Hot melt adhesive with easy heat dissipation and preparation method thereof

Abstract

The present application discloses a heat-dissipating hot melt adhesive and its preparation method, relating to the field of hot melt adhesives. The heat-dissipating hot melt adhesive comprises 100 parts by weight of a modified EVA resin, 10-15 parts by weight of a tackifier, 4.5-5.5 parts by weight of a viscosity modifier, 20-25 parts by weight of an isocyanate-silane coupling agent-modified thermally conductive filler, and 0.5-1 parts by weight of an antioxidant. The modified EVA resin is an EVA resin graft-modified with maleimide and vinylmethylphenyl silicone oil. The present application obtains a hot melt adhesive with good thermal conductivity, high bonding strength with the base material, good heat aging resistance, and good low-temperature resistance through the coordination of the various raw materials.

Description

Technical Field

[0001] The present application relates to the field of hot melt adhesives, and in particular to a hot melt adhesive that is easy to dissipate heat and a preparation method thereof. Background Art

[0002] EVA hot melt adhesive is an adhesive composed of EVA resin, tackifiers, antioxidants, and other ingredients. When heated to a certain temperature, it changes from a solid state to a liquid state, allowing for bonding between substrate materials. However, traditional EVA hot melt adhesive has low thermal conductivity. When used to bond electronic components, if the electronic components generate heat during operation, this heat is difficult to dissipate quickly through the EVA hot melt adhesive, and thus accumulates within the adhesive layer, which can adversely affect its durability.

[0003] In addition, traditional EVA hot melt adhesive has poor heat aging resistance. Improving the heat aging resistance of EVA hot melt adhesive is also beneficial to improving the durability of the adhesive layer. However, it should be noted that while improving the heat aging resistance of EVA hot melt adhesive, the low-temperature flexibility of EVA hot melt adhesive cannot be affected, otherwise the low-temperature resistance of EVA hot melt adhesive will be easily reduced. Summary of the Invention

[0004] The present application provides a hot melt adhesive that is easy to dissipate heat and a preparation method thereof. The hot melt adhesive has the characteristics of good thermal conductivity, high bonding strength with the base material, good heat aging resistance and good low temperature resistance, which is beneficial to improving the durability of the adhesive layer.

[0005] In the first aspect, the present application provides a heat-dissipating hot melt adhesive that adopts the following technical solution:

[0006] A heat-dissipating hot-melt adhesive comprises 100 parts by weight of a modified EVA resin, 10-15 parts by weight of a tackifier, 4.5-5.5 parts by weight of a viscosity modifier, 20-25 parts by weight of an isocyanate-silane coupling agent-modified thermally conductive filler, and 0.5-1 part by weight of an antioxidant. The modified EVA resin is an EVA resin grafted with maleimide and vinylmethylphenyl silicone oil.

[0007] In the heat-dissipating hot melt adhesive of the present application, EVA resin grafted with maleimide and vinylmethylphenyl silicone oil is used as the base material. Compared with directly using EVA resin as the base material, the EVA resin grafted with maleimide and vinylmethylphenyl silicone oil has excellent heat aging resistance. In addition, the introduction of vinylmethylphenyl silicone oil can make the modified EVA resin have both heat aging resistance and good flexibility, thereby reducing the impact of low temperature environment on the hot melt adhesive.

[0008] Secondly, the thermal conductive filler in this application is added in the form of an isocyanate silane coupling agent modified thermal conductive filler. The isocyanate silane coupling agent modified thermal conductive filler has good dispersibility in the EVA resin grafted modified with maleimide and vinylmethylphenyl silicone oil, which is conducive to building a complete thermal conductive network and facilitating the rapid extraction of heat.

