Thermal insulation type aluminum material and method for manufacturing the same

Abstract

This invention relates to the field of thermally insulated aluminum materials, and discloses a thermally insulated aluminum material and its preparation method. The aluminum material consists of a 6061 aluminum substrate and a composite thermally insulated coating layer. The coating layer uses 40-45 parts by weight of bisphenol A type epoxy resin as the matrix, and is formulated with modified silica, coupling agent-modified adamantane, polyethyleneimine-modified hollow glass microspheres, and other modified fillers and additives. The aluminum material is prepared by roughening the substrate through grinding, coating it with the coating, and curing at room temperature for 45-55 minutes. This aluminum material exhibits significantly reduced thermal conductivity, coating adhesion reaching grade 0, excellent aging resistance and water resistance, and a simple preparation process with mild reaction conditions and readily available raw materials. The components work synergistically, making it suitable for industrial mass production and applicable to various thermally insulated aluminum material applications such as construction, automotive, and chemical industries.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation aluminum materials, specifically to a thermal insulation aluminum material and its preparation method. Background Technology

[0002] Aluminum has advantages such as low density, high strength, corrosion resistance, ease of processing, and good thermal and electrical conductivity, and is widely used in many fields such as construction, automobiles, electronics, aerospace, and chemicals. However, aluminum has a high thermal conductivity and poor thermal insulation performance. In some scenarios requiring thermal insulation, such as building exterior walls, automobile bodies, and chemical equipment casings, aluminum alone is insufficient to meet the requirements, easily leading to rapid heat conduction, resulting in energy waste or uncontrolled internal temperature of the equipment.

[0003] To improve the thermal insulation performance of aluminum, existing technologies typically employ two methods: one is to fill the aluminum material with insulating material to form a composite insulating aluminum material. However, this method increases the weight and manufacturing cost of the aluminum material, and the processing technology is complex, making it unsuitable for thin-walled aluminum products. The other method is to apply a coating to the surface of the aluminum material, which blocks heat conduction to achieve an insulating effect. However, most existing insulating coatings used on aluminum surfaces suffer from poor insulation performance, weak adhesion to the aluminum substrate, and easy peeling after long-term use. They fail to balance thermal insulation performance and coating stability, and cannot meet the needs of industrial mass production and long-term use.

[0004] Therefore, developing a heat-insulating aluminum material with a simple coating preparation process, excellent heat insulation performance, and strong coating adhesion, as well as its preparation method, has become an urgent technical problem to be solved in the current aluminum processing field. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a heat-insulating aluminum material and its preparation method, thereby improving the heat insulation performance of the aluminum material while ensuring the bonding strength and weather resistance of the coating to the aluminum substrate.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a heat-insulating aluminum material, comprising an aluminum substrate and a composite heat-insulating coating layer, wherein the composite heat-insulating coating layer is uniformly coated on the outer surface of the aluminum substrate; the composite heat-insulating coating layer is composed of the following components in parts by weight: 40-45 parts of bisphenol A type epoxy resin, 4-6 parts of modified silica, 1-3 parts of coupling agent modified adamantane, 2-3 parts of polyethyleneimine modified hollow glass microspheres, 3-6 parts of ethylene glycol butyl ether, and 4-6 parts of diethylenetriamine.

[0007] The modified silica is prepared by grafting honokiol with silica as a base through KH590 mercaptoylation. It has excellent heat insulation, dispersibility and bonding strength with epoxy resin matrix. The coupling agent modified adamantane is prepared by reacting 1-adamantane methanol with 3-isocyanate-propyltrimethoxysilane. The cage structure of adamantane has good heat insulation properties. After modification with coupling agent, the compatibility with epoxy resin is improved. The polyethyleneimine modified hollow glass microspheres are grafted with polyethyleneimine groups on the surface. The hollow structure inside can effectively block heat conduction. At the same time, the modified microspheres have better bonding with the coating matrix and are less prone to agglomeration.

