Epoxy resin powder coating with high heat dissipation performance and preparation method thereof

Abstract

The invention relates to an epoxy resin powder coating with high heat dissipation performance and a preparation method thereof, and the preparation method comprises the following steps: mixing graphene oxide and aromatic monoepoxy ether, reacting for 12-24 hours at 150-200 DEG C under the catalysis of a catalyst, washing with ethanol, and drying to obtain polyether modified graphene oxide. Then preheating the obtained polyether modified graphene oxide and epoxy resin, adding the micro expanded graphite powder, a curing agent, a defoaming agent, a flatting agent and other auxiliaries, mixing by using a screw extruder, and grinding and sieving to obtain the powder coating. And the coating is sprayed and cured at high temperature to obtain a coating. The obtained product has high heat dissipation performance, the compatibility of graphene oxide and epoxy resin is remarkably improved through the polyether chain segment, and the thermal conductivity and mechanical strength are enhanced through the micro expanded graphite powder. The coating is suitable for the fields of electronic packaging, heat-conducting coatings and structure enhancement.

Description

[0001] The present invention relates to the field of heat - dissipating coatings, and particularly to an epoxy resin powder coating with high heat - dissipating performance and a preparation method thereof. Background Art

[0002] With the rapid development of modern industrial technology, the requirements for heat - dissipating performance of electronic devices, electrical products, and numerous industrial components are becoming increasingly stringent. Among various protective and decorative coating materials, epoxy resin powder coatings have been widely used in many fields due to their excellent physical and chemical properties, such as good adhesion, corrosion resistance, mechanical strength, and environmental protection characteristics. However, traditional epoxy resin powder coatings have obvious limitations in heat - dissipating performance and are difficult to meet the current urgent need for efficient heat dissipation.

[0003] In the field of electronic devices, such as computer CPUs, GPUs and other chips, as well as various power electronic devices, a large amount of heat is generated during operation. If these heats cannot be dissipated in a timely and effective manner, the device temperature will continue to rise, which will lead to a decline in the performance of electronic components, a shortening of their lifespan, and even failures, seriously affecting the stability and reliability of electronic devices. According to relevant research, for every 10°C increase in the temperature of electronic components, their failure rate increases by about 50%. In the case of electrical products, such as transformers, motors, etc., excessive temperature not only reduces the operating efficiency of the device but also may cause the aging of insulating materials and increase the risk of electrical accidents.

[0004] The main reason for the poor heat - dissipating performance of traditional epoxy resin powder coatings lies in their own chemical structure and composition. The close packing between the molecular chain segments of epoxy resin and its low thermal conductivity hinder the conduction of heat within the coating. Although adding some conventional heat - dissipating fillers, such as alumina, silica, etc., to the coating formulation can improve the heat - dissipating performance to a certain extent, the effect is not ideal. The heat - dissipating efficiency of these conventional fillers is limited, and their dispersibility in the coating system is poor, easily agglomerating, resulting in the inability to effectively construct heat - dissipating channels and making it difficult to meet the high - standard requirements for heat - dissipating performance of high - power devices.

[0005] In some special application scenarios, such as aerospace and the automotive industry, more stringent requirements are put forward for the heat - dissipating performance and comprehensive performance of coatings. In the aerospace field, the electronic devices and engine components of aircraft operate under high loads and extreme environments, and coatings are required to have excellent heat - dissipating performance to ensure the normal operation and flight safety of the devices. In the automotive industry, the demand for heat - dissipating coatings for the battery packs and motor systems of new - energy vehicles is also increasing day by day. Good heat - dissipating coatings help improve the charge - discharge efficiency and service life of batteries and enhance the overall performance of vehicles. However, due to the bottleneck of heat - dissipating performance, the promotion and application of existing epoxy resin powder coatings in these high - end application fields have been greatly restricted.

