A2 grade aluminum plastic plate fireproof core material with adhesive resin, hot melt adhesive film and aluminum plastic plate

Abstract

The present application relates to the technical field of high polymer adhesive, in particular to a kind of A2 level aluminum-plastic panel fireproof core material bonding resin, hot melt adhesive film and aluminum-plastic panel.A2 level aluminum-plastic panel fireproof core material bonding resin includes the following components by weight fraction: silane grafting polyolefin elastomer 10~30 parts, maleic anhydride grafting polyethylene 10~30 parts, ethylene-vinyl acetate copolymer 20~60 parts, K resin 5~20 parts and antioxidant 0.1~0.5 parts.In the bonding resin of the present application, silane grafting polyolefin elastomer, maleic anhydride grafting polyethylene and K resin are used to modify ethylene-vinyl acetate copolymer synergistically, which not only significantly improves the peel strength of the bonding resin to A2 level aluminum-plastic panel fireproof core material, but also has a high retention rate of peel strength after soaking.

Description

Technical Field

[0001] This invention relates to the field of polymer adhesive technology, and in particular to an adhesive resin, hot melt adhesive film, and aluminum composite panel for A2 grade fireproof core material of aluminum composite panel. Background Technology

[0002] Aluminum composite panel (ACP), also known as aluminum-plastic composite board, is a new type of building material made by laminating aluminum sheets with a coated and painted surface and polyethylene plastic sheets as the core material using a hot-melt adhesive film process. In recent years, with increasingly stringent fire safety requirements from fire protection, environmental protection, and construction departments, decorative materials that combine aesthetics, lightweight, environmental friendliness, durability, and fire resistance have become increasingly popular. Among them, fire-resistant aluminum composite panels, with their comprehensive advantages, are widely used in urban construction.

[0003] To meet increasingly stringent fire safety standards, aluminum composite panel (ACP) core materials with inorganic mineral substrates currently achieve a fire performance rating of A2 as specified in GB8624-2012, making them widely applicable for exterior wall decoration in various buildings. Mainstream A2-grade fire-resistant core materials primarily utilize inorganic materials such as magnesium hydroxide, aluminum hydroxide, calcium carbonate, and wollastonite as main components. These are mixed, adhesives are added, and fiberglass cloth is applied to both the top and bottom surfaces before rolling and drying. In recent years, some companies have successfully developed A2-grade fire-resistant core materials that can be formed through a co-extrusion casting process. These new materials still primarily consist of inorganic materials such as calcium carbonate, magnesium hydroxide, and aluminum hydroxide, but use a small amount of EVA resin as a carrier. Compared to traditional core materials, this extrudable A2-grade fire-resistant core material has a further reduced organic resin content, significantly increasing the difficulty of bonding. Traditional hot-melt adhesive films for ACP are no longer sufficient for effective bonding.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide an adhesive resin, a hot melt adhesive film, and an aluminum composite panel for fire-resistant core material of A2 grade aluminum composite panel. The adhesive resin of this invention has excellent peel strength and excellent water resistance for A2 grade aluminum composite panel fire-resistant core material. After immersion in water, its peel strength retention rate is not less than 90%.

[0006] To achieve the above-mentioned objectives of the present invention, a first aspect of the present invention provides an adhesive resin for the fire-resistant core material of A2 grade aluminum composite panels, comprising the following components in parts by weight: The mixture contains 10-30 parts of silane-grafted polyolefin elastomer, 10-30 parts of maleic anhydride-grafted polyethylene, 20-60 parts of ethylene-vinyl acetate copolymer, 5-20 parts of K resin, and 0.1-0.5 parts of antioxidant.

[0007] In a specific embodiment of the present invention, the silane-grafted polyolefin elastomer includes at least one of vinyltrimethoxysilane-grafted polyolefin elastomer and vinyltriethoxysilane-grafted polyolefin elastomer. Further, the grafting rate of the silane-grafted polyolefin elastomer is 2% to 6%.

[0008] In a specific embodiment of the present invention, the melt flow index of the silane-grafted polyolefin elastomer at 190°C and 2.16 kg is 3~20 g / 10 min.

[0009] In a specific embodiment of the present invention, the grafting rate of the maleic anhydride-grafted polyethylene is greater than 0.2%. Further, the melt flow index of the maleic anhydride-grafted polyethylene at 190°C and 2.16 kg is 0.5~6 g / 10 min.