[0008] Furthermore, the preparation method of the modified silica is as follows: S1. Add silica to an ethanol-water solution (ethanol to water volume ratio of 4 / 1) and sonicate for 32-36 min. Then place the solution in a 55-60℃ water bath and stir at a speed of 580-610 r / min. Add KH590 and adjust the pH to 3-3.2 with 20% dilute sulfuric acid. React for 5-7 h. After the reaction is completed, filter the solution and wash with anhydrous ethanol to remove residual KH590. Dry the solution to obtain mercapto-modified silica. S2. Add 4-6g of mercapto-modified silica to 50-55mL of anhydrous ethanol and stir to disperse for 1-2h to obtain solution A; add 1-2g of magnolol to 45-55mL of anhydrous ethanol and stir to dissolve for 3-4h to obtain solution B; add solution A to solution B and stir at 1000-1100r / min for 5-6h, then add 0.01-0.02g of benzoin dimethyl ether and irradiate with a 365nm UV lamp. After the irradiation is complete, centrifuge and wash to obtain modified silica.

[0009] Furthermore, in S1, the ratio of silica, aqueous ethanol solution, and KH590 is 8-10g: 160-200mL: 0.4-0.51g.

[0010] Furthermore, in S2, the ultraviolet lamp irradiation time is 30-35 minutes.

[0011] Further, the preparation method of the coupling agent modified adamantane is as follows: 1-adamantane methanol and 3-isocyanate propyltrimethoxysilane are added to a reaction flask containing toluene solvent, the temperature is raised to 65-70℃, stannous isooctanoate is added under a nitrogen atmosphere, the reaction is carried out for 20-24 hours, and toluene is removed by a rotary evaporator after the reaction is completed to obtain coupling agent modified adamantane.

[0012] Furthermore, the ratio of toluene, 1-adamantylmethanol, and 3-isocyanate-propyltrimethoxysilane is 30-35 mL: 2-3 mmol: 2-3 mmol.

[0013] Furthermore, the preparation method of the heat-insulating aluminum material is as follows: the surface of the 6061 aluminum substrate is roughened by grinding and cleaned with ethanol or acetone to remove oil, and then dried for later use; bisphenol A type epoxy resin, modified silica, coupling agent modified adamantane, polyethyleneimine modified hollow glass microspheres, ethylene glycol butyl ether, and diethylenetriamine are stirred and mixed, and then coated on the surface of the aluminum alloy profile and cured at room temperature to obtain the heat-insulating aluminum material.

[0014] Furthermore, the curing time at room temperature is 45-55 minutes.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: In this invention, the components of the composite heat-insulating coating layer work together to block heat conduction at the structural level. The hollow structure of the polyethyleneimine-modified hollow glass microspheres can effectively block heat transfer. The cage structure of the coupling agent-modified adamantane has excellent heat resistance and heat insulation properties. The modified silica itself has low thermal conductivity, and the modified fillers are evenly dispersed without agglomeration, avoiding the formation of heat insulation dead zones. After being combined with the dense epoxy resin matrix, it reduces heat conduction efficiency from multiple dimensions, achieving a synergistic improvement in heat insulation performance.

[0016] Strong adhesion between coating and substrate: The functional fillers are all subject to targeted surface modification. Modified silica, coupling agent-modified adamantane, and polyethyleneimine-modified hollow glass microspheres are all introduced with functional groups compatible with bisphenol A type epoxy resin matrix, which can form chemical bonds with the matrix rather than simply physical mixing. At the same time, it improves the interfacial adhesion between the filler and the aluminum substrate, and between the filler and the coating matrix, so that the coating is firmly bonded to the aluminum substrate and is not prone to peeling or flaking.