[0009] In addition, the main function of the tackifier is to improve the bonding strength between the hot melt adhesive and the base material. The addition of the viscosity modifier can help improve the dispersibility of the isocyanate silane coupling agent modified thermal conductive filler in the EVA resin grafted with maleimide and vinylmethylphenyl silicone oil. The role of the antioxidant is to prevent the thermal degradation of the modified EVA resin during the melt extrusion process and improve the heat aging resistance of the hot melt adhesive.

[0010] In some specific embodiments, the raw materials for preparing the EVA resin grafted modified with maleimide and vinylmethylphenyl silicone oil include maleimide, vinylmethylphenyl silicone oil, EVA resin, a thermal stabilizer and an initiator, and the weight ratio of the maleimide, vinylmethylphenyl silicone oil, EVA resin, a thermal stabilizer and an initiator is (4.2-4.8): (2.0-2.5): 100: (0.8-1.2): (0.1-0.2).

[0011] In the present application, the weight ratio of maleimide, vinylmethylphenyl silicone oil, EVA resin, thermal stabilizer and initiator is preferably in the range of (4.2-4.8): (2.0-2.5): 100: (0.8-1.2): (0.1-0.2), which is conducive to obtaining EVA resin grafted with maleimide and vinylmethylphenyl silicone oil with good heat aging resistance. At the same time, the melt viscosity of the modified EVA resin will not be too viscous, which is conducive to the uniform dispersion of the thermal conductive filler modified by the isocyanate silane coupling agent and promotes the formation of a complete thermal conductive network.

[0012] In some specific embodiments, the vinylmethylphenyl silicone oil is vinyl-terminated and hydroxy-terminated methylphenyl silicone oil.

[0013] In the present application, the vinyl methyl phenyl silicone oil adopts the vinyl-terminated hydroxyl-terminated methyl phenyl silicone oil, which can further improve the wettability of the hot melt adhesive to the base material, and is conducive to further improving the bonding strength of the hot melt adhesive to the base material.

[0014] In some specific embodiments, in the vinyl-terminated hydroxy-terminated methylphenyl silicone oil, the degree of polymerization of the diphenylsiloxane segment is 8-12.

[0015] In the modified EVA resin, the degree of polymerization of the diphenylsiloxane chain segment in the vinyl-terminated hydroxy-terminated methylphenyl silicone oil is preferably 8-12, which is conducive to obtaining a modified EVA resin with good low-temperature flexibility. At the same time, the melt viscosity of the modified EVA resin will not be too viscous, which is conducive to the uniform dispersion of the isocyanate-based silane coupling agent-modified thermal conductive filler and the improvement of the thermal conductivity of the hot melt adhesive.

[0016] In some specific embodiments, the heat stabilizer is an organotin stabilizer, and the initiator is at least one of benzoyl peroxide, cumene hydroperoxide, and tert-butyl peroxyvalerate.

[0017] In some specific embodiments, the preparation method of the modified EVA resin is as follows:

[0018] Maleimide, vinylmethylphenyl silicone oil, EVA resin, heat stabilizer and initiator are uniformly mixed to obtain a premix;

[0019] The premix is ​​melt-extruded at 140-150° C. and crushed to obtain an EVA resin graft-modified with maleimide and vinylmethylphenyl silicone oil.

[0020] The present application adopts the above method to graft maleimide and vinylmethylphenyl silicone oil onto EVA resin, thereby improving the heat aging resistance of EVA resin.

[0021] In some specific embodiments, the preparation method of the isocyanate silane coupling agent modified thermal conductive filler comprises the following steps:

[0022] Disperse the isocyanate silane coupling agent in isopropyl alcohol, adjust the pH to 3-4, then add the thermal conductive filler, heat to 30-40°C and stir for 1-2 hours, then centrifuge, wash and dry to obtain the isocyanate silane coupling agent modified thermal conductive filler.

[0023] The present application adopts the above method to prepare isocyanate silane coupling agent modified thermal conductive filler, which can graft the isocyanate silane coupling agent on the surface of the thermal conductive filler and improve the dispersibility of the isocyanate silane coupling agent modified thermal conductive filler in the modified EVA resin.