[0010] In a specific embodiment of the present invention, the VA content in the ethylene-vinyl acetate copolymer is 8% to 25%. Further, the melt flow index of the ethylene-vinyl acetate copolymer at 190°C and 2.16 kg is 1 to 15 g / 10 min.

[0011] In a specific embodiment of the present invention, the melt flow index of the K resin at 200°C and 5kg is 1~15g / 10min.

[0012] In a specific embodiment of the present invention, the mass ratio of the silane-grafted polyolefin elastomer to the maleic anhydride-grafted polyethylene is 1:(0.6~1.5).

[0013] The second aspect of the present invention provides a hot melt adhesive film, comprising a first adhesive layer, a core layer and a second adhesive layer stacked together; the first adhesive layer comprises the adhesive resin provided in the first aspect of the present invention.

[0014] In a specific embodiment of the present invention, the core layer is a polyethylene layer.

[0015] In a specific embodiment of the present invention, the second adhesive layer comprises maleic anhydride-grafted polyethylene; the melt flow index of the maleic anhydride-grafted polyethylene at 190°C and 2.16 kg is 1 to 15 g / 10 min.

[0016] In a specific embodiment of the present invention, the mass ratio of the first adhesive layer, the core layer and the second adhesive layer is (3~5) : (2~3) : (2~3).

[0017] A third aspect of the present invention also provides an aluminum composite panel, comprising the hot melt adhesive film provided in the second aspect of the present invention.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In the adhesive resin of the present invention, silane-grafted polyolefin elastomer, maleic anhydride-grafted polyethylene and K resin are used to modify the ethylene-vinyl acetate copolymer in a synergistic manner, which not only significantly improves the peel strength of the adhesive resin to the fireproof core material of A2 grade aluminum composite panel, but also has a high peel strength retention rate after soaking in water.

[0019] (2) The hot melt adhesive film of the present invention has a three-layer composite structure. Polyethylene is used as the intermediate cross-linking layer to firmly bond the first adhesive layer and the second adhesive layer, which can achieve effective bonding of aluminum plate and fireproof core material. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. 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. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0021] The first aspect of this invention provides an adhesive resin for the fire-resistant core material of A2 grade aluminum composite panels, comprising the following components in parts by weight: The mixture contains 10-30 parts of silane-grafted polyolefin elastomer, 10-30 parts of maleic anhydride-grafted polyethylene, 20-60 parts of ethylene-vinyl acetate copolymer, 5-20 parts of K resin, and 0.1-0.5 parts of antioxidant.

[0022] In the adhesive resin of the present invention, silane-grafted polyolefin elastomer, maleic anhydride-grafted polyethylene and K resin are used to synergistically modify the ethylene-vinyl acetate copolymer, which not only significantly improves the peel strength of the adhesive resin to the fireproof core material of A2 grade aluminum composite panel, but also has a high peel strength retention rate after soaking in water.

[0023] In some embodiments, the amount of ethylene-vinyl acetate copolymer in the adhesive resin is 20 to 60 parts by weight, specifically 20, 30, 40, 50, or 60 parts, or any combination thereof. Ethylene-vinyl acetate, as the matrix resin, possesses good processability, toughness, and cohesive strength.

[0024] In some embodiments, the VA content in the ethylene-vinyl acetate copolymer is 8% to 25%, specifically within the range of 8%, 10%, 12%, 18%, 20%, 25%, or any combination thereof. Further, the melt flow index of the ethylene-vinyl acetate copolymer at 190°C and 2.16 kg is 1 to 15 g / 10 min, specifically within the range of 1 g / 10 min, 3 g / 10 min, 5 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 15 g / 10 min, or any combination thereof.

[0025] In some embodiments, the ethylene-vinyl acetate copolymer is a blown film grade ethylene-vinyl acetate copolymer.

[0026] In some embodiments, the amount of maleic anhydride-grafted polyethylene in the adhesive resin is 10 to 30 parts by weight, specifically 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, or any combination thereof. The main chain of maleic anhydride-grafted polyethylene has good compatibility with ethylene-vinyl acetate copolymers and polyolefin elastomers. The grafted maleic anhydride groups not only improve the wettability of the fire-retardant core material, but also, during subsequent processing and use, can undergo ring-opening reactions with hydroxyl groups on the inorganic surface of the fire-retardant core material to form chemical bonds, thereby significantly improving the peel strength of the fire-retardant core material. If the amount of maleic anhydride-grafted polyethylene is too low, the wettability of the fireproof core material will be insufficient, and the number of maleic anhydride groups that can react with the inorganic materials of the fireproof core material will be insufficient, resulting in reduced peel strength. If the amount of maleic anhydride-grafted polyethylene is too high, the number of maleic anhydride groups will be too high, which will easily cause excessive cross-linking of the adhesive layer during processing or long-term use, resulting in poor flexibility.