[0017] Bisphenol A type epoxy resin matrix itself possesses excellent corrosion resistance and aging resistance. The cage-like structure of adamantane exhibits high chemical stability, enhancing the coating's heat resistance and resistance to media erosion. Modified silica provides mechanical reinforcement to the coating, reducing cracking and chalking caused by environmental factors. This allows the thermal insulation coating to adapt to various complex operating environments, effectively extending the service life of aluminum materials. Surface-modified fillers exhibit improved dispersibility, forming a uniform and dense coating structure when mixed with the epoxy resin matrix. This prevents filler agglomeration from creating pores that affect the thermal insulation effect, while simultaneously reducing the risk of coating damage and ensuring the long-term thermal insulation stability of the aluminum materials. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] KH590: 3-Mercaptopropyltriethoxysilane, CAS No.: 14814-09-6.

[0020] 3-Isocyanate-propyltrimethoxysilane, CAS No.: 15396-00-6.

[0021] The aluminum substrate is 6061 aluminum alloy with a thickness of 2mm.

[0022] Preparation of polyethyleneimine-modified hollow glass microspheres: Referring to the literature "Preparation and Properties of Hollow Glass Microsphere Reinforced Epoxy Resin Composites", HGS was placed in 0.3 mol / L NaOH solution for 30 min, filtered, and dried to obtain hydroxyl-modified HGS. It was then placed in N,N-dimethylamide solvent and stirred for 15 min for ultrasonic dispersion. Epichlorohydrin solution was then added and stirred uniformly for 1 h. PEI was then added and stirred for 20 min. Finally, the mixture was filtered and separated, and freeze-dried to obtain PEI / HGS particles.

[0023] Example 1 A heat-insulating aluminum material includes an aluminum substrate and a composite heat-insulating coating layer, wherein the composite heat-insulating coating layer is uniformly coated on the outer surface of the aluminum substrate; the composite heat-insulating coating layer is composed of the following components in parts by weight: 40 parts of bisphenol A type epoxy resin, 4 parts of modified silica, 1 part of coupling agent modified adamantane, 2 parts of polyethyleneimine modified hollow glass microspheres, 3 parts of ethylene glycol butyl ether, and 4 parts of diethylenetriamine.

[0024] The modified silica is prepared by: S1. Add 8g of silica to 160mL of ethanol-water solution (ethanol to water volume ratio of 4 / 1) and sonicate for 32min. Then place the solution in a 55℃ water bath and stir at 580r / min. Add 0.4g of KH590 and adjust the pH to 3 with 20% dilute sulfuric acid. React for 5h. After the reaction is completed, filter the solution and wash with anhydrous ethanol to remove residual KH590. Dry the solution to obtain mercapto-modified silica. S2. Add 4g of mercapto-modified silica to 50mL of anhydrous ethanol and stir to disperse for 1h to obtain solution A; add 1g of magnolol to 45mL of anhydrous ethanol and stir to dissolve for 3h to obtain solution B; add solution A to solution B and stir at 1000r / min for 5h, then add 0.01g of benzoin dimethyl ether and irradiate with a 365nm UV lamp for 30min. After the irradiation, centrifuge and wash to obtain modified silica.

[0025] The preparation method of the coupling agent modified adamantane is as follows: 2 mmol of 1-adamantane methanol and 2 mmol of 3-isocyanatopropyltrimethoxysilane are added to a reaction flask containing 30 mL of toluene, the temperature is raised to 65 °C, stannous isooctanoate is added under a nitrogen atmosphere, the reaction is carried out for 20 h, and after the reaction is completed, toluene is removed by a rotary evaporator to obtain coupling agent modified adamantane.

[0026] The preparation method of heat-insulating aluminum material is as follows: the surface of 6061 aluminum substrate is roughened by grinding and cleaned with ethanol or acetone to remove oil, and then dried for later use; bisphenol A type epoxy resin, modified silica, coupling agent modified adamantane, polyethyleneimine modified hollow glass microspheres, ethylene glycol butyl ether, and diethylenetriamine are stirred and mixed, and then coated on the surface of aluminum alloy profile and cured at room temperature for 45 minutes to obtain heat-insulating aluminum material.

