Preparation method and application of photo-thermal enhanced antirust self-repairing coating

Abstract

The invention provides a preparation method and application of a photo-thermal enhanced antirust self-repairing coating, and the photo-thermal enhanced antirust self-repairing coating comprises an acrylate component A, a photo-thermal filler component B, an antirust filler component C and a photoinitiator component D. The component A is prepared by mixing hard-segment acrylate and soft-segment acrylate according to a molar ratio of (1-5): (1-5); mixing a cross-linking agent and acrylic ester according to a mass ratio of 1: (10-50); the component B is prepared from titanium dioxide, magnesium powder and metal chlorate according to the mass ratio of 2: (1-2): (2.5-5). The component B, the component C and the component D are respectively added according to the mass ratios of the component B, the component C and the component D to the component A being 1: (10-200), 1: (10-200) and 0.1: (2.5-10). According to the invention, the partially rusted Q235 carbon steel is taken as a test object, and the photo-thermal performance of the coating is improved through controllable preparation of the filler; aluminum triphosphate and rust form a compact protective film, and a new thought is provided for treatment and protection of the rusted steel sheet.

Description

Technical Field

[0001] The present invention relates to the technical field of the synthesis of nanomaterials, polymer materials and organic coatings, and specifically relates to a preparation method and application of a photothermal enhanced rust self-repairing coating. Background Art

[0002] Problems such as resource waste, environmental pollution and safety hazards caused by metal corrosion have been plaguing the global industrial field. In recent years, the research and development of self-repairing coatings that can self-repair damage after being damaged has become one of the forefront research hotspots in the field of corrosion and protection. The self-repairing function is mainly realized by means of film-forming substances or corrosion inhibitors embedded in the organic coating, as well as the reversible or dynamic bonds inherent in the organic coating. However, once the pre-embedded film-forming substances or corrosion inhibitors are exhausted, the self-repairing ability of the coating will disappear. In this regard, the demand for self-repairing coatings based on reversible or dynamic bonds is very urgent. Among them, acrylate materials have received more extensive attention due to their generally high molecular mobility and strong self-crosslinking ability.

[0003] Before covering the protective layer on the steel surface, rust treatment must be carried out first to clean the steel surface and generate a certain roughness, so as to ensure good adhesion between the covering layer and the substrate. Otherwise, the service life of the anti-corrosion coating will be reduced due to the continuous expansion of rust. Rust treatment is an essential pretreatment process for the long-term application of anti-corrosion coatings. Rust-inhibiting coatings can be directly applied to the surface of incompletely derusted metals, and can impart a certain protective effect to the substrate while converting rust. There may be rust or a small amount of oil and other impurities on the metal substrate coated with the rust-inhibiting coating. Due to its low requirements for the substrate, it has been widely studied.

[0004] The self-repairing process triggered by photothermal has the advantages of remote activation, strong controllability, high-precision self-repair, fast repair process, etc. in practical applications. The repair mechanism of the photothermal self-repairing coating is that the filler at the damaged part of the coating generates heat under light irradiation, triggering a series of physical and chemical reactions in the coating, so as to achieve the closure and disappearance of the crack, and thus restore the physical barrier function of the coating. Therefore, photothermal fillers play a crucial role in the self-repairing process of the coating. Semiconductor materials have become one of the most promising photothermal materials due to their widely adjustable light absorption range, chemical stability and recyclability. Therefore, it is urgent to invent an anti-corrosion rust-inhibiting organic coating based on photothermal fillers, with both low cost and excellent photothermal self-repairing performance. Summary of the Invention

[0005] The technical task of the present invention is to provide a photothermal nanoheterojunction, a preparation method and an application of a self-repairing anti-corrosion coating in view of the deficiencies of the prior art.

[0006] The innovation points of the present invention are mainly in the following aspects: 1. The present invention conducts self - repair through the molecular mobility and strong self - crosslinking ability of acrylate materials. The hard - segment acrylate materials and soft - segment acrylate materials cause nano - phase separation, which ensures the high mechanical strength and molecular chain segment activity of the materials; 2. The present invention treats the rust of the metal substrate by introducing aluminum tripolyphosphate. Aluminum tripolyphosphate reacts with the rusty part to form a dense protective film, which can effectively improve the adhesion between the coating and the substrate surface, enabling the coating to be applied to a metal substrate with partial rust; 3. The present invention increases the photothermal conversion performance of the coating by introducing photothermal fillers. In addition, the addition of photothermal fillers helps to fill the micro - pores of the coating, enabling the coating to have a longer - lasting anti - corrosion ability; 4. Through the synergistic effect of the coating matrix and fillers, the composite coating exhibits excellent rust conversion ability and anti - corrosion ability. In addition, its self - repair characteristics extend the service life of the coating and significantly improve its weather resistance.