[0027] In some embodiments, the grafting rate of maleic anhydride-grafted polyethylene is greater than 0.2%, specifically within the range of 0.21%, 0.5%, 1%, 2%, 3%, 4%, or any combination thereof. Further, the melt flow index of maleic anhydride-grafted polyethylene at 190°C and 2.16 kg is 0.5~6 g / 10 min, specifically within the range of 0.5 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, or any combination thereof.

[0028] In some embodiments, the amount of silane-grafted polyolefin elastomer in the adhesive resin is 10-30 parts by weight, specifically 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, or any combination thereof. The silane groups grafted into the silane-grafted polyolefin elastomer form silanols after hydrolysis, which can undergo condensation reactions with hydroxyl groups on the surface of the inorganic material of the fire-retardant core material, forming chemical bonds with high bond energy and insensitivity to water. This not only helps improve peel strength but also significantly improves the water resistance of the adhesive resin. Furthermore, some silane groups can undergo in-situ crosslinking under ambient humidity, forming a flexible network structure, further enhancing cohesive strength and water resistance. In addition, the main chain of the silane-grafted polyolefin elastomer exhibits excellent flexibility, which helps prevent embrittlement of the adhesive layer. When the amount of silane-grafted polyolefin elastomer is too low, the improvement in water resistance is not significant; when the amount of silane-grafted polyolefin elastomer is too high, its non-polar main chain is prone to phase separation from the system, resulting in a decrease in cohesive strength.

[0029] In some embodiments, the silane-grafted polyolefin elastomer includes at least one of vinyltrimethoxysilane-grafted polyolefin elastomer (POE-VTMS) and vinyltriethoxysilane-grafted polyolefin elastomer (POE-VTES). Further, the grafting rate of the silane-grafted polyolefin elastomer is 2% to 6%, specifically within the range of 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, or any combination thereof.

[0030] In some embodiments, the melt flow index of the silane-grafted polyolefin elastomer at 190°C and 2.16 kg is 3 to 20 g / 10 min, specifically 3 g / 10 min, 5 g / 10 min, 9 g / 10 min, 12 g / 10 min, 15 g / 10 min, 20 g / 10 min, or any combination thereof.

[0031] In some embodiments, the amount of K resin in the adhesive resin is 5 to 20 parts by weight, specifically 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, or any combination thereof. K resin is a butadiene-styrene copolymer. The introduction of an appropriate amount of K resin helps to better disperse the silane-grafted polyolefin elastomer and maleic anhydride-grafted polyethylene in the ethylene-vinyl acetate copolymer, preventing the agglomeration of polar components. When the amount of K resin is too low, it is detrimental to the dispersion of the silane-grafted polyolefin elastomer and maleic anhydride-grafted polyethylene in the system; when the amount of K resin is too high, the styrene hard segments it contains will lead to poor flexibility and affect the effective contact between the reactive groups and the core material surface.

[0032] In some embodiments, the amount of K resin is 10% to 60% of the total mass of the silane-grafted polyolefin elastomer and the maleic anhydride-grafted polyethylene, specifically in the range of 10%, 20%, 30%, 40%, 50%, 60% or any combination thereof, preferably 25% to 40%.

[0033] In some embodiments, the melt flow index of K resin at 200°C and 5 kg is 1~15 g / 10 min, specifically it can be a range of 1 g / 10 min, 3 g / 10 min, 5 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 15 g / 10 min or any combination thereof.

[0034] In some embodiments, the mass ratio of silane-grafted polyolefin elastomer to maleic anhydride-grafted polyethylene is 1:(0.6~1.5), specifically within the range of 1:0.6, 1:0.7, 1:0.8, 1:1, 1:1.2, 1:1.5, or any combination thereof. This is more conducive to a balance between the peel strength of the adhesive resin to the fire-retardant core material and its water resistance.

