A self-healing UV-curable electroplated aluminum color coating and its preparation method

Abstract

This invention relates to the field of polymer materials technology, specifically proposing a self-healing UV-curable electroplated aluminum color coating and its preparation method. By weight, it comprises: 30-50 parts polyurethane acrylic resin, 10-25 parts modified acrylic oligomer containing dynamic covalent bonds, 2-5 parts photoinitiator, 3-8 parts hydrophobically modified nanofiller, and 1-3 parts crosslinking agent. The dynamic covalent bonds are selected from at least one of hydrazide bonds, borate ester bonds, and Diels-Alder bonds. This invention achieves rapid self-healing and thermally triggered remodeling of the coating at room temperature through the introduction of a gradient energy synergistic network of dynamic covalent bonds and quadruple hydrogen bonds. Simultaneously, the microphase separation design of the hydrophobic core-shell filler and grafted modified silicon carbide nanowires enhances hydrolysis resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a self-healing UV-curable electroplated aluminum color coating and its preparation method. Background Technology

[0002] In recent years, UV-curable coatings have been widely used in the field of electroplated aluminum color layer coating due to their advantages such as rapid curing and low VOC emissions. However, there is a contradiction between the coating hardness and self-healing performance of traditional UV coatings: although the highly cross-linked system has excellent wear resistance, the movement of molecular chains is restricted, resulting in insufficient scratch repair efficiency. Especially in electroplated aluminum hot stamping scenarios, the coating needs to withstand the mechanical stress of processes such as molding and hot stamping. Traditional coatings are prone to optical degradation due to the propagation of microcracks, and cannot be effectively repaired by conventional heating.

[0003] Existing self-healing UV coatings mostly rely on single dynamic bonds (such as hydrogen bonds or disulfide bonds), which has significant limitations. For example, polyurethane acrylate systems achieve repair through elastic recovery, but require high temperature (>80℃) or long duration (>2 hours) stimulation, and the mechanical strength decreases by more than 30% after repair. In water-based systems, dynamic covalent bonds (such as acylhydrazone bonds and borate ester bonds) are easily corroded by moisture, with hydrolysis rates reaching 40%-50% in high humidity environments, leading to the failure of the repair network. In addition, existing technologies struggle to balance coating density and molecular chain migration: while highly cross-linked UV-cured networks improve scratch resistance, they hinder dynamic bond recombination, resulting in low repair efficiency.

[0004] To overcome the aforementioned bottlenecks, some experts in this field have proposed dynamic bond synergy strategies. For example, introducing a gradient energy network of metal coordination bonds and hydrogen bonds can achieve rapid repair and maintain high hardness at room temperature. However, the hydrolytic stability of dynamic bonds in aqueous systems still needs optimization: existing hydrophobic modification schemes (such as fluorinated / silicone resins) lead to decreased coating adhesion and poor compatibility with UV curing processes. Therefore, developing waterborne self-healing UV coatings that combine hydrolysis resistance, high repair efficiency, and process adaptability has become a pressing technical challenge in the field of electroplated aluminum color layer protection. Summary of the Invention

[0005] In view of this, the present invention proposes a self-healing UV-curable electroplated aluminum color coating and its preparation method.

[0006] The technical solution of this invention is achieved as follows: This invention provides a self-healing UV-curable electroplated aluminum color coating, which, by weight, comprises the following components:

[0007] 30-50 parts of polyurethane acrylic resin

[0008] 10-25 parts of modified acrylic oligomer containing dynamic covalent bonds

[0009] 2-5 parts of photoinitiator

[0010] 3-8 parts of hydrophobic modified nanofiller

[0011] 1-3 parts crosslinking agent

[0012] The dynamic covalent bond is selected from at least one of hydrazide bond, borate ester bond and Diels-Alder bond.

[0013] In some embodiments, the dynamic covalent bond is an acylhydrazine bond, and the modified acrylic oligomer containing the dynamic covalent bond is formed by reacting an acrylic oligomer containing an acylhydrazine group with an aldehyde-modified acrylic resin. The molar ratio of the acrylic oligomer containing the acylhydrazine group to the aldehyde-modified acrylic resin is 1:1-1.2, and the acylhydrazine bond is formed by condensation reaction in an acetate buffer solution at pH 4.5-5.0.

