked in sequence on the surface of a substrate;

[0008] The adhesive layer is used to fix the carbon nanotube heating layer on the surface of the substrate, and the carbon nanotube heating layer is tightly combined with the anti-icing layer;

[0009] The anti-icing layer is formed by a cross-linking curing reaction of a polyaspartic acid ester resin, a fluoroalcohol-modified first polyisocyanate, a silicone resin and a second polyisocyanate; wherein the fluoroalcohol-modified first polyisocyanate has a fluoroalcohol group and retains at least 2 isocyanate groups, the second polyisocyanate has at least 3 isocyanate groups, the polyaspartic acid ester resin has a plurality of first amino end groups, the silicone resin has a second amino end group, and the first amino end group and the second amino end group both react with the isocyanate group to form a polyurea cross-linking structure.

[0010] In a second aspect, the present invention further provides a method for preparing the above-mentioned anti-icing composite coating structure, which comprises:

[0011] Coating on the surface of the substrate to form an adhesive layer;

[0012] Covering the carbon nanotube heating layer on the surface of the adhesive layer and fixing and pasting it;

[0013] An anti-icing coating is applied on the surface of the carbon nanotube heating layer to form an anti-icing precursor, and the anti-icing precursor is cross-linked and cured to form an anti-icing layer;

[0014] The anti-icing coating comprises polyaspartic acid ester resin, a fluoroalcohol-modified first polyisocyanate, a silicone resin, a second polyisocyanate, a solvent, a filler and an additive.

[0015] In a third aspect, the present invention further provides an active and passive coordinated anti-icing system, which includes the above-mentioned anti-icing composite coating structure and an electronic control unit;

[0016] The electric control unit is connected to the carbon nanotube electric heating layer and is used to apply current to the carbon nanotube electric heating layer.

[0017] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention at least include:

[0018] The anti-icing composite coating structure provided by the present invention has the functions of passive anti-icing and active deicing, and has both the hydrophobic property of low surface energy and the electric heating deicing function of the carbon nanotube film. It has excellent anti-icing and deicing effects, is suitable for long-term protection of the surface, and has extremely high practical application value.

[0019] In addition, the present invention adopts a method of combining an anti-icing layer formed by cross-linking polymerization of four units with a carbon nanotube electric heating layer. The carbon nanotube film with a certain thickness and tube diameter distribution allows the polyurea coating covering the surface of the film to form a certain micro-nano rough structure. Combined with the fluorosilicone component with low surface energy in the polymer resin, the surface of the polyurea coating has excellent water repellency and easy deicing properties, and synergistically forms an efficient anti-icing and deicing system, which can significantly improve the anti-icing effect and provide an effective way to save energy in anti-icing and deicing for the problem of icing on the surface of industrial facilities and equipment.

[0020] The above description is only an overview of the technical solution of the present invention. In order to enable those skilled in the art to more clearly understand the technical means of the present application and implement them according to the contents of the specification, the following is a description of the preferred embodiments of the present invention in conjunction with detailed drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the molecular structure of an anti-icing layer provided by a typical implementation case of the present invention;

[0022] Figure 2 It is a schematic diagram of the cross-layer structure of the anti-icing composite coating structure provided by a typical implementation case of the present invention;

[0023] Figure 3It is a schematic diagram of the anti-icing state of the anti-icing composite coating structure provided by a typical implementation case of the present invention;

[0024] Figure 4 It is a temperature change curve diagram of the anti-icing composite coating structure provided by another typical embodiment of the present invention during multiple temperature rise and fall processes under room temperature environment;

[0025] Figure 5 It is a comparative test chart of ice adhesion strength (40% RH, -20°C) of the anti-icing composite coating structure provided by some typical implementation cases and comparative cases of the present invention;

[0026] Figure 6 It is a comparison chart of deicing results of anti-icing composite coating structures provided by some typical implementation cases and comparative cases of the present invention at -20°C. DETAILED DESCRIPTION

[0027] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0029] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component or method step from another with the same name, but do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0030] The main purpose of the present invention is to provide an anti-icing composite coating system with passive hydrophobic anti-icing and active heating deicing properties. After the composite coating is applied to wind turbine blades, high-altitude aircraft and other facility structure surfaces affected by icing, it can meet the anti-icing requirements during long-term use and overcome the shortcomings of the prior art.