[0035] In some embodiments, the amount of antioxidant in the adhesive resin is 0.1 to 0.5 parts by weight, specifically 0.1, 0.2, 0.3, 0.4, 0.5 parts, or any combination thereof.

[0036] In some embodiments, the antioxidant includes at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], ethylenediene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, and pentaerythritol tetrakis(3-lauryl thiopropionate).

[0037] This invention provides a method for preparing an optional A2-grade aluminum composite panel fireproof core material adhesive resin, comprising the following steps: mixing silane-grafted polyolefin elastomer, maleic anhydride-grafted polyethylene, ethylene-vinyl acetate copolymer, K resin and antioxidant in proportion, and then granulating by twin-screw extrusion to obtain the adhesive resin.

[0038] The twin-screw extruder can have a length-to-diameter ratio of 40:1, an extrusion section temperature of 110~190℃, and a die temperature of 185℃. The specific temperature can be adjusted according to the actual conditions within the temperature range where the raw material can be melted and extruded. The screw speed includes, but is not limited to, 300r / min.

[0039] The second aspect of the present invention provides a hot melt adhesive film, comprising a first adhesive layer, a core layer and a second adhesive layer stacked together; the first adhesive layer comprises the adhesive resin provided in the first aspect of the present invention.

[0040] In some implementations, the core layer is a polyethylene layer.

[0041] In some embodiments, the second adhesive layer comprises maleic anhydride-grafted polyethylene; the melt flow index of the maleic anhydride-grafted polyethylene at 190°C and 2.16 kg is 1 to 15 g / 10 min, specifically 1 g / 10 min, 3 g / 10 min, 5 g / 10 min, 8 g / 10 min, 10 g / 10 min, 12 g / 10 min, 15 g / 10 min, or any combination thereof.

[0042] In some embodiments, the maleic anhydride-grafted polyethylene in the second adhesive layer satisfies the following condition: peel strength after thermal bonding with the aluminum sheet > 65 N / 25 mm; wherein the thermal bonding conditions include: hot pressing at 130 °C and 0.6 MPa for 5 s in the order of aluminum sheet, 10 μm thick maleic anhydride-grafted polyethylene film, and PE 7042.

[0043] In some embodiments, the raw material of the second adhesive layer is at least one of VB550C (Guangzhou Lushan New Materials Co., Ltd.) and VB550A (Guangzhou Lushan New Materials Co., Ltd.). In some embodiments, the mass ratio of the first adhesive layer, the core layer, and the second adhesive layer is (3~5):(2~3):(2~3). Specifically, the mass ratio of the first adhesive layer to the core layer can be 3:2, 3:3, 4:2, 4:4, 5:2, 5:3, or any combination thereof, and the mass ratio of the first adhesive layer to the second adhesive layer can be 3:2, 3:3, 4:2, 4:4, 5:2, 5:3, or any combination thereof.

[0044] The present invention provides an optional method for preparing a hot melt adhesive film, comprising the following steps: multi-layer co-extrusion casting of a first adhesive layer material, a core layer material, and a second adhesive layer material.

[0045] In some embodiments, the temperature during co-extrusion casting is 140~190°C. Further, the extrusion temperature of the first adhesive layer is 150~180°C, the extrusion temperature of the core layer is 150~180°C, the extrusion temperature of the second adhesive layer is 140~170°C, and the die temperature is 160~190°C.

[0046] In some implementations, the core layer material is a commonly used polyethylene material, including but not limited to PE 7042.

[0047] A third aspect of the present invention also provides an aluminum composite panel, comprising the hot melt adhesive film provided in the second aspect of the present invention.

[0048] The aluminum composite panel includes a laminated aluminum plate, a hot melt adhesive film, a fire-resistant core material, and another aluminum plate; the first adhesive layer of the hot melt adhesive film is bonded to the fire-resistant core material, and the second adhesive layer of the hot melt adhesive film is bonded to the aluminum plate. The fire-resistant core material includes, but is not limited to, A2-grade aluminum composite panel fire-resistant core material, and may further include extrudable A2-grade aluminum composite panel fire-resistant core material.

[0049] The raw materials used in the following specific embodiments and comparative examples are all commercially available conventional products.