[0007] The technical solution adopted by the present invention to solve its technical problems is as follows: 1. The present invention provides a preparation method and application of a photothermal - enhanced rust - proof self - repair coating, including acrylate monomer component A, photothermal filler component B, rust - proof filler component C, and photo - initiator component D: Among them, acrylate monomer component A is composed of hard - segment acrylate monomers and soft - segment acrylate monomers mixed in a molar ratio of 1 - 5:1 - 5, and then the cross - linker and acrylate monomers are proportioned in a mass ratio of 1:10 - 50; photothermal filler component B is prepared from titanium dioxide, magnesium powder, and metal chloride in a mass ratio of 2:1 - 2:2.5 - 5. Photothermal filler component B, rust - proof filler component C, and photo - initiator component D are added in proportions of 1:10 - 200, 1:10 - 200, and 0.1:2.5 - 10 by mass with respect to component A respectively; Mix acrylate monomer component A, photothermal filler component B, rust - proof filler component C, and photo - initiator component D and stir evenly. Quickly transfer the mixed solution to the surface of the rusty steel sheet. First, set the distance between the mold and the ultraviolet lamp to 5 - 20 cm, and the power of the ultraviolet lamp to 60 - 120 W; after ultraviolet light curing for 1 - 4 hours, a rust - proof self - repair organic coating can be obtained; 2. The present invention further provides a preparation method and application of a photothermal - enhanced rust - proof self - repair coating, and the specific implementation steps are as follows: 1) Synthesis of component A acrylate monomer solution: Mix hard - segment acrylate monomers and soft - segment acrylate monomers in a molar ratio of 1 - 5:1 - 5, and then weigh the cross - linker and acrylate monomers in a mass ratio of 1:10 - 50. The order of adding the drugs is as follows: 1.1) First, mix the hard-segment acrylate monomer and the soft-segment acrylate monomer, and stir at a rotation speed of 300–1000 rmp for 0.5–3 hours within the temperature range of 20–35°C; 1.2) Then add the cross-linking agent and stir at a rotation speed of 200–500 rmp for 0.5–2 hours within the temperature range of 20–35°C; 2) Preparation of the nano-filler B component: Weigh titanium dioxide, magnesium powder, and metal chloride according to the mass ratio of 2:1–2:2.5–5. Mechanically mix titanium dioxide, magnesium powder, and metal chloride in an alumina crucible, and then heat at a temperature of 600–1000°C for 1–3 hours in a nitrogen atmosphere. After the reaction, cool naturally. After the reactant cools to room temperature, wash it with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 80–130°C for 5–15 hours to obtain the required filler TiN; 3) Preparation of the coating solution: Weigh the photo-thermal filler B component and the rust-proof filler C component respectively according to the mass ratio of 1:10–200 and 1:10–200 to the A component, and stir at a rotation speed of 300–1000 rmp for 0.5–3 hours within the temperature range of 20–35°C. Add the photoinitiator D component according to the mass ratio of 0.1:2.5–10 to the A component; then quickly perform a light-shielding treatment and stir at a rotation speed of 300–1000 rmp for 1–10 minutes within the temperature range of 20–35°C; 4) Coating method and steps of the coating: Stack the rusty Q235 steel sheet, the PU rubber pad, the silicone oil film, and the glass plate in sequence as the mold for coating polymerization and curing. There is a cavity with dimensions of 8 × 4 × 0.05 cm between the rusty Q235 steel sheet and the glass plate. 3 Transfer the coating solution to the assembled mold to avoid generating bubbles. Irradiate the mold under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 5–20 cm, and the power of the ultraviolet lamp to 60–120 W; 4.2) After ultraviolet light curing for 1–4 hours, a rust-proof self-healing organic coating can be obtained.

[0008] According to the embodiments of the present invention, the hard-segment acrylate monomer can be selected from one or more of methyl methacrylate, benzyl methacrylate, butyl methacrylate, etc.; According to the embodiments of the present invention, the soft-segment acrylate monomer can be selected from one or more of butyl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, trifluoroethyl methacrylate, etc.; According to an embodiment of the present invention, the crosslinking agent may be selected from one or more of divinylbenzene, diisocyanate, N,N-methylenebisacrylamide, 1,4-bis(acryloyloxy)butane, N,N-bisacryloylethylenediamine, and diallyldimethylammonium chloride; According to an embodiment of the present invention, the metal chloride salt may be selected from one or more of sodium chloride, magnesium chloride, potassium chloride, barium chloride, calcium chloride, aluminum chloride, zinc chloride, etc.; According to an embodiment of the present invention, the initiator may be selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, methyl benzoylformate, 2,2-dimethoxy-2-phenylacetophenone, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone.

[0009] 3. Among them, the metal substrate to be protected can be steel materials with wide applications, or other materials such as iron.

[0010] The preparation method and application of a photothermal enhanced rust-proof self-healing coating of the present invention have the following beneficial effects compared with the prior art: 1. The present invention performs self-healing through the molecular mobility and strong self-crosslinking ability of acrylate materials. The hard-segment acrylate materials and soft-segment acrylate materials cause nano-phase separation, which ensures the high mechanical strength and molecular chain segment activity of the material; 2. The present invention treats the rust of the metal substrate by introducing aluminum tripolyphosphate. Aluminum tripolyphosphate depolymerizes in an aqueous solution to produce low-molecular compounds such as pyrophosphate and orthophosphate. These substances chelate with the metal substrate to form a dense protective film, which can effectively improve the adhesion between the coating and the substrate surface, enabling the coating to be applied to a metal substrate with partial rust; 3. The present invention increases the photothermal conversion performance of the coating by introducing the photothermal filler TiN. In addition, the addition of the photothermal filler can also fill the micro-pores of the coating, and its good conductivity can transfer the position of the corrosion electrochemical reaction, enabling the coating to have a longer-lasting anti-corrosion ability; 4. Through the synergistic effect of the coating matrix and the filler, the composite coating exhibits excellent rust conversion ability and anti-corrosion ability. In addition, its self-healing property extends the service life of the coating and significantly improves the weather resistance, having broad application prospects and market value in future marine anti-corrosion rusty coatings. Description of the Drawings

[0011] Attached Figure 1 is the scanning electron microscope image and EDS energy spectrum analysis chart of the TiN and PMMA-LMA / ATP / TiN coatings prepared in Example 1 of the present invention.

[0012] Attached Figure 2It is the XRD pattern of the filler TiN and the PMMA-LMA series coatings prepared in Example 1 of the present invention.

[0013] Attached Figure 3 It is the infrared spectrum of the PMMA-LMA organic coating prepared in Example 1 of the present invention.

[0014] Attached Figure 4 It is the Raman spectrum comparison diagram of the PMMA-LMA organic coating prepared in Example 1 of the present invention and its monomer copolymer.

[0015] Attached Figure 5 It is the thermogravimetric curve of the PMMA-LMA series coatings prepared in Example 1 of the present invention.

[0016] Attached Figure 6 It is the AFM phase diagram and the AFM height diagram of the PBMA-LMA organic coating prepared in Example 2 of the present invention.

[0017] Attached Figure 7 It is the stress-strain curve of the PBMA-LMA series coatings prepared in Example 2 of the present invention.