[0031] See also Figure 1-Figure 3As shown, for the above-mentioned purpose, an embodiment of the present invention provides an active and passive synergistic anti-icing composite coating structure, which includes an adhesive layer, a carbon nanotube electric heating layer and an anti-icing layer stacked in sequence on the surface of a substrate; the adhesive layer is used to fix the carbon nanotube heating layer on the surface of the substrate, and the carbon nanotube heating layer is tightly combined with the anti-icing layer; the anti-icing layer is formed by a cross-linking and curing reaction of a polyaspartic acid ester resin, a fluoroalcohol-modified first polyisocyanate, a silicone resin and a second polyisocyanate; wherein the fluoroalcohol-modified first polyisocyanate has a fluoroalcohol group and retains at least 2 isocyanate groups, the second polyisocyanate has at least 3 isocyanate groups, the polyaspartic acid ester resin has multiple first amino end groups, the silicone resin has a second amino end group, and the first amino end group and the second amino end group both react with the isocyanate group to form a polyurea cross-linking structure.

[0032] In the above technical scheme, the present invention adopts a strategy combining active carbon nanotube film heating deicing technology and passive hydrophobic coating anti-icing technology. The carbon nanotube film with a certain thickness and tube diameter distribution allows the polyurea coating covering the surface of the film to form a micro-nano rough structure. Combined with the low surface energy fluorosilicon component in the polymer resin, the polyurea coating surface has excellent water repellency and easy deicing. The hydrophobic anti-icing property of the material surface can effectively prolong the nucleation and freezing time of water droplets on the coating surface and reduce the adhesion strength of ice cubes on the coating surface. In addition, the strong polar urea bonds inside the cross-linked polymer and the high density and high orientation of the carbon nanotube film are conducive to improving the mechanical properties of the composite coating and avoiding problems such as film layer delamination or shedding failure under heating conditions.

[0033] Under long-term low temperature environment, water will inevitably penetrate into the hydrophobic coating or remain in the concave corners of the surface. Once water or snow forms ice, the adhesion of the ice layer will be greatly increased due to the interlocking effect of the micro-nano structure, and the anti-icing function of the coating will be lost. The composite coating system composed of carbon nanotube film with active heating function has excellent thermal stability and low thermal conductivity of the adhesive layer, so that the carbon nanotube film can maintain the surface of the composite coating at the melting temperature through electrothermal conversion through low power or pulsed power supply, which greatly saves heating energy consumption, extends the service life of the equipment, and reduces the adverse effects of high temperature on the substrate equipment. It also solves the problem that a single carbon nanotube film heating or a single hydrophobic anti-icing coating cannot remove ice in a low temperature environment. In some examples, the provided composite coating still has excellent anti-icing and de-icing effects at -20°C.

[0034] Compared with the anti-icing strategy of using a hydrophobic coating alone, the strategy of a composite coating can effectively avoid the problem of the hydrophobic coating losing its effect after icing. Therefore, the composite coating system that combines carbon nanotube film heating with a hydrophobic polyurea coating surface is an effective way for the present invention to provide energy-saving anti-icing and deicing for the problem of icing on the surface of industrial facilities and equipment. A key factor that enables the present invention to achieve a very excellent anti-icing / deicing effect is the combination of a carbon nanotube network film layer and an anti-icing layer of a specified component. The present invention adopts a method of combining an anti-icing layer formed by cross-linking polymerization of four units with a carbon nanotube electric heating layer. The carbon nanotube film with a certain thickness and tube diameter distribution allows the polyurea coating covering the surface of the membrane to form a certain micro-nano rough structure, and the thickness of the anti-icing coating is preferably 100-150μm. Combined with the fluorosilicon component with low surface energy in the polymer resin, the surface of the polyurea coating has excellent water repellency and easy deicing, and synergistically forms an efficient anti-icing and deicing system, which can significantly improve the anti-icing effect and provide an effective way to save energy for anti-icing and deicing on the surface of industrial facilities and equipment.

[0035] In addition, regarding the components and specific proportions of the anti-icing layer, in some embodiments, the mass ratio of the polyaspartic acid ester resin, the first polyisocyanate, the silicone resin and the second polyisocyanate in the anti-icing layer is (10-80): (10-30): (10-40): (10-30).

