Thermal insulation aluminum profile and preparation method thereof

Abstract

The application discloses a kind of heat-insulating aluminum profiles and preparation method thereof, belong to heat-insulating material technical field.The application is chemically modified to bisphenol A type epoxy resin by ultraviolet absorber, crosslinking agent, not only promote the absorption and conversion capacity of resin to ultraviolet, but also enhance the cohesive strength and crosslinking density of coating, join the dispersion and interfacial adhesion of composite filler A and composite filler B in resin system, effectively improve its, form chemical bond effect, adhesion is better, weather resistance and anti-aging performance significantly improve, help to prolong the service life of heat-insulating aluminum profile;In addition, by using modified epoxy resin and polyester resin as film-forming material, and introducing composite filler A (titanium dioxide, lanthanum oxide, mica) and composite filler B (perlite, hollow glass microsphere) modified by specific silane, the heat-insulating performance of coating can be significantly improved, and the heat-insulating aluminum profile with excellent heat-insulating effect can be obtained as a whole.

Description

Technical Field

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

[0002] Aluminum alloy profiles are widely used in building doors, windows, and curtain walls due to their advantages such as light weight, high strength, corrosion resistance, good processing performance, and beautiful appearance. However, with the increasing standards for building energy conservation, the inherent defects of pure aluminum alloy doors and windows are gradually becoming apparent. Aluminum alloy is a high thermal conductivity metal material, with a thermal conductivity as high as 200 W / (m·K), which is 3 times that of steel and more than 10 times that of glass. This inherent defect severely limits its application in scenarios with high requirements for thermal insulation performance. In the construction field, doors, windows, and curtain walls are the most frequent parts of the building envelope for heat exchange, and their thermal insulation performance directly affects indoor comfort and energy consumption. Doors, windows, and curtain walls made of traditional aluminum profiles without thermal insulation treatment will create a significant "thermal bridge" effect—in winter, indoor heat will be quickly conducted to the outside through the aluminum profiles, causing the indoor temperature to drop rapidly and increasing the energy consumption of heating equipment; in summer, high outdoor temperatures will flood into the room through the aluminum profiles, significantly increasing the air conditioning load and further exacerbating energy waste.

[0003] To address the poor thermal insulation performance of aluminum profiles, the industry has developed various thermal insulation technologies, among which thermal break technology is the most widely used. This technology is mainly divided into two types: strip-type and cast-type. However, existing thermal break aluminum profiles still have many shortcomings: On the one hand, the manufacturing process of thermal break structures is complex, requiring specialized processing equipment and thermal break strips, resulting in high production costs. Furthermore, the connection strength between the thermal break strip and the aluminum profile is limited, and loosening and detachment are likely to occur after long-term use, affecting the thermal insulation effect and structural stability. On the other hand, the design and processing of multi-cavity structures are difficult, requiring extremely high precision in the extrusion process. Moreover, the thermal insulation effect achieved solely through structural optimization is limited, making it difficult to meet the high-end energy-saving needs of extremely cold and hot regions. Simultaneously, the performance of the thermal break strips in some thermal break aluminum profiles degrades over long-term use due to environmental aging, temperature changes, and other factors, further reducing thermal insulation performance.

[0004] In addition, existing technologies also involve coating the surface of aluminum alloy profiles with heat-insulating coatings. This method has advantages such as simple process, low cost, convenient construction, and wide applicability. It does not require complex modifications to the structure of the aluminum profile; the coating can be applied directly to the existing aluminum profile surface, achieving both heat insulation and providing some corrosion protection and decorative effects. For example, Chinese patent application number CN202411541732.1 discloses a heat-insulating aluminum profile and its preparation method. This invention involves electrostatically spraying a heat-insulating coating onto the surface of the aluminum profile, resulting in a coating with stable and efficient flame retardancy and heat resistance.

[0005] However, current aluminum profile thermal insulation coatings on the market still suffer from poor thermal insulation performance, poor adhesion, and poor weather resistance. Therefore, developing a thermal insulation aluminum profile with excellent thermal insulation performance, strong adhesion, good weather resistance, and environmental friendliness, as well as its preparation method, has become an urgent technical problem to be solved in the industry. Summary of the Invention

[0006] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides a heat-insulating aluminum profile and its preparation method, the specific technical solution of which is as follows:

[0007] A heat-insulating aluminum profile, comprising a base aluminum profile and a heat-insulating coating covering the surface of the base aluminum profile, wherein the heat-insulating coating is obtained by curing a heat-insulating paint.