[0018] Attached Figure 8 It is the optical photo of the damaged coating repair after the PBMA-LMA organic coating prepared in Example 2 of the present invention is irradiated by a near-infrared laser with a power of 1.5W and a wavelength of 808nm for 30s.

[0019] Attached Figure 9 It is the real-time temperature change curve of the filler TiN and the PBMA-BA series coatings prepared in Example 3 of the present invention under the irradiation of a near-infrared laser with a power of 1.5W and a wavelength of 808nm.

[0020] Attached Figure 10 It is the optical photo of the damaged coating repair after the PBMA-BA / ATP / TiN organic coating prepared in Example 3 of the present invention is irradiated by a near-infrared laser with a power of 1.5W and a wavelength of 808nm for 30s.

[0021] Attached Figure 11 It is the comparison diagram of the adhesion test results of the PBUMA-TFEMA / ATP / TiN coating prepared in Example 4 of the present invention on the steel sheet surface with different rust thicknesses and the comparison diagram of the adhesion test results of the PBUMA-TFEMA series coatings on the steel sheet surface with a rust thickness of 10μm.

[0022] Attached Figure 12 It is the optical photo of the damaged coating repair after the PBUMA-TFEMA / ATP / TiN coating prepared in Example 4 of the present invention is irradiated by a near-infrared laser with a power of 1.5W and a wavelength of 808nm for 30s.

[0023] Appendix Figure 13 It is a thermal imaging diagram showing the change of the filler TiN prepared in Example 5 of the present invention and the PMMA-2-EHA series coatings over time under the irradiation of a near-infrared laser with a power of 1.5 W and a wavelength of 808 nm.

[0024] Appendix Figure 14 It is the test result of electrochemical impedance analysis of the PMMA-2-EHA coating prepared in Example 5 of the present invention and the electrodes modified with PMMA-2-EHA / ATP / TiN coating during a 60-day immersion process. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] The present invention provides a preparation method and application of a photothermal-enhanced rust-proof self-healing coating, including an acrylate monomer A component, a photothermal filler B component, a rust-proof filler C component, and a photoinitiator D component: Among them, the acrylate monomer A component is prepared by mixing a hard-segment acrylate monomer and a soft-segment acrylate monomer in a molar ratio of 1–5:1–5, and then mixing a crosslinking agent with the acrylate monomer in a mass ratio of 1:10–50; the photothermal filler B component is prepared by mixing titanium dioxide, magnesium powder, and metal chloride in a mass ratio of 2:1–2:2.5–5. The photothermal filler B component, the rust-proof filler C component, and the photoinitiator D component are added in proportions of 1:10–200, 1:10–200, and 0.1:2.5–10 by mass with respect to the A component, respectively; Mix the acrylate monomer A component, the photothermal filler B component, the rust-proof filler C component, and the photoinitiator D component and stir evenly, and quickly transfer the mixed solution to the surface of the rusted steel sheet. First, set the distance between the mold and the ultraviolet lamp to 5–20 cm, and the power of the ultraviolet lamp to 60–120 W; after ultraviolet light curing for 1–4 hours, a rust-proof self-healing organic coating can be obtained; The present invention further provides a preparation method and application of a photothermal-enhanced rust-proof self-healing coating, and the specific implementation steps are as follows: 1) Synthesis of the acrylate monomer solution of component A: Mix the hard-segment acrylate monomer and the soft-segment acrylate monomer in a molar ratio of 1–5:1–5, and then weigh the crosslinking agent and the acrylate monomer in a mass ratio of 1:10–50. The order of adding the drugs is as follows: 1.1) First, mix the hard-segment acrylate monomer and the soft-segment acrylate monomer, and stir at a rotation speed of 300–1000 rmp for 0.5–3 hours within the temperature range of 20–35 °C; 1.2) Then add the crosslinking agent and stir at a rotation speed of 200–500 rmp for 0.5–2 hours within the temperature range of 20–35 °C; 2) Preparation of the nano-filler B component: Weigh titanium dioxide, magnesium powder, and metal chloride in a mass ratio of 2:1–2:2.5–5. Mechanically mix titanium dioxide, magnesium powder, and metal chloride in an alumina crucible, and then heat at a temperature of 600–1000 °C for 1–3 hours in a nitrogen atmosphere. After the reaction, cool naturally. After the reactants cool to room temperature, wash them with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 80–130 °C for 5–15 hours to obtain the required filler TiN; 3) Preparation of the coating solution: Weigh the photo-thermal filler B component and the rust-inhibiting filler C component in a mass ratio of 1:10–200 and 1:10–200 to component A respectively, and stir at a rotation speed of 300–1000 rmp for 0.5–3 hours within the temperature range of 20–35 °C. Add the photoinitiator D component in a mass ratio of 0.1:2.5–10 to component A; then quickly carry out light-shielding treatment and stir at a rotation speed of 300–1000 rmp for 1–10 minutes within the temperature range of 20–35 °C; 4) Coating application method and steps: Stack the rusty Q235 steel sheet, the PU rubber pad, the silicone oil film, and the glass plate in sequence as the mold for coating polymerization and curing. There is a cavity with dimensions of 8 × 4 × 0.05 cm 3 between the rusty Q235 steel sheet and the glass plate. Transfer the coating solution to the assembled mold, avoiding the generation of bubbles. Irradiate the mold under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 5–20 cm, and the power of the ultraviolet lamp to 60–120 W; 4.2) After ultraviolet light curing for 1–4 hours, an anti-rust self-healing organic coating can be obtained.

[0027] Among them, the hard-segment acrylate monomer described in step 1) can be selected from one or more of methyl methacrylate, benzyl methacrylate, butyl methacrylate, etc.; Among them, the soft-segment acrylate monomer described in step 1) can be selected from one or more of butyl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, trifluoroethyl methacrylate, etc.; Among them, the crosslinking agent described in step 1) can be selected from one or more of divinylbenzene, diisocyanate, N,N-methylenebisacrylamide, 1,4-bis(acryloyloxy)butane, N,N-bisacryloylethylenediamine, and diallyldimethylammonium chloride; Among them, the metal chloride salt described in step 2) can be selected from one or more of sodium chloride, magnesium chloride, potassium chloride, barium chloride, calcium chloride, aluminum chloride, zinc chloride, etc.; Among them, the initiator described in step 3) can be selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl propanone, methyl benzoylformate, 2,2-dimethoxy-2-phenyl acetophenone, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methyl acetophenone.