[0036] In some embodiments, the polyaspartic acid resin includes any one or a combination of two or more of the compounds represented by the following formula:

[0037]

[0038] In some embodiments, the first polyisocyanate and the second polyisocyanate include any one or a combination of two or more of hexamethylene diisocyanate trimer, fluorosilicone-modified hexamethylene diisocyanate trimer, L-lysine triisocyanate, fluorosilicone-modified L-lysine triisocyanate, triphenylmethane triisocyanate, and fluorosilicone-modified triphenylmethane triisocyanate, preferably hexamethylene diisocyanate trimer.

[0039] In some embodiments, the silicone resin includes any one or a combination of two or more of the compounds shown in the following formulae:

[0040]

[0041] Where n is 10 to 1000.

[0042] In some embodiments, the fluoroalcohol corresponding to the fluoroalcohol group includes any one or a combination of two or more of the compounds shown in the following formulae:

[0043]

[0044] The specific optional range includes any one or more combinations of tetrafluoropropanol, hexafluoroisopropanol, octafluoropentanol, dodecafluoroheptanol, tridecafluorooctanol and perfluoropolyether alcohol, preferably octafluoropentanol.

[0045] Regarding the carbon nanotube electric heating layer, in some embodiments, the carbon nanotube electric heating layer has a thickness of 50-100 μm and a density of 1.35-1.6 g / cm 3 , resistivity is 10-20Ω·m.

[0046] In some embodiments, the carbon nanotube electric heating layer comprises single-walled carbon nanotubes and / or multi-walled carbon nanotubes, the single-walled carbon nanotubes have a diameter of 0.6-2 nm, and the multi-walled carbon nanotubes have a diameter of 2-100 nm.

[0047] As some typical examples, the thickness of the carbon nanotube electric heating film is about 60μm, the density of the carbon nanotube film is 1.35-1.6g / cm3, preferably 1.5-1.6g / cm3, the resistivity is 10-20Ω·m, preferably 12-15Ω·m, the operating voltage range is 12-40V, preferably 24-32V, and the heating power is 20-150W, preferably 50-150W.

[0048] Another aspect of the embodiments of the present invention further provides a method for preparing the anti-icing composite coating structure provided in any of the above embodiments, which comprises the following steps:

[0049] Coating on the surface of the substrate to form an adhesive layer;

[0050] Covering the carbon nanotube heating layer on the surface of the adhesive layer and fixing and pasting it;

[0051] An anti-icing coating is applied on the surface of the carbon nanotube heating layer to form an anti-icing precursor, and the anti-icing precursor is cross-linked and cured to form an anti-icing layer;

[0052] The anti-icing coating comprises polyaspartic acid ester resin, a fluoroalcohol-modified first polyisocyanate, a silicone resin, a second polyisocyanate, a solvent, a filler and an additive.

[0053] As a typical example, polyisocyanate and fluoroalcohol can be mixed and reacted under the action of a catalyst and at a constant temperature, and then uniformly mixed with the remaining raw materials to form a coating composition. Of course, the finished polyisocyanate modified by fluoroalcohol can also be directly purchased. Specifically, an excess of polyisocyanate and fluoroalcohol can be mixed and reacted at 0-80°C in a protective atmosphere (such as a nitrogen atmosphere) to form a mixture of a modified first polyisocyanate and an unmodified second polyisocyanate, which is then mixed with a polyaspartic acid ester resin, a silicone resin, etc., and reacted and cured at 0-50°C to obtain a target resin system as an anti-icing layer.

[0054] In specific applications, the epoxy resin layer can be sprayed, rolled or brushed on the aluminum alloy plate, composite material, other metal substrate or coating surface, and the carbon nanotube electric heating film can be directly covered on the glue layer and flattened, and cured and dried at room temperature. After the epoxy glue layer is cured, the anti-icing coating is sprayed, rolled or brushed on the surface of the carbon nanotube electric heating film, and cured at room temperature to obtain a composite coating with both passive hydrophobic anti-icing and active electric heating deicing performance.

[0055] In some embodiments, the mass fraction of the polyaspartic acid ester resin in the anti-icing coating is 10%-70%, the mass fraction of the first polyisocyanate is 10%-30%, the mass fraction of the silicone resin is 10-40%, the mass fraction of the second polyisocyanate is 10%-30%, the mass fraction of the solvent is 5-10%, the mass fraction of the filler is 1-40%, and the mass fraction of the additive is 1-20%.