[0014] The specific reaction conditions are as follows: Acrylic oligomers containing hydrazide groups are mixed with aldehyde-modified acrylic resin at a molar ratio of 1:1-1.2 and reacted in an acetic acid buffer (pH 4.5) at 60°C for 4-6 hours with stirring. 0.1-0.5 wt% of a carboxylic acid catalyst (such as p-toluenesulfonic acid) is added to accelerate the condensation reaction. The crosslinking density is adjusted by controlling the reaction time to achieve a dynamic bond density of 5-15 mol% to balance mechanical strength and repair efficiency. After the reaction, unreacted material is removed by centrifugation, and the product is freeze-dried to obtain modified acrylic oligomers containing dynamic hydrazide bonds. The glass transition temperature (Tg) can be adjusted from -20°C to 50°C by controlling the dynamic bond density.

[0015] Acrylic acid oligomers containing hydrazide groups are prepared by the following steps:

[0016] Using methyl acrylate and butyl acrylate as monomers (molar ratio (3-5):1), and adding azobisisobutyronitrile as an initiator (0.5-2wt%), a free radical polymerization reaction was carried out at 60-80℃ for 4-6 hours under nitrogen protection.

[0017] The polymer product was stirred with hydrazine hydrate (molar ratio 1:(3-5)) at room temperature for 8-12 hours to introduce hydrazide groups (-CONHNH2) through ester substitution reaction. The product was then dialyzed through a 3K dialysis bag for 2-3 days and freeze-dried to obtain the final product.

[0018] Aldehyde-modified acrylic resin is prepared by the following steps:

[0019] Hydroxyl acrylate and butyl acrylate are copolymerized (molar ratio 1:4), and an initiator (0.2-1 wt%) is added. The reaction is carried out at 60°C for 6-8 hours to generate hydroxyl-containing acrylic resin.

[0020] Hydroxyl groups were oxidized to aldehyde groups (-CHO) using sodium periodate (NaIO4) at pH 4-5, with the aldehyde group mass fraction ≥8%.

[0021] In some embodiments, the dynamic covalent system further includes a quadruple hydrogen bond network as an auxiliary repair mechanism, which is formed by copolymerizing ureidopyrimidinone-functionalized acrylic monomers, wherein the monomers account for 5-15% of the total mass of the modified acrylic oligomers.

[0022] The UPy group can form a strong reversible network through quadruple hydrogen bonds (bond energy ≈ 40 kJ / mol). Its dissociation temperature (Td ≈ 80℃) is higher than room temperature but lower than the breaking temperature of dynamic covalent bonds (such as hydrazide bonds), thus achieving hierarchical repair.

[0023] The quadruple hydrogen bond network repairs microcracks at room temperature through rapid dissociation and recombination, while deep damage requires heat treatment at 60-80℃ to trigger hydrazide bond rearrangement, resulting in an energy gradient response. The double bond reactivity of the UPy monomer is close to that of the acrylate monomer, and the copolymer sequence is uniformly distributed.

[0024] In some embodiments, the hydrophobic modified nanofiller is a core-shell structure particle with silica as the core and polytetrafluoroethylene as the shell, wherein the thickness of the polytetrafluoroethylene shell is 5-20 nm and the particle size ranges from 50-200 nm.

[0025] In the above embodiments, the silica core material can be prepared by the sol-gel method, using tetraethyl orthosilicate as the silicon source, ammonia water as the catalyst, and hydrolyzing and condensing in an ethanol / water mixed solvent at 25-40℃ to generate monodisperse SiO2 nanoparticles with a particle size of 50-200nm. The core size can be controlled by adjusting the TEOS concentration (0.1-0.5mol / L) and the reaction time (2-6 hours).