[0008] The heat-insulating coating comprises the following raw materials in parts by weight: 30-35 parts modified epoxy resin, 20-25 parts polyester resin, 10-15 parts curing agent, 10-15 parts composite filler A, 15-20 parts composite filler B, 1-3 parts dispersant, 0.1-3 parts antioxidant, 0.1-3 parts light stabilizer, 1-2 parts leveling agent, and 1-2 parts film-forming aid;

[0009] The composite filler A is obtained by mixing titanium dioxide, lanthanum oxide and mica in a mass ratio of (1~5):(1~3):(1~7) and then modifying it with a silane modifier.

[0010] The composite filler B is obtained by mixing perlite powder and hollow glass microspheres in a mass ratio of (1~7):(3~9) and then modifying them with a silane modifier.

[0011] Furthermore, the modified epoxy resin is prepared by heating bisphenol A type epoxy resin to 50℃~80℃, then adding ultraviolet absorber, crosslinking agent and catalyst, and stirring continuously at a speed of 500r / min~1000r / min for 30min~60min to obtain modified epoxy resin.

[0012] Further, by weight, the ratio of the bisphenol A type epoxy resin, the ultraviolet absorber, the crosslinking agent and the catalyst is 100:(5~20):(0.5~3):(0.1~1).

[0013] Further, the ultraviolet absorber is at least one of 2-hydroxy-4-(methacryloyloxy)benzophenone and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole.

[0014] Further, the crosslinking agent is at least one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane.

[0015] Furthermore, the catalyst is at least one of chloroplatinic acid, tetraethylammonium bromide, and tetramethylammonium iodide.

[0016] Furthermore, the particle size of the titanium dioxide and the lanthanum oxide is 50~100nm; the particle size of the mica is 3~8μm; the particle size of the perlite powder is 1~5μm; and the particle size of the hollow glass microspheres is 10~20μm.

[0017] Furthermore, the curing agent is at least one of triglycidyl isocyanate, β-hydroxyalkylamide, dicyandiamide, and blocked isocyanate.

[0018] Furthermore, the dispersant is at least one selected from hydroxypropyl methylcellulose, carboxymethyl cellulose, and sodium dodecyl sulfate.

[0019] In addition, the present invention also provides a method for preparing a heat-insulating aluminum profile, the method comprising the following steps:

[0020] S1. Modified epoxy resin, polyester resin, curing agent, composite filler A, composite filler B, dispersant, antioxidant, light stabilizer, leveling agent and film-forming aid are added to a mixing tank and mixed at a speed of 500 r / min to 800 r / min for 5 min to 10 min. Then the mixture is added to a twin-screw extruder, and the temperature of each section is controlled at 100℃ to 160℃ and the screw speed is controlled at 200 r / min to 300 r / min. The mixture is melt-extruded, pressed into sheets, and then pulverized to obtain a heat-insulating coating.

[0021] S2. Perform surface treatment on the base aluminum profile to obtain a surface-treated base aluminum profile;

[0022] S3. The heat-insulating coating is sprayed onto the surface of the surface-treated base aluminum profile using electrostatic spraying, followed by curing and cooling to form a heat-insulating coating, thus obtaining a heat-insulating aluminum profile.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. This invention chemically modifies bisphenol A type epoxy resin using UV absorbers and crosslinking agents, introducing UV-absorbing groups into the resin molecular chain through chemical bonds. This not only enhances the resin's ability to absorb and convert ultraviolet light but also strengthens the coating's cohesive strength and crosslinking density. Combined with silane modification of composite fillers A and B, the dispersibility and interfacial bonding of inorganic fillers in the resin system are improved, forming chemical bonds. This results in better adhesion of the coating to the aluminum substrate, significantly improved weather resistance and anti-aging properties, and helps extend the service life of the thermal insulation aluminum profile.