[0028] 3. Among them, the metal substrate to be protected can be steel material with wide application, or other materials such as iron. Example 1

[0029] The present invention provides a preparation method and application of a photothermal enhanced rust-proof self-repairing coating, including acrylate monomer component A, photothermal filler component B, rust-proof filler component C, and photoinitiator component D. The specific steps are as follows: 1) Synthesis of component A acrylate monomer solution: The hard segment acrylate monomer methyl methacrylate and the soft segment acrylate monomer lauryl methacrylate are mixed in a molar ratio of 2:1, and then the crosslinking agent and the acrylate monomer are weighed in a mass ratio of 1:30. The order of adding the drugs is as follows: 1.1) Add 12.75 g of lauryl methacrylate to 10 g of methyl methacrylate solution, stir at a temperature of 25°C and a speed of 500 rmp for 1 hour; 1.2) Then add 0.75 g of the crosslinking agent N,N'-methylenebisacrylamide, stir at a temperature of 25°C and a speed of 500 rmp for 30 minutes; 2) Preparation of nano-filler component B: Weigh titanium dioxide, magnesium powder, and metal chloride salt in a mass ratio of 2:1.5:5. Take 10 g of titanium dioxide, 7.5 g of magnesium powder, and 25 g of magnesium chloride and mechanically mix them in an alumina crucible. Then, in a nitrogen atmosphere, heat at a temperature of 800°C for 1 hour. After the reaction ends, cool naturally. After the reactant cools to room temperature, wash it with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 100°C for 10 hours to obtain the required filler TiN; 3) Preparation of the coating solution: First, weigh 0.18 g of the photothermal filler TiN powder and 0.25 g of the rust inhibitor filler aluminum tripolyphosphate powder. Slowly add the two powders to component A of the acrylate monomer and stir at a temperature of 25°C and a speed of 500 rmp for 1 hour. Subsequently, add 400 μL of the photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone; then quickly perform a light-shielding treatment and stir at a temperature of 25°C and a speed of 500 rmp for 1 minute; 4) Coating application method and steps: Stack the rusted Q235 steel sheet, PU gasket, silicone oil film, and glass plate in sequence as the mold for coating polymerization and curing. There is a cavity with dimensions of 8 × 4 × 0.05 cm between the rusted Q235 steel sheet and the glass plate. 3 Transfer the coating solution to the assembled mold, avoiding the generation of bubbles. Irradiate the mold under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 10 cm and the power of the ultraviolet lamp to 80 W; 4.2) After ultraviolet light curing for 2 hours, a rust-proof self-healing organic coating can be obtained.

[0030] Characterize the synthesized filler TiN and the elastomer coating sample as described above: The scanning electron microscope images and EDS energy spectrum analyses of the prepared TiN and PMMA-LMA / ATP / TiN coatings are as Figure 1 shown. It can be observed that the particle size of the TiN particles is in the nanometer range, indicating the successful preparation of the nano-TiN sample. The surface of the PMMA-LMA / ATP / TiN coating presents a typical orange peel-like morphology, with local height differences, which may be related to the substrate roughness or the solvent evaporation rate gradient. Through EDS elemental analysis, it can be known that the Al, P, Ti, and N elements are successfully introduced into the PMMA-LMA / ATP / TiN coating, and the filler is evenly embedded in the acrylate matrix, further proving the successful preparation of the organic composite coating.

[0031] The XRD analyses of the prepared TiN and PMMA-LMA series coatings are as Figure 2As shown, the XRD pattern of the filler TiN has high-intensity diffraction peaks, which correspond to the characteristic peaks of TiN. The diffraction peaks at 2θ values of 36.85°, 42.82°, 62.17°, and 74.37° are consistent with the (111), (200), (220), and (311) crystal planes of the TiN cubic unit cell (JCPDS No. 38-1420), indicating a relatively high crystallinity and purity of TiN. The intensity of the peaks in the XRD pattern of aluminum tripolyphosphate is closely related to factors such as the degree of crystal order and the grain size of the sample. The relatively strong and sharp peaks between 10 - 40° indicate a relatively high purity of the aluminum tripolyphosphate used. The diffuse diffraction peaks appearing near 20° in the XRD spectra of the PMMA-LMA series coatings confirm that the prepared polymer coatings all exhibit amorphous characteristics. The mechanical properties of the PMMA-LMA copolymer mainly originate from the intermolecular van der Waals interactions. Its amorphous structure feature allows the "rigid" components to be uniformly dispersed. This unique microstructure not only ensures good mechanical properties of the material but also provides sufficient freedom of movement for the molecular segments.

[0032] The infrared spectrum analysis of the above-prepared PMMA-LMA organic coating is as Figure 3 shown, where the absorption peaks at 2883 cm –1 , 2934 cm –1 , and 2962 cm –1 originate from the stretching vibrations of C-H on the main chain and methyl groups. The absorption peaks at 746 cm –1 and 691 cm –1 correspond to the out-of-plane bending vibrations of C-H in the side chain. The vibration absorption peaks at 1728 cm –1 and 1158 cm –1 correspond to the ester groups (-COOR) in the copolymer. In addition, the C=C stretching vibration peak originally located at 1640 cm –1 disappears in the figure. The disappearance of C=C indicates that the acrylate monomer has successfully undergone copolymerization.

