Heat dissipation coating composition, preparation method thereof and application of heat dissipation coating composition in battery protection plate

Abstract

The invention relates to a heat dissipation coating composition, a preparation method thereof and application of the heat dissipation coating composition in a battery protection plate, and belongs to the technical field of new energy heat dissipation coatings. According to the preparation method, methyl methacrylate, 2-vinylpyridine, methacrylamide, dipropylene glycol diacrylate, azodiisobutyronitrile and tetradecane are taken as raw materials, a coating dispersion liquid is prepared firstly, then hydroxylated graphene is subjected to polymerization coating by utilizing the coating dispersion liquid based on an in-situ polymerization method, a coating layer with amino and pyridine rings is constructed, and the coating layer with amino and pyridine rings is prepared. The preparation method comprises the following steps: coating a coating particle with amino boron nitride to obtain a coated particle, compounding the amino boron nitride onto the coated particle through addition of amino and epoxy groups by taking ethylene glycol diglycidyl ether containing double-terminal epoxy groups as a bridging agent to prepare a modified composite particle, and blending the modified composite particle with water-borne epoxy resin and other components to obtain the heat-dissipating coating composition. The coating has excellent heat dissipation performance, can still keep a good heat dissipation effect even after being heated and cooled for multiple times, and is suitable for being applied to the battery protection plate.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat dissipation coatings, and particularly relates to a heat dissipation coating composition, a preparation method thereof, and an application thereof in a battery guard plate. Background Art

[0002] A heat dissipation coating is a special coating used to improve the heat dissipation efficiency of an object surface and reduce the system temperature. Due to its excellent heat dissipation, anti-corrosion, waterproof and other properties, heat dissipation coatings are widely used in fields such as batteries, buildings, and automobiles. Among them, most heat dissipation coatings are mainly composed of components such as epoxy resin, inorganic particles, and curing agents. As a functional component, inorganic particles directly determine the level of heat dissipation performance of the heat dissipation coating. Although many existing technologies will form a complementary effect by compounding different types and particle sizes of inorganic particles, so that the heat dissipation coating can have a more excellent heat dissipation effect, these existing technologies still have certain drawbacks that limit their actual application effectiveness. This is because the simple compounding use of inorganic particles cannot greatly promote the heat dissipation effect to a large extent, and there is still room for further improvement. At the same time, during the application process of the heat dissipation coating (heat dissipation coating), especially when applied to a battery guard plate, it will inevitably face heating and cooling. Such continuous cyclic cycles are extremely likely to cause the migration of inorganic particles, resulting in precipitation, and thus the heat dissipation effect is severely reduced. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a heat dissipation coating composition, a preparation method thereof, and an application thereof in a battery guard plate. The present invention uses methyl methacrylate, 2-vinylpyridine, methacrylamide, dipropylene glycol diacrylate, azobisisobutyronitrile, and tetradecane as raw materials to first prepare a coating dispersion liquid, and then based on the in-situ polymerization method, uses the coating dispersion liquid to polymerize and coat hydroxylated graphene to construct a coating layer with amino groups and pyridine rings to obtain coated particles. Then, ethylene glycol diglycidyl ether containing double-terminal epoxy groups is used as a bridging agent, and through the addition of amino groups and epoxy groups, amino boron nitride is compounded onto the coated particles, thereby preparing modified composite particles. After being blended with components such as water-based epoxy resin, a heat dissipation coating composition is prepared, which has excellent heat dissipation performance. Even after multiple heating and cooling cycles, its coating can still maintain a good heat dissipation effect and is suitable for application in battery guard plates.

[0004] The purpose of the present invention can be achieved by the following technical solutions: A heat dissipation coating composition is prepared from 50 parts by weight of water-based epoxy resin, 3 - 4 parts by weight of modified composite particles, 10 - 12 parts by weight of curing agent, and 0.2 - 0.3 parts by weight of defoaming agent.