[0056] As a specific example, the mass ratio of fluoroalcohol to the second isocyanate in the anti-icing coating is 1:1-10, preferably 1:2-5; the mass ratio of polyaspartic acid ester resin to silicone resin is 1:1-5, preferably 1:1-2; the mass ratio of the polyaspartic acid ester resin to the fluoroalcohol-modified first polyisocyanate is 1:0~5, preferably 1:1-2.

[0057] It should be noted that the usage of polyaspartic acid ester resin, polyisocyanate, fluoroalcohol and silicone resin are all greater than 0.

[0058] In some embodiments, the solvent includes any one of chloroform, butyl acetate, ethyl acetate, and xylene, or a combination of two or more thereof.

[0059] In some embodiments, the filler includes any one of barium sulfate, titanium dioxide, talc, and calcium carbonate, or a combination of two or more thereof.

[0060] In some embodiments, the auxiliary agent includes any one or a combination of two or more of a leveling agent, a defoaming agent, a dispersant, a thickener, and a silane coupling agent.

[0061] In some embodiments, the cross-linking and curing is performed at a temperature of 10-40° C. and for a time of 5-24 hours.

[0062] Correspondingly, an embodiment of the present invention also provides a further application of the above-mentioned technical solution, namely, an active and passive coordinated anti-icing system, which includes the anti-icing composite coating structure and an electronic control unit provided by any of the above-mentioned embodiments; the electronic control unit is connected to the carbon nanotube electric heating layer for applying current to the carbon nanotube electric heating layer.

[0063] This composite coating system can solve the problem of icing and deicing on wind turbine blades, flight facilities, bridge cables and vehicle surfaces at low temperatures.

[0064] The technical scheme of the present invention is further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only used to illustrate the present invention, and do not limit the scope of the present invention. In addition, unless otherwise specified, the various raw materials used in the following embodiments can be purchased from the market or other channels, or can be obtained by self-production according to reference books in the field, and the various production and testing equipment used are also equipment known in the art.

[0065] Example 1

[0066] This embodiment provides a method for preparing a fluorosilicone-modified hydrophobic anti-icing coating, comprising:

[0067] Preparation of component A of the coating: At room temperature, 30 parts by weight of polyaspartic acid ester resin (Nanjing Lanfeng New Material Technology Co., Ltd.), 0.4 parts by weight of dispersant, 3 parts by weight of moisture-proof agent, 0.6 parts by weight of anti-sagging agent, 11 parts by weight of pigment, 0.3 parts by weight of defoamer, 6.4 parts by weight of barium sulfate and 10.6 parts by weight of talc were mixed and dispersed at high speed for 30 minutes at a dispersion speed of 1500 r / min, and then ground to a fineness of less than 30 μm, and further added 0.2 parts by weight of defoamer A, 0.2 parts by weight of defoamer B, 1 part by weight of silane coupling agent, 0.3 parts by weight of rheological additive, 6 parts by weight of solvent and 40 parts by weight of silicone resin polydimethoxysilane, and dispersed at high speed for 10 minutes.

[0068] Preparation of component B of the coating: 0.1 parts by weight of catalyst, 40.5 parts by weight of polyisocyanate HT600 (Wanhua Chemical Group Co., Ltd.), 15 parts by weight of octafluoropentanol and 4.5 parts by weight of solvent were mixed at a temperature of 60° C. and dispersed at high speed for 5 minutes.

[0069] At room temperature, the above-mentioned components A and B are evenly mixed in a weight ratio of 1:0.5 to form a coating.

[0070] Example 2

[0071] This embodiment provides a method for preparing a coating system of a hydrophobic anti-icing coating and a carbon nanotube film, comprising:

[0072] Spray, roll or brush the epoxy resin layer on the surface of the aluminum alloy plate, composite material or other substrate, and directly cover the surface with the carbon nanotube electric heating film, and dry it at room temperature. After the epoxy layer is cured, the hydrophobic modified anti-icing coating in Example 1 is sprayed, rolled or brushed on the surface of the carbon nanotube electric heating film, and dried at room temperature to obtain a composite coating with both passive hydrophobic anti-icing and active electric heating deicing performance, and the thickness of the anti-icing layer is 100-150μm.