[0025] 2. This invention significantly improves the thermal insulation performance of the coating by using a modified epoxy resin and polyester resin compound as the film-forming material, and introducing composite filler A (titanium dioxide, lanthanum oxide, mica) and composite filler B (perlite powder, hollow glass microspheres) modified with specific silanes. Specifically, nano-titanium dioxide and lanthanum oxide effectively reflect near-infrared light; mica, with its layered structure, forms superimposed thermal insulation layers in the coating, and its labyrinth effect extends the heat conduction path, enhancing the thermal insulation effect; perlite powder and hollow glass microspheres have low thermal conductivity, and the perlite powder, with its porous structure and high porosity, effectively blocks heat conduction; the hollow glass microspheres, with their hollow structure, work synergistically through different mechanisms to form a highly efficient thermal barrier on the aluminum profile surface, effectively reducing heat conduction and solving the "thermal bridge" effect of the aluminum profile, thus meeting the energy-saving requirements of high-standard buildings.

[0026] 3. By adding composite filler A and composite filler B and using different particle size components, this invention can also form a bridging and full filling effect, which can effectively improve the density and mechanical strength of the heat insulation coating. After modification, it has excellent compatibility and dispersibility, which helps to improve the interfacial bonding force between the heat insulation coating and the base aluminum profile, and the weather resistance is improved.

[0027] 4. The heat-insulating coating of this invention adopts a powder electrostatic spraying process. The preparation process does not require the use of organic solvents, making it environmentally friendly and pollution-free, in line with the development trend of green manufacturing. Furthermore, this process does not require complex modifications to the original structure of the aluminum profile, and can directly form a uniform and dense heat-insulating coating on the surface of the existing profile. It also has excellent anti-corrosion and decorative effects, and boasts advantages such as simple process, low cost, and ease of industrial production. Overall, it can produce heat-insulating aluminum profiles with excellent heat insulation performance. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0029] 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 this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] According to one embodiment of the present invention, a heat-insulating aluminum profile includes a base aluminum profile and a heat-insulating coating covering the surface of the base aluminum profile, wherein the heat-insulating coating is obtained by curing a heat-insulating coating.

[0031] The heat-insulating coating comprises the following raw materials in parts by weight: 30-35 parts modified epoxy resin, 20-25 parts polyester resin, 10-15 parts curing agent, 10-15 parts composite filler A, 15-20 parts composite filler B, 1-3 parts dispersant, 0.1-3 parts antioxidant, 0.1-3 parts light stabilizer, 1-2 parts leveling agent, and 1-2 parts film-forming aid;

[0032] The composite filler A is obtained by mixing titanium dioxide, lanthanum oxide and mica in a mass ratio of (1~5):(1~3):(1~7) and then modifying it with a silane modifier.

[0033] The composite filler B is obtained by mixing perlite powder and hollow glass microspheres in a mass ratio of (1~7):(3~9) and then modifying them with a silane modifier.

[0034] In one embodiment, the silane modifier in composite filler A and composite filler B is obtained by mixing γ-aminopropyltriethoxysilane, ethanol, and water in a volume ratio of (1~5):(1~5):(1~3). After modification, composite filler A and composite filler B of the present invention can be uniformly dispersed in the resin system, avoiding filler agglomeration, exhibiting good powder flowability, and not affecting the extrusion and spraying performance of powder coatings.

[0035] In one embodiment, the modification process of the composite filler A is as follows: stirring at a speed of 50 r / min to 100 r / min for 1 h to 2 h, followed by filtration and drying.

[0036] In one embodiment, the modification process of the composite filler B is as follows: stirring at a speed of 50 r / min to 100 r / min for 1 h to 2 h, followed by filtration and drying.

[0037] In one embodiment, the modified epoxy resin is prepared by heating bisphenol A type epoxy resin to 50°C~80°C, then adding ultraviolet absorber, crosslinking agent and catalyst, and stirring continuously at a speed of 500r / min~1000r / min for 30min~60min to obtain modified epoxy resin.

[0038] In one embodiment, the ratio of the bisphenol A type epoxy resin, the ultraviolet absorber, the crosslinking agent and the catalyst by weight is 100:(5~20):(0.5~3):(0.1~1).

[0039] In one embodiment, the bisphenol A type epoxy resin has an epoxy value of 0.08~0.12 eq / 100g.

[0040] In one embodiment, the ultraviolet absorber is at least one of 2-hydroxy-4-(methacryloyloxy)benzophenone and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole.

[0041] In one embodiment, the crosslinking agent is at least one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane.