[0027] Example 2 A heat-insulating aluminum material includes an aluminum substrate and a composite heat-insulating coating layer, wherein the composite heat-insulating coating layer is uniformly coated on the outer surface of the aluminum substrate; the composite heat-insulating coating layer is composed of the following components in parts by weight: 45 parts of bisphenol A type epoxy resin, 6 parts of modified silica, 3 parts of coupling agent-modified adamantane, 3 parts of polyethyleneimine-modified hollow glass microspheres, 6 parts of ethylene glycol butyl ether, and 6 parts of diethylenetriamine.

[0028] The modified silica is prepared by: S1. Add 10g of silica to 200mL of ethanol-water solution (ethanol to water volume ratio of 4 / 1) and sonicate for 36min. Then place the solution in a 60℃ water bath and stir at 610r / min. Add 0.51g of KH590 and adjust the pH to 3.2 with 20% dilute sulfuric acid. React for 7h. After the reaction is completed, filter the solution and wash with anhydrous ethanol to remove residual KH590. Dry the solution to obtain mercapto-modified silica. S2. Add 6g of mercapto-modified silica to 55mL of anhydrous ethanol and stir to disperse for 2h to obtain solution A; add 2g of magnolol to 55mL of anhydrous ethanol and stir to dissolve for 4h to obtain solution B; add solution A to solution B and stir at 1100r / min for 6h, then add 0.02g of benzoin dimethyl ether and irradiate with a 365nm UV lamp for 35min. After the irradiation, centrifuge and wash to obtain modified silica.

[0029] The preparation method of the coupling agent modified adamantane is as follows: 3 mmol of 1-adamantane methanol and 3 mmol of 3-isocyanatopropyltrimethoxysilane are added to a reaction flask containing 35 mL of toluene, the temperature is raised to 70 °C, stannous isooctanoate is added under a nitrogen atmosphere, the reaction is carried out for 24 h, and after the reaction is completed, toluene is removed by a rotary evaporator to obtain coupling agent modified adamantane.

[0030] The preparation method of heat-insulating aluminum material is as follows: the surface of 6061 aluminum substrate is roughened by grinding and cleaned with ethanol or acetone to remove oil, and then dried for later use; bisphenol A type epoxy resin, modified silica, coupling agent modified adamantane, polyethyleneimine modified hollow glass microspheres, ethylene glycol butyl ether, and diethylenetriamine are stirred and mixed, and then coated on the surface of aluminum alloy profile and cured at room temperature for 55 minutes to obtain heat-insulating aluminum material.

[0031] Example 3 A heat-insulating aluminum material includes an aluminum substrate and a composite heat-insulating coating layer, wherein the composite heat-insulating coating layer is uniformly coated on the outer surface of the aluminum substrate; the composite heat-insulating coating layer is composed of the following components in parts by weight: 42 parts of bisphenol A type epoxy resin, 5 parts of modified silica, 2 parts of coupling agent-modified adamantane, 2.5 parts of polyethyleneimine-modified hollow glass microspheres, 4 parts of ethylene glycol butyl ether, and 5 parts of diethylenetriamine.

[0032] The modified silica is prepared by: S1. Add 9g of silica to 180mL of ethanol-water solution (ethanol to water volume ratio of 4 / 1) and sonicate for 34min. Then place the solution in a 57℃ water bath and stir at 600r / min. Add 0.45g of KH590 and adjust the pH to 3.1 with 20% dilute sulfuric acid. React for 6h. After the reaction is completed, filter the solution and wash with anhydrous ethanol to remove residual KH590. Dry the solution to obtain mercapto-modified silica. S2. Add 5g of mercapto-modified silica to 53mL of anhydrous ethanol and stir to disperse for 1h to obtain solution A; add 1.5g of magnolol to 50mL of anhydrous ethanol and stir to dissolve for 3h to obtain solution B; add solution A to solution B and stir at 1050r / min for 5h, then add 0.015g of benzoin dimethyl ether and irradiate with a 365nm UV lamp for 32.5min. After the irradiation is completed, centrifuge and wash to obtain modified silica.