[0026] The shell coating process includes: coating a PTFE shell onto the SiO2 surface via emulsion polymerization: SiO2 is dispersed in an emulsion containing fluorinated monomers (tetrafluoroethylene, TFE), ammonium perfluorooctanoate (PFOA) is added as an emulsifier, and ammonium persulfate (APS) is used as an initiator. The reaction is carried out at 70-90℃ and 0.5-1.0 MPa for 2-4 hours. By adjusting the TFE monomer concentration (5-20 wt%) and the reaction time (1-3 hours), the PTFE shell thickness is made to be 5-20 nm.

[0027] The PTFE shell blocks water molecule penetration, while the SiO2 hard core enhances the coating hardness through physical anchoring. The low surface energy of the PTFE shell drives the formation of hydrophobic microdomains in the resin matrix, forming a microphase separation structure with the hydrophilic soft segments, which promotes the self-healing response of the dynamic bond network.

[0028] In some embodiments, the photoinitiator is a composite system of diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, wherein the mass ratio of diphenylphosphine oxide to 1-hydroxycyclohexylphenyl ketone is 1:2 to 1:4.

[0029] In some embodiments, the product also includes 0.5-2 parts of silicon carbide nanowires, which, after being activated by plasma, form a grafted layer with maleic anhydride-styrene monomers through a free radical grafting reaction in the presence of an initiator, with a grafting rate of 10-30%.

[0030] The silicon carbide nanowires have a diameter of 50-100 nm, a length of 5-20 μm, and a specific surface area ≥20 m². 2 / g. Its plasma activation conditions include: Ar plasma treatment (power 50-100W, treatment time 5-10 minutes, pressure 10-30Pa) to generate active sites on the nanowire surface, with the surface oxygen content increasing to 15-25 at% as detected by XPS.

[0031] Reaction system:

[0032] The molar ratio of maleic anhydride to styrene is 1:(1-3). Dissolve in xylene (solid content 5-10wt%) and add 0.5-2wt% benzoyl peroxide.

[0033] Reaction conditions:

[0034] Under nitrogen protection, the reaction was carried out at 70-90℃ for 4-8 hours. After the reaction was completed, the mixture was centrifuged at 8000rpm for 15 minutes, washed three times with acetone and ethanol, and then dried under vacuum at 60℃ for 12 hours.

[0035] The hydrophobic benzene rings and ester groups of the maleic anhydride-styrene copolymer form a physical barrier, inhibiting water molecules from penetrating into the dynamic bond network, resulting in improved dynamic bond retention after 240 hours of damp heat aging. The polar ester groups in the grafted layer form hydrogen bonds with the resin matrix, enhancing nanowire dispersibility and stress transfer efficiency.

[0036] A compound system of epoxy-based siloxanes, in which trimethylolpropane triacrylate and epoxy-based siloxane are mixed in a ratio of 3:1 to 5:1, is used to achieve thermally triggered dynamic bond recombination after UV curing.

[0037] In some embodiments, 0.1-1 parts of pigment particles are also included.

[0038] A second aspect of the present invention also provides a method for preparing the above-mentioned self-healing UV-curable electroplated aluminum color coating, comprising the following steps:

[0039] Step 1: Emulsify the polyurethane acrylic resin and the dynamically covalently modified acrylic oligomer at 60-80℃ and 500-1000rpm for 30-60 minutes.

[0040] Step 2: Add hydrophobically modified nanofiller and ultrasonically disperse for 30-60 minutes;

[0041] Step 3: Add the photoinitiator, crosslinking agent and other additives in sequence, and stir until the viscosity of the system reaches 2000-5000 mPa·s;

[0042] Step 4: Apply the coating to the anodized aluminum substrate using a scraping or spraying process and then UV cure it. The UV curing energy is 300-500 mJ / cm². 2 .

[0043] In some implementations, after UV curing in step four, the device is heat-treated at 60-80°C for 1-3 minutes to activate the dynamic bond repair function.