[0006] Therefore, the development of an epoxy resin powder coating with high heat dissipation performance has important practical significance and broad market prospects. By innovating the formulation and preparation process of epoxy resin powder coatings, introducing new heat dissipation materials and modification methods to significantly improve their heat dissipation performance and meet the requirements of high-performance heat dissipation coatings in different fields has become a key issue urgently to be solved in the current coating industry. Among them, polyether-modified graphene oxide can significantly improve the compatibility between graphite powder and epoxy resin, thereby increasing the filling ratio of graphene powder. In the epoxy resin powder coating reported in this patent, polyether-modified graphene oxide provides excellent thermal conductivity. Micro-expanded graphite powder has a high thermal conductivity, and its lamellar structure can form heat conduction paths inside the coating. Heat can be quickly transferred along these paths, conducting the heat inside the coating to the surface of the coating and then dissipating it. Its heat dissipation effect is remarkable, and it has broad market prospects. Summary of the Invention

[0007] The object of the present invention is to provide a method for polyether modification of graphene oxide in view of the deficiencies of the prior art. Utilizing the hydroxyl groups present on the surface of graphene oxide, under the action of an acetylacetonate metal catalyst, ring-opening polymerization with an epoxide is carried out at high temperature, thereby forming polyether grafting on the surface. The polyether-grafted graphene oxide is equivalent to a compatibilizer between graphite powder and epoxy resin for coatings.

[0008] The object of the present invention is achieved through the following technical solutions: A high heat dissipation performance epoxy resin powder coating and its preparation method, including the following steps:

[0009] (1) Mix 1 part by mole of graphene oxide with 1.0 - 1.5 parts by mole of an aromatic monoepoxy ether and add a catalyst, react at 150°C - 200°C for 12 - 24 hours, wash with ethanol and dry to obtain polyether-modified graphene oxide;

[0010] (2) Preheat 1 - 5 parts of the obtained polyether-modified graphene oxide and 30 - 40 parts of epoxy resin, add 10 - 20 parts of micro-expanded graphite powder and additives such as a curing agent, defoaming agent, and leveling agent, and mix with a screw extruder. After grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0011] Further, the aromatic monoepoxy ether is phenyl glycidyl ether, benzyl glycidyl ether, p-chlorophenyl glycidyl ether, p-nitrophenyl glycidyl ether, naphthyl glycidyl ether, etc., but is not limited thereto.

[0012] Further, the catalyst is aluminum acetylacetonate, iron acetylacetonate, zinc acetylacetonate, copper acetylacetonate, nickel acetylacetonate, cobalt acetylacetonate, manganese acetylacetonate, chromium acetylacetonate, etc., but is not limited thereto.

[0013] Further, the epoxy resin is bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, hydrogenated bisphenol A epoxy resin, etc., but not limited thereto.

[0014] Further, the curing agent is polyazelaic anhydride, 647 anhydride, dicyandiamide, hexahydrophthalic anhydride, phenolic resin, etc., but not limited thereto.

[0015] Further, the defoaming agent is polydimethylsiloxane, polyacrylate, mineral oil, etc., but not limited thereto.

[0016] Further, the leveling agent is polyacrylate, polyether-modified polydimethylsiloxane, fluorocarbon surfactant, etc., but not limited thereto.

[0017] The beneficial effect of the present invention is that the polyether-modified graphene oxide enhances the compatibility between graphene oxide and epoxy resin. Through the interweaving of polyether-modified graphene oxide and micro-expanded graphite powder in the epoxy resin system, a complex and efficient thermal conduction network structure is constructed, endowing the material with good heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a thermogravimetric analysis curve graph of the polyether-modified graphene oxide prepared in Example 1.

[0019] Figure 2 It is a thermal degradation curve graph of the polyether-modified graphene oxide prepared in Example 1.

[0020] Figure 3 It is the thermal conductivity of the coating of the epoxy resin powder coating prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the protection scope of the present invention.