[0024] In some specific embodiments, the thermally conductive filler is aluminum nitride.

[0025] In the present application, the thermally conductive filler is preferably aluminum nitride, which has good thermal conductivity, insulation and acid and alkali resistance.

[0026] In some specific embodiments, the tackifier is at least one of rosin resin and terpene resin, and the viscosity modifier is at least one of paraffin wax, polyethylene wax, and polypropylene wax.

[0027] In a second aspect, the present application provides a method for preparing a hot melt adhesive that dissipates heat using the following technical solutions:

[0028] A method for preparing a hot melt adhesive with easy heat dissipation comprises the following steps:

[0029] The modified EVA resin, tackifier, viscosity modifier, silane coupling agent modified thermal conductive filler and antioxidant are uniformly mixed according to the proportion, melt-extruded at 160-170°C, cooled and granulated to obtain a heat-dissipating hot melt adhesive.

[0030] The above method is used in the present application to prepare hot melt adhesive, which is beneficial to the uniform dispersion and mixing of the raw materials, and can obtain a stable hot melt adhesive that is easy to dissipate heat.

[0031] In summary, this application has at least the following beneficial technical effects:

[0032] (1) This application uses EVA resin modified by grafting maleimide and vinylmethylphenyl silicone oil with good heat aging resistance as the base material, and adds a specific ratio of thickener, viscosity modifier, isocyanate silane coupling agent modified thermal conductive filler and antioxidant. The isocyanate silane coupling agent modified thermal conductive filler has good dispersibility in the EVA resin modified by grafting maleimide and vinylmethylphenyl silicone oil, which is conducive to building a complete thermal conductive network and facilitating the rapid heat extraction. The addition of viscosity modifier can help improve the dispersibility of the isocyanate silane coupling agent modified thermal conductive filler and improve the heat dissipation performance of the hot melt adhesive. The role of the thickener is mainly to improve the bonding strength between the hot melt adhesive and the base material. The role of the antioxidant is to prevent thermal degradation of the modified EVA resin during the melt extrusion process and help improve the heat aging resistance of the hot melt adhesive. That is, this application obtains a hot melt adhesive with good thermal conductivity, high bonding strength with the base material, good heat aging resistance and good low temperature resistance through the coordination of various raw materials.

[0033] (2) In the present application, vinyl methyl phenyl silicone oil adopts vinyl-terminated hydroxy-terminated methyl phenyl silicone oil, which can further improve the wettability of the hot melt adhesive to the base material, and is conducive to further improving the bonding strength of the hot melt adhesive to the base material. DETAILED DESCRIPTION

[0034] The present application is further described below in conjunction with specific experiments.

[0035] Preparation Example

[0036] [Preparation Example 1]

[0037] A modified EVA resin comprises 4.2 kg of maleimide, 2.5 kg of vinyl methyl phenyl silicone oil, 100 kg of EVA resin (Mitsui, Japan, EV210ETR), 0.8 kg of a heat stabilizer (octyltin), and 0.1 kg of an initiator (benzoyl peroxide). The structural formula of the vinyl methyl phenyl silicone oil is CH2=CH(CH3)2SiO[Si(C6H5)2O]8Si(CH3)3.

[0038] Wherein, the preparation method of modified EVA resin comprises the following steps:

[0039] Maleimide, vinylmethylphenyl silicone oil, EVA resin, heat stabilizer and initiator are uniformly mixed to obtain a premix;

[0040] The premix is ​​melt-extruded at 145° C. and crushed to obtain an EVA resin graft-modified with maleimide and vinylmethylphenyl silicone oil.

[0041] [Preparation Example 2]

[0042] A modified EVA resin comprises 4.8 kg maleimide, 2.0 kg vinyl methyl phenyl silicone oil, 100 kg EVA resin (Mitsui, Japan, EV210ETR), 1.2 kg thermal stabilizer (octyltin) and 0.2 kg initiator (benzoyl peroxide), wherein the structural formula of the vinyl methyl phenyl silicone oil is CH2=CH(CH3)2SiO[Si(C6H5)2O]8Si(CH3)3.