[0033] The Raman comparative analysis of the above-prepared PMMA-LMA organic coating and its monomer copolymer is as Figure 4 shown. The obvious C-H stretching vibration peak at about 3000 cm –1 appears in the Raman spectrum of PMMA-LMA. In addition, the peak related to the stretching vibration of the carbonyl group (C=O) at 1725 cm –1 , the peak related to the bending vibration of the methyl group at 1450 cm –1 , and the peak at 1350 cm –1The peaks near the C-H deformation vibration can all be corresponded one by one in the PLMA spectrum and the PMMA-LMA spectrum. In the spectrum of PLMA, the peaks in the lower wavenumber region (700-800 cm –1 ) are caused by the C-H vibration in the molecular chain. However, this peak shows a blue shift in the spectrum of PMMA-LMA. The reason is that different types of molecular chains in the copolymer system will affect each other, thereby restricting the C-H vibration in the LMA chain. This also proves the successful synthesis of the PMMA-LMA copolymer.

[0034] The thermogravimetric curves of the above-prepared PMMA-LMA series coatings are as Figure 5 shown. The coatings start to show weight loss at about 300 °C and have excellent heat resistance. The free movement of molecular segments and the interaction between segments greatly improve the thermal stability of the PMMA-LMA copolymer system. After adding TiN and aluminum tripolyphosphate, the initial weight loss temperature of the PMMA-LMA / ATP / TiN composite coating system decreases slightly. The reason is that the presence of the fillers TiN and aluminum tripolyphosphate hinders the free movement of molecular segments, thereby reducing the heat resistance of the system. However, the presence of TiN and aluminum tripolyphosphate reduces the weight loss rate of the coating. The reason may be that the two change the thermal conduction characteristics of the coating. Since fillers with poor thermal conductivity are added to the coating, the heat distribution in the coating is uneven during heating. Although this uneven temperature distribution causes the coating to reach the decomposition temperature in some regions in advance, thereby reducing the initial decomposition temperature, overall, the slow heat transfer leads to the gradualness of the decomposition process, thereby slowing down the decomposition process and reducing the weight loss rate. The PMMA-LMA / ATP / TiN system exhibits excellent thermal stability, which ensures a stable repair effect of the material during the photothermal-assisted self-healing process. Example Two

[0035] The present invention provides a preparation method and application of a photothermal-enhanced rust-proof self-healing coating, including an acrylate monomer A component, a photothermal filler B component, a rust-proof filler C component, and a photoinitiator D component. The specific steps are as follows: 1) Synthesis of the A component acrylate monomer solution: Mix the hard-segment acrylate monomer benzyl methacrylate and the soft-segment acrylate monomer lauryl methacrylate in a molar ratio of 1:1, and then weigh the cross-linking agent and the acrylate monomer in a mass ratio of 1:25. The order of adding the drugs is as follows: 1.1) Add 12.75 g of lauryl methacrylate to 8.8 g of benzyl methacrylate solution, and stir at a temperature of 25 °C and a speed of 500 rmp for 1 hour; 1.2) Then, 0.86 g of cross-linking agent 1,4-bis(acryloyloxy)butane was added, and the mixture was stirred at 25 °C and 500 rmp for 30 minutes; 2) Preparation of nano-filler B component: Titanium dioxide, magnesium powder, and metal chloride were weighed according to the mass ratio of 2:2:5. 10 g of titanium dioxide, 10 g of magnesium powder, and 25 g of sodium chloride were mechanically mixed in an alumina crucible, and then heated at 900 °C for 1.5 hours in a nitrogen atmosphere. After the reaction ended, it was naturally cooled. After the reactant cooled to room temperature, it was washed with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, the obtained sample was dried at 110 °C for 12 hours to obtain the required filler TiN; 3) Preparation of coating solution: First, 0.3 g of photothermal filler TiN powder and 0.5 g of rust-proof filler aluminum tripolyphosphate powder were weighed, and the two powders were slowly added to the acrylate monomer A component, and stirred at 25 °C and 500 rmp for 1 hour. Subsequently, 400 μL of photoinitiator methyl benzoylformate was added; then it was quickly shielded from light and stirred at 25 °C and 500 rmp for 3 minutes; 4) Coating application method and steps: The rusted Q235 steel sheet, PU gasket, silicone oil film, and glass plate were stacked in sequence as the mold for coating polymerization and curing. There was a cavity with dimensions of 8 × 4 × 0.05 cm 3 between the rusted Q235 steel sheet and the glass plate. The coating solution was transferred to the assembled mold to avoid generating bubbles. The mold was irradiated under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 10 cm, and the power of the ultraviolet lamp to 90 W; 4.2) After ultraviolet light curing for 1.5 hours, a rust-proof self-healing organic coating can be obtained.

[0036] The prepared elastomer coating samples were characterized: The AFM phase diagram and AFM height diagram of the prepared PBMA-LMA organic coating are as Figure 6 shown. The bright region corresponding to the high phase angle characterizes the rigid phase composed of BMA units in the copolymer, while the dark region corresponding to the low phase angle reflects the flexible phase formed by the long alkyl chains of LMA. This unique microphase separation structure not only ensures the mechanical properties of the material through intermolecular van der Waals forces, but also provides the necessary degree of freedom of movement for the molecular chain segments with its appropriate phase region size, thus promoting the self-healing process. The periodic light and dark distribution presented in the AFM image confirms that the elastomer material with nano-scale phase separation characteristics has been successfully prepared.

[0037] The stress-strain curves of the prepared PBMA-LMA series coatings are as Figure 7As shown, the stress-strain behavior of the copolymer system shows a similar change pattern: the material first undergoes a typical elastic deformation stage, then enters a significant high-elastic deformation region, and finally reaches the fracture point. The mechanical properties of the elastomer after adding fillers have all been improved. Compared with the unfilled elastomer, the yield point and tensile strength have both increased. In addition, the fracture energy of the material also increases after adding fillers, and the toughness is enhanced. This is because the fillers enhance the overall rigidity of the material by forming a network structure or being uniformly distributed inside the elastomer. The fillers act as a "skeleton" to support the structure of the matrix material, reducing the deformation of the matrix material under external forces, thereby improving the mechanical properties such as tensile strength and toughness. In addition, the introduction of ATP and TiN fillers can reduce the stress concentration phenomenon inside the elastomer. Their distribution inside the material helps to evenly distribute the stress, enabling the material to better share the stress, reducing the generation and propagation of cracks, and thus enhancing the mechanical properties.