[0005] As a preferred technical solution of the present invention, the modified composite particles are prepared by the following steps: Step A: Mix 3 - 3.5 parts by weight of methyl methacrylate, 0.15 parts by weight of 2 - vinylpyridine, 0.2 parts by weight of methacrylamide, 0.9 - 1 part by weight of dipropylene glycol diacrylate, and 0.15 parts by weight of azobisisobutyronitrile under ultrasonic irradiation in the dark at room temperature for 5 - 10 min. Then add 60 - 70 parts by weight of tetradecane, and centrifuge to obtain a coated dispersion; Step B: Mix 10 parts by weight of hydroxylated graphene and 100 parts by weight of tetradecane under ultrasonic irradiation at room temperature for 15 - 30 min to obtain a particle dispersion; Step C: Under a nitrogen atmosphere, dropwise add 80 parts by weight of the coated dispersion to 100 parts by weight of the particle dispersion while stirring at 75 - 80 °C. After complete addition, continue stirring at a constant temperature for 2 - 3 h, filter, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 30 - 60 °C until constant weight to obtain coated particles; Step D: Add 8 - 10 parts by weight of ethanol, 4.5 - 5 parts by weight of the coated particles, and 1 part by weight of amino boron nitride to 100 parts by weight of deionized water, and then mix them under ultrasonic irradiation at room temperature for 10 - 15 min. Then, while stirring, dropwise add 0.7 parts by weight of ethylene glycol diglycidyl ether at 35 - 40 °C. After complete addition, continue stirring at a constant temperature for 1 - 2 h, filter, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 30 - 60 °C until constant weight, thus completing the preparation.

[0006] Further, the power of the ultrasonic irradiation in Step A is 300 - 400 W.

[0007] Further, the centrifugation in Step A means centrifuging at a rotational speed of 500 - 800 rpm for 5 min.

[0008] Further, the power of the ultrasonic irradiation in Step B is 300 - 400 W.

[0009] Further, the dropping rate in Step C is controlled at 1 - 2 s / drop.

[0010] Further, the amino boron nitride in Step D is prepared by the following steps: (1) Add 1 - 2 parts by weight of boron nitride to 100 parts by weight of an aqueous sodium hydroxide solution, and then stir and mix at 90 - 95 °C for 10 - 14 h. Filter, collect the filter residue, wash it with deionized water, and finally vacuum dry it at 50 - 80 °C until constant weight to obtain pretreated boron nitride; (2) Pre-treat the boron nitride, γ-aminopropyltrimethoxysilane, and ethanol aqueous solution in a mass ratio of 1:2 - 3:100 - 110, stir and mix at 60 - 70 °C for 8 - 10 h, filter, take the filter residue, wash it with deionized water, and finally dry it under vacuum at 50 - 80 °C until constant weight, then the preparation is completed.

[0011] Preferably, the concentration of the sodium hydroxide aqueous solution in step (1) is 3 - 5 mol / L.

[0012] Preferably, the mass fraction of the ethanol aqueous solution in step (2) is 95%.

[0013] Further, the power of the ultrasonic wave in step D is 300 - 400 W.

[0014] Further, the dropping rate in step D is controlled at 3 - 4 s / drop.

[0015] As a preferred technical solution of the present invention, the curing agent is diethylenetriamine.

[0016] As a preferred technical solution of the present invention, the defoaming agent is defoaming agent BYK - 028.

[0017] A preparation method of a heat - dissipating coating composition, the preparation method comprising the following steps: Stir and mix the water - based epoxy resin, modified composite particles, curing agent, and defoaming agent at 20 - 25 °C for 10 - 15 min, then the preparation is completed.

[0018] An application of a heat - dissipating coating composition in a battery guard plate, the application comprising the following steps: Coat the heat - dissipating coating composition on the outer surface of the battery guard plate, then cure it at 40 - 50 °C for 8 - 10 h, and naturally cool it to room temperature to form a coating with a thickness of 80 - 100 μm.

[0019] The beneficial effects of the present invention: (1) The present invention uses methyl methacrylate, 2 - vinylpyridine, methacrylamide, dipropylene glycol diacrylate, azobisisobutyronitrile, and tetradecane as raw materials. First, a coating dispersion liquid is prepared, and then based on the in - situ polymerization method, the coating dispersion liquid is used to polymerize and coat the hydroxylated graphene to construct a coating layer with amino groups and pyridine rings to obtain coated particles. Then, using ethylene glycol diglycidyl ether containing double - terminal epoxy groups as a bridging agent, through the addition of amino groups and epoxy groups, amino - functionalized boron nitride is compounded onto the coated particles, thereby preparing modified composite particles. After blending with components such as water - based epoxy resin, a heat - dissipating coating composition is prepared, which has excellent heat - dissipating performance. Even after multiple heating and cooling cycles, its coating can still maintain good heat - dissipating effects and is suitable for application in battery guard plates.