[0043] Wherein, the preparation method of modified EVA resin comprises the following steps:

[0044] Maleimide, vinylmethylphenyl silicone oil, EVA resin, heat stabilizer and initiator are uniformly mixed to obtain a premix;

[0045] The premix is ​​melt-extruded at 145° C. and crushed to obtain an EVA resin graft-modified with maleimide and vinylmethylphenyl silicone oil.

[0046] [Preparation Example 3]

[0047] A modified EVA resin comprises 5.4 kg of maleimide, 6.2 kg of vinyl methyl phenyl silicone oil, 100 kg of EVA resin (Mitsui, Japan, EV210ETR), 1.2 kg of a heat stabilizer (octyltin) and 0.2 kg of an initiator (benzoyl peroxide), wherein the structural formula of the vinyl methyl phenyl silicone oil is CH2=CH(CH3)2SiO[Si(C6H5)2O]8Si(CH3)3.

[0048] Wherein, the preparation method of modified EVA resin comprises the following steps:

[0049] Maleimide, vinylmethylphenyl silicone oil, EVA resin, heat stabilizer and initiator are uniformly mixed to obtain a premix;

[0050] The premix is ​​melt-extruded at 145° C. and crushed to obtain an EVA resin graft-modified with maleimide and vinylmethylphenyl silicone oil.

[0051] [Preparation Example 4]

[0052] A modified EVA resin differs from [Preparation Example 1] in that the vinyl methyl phenyl silicone oil is different.

[0053] In this preparation example, the structural formula of vinylmethylphenyl silicone oil is CH2=CH(CH3)2SiO[Si(C6H5)2O]8Si(CH3)2OH.

[0054] Preparation Example 5

[0055] A modified EVA resin differs from [Preparation Example 1] in that the vinyl methyl phenyl silicone oil is different.

[0056] In this preparation example, vinyl methyl phenyl silicone oil adopts vinyl-terminated hydroxyl-terminated methyl phenyl silicone oil, and the structural formula of vinyl-terminated hydroxyl-terminated methyl phenyl silicone oil is CH2=CH(CH3)2SiO[Si(C6H5)2O] 12 Si(CH3)2OH.

[0057] Preparation Example 6

[0058] A modified EVA resin differs from [Preparation Example 1] in that the vinyl methyl phenyl silicone oil is different.

[0059] In this preparation example, vinyl methyl phenyl silicone oil adopts vinyl-terminated hydroxyl-terminated methyl phenyl silicone oil, and the structural formula of vinyl-terminated hydroxyl-terminated methyl phenyl silicone oil is CH2=CH(CH3)2SiO[Si(C6H5)2O] 20 Si(CH3)2OH.

[0060] Comparative Preparation Example

[0061] [Comparative Preparation Example 1]

[0062] A modified EVA resin, which differs from [Preparation Example 1] in that maleimide is replaced by an equal amount of vinylmethylphenyl silicone oil.

[0063] [Comparative Preparation Example 2]

[0064] A modified EVA resin, which differs from [Preparation Example 1] in that an equal amount of maleimide is used instead of vinylmethylphenyl silicone oil.

[0065] [Comparative Preparation Example 3]

[0066] A modified EVA resin is different from [Preparation Example 1] in that an equal amount of 2-vinyl-1-benzofuran is used instead of vinylmethylphenyl silicone oil.

[0067] Example

[0068] [Example 1]

[0069] A hot melt adhesive that is easy to dissipate heat, comprising 100 kg of modified EVA resin prepared in [Preparation Example 1], 10 kg of a tackifier (145 rosin pentaerythritol ester), 4.5 kg of a viscosity modifier (polyethylene wax), 20 kg of an isocyanate silane coupling agent-modified thermal conductive filler (isocyanate silane coupling agent-modified aluminum nitride), and 0.5 kg of an antioxidant (antioxidant 1010).