[0073] Example 3

[0074] This embodiment provides a method for preparing a fluorosilicone-modified hydrophobic anti-icing coating. This embodiment is substantially the same as Embodiments 1 and 2, except that:

[0075] The addition amount of polyaspartic acid ester resin is adjusted to 10 parts by weight, the addition amount of polydimethoxysilane is adjusted to 10 parts by weight, the addition amount of polyisocyanate is adjusted to 20 parts by weight, and the fluoroalcohol is hexafluoroisopropanol, and its addition amount corresponds to half the molar number of polyisocyanate.

[0076] Example 4

[0077] This embodiment provides a method for preparing a fluorosilicone-modified hydrophobic anti-icing coating. This embodiment is substantially the same as Embodiments 1 and 2, except that:

[0078] The addition amount of polyaspartic acid ester resin is adjusted to 60 parts by weight, the addition amount of polydimethoxysilane is adjusted to 30 parts by weight, the addition amount of polyisocyanate is adjusted to 60 parts by weight, and the fluoroalcohol is replaced by hexafluoroisopropanol, and its addition amount corresponds to half the molar number of polyisocyanate.

[0079] Comparative Example 1

[0080] The comparative example provides a method for preparing a hydrophobic coating without fluorine-silicon components, comprising:

[0081] Preparation of component A of the coating: At room temperature, 30 parts by weight of polyaspartic acid ester resin (Nanjing Lanfeng New Material Technology Co., Ltd.), 0.4 parts by weight of dispersant, 3 parts by weight of moisture-proof agent, 0.6 parts by weight of anti-sagging agent, 11 parts by weight of pigment, 0.3 parts by weight of defoamer, 6.4 parts by weight of barium sulfate and 10.6 parts by weight of talc were mixed and dispersed at high speed for 30 minutes at a dispersion speed of 1500 r / min, and then ground to a fineness of less than 30 μm, and further added 0.2 parts by weight of defoamer A, 0.2 parts by weight of defoamer B, 1 part by weight of silane coupling agent, 0.3 parts by weight of rheological additive and 6 parts by weight of solvent, and dispersed at high speed for 10 minutes.

[0082] Preparation of component B of the coating: 0.1 parts by weight of catalyst, 20 parts by weight of polyisocyanate HT600 (Wanhua Chemical Group Co., Ltd.) and 4.5 parts by weight of solvent were mixed at a temperature of 60° C. and dispersed at high speed for 5 minutes.

[0083] At room temperature, the above-mentioned components A and B are evenly mixed in a weight ratio of 1:0.375 to form a coating.

[0084] Comparative Example 2

[0085] The comparative example provides a method for preparing an active electrothermal deicing carbon nanotube film, comprising:

[0086] Spray, roll or brush an epoxy resin layer on the surface of an aluminum alloy plate, a composite material or other substrate, and directly cover the surface with a carbon nanotube electric heating film, and dry it at room temperature.

[0087] Comparative Example 3

[0088] The comparative example provides a method for preparing an active electrothermal deicing carbon nanotube film and a hydrophobic anti-icing coating, comprising:

[0089] The epoxy resin layer is sprayed, rolled or brushed on the surface of the aluminum alloy plate, composite material or other substrate, and the carbon nanotube electric heating film is directly covered on the surface and dried at room temperature. After the epoxy layer is cured, the hydrophobic modified coating of Comparative Example 1 is sprayed, rolled or brushed on the surface of the carbon nanotube electric heating film and dried at room temperature to obtain a composite coating.

[0090] Comparative Example 4

[0091] The comparative example provides a method for preparing an active electrothermal deicing carbon nanotube film and a hydrophobic anti-icing coating, comprising:

[0092] The epoxy resin layer is sprayed, rolled or brushed on the surface of the aluminum alloy plate, composite material or other substrate, and the carbon nanotube electric heating film is directly covered on the surface and dried at room temperature. After the epoxy layer is cured, the single-component polyurea anti-icing coating prepared by referring to the prior art with publication number CN 116751506 A is sprayed, rolled or brushed on the surface of the carbon nanotube electric heating film, and dried at room temperature to obtain a composite coating.