[0020] (2) Most of the heat dissipation is basically the result of the combined action of heat conduction, radiation and convection. Therefore, in the present invention, methyl methacrylate, 2-vinylpyridine, methacrylamide, dipropylene glycol diacrylate, azobisisobutyronitrile and tetradecane are used as raw materials to first prepare a coating dispersion liquid. Then, based on the in-situ polymerization method, the coating dispersion liquid is used to polymerize and coat hydroxylated graphene to construct a coating layer with amino groups and pyridine rings, obtaining coated particles. As a conjugated structure containing nitrogen atoms, a certain amount of surface coating of the pyridine ring can adjust the electron-phonon coupling effect, enabling the vibrational energy of hydroxylated graphene to be released more quickly in the form of radiation, improving the radiation efficiency and promoting the heat dissipation effect. However, too many pyridine rings will act counterproductively on the actual heat dissipation ability due to severe shielding and steric effects. As for the amino groups in the coating layer, they can achieve the composite of the coated particles and boron nitride amino under the bridging action of ethylene glycol diglycidyl ether at a certain temperature (a suitable temperature can efficiently promote the addition of amino groups, i.e., primary amines, and epoxy groups, inhibiting the occurrence of side reactions). The introduction of boron nitride amino can greatly improve the overall heat conduction effect, i.e., the thermal conductivity. Compared with the prior art where different inorganic particles are simply compounded and used, the modified composite particles of the present invention form a more complex morphology, which can not only better build a heat conduction network and promote the heat conduction effect, but also increase the contact area with air and enhance the convection effect. In addition, the present invention specifically selects to polymerize and coat hydroxylated graphene to ensure the coating effect. Because of its low surface activity, graphene cannot well construct a coating layer, and due to the large steric hindrance of the carboxyl groups on the surface of graphene oxide, the degree of binding with the coating layer is reduced.

[0021] (3) The amino groups remaining in the coating layer structure of the modified composite particles prepared in the present invention and / or on the surface structure of boron nitride amino can participate in the curing of the waterborne epoxy resin, so as to achieve the purpose of reducing migration. Description of the Drawings

[0022] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 It is a physical picture of the heat dissipation coating composition prepared in Example 1 of the present invention after being applied to the battery guard plate.

[0024] Figure 2 It is a physical picture of the heat dissipation coating composition prepared in Example 2 of the present invention after being applied to the battery guard plate. Detailed Embodiments

[0025] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will describe in detail the specific embodiments, structures, features and their effects of the present invention with reference to the accompanying drawings and preferred embodiments.

[0026] The waterborne epoxy resins in the examples and comparative examples were all purchased from Guangzhou Weichuang High-Tech Materials Technology Co., Ltd., with the model of waterborne epoxy resin emulsion 0947A-60W; the hydroxylated graphene was all purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., with the model of XF307; the boron nitride was all purchased from Shanghai Pantian Powder Materials Co., Ltd., with the model of PT-BN-100nm.

[0027] Example 1 A heat-dissipating coating composition is prepared from 50 parts by weight of waterborne epoxy resin, 3 parts by weight of modified composite particles, 10 parts by weight of curing agent and 0.2 parts by weight of defoamer.

[0028] The modified composite particles are prepared by the following steps: Step A: Mix 3 parts by weight of methyl methacrylate, 0.15 parts by weight of 2-vinylpyridine, 0.2 parts by weight of methacrylamide, 0.9 parts by weight of dipropylene glycol diacrylate and 0.15 parts by weight of azobisisobutyronitrile under ultrasonic irradiation in the dark at room temperature for 5 min, then add 60 parts by weight of tetradecane, and centrifuge to obtain a coated dispersion; Step B: Mix 10 parts by weight of hydroxylated graphene and 100 parts by weight of tetradecane under ultrasonic irradiation at room temperature for 15 min to obtain a particle dispersion; Step C: Dropwise add 80 parts by weight of the coated dispersion to 100 parts by weight of the particle dispersion while stirring at 75 °C in a nitrogen atmosphere. After complete addition, continue stirring at a constant temperature for 2 h, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 30 °C until constant weight to obtain coated particles; Step D: Add 8 parts by weight of ethanol, 4.5 parts by weight of the coated particles and 1 part by weight of amino boron nitride to 100 parts by weight of deionized water, then mix them under ultrasonic irradiation at room temperature for 10 min, and then dropwise add 0.7 parts by weight of ethylene glycol diglycidyl ether while stirring at 35 °C. After complete addition, continue stirring at a constant temperature for 1 h, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 30 °C until constant weight, thus completing the preparation.