[0070] The preparation method of the hot melt adhesive with easy heat dissipation comprises the following steps:

[0071] 3-isocyanatepropyltrimethoxysilane is dispersed in isopropyl alcohol, the pH is adjusted to 3-4, and then aluminum nitride is added. The temperature is raised to 40°C and stirred for 1 hour, and then centrifuged, washed, and dried to obtain an isocyanate silane coupling agent modified thermal conductive filler. The modified EVA resin, tackifier, viscosity modifier, silane coupling agent modified thermal conductive filler, and antioxidant are uniformly mixed according to the ratio, melt-extruded at 160°C, cooled, and granulated to obtain a heat-dissipating hot melt adhesive.

[0072] [Example 2]

[0073] A hot melt adhesive that is easy to dissipate heat, comprising 100 kg of modified EVA resin prepared in [Preparation Example 1], 15 kg of a tackifier (145 rosin pentaerythritol ester), 5.5 kg of a viscosity modifier (polyethylene wax), 25 kg of an isocyanate silane coupling agent-modified thermal conductive filler (isocyanate silane coupling agent-modified aluminum nitride), and 1 kg of an antioxidant (antioxidant 1010).

[0074] The preparation method of the hot melt adhesive with easy heat dissipation comprises the following steps:

[0075] 3-isocyanatepropyltrimethoxysilane is dispersed in isopropyl alcohol, the pH is adjusted to 3-4, and then aluminum nitride is added. The temperature is raised to 30°C and stirred for 2 hours, and then centrifuged, washed, and dried to obtain an isocyanate silane coupling agent modified thermal conductive filler. The modified EVA resin, tackifier, viscosity modifier, silane coupling agent modified thermal conductive filler, and antioxidant are uniformly mixed according to the ratio, melt-extruded at 170°C, cooled, and granulated to obtain a heat-dissipating hot melt adhesive.

[0076] [Example 3]

[0077] A hot melt adhesive that is easy to dissipate heat, which differs from [Example 1] in that:

[0078] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Preparation Example 2].

[0079] [Example 4]

[0080] A hot melt adhesive that is easy to dissipate heat, which differs from [Example 1] in that:

[0081] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Preparation Example 3].

[0082] [Example 5]

[0083] A hot melt adhesive that is easy to dissipate heat, which differs from [Example 1] in that:

[0084] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Preparation Example 4].

[0085] [Example 6]

[0086] A hot melt adhesive that is easy to dissipate heat, which differs from [Example 1] in that:

[0087] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Preparation Example 5].

[0088] [Example 7]

[0089] A hot melt adhesive that is easy to dissipate heat, which differs from [Example 1] in that:

[0090] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Preparation Example 6].

[0091] Comparative Example

[0092] [Comparative Example 1]

[0093] A hot melt adhesive, which differs from [Example 1] in that:

[0094] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Comparative Preparation Example 1].

[0095] [Comparative Example 2]

[0096] A hot melt adhesive, which differs from [Example 1] in that:

[0097] In this embodiment, the modified EVA resin is the modified EVA resin prepared in [Comparative Preparation Example 2].

[0098] [Comparative Example 3]

[0099] A hot melt adhesive, which differs from [Example 1] in that:

[0100] In this embodiment, the modified EVA resin used is the modified EVA resin prepared in [Comparative Preparation Example 3].

[0101] Performance testing

[0102] Test 1: Thermal Conductivity: The hot melt adhesives in the examples and comparative examples were made into hot melt adhesive sheets, and the thermal conductivity of the different hot melt adhesive sheets was tested according to ISO 22007-2.