[0042] In one embodiment, the catalyst is at least one of chloroplatinic acid, tetraethylammonium bromide, and tetramethylammonium iodide.

[0043] In one embodiment, the titanium dioxide and lanthanum oxide have a particle size of 50-100 nm; the mica has a particle size of 3-8 μm; the perlite powder has a particle size of 1-5 μm; and the hollow glass microspheres have a particle size of 10-20 μm.

[0044] In one embodiment, the curing agent is at least one of triglycidyl isocyanurate, β-hydroxyalkylamide, dicyandiamide, and blocked isocyanate.

[0045] In one embodiment, the dispersant is at least one of hydroxypropyl methylcellulose, carboxymethyl cellulose, and sodium dodecyl sulfate.

[0046] In one embodiment, the antioxidant is at least one selected from 2,6-di-tert-butylhydroquinone, propyl gallate, ditetradecyl alcohol ester, and dioctadecyl alcohol ester.

[0047] In one embodiment, the light stabilizer is nickel tetra-n-butyldithiocarbamate.

[0048] In one embodiment, the leveling agent is an end-group modified organosilicon.

[0049] In one embodiment, the film-forming aid is at least one of propylene glycol butyl ether, anhydrous ethanol, and propylene glycol methyl ether acetate.

[0050] In addition, the present invention also provides a method for preparing a heat-insulating aluminum profile, the method comprising the following steps:

[0051] S1. Modified epoxy resin, polyester resin, curing agent, composite filler A, composite filler B, dispersant, antioxidant, light stabilizer, leveling agent and film-forming aid are added to a mixing tank and mixed at a speed of 500 r / min to 800 r / min for 5 min to 10 min. Then the mixture is added to a twin-screw extruder, and the temperature of each section is controlled at 100℃ to 160℃ and the screw speed is controlled at 200 r / min to 300 r / min. The mixture is melt-extruded, pressed into sheets, and then pulverized to obtain a heat-insulating coating.

[0052] S2. Perform surface treatment on the base aluminum profile to obtain a surface-treated base aluminum profile;

[0053] S3. The heat-insulating coating is sprayed onto the surface of the surface-treated base aluminum profile using electrostatic spraying, followed by curing and cooling to form a heat-insulating coating, thus obtaining a heat-insulating aluminum profile.

[0054] In one embodiment, in step S1, the temperature of the feed section of the twin-screw extruder is 100~120°C, the temperature of the melting section is 120~140°C, and the temperature of the die head section is 140~160°C.

[0055] In one embodiment, in step S1, the material is crushed through a 180-300 mesh sieve.

[0056] In one embodiment, step S2 includes alkaline degreasing, acid washing to remove oxide scale, neutralization, water washing, anodizing, and sealing. These surface treatments are conventional techniques and will not be described in detail here.

[0057] In one embodiment, in step S2, the oxide film formed by the oxidation treatment has a thickness of 10~15μm.

[0058] In one embodiment, in step S3, the thickness of the heat-insulating coating is 50~100μm.

[0059] In one embodiment, in step S3, the electrostatic spraying voltage is 60~80 kV, the spraying distance is 20~30 cm, and the powder spraying rate is 50~80 g / min.

[0060] In one embodiment, in step S3, the curing temperature is 100~150℃ and the time is 15~30min.

[0061] The embodiments of the present invention will be described in detail below with reference to specific examples. Components and processes not specified in the following embodiments are considered conventional techniques.

[0062] Example 1:

[0063] A method for preparing a heat-insulating aluminum profile includes the following steps:

[0064] S1. By weight, 32 parts modified epoxy resin, 23 parts polyester resin, 11 parts triglycidyl isocyanurate, 14 parts composite filler A, 16 parts composite filler B, 2 parts hydroxypropyl methylcellulose, 1 part 2,6-di-tert-butylhydroquinone, 1 part tetra-n-butyl dithiocarbamate, 2 parts end-modified organosilicon, and 2 parts propylene glycol butyl ether are added to a mixing tank and mixed at 500 r / min for 10 min. The mixture is then added to a twin-screw extruder with the feed section temperature at 110℃, the melt section temperature at 125℃, the die head section temperature at 145℃, and the screw speed at 200 r / min. The mixture is melt-extruded, pressed into sheets, and then pulverized and passed through a 250-mesh sieve to obtain a heat-insulating coating.