[0044] The present invention has the following advantages over the prior art:

[0045] This invention achieves rapid self-repair and thermally triggered recombination of coatings at room temperature by introducing a gradient energy synergistic network of dynamic covalent bonds and quadruple hydrogen bonds. At the same time, the microphase separation design of hydrophobic core-shell fillers and grafted modified silicon carbide nanowires enhances hydrolysis resistance. Combined with a photoinitiator compound system and a crosslinking agent thermal activation process, this invention resolves the contradiction between high crosslinking degree and self-repair performance in traditional UV coatings while maintaining high hardness and excellent adhesion. It also takes into account mechanical tolerance and environmental adaptability in electroplated aluminum hot stamping scenarios, significantly expanding the application potential in high-end packaging, electronic devices and other fields. Detailed Implementation

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not 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 effort are within the scope of protection of the present invention.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of this invention pertain. If any definition stated in this section is contrary to or otherwise inconsistent with a definition stated in a patent, patent application, published patent application, or other publication incorporated herein by reference, the definitions listed here shall prevail over those incorporated herein by reference.

[0048] Unless otherwise specified, the methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials, reagents, and instruments used are conventional materials, reagents, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0049] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 5” is disclosed, the described range should be interpreted as including ranges “1 to 4”, “1 to 3”, “1 to 2”, “1 to 2 and 4 to 5”, “1 to 3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range. In this specification and claims, range definitions may be combined and / or interchanged, unless otherwise stated, these ranges include all subranges contained therein.

[0050] Example 1

[0051] Raw material ratio:

[0052] Polyurethane acrylic resin: 40g

[0053] Acylhydrazine bond modified acrylic oligomer (dynamic bond density 12 mol%): 18 g

[0054] Diphenylphosphine oxide: 3g of photoinitiator with a mass ratio of 3:1 to 1-hydroxycyclohexylmethyl ketone.

[0055] Core-shell structured particles with silica core and polytetrafluoroethylene (PTFE) shell (particle size 120nm, PTFE shell 12nm): 5g

[0056] TMPTA: Crosslinking agent with an epoxy siloxane mass ratio of 4:1: 2g

[0057] Silicon carbide nanowires (grafting rate 22%): 1.5g

[0058] Pigment particles: 0.5g

[0059] UPy-methyl acrylate can be synthesized from the following raw materials using the following methods:

[0060] 10g of UPy-OH and 26.6g of IPDI were placed in 100ml of anhydrous THF under a nitrogen atmosphere. 36mg of DBTDL was added, and the mixture was heated to 60℃ and reacted for 4h to generate UPy-NCO. Then, 20g of UPy-NCO and 6.5g of HEA were dissolved in 50ml of THF, and 13mg of DBTDL was added. The mixture was reacted at 60℃ for 6h, followed by silica gel column chromatography (eluent: ethyl acetate / petroleum ether = 1:3). The target fraction was collected and dried to obtain UPy-methyl acrylate.

[0061] Preparation steps:

[0062] Step 1: Preparation of acrylic oligomers modified with hydrazide bonds:

[0063] Methyl acrylate:butyl acrylate molar ratio of 4:1, with the addition of 1 wt% AIBN, was polymerized at 70°C for 5 h under a nitrogen atmosphere to obtain acrylic oligomers (Mn = 3200 Da, PDI = 1.3). The acrylic oligomers were reacted with hydrazine hydrate at a molar ratio of 1:4 at 25°C with stirring for 10 h, followed by dialyzing through a 3K dialysis bag and freeze-drying to obtain hydrazide-substituted oligomers (FTIR analysis showed hydrazide group substitution rate of 85%). The methyl acrylate contained 10 wt% UPy-methyl acrylate.

[0064] Step 2: Preparation of aldehyde-modified acrylic resin:

[0065] Hydroxyethyl acrylate and butyl acrylate were copolymerized at a molar ratio of 1:4. 0.5 wt% APS was added, and the reaction was carried out at 60°C for 7 hours to obtain a hydroxylated resin. Then, 1.3 molar amounts of NaIO4 were added, and the reaction was carried out at pH 4.5 at 30°C in the dark for 3 hours. NMR analysis revealed an aldehyde content of 9.2%.