[0033] The preparation method of the coupling agent modified adamantane is as follows: 2.5 mmol of 1-adamantane methanol and 2.5 mmol of 3-isocyanatopropyltrimethoxysilane are added to a reaction flask containing 32 mL of toluene, the temperature is raised to 67 °C, stannous isooctanoate is added under a nitrogen atmosphere, the reaction is carried out for 22 h, and after the reaction is completed, toluene is removed by a rotary evaporator to obtain coupling agent modified adamantane.

[0034] The preparation method of heat-insulating aluminum material is as follows: the surface of 6061 aluminum substrate is roughened by grinding and cleaned with ethanol or acetone to remove oil, and then dried for later use; bisphenol A type epoxy resin, modified silica, coupling agent modified adamantane, polyethyleneimine modified hollow glass microspheres, ethylene glycol butyl ether, and diethylenetriamine are stirred and mixed, and then coated on the surface of aluminum alloy profile and cured at room temperature for 50 minutes to obtain heat-insulating aluminum material.

[0035] Comparative Example 1 The difference between this comparative example and Example 3 is that silica was used instead of modified silica.

[0036] Comparative Example 2 The difference between this comparative example and Example 3 is that 1-adamantane methanol was used instead of coupling agent to modify adamantane.

[0037] Comparative Example 3 The difference between this comparative example and Example 3 is that hollow glass microspheres were used instead of polyethyleneimine modified hollow glass microspheres.

[0038] Thermal insulation performance: The thermal diffusivity of the sample was tested using a laser pulse flash thermal conductivity meter, and the thermal conductivity of the sample was calculated. Adhesion: Tested according to GB / T9286-2021 standard; Impact resistance (cm): According to GB / T1732-2020 test, record the maximum height from which the coating does not crack or peel off; Aging resistance: Tested using a xenon lamp aging test chamber for 1000 hours. Observe whether cracking, peeling, or powdering occurs on the coating surface. No obvious changes indicate that it is qualified.

[0039] Table 1: Performance Tests

[0040] As shown in Table 1, compared to Example 3, Comparative Example 1, replacing the modified silica with ordinary silica resulted in extremely poor compatibility between the unmodified silica and the epoxy resin matrix. Furthermore, it lost the insulation, reinforcement, and bonding functions of the modified filler, leading to performance degradation. Specific reasons for this performance degradation include: Thermal conductivity increased to 0.078 W / (m·K): Ordinary silica has a hydrophilic surface, which is incompatible with the polarity of the hydrophobic bisphenol A epoxy resin matrix. This leads to easy agglomeration in the coating, forming large particles. This not only creates insulation dead zones but also creates internal pores in the coating, allowing heat to be rapidly conducted through these pores and agglomerated particles, disrupting the original multi-dimensional insulation system and significantly increasing heat transfer efficiency. Adhesion dropped to level 1: Modified silica forms chemical bonds with the epoxy resin matrix through grafted organic functional groups, while unmodified silica only physically mixes with the matrix and cannot form chemical bonds. This weakens the interfacial bonding between the filler and the epoxy resin, and between the filler and the aluminum substrate, resulting in a decrease in the adhesion strength between the coating and the substrate. Impact resistance decreased to 40cm: Modified silica originally had a mechanical reinforcing effect on the coating, improving its density and toughness; however, the agglomeration of unmodified silica led to an uneven coating structure with numerous micro-defects. Under impact, stress tends to concentrate at these defects, causing the coating to crack and peel off, significantly reducing its impact resistance. Slight chalking appeared in aging resistance: The porosity created by agglomeration allows ultraviolet light, moisture, and corrosive media to penetrate the coating more easily, directly damaging the molecular structure of the epoxy resin matrix. Simultaneously, unmodified silica could not effectively reinforce the coating, reducing its resistance to environmental erosion, resulting in surface chalking after 1000 hours of xenon lamp aging.