[0065] The modified epoxy resin is prepared by heating 100 parts of bisphenol A type epoxy resin to 75°C, then adding 12 parts of 2-hydroxy-4-(methacryloyloxy)benzophenone, 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 0.5 parts of chloroplatinic acid, and stirring continuously for 60 minutes at a speed of 500 r / min to obtain the modified epoxy resin.

[0066] The composite filler A is made by mixing titanium dioxide, lanthanum oxide and mica in a mass ratio of 3:2:5, and then adding it to a silane modification agent (obtained by mixing γ-aminopropyltriethoxysilane, ethanol and water in a volume ratio of 4:3:3). The mixture is stirred at 50 r / min for 1 h, filtered, and then dried.

[0067] The composite filler B is made by mixing perlite powder and hollow glass microspheres in a mass ratio of 6:4, adding the mixture to a silane modifier (obtained by mixing γ-aminopropyltriethoxysilane, ethanol and water in a volume ratio of 4:3:3), stirring at 50 r / min for 1 h, filtering and drying.

[0068] The titanium dioxide and lanthanum oxide both have a particle size of 60 nm; the mica has a particle size of 5 μm; the perlite powder has a particle size of 3 μm; and the hollow glass microspheres have a particle size of 15 μm.

[0069] S2. The basic aluminum profile is subjected to surface treatment, and the surface treatment includes alkaline washing and degreasing, acid washing to remove oxide scale, neutralization, water washing, anodizing and sealing treatment, to obtain a surface-treated basic aluminum profile;

[0070] S3. Using electrostatic spraying with a voltage of 65 kV, a spraying distance of 25 cm, and a powder spraying rate of 50 g / min, the heat-insulating coating is sprayed onto the surface of the surface-treated base aluminum profile, and then cured at 105°C for 15 min. After cooling, a heat-insulating coating with a thickness of 80 μm is formed, resulting in a heat-insulating aluminum profile.

[0071] Example 2:

[0072] A method for preparing a heat-insulating aluminum profile includes the following steps:

[0073] S1. By weight, 33 parts modified epoxy resin, 22 parts polyester resin, 10 parts triglycidyl isocyanurate, 12 parts composite filler A, 18 parts composite filler B, 3 parts hydroxypropyl methylcellulose, 1 part 2,6-di-tert-butylhydroquinone, 1 part tetra-n-butyl dithiocarbamate, 2 parts end-modified organosilicon, and 2 parts propylene glycol butyl ether are added to a mixing tank and mixed at 500 r / min for 10 min. The mixture is then added to a twin-screw extruder with the following temperatures: feed section temperature 110℃, melt section temperature 130℃, die head section temperature 150℃, screw speed 200 r / min. The mixture is melt-extruded, pressed into sheets, and then pulverized and passed through a 250-mesh sieve to obtain a heat-insulating coating.

[0074] The modified epoxy resin is prepared by heating 100 parts of bisphenol A type epoxy resin to 80°C, then adding 11 parts of 2-hydroxy-4-(methacryloyloxy)benzophenone, 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 0.6 parts of chloroplatinic acid, and stirring continuously for 60 minutes at a speed of 500 r / min to obtain the modified epoxy resin.

[0075] The composite filler A is made by mixing titanium dioxide, lanthanum oxide and mica in a mass ratio of 4:2:4, and then adding it to a silane modification agent (obtained by mixing γ-aminopropyltriethoxysilane, ethanol and water in a volume ratio of 4:3:3). The mixture is stirred at 50 r / min for 1 h, filtered, and then dried.

[0076] The composite filler B is made by mixing perlite powder and hollow glass microspheres in a mass ratio of 5:5, adding the mixture to a silane modifier (obtained by mixing γ-aminopropyltriethoxysilane, ethanol and water in a volume ratio of 4:3:3), stirring at 50 r / min for 1 h, filtering and drying.

[0077] The titanium dioxide and lanthanum oxide both have a particle size of 60 nm; the mica has a particle size of 5 μm; the perlite powder has a particle size of 3 μm; and the hollow glass microspheres have a particle size of 15 μm.