[0093] The anti-icing structures provided in the above embodiments and comparative examples were tested in the following manner:

[0094] (1) Use a digital push-pull dynamometer to test the ice adhesion strength of the coating surface;

[0095] (2) The coating surface temperature and the temperature of the carbon nanotube electric heating film are respectively recorded and monitored in real time using a near-infrared thermal imager and a thermocouple;

[0096] (3) The mechanical properties of the coating are recorded and tested by a universal tensile testing machine;

[0097] (4) The surface roughness of the coating was recorded by 3D confocal laser microscopy.

[0098] Table 1 below shows the performance test data of the anti-icing composite coating provided by the above-mentioned embodiments and comparative examples. It can be clearly seen that the various performances of the deicing / anti-icing method provided by the embodiments of the present invention are significantly better than those of the comparative examples.

[0099] Table 1

[0100] Coating performance Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Contact angle (°) 128.0 139.8 137.5 135.1 113.6 60.7 120.6 118.3 Roughness(μm) 0.35 0.42 0.40 0.39 0.33 0.15 0.36 0.22 Stress(MPa) 6.76 7.15 7.22 7.09 4.76 4.78 5.23 3.12 strain(%) 52.08 53.15 51.27 60.34 55.73 60.15 60.18 99.23 Ice adhesion strength (kPa) 12.80 10.43 11.67 11.15 25.25 30.06 20.13 19.13 Deicing time(s) -- 730 765 793 -- -- -- --

[0101] Figure 4 This is the temperature change curve of the composite anti-icing coating in Example 2 during multiple heating and cooling processes under room temperature. The figure shows that within the same heating and cooling time, the temperature of the coating surface is still higher than the temperature before heating. As the number of heating and cooling times increases, the maximum temperature of the coating during the heating process increases from 65°C in the first heating to about 80°C. This means that during the cyclic heating process, the heating time for the coating to reach the preset temperature will decrease with the increase in the number of cycles, which is very beneficial for saving energy.

[0102] Figure 5The test results of ice adhesion strength of different embodiments and comparative examples at -20°C show that compared with the ice adhesion strength of 25.25 kPa of the coating of comparative example 1, the ice adhesion strength of the composite coating composed of comparative example 1 and comparative example 2 is slightly lower, which is 20.13 kPa. However, the ice adhesion strength of the coating of each embodiment is lower. The ice adhesion strength of embodiments 1 to 4 are 12.80, 10.43, 11.67, and 11.15 kPa, respectively. The ice adhesion strength of comparative example 4 (19.13 kPa) is also higher than that of the embodiments, indicating the excellence of the anti-icing layer of the present invention.

[0103] Figure 6 The results of deicing under heating at -20°C for different embodiments and comparative examples are shown. After heating for 30,000 seconds, ice cubes are still attached to the coating surface in Embodiment 1 and Comparative Examples 1-3, while ice cubes on the coating surface can be removed by heating for only 730 seconds in Embodiment 2. Ice cubes on the coating surface can also be removed in Embodiment 3 and Embodiment 4 after heating for a period of time, with deicing times of 765 and 793 respectively. Comparative Example 4 still cannot remove ice cubes on the coating surface after heating for 30,000 seconds, which shows the superiority of the invention patent in deicing performance.

[0104] Based on the above embodiments and comparative examples, it can be clearly seen that the anti-icing composite coating provided by the embodiments of the present invention is composed of an anti-icing layer formed by the reaction of polyaspartic acid ester resin, polyisocyanate and silicone resin, a carbon nanotube electric heating film, and an epoxy resin adhesive layer. It has the advantages of low surface energy of the hydrophobic anti-icing coating and the electric heating deicing function of the carbon nanotube film. The higher density and orientation arrangement of the carbon nanotube film enhance the mechanical properties of the composite coating. The composite coating system composed of the carbon nanotube film combined with the active heating function has excellent thermal stability and low thermal conductivity, which allows the carbon nanotube film to maintain the surface of the composite coating at the melting temperature through electrothermal conversion by low power or pulsed power supply, greatly saving heating energy consumption. Therefore, the final composite coating has excellent anti-icing effect, can be used for long-term surface protection of wind turbine blades and other parts, and has extremely high practical application value.