[0041] Comparative Example 2: 1-Adamantane methanol was used to replace the coupling agent in modifying adamantane. Unmodified adamantane lacked reactive functional groups compatible with the matrix, the cage-like thermal insulation structure could not be fully utilized, and interfacial bonding was lacking. Specific reasons for the deterioration of various properties: Thermal conductivity increased to 0.072 W / (m·K): The coupling agent-modified adamantane formed bonds with epoxy resin through siloxane groups, allowing it to be uniformly dispersed in the matrix. Its cage-like structure effectively blocked heat conduction. In contrast, pure 1-adamantane methanol had poor compatibility with epoxy resin and poor dispersibility, weakening the thermal insulation effect of the cage-like structure. Heat was easily conducted through the micro-gap between the filler and the matrix, increasing the thermal conductivity. Adhesion dropped to Grade 1: One end of the 3-isocyanate-propyltrimethoxysilane coupling agent was bonded to adamantane, while the other end could form chemical bonds with epoxy resin and aluminum substrate, improving interfacial bonding. Pure 1-adamantane methanol could not form chemical bonds with the matrix and substrate, only physically mixing, resulting in insufficient adhesion between the coating and the substrate, and a decrease in the adhesion grade. Impact resistance decreased to 45 cm: 1-adamantane methanol has poor compatibility with the matrix, resulting in micro-gaps inside the coating and reduced structural density. When subjected to impact, stress cannot be uniformly transmitted in the coating, and cracks are easily generated at the micro-gaps. The impact resistance is reduced compared to Example 3.

[0042] Comparative Example 3: Ordinary hollow glass microspheres replaced polyethyleneimine-modified hollow glass microspheres. While ordinary hollow glass microspheres retained the basic thermal insulation function of the hollow structure, they lost the compatibility, bonding, and dispersibility of the modified microspheres. Specific reasons for the deterioration in various properties include: Thermal conductivity increased to 0.064 W / (m·K): Polyethyleneimine-modified hollow glass microspheres have polyethyleneimine groups grafted onto their surface, exhibiting excellent compatibility with epoxy resin. They can be uniformly dispersed and fully utilize the physical thermal insulation effect of the hollow structure. Ordinary hollow glass microspheres have a smooth surface and few functional groups, resulting in poor compatibility with the matrix. A small amount of agglomeration forms heat conduction channels. Although the hollow structure can still block some heat, the thermal insulation efficiency decreases, and the thermal conductivity increases. Adhesion decreased to level 1: The modified hollow glass microspheres form chemical bonds with the epoxy resin through polyethyleneimine groups, improving the interfacial bonding force between the filler and the matrix. Ordinary hollow glass microspheres cannot form chemical bonds with the matrix, relying only on physical adsorption, resulting in weak interfacial bonding and decreased coating adhesion. Impact resistance decreased to 43 cm: Ordinary hollow glass microspheres have large gaps between the microspheres and the substrate, resulting in slightly poor coating density. Upon impact, the microspheres easily separate from the substrate, forming tiny pores, thus reducing the coating's impact resistance. However, because the hollow structure itself provides some support to the coating, the decrease in impact resistance is less than in Comparative Example 1. Slight cracking appeared in aging resistance: Ordinary hollow glass microspheres are not tightly bonded to the substrate, allowing moisture and ultraviolet rays to easily penetrate the coating through the gaps, damaging the substrate structure. Simultaneously, during aging, the stress difference generated by thermal expansion and contraction exacerbates the micro-separation between the microspheres and the substrate, leading to slight cracking of the coating. In contrast, the modified microspheres, due to chemical bonding, allow stress to be effectively transferred between the filler and the substrate, avoiding micro-separation.