[0078] S2. The basic aluminum profile is subjected to surface treatment, and the surface treatment includes alkaline washing and degreasing, acid washing to remove oxide scale, neutralization, water washing, anodizing and sealing treatment, to obtain a surface-treated basic aluminum profile;

[0079] S3. Using electrostatic spraying with a voltage of 65 kV, a spraying distance of 25 cm, and a powder spraying rate of 50 g / min, the heat-insulating coating is sprayed onto the surface of the surface-treated base aluminum profile, and then cured at 105°C for 15 min. After cooling, a heat-insulating coating with a thickness of 80 μm is formed, resulting in a heat-insulating aluminum profile.

[0080] Example 3:

[0081] A method for preparing a heat-insulating aluminum profile includes the following steps:

[0082] S1. By weight, 31 parts modified epoxy resin, 24 parts polyester resin, 12 parts triglycidyl isocyanurate, 13 parts composite filler A, 17 parts composite filler B, 3 parts hydroxypropyl methylcellulose, 1 part 2,6-di-tert-butylhydroquinone, 1 part tetra-n-butyl dithiocarbamate, 2 parts end-modified organosilicon, and 2 parts propylene glycol butyl ether are added to a mixing tank and mixed at 500 r / min for 10 min. The mixture is then added to a twin-screw extruder with the feed section temperature at 110℃, the melt section temperature at 125℃, the die head section temperature at 145℃, and the screw speed at 200 r / min. The mixture is melt-extruded, pressed into sheets, and then pulverized and passed through a 250-mesh sieve to obtain a heat-insulating coating.

[0083] The modified epoxy resin is prepared by heating 100 parts of bisphenol A type epoxy resin to 80°C, then adding 10 parts of 2-hydroxy-4-(methacryloyloxy)benzophenone, 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 0.5 parts of chloroplatinic acid, and stirring continuously for 60 minutes at a speed of 500 r / min to obtain the modified epoxy resin.

[0084] The composite filler A is made by mixing titanium dioxide, lanthanum oxide and mica in a mass ratio of 5:2:3, and then adding it to a silane modification agent (obtained by mixing γ-aminopropyltriethoxysilane, ethanol and water in a volume ratio of 4:3:3). The mixture is stirred at 50 r / min for 1 h, filtered, and then dried.

[0085] The composite filler B is made by mixing perlite powder and hollow glass microspheres in a mass ratio of 7:3, adding the mixture to a silane modifier (obtained by mixing γ-aminopropyltriethoxysilane, ethanol and water in a volume ratio of 4:3:3), stirring at 50 r / min for 1 h, filtering and drying.

[0086] The titanium dioxide and lanthanum oxide both have a particle size of 60 nm; the mica has a particle size of 5 μm; the perlite powder has a particle size of 3 μm; and the hollow glass microspheres have a particle size of 15 μm.

[0087] S2. The basic aluminum profile is subjected to surface treatment, and the surface treatment includes alkaline washing and degreasing, acid washing to remove oxide scale, neutralization, water washing, anodizing and sealing treatment, to obtain a surface-treated basic aluminum profile;

[0088] S3. Using electrostatic spraying with a voltage of 65kV, a spraying distance of 25cm, and a powder spraying rate of 50 g / min, the heat-insulating coating is sprayed onto the surface of the surface-treated base aluminum profile, and then cured at 105℃ for 15min. After cooling, a heat-insulating coating with a thickness of 80μm is formed, resulting in a heat-insulating aluminum profile.

[0089] Comparative Example 1:

[0090] The difference between Comparative Example 1 and Example 3 is that bisphenol A type epoxy resin was used to replace the modified epoxy resin (i.e., no modification treatment was performed) in Comparative Example 1, while the rest is the same as in Example 3.

[0091] Comparative Example 2:

[0092] The difference between Comparative Example 2 and Example 3 is that the composite filler A in Comparative Example 2 uses a single titanium dioxide, while the rest is the same as in Example 3.

[0093] Comparative Example 3:

[0094] The difference between Comparative Example 3 and Example 3 is that the composite filler A in Comparative Example 3 uses a single lanthanum oxide, while the rest is the same as in Example 3.

[0095] Comparative Example 4:

[0096] The difference between Comparative Example 4 and Example 3 is that the composite filler A in Comparative Example 4 uses a single type of mica, while the rest is the same as in Example 3.

[0097] Comparative Example 5:

[0098] The difference between Comparative Example 5 and Example 3 is that no composite filler A was added in Comparative Example 5, but otherwise it is the same as Example 3.