[0029] The power of the ultrasonic irradiation in Step A is 300 W.

[0030] The centrifugation in Step A means centrifuging at a speed of 500 rpm for 5 min.

[0031] The power of the ultrasonic irradiation in Step B is 300 W.

[0032] The dropping rate in Step C is controlled at 1 drop / s.

[0033] The amino boron nitride described in step D is prepared through the following steps: (1) Add 1 part by weight of boron nitride to 100 parts by weight of an aqueous sodium hydroxide solution, then stir and mix at 90 °C for 10 h, filter, take the filter residue, wash it with deionized water, and finally vacuum dry at 50 °C until constant weight to obtain pretreated boron nitride; (2) Mix the pretreated boron nitride, γ-aminopropyltrimethoxysilane, and an aqueous ethanol solution in a mass ratio of 1:2:100, stir and mix at 60 °C for 8 h, filter, take the filter residue, wash it with deionized water, and finally vacuum dry at 50 °C until constant weight, thus completing the preparation.

[0034] The concentration of the aqueous sodium hydroxide solution described in step (1) is 3 mol / L.

[0035] The mass fraction of the aqueous ethanol solution described in step (2) is 95%.

[0036] The power of the ultrasonic wave described in step D is 300 W.

[0037] The dropping rate described in step D is controlled at 3 s / drop.

[0038] The curing agent is diethylenetriamine.

[0039] The defoaming agent is defoaming agent BYK-028.

[0040] A preparation method of a heat dissipation coating composition, the preparation method comprising the following steps: Mix an aqueous epoxy resin, modified composite particles, a curing agent, and a defoaming agent at 20 °C for 10 min, thus completing the preparation.

[0041] An application of a heat dissipation coating composition in a battery guard plate, the application comprising the following steps: Coat the heat dissipation coating composition on the outer surface of the battery guard plate, then cure at 40 °C for 8 h, and naturally cool to room temperature to form a coating with a thickness of 80 μm.

[0042] Example 2 A heat dissipation coating composition, the heat dissipation coating composition is prepared from 50 parts by weight of an aqueous epoxy resin, 4 parts by weight of modified composite particles, 12 parts by weight of a curing agent, and 0.3 parts by weight of a defoaming agent.

[0043] The modified composite particles are prepared through the following steps: Step A: Mix 3.5 parts by weight of methyl methacrylate, 0.15 parts by weight of 2-vinylpyridine, 0.2 parts by weight of methacrylamide, 1 part by weight of dipropylene glycol diacrylate, and 0.15 parts by weight of azobisisobutyronitrile under ultrasonic irradiation in the dark at room temperature for 10 min. Then add 70 parts by weight of tetradecane and centrifuge to obtain a coated dispersion; Step B: Mix 10 parts by weight of hydroxylated graphene and 100 parts by weight of tetradecane under ultrasonic irradiation at room temperature for 30 min to obtain a particle dispersion; Step C: While stirring, dropwise add 80 parts by weight of the coated dispersion to 100 parts by weight of the particle dispersion at 80 °C under a nitrogen atmosphere. After complete addition, continue stirring at a constant temperature for 3 h, filter, collect the residue, wash with deionized water, and finally dry under vacuum at 60 °C until a constant weight is obtained to obtain coated particles; Step D: Add 10 parts by weight of ethanol, 5 parts by weight of the coated particles, and 1 part by weight of amino boron nitride to 100 parts by weight of deionized water, then mix under ultrasonic irradiation at room temperature for 15 min. Then, while stirring, dropwise add 0.7 parts by weight of ethylene glycol diglycidyl ether at 40 °C. After complete addition, continue stirring at a constant temperature for 2 h, filter, collect the residue, wash with deionized water, and finally dry under vacuum at 60 °C until a constant weight is obtained, thus completing the preparation.

[0044] The ultrasonic power in Step A is 400 W.

[0045] The centrifugation in Step A refers to centrifuging at a speed of 800 rpm for 5 min.

[0046] The ultrasonic power in Step B is 400 W.

[0047] The dropping rate in Step C is controlled at 2 s / drop.