[0103] Test 2: Shear Strength: The hot-melt adhesives from each example and comparative example were melted and applied between two PE sheets. After pressing for 5 minutes, the pressure was removed and the sheets were allowed to stand for 12 hours to produce test samples. Shear strength of the test samples was tested in accordance with GB / T 7124-2008, and the results are recorded in the table below.

[0104] Test 3: Heat aging resistance: The test sample prepared in Test 2 was placed in an environment with a temperature of 85°C and a humidity of 85% for 1500 hours. After being taken out and cooled to room temperature, the shear strength of the sample was tested in accordance with GB / T 7124-2008.

[0105] Test 4, Low-temperature flexibility: The hot melt adhesives in each embodiment and comparative example were made into hot melt adhesive sheets, each having a size of 75 mm * 10 mm * 1.25 mm. 40 hot melt adhesive sheets corresponding to each embodiment and comparative example were randomly selected and evenly divided into two groups of 20 each. One group was conditioned at 5°C for 24 hours, and the other group was conditioned at -20°C for 24 hours. The minimum core shaft diameter that different hot melt adhesive sheets could withstand was then tested with reference to HG / T4222-2011.

[0106] Table 1

[0107]

[0108] According to Example 1 and Comparative Examples 1-2 and combined with the test data in Table 1, it can be seen that: compared with Example 1, the thermal conductivity of the hot melt adhesive in Comparative Examples 1 and Comparative Example 2 is significantly reduced, indicating that the simultaneous use of maleimide and vinylmethylphenyl silicone oil to modify the EVA resin is more conducive to the isocyanate silane coupling agent to modify the thermally conductive filler to form a complete thermal conductive network, thereby improving the thermal conductivity efficiency. Secondly, the shear strength and heat aging resistance of the hot melt adhesive in Comparative Example 1 decreased, and the heat aging resistance of the hot melt adhesive in Comparative Example 2 also decreased, indicating that the simultaneous use of maleimide and vinylmethylphenyl silicone oil to modify the EVA resin is more conducive to improving the heat aging resistance of the hot melt adhesive. In addition, the low-temperature deflection of the hot melt adhesive in Comparative Example 2 at -20°C is much lower than the low-temperature deflection of the hot melt adhesive in Example 1, indicating that when maleimide alone is used to modify the EVA resin, the low-temperature resistance of the hot melt adhesive decreases.

[0109] According to Example 1 and Comparative Example 3 and combined with the test data in Table 1, it can be seen that when 2-vinyl-1-benzofuran is used instead of vinylmethylphenyl silicone oil to modify the EVA resin with maleimide, the low-temperature deflection of the hot melt adhesive is much lower than the low-temperature deflection of the hot melt adhesive in Example 1, indicating that the simultaneous use of maleimide and vinylmethylphenyl silicone oil to modify the EVA resin is also beneficial to improving the low-temperature deflection of the hot melt adhesive.

[0110] According to Examples 1 and 3-4 and in combination with the test data in Table 1, it can be seen that in the modified EVA resin of Example 4, the weight ratio of maleimide, vinylmethylphenyl silicone oil, EVA resin, thermal stabilizer and initiator is not in the range of (4.2-4.8): (2.0-2.5): 100: (0.8-1.2): (0.1-0.2), and the thermal conductivity of the hot melt adhesive is reduced, indicating that the weight ratio of maleimide, vinylmethylphenyl silicone oil, EVA resin, thermal stabilizer and initiator is preferably in the range of (4.2-4.8): (2.0-2.5): 100: (0.8-1.2): (0.1-0.2), which is conducive to the formation of a complete thermal conductive network by the isocyanate silane coupling agent-modified thermal conductive filler.

[0111] According to Example 1 and Example 5 and combined with the test data in Table 1, it can be seen that the shear strength of the hot melt adhesive in Example 5 before heat treatment is greater than that in Example 1, indicating that the use of vinyl-terminated and hydroxy-terminated vinyl methylphenyl silicone oil can further improve the wettability of the hot melt adhesive to the base material, which is beneficial to further improve the bonding strength of the hot melt adhesive to the base material.