[0066] Step 3: Synthesis of dynamic bond oligomers:

[0067] The products from step 1 and step 2 were mixed at a molar ratio of 1:1.1, and 0.3 wt% p-toluenesulfonic acid was added. The mixture was reacted at pH 4.8 and 60°C for 5 hours. After centrifugation and purification, the dynamic bond density of DMA was measured to be 12 mol%.

[0068] Step 4: Coating preparation:

[0069] Polyurethane acrylic resin and hydrazide-modified acrylic oligomer were stirred and emulsified at 70°C and 800 rpm for 40 min.

[0070] Add core-shell structured particles with silica as the core and polytetrafluoroethylene as the shell and ultrasonically disperse for 40 min;

[0071] Add the photoinitiator, crosslinking agent and pigment particles in sequence, and stir until the system viscosity reaches 3000 mPa·s;

[0072] The coating is applied to the surface of the electroplated aluminum base film by scraping, and then 400mJ / cm 2 UV curing followed by heat treatment at 70°C for 2 minutes.

[0073] Example 2

[0074] This embodiment is based on Example 1, but omits the core-shell structure particles and grafted nanowires.

[0075] Example 3

[0076] This embodiment is based on Embodiment 1, but the grafted nanowires are replaced with ungrafted nanowires.

[0077] Example 4

[0078] This embodiment is based on Example 1, and uses a photoinitiator with a mass ratio of diphenylphosphine oxide to 1-hydroxycyclohexylmethyl ketone of 1:2.

[0079] Example 5

[0080] This embodiment is based on Example 1, but uses a single diphenylphosphine oxide as the photoinitiator.

[0081] Example 6

[0082] This embodiment is based on Example 1, but the photoinitiator used is 1-hydroxycyclohexylmethyl ketone.

[0083] The performance of the color coatings prepared in the different embodiments described above was tested.

[0084] Self-repair efficiency:

[0085] A nanoindenter (Hysitron TI 950) was used to create scratches 2 μm deep and 10 μm wide on the coating surface.

[0086] Parameters: Load 50mN, loading rate 0.5mN / s.

[0087] Restoration at room temperature: Let stand at 25℃ for 1 hour.

[0088] Thermal trigger repair: Heat treatment at 80℃ for 3 minutes.

[0089] The volume recovery rate of scratches was measured using a laser confocal microscope (Keyence VK-X1000).

[0090] Hydrolysis resistance test:

[0091] The test was conducted in a constant temperature and humidity chamber (85% RH, 60℃) for 240 hours.

[0092] The characteristic peak of the acylhydrazine bond (1640 cm⁻¹) was analyzed by Fourier transform infrared spectroscopy (FTIR, Nicolet iS50). -1 Area change.

[0093] Mechanical property testing:

[0094] Tested using a Mitsubishi pencil hardness tester (load 750g) according to ASTM D3363 standard.

[0095] Cross-cut test (ASTM D3359), cutter spacing 1 mm, assess the detachment grade (0B-5B).

[0096] Universal testing machine (Instron 5967), tensile rate 10 mm / min, specimen size ISO 527-2 standard.

[0097] The test results are shown in the table below:

[0098] Example Room temperature self-healing efficiency Hot-triggered self-healing efficiency Acylhydrazine bond retention rate Pencil hardness Tensile strength 1 92％ 95％ 89％ 9H 25MPa 2 85％ 88％ 65％ 7H 18MPa 3 75％ 80％ 72％ 6H 15MPa 4 87％ 90％ 78％ 8H 22MPa 5 70％ 75％ 60％ 6H 14MPa 6 68％ 73％ 58％ 5H 12MPa

[0099] Example 1 showed a significantly higher room temperature repair rate than Example 2. The core-shell particles blocked moisture through the hydrophobic shell, protecting the integrity of the dynamic bond network; the grafted nanowires enhanced the interfacial bonding force and avoided stress concentration. The two worked together to increase the repair rate by 8%.

[0100] In Example 1, the retention rate of hydrazide bonds was much higher than that in Example 2. The PTFE shell reduced the permeability of water molecules, and the grafted nanowires filled the interfacial micropores, forming a physical barrier.