[0048] The amino boron nitride in Step D is prepared through the following steps: (1) Add 2 parts by weight of boron nitride to 100 parts by weight of an aqueous sodium hydroxide solution, then mix under stirring at 95 °C for 14 h, filter, collect the residue, wash with deionized water, and finally dry under vacuum at 80 °C until a constant weight is obtained to obtain pretreated boron nitride; (2) Mix the pretreated boron nitride, γ-aminopropyltrimethoxysilane, and an aqueous ethanol solution at a mass ratio of 1:3:110 under stirring at 70 °C for 10 h, filter, collect the residue, wash with deionized water, and finally dry under vacuum at 80 °C until a constant weight is obtained, thus completing the preparation.

[0049] The concentration of the aqueous sodium hydroxide solution in Step (1) is 5 mol / L.

[0050] The mass fraction of the aqueous ethanol solution in Step (2) is 95%.

[0051] The power of the ultrasonic wave described in step D is 400 W.

[0052] The dropping rate described in step D is controlled at 4 s / drop.

[0053] The curing agent is diethylenetriamine.

[0054] The defoaming agent is defoaming agent BYK-028.

[0055] A preparation method of a heat dissipation coating composition, the preparation method comprising the following steps: Mix the waterborne epoxy resin, modified composite particles, curing agent and defoaming agent by stirring at 25°C for 15 min, and the preparation is completed.

[0056] An application of a heat dissipation coating composition in a battery guard plate, the application comprising the following steps: Coat the heat dissipation coating composition on the outer surface of the battery guard plate, then cure at 50°C for 10 h, and naturally cool to room temperature to form a coating with a thickness of 100 μm.

[0057] Example 3 A heat dissipation coating composition, the heat dissipation coating composition is prepared from 50 parts by weight of waterborne epoxy resin, 3.5 parts by weight of modified composite particles, 11 parts by weight of curing agent and 0.25 parts by weight of defoaming agent.

[0058] The modified composite particles are prepared by the following steps: Step A: Mix 3.3 parts by weight of methyl methacrylate, 0.15 parts by weight of 2-vinylpyridine, 0.2 parts by weight of methacrylamide, 0.95 parts by weight of dipropylene glycol diacrylate and 0.15 parts by weight of azobisisobutyronitrile in the dark under ultrasonic waves at room temperature for 8 min, then add 65 parts by weight of tetradecane, and centrifuge to obtain a coated dispersion; Step B: Mix 10 parts by weight of hydroxylated graphene and 100 parts by weight of tetradecane by stirring under ultrasonic waves at room temperature for 20 min to obtain a particle dispersion; Step C: Drop 80 parts by weight of the coated dispersion into 100 parts by weight of the particle dispersion while stirring at 77°C under a nitrogen atmosphere. After all the dropping is completed, continue stirring at a constant temperature for 2.5 h, filter, take the filter residue, wash it with deionized water, and finally dry it in vacuo at 45°C until constant weight to obtain coated particles; Step D: Add 9 parts by weight of ethanol, 4.8 parts by weight of coated particles, and 1 part by weight of amino boron nitride to 100 parts by weight of deionized water, then stir and mix in an ultrasonic bath at room temperature for 13 min. Next, dropwise add 0.7 parts by weight of ethylene glycol diglycidyl ether while stirring at 38 °C. After complete addition, continue stirring at a constant temperature for 1.5 h for mixing. Then filter, collect the filter residue, wash it with deionized water, and finally dry it in vacuo at 40 °C until a constant weight is achieved, thus completing the preparation.

[0059] The ultrasonic power in Step A is 400 W.

[0060] The centrifugation in Step A refers to centrifuging at a rotational speed of 600 rpm for 5 min.

[0061] The ultrasonic power in Step B is 400 W.

[0062] The dropping rate in Step C is controlled at 1.5 s / drop.

[0063] The amino boron nitride in Step D is prepared through the following steps: (1) Add 1.5 parts by weight of boron nitride to 100 parts by weight of sodium hydroxide aqueous solution, then stir and mix at 93 °C for 12 h. Filter, collect the filter residue, wash it with deionized water, and finally dry it in vacuo at 70 °C until a constant weight is achieved to obtain pretreated boron nitride; (2) Mix the pretreated boron nitride, γ-aminopropyltrimethoxysilane, and ethanol aqueous solution in a mass ratio of 1:2.5:105 and stir at 65 °C for 9 h. Filter, collect the filter residue, wash it with deionized water, and finally dry it in vacuo at 70 °C until a constant weight is achieved, thus completing the preparation.