[0105] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An active and passive synergistic anti-icing composite coating structure, characterized in that: It includes a glue layer, a carbon nanotube electric heating layer and an anti-icing layer which are sequentially stacked on the surface of the substrate; The adhesive layer is used to fix the carbon nanotube heating layer on the surface of the substrate, and the carbon nanotube heating layer is tightly combined with the anti-icing layer; The anti-icing layer is formed by a cross-linking curing reaction of a polyaspartic acid ester resin, a fluoroalcohol-modified first polyisocyanate, a silicone resin and a second polyisocyanate; wherein the fluoroalcohol-modified first polyisocyanate has a fluoroalcohol group and retains at least 2 isocyanate groups, the second polyisocyanate has at least 3 isocyanate groups, the polyaspartic acid ester resin has a plurality of first amino end groups, the silicone resin has a second amino end group, and the first amino end group and the second amino end group both react with the isocyanate group to form a polyurea cross-linking structure.

2. The anti-icing composite coating structure according to claim 1, characterized in that: The anti-icing layer has a thickness of 100-150 μm.

3. The anti-icing composite coating structure according to claim 1, characterized in that: The mass ratio of the polyaspartic acid ester resin, the first polyisocyanate, the silicone resin and the second polyisocyanate in the anti-icing layer is (10-70): (10-30): (10-40): (10-30).

4. The anti-icing composite coating structure according to claim 1, characterized in that: The polyaspartic acid resin includes any one or a combination of two or more of the compounds shown in the following formula: And / or, the first polyisocyanate and the second polyisocyanate include any one or a combination of two or more of hexamethylene diisocyanate trimer, fluorosilicone-modified hexamethylene diisocyanate trimer, L-lysine triisocyanate, fluorosilicone-modified L-lysine triisocyanate, triphenylmethane triisocyanate, and fluorosilicone-modified triphenylmethane triisocyanate; And / or, the organic silicone resin includes any one or a combination of two or more of the compounds represented by the following formula: Where n is 10 to 1000; And / or, the fluoroalcohol corresponding to the fluoroalcohol group includes any one or a combination of two or more of the compounds shown in the following formula:

5. The anti-icing composite coating structure according to claim 1, characterized in that: The thickness of the carbon nanotube electric heating layer is 50-100 μm and the density is 1.35-1.6 g / cm 3 , the resistivity is 10-20ΩΩ·m; And / or, the carbon nanotube electric heating layer comprises single-walled carbon nanotubes and / or multi-walled carbon nanotubes, the diameter of the single-walled carbon nanotubes is 0.6-2 nm, and the diameter of the multi-walled carbon nanotubes is 2-100 nm.

6. The method for preparing the anti-icing composite coating structure according to any one of claims 1 to 5, characterized in that: include: Coating on the surface of the substrate to form an adhesive layer; Covering the carbon nanotube heating layer on the surface of the adhesive layer and fixing and pasting it; An anti-icing coating is applied on the surface of the carbon nanotube heating layer to form an anti-icing precursor, and the anti-icing precursor is cross-linked and cured to form an anti-icing layer; The anti-icing coating comprises polyaspartic acid ester resin, a fluoroalcohol-modified first polyisocyanate, a silicone resin, a second polyisocyanate, a solvent, a filler and an additive.

7. The preparation method according to claim 6, characterized in that: The mass fraction of the polyaspartic acid ester resin in the anti-icing coating is 10%-70%, the mass fraction of the first polyisocyanate is 10%-30%, the mass fraction of the silicone resin is 10-40%, the mass fraction of the second polyisocyanate is 10%-30%, the mass fraction of the solvent is 5-10%, the mass fraction of the filler is 1-40%, and the mass fraction of the auxiliary agent is 1-20%.

8. The preparation method according to claim 6, characterized in that: The solvent includes any one of chloroform, butyl acetate, ethyl acetate, and xylene, or a combination of two or more thereof; And / or, the filler includes any one of barium sulfate, titanium dioxide, talc, and calcium carbonate, or a combination of two or more thereof; And / or, the auxiliary agent includes any one or a combination of two or more of a leveling agent, a defoaming agent, a dispersant, a thickener, and a silane coupling agent.

9. The preparation method according to claim 6, characterized in that: The cross-linking and curing process is carried out at a temperature of 10-40° C. and for a time of 5-24 hours.

10. An active and passive coordinated anti-icing system, characterized in that: Comprising the anti-icing composite coating structure according to any one of claims 1 to 5 and an electronic control unit; The electric control unit is connected to the carbon nanotube electric heating layer and is used to apply current to the carbon nanotube electric heating layer.

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