[0112] According to Examples 5-7 and the test data in Table 1, it can be seen that in the modified EVA resin, the degree of polymerization of the diphenylsiloxane segment in the vinyl-terminated hydroxy-terminated methylphenyl silicone oil is preferably 8-12, which is conducive to obtaining a modified EVA resin with good low-temperature flexibility. At the same time, the melt viscosity of the modified EVA resin will not be too viscous, which is conducive to the uniform dispersion of the isocyanate-based silane coupling agent-modified thermal conductive filler and improves the thermal conductivity of the hot melt adhesive.

[0113] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A hot melt adhesive with easy heat dissipation, characterized by: The invention comprises 100 parts by weight of modified EVA resin, 10-15 parts by weight of tackifier, 4.5-5.5 parts by weight of viscosity modifier, 20-25 parts by weight of isocyanate silane coupling agent modified thermal conductive filler and 0.5-1 part by weight of antioxidant. The modified EVA resin is EVA resin grafted with maleimide and vinylmethylphenyl silicone oil.

2. The heat-dissipating hot melt adhesive according to claim 1, characterized in that: The raw materials for preparing the maleimide and vinylmethylphenyl silicone oil grafted modified EVA resin include maleimide, vinylmethylphenyl silicone oil, EVA resin, a heat stabilizer and an initiator. The weight ratio of the maleimide, vinylmethylphenyl silicone oil, EVA resin, a heat stabilizer and an initiator is (4.2-4.8): (2.0-2.5): 100: (0.8-1.2): (0.1-0.2).

3. The heat-dissipating hot melt adhesive according to claim 2, characterized in that: The vinyl methyl phenyl silicone oil is vinyl-terminated and hydroxy-terminated methyl phenyl silicone oil.

4. The heat-dissipating hot melt adhesive according to claim 3, characterized in that: In the vinyl-terminated hydroxy-terminated methylphenyl silicone oil, the polymerization degree of the diphenylsiloxane chain segment is 8-12.

5. The heat-dissipating hot melt adhesive according to claim 2, characterized in that: The heat stabilizer is an organic tin stabilizer, and the initiator is at least one of benzoyl peroxide, cumene hydroperoxide, and tert-butyl peroxyvalerate.

6. The heat-dissipating hot melt adhesive according to any one of claims 2 to 5, characterized in that: The preparation method of the modified EVA resin comprises the following steps: uniformly mixing maleimide, vinylmethylphenyl silicone oil, EVA resin, a heat stabilizer and an initiator to obtain a premix; and melt-extruding the premix at 140-150° C. and crushing the premix to obtain an EVA resin grafted with maleimide and vinylmethylphenyl silicone oil.

7. The heat-dissipating hot melt adhesive according to any one of claims 1 to 5, characterized in that: The preparation method of the isocyanate silane coupling agent modified thermal conductive filler includes the following steps: dispersing the isocyanate silane coupling agent in isopropyl alcohol, adjusting the pH to 3-4, then adding the thermal conductive filler, heating to 30-40°C and stirring for 1-2 hours, and then centrifuging, washing, and drying to obtain the isocyanate silane coupling agent modified thermal conductive filler.

8. The heat-dissipating hot melt adhesive according to claim 7, characterized in that: The thermal conductive filler is aluminum nitride.

9. The heat-dissipating hot melt adhesive according to any one of claims 1 to 5, characterized in that: The viscosity modifier is at least one of paraffin wax, polyethylene wax and polypropylene wax.

10. The method for preparing a hot melt adhesive with easy heat dissipation according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: uniformly mixing modified EVA resin, tackifier, viscosity modifier, isocyanate silane coupling agent modified thermal conductive filler and antioxidant according to a proportion, melt-extruding at 160-170°C, cooling and granulating to obtain a heat-dissipating hot melt adhesive.

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