[0101] The pencil in Example 1 was significantly harder than that in Example 3. The ungrafted nanowires exhibited poor interfacial compatibility, leading to stress concentration and disrupting the continuity of the dynamic network. Grafting treatment enhanced the nanowire-matrix bonding force through chemical bonds.

[0102] Example 1, using diphenylphosphine oxide and 1-hydroxycyclohexyl ketone (3:1), achieved the best match between photoinitiation depth and dynamic bond density (12 mol%), resulting in a repair rate of 92%. However, Example 4 (1:2) suffered from insufficient deep curing, leading to a reduced dynamic bond density and a repair rate of only 87%.

[0103] When the ratio of photoinitiator deviates from 3:1, incomplete curing leads to an increase in porosity, and a sharp decrease in hydrolysis resistance and mechanical strength.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-healing UV-curable electroplated aluminum color coating, characterized in that, Calculated by weight, it includes the following components: 30-50 parts of polyurethane acrylic resin 10-25 parts of modified acrylic oligomer containing dynamic covalent bonds 2-5 parts of photoinitiator 3-8 parts of hydrophobic modified nanofiller 1-3 parts crosslinking agent The dynamic covalent bond is an acylhydrazone bond. The modified acrylic oligomer containing the dynamic covalent bond is formed by reacting an acrylic oligomer containing an acylhydrazine group with an aldehyde-modified acrylic resin. The molar ratio of the acrylic oligomer containing the acylhydrazine group to the aldehyde-modified acrylic resin is 1:1-1.2, and the acylhydrazone bond is formed by condensation reaction in an acetate buffer solution with a pH of 4.5-5.

0. The photoinitiator is a composite system of diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone, and the mass ratio of diphenylphosphine oxide to 1-hydroxycyclohexylphenyl ketone is 1:2-1:

4.

2. The self-healing UV-curable electroplated aluminum color coating as described in claim 1, characterized in that, The dynamic covalent bonds and the quadruple hydrogen bond network together constitute an auxiliary repair mechanism. The quadruple hydrogen bond network is formed by introducing ureidopyrimidinone functionalized acrylic monomers through copolymerization. The monomers account for 5-15% of the total mass of the modified acrylic oligomers.

3. The self-healing UV-curable electroplated aluminum color coating as described in claim 1, characterized in that, The hydrophobic modified nanofiller is a core-shell structure particle with silica as the core and polytetrafluoroethylene as the shell, wherein the thickness of the polytetrafluoroethylene shell is 5-20 nm and the particle size ranges from 50-200 nm.

4. The self-healing UV-curable electroplated aluminum color coating as described in claim 1, characterized in that, It also includes 0.5-2 parts of silicon carbide nanowires, which, after being activated by plasma, form a grafted layer with maleic anhydride-styrene monomer through a free radical grafting reaction in the presence of an initiator, with a grafting rate of 10-30%.

5. The self-healing UV-curable electroplated aluminum color coating as described in claim 1, characterized in that, The crosslinking agent is a compound system of trimethylolpropane triacrylate and epoxy siloxane, with a compounding ratio of 3:1 to 5:1, used to achieve thermally triggered dynamic bond recombination after UV curing.

6. The self-healing UV-curable electroplated aluminum color coating as described in claim 1, characterized in that, It also includes 0.1-1 part of pigment particles.

7. The method for preparing the self-healing UV-curable electroplated aluminum color coating according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Emulsify the polyurethane acrylic resin and the dynamically covalently modified acrylic oligomer at 60-80℃ and 500-1000rpm for 30-60 minutes. Step 2: Add hydrophobically modified nanofiller and ultrasonically disperse for 30-60 minutes; Step 3: Add the photoinitiator, crosslinking agent and other additives in sequence, and stir until the viscosity of the system reaches 2000-5000 mPa·s; Step 4: Apply the coating to the electroplated aluminum substrate using a scraping or spraying process and then UV cure it. The UV curing energy is 300-500 mJ / cm². 2 .

8. The preparation method of the self-healing UV-curable electroplated aluminum color coating as described in claim 7, characterized in that, After UV curing in step four, heat-treat at 60-80℃ for 1-3 minutes to activate the dynamic bond repair function.