[0064] The concentration of the sodium hydroxide aqueous solution in Step (1) is 4 mol / L.

[0065] The mass fraction of the ethanol aqueous solution in Step (2) is 95%.

[0066] The ultrasonic power in Step D is 300 W.

[0067] The dropping rate in Step D is controlled at 3.5 s / drop.

[0068] The curing agent is diethylenetriamine.

[0069] The defoaming agent is defoaming agent BYK-028.

[0070] A preparation method of a heat dissipation coating composition, the preparation method comprising the following steps: Mix an aqueous epoxy resin, a modified composite particle, a curing agent, and a defoaming agent at 23 °C for 13 min to complete the preparation.

[0071] Application of a heat dissipation coating composition in a battery guard plate, said application comprising the following steps: Coat the outer surface of the battery guard plate with the heat dissipation coating composition, then cure at 45 °C for 9 h, and naturally cool to room temperature to form a coating with a thickness of 90 μm.

[0072] Comparative Example 1 On the basis of Example 1, hydroxylated graphene was changed to graphene oxide (purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., model XF002-1), and the rest remained unchanged.

[0073] Comparative Example 2 On the basis of Example 1, hydroxylated graphene was changed to graphene (purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd., model XF022-1), and the rest remained unchanged.

[0074] Comparative Example 3 On the basis of Example 1, 2-vinylpyridine in Step A was changed to an equal weight of methyl methacrylate, and the rest remained unchanged.

[0075] Comparative Example 4 On the basis of Example 1, the dosage of 2-vinylpyridine in Step A was changed to 0.25 parts by weight, and the rest remained unchanged.

[0076] Comparative Example 5 On the basis of Example 1, methacrylamide in Step A was changed to an equal weight of methyl methacrylate, and ethylene glycol diglycidyl ether in Step D was changed to an equal weight of deionized water, and the rest remained unchanged.

[0077] Comparative Example 6 On the basis of Example 1, ethylene glycol diglycidyl ether in Step D was changed to an equal weight of deionized water, and the rest remained unchanged.

[0078] Test Example 1 Heat dissipation performance test: Coat the surfaces (single-sided, the square side) of aluminum plates (each with dimensions of 100 mm × 100 mm × 5 mm) with the heat dissipation coating compositions prepared in Example 1 and Comparative Examples 1-6 respectively, then cure at 50 °C for 10 h, and naturally cool to room temperature to form coatings with a thickness of 100 μm each, thereby obtaining test specimens.

[0079] Use a thermal conductivity tester to measure the thermal conductivity of the coatings of the above test specimens.

[0080] Place the above test specimens in an oven at 85 °C for heat treatment until the temperature of the test specimens stabilizes at 85 °C (i.e., the temperatures of the coatings and the aluminum plates are both 85 °C), take them out, and let them stand naturally at room temperature, and record the temperature of the coatings after 5 min.

[0081] Table 1. Test Results of Heat Dissipation Performance

[0082] Test Example 2 Migration Test: The heat dissipation coating compositions prepared in Example 1 and Comparative Examples 1-6 were respectively coated on the surface (one side, the square side) of an aluminum plate (with dimensions of 100 mm × 100 mm × 5 mm), then cured at 50 °C for 10 h, and naturally cooled to room temperature to form coatings with a thickness of 100 μm, thereby obtaining test specimens.

[0083] The above test specimens were placed in an oven at 50 °C for heat treatment for 30 min, taken out, and naturally cooled to room temperature. After repeating the heat treatment and cooling 50 times (one cooling after heat treatment is counted as one time), they were washed with deionized water and naturally dried, thereby obtaining cyclic test specimens; a thermal conductivity tester was used to measure the thermal conductivity of the coatings of the above cyclic test specimens.

[0084] Table 2. Migration Test Results

[0085] It can be seen from the comparison of Example 1, Comparative Examples 1-6 and Test Examples 1-2 that the heat dissipation coating composition prepared by the present invention has excellent heat dissipation performance. Even after multiple heating and cooling treatments, its coating can still maintain a high thermal conductivity, indicating that the migration of the modified composite particles is small, effectively ensuring the heat dissipation effect.