[0038] After the above-prepared PBMA-LMA organic coating is irradiated by a near-infrared laser with a power of 1.5 W and a wavelength of 808 nm for 30 s, the optical photograph of the damaged coating repair is as Figure 8 shown. Although the PBMA-LMA coating shows a certain tendency to close the scratches, limited by the insufficient system temperature and the limited molecular chain movement ability, the repair efficiency is low. Example 3

[0039] The present invention provides a preparation method and application of a photothermal-enhanced rust-proof self-healing coating, including an acrylate monomer A component, a photothermal filler B component, a rust-proof filler C component, and a photoinitiator D component. The specific steps are as follows: 1) Synthesis of the acrylate monomer solution of component A: Mix the hard-segment acrylate monomer benzyl methacrylate and the soft-segment acrylate monomer butyl acrylate in a molar ratio of 1:1, and then weigh the crosslinking agent and the acrylate monomer in a mass ratio of 1:30. The order of adding the drugs is as follows: 1.1) Add 6.4 g of butyl acrylate to 8.8 g of benzyl methacrylate solution, stir at a temperature of 25 °C and a speed of 500 rmp for 1 hour; 1.2) Then add 0.5 g of the crosslinking agent N,N′-methylenebisacrylamide, stir at a temperature of 25 °C and a speed of 500 rmp for 30 minutes; 2) Preparation of the nano-filler B component: Weigh titanium dioxide, magnesium powder, and metal chloride salts in a mass ratio of 2:1.5:4. Take 10 g of titanium dioxide, 7.5 g of magnesium powder, 10 g of potassium chloride, and 10 g of zinc chloride and perform mechanical mixing in an alumina crucible. Then, in a nitrogen atmosphere, heat at a temperature of 1000 °C for 1 hour. After the reaction, let it cool naturally. After the reactants cool to room temperature, wash them with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 100 °C for 12 hours to obtain the required filler TiN; 3) Preparation of the coating solution: First, weigh 0.4 g of the photothermal filler TiN powder and 0.5 g of the rust-proof filler aluminum tripolyphosphate powder. Slowly add the two powders to the acrylate monomer A component and stir at a speed of 500 rmp at a temperature of 25 °C for 1 hour. Subsequently, add 400 μL of the photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone; then quickly perform light-shielding treatment and stir at a speed of 500 rmp at a temperature of 25 °C for 5 minutes; 4) Coating application method and steps: Stack the rusted Q235 steel sheet, PU gasket, silicone oil film, and glass plate in sequence as the mold for coating polymerization and curing. Leave a cavity with dimensions of 8 × 4 × 0.05 cm 3 between the rusted Q235 steel sheet and the glass plate. Transfer the coating solution to the assembled mold, avoiding the generation of bubbles. Irradiate the mold under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 10 cm and the power of the ultraviolet lamp to 100 W; 4.2) After ultraviolet light curing for 1 hour, a rust-proof self-healing organic coating can be obtained.

[0040] Characterize the synthesized filler TiN and the elastomer coating sample as described above: The real-time temperature change curves of the above-prepared filler TiN and the PBMA-BA series coatings under near-infrared laser irradiation with a power of 1.5 W and a wavelength of 808 nm are as Figure 9 shown. After 120 s of irradiation, the central temperature of TiN reached 121.6 °C. The prepared TiN has excellent photothermal conversion temperature and heating-up efficiency. Under irradiation for about 10 s, the temperature of TiN quickly rose to 94.6% of the highest temperature. During the subsequent irradiation process, TiN showed excellent photothermal stability, and the central temperature was stable at about 121 °C. In addition, aluminum tripolyphosphate in the composite coating system has no photothermal conversion effect, and the excellent photothermal performance all comes from TiN. The photothermal conversion efficiency is the key factor affecting the self-healing performance. Rapid heating can significantly enhance the movement ability of polymer molecular chains, thereby improving the repair effect of the coating.

[0041] After the above-prepared PBMA-BA / ATP / TiN organic coating was irradiated with near-infrared laser at a power of 1.5 W and a wavelength of 808 nm for 30 s, the optical photograph of the damaged coating repair is as Figure 10 shown, and the composite coating exhibits excellent photothermal repair performance, and the surface scratches almost completely disappear. Example 4

[0042] The present invention provides a preparation method and application of a photothermal enhanced rust-proof self-healing coating, including acrylate monomer component A, photothermal filler component B, rust-proof filler component C and photoinitiator component D. The specific steps are as follows: 1) Synthesis of acrylate monomer solution of component A: Mix the hard-segment acrylate monomer butyl methacrylate and the soft-segment acrylate monomer trifluoroethyl methacrylate in a molar ratio of 1:1, and then weigh the cross-linking agent and the acrylate monomer in a mass ratio of 1:20. The order of adding the drugs is as follows: 1.1) Add 8.4 g of trifluoroethyl methacrylate to 7.1 g of butyl methacrylate solution, and stir at a temperature of 25 °C and a speed of 500 rmp for 1 hour; 1.2) Then add 0.775 g of cross-linking agent diisocyanate, and stir at a temperature of 25 °C and a speed of 500 rmp for 30 minutes; 2) Preparation of nano-filler component B: Weigh titanium dioxide, magnesium powder, and metal chloride in a mass ratio of 2:1.5:3. Take 10 g of titanium dioxide, 7.5 g of magnesium powder, 10 g of barium chloride, and 5 g of magnesium chloride and mechanically mix them in an alumina crucible. Then, in a nitrogen atmosphere, heat at a temperature of 900 °C for 2 hours. After the reaction is completed, cool naturally. After the reactant is cooled to room temperature, wash it with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 120 °C for 15 hours to obtain the required filler TiN; 3) Preparation of coating solution: First, weigh 0.8 g of photothermal filler TiN powder and 0.8 g of rust-proof filler aluminum tripolyphosphate powder, and slowly add the two powders to acrylate monomer component A. Stir at a temperature of 25 °C and a speed of 500 rmp for 1 hour. Then add 500 μL of photoinitiator 1-hydroxycyclohexyl phenyl ketone; then quickly perform light-shielding treatment, and stir at a temperature of 25 °C and a speed of 500 rmp for 2 minutes; 4) Coating application method and steps: Stack the rusted Q235 steel sheet, PU gasket, silicone oil film, and glass plate in sequence as the mold for coating polymerization and curing. There is a cavity with dimensions of 8 × 4 × 0.05 cm 3 between the rusted Q235 steel sheet and the glass plate. Transfer the coating solution to the assembled mold to avoid generating bubbles. Irradiate the mold under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 15 cm, and the power of the ultraviolet lamp to 100 W; 4.2) After ultraviolet curing for 2 hours, a rust-proof self-healing organic coating can be obtained.