[0022] In the following embodiments, the experimental methods are all conventional methods unless otherwise specified; the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0023] Example 1

[0024] (1) Mix graphene oxide (1 g) with phenyl glycidyl ether (1.35 g) and add aluminum acetylacetonate, react at 150 °C for 24 hours, wash with ethanol and dry to obtain polyether-modified graphene oxide;

[0025] (2) The obtained 1 part of polyether-modified graphene oxide is preheated with 30 parts of bisphenol A epoxy resin, and 10 parts of fine expanded graphite powder and additives such as dicyandiamide, polydimethylsiloxane, and polyacrylate are mixed with a screw extruder. After grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0026] By adjusting the graphene oxide / aromatic monoepoxy ether δ = 1:1.

[0027] Example 2

[0028] (1) Graphene oxide (1 g) and phenyl glycidyl ether (2.03 g) are mixed and ferric acetylacetonate is added, and the reaction is carried out at 200 °C for 12 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0029] (2) The obtained 5 parts of polyether-modified graphene oxide is preheated with 40 parts of bisphenol A epoxy resin, and 20 parts of fine expanded graphite powder and additives such as dicyandiamide, polyacrylate, and polyether-modified polydimethylsiloxane are mixed with a screw extruder. After grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0030] By adjusting the graphene oxide / aromatic monoepoxy ether δ = 1:1.5.

[0031] Example 3

[0032] (1) Graphene oxide (1 g) and phenyl glycidyl ether (1.62 g) are mixed and zinc acetylacetonate is added, and the reaction is carried out at 180 °C for 18 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0033] (2) The obtained 2 parts of polyether-modified graphene oxide is preheated with 30 parts of bisphenol A epoxy resin, and 20 parts of fine expanded graphite powder and additives such as 647 anhydride, mineral oil, and fluorocarbon surfactant are mixed with a screw extruder. After grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing

[0034] By adjusting the graphene oxide / aromatic monoepoxy ether δ = 1:1.2.

[0035] Example 4

[0036] (1) Graphene oxide (1 g) and phenyl glycidyl ether (1.76 g) are mixed and copper acetylacetonate is added, and the reaction is carried out at 150 °C for 24 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0037] (2) The 3 parts of polyether-modified graphene oxide obtained are preheated with 35 parts of phenolic epoxy resin, 20 parts of fine expanded graphite powder and additives such as hexahydrophthalic anhydride, polydimethylsiloxane, and polyacrylate are mixed with a screw extruder, and after grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0038] By adjusting the ratio of graphene oxide / aromatic monoepoxy ether δ = 1:1.3.

[0039] Example 5

[0040] (1) Graphene oxide (1 g) is mixed with phenyl glycidyl ether (1.89 g), and nickel acetylacetonate is added, and the reaction is carried out at 180 °C for 18 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0041] (2) The 5 parts of polyether-modified graphene oxide obtained are preheated with 40 parts of bisphenol A epoxy resin, 20 parts of fine expanded graphite powder and additives such as phenolic resin, polyacrylate, and polyether-modified polydimethylsiloxane are mixed with a screw extruder, and after grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0042] By adjusting the ratio of graphene oxide / aromatic monoepoxy ether δ = 1:1.4.

[0043] Example 6

[0044] (1) Graphene oxide (1 g) is mixed with phenyl glycidyl ether (2.03 g), and cobalt acetylacetonate is added, and the reaction is carried out at 150 °C for 24 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0045] (2) The 5 parts of polyether-modified graphene oxide obtained are preheated with 40 parts of bisphenol F epoxy resin, 20 parts of fine expanded graphite powder and additives such as polyazelaic anhydride, polyacrylate, and fluorocarbon surfactant are mixed with a screw extruder, and after grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0046] By adjusting the ratio of graphene oxide / aromatic monoepoxy ether δ = 1:1.5.