[0099] Comparative Example 6:

[0100] The difference between Comparative Example 6 and Example 3 is that the composite filler B in Comparative Example 6 uses a single type of perlite powder, while the rest is the same as in Example 3.

[0101] Comparative Example 7:

[0102] The difference between Comparative Example 7 and Example 3 is that the composite filler B in Comparative Example 7 uses a single hollow glass microsphere, while the rest is the same as in Example 3.

[0103] Comparative Example 8:

[0104] The difference between Comparative Example 8 and Example 3 is that no composite filler B was added in Comparative Example 8, but otherwise it is compatible with Example 3.

[0105] Comparative Example 9:

[0106] The difference between Comparative Example 9 and Example 3 is that the particle sizes of the components in Composite Packer A and Composite Packer B in Comparative Example 9 are different; otherwise, they are the same as in Example 3.

[0107] In Comparative Example 9, the particle size of titanium dioxide and lanthanum oxide is 30 nm; the particle size of mica is 10 μm; the particle size of perlite powder is 10 μm; and the particle size of hollow glass microspheres is 10 μm.

[0108] Comparative Example 10:

[0109] Compared with Example 3, Comparative Example 10 differs in that neither composite filler A nor composite filler B in Comparative Example 10 has been modified by a silane modifier. Otherwise, they are the same as in Example 3.

[0110] The performance of the thermally insulated aluminum profiles of Examples 1-3 and Comparative Examples 1-10 was tested, and the results are shown in Table 1 below.

[0111] The appearance of the coating is determined by visual observation by those skilled in the art, with the aid of a magnifying glass if necessary; adhesion testing is performed in accordance with GB / T9286-2021; weathering resistance testing is performed in accordance with GB / T1865. In 2009, the QUVB accelerated aging test was conducted for 4000 hours; the acid and alkali resistance test was conducted in accordance with GB / T1763; and the thermal conductivity test was conducted in accordance with GB / T10294 (the lower the coefficient, the better the thermal insulation performance).

[0112] Table 1: Performance Test Results

[0113]

[0114] As can be seen from the data analysis in Table 1, the present invention significantly improves the adhesion, weather resistance, chemical corrosion resistance and thermal insulation performance of the thermal insulation coating through the compounding of modified epoxy resin and polyester resin, the synergistic effect of composite filler A and composite filler B, and silane modification treatment. It can effectively block heat conduction and meet the energy-saving requirements of high-standard buildings. Compared to Example 3, the bisphenol A epoxy resin in Comparative Example 1 was not modified, and no ultraviolet absorbing groups or cross-linking structures were introduced. This resulted in decreased coating cohesive strength and cross-linking density, leading to poorer adhesion, acid and alkali resistance, and weather resistance compared to Example 1. Furthermore, the thermal conductivity was significantly increased, resulting in poor thermal insulation performance. In Comparative Examples 2-4, composite filler A used a single component. Comparative Example 2 used only titanium dioxide, which reflects infrared light, but lacked the synergistic effect of layered mica and porous materials, resulting in performance inferior to Example 3. Comparative Example 3 used only lanthanum oxide, which, while having some thermal insulation effect, lacked synergistic effects, leading to performance inferior to Example 3. Comparative Example 4 used only mica, which, while having some labyrinth effect, lacked reflectivity and the synergistic effect of low thermal conductivity fillers, resulting in performance inferior to Example 3. Comparative Example 5 did not add composite filler A, thus lacking the synergistic thermal insulation mechanism of titanium dioxide, lanthanum oxide, and mica, resulting in significantly worse performance than Example 3. This indicates that the components in composite filler A of the present invention have a synergistic effect, and composite filler A can also form a synergistic effect with composite filler B in the system, effectively improving thermal insulation. The overall performance of aluminum profiles was assessed. In Comparative Example 6, composite filler B consisted of single-component perlite powder. While the porous structure of perlite powder provides some insulation, the lack of synergistic effect from the hollow structure of hollow glass microspheres resulted in performance inferior to Example 3. In Comparative Example 7, composite filler B also consisted of single-component hollow glass microspheres, which provided good insulation. However, the lack of synergistic effect from porous materials led to overall performance inferior to Example 3. In Comparative Example 8, no composite filler B was added. Without the filler support provided by composite filler B, the acid and alkali resistance, weather resistance, and thermal conductivity significantly deteriorated, indicating that composite filler B can promote… The role of coating stability: In Comparative Example 9, the filler used had a different particle size, resulting in agglomeration. The filling effect was not as good as in Example 3, indicating that particle size control affects the dispersibility and thermal insulation performance of the filler. Comparative Example 10 did not undergo silane modification treatment. The filler was not modified and had poor compatibility with the resin, making it prone to agglomeration. This led to a decrease in coating density, and the adhesion, acid and alkali resistance, weather resistance, and thermal conductivity were all worse than in Example 3. This indicates that silane modification treatment can significantly improve the dispersibility and interfacial bonding of the filler, indirectly affecting the acid and alkali resistance, weather resistance, and thermal conductivity of the thermal insulation coating.