[0043] Characterize the elastomer coating samples prepared above: Comparative analysis of the adhesion test results of the above-prepared PBUMA-TFEMA / ATP / TiN coating on the surfaces of steel sheets with different rust thicknesses and the adhesion test results of the PBUMA-TFEMA series coatings on the surface of a steel sheet with a rust thickness of 10 μm are as Figure 11 shown. Adhesion has an important impact on the application of the coating in rust prevention. After adding aluminum tripolyphosphate, the adhesion of the coating is significantly improved compared with the blank coating; TiN has no obvious effect on the improvement of the coating adhesion. Aluminum tripolyphosphate can form a dense chelate with rust, and the formed chelate slowly transforms into a normal phosphate film layer, thereby reducing rust defects and increasing adhesion. The adhesion of the coating on the bare steel surface is 6.11 Mpa. However, the adhesion of the coating on the surface of a steel sheet with a rust thickness of 10 μm reaches 6.15 Mpa, and the adhesion of the coating on the surface of a steel sheet with a rust thickness of 30 μm reaches 6.36 Mpa. The main reason for the increase in coating adhesion is that aluminum tripolyphosphate can form a dense chelate with rust, and the chelate improves the bonding force between the coating and the rusted steel sheet. As more and more rust appears on the steel sheet surface, the positive effect of aluminum tripolyphosphate rust conversion on adhesion is gradually offset by the negative effect of rust on adhesion, and the coating adhesion begins to decline.

[0044] After the above-prepared PBUMA-TFEMA / ATP / TiN coating is irradiated with a near-infrared laser with a power of 1.5 W and a wavelength of 808 nm for 30 s, the optical photograph of the damaged coating repair is as Figure 12 shown. The composite coating exhibits excellent photothermal repair performance, and the surface scratches almost completely disappear. Example Five

[0045] The present invention provides a preparation method and application of a photothermal enhanced rust-proof self-healing coating, including acrylate monomer component A, photothermal filler component B, rust-proof filler component C, and photoinitiator component D. The specific steps are as follows: 1) Synthesis of component A acrylate monomer solution: Mix the hard-segment acrylate monomer methyl methacrylate and the soft-segment acrylate monomer 2-ethylhexyl acrylate in a molar ratio of 1:1, and then weigh the cross-linking agent and the acrylate monomer in a mass ratio of 1:30. The order of adding the drugs is: 1.1) Add 14.2 g of 2-ethylhexyl acrylate to 10 g of methyl methacrylate solution, and stir at a temperature of 25 °C and a rotation speed of 500 rmp for 1 hour; 1.2) Then, add 0.8 g of crosslinking agent divinylbenzene, and stir at a speed of 500 rmp for 30 minutes at a temperature of 25 °C; 2) Preparation of nano-filler B component: Weigh titanium dioxide, magnesium powder, and metal chloride in a mass ratio of 2:1:3. Take 10 g of titanium dioxide, 5 g of magnesium powder, and 15 g of magnesium chloride and mechanically mix them in an alumina crucible. Then, heat them at a temperature of 800 °C for 2 hours in a nitrogen atmosphere. After the reaction ends, let it cool naturally. After the reactant cools to room temperature, wash it with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 120 °C for 15 hours to obtain the required filler TiN; 3) Preparation of coating solution: First, weigh 0.15 g of photothermal filler TiN powder and 0.5 g of rust-proof filler aluminum tripolyphosphate powder. Slowly add the two powders to the acrylate monomer A component and stir at a speed of 500 rmp for 1 hour at a temperature of 25 °C. Then, add 400 μL of photoinitiator 2-hydroxy-2-methyl-1-phenylpropanone; then quickly carry out light-shielding treatment and stir at a speed of 500 rmp for 1 minute at a temperature of 25 °C; 4) Coating application method and steps: Stack the rusted Q235 steel sheet, PU rubber pad, silicone oil film, and glass plate in sequence as the mold for coating polymerization and curing. There is a cavity with dimensions of 8 × 4 × 0.05 cm 3 between the rusted Q235 steel sheet and the glass plate. Transfer the coating solution to the assembled mold to avoid generating bubbles. Irradiate the mold under an ultraviolet lamp. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 10 cm, and the power of the ultraviolet lamp to 80 W; 4.2) After ultraviolet light curing for 3 hours, a rust-proof self-healing organic coating can be obtained.

[0046] Characterize the above-prepared filler TiN and elastomer coating samples: The thermal imaging diagrams of the above-prepared filler TiN and PMMA-2-EHA series coatings under near-infrared laser irradiation with a power of 1.5 W and a wavelength of 808 nm over time are as Figure 13As shown, it can be intuitively seen that the central temperature of the red region of the TiN filler is high, indicating excellent photothermal performance, presenting the LSPR effect, and having a strong absorption effect on ultraviolet-near infrared light. After 180 s of irradiation, the central temperatures of the PMMA-2-EHA, PMMA-2-EHA / ATP, PMMA-2-EHA / TiN, and PMMA-2-EHA / ATP / TiN coatings reached 44.6 °C, 44.5 °C, 80.7 °C, and 90.6 °C, respectively. It can be inferred therefrom that aluminum tripolyphosphate has no photothermal conversion effect, and the excellent photothermal performance all comes from TiN. The photothermal conversion efficiency is the key factor affecting the self-healing performance.