[0050] Examples 1-5 Examples 1-5 provide methods for preparing hot melt adhesive films, including the following steps: (1) Take silane-grafted polyolefin elastomer, maleic anhydride-grafted polyethylene, ethylene-vinyl acetate copolymer, K resin (K resin is K resin 8036, Guangdong Zhonghe Chemical Plastics Co., Ltd.) and antioxidant (antioxidant is antioxidant B215) in proportion, mix them evenly and then granulate them by twin-screw extrusion to obtain the raw material of the first adhesive layer; wherein, the length-to-diameter ratio of the twin-screw extruder can be 40:1, the extrusion section temperature is 110~190℃, the die temperature is 185℃, and the screw speed is 300r / min.

[0051] (2) The first adhesive layer material, the core layer material (PE 7042) and the second adhesive layer material (VB550A, Guangzhou Lushan New Material Co., Ltd.) are subjected to multi-layer co-extrusion casting, cooling and winding to obtain a hot melt adhesive film; the mass ratio of the first adhesive layer, the core layer and the second adhesive layer of the hot melt adhesive film is 4:2:4; the total thickness of the hot melt adhesive film is 80μm; wherein, in the multi-layer co-extrusion casting, the extrusion section temperature of the first adhesive layer is 150~180℃, the extrusion section temperature of the core layer is 150~180℃, the extrusion section temperature of the second adhesive layer is 140~170℃, and the die head temperature is 170℃.

[0052] In Examples 1 to 5, the composition and information of the raw materials of the first adhesive layer in step (1) are shown in Table 1 and Table 2, respectively.

[0053] Table 1. Raw material composition (parts by weight) of the first adhesive layer in Examples 1-5

[0054] Table 2. Partial material information of the first adhesive layer in Examples 1-5

[0055] Example 6 group This embodiment group provides a method for preparing hot melt adhesive film with reference to Example 3. The only difference is that in step (1), the amounts of silane-grafted polyolefin elastomer and maleic anhydride-grafted polyethylene are different. The specific differences are as follows: Example 6a: The amount of silane-grafted polyolefin elastomer used was 25 parts, and the amount of maleic anhydride-grafted polyethylene used was 10 parts. Example 6b: The amount of silane-grafted polyolefin elastomer used was 14 parts, and the amount of maleic anhydride-grafted polyethylene used was 21 parts. Example 6c: The amount of silane-grafted polyolefin elastomer used was 10 parts, and the amount of maleic anhydride-grafted polyethylene used was 25 parts.

[0056] Example 7 group This embodiment group provides a method for preparing hot melt adhesive film with reference to Example 3. The only difference is that the amounts of ethylene-vinyl acetate copolymer and K resin are different in step (1). The specific differences are as follows: Example 7a: 60 parts by weight of ethylene-vinyl acetate copolymer, 5 parts by weight of K resin; Example 7b: 45 parts by weight of ethylene-vinyl acetate copolymer, 20 parts by weight of K resin; Example 7c: 65 parts by weight of ethylene-vinyl acetate copolymer, 0 parts by weight of K resin; Example 7d: 40 parts by weight of ethylene-vinyl acetate copolymer, 25 parts by weight of K resin.

[0057] Comparative Example 1 Comparative Example 1 provides a method for preparing a hot melt adhesive film, with the only difference being that in step (1), an equal weight of polyolefin elastomer is used instead of the silane-grafted polyolefin elastomer in Example 1; the density of the polyolefin elastomer in this comparative example is 0.877 g / cm³. 3 The melt flow index at 190℃ / 2.16kg was 14g / 10min.

[0058] Comparative Example 2 Comparative Example 2 provides a method for preparing a hot melt adhesive film with reference to Example 3. The only difference is that in step (1), an equal weight of polyethylene is used to replace the maleic anhydride-grafted polyethylene in Example 3. The polyethylene in this comparative example is LDPE 2420H (Yangtze BASF).

[0059] Comparative Example 3 Comparative Example 3 provides a method for preparing a hot melt adhesive film, with the only difference being that in step (1), polyethylene of equal weight is used instead of the ethylene-vinyl acetate copolymer in Example 3; the polyethylene in this comparative example is LDPE2420H (Yangzi BASF).

[0060] Comparative Example 4 Comparative Example 4 provides a method for preparing a hot melt adhesive film with reference to Example 3, the only difference being that in step (1), an equal weight of SIS 1106P (Baling Petrochemical) is used to replace the K resin in Example 3.