[0047] Example 7

[0048] (1) Graphene oxide (1 g) is mixed with phenyl glycidyl ether (1.62 g), and manganese acetylacetonate is added, and the reaction is carried out at 200 °C for 12 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0049] (2) The obtained 5 parts of polyether-modified graphene oxide and 40 parts of bisphenol A epoxy resin are preheated, and 20 parts of fine expanded graphite powder, together with auxiliaries such as dicyandiamide, mineral oil, and polyether-modified polydimethylsiloxane, are mixed by a screw extruder. After grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0050] By adjusting the ratio of graphene oxide / aromatic monoepoxy ether δ = 1:1.2.

[0051] Example 8

[0052] (1) Graphene oxide (1 g) and phenyl glycidyl ether (1.49 g) are mixed and chromium acetylacetonate is added, and the reaction is carried out at 150 °C for 24 hours. After washing with ethanol and drying, polyether-modified graphene oxide is obtained;

[0053] (2) The obtained 1 part of polyether-modified graphene oxide and 30 parts of bisphenol F epoxy resin are preheated, and 20 parts of fine expanded graphite powder, together with auxiliaries such as dicyandiamide, polyacrylate, and fluorocarbon surfactant, are mixed by a screw extruder. After grinding and sieving, a powder coating is obtained. The coating is obtained after spraying and high-temperature curing.

[0054] By adjusting the ratio of graphene oxide / aromatic monoepoxy ether δ = 1:1.1.

[0055] Figure 1 It is the thermogravimetric analysis curve of the polyether-modified graphene oxide prepared in Example 1.

[0056] Figure 2 It is the thermal degradation curve of the polyether-modified graphene oxide prepared in Example 1.

[0057] Figure 3 It is the thermal conductivity of the epoxy resin powder coating prepared in Example 1.

[0058] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An epoxy resin powder coating with high heat dissipation performance and a preparation method thereof, characterized in that: The following steps are involved: (1) mixing 1 mol of graphene oxide with 1.0-1.5 mol of aromatic monocyclic ether and adding a catalyst, reacting at 150° C. to 200° C. for 12 to 24 hours, washing with ethanol, and drying to obtain polyether-modified graphene oxide; (2) Preheating 1-5 parts of the obtained polyether-modified graphene oxide and 30-40 parts of epoxy resin, adding 10-20 parts of fine expanded graphite powder and curing agent, defoaming agent, leveling agent and other additives, mixing with a screw extruder, grinding and sieving to obtain a powder coating. The coating is sprayed and cured at high temperature to obtain a coating.

2. The epoxy resin powder coating with high heat dissipation performance and the preparation method thereof according to claim 1, characterized in that: The aromatic monocyclic ethers are phenyl glycidyl ether, benzyl glycidyl ether, p-chlorophenyl glycidyl ether, p-nitrophenyl glycidyl ether, naphthyl glycidyl ether, etc., but are not limited thereto.

3. The epoxy resin powder coating with high heat dissipation performance and the preparation method thereof according to claim 1, characterized in that: The catalyst is aluminum acetylacetonate, iron acetylacetonate, zinc acetylacetonate, copper acetylacetonate, nickel acetylacetonate, cobalt acetylacetonate, manganese acetylacetonate, chromium acetylacetonate, etc., but is not limited thereto.

4. The epoxy resin powder coating with high heat dissipation performance and the preparation method thereof according to claim 1, characterized in that: The epoxy resin is bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, hydrogenated bisphenol A epoxy resin, etc., but is not limited thereto.

5. The epoxy resin powder coating with high heat dissipation performance and the preparation method thereof according to claim 1, characterized in that: The curing agent is polyazelaic anhydride, 647 anhydride, dicyandiamide, hexahydrophthalic anhydride, phenolic resin, etc., but is not limited thereto.

6. The epoxy resin powder coating with high heat dissipation performance and the preparation method thereof according to claim 1, characterized in that: The defoaming agent is polydimethylsiloxane, polyacrylate, mineral oil, etc., but is not limited thereto.

7. The epoxy resin powder coating with high heat dissipation performance and the preparation method thereof according to claim 1, characterized in that: The leveling agent is polyacrylate, polyether-modified polydimethylsiloxane, fluorocarbon surfactant, etc., but is not limited thereto.

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