[0043] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat-insulating aluminum material, characterized in that, The product comprises an aluminum substrate and a composite heat-insulating coating layer, wherein the composite heat-insulating coating layer is uniformly coated on the outer surface of the aluminum substrate; the composite heat-insulating coating layer is composed of the following components in parts by weight: 40-45 parts of bisphenol A type epoxy resin, 4-6 parts of modified silica, 1-3 parts of coupling agent modified adamantane, 2-3 parts of polyethyleneimine modified hollow glass microspheres, 3-6 parts of ethylene glycol butyl ether, and 4-6 parts of diethylenetriamine; The modified silica is prepared by first treating silica in an aqueous ethanol solution with KH590 to obtain thiolated silica; then mixing it with magnolol in anhydrous ethanol, adding benzoin dimethyl ether, reacting under ultraviolet light, and finally obtaining the modified silica by separation and washing.

2. The heat-insulating aluminum material according to claim 1, characterized in that, The modified silica is prepared by: S1. Add silica to an ethanol-water solution and sonicate for 32-36 min. Then place the solution in a 55-60℃ water bath and stir at 580-610 r / min. Add KH590 and adjust the pH to 3-3.2 with 20% dilute sulfuric acid. React for 5-7 h. After the reaction is complete, filter the solution and wash with anhydrous ethanol to remove residual KH590. Dry the solution to obtain mercapto-modified silica. S2. Add 4-6g of mercapto-modified silica to 50-55mL of anhydrous ethanol and stir to disperse for 1-2h to obtain solution A; add 1-2g of magnolol to 45-55mL of anhydrous ethanol and stir to dissolve for 3-4h to obtain solution B; add solution A to solution B and stir at 1000-1100r / min for 5-6h, then add 0.01-0.02g of benzoin dimethyl ether and irradiate with a 365nm UV lamp. After the irradiation is complete, centrifuge and wash to obtain modified silica.

3. The heat-insulating aluminum material according to claim 2, characterized in that, In S1, the ratio of silica, ethanol aqueous solution, and KH590 is 8-10g: 160-200mL: 0.4-0.51g.

4. The heat-insulating aluminum material according to claim 2, characterized in that, In step S2, the ultraviolet lamp irradiation time is 30-35 minutes.

5. The heat-insulating aluminum material according to claim 1, characterized in that, The preparation method of the coupling agent modified adamantane is as follows: 1-adamantane methanol and 3-isocyanate propyltrimethoxysilane are added to a reaction flask containing toluene solvent, the temperature is raised to 65-70℃, stannous isooctanoate is added under a nitrogen atmosphere, the reaction is carried out for 20-24 hours, and toluene is removed by a rotary evaporator after the reaction is completed to obtain coupling agent modified adamantane.

6. The heat-insulating aluminum material according to claim 5, characterized in that, The ratio of toluene, 1-adamantylmethanol, and 3-isocyanate-propyltrimethoxysilane is 30-35 mL: 2-3 mmol: 2-3 mmol.

7. A method for preparing a heat-insulating aluminum material as described in any one of claims 1-6, characterized in that, The preparation method of the heat-insulating aluminum material is as follows: the surface of the 6061 aluminum substrate is roughened by grinding and cleaned with ethanol or acetone to remove oil, and then dried for later use; bisphenol A type epoxy resin, modified silica, coupling agent modified adamantane, polyethyleneimine modified hollow glass microspheres, ethylene glycol butyl ether, and diethylenetriamine are stirred and mixed, and then coated on the surface of the aluminum alloy profile and cured at room temperature to obtain the heat-insulating aluminum material.

8. The method for preparing the heat-insulating aluminum material according to claim 7, characterized in that, The curing time at room temperature is 45-55 minutes.

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