[0061] Experimental Example The performance of the hot melt adhesive films prepared in each embodiment and comparative example was tested. The hot melt adhesive films of each embodiment were hot-pressed in the following order: A2 fire-retardant core material / hot melt adhesive film / aluminum sheet (the first adhesive layer of the hot melt adhesive film was bonded to the A2 fire-retardant core material sheet, and the second adhesive layer was bonded to the metal aluminum sheet; wherein, the A2 fire-retardant core material sheet was a conventional commercially available A2 fire-retardant core material with a calorific value between 2.6 and 2.9 MJ / kg) for 5 seconds on a flat vulcanizing machine at 150°C and 0.6 MPa. After cooling, the samples were tested.

[0062] Peel strength: The test was conducted according to the 180° peel strength test method in GB / T 2792. The peel strength between the hot melt adhesive film and the core material after the sample was placed at room temperature (23±2℃) for 30 min was tested, as well as the peel strength and the interface failure type after the sample was immersed in water at room temperature (23±2℃) for 24 h. The test results are shown in Table 3.

[0063] Table 3 Performance test results of different hot melt adhesive films

[0064] The test results above show that the adhesive resin of the present invention uses silane-grafted polyolefin elastomer, maleic anhydride-grafted polyethylene and K resin to synergistically modify the ethylene-vinyl acetate copolymer, which not only significantly improves the peel strength of the adhesive resin to the fireproof core material of A2 grade aluminum composite panel, but also has a high peel strength retention rate after soaking in water.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adhesive resin for the fire-resistant core material of A2 grade aluminum composite panels, characterized in that, Includes the following components by weight: The composition includes 10-30 parts of silane-grafted polyolefin elastomer, 10-30 parts of maleic anhydride-grafted polyethylene, 45-60 parts of ethylene-vinyl acetate copolymer, 5-20 parts of K resin, and 0.1-0.5 parts of antioxidant. Furthermore, the mass ratio of the silane-grafted polyolefin elastomer to the maleic anhydride-grafted polyethylene is 1:(0.6~1.5).

2. The adhesive resin for the fire-resistant core material of A2 grade aluminum composite panel according to claim 1, characterized in that, The silane-grafted polyolefin elastomer includes at least one of vinyltrimethoxysilane-grafted polyolefin elastomer and vinyltriethoxysilane-grafted polyolefin elastomer.

3. The adhesive resin for the fire-resistant core material of A2 grade aluminum composite panel according to claim 1, characterized in that, The silane-grafted polyolefin elastomer has at least one of the following characteristics: (1) The grafting rate of the silane-grafted polyolefin elastomer is 2%~6%; (2) The melt flow index of the silane-grafted polyolefin elastomer at 190°C and 2.16 kg is 3~20 g / 10 min.

4. The adhesive resin for the fire-resistant core material of A2-grade aluminum composite panels according to claim 1, characterized in that, The maleic anhydride-grafted polyethylene has at least one of the following characteristics: (1) The grafting rate of the maleic anhydride-grafted polyethylene is greater than 0.2%; (2) The melt flow index of the maleic anhydride grafted polyethylene at 190℃ and 2.16kg is 0.5~6g / 10min.

5. The adhesive resin for the fire-resistant core material of A2 grade aluminum composite panel according to claim 1, characterized in that, The ethylene-vinyl acetate copolymer has at least one of the following characteristics: (1) The VA content in the ethylene-vinyl acetate copolymer is 8%~25%; (2) The melt flow index of the ethylene-vinyl acetate copolymer at 190°C and 2.16 kg is 1~15 g / 10 min.

6. The adhesive resin for the fire-resistant core material of A2 grade aluminum composite panel according to claim 1, characterized in that, The melt flow index of the K resin at 200℃ and 5kg is 1~15g / 10min.

7. A hot melt adhesive film, characterized in that, It includes a first adhesive layer, a core layer, and a second adhesive layer stacked together; the first adhesive layer includes the adhesive resin for the fire-resistant core material of A2 grade aluminum composite panel as described in any one of claims 1 to 6; The core layer is a polyethylene layer; The second adhesive layer comprises maleic anhydride-grafted polyethylene; the melt flow index of the maleic anhydride-grafted polyethylene at 190°C and 2.16 kg is 1–15 g / 10 min.

8. The hot melt adhesive film according to claim 7, characterized in that, The mass ratio of the first adhesive layer, the core layer and the second adhesive layer is (3~5):(2~3):(2~3).

9. An aluminum composite panel, characterized in that, Includes the hot melt adhesive film as described in claim 7 or 8.

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