[0115] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A heat-insulating aluminum profile, characterized in that, The heat-insulating aluminum profile includes a base aluminum profile and a heat-insulating coating covering the surface of the base aluminum profile, wherein the heat-insulating coating is obtained by curing a heat-insulating paint. The heat-insulating coating comprises the following raw materials in parts by weight: 30-35 parts modified epoxy resin, 20-25 parts polyester resin, 10-15 parts curing agent, 10-15 parts composite filler A, 15-20 parts composite filler B, 1-3 parts dispersant, 0.1-3 parts antioxidant, 0.1-3 parts light stabilizer, 1-2 parts leveling agent, and 1-2 parts film-forming aid; The modified epoxy resin is prepared by heating bisphenol A type epoxy resin to 50℃~80℃, then adding ultraviolet absorber, crosslinking agent and catalyst, and stirring continuously for 30min~60min at a speed of 500r / min~1000r / min to obtain modified epoxy resin. The ultraviolet absorber is at least one of 2-hydroxy-4-(methacryloyloxy)benzophenone and 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole; The crosslinking agent is at least one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, and 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane. The composite filler A is obtained by mixing titanium dioxide, lanthanum oxide and mica in a mass ratio of (1~5):(1~3):(1~7) and then modifying it with a silane modifier. The composite filler B is obtained by mixing perlite powder and hollow glass microspheres in a mass ratio of (1~7):(3~9) and then modifying them with a silane modifier. The titanium dioxide and lanthanum oxide have a particle size of 50-100 nm; the mica has a particle size of 3-8 μm; the perlite powder has a particle size of 1-5 μm; and the hollow glass microspheres have a particle size of 10-20 μm.

2. The thermally insulated aluminum profile according to claim 1, characterized in that, The ratio of the bisphenol A type epoxy resin, ultraviolet absorber, crosslinking agent and catalyst by weight is 100:(5~20):(0.5~3):(0.1~1).

3. The thermally insulated aluminum profile according to claim 2, characterized in that, The catalyst is at least one of chloroplatinic acid, tetraethylammonium bromide, and tetramethylammonium iodide.

4. The thermally insulated aluminum profile according to claim 1, characterized in that, The curing agent is at least one of triglycidyl isocyanurate, β-hydroxyalkylamide, dicyandiamide, and blocked isocyanate.

5. The thermally insulated aluminum profile according to claim 1, characterized in that, The dispersant is at least one of hydroxypropyl methylcellulose, carboxymethyl cellulose, and sodium dodecyl sulfate.

6. A method for preparing a heat-insulating aluminum profile, characterized in that, The preparation method is used to prepare the heat-insulating aluminum profile as described in claim 1, and the preparation method includes the following steps: S1. Modified epoxy resin, polyester resin, curing agent, composite filler A, composite filler B, dispersant, antioxidant, light stabilizer, leveling agent and film-forming aid are added to a mixing tank and mixed at a speed of 500 r / min to 800 r / min for 5 min to 10 min. Then the mixture is added to a twin-screw extruder, and the temperature of each section is controlled at 100℃ to 160℃ and the screw speed is controlled at 200 r / min to 300 r / min. The mixture is melt-extruded, pressed into sheets, and then pulverized to obtain a heat-insulating coating. S2. Perform surface treatment on the base aluminum profile to obtain a surface-treated base aluminum profile; S3. The heat-insulating coating is sprayed onto the surface of the surface-treated base aluminum profile using electrostatic spraying, followed by curing and cooling to form a heat-insulating coating, thus obtaining a heat-insulating aluminum profile.

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