[0086] Regarding Figure 1 Analysis: This is a physical picture of the heat dissipation coating composition prepared in Example 1 of the present invention after being applied to a battery guard plate.

[0087] Regarding Figure 2 Analysis: This is a physical picture of the heat dissipation coating composition prepared in Example 2 of the present invention after being applied to a battery guard plate.

[0088] The above is only the preferred embodiments of the present invention, and does not impose any form of limitation on the present invention. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or equivalent changes and modifications within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A heat dissipation coating composition, characterized in that: The heat-dissipating coating composition is prepared from 50 parts by weight of waterborne epoxy resin, 3 - 4 parts by weight of modified composite particles, 10 - 12 parts by weight of curing agent, and 0.2 - 0.3 parts by weight of defoamer; The modified composite particles are prepared through the following steps: Step A: Mix 3 - 3.5 parts by weight of methyl methacrylate, 0.15 parts by weight of 2 - vinylpyridine, 0.2 parts by weight of methacrylamide, 0.9 - 1 part by weight of dipropylene glycol diacrylate, and 0.15 parts by weight of azobisisobutyronitrile under ultrasonic irradiation in the dark at room temperature for 5 - 10 min, then add 60 - 70 parts by weight of tetradecane, and centrifuge to obtain a coated dispersion; Step B: Mix 10 parts by weight of hydroxylated graphene and 100 parts by weight of tetradecane under ultrasonic irradiation at room temperature for 15 - 30 min to obtain a particle dispersion; Step C: While stirring, dropwise add 80 parts by weight of the coated dispersion to 100 parts by weight of the particle dispersion at 75 - 80 °C under a nitrogen atmosphere. After complete addition, continue stirring at a constant temperature for 2 - 3 h, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 30 - 60 °C until a constant weight is obtained to obtain coated particles; Step D: Add 8 - 10 parts by weight of ethanol, 4.5 - 5 parts by weight of the coated particles, and 1 part by weight of amino boron nitride to 100 parts by weight of deionized water, then mix under ultrasonic irradiation at room temperature for 10 - 15 min. Then, while stirring, dropwise add 0.7 parts by weight of ethylene glycol diglycidyl ether at 35 - 40 °C. After complete addition, continue stirring at a constant temperature for 1 - 2 h, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 30 - 60 °C until a constant weight is obtained, thus completing the preparation.

2. The heat-dissipating coating composition according to claim 1, characterized in that: The dropping rate in Step C is controlled at 1 - 2 s / drop.

3. The heat dissipation coating composition according to claim 1, wherein: The amino boron nitride in Step D is prepared through the following steps: (1) Add 1 - 2 parts by weight of boron nitride to 100 parts by weight of sodium hydroxide aqueous solution, then stir at 90 - 95 °C for 10 - 14 h, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 50 - 80 °C until a constant weight is obtained to obtain pretreated boron nitride; (2) Mix the pretreated boron nitride, γ - aminopropyltrimethoxysilane, and ethanol aqueous solution in a mass ratio of 1:2 - 3:100 - 110 at 60 - 70 °C for 8 - 10 h, filter, collect the filter residue, wash it with deionized water, and finally dry it under vacuum at 50 - 80 °C until a constant weight is obtained, thus completing the preparation.

4. The heat-dissipating coating composition according to claim 3, wherein: The concentration of the sodium hydroxide aqueous solution in Step (1) is 3 - 5 mol / L.

5. The heat-dissipating coating composition according to claim 1, wherein: The dropping rate in Step D is controlled at 3 - 4 s / drop.

6. The heat dissipation coating composition according to claim 1, wherein: The curing agent is diethylenetriamine.

7. The heat dissipation coating composition according to claim 1, characterized in that: The defoamer is defoamer BYK - 028.

8. A method for preparing a heat-dissipating coating composition according to any one of claims 1-7, characterized in that: The preparation method includes the following steps: Mix the waterborne epoxy resin, modified composite particles, curing agent, and defoamer at 20 - 25 °C for 10 - 15 min, thus completing the preparation.

9. Use of a heat dissipation coating composition according to any one of claims 1-7 in a battery guard plate, characterized in that: The application includes the following steps: Apply a heat-dissipating coating composition on the outer surface of the battery guard plate, then cure it at 40 - 50 °C for 8 - 10 h, and naturally cool it to room temperature to form a coating with a thickness of 80 - 100 μm.

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