[0047] The electrochemical impedance analysis of the above-prepared PMMA-2-EHA coating and the electrode modified with the PMMA-2-EHA / ATP / TiN coating during the 60-day immersion process is as Figure 14 shown. In the initial stage of immersion, the PMMA-2-EHA / ATP / TiN composite coating showed a change different from that of the blank coating PMMA-2-EHA. After 3 days of immersion, the impedance arc radius of the coating slightly increased. After 7 days of immersion, the electrochemical impedance value was basically the same as that at the time of immersion for 0 days, and then the electrochemical impedance gradually decreased. As the electrolyte solution penetrated, aluminum tripolyphosphate could form a dense chelate with iron, and the formed chelate was slowly converted into a normal phosphate film layer, thereby further improving the corrosion resistance. The PMMA-2-EHA / ATP / TiN composite coating has excellent corrosion resistance and rust prevention ability, and the impedance decline rate during immersion is much lower than that of the blank coating. After 60 days of immersion, the low-frequency impedance modulus can still reach 1.15×10 9 Ω·cm 2 , which is much higher than that of the PMMA-2-EHA coating. This can be attributed to the rust conversion ability of aluminum tripolyphosphate and the anti-corrosion ability of TiN.

[0048] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0049] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

[0050] Except for the technical features described in the specification, they are all well-known technologies to those skilled in the art.

Claims

1. A preparation method and application of a photothermal enhanced rust-proof self-healing coating, including acrylate monomer component A, photothermal filler component B, rust-proof filler component C, and photoinitiator component D: Among them, acrylate monomer component A is composed of a hard segment acrylate monomer and a soft segment acrylate monomer mixed in a molar ratio of 1–5:1–5, and then a cross-linking agent and acrylate monomer are proportioned in a mass ratio of 1:10–50; photothermal filler component B is prepared from titanium dioxide, magnesium powder, and metal chloride in a mass ratio of 2:1–2:2.5–5. Photothermal filler component B, rust-proof filler component C, and photoinitiator component D are added in proportions of 1:10–200, 1:10–200, and 0.1:2.5–10 by mass ratio to component A respectively; Mix acrylate monomer component A, photothermal filler component B, rust-proof filler component C, and photoinitiator component D and stir evenly. Quickly transfer the mixed solution to the surface of the rusty steel sheet. First, set the distance between the mold and the ultraviolet lamp to 5–20 cm, and the power of the ultraviolet lamp to 60–120 W; after ultraviolet curing for 1–4 hours, a rust-proof self-healing organic coating can be obtained; Among them, the hard segment acrylate monomer can be selected from one or more of methyl methacrylate, benzyl methacrylate, butyl methacrylate, etc.; Among them, the soft segment acrylate monomer can be selected from one or more of butyl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, trifluoroethyl methacrylate, etc.; Among them, the cross-linking agent can be selected from one or more of divinylbenzene, diisocyanate, N,N-methylenebisacrylamide, 1,4-bis(acryloyloxy)butane, N,N-bisacryloylethylenediamine, and diallyldimethylammonium chloride; Among them, the metal chloride can be selected from one or more of sodium chloride, magnesium chloride, potassium chloride, barium chloride, calcium chloride, aluminum chloride, zinc chloride, etc.; Among them, the initiator can be selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl propanone, methyl benzoylformate, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methyl acetophenone; 2. The preparation method and application of a photothermal enhanced rust-proof self-healing coating according to claim 1, and the specific implementation steps are as follows: 1) Synthesis of acrylate monomer solution of component A: Mix the hard segment acrylate monomer and the soft segment acrylate monomer in a molar ratio of 1–5:1–5, and then weigh the cross-linking agent and acrylate monomer in a mass ratio of 1:10–50. The order of adding the drugs is as follows: 1.1) First mix the hard segment acrylate monomer and the soft segment acrylate monomer, and stir at a speed of 300–1000 rmp for 0.5–3 hours within a temperature range of 20–35 °C; 1.2) Then add the cross-linking agent and stir at a speed of 200–500 rmp for 0.5–2 hours within a temperature range of 20–35 °C; 2) Preparation of the nano-filler B component: Weigh titanium dioxide, magnesium powder, and metal chloride salts in a mass ratio of 2:1–2:2.5–5. Mechanically mix titanium dioxide, magnesium powder, and metal chloride salts in an alumina crucible, and then heat them at a temperature of 600–1000 °C for 1–3 hours in a nitrogen atmosphere. After the reaction is completed, let it cool naturally. After the reactants are cooled to room temperature, wash them with 0.5 mol / L hydrochloric acid solution and distilled water to remove excess by-products and residual salts. Finally, dry the obtained sample at 80–130 °C for 5–15 hours to obtain the required filler TiN; 3) Preparation of the coating solution: Weigh the photo-thermal filler B component and the rust-proof filler C component respectively in a mass ratio of 1:10–200 and 1:10–200 to the A component, and stir at a rotation speed of 300–1000 rmp for 0.5–3 hours within a temperature range of 20–35 °C. Add the photoinitiator D component in a mass ratio of 0.1:2.5–10 to the A component; then quickly carry out light-shielding treatment and stir at a rotation speed of 300–1000 rmp for 1–10 minutes within a temperature range of 20–35 °C; 4) Coating application method and steps: Stack the rusty Q235 steel sheet, PU rubber pad, silicone oil film, and glass plate in sequence as the mold for coating polymerization and curing. There is a cavity with dimensions of 8 × 4 × 0.05 cm between the rusty Q235 steel sheet and the glass plate. 3 Transfer the coating solution to the assembled mold, avoiding the generation of bubbles. Irradiate the mold under ultraviolet light. Specifically: 4.1) First, set the distance between the mold and the ultraviolet lamp to 5–20 cm, and the power of the ultraviolet lamp to 60–120 W; 4.2) After ultraviolet light curing for 1–4 hours, a rust-proof self-repairing organic coating can be obtained.

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